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      1 /* Copyright (C) 1991,1992,1993,1995-2006,2007 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    _XOPEN_SOURCE	Includes POSIX and XPG things.  Set to 500 if
     33 			Single Unix conformance is wanted, to 600 for the
     34 			upcoming sixth revision.
     35    _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
     36    _LARGEFILE_SOURCE	Some more functions for correct standard I/O.
     37    _LARGEFILE64_SOURCE	Additional functionality from LFS for large files.
     38    _FILE_OFFSET_BITS=N	Select default filesystem interface.
     39    _BSD_SOURCE		ISO C, POSIX, and 4.3BSD things.
     40    _SVID_SOURCE		ISO C, POSIX, and SVID things.
     41    _ATFILE_SOURCE	Additional *at interfaces.
     42    _GNU_SOURCE		All of the above, plus GNU extensions.
     43    _REENTRANT		Select additionally reentrant object.
     44    _THREAD_SAFE		Same as _REENTRANT, often used by other systems.
     45    _FORTIFY_SOURCE	If set to numeric value > 0 additional security
     46 			measures are defined, according to level.
     47 
     48    The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
     49    If none of these are defined, the default is to have _SVID_SOURCE,
     50    _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
     51    200112L.  If more than one of these are defined, they accumulate.
     52    For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
     53    together give you ISO C, 1003.1, and 1003.2, but nothing else.
     54 
     55    These are defined by this file and are used by the
     56    header files to decide what to declare or define:
     57 
     58    __USE_ISOC99		Define ISO C99 things.
     59    __USE_ISOC95		Define ISO C90 AMD1 (C95) things.
     60    __USE_POSIX		Define IEEE Std 1003.1 things.
     61    __USE_POSIX2		Define IEEE Std 1003.2 things.
     62    __USE_POSIX199309	Define IEEE Std 1003.1, and .1b things.
     63    __USE_POSIX199506	Define IEEE Std 1003.1, .1b, .1c and .1i things.
     64    __USE_XOPEN		Define XPG things.
     65    __USE_XOPEN_EXTENDED	Define X/Open Unix things.
     66    __USE_UNIX98		Define Single Unix V2 things.
     67    __USE_XOPEN2K        Define XPG6 things.
     68    __USE_LARGEFILE	Define correct standard I/O things.
     69    __USE_LARGEFILE64	Define LFS things with separate names.
     70    __USE_FILE_OFFSET64	Define 64bit interface as default.
     71    __USE_BSD		Define 4.3BSD things.
     72    __USE_SVID		Define SVID things.
     73    __USE_MISC		Define things common to BSD and System V Unix.
     74    __USE_ATFILE		Define *at interfaces and AT_* constants for them.
     75    __USE_GNU		Define GNU extensions.
     76    __USE_REENTRANT	Define reentrant/thread-safe *_r functions.
     77    __USE_FORTIFY_LEVEL	Additional security measures used, according to level.
     78    __FAVOR_BSD		Favor 4.3BSD things in cases of conflict.
     79 
     80    The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
     81    defined by this file unconditionally.  `__GNU_LIBRARY__' is provided
     82    only for compatibility.  All new code should use the other symbols
     83    to test for features.
     84 
     85    All macros listed above as possibly being defined by this file are
     86    explicitly undefined if they are not explicitly defined.
     87    Feature-test macros that are not defined by the user or compiler
     88    but are implied by the other feature-test macros defined (or by the
     89    lack of any definitions) are defined by the file.  */
     90 
     91 
     92 /* Undefine everything, so we get a clean slate.  */
     93 #undef	__USE_ISOC99
     94 #undef	__USE_ISOC95
     95 #undef	__USE_POSIX
     96 #undef	__USE_POSIX2
     97 #undef	__USE_POSIX199309
     98 #undef	__USE_POSIX199506
     99 #undef	__USE_XOPEN
    100 #undef	__USE_XOPEN_EXTENDED
    101 #undef	__USE_UNIX98
    102 #undef	__USE_XOPEN2K
    103 #undef	__USE_LARGEFILE
    104 #undef	__USE_LARGEFILE64
    105 #undef	__USE_FILE_OFFSET64
    106 #undef	__USE_BSD
    107 #undef	__USE_SVID
    108 #undef	__USE_MISC
    109 #undef	__USE_ATFILE
    110 #undef	__USE_GNU
    111 #undef	__USE_REENTRANT
    112 #undef	__USE_FORTIFY_LEVEL
    113 #undef	__FAVOR_BSD
    114 #undef	__KERNEL_STRICT_NAMES
    115 
    116 /* Suppress kernel-name space pollution unless user expressedly asks
    117    for it.  */
    118 #ifndef _LOOSE_KERNEL_NAMES
    119 # define __KERNEL_STRICT_NAMES
    120 #endif
    121 
    122 /* Always use ISO C things.  */
    123 #define	__USE_ANSI	1
    124 
    125 /* Convenience macros to test the versions of glibc and gcc.
    126    Use them like this:
    127    #if __GNUC_PREREQ (2,8)
    128    ... code requiring gcc 2.8 or later ...
    129    #endif
    130    Note - they won't work for gcc1 or glibc1, since the _MINOR macros
    131    were not defined then.  */
    132 #if defined __GNUC__ && defined __GNUC_MINOR__
    133 # define __GNUC_PREREQ(maj, min) \
    134 	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
    135 #else
    136 # define __GNUC_PREREQ(maj, min) 0
    137 #endif
    138 
    139 
    140 /* If _BSD_SOURCE was defined by the user, favor BSD over POSIX.  */
    141 #if defined _BSD_SOURCE && \
    142     !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
    143       defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
    144       defined _GNU_SOURCE || defined _SVID_SOURCE)
    145 # define __FAVOR_BSD	1
    146 #endif
    147 
    148 /* If _GNU_SOURCE was defined by the user, turn on all the other features.  */
    149 #ifdef _GNU_SOURCE
    150 # undef  _ISOC99_SOURCE
    151 # define _ISOC99_SOURCE	1
    152 # undef  _POSIX_SOURCE
    153 # define _POSIX_SOURCE	1
    154 # undef  _POSIX_C_SOURCE
    155 # define _POSIX_C_SOURCE	200112L
    156 # undef  _XOPEN_SOURCE
    157 # define _XOPEN_SOURCE	600
    158 # undef  _XOPEN_SOURCE_EXTENDED
    159 # define _XOPEN_SOURCE_EXTENDED	1
    160 # undef	 _LARGEFILE64_SOURCE
    161 # define _LARGEFILE64_SOURCE	1
    162 # undef  _BSD_SOURCE
    163 # define _BSD_SOURCE	1
    164 # undef  _SVID_SOURCE
    165 # define _SVID_SOURCE	1
    166 # undef  _ATFILE_SOURCE
    167 # define _ATFILE_SOURCE	1
    168 #endif
    169 
    170 /* If nothing (other than _GNU_SOURCE) is defined,
    171    define _BSD_SOURCE and _SVID_SOURCE.  */
    172 #if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
    173      !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
    174      !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
    175      !defined _BSD_SOURCE && !defined _SVID_SOURCE)
    176 # define _BSD_SOURCE	1
    177 # define _SVID_SOURCE	1
    178 #endif
    179 
    180 /* This is to enable the ISO C99 extension.  Also recognize the old macro
    181    which was used prior to the standard acceptance.  This macro will
    182    eventually go away and the features enabled by default once the ISO C99
    183    standard is widely adopted.  */
    184 #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
    185      || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
    186 # define __USE_ISOC99	1
    187 #endif
    188 
    189 /* This is to enable the ISO C90 Amendment 1:1995 extension.  */
    190 #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
    191      || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
    192 # define __USE_ISOC95	1
    193 #endif
    194 
    195 /* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
    196    (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined).  */
    197 #if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
    198      !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
    199 # define _POSIX_SOURCE	1
    200 # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
    201 #  define _POSIX_C_SOURCE	2
    202 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
    203 #  define _POSIX_C_SOURCE	199506L
    204 # else
    205 #  define _POSIX_C_SOURCE	200112L
    206 # endif
    207 #endif
    208 
    209 #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
    210 # define __USE_POSIX	1
    211 #endif
    212 
    213 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
    214 # define __USE_POSIX2	1
    215 #endif
    216 
    217 #if (_POSIX_C_SOURCE - 0) >= 199309L
    218 # define __USE_POSIX199309	1
    219 #endif
    220 
    221 #if (_POSIX_C_SOURCE - 0) >= 199506L
    222 # define __USE_POSIX199506	1
    223 #endif
    224 
    225 #if (_POSIX_C_SOURCE - 0) >= 200112L
    226 # define __USE_XOPEN2K		1
    227 #endif
    228 
    229 #ifdef	_XOPEN_SOURCE
    230 # define __USE_XOPEN	1
    231 # if (_XOPEN_SOURCE - 0) >= 500
    232 #  define __USE_XOPEN_EXTENDED	1
    233 #  define __USE_UNIX98	1
    234 #  undef _LARGEFILE_SOURCE
    235 #  define _LARGEFILE_SOURCE	1
    236 #  if (_XOPEN_SOURCE - 0) >= 600
    237 #   define __USE_XOPEN2K	1
    238 #   undef __USE_ISOC99
    239 #   define __USE_ISOC99		1
    240 #  endif
    241 # else
    242 #  ifdef _XOPEN_SOURCE_EXTENDED
    243 #   define __USE_XOPEN_EXTENDED	1
    244 #  endif
    245 # endif
    246 #endif
    247 
    248 #ifdef _LARGEFILE_SOURCE
    249 # define __USE_LARGEFILE	1
    250 #endif
    251 
    252 #ifdef _LARGEFILE64_SOURCE
    253 # define __USE_LARGEFILE64	1
    254 #endif
    255 
    256 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
    257 # define __USE_FILE_OFFSET64	1
    258 #endif
    259 
    260 #if defined _BSD_SOURCE || defined _SVID_SOURCE
    261 # define __USE_MISC	1
    262 #endif
    263 
    264 #ifdef	_BSD_SOURCE
    265 # define __USE_BSD	1
    266 #endif
    267 
    268 #ifdef	_SVID_SOURCE
    269 # define __USE_SVID	1
    270 #endif
    271 
    272 #ifdef	_ATFILE_SOURCE
    273 # define __USE_ATFILE	1
    274 #endif
    275 
    276 #ifdef	_GNU_SOURCE
    277 # define __USE_GNU	1
    278 #endif
    279 
    280 #if defined _REENTRANT || defined _THREAD_SAFE
    281 # define __USE_REENTRANT	1
    282 #endif
    283 
    284 #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 \
    285     && __GNUC_PREREQ (4, 1) && defined __OPTIMIZE__ && __OPTIMIZE__ > 0
    286 # if _FORTIFY_SOURCE > 1
    287 #  define __USE_FORTIFY_LEVEL 2
    288 # else
    289 #  define __USE_FORTIFY_LEVEL 1
    290 # endif
    291 #else
    292 # define __USE_FORTIFY_LEVEL 0
    293 #endif
    294 
    295 /* We do support the IEC 559 math functionality, real and complex.  */
    296 #define __STDC_IEC_559__		1
    297 #define __STDC_IEC_559_COMPLEX__	1
    298 
    299 /* wchar_t uses ISO 10646-1 (2nd ed., published 2000-09-15) / Unicode 3.1.  */
    300 #define __STDC_ISO_10646__		200009L
    301 
    302 /* This macro indicates that the installed library is the GNU C Library.
    303    For historic reasons the value now is 6 and this will stay from now
    304    on.  The use of this variable is deprecated.  Use __GLIBC__ and
    305    __GLIBC_MINOR__ now (see below) when you want to test for a specific
    306    GNU C library version and use the values in <gnu/lib-names.h> to get
    307    the sonames of the shared libraries.  */
    308 #undef  __GNU_LIBRARY__
    309 #define __GNU_LIBRARY__ 6
    310 
    311 /* Major and minor version number of the GNU C library package.  Use
    312    these macros to test for features in specific releases.  */
    313 #define	__GLIBC__	2
    314 #define	__GLIBC_MINOR__	7
    315 
    316 #define __GLIBC_PREREQ(maj, min) \
    317 	((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
    318 
    319 /* Decide whether a compiler supports the long long datatypes.  */
    320 #if defined __GNUC__ \
    321     || (defined __PGI && defined __i386__ ) \
    322     || (defined __INTEL_COMPILER && (defined __i386__ || defined __ia64__)) \
    323     || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
    324 # define __GLIBC_HAVE_LONG_LONG	1
    325 #endif
    326 
    327 /* This is here only because every header file already includes this one.  */
    328 #ifndef __ASSEMBLER__
    329 # ifndef _SYS_CDEFS_H
    330 #  include <sys/cdefs.h>
    331 # endif
    332 
    333 /* If we don't have __REDIRECT, prototypes will be missing if
    334    __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
    335 # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
    336 #  define __USE_LARGEFILE	1
    337 #  define __USE_LARGEFILE64	1
    338 # endif
    339 
    340 #endif	/* !ASSEMBLER */
    341 
    342 /* Decide whether we can define 'extern inline' functions in headers.  */
    343 #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
    344     && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
    345     && defined __extern_inline
    346 # define __USE_EXTERN_INLINES	1
    347 #endif
    348 
    349 
    350 /* This is here only because every header file already includes this one.
    351    Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
    352    <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
    353    that will always return failure (and set errno to ENOSYS).  */
    354 #include <gnu/stubs.h>
    355 
    356 
    357 #endif	/* features.h  */
    358