* m4/getdate.m4 (gl_C_COMPOUND_LITERALS): New macro.

[gnulib.git] / m4 / strerror_r.m4

diff --git a/m4/strerror_r.m4 b/m4/strerror_r.m4
index 34a2d24..28924b1 100644 (file)
--- a/m4/strerror_r.m4
+++ b/m4/strerror_r.m4
@@ -1,44 +1,49 @@
-#serial 1000
+#serial 1004
+# This file is not needed if you can assume Autoconf 2.54 or later.
 # Experimental replacement for the function in the latest CVS autoconf.
 # Use with the error.c file in ../lib.
 
+# Copyright (C) 2001 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
 undefine([AC_FUNC_STRERROR_R])
 
 # AC_FUNC_STRERROR_R
 # ------------------
 AC_DEFUN([AC_FUNC_STRERROR_R],
-[# Check strerror_r
-AC_CHECK_DECLS([strerror_r])
+[AC_CHECK_DECLS([strerror_r])
 AC_CHECK_FUNCS([strerror_r])
-if test $ac_cv_func_strerror_r = yes; then
-  AC_CHECK_HEADERS(string.h)
-  AC_CACHE_CHECK([for working strerror_r],
-                 ac_cv_func_strerror_r_works,
+AC_CACHE_CHECK([whether strerror_r returns char *],
+               ac_cv_func_strerror_r_char_p,
    [
-    AC_TRY_COMPILE(
-     [
-#       include <stdio.h>
-#       if HAVE_STRING_H
-#        include <string.h>
-#       endif
-#ifndef HAVE_DECL_STRERROR_R
-"this configure-time declaration test was not run"
-#endif
-#if !HAVE_DECL_STRERROR_R
-char *strerror_r ();
-#endif
-     ],
-     [
-       char buf;
-       char x = *strerror_r (0, &buf, sizeof buf);
-     ],
-     ac_cv_func_strerror_r_works=yes,
-     ac_cv_func_strerror_r_works=no
-    )
-    if test $ac_cv_func_strerror_r_works = yes; then
-      AC_DEFINE_UNQUOTED(HAVE_WORKING_STRERROR_R, 1,
-        [Define to 1 if `strerror_r' returns a string.])
+    ac_cv_func_strerror_r_char_p=no
+    if test $ac_cv_have_decl_strerror_r = yes; then
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
+       [[
+         char buf[100];
+         char x = *strerror_r (0, buf, sizeof buf);
+         char *p = strerror_r (0, buf, sizeof buf);
+       ]])],
+                       ac_cv_func_strerror_r_char_p=yes)
+    else
+      # strerror_r is not declared.  Choose between
+      # systems that have relatively inaccessible declarations for the
+      # function.  BeOS and DEC UNIX 4.0 fall in this category, but the
+      # former has a strerror_r that returns char*, while the latter
+      # has a strerror_r that returns `int'.
+      # This test should segfault on the DEC system.
+      AC_RUN_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT
+       extern char *strerror_r ();],
+       [[char buf[100];
+         char x = *strerror_r (0, buf, sizeof buf);
+         exit (!isalpha (x));]])],
+                    ac_cv_func_strerror_r_char_p=yes, , :)
     fi
   ])
+if test $ac_cv_func_strerror_r_char_p = yes; then
+  AC_DEFINE([STRERROR_R_CHAR_P], 1,
+           [Define to 1 if strerror_r returns char *.])
 fi
 ])# AC_FUNC_STRERROR_R