[glib] gsignal: improve warning output

[Ryan Lortie <ryanl src gnome org>]

commit f5d40bd8138991287bbdc2e249bd35cf82caf123
Author: Ryan Lortie <desrt desrt ca>
Date:   Thu Feb 21 11:25:26 2013 +0000

    gsignal: improve warning output
    
    When looking up signals by name (to connect, for example) and the named
    signal cannot be found on the given instance, report the type of the
    instance.
    
    This is quite a lot more useful as a diagnostic message than only a
    memory address.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=694350

 gobject/gsignal.c |   26 ++++++++++++++++++--------
 1 files changed, 18 insertions(+), 8 deletions(-)
---
diff --git a/gobject/gsignal.c b/gobject/gsignal.c
index e2a8439..f5942ab 100644
--- a/gobject/gsignal.c
+++ b/gobject/gsignal.c
@@ -1157,7 +1157,8 @@ g_signal_stop_emission_by_name (gpointer     instance,
       if (detail && !(node->flags & G_SIGNAL_DETAILED))
        g_warning ("%s: signal `%s' does not support details", G_STRLOC, detailed_signal);
       else if (!g_type_is_a (itype, node->itype))
-       g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance);
+        g_warning ("%s: signal `%s' is invalid for instance `%p' of type `%s'",
+                   G_STRLOC, detailed_signal, instance, g_type_name (itype));
       else
        {
          Emission *emission_list = node->flags & G_SIGNAL_NO_RECURSE ? g_restart_emissions : 
g_recursive_emissions;
@@ -1177,7 +1178,8 @@ g_signal_stop_emission_by_name (gpointer     instance,
        }
     }
   else
-    g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance);
+    g_warning ("%s: signal `%s' is invalid for instance `%p' of type `%s'",
+               G_STRLOC, detailed_signal, instance, g_type_name (itype));
   SIGNAL_UNLOCK ();
 }
 
@@ -2348,7 +2350,8 @@ g_signal_connect_closure (gpointer     instance,
       if (detail && !(node->flags & G_SIGNAL_DETAILED))
        g_warning ("%s: signal `%s' does not support details", G_STRLOC, detailed_signal);
       else if (!g_type_is_a (itype, node->itype))
-       g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance);
+        g_warning ("%s: signal `%s' is invalid for instance `%p' of type `%s'",
+                   G_STRLOC, detailed_signal, instance, g_type_name (itype));
       else
        {
          Handler *handler = handler_new (after);
@@ -2368,7 +2371,8 @@ g_signal_connect_closure (gpointer     instance,
        }
     }
   else
-    g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance);
+    g_warning ("%s: signal `%s' is invalid for instance `%p' of type `%s'",
+               G_STRLOC, detailed_signal, instance, g_type_name (itype));
   SIGNAL_UNLOCK ();
 
   return handler_seq_no;
@@ -2447,7 +2451,8 @@ g_signal_connect_data (gpointer       instance,
       if (detail && !(node->flags & G_SIGNAL_DETAILED))
        g_warning ("%s: signal `%s' does not support details", G_STRLOC, detailed_signal);
       else if (!g_type_is_a (itype, node->itype))
-       g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance);
+        g_warning ("%s: signal `%s' is invalid for instance `%p' of type `%s'",
+                   G_STRLOC, detailed_signal, instance, g_type_name (itype));
       else
        {
          Handler *handler = handler_new (after);
@@ -2466,7 +2471,8 @@ g_signal_connect_data (gpointer       instance,
         }
     }
   else
-    g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance);
+    g_warning ("%s: signal `%s' is invalid for instance `%p' of type `%s'",
+               G_STRLOC, detailed_signal, instance, g_type_name (itype));
   SIGNAL_UNLOCK ();
 
   return handler_seq_no;
@@ -3399,12 +3405,15 @@ g_signal_emit_by_name (gpointer     instance,
 {
   GQuark detail = 0;
   guint signal_id;
+  GType itype;
 
   g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance));
   g_return_if_fail (detailed_signal != NULL);
 
+  itype = G_TYPE_FROM_INSTANCE (instance);
+
   SIGNAL_LOCK ();
-  signal_id = signal_parse_name (detailed_signal, G_TYPE_FROM_INSTANCE (instance), &detail, TRUE);
+  signal_id = signal_parse_name (detailed_signal, itype, &detail, TRUE);
   SIGNAL_UNLOCK ();
 
   if (signal_id)
@@ -3416,7 +3425,8 @@ g_signal_emit_by_name (gpointer     instance,
       va_end (var_args);
     }
   else
-    g_warning ("%s: signal name `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance);
+    g_warning ("%s: signal name `%s' is invalid for instance `%p' of type `%s'",
+               G_STRLOC, detailed_signal, instance, g_type_name (itype));
 }
 
 static gboolean