Clean up type registration structs

* reset all structVersions to 0, removing checks for higher versions
* add structVerions where they are missing
* consistently check for compatibility in qqmlmetatype.cpp
* remove unused members
* rename RegisterSingletonFunctor

Fixes: QTBUG-82241
Change-Id: I74f1876b3298dbb60ff7cfab8c13e8ad4f9f8cdc
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

4 files changed, 78 insertions, 75 deletions

diff --git a/src/qml/qml/qqml.cpp b/src/qml/qml/qqml.cpp
index 79f853487c..28b48e2eee 100644
--- a/src/qml/qml/qqml.cpp
+++ b/src/qml/qml/qqml.cpp
@@ -79,7 +79,7 @@ int qmlTypeId(const char *uri, int versionMajor, int versionMinor, const char *q
 }
 
 // From qqmlprivate.h
-QObject *QQmlPrivate::RegisterSingletonFunctor::operator()(QQmlEngine *qeng, QJSEngine *)
+QObject *QQmlPrivate::SingletonFunctor::operator()(QQmlEngine *qeng, QJSEngine *)
 {
     if (!m_object) {
         QQmlError error;
@@ -206,7 +206,7 @@ int QQmlPrivate::qmlregister(RegistrationType type, void *data)
                 ? QString()
                 : QString::fromUtf8(classInfo(type.classInfoMetaObject, "QML.UncreatableReason"));
         RegisterType revisionRegistration = {
-            1,
+            0,
             type.typeId,
             type.listId,
             creatable ? type.objectSize : 0,
@@ -264,18 +264,15 @@ int QQmlPrivate::qmlregister(RegistrationType type, void *data)
                 = *reinterpret_cast<RegisterSingletonTypeAndRevisions *>(data);
         const char *elementName = classElementName(type.classInfoMetaObject);
         RegisterSingletonType revisionRegistration = {
-            QmlCurrentSingletonTypeRegistrationVersion,
+            0,
             type.uri,
             type.version,
             elementName,
-
-            type.scriptApi,
             nullptr,
+            type.qObjectApi,
             type.instanceMetaObject,
             type.typeId,
-            QTypeRevision(),
-
-            type.generalizedQobjectApi
+            QTypeRevision()
         };
 
         const QTypeRevision added = revisionClassInfo(
@@ -294,12 +291,10 @@ int QQmlPrivate::qmlregister(RegistrationType type, void *data)
             // When removed, we still add revisions, but anonymous ones
             if (removed.isValid() && !(revision < removed)) {
                 revisionRegistration.typeName = nullptr;
-                revisionRegistration.scriptApi = nullptr;
-                revisionRegistration.generalizedQobjectApi = nullptr;
+                revisionRegistration.qObjectApi = nullptr;
             } else {
                 revisionRegistration.typeName = elementName;
-                revisionRegistration.scriptApi = type.scriptApi;
-                revisionRegistration.generalizedQobjectApi = type.generalizedQobjectApi;
+                revisionRegistration.qObjectApi = type.qObjectApi;
             }
 
             assignVersions(&revisionRegistration, revision, type.version);
diff --git a/src/qml/qml/qqml.h b/src/qml/qml/qqml.h
index fff1db5125..7404a62d23 100644
--- a/src/qml/qml/qqml.h
+++ b/src/qml/qml/qqml.h
@@ -228,7 +228,7 @@ template<typename T, int metaObjectRevision>
 int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMinor, const char *qmlName, const QString& reason)
 {
     QQmlPrivate::RegisterType type = {
-        1,
+        0,
 
         QMetaType::fromType<T *>(),
         QMetaType::fromType<QQmlListProperty<T> >(),
@@ -302,7 +302,7 @@ int qmlRegisterExtendedUncreatableType(const char *uri, int versionMajor, int ve
     }
 
     QQmlPrivate::RegisterType type = {
-        1,
+        0,
 
         QMetaType::fromType<T *>(),
         QMetaType::fromType<QQmlListProperty<T> >(),
@@ -363,7 +363,7 @@ template<typename T, int metaObjectRevision>
 int qmlRegisterType(const char *uri, int versionMajor, int versionMinor, const char *qmlName)
 {
     QQmlPrivate::RegisterType type = {
-        1,
+        0,
 
         QMetaType::fromType<T *>(),
         QMetaType::fromType<QQmlListProperty<T> >(),
@@ -392,7 +392,7 @@ template<typename T, int metaObjectRevision>
 int qmlRegisterRevision(const char *uri, int versionMajor, int versionMinor)
 {
     QQmlPrivate::RegisterType type = {
-        1,
+        0,
 
         QMetaType::fromType<T *>(),
         QMetaType::fromType<QQmlListProperty<T> >(),
@@ -504,7 +504,7 @@ int qmlRegisterInterface(const char *typeName)
     QByteArray listName("QQmlListProperty<" + name + '>');
 
     QQmlPrivate::RegisterInterface qmlInterface = {
-        1,
+        0,
 
         QMetaType::fromType<T *>(),
         QMetaType::fromType<QQmlListProperty<T> >(),
@@ -522,7 +522,7 @@ template<typename T>
 int qmlRegisterInterface(const char *uri, int versionMajor)
 {
     QQmlPrivate::RegisterInterface qmlInterface = {
-        1,
+        0,
         QMetaType::fromType<T *>(),
         QMetaType::fromType<QQmlListProperty<T> >(),
         qobject_interface_iid<T *>(),
@@ -569,7 +569,7 @@ int qmlRegisterCustomType(const char *uri, int versionMajor, int versionMinor,
                           const char *qmlName, QQmlCustomParser *parser)
 {
     QQmlPrivate::RegisterType type = {
-        1,
+        0,
 
         QMetaType::fromType<T *>(),
         QMetaType::fromType<QQmlListProperty<T> >(),
@@ -690,24 +690,27 @@ inline int qmlRegisterSingletonType(const char *uri, int versionMajor, int versi
 
         uri, QTypeRevision::fromVersion(versionMajor, versionMinor), typeName,
 
-        callback, nullptr, nullptr, QMetaType(), QTypeRevision::zero(), {}
+        callback, nullptr, nullptr, QMetaType(), QTypeRevision::zero()
     };
 
     return QQmlPrivate::qmlregister(QQmlPrivate::SingletonRegistration, &api);
 }
 
-enum { QmlCurrentSingletonTypeRegistrationVersion = 3 };
 template <typename T>
-inline int qmlRegisterSingletonType(const char *uri, int versionMajor, int versionMinor, const char *typeName,
-                                QObject *(*callback)(QQmlEngine *, QJSEngine *))
+inline int qmlRegisterSingletonType(
+        const char *uri, int versionMajor, int versionMinor,  const char *typeName,
+        QObject *(*callback)(QQmlEngine *, QJSEngine *))
 {
     QQmlPrivate::RegisterSingletonType api = {
-        QmlCurrentSingletonTypeRegistrationVersion,
-
-        uri, QTypeRevision::fromVersion(versionMajor, versionMinor), typeName,
-
-
-        nullptr, nullptr, &T::staticMetaObject, QMetaType::fromType<T *>(), QTypeRevision::zero(), callback
+        0,
+        uri,
+        QTypeRevision::fromVersion(versionMajor, versionMinor),
+        typeName,
+        nullptr,
+        callback,
+        &T::staticMetaObject,
+        QMetaType::fromType<T *>(),
+        QTypeRevision::zero()
     };
 
     return QQmlPrivate::qmlregister(QQmlPrivate::SingletonRegistration, &api);
@@ -719,12 +722,15 @@ inline int qmlRegisterSingletonType(const char *uri, int versionMajor, int versi
                                     F&& callback)
 {
     QQmlPrivate::RegisterSingletonType api = {
-        QmlCurrentSingletonTypeRegistrationVersion,
-
-        uri, QTypeRevision::fromVersion(versionMajor, versionMinor), typeName,
-
-
-        nullptr, nullptr, &T::staticMetaObject, QMetaType::fromType<T *>(), QTypeRevision::zero(), callback
+        0,
+        uri,
+        QTypeRevision::fromVersion(versionMajor, versionMinor),
+        typeName,
+        nullptr,
+        callback,
+        &T::staticMetaObject,
+        QMetaType::fromType<T *>(),
+        QTypeRevision::zero()
     };
 
     return QQmlPrivate::qmlregister(QQmlPrivate::SingletonRegistration, &api);
@@ -734,7 +740,7 @@ template<typename T>
 inline auto qmlRegisterSingletonInstance(const char *uri, int versionMajor, int versionMinor,
                                          const char *typeName, T *cppObject) -> typename std::enable_if<std::is_base_of<QObject, T>::value, int>::type
 {
-    QQmlPrivate::RegisterSingletonFunctor registrationFunctor;
+    QQmlPrivate::SingletonFunctor registrationFunctor;
     registrationFunctor.m_object = cppObject;
     return qmlRegisterSingletonType<T>(uri, versionMajor, versionMinor, typeName, registrationFunctor);
 }
@@ -748,6 +754,7 @@ inline int qmlRegisterSingletonType(const QUrl &url, const char *uri, int versio
     }
 
     QQmlPrivate::RegisterCompositeSingletonType type = {
+        0,
         url,
         uri,
         QTypeRevision::fromVersion(versionMajor, versionMinor),
@@ -766,6 +773,7 @@ inline int qmlRegisterType(const QUrl &url, const char *uri, int versionMajor, i
     }
 
     QQmlPrivate::RegisterCompositeType type = {
+        0,
         url,
         uri,
         QTypeRevision::fromVersion(versionMajor, versionMinor),
diff --git a/src/qml/qml/qqmlmetatype.cpp b/src/qml/qml/qqmlmetatype.cpp
index 0df8992079..c692986e74 100644
--- a/src/qml/qml/qqmlmetatype.cpp
+++ b/src/qml/qml/qqmlmetatype.cpp
@@ -92,12 +92,8 @@ static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data,
     d->typeId = type.typeId;
     d->listId = type.listId;
     d->isSetup = true;
-    if (type.structVersion > 0) {
-        d->module = QString::fromUtf8(type.uri);
-        d->version = type.version;
-    } else {
-        d->version = QTypeRevision::zero();
-    }
+    d->module = QString::fromUtf8(type.uri);
+    d->version = type.version;
     data->registerType(d);
     return d;
 }
@@ -111,28 +107,18 @@ static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &el
     d->setName(QString::fromUtf8(type.uri), elementName);
     d->version = type.version;
 
-    if (type.qobjectApi || (type.structVersion >= 3 && type.generalizedQobjectApi)) {
-        if (type.structVersion >= 1) // static metaobject added in version 1
-            d->baseMetaObject = type.instanceMetaObject;
-        if (type.structVersion >= 2) // typeId added in version 2
-            d->typeId = type.typeId;
-        if (type.structVersion >= 2) // revisions added in version 2
-            d->revision = type.revision;
+    if (type.qObjectApi) {
+        d->baseMetaObject = type.instanceMetaObject;
+        d->typeId = type.typeId;
+        d->revision = type.revision;
     }
 
     d->extraData.sd->singletonInstanceInfo = new QQmlType::SingletonInstanceInfo;
     d->extraData.sd->singletonInstanceInfo->scriptCallback = type.scriptApi;
-    if (type.structVersion >= 3) {
-        d->extraData.sd->singletonInstanceInfo->qobjectCallback = type.generalizedQobjectApi;
-    } else {
-        d->extraData.sd->singletonInstanceInfo->qobjectCallback = type.qobjectApi;
-    }
+    d->extraData.sd->singletonInstanceInfo->qobjectCallback = type.qObjectApi;
     d->extraData.sd->singletonInstanceInfo->typeName = QString::fromUtf8(type.typeName);
     d->extraData.sd->singletonInstanceInfo->instanceMetaObject
-            = ((type.qobjectApi || (type.structVersion >= 3 && type.generalizedQobjectApi) )
-               && type.structVersion >= 1)
-            ? type.instanceMetaObject
-            : nullptr;
+            = type.qObjectApi ? type.instanceMetaObject : nullptr;
 
     return d;
 }
@@ -145,8 +131,7 @@ static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &el
     d->setName(QString::fromUtf8(type.uri), elementName);
 
     d->version = type.version;
-    if (type.structVersion >= 1) // revisions added in version 1
-        d->revision = type.revision;
+    d->revision = type.revision;
     d->typeId = type.typeId;
     d->listId = type.listId;
     d->extraData.cd->allocationSize = type.objectSize;
@@ -328,11 +313,14 @@ void QQmlMetaType::clearTypeRegistrations()
     data->undeletableTypes.clear();
 }
 
-int QQmlMetaType::registerAutoParentFunction(const QQmlPrivate::RegisterAutoParent &autoparent)
+int QQmlMetaType::registerAutoParentFunction(const QQmlPrivate::RegisterAutoParent &function)
 {
+    if (function.structVersion > 0)
+        qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
+
     QQmlMetaTypeDataPtr data;
 
-    data->parentFunctions.append(autoparent.function);
+    data->parentFunctions.append(function.function);
 
     return data->parentFunctions.count() - 1;
 }
@@ -345,7 +333,7 @@ void QQmlMetaType::unregisterAutoParentFunction(const QQmlPrivate::AutoParentFun
 
 QQmlType QQmlMetaType::registerInterface(const QQmlPrivate::RegisterInterface &type)
 {
-    if (type.structVersion > 1)
+    if (type.structVersion > 0)
         qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
 
     QQmlMetaTypeDataPtr data;
@@ -459,6 +447,9 @@ void addTypeToData(QQmlTypePrivate *type, QQmlMetaTypeData *data)
 
 QQmlType QQmlMetaType::registerType(const QQmlPrivate::RegisterType &type)
 {
+    if (type.structVersion > 0)
+        qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
+
     QQmlMetaTypeDataPtr data;
 
     QString elementName = QString::fromUtf8(type.elementName);
@@ -476,6 +467,9 @@ QQmlType QQmlMetaType::registerType(const QQmlPrivate::RegisterType &type)
 
 QQmlType QQmlMetaType::registerSingletonType(const QQmlPrivate::RegisterSingletonType &type)
 {
+    if (type.structVersion > 0)
+        qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
+
     QQmlMetaTypeDataPtr data;
 
     QString typeName = QString::fromUtf8(type.typeName);
@@ -491,6 +485,9 @@ QQmlType QQmlMetaType::registerSingletonType(const QQmlPrivate::RegisterSingleto
 
 QQmlType QQmlMetaType::registerCompositeSingletonType(const QQmlPrivate::RegisterCompositeSingletonType &type)
 {
+    if (type.structVersion > 0)
+        qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
+
     // Assumes URL is absolute and valid. Checking of user input should happen before the URL enters type.
     QQmlMetaTypeDataPtr data;
 
@@ -514,6 +511,9 @@ QQmlType QQmlMetaType::registerCompositeSingletonType(const QQmlPrivate::Registe
 
 QQmlType QQmlMetaType::registerCompositeType(const QQmlPrivate::RegisterCompositeType &type)
 {
+    if (type.structVersion > 0)
+        qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
+
     // Assumes URL is absolute and valid. Checking of user input should happen before the URL enters type.
     QQmlMetaTypeDataPtr data;
 
diff --git a/src/qml/qml/qqmlprivate.h b/src/qml/qml/qqmlprivate.h
index 968811e602..259deb5f32 100644
--- a/src/qml/qml/qqmlprivate.h
+++ b/src/qml/qml/qqmlprivate.h
@@ -400,7 +400,7 @@ namespace QQmlPrivate
     };
 
     struct RegisterAutoParent {
-        int version;
+        int structVersion;
 
         AutoParentFunction function;
     };
@@ -413,12 +413,11 @@ namespace QQmlPrivate
         const char *typeName;
 
         QJSValue (*scriptApi)(QQmlEngine *, QJSEngine *);
-        QObject *(*qobjectApi)(QQmlEngine *, QJSEngine *);
-        const QMetaObject *instanceMetaObject; // new in version 1
-        QMetaType typeId; // new in version 2
-        QTypeRevision revision; // new in version 2
-        std::function<QObject*(QQmlEngine *, QJSEngine *)> generalizedQobjectApi; // new in version 3
-        // If this is extended ensure "version" is bumped!!!
+        std::function<QObject*(QQmlEngine *, QJSEngine *)> qObjectApi;
+
+        const QMetaObject *instanceMetaObject;
+        QMetaType typeId;
+        QTypeRevision revision;
     };
 
     struct RegisterSingletonTypeAndRevisions {
@@ -426,16 +425,17 @@ namespace QQmlPrivate
         const char *uri;
         QTypeRevision version;
 
-        QJSValue (*scriptApi)(QQmlEngine *, QJSEngine *);
+        std::function<QObject*(QQmlEngine *, QJSEngine *)> qObjectApi;
+
         const QMetaObject *instanceMetaObject;
         const QMetaObject *classInfoMetaObject;
 
         QMetaType typeId;
-        std::function<QObject*(QQmlEngine *, QJSEngine *)> generalizedQobjectApi; // new in version 3
         QVector<int> *qmlTypeIds;
     };
 
     struct RegisterCompositeType {
+        int structVersion;
         QUrl url;
         const char *uri;
         QTypeRevision version;
@@ -443,6 +443,7 @@ namespace QQmlPrivate
     };
 
     struct RegisterCompositeSingletonType {
+        int structVersion;
         QUrl url;
         const char *uri;
         QTypeRevision version;
@@ -475,7 +476,7 @@ namespace QQmlPrivate
 
     int Q_QML_EXPORT qmlregister(RegistrationType, void *);
     void Q_QML_EXPORT qmlunregister(RegistrationType, quintptr);
-    struct Q_QML_EXPORT RegisterSingletonFunctor
+    struct Q_QML_EXPORT SingletonFunctor
     {
         QObject *operator()(QQmlEngine *, QJSEngine *);
 
@@ -593,13 +594,12 @@ namespace QQmlPrivate
             uri,
             QTypeRevision::fromMajorVersion(versionMajor),
 
-            nullptr,
+            Constructors<T>::createSingletonInstance,
 
             &T::staticMetaObject,
             classInfoMetaObject,
 
             QMetaType::fromType<T *>(),
-            Constructors<T>::createSingletonInstance,
             qmlTypeIds
         };