C++ JSActivation类代码示例

JSValue* JSActivation::argumentsGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
{
    JSActivation* thisObj = static_cast<JSActivation*>(slot.slotBase());
    if (!thisObj->d()->argumentsObject)
        thisObj->d()->argumentsObject = thisObj->createArgumentsObject(exec);

    return thisObj->d()->argumentsObject;
}

JSValue JSActivation::argumentsGetter(ExecState*, JSValue slotBase, const Identifier&)
{
    JSActivation* activation = asActivation(slotBase);
    CallFrame* callFrame = CallFrame::create(activation->d()->registers);
    int argumentsRegister = activation->d()->functionExecutable->generatedBytecode().argumentsRegister();
    if (!callFrame->uncheckedR(argumentsRegister).jsValue()) {
        JSValue arguments = JSValue(new (callFrame) Arguments(callFrame));
        callFrame->uncheckedR(argumentsRegister) = arguments;
        callFrame->uncheckedR(unmodifiedArgumentsRegister(argumentsRegister)) = arguments;
    }

    ASSERT(callFrame->uncheckedR(argumentsRegister).jsValue().inherits(&Arguments::info));
    return callFrame->uncheckedR(argumentsRegister).jsValue();
}

void JSActivation::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
{
    JSActivation* thisObject = jsCast<JSActivation*>(cell);
    ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(thisObject));

    if (thisObject->symbolTablePut(exec, propertyName, value, slot.isStrictMode()))
        return;

    // We don't call through to JSObject because __proto__ and getter/setter 
    // properties are non-standard extensions that other implementations do not
    // expose in the activation object.
    ASSERT(!thisObject->hasGetterSetterProperties());
    thisObject->putOwnDataProperty(exec->vm(), propertyName, value, slot);
}

void JSActivation::put(JSCell* cell, ExecState* exec, const Identifier& propertyName, JSValue value, PutPropertySlot& slot)
{
    JSActivation* thisObject = static_cast<JSActivation*>(cell);
    ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(thisObject));

    if (thisObject->symbolTablePut(exec->globalData(), propertyName, value))
        return;

    // We don't call through to JSObject because __proto__ and getter/setter 
    // properties are non-standard extensions that other implementations do not
    // expose in the activation object.
    ASSERT(!thisObject->hasGetterSetterProperties());
    thisObject->putDirect(exec->globalData(), propertyName, value, 0, true, slot);
}

// FIXME: Make this function honor ReadOnly (const) and DontEnum
void JSActivation::putDirectVirtual(JSObject* object, ExecState* exec, PropertyName propertyName, JSValue value, unsigned attributes)
{
    JSActivation* thisObject = jsCast<JSActivation*>(object);
    ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(thisObject));

    if (thisObject->symbolTablePutWithAttributes(exec->globalData(), propertyName, value, attributes))
        return;

    // We don't call through to JSObject because __proto__ and getter/setter 
    // properties are non-standard extensions that other implementations do not
    // expose in the activation object.
    ASSERT(!thisObject->hasGetterSetterProperties());
    JSObject::putDirectVirtual(thisObject, exec, propertyName, value, attributes);
}

void JSActivation::getOwnPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
{
    JSActivation* thisObject = jsCast<JSActivation*>(object);
    SymbolTable::const_iterator end = thisObject->symbolTable().end();
    for (SymbolTable::const_iterator it = thisObject->symbolTable().begin(); it != end; ++it) {
        if (it->second.getAttributes() & DontEnum && mode != IncludeDontEnumProperties)
            continue;
        if (it->second.getIndex() >= thisObject->m_numCapturedVars)
            continue;
        propertyNames.add(Identifier(exec, it->first.get()));
    }
    // Skip the JSVariableObject implementation of getOwnPropertyNames
    JSObject::getOwnPropertyNames(thisObject, exec, propertyNames, mode);
}

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]);
}

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, DontEnum, thisObject->getArgumentsGetter());
            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;
}

void JSActivation::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
    JSActivation* thisObject = static_cast<JSActivation*>(cell);
    ASSERT_GC_OBJECT_INHERITS(thisObject, &s_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 RegisterFile.
    WriteBarrier<Unknown>* registerArray = thisObject->m_registerArray.get();
    if (!registerArray)
        return;

    visitor.appendValues(registerArray, thisObject->m_numParametersMinusThis);

    // Skip the call frame, which sits between the parameters and vars.
    visitor.appendValues(registerArray + thisObject->m_numParametersMinusThis + RegisterFile::CallFrameHeaderSize, thisObject->m_numCapturedVars);
}

void JSActivation::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
    JSActivation* thisObject = jsCast<JSActivation*>(cell);
    ASSERT_GC_OBJECT_INHERITS(thisObject, &s_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 RegisterFile.
    WriteBarrier<Unknown>* registerArray = thisObject->m_registerArray.get();
    if (!registerArray)
        return;

    visitor.appendValues(registerArray, thisObject->m_numCapturedArgs);

    // Skip 'this' and call frame.
    visitor.appendValues(registerArray + CallFrame::offsetFor(thisObject->m_numCapturedArgs + 1), thisObject->m_numCapturedVars);
}

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);
}

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());
}

JSValue JSActivation::argumentsGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
{
    JSActivation* activation = asActivation(slot.slotBase());

    if (activation->d()->functionExecutable->usesArguments()) {
        PropertySlot slot;
        activation->symbolTableGet(exec->propertyNames().arguments, slot);
        return slot.getValue(exec, exec->propertyNames().arguments);
    }

    CallFrame* callFrame = CallFrame::create(activation->d()->registers);
    Arguments* arguments = callFrame->optionalCalleeArguments();
    if (!arguments) {
        arguments = new (callFrame) Arguments(callFrame);
        arguments->copyRegisters();
        callFrame->setCalleeArguments(arguments);
    }
    ASSERT(arguments->inherits(&Arguments::info));

    return arguments;
}

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);
}