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1 /* Copyright (C) 1991, 92, 93, 95, 96, 97 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 Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 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 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 Boston, MA 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 _ISOC9X_SOURCE Extensions to ISO C 89 from ISO C 9x.
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 _XOPEN_SOURCE Includes POSIX and XPG things. Set to 500 if
31 Single Unix conformance is wanted.
32 _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
33 _LARGEFILE_SOURCE Some more functions for correct standard I/O.
34 _LARGEFILE64_SOURCE Additional functionality from LFS for large files.
35 _FILE_OFFSET_BITS=N Select default filesystem interface.
36 _BSD_SOURCE ISO C, POSIX, and 4.3BSD things.
37 _SVID_SOURCE ISO C, POSIX, and SVID things.
38 _GNU_SOURCE All of the above, plus GNU extensions.
39 _REENTRANT Select additionally reentrant object.
40 _THREAD_SAFE Same as _REENTRANT, often used by other systems.
42 The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
43 If none of these are defined, the default is all but _GNU_SOURCE.
44 If more than one of these are defined, they accumulate.
45 For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
46 together give you ISO C, 1003.1, and 1003.2, but nothing else.
48 These are defined by this file and are used by the
49 header files to decide what to declare or define:
51 __USE_ISOC9X Define ISO C 9X things.
52 __USE_POSIX Define IEEE Std 1003.1 things.
53 __USE_POSIX2 Define IEEE Std 1003.2 things.
54 __USE_POSIX199309 Define IEEE Std 1003.1b things.
55 __USE_XOPEN Define XPG things.
56 __USE_XOPEN_EXTENDED Define X/Open Unix things.
57 __USE_UNIX98 Define Single Unix V2 things.
58 __USE_LARGEFILE64 Define LFS things with separate names.
59 __USE_FILE_OFFSET64 Define 64bit interface as default.
60 __USE_BSD Define 4.3BSD things.
61 __USE_SVID Define SVID things.
62 __USE_MISC Define things common to BSD and System V Unix.
63 __USE_GNU Define GNU extensions.
64 __USE_REENTRANT Define reentrant/thread-safe *_r functions.
65 __FAVOR_BSD Favor 4.3BSD things in cases of conflict.
67 The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
68 defined by this file unconditionally. `__GNU_LIBRARY__' is provided
69 only for compatibility. All new code should use the other symbols
70 to test for features.
72 All macros listed above as possibly being defined by this file are
73 explicitly undefined if they are not explicitly defined.
74 Feature-test macros that are not defined by the user or compiler
75 but are implied by the other feature-test macros defined (or by the
76 lack of any definitions) are defined by the file. */
79 /* Undefine everything, so we get a clean slate. */
80 #undef __USE_ISOC9X
81 #undef __USE_POSIX
82 #undef __USE_POSIX2
83 #undef __USE_POSIX199309
84 #undef __USE_XOPEN
85 #undef __USE_XOPEN_EXTENDED
86 #undef __USE_UNIX98
87 #undef __USE_LARGEFILE
88 #undef __USE_LARGEFILE64
89 #undef __USE_FILE_OFFSET64
90 #undef __USE_BSD
91 #undef __USE_SVID
92 #undef __USE_MISC
93 #undef __USE_GNU
94 #undef __USE_REENTRANT
95 #undef __FAVOR_BSD
96 #undef __KERNEL_STRICT_NAMES
98 /* Suppress kernel-name space pollution unless user expressedly asks
99 for it. */
100 #ifndef _LOOSE_KERNEL_NAMES
101 # define __KERNEL_STRICT_NAMES
102 #endif
104 /* Always use ISO C things. */
105 #define __USE_ANSI 1
108 /* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
109 #if defined _BSD_SOURCE && \
110 !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
111 defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
112 defined _LARGEFILE64_SOURCE || defined _FILE_OFFSET_BITS || \
113 defined _GNU_SOURCE || defined _SVID_SOURCE)
114 # define __FAVOR_BSD 1
115 #endif
117 /* If _GNU_SOURCE was defined by the user, turn on all the other features. */
118 #ifdef _GNU_SOURCE
119 # undef _ISOC9X_SOURCE
120 # define _ISOC9X_SOURCE 1
121 # undef _POSIX_SOURCE
122 # define _POSIX_SOURCE 1
123 # undef _POSIX_C_SOURCE
124 # define _POSIX_C_SOURCE 199309L
125 # undef _XOPEN_SOURCE
126 # define _XOPEN_SOURCE 500
127 # undef _XOPEN_SOURCE_EXTENDED
128 # define _XOPEN_SOURCE_EXTENDED 1
129 # undef _LARGEFILE64_SOURCE
130 # define _LARGEFILE64_SOURCE 1
131 # undef _BSD_SOURCE
132 # define _BSD_SOURCE 1
133 # undef _SVID_SOURCE
134 # define _SVID_SOURCE 1
135 #endif
137 /* If nothing (other than _GNU_SOURCE) is defined,
138 define _BSD_SOURCE and _SVID_SOURCE. */
139 #if (!defined __STRICT_ANSI__ && !defined _ISOC9X_SOURCE && \
140 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
141 !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
142 !defined _LARGEFILE64_SOURCE && !defined _FILE_OFFSET_BITS && \
143 !defined _BSD_SOURCE && !defined _SVID_SOURCE)
144 # define _BSD_SOURCE 1
145 # define _SVID_SOURCE 1
146 #endif
148 /* This is to enable the ISO C 9x extension. It will go away as soon
149 as this standard is officially released. */
150 #ifdef _ISOC9X_SOURCE
151 # define __USE_ISOC9X 1
152 #endif
154 /* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
155 (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
156 #if (!defined __STRICT_ANSI__ && !defined _POSIX_SOURCE && \
157 !defined _POSIX_C_SOURCE)
158 # define _POSIX_SOURCE 1
159 # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) != 500
160 # define _POSIX_C_SOURCE 2
161 # else
162 # define _POSIX_C_SOURCE 199309L
163 # endif
164 #endif
166 #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
167 # define __USE_POSIX 1
168 #endif
170 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
171 # define __USE_POSIX2 1
172 #endif
174 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 199309L
175 # define __USE_POSIX199309 1
176 #endif
178 #ifdef _XOPEN_SOURCE
179 # define __USE_XOPEN 1
180 # if (_XOPEN_SOURCE - 0) == 500
181 # define __USE_XOPEN_EXTENDED 1
182 # define __USE_UNIX98 1
183 # undef _LARGEFILE_SOURCE
184 # define _LARGEFILE_SOURCE 1
185 # else
186 # ifdef _XOPEN_SOURCE_EXTENDED
187 # define __USE_XOPEN_EXTENDED 1
188 # endif
189 # endif
190 #endif
192 #ifdef _LARGEFILE_SOURCE
193 # define __USE_LARGEFILE 1
194 #endif
196 #ifdef _LARGEFILE64_SOURCE
197 # define __USE_LARGEFILE64 1
198 #endif
200 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
201 # define __USE_FILE_OFFSET64 1
202 #endif
204 #if defined _BSD_SOURCE || defined _SVID_SOURCE
205 # define __USE_MISC 1
206 #endif
208 #ifdef _BSD_SOURCE
209 # define __USE_BSD 1
210 #endif
212 #ifdef _SVID_SOURCE
213 # define __USE_SVID 1
214 #endif
216 #ifdef _GNU_SOURCE
217 # define __USE_GNU 1
218 #endif
220 #if defined _REENTRANT || defined _THREAD_SAFE
221 # define __USE_REENTRANT 1
222 #endif
224 /* We do support the IEC 559 math functionality, real and complex. */
225 #define __STDC_IEC_559__ 1
226 #define __STDC_IEC_559_COMPLEX__ 1
228 /* This macro indicates that the installed library is the GNU C Library.
229 For historic reasons the value now is 6 and this will stay from now
230 on. The use of this variable is deprecated. Use __GLIBC__ and
231 __GLIBC_MINOR__ now (see below) when you want to test for a specific
232 GNU C library version and use the values in <gnu/lib-names.h> to get
233 the sonames of the shared libraries. */
234 #undef __GNU_LIBRARY__
235 #define __GNU_LIBRARY__ 6
237 /* Major and minor version number of the GNU C library package. Use
238 these macros to test for features in specific releases. */
239 #define __GLIBC__ 2
240 #define __GLIBC_MINOR__ 1
243 #if !defined __GNUC__ || __GNUC__ < 2
244 /* In GCC version 2, (__extension__ EXPR) will not complain
245 about GCC extensions used in EXPR under -ansi or -pedantic. */
246 # define __extension__
247 #endif
250 /* This is here only because every header file already includes this one. */
251 #ifndef __ASSEMBLER__
252 # include <sys/cdefs.h>
253 #endif
255 /* This is here only because every header file already includes this one. */
256 #ifndef _LIBC
257 /* Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
258 <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
259 which will always return failure (and set errno to ENOSYS).
261 We avoid including <gnu/stubs.h> when compiling the C library itself to
262 avoid a dependency loop. stubs.h depends on every object file. If
263 this #include were done for the library source code, then every object
264 file would depend on stubs.h. */
266 # include <gnu/stubs.h>
267 #endif