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1 | # serial 13 -*- Autoconf -*- |
2 | # Enable extensions on systems that normally disable them. | |
3 | ||
4 | # Copyright (C) 2003, 2006-2016 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__). | |
38 | AC_DEFUN_ONCE([AC_USE_SYSTEM_EXTENSIONS], | |
39 | [AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl | |
40 | AC_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 | ||
56 | dnl Use a different key than __EXTENSIONS__, as that name broke existing | |
57 | dnl 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 OS X. */ | |
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 | /* Use GNU style printf and scanf. */ | |
72 | #ifndef __USE_MINGW_ANSI_STDIO | |
73 | # undef __USE_MINGW_ANSI_STDIO | |
74 | #endif | |
75 | /* Enable threading extensions on Solaris. */ | |
76 | #ifndef _POSIX_PTHREAD_SEMANTICS | |
77 | # undef _POSIX_PTHREAD_SEMANTICS | |
78 | #endif | |
79 | /* Enable extensions on HP NonStop. */ | |
80 | #ifndef _TANDEM_SOURCE | |
81 | # undef _TANDEM_SOURCE | |
82 | #endif | |
83 | /* Enable X/Open extensions if necessary. HP-UX 11.11 defines | |
84 | mbstate_t only if _XOPEN_SOURCE is defined to 500, regardless of | |
85 | whether compiling with -Ae or -D_HPUX_SOURCE=1. */ | |
86 | #ifndef _XOPEN_SOURCE | |
87 | # undef _XOPEN_SOURCE | |
88 | #endif | |
89 | /* Enable general extensions on Solaris. */ | |
90 | #ifndef __EXTENSIONS__ | |
91 | # undef __EXTENSIONS__ | |
92 | #endif | |
93 | ]) | |
94 | AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__], | |
95 | [ac_cv_safe_to_define___extensions__], | |
96 | [AC_COMPILE_IFELSE( | |
97 | [AC_LANG_PROGRAM([[ | |
98 | # define __EXTENSIONS__ 1 | |
99 | ]AC_INCLUDES_DEFAULT])], | |
100 | [ac_cv_safe_to_define___extensions__=yes], | |
101 | [ac_cv_safe_to_define___extensions__=no])]) | |
102 | test $ac_cv_safe_to_define___extensions__ = yes && | |
103 | AC_DEFINE([__EXTENSIONS__]) | |
104 | AC_DEFINE([_ALL_SOURCE]) | |
105 | AC_DEFINE([_DARWIN_C_SOURCE]) | |
106 | AC_DEFINE([_GNU_SOURCE]) | |
107 | AC_DEFINE([__USE_MINGW_ANSI_STDIO]) | |
108 | AC_DEFINE([_POSIX_PTHREAD_SEMANTICS]) | |
109 | AC_DEFINE([_TANDEM_SOURCE]) | |
110 | AC_CACHE_CHECK([whether _XOPEN_SOURCE should be defined], | |
111 | [ac_cv_should_define__xopen_source], | |
112 | [ac_cv_should_define__xopen_source=no | |
113 | AC_COMPILE_IFELSE( | |
114 | [AC_LANG_PROGRAM([[ | |
115 | #include <wchar.h> | |
116 | mbstate_t x;]])], | |
117 | [], | |
118 | [AC_COMPILE_IFELSE( | |
119 | [AC_LANG_PROGRAM([[ | |
120 | #define _XOPEN_SOURCE 500 | |
121 | #include <wchar.h> | |
122 | mbstate_t x;]])], | |
123 | [ac_cv_should_define__xopen_source=yes])])]) | |
124 | test $ac_cv_should_define__xopen_source = yes && | |
125 | AC_DEFINE([_XOPEN_SOURCE], [500]) | |
126 | ])# AC_USE_SYSTEM_EXTENSIONS | |
127 | ||
128 | # gl_USE_SYSTEM_EXTENSIONS | |
129 | # ------------------------ | |
130 | # Enable extensions on systems that normally disable them, | |
131 | # typically due to standards-conformance issues. | |
132 | AC_DEFUN_ONCE([gl_USE_SYSTEM_EXTENSIONS], | |
133 | [ | |
134 | dnl Require this macro before AC_USE_SYSTEM_EXTENSIONS. | |
135 | dnl gnulib does not need it. But if it gets required by third-party macros | |
136 | dnl after AC_USE_SYSTEM_EXTENSIONS is required, autoconf 2.62..2.63 emit a | |
137 | dnl warning: "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS". | |
138 | dnl Note: We can do this only for one of the macros AC_AIX, AC_GNU_SOURCE, | |
139 | dnl AC_MINIX. If people still use AC_AIX or AC_MINIX, they are out of luck. | |
140 | AC_REQUIRE([AC_GNU_SOURCE]) | |
141 | ||
142 | AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) | |
143 | ]) |