1/* Copyright (C) 1991-1993,1995-2000,2001,2002 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, write to the Free
16   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17   02111-1307 USA.  */
18
19#ifndef	_FEATURES_H
20#define	_FEATURES_H	1
21
22/* These are defined by the user (or the compiler)
23   to specify the desired environment:
24
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   _XOPEN_SOURCE	Includes POSIX and XPG things.  Set to 500 if
32			Single Unix conformance is wanted, to 600 for the
33			upcoming sixth revision.
34   _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
35   _LARGEFILE_SOURCE	Some more functions for correct standard I/O.
36   _LARGEFILE64_SOURCE	Additional functionality from LFS for large files.
37   _FILE_OFFSET_BITS=N	Select default filesystem interface.
38   _BSD_SOURCE		ISO C, POSIX, and 4.3BSD things.
39   _SVID_SOURCE		ISO C, POSIX, and SVID things.
40   _GNU_SOURCE		All of the above, plus GNU extensions.
41   _REENTRANT		Select additionally reentrant object.
42   _THREAD_SAFE		Same as _REENTRANT, often used by other systems.
43
44   The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
45   If none of these are defined, the default is to have _SVID_SOURCE,
46   _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
47   199506L.  If more than one of these are defined, they accumulate.
48   For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
49   together give you ISO C, 1003.1, and 1003.2, but nothing else.
50
51   These are defined by this file and are used by the
52   header files to decide what to declare or define:
53
54   __USE_ISOC99		Define ISO C99 things.
55   __USE_POSIX		Define IEEE Std 1003.1 things.
56   __USE_POSIX2		Define IEEE Std 1003.2 things.
57   __USE_POSIX199309	Define IEEE Std 1003.1, and .1b things.
58   __USE_POSIX199506	Define IEEE Std 1003.1, .1b, .1c and .1i things.
59   __USE_XOPEN		Define XPG things.
60   __USE_XOPEN_EXTENDED	Define X/Open Unix things.
61   __USE_UNIX98		Define Single Unix V2 things.
62   __USE_XOPEN2K        Define XPG6 things.
63   __USE_LARGEFILE	Define correct standard I/O things.
64   __USE_LARGEFILE64	Define LFS things with separate names.
65   __USE_FILE_OFFSET64	Define 64bit interface as default.
66   __USE_BSD		Define 4.3BSD things.
67   __USE_SVID		Define SVID things.
68   __USE_MISC		Define things common to BSD and System V Unix.
69   __USE_GNU		Define GNU extensions.
70   __USE_REENTRANT	Define reentrant/thread-safe *_r functions.
71   __FAVOR_BSD		Favor 4.3BSD things in cases of conflict.
72
73   The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
74   defined by this file unconditionally.  `__GNU_LIBRARY__' is provided
75   only for compatibility.  All new code should use the other symbols
76   to test for features.
77
78   All macros listed above as possibly being defined by this file are
79   explicitly undefined if they are not explicitly defined.
80   Feature-test macros that are not defined by the user or compiler
81   but are implied by the other feature-test macros defined (or by the
82   lack of any definitions) are defined by the file.  */
83
84
85/* Undefine everything, so we get a clean slate.  */
86#undef	__USE_ISOC99
87#undef	__USE_POSIX
88#undef	__USE_POSIX2
89#undef	__USE_POSIX199309
90#undef	__USE_POSIX199506
91#undef	__USE_XOPEN
92#undef	__USE_XOPEN_EXTENDED
93#undef	__USE_UNIX98
94#undef	__USE_XOPEN2K
95#undef	__USE_LARGEFILE
96#undef	__USE_LARGEFILE64
97#undef	__USE_FILE_OFFSET64
98#undef	__USE_BSD
99#undef	__USE_SVID
100#undef	__USE_MISC
101#undef	__USE_GNU
102#undef	__USE_REENTRANT
103#undef	__FAVOR_BSD
104#undef	__KERNEL_STRICT_NAMES
105
106/* Suppress kernel-name space pollution unless user expressedly asks
107   for it.  */
108#ifndef _LOOSE_KERNEL_NAMES
109# define __KERNEL_STRICT_NAMES
110#endif
111
112/* Always use ISO C things.  */
113#define	__USE_ANSI	1
114
115
116/* If _BSD_SOURCE was defined by the user, favor BSD over POSIX.  */
117#if defined _BSD_SOURCE && \
118    !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
119      defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
120      defined _GNU_SOURCE || defined _SVID_SOURCE)
121# define __FAVOR_BSD	1
122#endif
123
124/* If _GNU_SOURCE was defined by the user, turn on all the other features.  */
125#ifdef _GNU_SOURCE
126# undef  _ISOC99_SOURCE
127# define _ISOC99_SOURCE	1
128# undef  _POSIX_SOURCE
129# define _POSIX_SOURCE	1
130# undef  _POSIX_C_SOURCE
131# define _POSIX_C_SOURCE	199506L
132# undef  _XOPEN_SOURCE
133# define _XOPEN_SOURCE	600
134# undef  _XOPEN_SOURCE_EXTENDED
135# define _XOPEN_SOURCE_EXTENDED	1
136# undef	 _LARGEFILE64_SOURCE
137# define _LARGEFILE64_SOURCE	1
138# undef  _BSD_SOURCE
139# define _BSD_SOURCE	1
140# undef  _SVID_SOURCE
141# define _SVID_SOURCE	1
142#endif
143
144/* If nothing (other than _GNU_SOURCE) is defined,
145   define _BSD_SOURCE and _SVID_SOURCE.  */
146#if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
147     !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
148     !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
149     !defined _BSD_SOURCE && !defined _SVID_SOURCE)
150# define _BSD_SOURCE	1
151# define _SVID_SOURCE	1
152#endif
153
154/* This is to enable the ISO C99 extension.  Also recognize the old macro
155   which was used prior to the standard acceptance.  This macro will
156   eventually go away and the features enabled by default once the ISO C99
157   standard is widely adopted.  */
158#if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
159     || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
160# define __USE_ISOC99	1
161#endif
162
163/* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
164   (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined).  */
165#if (!defined __STRICT_ANSI__ && !defined _POSIX_SOURCE && \
166     !defined _POSIX_C_SOURCE)
167# define _POSIX_SOURCE	1
168# if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
169#  define _POSIX_C_SOURCE	2
170# else
171#  define _POSIX_C_SOURCE	199506L
172# endif
173#endif
174
175#if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
176# define __USE_POSIX	1
177#endif
178
179#if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
180# define __USE_POSIX2	1
181#endif
182
183#if (_POSIX_C_SOURCE - 0) >= 199309L
184# define __USE_POSIX199309	1
185#endif
186
187#if (_POSIX_C_SOURCE - 0) >= 199506L
188# define __USE_POSIX199506	1
189#endif
190
191#ifdef	_XOPEN_SOURCE
192# define __USE_XOPEN	1
193# if (_XOPEN_SOURCE - 0) >= 500
194#  define __USE_XOPEN_EXTENDED	1
195#  define __USE_UNIX98	1
196#  undef _LARGEFILE_SOURCE
197#  define _LARGEFILE_SOURCE	1
198#  if (_XOPEN_SOURCE - 0) >= 600
199#   define __USE_XOPEN2K	1
200#   undef __USE_ISOC99
201#   define __USE_ISOC99		1
202#  endif
203# else
204#  ifdef _XOPEN_SOURCE_EXTENDED
205#   define __USE_XOPEN_EXTENDED	1
206#  endif
207# endif
208#endif
209
210#ifdef _LARGEFILE_SOURCE
211# define __USE_LARGEFILE	1
212#endif
213
214#ifdef _LARGEFILE64_SOURCE
215# define __USE_LARGEFILE64	1
216#endif
217
218#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
219# define __USE_FILE_OFFSET64	1
220#endif
221
222#if defined _BSD_SOURCE || defined _SVID_SOURCE
223# define __USE_MISC	1
224#endif
225
226#ifdef	_BSD_SOURCE
227# define __USE_BSD	1
228#endif
229
230#ifdef	_SVID_SOURCE
231# define __USE_SVID	1
232#endif
233
234#ifdef	_GNU_SOURCE
235# define __USE_GNU	1
236#endif
237
238#if defined _REENTRANT || defined _THREAD_SAFE
239# define __USE_REENTRANT	1
240#endif
241
242/* We do support the IEC 559 math functionality, real and complex.  */
243#define __STDC_IEC_559__		1
244#define __STDC_IEC_559_COMPLEX__	1
245
246/* wchar_t uses ISO 10646-1 (2nd ed., published 2000-09-15) / Unicode 3.1.  */
247#ifndef __STDC_ISO_10646__
248#define __STDC_ISO_10646__		200009L
249#endif
250
251/* This macro indicates that the installed library is the GNU C Library.
252   For historic reasons the value now is 6 and this will stay from now
253   on.  The use of this variable is deprecated.  Use __GLIBC__ and
254   __GLIBC_MINOR__ now (see below) when you want to test for a specific
255   GNU C library version and use the values in <gnu/lib-names.h> to get
256   the sonames of the shared libraries.  */
257#undef  __GNU_LIBRARY__
258#define __GNU_LIBRARY__ 6
259
260/* Major and minor version number of the GNU C library package.  Use
261   these macros to test for features in specific releases.  */
262#define	__GLIBC__	2
263#define	__GLIBC_MINOR__	3
264
265/* Convenience macros to test the versions of glibc and gcc.
266   Use them like this:
267   #if __GNUC_PREREQ (2,8)
268   ... code requiring gcc 2.8 or later ...
269   #endif
270   Note - they won't work for gcc1 or glibc1, since the _MINOR macros
271   were not defined then.  */
272#if defined __GNUC__ && defined __GNUC_MINOR__
273# define __GNUC_PREREQ(maj, min) \
274	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
275#else
276# define __GNUC_PREREQ(maj, min) 0
277#endif
278
279#define __GLIBC_PREREQ(maj, min) \
280	((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
281
282/* Decide whether a compiler supports the long long datatypes.  */
283#if defined __GNUC__ \
284    || (defined __PGI && defined __i386__ ) \
285    || (defined __INTEL_COMPILER && (defined __i386__ || defined __ia64__)) \
286    || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
287# define __GLIBC_HAVE_LONG_LONG	1
288#endif
289
290/* This is here only because every header file already includes this one.  */
291#ifndef __ASSEMBLER__
292# ifndef _SYS_CDEFS_H
293#  include <sys/cdefs.h>
294# endif
295
296/* If we don't have __REDIRECT, prototypes will be missing if
297   __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
298# if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
299#  define __USE_LARGEFILE	1
300#  define __USE_LARGEFILE64	1
301# endif
302
303#endif	/* !ASSEMBLER */
304
305/* Decide whether we can define 'extern inline' functions in headers.  */
306#if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
307    && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__
308# define __USE_EXTERN_INLINES	1
309#endif
310
311
312/* This is here only because every header file already includes this one.
313   Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
314   <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
315   that will always return failure (and set errno to ENOSYS).  */
316#include <gnu/stubs.h>
317
318
319#endif	/* features.h  */
320