--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m4/errno_h.m4	Tue Dec 22 05:33:32 2009 +0000
@@ -0,0 +1,113 @@
+# errno_h.m4 serial 4
+dnl Copyright (C) 2004, 2006, 2008, 2009 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 macro must pass through AC_REQUIRE (never directly invoke it).
+AC_DEFUN_ONCE([gl_HEADER_ERRNO_H],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_CACHE_CHECK([for complete errno.h], [gl_cv_header_errno_h_complete], [
+    AC_EGREP_CPP([booboo],[
+#include <errno.h>
+#if !defined ENOMSG
+booboo
+#endif
+#if !defined EIDRM
+booboo
+#endif
+#if !defined ENOLINK
+booboo
+#endif
+#if !defined EPROTO
+booboo
+#endif
+#if !defined EMULTIHOP
+booboo
+#endif
+#if !defined EBADMSG
+booboo
+#endif
+#if !defined EOVERFLOW
+booboo
+#endif
+#if !defined ENOTSUP
+booboo
+#endif
+#if !defined ECANCELED
+booboo
+#endif
+      ],
+      [gl_cv_header_errno_h_complete=no],
+      [gl_cv_header_errno_h_complete=yes])
+  ])
+  if test $gl_cv_header_errno_h_complete = yes; then
+    ERRNO_H=''
+  else
+    gl_CHECK_NEXT_HEADERS([errno.h])
+    ERRNO_H='errno.h'
+  fi
+  AC_SUBST([ERRNO_H])
+  gl_REPLACE_ERRNO_VALUE([EMULTIHOP])
+  gl_REPLACE_ERRNO_VALUE([ENOLINK])
+  gl_REPLACE_ERRNO_VALUE([EOVERFLOW])
+])
+
+# Assuming $1 = EOVERFLOW.
+# The EOVERFLOW errno value ought to be defined in <errno.h>, according to
+# POSIX.  But some systems (like OpenBSD 4.0 or AIX 3) don't define it, and
+# some systems (like OSF/1) define it when _XOPEN_SOURCE_EXTENDED is defined.
+# Check for the value of EOVERFLOW.
+# Set the variables EOVERFLOW_HIDDEN and EOVERFLOW_VALUE.
+AC_DEFUN([gl_REPLACE_ERRNO_VALUE],
+[
+  if test -n "$ERRNO_H"; then
+    AC_CACHE_CHECK([for ]$1[ value], [gl_cv_header_errno_h_]$1, [
+      AC_EGREP_CPP([yes],[
+#include <errno.h>
+#ifdef ]$1[
+yes
+#endif
+      ],
+      [gl_cv_header_errno_h_]$1[=yes],
+      [gl_cv_header_errno_h_]$1[=no])
+      if test $gl_cv_header_errno_h_]$1[ = no; then
+        AC_EGREP_CPP([yes],[
+#define _XOPEN_SOURCE_EXTENDED 1
+#include <errno.h>
+#ifdef ]$1[
+yes
+#endif
+          ], [gl_cv_header_errno_h_]$1[=hidden])
+        if test $gl_cv_header_errno_h_]$1[ = hidden; then
+          dnl The macro exists but is hidden.
+          dnl Define it to the same value.
+          AC_COMPUTE_INT([gl_cv_header_errno_h_]$1, $1, [
+#define _XOPEN_SOURCE_EXTENDED 1
+#include <errno.h>
+/* The following two lines are a workaround against an autoconf-2.52 bug.  */
+#include <stdio.h>
+#include <stdlib.h>
+])
+        fi
+      fi
+    ])
+    case $gl_cv_header_errno_h_]$1[ in
+      yes | no)
+        ]$1[_HIDDEN=0; ]$1[_VALUE=
+        ;;
+      *)
+        ]$1[_HIDDEN=1; ]$1[_VALUE="$gl_cv_header_errno_h_]$1["
+        ;;
+    esac
+    AC_SUBST($1[_HIDDEN])
+    AC_SUBST($1[_VALUE])
+  fi
+])
+
+dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
+dnl Remove this when we can assume autoconf >= 2.61.
+m4_ifdef([AC_COMPUTE_INT], [], [
+  AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
+])