[PATCH for-4.15 2/2] tools/xenstore: Check the format printf for xprintf() and barf{,_perror}()

[Julien Grall <julien@xxxxxxx>]

From: Julien Grall <jgrall@xxxxxxxxxx>

Allow GCC to analyze the format printf for xprintf() and
barf{,_perror}().

Take the opportunity to define __noreturn to make the prototype for
barf{,_perror})() easier to read.

Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
---
 tools/xenstore/utils.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/xenstore/utils.h b/tools/xenstore/utils.h
index 3dfb96b556dd..ccfb9b8fb699 100644
--- a/tools/xenstore/utils.h
+++ b/tools/xenstore/utils.h
@@ -29,10 +29,12 @@ const char *dump_state_align(FILE *fp);
 
 #define PRINTF_ATTRIBUTE(a1, a2) __attribute__((format (printf, a1, a2)))
 
-void barf(const char *fmt, ...) __attribute__((noreturn));
-void barf_perror(const char *fmt, ...) __attribute__((noreturn));
+#define __noreturn __attribute__((noreturn))
 
-extern void (*xprintf)(const char *fmt, ...);
+void barf(const char *fmt, ...) __noreturn PRINTF_ATTRIBUTE(1, 2);
+void barf_perror(const char *fmt, ...) __noreturn PRINTF_ATTRIBUTE(1, 2);
+
+extern void (*xprintf)(const char *fmt, ...) PRINTF_ATTRIBUTE(1, 2);
 
 #define eprintf(_fmt, _args...) xprintf("[ERR] %s" _fmt, __FUNCTION__, ##_args)
 
-- 
2.17.1