C++ JSFunction::isHostOrBuiltinFunction方法代码示例

void JSFunction::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
{
    JSFunction* thisObject = jsCast<JSFunction*>(cell);
    if (thisObject->isHostOrBuiltinFunction()) {
        Base::put(thisObject, exec, propertyName, value, slot);
        return;
    }
    if (propertyName == exec->propertyNames().prototype) {
        // Make sure prototype has been reified, such that it can only be overwritten
        // following the rules set out in ECMA-262 8.12.9.
        PropertySlot slot(thisObject);
        thisObject->methodTable(exec->vm())->getOwnPropertySlot(thisObject, exec, propertyName, slot);
        if (thisObject->m_rareData)
            thisObject->m_rareData->clear("Store to prototype property of a function");
        // Don't allow this to be cached, since a [[Put]] must clear m_rareData.
        PutPropertySlot dontCache(thisObject);
        Base::put(thisObject, exec, propertyName, value, dontCache);
        return;
    }
    if (thisObject->jsExecutable()->isStrictMode() && (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().caller)) {
        // This will trigger the property to be reified, if this is not already the case!
        bool okay = thisObject->hasProperty(exec, propertyName);
        ASSERT_UNUSED(okay, okay);
        Base::put(thisObject, exec, propertyName, value, slot);
        return;
    }
    if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length || propertyName == exec->propertyNames().name || propertyName == exec->propertyNames().caller) {
        if (slot.isStrictMode())
            throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
        return;
    }
    Base::put(thisObject, exec, propertyName, value, slot);
}

EncodedJSValue JSC_HOST_CALL functionProtoFuncToString(ExecState* exec)
{
    JSValue thisValue = exec->thisValue();
    if (thisValue.inherits(JSFunction::info())) {
        JSFunction* function = jsCast<JSFunction*>(thisValue);
        if (function->isHostOrBuiltinFunction()) {
            String name;
            if (JSBoundFunction* boundFunction = jsDynamicCast<JSBoundFunction*>(function))
                name = boundFunction->toStringName(exec);
            else
                name = function->name(exec);
            return JSValue::encode(jsMakeNontrivialString(exec, "function ", name, "() {\n    [native code]\n}"));
        }

        FunctionExecutable* executable = function->jsExecutable();
        
        String functionHeader = executable->isArrowFunction() ? "" : "function ";
        
        StringView source = executable->source().provider()->getRange(
            executable->parametersStartOffset(),
            executable->parametersStartOffset() + executable->source().length());
        return JSValue::encode(jsMakeNontrivialString(exec, functionHeader, function->name(exec), source));
    }

    if (thisValue.inherits(InternalFunction::info())) {
        InternalFunction* function = asInternalFunction(thisValue);
        return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(exec), "() {\n    [native code]\n}"));
    }

    return throwVMTypeError(exec);
}

CallIdentifier createCallIdentifierFromFunctionImp(ExecState* exec, JSObject* function, const String& defaultSourceURL, unsigned defaultLineNumber, unsigned defaultColumnNumber)
{
    const String& name = getCalculatedDisplayName(exec, function);
    JSFunction* jsFunction = jsDynamicCast<JSFunction*>(function);
    if (jsFunction && !jsFunction->isHostOrBuiltinFunction())
        return CallIdentifier(name.isEmpty() ? ASCIILiteral(AnonymousFunction) : name, jsFunction->jsExecutable()->sourceURL(), jsFunction->jsExecutable()->lineNo(), jsFunction->jsExecutable()->startColumn());
    return CallIdentifier(name.isEmpty() ? ASCIILiteral(AnonymousFunction) : name, defaultSourceURL, defaultLineNumber, defaultColumnNumber);
}

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

    JSValue thisValue = exec->thisValue();
    if (thisValue.inherits(JSFunction::info())) {
        JSFunction* function = jsCast<JSFunction*>(thisValue);
        if (function->isHostOrBuiltinFunction()) {
            scope.release();
            return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(vm), "() {\n    [native code]\n}"));
        }

        FunctionExecutable* executable = function->jsExecutable();
        if (executable->isClass()) {
            StringView classSource = executable->classSource().view();
            return JSValue::encode(jsString(exec, classSource.toStringWithoutCopying()));
        }

        if (thisValue.inherits(JSAsyncFunction::info())) {
            String functionHeader = executable->isArrowFunction() ? "async " : "async function ";

            StringView source = executable->source().provider()->getRange(
                executable->parametersStartOffset(),
                executable->parametersStartOffset() + executable->source().length());
            return JSValue::encode(jsMakeNontrivialString(exec, functionHeader, function->name(vm), source));
        }

        String functionHeader = executable->isArrowFunction() ? "" : "function ";
        
        StringView source = executable->source().provider()->getRange(
            executable->parametersStartOffset(),
            executable->parametersStartOffset() + executable->source().length());
        scope.release();
        return JSValue::encode(jsMakeNontrivialString(exec, functionHeader, function->name(vm), source));
    }

    if (thisValue.inherits(InternalFunction::info())) {
        InternalFunction* function = asInternalFunction(thisValue);
        scope.release();
        return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(), "() {\n    [native code]\n}"));
    }

    if (thisValue.isObject()) {
        JSObject* object = asObject(thisValue);
        if (object->inlineTypeFlags() & TypeOfShouldCallGetCallData) {
            CallData callData;
            if (object->methodTable(vm)->getCallData(object, callData) != CallType::None) {
                if (auto* classInfo = object->classInfo()) {
                    scope.release();
                    return JSValue::encode(jsMakeNontrivialString(exec, "function ", classInfo->className, "() {\n    [native code]\n}"));
                }
            }
        }
    }

    return throwVMTypeError(exec, scope);
}

bool JSFunction::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName)
{
    JSFunction* thisObject = jsCast<JSFunction*>(cell);
    // For non-host functions, don't let these properties by deleted - except by DefineOwnProperty.
    if (!thisObject->isHostOrBuiltinFunction() && !exec->vm().isInDefineOwnProperty()
        && (propertyName == exec->propertyNames().arguments
            || propertyName == exec->propertyNames().length
            || propertyName == exec->propertyNames().name
            || propertyName == exec->propertyNames().prototype
            || propertyName == exec->propertyNames().caller))
        return false;
    return Base::deleteProperty(thisObject, exec, propertyName);
}

EncodedJSValue JSFunction::callerGetter(ExecState* exec, JSObject* slotBase, EncodedJSValue, PropertyName)
{
    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
    ASSERT(!thisObj->isHostFunction());
    JSValue caller = retrieveCallerFunction(exec, thisObj);

    // See ES5.1 15.3.5.4 - Function.caller may not be used to retrieve a strict caller.
    if (!caller.isObject() || !asObject(caller)->inherits(JSFunction::info()))
        return JSValue::encode(caller);
    JSFunction* function = jsCast<JSFunction*>(caller);
    if (function->isHostOrBuiltinFunction() || !function->jsExecutable()->isStrictMode())
        return JSValue::encode(caller);
    return JSValue::encode(throwTypeError(exec, ASCIILiteral("Function.caller used to retrieve strict caller")));
}

void JSFunction::getOwnNonIndexPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
{
    JSFunction* thisObject = jsCast<JSFunction*>(object);
    if (!thisObject->isHostOrBuiltinFunction() && mode.includeDontEnumProperties()) {
        VM& vm = exec->vm();
        // Make sure prototype has been reified.
        PropertySlot slot(thisObject);
        thisObject->methodTable(vm)->getOwnPropertySlot(thisObject, exec, vm.propertyNames->prototype, slot);

        propertyNames.add(vm.propertyNames->arguments);
        propertyNames.add(vm.propertyNames->caller);
        propertyNames.add(vm.propertyNames->length);
        propertyNames.add(vm.propertyNames->name);
    }
    Base::getOwnNonIndexPropertyNames(thisObject, exec, propertyNames, mode);
}

EncodedJSValue JSC_HOST_CALL functionProtoFuncToString(ExecState* exec)
{
    JSValue thisValue = exec->thisValue();
    if (thisValue.inherits(JSFunction::info())) {
        JSFunction* function = jsCast<JSFunction*>(thisValue);
        if (function->isHostOrBuiltinFunction())
            return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(exec), "() {\n    [native code]\n}"));
        FunctionExecutable* executable = function->jsExecutable();
        String sourceString = executable->source().toString();
        insertSemicolonIfNeeded(sourceString, executable->bodyIncludesBraces());
        return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(exec), "(", executable->paramString(), ") ", sourceString));
    }

    if (thisValue.inherits(InternalFunction::info())) {
        InternalFunction* function = asInternalFunction(thisValue);
        return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(exec), "() {\n    [native code]\n}"));
    }

    return throwVMTypeError(exec);
}

EncodedJSValue JSC_HOST_CALL functionProtoFuncToString(ExecState* exec)
{
    JSValue thisValue = exec->thisValue();
    if (thisValue.inherits(JSFunction::info())) {
        JSFunction* function = jsCast<JSFunction*>(thisValue);
        if (function->isHostOrBuiltinFunction())
            return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(exec), "() {\n    [native code]\n}"));

        FunctionExecutable* executable = function->jsExecutable();
        String source = executable->source().provider()->getRange(
            executable->parametersStartOffset(),
            executable->typeProfilingEndOffset() + 1); // Type profiling end offset is the character before the '}'.
        return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(exec), source));
    }

    if (thisValue.inherits(InternalFunction::info())) {
        InternalFunction* function = asInternalFunction(thisValue);
        return JSValue::encode(jsMakeNontrivialString(exec, "function ", function->name(exec), "() {\n    [native code]\n}"));
    }

    return throwVMTypeError(exec);
}

bool JSFunction::defineOwnProperty(JSObject* object, ExecState* exec, PropertyName propertyName, const PropertyDescriptor& descriptor, bool throwException)
{
    JSFunction* thisObject = jsCast<JSFunction*>(object);
    if (thisObject->isHostOrBuiltinFunction())
        return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);

    if (propertyName == exec->propertyNames().prototype) {
        // Make sure prototype has been reified, such that it can only be overwritten
        // following the rules set out in ECMA-262 8.12.9.
        PropertySlot slot(thisObject);
        thisObject->methodTable(exec->vm())->getOwnPropertySlot(thisObject, exec, propertyName, slot);
        if (thisObject->m_rareData)
            thisObject->m_rareData->clear("Store to prototype property of a function");
        return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
    }

    bool valueCheck;
    if (propertyName == exec->propertyNames().arguments) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            PropertySlot slot(thisObject);
            if (!Base::getOwnPropertySlot(thisObject, exec, propertyName, slot))
                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec->vm()), DontDelete | DontEnum | Accessor);
            return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
        }
        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), retrieveArguments(exec, thisObject));
    } else if (propertyName == exec->propertyNames().caller) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            PropertySlot slot(thisObject);
            if (!Base::getOwnPropertySlot(thisObject, exec, propertyName, slot))
                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec->vm()), DontDelete | DontEnum | Accessor);
            return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
        }
        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), retrieveCallerFunction(exec, thisObject));
    } else if (propertyName == exec->propertyNames().length)
        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), jsNumber(thisObject->jsExecutable()->parameterCount()));
    else if (propertyName == exec->propertyNames().name)
        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), thisObject->jsExecutable()->nameValue());
    else
        return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
     
    if (descriptor.configurablePresent() && descriptor.configurable()) {
        if (throwException)
            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to configurable attribute of unconfigurable property.")));
        return false;
    }
    if (descriptor.enumerablePresent() && descriptor.enumerable()) {
        if (throwException)
            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to change enumerable attribute of unconfigurable property.")));
        return false;
    }
    if (descriptor.isAccessorDescriptor()) {
        if (throwException)
            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to change access mechanism for an unconfigurable property.")));
        return false;
    }
    if (descriptor.writablePresent() && descriptor.writable()) {
        if (throwException)
            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to change writable attribute of unconfigurable property.")));
        return false;
    }
    if (!valueCheck) {
        if (throwException)
            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to change value of a readonly property.")));
        return false;
    }
    return true;
}

bool JSFunction::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
    JSFunction* thisObject = jsCast<JSFunction*>(object);
    if (thisObject->isHostOrBuiltinFunction())
        return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);

    if (propertyName == exec->propertyNames().prototype) {
        VM& vm = exec->vm();
        unsigned attributes;
        PropertyOffset offset = thisObject->getDirectOffset(vm, propertyName, attributes);
        if (!isValidOffset(offset)) {
            JSObject* prototype = constructEmptyObject(exec);
            prototype->putDirect(vm, exec->propertyNames().constructor, thisObject, DontEnum);
            thisObject->putDirect(vm, exec->propertyNames().prototype, prototype, DontDelete | DontEnum);
            offset = thisObject->getDirectOffset(vm, exec->propertyNames().prototype, attributes);
            ASSERT(isValidOffset(offset));
        }

        slot.setValue(thisObject, attributes, thisObject->getDirect(offset), offset);
    }

    if (propertyName == exec->propertyNames().arguments) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
            if (!result) {
                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec->vm()), DontDelete | DontEnum | Accessor);
                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
                ASSERT(result);
            }
            return result;
        }
        slot.setCacheableCustom(thisObject, ReadOnly | DontEnum | DontDelete, argumentsGetter);
        return true;
    }

    if (propertyName == exec->propertyNames().length) {
        slot.setCacheableCustom(thisObject, ReadOnly | DontEnum | DontDelete, lengthGetter);
        return true;
    }

    if (propertyName == exec->propertyNames().name) {
        slot.setCacheableCustom(thisObject, ReadOnly | DontEnum | DontDelete, nameGetter);
        return true;
    }

    if (propertyName == exec->propertyNames().caller) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
            if (!result) {
                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec->vm()), DontDelete | DontEnum | Accessor);
                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
                ASSERT(result);
            }
            return result;
        }
        slot.setCacheableCustom(thisObject, ReadOnly | DontEnum | DontDelete, callerGetter);
        return true;
    }

    return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
}