Eliminate excessive friendlyness of QQmlType

QQmlMetaTypeData does need to be exposed to the QQmlType ctors. Rather,
we can use factory functions to create the QQmlTypePrivate objects.

The static attachedPropertyIds should really be part of QQmlMetaTypeData
and access to them should be protected by the lock.

Task-number: QTBUG-73271
Change-Id: I154a3842fab03a02c710901a20afd1652364808d
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

7 files changed, 183 insertions, 163 deletions

diff --git a/src/qml/qml/qqmlmetatype.cpp b/src/qml/qml/qqmlmetatype.cpp
index f7b5ee8bf0..35340aed47 100644
--- a/src/qml/qml/qqmlmetatype.cpp
+++ b/src/qml/qml/qqmlmetatype.cpp
@@ -81,6 +81,129 @@ private:
     LockedData *data = nullptr;
 };
 
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data,
+                                       const QQmlPrivate::RegisterInterface &type)
+{
+    auto *d = new QQmlTypePrivate(QQmlType::InterfaceType);
+    d->iid = type.iid;
+    d->typeId = type.typeId;
+    d->listId = type.listId;
+    d->isSetup = true;
+    d->version_maj = 0;
+    d->version_min = 0;
+    data->registerType(d);
+    return d;
+}
+
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &elementName,
+                                       const QQmlPrivate::RegisterSingletonType &type)
+{
+    auto *d = new QQmlTypePrivate(QQmlType::SingletonType);
+    data->registerType(d);
+
+    d->elementName = elementName;
+    d->module = QString::fromUtf8(type.uri);
+
+    d->version_maj = type.versionMajor;
+    d->version_min = type.versionMinor;
+
+    if (type.qobjectApi) {
+        if (type.version >= 1) // static metaobject added in version 1
+            d->baseMetaObject = type.instanceMetaObject;
+        if (type.version >= 2) // typeId added in version 2
+            d->typeId = type.typeId;
+        if (type.version >= 2) // revisions added in version 2
+            d->revision = type.revision;
+    }
+
+    d->extraData.sd->singletonInstanceInfo = new QQmlType::SingletonInstanceInfo;
+    d->extraData.sd->singletonInstanceInfo->scriptCallback = type.scriptApi;
+    d->extraData.sd->singletonInstanceInfo->qobjectCallback = type.qobjectApi;
+    d->extraData.sd->singletonInstanceInfo->typeName = QString::fromUtf8(type.typeName);
+    d->extraData.sd->singletonInstanceInfo->instanceMetaObject
+            = (type.qobjectApi && type.version >= 1) ? type.instanceMetaObject : nullptr;
+
+    return d;
+}
+
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &elementName,
+                                       const QQmlPrivate::RegisterType &type)
+{
+    QQmlTypePrivate *d = new QQmlTypePrivate(QQmlType::CppType);
+    data->registerType(d);
+    d->elementName = elementName;
+    d->module = QString::fromUtf8(type.uri);
+
+    d->version_maj = type.versionMajor;
+    d->version_min = type.versionMinor;
+    if (type.version >= 1) // revisions added in version 1
+        d->revision = type.revision;
+    d->typeId = type.typeId;
+    d->listId = type.listId;
+    d->extraData.cd->allocationSize = type.objectSize;
+    d->extraData.cd->newFunc = type.create;
+    d->extraData.cd->noCreationReason = type.noCreationReason;
+    d->baseMetaObject = type.metaObject;
+    d->extraData.cd->attachedPropertiesFunc = type.attachedPropertiesFunction;
+    d->extraData.cd->attachedPropertiesType = type.attachedPropertiesMetaObject;
+    if (d->extraData.cd->attachedPropertiesType) {
+        d->extraData.cd->attachedPropertiesId = data->attachedPropertyId(d->baseMetaObject,
+                                                                         d->index);
+    } else {
+        d->extraData.cd->attachedPropertiesId = -1;
+    }
+    d->extraData.cd->parserStatusCast = type.parserStatusCast;
+    d->extraData.cd->propertyValueSourceCast = type.valueSourceCast;
+    d->extraData.cd->propertyValueInterceptorCast = type.valueInterceptorCast;
+    d->extraData.cd->extFunc = type.extensionObjectCreate;
+    d->extraData.cd->customParser = type.customParser;
+    d->extraData.cd->registerEnumClassesUnscoped = true;
+
+    if (type.extensionMetaObject)
+        d->extraData.cd->extMetaObject = type.extensionMetaObject;
+
+    // Check if the user wants only scoped enum classes
+    if (d->baseMetaObject) {
+        auto indexOfClassInfo = d->baseMetaObject->indexOfClassInfo("RegisterEnumClassesUnscoped");
+        if (indexOfClassInfo != -1 && QString::fromUtf8(d->baseMetaObject->classInfo(indexOfClassInfo).value()) == QLatin1String("false"))
+            d->extraData.cd->registerEnumClassesUnscoped = false;
+    }
+
+    return d;
+}
+
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &elementName,
+                                       const QQmlPrivate::RegisterCompositeType &type)
+{
+    auto *d = new QQmlTypePrivate(QQmlType::CompositeType);
+    data->registerType(d);
+    d->elementName = elementName;
+
+    d->module = QString::fromUtf8(type.uri);
+    d->version_maj = type.versionMajor;
+    d->version_min = type.versionMinor;
+
+    d->extraData.fd->url = QQmlTypeLoader::normalize(type.url);
+    return d;
+}
+
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &elementName,
+                                       const QQmlPrivate::RegisterCompositeSingletonType &type)
+{
+    auto *d = new QQmlTypePrivate(QQmlType::CompositeSingletonType);
+    data->registerType(d);
+    d->elementName = elementName;
+    d->module = QString::fromUtf8(type.uri);
+
+    d->version_maj = type.versionMajor;
+    d->version_min = type.versionMinor;
+
+    d->extraData.sd->singletonInstanceInfo = new QQmlType::SingletonInstanceInfo;
+    d->extraData.sd->singletonInstanceInfo->url = QQmlTypeLoader::normalize(type.url);
+    d->extraData.sd->singletonInstanceInfo->typeName = QString::fromUtf8(type.typeName);
+    return d;
+}
+
 void QQmlMetaType::clone(QMetaObjectBuilder &builder, const QMetaObject *mo,
                          const QMetaObject *ignoreStart, const QMetaObject *ignoreEnd)
 {
@@ -182,9 +305,7 @@ QQmlType QQmlMetaType::registerInterface(const QQmlPrivate::RegisterInterface &t
         qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
 
     QQmlMetaTypeDataPtr data;
-
-    QQmlType dtype(data, type);
-    QQmlTypePrivate *priv = dtype.priv();
+    QQmlTypePrivate *priv = createQQmlType(data, type);
     Q_ASSERT(priv);
 
     data->idToType.insert(priv->typeId, priv);
@@ -200,7 +321,7 @@ QQmlType QQmlMetaType::registerInterface(const QQmlPrivate::RegisterInterface &t
     data->interfaces.setBit(type.typeId, true);
     data->lists.setBit(type.listId, true);
 
-    return dtype;
+    return QQmlType(priv);
 }
 
 QString registrationTypeString(QQmlType::RegistrationType typeType)
@@ -321,13 +442,13 @@ QQmlType QQmlMetaType::registerType(const QQmlPrivate::RegisterType &type)
     if (!checkRegistration(QQmlType::CppType, data, type.uri, elementName, type.versionMajor))
         return QQmlType();
 
-    QQmlType dtype(data, elementName, type);
+    QQmlTypePrivate *priv = createQQmlType(data, elementName, type);
 
-    addTypeToData(dtype.priv(), data);
+    addTypeToData(priv, data);
     if (!type.typeId)
-        data->idToType.insert(dtype.typeId(), dtype.priv());
+        data->idToType.insert(priv->typeId, priv);
 
-    return dtype;
+    return QQmlType(priv);
 }
 
 QQmlType QQmlMetaType::registerSingletonType(const QQmlPrivate::RegisterSingletonType &type)
@@ -338,11 +459,11 @@ QQmlType QQmlMetaType::registerSingletonType(const QQmlPrivate::RegisterSingleto
     if (!checkRegistration(QQmlType::SingletonType, data, type.uri, typeName, type.versionMajor))
         return QQmlType();
 
-    QQmlType dtype(data, typeName, type);
+    QQmlTypePrivate *priv = createQQmlType(data, typeName, type);
 
-    addTypeToData(dtype.priv(), data);
+    addTypeToData(priv, data);
 
-    return dtype;
+    return QQmlType(priv);
 }
 
 QQmlType QQmlMetaType::registerCompositeSingletonType(const QQmlPrivate::RegisterCompositeSingletonType &type)
@@ -357,14 +478,13 @@ QQmlType QQmlMetaType::registerCompositeSingletonType(const QQmlPrivate::Registe
     if (!checkRegistration(QQmlType::CompositeSingletonType, data, fileImport ? nullptr : type.uri, typeName))
         return QQmlType();
 
-    QQmlType dtype(data, typeName, type);
-
-    addTypeToData(dtype.priv(), data);
+    QQmlTypePrivate *priv = createQQmlType(data, typeName, type);
+    addTypeToData(priv, data);
 
     QQmlMetaTypeData::Files *files = fileImport ? &(data->urlToType) : &(data->urlToNonFileImportType);
-    files->insertMulti(QQmlTypeLoader::normalize(type.url), dtype.priv());
+    files->insertMulti(QQmlTypeLoader::normalize(type.url), priv);
 
-    return dtype;
+    return QQmlType(priv);
 }
 
 QQmlType QQmlMetaType::registerCompositeType(const QQmlPrivate::RegisterCompositeType &type)
@@ -379,13 +499,13 @@ QQmlType QQmlMetaType::registerCompositeType(const QQmlPrivate::RegisterComposit
     if (!checkRegistration(QQmlType::CompositeType, data, fileImport?nullptr:type.uri, typeName, type.versionMajor))
         return QQmlType();
 
-    QQmlType dtype(data, typeName, type);
-    addTypeToData(dtype.priv(), data);
+    QQmlTypePrivate *priv = createQQmlType(data, typeName, type);
+    addTypeToData(priv, data);
 
     QQmlMetaTypeData::Files *files = fileImport ? &(data->urlToType) : &(data->urlToNonFileImportType);
-    files->insertMulti(QQmlTypeLoader::normalize(type.url), dtype.priv());
+    files->insertMulti(QQmlTypeLoader::normalize(type.url), priv);
 
-    return dtype;
+    return QQmlType(priv);
 }
 
 void QQmlMetaType::registerInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit)
@@ -484,6 +604,19 @@ void QQmlMetaType::registerUndeletableType(const QQmlType &dtype)
     data->undeletableTypes.insert(dtype);
 }
 
+int QQmlMetaType::registerAttachedPropertyId(const QMetaObject *metaObject, int index)
+{
+    QQmlMetaTypeDataPtr data;
+    return data->attachedPropertyId(metaObject, index);
+}
+
+bool QQmlMetaType::unregisterAttachedPropertyId(const QMetaObject *metaObject, int index)
+{
+    QQmlMetaTypeDataPtr data;
+    // This is run from the QQmlType dtor. QQmlTypes in user code can outlive QQmlMetaTypeData.
+    return data ? data->removeAttachedPropertyId(metaObject, index) : false;
+}
+
 static bool namespaceContainsRegistrations(const QQmlMetaTypeData *data, const QString &uri,
                                            int majorVersion)
 {
@@ -664,7 +797,6 @@ QQmlType QQmlMetaType::typeForUrl(const QString &urlString,
         }
 
         data->registerType(priv);
-        priv->refCount.deref();
         addTypeToData(priv, data);
         data->urlToType.insertMulti(url, priv);
         return QQmlType(priv);
diff --git a/src/qml/qml/qqmlmetatype_p.h b/src/qml/qml/qqmlmetatype_p.h
index 2d22eb519f..dbfa10d044 100644
--- a/src/qml/qml/qqmlmetatype_p.h
+++ b/src/qml/qml/qqmlmetatype_p.h
@@ -88,6 +88,9 @@ public:
 
     static void registerUndeletableType(const QQmlType &dtype);
 
+    static int registerAttachedPropertyId(const QMetaObject *metaObject, int index);
+    static bool unregisterAttachedPropertyId(const QMetaObject *metaObject, int index);
+
     static QList<QString> qmlTypeNames();
     static QList<QQmlType> qmlTypes();
     static QList<QQmlType> qmlSingletonTypes();
diff --git a/src/qml/qml/qqmlmetatypedata.cpp b/src/qml/qml/qqmlmetatypedata.cpp
index 989f1adf7c..f4f127ab9a 100644
--- a/src/qml/qml/qqmlmetatypedata.cpp
+++ b/src/qml/qml/qqmlmetatypedata.cpp
@@ -56,8 +56,13 @@ QQmlMetaTypeData::~QQmlMetaTypeData()
     for (QHash<const QMetaObject *, QQmlPropertyCache *>::Iterator it = propertyCaches.begin(), end = propertyCaches.end();
          it != end; ++it)
         (*it)->release();
+
+    // Do this before the attached properties disappear.
+    types.clear();
+    undeletableTypes.clear();
 }
 
+// This expects a "fresh" QQmlTypePrivate and adopts its reference.
 void QQmlMetaTypeData::registerType(QQmlTypePrivate *priv)
 {
     for (int i = 0; i < types.count(); ++i) {
@@ -69,6 +74,7 @@ void QQmlMetaTypeData::registerType(QQmlTypePrivate *priv)
     }
     types.append(QQmlType(priv));
     priv->index = types.count() - 1;
+    priv->refCount.deref();
 }
 
 QQmlPropertyCache *QQmlMetaTypeData::propertyCache(const QMetaObject *metaObject)
diff --git a/src/qml/qml/qqmlmetatypedata_p.h b/src/qml/qml/qqmlmetatypedata_p.h
index cde6294c37..f61adada2c 100644
--- a/src/qml/qml/qqmlmetatypedata_p.h
+++ b/src/qml/qml/qqmlmetatypedata_p.h
@@ -128,8 +128,27 @@ struct QQmlMetaTypeData
             qWarning("%s", message.toUtf8().constData());
     }
 
+    int attachedPropertyId(const QMetaObject *metaObject, int ownIndex)
+    {
+        auto iter = attachedPropertyIds.find(metaObject);
+        return (iter == attachedPropertyIds.end())
+                ? *attachedPropertyIds.insert(metaObject, ownIndex)
+                : *iter;
+    }
+
+    bool removeAttachedPropertyId(const QMetaObject *metaObject, int ownIndex)
+    {
+        auto iter = attachedPropertyIds.find(metaObject);
+        if (iter != attachedPropertyIds.end() && *iter == ownIndex) {
+            attachedPropertyIds.erase(iter);
+            return true;
+        }
+        return false;
+    }
+
 private:
     QStringList *m_typeRegistrationFailures = nullptr;
+    QHash<const QMetaObject *, int> attachedPropertyIds;
 };
 
 inline uint qHash(const QQmlMetaTypeData::VersionedUri &v)
diff --git a/src/qml/qml/qqmltype.cpp b/src/qml/qml/qqmltype.cpp
index 1c69cedcd6..2a1b4715d0 100644
--- a/src/qml/qml/qqmltype.cpp
+++ b/src/qml/qml/qqmltype.cpp
@@ -115,8 +115,6 @@ QJSValue QQmlType::SingletonInstanceInfo::scriptApi(QQmlEngine *e) const
     return scriptApis.value(e);
 }
 
-QHash<const QMetaObject *, int> QQmlTypePrivate::attachedPropertyIds;
-
 QQmlTypePrivate::QQmlTypePrivate(QQmlType::RegistrationType type)
     : refCount(1), regType(type), iid(nullptr), typeId(0), listId(0), revision(0),
     containsRevisionedAttributes(false), baseMetaObject(nullptr),
@@ -173,122 +171,6 @@ QQmlTypePrivate::~QQmlTypePrivate()
     }
 }
 
-QQmlType::QQmlType(QQmlMetaTypeData *data, const QQmlPrivate::RegisterInterface &interface)
-    : d(new QQmlTypePrivate(InterfaceType))
-{
-    d->iid = interface.iid;
-    d->typeId = interface.typeId;
-    d->listId = interface.listId;
-    d->isSetup = true;
-    d->version_maj = 0;
-    d->version_min = 0;
-    data->registerType(d);
-}
-
-QQmlType::QQmlType(QQmlMetaTypeData *data, const QString &elementName, const QQmlPrivate::RegisterSingletonType &type)
-    : d(new QQmlTypePrivate(SingletonType))
-{
-    data->registerType(d);
-
-    d->elementName = elementName;
-    d->module = QString::fromUtf8(type.uri);
-
-    d->version_maj = type.versionMajor;
-    d->version_min = type.versionMinor;
-
-    if (type.qobjectApi) {
-        if (type.version >= 1) // static metaobject added in version 1
-            d->baseMetaObject = type.instanceMetaObject;
-        if (type.version >= 2) // typeId added in version 2
-            d->typeId = type.typeId;
-        if (type.version >= 2) // revisions added in version 2
-            d->revision = type.revision;
-    }
-
-    d->extraData.sd->singletonInstanceInfo = new SingletonInstanceInfo;
-    d->extraData.sd->singletonInstanceInfo->scriptCallback = type.scriptApi;
-    d->extraData.sd->singletonInstanceInfo->qobjectCallback = type.qobjectApi;
-    d->extraData.sd->singletonInstanceInfo->typeName = QString::fromUtf8(type.typeName);
-    d->extraData.sd->singletonInstanceInfo->instanceMetaObject
-            = (type.qobjectApi && type.version >= 1) ? type.instanceMetaObject : nullptr;
-}
-
-QQmlType::QQmlType(QQmlMetaTypeData *data, const QString &elementName, const QQmlPrivate::RegisterCompositeSingletonType &type)
-    : d(new QQmlTypePrivate(CompositeSingletonType))
-{
-    data->registerType(d);
-
-    d->elementName = elementName;
-    d->module = QString::fromUtf8(type.uri);
-
-    d->version_maj = type.versionMajor;
-    d->version_min = type.versionMinor;
-
-    d->extraData.sd->singletonInstanceInfo = new SingletonInstanceInfo;
-    d->extraData.sd->singletonInstanceInfo->url = QQmlTypeLoader::normalize(type.url);
-    d->extraData.sd->singletonInstanceInfo->typeName = QString::fromUtf8(type.typeName);
-}
-
-QQmlType::QQmlType(QQmlMetaTypeData *data, const QString &elementName, const QQmlPrivate::RegisterType &type)
-    : d(new QQmlTypePrivate(CppType))
-{
-    data->registerType(d);
-
-    d->elementName = elementName;
-    d->module = QString::fromUtf8(type.uri);
-
-    d->version_maj = type.versionMajor;
-    d->version_min = type.versionMinor;
-    if (type.version >= 1) // revisions added in version 1
-        d->revision = type.revision;
-    d->typeId = type.typeId;
-    d->listId = type.listId;
-    d->extraData.cd->allocationSize = type.objectSize;
-    d->extraData.cd->newFunc = type.create;
-    d->extraData.cd->noCreationReason = type.noCreationReason;
-    d->baseMetaObject = type.metaObject;
-    d->extraData.cd->attachedPropertiesFunc = type.attachedPropertiesFunction;
-    d->extraData.cd->attachedPropertiesType = type.attachedPropertiesMetaObject;
-    if (d->extraData.cd->attachedPropertiesType) {
-        auto iter = QQmlTypePrivate::attachedPropertyIds.find(d->baseMetaObject);
-        if (iter == QQmlTypePrivate::attachedPropertyIds.end())
-            iter = QQmlTypePrivate::attachedPropertyIds.insert(d->baseMetaObject, d->index);
-        d->extraData.cd->attachedPropertiesId = *iter;
-    } else {
-        d->extraData.cd->attachedPropertiesId = -1;
-    }
-    d->extraData.cd->parserStatusCast = type.parserStatusCast;
-    d->extraData.cd->propertyValueSourceCast = type.valueSourceCast;
-    d->extraData.cd->propertyValueInterceptorCast = type.valueInterceptorCast;
-    d->extraData.cd->extFunc = type.extensionObjectCreate;
-    d->extraData.cd->customParser = type.customParser;
-    d->extraData.cd->registerEnumClassesUnscoped = true;
-
-    if (type.extensionMetaObject)
-        d->extraData.cd->extMetaObject = type.extensionMetaObject;
-
-    // Check if the user wants only scoped enum classes
-    if (d->baseMetaObject) {
-        auto indexOfClassInfo = d->baseMetaObject->indexOfClassInfo("RegisterEnumClassesUnscoped");
-        if (indexOfClassInfo != -1 && QString::fromUtf8(d->baseMetaObject->classInfo(indexOfClassInfo).value()) == QLatin1String("false"))
-            d->extraData.cd->registerEnumClassesUnscoped = false;
-    }
-}
-
-QQmlType::QQmlType(QQmlMetaTypeData *data, const QString &elementName, const QQmlPrivate::RegisterCompositeType &type)
-    : d(new QQmlTypePrivate(CompositeType))
-{
-    data->registerType(d);
-
-    d->elementName = elementName;
-
-    d->module = QString::fromUtf8(type.uri);
-    d->version_maj = type.versionMajor;
-    d->version_min = type.versionMinor;
-
-    d->extraData.fd->url = QQmlTypeLoader::normalize(type.url);
-}
-
 QQmlType::QQmlType()
     : d(nullptr)
 {
@@ -325,11 +207,8 @@ QQmlType::~QQmlType()
     if (d && !d->refCount.deref()) {
         // If attached properties were successfully registered, deregister them.
         // (They may not have been registered if some other type used the same baseMetaObject)
-        if (d->regType == CppType && d->extraData.cd->attachedPropertiesType) {
-            auto it = QQmlTypePrivate::attachedPropertyIds.find(d->baseMetaObject);
-            if (it != QQmlTypePrivate::attachedPropertyIds.end() && *it == d->index)
-                QQmlTypePrivate::attachedPropertyIds.erase(it);
-        }
+        if (d->regType == CppType && d->extraData.cd->attachedPropertiesType)
+            QQmlMetaType::unregisterAttachedPropertyId(d->baseMetaObject, d->index);
         delete d;
     }
 }
diff --git a/src/qml/qml/qqmltype_p.h b/src/qml/qml/qqmltype_p.h
index edc1b01a07..969c096aeb 100644
--- a/src/qml/qml/qqmltype_p.h
+++ b/src/qml/qml/qqmltype_p.h
@@ -60,7 +60,6 @@
 
 QT_BEGIN_NAMESPACE
 
-struct QQmlMetaTypeData;
 class QHashedCStringRef;
 class QQmlTypePrivate;
 class QHashedString;
@@ -194,23 +193,7 @@ private:
     QQmlType resolveCompositeBaseType(QQmlEnginePrivate *engine) const;
     int resolveCompositeEnumValue(QQmlEnginePrivate *engine, const QString &name, bool *ok) const;
     QQmlPropertyCache *compositePropertyCache(QQmlEnginePrivate *engine) const;
-    friend class QQmlTypePrivate;
-
-    friend QString registrationTypeString(RegistrationType);
-    friend bool checkRegistration(RegistrationType, QQmlMetaTypeData *, const char *, const QString &, int);
-    friend QQmlType registerType(const QQmlPrivate::RegisterType &);
-    friend QQmlType registerSingletonType(const QQmlPrivate::RegisterSingletonType &);
-    friend QQmlType registerInterface(const QQmlPrivate::RegisterInterface &);
-    friend int registerQmlUnitCacheHook(const QQmlPrivate::RegisterQmlUnitCacheHook &);
     friend uint qHash(const QQmlType &t, uint seed);
-    friend Q_QML_EXPORT void qmlClearTypeRegistrations();
-    friend class QQmlMetaType;
-
-    QQmlType(QQmlMetaTypeData *data, const QQmlPrivate::RegisterInterface &);
-    QQmlType(QQmlMetaTypeData *data, const QString &, const QQmlPrivate::RegisterSingletonType &);
-    QQmlType(QQmlMetaTypeData *data, const QString &, const QQmlPrivate::RegisterType &);
-    QQmlType(QQmlMetaTypeData *data, const QString &, const QQmlPrivate::RegisterCompositeType &);
-    QQmlType(QQmlMetaTypeData *data, const QString &, const QQmlPrivate::RegisterCompositeSingletonType &);
 
     QQmlTypePrivate *d;
 };
diff --git a/src/qml/qml/qqmltype_p_p.h b/src/qml/qml/qqmltype_p_p.h
index fd9b28c322..faff0808ec 100644
--- a/src/qml/qml/qqmltype_p_p.h
+++ b/src/qml/qml/qqmltype_p_p.h
@@ -129,8 +129,6 @@ public:
     mutable QStringHash<int> scopedEnumIndex; // maps from enum name to index in scopedEnums
     mutable QList<QStringHash<int>*> scopedEnums;
 
-    static QHash<const QMetaObject *, int> attachedPropertyIds;
-
     struct PropertyCacheByMinorVersion
     {
         PropertyCacheByMinorVersion() : cache(nullptr), minorVersion(-1) {}