1# serial 8 -*- Autoconf -*- 2# Enable extensions on systems that normally disable them. 3 4# Copyright (C) 2003, 2006-2009 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# 2.62 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. 19# Remember that #undef in AH_VERBATIM gets replaced with #define by 20# AC_DEFINE. The goal here is to define all known feature-enabling 21# macros, then, if reports of conflicts are made, disable macros that 22# cause problems on some platforms (such as __EXTENSIONS__). 23AC_DEFUN_ONCE([AC_USE_SYSTEM_EXTENSIONS], 24[AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl 25AC_BEFORE([$0], [AC_RUN_IFELSE])dnl 26 27 AC_REQUIRE([AC_CANONICAL_HOST]) 28 29 AC_CHECK_HEADER([minix/config.h], [MINIX=yes], [MINIX=]) 30 if test "$MINIX" = yes; then 31 AC_DEFINE([_POSIX_SOURCE], [1], 32 [Define to 1 if you need to in order for `stat' and other 33 things to work.]) 34 AC_DEFINE([_POSIX_1_SOURCE], [2], 35 [Define to 2 if the system does not provide POSIX.1 features 36 except with this defined.]) 37 AC_DEFINE([_MINIX], [1], 38 [Define to 1 if on MINIX.]) 39 fi 40 41 dnl HP-UX 11.11 defines mbstate_t only if _XOPEN_SOURCE is defined to 500, 42 dnl regardless of whether the flags -Ae or _D_HPUX_SOURCE=1 are already 43 dnl provided. 44 case "$host_os" in 45 hpux*) 46 AC_DEFINE([_XOPEN_SOURCE], [500], 47 [Define to 500 only on HP-UX.]) 48 ;; 49 esac 50 51 AH_VERBATIM([__EXTENSIONS__], 52[/* Enable extensions on AIX 3, Interix. */ 53#ifndef _ALL_SOURCE 54# undef _ALL_SOURCE 55#endif 56/* Enable GNU extensions on systems that have them. */ 57#ifndef _GNU_SOURCE 58# undef _GNU_SOURCE 59#endif 60/* Enable threading extensions on Solaris. */ 61#ifndef _POSIX_PTHREAD_SEMANTICS 62# undef _POSIX_PTHREAD_SEMANTICS 63#endif 64/* Enable extensions on HP NonStop. */ 65#ifndef _TANDEM_SOURCE 66# undef _TANDEM_SOURCE 67#endif 68/* Enable general extensions on Solaris. */ 69#ifndef __EXTENSIONS__ 70# undef __EXTENSIONS__ 71#endif 72]) 73 AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__], 74 [ac_cv_safe_to_define___extensions__], 75 [AC_COMPILE_IFELSE( 76 [AC_LANG_PROGRAM([[ 77# define __EXTENSIONS__ 1 78 ]AC_INCLUDES_DEFAULT])], 79 [ac_cv_safe_to_define___extensions__=yes], 80 [ac_cv_safe_to_define___extensions__=no])]) 81 test $ac_cv_safe_to_define___extensions__ = yes && 82 AC_DEFINE([__EXTENSIONS__]) 83 AC_DEFINE([_ALL_SOURCE]) 84 AC_DEFINE([_GNU_SOURCE]) 85 AC_DEFINE([_POSIX_PTHREAD_SEMANTICS]) 86 AC_DEFINE([_TANDEM_SOURCE]) 87])# AC_USE_SYSTEM_EXTENSIONS 88 89# gl_USE_SYSTEM_EXTENSIONS 90# ------------------------ 91# Enable extensions on systems that normally disable them, 92# typically due to standards-conformance issues. 93AC_DEFUN_ONCE([gl_USE_SYSTEM_EXTENSIONS], 94[ 95 dnl Require this macro before AC_USE_SYSTEM_EXTENSIONS. 96 dnl gnulib does not need it. But if it gets required by third-party macros 97 dnl after AC_USE_SYSTEM_EXTENSIONS is required, autoconf 2.62..2.63 emit a 98 dnl warning: "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS". 99 dnl Note: We can do this only for one of the macros AC_AIX, AC_GNU_SOURCE, 100 dnl AC_MINIX. If people still use AC_AIX or AC_MINIX, they are out of luck. 101 AC_REQUIRE([AC_GNU_SOURCE]) 102 103 AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) 104]) 105