[PATCH] regex: avoid new dead-code warning with gcc-4.6.0

[Jim Meyering]

FYI,
Without the patch below, I'd get this warning when building coreutils with 
gcc-4.6.0:

  regex_internal.c: In function 're_string_reconstruct':
  regex_internal.c:740:20: warning: variable 'buf' set but not used 
[-Werror=unused-but-set-variable]


>From 7873eb96d23bb7d369a0ac6cd5f8e811b0147bfd Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Mon, 7 Jun 2010 07:58:49 +0200
Subject: [PATCH] regex: avoid new dead-code warning with gcc-4.6.0

* lib/regex_internal.c (re_string_reconstruct): #if-0-out a dead
if-block containing a while-loop.  It's been unused for at least
5 years.
---
 ChangeLog            |    7 +++++++
 lib/regex_internal.c |    4 +++-
 2 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 29475fa..845bc6e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-06-07  Jim Meyering  <address@hidden>
+
+       regex: avoid new dead-code warning with gcc-4.6.0
+       * lib/regex_internal.c (re_string_reconstruct): #if-0-out a dead
+       if-block containing a while-loop.  It's been unused for at least
+       5 years.
+
 2010-06-05  Bruno Haible  <address@hidden>

        * doc/posix-functions/strcoll.texi: Mention Solaris limitation.
diff --git a/lib/regex_internal.c b/lib/regex_internal.c
index 378b767..787a3a6 100644
--- a/lib/regex_internal.c
+++ b/lib/regex_internal.c
@@ -733,15 +733,17 @@ re_string_reconstruct (re_string_t *pstr, Idx idx, int 
eflags)
                          mbstate_t cur_state;
                          wchar_t wc2;
                          Idx mlen = raw + pstr->len - p;
-                         unsigned char buf[6];
                          size_t mbclen;

+#if 0 /* dead code: buf is set but never used */
+                         unsigned char buf[6];
                          if (BE (pstr->trans != NULL, 0))
                            {
                              int i = mlen < 6 ? mlen : 6;
                              while (--i >= 0)
                                buf[i] = pstr->trans[p[i]];
                            }
+#endif
                          /* XXX Don't use mbrtowc, we know which conversion
                             to use (UTF-8 -> UCS4).  */
                          memset (&cur_state, 0, sizeof (cur_state));
--
1.7.1.445.gc54f1