summaryrefslogtreecommitdiffstats
path: root/m4/extensions.m4
diff options
context:
space:
mode:
Diffstat (limited to 'm4/extensions.m4')
-rw-r--r--m4/extensions.m4227
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
+])