C++ JSActivation::isTornOff方法代码示例

bool JSActivation::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
    JSActivation* thisObject = jsCast<JSActivation*>(object);

    if (propertyName == exec->propertyNames().arguments) {
        // Defend against the inspector asking for the arguments object after it has been optimized out.
        CallFrame* callFrame = CallFrame::create(reinterpret_cast<Register*>(thisObject->m_registers));
        if (!thisObject->isTornOff() && (callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval())) {
            slot.setCustom(thisObject, DontEnum, argumentsGetter);
            return true;
        }
    }

    if (thisObject->symbolTableGet(propertyName, slot))
        return true;

    unsigned attributes;
    if (JSValue value = thisObject->getDirect(exec->vm(), propertyName, attributes)) {
        slot.setValue(thisObject, attributes, value);
        return true;
    }

    // We don't call through to JSObject because there's no way to give an 
    // activation object getter properties or a prototype.
    ASSERT(!thisObject->hasGetterSetterProperties());
    ASSERT(thisObject->prototype().isNull());
    return false;
}

bool JSActivation::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
    JSActivation* thisObject = jsCast<JSActivation*>(object);

    if (propertyName == exec->propertyNames().arguments) {
        // Defend against the inspector asking for the arguments object after it has been optimized out.
        if (!thisObject->isTornOff()) {
            slot.setCustom(thisObject, thisObject->getArgumentsGetter());
            return true;
        }
    }

    if (thisObject->symbolTableGet(propertyName, slot))
        return true;

    if (JSValue value = thisObject->getDirect(exec->vm(), propertyName)) {
        slot.setValue(value);
        return true;
    }

    // We don't call through to JSObject because there's no way to give an 
    // activation object getter properties or a prototype.
    ASSERT(!thisObject->hasGetterSetterProperties());
    ASSERT(thisObject->prototype().isNull());
    return false;
}

EncodedJSValue JSActivation::argumentsGetter(ExecState*, EncodedJSValue slotBase, EncodedJSValue, PropertyName)
{
    JSActivation* activation = jsCast<JSActivation*>(JSValue::decode(slotBase));
    CallFrame* callFrame = CallFrame::create(reinterpret_cast<Register*>(activation->m_registers));
    ASSERT(!activation->isTornOff() && (callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval()));
    if (activation->isTornOff() || !(callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval()))
        return JSValue::encode(jsUndefined());

    VirtualRegister argumentsRegister = callFrame->codeBlock()->argumentsRegister();
    if (JSValue arguments = callFrame->uncheckedR(argumentsRegister.offset()).jsValue())
        return JSValue::encode(arguments);
    int realArgumentsRegister = unmodifiedArgumentsRegister(argumentsRegister).offset();

    JSValue arguments = JSValue(Arguments::create(callFrame->vm(), callFrame));
    callFrame->uncheckedR(argumentsRegister.offset()) = arguments;
    callFrame->uncheckedR(realArgumentsRegister) = arguments;
    
    ASSERT(callFrame->uncheckedR(realArgumentsRegister).jsValue().inherits(Arguments::info()));
    return JSValue::encode(callFrame->uncheckedR(realArgumentsRegister).jsValue());
}

void JSActivation::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
    JSActivation* thisObject = jsCast<JSActivation*>(cell);
    ASSERT_GC_OBJECT_INHERITS(thisObject, info());
    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
    Base::visitChildren(thisObject, visitor);

    // No need to mark our registers if they're still in the JSStack.
    if (!thisObject->isTornOff())
        return;

    for (int i = 0; i < thisObject->symbolTable()->captureCount(); ++i)
        visitor.append(&thisObject->storage()[i]);
}

JSValue JSActivation::argumentsGetter(ExecState*, JSValue slotBase, PropertyName)
{
    JSActivation* activation = jsCast<JSActivation*>(slotBase);
    if (activation->isTornOff())
        return jsUndefined();

    CallFrame* callFrame = CallFrame::create(reinterpret_cast<Register*>(activation->m_registers));
    int argumentsRegister = callFrame->codeBlock()->argumentsRegister();
    if (JSValue arguments = callFrame->uncheckedR(argumentsRegister).jsValue())
        return arguments;
    int realArgumentsRegister = unmodifiedArgumentsRegister(argumentsRegister);

    JSValue arguments = JSValue(Arguments::create(callFrame->vm(), callFrame));
    callFrame->uncheckedR(argumentsRegister) = arguments;
    callFrame->uncheckedR(realArgumentsRegister) = arguments;
    
    ASSERT(callFrame->uncheckedR(realArgumentsRegister).jsValue().inherits(Arguments::info()));
    return callFrame->uncheckedR(realArgumentsRegister).jsValue();
}

bool JSActivation::getOwnPropertyDescriptor(JSObject* object, ExecState* exec, PropertyName propertyName, PropertyDescriptor& descriptor)
{
    JSActivation* thisObject = jsCast<JSActivation*>(object);

    if (propertyName == exec->propertyNames().arguments) {
        // Defend against the inspector asking for the arguments object after it has been optimized out.
        if (!thisObject->isTornOff()) {
            PropertySlot slot(thisObject);
            JSActivation::getOwnPropertySlot(thisObject, exec, propertyName, slot);
            descriptor.setDescriptor(slot.getValue(exec, propertyName), DontEnum);
            return true;
        }
    }

    if (thisObject->symbolTableGet(propertyName, descriptor))
        return true;

    return Base::getOwnPropertyDescriptor(object, exec, propertyName, descriptor);
}

void JSActivation::getOwnNonIndexPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
{
    JSActivation* thisObject = jsCast<JSActivation*>(object);

    if (mode == IncludeDontEnumProperties && !thisObject->isTornOff())
        propertyNames.add(exec->propertyNames().arguments);

    {
        ConcurrentJITLocker locker(thisObject->symbolTable()->m_lock);
        SymbolTable::Map::iterator end = thisObject->symbolTable()->end(locker);
        for (SymbolTable::Map::iterator it = thisObject->symbolTable()->begin(locker); it != end; ++it) {
            if (it->value.getAttributes() & DontEnum && mode != IncludeDontEnumProperties)
                continue;
            if (!thisObject->isValid(it->value))
                continue;
            propertyNames.add(Identifier(exec, it->key.get()));
        }
    }
    // Skip the JSVariableObject implementation of getOwnNonIndexPropertyNames
    JSObject::getOwnNonIndexPropertyNames(thisObject, exec, propertyNames, mode);
}