C++ ExecState::dynamicInterpreter方法代码示例

/*!
// Doc here in case we make this public. (Hopefully we won't.)
@function
 @abstract Returns the prototype that will be used when constructing an object with a given class.
 @param ctx The execution context to use.
 @param jsClass A JSClass whose prototype you want to get.
 @result The JSObject prototype that was automatically generated for jsClass, or NULL if no prototype was automatically generated. This is the prototype that will be used when constructing an object using jsClass.
*/
JSObject* OpaqueJSClass::prototype(JSContextRef ctx)
{
    /* Class (C++) and prototype (JS) inheritance are parallel, so:
     *     (C++)      |        (JS)
     *   ParentClass  |   ParentClassPrototype
     *       ^        |          ^
     *       |        |          |
     *  DerivedClass  |  DerivedClassPrototype
     */
    
    if (!prototypeClass)
        return 0;
    
    ExecState* exec = toJS(ctx);
    
    if (!cachedPrototype) {
        // Recursive, but should be good enough for our purposes
        JSObject* parentPrototype = 0;
        if (parentClass)
            parentPrototype = parentClass->prototype(ctx); // can be null
        if (!parentPrototype)
            parentPrototype = exec->dynamicInterpreter()->builtinObjectPrototype();
        cachedPrototype = new JSCallbackObject(exec, prototypeClass, parentPrototype, this); // set ourself as the object's private data, so it can clear our reference on destruction
    }
    return cachedPrototype;
}

JSObjectRef JSObjectMakeConstructor(JSContextRef ctx, JSClassRef jsClass, JSObjectCallAsConstructorCallback callAsConstructor)
{
    JSLock lock;
    ExecState* exec = toJS(ctx);
    
    JSValue* jsPrototype = jsClass 
        ? jsClass->prototype(ctx)
        : exec->dynamicInterpreter()->builtinObjectPrototype();
    
    JSObject* constructor = new JSCallbackConstructor(exec, jsClass, callAsConstructor);
    constructor->put(exec, exec->propertyNames().prototype, jsPrototype, DontEnum|DontDelete|ReadOnly);
    return toRef(constructor);
}

EXPORT
JSValueRef JSObjectCallAsFunction(JSContextRef ctx, JSObjectRef object, JSObjectRef thisObject, size_t argumentCount, const JSValueRef arguments[], JSValueRef* exception)
{
    JSLock lock;
    ExecState* exec = toJS(ctx);
    JSObject* jsObject = toJS(object);
    JSObject* jsThisObject = toJS(thisObject);

    if (!jsThisObject)
        jsThisObject = exec->dynamicInterpreter()->globalObject();
    
    List argList;
    for (size_t i = 0; i < argumentCount; i++)
        argList.append(toJS(arguments[i]));

    JSValueRef result = toRef(jsObject->call(exec, jsThisObject, argList)); // returns NULL if object->implementsCall() is false
    if (exec->hadException()) {
        if (exception)
            *exception = toRef(exec->exception());
        exec->clearException();
        result = 0;
    }
    return result;
}

JSObjectRef JSObjectMakeFunction(JSContextRef ctx, JSStringRef name, unsigned parameterCount, const JSStringRef parameterNames[], JSStringRef body, JSStringRef sourceURL, int startingLineNumber, JSValueRef* exception)
{
    JSLock lock;
    
    ExecState* exec = toJS(ctx);
    UString::Rep* bodyRep = toJS(body);
    UString::Rep* sourceURLRep = sourceURL ? toJS(sourceURL) : &UString::Rep::null;
    
    Identifier nameID = name ? Identifier(toJS(name)) : Identifier("anonymous");
    
    List args;
    for (unsigned i = 0; i < parameterCount; i++)
        args.append(jsString(UString(toJS(parameterNames[i]))));
    args.append(jsString(UString(bodyRep)));

    JSObject* result = exec->dynamicInterpreter()->builtinFunction()->construct(exec, args, nameID, UString(sourceURLRep), startingLineNumber);
    if (exec->hadException()) {
        if (exception)
            *exception = toRef(exec->exception());
        exec->clearException();
        result = 0;
    }
    return toRef(result);
}