-# memcmp.m4 serial 10
-dnl Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
-dnl This file is free software, distributed under the terms of the GNU
-dnl General Public License. As a special exception to the GNU General
-dnl Public License, this file may be distributed as part of a program
-dnl that contains a configuration script generated by Autoconf, under
-dnl the same distribution terms as the rest of that program.
+# memcmp.m4 serial 15
+dnl Copyright (C) 2002-2004, 2007-2011 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_MEMCMP],
[
- AC_REQUIRE([AC_FUNC_MEMCMP])
+ if test $cross_compiling != no; then
+ # AC_FUNC_MEMCMP as of 2.62 defaults to 'no' when cross compiling.
+ # We default to yes if memcmp appears to exist, which works
+ # better for MinGW.
+ AC_CACHE_CHECK([whether cross-compiling target has memcmp],
+ [ac_cv_func_memcmp_working],
+ [AC_LINK_IFELSE([
+ AC_LANG_PROGRAM([[#include <string.h>
+ ]], [[int ret = memcmp ("foo", "bar", 0);]])],
+ [ac_cv_func_memcmp_working=yes],
+ [ac_cv_func_memcmp_working=no])])
+ fi
+ AC_FUNC_MEMCMP
+ dnl Note: AC_FUNC_MEMCMP does AC_LIBOBJ([memcmp]).
if test $ac_cv_func_memcmp_working = no; then
- AC_DEFINE(memcmp, rpl_memcmp,
+ AC_DEFINE([memcmp], [rpl_memcmp],
[Define to rpl_memcmp if the replacement function should be used.])
gl_PREREQ_MEMCMP
fi
])
+# Redefine AC_FUNC_MEMCMP, because it is no longer maintained in Autoconf.
+AC_DEFUN([AC_FUNC_MEMCMP],
+[
+ AC_CACHE_CHECK([for working memcmp], [ac_cv_func_memcmp_working],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [AC_INCLUDES_DEFAULT],
+ [[/* Some versions of memcmp are not 8-bit clean. */
+ char c0 = '\100', c1 = '\200', c2 = '\201';
+ if (memcmp(&c0, &c2, 1) >= 0 || memcmp(&c1, &c2, 1) >= 0)
+ return 1;
+ /* The Next x86 OpenStep bug shows up only when comparing 16 bytes
+ or more and with at least one buffer not starting on a 4-byte
+ boundary. William Lewis provided this test program. */
+ {
+ char foo[21];
+ char bar[21];
+ int i;
+ for (i = 0; i < 4; i++)
+ {
+ char *a = foo + i;
+ char *b = bar + i;
+ strcpy (a, "--------01111111");
+ strcpy (b, "--------10000000");
+ if (memcmp (a, b, 16) >= 0)
+ return 1;
+ }
+ return 0;
+ }
+ ]])],
+ [ac_cv_func_memcmp_working=yes],
+ [ac_cv_func_memcmp_working=no],
+ [ac_cv_func_memcmp_working=no])])
+ test $ac_cv_func_memcmp_working = no &&
+ AC_LIBOBJ([memcmp])
+])
+
# Prerequisites of lib/memcmp.c.
AC_DEFUN([gl_PREREQ_MEMCMP], [:])