1/* Copyright (C) 1991-2014 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
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.
8
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.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18#ifndef _FEATURES_H
19#define _FEATURES_H 1
20
21/* These are defined by the user (or the compiler)
22 to specify the desired environment:
23
24 __STRICT_ANSI__ ISO Standard C.
25 _ISOC99_SOURCE Extensions to ISO C89 from ISO C99.
26 _ISOC11_SOURCE Extensions to ISO C99 from ISO C11.
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 if >=200809L, all of IEEE 1003.1-2008
33 _XOPEN_SOURCE Includes POSIX and XPG things. Set to 500 if
34 Single Unix conformance is wanted, to 600 for the
35 sixth revision, to 700 for the seventh revision.
36 _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
37 _LARGEFILE_SOURCE Some more functions for correct standard I/O.
38 _LARGEFILE64_SOURCE Additional functionality from LFS for large files.
39 _FILE_OFFSET_BITS=N Select default filesystem interface.
40 _BSD_SOURCE ISO C, POSIX, and 4.3BSD things.
41 _SVID_SOURCE ISO C, POSIX, and SVID things.
42 _ATFILE_SOURCE Additional *at interfaces.
43 _GNU_SOURCE All of the above, plus GNU extensions.
44 _DEFAULT_SOURCE The default set of features (taking precedence over
45 __STRICT_ANSI__).
46 _REENTRANT Select additionally reentrant object.
47 _THREAD_SAFE Same as _REENTRANT, often used by other systems.
48 _FORTIFY_SOURCE If set to numeric value > 0 additional security
49 measures are defined, according to level.
50
51 The `-ansi' switch to the GNU C compiler, and standards conformance
52 options such as `-std=c99', define __STRICT_ANSI__. If none of
53 these are defined, or if _DEFAULT_SOURCE is defined, the default is
54 to have _SVID_SOURCE, _BSD_SOURCE, and _POSIX_SOURCE set to one and
55 _POSIX_C_SOURCE set to 200809L. If more than one of these are
56 defined, they accumulate. For example __STRICT_ANSI__,
57 _POSIX_SOURCE and _POSIX_C_SOURCE together give you ISO C, 1003.1,
58 and 1003.2, but nothing else.
59
60 These are defined by this file and are used by the
61 header files to decide what to declare or define:
62
63 __USE_ISOC11 Define ISO C11 things.
64 __USE_ISOC99 Define ISO C99 things.
65 __USE_ISOC95 Define ISO C90 AMD1 (C95) things.
66 __USE_POSIX Define IEEE Std 1003.1 things.
67 __USE_POSIX2 Define IEEE Std 1003.2 things.
68 __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
69 __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things.
70 __USE_XOPEN Define XPG things.
71 __USE_XOPEN_EXTENDED Define X/Open Unix things.
72 __USE_UNIX98 Define Single Unix V2 things.
73 __USE_XOPEN2K Define XPG6 things.
74 __USE_XOPEN2KXSI Define XPG6 XSI things.
75 __USE_XOPEN2K8 Define XPG7 things.
76 __USE_XOPEN2K8XSI Define XPG7 XSI things.
77 __USE_LARGEFILE Define correct standard I/O things.
78 __USE_LARGEFILE64 Define LFS things with separate names.
79 __USE_FILE_OFFSET64 Define 64bit interface as default.
80 __USE_BSD Define 4.3BSD things.
81 __USE_SVID Define SVID things.
82 __USE_MISC Define things common to BSD and System V Unix.
83 __USE_ATFILE Define *at interfaces and AT_* constants for them.
84 __USE_GNU Define GNU extensions.
85 __USE_REENTRANT Define reentrant/thread-safe *_r functions.
86 __USE_FORTIFY_LEVEL Additional security measures used, according to level.
87
88 The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
89 defined by this file unconditionally. `__GNU_LIBRARY__' is provided
90 only for compatibility. All new code should use the other symbols
91 to test for features.
92
93 All macros listed above as possibly being defined by this file are
94 explicitly undefined if they are not explicitly defined.
95 Feature-test macros that are not defined by the user or compiler
96 but are implied by the other feature-test macros defined (or by the
97 lack of any definitions) are defined by the file. */
98
99
100/* Undefine everything, so we get a clean slate. */
101#undef __USE_ISOC11
102#undef __USE_ISOC99
103#undef __USE_ISOC95
104#undef __USE_ISOCXX11
105#undef __USE_POSIX
106#undef __USE_POSIX2
107#undef __USE_POSIX199309
108#undef __USE_POSIX199506
109#undef __USE_XOPEN
110#undef __USE_XOPEN_EXTENDED
111#undef __USE_UNIX98
112#undef __USE_XOPEN2K
113#undef __USE_XOPEN2KXSI
114#undef __USE_XOPEN2K8
115#undef __USE_XOPEN2K8XSI
116#undef __USE_LARGEFILE
117#undef __USE_LARGEFILE64
118#undef __USE_FILE_OFFSET64
119#undef __USE_BSD
120#undef __USE_SVID
121#undef __USE_MISC
122#undef __USE_ATFILE
123#undef __USE_GNU
124#undef __USE_REENTRANT
125#undef __USE_FORTIFY_LEVEL
126#undef __KERNEL_STRICT_NAMES
127
128/* Suppress kernel-name space pollution unless user expressedly asks
129 for it. */
130#ifndef _LOOSE_KERNEL_NAMES
131# define __KERNEL_STRICT_NAMES
132#endif
133
134/* Convenience macros to test the versions of glibc and gcc.
135 Use them like this:
136 #if __GNUC_PREREQ (2,8)
137 ... code requiring gcc 2.8 or later ...
138 #endif
139 Note - they won't work for gcc1 or glibc1, since the _MINOR macros
140 were not defined then. */
141#if defined __GNUC__ && defined __GNUC_MINOR__
142# define __GNUC_PREREQ(maj, min) \
143 ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
144#else
145# define __GNUC_PREREQ(maj, min) 0
146#endif
147
148
149/* If _GNU_SOURCE was defined by the user, turn on all the other features. */
150#ifdef _GNU_SOURCE
151# undef _ISOC95_SOURCE
152# define _ISOC95_SOURCE 1
153# undef _ISOC99_SOURCE
154# define _ISOC99_SOURCE 1
155# undef _ISOC11_SOURCE
156# define _ISOC11_SOURCE 1
157# undef _POSIX_SOURCE
158# define _POSIX_SOURCE 1
159# undef _POSIX_C_SOURCE
160# define _POSIX_C_SOURCE 200809L
161# undef _XOPEN_SOURCE
162# define _XOPEN_SOURCE 700
163# undef _XOPEN_SOURCE_EXTENDED
164# define _XOPEN_SOURCE_EXTENDED 1
165# undef _LARGEFILE64_SOURCE
166# define _LARGEFILE64_SOURCE 1
167# undef _DEFAULT_SOURCE
168# define _DEFAULT_SOURCE 1
169# undef _BSD_SOURCE
170# define _BSD_SOURCE 1
171# undef _SVID_SOURCE
172# define _SVID_SOURCE 1
173# undef _ATFILE_SOURCE
174# define _ATFILE_SOURCE 1
175#endif
176
177/* If nothing (other than _GNU_SOURCE and _DEFAULT_SOURCE) is defined,
178 define _DEFAULT_SOURCE, _BSD_SOURCE and _SVID_SOURCE. */
179#if (defined _DEFAULT_SOURCE \
180 || (!defined __STRICT_ANSI__ \
181 && !defined _ISOC99_SOURCE \
182 && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE \
183 && !defined _XOPEN_SOURCE \
184 && !defined _BSD_SOURCE && !defined _SVID_SOURCE))
185# undef _DEFAULT_SOURCE
186# define _DEFAULT_SOURCE 1
187# undef _BSD_SOURCE
188# define _BSD_SOURCE 1
189# undef _SVID_SOURCE
190# define _SVID_SOURCE 1
191#endif
192
193/* This is to enable the ISO C11 extension. */
194#if (defined _ISOC11_SOURCE \
195 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
196# define __USE_ISOC11 1
197#endif
198
199/* This is to enable the ISO C99 extension. */
200#if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \
201 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
202# define __USE_ISOC99 1
203#endif
204
205/* This is to enable the ISO C90 Amendment 1:1995 extension. */
206#if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \
207 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
208# define __USE_ISOC95 1
209#endif
210
211/* This is to enable compatibility for ISO C++11.
212
213 So far g++ does not provide a macro. Check the temporary macro for
214 now, too. */
215#if ((defined __cplusplus && __cplusplus >= 201103L) \
216 || defined __GXX_EXPERIMENTAL_CXX0X__)
217# define __USE_ISOCXX11 1
218#endif
219
220/* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE
221 is defined, use POSIX.1-2008 (or another version depending on
222 _XOPEN_SOURCE). */
223#ifdef _DEFAULT_SOURCE
224# if !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE
225# define __USE_POSIX_IMPLICITLY 1
226# endif
227# undef _POSIX_SOURCE
228# define _POSIX_SOURCE 1
229# undef _POSIX_C_SOURCE
230# define _POSIX_C_SOURCE 200809L
231#endif
232#if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
233 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
234# define _POSIX_SOURCE 1
235# if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
236# define _POSIX_C_SOURCE 2
237# elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
238# define _POSIX_C_SOURCE 199506L
239# elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700
240# define _POSIX_C_SOURCE 200112L
241# else
242# define _POSIX_C_SOURCE 200809L
243# endif
244# define __USE_POSIX_IMPLICITLY 1
245#endif
246
247#if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
248# define __USE_POSIX 1
249#endif
250
251#if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
252# define __USE_POSIX2 1
253#endif
254
255#if (_POSIX_C_SOURCE - 0) >= 199309L
256# define __USE_POSIX199309 1
257#endif
258
259#if (_POSIX_C_SOURCE - 0) >= 199506L
260# define __USE_POSIX199506 1
261#endif
262
263#if (_POSIX_C_SOURCE - 0) >= 200112L
264# define __USE_XOPEN2K 1
265# undef __USE_ISOC95
266# define __USE_ISOC95 1
267# undef __USE_ISOC99
268# define __USE_ISOC99 1
269#endif
270
271#if (_POSIX_C_SOURCE - 0) >= 200809L
272# define __USE_XOPEN2K8 1
273# undef _ATFILE_SOURCE
274# define _ATFILE_SOURCE 1
275#endif
276
277#ifdef _XOPEN_SOURCE
278# define __USE_XOPEN 1
279# if (_XOPEN_SOURCE - 0) >= 500
280# define __USE_XOPEN_EXTENDED 1
281# define __USE_UNIX98 1
282# undef _LARGEFILE_SOURCE
283# define _LARGEFILE_SOURCE 1
284# if (_XOPEN_SOURCE - 0) >= 600
285# if (_XOPEN_SOURCE - 0) >= 700
286# define __USE_XOPEN2K8 1
287# define __USE_XOPEN2K8XSI 1
288# endif
289# define __USE_XOPEN2K 1
290# define __USE_XOPEN2KXSI 1
291# undef __USE_ISOC95
292# define __USE_ISOC95 1
293# undef __USE_ISOC99
294# define __USE_ISOC99 1
295# endif
296# else
297# ifdef _XOPEN_SOURCE_EXTENDED
298# define __USE_XOPEN_EXTENDED 1
299# endif
300# endif
301#endif
302
303#ifdef _LARGEFILE_SOURCE
304# define __USE_LARGEFILE 1
305#endif
306
307#ifdef _LARGEFILE64_SOURCE
308# define __USE_LARGEFILE64 1
309#endif
310
311#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
312# define __USE_FILE_OFFSET64 1
313#endif
314
315#if defined _BSD_SOURCE || defined _SVID_SOURCE
316# define __USE_MISC 1
317#endif
318
319#ifdef _BSD_SOURCE
320# define __USE_BSD 1
321#endif
322
323#ifdef _SVID_SOURCE
324# define __USE_SVID 1
325#endif
326
327#ifdef _ATFILE_SOURCE
328# define __USE_ATFILE 1
329#endif
330
331#ifdef _GNU_SOURCE
332# define __USE_GNU 1
333#endif
334
335#if defined _REENTRANT || defined _THREAD_SAFE
336# define __USE_REENTRANT 1
337#endif
338
339#if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 \
340 && __GNUC_PREREQ (4, 1) && defined __OPTIMIZE__ && __OPTIMIZE__ > 0
341# if _FORTIFY_SOURCE > 1
342# define __USE_FORTIFY_LEVEL 2
343# else
344# define __USE_FORTIFY_LEVEL 1
345# endif
346#else
347# define __USE_FORTIFY_LEVEL 0
348#endif
349
350/* Get definitions of __STDC_* predefined macros, if the compiler has
351 not preincluded this header automatically. */
352#include <stdc-predef.h>
353
354/* This macro indicates that the installed library is the GNU C Library.
355 For historic reasons the value now is 6 and this will stay from now
356 on. The use of this variable is deprecated. Use __GLIBC__ and
357 __GLIBC_MINOR__ now (see below) when you want to test for a specific
358 GNU C library version and use the values in <gnu/lib-names.h> to get
359 the sonames of the shared libraries. */
360#undef __GNU_LIBRARY__
361#define __GNU_LIBRARY__ 6
362
363/* Major and minor version number of the GNU C library package. Use
364 these macros to test for features in specific releases. */
365#define __GLIBC__ 2
366#define __GLIBC_MINOR__ 19
367
368#define __GLIBC_PREREQ(maj, min) \
369 ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
370
371/* This is here only because every header file already includes this one. */
372#ifndef __ASSEMBLER__
373# ifndef _SYS_CDEFS_H
374# include <sys/cdefs.h>
375# endif
376
377/* If we don't have __REDIRECT, prototypes will be missing if
378 __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
379# if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
380# define __USE_LARGEFILE 1
381# define __USE_LARGEFILE64 1
382# endif
383
384#endif /* !ASSEMBLER */
385
386/* Decide whether we can define 'extern inline' functions in headers. */
387#if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
388 && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
389 && defined __extern_inline
390# define __USE_EXTERN_INLINES 1
391#endif
392
393
394/* This is here only because every header file already includes this one.
395 Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
396 <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
397 that will always return failure (and set errno to ENOSYS). */
398#include <gnu/stubs.h>
399
400
401#endif /* features.h */
402