1/* Copyright (C) 1991-2013 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 _REENTRANT Select additionally reentrant object.
45 _THREAD_SAFE Same as _REENTRANT, often used by other systems.
46 _FORTIFY_SOURCE If set to numeric value > 0 additional security
47 measures are defined, according to level.
48
49 The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
50 If none of these are defined, the default is to have _SVID_SOURCE,
51 _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
52 200112L. If more than one of these are defined, they accumulate.
53 For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
54 together give you ISO C, 1003.1, and 1003.2, but nothing else.
55
56 These are defined by this file and are used by the
57 header files to decide what to declare or define:
58
59 __USE_ISOC11 Define ISO C11 things.
60 __USE_ISOC99 Define ISO C99 things.
61 __USE_ISOC95 Define ISO C90 AMD1 (C95) things.
62 __USE_POSIX Define IEEE Std 1003.1 things.
63 __USE_POSIX2 Define IEEE Std 1003.2 things.
64 __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
65 __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things.
66 __USE_XOPEN Define XPG things.
67 __USE_XOPEN_EXTENDED Define X/Open Unix things.
68 __USE_UNIX98 Define Single Unix V2 things.
69 __USE_XOPEN2K Define XPG6 things.
70 __USE_XOPEN2KXSI Define XPG6 XSI things.
71 __USE_XOPEN2K8 Define XPG7 things.
72 __USE_XOPEN2K8XSI Define XPG7 XSI things.
73 __USE_LARGEFILE Define correct standard I/O things.
74 __USE_LARGEFILE64 Define LFS things with separate names.
75 __USE_FILE_OFFSET64 Define 64bit interface as default.
76 __USE_BSD Define 4.3BSD things.
77 __USE_SVID Define SVID things.
78 __USE_MISC Define things common to BSD and System V Unix.
79 __USE_ATFILE Define *at interfaces and AT_* constants for them.
80 __USE_GNU Define GNU extensions.
81 __USE_REENTRANT Define reentrant/thread-safe *_r functions.
82 __USE_FORTIFY_LEVEL Additional security measures used, according to level.
83 __FAVOR_BSD Favor 4.3BSD things in cases of conflict.
84
85 The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
86 defined by this file unconditionally. `__GNU_LIBRARY__' is provided
87 only for compatibility. All new code should use the other symbols
88 to test for features.
89
90 All macros listed above as possibly being defined by this file are
91 explicitly undefined if they are not explicitly defined.
92 Feature-test macros that are not defined by the user or compiler
93 but are implied by the other feature-test macros defined (or by the
94 lack of any definitions) are defined by the file. */
95
96
97/* Undefine everything, so we get a clean slate. */
98#undef __USE_ISOC11
99#undef __USE_ISOC99
100#undef __USE_ISOC95
101#undef __USE_ISOCXX11
102#undef __USE_POSIX
103#undef __USE_POSIX2
104#undef __USE_POSIX199309
105#undef __USE_POSIX199506
106#undef __USE_XOPEN
107#undef __USE_XOPEN_EXTENDED
108#undef __USE_UNIX98
109#undef __USE_XOPEN2K
110#undef __USE_XOPEN2KXSI
111#undef __USE_XOPEN2K8
112#undef __USE_XOPEN2K8XSI
113#undef __USE_LARGEFILE
114#undef __USE_LARGEFILE64
115#undef __USE_FILE_OFFSET64
116#undef __USE_BSD
117#undef __USE_SVID
118#undef __USE_MISC
119#undef __USE_ATFILE
120#undef __USE_GNU
121#undef __USE_REENTRANT
122#undef __USE_FORTIFY_LEVEL
123#undef __FAVOR_BSD
124#undef __KERNEL_STRICT_NAMES
125
126/* Suppress kernel-name space pollution unless user expressedly asks
127 for it. */
128#ifndef _LOOSE_KERNEL_NAMES
129# define __KERNEL_STRICT_NAMES
130#endif
131
132/* Convenience macros to test the versions of glibc and gcc.
133 Use them like this:
134 #if __GNUC_PREREQ (2,8)
135 ... code requiring gcc 2.8 or later ...
136 #endif
137 Note - they won't work for gcc1 or glibc1, since the _MINOR macros
138 were not defined then. */
139#if defined __GNUC__ && defined __GNUC_MINOR__
140# define __GNUC_PREREQ(maj, min) \
141 ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
142#else
143# define __GNUC_PREREQ(maj, min) 0
144#endif
145
146
147/* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
148#if defined _BSD_SOURCE && \
149 !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
150 defined _XOPEN_SOURCE || defined _GNU_SOURCE || defined _SVID_SOURCE)
151# define __FAVOR_BSD 1
152#endif
153
154/* If _GNU_SOURCE was defined by the user, turn on all the other features. */
155#ifdef _GNU_SOURCE
156# undef _ISOC95_SOURCE
157# define _ISOC95_SOURCE 1
158# undef _ISOC99_SOURCE
159# define _ISOC99_SOURCE 1
160# undef _ISOC11_SOURCE
161# define _ISOC11_SOURCE 1
162# undef _POSIX_SOURCE
163# define _POSIX_SOURCE 1
164# undef _POSIX_C_SOURCE
165# define _POSIX_C_SOURCE 200809L
166# undef _XOPEN_SOURCE
167# define _XOPEN_SOURCE 700
168# undef _XOPEN_SOURCE_EXTENDED
169# define _XOPEN_SOURCE_EXTENDED 1
170# undef _LARGEFILE64_SOURCE
171# define _LARGEFILE64_SOURCE 1
172# undef _BSD_SOURCE
173# define _BSD_SOURCE 1
174# undef _SVID_SOURCE
175# define _SVID_SOURCE 1
176# undef _ATFILE_SOURCE
177# define _ATFILE_SOURCE 1
178#endif
179
180/* If nothing (other than _GNU_SOURCE) is defined,
181 define _BSD_SOURCE and _SVID_SOURCE. */
182#if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
183 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
184 !defined _XOPEN_SOURCE && !defined _BSD_SOURCE && !defined _SVID_SOURCE)
185# define _BSD_SOURCE 1
186# define _SVID_SOURCE 1
187#endif
188
189/* This is to enable the ISO C11 extension. */
190#if (defined _ISOC11_SOURCE \
191 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
192# define __USE_ISOC11 1
193#endif
194
195/* This is to enable the ISO C99 extension. */
196#if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \
197 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
198# define __USE_ISOC99 1
199#endif
200
201/* This is to enable the ISO C90 Amendment 1:1995 extension. */
202#if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \
203 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
204# define __USE_ISOC95 1
205#endif
206
207/* This is to enable compatibility for ISO C++11.
208
209 So far g++ does not provide a macro. Check the temporary macro for
210 now, too. */
211#if ((defined __cplusplus && __cplusplus >= 201103L) \
212 || defined __GXX_EXPERIMENTAL_CXX0X__)
213# define __USE_ISOCXX11 1
214#endif
215
216/* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
217 (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
218#if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
219 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
220# define _POSIX_SOURCE 1
221# if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
222# define _POSIX_C_SOURCE 2
223# elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
224# define _POSIX_C_SOURCE 199506L
225# elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700
226# define _POSIX_C_SOURCE 200112L
227# else
228# define _POSIX_C_SOURCE 200809L
229# endif
230# define __USE_POSIX_IMPLICITLY 1
231#endif
232
233#if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
234# define __USE_POSIX 1
235#endif
236
237#if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
238# define __USE_POSIX2 1
239#endif
240
241#if (_POSIX_C_SOURCE - 0) >= 199309L
242# define __USE_POSIX199309 1
243#endif
244
245#if (_POSIX_C_SOURCE - 0) >= 199506L
246# define __USE_POSIX199506 1
247#endif
248
249#if (_POSIX_C_SOURCE - 0) >= 200112L
250# define __USE_XOPEN2K 1
251# undef __USE_ISOC95
252# define __USE_ISOC95 1
253# undef __USE_ISOC99
254# define __USE_ISOC99 1
255#endif
256
257#if (_POSIX_C_SOURCE - 0) >= 200809L
258# define __USE_XOPEN2K8 1
259# undef _ATFILE_SOURCE
260# define _ATFILE_SOURCE 1
261#endif
262
263#ifdef _XOPEN_SOURCE
264# define __USE_XOPEN 1
265# if (_XOPEN_SOURCE - 0) >= 500
266# define __USE_XOPEN_EXTENDED 1
267# define __USE_UNIX98 1
268# undef _LARGEFILE_SOURCE
269# define _LARGEFILE_SOURCE 1
270# if (_XOPEN_SOURCE - 0) >= 600
271# if (_XOPEN_SOURCE - 0) >= 700
272# define __USE_XOPEN2K8 1
273# define __USE_XOPEN2K8XSI 1
274# endif
275# define __USE_XOPEN2K 1
276# define __USE_XOPEN2KXSI 1
277# undef __USE_ISOC95
278# define __USE_ISOC95 1
279# undef __USE_ISOC99
280# define __USE_ISOC99 1
281# endif
282# else
283# ifdef _XOPEN_SOURCE_EXTENDED
284# define __USE_XOPEN_EXTENDED 1
285# endif
286# endif
287#endif
288
289#ifdef _LARGEFILE_SOURCE
290# define __USE_LARGEFILE 1
291#endif
292
293#ifdef _LARGEFILE64_SOURCE
294# define __USE_LARGEFILE64 1
295#endif
296
297#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
298# define __USE_FILE_OFFSET64 1
299#endif
300
301#if defined _BSD_SOURCE || defined _SVID_SOURCE
302# define __USE_MISC 1
303#endif
304
305#ifdef _BSD_SOURCE
306# define __USE_BSD 1
307#endif
308
309#ifdef _SVID_SOURCE
310# define __USE_SVID 1
311#endif
312
313#ifdef _ATFILE_SOURCE
314# define __USE_ATFILE 1
315#endif
316
317#ifdef _GNU_SOURCE
318# define __USE_GNU 1
319#endif
320
321#if defined _REENTRANT || defined _THREAD_SAFE
322# define __USE_REENTRANT 1
323#endif
324
325#if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0
326# if !defined __OPTIMIZE__ || __OPTIMIZE__ <= 0
327# warning _FORTIFY_SOURCE requires compiling with optimization (-O)
328# elif !__GNUC_PREREQ (4, 1)
329# warning _FORTIFY_SOURCE requires GCC 4.1 or later
330# elif _FORTIFY_SOURCE > 1
331# define __USE_FORTIFY_LEVEL 2
332# else
333# define __USE_FORTIFY_LEVEL 1
334# endif
335#endif
336#ifndef __USE_FORTIFY_LEVEL
337# define __USE_FORTIFY_LEVEL 0
338#endif
339
340/* Get definitions of __STDC_* predefined macros, if the compiler has
341 not preincluded this header automatically. */
342#include <stdc-predef.h>
343
344/* This macro indicates that the installed library is the GNU C Library.
345 For historic reasons the value now is 6 and this will stay from now
346 on. The use of this variable is deprecated. Use __GLIBC__ and
347 __GLIBC_MINOR__ now (see below) when you want to test for a specific
348 GNU C library version and use the values in <gnu/lib-names.h> to get
349 the sonames of the shared libraries. */
350#undef __GNU_LIBRARY__
351#define __GNU_LIBRARY__ 6
352
353/* Major and minor version number of the GNU C library package. Use
354 these macros to test for features in specific releases. */
355#define __GLIBC__ 2
356#define __GLIBC_MINOR__ 18
357
358#define __GLIBC_PREREQ(maj, min) \
359 ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
360
361/* This is here only because every header file already includes this one. */
362#ifndef __ASSEMBLER__
363# ifndef _SYS_CDEFS_H
364# include <sys/cdefs.h>
365# endif
366
367/* If we don't have __REDIRECT, prototypes will be missing if
368 __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
369# if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
370# define __USE_LARGEFILE 1
371# define __USE_LARGEFILE64 1
372# endif
373
374#endif /* !ASSEMBLER */
375
376/* Decide whether we can define 'extern inline' functions in headers. */
377#if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
378 && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
379 && defined __extern_inline
380# define __USE_EXTERN_INLINES 1
381#endif
382
383
384/* This is here only because every header file already includes this one.
385 Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
386 <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
387 that will always return failure (and set errno to ENOSYS). */
388#include <gnu/stubs.h>
389
390
391#endif /* features.h */
392