diff options
Diffstat (limited to 'm4/extensions.m4')
| -rw-r--r-- | m4/extensions.m4 | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/m4/extensions.m4 b/m4/extensions.m4 new file mode 100644 index 0000000..6d378ec --- /dev/null +++ b/m4/extensions.m4 @@ -0,0 +1,143 @@ +# serial 13 -*- Autoconf -*- +# Enable extensions on systems that normally disable them. + +# Copyright (C) 2003, 2006-2016 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. + +# This definition of AC_USE_SYSTEM_EXTENSIONS is stolen from git +# Autoconf. Perhaps we can remove this once we can assume Autoconf +# 2.70 or later 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. + +# AC_USE_SYSTEM_EXTENSIONS +# ------------------------ +# Enable extensions on systems that normally disable them, +# typically due to standards-conformance issues. +# +# Remember that #undef in AH_VERBATIM gets replaced with #define by +# AC_DEFINE. The goal here is to define all known feature-enabling +# macros, then, if reports of conflicts are made, disable macros that +# cause problems on some platforms (such as __EXTENSIONS__). +AC_DEFUN_ONCE([AC_USE_SYSTEM_EXTENSIONS], +[AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl +AC_BEFORE([$0], [AC_RUN_IFELSE])dnl + + AC_CHECK_HEADER([minix/config.h], [MINIX=yes], [MINIX=]) + if test "$MINIX" = yes; then + AC_DEFINE([_POSIX_SOURCE], [1], + [Define to 1 if you need to in order for 'stat' and other + things to work.]) + AC_DEFINE([_POSIX_1_SOURCE], [2], + [Define to 2 if the system does not provide POSIX.1 features + except with this defined.]) + AC_DEFINE([_MINIX], [1], + [Define to 1 if on MINIX.]) + AC_DEFINE([_NETBSD_SOURCE], [1], + [Define to 1 to make NetBSD features available. MINIX 3 needs this.]) + fi + +dnl Use a different key than __EXTENSIONS__, as that name broke existing +dnl configure.ac when using autoheader 2.62. + AH_VERBATIM([USE_SYSTEM_EXTENSIONS], +[/* Enable extensions on AIX 3, Interix. */ +#ifndef _ALL_SOURCE +# undef _ALL_SOURCE +#endif +/* Enable general extensions on OS X. */ +#ifndef _DARWIN_C_SOURCE +# undef _DARWIN_C_SOURCE +#endif +/* Enable GNU extensions on systems that have them. */ +#ifndef _GNU_SOURCE +# undef _GNU_SOURCE +#endif +/* Use GNU style printf and scanf. */ +#ifndef __USE_MINGW_ANSI_STDIO +# undef __USE_MINGW_ANSI_STDIO +#endif +/* Enable threading extensions on Solaris. */ +#ifndef _POSIX_PTHREAD_SEMANTICS +# undef _POSIX_PTHREAD_SEMANTICS +#endif +/* Enable extensions on HP NonStop. */ +#ifndef _TANDEM_SOURCE +# undef _TANDEM_SOURCE +#endif +/* Enable X/Open extensions if necessary. HP-UX 11.11 defines + mbstate_t only if _XOPEN_SOURCE is defined to 500, regardless of + whether compiling with -Ae or -D_HPUX_SOURCE=1. */ +#ifndef _XOPEN_SOURCE +# undef _XOPEN_SOURCE +#endif +/* Enable general extensions on Solaris. */ +#ifndef __EXTENSIONS__ +# undef __EXTENSIONS__ +#endif +]) + 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])]) + test $ac_cv_safe_to_define___extensions__ = yes && + AC_DEFINE([__EXTENSIONS__]) + AC_DEFINE([_ALL_SOURCE]) + AC_DEFINE([_DARWIN_C_SOURCE]) + AC_DEFINE([_GNU_SOURCE]) + AC_DEFINE([__USE_MINGW_ANSI_STDIO]) + AC_DEFINE([_POSIX_PTHREAD_SEMANTICS]) + AC_DEFINE([_TANDEM_SOURCE]) + AC_CACHE_CHECK([whether _XOPEN_SOURCE should be defined], + [ac_cv_should_define__xopen_source], + [ac_cv_should_define__xopen_source=no + 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])])]) + 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], +[ + dnl Require this macro before AC_USE_SYSTEM_EXTENSIONS. + dnl gnulib does not need it. But if it gets required by third-party macros + dnl after AC_USE_SYSTEM_EXTENSIONS is required, autoconf 2.62..2.63 emit a + dnl warning: "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS". + dnl Note: We can do this only for one of the macros AC_AIX, AC_GNU_SOURCE, + dnl AC_MINIX. If people still use AC_AIX or AC_MINIX, they are out of luck. + AC_REQUIRE([AC_GNU_SOURCE]) + + AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) +]) |