bool QmcTypeUnitComponentAndAliasResolver::addAliases()
{
    // add aliases
    //QmcUnitAlias al = {0, 0, 0, 8, 0, 0, 24};
    //qmcTypeUnit->unit->aliases.append(al);
    // see QQmlComponentAndAliasResolver::resolve
    int effectiveAliasIndex = -1;
    int effectivePropertyIndex = -1;
    int effectiveSignalIndex = -1;
    int currentObjectIndex = -1;
    QQmlPropertyCache *propertyCache = NULL;
    foreach (const QmcUnitAlias &alias, qmcTypeUnit->unit->aliases) {
        if ((int)alias.objectIndex != currentObjectIndex) {
            currentObjectIndex = alias.objectIndex;
            effectiveAliasIndex = 0;
            propertyCache = qmcTypeUnit->propertyCaches.at(alias.objectIndex);
            effectivePropertyIndex = propertyCache->propertyIndexCacheStart + propertyCache->propertyIndexCache.count();
            effectiveSignalIndex = propertyCache->signalHandlerIndexCacheStart + propertyCache->propertyIndexCache.count();
        }
        Q_ASSERT(propertyCache);
        QQmlVMEMetaData::AliasData aliasData;
        aliasData.contextIdx = alias.contextIndex;
        aliasData.propertyIdx = alias.targetPropertyIndex;
        aliasData.propType = alias.propertyType;
        aliasData.flags = alias.flags;
        aliasData.notifySignal = alias.notifySignal;

        typedef QQmlVMEMetaData VMD;
        QByteArray &dynamicData = qmcTypeUnit->vmeMetaObjects[alias.objectIndex];
        Q_ASSERT(!dynamicData.isEmpty());
        VMD *vmd = (QQmlVMEMetaData *)dynamicData.data();
        *(vmd->aliasData() + effectiveAliasIndex++) = aliasData;

        Q_ASSERT(dynamicData.isDetached());

        // TBD: propertyCache
        const QV4::CompiledData::Object *obj = qmcTypeUnit->compiledData->qmlUnit->objectAt(alias.objectIndex);
        Q_ASSERT(obj);
        Q_ASSERT(alias.propertyIndex < obj->nProperties);
        const QV4::CompiledData::Property *p = &obj->propertyTable()[alias.propertyIndex];
        Q_ASSERT(p);
        QString propertyName = qmcTypeUnit->stringAt(p->nameIndex);
        const QString aliasPropertyValue = qmcTypeUnit->stringAt(p->aliasPropertyValueIndex);

        //const int idIndex = p->aliasIdValueIndex;
        const int targetObjectIndex = alias.targetObjectIndex;
#if 0
        const int idIndex = p->aliasIdValueIndex;
        const int targetObjectIndex = _idToObjectIndex.value(idIndex, -1);
        if (targetObjectIndex == -1) {
            recordError(p->aliasLocation, tr("Invalid alias reference. Unable to find id \"%1\"").arg(stringAt(idIndex)));
            return false;
        }
#endif
        QStringRef property;
        QStringRef subProperty;

        const int propertySeparator = aliasPropertyValue.indexOf(QLatin1Char('.'));
        if (propertySeparator != -1) {
            property = aliasPropertyValue.leftRef(propertySeparator);
            subProperty = aliasPropertyValue.midRef(propertySeparator + 1);
        } else
            property = QStringRef(&aliasPropertyValue, 0, aliasPropertyValue.length());

        quint32 propertyFlags = QQmlPropertyData::IsAlias;
        int type = 0;
        bool writable = false;
        bool resettable = false;

        if (property.isEmpty()) {
            const QV4::CompiledData::Object *targetObject = qmcTypeUnit->compiledData->qmlUnit->objectAt(targetObjectIndex);
            QQmlCompiledData::TypeReference *typeRef = qmcTypeUnit->compiledData->resolvedTypes.value(targetObject->inheritedTypeNameIndex);
            Q_ASSERT(typeRef);

            if (typeRef->type)
                type = typeRef->type->typeId();
            else
                type = typeRef->component->metaTypeId;

            //flags |= QML_ALIAS_FLAG_PTR;
            propertyFlags |= QQmlPropertyData::IsQObjectDerived;
        } else {
            QQmlPropertyCache *targetCache = qmcTypeUnit->propertyCaches.at(targetObjectIndex);
            Q_ASSERT(targetCache);
            QmlIR::PropertyResolver resolver(targetCache);

            QQmlPropertyData *targetProperty = resolver.property(property.toString());
            if (!targetProperty || targetProperty->coreIndex > 0x0000FFFF) {
                return false;
            }

            //propIdx = targetProperty->coreIndex;
            type = targetProperty->propType;

            writable = targetProperty->isWritable();
            resettable = targetProperty->isResettable();
            //notifySignal = targetProperty->notifyIndex;

            if (!subProperty.isEmpty()) {
                QQmlValueType *valueType = QQmlValueTypeFactory::valueType(type);
                if (!valueType) {
                    return false;
                }

                //propType = type;

                int valueTypeIndex =
                    valueType->metaObject()->indexOfProperty(subProperty.toString().toUtf8().constData());
                if (valueTypeIndex == -1) {
                    return false;
                }
                Q_ASSERT(valueTypeIndex <= 0x0000FFFF);

                //propIdx |= (valueTypeIndex << 16);
                if (valueType->metaObject()->property(valueTypeIndex).isEnumType())
                    type = QVariant::Int;
                else
                    type = valueType->metaObject()->property(valueTypeIndex).userType();

            } else {
                if (targetProperty->isEnum()) {
                    type = QVariant::Int;
                } else {
                    // Copy type flags
                    propertyFlags |= targetProperty->getFlags() & QQmlPropertyData::PropTypeFlagMask;

                    if (targetProperty->isVarProperty())
                        propertyFlags |= QQmlPropertyData::IsQVariant;

#if 0
                    if (targetProperty->isQObject())
                        flags |= QML_ALIAS_FLAG_PTR;
#endif
                }
            }
        }

        if (!(p->flags & QV4::CompiledData::Property::IsReadOnly) && writable)
            propertyFlags |= QQmlPropertyData::IsWritable;
        else
            propertyFlags &= ~QQmlPropertyData::IsWritable;

        if (resettable)
            propertyFlags |= QQmlPropertyData::IsResettable;
        else
            propertyFlags &= ~QQmlPropertyData::IsResettable;

        if ((int)alias.propertyIndex == obj->indexOfDefaultProperty) propertyCache->_defaultPropertyName = propertyName;
        propertyCache->appendProperty(propertyName, propertyFlags, effectivePropertyIndex++,
                                      type, effectiveSignalIndex++);
    }

    return true;
}
int QQmlVMEMetaObject::metaCall(QMetaObject::Call c, int _id, void **a)
{
    int id = _id;
    if (c == QMetaObject::WriteProperty && interceptors &&
       !(*reinterpret_cast<int*>(a[3]) & QQmlPropertyPrivate::BypassInterceptor)) {

        for (QQmlPropertyValueInterceptor *vi = interceptors; vi; vi = vi->m_next) {
            if (vi->m_coreIndex != id)
                continue;

            int valueIndex = vi->m_valueTypeCoreIndex;
            int type = QQmlData::get(object)->propertyCache->property(id)->propType;

            if (type != QVariant::Invalid) {
                if (valueIndex != -1) {
                    QQmlValueType *valueType = QQmlValueTypeFactory::valueType(type);
                    Q_ASSERT(valueType);

                    //
                    // Consider the following case:
                    //  color c = { 0.1, 0.2, 0.3 }
                    //  interceptor exists on c.r
                    //  write { 0.2, 0.4, 0.6 }
                    //
                    // The interceptor may choose not to update the r component at this
                    // point (for example, a behavior that creates an animation). But we
                    // need to ensure that the g and b components are updated correctly.
                    //
                    // So we need to perform a full write where the value type is:
                    //    r = old value, g = new value, b = new value
                    //
                    // And then call the interceptor which may or may not write the
                    // new value to the r component.
                    //
                    // This will ensure that the other components don't contain stale data
                    // and any relevant signals are emitted.
                    //
                    // To achieve this:
                    //   (1) Store the new value type as a whole (needed due to
                    //       aliasing between a[0] and static storage in value type).
                    //   (2) Read the entire existing value type from object -> valueType temp.
                    //   (3) Read the previous value of the component being changed
                    //       from the valueType temp.
                    //   (4) Write the entire new value type into the temp.
                    //   (5) Overwrite the component being changed with the old value.
                    //   (6) Perform a full write to the value type (which may emit signals etc).
                    //   (7) Issue the interceptor call with the new component value.
                    //

                    QMetaProperty valueProp = valueType->metaObject()->property(valueIndex);
                    QVariant newValue(type, a[0]);

                    valueType->read(object, id);
                    QVariant prevComponentValue = valueProp.read(valueType);

                    valueType->setValue(newValue);
                    QVariant newComponentValue = valueProp.read(valueType);

                    // Don't apply the interceptor if the intercepted value has not changed
                    bool updated = false;
                    if (newComponentValue != prevComponentValue) {
                        valueProp.write(valueType, prevComponentValue);
                        valueType->write(object, id, QQmlPropertyPrivate::DontRemoveBinding | QQmlPropertyPrivate::BypassInterceptor);

                        vi->write(newComponentValue);
                        updated = true;
                    }

                    if (updated)
                        return -1;
                } else {
                    vi->write(QVariant(type, a[0]));
                    return -1;
                }
            }
        }
    }
    if (c == QMetaObject::ReadProperty || c == QMetaObject::WriteProperty || c == QMetaObject::ResetProperty) {
        if (id >= propOffset()) {
            id -= propOffset();

            if (id < metaData->propertyCount) {
               int t = (metaData->propertyData() + id)->propertyType;
                bool needActivate = false;

                if (id >= firstVarPropertyIndex) {
                    Q_ASSERT(t == QMetaType::QVariant);
                    // the context can be null if accessing var properties from cpp after re-parenting an item.
                    QQmlEnginePrivate *ep = (ctxt == 0 || ctxt->engine == 0) ? 0 : QQmlEnginePrivate::get(ctxt->engine);
                    QV8Engine *v8e = (ep == 0) ? 0 : ep->v8engine();
                    if (v8e) {
                        if (c == QMetaObject::ReadProperty) {
                            *reinterpret_cast<QVariant *>(a[0]) = readPropertyAsVariant(id);
                        } else if (c == QMetaObject::WriteProperty) {
                            writeProperty(id, *reinterpret_cast<QVariant *>(a[0]));
                        }
                    } else if (c == QMetaObject::ReadProperty) {
                        // if the context was disposed, we just return an invalid variant from read.
                        *reinterpret_cast<QVariant *>(a[0]) = QVariant();
                    }

                } else {

                    if (c == QMetaObject::ReadProperty) {
                        switch(t) {
                        case QVariant::Int:
                            *reinterpret_cast<int *>(a[0]) = data[id].asInt();
                            break;
                        case QVariant::Bool:
                            *reinterpret_cast<bool *>(a[0]) = data[id].asBool();
                            break;
                        case QVariant::Double:
                            *reinterpret_cast<double *>(a[0]) = data[id].asDouble();
                            break;
                        case QVariant::String:
                            *reinterpret_cast<QString *>(a[0]) = data[id].asQString();
                            break;
                        case QVariant::Url:
                            *reinterpret_cast<QUrl *>(a[0]) = data[id].asQUrl();
                            break;
                        case QVariant::Date:
                            *reinterpret_cast<QDate *>(a[0]) = data[id].asQDate();
                            break;
                        case QVariant::DateTime:
                            *reinterpret_cast<QDateTime *>(a[0]) = data[id].asQDateTime();
                            break;
                        case QVariant::RectF:
                            *reinterpret_cast<QRectF *>(a[0]) = data[id].asQRectF();
                            break;
                        case QVariant::SizeF:
                            *reinterpret_cast<QSizeF *>(a[0]) = data[id].asQSizeF();
                            break;
                        case QVariant::PointF:
                            *reinterpret_cast<QPointF *>(a[0]) = data[id].asQPointF();
                            break;
                        case QMetaType::QObjectStar:
                            *reinterpret_cast<QObject **>(a[0]) = data[id].asQObject();
                            break;
                        case QMetaType::QVariant:
                            *reinterpret_cast<QVariant *>(a[0]) = readPropertyAsVariant(id);
                            break;
                        default:
                            QQml_valueTypeProvider()->readValueType(data[id].dataType(), data[id].dataPtr(), data->dataSize(), t, a[0]);
                            break;
                        }
                        if (t == qMetaTypeId<QQmlListProperty<QObject> >()) {
                            int listIndex = data[id].asInt();
                            const List *list = &listProperties.at(listIndex);
                            *reinterpret_cast<QQmlListProperty<QObject> *>(a[0]) =
                                QQmlListProperty<QObject>(object, (void *)list,
                                                                  list_append, list_count, list_at,
                                                                  list_clear);
                        }

                    } else if (c == QMetaObject::WriteProperty) {

                        switch(t) {
                        case QVariant::Int:
                            needActivate = *reinterpret_cast<int *>(a[0]) != data[id].asInt();
                            data[id].setValue(*reinterpret_cast<int *>(a[0]));
                            break;
                        case QVariant::Bool:
                            needActivate = *reinterpret_cast<bool *>(a[0]) != data[id].asBool();
                            data[id].setValue(*reinterpret_cast<bool *>(a[0]));
                            break;
                        case QVariant::Double:
                            needActivate = *reinterpret_cast<double *>(a[0]) != data[id].asDouble();
                            data[id].setValue(*reinterpret_cast<double *>(a[0]));
                            break;
                        case QVariant::String:
                            needActivate = *reinterpret_cast<QString *>(a[0]) != data[id].asQString();
                            data[id].setValue(*reinterpret_cast<QString *>(a[0]));
                            break;
                        case QVariant::Url:
                            needActivate = *reinterpret_cast<QUrl *>(a[0]) != data[id].asQUrl();
                            data[id].setValue(*reinterpret_cast<QUrl *>(a[0]));
                            break;
                        case QVariant::Date:
                            needActivate = *reinterpret_cast<QDate *>(a[0]) != data[id].asQDate();
                            data[id].setValue(*reinterpret_cast<QDate *>(a[0]));
                            break;
                        case QVariant::DateTime:
                            needActivate = *reinterpret_cast<QDateTime *>(a[0]) != data[id].asQDateTime();
                            data[id].setValue(*reinterpret_cast<QDateTime *>(a[0]));
                            break;
                        case QVariant::RectF:
                            needActivate = *reinterpret_cast<QRectF *>(a[0]) != data[id].asQRectF();
                            data[id].setValue(*reinterpret_cast<QRectF *>(a[0]));
                            break;
                        case QVariant::SizeF:
                            needActivate = *reinterpret_cast<QSizeF *>(a[0]) != data[id].asQSizeF();
                            data[id].setValue(*reinterpret_cast<QSizeF *>(a[0]));
                            break;
                        case QVariant::PointF:
                            needActivate = *reinterpret_cast<QPointF *>(a[0]) != data[id].asQPointF();
                            data[id].setValue(*reinterpret_cast<QPointF *>(a[0]));
                            break;
                        case QMetaType::QObjectStar:
                            needActivate = *reinterpret_cast<QObject **>(a[0]) != data[id].asQObject();
                            data[id].setValue(*reinterpret_cast<QObject **>(a[0]), this, id);
                            break;
                        case QMetaType::QVariant:
                            writeProperty(id, *reinterpret_cast<QVariant *>(a[0]));
                            break;
                        default:
                            data[id].ensureValueType(t);
                            needActivate = !QQml_valueTypeProvider()->equalValueType(t, a[0], data[id].dataPtr(), data[id].dataSize());
                            QQml_valueTypeProvider()->writeValueType(t, a[0], data[id].dataPtr(), data[id].dataSize());
                            break;
                        }
                    }

                }

                if (c == QMetaObject::WriteProperty && needActivate) {
                    activate(object, methodOffset() + id, 0);
                }

                return -1;
            }

            id -= metaData->propertyCount;

            if (id < metaData->aliasCount) {

                QQmlVMEMetaData::AliasData *d = metaData->aliasData() + id;

                if (d->flags & QML_ALIAS_FLAG_PTR && c == QMetaObject::ReadProperty)
                        *reinterpret_cast<void **>(a[0]) = 0;

                if (!ctxt) return -1;

                QQmlContext *context = ctxt->asQQmlContext();
                QQmlContextPrivate *ctxtPriv = QQmlContextPrivate::get(context);

                QObject *target = ctxtPriv->data->idValues[d->contextIdx].data();
                if (!target)
                    return -1;

                connectAlias(id);

                if (d->isObjectAlias()) {
                    *reinterpret_cast<QObject **>(a[0]) = target;
                    return -1;
                }

                // Remove binding (if any) on write
                if(c == QMetaObject::WriteProperty) {
                    int flags = *reinterpret_cast<int*>(a[3]);
                    if (flags & QQmlPropertyPrivate::RemoveBindingOnAliasWrite) {
                        QQmlData *targetData = QQmlData::get(target);
                        if (targetData && targetData->hasBindingBit(d->propertyIndex())) {
                            QQmlAbstractBinding *binding = QQmlPropertyPrivate::setBinding(target, d->propertyIndex(), d->isValueTypeAlias()?d->valueTypeIndex():-1, 0);
                            if (binding) binding->destroy();
                        }
                    }
                }

                if (d->isValueTypeAlias()) {
                    // Value type property
                    QQmlValueType *valueType = QQmlValueTypeFactory::valueType(d->valueType());
                    Q_ASSERT(valueType);

                    valueType->read(target, d->propertyIndex());
                    int rv = QMetaObject::metacall(valueType, c, d->valueTypeIndex(), a);

                    if (c == QMetaObject::WriteProperty)
                        valueType->write(target, d->propertyIndex(), 0x00);

                    return rv;

                } else {
                    return QMetaObject::metacall(target, c, d->propertyIndex(), a);
                }

            }
            return -1;

        }

    } else if(c == QMetaObject::InvokeMetaMethod) {

        if (id >= methodOffset()) {

            id -= methodOffset();
            int plainSignals = metaData->signalCount + metaData->propertyCount +
                               metaData->aliasCount;
            if (id < plainSignals) {
                activate(object, _id, a);
                return -1;
            }

            id -= plainSignals;

            if (id < metaData->methodCount) {
                if (!ctxt->engine)
                    return -1; // We can't run the method

                QQmlEnginePrivate *ep = QQmlEnginePrivate::get(ctxt->engine);
                ep->referenceScarceResources(); // "hold" scarce resources in memory during evaluation.
                QV4::Scope scope(ep->v4engine());


                QV4::Scoped<QV4::FunctionObject> function(scope, method(id));
                if (!function) {
                    // The function was not compiled.  There are some exceptional cases which the
                    // expression rewriter does not rewrite properly (e.g., \r-terminated lines
                    // are not rewritten correctly but this bug is deemed out-of-scope to fix for
                    // performance reasons; see QTBUG-24064) and thus compilation will have failed.
                    QQmlError e;
                    e.setDescription(QString(QLatin1String("Exception occurred during compilation of function: %1")).
                                     arg(QLatin1String(QMetaObject::method(_id).methodSignature().constData())));
                    ep->warning(e);
                    return -1; // The dynamic method with that id is not available.
                }

                QQmlVMEMetaData::MethodData *data = metaData->methodData() + id;

                QV4::ScopedCallData callData(scope, data->parameterCount);
                callData->thisObject = ep->v8engine()->global();

                for (int ii = 0; ii < data->parameterCount; ++ii)
                    callData->args[ii] = ep->v8engine()->fromVariant(*(QVariant *)a[ii + 1]);

                QV4::ScopedValue result(scope);
                QV4::ExecutionContext *ctx = function->engine()->currentContext();
                result = function->call(callData);
                if (scope.hasException()) {
                    QQmlError error = QV4::ExecutionEngine::catchExceptionAsQmlError(ctx);
                    if (error.isValid())
                        ep->warning(error);
                    if (a[0]) *(QVariant *)a[0] = QVariant();
                } else {
                    if (a[0]) *(QVariant *)a[0] = ep->v8engine()->toVariant(result, 0);
                }

                ep->dereferenceScarceResources(); // "release" scarce resources if top-level expression evaluation is complete.
                return -1;
            }
            return -1;
        }
    }

    if (parent.isT1())
        return parent.asT1()->metaCall(object, c, _id, a);
    else
        return object->qt_metacall(c, _id, a);
}