EncodedJSValue JSC_HOST_CALL JSAudioContextConstructor::constructJSAudioContext(ExecState* exec)
{
    JSAudioContextConstructor* jsConstructor = jsCast<JSAudioContextConstructor*>(exec->callee());
    if (!jsConstructor)
        return throwVMError(exec, createReferenceError(exec, "AudioContext constructor callee is unavailable"));

    ScriptExecutionContext* scriptExecutionContext = jsConstructor->scriptExecutionContext();
    if (!scriptExecutionContext)
        return throwVMError(exec, createReferenceError(exec, "AudioContext constructor script execution context is unavailable"));
        
    if (!scriptExecutionContext->isDocument())
        return throwVMError(exec, createReferenceError(exec, "AudioContext constructor called in a script execution context which is not a document"));

    Document* document = static_cast<Document*>(scriptExecutionContext);

    RefPtr<AudioContext> audioContext;
    
    if (!exec->argumentCount()) {
        // Constructor for default AudioContext which talks to audio hardware.
        ExceptionCode ec = 0;
        audioContext = AudioContext::create(document, ec);
        if (ec) {
            setDOMException(exec, ec);
            return JSValue::encode(JSValue());
        }
        if (!audioContext.get())
            return throwVMError(exec, createSyntaxError(exec, "audio resources unavailable for AudioContext construction"));
    } else {
        // Constructor for offline (render-target) AudioContext which renders into an AudioBuffer.
        // new AudioContext(in unsigned long numberOfChannels, in unsigned long numberOfFrames, in float sampleRate);
        if (exec->argumentCount() < 3)
            return throwVMError(exec, createNotEnoughArgumentsError(exec));

        int32_t numberOfChannels = exec->argument(0).toInt32(exec);
        int32_t numberOfFrames = exec->argument(1).toInt32(exec);
        float sampleRate = exec->argument(2).toFloat(exec);
        
        if (numberOfChannels <= 0 || numberOfChannels > 10)
            return throwVMError(exec, createSyntaxError(exec, "Invalid number of channels"));

        if (numberOfFrames <= 0)
            return throwVMError(exec, createSyntaxError(exec, "Invalid number of frames"));

        if (sampleRate <= 0)
            return throwVMError(exec, createSyntaxError(exec, "Invalid sample rate"));

        ExceptionCode ec = 0;
        audioContext = AudioContext::createOfflineContext(document, numberOfChannels, numberOfFrames, sampleRate, ec);
        if (ec) {
            setDOMException(exec, ec);
            return throwVMError(exec, createSyntaxError(exec, "Error creating OfflineAudioContext"));
        }
    }

    if (!audioContext.get())
        return throwVMError(exec, createReferenceError(exec, "Error creating AudioContext"));

    return JSValue::encode(CREATE_DOM_WRAPPER(exec, jsConstructor->globalObject(), AudioContext, audioContext.get()));
}

JSObject* createUndefinedVariableError(ExecState* exec, const Identifier& ident)
{
    if (exec->propertyNames().isPrivateName(ident)) {
        String message(makeString("Can't find private variable: @", exec->propertyNames().lookUpPublicName(ident).string()));
        return createReferenceError(exec, message);
    }
    String message(makeString("Can't find variable: ", ident.string()));
    return createReferenceError(exec, message);
}

EncodedJSValue JSC_HOST_CALL JSKeyboardEventConstructor::constructJSKeyboardEvent(ExecState* exec)
{
    JSKeyboardEventConstructor* jsConstructor = jsCast<JSKeyboardEventConstructor*>(exec->callee());

    ScriptExecutionContext* executionContext = jsConstructor->scriptExecutionContext();
    if (!executionContext)
        return throwVMError(exec, createReferenceError(exec, "Constructor associated execution context is unavailable"));

    AtomicString eventType = exec->argument(0).toString(exec)->value(exec);
    if (exec->hadException())
        return JSValue::encode(jsUndefined());

    KeyboardEventInit eventInit;

    JSValue initializerValue = exec->argument(1);
    if (!initializerValue.isUndefinedOrNull()) {
        // Given the above test, this will always yield an object.
        JSObject* initializerObject = initializerValue.toObject(exec);

        // Create the dictionary wrapper from the initializer object.
        JSDictionary dictionary(exec, initializerObject);

        // Attempt to fill in the EventInit.
        if (!fillKeyboardEventInit(eventInit, dictionary))
            return JSValue::encode(jsUndefined());
    }

    RefPtr<KeyboardEvent> event = KeyboardEvent::create(eventType, eventInit);
    return JSValue::encode(toJS(exec, jsConstructor->globalObject(), event.get()));
}

EncodedJSValue JSC_HOST_CALL constructJSRTCPeerConnection(ExecState* exec)
{
    // Spec says that we must have at least one arument, the RTCConfiguration.
    if (exec->argumentCount() < 1)
        return throwVMError(exec, createNotEnoughArgumentsError(exec));

    ExceptionCode ec = 0;
    Dictionary rtcConfiguration(exec, exec->argument(0));
    if (exec->hadException())
        return JSValue::encode(jsUndefined());

    if (!rtcConfiguration.isObject())
        return throwVMError(exec, createTypeError(exec, "RTCPeerConnection argument must be a valid Dictionary"));

    DOMConstructorObject* jsConstructor = jsCast<DOMConstructorObject*>(exec->callee());
    ScriptExecutionContext* scriptExecutionContext = jsConstructor->scriptExecutionContext();
    if (!scriptExecutionContext)
        return throwVMError(exec, createReferenceError(exec, "RTCPeerConnection constructor associated document is unavailable"));

    auto peerConnection = RTCPeerConnection::create(*scriptExecutionContext, rtcConfiguration, ec);
    if (ec == TYPE_MISMATCH_ERR) {
        setDOMException(exec, ec);
        return throwVMError(exec, createTypeError(exec, "Invalid RTCPeerConnection constructor arguments"));
    }

    if (ec) {
        setDOMException(exec, ec);
        return throwVMError(exec, createTypeError(exec, "Error creating RTCPeerConnection"));
    }

    return JSValue::encode(CREATE_DOM_WRAPPER(jsConstructor->globalObject(), RTCPeerConnection, peerConnection.releaseNonNull()));
}

EncodedJSValue JSC_HOST_CALL JSTestInterfaceConstructor::constructJSTestInterface(ExecState* exec)
{
    ScriptExecutionContext* context = static_cast<JSTestInterfaceConstructor*>(exec->callee())->scriptExecutionContext();
    if (!context)
        return throwVMError(exec, createReferenceError(exec, "Reference error"));
    return JSValue::encode(asObject(toJS(exec, static_cast<JSTestInterfaceConstructor*>(exec->callee())->globalObject(), TestInterface::create(context))));
}

static EncodedJSValue JSC_HOST_CALL constructHTMLOptionElement(ExecState* exec)
{
    JSOptionConstructor* jsConstructor = static_cast<JSOptionConstructor*>(exec->callee());
    Document* document = jsConstructor->document();
    if (!document)
        return throwVMError(exec, createReferenceError(exec, "Option constructor associated document is unavailable"));

    String data;
    if ((exec->argumentCount() >= 1) && !exec->argument(0).isUndefined())
        data = ustringToString(exec->argument(0).toString(exec));

    String value;
    if ((exec->argumentCount() >= 2)  && !exec->argument(1).isUndefined())
        value = ustringToString(exec->argument(1).toString(exec));
    bool defaultSelected = (exec->argumentCount() >= 3) && exec->argument(2).toBoolean(exec);
    bool selected = (exec->argumentCount() >= 4) && exec->argument(3).toBoolean(exec);

    ExceptionCode ec = 0;
    RefPtr<HTMLOptionElement> element = HTMLOptionElement::createForJSConstructor(document, data, value, defaultSelected, selected, ec);
    if (ec) {
        setDOMException(exec, ec);
        return JSValue::encode(JSValue());
    }

    return JSValue::encode(asObject(toJS(exec, jsConstructor->globalObject(), element.release())));
}

static EncodedJSValue JSC_HOST_CALL constructImage(ExecState* exec)
{
    JSImageConstructor* jsConstructor = jsCast<JSImageConstructor*>(exec->callee());
    Document* document = jsConstructor->document();
    if (!document)
        return throwVMError(exec, createReferenceError(exec, "Image constructor associated document is unavailable"));

    // Calling toJS on the document causes the JS document wrapper to be
    // added to the window object. This is done to ensure that JSDocument::visit
    // will be called, which will cause the image element to be marked if necessary.
    toJS(exec, jsConstructor->globalObject(), document);
    int width;
    int height;
    int* optionalWidth = 0;
    int* optionalHeight = 0;
    if (exec->argumentCount() > 0) {
        width = exec->argument(0).toInt32(exec);
        optionalWidth = &width;
    }
    if (exec->argumentCount() > 1) {
        height = exec->argument(1).toInt32(exec);
        optionalHeight = &height;
    }

    return JSValue::encode(asObject(toJS(exec, jsConstructor->globalObject(),
        HTMLImageElement::createForJSConstructor(*document, optionalWidth, optionalHeight))));
}

EncodedJSValue JSC_HOST_CALL JSMessageChannelConstructor::constructJSMessageChannel(ExecState* exec)
{
    JSMessageChannelConstructor* jsConstructor = static_cast<JSMessageChannelConstructor*>(exec->callee());
    ScriptExecutionContext* context = jsConstructor->scriptExecutionContext();
    if (!context)
        return throwVMError(exec, createReferenceError(exec, "MessageChannel constructor associated document is unavailable"));

    return JSValue::encode(asObject(toJS(exec, jsConstructor->globalObject(), MessageChannel::create(context))));
}

EncodedJSValue JSC_HOST_CALL JSMessageChannelConstructor::constructJSMessageChannel(ExecState* exec)
{
    JSMessageChannelConstructor* castedThis = jsCast<JSMessageChannelConstructor*>(exec->callee());
    ScriptExecutionContext* context = castedThis->scriptExecutionContext();
    if (!context)
        return throwVMError(exec, createReferenceError(exec, "MessageChannel constructor associated document is unavailable"));
    RefPtr<MessageChannel> object = MessageChannel::create(*context);
    return JSValue::encode(asObject(toJS(exec, castedThis->globalObject(), object.get())));
}

JSValue createUndefinedVariableError(ExecState* exec, const Identifier& ident, unsigned bytecodeOffset, CodeBlock* codeBlock)
{
    int startOffset = 0;
    int endOffset = 0;
    int divotPoint = 0;
    int line = codeBlock->expressionRangeForBytecodeOffset(exec, bytecodeOffset, divotPoint, startOffset, endOffset);
    UString message(makeUString("Can't find variable: ", ident.ustring()));
    JSObject* exception = addErrorInfo(exec, createReferenceError(exec, message), line, codeBlock->ownerExecutable()->source(), divotPoint, startOffset, endOffset);
    return exception;
}

EncodedJSValue JSC_HOST_CALL JSXMLHttpRequestConstructor::constructJSXMLHttpRequest(ExecState* exec)
{
    JSXMLHttpRequestConstructor* jsConstructor = static_cast<JSXMLHttpRequestConstructor*>(exec->callee());
    ScriptExecutionContext* context = jsConstructor->scriptExecutionContext();
    if (!context)
        return throwVMError(exec, createReferenceError(exec, "XMLHttpRequest constructor associated document is unavailable"));

    RefPtr<XMLHttpRequest> xmlHttpRequest = XMLHttpRequest::create(context);
    return JSValue::encode(CREATE_DOM_OBJECT_WRAPPER(exec, jsConstructor->globalObject(), XMLHttpRequest, xmlHttpRequest.get()));
}

EncodedJSValue JSC_HOST_CALL JSDeprecatedPeerConnectionConstructor::constructJSDeprecatedPeerConnection(ExecState* exec)
{
    JSDeprecatedPeerConnectionConstructor* jsConstructor = static_cast<JSDeprecatedPeerConnectionConstructor*>(exec->callee());
    ScriptExecutionContext* context = jsConstructor->scriptExecutionContext();
    if (!context)
        return throwVMError(exec, createReferenceError(exec, "DeprecatedPeerConnection constructor associated document is unavailable"));

    if (exec->argumentCount() < 2)
        return throwVMError(exec, createTypeError(exec, "Not enough arguments"));

    String serverConfiguration = ustringToString(exec->argument(0).toString(exec)->value(exec));
    if (exec->hadException())
        return JSValue::encode(JSValue());

    RefPtr<SignalingCallback> signalingCallback = createFunctionOnlyCallback<JSSignalingCallback>(exec, static_cast<JSDOMGlobalObject*>(exec->lexicalGlobalObject()), exec->argument(1));
    if (exec->hadException())
        return JSValue::encode(JSValue());

    RefPtr<DeprecatedPeerConnection> peerConnection = DeprecatedPeerConnection::create(context, serverConfiguration, signalingCallback.release());
    return JSValue::encode(CREATE_DOM_WRAPPER(exec, jsConstructor->globalObject(), DeprecatedPeerConnection, peerConnection.get()));
}

EncodedJSValue JSC_HOST_CALL JSWebSocketConstructor::constructJSWebSocket(ExecState* exec)
{
    JSWebSocketConstructor* jsConstructor = static_cast<JSWebSocketConstructor*>(exec->callee());
    ScriptExecutionContext* context = jsConstructor->scriptExecutionContext();
    if (!context)
        return throwVMError(exec, createReferenceError(exec, "WebSocket constructor associated document is unavailable"));

    if (!exec->argumentCount())
        return throwVMError(exec, createSyntaxError(exec, "Not enough arguments"));

    String urlString = ustringToString(exec->argument(0).toString(exec)->value(exec));
    if (exec->hadException())
        return throwVMError(exec, createSyntaxError(exec, "wrong URL"));
    RefPtr<WebSocket> webSocket = WebSocket::create(context);
    ExceptionCode ec = 0;
    if (exec->argumentCount() < 2)
        webSocket->connect(urlString, ec);
    else {
        JSValue protocolsValue = exec->argument(1);
        if (isJSArray(protocolsValue)) {
            Vector<String> protocols;
            JSArray* protocolsArray = asArray(protocolsValue);
            for (unsigned i = 0; i < protocolsArray->length(); ++i) {
                String protocol = ustringToString(protocolsArray->getIndex(i).toString(exec)->value(exec));
                if (exec->hadException())
                    return JSValue::encode(JSValue());
                protocols.append(protocol);
            }
            webSocket->connect(urlString, protocols, ec);
        } else {
            String protocol = ustringToString(protocolsValue.toString(exec)->value(exec));
            if (exec->hadException())
                return JSValue::encode(JSValue());
            webSocket->connect(urlString, protocol, ec);
        }
    }
    setDOMException(exec, ec);
    return JSValue::encode(CREATE_DOM_WRAPPER(exec, jsConstructor->globalObject(), WebSocket, webSocket.get()));
}

static EncodedJSValue JSC_HOST_CALL constructAudio(ExecState* exec)
{
    JSAudioConstructor* jsConstructor = static_cast<JSAudioConstructor*>(exec->callee());

    Document* document = jsConstructor->document();
    if (!document)
        return throwVMError(exec, createReferenceError(exec, "Audio constructor associated document is unavailable"));

    // Calling toJS on the document causes the JS document wrapper to be
    // added to the window object. This is done to ensure that JSDocument::visitChildren
    // will be called, which will cause the audio element to be marked if necessary.
    toJS(exec, jsConstructor->globalObject(), document);

    // FIXME: This converts an undefined argument to the string "undefined", but possibly we
    // should treat it as if no argument was passed instead, by checking the value of exec->argument
    // rather than looking at exec->argumentCount.
    String src;
    if (exec->argumentCount() > 0)
        src = ustringToString(exec->argument(0).toString(exec));
    return JSValue::encode(asObject(toJS(exec, jsConstructor->globalObject(),
        HTMLAudioElement::createForJSConstructor(document, src))));
}

JSValue JSIDBObjectStore::createIndex(ExecState* exec)
{
    ScriptExecutionContext* context = jsCast<JSDOMGlobalObject*>(exec->lexicalGlobalObject())->scriptExecutionContext();
    if (!context)
        return exec->vm().throwException(exec, createReferenceError(exec, "IDBObjectStore script execution context is unavailable"));

    if (exec->argumentCount() < 2)
        return exec->vm().throwException(exec, createNotEnoughArgumentsError(exec));

    String name = exec->argument(0).toString(exec)->value(exec);
    if (exec->hadException())
        return jsUndefined();

    IDBKeyPath keyPath = idbKeyPathFromValue(exec, exec->argument(1));
    if (exec->hadException())
        return jsUndefined();

    JSValue optionsValue = exec->argument(2);
    if (!optionsValue.isUndefinedOrNull() && !optionsValue.isObject())
        return throwTypeError(exec, "Not an object.");

    bool unique = false;
    bool multiEntry = false;
    if (!optionsValue.isUndefinedOrNull()) {
        unique = optionsValue.get(exec, Identifier(exec, "unique")).toBoolean(exec);
        if (exec->hadException())
            return jsUndefined();

        multiEntry = optionsValue.get(exec, Identifier(exec, "multiEntry")).toBoolean(exec);
        if (exec->hadException())
            return jsUndefined();
    }

    ExceptionCode ec = 0;
    JSValue result = toJS(exec, globalObject(), impl().createIndex(context, name, keyPath, unique, multiEntry, ec).get());
    setDOMException(exec, ec);
    return result;
}

EncodedJSValue JSC_HOST_CALL JSEventSourceConstructor::constructJSEventSource(ExecState* exec)
{
    if (exec->argumentCount() < 1)
        return throwVMError(exec, createTypeError(exec, "Not enough arguments"));

    UString url = exec->argument(0).toString(exec);
    if (exec->hadException())
        return JSValue::encode(JSValue());

    JSEventSourceConstructor* jsConstructor =  static_cast<JSEventSourceConstructor*>(exec->callee());
    ScriptExecutionContext* context = jsConstructor->scriptExecutionContext();
    if (!context)
        return throwVMError(exec, createReferenceError(exec, "EventSource constructor associated document is unavailable"));

    ExceptionCode ec = 0;
    RefPtr<EventSource> eventSource = EventSource::create(ustringToString(url), context, ec);
    if (ec) {
        setDOMException(exec, ec);
        return JSValue::encode(JSValue());
    }

    return JSValue::encode(asObject(toJS(exec, jsConstructor->globalObject(), eventSource.release())));
}

JSObject* createErrorForInvalidGlobalAssignment(ExecState* exec, const UString& propertyName)
{
    return createReferenceError(exec, makeUString("Strict mode forbids implicit creation of global property '", propertyName, "'"));
}

JSObject* createUndefinedVariableError(ExecState* exec, const Identifier& ident)
{
    UString message(makeUString("Can't find variable: ", ident.ustring()));
    return createReferenceError(exec, message);
}

EncodedJSValue JSC_HOST_CALL JSBlobConstructor::constructJSBlob(ExecState* exec)
{
    JSBlobConstructor* jsConstructor = jsCast<JSBlobConstructor*>(exec->callee());
    ScriptExecutionContext* context = jsConstructor->scriptExecutionContext();
    if (!context)
        return throwVMError(exec, createReferenceError(exec, "Blob constructor associated document is unavailable"));

    if (!exec->argumentCount()) {
        RefPtr<Blob> blob = Blob::create();
        return JSValue::encode(CREATE_DOM_WRAPPER(jsConstructor->globalObject(), Blob, blob.get()));
    }

    unsigned blobPartsLength = 0;
    JSObject* blobParts = toJSSequence(exec, exec->argument(0), blobPartsLength);
    if (exec->hadException())
        return JSValue::encode(jsUndefined());
    ASSERT(blobParts);

    String type;
    String endings = ASCIILiteral("transparent");

    if (exec->argumentCount() > 1) {
        JSValue blobPropertyBagValue = exec->argument(1);

        if (!blobPropertyBagValue.isObject())
            return throwVMError(exec, createTypeError(exec, "Second argument of the constructor is not of type Object"));

        // Given the above test, this will always yield an object.
        JSObject* blobPropertyBagObject = blobPropertyBagValue.toObject(exec);

        // Create the dictionary wrapper from the initializer object.
        JSDictionary dictionary(exec, blobPropertyBagObject);

        // Attempt to get the endings property and validate it.
        bool containsEndings = dictionary.get("endings", endings);
        if (exec->hadException())
            return JSValue::encode(jsUndefined());

        if (containsEndings) {
            if (endings != "transparent" && endings != "native")
                return throwVMError(exec, createTypeError(exec, "The endings property must be either \"transparent\" or \"native\""));
        }

        // Attempt to get the type property.
        dictionary.get("type", type);
        if (exec->hadException())
            return JSValue::encode(jsUndefined());
    }

    ASSERT(endings == "transparent" || endings == "native");

    BlobBuilder blobBuilder;

    for (unsigned i = 0; i < blobPartsLength; ++i) {
        JSValue item = blobParts->get(exec, i);
        if (exec->hadException())
            return JSValue::encode(jsUndefined());

#if ENABLE(BLOB)
        if (ArrayBuffer* arrayBuffer = toArrayBuffer(item))
            blobBuilder.append(arrayBuffer);
        else if (RefPtr<ArrayBufferView> arrayBufferView = toArrayBufferView(item))
            blobBuilder.append(arrayBufferView.release());
        else
#endif
        if (Blob* blob = toBlob(item))
            blobBuilder.append(blob);
        else {
            String string = item.toString(exec)->value(exec);
            if (exec->hadException())
                return JSValue::encode(jsUndefined());
            blobBuilder.append(string, endings);
        }
    }

    RefPtr<Blob> blob = Blob::create(blobBuilder.finalize(), Blob::normalizedContentType(type));

    return JSValue::encode(CREATE_DOM_WRAPPER(jsConstructor->globalObject(), Blob, blob.get()));
}

JSObject* RuntimeObject::throwInvalidAccessError(ExecState* exec)
{
    return exec->vm().throwException(exec, createReferenceError(exec, "Trying to access object from destroyed plug-in."));
}