Use QQmlType by value

QQmlType is now refcounted, and we need to use it by
value, to control it's lifetime properly. This is
required, so we can clean up the QQmlMetaTypeData
cache on engine destruction and with trimComponentCache()

Task-number: QTBUG-61536
Change-Id: If86391c86ea20a646ded7c9925d8f743f628fb91
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

6 files changed, 70 insertions, 74 deletions

diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 60045952c9..5bbf067320 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -1767,14 +1767,14 @@ static QV4::IR::DiscoveredType resolveImportNamespace(
         if (r.scriptIndex != -1) {
             // TODO: remember the index and replace with subscript later.
             result = QV4::IR::VarType;
-        } else if (r.type) {
+        } else if (r.type.isValid()) {
             // TODO: Propagate singleton information, so that it is loaded
             // through the singleton getter in the run-time. Until then we
             // can't accelerate access :(
-            if (!r.type->isSingleton()) {
+            if (!r.type.isSingleton()) {
                 auto newResolver = resolver->owner->New<QV4::IR::MemberExpressionResolver>();
                 newResolver->owner = resolver->owner;
-                initQmlTypeResolver(newResolver, *r.type);
+                initQmlTypeResolver(newResolver, r.type);
                 return QV4::IR::DiscoveredType(newResolver);
             }
         } else {
@@ -1950,10 +1950,10 @@ QV4::IR::Expr *JSCodeGen::fallbackNameLookup(const QString &name, int line, int
             if (r.scriptIndex != -1) {
                 return _block->SUBSCRIPT(_block->TEMP(_importedScriptsTemp),
                                          _block->CONST(QV4::IR::SInt32Type, r.scriptIndex));
-            } else if (r.type) {
+            } else if (r.type.isValid()) {
                 QV4::IR::Name *typeName = _block->NAME(name, line, col);
                 // Make sure the run-time loads this through the more efficient singleton getter.
-                typeName->qmlSingleton = r.type->isCompositeSingleton();
+                typeName->qmlSingleton = r.type.isCompositeSingleton();
                 typeName->freeOfSideEffects = true;
                 QV4::IR::Temp *result = _block->TEMP(_block->newTemp());
                 _block->MOVE(result, typeName);
@@ -1961,7 +1961,7 @@ QV4::IR::Expr *JSCodeGen::fallbackNameLookup(const QString &name, int line, int
                 result = _block->TEMP(result->index);
                 result->memberResolver = _function->New<QV4::IR::MemberExpressionResolver>();
                 result->memberResolver->owner = _function;
-                initQmlTypeResolver(result->memberResolver, *r.type);
+                initQmlTypeResolver(result->memberResolver, r.type);
                 return result;
             } else {
                 Q_ASSERT(r.importNamespace);
diff --git a/src/qml/compiler/qqmlpropertycachecreator_p.h b/src/qml/compiler/qqmlpropertycachecreator_p.h
index 3c14abc019..8fc8943366 100644
--- a/src/qml/compiler/qqmlpropertycachecreator_p.h
+++ b/src/qml/compiler/qqmlpropertycachecreator_p.h
@@ -211,12 +211,12 @@ inline QQmlPropertyCache *QQmlPropertyCacheCreator<ObjectContainer>::propertyCac
     } else if (context.instantiatingBinding && context.instantiatingBinding->isAttachedProperty()) {
         auto *typeRef = objectContainer->resolvedTypes.value(context.instantiatingBinding->propertyNameIndex);
         Q_ASSERT(typeRef);
-        QQmlType *qmltype = typeRef->type;
-        if (!qmltype) {
+        QQmlType qmltype = typeRef->type;
+        if (!qmltype.isValid()) {
             QString propertyName = stringAt(context.instantiatingBinding->propertyNameIndex);
             if (imports->resolveType(propertyName, &qmltype, 0, 0, 0)) {
-                if (qmltype->isComposite()) {
-                    QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype->sourceUrl());
+                if (qmltype.isComposite()) {
+                    QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype.sourceUrl());
                     Q_ASSERT(tdata);
                     Q_ASSERT(tdata->isComplete());
 
@@ -228,7 +228,7 @@ inline QQmlPropertyCache *QQmlPropertyCacheCreator<ObjectContainer>::propertyCac
             }
         }
 
-        const QMetaObject *attachedMo = qmltype ? qmltype->attachedPropertiesType(enginePrivate) : 0;
+        const QMetaObject *attachedMo = qmltype.attachedPropertiesType(enginePrivate);
         if (!attachedMo) {
             *error = QQmlCompileError(context.instantiatingBinding->location, QQmlPropertyCacheCreatorBase::tr("Non-existent attached object"));
             return nullptr;
@@ -395,12 +395,12 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
                     // lazily resolved type
                     Q_ASSERT(param->type == QV4::CompiledData::Property::Custom);
                     const QString customTypeName = stringAt(param->customTypeNameIndex);
-                    QQmlType *qmltype = 0;
+                    QQmlType qmltype;
                     if (!imports->resolveType(customTypeName, &qmltype, 0, 0, 0))
                         return QQmlCompileError(s->location, QQmlPropertyCacheCreatorBase::tr("Invalid signal parameter type: %1").arg(customTypeName));
 
-                    if (qmltype->isComposite()) {
-                        QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype->sourceUrl());
+                    if (qmltype.isComposite()) {
+                        QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype.sourceUrl());
                         Q_ASSERT(tdata);
                         Q_ASSERT(tdata->isComplete());
 
@@ -410,7 +410,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
 
                         tdata->release();
                     } else {
-                        paramTypes[i + 1] = qmltype->typeId();
+                        paramTypes[i + 1] = qmltype.typeId();
                     }
                 }
             }
@@ -475,14 +475,14 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
             Q_ASSERT(p->type == QV4::CompiledData::Property::CustomList ||
                      p->type == QV4::CompiledData::Property::Custom);
 
-            QQmlType *qmltype = 0;
+            QQmlType qmltype;
             if (!imports->resolveType(stringAt(p->customTypeNameIndex), &qmltype, 0, 0, 0)) {
                 return QQmlCompileError(p->location, QQmlPropertyCacheCreatorBase::tr("Invalid property type"));
             }
 
-            Q_ASSERT(qmltype);
-            if (qmltype->isComposite()) {
-                QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype->sourceUrl());
+            Q_ASSERT(qmltype.isValid());
+            if (qmltype.isComposite()) {
+                QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype.sourceUrl());
                 Q_ASSERT(tdata);
                 Q_ASSERT(tdata->isComplete());
 
@@ -497,9 +497,9 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
                 tdata->release();
             } else {
                 if (p->type == QV4::CompiledData::Property::Custom) {
-                    propertyType = qmltype->typeId();
+                    propertyType = qmltype.typeId();
                 } else {
-                    propertyType = qmltype->qListTypeId();
+                    propertyType = qmltype.qListTypeId();
                 }
             }
 
@@ -675,8 +675,8 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataForAlias
         auto *typeRef = objectContainer->resolvedTypes.value(targetObject.inheritedTypeNameIndex);
         Q_ASSERT(typeRef);
 
-        if (typeRef->type)
-            *type = typeRef->type->typeId();
+        if (typeRef->type.isValid())
+            *type = typeRef->type.typeId();
         else
             *type = typeRef->compilationUnit->metaTypeId;
 
diff --git a/src/qml/compiler/qqmlpropertyvalidator.cpp b/src/qml/compiler/qqmlpropertyvalidator.cpp
index da652e8f5d..4ac7aad553 100644
--- a/src/qml/compiler/qqmlpropertyvalidator.cpp
+++ b/src/qml/compiler/qqmlpropertyvalidator.cpp
@@ -106,8 +106,8 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
 
     QQmlCustomParser *customParser = 0;
     if (auto typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex)) {
-        if (typeRef->type)
-            customParser = typeRef->type->customParser();
+        if (typeRef->type.isValid())
+            customParser = typeRef->type.customParser();
     }
 
     QList<const QV4::CompiledData::Binding*> customBindings;
@@ -178,8 +178,8 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
             if (notInRevision) {
                 QString typeName = stringAt(obj->inheritedTypeNameIndex);
                 auto *objectType = resolvedTypes.value(obj->inheritedTypeNameIndex);
-                if (objectType && objectType->type) {
-                    return recordError(binding->location, tr("\"%1.%2\" is not available in %3 %4.%5.").arg(typeName).arg(name).arg(objectType->type->module()).arg(objectType->majorVersion).arg(objectType->minorVersion));
+                if (objectType && objectType->type.isValid()) {
+                    return recordError(binding->location, tr("\"%1.%2\" is not available in %3 %4.%5.").arg(typeName).arg(name).arg(objectType->type.module()).arg(objectType->majorVersion).arg(objectType->minorVersion));
                 } else {
                     return recordError(binding->location, tr("\"%1.%2\" is not available due to component versioning.").arg(typeName).arg(name));
                 }
@@ -197,7 +197,7 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
             collectedBindingPropertyData[i] = pd;
 
         if (name.constData()->isUpper() && !binding->isAttachedProperty()) {
-            QQmlType *type = 0;
+            QQmlType type;
             QQmlImportNamespace *typeNamespace = 0;
             imports.resolveType(stringAt(binding->propertyNameIndex), &type, 0, 0, &typeNamespace);
             if (typeNamespace)
@@ -632,15 +632,15 @@ QQmlCompileError QQmlPropertyValidator::validateObjectBinding(QQmlPropertyData *
         if (auto *typeRef = resolvedTypes.value(targetObject->inheritedTypeNameIndex)) {
             QQmlPropertyCache *cache = typeRef->createPropertyCache(QQmlEnginePrivate::get(enginePrivate));
             const QMetaObject *mo = cache->firstCppMetaObject();
-            QQmlType *qmlType = 0;
-            while (mo && !qmlType) {
+            QQmlType qmlType;
+            while (mo && !qmlType.isValid()) {
                 qmlType = QQmlMetaType::qmlType(mo);
                 mo = mo->superClass();
             }
-            Q_ASSERT(qmlType);
+            Q_ASSERT(qmlType.isValid());
 
-            isValueSource = qmlType->propertyValueSourceCast() != -1;
-            isPropertyInterceptor = qmlType->propertyValueInterceptorCast() != -1;
+            isValueSource = qmlType.propertyValueSourceCast() != -1;
+            isPropertyInterceptor = qmlType.propertyValueInterceptorCast() != -1;
         }
 
         if (!isValueSource && !isPropertyInterceptor) {
diff --git a/src/qml/compiler/qqmltypecompiler.cpp b/src/qml/compiler/qqmltypecompiler.cpp
index d1d22be0ac..f5cb468479 100644
--- a/src/qml/compiler/qqmltypecompiler.cpp
+++ b/src/qml/compiler/qqmltypecompiler.cpp
@@ -75,7 +75,7 @@ QV4::CompiledData::CompilationUnit *QQmlTypeCompiler::compile()
 
     for (auto it = resolvedTypes.constBegin(), end = resolvedTypes.constEnd();
          it != end; ++it) {
-        QQmlCustomParser *customParser = (*it)->type ? (*it)->type->customParser() : 0;
+        QQmlCustomParser *customParser = (*it)->type.customParser();
         if (customParser)
             customParsers.insert(it.key(), customParser);
     }
@@ -171,7 +171,6 @@ QV4::CompiledData::CompilationUnit *QQmlTypeCompiler::compile()
     compilationUnit->propertyCaches = std::move(m_propertyCaches);
     Q_ASSERT(compilationUnit->propertyCaches.count() == static_cast<int>(compilationUnit->data->nObjects));
 
-
     if (errors.isEmpty())
         return compilationUnit;
     else
@@ -345,11 +344,11 @@ bool SignalHandlerConverter::convertSignalHandlerExpressionsToFunctionDeclaratio
         if (binding->type == QV4::CompiledData::Binding::Type_AttachedProperty) {
             const QmlIR::Object *attachedObj = qmlObjects.at(binding->value.objectIndex);
             auto *typeRef = resolvedTypes.value(binding->propertyNameIndex);
-            QQmlType *type = typeRef ? typeRef->type : 0;
-            if (!type) {
+            QQmlType type = typeRef ? typeRef->type : nullptr;
+            if (!type.isValid()) {
                 if (imports->resolveType(propertyName, &type, 0, 0, 0)) {
-                    if (type->isComposite()) {
-                        QQmlTypeData *tdata = enginePrivate->typeLoader.getType(type->sourceUrl());
+                    if (type.isComposite()) {
+                        QQmlTypeData *tdata = enginePrivate->typeLoader.getType(type.sourceUrl());
                         Q_ASSERT(tdata);
                         Q_ASSERT(tdata->isComplete());
 
@@ -361,7 +360,7 @@ bool SignalHandlerConverter::convertSignalHandlerExpressionsToFunctionDeclaratio
                 }
             }
 
-            const QMetaObject *attachedType = type ? type->attachedPropertiesType(enginePrivate) : 0;
+            const QMetaObject *attachedType = type.attachedPropertiesType(enginePrivate);
             if (!attachedType)
                 COMPILE_EXCEPTION(binding, tr("Non-existent attached object"));
             QQmlPropertyCache *cache = compiler->enginePrivate()->cache(attachedType);
@@ -418,9 +417,9 @@ bool SignalHandlerConverter::convertSignalHandlerExpressionsToFunctionDeclaratio
                 const QString &originalPropertyName = stringAt(binding->propertyNameIndex);
 
                 auto *typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex);
-                const QQmlType *type = typeRef ? typeRef->type : 0;
-                if (type) {
-                    COMPILE_EXCEPTION(binding, tr("\"%1.%2\" is not available in %3 %4.%5.").arg(typeName).arg(originalPropertyName).arg(type->module()).arg(type->majorVersion()).arg(type->minorVersion()));
+                const QQmlType type = typeRef->type;
+                if (type.isValid()) {
+                    COMPILE_EXCEPTION(binding, tr("\"%1.%2\" is not available in %3 %4.%5.").arg(typeName).arg(originalPropertyName).arg(type.module()).arg(type.majorVersion()).arg(type.minorVersion()));
                 } else {
                     COMPILE_EXCEPTION(binding, tr("\"%1.%2\" is not available due to component versioning.").arg(typeName).arg(originalPropertyName));
                 }
@@ -612,17 +611,17 @@ bool QQmlEnumTypeResolver::tryQualifiedEnumAssignment(const QmlIR::Object *obj,
         }
         return true;
     }
-    QQmlType *type = 0;
+    QQmlType type;
     imports->resolveType(typeName, &type, 0, 0, 0);
 
-    if (!type && !isQtObject)
+    if (!type.isValid() && !isQtObject)
         return true;
 
     int value = 0;
     bool ok = false;
 
     auto *tr = resolvedTypes->value(obj->inheritedTypeNameIndex);
-    if (type && tr && tr->type == type) {
+    if (type.isValid() && tr && tr->type == type) {
         QMetaProperty mprop = propertyCache->firstCppMetaObject()->property(prop->coreIndex());
 
         // When these two match, we can short cut the search
@@ -633,8 +632,8 @@ bool QQmlEnumTypeResolver::tryQualifiedEnumAssignment(const QmlIR::Object *obj,
         }
     } else {
         // Otherwise we have to search the whole type
-        if (type) {
-            value = type->enumValue(compiler->enginePrivate(), QHashedStringRef(enumValue), &ok);
+        if (type.isValid()) {
+            value = type.enumValue(compiler->enginePrivate(), QHashedStringRef(enumValue), &ok);
         } else {
             QByteArray enumName = enumValue.toUtf8();
             const QMetaObject *metaObject = StaticQtMetaObject::get();
@@ -657,11 +656,9 @@ int QQmlEnumTypeResolver::evaluateEnum(const QString &scope, const QByteArray &e
     *ok = false;
 
     if (scope != QLatin1String("Qt")) {
-        QQmlType *type = 0;
+        QQmlType type;
         imports->resolveType(scope, &type, 0, 0, 0);
-        if (!type)
-            return -1;
-        return type->enumValue(compiler->enginePrivate(), QHashedCStringRef(enumValue.constData(), enumValue.length()), ok);
+        return type.enumValue(compiler->enginePrivate(), QHashedCStringRef(enumValue.constData(), enumValue.length()), ok);
     }
 
     const QMetaObject *mo = StaticQtMetaObject::get();
@@ -799,8 +796,8 @@ void QQmlComponentAndAliasResolver::findAndRegisterImplicitComponents(const QmlI
         const QmlIR::Object *targetObject = qmlObjects->at(binding->value.objectIndex);
         auto *tr = resolvedTypes->value(targetObject->inheritedTypeNameIndex);
         Q_ASSERT(tr);
-        if (QQmlType *targetType = tr->type) {
-            if (targetType->metaObject() == &QQmlComponent::staticMetaObject)
+        if (tr->type.isValid()) {
+            if (tr->type.metaObject() == &QQmlComponent::staticMetaObject)
                 continue;
         } else if (tr->compilationUnit) {
             if (tr->compilationUnit->rootPropertyCache()->firstCppMetaObject() == &QQmlComponent::staticMetaObject)
@@ -829,22 +826,22 @@ void QQmlComponentAndAliasResolver::findAndRegisterImplicitComponents(const QmlI
             continue;
 
         // emulate "import Qml 2.0 as QmlInternals" and then wrap the component in "QmlInternals.Component {}"
-        QQmlType *componentType = QQmlMetaType::qmlType(&QQmlComponent::staticMetaObject);
-        Q_ASSERT(componentType);
+        QQmlType componentType = QQmlMetaType::qmlType(&QQmlComponent::staticMetaObject);
+        Q_ASSERT(componentType.isValid());
         const QString qualifier = QStringLiteral("QmlInternals");
 
-        compiler->addImport(componentType->module(), qualifier, componentType->majorVersion(), componentType->minorVersion());
+        compiler->addImport(componentType.module(), qualifier, componentType.majorVersion(), componentType.minorVersion());
 
         QmlIR::Object *syntheticComponent = pool->New<QmlIR::Object>();
-        syntheticComponent->init(pool, compiler->registerString(qualifier + QLatin1Char('.') + componentType->elementName()), compiler->registerString(QString()));
+        syntheticComponent->init(pool, compiler->registerString(qualifier + QLatin1Char('.') + componentType.elementName()), compiler->registerString(QString()));
         syntheticComponent->location = binding->valueLocation;
         syntheticComponent->flags |= QV4::CompiledData::Object::IsComponent;
 
         if (!resolvedTypes->contains(syntheticComponent->inheritedTypeNameIndex)) {
             auto typeRef = new QV4::CompiledData::ResolvedTypeReference;
             typeRef->type = componentType;
-            typeRef->majorVersion = componentType->majorVersion();
-            typeRef->minorVersion = componentType->minorVersion();
+            typeRef->majorVersion = componentType.majorVersion();
+            typeRef->minorVersion = componentType.minorVersion();
             resolvedTypes->insert(syntheticComponent->inheritedTypeNameIndex, typeRef);
         }
 
@@ -885,7 +882,7 @@ bool QQmlComponentAndAliasResolver::resolve()
         if (obj->inheritedTypeNameIndex) {
             auto *tref = resolvedTypes->value(obj->inheritedTypeNameIndex);
             Q_ASSERT(tref);
-            if (tref->type && tref->type->metaObject() == &QQmlComponent::staticMetaObject)
+            if (tref->type.metaObject() == &QQmlComponent::staticMetaObject)
                 isExplicitComponent = true;
         }
         if (!isExplicitComponent) {
diff --git a/src/qml/compiler/qv4compileddata.cpp b/src/qml/compiler/qv4compileddata.cpp
index db707061fe..6223c4b3a1 100644
--- a/src/qml/compiler/qv4compileddata.cpp
+++ b/src/qml/compiler/qv4compileddata.cpp
@@ -295,8 +295,8 @@ void CompilationUnit::finalize(QQmlEnginePrivate *engine)
             metaTypeId = typeRef->compilationUnit->metaTypeId;
             listMetaTypeId = typeRef->compilationUnit->listMetaTypeId;
         } else {
-            metaTypeId = typeRef->type->typeId();
-            listMetaTypeId = typeRef->type->qListTypeId();
+            metaTypeId = typeRef->type.typeId();
+            listMetaTypeId = typeRef->type.qListTypeId();
         }
     }
 
@@ -308,8 +308,8 @@ void CompilationUnit::finalize(QQmlEnginePrivate *engine)
         const QV4::CompiledData::Object *obj = data->objectAt(i);
         bindingCount += obj->nBindings;
         if (auto *typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex)) {
-            if (QQmlType *qmlType = typeRef->type) {
-                if (qmlType->parserStatusCast() != -1)
+            if (typeRef->type.isValid()) {
+                if (typeRef->type.parserStatusCast() != -1)
                     ++parserStatusCount;
             }
             ++objectCount;
@@ -673,7 +673,7 @@ Returns the property cache, if one alread exists.  The cache is not referenced.
 */
 QQmlPropertyCache *ResolvedTypeReference::propertyCache() const
 {
-    if (type)
+    if (type.isValid())
         return typePropertyCache;
     else
         return compilationUnit->rootPropertyCache();
@@ -686,8 +686,8 @@ QQmlPropertyCache *ResolvedTypeReference::createPropertyCache(QQmlEngine *engine
 {
     if (typePropertyCache) {
         return typePropertyCache;
-    } else if (type) {
-        typePropertyCache = QQmlEnginePrivate::get(engine)->cache(type->metaObject());
+    } else if (type.isValid()) {
+        typePropertyCache = QQmlEnginePrivate::get(engine)->cache(type.metaObject());
         return typePropertyCache;
     } else {
         return compilationUnit->rootPropertyCache();
@@ -696,7 +696,7 @@ QQmlPropertyCache *ResolvedTypeReference::createPropertyCache(QQmlEngine *engine
 
 bool ResolvedTypeReference::addToHash(QCryptographicHash *hash, QQmlEngine *engine)
 {
-    if (type) {
+    if (type.isValid()) {
         bool ok = false;
         hash->addData(createPropertyCache(engine)->checksum(&ok));
         return ok;
@@ -720,8 +720,8 @@ void ResolvedTypeReference::doDynamicTypeCheck()
     const QMetaObject *mo = 0;
     if (typePropertyCache)
         mo = typePropertyCache->firstCppMetaObject();
-    else if (type)
-        mo = type->metaObject();
+    else if (type.isValid())
+        mo = type.metaObject();
     else if (compilationUnit)
         mo = compilationUnit->rootPropertyCache()->firstCppMetaObject();
     isFullyDynamicType = qtTypeInherits<QQmlPropertyMap>(mo);
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 23f5e31ebe..bca0dcdf8f 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -923,13 +923,12 @@ protected:
 struct ResolvedTypeReference
 {
     ResolvedTypeReference()
-        : type(0)
-        , majorVersion(0)
+        : majorVersion(0)
         , minorVersion(0)
         , isFullyDynamicType(false)
     {}
 
-    QQmlType *type;
+    QQmlType type;
     QQmlRefPointer<QQmlPropertyCache> typePropertyCache;
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;