make the signal callback signature check fully compile-time

This will fail building until all positives fixed.

Author: dterrahe

src/gui/gtk.c

@@ -4666,24 +4666,6 @@ void dt_gui_dialog_restore_size(GtkDialog *dialog, const char *conf)
   g_signal_connect(dialog, "configure-event", G_CALLBACK(_resize_dialog), (gpointer)conf);
 }
 
-gulong dt_signal_connect_data_with_caller(gpointer instance,
-                                          const gchar *detailed_signal,
-                                          GCallback c_handler,
-                                          gpointer data,
-                                          GClosureNotify destroy_data,
-                                          GConnectFlags connect_flags,
-                                          gboolean gboolean_return,
-                                          const char *file,
-                                          const int line)
-{
-  GSignalQuery type_query = {};
-  if(!g_str_has_prefix(detailed_signal, "notify::"))
-    g_signal_query(g_signal_lookup(detailed_signal, G_OBJECT_TYPE(instance)), &type_query);
-  if((type_query.return_type  == G_TYPE_BOOLEAN) ^ gboolean_return)
-    dt_print(DT_DEBUG_ALWAYS, "connecting signal %s to handler with wrong return type %s:%d", detailed_signal, file, line);
-  return g_signal_connect_data(instance, detailed_signal, c_handler, data, destroy_data, connect_flags);
-}
-
 // clang-format off
 // modelines: These editor modelines have been set for all relevant files by tools/update_modelines.py
 // vim: shiftwidth=2 expandtab tabstop=2 cindent

src/gui/gtk.h

@@ -639,26 +639,37 @@ void dt_gui_dialog_restore_size(GtkDialog *dialog, const char *conf);
 dt_gui_session_type_t dt_gui_get_session_type(void);
 
 #if !defined(__cplusplus)
-gulong dt_signal_connect_data_with_caller(gpointer instance,
-                                          const gchar *detailed_signal,
-                                          GCallback c_handler,
-                                          gpointer data,
-                                          GClosureNotify destroy_data,
-                                          GConnectFlags connect_flags,
-                                          gboolean gboolean_return,
-                                          const char *file,
-                                          const int line);
 #undef G_CALLBACK
 static inline GCallback G_CALLBACK(void *f) { return (GCallback)f; } // as a macro it gets expanded before reaching here
 #define DISABLINGPREFIXG_CALLBACK
+#define BOOLSIGNAL(s, signal) || !strcmp(s, #signal)
+#undef _Static_assert
 #undef  g_signal_connect
-#define g_signal_connect(instance, signal, c_handler, user_data) \
-  dt_signal_connect_data_with_caller((instance), (signal), (GCallback)(c_handler), (user_data), NULL, (GConnectFlags) 0, \
-                                     _Generic((DISABLINGPREFIX##c_handler), \
-                                              gboolean(*)() : TRUE, \
-                                              void(*)() : FALSE, \
-                                              gpointer: FALSE), \
-                                     __FILE__, __LINE__)
+#define g_signal_connect(instance, signal, c_handler, user_data) do { \
+  _Static_assert((FALSE \
+    BOOLSIGNAL(signal, button-press-event) \
+    BOOLSIGNAL(signal, button-release-event) \
+    BOOLSIGNAL(signal, motion-notify-event) \
+    BOOLSIGNAL(signal, enter-notify-event) \
+    BOOLSIGNAL(signal, leave-notify-event) \
+    BOOLSIGNAL(signal, key-press-event) \
+    BOOLSIGNAL(signal, configure-event) \
+    BOOLSIGNAL(signal, focus-out-event) \
+    BOOLSIGNAL(signal, focus-in-event) \
+    BOOLSIGNAL(signal, scroll-event) \
+    BOOLSIGNAL(signal, delete-event) \
+    BOOLSIGNAL(signal, drag-motion) \
+    BOOLSIGNAL(signal, drag-failed) \
+    BOOLSIGNAL(signal, drag-drop) \
+    BOOLSIGNAL(signal, event) \
+    BOOLSIGNAL(signal, focus) \
+    BOOLSIGNAL(signal, draw) \
+    BOOLSIGNAL(signal, popup-menu) \
+    BOOLSIGNAL(signal, query-tooltip) \
+    BOOLSIGNAL(signal, match-selected) \
+    ) == _Generic((DISABLINGPREFIX##c_handler), gboolean(*)(): TRUE, default: FALSE), \
+    "signal " signal " return type does not match specified handler " #c_handler); \
+  g_signal_connect_data((instance), (signal), (GCallback)(c_handler), (user_data), NULL, (GConnectFlags) 0); } while(0)
 #endif // __cplusplus
 
 G_END_DECLS

src/lua/widget/widget.c

@@ -107,7 +107,7 @@ static int get_widget_params(lua_State *L)
   lua_pushnil(L); /* first key */
   while(lua_next(L, -2) != 0)
   {
-    g_signal_connect(widget->widget, lua_tostring(L,-2), G_CALLBACK(lua_touserdata(L,-1)), widget);
+    g_signal_connect_data(widget->widget, lua_tostring(L,-2), G_CALLBACK(lua_touserdata(L,-1)), widget, NULL, 0);
     lua_pop(L,1);
   }
   lua_pop(L,1);