[PATCH] hash: declare some functions with the warn_unused_result attribute

[Jim Meyering]

A few of the function declarations in hash.h could benefit from
gcc's warn_unused_result attribute, so I'm adding it:

>From 28e62601bcb5c76e7d4a24ef7d2faaf281503353 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyer...@redhat.com>
Date: Sat, 6 Jun 2009 22:39:23 +0200
Subject: [PATCH] hash: declare some functions with the warn_unused_result 
attribute

* lib/hash.h (__attribute__, ATTRIBUTE_WUR): Define.
---
 ChangeLog  |    5 +++++
 lib/hash.h |   20 ++++++++++++++++----
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index e845591..e4cc433 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-06-06  Jim Meyering  <meyer...@redhat.com>
+
+       hash: declare some functions with the warn_unused_result attribute
+       * lib/hash.h (__attribute__, ATTRIBUTE_WUR): Define.
+
 2009-06-04  Jim Meyering  <meyer...@redhat.com>

        gitlog-to-changelog: don't infloop on an empty commit log
diff --git a/lib/hash.h b/lib/hash.h
index fc1af28..9d2fdaf 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -1,5 +1,5 @@
 /* hash - hashing table processing.
-   Copyright (C) 1998, 1999, 2001, 2003 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2001, 2003, 2009 Free Software Foundation, Inc.
    Written by Jim Meyering <meyer...@ascend.com>, 1998.

    This program is free software: you can redistribute it and/or modify
@@ -23,6 +23,18 @@
 #ifndef HASH_H_
 # define HASH_H_

+/* The warn_unused_result attribute appeared first in gcc-3.4.0 */
+# ifndef __attribute__
+#  if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
+#   define __attribute__(x)
+#  endif
+# endif
+
+# ifndef ATTRIBUTE_WUR
+#  define ATTRIBUTE_WUR __attribute__ ((__warn_unused_result__))
+# endif
+
+
 # include <stdio.h>
 # include <stdbool.h>

@@ -75,13 +87,13 @@ size_t hash_string (const char *, size_t);
 void hash_reset_tuning (Hash_tuning *);
 Hash_table *hash_initialize (size_t, const Hash_tuning *,
                             Hash_hasher, Hash_comparator,
-                            Hash_data_freer);
+                            Hash_data_freer) ATTRIBUTE_WUR;
 void hash_clear (Hash_table *);
 void hash_free (Hash_table *);

 /* Insertion and deletion.  */
-bool hash_rehash (Hash_table *, size_t);
-void *hash_insert (Hash_table *, const void *);
+bool hash_rehash (Hash_table *, size_t) ATTRIBUTE_WUR;
+void *hash_insert (Hash_table *, const void *) ATTRIBUTE_WUR;
 void *hash_delete (Hash_table *, const void *);

 #endif
--
1.6.3.2.277.gd10543.dirty