*** empty log message ***

[gnulib.git] / m4 / strerror_r.m4

diff --git a/m4/strerror_r.m4 b/m4/strerror_r.m4
index 8ae4c71..6cf4624 100644 (file)
--- a/m4/strerror_r.m4
+++ b/m4/strerror_r.m4
@@ -1,5 +1,7 @@
-#serial 1000
+#serial 1002
 # Experimental replacement for the function in the latest CVS autoconf.
+# If the compile-test says strerror_r doesn't work, then resort to a
+# `run'-test that works on BeOS and segfaults on DEC Unix.
 # Use with the error.c file in ../lib.
 
 undefine([AC_FUNC_STRERROR_R])
@@ -7,11 +9,10 @@ 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_FUNCS([strerror_r])
 if test $ac_cv_func_strerror_r = yes; then
   AC_CHECK_HEADERS(string.h)
-  AC_CHECK_DECLS([strerror_r])
   AC_CACHE_CHECK([for working strerror_r],
                  ac_cv_func_strerror_r_works,
    [
@@ -21,24 +22,45 @@ if test $ac_cv_func_strerror_r = yes; then
 #       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);
+       char buf[100];
+       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.])
+    if test $ac_cv_func_strerror_r_works = no; then
+      # strerror_r seems not to work, but now we have to 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_TRY_RUN(
+       [
+#       include <stdio.h>
+#       include <string.h>
+#       include <ctype.h>
+
+       extern char *strerror_r ();
+
+       int
+       main ()
+       {
+         char buf[100];
+         char x = *strerror_r (0, buf, sizeof buf);
+         exit (!isalpha (x));
+       }
+       ],
+       ac_cv_func_strerror_r_works=yes,
+       ac_cv_func_strerror_r_works=no,
+       ac_cv_func_strerror_r_works=no)
     fi
   ])
+  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.])
+  fi
 fi
 ])# AC_FUNC_STRERROR_R