1# serial 18 -*- Autoconf -*- 2# Enable extensions on systems that normally disable them. 3 4# Copyright (C) 2003, 2006-2020 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 git 10# Autoconf. Perhaps we can remove this once we can assume Autoconf 11# 2.70 or later everywhere, but since 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# If autoconf reports a warning 16# warning: AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS 17# or warning: AC_RUN_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS 18# the fix is 19# 1) to ensure that AC_USE_SYSTEM_EXTENSIONS is never directly invoked 20# but always AC_REQUIREd, 21# 2) to ensure that for each occurrence of 22# AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) 23# or 24# AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) 25# the corresponding gnulib module description has 'extensions' among 26# its dependencies. This will ensure that the gl_USE_SYSTEM_EXTENSIONS 27# invocation occurs in gl_EARLY, not in gl_INIT. 28 29# AC_USE_SYSTEM_EXTENSIONS 30# ------------------------ 31# Enable extensions on systems that normally disable them, 32# typically due to standards-conformance issues. 33# 34# Remember that #undef in AH_VERBATIM gets replaced with #define by 35# AC_DEFINE. The goal here is to define all known feature-enabling 36# macros, then, if reports of conflicts are made, disable macros that 37# cause problems on some platforms (such as __EXTENSIONS__). 38AC_DEFUN_ONCE([AC_USE_SYSTEM_EXTENSIONS], 39[AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl 40AC_BEFORE([$0], [AC_RUN_IFELSE])dnl 41 42 AC_CHECK_HEADER([minix/config.h], [MINIX=yes], [MINIX=]) 43 if test "$MINIX" = yes; then 44 AC_DEFINE([_POSIX_SOURCE], [1], 45 [Define to 1 if you need to in order for 'stat' and other 46 things to work.]) 47 AC_DEFINE([_POSIX_1_SOURCE], [2], 48 [Define to 2 if the system does not provide POSIX.1 features 49 except with this defined.]) 50 AC_DEFINE([_MINIX], [1], 51 [Define to 1 if on MINIX.]) 52 AC_DEFINE([_NETBSD_SOURCE], [1], 53 [Define to 1 to make NetBSD features available. MINIX 3 needs this.]) 54 fi 55 56dnl Use a different key than __EXTENSIONS__, as that name broke existing 57dnl configure.ac when using autoheader 2.62. 58 AH_VERBATIM([USE_SYSTEM_EXTENSIONS], 59[/* Enable extensions on AIX 3, Interix. */ 60#ifndef _ALL_SOURCE 61# undef _ALL_SOURCE 62#endif 63/* Enable general extensions on macOS. */ 64#ifndef _DARWIN_C_SOURCE 65# undef _DARWIN_C_SOURCE 66#endif 67/* Enable GNU extensions on systems that have them. */ 68#ifndef _GNU_SOURCE 69# undef _GNU_SOURCE 70#endif 71/* Enable NetBSD extensions on NetBSD. */ 72#ifndef _NETBSD_SOURCE 73# undef _NETBSD_SOURCE 74#endif 75/* Enable OpenBSD extensions on NetBSD. */ 76#ifndef _OPENBSD_SOURCE 77# undef _OPENBSD_SOURCE 78#endif 79/* Enable threading extensions on Solaris. */ 80#ifndef _POSIX_PTHREAD_SEMANTICS 81# undef _POSIX_PTHREAD_SEMANTICS 82#endif 83/* Enable extensions specified by ISO/IEC TS 18661-5:2014. */ 84#ifndef __STDC_WANT_IEC_60559_ATTRIBS_EXT__ 85# undef __STDC_WANT_IEC_60559_ATTRIBS_EXT__ 86#endif 87/* Enable extensions specified by ISO/IEC TS 18661-1:2014. */ 88#ifndef __STDC_WANT_IEC_60559_BFP_EXT__ 89# undef __STDC_WANT_IEC_60559_BFP_EXT__ 90#endif 91/* Enable extensions specified by ISO/IEC TS 18661-2:2015. */ 92#ifndef __STDC_WANT_IEC_60559_DFP_EXT__ 93# undef __STDC_WANT_IEC_60559_DFP_EXT__ 94#endif 95/* Enable extensions specified by ISO/IEC TS 18661-4:2015. */ 96#ifndef __STDC_WANT_IEC_60559_FUNCS_EXT__ 97# undef __STDC_WANT_IEC_60559_FUNCS_EXT__ 98#endif 99/* Enable extensions specified by ISO/IEC TS 18661-3:2015. */ 100#ifndef __STDC_WANT_IEC_60559_TYPES_EXT__ 101# undef __STDC_WANT_IEC_60559_TYPES_EXT__ 102#endif 103/* Enable extensions specified by ISO/IEC TR 24731-2:2010. */ 104#ifndef __STDC_WANT_LIB_EXT2__ 105# undef __STDC_WANT_LIB_EXT2__ 106#endif 107/* Enable extensions specified by ISO/IEC 24747:2009. */ 108#ifndef __STDC_WANT_MATH_SPEC_FUNCS__ 109# undef __STDC_WANT_MATH_SPEC_FUNCS__ 110#endif 111/* Enable extensions on HP NonStop. */ 112#ifndef _TANDEM_SOURCE 113# undef _TANDEM_SOURCE 114#endif 115/* Enable X/Open extensions if necessary. HP-UX 11.11 defines 116 mbstate_t only if _XOPEN_SOURCE is defined to 500, regardless of 117 whether compiling with -Ae or -D_HPUX_SOURCE=1. */ 118#ifndef _XOPEN_SOURCE 119# undef _XOPEN_SOURCE 120#endif 121/* Enable X/Open compliant socket functions that do not require linking 122 with -lxnet on HP-UX 11.11. */ 123#ifndef _HPUX_ALT_XOPEN_SOCKET_API 124# undef _HPUX_ALT_XOPEN_SOCKET_API 125#endif 126/* Enable general extensions on Solaris. */ 127#ifndef __EXTENSIONS__ 128# undef __EXTENSIONS__ 129#endif 130]) 131 AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__], 132 [ac_cv_safe_to_define___extensions__], 133 [AC_COMPILE_IFELSE( 134 [AC_LANG_PROGRAM([[ 135# define __EXTENSIONS__ 1 136 ]AC_INCLUDES_DEFAULT])], 137 [ac_cv_safe_to_define___extensions__=yes], 138 [ac_cv_safe_to_define___extensions__=no])]) 139 test $ac_cv_safe_to_define___extensions__ = yes && 140 AC_DEFINE([__EXTENSIONS__]) 141 AC_DEFINE([_ALL_SOURCE]) 142 AC_DEFINE([_DARWIN_C_SOURCE]) 143 AC_DEFINE([_GNU_SOURCE]) 144 AC_DEFINE([_NETBSD_SOURCE]) 145 AC_DEFINE([_OPENBSD_SOURCE]) 146 AC_DEFINE([_POSIX_PTHREAD_SEMANTICS]) 147 AC_DEFINE([__STDC_WANT_IEC_60559_ATTRIBS_EXT__]) 148 AC_DEFINE([__STDC_WANT_IEC_60559_BFP_EXT__]) 149 AC_DEFINE([__STDC_WANT_IEC_60559_DFP_EXT__]) 150 AC_DEFINE([__STDC_WANT_IEC_60559_FUNCS_EXT__]) 151 AC_DEFINE([__STDC_WANT_IEC_60559_TYPES_EXT__]) 152 AC_DEFINE([__STDC_WANT_LIB_EXT2__]) 153 AC_DEFINE([__STDC_WANT_MATH_SPEC_FUNCS__]) 154 AC_DEFINE([_TANDEM_SOURCE]) 155 AC_CACHE_CHECK([whether _XOPEN_SOURCE should be defined], 156 [ac_cv_should_define__xopen_source], 157 [ac_cv_should_define__xopen_source=no 158 AC_COMPILE_IFELSE( 159 [AC_LANG_PROGRAM([[ 160 #include <wchar.h> 161 mbstate_t x;]])], 162 [], 163 [AC_COMPILE_IFELSE( 164 [AC_LANG_PROGRAM([[ 165 #define _XOPEN_SOURCE 500 166 #include <wchar.h> 167 mbstate_t x;]])], 168 [ac_cv_should_define__xopen_source=yes])])]) 169 test $ac_cv_should_define__xopen_source = yes && 170 AC_DEFINE([_XOPEN_SOURCE], [500]) 171 AC_DEFINE([_HPUX_ALT_XOPEN_SOCKET_API]) 172])# AC_USE_SYSTEM_EXTENSIONS 173 174# gl_USE_SYSTEM_EXTENSIONS 175# ------------------------ 176# Enable extensions on systems that normally disable them, 177# typically due to standards-conformance issues. 178AC_DEFUN_ONCE([gl_USE_SYSTEM_EXTENSIONS], 179[ 180 dnl Require this macro before AC_USE_SYSTEM_EXTENSIONS. 181 dnl gnulib does not need it. But if it gets required by third-party macros 182 dnl after AC_USE_SYSTEM_EXTENSIONS is required, autoconf 2.62..2.63 emit a 183 dnl warning: "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS". 184 dnl Note: We can do this only for one of the macros AC_AIX, AC_GNU_SOURCE, 185 dnl AC_MINIX. If people still use AC_AIX or AC_MINIX, they are out of luck. 186 AC_REQUIRE([AC_GNU_SOURCE]) 187 188 AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) 189]) 190