QObject: allow connecting to functors with a receiver object

Up to now, it was only possible to connect to functors in a direct
way, without being capable of using Qt::ConnectionType. This patch
allows for specifying a receiver for Functors and function
pointers, hence making it possible to specify effectively the
connection type.

To do this properly, it was needed to add an enum in FunctionPointer
representing whether the considered function is a member function
or not, to reduce ambiguity upon overloaded calls.

Moreover, now senders are checked for the existence of a slot obj
as well. This way, should the context be freed, the slot obj and
the functor contained in it will be freed as well.

On a side note, connecting to a static slot
(like QCoreApplication::quit) specifying the receiver object is
now compiling.

Change-Id: I46474099413b1dc6ca4db9934191d469baeef070
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

1 files changed, 26 insertions, 26 deletions

diff --git a/src/corelib/kernel/qobjectdefs_impl.h b/src/corelib/kernel/qobjectdefs_impl.h
index d775ef1b65..fb6601f21b 100644
--- a/src/corelib/kernel/qobjectdefs_impl.h
+++ b/src/corelib/kernel/qobjectdefs_impl.h
@@ -129,7 +129,7 @@ namespace QtPrivate {
        its call function is the same as the FunctionPointer::call function.
      */
 #ifndef Q_COMPILER_VARIADIC_TEMPLATES
-    template<typename Func> struct FunctionPointer { enum {ArgumentCount = -1}; };
+    template<typename Func> struct FunctionPointer { enum {ArgumentCount = -1, IsPointerToMemberFunction = false}; };
     //Pointers to member functions
     template<class Obj, typename Ret> struct FunctionPointer<Ret (Obj::*) ()>
     {
@@ -137,7 +137,7 @@ namespace QtPrivate {
         typedef void Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) ();
-        enum {ArgumentCount = 0};
+        enum {ArgumentCount = 0, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) { (o->*f)(), ApplyReturnValue<R>(arg[0]); }
     };
@@ -147,7 +147,7 @@ namespace QtPrivate {
         typedef List<Arg1, void> Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1);
-        enum {ArgumentCount = 1};
+        enum {ArgumentCount = 1, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)((*reinterpret_cast<typename RemoveRef<typename Args::Car>::Type *>(arg[1]))), ApplyReturnValue<R>(arg[0]);
@@ -159,7 +159,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, void> >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2);
-        enum {ArgumentCount = 2};
+        enum {ArgumentCount = 2, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -172,7 +172,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, void> > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2, Arg3);
-        enum {ArgumentCount = 3};
+        enum {ArgumentCount = 3, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -186,7 +186,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, List<Arg4, void> > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2, Arg3, Arg4);
-        enum {ArgumentCount = 4};
+        enum {ArgumentCount = 4, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -201,7 +201,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, List<Arg4, List<Arg5, void> > > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2, Arg3, Arg4, Arg5);
-        enum {ArgumentCount = 5};
+        enum {ArgumentCount = 5, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -218,7 +218,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, List<Arg4, List<Arg5, List<Arg6, void> > > > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2, Arg3, Arg4, Arg5, Arg6);
-        enum {ArgumentCount = 6};
+        enum {ArgumentCount = 6, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -237,7 +237,7 @@ namespace QtPrivate {
         typedef void Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) () const;
-        enum {ArgumentCount = 0};
+        enum {ArgumentCount = 0, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) { (o->*f)(), ApplyReturnValue<R>(arg[0]); }
     };
@@ -247,7 +247,7 @@ namespace QtPrivate {
         typedef List<Arg1, void> Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1) const;
-        enum {ArgumentCount = 1};
+        enum {ArgumentCount = 1, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)((*reinterpret_cast<typename RemoveRef<typename Args::Car>::Type *>(arg[1]))), ApplyReturnValue<R>(arg[0]);
@@ -259,7 +259,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, void> >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2) const;
-        enum {ArgumentCount = 2};
+        enum {ArgumentCount = 2, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -272,7 +272,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, void> > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2, Arg3) const;
-        enum {ArgumentCount = 3};
+        enum {ArgumentCount = 3, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -286,7 +286,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, List<Arg4, void> > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2, Arg3, Arg4) const;
-        enum {ArgumentCount = 4};
+        enum {ArgumentCount = 4, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -301,7 +301,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, List<Arg4, List<Arg5, void> > > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2, Arg3, Arg4, Arg5) const;
-        enum {ArgumentCount = 5};
+        enum {ArgumentCount = 5, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -318,7 +318,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, List<Arg4, List<Arg5, List<Arg6, void> > > > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Arg1, Arg2, Arg3, Arg4, Arg5, Arg6) const;
-        enum {ArgumentCount = 6};
+        enum {ArgumentCount = 6, IsPointerToMemberFunction = true};
         template <typename Args, typename R>
         static void call(Function f, Obj *o, void **arg) {
             (o->*f)( *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -336,7 +336,7 @@ namespace QtPrivate {
         typedef void Arguments;
         typedef Ret (*Function) ();
         typedef Ret ReturnType;
-        enum {ArgumentCount = 0};
+        enum {ArgumentCount = 0, IsPointerToMemberFunction = false};
         template <typename Args, typename R>
         static void call(Function f, void *, void **arg) { f(), ApplyReturnValue<R>(arg[0]); }
     };
@@ -345,7 +345,7 @@ namespace QtPrivate {
         typedef List<Arg1, void> Arguments;
         typedef Ret ReturnType;
         typedef Ret (*Function) (Arg1);
-        enum {ArgumentCount = 1};
+        enum {ArgumentCount = 1, IsPointerToMemberFunction = false};
         template <typename Args, typename R>
         static void call(Function f, void *, void **arg)
         { f(*reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1])), ApplyReturnValue<R>(arg[0]); }
@@ -355,7 +355,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, void> > Arguments;
         typedef Ret ReturnType;
         typedef Ret (*Function) (Arg1, Arg2);
-        enum {ArgumentCount = 2};
+        enum {ArgumentCount = 2, IsPointerToMemberFunction = false};
         template <typename Args, typename R>
         static void call(Function f, void *, void **arg) {
             f(*reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -366,7 +366,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, void> > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (*Function) (Arg1, Arg2, Arg3);
-        enum {ArgumentCount = 3};
+        enum {ArgumentCount = 3, IsPointerToMemberFunction = false};
         template <typename Args, typename R>
         static void call(Function f, void *, void **arg) {
             f(       *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -379,7 +379,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, List<Arg4, void> > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (*Function) (Arg1, Arg2, Arg3, Arg4);
-        enum {ArgumentCount = 4};
+        enum {ArgumentCount = 4, IsPointerToMemberFunction = false};
         template <typename Args, typename R>
         static void call(Function f, void *, void **arg) {
             f(       *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -394,7 +394,7 @@ namespace QtPrivate {
         List<Arg4, List<Arg5, void > > > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (*Function) (Arg1, Arg2, Arg3, Arg4, Arg5);
-        enum {ArgumentCount = 5};
+        enum {ArgumentCount = 5, IsPointerToMemberFunction = false};
         template <typename Args, typename R>
         static void call(Function f, void *, void **arg) {
             f(       *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -409,7 +409,7 @@ namespace QtPrivate {
         typedef List<Arg1, List<Arg2, List<Arg3, List<Arg4, List<Arg5, List<Arg6, void> > > > > >  Arguments;
         typedef Ret ReturnType;
         typedef Ret (*Function) (Arg1, Arg2, Arg3, Arg4, Arg5, Arg6);
-        enum {ArgumentCount = 6};
+        enum {ArgumentCount = 6, IsPointerToMemberFunction = false};
         template <typename Args, typename R>
         static void call(Function f, void *, void **arg) {
             f(       *reinterpret_cast<typename RemoveRef<typename List_Select<Args, 0>::Value>::Type *>(arg[1]),
@@ -493,7 +493,7 @@ namespace QtPrivate {
     template <int N> struct Indexes
     { typedef typename IndexesAppend<typename Indexes<N - 1>::Value, N - 1>::Value Value; };
     template <> struct Indexes<0> { typedef IndexesList<> Value; };
-    template<typename Func> struct FunctionPointer { enum {ArgumentCount = -1}; };
+    template<typename Func> struct FunctionPointer { enum {ArgumentCount = -1, IsPointerToMemberFunction = false}; };
 
     template <typename, typename, typename, typename> struct FunctorCall;
     template <int... II, typename... SignalArgs, typename R, typename Function>
@@ -521,7 +521,7 @@ namespace QtPrivate {
         typedef List<Args...>  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Args...);
-        enum {ArgumentCount = sizeof...(Args)};
+        enum {ArgumentCount = sizeof...(Args), IsPointerToMemberFunction = true};
         template <typename SignalArgs, typename R>
         static void call(Function f, Obj *o, void **arg) {
             FunctorCall<typename Indexes<ArgumentCount>::Value, SignalArgs, R, Function>::call(f, o, arg);
@@ -533,7 +533,7 @@ namespace QtPrivate {
         typedef List<Args...>  Arguments;
         typedef Ret ReturnType;
         typedef Ret (Obj::*Function) (Args...) const;
-        enum {ArgumentCount = sizeof...(Args)};
+        enum {ArgumentCount = sizeof...(Args), IsPointerToMemberFunction = true};
         template <typename SignalArgs, typename R>
         static void call(Function f, Obj *o, void **arg) {
             FunctorCall<typename Indexes<ArgumentCount>::Value, SignalArgs, R, Function>::call(f, o, arg);
@@ -545,7 +545,7 @@ namespace QtPrivate {
         typedef List<Args...> Arguments;
         typedef Ret ReturnType;
         typedef Ret (*Function) (Args...);
-        enum {ArgumentCount = sizeof...(Args)};
+        enum {ArgumentCount = sizeof...(Args), IsPointerToMemberFunction = false};
         template <typename SignalArgs, typename R>
         static void call(Function f, void *, void **arg) {
             FunctorCall<typename Indexes<ArgumentCount>::Value, SignalArgs, R, Function>::call(f, arg);