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1 /* Copyright (C) 1991-1993,1995-2000,2001,2002 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
19 #ifndef _FEATURES_H
20 #define _FEATURES_H 1
22 /* These are defined by the user (or the compiler)
23 to specify the desired environment:
25 __STRICT_ANSI__ ISO Standard C.
26 _ISOC99_SOURCE Extensions to ISO C89 from ISO C99.
27 _POSIX_SOURCE IEEE Std 1003.1.
28 _POSIX_C_SOURCE If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2;
29 if >=199309L, add IEEE Std 1003.1b-1993;
30 if >=199506L, add IEEE Std 1003.1c-1995
31 _XOPEN_SOURCE Includes POSIX and XPG things. Set to 500 if
32 Single Unix conformance is wanted, to 600 for the
33 upcoming sixth revision.
34 _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
35 _LARGEFILE_SOURCE Some more functions for correct standard I/O.
36 _LARGEFILE64_SOURCE Additional functionality from LFS for large files.
37 _FILE_OFFSET_BITS=N Select default filesystem interface.
38 _BSD_SOURCE ISO C, POSIX, and 4.3BSD things.
39 _SVID_SOURCE ISO C, POSIX, and SVID things.
40 _GNU_SOURCE All of the above, plus GNU extensions.
41 _REENTRANT Select additionally reentrant object.
42 _THREAD_SAFE Same as _REENTRANT, often used by other systems.
44 The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
45 If none of these are defined, the default is to have _SVID_SOURCE,
46 _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
47 199506L. If more than one of these are defined, they accumulate.
48 For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
49 together give you ISO C, 1003.1, and 1003.2, but nothing else.
51 These are defined by this file and are used by the
52 header files to decide what to declare or define:
54 __USE_ISOC99 Define ISO C99 things.
55 __USE_POSIX Define IEEE Std 1003.1 things.
56 __USE_POSIX2 Define IEEE Std 1003.2 things.
57 __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
58 __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things.
59 __USE_XOPEN Define XPG things.
60 __USE_XOPEN_EXTENDED Define X/Open Unix things.
61 __USE_UNIX98 Define Single Unix V2 things.
62 __USE_XOPEN2K Define XPG6 things.
63 __USE_LARGEFILE Define correct standard I/O things.
64 __USE_LARGEFILE64 Define LFS things with separate names.
65 __USE_FILE_OFFSET64 Define 64bit interface as default.
66 __USE_BSD Define 4.3BSD things.
67 __USE_SVID Define SVID things.
68 __USE_MISC Define things common to BSD and System V Unix.
69 __USE_GNU Define GNU extensions.
70 __USE_REENTRANT Define reentrant/thread-safe *_r functions.
71 __FAVOR_BSD Favor 4.3BSD things in cases of conflict.
73 The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
74 defined by this file unconditionally. `__GNU_LIBRARY__' is provided
75 only for compatibility. All new code should use the other symbols
76 to test for features.
78 All macros listed above as possibly being defined by this file are
79 explicitly undefined if they are not explicitly defined.
80 Feature-test macros that are not defined by the user or compiler
81 but are implied by the other feature-test macros defined (or by the
82 lack of any definitions) are defined by the file. */
85 /* Undefine everything, so we get a clean slate. */
86 #undef __USE_ISOC99
87 #undef __USE_POSIX
88 #undef __USE_POSIX2
89 #undef __USE_POSIX199309
90 #undef __USE_POSIX199506
91 #undef __USE_XOPEN
92 #undef __USE_XOPEN_EXTENDED
93 #undef __USE_UNIX98
94 #undef __USE_XOPEN2K
95 #undef __USE_LARGEFILE
96 #undef __USE_LARGEFILE64
97 #undef __USE_FILE_OFFSET64
98 #undef __USE_BSD
99 #undef __USE_SVID
100 #undef __USE_MISC
101 #undef __USE_GNU
102 #undef __USE_REENTRANT
103 #undef __FAVOR_BSD
104 #undef __KERNEL_STRICT_NAMES
106 /* Suppress kernel-name space pollution unless user expressedly asks
107 for it. */
108 #ifndef _LOOSE_KERNEL_NAMES
109 # define __KERNEL_STRICT_NAMES
110 #endif
112 /* Always use ISO C things. */
113 #define __USE_ANSI 1
116 /* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
117 #if defined _BSD_SOURCE && \
118 !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
119 defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
120 defined _GNU_SOURCE || defined _SVID_SOURCE)
121 # define __FAVOR_BSD 1
122 #endif
124 /* If _GNU_SOURCE was defined by the user, turn on all the other features. */
125 #ifdef _GNU_SOURCE
126 # undef _ISOC99_SOURCE
127 # define _ISOC99_SOURCE 1
128 # undef _POSIX_SOURCE
129 # define _POSIX_SOURCE 1
130 # undef _POSIX_C_SOURCE
131 # define _POSIX_C_SOURCE 199506L
132 # undef _XOPEN_SOURCE
133 # define _XOPEN_SOURCE 600
134 # undef _XOPEN_SOURCE_EXTENDED
135 # define _XOPEN_SOURCE_EXTENDED 1
136 # undef _LARGEFILE64_SOURCE
137 # define _LARGEFILE64_SOURCE 1
138 # undef _BSD_SOURCE
139 # define _BSD_SOURCE 1
140 # undef _SVID_SOURCE
141 # define _SVID_SOURCE 1
142 #endif
144 /* If nothing (other than _GNU_SOURCE) is defined,
145 define _BSD_SOURCE and _SVID_SOURCE. */
146 #if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
147 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
148 !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
149 !defined _BSD_SOURCE && !defined _SVID_SOURCE)
150 # define _BSD_SOURCE 1
151 # define _SVID_SOURCE 1
152 #endif
154 /* This is to enable the ISO C99 extension. Also recognize the old macro
155 which was used prior to the standard acceptance. This macro will
156 eventually go away and the features enabled by default once the ISO C99
157 standard is widely adopted. */
158 #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
159 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
160 # define __USE_ISOC99 1
161 #endif
163 /* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
164 (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
165 #if (!defined __STRICT_ANSI__ && !defined _POSIX_SOURCE && \
166 !defined _POSIX_C_SOURCE)
167 # define _POSIX_SOURCE 1
168 # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
169 # define _POSIX_C_SOURCE 2
170 # else
171 # define _POSIX_C_SOURCE 199506L
172 # endif
173 #endif
175 #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
176 # define __USE_POSIX 1
177 #endif
179 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
180 # define __USE_POSIX2 1
181 #endif
183 #if (_POSIX_C_SOURCE - 0) >= 199309L
184 # define __USE_POSIX199309 1
185 #endif
187 #if (_POSIX_C_SOURCE - 0) >= 199506L
188 # define __USE_POSIX199506 1
189 #endif
191 #ifdef _XOPEN_SOURCE
192 # define __USE_XOPEN 1
193 # if (_XOPEN_SOURCE - 0) >= 500
194 # define __USE_XOPEN_EXTENDED 1
195 # define __USE_UNIX98 1
196 # undef _LARGEFILE_SOURCE
197 # define _LARGEFILE_SOURCE 1
198 # if (_XOPEN_SOURCE - 0) >= 600
199 # define __USE_XOPEN2K 1
200 # undef __USE_ISOC99
201 # define __USE_ISOC99 1
202 # endif
203 # else
204 # ifdef _XOPEN_SOURCE_EXTENDED
205 # define __USE_XOPEN_EXTENDED 1
206 # endif
207 # endif
208 #endif
210 #ifdef _LARGEFILE_SOURCE
211 # define __USE_LARGEFILE 1
212 #endif
214 #ifdef _LARGEFILE64_SOURCE
215 # define __USE_LARGEFILE64 1
216 #endif
218 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
219 # define __USE_FILE_OFFSET64 1
220 #endif
222 #if defined _BSD_SOURCE || defined _SVID_SOURCE
223 # define __USE_MISC 1
224 #endif
226 #ifdef _BSD_SOURCE
227 # define __USE_BSD 1
228 #endif
230 #ifdef _SVID_SOURCE
231 # define __USE_SVID 1
232 #endif
234 #ifdef _GNU_SOURCE
235 # define __USE_GNU 1
236 #endif
238 #if defined _REENTRANT || defined _THREAD_SAFE
239 # define __USE_REENTRANT 1
240 #endif
242 /* We do support the IEC 559 math functionality, real and complex. */
243 #define __STDC_IEC_559__ 1
244 #define __STDC_IEC_559_COMPLEX__ 1
246 /* wchar_t uses ISO 10646-1 (2nd ed., published 2000-09-15) / Unicode 3.1. */
247 #define __STDC_ISO_10646__ 200009L
249 /* This macro indicates that the installed library is the GNU C Library.
250 For historic reasons the value now is 6 and this will stay from now
251 on. The use of this variable is deprecated. Use __GLIBC__ and
252 __GLIBC_MINOR__ now (see below) when you want to test for a specific
253 GNU C library version and use the values in <gnu/lib-names.h> to get
254 the sonames of the shared libraries. */
255 #undef __GNU_LIBRARY__
256 #define __GNU_LIBRARY__ 6
258 /* Major and minor version number of the GNU C library package. Use
259 these macros to test for features in specific releases. */
260 #define __GLIBC__ 2
261 #define __GLIBC_MINOR__ 3
263 /* Convenience macros to test the versions of glibc and gcc.
264 Use them like this:
265 #if __GNUC_PREREQ (2,8)
266 ... code requiring gcc 2.8 or later ...
267 #endif
268 Note - they won't work for gcc1 or glibc1, since the _MINOR macros
269 were not defined then. */
270 #if defined __GNUC__ && defined __GNUC_MINOR__
271 # define __GNUC_PREREQ(maj, min) \
272 ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
273 #else
274 # define __GNUC_PREREQ(maj, min) 0
275 #endif
277 #define __GLIBC_PREREQ(maj, min) \
278 ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
280 /* Decide whether a compiler supports the long long datatypes. */
281 #if defined __GNUC__ \
282 || (defined __PGI && defined __i386__ ) \
283 || (defined __INTEL_COMPILER && (defined __i386__ || defined __ia64__)) \
284 || (defined __STDC_VERSION && __STDC_VERSION >= 199901L)
285 # define __GLIBC_HAVE_LONG_LONG 1
286 #endif
288 /* This is here only because every header file already includes this one. */
289 #ifndef __ASSEMBLER__
290 # ifndef _SYS_CDEFS_H
291 # include <sys/cdefs.h>
292 # endif
294 /* If we don't have __REDIRECT, prototypes will be missing if
295 __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
296 # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
297 # define __USE_LARGEFILE 1
298 # define __USE_LARGEFILE64 1
299 # endif
303 /* Decide whether we can define 'extern inline' functions in headers. */
304 #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
305 && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__
306 # define __USE_EXTERN_INLINES 1
307 #endif
309 /* This is here only because every header file already includes this one. */
310 #ifndef _LIBC
311 /* Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
312 <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
313 which will always return failure (and set errno to ENOSYS).
315 We avoid including <gnu/stubs.h> when compiling the C library itself to
316 avoid a dependency loop. stubs.h depends on every object file. If
317 this #include were done for the library source code, then every object
318 file would depend on stubs.h. */
320 # include <gnu/stubs.h>
321 #endif