[patch] add G_GNUC_WARNUNCHECKED define

[Arjan van de Ven <arjanv redhat com>]

Hi,

gcc versions 3.4 and later have an attribute that you can give to a function
that will cause gcc to warn if you don't check/use the return value of such
function. The patch below adds a G_GNUC_WARNUNCHECKED define for this
attribute. A typical use for this is in realloc() definitions where not
using the return valueof such functions is always a bad bug in the program.
The patch below thus adds this attribute to g_realloc() and g_try_realloc().

Greetings,
     Arjan van de Ven

diff -purN glib-2.4.2/glib.org/gmacros.h glib-2.4.2/glib/gmacros.h
--- glib-2.4.2/glib.org/gmacros.h	2004-07-05 16:40:35.605509000 +0200
+++ glib-2.4.2/glib/gmacros.h	2004-07-05 17:55:48.026517424 +0200
@@ -96,6 +96,13 @@
 #define G_GNUC_DEPRECATED
 #endif /* __GNUC__ */
 
+#if    __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+#define G_GNUC_WARNUNCHECKED                            \
+  __attribute__((warn_unused_result))
+#else
+#define G_GNUC_WARNUNCHECKED
+#endif /* __GNUC__ */
+
 /* Wrap the gcc __PRETTY_FUNCTION__ and __FUNCTION__ variables with
  * macros, so we can refer to them as strings unconditionally.
  * usage not-recommended since gcc-3.0
diff -purN glib-2.4.2/glib.org/gmem.h glib-2.4.2/glib/gmem.h
--- glib-2.4.2/glib.org/gmem.h	2003-02-06 20:57:14.000000000 +0100
+++ glib-2.4.2/glib/gmem.h	2004-07-05 17:57:56.247024944 +0200
@@ -48,11 +48,11 @@ typedef struct _GMemVTable GMemVTable;
 gpointer g_malloc         (gulong	 n_bytes);
 gpointer g_malloc0        (gulong	 n_bytes);
 gpointer g_realloc        (gpointer	 mem,
-			   gulong	 n_bytes);
+			   gulong	 n_bytes) G_GNUC_WARNUNCHECKED;
 void	 g_free	          (gpointer	 mem);
 gpointer g_try_malloc     (gulong	 n_bytes);
 gpointer g_try_realloc    (gpointer	 mem,
-			   gulong	 n_bytes);
+			   gulong	 n_bytes) G_GNUC_WARNUNCHECKED;
 
 
 /* Convenience memory allocators