Thanks, it doesn't hurt to squash those warnings so I installed the following (slightly different) patch.
>From 1ee5bc84f36b90fe4d95ba630c0840525cc33991 Mon Sep 17 00:00:00 2001 From: Paul Eggert <egg...@cs.ucla.edu> Date: Mon, 10 Dec 2012 10:06:10 -0800 Subject: [PATCH] AC_PROG_CC_C99: avoid unused-var warning * lib/autoconf/c.m4 (_AC_C_C99_TEST_HEADER): Rewrite to use vars. Problem reported by ChangZhuo Chen in <http://lists.gnu.org/archive/html/bug-autoconf/2012-12/msg00000.html>. --- lib/autoconf/c.m4 | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4 index 02b999e..e17df1e 100644 --- a/lib/autoconf/c.m4 +++ b/lib/autoconf/c.m4 @@ -1257,7 +1257,7 @@ test_restrict (ccp restrict text) } // Check varargs and va_copy. -static void +static bool test_varargs (const char *format, ...) { va_list args; @@ -1265,9 +1265,9 @@ test_varargs (const char *format, ...) va_list args_copy; va_copy (args_copy, args); - const char *str; - int number; - float fnumber; + const char *str = ""; + int number = 0; + float fnumber = 0; while (*format) { @@ -1288,6 +1288,8 @@ test_varargs (const char *format, ...) } va_end (args_copy); va_end (args); + + return *str && number && fnumber; }]])# _AC_C_C99_TEST_HEADER # _AC_C_C99_TEST_BODY @@ -1304,7 +1306,7 @@ AC_DEFUN([_AC_C_C99_TEST_BODY], char *restrict newvar = "Another string"; // Check varargs. - test_varargs ("s, d' f .", "string", 65, 34.234); + success &= test_varargs ("s, d' f .", "string", 65, 34.234); test_varargs_macros (); // Check flexible array members. -- 1.7.11.7
