builder: Warn about dropped objects

Use GTK_DEBUG=builder-objects to make GtkBuilder warn
if a named object from a ui files doesn't get claimed
by gtk_builder_get_object(). This is useful for finding
dead wood in .ui files.

gtk/gtkbuilder.c

@@ -225,6 +225,8 @@
 #include "gtkicontheme.h"
 #include "gtkiconthemeprivate.h"
 #include "gdkpixbufutilsprivate.h"
+#include "gtkdebug.h"
+
 
 static void gtk_builder_finalize       (GObject         *object);
 static void gtk_builder_set_property   (GObject         *object,
@@ -359,6 +361,22 @@ gtk_builder_finalize (GObject *object)
   g_free (priv->filename);
   g_free (priv->resource_prefix);
 
+#ifdef G_ENABLE_DEBUG
+  if (GTK_DEBUG_CHECK (BUILDER_OBJECTS))
+    {
+      GHashTableIter iter;
+      gpointer key, value;
+
+      g_hash_table_iter_init (&iter, priv->objects);
+      while (g_hash_table_iter_next (&iter, &key, &value))
+        {
+          if (G_OBJECT (value)->ref_count == 1)
+            g_message ("builder: %s with id %s unused",
+                       G_OBJECT_TYPE_NAME (value), (const char *)key);
+        }
+    }
+#endif
+
   g_hash_table_destroy (priv->objects);
 
   g_slist_free_full (priv->signals, (GDestroyNotify)_free_signal_info);

gtk/gtkdebug.h

@@ -53,6 +53,7 @@ typedef enum {
   GTK_DEBUG_LAYOUT          = 1 << 15,
   GTK_DEBUG_SNAPSHOT        = 1 << 16,
   GTK_DEBUG_CONSTRAINTS     = 1 << 17,
+  GTK_DEBUG_BUILDER_OBJECTS = 1 << 18,
 } GtkDebugFlag;
 
 #ifdef G_ENABLE_DEBUG

gtk/gtkmain.c

@@ -168,6 +168,7 @@ static const GDebugKey gtk_debug_keys[] = {
   { "icontheme", GTK_DEBUG_ICONTHEME },
   { "printing", GTK_DEBUG_PRINTING} ,
   { "builder", GTK_DEBUG_BUILDER },
+  { "builder-objects", GTK_DEBUG_BUILDER_OBJECTS },
   { "size-request", GTK_DEBUG_SIZE_REQUEST },
   { "no-css-cache", GTK_DEBUG_NO_CSS_CACHE },
   { "shortcuts", GTK_DEBUG_SHORTCUTS },