include/features.h

   1 /* Copyright (C) 1991-1993,1995-2006,2007,2009 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                         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_ISOC99         Define ISO C99 things.
  60    __USE_ISOC95         Define ISO C90 AMD1 (C95) things.
  61    __USE_POSIX          Define IEEE Std 1003.1 things.
  62    __USE_POSIX2         Define IEEE Std 1003.2 things.
  63    __USE_POSIX199309    Define IEEE Std 1003.1, and .1b things.
  64    __USE_POSIX199506    Define IEEE Std 1003.1, .1b, .1c and .1i things.
  65    __USE_XOPEN          Define XPG things.
  66    __USE_XOPEN_EXTENDED Define X/Open Unix things.
  67    __USE_UNIX98         Define Single Unix V2 things.
  68    __USE_XOPEN2K        Define XPG6 things.
  69    __USE_XOPEN2K8       Define XPG7 things.
  70    __USE_LARGEFILE      Define correct standard I/O things.
  71    __USE_LARGEFILE64    Define LFS things with separate names.
  72    __USE_FILE_OFFSET64  Define 64bit interface as default.
  73    __USE_BSD            Define 4.3BSD things.
  74    __USE_SVID           Define SVID things.
  75    __USE_MISC           Define things common to BSD and System V Unix.
  76    __USE_ATFILE         Define *at interfaces and AT_* constants for them.
  77    __USE_GNU            Define GNU extensions.
  78    __USE_REENTRANT      Define reentrant/thread-safe *_r functions.
  79    __USE_FORTIFY_LEVEL  Additional security measures used, according to level.
  80    __FAVOR_BSD          Favor 4.3BSD things in cases of conflict.
  81
  82    The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
  83    defined by this file unconditionally.  `__GNU_LIBRARY__' is provided
  84    only for compatibility.  All new code should use the other symbols
  85    to test for features.
  86
  87    All macros listed above as possibly being defined by this file are
  88    explicitly undefined if they are not explicitly defined.
  89    Feature-test macros that are not defined by the user or compiler
  90    but are implied by the other feature-test macros defined (or by the
  91    lack of any definitions) are defined by the file.  */
  92
  93
  94 /* Undefine everything, so we get a clean slate.  */
  95 #undef  __USE_ISOC99
  96 #undef  __USE_ISOC95
  97 #undef  __USE_POSIX
  98 #undef  __USE_POSIX2
  99 #undef  __USE_POSIX199309
 100 #undef  __USE_POSIX199506
 101 #undef  __USE_XOPEN
 102 #undef  __USE_XOPEN_EXTENDED
 103 #undef  __USE_UNIX98
 104 #undef  __USE_XOPEN2K
 105 #undef  __USE_XOPEN2K8
 106 #undef  __USE_LARGEFILE
 107 #undef  __USE_LARGEFILE64
 108 #undef  __USE_FILE_OFFSET64
 109 #undef  __USE_BSD
 110 #undef  __USE_SVID
 111 #undef  __USE_MISC
 112 #undef  __USE_ATFILE
 113 #undef  __USE_GNU
 114 #undef  __USE_REENTRANT
 115 #undef  __USE_FORTIFY_LEVEL
 116 #undef  __FAVOR_BSD
 117 #undef  __KERNEL_STRICT_NAMES
 118
 119 /* Suppress kernel-name space pollution unless user expressedly asks
 120    for it.  */
 121 #ifndef _LOOSE_KERNEL_NAMES
 122 # define __KERNEL_STRICT_NAMES
 123 #endif
 124
 125 /* Always use ISO C things.  */
 126 #define __USE_ANSI      1
 127
 128 /* Convenience macros to test the versions of glibc and gcc.
 129    Use them like this:
 130    #if __GNUC_PREREQ (2,8)
 131    ... code requiring gcc 2.8 or later ...
 132    #endif
 133    Note - they won't work for gcc1 or glibc1, since the _MINOR macros
 134    were not defined then.  */
 135 #if defined __GNUC__ && defined __GNUC_MINOR__
 136 # define __GNUC_PREREQ(maj, min) \
 137         ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
 138 #else
 139 # define __GNUC_PREREQ(maj, min) 0
 140 #endif
 141
 142
 143 /* If _BSD_SOURCE was defined by the user, favor BSD over POSIX.  */
 144 #if defined _BSD_SOURCE && \
 145     !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
 146       defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
 147       defined _GNU_SOURCE || defined _SVID_SOURCE)
 148 # define __FAVOR_BSD    1
 149 #endif
 150
 151 /* If _GNU_SOURCE was defined by the user, turn on all the other features.  */
 152 #ifdef _GNU_SOURCE
 153 # undef  _ISOC99_SOURCE
 154 # define _ISOC99_SOURCE 1
 155 # undef  _POSIX_SOURCE
 156 # define _POSIX_SOURCE  1
 157 # undef  _POSIX_C_SOURCE
 158 # define _POSIX_C_SOURCE        200809L
 159 # undef  _XOPEN_SOURCE
 160 # define _XOPEN_SOURCE  700
 161 # undef  _XOPEN_SOURCE_EXTENDED
 162 # define _XOPEN_SOURCE_EXTENDED 1
 163 # undef  _LARGEFILE64_SOURCE
 164 # define _LARGEFILE64_SOURCE    1
 165 # undef  _BSD_SOURCE
 166 # define _BSD_SOURCE    1
 167 # undef  _SVID_SOURCE
 168 # define _SVID_SOURCE   1
 169 # undef  _ATFILE_SOURCE
 170 # define _ATFILE_SOURCE 1
 171 #endif
 172
 173 /* If nothing (other than _GNU_SOURCE) is defined,
 174    define _BSD_SOURCE and _SVID_SOURCE.  */
 175 #if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
 176      !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
 177      !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
 178      !defined _BSD_SOURCE && !defined _SVID_SOURCE)
 179 # define _BSD_SOURCE    1
 180 # define _SVID_SOURCE   1
 181 #endif
 182
 183 /* This is to enable the ISO C99 extension.  Also recognize the old macro
 184    which was used prior to the standard acceptance.  This macro will
 185    eventually go away and the features enabled by default once the ISO C99
 186    standard is widely adopted.  */
 187 #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
 188      || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
 189 # define __USE_ISOC99   1
 190 #endif
 191
 192 /* This is to enable the ISO C90 Amendment 1:1995 extension.  */
 193 #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
 194      || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
 195 # define __USE_ISOC95   1
 196 #endif
 197
 198 /* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
 199    (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined).  */
 200 #if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
 201      !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
 202 # define _POSIX_SOURCE  1
 203 # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
 204 #  define _POSIX_C_SOURCE       2
 205 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
 206 #  define _POSIX_C_SOURCE       199506L
 207 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700
 208 #  define _POSIX_C_SOURCE       200112L
 209 # else
 210 #  define _POSIX_C_SOURCE       200809L
 211 # endif
 212 # define __USE_POSIX_IMPLICITLY 1
 213 #endif
 214
 215 #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
 216 # define __USE_POSIX    1
 217 #endif
 218
 219 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
 220 # define __USE_POSIX2   1
 221 #endif
 222
 223 #if (_POSIX_C_SOURCE - 0) >= 199309L
 224 # define __USE_POSIX199309      1
 225 #endif
 226
 227 #if (_POSIX_C_SOURCE - 0) >= 199506L
 228 # define __USE_POSIX199506      1
 229 #endif
 230
 231 #if (_POSIX_C_SOURCE - 0) >= 200112L
 232 # define __USE_XOPEN2K          1
 233 #endif
 234
 235 #if (_POSIX_C_SOURCE - 0) >= 200809L
 236 # define __USE_XOPEN2K8         1
 237 # undef  _ATFILE_SOURCE
 238 # define _ATFILE_SOURCE 1
 239 #endif
 240
 241 #ifdef  _XOPEN_SOURCE
 242 # define __USE_XOPEN    1
 243 # if (_XOPEN_SOURCE - 0) >= 500
 244 #  define __USE_XOPEN_EXTENDED  1
 245 #  define __USE_UNIX98  1
 246 #  undef _LARGEFILE_SOURCE
 247 #  define _LARGEFILE_SOURCE     1
 248 #  if (_XOPEN_SOURCE - 0) >= 600
 249 #   if (_XOPEN_SOURCE - 0) >= 700
 250 #    define __USE_XOPEN2K8      1
 251 #   endif
 252 #   define __USE_XOPEN2K        1
 253 #   undef __USE_ISOC99
 254 #   define __USE_ISOC99         1
 255 #  endif
 256 # else
 257 #  ifdef _XOPEN_SOURCE_EXTENDED
 258 #   define __USE_XOPEN_EXTENDED 1
 259 #  endif
 260 # endif
 261 #endif
 262
 263 #ifdef _LARGEFILE_SOURCE
 264 # define __USE_LARGEFILE        1
 265 #endif
 266
 267 #ifdef _LARGEFILE64_SOURCE
 268 # define __USE_LARGEFILE64      1
 269 #endif
 270
 271 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
 272 # define __USE_FILE_OFFSET64    1
 273 #endif
 274
 275 #if defined _BSD_SOURCE || defined _SVID_SOURCE
 276 # define __USE_MISC     1
 277 #endif
 278
 279 #ifdef  _BSD_SOURCE
 280 # define __USE_BSD      1
 281 #endif
 282
 283 #ifdef  _SVID_SOURCE
 284 # define __USE_SVID     1
 285 #endif
 286
 287 #ifdef  _ATFILE_SOURCE
 288 # define __USE_ATFILE   1
 289 #endif
 290
 291 #ifdef  _GNU_SOURCE
 292 # define __USE_GNU      1
 293 #endif
 294
 295 #if defined _REENTRANT || defined _THREAD_SAFE
 296 # define __USE_REENTRANT        1
 297 #endif
 298
 299 #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 \
 300     && __GNUC_PREREQ (4, 1) && defined __OPTIMIZE__ && __OPTIMIZE__ > 0
 301 # if _FORTIFY_SOURCE > 1
 302 #  define __USE_FORTIFY_LEVEL 2
 303 # else
 304 #  define __USE_FORTIFY_LEVEL 1
 305 # endif
 306 #else
 307 # define __USE_FORTIFY_LEVEL 0
 308 #endif
 309
 310 /* We do support the IEC 559 math functionality, real and complex.  */
 311 #define __STDC_IEC_559__                1
 312 #define __STDC_IEC_559_COMPLEX__        1
 313
 314 /* wchar_t uses ISO 10646-1 (2nd ed., published 2000-09-15) / Unicode 3.1.  */
 315 #define __STDC_ISO_10646__              200009L
 316
 317 /* This macro indicates that the installed library is the GNU C Library.
 318    For historic reasons the value now is 6 and this will stay from now
 319    on.  The use of this variable is deprecated.  Use __GLIBC__ and
 320    __GLIBC_MINOR__ now (see below) when you want to test for a specific
 321    GNU C library version and use the values in <gnu/lib-names.h> to get
 322    the sonames of the shared libraries.  */
 323 #undef  __GNU_LIBRARY__
 324 #define __GNU_LIBRARY__ 6
 325
 326 /* Major and minor version number of the GNU C library package.  Use
 327    these macros to test for features in specific releases.  */
 328 #define __GLIBC__       2
 329 #define __GLIBC_MINOR__ 9
 330
 331 #define __GLIBC_PREREQ(maj, min) \
 332         ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
 333
 334 /* Decide whether a compiler supports the long long datatypes.  */
 335 #if defined __GNUC__ \
 336     || (defined __PGI && defined __i386__ ) \
 337     || (defined __INTEL_COMPILER && (defined __i386__ || defined __ia64__)) \
 338     || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
 339 # define __GLIBC_HAVE_LONG_LONG 1
 340 #endif
 341
 342 /* This is here only because every header file already includes this one.  */
 343 #ifndef __ASSEMBLER__
 344 # ifndef _SYS_CDEFS_H
 345 #  include <sys/cdefs.h>
 346 # endif
 347
 348 /* If we don't have __REDIRECT, prototypes will be missing if
 349    __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
 350 # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
 351 #  define __USE_LARGEFILE       1
 352 #  define __USE_LARGEFILE64     1
 353 # endif
 354
 355 #endif  /* !ASSEMBLER */
 356
 357 /* Decide whether we can define 'extern inline' functions in headers.  */
 358 #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
 359     && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
 360     && defined __extern_inline
 361 # define __USE_EXTERN_INLINES   1
 362 #endif
 363
 364
 365 /* This is here only because every header file already includes this one.
 366    Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
 367    <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
 368    that will always return failure (and set errno to ENOSYS).  */
 369 #include <gnu/stubs.h>
 370
 371
 372 #endif  /* features.h  */