1 /* Copyright (C) 1991-2015 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 _ATFILE_SOURCE Additional *at interfaces. 41 _GNU_SOURCE All of the above, plus GNU extensions. 42 _DEFAULT_SOURCE The default set of features (taking precedence over 43 __STRICT_ANSI__). 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, and standards conformance 50 options such as `-std=c99', define __STRICT_ANSI__. If none of 51 these are defined, or if _DEFAULT_SOURCE is defined, the default is 52 to have _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to 53 200809L, as well as enabling miscellaneous functions from BSD and 54 SVID. If more than one of these are defined, they accumulate. For 55 example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE together 56 give you ISO C, 1003.1, and 1003.2, but nothing else. 57 58 These are defined by this file and are used by the 59 header files to decide what to declare or define: 60 61 __USE_ISOC11 Define ISO C11 things. 62 __USE_ISOC99 Define ISO C99 things. 63 __USE_ISOC95 Define ISO C90 AMD1 (C95) things. 64 __USE_POSIX Define IEEE Std 1003.1 things. 65 __USE_POSIX2 Define IEEE Std 1003.2 things. 66 __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things. 67 __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things. 68 __USE_XOPEN Define XPG things. 69 __USE_XOPEN_EXTENDED Define X/Open Unix things. 70 __USE_UNIX98 Define Single Unix V2 things. 71 __USE_XOPEN2K Define XPG6 things. 72 __USE_XOPEN2KXSI Define XPG6 XSI things. 73 __USE_XOPEN2K8 Define XPG7 things. 74 __USE_XOPEN2K8XSI Define XPG7 XSI things. 75 __USE_LARGEFILE Define correct standard I/O things. 76 __USE_LARGEFILE64 Define LFS things with separate names. 77 __USE_FILE_OFFSET64 Define 64bit interface as default. 78 __USE_MISC Define things from 4.3BSD or 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 84 The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are 85 defined by this file unconditionally. `__GNU_LIBRARY__' is provided 86 only for compatibility. All new code should use the other symbols 87 to test for features. 88 89 All macros listed above as possibly being defined by this file are 90 explicitly undefined if they are not explicitly defined. 91 Feature-test macros that are not defined by the user or compiler 92 but are implied by the other feature-test macros defined (or by the 93 lack of any definitions) are defined by the file. */ 94 95 96 /* Undefine everything, so we get a clean slate. */ 97 #undef __USE_ISOC11 98 #undef __USE_ISOC99 99 #undef __USE_ISOC95 100 #undef __USE_ISOCXX11 101 #undef __USE_POSIX 102 #undef __USE_POSIX2 103 #undef __USE_POSIX199309 104 #undef __USE_POSIX199506 105 #undef __USE_XOPEN 106 #undef __USE_XOPEN_EXTENDED 107 #undef __USE_UNIX98 108 #undef __USE_XOPEN2K 109 #undef __USE_XOPEN2KXSI 110 #undef __USE_XOPEN2K8 111 #undef __USE_XOPEN2K8XSI 112 #undef __USE_LARGEFILE 113 #undef __USE_LARGEFILE64 114 #undef __USE_FILE_OFFSET64 115 #undef __USE_MISC 116 #undef __USE_ATFILE 117 #undef __USE_GNU 118 #undef __USE_REENTRANT 119 #undef __USE_FORTIFY_LEVEL 120 #undef __KERNEL_STRICT_NAMES 121 122 /* Suppress kernel-name space pollution unless user expressedly asks 123 for it. */ 124 #ifndef _LOOSE_KERNEL_NAMES 125 # define __KERNEL_STRICT_NAMES 126 #endif 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 /* _BSD_SOURCE and _SVID_SOURCE are deprecated aliases for 143 _DEFAULT_SOURCE. If _DEFAULT_SOURCE is present we do not 144 issue a warning; the expectation is that the source is being 145 transitioned to use the new macro. */ 146 #if (defined _BSD_SOURCE || defined _SVID_SOURCE) \ 147 && !defined _DEFAULT_SOURCE 148 /* # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" */ 149 # undef _DEFAULT_SOURCE 150 # define _DEFAULT_SOURCE 1 151 #endif 152 153 /* If _GNU_SOURCE was defined by the user, turn on all the other features. */ 154 #ifdef _GNU_SOURCE 155 # undef _ISOC95_SOURCE 156 # define _ISOC95_SOURCE 1 157 # undef _ISOC99_SOURCE 158 # define _ISOC99_SOURCE 1 159 # undef _ISOC11_SOURCE 160 # define _ISOC11_SOURCE 1 161 # undef _POSIX_SOURCE 162 # define _POSIX_SOURCE 1 163 # undef _POSIX_C_SOURCE 164 # define _POSIX_C_SOURCE 200809L 165 # undef _XOPEN_SOURCE 166 # define _XOPEN_SOURCE 700 167 # undef _XOPEN_SOURCE_EXTENDED 168 # define _XOPEN_SOURCE_EXTENDED 1 169 # undef _LARGEFILE64_SOURCE 170 # define _LARGEFILE64_SOURCE 1 171 # undef _DEFAULT_SOURCE 172 # define _DEFAULT_SOURCE 1 173 # undef _ATFILE_SOURCE 174 # define _ATFILE_SOURCE 1 175 #endif 176 177 /* If nothing (other than _GNU_SOURCE and _DEFAULT_SOURCE) is defined, 178 define _DEFAULT_SOURCE. */ 179 #if (defined _DEFAULT_SOURCE \ 180 || (!defined __STRICT_ANSI__ \ 181 && !defined _ISOC99_SOURCE \ 182 && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE \ 183 && !defined _XOPEN_SOURCE)) 184 # undef _DEFAULT_SOURCE 185 # define _DEFAULT_SOURCE 1 186 #endif 187 188 /* This is to enable the ISO C11 extension. */ 189 #if (defined _ISOC11_SOURCE \ 190 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L)) 191 # define __USE_ISOC11 1 192 #endif 193 194 /* This is to enable the ISO C99 extension. */ 195 #if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \ 196 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)) 197 # define __USE_ISOC99 1 198 #endif 199 200 /* This is to enable the ISO C90 Amendment 1:1995 extension. */ 201 #if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \ 202 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L)) 203 # define __USE_ISOC95 1 204 #endif 205 206 /* This is to enable compatibility for ISO C++11. 207 208 So far g++ does not provide a macro. Check the temporary macro for 209 now, too. */ 210 #if ((defined __cplusplus && __cplusplus >= 201103L) \ 211 || defined __GXX_EXPERIMENTAL_CXX0X__) 212 # define __USE_ISOCXX11 1 213 #endif 214 215 /* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE 216 is defined, use POSIX.1-2008 (or another version depending on 217 _XOPEN_SOURCE). */ 218 #ifdef _DEFAULT_SOURCE 219 # if !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE 220 # define __USE_POSIX_IMPLICITLY 1 221 # endif 222 # undef _POSIX_SOURCE 223 # define _POSIX_SOURCE 1 224 # undef _POSIX_C_SOURCE 225 # define _POSIX_C_SOURCE 200809L 226 #endif 227 #if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \ 228 !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE) 229 # define _POSIX_SOURCE 1 230 # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500 231 # define _POSIX_C_SOURCE 2 232 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600 233 # define _POSIX_C_SOURCE 199506L 234 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700 235 # define _POSIX_C_SOURCE 200112L 236 # else 237 # define _POSIX_C_SOURCE 200809L 238 # endif 239 # define __USE_POSIX_IMPLICITLY 1 240 #endif 241 242 #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE 243 # define __USE_POSIX 1 244 #endif 245 246 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE 247 # define __USE_POSIX2 1 248 #endif 249 250 #if (_POSIX_C_SOURCE - 0) >= 199309L 251 # define __USE_POSIX199309 1 252 #endif 253 254 #if (_POSIX_C_SOURCE - 0) >= 199506L 255 # define __USE_POSIX199506 1 256 #endif 257 258 #if (_POSIX_C_SOURCE - 0) >= 200112L 259 # define __USE_XOPEN2K 1 260 # undef __USE_ISOC95 261 # define __USE_ISOC95 1 262 # undef __USE_ISOC99 263 # define __USE_ISOC99 1 264 #endif 265 266 #if (_POSIX_C_SOURCE - 0) >= 200809L 267 # define __USE_XOPEN2K8 1 268 # undef _ATFILE_SOURCE 269 # define _ATFILE_SOURCE 1 270 #endif 271 272 #ifdef _XOPEN_SOURCE 273 # define __USE_XOPEN 1 274 # if (_XOPEN_SOURCE - 0) >= 500 275 # define __USE_XOPEN_EXTENDED 1 276 # define __USE_UNIX98 1 277 # undef _LARGEFILE_SOURCE 278 # define _LARGEFILE_SOURCE 1 279 # if (_XOPEN_SOURCE - 0) >= 600 280 # if (_XOPEN_SOURCE - 0) >= 700 281 # define __USE_XOPEN2K8 1 282 # define __USE_XOPEN2K8XSI 1 283 # endif 284 # define __USE_XOPEN2K 1 285 # define __USE_XOPEN2KXSI 1 286 # undef __USE_ISOC95 287 # define __USE_ISOC95 1 288 # undef __USE_ISOC99 289 # define __USE_ISOC99 1 290 # endif 291 # else 292 # ifdef _XOPEN_SOURCE_EXTENDED 293 # define __USE_XOPEN_EXTENDED 1 294 # endif 295 # endif 296 #endif 297 298 #ifdef _LARGEFILE_SOURCE 299 # define __USE_LARGEFILE 1 300 #endif 301 302 #ifdef _LARGEFILE64_SOURCE 303 # define __USE_LARGEFILE64 1 304 #endif 305 306 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64 307 # define __USE_FILE_OFFSET64 1 308 #endif 309 310 #if defined _DEFAULT_SOURCE 311 # define __USE_MISC 1 312 #endif 313 314 #ifdef _ATFILE_SOURCE 315 # define __USE_ATFILE 1 316 #endif 317 318 #ifdef _GNU_SOURCE 319 # define __USE_GNU 1 320 #endif 321 322 #if defined _REENTRANT || defined _THREAD_SAFE 323 # define __USE_REENTRANT 1 324 #endif 325 326 #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 327 # if !defined __OPTIMIZE__ || __OPTIMIZE__ <= 0 328 # warning _FORTIFY_SOURCE requires compiling with optimization (-O) 329 # elif !__GNUC_PREREQ (4, 1) 330 # warning _FORTIFY_SOURCE requires GCC 4.1 or later 331 # elif _FORTIFY_SOURCE > 1 332 # define __USE_FORTIFY_LEVEL 2 333 # else 334 # define __USE_FORTIFY_LEVEL 1 335 # endif 336 #endif 337 #ifndef __USE_FORTIFY_LEVEL 338 # define __USE_FORTIFY_LEVEL 0 339 #endif 340 341 /* Get definitions of __STDC_* predefined macros, if the compiler has 342 not preincluded this header automatically. */ 343 #include <stdc-predef.h> 344 345 /* This macro indicates that the installed library is the GNU C Library. 346 For historic reasons the value now is 6 and this will stay from now 347 on. The use of this variable is deprecated. Use __GLIBC__ and 348 __GLIBC_MINOR__ now (see below) when you want to test for a specific 349 GNU C library version and use the values in <gnu/lib-names.h> to get 350 the sonames of the shared libraries. */ 351 #undef __GNU_LIBRARY__ 352 #define __GNU_LIBRARY__ 6 353 354 /* Major and minor version number of the GNU C library package. Use 355 these macros to test for features in specific releases. */ 356 #define __GLIBC__ 2 357 #define __GLIBC_MINOR__ 22 358 359 #define __GLIBC_PREREQ(maj, min) \ 360 ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min)) 361 362 /* This is here only because every header file already includes this one. */ 363 #ifndef __ASSEMBLER__ 364 # ifndef _SYS_CDEFS_H 365 # include <sys/cdefs.h> 366 # endif 367 368 /* If we don't have __REDIRECT, prototypes will be missing if 369 __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */ 370 # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT 371 # define __USE_LARGEFILE 1 372 # define __USE_LARGEFILE64 1 373 # endif 374 375 #endif /* !ASSEMBLER */ 376 377 /* Decide whether we can define 'extern inline' functions in headers. */ 378 #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \ 379 && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \ 380 && defined __extern_inline 381 # define __USE_EXTERN_INLINES 1 382 #endif 383 384 385 /* This is here only because every header file already includes this one. 386 Get the definitions of all the appropriate `__stub_FUNCTION' symbols. 387 <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub 388 that will always return failure (and set errno to ENOSYS). */ 389 #include <gnu/stubs.h> 390 391 392 #endif /* features.h */ 393