include: define format to be constant in xasprintf()

Add also format function attribute to add robustness.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/include/xalloc.h b/include/xalloc.h
index 8c22ff76a9906b52914eed7c4667175dc259b335..1704259bca804a2bfcbca5026503457dfb1c52ea 100644 (file)
--- a/include/xalloc.h
+++ b/include/xalloc.h
@@ -63,7 +63,8 @@ static inline char *xstrdup(const char *str)
         return ret;
 }
 
-static inline int xasprintf(char **strp, char *fmt, ...)
+static inline int __attribute__ ((__format__(printf, 2, 3)))
+    xasprintf(char **strp, const char *fmt, ...)
 {
        int ret;
        va_list args;