xref: /netbsd-src/external/gpl2/gettext/dist/gettext-runtime/gnulib-m4/extensions.m4 (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1# serial 4  -*- Autoconf -*-
2# Enable extensions on systems that normally disable them.
3
4# Copyright (C) 2003, 2006 Free Software Foundation, Inc.
5# This file is free software; the Free Software Foundation
6# gives unlimited permission to copy and/or distribute it,
7# with or without modifications, as long as this notice is preserved.
8
9# This definition of AC_USE_SYSTEM_EXTENSIONS is stolen from CVS
10# Autoconf.  Perhaps we can remove this once we can assume Autoconf
11# 2.61 or later everywhere, but since CVS Autoconf mutates rapidly
12# enough in this area it's likely we'll need to redefine
13# AC_USE_SYSTEM_EXTENSIONS for quite some time.
14
15# AC_USE_SYSTEM_EXTENSIONS
16# ------------------------
17# Enable extensions on systems that normally disable them,
18# typically due to standards-conformance issues.
19AC_DEFUN([AC_USE_SYSTEM_EXTENSIONS],
20[
21  AC_BEFORE([$0], [AC_COMPILE_IFELSE])
22  AC_BEFORE([$0], [AC_RUN_IFELSE])
23
24  AC_REQUIRE([AC_GNU_SOURCE])
25  AC_REQUIRE([AC_AIX])
26  AC_REQUIRE([AC_MINIX])
27
28  AH_VERBATIM([__EXTENSIONS__],
29[/* Enable extensions on Solaris.  */
30#ifndef __EXTENSIONS__
31# undef __EXTENSIONS__
32#endif
33#ifndef _POSIX_PTHREAD_SEMANTICS
34# undef _POSIX_PTHREAD_SEMANTICS
35#endif
36#ifndef _TANDEM_SOURCE
37# undef _TANDEM_SOURCE
38#endif])
39  AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__],
40    [ac_cv_safe_to_define___extensions__],
41    [AC_COMPILE_IFELSE(
42       [AC_LANG_PROGRAM([
43#	  define __EXTENSIONS__ 1
44	  AC_INCLUDES_DEFAULT])],
45       [ac_cv_safe_to_define___extensions__=yes],
46       [ac_cv_safe_to_define___extensions__=no])])
47  test $ac_cv_safe_to_define___extensions__ = yes &&
48    AC_DEFINE([__EXTENSIONS__])
49  AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
50  AC_DEFINE([_TANDEM_SOURCE])
51])
52
53# gl_USE_SYSTEM_EXTENSIONS
54# ------------------------
55# Enable extensions on systems that normally disable them,
56# typically due to standards-conformance issues.
57AC_DEFUN([gl_USE_SYSTEM_EXTENSIONS],
58  [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])])
59