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1 /* Copyright (C) 1991-1993,1995-2003,2004,2005 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 _GNU_SOURCE All of the above, plus GNU extensions.
42 _REENTRANT Select additionally reentrant object.
43 _THREAD_SAFE Same as _REENTRANT, often used by other systems.
44 _FORTIFY_SOURCE If set to numeric value > 0 additional security
45 measures are defined, according to level.
47 The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
48 If none of these are defined, the default is to have _SVID_SOURCE,
49 _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
50 199506L. If more than one of these are defined, they accumulate.
51 For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
52 together give you ISO C, 1003.1, and 1003.2, but nothing else.
54 These are defined by this file and are used by the
55 header files to decide what to declare or define:
57 __USE_ISOC99 Define ISO C99 things.
58 __USE_POSIX Define IEEE Std 1003.1 things.
59 __USE_POSIX2 Define IEEE Std 1003.2 things.
60 __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
61 __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things.
62 __USE_XOPEN Define XPG things.
63 __USE_XOPEN_EXTENDED Define X/Open Unix things.
64 __USE_UNIX98 Define Single Unix V2 things.
65 __USE_XOPEN2K Define XPG6 things.
66 __USE_LARGEFILE Define correct standard I/O things.
67 __USE_LARGEFILE64 Define LFS things with separate names.
68 __USE_FILE_OFFSET64 Define 64bit interface as default.
69 __USE_BSD Define 4.3BSD things.
70 __USE_SVID Define SVID things.
71 __USE_MISC Define things common to BSD and System V Unix.
72 __USE_GNU Define GNU extensions.
73 __USE_REENTRANT Define reentrant/thread-safe *_r functions.
74 __USE_FORTIFY_LEVEL Additional security measures used, according to level.
75 __FAVOR_BSD Favor 4.3BSD things in cases of conflict.
77 The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
78 defined by this file unconditionally. `__GNU_LIBRARY__' is provided
79 only for compatibility. All new code should use the other symbols
80 to test for features.
82 All macros listed above as possibly being defined by this file are
83 explicitly undefined if they are not explicitly defined.
84 Feature-test macros that are not defined by the user or compiler
85 but are implied by the other feature-test macros defined (or by the
86 lack of any definitions) are defined by the file. */
89 /* Undefine everything, so we get a clean slate. */
90 #undef __USE_ISOC99
91 #undef __USE_POSIX
92 #undef __USE_POSIX2
93 #undef __USE_POSIX199309
94 #undef __USE_POSIX199506
95 #undef __USE_XOPEN
96 #undef __USE_XOPEN_EXTENDED
97 #undef __USE_UNIX98
98 #undef __USE_XOPEN2K
99 #undef __USE_LARGEFILE
100 #undef __USE_LARGEFILE64
101 #undef __USE_FILE_OFFSET64
102 #undef __USE_BSD
103 #undef __USE_SVID
104 #undef __USE_MISC
105 #undef __USE_GNU
106 #undef __USE_REENTRANT
107 #undef __USE_FORTIFY_LEVEL
108 #undef __FAVOR_BSD
109 #undef __KERNEL_STRICT_NAMES
111 /* Suppress kernel-name space pollution unless user expressedly asks
112 for it. */
113 #ifndef _LOOSE_KERNEL_NAMES
114 # define __KERNEL_STRICT_NAMES
115 #endif
117 /* Always use ISO C things. */
118 #define __USE_ANSI 1
120 /* Convenience macros to test the versions of glibc and gcc.
121 Use them like this:
122 #if __GNUC_PREREQ (2,8)
123 ... code requiring gcc 2.8 or later ...
124 #endif
125 Note - they won't work for gcc1 or glibc1, since the _MINOR macros
126 were not defined then. */
127 #if defined __GNUC__ && defined __GNUC_MINOR__
128 # define __GNUC_PREREQ(maj, min) \
129 ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
130 #else
131 # define __GNUC_PREREQ(maj, min) 0
132 #endif
135 /* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
136 #if defined _BSD_SOURCE && \
137 !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
138 defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
139 defined _GNU_SOURCE || defined _SVID_SOURCE)
140 # define __FAVOR_BSD 1
141 #endif
143 /* If _GNU_SOURCE was defined by the user, turn on all the other features. */
144 #ifdef _GNU_SOURCE
145 # undef _ISOC99_SOURCE
146 # define _ISOC99_SOURCE 1
147 # undef _POSIX_SOURCE
148 # define _POSIX_SOURCE 1
149 # undef _POSIX_C_SOURCE
150 # define _POSIX_C_SOURCE 199506L
151 # undef _XOPEN_SOURCE
152 # define _XOPEN_SOURCE 600
153 # undef _XOPEN_SOURCE_EXTENDED
154 # define _XOPEN_SOURCE_EXTENDED 1
155 # undef _LARGEFILE64_SOURCE
156 # define _LARGEFILE64_SOURCE 1
157 # undef _BSD_SOURCE
158 # define _BSD_SOURCE 1
159 # undef _SVID_SOURCE
160 # define _SVID_SOURCE 1
161 #endif
163 /* If nothing (other than _GNU_SOURCE) is defined,
164 define _BSD_SOURCE and _SVID_SOURCE. */
165 #if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
166 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
167 !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
168 !defined _BSD_SOURCE && !defined _SVID_SOURCE)
169 # define _BSD_SOURCE 1
170 # define _SVID_SOURCE 1
171 #endif
173 /* This is to enable the ISO C99 extension. Also recognize the old macro
174 which was used prior to the standard acceptance. This macro will
175 eventually go away and the features enabled by default once the ISO C99
176 standard is widely adopted. */
177 #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
178 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
179 # define __USE_ISOC99 1
180 #endif
182 /* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
183 (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
184 #if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
185 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
186 # define _POSIX_SOURCE 1
187 # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
188 # define _POSIX_C_SOURCE 2
189 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
190 # define _POSIX_C_SOURCE 199506L
191 # else
192 # define _POSIX_C_SOURCE 200112L
193 # endif
194 #endif
196 #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
197 # define __USE_POSIX 1
198 #endif
200 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
201 # define __USE_POSIX2 1
202 #endif
204 #if (_POSIX_C_SOURCE - 0) >= 199309L
205 # define __USE_POSIX199309 1
206 #endif
208 #if (_POSIX_C_SOURCE - 0) >= 199506L
209 # define __USE_POSIX199506 1
210 #endif
212 #if (_POSIX_C_SOURCE - 0) >= 200112L
213 # define __USE_XOPEN2K 1
214 #endif
216 #ifdef _XOPEN_SOURCE
217 # define __USE_XOPEN 1
218 # if (_XOPEN_SOURCE - 0) >= 500
219 # define __USE_XOPEN_EXTENDED 1
220 # define __USE_UNIX98 1
221 # undef _LARGEFILE_SOURCE
222 # define _LARGEFILE_SOURCE 1
223 # if (_XOPEN_SOURCE - 0) >= 600
224 # define __USE_XOPEN2K 1
225 # undef __USE_ISOC99
226 # define __USE_ISOC99 1
227 # endif
228 # else
229 # ifdef _XOPEN_SOURCE_EXTENDED
230 # define __USE_XOPEN_EXTENDED 1
231 # endif
232 # endif
233 #endif
235 #ifdef _LARGEFILE_SOURCE
236 # define __USE_LARGEFILE 1
237 #endif
239 #ifdef _LARGEFILE64_SOURCE
240 # define __USE_LARGEFILE64 1
241 #endif
243 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
244 # define __USE_FILE_OFFSET64 1
245 #endif
247 #if defined _BSD_SOURCE || defined _SVID_SOURCE
248 # define __USE_MISC 1
249 #endif
251 #ifdef _BSD_SOURCE
252 # define __USE_BSD 1
253 #endif
255 #ifdef _SVID_SOURCE
256 # define __USE_SVID 1
257 #endif
259 #ifdef _GNU_SOURCE
260 # define __USE_GNU 1
261 #endif
263 #if defined _REENTRANT || defined _THREAD_SAFE
264 # define __USE_REENTRANT 1
265 #endif
267 #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 \
268 && __GNUC_PREREQ (4, 1) && defined __OPTIMIZE__ && __OPTIMIZE__ > 0
269 # if _FORTIFY_SOURCE > 1
270 # define __USE_FORTIFY_LEVEL 2
271 # else
272 # define __USE_FORTIFY_LEVEL 1
273 # endif
274 #else
275 # define __USE_FORTIFY_LEVEL 0
276 #endif
278 /* We do support the IEC 559 math functionality, real and complex. */
279 #define __STDC_IEC_559__ 1
280 #define __STDC_IEC_559_COMPLEX__ 1
282 /* wchar_t uses ISO 10646-1 (2nd ed., published 2000-09-15) / Unicode 3.1. */
283 #define __STDC_ISO_10646__ 200009L
285 /* This macro indicates that the installed library is the GNU C Library.
286 For historic reasons the value now is 6 and this will stay from now
287 on. The use of this variable is deprecated. Use __GLIBC__ and
288 __GLIBC_MINOR__ now (see below) when you want to test for a specific
289 GNU C library version and use the values in <gnu/lib-names.h> to get
290 the sonames of the shared libraries. */
291 #undef __GNU_LIBRARY__
292 #define __GNU_LIBRARY__ 6
294 /* Major and minor version number of the GNU C library package. Use
295 these macros to test for features in specific releases. */
296 #define __GLIBC__ 2
297 #define __GLIBC_MINOR__ 4
299 #define __GLIBC_PREREQ(maj, min) \
300 ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
302 /* Decide whether a compiler supports the long long datatypes. */
303 #if defined __GNUC__ \
304 || (defined __PGI && defined __i386__ ) \
305 || (defined __INTEL_COMPILER && (defined __i386__ || defined __ia64__)) \
306 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
307 # define __GLIBC_HAVE_LONG_LONG 1
308 #endif
310 /* This is here only because every header file already includes this one. */
311 #ifndef __ASSEMBLER__
312 # ifndef _SYS_CDEFS_H
313 # include <sys/cdefs.h>
314 # endif
316 /* If we don't have __REDIRECT, prototypes will be missing if
317 __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
318 # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
319 # define __USE_LARGEFILE 1
320 # define __USE_LARGEFILE64 1
321 # endif
325 /* Decide whether we can define 'extern inline' functions in headers. */
326 #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
327 && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__
328 # define __USE_EXTERN_INLINES 1
329 #endif
332 /* This is here only because every header file already includes this one.
333 Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
334 <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
335 that will always return failure (and set errno to ENOSYS). */
336 #include <gnu/stubs.h>