MetaObject: Store the QMetaType of the methods

This does the analog of 46f407126ef3e94d59254012cdc34d6a4ad2faf2 for the
methods we care about (signals, slots, Q_INVOKABLEs). In addition to the
actual QMetaType, we store an array with offsets so that we later can do
a mapping from methodIndex to metatype.

The newly added QMetaMethod::{return,parameter}MetaType methods can then
be used to retrieve the metatypes.

This does however require that all involved types are complete. This is
unfortunately not a feasible requirement. Thus, we only populate the
metatype array on a best effort basis. For any incomplete type, we store
QMetaType::Unknown. Then, when accessing the metatype, we fall back to
the old string based code base if it's Unknown.

Squashes "moc: support incomplete types" and  "Fix compile failures
after QMetaMethod change"


Fixes: QTBUG-82932
Change-Id: I6b7a587cc364b7cad0c158d6de54e8a204289ad4
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

41 files changed, 280 insertions, 92 deletions

diff --git a/src/corelib/kernel/qmetaobject.cpp b/src/corelib/kernel/qmetaobject.cpp
index f68a042db0..a234b46d70 100644
--- a/src/corelib/kernel/qmetaobject.cpp
+++ b/src/corelib/kernel/qmetaobject.cpp
@@ -618,7 +618,7 @@ static inline int indexOfMethodRelative(const QMetaObject **baseObject,
                         ? (priv(m->d.data)->signalCount) : 0;
 
         for (; i >= end; --i) {
-            int handle = priv(m->d.data)->methodData + 5*i;
+            int handle = priv(m->d.data)->methodData + QMetaObjectPrivate::IntsPerMethod*i;
             if (methodMatch(m, handle, name, argc, types)) {
                 *baseObject = m;
                 return i;
@@ -819,7 +819,7 @@ int QMetaObjectPrivate::indexOfConstructor(const QMetaObject *m, const QByteArra
                                            int argc, const QArgumentType *types)
 {
     for (int i = priv(m->d.data)->constructorCount-1; i >= 0; --i) {
-        int handle = priv(m->d.data)->constructorData + 5*i;
+        int handle = priv(m->d.data)->constructorData + QMetaObjectPrivate::IntsPerMethod*i;
         if (methodMatch(m, handle, name, argc, types))
             return i;
     }
@@ -895,7 +895,7 @@ QMetaMethod QMetaObjectPrivate::signal(const QMetaObject *m, int signal_index)
 
     if (i >= 0 && i < priv(m->d.data)->signalCount) {
         result.mobj = m;
-        result.handle = priv(m->d.data)->methodData + 5*i;
+        result.handle = priv(m->d.data)->methodData + QMetaObjectPrivate::IntsPerMethod*i;
     }
     return result;
 }
@@ -1078,7 +1078,7 @@ QMetaMethod QMetaObject::constructor(int index) const
     Q_ASSERT(priv(d.data)->revision >= 2);
     if (i >= 0 && i < priv(d.data)->constructorCount) {
         result.mobj = this;
-        result.handle = priv(d.data)->constructorData + 5*i;
+        result.handle = priv(d.data)->constructorData + QMetaObjectPrivate::IntsPerMethod*i;
     }
     return result;
 }
@@ -1098,7 +1098,7 @@ QMetaMethod QMetaObject::method(int index) const
     QMetaMethod result;
     if (i >= 0 && i < priv(d.data)->methodCount) {
         result.mobj = this;
-        result.handle = priv(d.data)->methodData + 5*i;
+        result.handle = priv(d.data)->methodData + QMetaObjectPrivate::IntsPerMethod*i;
     }
     return result;
 }
@@ -1844,7 +1844,7 @@ QByteArray QMetaMethodPrivate::tag() const
 int QMetaMethodPrivate::ownMethodIndex() const
 {
     // recompute the methodIndex by reversing the arithmetic in QMetaObject::property()
-    return (handle - priv(mobj->d.data)->methodData) / 5;
+    return (handle - priv(mobj->d.data)->methodData) / QMetaObjectPrivate::IntsPerMethod;
 }
 
 /*!
@@ -1884,13 +1884,30 @@ QByteArray QMetaMethod::name() const
     The return value is one of the types that are registered
     with QMetaType, or QMetaType::UnknownType if the type is not registered.
 
-    \sa parameterType(), QMetaType, typeName()
+    \sa parameterType(), QMetaType, typeName(), returnMetaType()
 */
 int QMetaMethod::returnType() const
  {
      if (!mobj)
          return QMetaType::UnknownType;
-    return QMetaMethodPrivate::get(this)->returnType();
+     return QMetaMethodPrivate::get(this)->returnType();
+}
+
+/*!
+    \since 6.0
+
+    Returns the return type of this method.
+    \sa parameterMetaType(), QMetaType, typeName()
+*/
+QMetaType QMetaMethod::returnMetaType() const
+{
+    if (!mobj || methodType() == QMetaMethod::Constructor)
+        return QMetaType{};
+    auto mt = QMetaType(mobj->d.metaTypes[mobj->d.data[handle + 5]]);
+    if (mt.id() == QMetaType::UnknownType)
+        return QMetaType(QMetaMethodPrivate::get(this)->returnType());
+    else
+        return mt;
 }
 
 /*!
@@ -1915,24 +1932,37 @@ int QMetaMethod::parameterCount() const
     The return value is one of the types that are registered
     with QMetaType, or QMetaType::UnknownType if the type is not registered.
 
-    \sa parameterCount(), returnType(), QMetaType
+    \sa parameterCount(), parameterMetaType(), returnType(), QMetaType
 */
 int QMetaMethod::parameterType(int index) const
 {
-    if (!mobj || index < 0)
-        return QMetaType::UnknownType;
-    if (index >= QMetaMethodPrivate::get(this)->parameterCount())
-        return QMetaType::UnknownType;
+    return parameterMetaType(index).id();
+}
+
+/*!
+    \since 6.0
+
+    Returns the metatype of the parameter at the given \a index.
 
-    int type = QMetaMethodPrivate::get(this)->parameterType(index);
-    if (type != QMetaType::UnknownType)
-        return type;
+    If the \a index is smaller than zero or larger than
+    parameterCount(), an invalid QMetaType is returned.
 
-    void *argv[] = { &type, &index };
-    mobj->static_metacall(QMetaObject::RegisterMethodArgumentMetaType, QMetaMethodPrivate::get(this)->ownMethodIndex(), argv);
-    if (type != -1)
-        return type;
-    return QMetaType::UnknownType;
+    \sa parameterCount(), returnMetaType(), QMetaType
+*/
+QMetaType QMetaMethod::parameterMetaType(int index) const
+{
+    if (!mobj || index < 0)
+        return {};
+    auto priv = QMetaMethodPrivate::get(this);
+    if (index >= priv->parameterCount())
+        return {};
+    // + 1 if there exists a return type
+    auto parameterOffset = index + (methodType() == QMetaMethod::Constructor ? 0 : 1);
+    auto mt = QMetaType(mobj->d.metaTypes[mobj->d.data[handle + 5] + parameterOffset]);
+    if (mt.id() == QMetaType::UnknownType)
+        return QMetaType(QMetaMethodPrivate::get(this)->parameterType(index));
+    else
+        return mt;
 }
 
 /*!
@@ -2055,7 +2085,7 @@ int QMetaMethod::revision() const
         return 0;
     if ((QMetaMethod::Access)(mobj->d.data[handle + 4] & MethodRevisioned)) {
         int offset = priv(mobj->d.data)->methodData
-                     + priv(mobj->d.data)->methodCount * 5
+                     + priv(mobj->d.data)->methodCount * QMetaObjectPrivate::IntsPerMethod
                      + QMetaMethodPrivate::get(this)->ownMethodIndex();
         return mobj->d.data[offset];
     }
@@ -2120,7 +2150,7 @@ QMetaMethod QMetaMethod::fromSignalImpl(const QMetaObject *metaObject, void **si
         m->static_metacall(QMetaObject::IndexOfMethod, 0, args);
         if (i >= 0) {
             result.mobj = m;
-            result.handle = priv(m->d.data)->methodData + 5*i;
+            result.handle = priv(m->d.data)->methodData + QMetaObjectPrivate::IntsPerMethod*i;
             break;
         }
     }
@@ -3712,10 +3742,10 @@ const char* QMetaClassInfo::value() const
 int QMetaObjectPrivate::originalClone(const QMetaObject *mobj, int local_method_index)
 {
     Q_ASSERT(local_method_index < get(mobj)->methodCount);
-    int handle = get(mobj)->methodData + 5 * local_method_index;
+    int handle = get(mobj)->methodData + QMetaObjectPrivate::IntsPerMethod * local_method_index;
     while (mobj->d.data[handle + 4] & MethodCloned) {
         Q_ASSERT(local_method_index > 0);
-        handle -= 5;
+        handle -= QMetaObjectPrivate::IntsPerMethod;
         local_method_index--;
     }
     return local_method_index;
diff --git a/src/corelib/kernel/qmetaobject.h b/src/corelib/kernel/qmetaobject.h
index b0d6cb7446..67f5efe6f6 100644
--- a/src/corelib/kernel/qmetaobject.h
+++ b/src/corelib/kernel/qmetaobject.h
@@ -57,8 +57,10 @@ public:
     QByteArray name() const;
     const char *typeName() const;
     int returnType() const;
+    QMetaType returnMetaType() const;
     int parameterCount() const;
     int parameterType(int index) const;
+    QMetaType parameterMetaType(int index) const;
     void getParameterTypes(int *types) const;
     QList<QByteArray> parameterTypes() const;
     QList<QByteArray> parameterNames() const;
diff --git a/src/corelib/kernel/qmetaobject_p.h b/src/corelib/kernel/qmetaobject_p.h
index 49c43e3d79..b825c983f9 100644
--- a/src/corelib/kernel/qmetaobject_p.h
+++ b/src/corelib/kernel/qmetaobject_p.h
@@ -176,7 +176,9 @@ struct QMetaObjectPrivate
 {
     // revision 7 is Qt 5.0 everything lower is not supported
     // revision 8 is Qt 5.12: It adds the enum name to QMetaEnum
-    enum { OutputRevision = 8 }; // Used by moc, qmetaobjectbuilder and qdbus
+    // revision 9 is Qt 6.0: It adds the metatype of properties and methods
+    enum { OutputRevision = 9 }; // Used by moc, qmetaobjectbuilder and qdbus
+    enum { IntsPerMethod = 6};
 
     int revision;
     int className;
diff --git a/src/corelib/kernel/qmetaobjectbuilder.cpp b/src/corelib/kernel/qmetaobjectbuilder.cpp
index a2dedda0ad..7b9b06ed3e 100644
--- a/src/corelib/kernel/qmetaobjectbuilder.cpp
+++ b/src/corelib/kernel/qmetaobjectbuilder.cpp
@@ -1216,7 +1216,7 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
             - int(d->methods.size())       // return "parameters" don't have names
             - int(d->constructors.size()); // "this" parameters don't have names
     if (buf) {
-        Q_STATIC_ASSERT_X(QMetaObjectPrivate::OutputRevision == 8, "QMetaObjectBuilder should generate the same version as moc");
+        Q_STATIC_ASSERT_X(QMetaObjectPrivate::OutputRevision == 9, "QMetaObjectBuilder should generate the same version as moc");
         pmeta->revision = QMetaObjectPrivate::OutputRevision;
         pmeta->flags = d->flags;
         pmeta->className = 0;   // Class name is always the first string.
@@ -1228,7 +1228,7 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
 
         pmeta->methodCount = int(d->methods.size());
         pmeta->methodData = dataIndex;
-        dataIndex += 5 * int(d->methods.size());
+        dataIndex += QMetaObjectPrivate::IntsPerMethod * int(d->methods.size());
         if (hasRevisionedMethods)
             dataIndex += int(d->methods.size());
         paramsIndex = dataIndex;
@@ -1248,10 +1248,10 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
 
         pmeta->constructorCount = int(d->constructors.size());
         pmeta->constructorData = dataIndex;
-        dataIndex += 5 * int(d->constructors.size());
+        dataIndex += QMetaObjectPrivate::IntsPerMethod * int(d->constructors.size());
     } else {
         dataIndex += 2 * int(d->classInfoNames.size());
-        dataIndex += 5 * int(d->methods.size());
+        dataIndex += QMetaObjectPrivate::IntsPerMethod * int(d->methods.size());
         if (hasRevisionedMethods)
             dataIndex += int(d->methods.size());
         paramsIndex = dataIndex;
@@ -1262,7 +1262,7 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
         if (hasRevisionedProperties)
             dataIndex += int(d->properties.size());
         dataIndex += 5 * int(d->enumerators.size());
-        dataIndex += 5 * int(d->constructors.size());
+        dataIndex += QMetaObjectPrivate::IntsPerMethod * int(d->constructors.size());
     }
 
     // Allocate space for the enumerator key names and values.
@@ -1307,6 +1307,7 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
 
     // Output the methods in the class.
     Q_ASSERT(!buf || dataIndex == pmeta->methodData);
+    int parameterMetaTypesIndex = d->properties.size();
     for (const auto &method : d->methods) {
         int name = strings.enter(method.name());
         int argc = method.parameterCount();
@@ -1318,11 +1319,13 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
             data[dataIndex + 2] = paramsIndex;
             data[dataIndex + 3] = tag;
             data[dataIndex + 4] = attrs;
+            data[dataIndex + 5] = parameterMetaTypesIndex;
             if (method.methodType() == QMetaMethod::Signal)
                 pmeta->signalCount++;
         }
-        dataIndex += 5;
+        dataIndex += QMetaObjectPrivate::IntsPerMethod;
         paramsIndex += 1 + argc * 2;
+        parameterMetaTypesIndex += 1 + argc;
     }
     if (hasRevisionedMethods) {
         for (const auto &method : d->methods) {
@@ -1333,7 +1336,7 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
     }
 
     // Output the method parameters in the class.
-    Q_ASSERT(!buf || dataIndex == pmeta->methodData + int(d->methods.size()) * 5
+    Q_ASSERT(!buf || dataIndex == pmeta->methodData + int(d->methods.size()) * QMetaObjectPrivate::IntsPerMethod
              + (hasRevisionedMethods ? int(d->methods.size()) : 0));
     for (int x = 0; x < 2; ++x) {
         const std::vector<QMetaMethodBuilderPrivate> &methods = (x == 0) ? d->methods : d->constructors;
@@ -1446,9 +1449,11 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
             data[dataIndex + 2] = paramsIndex;
             data[dataIndex + 3] = tag;
             data[dataIndex + 4] = attrs;
+            data[dataIndex + 5] = parameterMetaTypesIndex;
         }
-        dataIndex += 5;
+        dataIndex += QMetaObjectPrivate::IntsPerMethod;
         paramsIndex += 1 + argc * 2;
+        parameterMetaTypesIndex += argc;
     }
 
     size += strings.blobSize();
@@ -1474,7 +1479,7 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
         size += sizeof(SuperData) * (d->relatedMetaObjects.size() + 1);
     }
 
-    if (d->properties.size() > 0) {
+    if (d->properties.size() > 0 || d->methods.size() > 0 || d->constructors.size() > 0) {
         ALIGN(size, QtPrivate::QMetaTypeInterface *);
         auto types = reinterpret_cast<QtPrivate::QMetaTypeInterface **>(buf + size);
         if (buf) {
@@ -1484,8 +1489,26 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
                 *types = reinterpret_cast<QtPrivate::QMetaTypeInterface *&>(mt);
                 types++;
             }
+            for (const auto &method: d->methods) {
+                QMetaType mt(QMetaType::type(method.returnType));
+                *types = reinterpret_cast<QtPrivate::QMetaTypeInterface *&>(mt);
+                types++;
+                for (const auto &parameterType: method.parameterTypes()) {
+                    QMetaType mt(QMetaType::type(parameterType));
+                    *types = reinterpret_cast<QtPrivate::QMetaTypeInterface *&>(mt);
+                    types++;
+                }
+            }
+            for (const auto &constructor: d->constructors) {
+                for (const auto &parameterType: constructor.parameterTypes()) {
+                    QMetaType mt(QMetaType::type(parameterType));
+                    *types = reinterpret_cast<QtPrivate::QMetaTypeInterface *&>(mt);
+                    types++;
+                }
+            }
         }
-        size += static_cast<int>(sizeof(QMetaType) * d->properties.size());
+        // parameterMetaTypesIndex is equal to the total number of metatypes
+        size += static_cast<int>(sizeof(QMetaType) * parameterMetaTypesIndex);
     }
 
     // Align the final size and return it.
diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index 05fe4450df..60192e4131 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -2796,6 +2796,35 @@ constexpr QMetaTypeInterface *qMetaTypeInterfaceForType()
     }
 }
 
+namespace detail {
+
+template <typename T, typename ODR_VIOLATION_PREVENTER>
+struct is_complete_helper {
+    template <typename U>
+    static auto check(U*)  -> std::integral_constant<bool, sizeof(U) != 0>;
+    static auto check(...) -> std::false_type;
+    using type = decltype(check(static_cast<T*>(nullptr)));
+};
+
+}
+
+template <typename T, typename ODR_VIOLATION_PREVENTER>
+struct is_complete : detail::is_complete_helper<T, ODR_VIOLATION_PREVENTER>::type {};
+
+template<typename Unique, typename T>
+constexpr QMetaTypeInterface *qTryMetaTypeInterfaceForType()
+{
+    using Ty = std::remove_cv_t<std::remove_reference_t<T>>;
+    using Tz = std::remove_pointer_t<Ty>;
+    if constexpr (!is_complete<Tz, Unique>::value) {
+        return nullptr;
+    } else if constexpr (std::is_same_v<Ty, void>) {
+        return nullptr;
+    } else {
+        return &QMetaTypeForType<Ty>::metaType;
+    }
+}
+
 } // namespace QtPrivate
 
 template<typename T>
@@ -2809,6 +2838,11 @@ QtPrivate::QMetaTypeInterface *const qt_metaTypeArray[] = {
     QtPrivate::qMetaTypeInterfaceForType<T>()...
 };
 
+template<typename Unique,typename... T>
+QtPrivate::QMetaTypeInterface *const qt_incomplete_metaTypeArray[] = {
+    QtPrivate::qTryMetaTypeInterfaceForType<Unique, T>()...
+};
+
 QT_END_NAMESPACE
 
 #endif // QMETATYPE_H
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index ad810c8b26..11ec534434 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -2562,7 +2562,7 @@ bool QObject::isSignalConnected(const QMetaMethod &signal) const
 
     Q_ASSERT_X(signal.mobj->cast(this) && signal.methodType() == QMetaMethod::Signal,
                "QObject::isSignalConnected" , "the parameter must be a signal member of the object");
-    uint signalIndex = (signal.handle - QMetaObjectPrivate::get(signal.mobj)->methodData)/5;
+    uint signalIndex = (signal.handle - QMetaObjectPrivate::get(signal.mobj)->methodData)/QMetaObjectPrivate::IntsPerMethod;
 
     if (signal.mobj->d.data[signal.handle + 4] & MethodCloned)
         signalIndex = QMetaObjectPrivate::originalClone(signal.mobj, signalIndex);
@@ -2610,7 +2610,7 @@ void QMetaObjectPrivate::memberIndexes(const QObject *obj,
         m = m->d.superdata;
     if (!m)
         return;
-    *signalIndex = *methodIndex = (member.handle - get(member.mobj)->methodData)/5;
+    *signalIndex = *methodIndex = (member.handle - get(member.mobj)->methodData)/QMetaObjectPrivate::IntsPerMethod;
 
     int signalOffset;
     int methodOffset;
diff --git a/src/dbus/qdbusconnection.cpp b/src/dbus/qdbusconnection.cpp
index 412b428bdc..409be08ff0 100644
--- a/src/dbus/qdbusconnection.cpp
+++ b/src/dbus/qdbusconnection.cpp
@@ -76,25 +76,6 @@ static void preventDllUnload();
 
 Q_GLOBAL_STATIC(QDBusConnectionManager, _q_manager)
 
-struct QDBusConnectionManager::ConnectionRequestData
-{
-    enum RequestType {
-        ConnectToStandardBus,
-        ConnectToBusByAddress,
-        ConnectToPeerByAddress
-    } type;
-
-    union {
-        QDBusConnection::BusType busType;
-        const QString *busAddress;
-    };
-    const QString *name;
-
-    QDBusConnectionPrivate *result;
-
-    bool suspendedDelivery;
-};
-
 QDBusConnectionPrivate *QDBusConnectionManager::busConnection(QDBusConnection::BusType type)
 {
     Q_STATIC_ASSERT(int(QDBusConnection::SessionBus) + int(QDBusConnection::SystemBus) == 1);
diff --git a/src/dbus/qdbusconnection.h b/src/dbus/qdbusconnection.h
index 1361fc5035..7304f2a8a2 100644
--- a/src/dbus/qdbusconnection.h
+++ b/src/dbus/qdbusconnection.h
@@ -77,6 +77,8 @@ class QDBusConnectionPrivate;
 class Q_DBUS_EXPORT QDBusConnection
 {
     Q_GADGET
+    Q_MOC_INCLUDE(<QtDBus/qdbuspendingcall.h>)
+
 public:
     enum BusType { SessionBus, SystemBus, ActivationBus };
     Q_ENUM(BusType)
diff --git a/src/dbus/qdbusconnection_p.h b/src/dbus/qdbusconnection_p.h
index 9bedbcc3a5..ce83270ac2 100644
--- a/src/dbus/qdbusconnection_p.h
+++ b/src/dbus/qdbusconnection_p.h
@@ -70,6 +70,7 @@
 
 #include <qdbusmessage.h>
 #include <qdbusservicewatcher.h>    // for the WatchMode enum
+Q_MOC_INCLUDE(<QtDBus/private/qdbuspendingcall_p.h>)
 
 #ifndef QT_NO_DBUS
 
diff --git a/src/dbus/qdbusconnectionmanager_p.h b/src/dbus/qdbusconnectionmanager_p.h
index ac49683cee..e080abca5e 100644
--- a/src/dbus/qdbusconnectionmanager_p.h
+++ b/src/dbus/qdbusconnectionmanager_p.h
@@ -100,6 +100,26 @@ private:
     QString senderName; // internal; will probably change
 };
 
+// TODO: move into own header and use Q_MOC_INCLUDE
+struct QDBusConnectionManager::ConnectionRequestData
+{
+    enum RequestType {
+        ConnectToStandardBus,
+        ConnectToBusByAddress,
+        ConnectToPeerByAddress
+    } type;
+
+    union {
+        QDBusConnection::BusType busType;
+        const QString *busAddress;
+    };
+    const QString *name;
+
+    QDBusConnectionPrivate *result;
+
+    bool suspendedDelivery;
+};
+
 QT_END_NAMESPACE
 
 #endif // QT_NO_DBUS
diff --git a/src/dbus/qdbuserror.h b/src/dbus/qdbuserror.h
index 50538b395b..8964f20415 100644
--- a/src/dbus/qdbuserror.h
+++ b/src/dbus/qdbuserror.h
@@ -141,6 +141,9 @@ Q_DBUS_EXPORT QDebug operator<<(QDebug, const QDBusError &);
 QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(QDBusError)
-
+#else
+QT_BEGIN_NAMESPACE
+class Q_DBUS_EXPORT QDBusError {}; // dummy class for moc
+QT_END_NAMESPACE
 #endif // QT_NO_DBUS
 #endif
diff --git a/src/dbus/qdbusmessage.h b/src/dbus/qdbusmessage.h
index 33a706abd2..cd8f74d8bc 100644
--- a/src/dbus/qdbusmessage.h
+++ b/src/dbus/qdbusmessage.h
@@ -139,6 +139,8 @@ QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(QDBusMessage)
 
+#else
+class Q_DBUS_EXPORT QDBusMessage {}; // dummy class for moc
 #endif // QT_NO_DBUS
 #endif
 
diff --git a/src/dbus/qdbusmetaobject.cpp b/src/dbus/qdbusmetaobject.cpp
index 01eb1aee3f..265d0eacfa 100644
--- a/src/dbus/qdbusmetaobject.cpp
+++ b/src/dbus/qdbusmetaobject.cpp
@@ -416,7 +416,7 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
             - methods.count(); // ditto
 
     QDBusMetaObjectPrivate *header = reinterpret_cast<QDBusMetaObjectPrivate *>(idata.data());
-    Q_STATIC_ASSERT_X(QMetaObjectPrivate::OutputRevision == 8, "QtDBus meta-object generator should generate the same version as moc");
+    Q_STATIC_ASSERT_X(QMetaObjectPrivate::OutputRevision == 9, "QtDBus meta-object generator should generate the same version as moc");
     header->revision = QMetaObjectPrivate::OutputRevision;
     header->className = 0;
     header->classInfoCount = 0;
@@ -424,7 +424,7 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
     header->methodCount = signals_.count() + methods.count();
     header->methodData = idata.size();
     header->propertyCount = properties.count();
-    header->propertyData = header->methodData + header->methodCount * 5 + methodParametersDataSize;
+    header->propertyData = header->methodData + header->methodCount * QMetaObjectPrivate::IntsPerMethod + methodParametersDataSize;
     header->enumeratorCount = 0;
     header->enumeratorData = 0;
     header->constructorCount = 0;
@@ -436,7 +436,7 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
     header->methodDBusData = header->propertyDBusData + header->propertyCount * intsPerProperty;
 
     int data_size = idata.size() +
-                    (header->methodCount * (5+intsPerMethod)) + methodParametersDataSize +
+                    (header->methodCount * (QMetaObjectPrivate::IntsPerMethod+intsPerMethod)) + methodParametersDataSize +
                     (header->propertyCount * (3+intsPerProperty));
     for (const Method &mm : qAsConst(signals_))
         data_size += 2 + mm.inputTypes.count() + mm.outputTypes.count();
@@ -447,12 +447,23 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
     QMetaStringTable strings(className.toLatin1());
 
     int offset = header->methodData;
-    int parametersOffset = offset + header->methodCount * 5;
+    int parametersOffset = offset + header->methodCount * QMetaObjectPrivate::IntsPerMethod;
     int signatureOffset = header->methodDBusData;
     int typeidOffset = header->methodDBusData + header->methodCount * intsPerMethod;
     idata[typeidOffset++] = 0;                           // eod
 
+    int totalMetaTypeCount = properties.count();
+    for (const auto& methodContainer: {signals_, methods}) {
+        for (const auto& method: methodContainer) {
+            int argc = method.inputTypes.size() + qMax(qsizetype(0), method.outputTypes.size() - 1);
+            totalMetaTypeCount += argc + 1;
+        }
+    }
+    QMetaType *metaTypes = new QMetaType[totalMetaTypeCount];
+    int propertyId = 0;
+
     // add each method:
+    int currentMethodMetaTypeOffset = properties.count();
     for (int x = 0; x < 2; ++x) {
         // Signals must be added before other methods, to match moc.
         QMap<QByteArray, Method> &map = (x == 0) ? signals_ : methods;
@@ -467,6 +478,7 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
             idata[offset++] = parametersOffset;
             idata[offset++] = strings.enter(mm.tag);
             idata[offset++] = mm.flags;
+            idata[offset++] = currentMethodMetaTypeOffset;
 
             // Parameter types
             for (int i = -1; i < argc; ++i) {
@@ -496,6 +508,7 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
                     typeInfo = IsUnresolvedType | strings.enter(typeName);
                 else
                     typeInfo = type;
+                metaTypes[currentMethodMetaTypeOffset++] = QMetaType (type);
                 idata[parametersOffset++] = typeInfo;
             }
             // Parameter names
@@ -514,16 +527,13 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
         }
     }
 
-    Q_ASSERT(offset == header->methodData + header->methodCount * 5);
+    Q_ASSERT(offset == header->methodData + header->methodCount * QMetaObjectPrivate::IntsPerMethod);
     Q_ASSERT(parametersOffset == header->propertyData);
     Q_ASSERT(signatureOffset == header->methodDBusData + header->methodCount * intsPerMethod);
     Q_ASSERT(typeidOffset == idata.size());
     offset += methodParametersDataSize;
     Q_ASSERT(offset == header->propertyData);
 
-    QMetaType *metaTypes = new QMetaType[properties.count()];
-    int propertyId = 0;
-
     // add each property
     signatureOffset = header->propertyDBusData;
     for (QMap<QByteArray, Property>::ConstIterator it = properties.constBegin();
diff --git a/src/gui/kernel/qoffscreensurface.h b/src/gui/kernel/qoffscreensurface.h
index 1b9e7c00ca..cfdcd758ec 100644
--- a/src/gui/kernel/qoffscreensurface.h
+++ b/src/gui/kernel/qoffscreensurface.h
@@ -43,6 +43,7 @@
 #include <QtGui/qtguiglobal.h>
 #include <QtCore/QObject>
 #include <QtGui/qsurface.h>
+Q_MOC_INCLUDE(<QScreen>)
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/gui/kernel/qplatformdialoghelper.h b/src/gui/kernel/qplatformdialoghelper.h
index ba800a696f..fa58177a2d 100644
--- a/src/gui/kernel/qplatformdialoghelper.h
+++ b/src/gui/kernel/qplatformdialoghelper.h
@@ -58,6 +58,8 @@
 #include <QtCore/QDir>
 #include <QtCore/QUrl>
 #include <QtGui/QRgb>
+Q_MOC_INCLUDE(<QFont>)
+Q_MOC_INCLUDE(<QColor>)
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/gui/kernel/qplatformnativeinterface.h b/src/gui/kernel/qplatformnativeinterface.h
index 95d6a03dbb..58c8f6b414 100644
--- a/src/gui/kernel/qplatformnativeinterface.h
+++ b/src/gui/kernel/qplatformnativeinterface.h
@@ -66,6 +66,7 @@ class QBackingStore;
 class Q_GUI_EXPORT QPlatformNativeInterface : public QObject
 {
     Q_OBJECT
+    Q_MOC_INCLUDE(<qpa/qplatformwindow.h>)
 public:
     virtual void *nativeResourceForIntegration(const QByteArray &resource);
     virtual void *nativeResourceForContext(const QByteArray &resource, QOpenGLContext *context);
diff --git a/src/gui/kernel/qplatformsystemtrayicon.h b/src/gui/kernel/qplatformsystemtrayicon.h
index 948a6c099d..bd74a2cc0a 100644
--- a/src/gui/kernel/qplatformsystemtrayicon.h
+++ b/src/gui/kernel/qplatformsystemtrayicon.h
@@ -57,6 +57,7 @@ class QRect;
 class Q_GUI_EXPORT QPlatformSystemTrayIcon : public QObject
 {
     Q_OBJECT
+    Q_MOC_INCLUDE(<qpa/qplatformscreen.h>)
 public:
     enum ActivationReason {
         Unknown,
diff --git a/src/gui/text/qtextdocument.h b/src/gui/text/qtextdocument.h
index b34175994d..175a34313c 100644
--- a/src/gui/text/qtextdocument.h
+++ b/src/gui/text/qtextdocument.h
@@ -47,6 +47,7 @@
 #include <QtCore/qvariant.h>
 #include <QtGui/qfont.h>
 #include <QtCore/qurl.h>
+Q_MOC_INCLUDE(<QtGui/qtextcursor.h>)
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/network/access/qhttpnetworkreply_p.h b/src/network/access/qhttpnetworkreply_p.h
index 59010606b9..f8b45a8adc 100644
--- a/src/network/access/qhttpnetworkreply_p.h
+++ b/src/network/access/qhttpnetworkreply_p.h
@@ -75,6 +75,11 @@ struct z_stream_s;
 #include <private/qringbuffer_p.h>
 #include <private/qbytedata_p.h>
 
+#ifndef QT_NO_NETWORKPROXY
+Q_MOC_INCLUDE(<QtNetwork/QNetworkProxy>)
+#endif
+Q_MOC_INCLUDE(<QtNetwork/QAuthenticator>)
+
 QT_REQUIRE_CONFIG(http);
 
 QT_BEGIN_NAMESPACE
diff --git a/src/network/access/qnetworkaccessbackend_p.h b/src/network/access/qnetworkaccessbackend_p.h
index 4b5422ce29..b18f30c287 100644
--- a/src/network/access/qnetworkaccessbackend_p.h
+++ b/src/network/access/qnetworkaccessbackend_p.h
@@ -54,10 +54,11 @@
 #include <QtNetwork/private/qtnetworkglobal_p.h>
 #include "qnetworkreplyimpl_p.h"
 #include "QtCore/qobject.h"
+Q_MOC_INCLUDE(<QAuthenticator>)
+Q_MOC_INCLUDE(<QtNetwork/QSslError>)
 
 QT_BEGIN_NAMESPACE
 
-class QAuthenticator;
 class QNetworkProxy;
 class QNetworkProxyQuery;
 class QNetworkRequest;
diff --git a/src/network/access/qnetworkaccessmanager.cpp b/src/network/access/qnetworkaccessmanager.cpp
index 1c5e29f8ac..351eca43df 100644
--- a/src/network/access/qnetworkaccessmanager.cpp
+++ b/src/network/access/qnetworkaccessmanager.cpp
@@ -1532,17 +1532,15 @@ void QNetworkAccessManagerPrivate::_q_replySslErrors(const QList<QSslError> &err
 #endif
 }
 
+#ifndef QT_NO_SSL
 void QNetworkAccessManagerPrivate::_q_replyPreSharedKeyAuthenticationRequired(QSslPreSharedKeyAuthenticator *authenticator)
 {
-#ifndef QT_NO_SSL
     Q_Q(QNetworkAccessManager);
     QNetworkReply *reply = qobject_cast<QNetworkReply *>(q->sender());
     if (reply)
     emit q->preSharedKeyAuthenticationRequired(reply, authenticator);
-#else
-    Q_UNUSED(authenticator);
-#endif
 }
+#endif
 
 QNetworkReply *QNetworkAccessManagerPrivate::postProcess(QNetworkReply *reply)
 {
diff --git a/src/network/access/qnetworkaccessmanager.h b/src/network/access/qnetworkaccessmanager.h
index 3a08c30a21..cbc9a0b660 100644
--- a/src/network/access/qnetworkaccessmanager.h
+++ b/src/network/access/qnetworkaccessmanager.h
@@ -49,6 +49,7 @@
 #include <QtNetwork/QSslConfiguration>
 #include <QtNetwork/QSslPreSharedKeyAuthenticator>
 #endif
+Q_MOC_INCLUDE(<QtNetwork/QSslError>)
 
 QT_BEGIN_NAMESPACE
 
@@ -178,7 +179,9 @@ private:
 #endif
     Q_DECLARE_PRIVATE(QNetworkAccessManager)
     Q_PRIVATE_SLOT(d_func(), void _q_replySslErrors(QList<QSslError>))
+#ifndef QT_NO_SSL
     Q_PRIVATE_SLOT(d_func(), void _q_replyPreSharedKeyAuthenticationRequired(QSslPreSharedKeyAuthenticator*))
+#endif
     Q_PRIVATE_SLOT(d_func(), void _q_onlineStateChanged(bool))
 };
 
diff --git a/src/network/access/qnetworkreplyhttpimpl_p.h b/src/network/access/qnetworkreplyhttpimpl_p.h
index a25adb668c..1dded7096d 100644
--- a/src/network/access/qnetworkreplyhttpimpl_p.h
+++ b/src/network/access/qnetworkreplyhttpimpl_p.h
@@ -71,6 +71,8 @@
 #include <QtNetwork/QSslConfiguration>
 #endif
 
+Q_MOC_INCLUDE(<QtNetwork/QAuthenticator>)
+
 QT_REQUIRE_CONFIG(http);
 
 QT_BEGIN_NAMESPACE
diff --git a/src/network/socket/qabstractsocket.h b/src/network/socket/qabstractsocket.h
index 46d25d5677..f76467b2a6 100644
--- a/src/network/socket/qabstractsocket.h
+++ b/src/network/socket/qabstractsocket.h
@@ -60,6 +60,8 @@ class QAuthenticator;
 class Q_NETWORK_EXPORT QAbstractSocket : public QIODevice
 {
     Q_OBJECT
+    Q_MOC_INCLUDE(<QtNetwork/qauthenticator.h>)
+
 public:
     enum SocketType {
         TcpSocket,
diff --git a/src/network/socket/qabstractsocketengine_p.h b/src/network/socket/qabstractsocketengine_p.h
index 112e7032d6..3d9ce96cb3 100644
--- a/src/network/socket/qabstractsocketengine_p.h
+++ b/src/network/socket/qabstractsocketengine_p.h
@@ -83,6 +83,7 @@ public:
 class Q_AUTOTEST_EXPORT QAbstractSocketEngine : public QObject
 {
     Q_OBJECT
+    Q_MOC_INCLUDE(<QtNetwork/qauthenticator.h>)
 public:
 
     static QAbstractSocketEngine *createSocketEngine(QAbstractSocket::SocketType socketType, const QNetworkProxy &, QObject *parent);
diff --git a/src/network/ssl/qdtls.h b/src/network/ssl/qdtls.h
index d057eadf19..fe1da23409 100644
--- a/src/network/ssl/qdtls.h
+++ b/src/network/ssl/qdtls.h
@@ -48,6 +48,8 @@
 #include <QtCore/qcryptographichash.h>
 #include <QtCore/qobject.h>
 
+Q_MOC_INCLUDE(<QtNetwork/QSslPreSharedKeyAuthenticator>)
+
 #ifndef Q_CLANG_QDOC
 QT_REQUIRE_CONFIG(dtls);
 #endif
diff --git a/src/network/ssl/qsslerror.h b/src/network/ssl/qsslerror.h
index 834684cd9d..6c4dabde96 100644
--- a/src/network/ssl/qsslerror.h
+++ b/src/network/ssl/qsslerror.h
@@ -131,7 +131,8 @@ class QDebug;
 Q_NETWORK_EXPORT QDebug operator<<(QDebug debug, const QSslError &error);
 Q_NETWORK_EXPORT QDebug operator<<(QDebug debug, const QSslError::SslError &error);
 #endif
-
+#else
+class Q_NETWORK_EXPORT QSslError {}; // dummy class so that moc has a complete type
 #endif // QT_NO_SSL
 
 QT_END_NAMESPACE
diff --git a/src/network/ssl/qsslsocket.h b/src/network/ssl/qsslsocket.h
index 7fd2b1cb08..238928e108 100644
--- a/src/network/ssl/qsslsocket.h
+++ b/src/network/ssl/qsslsocket.h
@@ -109,6 +109,7 @@ class QSslSocketPrivate;
 class Q_NETWORK_EXPORT QSslSocket : public QTcpSocket
 {
     Q_OBJECT
+    Q_MOC_INCLUDE(<QtNetwork/qsslpresharedkeyauthenticator.h>)
 public:
     enum SslMode {
         UnencryptedMode,
diff --git a/src/platformsupport/linuxaccessibility/application_p.h b/src/platformsupport/linuxaccessibility/application_p.h
index e980232bbf..6a8786dc07 100644
--- a/src/platformsupport/linuxaccessibility/application_p.h
+++ b/src/platformsupport/linuxaccessibility/application_p.h
@@ -56,6 +56,7 @@
 #include <QtCore/QQueue>
 #include <QtDBus/QDBusConnection>
 #include <QtGui/QAccessibleInterface>
+Q_MOC_INCLUDE(<QtDBus/QDBusMessage>)
 
 QT_REQUIRE_CONFIG(accessibility);
 
diff --git a/src/platformsupport/linuxaccessibility/dbusconnection_p.h b/src/platformsupport/linuxaccessibility/dbusconnection_p.h
index 860c18ca05..dde3bbb98f 100644
--- a/src/platformsupport/linuxaccessibility/dbusconnection_p.h
+++ b/src/platformsupport/linuxaccessibility/dbusconnection_p.h
@@ -55,6 +55,7 @@
 #include <QtCore/QString>
 #include <QtDBus/QDBusConnection>
 #include <QtDBus/QDBusVariant>
+Q_MOC_INCLUDE(<QtDBus/QDBusError>)
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuconnection_p.h b/src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuconnection_p.h
index f484795fbb..bbdaad1e89 100644
--- a/src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuconnection_p.h
+++ b/src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuconnection_p.h
@@ -56,6 +56,7 @@
 #include <QtDBus/QDBusVariant>
 
 #include <QtGui/qtgui-config.h>
+Q_MOC_INCLUDE(<QtDBus/QDBusError>)
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/plugins/generic/tuiotouch/qtuiohandler_p.h b/src/plugins/generic/tuiotouch/qtuiohandler_p.h
index 2e444f2a0d..eb68baa915 100644
--- a/src/plugins/generic/tuiotouch/qtuiohandler_p.h
+++ b/src/plugins/generic/tuiotouch/qtuiohandler_p.h
@@ -59,6 +59,7 @@ class QTuioToken;
 class QTuioHandler : public QObject
 {
     Q_OBJECT
+    Q_MOC_INCLUDE("qoscmessage_p.h")
 
 public:
     explicit QTuioHandler(const QString &specification);
diff --git a/src/plugins/platforminputcontexts/compose/qcomposeplatforminputcontext.h b/src/plugins/platforminputcontexts/compose/qcomposeplatforminputcontext.h
index b1de1b1094..29e862ecc1 100644
--- a/src/plugins/platforminputcontexts/compose/qcomposeplatforminputcontext.h
+++ b/src/plugins/platforminputcontexts/compose/qcomposeplatforminputcontext.h
@@ -45,6 +45,7 @@
 
 #include <xkbcommon/xkbcommon-compose.h>
 
+Q_DECLARE_OPAQUE_POINTER(xkb_context *)
 QT_BEGIN_NAMESPACE
 
 Q_DECLARE_LOGGING_CATEGORY(lcXkbCompose)
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 6b97eb710b..13a4b0301b 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -524,6 +524,6 @@ void QCocoaIntegration::focusWindowChanged(QWindow *focusWindow)
     setApplicationIcon(focusWindow->icon());
 }
 
-#include "moc_qcocoaintegration.cpp"
-
 QT_END_NAMESPACE
+
+#include "moc_qcocoaintegration.cpp"
diff --git a/src/plugins/platforms/cocoa/qcocoanativeinterface.h b/src/plugins/platforms/cocoa/qcocoanativeinterface.h
index 70d25e345a..c30297c8ca 100644
--- a/src/plugins/platforms/cocoa/qcocoanativeinterface.h
+++ b/src/plugins/platforms/cocoa/qcocoanativeinterface.h
@@ -44,6 +44,9 @@
 
 #include <qpa/qplatformnativeinterface.h>
 #include <QtGui/qpixmap.h>
+Q_MOC_INCLUDE(<QWindow>)
+Q_MOC_INCLUDE(<qpa/qplatformprintersupport.h>)
+Q_MOC_INCLUDE(<QPrintEngine>)
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/sql/models/qsqltablemodel.h b/src/sql/models/qsqltablemodel.h
index 97692c573e..90cddd7b61 100644
--- a/src/sql/models/qsqltablemodel.h
+++ b/src/sql/models/qsqltablemodel.h
@@ -58,6 +58,7 @@ class Q_SQL_EXPORT QSqlTableModel: public QSqlQueryModel
 {
     Q_OBJECT
     Q_DECLARE_PRIVATE(QSqlTableModel)
+    Q_MOC_INCLUDE(<QtSql/qsqlrecord.h>)
 
 public:
     enum EditStrategy {OnFieldChange, OnRowChange, OnManualSubmit};
diff --git a/src/tools/moc/generator.cpp b/src/tools/moc/generator.cpp
index 976d49ad20..849e25b76d 100644
--- a/src/tools/moc/generator.cpp
+++ b/src/tools/moc/generator.cpp
@@ -80,9 +80,9 @@ QT_FOR_EACH_STATIC_TYPE(RETURN_METATYPENAME_STRING)
     return nullptr;
  }
 
-Generator::Generator(ClassDef *classDef, const QVector<QByteArray> &metaTypes, const QHash<QByteArray, QByteArray> &knownQObjectClasses, const QHash<QByteArray, QByteArray> &knownGadgets, FILE *outfile)
+Generator::Generator(ClassDef *classDef, const QVector<QByteArray> &metaTypes, const QHash<QByteArray, QByteArray> &knownQObjectClasses, const QHash<QByteArray, QByteArray> &knownGadgets, FILE *outfile, bool requireCompleteTypes)
     : out(outfile), cdef(classDef), metaTypes(metaTypes), knownQObjectClasses(knownQObjectClasses)
-    , knownGadgets(knownGadgets)
+    , knownGadgets(knownGadgets), requireCompleteTypes(requireCompleteTypes)
 {
     if (cdef->superclassList.size())
         purestSuperClass = cdef->superclassList.constFirst().first;
@@ -350,7 +350,7 @@ void Generator::generateCode()
 
     int methodCount = cdef->signalList.count() + cdef->slotList.count() + cdef->methodList.count();
     fprintf(out, "    %4d, %4d, // methods\n", methodCount, methodCount ? index : 0);
-    index += methodCount * 5;
+    index += methodCount * QMetaObjectPrivate::IntsPerMethod;
     if (cdef->revisionedMethods)
         index += methodCount;
     int paramsIndex = index;
@@ -391,20 +391,22 @@ void Generator::generateCode()
 //
     generateClassInfos();
 
+    int initialMetaTypeOffset = cdef->propertyList.count();
+
 //
 // Build signals array first, otherwise the signal indices would be wrong
 //
-    generateFunctions(cdef->signalList, "signal", MethodSignal, paramsIndex);
+    generateFunctions(cdef->signalList, "signal", MethodSignal, paramsIndex, initialMetaTypeOffset);
 
 //
 // Build slots array
 //
-    generateFunctions(cdef->slotList, "slot", MethodSlot, paramsIndex);
+    generateFunctions(cdef->slotList, "slot", MethodSlot, paramsIndex, initialMetaTypeOffset);
 
 //
 // Build method array
 //
-    generateFunctions(cdef->methodList, "method", MethodMethod, paramsIndex);
+    generateFunctions(cdef->methodList, "method", MethodMethod, paramsIndex, initialMetaTypeOffset);
 
 //
 // Build method version arrays
@@ -438,7 +440,7 @@ void Generator::generateCode()
 // Build constructors array
 //
     if (isConstructible)
-        generateFunctions(cdef->constructorList, "constructor", MethodConstructor, paramsIndex);
+        generateFunctions(cdef->constructorList, "constructor", MethodConstructor, paramsIndex, initialMetaTypeOffset);
 
 //
 // Terminate data array
@@ -553,14 +555,48 @@ void Generator::generateCode()
     else
         fprintf(out, "    qt_meta_extradata_%s,\n", qualifiedClassNameIdentifier.constData());
 
-    if (cdef->propertyList.isEmpty()) {
+    bool constructorListContainsArgument = false;
+    for (int i = 0; i< cdef->constructorList.count(); ++i) {
+        const FunctionDef& fdef = cdef->constructorList.at(i);
+        if (fdef.arguments.count()) {
+            constructorListContainsArgument = true;
+            break;
+        }
+    }
+    if (cdef->propertyList.isEmpty() && cdef->signalList.isEmpty() && cdef->slotList.isEmpty() && cdef->methodList.isEmpty() && !constructorListContainsArgument) {
         fprintf(out, "    nullptr,\n");
     } else {
-        fprintf(out, "qt_metaTypeArray<\n");
+        bool needsComma = false;
+        if (!requireCompleteTypes) {
+            fprintf(out, "qt_incomplete_metaTypeArray<qt_meta_stringdata_%s_t\n", qualifiedClassNameIdentifier.constData());
+            needsComma = true;
+        } else {
+            fprintf(out, "qt_metaTypeArray<\n");
+        }
         for (int i = 0; i < cdef->propertyList.count(); ++i) {
             const PropertyDef &p = cdef->propertyList.at(i);
-            fprintf(out, "%s%s", i == 0 ? "" : ", ", p.type.data());
+            fprintf(out, "%s%s", needsComma ? ", " : "", p.type.data());
+            needsComma = true;
+        }
+        for (const QVector<FunctionDef> &methodContainer: {cdef->signalList, cdef->slotList, cdef->methodList} ) {
+            for (int i = 0; i< methodContainer.count(); ++i) {
+                const FunctionDef& fdef = methodContainer.at(i);
+                fprintf(out, "%s%s", needsComma ? ", " : "", fdef.type.name.data());
+                needsComma = true;
+                for (const auto &argument: fdef.arguments) {
+                    fprintf(out, ", %s", argument.type.name.data());
+                }
+            }
+            fprintf(out, "\n");
+        }
+        for (int i = 0; i< cdef->constructorList.count(); ++i) {
+            const FunctionDef& fdef = cdef->constructorList.at(i);
+            for (const auto &argument: fdef.arguments) {
+                fprintf(out, "%s%s", needsComma ? ", " : "", argument.type.name.data());
+                needsComma = true;
+            }
         }
+        fprintf(out, "\n");
         fprintf(out, ">,\n");
     }
 
@@ -572,6 +608,7 @@ void Generator::generateCode()
     fprintf(out, "\nconst QMetaObject *%s::metaObject() const\n{\n    return QObject::d_ptr->metaObject ? QObject::d_ptr->dynamicMetaObject() : &staticMetaObject;\n}\n",
             cdef->qualified.constData());
 
+
 //
 // Generate smart cast function
 //
@@ -688,11 +725,11 @@ void Generator::registerByteArrayVector(const QVector<QByteArray> &list)
         strreg(ba);
 }
 
-void Generator::generateFunctions(const QVector<FunctionDef>& list, const char *functype, int type, int &paramsIndex)
+void Generator::generateFunctions(const QVector<FunctionDef>& list, const char *functype, int type, int &paramsIndex, int &initialMetatypeOffset)
 {
     if (list.isEmpty())
         return;
-    fprintf(out, "\n // %ss: name, argc, parameters, tag, flags\n", functype);
+    fprintf(out, "\n // %ss: name, argc, parameters, tag, flags, initial metatype offsets\n", functype);
 
     for (int i = 0; i < list.count(); ++i) {
         const FunctionDef &f = list.at(i);
@@ -727,10 +764,12 @@ void Generator::generateFunctions(const QVector<FunctionDef>& list, const char *
         }
 
         int argc = f.arguments.count();
-        fprintf(out, "    %4d, %4d, %4d, %4d, 0x%02x /* %s */,\n",
-            stridx(f.name), argc, paramsIndex, stridx(f.tag), flags, comment.constData());
+        fprintf(out, "    %4d, %4d, %4d, %4d, 0x%02x, %4d /* %s */,\n",
+            stridx(f.name), argc, paramsIndex, stridx(f.tag), flags, initialMetatypeOffset, comment.constData());
 
         paramsIndex += 1 + argc * 2;
+        // constructors don't have a return type
+        initialMetatypeOffset += (f.isConstructor ? 0 : 1) + argc;
     }
 }
 
diff --git a/src/tools/moc/generator.h b/src/tools/moc/generator.h
index e92b9d1208..f3d3b40349 100644
--- a/src/tools/moc/generator.h
+++ b/src/tools/moc/generator.h
@@ -39,7 +39,7 @@ class Generator
     ClassDef *cdef;
     QVector<uint> meta_data;
 public:
-    Generator(ClassDef *classDef, const QVector<QByteArray> &metaTypes, const QHash<QByteArray, QByteArray> &knownQObjectClasses, const QHash<QByteArray, QByteArray> &knownGadgets, FILE *outfile = nullptr);
+    Generator(ClassDef *classDef, const QVector<QByteArray> &metaTypes, const QHash<QByteArray, QByteArray> &knownQObjectClasses, const QHash<QByteArray, QByteArray> &knownGadgets, FILE *outfile = nullptr, bool requireCompleteTypes = false);
     void generateCode();
 private:
     bool registerableMetaType(const QByteArray &propertyType);
@@ -47,7 +47,7 @@ private:
     void generateClassInfos();
     void registerFunctionStrings(const QVector<FunctionDef> &list);
     void registerByteArrayVector(const QVector<QByteArray> &list);
-    void generateFunctions(const QVector<FunctionDef> &list, const char *functype, int type, int &paramsIndex);
+    void generateFunctions(const QVector<FunctionDef> &list, const char *functype, int type, int &paramsIndex, int &initialMetatypeOffset);
     void generateFunctionRevisions(const QVector<FunctionDef> &list, const char *functype);
     void generateFunctionParameters(const QVector<FunctionDef> &list, const char *functype);
     void generateTypeInfo(const QByteArray &typeName, bool allowEmptyName = false);
@@ -70,6 +70,7 @@ private:
     QVector<QByteArray> metaTypes;
     QHash<QByteArray, QByteArray> knownQObjectClasses;
     QHash<QByteArray, QByteArray> knownGadgets;
+    bool requireCompleteTypes;
 };
 
 QT_END_NAMESPACE
diff --git a/src/tools/moc/main.cpp b/src/tools/moc/main.cpp
index b8c2d7f594..61f3666b16 100644
--- a/src/tools/moc/main.cpp
+++ b/src/tools/moc/main.cpp
@@ -367,6 +367,10 @@ int runMoc(int argc, char **argv)
     depFileRuleNameOption.setValueName(QStringLiteral("rule name"));
     parser.addOption(depFileRuleNameOption);
 
+    QCommandLineOption requireCompleTypesOption(QStringLiteral("require-complete-types"));
+    requireCompleTypesOption.setDescription(QStringLiteral("Require complete types for better performance"));
+    parser.addOption(requireCompleTypesOption);
+
     parser.addPositionalArgument(QStringLiteral("[header-file]"),
             QStringLiteral("Header file to read from, otherwise stdin."));
     parser.addPositionalArgument(QStringLiteral("[@option-file]"),
@@ -398,6 +402,8 @@ int runMoc(int argc, char **argv)
         moc.noInclude = true;
         autoInclude = false;
     }
+    if (parser.isSet(requireCompleTypesOption))
+        moc.requireCompleteTypes = true;
     if (!ignoreConflictingOptions) {
         if (parser.isSet(forceIncludeOption)) {
             moc.noInclude = false;
diff --git a/src/tools/moc/moc.cpp b/src/tools/moc/moc.cpp
index f04f4c5d0d..0ffbe7bb13 100644
--- a/src/tools/moc/moc.cpp
+++ b/src/tools/moc/moc.cpp
@@ -1125,7 +1125,7 @@ void Moc::generate(FILE *out, FILE *jsonOutput)
 
     fputs("", out);
     for (i = 0; i < classList.size(); ++i) {
-        Generator generator(&classList[i], metaTypes, knownQObjectClasses, knownGadgets, out);
+        Generator generator(&classList[i], metaTypes, knownQObjectClasses, knownGadgets, out, requireCompleteTypes);
         generator.generateCode();
     }
     fputs("", out);
diff --git a/src/tools/moc/moc.h b/src/tools/moc/moc.h
index 486d033049..84ddf47a89 100644
--- a/src/tools/moc/moc.h
+++ b/src/tools/moc/moc.h
@@ -224,13 +224,14 @@ class Moc : public Parser
 {
 public:
     Moc()
-        : noInclude(false), mustIncludeQPluginH(false)
+        : noInclude(false), mustIncludeQPluginH(false), requireCompleteTypes(false)
         {}
 
     QByteArray filename;
 
     bool noInclude;
     bool mustIncludeQPluginH;
+    bool requireCompleteTypes;
     QByteArray includePath;
     QVector<QByteArray> includeFiles;
     QVector<ClassDef> classList;