Mark usage() as _X_COLD _X_NORETURN

Suggested by clang:
xcompmgr.c:1963:1: warning: function 'usage' could be declared with
  attribute 'noreturn' [-Wmissing-noreturn]
{
^

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

2 files changed, 3 insertions, 2 deletions

diff --git a/configure.ac b/configure.ac
index 14320e9..bdc22a1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,8 @@ m4_ifndef([XORG_MACROS_VERSION],
 XORG_MACROS_VERSION(1.8)
 XORG_DEFAULT_OPTIONS
 
-PKG_CHECK_MODULES(XCOMPMGR, xcomposite xfixes xdamage xrender xext)
+PKG_CHECK_MODULES(XCOMPMGR,
+        [xcomposite xfixes xdamage xrender xext xproto >= 7.0.25])
 
 AC_CONFIG_FILES([
 	Makefile
diff --git a/xcompmgr.c b/xcompmgr.c
index 55e2085..4443779 100644
--- a/xcompmgr.c
+++ b/xcompmgr.c
@@ -1958,7 +1958,7 @@ ev_window (XEvent *ev)
 }
 #endif
 
-static void
+static void _X_COLD _X_NORETURN
 usage (const char *program)
 {
     fprintf (stderr, "%s v%s\n", program, PACKAGE_VERSION);