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Diffstat (limited to 'm4/extensions.m4')
| -rw-r--r-- | m4/extensions.m4 | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/m4/extensions.m4 b/m4/extensions.m4 new file mode 100644 index 0000000..0b3e4b5 --- /dev/null +++ b/m4/extensions.m4 @@ -0,0 +1,227 @@ +# serial 22 -*- Autoconf -*- +# Enable extensions on systems that normally disable them. + +# Copyright (C) 2003, 2006-2022 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 +]) |