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1 /* Copyright (C) 1991,1992,1993,1995-2006,2007 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 if >=200112L, all of IEEE 1003.1-2004
32 _XOPEN_SOURCE Includes POSIX and XPG things. Set to 500 if
33 Single Unix conformance is wanted, to 600 for the
34 upcoming sixth revision.
35 _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
36 _LARGEFILE_SOURCE Some more functions for correct standard I/O.
37 _LARGEFILE64_SOURCE Additional functionality from LFS for large files.
38 _FILE_OFFSET_BITS=N Select default filesystem interface.
39 _BSD_SOURCE ISO C, POSIX, and 4.3BSD things.
40 _SVID_SOURCE ISO C, POSIX, and SVID things.
41 _ATFILE_SOURCE Additional *at interfaces.
42 _GNU_SOURCE All of the above, plus GNU extensions.
43 _REENTRANT Select additionally reentrant object.
44 _THREAD_SAFE Same as _REENTRANT, often used by other systems.
45 _FORTIFY_SOURCE If set to numeric value > 0 additional security
46 measures are defined, according to level.
48 The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
49 If none of these are defined, the default is to have _SVID_SOURCE,
50 _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
51 200112L. If more than one of these are defined, they accumulate.
52 For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
53 together give you ISO C, 1003.1, and 1003.2, but nothing else.
55 These are defined by this file and are used by the
56 header files to decide what to declare or define:
58 __USE_ISOC99 Define ISO C99 things.
59 __USE_ISOC95 Define ISO C90 AMD1 (C95) things.
60 __USE_POSIX Define IEEE Std 1003.1 things.
61 __USE_POSIX2 Define IEEE Std 1003.2 things.
62 __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
63 __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things.
64 __USE_XOPEN Define XPG things.
65 __USE_XOPEN_EXTENDED Define X/Open Unix things.
66 __USE_UNIX98 Define Single Unix V2 things.
67 __USE_XOPEN2K Define XPG6 things.
68 __USE_LARGEFILE Define correct standard I/O things.
69 __USE_LARGEFILE64 Define LFS things with separate names.
70 __USE_FILE_OFFSET64 Define 64bit interface as default.
71 __USE_BSD Define 4.3BSD things.
72 __USE_SVID Define SVID things.
73 __USE_MISC Define things common to BSD and System V Unix.
74 __USE_ATFILE Define *at interfaces and AT_* constants for them.
75 __USE_GNU Define GNU extensions.
76 __USE_REENTRANT Define reentrant/thread-safe *_r functions.
77 __USE_FORTIFY_LEVEL Additional security measures used, according to level.
78 __FAVOR_BSD Favor 4.3BSD things in cases of conflict.
80 The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
81 defined by this file unconditionally. `__GNU_LIBRARY__' is provided
82 only for compatibility. All new code should use the other symbols
83 to test for features.
85 All macros listed above as possibly being defined by this file are
86 explicitly undefined if they are not explicitly defined.
87 Feature-test macros that are not defined by the user or compiler
88 but are implied by the other feature-test macros defined (or by the
89 lack of any definitions) are defined by the file. */
92 /* Undefine everything, so we get a clean slate. */
93 #undef __USE_ISOC99
94 #undef __USE_ISOC95
95 #undef __USE_POSIX
96 #undef __USE_POSIX2
97 #undef __USE_POSIX199309
98 #undef __USE_POSIX199506
99 #undef __USE_XOPEN
100 #undef __USE_XOPEN_EXTENDED
101 #undef __USE_UNIX98
102 #undef __USE_XOPEN2K
103 #undef __USE_LARGEFILE
104 #undef __USE_LARGEFILE64
105 #undef __USE_FILE_OFFSET64
106 #undef __USE_BSD
107 #undef __USE_SVID
108 #undef __USE_MISC
109 #undef __USE_ATFILE
110 #undef __USE_GNU
111 #undef __USE_REENTRANT
112 #undef __USE_FORTIFY_LEVEL
113 #undef __FAVOR_BSD
114 #undef __KERNEL_STRICT_NAMES
116 /* Suppress kernel-name space pollution unless user expressedly asks
117 for it. */
118 #ifndef _LOOSE_KERNEL_NAMES
119 # define __KERNEL_STRICT_NAMES
120 #endif
122 /* Always use ISO C things. */
123 #define __USE_ANSI 1
125 /* Convenience macros to test the versions of glibc and gcc.
126 Use them like this:
127 #if __GNUC_PREREQ (2,8)
128 ... code requiring gcc 2.8 or later ...
129 #endif
130 Note - they won't work for gcc1 or glibc1, since the _MINOR macros
131 were not defined then. */
132 #if defined __GNUC__ && defined __GNUC_MINOR__
133 # define __GNUC_PREREQ(maj, min) \
134 ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
135 #else
136 # define __GNUC_PREREQ(maj, min) 0
137 #endif
140 /* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
141 #if defined _BSD_SOURCE && \
142 !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
143 defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
144 defined _GNU_SOURCE || defined _SVID_SOURCE)
145 # define __FAVOR_BSD 1
146 #endif
148 /* If _GNU_SOURCE was defined by the user, turn on all the other features. */
149 #ifdef _GNU_SOURCE
150 # undef _ISOC99_SOURCE
151 # define _ISOC99_SOURCE 1
152 # undef _POSIX_SOURCE
153 # define _POSIX_SOURCE 1
154 # undef _POSIX_C_SOURCE
155 # define _POSIX_C_SOURCE 200112L
156 # undef _XOPEN_SOURCE
157 # define _XOPEN_SOURCE 600
158 # undef _XOPEN_SOURCE_EXTENDED
159 # define _XOPEN_SOURCE_EXTENDED 1
160 # undef _LARGEFILE64_SOURCE
161 # define _LARGEFILE64_SOURCE 1
162 # undef _BSD_SOURCE
163 # define _BSD_SOURCE 1
164 # undef _SVID_SOURCE
165 # define _SVID_SOURCE 1
166 # undef _ATFILE_SOURCE
167 # define _ATFILE_SOURCE 1
168 #endif
170 /* If nothing (other than _GNU_SOURCE) is defined,
171 define _BSD_SOURCE and _SVID_SOURCE. */
172 #if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
173 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
174 !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
175 !defined _BSD_SOURCE && !defined _SVID_SOURCE)
176 # define _BSD_SOURCE 1
177 # define _SVID_SOURCE 1
178 #endif
180 /* This is to enable the ISO C99 extension. Also recognize the old macro
181 which was used prior to the standard acceptance. This macro will
182 eventually go away and the features enabled by default once the ISO C99
183 standard is widely adopted. */
184 #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
185 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
186 # define __USE_ISOC99 1
187 #endif
189 /* This is to enable the ISO C90 Amendment 1:1995 extension. */
190 #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
191 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
192 # define __USE_ISOC95 1
193 #endif
195 /* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
196 (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
197 #if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
198 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
199 # define _POSIX_SOURCE 1
200 # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
201 # define _POSIX_C_SOURCE 2
202 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
203 # define _POSIX_C_SOURCE 199506L
204 # else
205 # define _POSIX_C_SOURCE 200112L
206 # endif
207 #endif
209 #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
210 # define __USE_POSIX 1
211 #endif
213 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
214 # define __USE_POSIX2 1
215 #endif
217 #if (_POSIX_C_SOURCE - 0) >= 199309L
218 # define __USE_POSIX199309 1
219 #endif
221 #if (_POSIX_C_SOURCE - 0) >= 199506L
222 # define __USE_POSIX199506 1
223 #endif
225 #if (_POSIX_C_SOURCE - 0) >= 200112L
226 # define __USE_XOPEN2K 1
227 #endif
229 #ifdef _XOPEN_SOURCE
230 # define __USE_XOPEN 1
231 # if (_XOPEN_SOURCE - 0) >= 500
232 # define __USE_XOPEN_EXTENDED 1
233 # define __USE_UNIX98 1
234 # undef _LARGEFILE_SOURCE
235 # define _LARGEFILE_SOURCE 1
236 # if (_XOPEN_SOURCE - 0) >= 600
237 # define __USE_XOPEN2K 1
238 # undef __USE_ISOC99
239 # define __USE_ISOC99 1
240 # endif
241 # else
242 # ifdef _XOPEN_SOURCE_EXTENDED
243 # define __USE_XOPEN_EXTENDED 1
244 # endif
245 # endif
246 #endif
248 #ifdef _LARGEFILE_SOURCE
249 # define __USE_LARGEFILE 1
250 #endif
252 #ifdef _LARGEFILE64_SOURCE
253 # define __USE_LARGEFILE64 1
254 #endif
256 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
257 # define __USE_FILE_OFFSET64 1
258 #endif
260 #if defined _BSD_SOURCE || defined _SVID_SOURCE
261 # define __USE_MISC 1
262 #endif
264 #ifdef _BSD_SOURCE
265 # define __USE_BSD 1
266 #endif
268 #ifdef _SVID_SOURCE
269 # define __USE_SVID 1
270 #endif
272 #ifdef _ATFILE_SOURCE
273 # define __USE_ATFILE 1
274 #endif
276 #ifdef _GNU_SOURCE
277 # define __USE_GNU 1
278 #endif
280 #if defined _REENTRANT || defined _THREAD_SAFE
281 # define __USE_REENTRANT 1
282 #endif
284 #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 \
285 && __GNUC_PREREQ (4, 1) && defined __OPTIMIZE__ && __OPTIMIZE__ > 0
286 # if _FORTIFY_SOURCE > 1
287 # define __USE_FORTIFY_LEVEL 2
288 # else
289 # define __USE_FORTIFY_LEVEL 1
290 # endif
291 #else
292 # define __USE_FORTIFY_LEVEL 0
293 #endif
295 /* We do support the IEC 559 math functionality, real and complex. */
296 #define __STDC_IEC_559__ 1
297 #define __STDC_IEC_559_COMPLEX__ 1
299 /* wchar_t uses ISO 10646-1 (2nd ed., published 2000-09-15) / Unicode 3.1. */
300 #define __STDC_ISO_10646__ 200009L
302 /* This macro indicates that the installed library is the GNU C Library.
303 For historic reasons the value now is 6 and this will stay from now
304 on. The use of this variable is deprecated. Use __GLIBC__ and
305 __GLIBC_MINOR__ now (see below) when you want to test for a specific
306 GNU C library version and use the values in <gnu/lib-names.h> to get
307 the sonames of the shared libraries. */
308 #undef __GNU_LIBRARY__
309 #define __GNU_LIBRARY__ 6
311 /* Major and minor version number of the GNU C library package. Use
312 these macros to test for features in specific releases. */
313 #define __GLIBC__ 2
314 #define __GLIBC_MINOR__ 8
316 #define __GLIBC_PREREQ(maj, min) \
317 ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
319 /* Decide whether a compiler supports the long long datatypes. */
320 #if defined __GNUC__ \
321 || (defined __PGI && defined __i386__ ) \
322 || (defined __INTEL_COMPILER && (defined __i386__ || defined __ia64__)) \
323 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
324 # define __GLIBC_HAVE_LONG_LONG 1
325 #endif
327 /* This is here only because every header file already includes this one. */
328 #ifndef __ASSEMBLER__
329 # ifndef _SYS_CDEFS_H
330 # include <sys/cdefs.h>
331 # endif
333 /* If we don't have __REDIRECT, prototypes will be missing if
334 __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
335 # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
336 # define __USE_LARGEFILE 1
337 # define __USE_LARGEFILE64 1
338 # endif
342 /* Decide whether we can define 'extern inline' functions in headers. */
343 #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
344 && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
345 && defined __extern_inline
346 # define __USE_EXTERN_INLINES 1
347 #endif
350 /* This is here only because every header file already includes this one.
351 Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
352 <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
353 that will always return failure (and set errno to ENOSYS). */
354 #include <gnu/stubs.h>