Re: Patch AC_USE_SYSTEM_EXTENSIONS for Minix3

Thanks, I installed the following patch, which is a bit
more general as it merges recent gnulib changes in.

From 773f366de4e8db4b2b40cde047c87a175eaa20a5 Mon Sep 17 00:00:00 2001
From: Paul Eggert <[email protected]>
Date: Wed, 6 Feb 2013 22:46:49 -0800
Subject: [PATCH] AC_USE_SYSTEM_EXTENSIONS: port to HP-UX, MINUX 3, OS X.

* NEWS: Mention this.
* lib/autoconf/specific.m4 (AC_USE_SYSTEM_EXTENSIONS):
Define _NETBSD_HOST on MINUX, for MINUX 3.
Define _DARWIN_C_SOURCE, for OS X.
On HP-UX, define _XOPEN_SOURCE.
---
 NEWS                     |  3 +++
 lib/autoconf/specific.m4 | 14 +++++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 16de922..1780cb9 100644
--- a/NEWS
+++ b/NEWS
@@ -33,6 +33,9 @@ GNU Autoconf NEWS - User visible changes.
 - AC_PROG_CC_STDC, AC_PROG_CC_C89, AC_PROG_CC_C99 have been marked as obsolete.
   Applications should use AC_PROG_CC.
 
+- AC_USE_SYSTEM_EXTENSIONS now enables more system extensions on HP-UX,
+  MINIX 3, and OS X.
+
 - AC_FUNC_VFORK now checks for the signal-handling bug in Solaris 2.4 'vfork'.
   Formerly, it ignored this bug, so that Emacs could use some tricky
   code on that platform.  Solaris 2.4 has not been supported since
diff --git a/lib/autoconf/specific.m4 b/lib/autoconf/specific.m4
index 0d173f2..248a7a3 100644
--- a/lib/autoconf/specific.m4
+++ b/lib/autoconf/specific.m4
@@ -369,13 +369,15 @@ AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
   AC_CHECK_HEADER([minix/config.h], [MINIX=yes], [MINIX=])
   if test "$MINIX" = yes; then
     AC_DEFINE([_POSIX_SOURCE], [1],
-      [Define to 1 if you need to in order for `stat' and other
+      [Define to 1 if you need to in order for 'stat' and other
        things to work.])
     AC_DEFINE([_POSIX_1_SOURCE], [2],
       [Define to 2 if the system does not provide POSIX.1 features
        except with this defined.])
     AC_DEFINE([_MINIX], [1],
       [Define to 1 if on MINIX.])
+    AC_DEFINE([_NETBSD_SOURCE], [1],
+      [Define to 1 to make NetBSD features available.  MINIX 3 needs this.])
   fi
 
 dnl Use a different key than __EXTENSIONS__, as that name broke existing
@@ -385,10 +387,19 @@ dnl configure.ac when using autoheader 2.62.
 #ifndef _ALL_SOURCE
 # undef _ALL_SOURCE
 #endif
+/* Enable general extensions on OS X.  */
+#ifndef _DARWIN_C_SOURCE
+# undef _DARWIN_C_SOURCE
+#endif
 /* Enable GNU extensions on systems that have them.  */
 #ifndef _GNU_SOURCE
 # undef _GNU_SOURCE
 #endif
+/* HP-UX 11.11 defines mbstate_t only if _XOPEN_SOURCE is defined to 500,
+   regardless of whether compiling with -Ae or -D_HPUX_SOURCE=1.  */
+#ifdef __hpux
+# define _XOPEN_SOURCE 500
+#endif
 /* Enable threading extensions on Solaris.  */
 #ifndef _POSIX_PTHREAD_SEMANTICS
 # undef _POSIX_PTHREAD_SEMANTICS
@@ -413,6 +424,7 @@ dnl configure.ac when using autoheader 2.62.
   test $ac_cv_safe_to_define___extensions__ = yes &&
     AC_DEFINE([__EXTENSIONS__])
   AC_DEFINE([_ALL_SOURCE])
+  AC_DEFINE([_DARWIN_C_SOURCE])
   AC_DEFINE([_GNU_SOURCE])
   AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
   AC_DEFINE([_TANDEM_SOURCE])
-- 
1.7.11.7