Encapsulate the dynamic meta object pointer

This change allows us to delay creating the actual meta object
until it is actually required.

Change-Id: I1c4a4226bd82fa606b206dd60322f49b49c32463
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

src/corelib/kernel/qmetaobject.cpp

@@ -300,8 +300,8 @@ int QMetaObject::static_metacall(Call cl, int idx, void **argv) const
 */
 int QMetaObject::metacall(QObject *object, Call cl, int idx, void **argv)
 {
-    if (QMetaObject *mo = object->d_ptr->metaObject)
-        return static_cast<QAbstractDynamicMetaObject*>(mo)->metaCall(cl, idx, argv);
+    if (object->d_ptr->metaObject)
+        return object->d_ptr->metaObject->metaCall(object, cl, idx, argv);
     else
         return object->qt_metacall(cl, idx, argv);
 }

src/corelib/kernel/qobject.cpp

@@ -187,6 +187,11 @@ int  (*QAbstractDeclarativeData::receivers)(QAbstractDeclarativeData *, const QO
 
 QObjectData::~QObjectData() {}
 
+QMetaObject *QObjectData::dynamicMetaObject() const
+{
+    return metaObject->toDynamicMetaObject(q_ptr);
+}
+
 QObjectPrivate::QObjectPrivate(int version)
     : threadData(0), connectionLists(0), senders(0), currentSender(0), currentChildBeingDeleted(0)
 {
@@ -227,7 +232,8 @@ QObjectPrivate::~QObjectPrivate()
 
     threadData->deref();
 
-    delete static_cast<QAbstractDynamicMetaObject*>(metaObject);
+    if (metaObject) metaObject->objectDestroyed(q_ptr);
+
 #ifndef QT_NO_USERDATA
     if (extraData)
         qDeleteAll(extraData->userData);

src/corelib/kernel/qobject.h

@@ -79,6 +79,7 @@ class QRegularExpression;
 #ifndef QT_NO_USERDATA
 class QObjectUserData;
 #endif
+class QDynamicMetaObjectData;
 
 typedef QList<QObject*> QObjectList;
 
@@ -90,11 +91,7 @@ Q_CORE_EXPORT void qt_qFindChildren_helper(const QObject *parent, const QRegular
                                            const QMetaObject &mo, QList<void *> *list, Qt::FindChildOptions options);
 Q_CORE_EXPORT QObject *qt_qFindChild_helper(const QObject *parent, const QString &name, const QMetaObject &mo, Qt::FindChildOptions options);
 
-class
-#if defined(__INTEL_COMPILER) && defined(Q_OS_WIN)
-Q_CORE_EXPORT
-#endif
-QObjectData {
+class Q_CORE_EXPORT QObjectData {
 public:
     virtual ~QObjectData() = 0;
     QObject *q_ptr;
@@ -110,7 +107,8 @@ public:
     uint isWindow : 1; //for QWindow
     uint unused : 25;
     int postedEvents;
-    QMetaObject *metaObject; // assert dynamic
+    QDynamicMetaObjectData *metaObject;
+    QMetaObject *dynamicMetaObject() const;
 };
 
 

src/corelib/kernel/qobject_p.h

@@ -286,12 +286,23 @@ private:
 
 void Q_CORE_EXPORT qDeleteInEventHandler(QObject *o);
 
-
-struct Q_CORE_EXPORT QAbstractDynamicMetaObject : public QMetaObject
+struct QAbstractDynamicMetaObject;
+struct Q_CORE_EXPORT QDynamicMetaObjectData
 {
-    virtual ~QAbstractDynamicMetaObject() {}
-    virtual int metaCall(QMetaObject::Call, int _id, void **) { return _id; }
+    virtual ~QDynamicMetaObjectData() {}
+    virtual void objectDestroyed(QObject *) { delete this; }
+
+    virtual QAbstractDynamicMetaObject *toDynamicMetaObject(QObject *) = 0;
+    virtual int metaCall(QObject *, QMetaObject::Call, int _id, void **) = 0;
+};
+
+struct Q_CORE_EXPORT QAbstractDynamicMetaObject : public QDynamicMetaObjectData, public QMetaObject
+{
+    virtual QAbstractDynamicMetaObject *toDynamicMetaObject(QObject *) { return this; }
     virtual int createProperty(const char *, const char *) { return -1; }
+    virtual int metaCall(QObject *, QMetaObject::Call c, int _id, void **a)
+    { return metaCall(c, _id, a); }
+    virtual int metaCall(QMetaObject::Call, int _id, void **) { return _id; } // Compat overload
 };
 
 QT_END_NAMESPACE

src/tools/moc/generator.cpp

@@ -449,7 +449,7 @@ void Generator::generateCode()
     if (!cdef->hasQObject)
         return;
 
-    fprintf(out, "\nconst QMetaObject *%s::metaObject() const\n{\n    return QObject::d_ptr->metaObject ? QObject::d_ptr->metaObject : &staticMetaObject;\n}\n",
+    fprintf(out, "\nconst QMetaObject *%s::metaObject() const\n{\n    return QObject::d_ptr->metaObject ? QObject::d_ptr->dynamicMetaObject() : &staticMetaObject;\n}\n",
             cdef->qualified.constData());
 
 //