| # memcmp.m4 | |
| # serial 16 | |
| dnl Copyright (C) 2002-2004, 2007-2026 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. | |
| dnl This file is offered as-is, without any warranty. | |
| AC_DEFUN([gl_FUNC_MEMCMP], | |
| [ | |
| dnl We don't use AC_FUNC_MEMCMP any more, because it is no longer maintained | |
| dnl in Autoconf and because it invokes AC_LIBOBJ. | |
| AC_CACHE_CHECK([for working memcmp], [gl_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; | |
| } | |
| ]])], | |
| [gl_cv_func_memcmp_working=yes], | |
| [gl_cv_func_memcmp_working=no], | |
| [dnl When cross-compiling, guess memcmp works when it exists. | |
| dnl This is useful for mingw. | |
| AC_LINK_IFELSE( | |
| [AC_LANG_PROGRAM( | |
| [[#include <string.h>]], | |
| [[int ret = memcmp ("foo", "bar", 0);]])], | |
| [gl_cv_func_memcmp_working="guessing yes"], | |
| [gl_cv_func_memcmp_working="guessing no"]) | |
| ]) | |
| ]) | |
| case "$gl_cv_func_memcmp_working" in | |
| *yes) gl_func_memcmp=yes ;; | |
| *) gl_func_memcmp=no ;; | |
| esac | |
| if test $gl_func_memcmp = no; then | |
| AC_DEFINE([memcmp], [rpl_memcmp], | |
| [Define to rpl_memcmp if the replacement function should be used.]) | |
| fi | |
| ]) | |
| # Prerequisites of lib/memcmp.c. | |
| AC_DEFUN([gl_PREREQ_MEMCMP], [:]) |