implement full-blown select(2) for winsock

[gnulib.git] / m4 / memcmp.m4

diff --git a/m4/memcmp.m4 b/m4/memcmp.m4
index e76aeda..a8d87b9 100644 (file)
--- a/m4/memcmp.m4
+++ b/m4/memcmp.m4
@@ -1,13 +1,31 @@
-#serial 1
+# memcmp.m4 serial 13
+dnl Copyright (C) 2002, 2003, 2004, 2007, 2008 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 If you use this macro in a package, you should
-dnl add the following two lines to acconfig.h:
-dnl   /* Define to rpl_memcmp if the replacement function should be used.  */
-dnl   #undef memcmp
-dnl
-AC_DEFUN(jm_FUNC_MEMCMP,
-[AC_REQUIRE([AC_FUNC_MEMCMP])dnl
- if test $ac_cv_func_memcmp_clean = no; then
-   AC_DEFINE_UNQUOTED(memcmp, rpl_memcmp)
- fi
+AC_DEFUN([gl_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,
+      [Define to rpl_memcmp if the replacement function should be used.])
+    gl_PREREQ_MEMCMP
+  fi
 ])
+
+# Prerequisites of lib/memcmp.c.
+AC_DEFUN([gl_PREREQ_MEMCMP], [:])