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-rw-r--r--config/extensions.m479
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diff --git a/config/extensions.m4 b/config/extensions.m4
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+++ b/config/extensions.m4
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+# serial 6 -*- Autoconf -*-
+# Enable extensions on systems that normally disable them.
+
+# Copyright (C) 2003, 2006, 2007, 2009 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.
+
+# This definition of AC_USE_SYSTEM_EXTENSIONS is stolen from CVS
+# Autoconf. Perhaps we can remove this once we can assume Autoconf
+# 2.62 or later everywhere, but since CVS Autoconf mutates rapidly
+# enough in this area it's likely we'll need to redefine
+# AC_USE_SYSTEM_EXTENSIONS for quite some time.
+
+m4_version_prereq([2.62],, [
+
+# AC_USE_SYSTEM_EXTENSIONS
+# ------------------------
+# Enable extensions on systems that normally disable them,
+# typically due to standards-conformance issues.
+# Remember that #undef in AH_VERBATIM gets replaced with #define by
+# AC_DEFINE. The goal here is to define all known feature-enabling
+# macros, then, if reports of conflicts are made, disable macros that
+# cause problems on some platforms (such as __EXTENSIONS__).
+AC_DEFUN([AC_USE_SYSTEM_EXTENSIONS],
+[AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl
+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
+ 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.])
+ fi
+
+ AH_VERBATIM([__EXTENSIONS__],
+[/* Enable extensions on AIX 3, Interix. */
+#ifndef _ALL_SOURCE
+# undef _ALL_SOURCE
+#endif
+/* Enable GNU extensions on systems that have them. */
+#ifndef _GNU_SOURCE
+# undef _GNU_SOURCE
+#endif
+/* Enable threading extensions on Solaris. */
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# undef _POSIX_PTHREAD_SEMANTICS
+#endif
+/* Enable extensions on HP NonStop. */
+#ifndef _TANDEM_SOURCE
+# undef _TANDEM_SOURCE
+#endif
+/* Enable general extensions on Solaris. */
+#ifndef __EXTENSIONS__
+# undef __EXTENSIONS__
+#endif
+])
+ AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__],
+ [ac_cv_safe_to_define___extensions__],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM([
+# define __EXTENSIONS__ 1
+ AC_INCLUDES_DEFAULT])],
+ [ac_cv_safe_to_define___extensions__=yes],
+ [ac_cv_safe_to_define___extensions__=no])])
+ test $ac_cv_safe_to_define___extensions__ = yes &&
+ AC_DEFINE([__EXTENSIONS__])
+ AC_DEFINE([_ALL_SOURCE])
+ AC_DEFINE([_GNU_SOURCE])
+ AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
+ AC_DEFINE([_TANDEM_SOURCE])
+])# AC_USE_SYSTEM_EXTENSIONS
+
+])