Source/WebCore/bindings/js/JSDOMBinding.cpp - platform/external/webkit - Git at Google

 /*
  *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
  *  Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *  Copyright (C) 2007 Samuel Weinig <sam@webkit.org>
  *
  *  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 "JSDOMBinding.h"

 #include "debugger/DebuggerCallFrame.h"

 #include "ActiveDOMObject.h"
 #include "DOMCoreException.h"
 #include "DOMObjectHashTableMap.h"
 #include "Document.h"
 #include "EventException.h"
 #include "ExceptionBase.h"
 #include "ExceptionCode.h"
 #include "Frame.h"
 #include "HTMLAudioElement.h"
 #include "HTMLCanvasElement.h"
 #include "HTMLFrameElementBase.h"
 #include "HTMLImageElement.h"
 #include "HTMLLinkElement.h"
 #include "HTMLNames.h"
 #include "HTMLScriptElement.h"
 #include "HTMLStyleElement.h"
 #include "JSDOMCoreException.h"
 #include "JSDOMWindowCustom.h"
 #include "JSEventException.h"
 #include "JSExceptionBase.h"
 #include "JSMainThreadExecState.h"
 #include "JSRangeException.h"
 #include "JSXMLHttpRequestException.h"
 #include "KURL.h"
 #include "MessagePort.h"
 #include "ProcessingInstruction.h"
 #include "RangeException.h"
 #include "ScriptCachedFrameData.h"
 #include "ScriptCallStack.h"
 #include "ScriptController.h"
 #include "Settings.h"
 #include "WebCoreJSClientData.h"
 #include "XMLHttpRequestException.h"
 #include <runtime/DateInstance.h>
 #include <runtime/Error.h>
 #include <runtime/JSFunction.h>
 #include <wtf/MathExtras.h>
 #include <wtf/StdLibExtras.h>

 #if ENABLE(SVG)
 #include "JSSVGException.h"
 #include "SVGException.h"
 #endif

 #if ENABLE(XPATH)
 #include "JSXPathException.h"
 #include "XPathException.h"
 #endif

 #if ENABLE(DATABASE)
 #include "JSSQLException.h"
 #include "SQLException.h"
 #endif

 #if ENABLE(BLOB) || ENABLE(FILE_SYSTEM)
 #include "FileException.h"
 #include "JSFileException.h"
 #endif

 #if ENABLE(INDEXED_DATABASE)
 #include "IDBDatabaseException.h"
 #include "JSIDBDatabaseException.h"
 #endif

 using namespace JSC;

 namespace WebCore {

 using namespace HTMLNames;

 class JSGlobalDataWorldIterator {
 public:
     JSGlobalDataWorldIterator(JSGlobalData* globalData)
         : m_pos(static_cast<WebCoreJSClientData*>(globalData->clientData)->m_worldSet.begin())
         , m_end(static_cast<WebCoreJSClientData*>(globalData->clientData)->m_worldSet.end())
     {
     }

     operator bool()
     {
         return m_pos != m_end;
     }

     DOMWrapperWorld* operator*()
     {
         ASSERT(m_pos != m_end);
         return *m_pos;
     }

     DOMWrapperWorld* operator->()
     {
         ASSERT(m_pos != m_end);
         return *m_pos;
     }

     JSGlobalDataWorldIterator& operator++()
     {
         ++m_pos;
         return *this;
     }

 private:
     HashSet<DOMWrapperWorld*>::iterator m_pos;
     HashSet<DOMWrapperWorld*>::iterator m_end;
 };

 const JSC::HashTable* getHashTableForGlobalData(JSGlobalData& globalData, const JSC::HashTable* staticTable)
 {
     return DOMObjectHashTableMap::mapFor(globalData).get(staticTable);
 }

 void markActiveObjectsForContext(MarkStack& markStack, JSGlobalData& globalData, ScriptExecutionContext* scriptExecutionContext)
 {
     // If an element has pending activity that may result in event listeners being called
     // (e.g. an XMLHttpRequest), we need to keep JS wrappers alive.

     const HashMap<ActiveDOMObject*, void*>& activeObjects = scriptExecutionContext->activeDOMObjects();
     HashMap<ActiveDOMObject*, void*>::const_iterator activeObjectsEnd = activeObjects.end();
     for (HashMap<ActiveDOMObject*, void*>::const_iterator iter = activeObjects.begin(); iter != activeObjectsEnd; ++iter) {
         if (iter->first->hasPendingActivity()) {
             // Generally, an active object with pending activity must have a wrapper to mark its listeners.
             // However, some ActiveDOMObjects don't have JS wrappers.
             markDOMObjectWrapper(markStack, globalData, iter->second);
         }
     }

     const HashSet<MessagePort*>& messagePorts = scriptExecutionContext->messagePorts();
     HashSet<MessagePort*>::const_iterator portsEnd = messagePorts.end();
     for (HashSet<MessagePort*>::const_iterator iter = messagePorts.begin(); iter != portsEnd; ++iter) {
         // If the message port is remotely entangled, then always mark it as in-use because we can't determine reachability across threads.
         if (!(*iter)->locallyEntangledPort() || (*iter)->hasPendingActivity())
             markDOMObjectWrapper(markStack, globalData, *iter);
     }
 }

 void markDOMObjectWrapper(MarkStack& markStack, JSGlobalData& globalData, void* object)
 {
     // FIXME: This could be changed to only mark wrappers that are "observable"
     // as markDOMNodesForDocument does, allowing us to collect more wrappers,
     // but doing this correctly would be challenging.
     if (!object)
         return;

     for (JSGlobalDataWorldIterator worldIter(&globalData); worldIter; ++worldIter) {
         if (JSDOMWrapper* wrapper = worldIter->m_wrappers.get(object).get())
             markStack.deprecatedAppend(reinterpret_cast<JSCell**>(&wrapper));
     }
 }

 static void stringWrapperDestroyed(JSString*, void* context)
 {
     StringImpl* cacheKey = static_cast<StringImpl*>(context);
     cacheKey->deref();
 }

 JSValue jsStringSlowCase(ExecState* exec, JSStringCache& stringCache, StringImpl* stringImpl)
 {
     JSString* wrapper = jsStringWithFinalizer(exec, UString(stringImpl), stringWrapperDestroyed, stringImpl);
     stringCache.set(exec->globalData(), stringImpl, wrapper);
     // ref explicitly instead of using a RefPtr-keyed hashtable because the wrapper can
     // outlive the cache, so the stringImpl has to match the wrapper's lifetime.
     stringImpl->ref();
     return wrapper;
 }

 JSValue jsStringOrNull(ExecState* exec, const String& s)
 {
     if (s.isNull())
         return jsNull();
     return jsString(exec, s);
 }

 JSValue jsOwnedStringOrNull(ExecState* exec, const String& s)
 {
     if (s.isNull())
         return jsNull();
     return jsOwnedString(exec, stringToUString(s));
 }

 JSValue jsStringOrUndefined(ExecState* exec, const String& s)
 {
     if (s.isNull())
         return jsUndefined();
     return jsString(exec, s);
 }

 JSValue jsStringOrFalse(ExecState* exec, const String& s)
 {
     if (s.isNull())
         return jsBoolean(false);
     return jsString(exec, s);
 }

 JSValue jsString(ExecState* exec, const KURL& url)
 {
     return jsString(exec, url.string());
 }

 JSValue jsStringOrNull(ExecState* exec, const KURL& url)
 {
     if (url.isNull())
         return jsNull();
     return jsString(exec, url.string());
 }

 JSValue jsStringOrUndefined(ExecState* exec, const KURL& url)
 {
     if (url.isNull())
         return jsUndefined();
     return jsString(exec, url.string());
 }

 JSValue jsStringOrFalse(ExecState* exec, const KURL& url)
 {
     if (url.isNull())
         return jsBoolean(false);
     return jsString(exec, url.string());
 }

 AtomicStringImpl* findAtomicString(const Identifier& identifier)
 {
     if (identifier.isNull())
         return 0;
     StringImpl* impl = identifier.impl();
     ASSERT(impl->existingHash());
     return AtomicString::find(impl->characters(), impl->length(), impl->existingHash());
 }

 String valueToStringWithNullCheck(ExecState* exec, JSValue value)
 {
     if (value.isNull())
         return String();
     return ustringToString(value.toString(exec));
 }

 String valueToStringWithUndefinedOrNullCheck(ExecState* exec, JSValue value)
 {
     if (value.isUndefinedOrNull())
         return String();
     return ustringToString(value.toString(exec));
 }

 JSValue jsDateOrNull(ExecState* exec, double value)
 {
     if (!isfinite(value))
         return jsNull();
     return new (exec) DateInstance(exec, exec->lexicalGlobalObject()->dateStructure(), value);
 }

 double valueToDate(ExecState* exec, JSValue value)
 {
     if (value.isNumber())
         return value.uncheckedGetNumber();
     if (!value.inherits(&DateInstance::s_info))
         return std::numeric_limits<double>::quiet_NaN();
     return static_cast<DateInstance*>(value.toObject(exec))->internalNumber();
 }

 void reportException(ExecState* exec, JSValue exception)
 {
     if (exception.isObject() && asObject(exception)->exceptionType() == Terminated)
         return;

     UString errorMessage = exception.toString(exec);
     JSObject* exceptionObject = exception.toObject(exec);
     int lineNumber = exceptionObject->get(exec, Identifier(exec, "line")).toInt32(exec);
     UString exceptionSourceURL = exceptionObject->get(exec, Identifier(exec, "sourceURL")).toString(exec);
     exec->clearException();

     if (ExceptionBase* exceptionBase = toExceptionBase(exception))
         errorMessage = stringToUString(exceptionBase->message() + ": "  + exceptionBase->description());

     ScriptExecutionContext* scriptExecutionContext = static_cast<JSDOMGlobalObject*>(exec->lexicalGlobalObject())->scriptExecutionContext();
     ASSERT(scriptExecutionContext);

     // Crash data indicates null-dereference crashes at this point in the Safari 4 Public Beta.
     // It's harmless to return here without reporting the exception to the log and the debugger in this case.
     if (!scriptExecutionContext)
         return;

     scriptExecutionContext->reportException(ustringToString(errorMessage), lineNumber, ustringToString(exceptionSourceURL), 0);
 }

 void reportCurrentException(ExecState* exec)
 {
     JSValue exception = exec->exception();
     exec->clearException();
     reportException(exec, exception);
 }

 void setDOMException(ExecState* exec, ExceptionCode ec)
 {
     if (!ec || exec->hadException())
         return;

     // FIXME: All callers to setDOMException need to pass in the right global object
     // for now, we're going to assume the lexicalGlobalObject.  Which is wrong in cases like this:
     // frames[0].document.createElement(null, null); // throws an exception which should have the subframes prototypes.
     JSDOMGlobalObject* globalObject = deprecatedGlobalObjectForPrototype(exec);

     ExceptionCodeDescription description;
     getExceptionCodeDescription(ec, description);

     JSValue errorObject;
     switch (description.type) {
         case DOMExceptionType:
             errorObject = toJS(exec, globalObject, DOMCoreException::create(description));
             break;
         case RangeExceptionType:
             errorObject = toJS(exec, globalObject, RangeException::create(description));
             break;
         case EventExceptionType:
             errorObject = toJS(exec, globalObject, EventException::create(description));
             break;
         case XMLHttpRequestExceptionType:
             errorObject = toJS(exec, globalObject, XMLHttpRequestException::create(description));
             break;
 #if ENABLE(SVG)
         case SVGExceptionType:
             errorObject = toJS(exec, globalObject, SVGException::create(description).get());
             break;
 #endif
 #if ENABLE(XPATH)
         case XPathExceptionType:
             errorObject = toJS(exec, globalObject, XPathException::create(description));
             break;
 #endif
 #if ENABLE(DATABASE)
         case SQLExceptionType:
             errorObject = toJS(exec, globalObject, SQLException::create(description));
             break;
 #endif
 #if ENABLE(BLOB) || ENABLE(FILE_SYSTEM)
         case FileExceptionType:
             errorObject = toJS(exec, globalObject, FileException::create(description));
             break;
 #endif
 #if ENABLE(INDEXED_DATABASE)
         case IDBDatabaseExceptionType:
             errorObject = toJS(exec, globalObject, IDBDatabaseException::create(description));
             break;
 #endif
     }

     ASSERT(errorObject);
     throwError(exec, errorObject);
 }

 DOMWindow* activeDOMWindow(ExecState* exec)
 {
     return asJSDOMWindow(exec->lexicalGlobalObject())->impl();
 }

 DOMWindow* firstDOMWindow(ExecState* exec)
 {
     return asJSDOMWindow(exec->dynamicGlobalObject())->impl();
 }

 bool checkNodeSecurity(ExecState* exec, Node* node)
 {
     return node && allowsAccessFromFrame(exec, node->document()->frame());
 }

 bool allowsAccessFromFrame(ExecState* exec, Frame* frame)
 {
     if (!frame)
         return false;
     JSDOMWindow* window = toJSDOMWindow(frame, currentWorld(exec));
     return window && window->allowsAccessFrom(exec);
 }

 bool allowsAccessFromFrame(ExecState* exec, Frame* frame, String& message)
 {
     if (!frame)
         return false;
     JSDOMWindow* window = toJSDOMWindow(frame, currentWorld(exec));
     return window && window->allowsAccessFrom(exec, message);
 }

 void printErrorMessageForFrame(Frame* frame, const String& message)
 {
     if (!frame)
         return;
     frame->domWindow()->printErrorMessage(message);
 }

 // FIXME: We should remove or at least deprecate this function. Callers can use firstDOMWindow directly.
 Frame* toDynamicFrame(ExecState* exec)
 {
     return firstDOMWindow(exec)->frame();
 }

 // FIXME: We should remove this function. Callers can use ScriptController directly.
 bool processingUserGesture()
 {
     return ScriptController::processingUserGesture();
 }

 JSValue objectToStringFunctionGetter(ExecState* exec, JSValue, const Identifier& propertyName)
 {
     return new (exec) JSFunction(exec, exec->lexicalGlobalObject(), exec->lexicalGlobalObject()->functionStructure(), 0, propertyName, objectProtoFuncToString);
 }

 Structure* getCachedDOMStructure(JSDOMGlobalObject* globalObject, const ClassInfo* classInfo)
 {
     JSDOMStructureMap& structures = globalObject->structures();
     return structures.get(classInfo).get();
 }

 Structure* cacheDOMStructure(JSDOMGlobalObject* globalObject, Structure* structure, const ClassInfo* classInfo)
 {
     JSDOMStructureMap& structures = globalObject->structures();
     ASSERT(!structures.contains(classInfo));
     return structures.set(classInfo, WriteBarrier<Structure>(globalObject->globalData(), globalObject, structure)).first->second.get();
 }

 JSC::JSObject* toJSSequence(ExecState* exec, JSValue value, unsigned& length)
 {
     JSObject* object = value.getObject();
     if (!object) {
         throwTypeError(exec);
         return 0;
     }
     JSValue lengthValue = object->get(exec, exec->propertyNames().length);
     if (exec->hadException())
         return 0;

     if (lengthValue.isUndefinedOrNull()) {
         throwTypeError(exec);
         return 0;
     }

     length = lengthValue.toUInt32(exec);
     if (exec->hadException())
         return 0;

     return object;
 }

 } // namespace WebCore
	/*
	* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
	* Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
	* Copyright (C) 2007 Samuel Weinig <sam@webkit.org>
	*
	* 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 "JSDOMBinding.h"

	#include "debugger/DebuggerCallFrame.h"

	#include "ActiveDOMObject.h"
	#include "DOMCoreException.h"
	#include "DOMObjectHashTableMap.h"
	#include "Document.h"
	#include "EventException.h"
	#include "ExceptionBase.h"
	#include "ExceptionCode.h"
	#include "Frame.h"
	#include "HTMLAudioElement.h"
	#include "HTMLCanvasElement.h"
	#include "HTMLFrameElementBase.h"
	#include "HTMLImageElement.h"
	#include "HTMLLinkElement.h"
	#include "HTMLNames.h"
	#include "HTMLScriptElement.h"
	#include "HTMLStyleElement.h"
	#include "JSDOMCoreException.h"
	#include "JSDOMWindowCustom.h"
	#include "JSEventException.h"
	#include "JSExceptionBase.h"
	#include "JSMainThreadExecState.h"
	#include "JSRangeException.h"
	#include "JSXMLHttpRequestException.h"
	#include "KURL.h"
	#include "MessagePort.h"
	#include "ProcessingInstruction.h"
	#include "RangeException.h"
	#include "ScriptCachedFrameData.h"
	#include "ScriptCallStack.h"
	#include "ScriptController.h"
	#include "Settings.h"
	#include "WebCoreJSClientData.h"
	#include "XMLHttpRequestException.h"
	#include <runtime/DateInstance.h>
	#include <runtime/Error.h>
	#include <runtime/JSFunction.h>
	#include <wtf/MathExtras.h>
	#include <wtf/StdLibExtras.h>

	#if ENABLE(SVG)
	#include "JSSVGException.h"
	#include "SVGException.h"
	#endif

	#if ENABLE(XPATH)
	#include "JSXPathException.h"
	#include "XPathException.h"
	#endif

	#if ENABLE(DATABASE)
	#include "JSSQLException.h"
	#include "SQLException.h"
	#endif

	#if ENABLE(BLOB) \|\| ENABLE(FILE_SYSTEM)
	#include "FileException.h"
	#include "JSFileException.h"
	#endif

	#if ENABLE(INDEXED_DATABASE)
	#include "IDBDatabaseException.h"
	#include "JSIDBDatabaseException.h"
	#endif

	using namespace JSC;

	namespace WebCore {

	using namespace HTMLNames;

	class JSGlobalDataWorldIterator {
	public:
	JSGlobalDataWorldIterator(JSGlobalData* globalData)
	: m_pos(static_cast<WebCoreJSClientData*>(globalData->clientData)->m_worldSet.begin())
	, m_end(static_cast<WebCoreJSClientData*>(globalData->clientData)->m_worldSet.end())
	{
	}

	operator bool()
	{
	return m_pos != m_end;
	}

	DOMWrapperWorld* operator*()
	{
	ASSERT(m_pos != m_end);
	return *m_pos;
	}

	DOMWrapperWorld* operator->()
	{
	ASSERT(m_pos != m_end);
	return *m_pos;
	}

	JSGlobalDataWorldIterator& operator++()
	{
	++m_pos;
	return *this;
	}

	private:
	HashSet<DOMWrapperWorld*>::iterator m_pos;
	HashSet<DOMWrapperWorld*>::iterator m_end;
	};

	const JSC::HashTable* getHashTableForGlobalData(JSGlobalData& globalData, const JSC::HashTable* staticTable)
	{
	return DOMObjectHashTableMap::mapFor(globalData).get(staticTable);
	}

	void markActiveObjectsForContext(MarkStack& markStack, JSGlobalData& globalData, ScriptExecutionContext* scriptExecutionContext)
	{
	// If an element has pending activity that may result in event listeners being called
	// (e.g. an XMLHttpRequest), we need to keep JS wrappers alive.

	const HashMap<ActiveDOMObject, void>& activeObjects = scriptExecutionContext->activeDOMObjects();
	HashMap<ActiveDOMObject, void>::const_iterator activeObjectsEnd = activeObjects.end();
	for (HashMap<ActiveDOMObject, void>::const_iterator iter = activeObjects.begin(); iter != activeObjectsEnd; ++iter) {
	if (iter->first->hasPendingActivity()) {
	// Generally, an active object with pending activity must have a wrapper to mark its listeners.
	// However, some ActiveDOMObjects don't have JS wrappers.
	markDOMObjectWrapper(markStack, globalData, iter->second);
	}
	}

	const HashSet<MessagePort*>& messagePorts = scriptExecutionContext->messagePorts();
	HashSet<MessagePort*>::const_iterator portsEnd = messagePorts.end();
	for (HashSet<MessagePort*>::const_iterator iter = messagePorts.begin(); iter != portsEnd; ++iter) {
	// If the message port is remotely entangled, then always mark it as in-use because we can't determine reachability across threads.
	if (!(iter)->locallyEntangledPort() \|\| (iter)->hasPendingActivity())
	markDOMObjectWrapper(markStack, globalData, *iter);
	}
	}

	void markDOMObjectWrapper(MarkStack& markStack, JSGlobalData& globalData, void* object)
	{
	// FIXME: This could be changed to only mark wrappers that are "observable"
	// as markDOMNodesForDocument does, allowing us to collect more wrappers,
	// but doing this correctly would be challenging.
	if (!object)
	return;

	for (JSGlobalDataWorldIterator worldIter(&globalData); worldIter; ++worldIter) {
	if (JSDOMWrapper* wrapper = worldIter->m_wrappers.get(object).get())
	markStack.deprecatedAppend(reinterpret_cast<JSCell**>(&wrapper));
	}
	}

	static void stringWrapperDestroyed(JSString, void context)
	{
	StringImpl* cacheKey = static_cast<StringImpl*>(context);
	cacheKey->deref();
	}

	JSValue jsStringSlowCase(ExecState* exec, JSStringCache& stringCache, StringImpl* stringImpl)
	{
	JSString* wrapper = jsStringWithFinalizer(exec, UString(stringImpl), stringWrapperDestroyed, stringImpl);
	stringCache.set(exec->globalData(), stringImpl, wrapper);
	// ref explicitly instead of using a RefPtr-keyed hashtable because the wrapper can
	// outlive the cache, so the stringImpl has to match the wrapper's lifetime.
	stringImpl->ref();
	return wrapper;
	}

	JSValue jsStringOrNull(ExecState* exec, const String& s)
	{
	if (s.isNull())
	return jsNull();
	return jsString(exec, s);
	}

	JSValue jsOwnedStringOrNull(ExecState* exec, const String& s)
	{
	if (s.isNull())
	return jsNull();
	return jsOwnedString(exec, stringToUString(s));
	}

	JSValue jsStringOrUndefined(ExecState* exec, const String& s)
	{
	if (s.isNull())
	return jsUndefined();
	return jsString(exec, s);
	}

	JSValue jsStringOrFalse(ExecState* exec, const String& s)
	{
	if (s.isNull())
	return jsBoolean(false);
	return jsString(exec, s);
	}

	JSValue jsString(ExecState* exec, const KURL& url)
	{
	return jsString(exec, url.string());
	}

	JSValue jsStringOrNull(ExecState* exec, const KURL& url)
	{
	if (url.isNull())
	return jsNull();
	return jsString(exec, url.string());
	}

	JSValue jsStringOrUndefined(ExecState* exec, const KURL& url)
	{
	if (url.isNull())
	return jsUndefined();
	return jsString(exec, url.string());
	}

	JSValue jsStringOrFalse(ExecState* exec, const KURL& url)
	{
	if (url.isNull())
	return jsBoolean(false);
	return jsString(exec, url.string());
	}

	AtomicStringImpl* findAtomicString(const Identifier& identifier)
	{
	if (identifier.isNull())
	return 0;
	StringImpl* impl = identifier.impl();
	ASSERT(impl->existingHash());
	return AtomicString::find(impl->characters(), impl->length(), impl->existingHash());
	}

	String valueToStringWithNullCheck(ExecState* exec, JSValue value)
	{
	if (value.isNull())
	return String();
	return ustringToString(value.toString(exec));
	}

	String valueToStringWithUndefinedOrNullCheck(ExecState* exec, JSValue value)
	{
	if (value.isUndefinedOrNull())
	return String();
	return ustringToString(value.toString(exec));
	}

	JSValue jsDateOrNull(ExecState* exec, double value)
	{
	if (!isfinite(value))
	return jsNull();
	return new (exec) DateInstance(exec, exec->lexicalGlobalObject()->dateStructure(), value);
	}

	double valueToDate(ExecState* exec, JSValue value)
	{
	if (value.isNumber())
	return value.uncheckedGetNumber();
	if (!value.inherits(&DateInstance::s_info))
	return std::numeric_limits<double>::quiet_NaN();
	return static_cast<DateInstance*>(value.toObject(exec))->internalNumber();
	}

	void reportException(ExecState* exec, JSValue exception)
	{
	if (exception.isObject() && asObject(exception)->exceptionType() == Terminated)
	return;

	UString errorMessage = exception.toString(exec);
	JSObject* exceptionObject = exception.toObject(exec);
	int lineNumber = exceptionObject->get(exec, Identifier(exec, "line")).toInt32(exec);
	UString exceptionSourceURL = exceptionObject->get(exec, Identifier(exec, "sourceURL")).toString(exec);
	exec->clearException();

	if (ExceptionBase* exceptionBase = toExceptionBase(exception))
	errorMessage = stringToUString(exceptionBase->message() + ": " + exceptionBase->description());

	ScriptExecutionContext* scriptExecutionContext = static_cast<JSDOMGlobalObject*>(exec->lexicalGlobalObject())->scriptExecutionContext();
	ASSERT(scriptExecutionContext);

	// Crash data indicates null-dereference crashes at this point in the Safari 4 Public Beta.
	// It's harmless to return here without reporting the exception to the log and the debugger in this case.
	if (!scriptExecutionContext)
	return;

	scriptExecutionContext->reportException(ustringToString(errorMessage), lineNumber, ustringToString(exceptionSourceURL), 0);
	}

	void reportCurrentException(ExecState* exec)
	{
	JSValue exception = exec->exception();
	exec->clearException();
	reportException(exec, exception);
	}

	void setDOMException(ExecState* exec, ExceptionCode ec)
	{
	if (!ec \|\| exec->hadException())
	return;

	// FIXME: All callers to setDOMException need to pass in the right global object
	// for now, we're going to assume the lexicalGlobalObject. Which is wrong in cases like this:
	// frames[0].document.createElement(null, null); // throws an exception which should have the subframes prototypes.
	JSDOMGlobalObject* globalObject = deprecatedGlobalObjectForPrototype(exec);

	ExceptionCodeDescription description;
	getExceptionCodeDescription(ec, description);

	JSValue errorObject;
	switch (description.type) {
	case DOMExceptionType:
	errorObject = toJS(exec, globalObject, DOMCoreException::create(description));
	break;
	case RangeExceptionType:
	errorObject = toJS(exec, globalObject, RangeException::create(description));
	break;
	case EventExceptionType:
	errorObject = toJS(exec, globalObject, EventException::create(description));
	break;
	case XMLHttpRequestExceptionType:
	errorObject = toJS(exec, globalObject, XMLHttpRequestException::create(description));
	break;
	#if ENABLE(SVG)
	case SVGExceptionType:
	errorObject = toJS(exec, globalObject, SVGException::create(description).get());
	break;
	#endif
	#if ENABLE(XPATH)
	case XPathExceptionType:
	errorObject = toJS(exec, globalObject, XPathException::create(description));
	break;
	#endif
	#if ENABLE(DATABASE)
	case SQLExceptionType:
	errorObject = toJS(exec, globalObject, SQLException::create(description));
	break;
	#endif
	#if ENABLE(BLOB) \|\| ENABLE(FILE_SYSTEM)
	case FileExceptionType:
	errorObject = toJS(exec, globalObject, FileException::create(description));
	break;
	#endif
	#if ENABLE(INDEXED_DATABASE)
	case IDBDatabaseExceptionType:
	errorObject = toJS(exec, globalObject, IDBDatabaseException::create(description));
	break;
	#endif
	}

	ASSERT(errorObject);
	throwError(exec, errorObject);
	}

	DOMWindow* activeDOMWindow(ExecState* exec)
	{
	return asJSDOMWindow(exec->lexicalGlobalObject())->impl();
	}

	DOMWindow* firstDOMWindow(ExecState* exec)
	{
	return asJSDOMWindow(exec->dynamicGlobalObject())->impl();
	}

	bool checkNodeSecurity(ExecState* exec, Node* node)
	{
	return node && allowsAccessFromFrame(exec, node->document()->frame());
	}

	bool allowsAccessFromFrame(ExecState* exec, Frame* frame)
	{
	if (!frame)
	return false;
	JSDOMWindow* window = toJSDOMWindow(frame, currentWorld(exec));
	return window && window->allowsAccessFrom(exec);
	}

	bool allowsAccessFromFrame(ExecState* exec, Frame* frame, String& message)
	{
	if (!frame)
	return false;
	JSDOMWindow* window = toJSDOMWindow(frame, currentWorld(exec));
	return window && window->allowsAccessFrom(exec, message);
	}

	void printErrorMessageForFrame(Frame* frame, const String& message)
	{
	if (!frame)
	return;
	frame->domWindow()->printErrorMessage(message);
	}

	// FIXME: We should remove or at least deprecate this function. Callers can use firstDOMWindow directly.
	Frame* toDynamicFrame(ExecState* exec)
	{
	return firstDOMWindow(exec)->frame();
	}

	// FIXME: We should remove this function. Callers can use ScriptController directly.
	bool processingUserGesture()
	{
	return ScriptController::processingUserGesture();
	}

	JSValue objectToStringFunctionGetter(ExecState* exec, JSValue, const Identifier& propertyName)
	{
	return new (exec) JSFunction(exec, exec->lexicalGlobalObject(), exec->lexicalGlobalObject()->functionStructure(), 0, propertyName, objectProtoFuncToString);
	}

	Structure* getCachedDOMStructure(JSDOMGlobalObject* globalObject, const ClassInfo* classInfo)
	{
	JSDOMStructureMap& structures = globalObject->structures();
	return structures.get(classInfo).get();
	}

	Structure* cacheDOMStructure(JSDOMGlobalObject* globalObject, Structure* structure, const ClassInfo* classInfo)
	{
	JSDOMStructureMap& structures = globalObject->structures();
	ASSERT(!structures.contains(classInfo));
	return structures.set(classInfo, WriteBarrier<Structure>(globalObject->globalData(), globalObject, structure)).first->second.get();
	}

	JSC::JSObject* toJSSequence(ExecState* exec, JSValue value, unsigned& length)
	{
	JSObject* object = value.getObject();
	if (!object) {
	throwTypeError(exec);
	return 0;
	}
	JSValue lengthValue = object->get(exec, exec->propertyNames().length);
	if (exec->hadException())
	return 0;

	if (lengthValue.isUndefinedOrNull()) {
	throwTypeError(exec);
	return 0;
	}

	length = lengthValue.toUInt32(exec);
	if (exec->hadException())
	return 0;

	return object;
	}

	} // namespace WebCore