X-Git-Url: https://git.cworth.org/git?p=tar;a=blobdiff_plain;f=lib%2Finttostr.h;h=a103caf587f1a4966888bc6aed4a983d34b4b194;hp=aa5820fd5af33a0af04e82f646b5f62107d53447;hb=cf7169a2ede9bb08b71de68fe0c8bbecf827abe6;hpb=138fc7e67e3d9845cd7d81aad0e9c7724784f9b9

diff --git a/lib/inttostr.h b/lib/inttostr.h
index aa5820f..a103caf 100644
--- a/lib/inttostr.h
+++ b/lib/inttostr.h
@@ -23,7 +23,24 @@
 
 #include "intprops.h"
 
-char *offtostr (off_t, char *);
-char *imaxtostr (intmax_t, char *);
-char *umaxtostr (uintmax_t, char *);
-char *uinttostr (unsigned int, char *);
+#ifndef __GNUC_PREREQ
+# if defined __GNUC__ && defined __GNUC_MINOR__
+#  define __GNUC_PREREQ(maj, min) \
+         ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+# else
+#  define __GNUC_PREREQ(maj, min) 0
+# endif
+#endif
+
+#if __GNUC_PREREQ (3,4)
+# undef __attribute_warn_unused_result__
+# define __attribute_warn_unused_result__ \
+   __attribute__ ((__warn_unused_result__))
+#else
+# define __attribute_warn_unused_result__ /* empty */
+#endif
+
+char *offtostr (off_t, char *) __attribute_warn_unused_result__;
+char *imaxtostr (intmax_t, char *) __attribute_warn_unused_result__;
+char *umaxtostr (uintmax_t, char *) __attribute_warn_unused_result__;
+char *uinttostr (unsigned int, char *) __attribute_warn_unused_result__;