C++ JSValue::isUndefinedOrNull方法代码示例

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

SpeculatedType speculationFromValue(JSValue value)
{
    if (value.isEmpty())
        return SpecEmpty;
    if (value.isInt32())
        return SpecInt32;
    if (value.isDouble()) {
        double number = value.asNumber();
        if (number == number) {
            int64_t asInt64 = static_cast<int64_t>(number);
            if (asInt64 == number && (asInt64 || !std::signbit(number))
                && asInt64 < (static_cast<int64_t>(1) << 47)
                && asInt64 >= -(static_cast<int64_t>(1) << 47)) {
                return SpecInt48AsDouble;
            }
            return SpecNonIntAsDouble;
        }
        return SpecDoubleNaN;
    }
    if (value.isCell())
        return speculationFromCell(value.asCell());
    if (value.isBoolean())
        return SpecBoolean;
    ASSERT(value.isUndefinedOrNull());
    return SpecOther;
}

EncodedJSValue JSC_HOST_CALL objectProtoFuncToString(ExecState* exec)
{
    VM& vm = exec->vm();
    JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
    if (thisValue.isUndefinedOrNull())
        return JSValue::encode(thisValue.isUndefined() ? vm.smallStrings.undefinedObjectString() : vm.smallStrings.nullObjectString());
    JSObject* thisObject = thisValue.toObject(exec);

    JSValue stringTag = thisObject->get(exec, exec->propertyNames().toStringTagSymbol);
    if (stringTag.isString()) {
        JSRopeString::RopeBuilder<RecordOverflow> ropeBuilder(vm);
        ropeBuilder.append(vm.smallStrings.objectStringStart());
        ropeBuilder.append(jsCast<JSString*>(stringTag));
        ropeBuilder.append(vm.smallStrings.singleCharacterString(']'));
        if(ropeBuilder.hasOverflowed())
            return JSValue::encode(throwOutOfMemoryError(exec));

        return JSValue::encode(ropeBuilder.release());
    }

    JSString* result = thisObject->structure(vm)->objectToStringValue();
    if (!result) {
        RefPtr<StringImpl> newString = WTF::tryMakeString("[object ", thisObject->methodTable(exec->vm())->className(thisObject), "]");
        if (!newString)
            return JSValue::encode(throwOutOfMemoryError(exec));

        result = jsNontrivialString(&vm, newString.release());
        thisObject->structure(vm)->setObjectToStringValue(vm, result);
    }
    return JSValue::encode(result);
}

JSValue JSXMLHttpRequest::send(ExecState* exec, const ArgList& args)
{
    ExceptionCode ec = 0;
    if (args.isEmpty())
        impl()->send(ec);
    else {
        JSValue val = args.at(0);
        if (val.isUndefinedOrNull())
            impl()->send(ec);
        else if (val.inherits(&JSDocument::s_info))
            impl()->send(toDocument(val), ec);
        else if (val.inherits(&JSBlob::s_info))
            impl()->send(toBlob(val), ec);
        else
            impl()->send(val.toString(exec), ec);
    }

    int signedLineNumber;
    intptr_t sourceID;
    UString sourceURL;
    JSValue function;
    exec->interpreter()->retrieveLastCaller(exec, signedLineNumber, sourceID, sourceURL, function);
    impl()->setLastSendLineNumber(signedLineNumber >= 0 ? signedLineNumber : 0);
    impl()->setLastSendURL(sourceURL);

    setDOMException(exec, ec);
    return jsUndefined();
}

JSValue JSXMLHttpRequest::send(ExecState* exec)
{
    InspectorInstrumentation::willSendXMLHttpRequest(impl().scriptExecutionContext(), impl().url());

    ExceptionCode ec = 0;
    JSValue val = exec->argument(0);
    if (val.isUndefinedOrNull())
        impl().send(ec);
    else if (val.inherits(JSDocument::info()))
        impl().send(toDocument(val), ec);
    else if (val.inherits(JSBlob::info()))
        impl().send(toBlob(val), ec);
    else if (val.inherits(JSDOMFormData::info()))
        impl().send(toDOMFormData(val), ec);
    else if (val.inherits(JSArrayBuffer::info()))
        impl().send(toArrayBuffer(val), ec);
    else if (val.inherits(JSArrayBufferView::info())) {
        RefPtr<ArrayBufferView> view = toArrayBufferView(val);
        impl().send(view.get(), ec);
    } else
        impl().send(val.toString(exec)->value(exec), ec);

    SendFunctor functor;
    exec->iterate(functor);
    impl().setLastSendLineNumber(functor.line());
    impl().setLastSendURL(functor.url());
    setDOMException(exec, ec);
    return jsUndefined();
}

JSValue JSXMLHttpRequest::send(ExecState* exec)
{
    ExceptionCode ec = 0;
    if (!exec->argumentCount())
        impl()->send(ec);
    else {
        JSValue val = exec->argument(0);
        if (val.isUndefinedOrNull())
            impl()->send(ec);
        else if (val.inherits(&JSDocument::s_info))
            impl()->send(toDocument(val), ec);
        else if (val.inherits(&JSBlob::s_info))
            impl()->send(toBlob(val), ec);
        else if (val.inherits(&JSDOMFormData::s_info))
            impl()->send(toDOMFormData(val), ec);
        else
            impl()->send(ustringToString(val.toString(exec)), ec);
    }

    int signedLineNumber;
    intptr_t sourceID;
    UString sourceURL;
    JSValue function;
    exec->interpreter()->retrieveLastCaller(exec, signedLineNumber, sourceID, sourceURL, function);
    impl()->setLastSendLineNumber(signedLineNumber >= 0 ? signedLineNumber : 0);
    impl()->setLastSendURL(ustringToString(sourceURL));

    setDOMException(exec, ec);
    return jsUndefined();
}

JSValue evaluate(ExecState* exec, const SourceCode& source, JSValue thisValue, NakedPtr<Exception>& returnedException)
{
    JSLockHolder lock(exec);
    RELEASE_ASSERT(exec->vm().atomicStringTable() == wtfThreadData().atomicStringTable());
    RELEASE_ASSERT(!exec->vm().isCollectorBusy());

    CodeProfiling profile(source);

    ProgramExecutable* program = ProgramExecutable::create(exec, source);
    if (!program) {
        returnedException = exec->vm().exception();
        exec->vm().clearException();
        return jsUndefined();
    }

    if (!thisValue || thisValue.isUndefinedOrNull())
        thisValue = exec->vmEntryGlobalObject();
    JSObject* thisObj = jsCast<JSObject*>(thisValue.toThis(exec, NotStrictMode));
    JSValue result = exec->interpreter()->execute(program, exec, thisObj);

    if (exec->hadException()) {
        returnedException = exec->exception();
        exec->clearException();
        return jsUndefined();
    }

    RELEASE_ASSERT(result);
    return result;
}

void fillMessagePortArray(JSC::ExecState* exec, JSC::JSValue value, MessagePortArray& portArray)
{
    // Convert from the passed-in JS array-like object to a MessagePortArray.
    // Also validates the elements per sections 4.1.13 and 4.1.15 of the WebIDL spec and section 8.3.3 of the HTML5 spec.
    if (value.isUndefinedOrNull()) {
        portArray.resize(0);
        return;
    }

    // Validation of sequence types, per WebIDL spec 4.1.13.
    unsigned length;
    JSObject* object = toJSSequence(exec, value, length);
    if (exec->hadException())
        return;

    portArray.resize(length);
    for (unsigned i = 0 ; i < length; ++i) {
        JSValue value = object->get(exec, i);
        if (exec->hadException())
            return;
        // Validation of non-null objects, per HTML5 spec 8.3.3.
        if (value.isUndefinedOrNull()) {
            setDOMException(exec, INVALID_STATE_ERR);
            return;
        }

        // Validation of Objects implementing an interface, per WebIDL spec 4.1.15.
        RefPtr<MessagePort> port = toMessagePort(value);
        if (!port) {
            throwTypeError(exec);
            return;
        }
        portArray[i] = port.release();
    }
}

static EncodedJSValue JSC_HOST_CALL constructWeakSet(ExecState* exec)
{
    VM& vm = exec->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    JSGlobalObject* globalObject = asInternalFunction(exec->jsCallee())->globalObject();
    Structure* weakSetStructure = InternalFunction::createSubclassStructure(exec, exec->newTarget(), globalObject->weakSetStructure());
    RETURN_IF_EXCEPTION(scope, encodedJSValue());
    JSWeakSet* weakSet = JSWeakSet::create(exec, weakSetStructure);
    JSValue iterable = exec->argument(0);
    if (iterable.isUndefinedOrNull())
        return JSValue::encode(weakSet);

    JSValue adderFunction = weakSet->JSObject::get(exec, vm.propertyNames->add);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    CallData adderFunctionCallData;
    CallType adderFunctionCallType = getCallData(adderFunction, adderFunctionCallData);
    if (adderFunctionCallType == CallType::None)
        return JSValue::encode(throwTypeError(exec, scope));

    scope.release();
    forEachInIterable(exec, iterable, [&](VM&, ExecState* exec, JSValue nextValue) {
        MarkedArgumentBuffer arguments;
        arguments.append(nextValue);
        call(exec, adderFunction, adderFunctionCallType, adderFunctionCallData, weakSet, arguments);
    });

    return JSValue::encode(weakSet);
}

static RefPtr<CryptoAlgorithmParameters> createRsaOaepParams(ExecState* exec, JSValue value)
{
    if (!value.isObject()) {
        throwTypeError(exec);
        return nullptr;
    }

    JSDictionary jsDictionary(exec, value.getObject());
    auto result = adoptRef(*new CryptoAlgorithmRsaOaepParams);

    if (!getHashAlgorithm(jsDictionary, result->hash, HashRequirement::Required)) {
        ASSERT(exec->hadException());
        return nullptr;
    }

    JSValue labelValue = getProperty(exec, value.getObject(), "label");
    if (exec->hadException())
        return nullptr;

    result->hasLabel = !labelValue.isUndefinedOrNull();
    if (!result->hasLabel)
        return WTFMove(result);

    CryptoOperationData labelData;
    if (!cryptoOperationDataFromJSValue(exec, labelValue, labelData)) {
        ASSERT(exec->hadException());
        return nullptr;
    }

    result->label.append(labelData.first, labelData.second);

    return WTFMove(result);
}

void JSDictionary::convertValue(ExecState* exec, JSValue value, ArrayValue& result)
{
    if (value.isUndefinedOrNull())
        return;

    result = ArrayValue(exec, value);
}

Completion evaluate(ExecState* exec, ScopeChain& scopeChain, const SourceCode& source, JSValue thisValue)
{
	//zyc
	/*
	ofstream out("fromCompletion.txt", ios::app);
    char *output = source.toString().ascii();
    out<<output<<endl;
    out.close();*/
    //done zyc
    //out.write(output.utf8().data(),output.utf8().length());
    //out.write('\n',1);
    JSLock lock(exec);
    ASSERT(exec->globalData().identifierTable == wtfThreadData().currentIdentifierTable());

    RefPtr<ProgramExecutable> program = ProgramExecutable::create(exec, source);
    JSObject* error = program->compile(exec, scopeChain.node());
    if (error)
        return Completion(Throw, error);

    JSObject* thisObj = (!thisValue || thisValue.isUndefinedOrNull()) ? exec->dynamicGlobalObject() : thisValue.toObject(exec);

    JSValue exception;
    JSValue result = exec->interpreter()->execute(program.get(), exec, scopeChain.node(), thisObj, &exception);

    if (exception) {
        ComplType exceptionType = Throw;
        if (exception.isObject())
            exceptionType = asObject(exception)->exceptionType();
        return Completion(exceptionType, exception);
    }
    return Completion(Normal, result);
}

EncodedJSValue JSC_HOST_CALL functionProtoFuncApply(ExecState* exec)
{
    JSValue thisValue = exec->hostThisValue();
    CallData callData;
    CallType callType = getCallData(thisValue, callData);
    if (callType == CallTypeNone)
        return throwVMTypeError(exec);

    JSValue array = exec->argument(1);

    MarkedArgumentBuffer applyArgs;
    if (!array.isUndefinedOrNull()) {
        if (!array.isObject())
            return throwVMTypeError(exec);
        if (asObject(array)->classInfo() == &Arguments::s_info) {
            if (asArguments(array)->length(exec) > Arguments::MaxArguments)
                return JSValue::encode(throwStackOverflowError(exec));
            asArguments(array)->fillArgList(exec, applyArgs);
        } else if (isJSArray(array)) {
            if (asArray(array)->length() > Arguments::MaxArguments)
                return JSValue::encode(throwStackOverflowError(exec));
            asArray(array)->fillArgList(exec, applyArgs);
        } else {
            unsigned length = asObject(array)->get(exec, exec->propertyNames().length).toUInt32(exec);
            if (length > Arguments::MaxArguments)
                return JSValue::encode(throwStackOverflowError(exec));

            for (unsigned i = 0; i < length; ++i)
                applyArgs.append(asObject(array)->get(exec, i));
        }
    }
    
    return JSValue::encode(call(exec, thisValue, callType, callData, exec->argument(0), applyArgs));
}

Completion evaluate(ExecState* exec, ScopeChainNode* scopeChain, const SourceCode& source, JSValue thisValue)
{
    JSLock lock(exec);
    ASSERT(exec->globalData().identifierTable == wtfThreadData().currentIdentifierTable());

    ProgramExecutable* program = ProgramExecutable::create(exec, source);
    if (!program) {
        JSValue exception = exec->globalData().exception;
        exec->globalData().exception = JSValue();
        return Completion(Throw, exception);
    }

    JSObject* thisObj = (!thisValue || thisValue.isUndefinedOrNull()) ? exec->dynamicGlobalObject() : thisValue.toObject(exec);

    JSValue result = exec->interpreter()->execute(program, exec, scopeChain, thisObj);

    if (exec->hadException()) {
        JSValue exception = exec->exception();
        exec->clearException();

        ComplType exceptionType = Throw;
        if (exception.isObject())
            exceptionType = asObject(exception)->exceptionType();
        return Completion(exceptionType, exception);
    }
    return Completion(Normal, result);
}

JSValue JSXMLHttpRequest::send(ExecState& state)
{
    InspectorInstrumentation::willSendXMLHttpRequest(wrapped().scriptExecutionContext(), wrapped().url());

    ExceptionCode ec = 0;
    JSValue val = state.argument(0);
    if (val.isUndefinedOrNull())
        wrapped().send(ec);
    else if (val.inherits(JSDocument::info()))
        wrapped().send(JSDocument::toWrapped(val), ec);
    else if (val.inherits(JSBlob::info()))
        wrapped().send(JSBlob::toWrapped(val), ec);
    else if (val.inherits(JSDOMFormData::info()))
        wrapped().send(JSDOMFormData::toWrapped(val), ec);
    else if (val.inherits(JSArrayBuffer::info()))
        wrapped().send(toArrayBuffer(val), ec);
    else if (val.inherits(JSArrayBufferView::info())) {
        RefPtr<ArrayBufferView> view = toArrayBufferView(val);
        wrapped().send(view.get(), ec);
    } else
        wrapped().send(val.toString(&state)->value(&state), ec);

    // FIXME: This should probably use ShadowChicken so that we get the right frame even when it did
    // a tail call.
    // https://bugs.webkit.org/show_bug.cgi?id=155688
    SendFunctor functor;
    state.iterate(functor);
    wrapped().setLastSendLineAndColumnNumber(functor.line(), functor.column());
    wrapped().setLastSendURL(functor.url());
    setDOMException(&state, ec);
    return jsUndefined();
}