jsdombinding.cpp

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        JSNode* jsNode = nodeIt->second;
        Node* node = jsNode->impl();

        if (jsNode->marked())
            continue;

        // No need to preserve a wrapper that has no custom properties or is no
        // longer fetchable through the DOM.
        if (!jsNode->hasCustomProperties() || !node->inDocument()) {
            //... unless the wrapper wraps a loading image, since the "new Image"
            // syntax allows an orphan image wrapper to be the last reference
            // to a loading image, whose load event might have important side-effects.
            if (!node->hasTagName(imgTag) || static_cast<HTMLImageElement*>(node)->haveFiredLoadEvent())
                continue;
        }

        jsNode->mark();
    }
}

void markActiveObjectsForContext(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()) {
            DOMObject* wrapper = getCachedDOMObjectWrapper(globalData, iter->second);
            // Generally, an active object with pending activity must have a wrapper to mark its listeners.
            // However, some ActiveDOMObjects don't have JS wrappers (timers created by setTimeout is one example).
            // FIXME: perhaps need to make sure even timers have a markable 'wrapper'.
            if (wrapper && !wrapper->marked())
                wrapper->mark();
        }
    }

    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 ((*iter)->hasPendingActivity()) {
            DOMObject* wrapper = getCachedDOMObjectWrapper(globalData, *iter);
            // A port with pending activity must have a wrapper to mark its listeners, so no null check.
            if (!wrapper->marked())
                wrapper->mark();
        }
    }
}

void updateDOMNodeDocument(Node* node, Document* oldDocument, Document* newDocument)
{
    ASSERT(oldDocument != newDocument);
    JSNode* wrapper = getCachedDOMNodeWrapper(oldDocument, node);
    if (!wrapper)
        return;
    removeWrapper(wrapper);
    cacheDOMNodeWrapper(newDocument, node, wrapper);
    forgetDOMNode(oldDocument, node);
    addWrapper(wrapper);
}

void markDOMObjectWrapper(JSGlobalData& globalData, void* object)
{
    if (!object)
        return;
    DOMObject* wrapper = getCachedDOMObjectWrapper(globalData, object);
    if (!wrapper || wrapper->marked())
        return;
    wrapper->mark();
}

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

JSValuePtr jsOwnedStringOrNull(ExecState* exec, const UString& s)
{
    if (s.isNull())
        return jsNull();
    return jsOwnedString(exec, s);
}

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

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

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

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

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

UString valueToStringWithNullCheck(ExecState* exec, JSValuePtr value)
{
    if (value.isNull())
        return UString();
    return value.toString(exec);
}

UString valueToStringWithUndefinedOrNullCheck(ExecState* exec, JSValuePtr value)
{
    if (value.isUndefinedOrNull())
        return UString();
    return value.toString(exec);
}

void reportException(JSC::ExecState* exec, JSValuePtr exception)
{
    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();

    ScriptExecutionContext* scriptExecutionContext = static_cast<JSDOMGlobalObject*>(exec->lexicalGlobalObject())->scriptExecutionContext();
    scriptExecutionContext->reportException(errorMessage, lineNumber, exceptionSourceURL);
}

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

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

    ExceptionCodeDescription description;
    getExceptionCodeDescription(ec, description);

    JSValuePtr errorObject = noValue();
    switch (description.type) {
        case DOMExceptionType:
            errorObject = toJS(exec, DOMCoreException::create(description));
            break;
        case RangeExceptionType:
            errorObject = toJS(exec, RangeException::create(description));
            break;
        case EventExceptionType:
            errorObject = toJS(exec, EventException::create(description));
            break;
        case XMLHttpRequestExceptionType:
            errorObject = toJS(exec, XMLHttpRequestException::create(description));
            break;
#if ENABLE(SVG)
        case SVGExceptionType:
            errorObject = toJS(exec, SVGException::create(description).get(), 0);
            break;
#endif
#if ENABLE(XPATH)
        case XPathExceptionType:
            errorObject = toJS(exec, XPathException::create(description));
            break;
#endif
    }

    ASSERT(errorObject);
    exec->setException(errorObject);
}

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);
    return window && window->allowsAccessFrom(exec);
}

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

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

JSValuePtr objectToStringFunctionGetter(ExecState* exec, const Identifier& propertyName, const PropertySlot&)
{
    return new (exec) PrototypeFunction(exec, 0, propertyName, objectProtoFuncToString);
}

ScriptState* scriptStateFromNode(Node* node)
{
    if (!node)
        return 0;
    Document* document = node->document();
    if (!document)
        return 0;
    Frame* frame = document->frame();
    if (!frame)
        return 0;
    if (!frame->script()->isEnabled())
        return 0;
    return frame->script()->globalObject()->globalExec();
}

Structure* getCachedDOMStructure(ExecState* exec, const ClassInfo* classInfo)
{
    JSDOMStructureMap& structures = static_cast<JSDOMGlobalObject*>(exec->lexicalGlobalObject())->structures();
    return structures.get(classInfo).get();
}

Structure* cacheDOMStructure(ExecState* exec, PassRefPtr<Structure> structure, const ClassInfo* classInfo)
{
    JSDOMStructureMap& structures = static_cast<JSDOMGlobalObject*>(exec->lexicalGlobalObject())->structures();
    ASSERT(!structures.contains(classInfo));
    return structures.set(classInfo, structure).first->second.get();
}

JSObject* getCachedDOMConstructor(ExecState* exec, const ClassInfo* classInfo)
{
    JSDOMConstructorMap& constructors = static_cast<JSDOMGlobalObject*>(exec->lexicalGlobalObject())->constructors();
    return constructors.get(classInfo);
}

void cacheDOMConstructor(ExecState* exec, const ClassInfo* classInfo, JSObject* constructor)
{
    JSDOMConstructorMap& constructors = static_cast<JSDOMGlobalObject*>(exec->lexicalGlobalObject())->constructors();
    ASSERT(!constructors.contains(classInfo));
    constructors.set(classInfo, constructor);
}

} // namespace WebCore