# HG changeset patch
# User Jim Meyering <meyering@redhat.com>
# Date 1251796841 -7200
# Node ID 4934b28baa2baa72f7bf73b89ae7ed510e6a59bd
# Parent  10d064d93551e7acabaf31afab97a61d5131cfc7
fts: help ensure that return values are not ignored

* lib/fts_.h (__GNUC_PREREQ): Define.
(__attribute_warn_unused_result__): Define.
(fts_children, fts_close, fts_open, fts_read): Declare with
__attribute_warn_unused_result__.

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2009-09-01  Jim Meyering  <meyering@redhat.com>
 
+	fts: help ensure that return values are not ignored
+	* lib/fts_.h (__GNUC_PREREQ): Define.
+	(__attribute_warn_unused_result__): Define.
+	(fts_children, fts_close, fts_open, fts_read): Declare with
+	__attribute_warn_unused_result__.
+
 	fts: fts_close now fails also when closing a dir file descriptor fails
 	* lib/fts.c (fts_close): Detect close failure, not just fchdir failure,
 	and propagate to caller, along with errno.
diff --git a/lib/fts_.h b/lib/fts_.h
--- a/lib/fts_.h
+++ b/lib/fts_.h
@@ -233,12 +233,30 @@
 	char fts_name[1];		/* file name */
 } FTSENT;
 
+#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
+
 __BEGIN_DECLS
-FTSENT	*fts_children (FTS *, int) __THROW;
-int	 fts_close (FTS *) __THROW;
+FTSENT	*fts_children (FTS *, int) __THROW __attribute_warn_unused_result__;
+int	 fts_close (FTS *) __THROW __attribute_warn_unused_result__;
 FTS	*fts_open (char * const *, int,
-		   int (*)(const FTSENT **, const FTSENT **)) __THROW;
-FTSENT	*fts_read (FTS *) __THROW;
+		   int (*)(const FTSENT **, const FTSENT **))
+  __THROW __attribute_warn_unused_result__;
+FTSENT	*fts_read (FTS *) __THROW __attribute_warn_unused_result__;
 int	 fts_set (FTS *, FTSENT *, int) __THROW;
 __END_DECLS