usage: add cold & noreturn attributes to function

As suggested by clang:
xlsatoms.c:56:1: warning: function 'usage' could be declared with
 attribute 'noreturn' [-Wmissing-noreturn]
{
^

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/xlsatoms.c b/xlsatoms.c
index 6c7f4b5..1dbe1e9 100644
--- a/xlsatoms.c
+++ b/xlsatoms.c
@@ -51,7 +51,17 @@ static void do_range ( xcb_connection_t *c, const char *format, char *range );
 static void list_atoms ( xcb_connection_t *c, const char *format, int mask,
 			 xcb_atom_t low, xcb_atom_t high );
 
-static void 
+#ifndef __has_attribute
+# define __has_attribute(x) 0  /* Compatibility with older compilers. */
+#endif
+
+static void
+#if __has_attribute(__cold__)
+__attribute__((__cold__))
+#endif
+#if __has_attribute(noreturn)
+__attribute__((noreturn))
+#endif
 usage(const char *errmsg)
 {
     if (errmsg != NULL)