1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
/* Copyright (C) 1991, 92, 93, 95, 96, 97 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef _FEATURES_H
#define _FEATURES_H 1
/* These are defined by the user (or the compiler)
to specify the desired environment:
__STRICT_ANSI__ ISO Standard C.
_ISOC9X_SOURCE Extensions to ISO C 89 from ISO C 9x.
_POSIX_SOURCE IEEE Std 1003.1.
_POSIX_C_SOURCE If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2;
if >=199309L, add IEEE Std 1003.1b-1993
_XOPEN_SOURCE Includes POSIX and XPG things.
_XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
_BSD_SOURCE ISO C, POSIX, and 4.3BSD things.
_SVID_SOURCE ISO C, POSIX, and SVID things.
_GNU_SOURCE All of the above, plus GNU extensions.
_REENTRANT Select additionally reentrant object.
_THREAD_SAFE Same as _REENTRANT, often used by other systems.
The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
If none of these are defined, the default is all but _GNU_SOURCE.
If more than one of these are defined, they accumulate.
For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
together give you ISO C, 1003.1, and 1003.2, but nothing else.
These are defined by this file and are used by the
header files to decide what to declare or define:
__USE_ISOC9X Define ISO C 9X things.
__USE_POSIX Define IEEE Std 1003.1 things.
__USE_POSIX2 Define IEEE Std 1003.2 things.
__USE_POSIX199309 Define IEEE Std 1003.1b things.
__USE_XOPEN Define XPG things.
__USE_XOPEN_EXTENDED Define X/Open Unix things.
__USE_BSD Define 4.3BSD things.
__USE_SVID Define SVID things.
__USE_MISC Define things common to BSD and System V Unix.
__USE_GNU Define GNU extensions.
__USE_REENTRANT Define reentrant/thread-safe *_r functions.
__FAVOR_BSD Favor 4.3BSD things in cases of conflict.
The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
defined by this file unconditionally. `__GNU_LIBRARY__' is provided
only for compatibility. All new code should use the other symbols
to test for features.
All macros listed above as possibly being defined by this file are
explicitly undefined if they are not explicitly defined.
Feature-test macros that are not defined by the user or compiler
but are implied by the other feature-test macros defined (or by the
lack of any definitions) are defined by the file. */
/* Undefine everything, so we get a clean slate. */
#undef __USE_ISOC9X
#undef __USE_POSIX
#undef __USE_POSIX2
#undef __USE_POSIX199309
#undef __USE_XOPEN
#undef __USE_XOPEN_EXTENDED
#undef __USE_BSD
#undef __USE_SVID
#undef __USE_MISC
#undef __USE_GNU
#undef __USE_REENTRANT
#undef __FAVOR_BSD
#undef __KERNEL_STRICT_NAMES
/* Suppress kernel-name space pollution unless user expressedly asks
for it. */
#ifndef _LOOSE_KERNEL_NAMES
# define __KERNEL_STRICT_NAMES
#endif
/* Always use ISO C things. */
#define __USE_ANSI 1
/* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
#if defined _BSD_SOURCE && \
!(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
defined _GNU_SOURCE || defined _SVID_SOURCE)
# define __FAVOR_BSD 1
#endif
/* If _GNU_SOURCE was defined by the user, turn on all the other features. */
#ifdef _GNU_SOURCE
#undef _ISOC9X_SOURCE
#define _ISOC9X_SOURCE 1
#undef _POSIX_SOURCE
#define _POSIX_SOURCE 1
#undef _POSIX_C_SOURCE
#define _POSIX_C_SOURCE 199309L
#undef _XOPEN_SOURCE
#define _XOPEN_SOURCE 1
#undef _XOPEN_SOURCE_EXTENDED
#define _XOPEN_SOURCE_EXTENDED 1
#undef _BSD_SOURCE
#define _BSD_SOURCE 1
#undef _SVID_SOURCE
#define _SVID_SOURCE 1
#endif
/* If nothing (other than _GNU_SOURCE) is defined,
define _BSD_SOURCE and _SVID_SOURCE. */
#if (!defined __STRICT_ANSI__ && !defined _ISOC9X_SOURCE && \
!defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
!defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
!defined _BSD_SOURCE && !defined _SVID_SOURCE)
#define _BSD_SOURCE 1
#define _SVID_SOURCE 1
#endif
/* This is to enable the ISO C 9x extension. It will go away as soon
as this standard is officially released. */
#ifdef _ISOC9X_SOURCE
#define __USE_ISOC9X 1
#endif
/* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
(and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
#if (!defined __STRICT_ANSI__ && !defined _POSIX_SOURCE && \
!defined _POSIX_C_SOURCE)
#define _POSIX_SOURCE 1
#ifdef _XOPEN_SOURCE
#define _POSIX_C_SOURCE 2
#else
#define _POSIX_C_SOURCE 199309L
#endif
#endif
#if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
#define __USE_POSIX 1
#endif
#if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
#define __USE_POSIX2 1
#endif
#if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 199309L
#define __USE_POSIX199309 1
#endif
#ifdef _XOPEN_SOURCE
#define __USE_XOPEN 1
#ifdef _XOPEN_SOURCE_EXTENDED
#define __USE_XOPEN_EXTENDED 1
#endif
#endif
#if defined _BSD_SOURCE || defined _SVID_SOURCE
#define __USE_MISC 1
#endif
#ifdef _BSD_SOURCE
#define __USE_BSD 1
#endif
#ifdef _SVID_SOURCE
#define __USE_SVID 1
#endif
#ifdef _GNU_SOURCE
#define __USE_GNU 1
#endif
#if defined _REENTRANT || defined _THREAD_SAFE
#define __USE_REENTRANT 1
#endif
/* We do support the IEC 559 math functionality, real and complex. */
#define __STDC_IEC_559__ 1
#define __STDC_IEC_559_COMPLEX__ 1
/* This macro indicates that the installed library is the GNU C Library.
For historic reasons the value now is 6 and this will stay from now
on. The use of this variable is deprecated. Use __GLIBC__ and
__GLIBC_MINOR__ now (see below) when you want to test for a specific
GNU C library version and use the values in <gnu/lib-names.h> to get
the sonames of the shared libraries. */
#undef __GNU_LIBRARY__
#define __GNU_LIBRARY__ 6
/* Major and minor version number of the GNU C library package. Use
these macros to test for features in specific releases. */
#define __GLIBC__ 2
#define __GLIBC_MINOR__ 1
#if !defined __GNUC__ || __GNUC__ < 2
/* In GCC version 2, (__extension__ EXPR) will not complain
about GCC extensions used in EXPR under -ansi or -pedantic. */
#define __extension__
#endif
/* This is here only because every header file already includes this one. */
#ifndef __ASSEMBLER__
#include <sys/cdefs.h>
#endif
/* This is here only because every header file already includes this one. */
#ifndef _LIBC
/* Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
<gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
which will always return failure (and set errno to ENOSYS).
We avoid including <gnu/stubs.h> when compiling the C library itself to
avoid a dependency loop. stubs.h depends on every object file. If
this #include were done for the library source code, then every object
file would depend on stubs.h. */
#include <gnu/stubs.h>
#endif
#endif /* features.h */
|
