# serial 22 -*- Autoconf -*-
# Enable extensions on systems that normally disable them.
# Copyright (C) 2003, 2006-2021 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.
dnl Define to empty for the benefit of Autoconf 2.69 and earlier, so that
dnl AC_USE_SYSTEM_EXTENSIONS (below) can be used unchanged from Autoconf 2.70+.
m4_ifndef([AC_CHECK_INCLUDES_DEFAULT],
[AC_DEFUN([AC_CHECK_INCLUDES_DEFAULT], [])])
# This definition of AC_USE_SYSTEM_EXTENSIONS is stolen from git
# Autoconf. Perhaps we can remove this once we can assume Autoconf
# is recent-enough everywhere, but since Autoconf mutates rapidly
# enough in this area it's likely we'll need to redefine
# AC_USE_SYSTEM_EXTENSIONS for quite some time.
# If autoconf reports a warning
# warning: AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS
# or warning: AC_RUN_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS
# the fix is
# 1) to ensure that AC_USE_SYSTEM_EXTENSIONS is never directly invoked
# but always AC_REQUIREd,
# 2) to ensure that for each occurrence of
# AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
# or
# AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
# the corresponding gnulib module description has 'extensions' among
# its dependencies. This will ensure that the gl_USE_SYSTEM_EXTENSIONS
# invocation occurs in gl_EARLY, not in gl_INIT.
m4_version_prereq([2.70.1], [], [
# AC_USE_SYSTEM_EXTENSIONS
# ------------------------
# Enable extensions on systems that normally disable them,
# typically due to standards-conformance issues.
# We unconditionally define as many of the known feature-enabling
# as possible, reserving conditional behavior for macros that are
# known to cause problems on some platforms (such as __EXTENSIONS__).
AC_DEFUN_ONCE([AC_USE_SYSTEM_EXTENSIONS],
[AC_BEFORE([$0], [AC_PREPROC_IFELSE])dnl
AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl
AC_BEFORE([$0], [AC_LINK_IFELSE])dnl
AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
AC_BEFORE([$0], [AC_CHECK_INCLUDES_DEFAULT])dnl
dnl #undef in AH_VERBATIM gets replaced with #define by AC_DEFINE.
dnl Use a different key than __EXTENSIONS__, as that name broke existing
dnl configure.ac when using autoheader 2.62.
dnl The macros below are in alphabetical order ignoring leading _ or __
dnl prefixes.
AH_VERBATIM([USE_SYSTEM_EXTENSIONS],
[/* Enable extensions on AIX 3, Interix. */
#ifndef _ALL_SOURCE
# undef _ALL_SOURCE
#endif
/* Enable general extensions on macOS. */
#ifndef _DARWIN_C_SOURCE
# undef _DARWIN_C_SOURCE
#endif
/* Enable general extensions on Solaris. */
#ifndef __EXTENSIONS__
# undef __EXTENSIONS__
#endif
/* Enable GNU extensions on systems that have them. */
#ifndef _GNU_SOURCE
# undef _GNU_SOURCE
#endif
/* Enable X/Open compliant socket functions that do not require linking
with -lxnet on HP-UX 11.11. */
#ifndef _HPUX_ALT_XOPEN_SOCKET_API
# undef _HPUX_ALT_XOPEN_SOCKET_API
#endif
/* Identify the host operating system as Minix.
This macro does not affect the system headers' behavior.
A future release of Autoconf may stop defining this macro. */
#ifndef _MINIX
# undef _MINIX
#endif
/* Enable general extensions on NetBSD.
Enable NetBSD compatibility extensions on Minix. */
#ifndef _NETBSD_SOURCE
# undef _NETBSD_SOURCE
#endif
/* Enable OpenBSD compatibility extensions on NetBSD.
Oddly enough, this does nothing on OpenBSD. */
#ifndef _OPENBSD_SOURCE
# undef _OPENBSD_SOURCE
#endif
/* Define to 1 if needed for POSIX-compatible behavior. */
#ifndef _POSIX_SOURCE
# undef _POSIX_SOURCE
#endif
/* Define to 2 if needed for POSIX-compatible behavior. */
#ifndef _POSIX_1_SOURCE
# undef _POSIX_1_SOURCE
#endif
/* Enable POSIX-compatible threading on Solaris. */
#ifndef _POSIX_PTHREAD_SEMANTICS
# undef _POSIX_PTHREAD_SEMANTICS
#endif
/* Enable extensions specified by ISO/IEC TS 18661-5:2014. */
#ifndef __STDC_WANT_IEC_60559_ATTRIBS_EXT__
# undef __STDC_WANT_IEC_60559_ATTRIBS_EXT__
#endif
/* Enable extensions specified by ISO/IEC TS 18661-1:2014. */
#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
# undef __STDC_WANT_IEC_60559_BFP_EXT__
#endif
/* Enable extensions specified by ISO/IEC TS 18661-2:2015. */
#ifndef __STDC_WANT_IEC_60559_DFP_EXT__
# undef __STDC_WANT_IEC_60559_DFP_EXT__
#endif
/* Enable extensions specified by ISO/IEC TS 18661-4:2015. */
#ifndef __STDC_WANT_IEC_60559_FUNCS_EXT__
# undef __STDC_WANT_IEC_60559_FUNCS_EXT__
#endif
/* Enable extensions specified by ISO/IEC TS 18661-3:2015. */
#ifndef __STDC_WANT_IEC_60559_TYPES_EXT__
# undef __STDC_WANT_IEC_60559_TYPES_EXT__
#endif
/* Enable extensions specified by ISO/IEC TR 24731-2:2010. */
#ifndef __STDC_WANT_LIB_EXT2__
# undef __STDC_WANT_LIB_EXT2__
#endif
/* Enable extensions specified by ISO/IEC 24747:2009. */
#ifndef __STDC_WANT_MATH_SPEC_FUNCS__
# undef __STDC_WANT_MATH_SPEC_FUNCS__
#endif
/* Enable extensions on HP NonStop. */
#ifndef _TANDEM_SOURCE
# undef _TANDEM_SOURCE
#endif
/* Enable X/Open extensions. Define to 500 only if necessary
to make mbstate_t available. */
#ifndef _XOPEN_SOURCE
# undef _XOPEN_SOURCE
#endif
])dnl
AC_REQUIRE([AC_CHECK_INCLUDES_DEFAULT])dnl
_AC_CHECK_HEADER_ONCE([wchar.h])
_AC_CHECK_HEADER_ONCE([minix/config.h])
dnl Defining __EXTENSIONS__ may break the system headers on some systems.
dnl (FIXME: Which ones?)
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])])
dnl HP-UX 11.11 defines mbstate_t only if _XOPEN_SOURCE is defined to
dnl 500, regardless of whether compiling with -Ae or -D_HPUX_SOURCE=1.
dnl But defining _XOPEN_SOURCE may turn *off* extensions on platforms
dnl not covered by turn-on-extensions macros (notably Dragonfly, Free,
dnl and OpenBSD, which don't have any equivalent of _NETBSD_SOURCE) so
dnl it should only be defined when necessary.
AC_CACHE_CHECK([whether _XOPEN_SOURCE should be defined],
[ac_cv_should_define__xopen_source],
[ac_cv_should_define__xopen_source=no
AS_IF([test $ac_cv_header_wchar_h = yes],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([[
#include <wchar.h>
mbstate_t x;]])],
[],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([[
#define _XOPEN_SOURCE 500
#include <wchar.h>
mbstate_t x;]])],
[ac_cv_should_define__xopen_source=yes])])])])
AC_DEFINE([_ALL_SOURCE])
AC_DEFINE([_DARWIN_C_SOURCE])
AC_DEFINE([_GNU_SOURCE])
AC_DEFINE([_HPUX_ALT_XOPEN_SOCKET_API])
AC_DEFINE([_NETBSD_SOURCE])
AC_DEFINE([_OPENBSD_SOURCE])
AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
AC_DEFINE([__STDC_WANT_IEC_60559_ATTRIBS_EXT__])
AC_DEFINE([__STDC_WANT_IEC_60559_BFP_EXT__])
AC_DEFINE([__STDC_WANT_IEC_60559_DFP_EXT__])
AC_DEFINE([__STDC_WANT_IEC_60559_FUNCS_EXT__])
AC_DEFINE([__STDC_WANT_IEC_60559_TYPES_EXT__])
AC_DEFINE([__STDC_WANT_LIB_EXT2__])
AC_DEFINE([__STDC_WANT_MATH_SPEC_FUNCS__])
AC_DEFINE([_TANDEM_SOURCE])
AS_IF([test $ac_cv_header_minix_config_h = yes],
[MINIX=yes
AC_DEFINE([_MINIX])
AC_DEFINE([_POSIX_SOURCE])
AC_DEFINE([_POSIX_1_SOURCE], [2])],
[MINIX=])
AS_IF([test $ac_cv_safe_to_define___extensions__ = yes],
[AC_DEFINE([__EXTENSIONS__])])
AS_IF([test $ac_cv_should_define__xopen_source = yes],
[AC_DEFINE([_XOPEN_SOURCE], [500])])
])# AC_USE_SYSTEM_EXTENSIONS
])
# gl_USE_SYSTEM_EXTENSIONS
# ------------------------
# Enable extensions on systems that normally disable them,
# typically due to standards-conformance issues.
AC_DEFUN_ONCE([gl_USE_SYSTEM_EXTENSIONS],
[
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
dnl On OpenBSD 6.8 with GCC, the include files contain a couple of
dnl definitions that are only activated with an explicit -D_ISOC11_SOURCE.
dnl That's because this version of GCC (4.2.1) supports the option
dnl '-std=gnu99' but not the option '-std=gnu11'.
AC_REQUIRE([AC_CANONICAL_HOST])
case "$host_os" in
openbsd*)
AC_DEFINE([_ISOC11_SOURCE], [1],
[Define to enable the declarations of ISO C 11 types and functions.])
;;
esac
])