ensure that return value of uinttostr et al are not ignored

[gnulib.git] / lib / inttostr.h

diff --git a/lib/inttostr.h b/lib/inttostr.h
index aa5820f..a103caf 100644 (file)
--- 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__;