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The C and C++ Include Header Files
cat -n /usr/include/features.h
1 /* Copyright (C) 1991-2026 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 <https://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 _ISOC23_SOURCE Extensions to ISO C99 from ISO C23. 28 _ISOC2X_SOURCE Old name for _ISOC23_SOURCE. 29 _ISOC2Y_SOURCE Extensions to ISO C23 from ISO C2Y. 30 __STDC_WANT_LIB_EXT2__ 31 Extensions to ISO C99 from TR 27431-2:2010. 32 __STDC_WANT_IEC_60559_BFP_EXT__ 33 Extensions to ISO C11 from TS 18661-1:2014. 34 __STDC_WANT_IEC_60559_FUNCS_EXT__ 35 Extensions to ISO C11 from TS 18661-4:2015. 36 __STDC_WANT_IEC_60559_TYPES_EXT__ 37 Extensions to ISO C11 from TS 18661-3:2015. 38 __STDC_WANT_IEC_60559_EXT__ 39 ISO C23 interfaces defined only in Annex F. 40 41 _POSIX_SOURCE IEEE Std 1003.1. 42 _POSIX_C_SOURCE If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2; 43 if >=199309L, add IEEE Std 1003.1b-1993; 44 if >=199506L, add IEEE Std 1003.1c-1995; 45 if >=200112L, all of IEEE 1003.1-2004 46 if >=200809L, all of IEEE 1003.1-2008 47 if >=202405L, all of IEEE 1003.1-2024 48 _XOPEN_SOURCE Includes POSIX and XPG things. Set to 500 if 49 Single Unix conformance is wanted, to 600 for the 50 sixth revision, to 700 for the seventh revision, 51 to 800 for the eighth revision. 52 _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions. 53 _LARGEFILE_SOURCE Some more functions for correct standard I/O. 54 _LARGEFILE64_SOURCE Additional functionality from LFS for large files. 55 _FILE_OFFSET_BITS=N Select default filesystem interface. 56 _ATFILE_SOURCE Additional *at interfaces. 57 _DYNAMIC_STACK_SIZE_SOURCE Select correct (but non compile-time constant) 58 MINSIGSTKSZ, SIGSTKSZ and PTHREAD_STACK_MIN. 59 _GNU_SOURCE All of the above, plus GNU extensions. 60 _DEFAULT_SOURCE The default set of features (taking precedence over 61 __STRICT_ANSI__). 62 63 _FORTIFY_SOURCE Add security hardening to many library functions. 64 Set to 1, 2 or 3; 3 performs stricter checks than 2, which 65 performs stricter checks than 1. 66 67 _REENTRANT, _THREAD_SAFE 68 Obsolete; equivalent to _POSIX_C_SOURCE=199506L. 69 70 The `-ansi' switch to the GNU C compiler, and standards conformance 71 options such as `-std=c99', define __STRICT_ANSI__. If none of 72 these are defined, or if _DEFAULT_SOURCE is defined, the default is 73 to have _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to 74 202405L, as well as enabling miscellaneous functions from BSD and 75 SVID. If more than one of these are defined, they accumulate. For 76 example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE together 77 give you ISO C, 1003.1, and 1003.2, but nothing else. 78 79 These are defined by this file and are used by the 80 header files to decide what to declare or define: 81 82 __GLIBC_USE (F) Define things from feature set F. This is defined 83 to 1 or 0; the subsequent macros are either defined 84 or undefined, and those tests should be moved to 85 __GLIBC_USE. 86 __USE_ISOC11 Define ISO C11 things. 87 __USE_ISOC99 Define ISO C99 things. 88 __USE_ISOC95 Define ISO C90 AMD1 (C95) things. 89 __USE_ISOCXX11 Define ISO C++11 things. 90 __USE_POSIX Define IEEE Std 1003.1 things. 91 __USE_POSIX2 Define IEEE Std 1003.2 things. 92 __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things. 93 __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things. 94 __USE_XOPEN Define XPG things. 95 __USE_XOPEN_EXTENDED Define X/Open Unix things. 96 __USE_UNIX98 Define Single Unix V2 things. 97 __USE_XOPEN2K Define XPG6 things. 98 __USE_XOPEN2KXSI Define XPG6 XSI things. 99 __USE_XOPEN2K8 Define XPG7 things. 100 __USE_XOPEN2K8XSI Define XPG7 XSI things. 101 __USE_XOPEN2K24 Define XPG8 things. 102 __USE_XOPEN2K24XSI Define XPG8 XSI things. 103 __USE_LARGEFILE Define correct standard I/O things. 104 __USE_LARGEFILE64 Define LFS things with separate names. 105 __USE_FILE_OFFSET64 Define 64bit interface as default. 106 __USE_MISC Define things from 4.3BSD or System V Unix. 107 __USE_ATFILE Define *at interfaces and AT_* constants for them. 108 __USE_DYNAMIC_STACK_SIZE Define correct (but non compile-time constant) 109 MINSIGSTKSZ, SIGSTKSZ and PTHREAD_STACK_MIN. 110 __USE_GNU Define GNU extensions. 111 __USE_FORTIFY_LEVEL Additional security measures used, according to level. 112 113 The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are 114 defined by this file unconditionally. `__GNU_LIBRARY__' is provided 115 only for compatibility. All new code should use the other symbols 116 to test for features. 117 118 All macros listed above as possibly being defined by this file are 119 explicitly undefined if they are not explicitly defined. 120 Feature-test macros that are not defined by the user or compiler 121 but are implied by the other feature-test macros defined (or by the 122 lack of any definitions) are defined by the file. 123 124 ISO C feature test macros depend on the definition of the macro 125 when an affected header is included, not when the first system 126 header is included, and so they are handled in 127 <bits/libc-header-start.h>, which does not have a multiple include 128 guard. Feature test macros that can be handled from the first 129 system header included are handled here. */ 130 131 132 /* Undefine everything, so we get a clean slate. */ 133 #undef __USE_ISOC11 134 #undef __USE_ISOC99 135 #undef __USE_ISOC95 136 #undef __USE_ISOCXX11 137 #undef __USE_POSIX 138 #undef __USE_POSIX2 139 #undef __USE_POSIX199309 140 #undef __USE_POSIX199506 141 #undef __USE_XOPEN 142 #undef __USE_XOPEN_EXTENDED 143 #undef __USE_UNIX98 144 #undef __USE_XOPEN2K 145 #undef __USE_XOPEN2KXSI 146 #undef __USE_XOPEN2K8 147 #undef __USE_XOPEN2K8XSI 148 #undef __USE_XOPEN2K24 149 #undef __USE_XOPEN2K24XSI 150 #undef __USE_LARGEFILE 151 #undef __USE_LARGEFILE64 152 #undef __USE_FILE_OFFSET64 153 #undef __USE_MISC 154 #undef __USE_ATFILE 155 #undef __USE_DYNAMIC_STACK_SIZE 156 #undef __USE_GNU 157 #undef __USE_FORTIFY_LEVEL 158 #undef __KERNEL_STRICT_NAMES 159 #undef __GLIBC_USE_ISOC23 160 #undef __GLIBC_USE_ISOC2Y 161 #undef __GLIBC_USE_DEPRECATED_GETS 162 #undef __GLIBC_USE_DEPRECATED_SCANF 163 #undef __GLIBC_USE_C23_STRTOL 164 165 /* Suppress kernel-name space pollution unless user explicitly asks 166 for it. */ 167 #ifndef _LOOSE_KERNEL_NAMES 168 # define __KERNEL_STRICT_NAMES 169 #endif 170 171 /* Convenience macro to test the version of gcc. 172 Use like this: 173 #if __GNUC_PREREQ (2,8) 174 ... code requiring gcc 2.8 or later ... 175 #endif 176 Note: only works for GCC 2.0 and later, because __GNUC_MINOR__ was 177 added in 2.0. */ 178 #if defined __GNUC__ && defined __GNUC_MINOR__ 179 # define __GNUC_PREREQ(maj, min) \ 180 ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) 181 #else 182 # define __GNUC_PREREQ(maj, min) 0 183 #endif 184 185 /* Similarly for clang. Features added to GCC after version 4.2 may 186 or may not also be available in clang, and clang's definitions of 187 __GNUC(_MINOR)__ are fixed at 4 and 2 respectively. Not all such 188 features can be queried via __has_extension/__has_feature. */ 189 #if defined __clang_major__ && defined __clang_minor__ 190 # define __glibc_clang_prereq(maj, min) \ 191 ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min)) 192 #else 193 # define __glibc_clang_prereq(maj, min) 0 194 #endif 195 196 /* Whether to use feature set F. */ 197 #define __GLIBC_USE(F) __GLIBC_USE_ ## F 198 199 /* _BSD_SOURCE and _SVID_SOURCE are deprecated aliases for 200 _DEFAULT_SOURCE. If _DEFAULT_SOURCE is present we do not 201 issue a warning; the expectation is that the source is being 202 transitioned to use the new macro. */ 203 #if (defined _BSD_SOURCE || defined _SVID_SOURCE) \ 204 && !defined _DEFAULT_SOURCE 205 # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" 206 # undef _DEFAULT_SOURCE 207 # define _DEFAULT_SOURCE 1 208 #endif 209 210 /* Remap the old name _ISOC2X_SOURCE to _ISOC23_SOURCE. */ 211 #ifdef _ISOC2X_SOURCE 212 # undef _ISOC2X_SOURCE 213 # undef _ISOC23_SOURCE 214 # define _ISOC23_SOURCE 1 215 #endif 216 217 /* If _GNU_SOURCE was defined by the user, turn on all the other features. */ 218 #ifdef _GNU_SOURCE 219 # undef _ISOC95_SOURCE 220 # define _ISOC95_SOURCE 1 221 # undef _ISOC99_SOURCE 222 # define _ISOC99_SOURCE 1 223 # undef _ISOC11_SOURCE 224 # define _ISOC11_SOURCE 1 225 # undef _ISOC23_SOURCE 226 # define _ISOC23_SOURCE 1 227 # undef _ISOC2Y_SOURCE 228 # define _ISOC2Y_SOURCE 1 229 # undef _POSIX_SOURCE 230 # define _POSIX_SOURCE 1 231 # undef _POSIX_C_SOURCE 232 # define _POSIX_C_SOURCE 202405L 233 # undef _XOPEN_SOURCE 234 # define _XOPEN_SOURCE 800 235 # undef _XOPEN_SOURCE_EXTENDED 236 # define _XOPEN_SOURCE_EXTENDED 1 237 # undef _LARGEFILE64_SOURCE 238 # define _LARGEFILE64_SOURCE 1 239 # undef _DEFAULT_SOURCE 240 # define _DEFAULT_SOURCE 1 241 # undef _ATFILE_SOURCE 242 # define _ATFILE_SOURCE 1 243 # undef _DYNAMIC_STACK_SIZE_SOURCE 244 # define _DYNAMIC_STACK_SIZE_SOURCE 1 245 #endif 246 247 /* If nothing (other than _GNU_SOURCE and _DEFAULT_SOURCE) is defined, 248 define _DEFAULT_SOURCE. */ 249 #if (defined _DEFAULT_SOURCE \ 250 || (!defined __STRICT_ANSI__ \ 251 && !defined _ISOC99_SOURCE && !defined _ISOC11_SOURCE \ 252 && !defined _ISOC23_SOURCE && !defined _ISOC2Y_SOURCE \ 253 && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE \ 254 && !defined _XOPEN_SOURCE)) 255 # undef _DEFAULT_SOURCE 256 # define _DEFAULT_SOURCE 1 257 #endif 258 259 /* This is to enable the ISO C2Y extension. */ 260 #if (defined _ISOC2Y_SOURCE \ 261 || (defined __STDC_VERSION__ && __STDC_VERSION__ > 202311L)) 262 # define __GLIBC_USE_ISOC2Y 1 263 #else 264 # define __GLIBC_USE_ISOC2Y 0 265 #endif 266 267 /* This is to enable the ISO C23 extension. */ 268 #if (defined _ISOC23_SOURCE || defined _ISOC2Y_SOURCE \ 269 || (defined __STDC_VERSION__ && __STDC_VERSION__ > 201710L)) 270 # define __GLIBC_USE_ISOC23 1 271 #else 272 # define __GLIBC_USE_ISOC23 0 273 #endif 274 275 /* This is to enable the ISO C11 extension. */ 276 #if (defined _ISOC11_SOURCE || defined _ISOC23_SOURCE \ 277 || defined _ISOC2Y_SOURCE \ 278 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L)) 279 # define __USE_ISOC11 1 280 #endif 281 282 /* This is to enable the ISO C99 extension. */ 283 #if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \ 284 || defined _ISOC23_SOURCE || defined _ISOC2Y_SOURCE \ 285 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)) 286 # define __USE_ISOC99 1 287 #endif 288 289 /* This is to enable the ISO C90 Amendment 1:1995 extension. */ 290 #if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \ 291 || defined _ISOC23_SOURCE || defined _ISOC2Y_SOURCE \ 292 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L)) 293 # define __USE_ISOC95 1 294 #endif 295 296 #ifdef __cplusplus 297 /* This is to enable compatibility for ISO C++17. */ 298 # if __cplusplus >= 201703L 299 # define __USE_ISOC11 1 300 # endif 301 /* This is to enable compatibility for ISO C++11. 302 Check the temporary macro for now, too. */ 303 # if __cplusplus >= 201103L || defined __GXX_EXPERIMENTAL_CXX0X__ 304 # define __USE_ISOCXX11 1 305 # define __USE_ISOC99 1 306 # endif 307 #endif 308 309 /* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE 310 is defined, use POSIX.1-2024 (or another version depending on 311 _XOPEN_SOURCE). */ 312 #ifdef _DEFAULT_SOURCE 313 # if !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE 314 # define __USE_POSIX_IMPLICITLY 1 315 # endif 316 # undef _POSIX_SOURCE 317 # define _POSIX_SOURCE 1 318 # undef _POSIX_C_SOURCE 319 # define _POSIX_C_SOURCE 202405L 320 #endif 321 322 #if ((!defined __STRICT_ANSI__ \ 323 || (defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) >= 500)) \ 324 && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE) 325 # define _POSIX_SOURCE 1 326 # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500 327 # define _POSIX_C_SOURCE 2 328 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600 329 # define _POSIX_C_SOURCE 199506L 330 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700 331 # define _POSIX_C_SOURCE 200112L 332 # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 800 333 # define _POSIX_C_SOURCE 200809L 334 # else 335 # define _POSIX_C_SOURCE 202405L 336 # endif 337 # define __USE_POSIX_IMPLICITLY 1 338 #endif 339 340 /* Some C libraries once required _REENTRANT and/or _THREAD_SAFE to be 341 defined in all multithreaded code. GNU libc has not required this 342 for many years. We now treat them as compatibility synonyms for 343 _POSIX_C_SOURCE=199506L, which is the earliest level of POSIX with 344 comprehensive support for multithreaded code. Using them never 345 lowers the selected level of POSIX conformance, only raises it. */ 346 #if ((!defined _POSIX_C_SOURCE || (_POSIX_C_SOURCE - 0) < 199506L) \ 347 && (defined _REENTRANT || defined _THREAD_SAFE)) 348 # define _POSIX_SOURCE 1 349 # undef _POSIX_C_SOURCE 350 # define _POSIX_C_SOURCE 199506L 351 #endif 352 353 #if (defined _POSIX_SOURCE \ 354 || (defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 1) \ 355 || defined _XOPEN_SOURCE) 356 # define __USE_POSIX 1 357 #endif 358 359 #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE 360 # define __USE_POSIX2 1 361 #endif 362 363 #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 199309L 364 # define __USE_POSIX199309 1 365 #endif 366 367 #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 199506L 368 # define __USE_POSIX199506 1 369 #endif 370 371 #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 200112L 372 # define __USE_XOPEN2K 1 373 # undef __USE_ISOC95 374 # define __USE_ISOC95 1 375 # undef __USE_ISOC99 376 # define __USE_ISOC99 1 377 #endif 378 379 #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 200809L 380 # define __USE_XOPEN2K8 1 381 # undef _ATFILE_SOURCE 382 # define _ATFILE_SOURCE 1 383 #endif 384 385 #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 202405L 386 # define __USE_XOPEN2K24 1 387 #endif 388 389 #ifdef _XOPEN_SOURCE 390 # define __USE_XOPEN 1 391 # if (_XOPEN_SOURCE - 0) >= 500 392 # define __USE_XOPEN_EXTENDED 1 393 # define __USE_UNIX98 1 394 # undef _LARGEFILE_SOURCE 395 # define _LARGEFILE_SOURCE 1 396 # if (_XOPEN_SOURCE - 0) >= 600 397 # if (_XOPEN_SOURCE - 0) >= 700 398 # define __USE_XOPEN2K8 1 399 # define __USE_XOPEN2K8XSI 1 400 # if (_XOPEN_SOURCE - 0) >= 800 401 # define __USE_XOPEN2K24 1 402 # define __USE_XOPEN2K24XSI 1 403 # endif 404 # endif 405 # define __USE_XOPEN2K 1 406 # define __USE_XOPEN2KXSI 1 407 # undef __USE_ISOC95 408 # define __USE_ISOC95 1 409 # undef __USE_ISOC99 410 # define __USE_ISOC99 1 411 # endif 412 # else 413 # ifdef _XOPEN_SOURCE_EXTENDED 414 # define __USE_XOPEN_EXTENDED 1 415 # endif 416 # endif 417 #endif 418 419 #ifdef _LARGEFILE_SOURCE 420 # define __USE_LARGEFILE 1 421 #endif 422 423 #ifdef _LARGEFILE64_SOURCE 424 # define __USE_LARGEFILE64 1 425 #endif 426 427 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64 428 # define __USE_FILE_OFFSET64 1 429 #endif 430 431 #include <features-time64.h> 432 433 #if defined _DEFAULT_SOURCE 434 # define __USE_MISC 1 435 #endif 436 437 #ifdef _ATFILE_SOURCE 438 # define __USE_ATFILE 1 439 #endif 440 441 #ifdef _DYNAMIC_STACK_SIZE_SOURCE 442 # define __USE_DYNAMIC_STACK_SIZE 1 443 #endif 444 445 #ifdef _GNU_SOURCE 446 # define __USE_GNU 1 447 #endif 448 449 #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 \ 450 && defined __OPTIMIZE__ && __OPTIMIZE__ > 0 451 # if !__GNUC_PREREQ (4, 1) 452 # warning _FORTIFY_SOURCE requires GCC 4.1 or later 453 # elif _FORTIFY_SOURCE > 2 && (__glibc_clang_prereq (9, 0) \ 454 || __GNUC_PREREQ (12, 0)) 455 456 # if _FORTIFY_SOURCE > 3 457 # warning _FORTIFY_SOURCE > 3 is treated like 3 on this platform 458 # endif 459 # define __USE_FORTIFY_LEVEL 3 460 # elif _FORTIFY_SOURCE > 1 461 # if _FORTIFY_SOURCE > 2 462 # warning _FORTIFY_SOURCE > 2 is treated like 2 on this platform 463 # endif 464 # define __USE_FORTIFY_LEVEL 2 465 # else 466 # define __USE_FORTIFY_LEVEL 1 467 # endif 468 #endif 469 #ifndef __USE_FORTIFY_LEVEL 470 # define __USE_FORTIFY_LEVEL 0 471 #endif 472 473 /* The function 'gets' existed in C89, but is impossible to use 474 safely. It has been removed from ISO C11 and ISO C++14. Note: for 475 compatibility with various implementations of <cstdio>, this test 476 must consider only the value of __cplusplus when compiling C++. */ 477 #if defined __cplusplus ? __cplusplus >= 201402L : defined __USE_ISOC11 478 # define __GLIBC_USE_DEPRECATED_GETS 0 479 #else 480 # define __GLIBC_USE_DEPRECATED_GETS 1 481 #endif 482 483 /* GNU formerly extended the scanf functions with modified format 484 specifiers %as, %aS, and %a[...] that allocate a buffer for the 485 input using malloc. This extension conflicts with ISO C99, which 486 defines %a as a standalone format specifier that reads a floating- 487 point number; moreover, POSIX.1-2008 provides the same feature 488 using the modifier letter 'm' instead (%ms, %mS, %m[...]). 489 490 We now follow C99 unless GNU extensions are active and the compiler 491 is specifically in C89 or C++98 mode (strict or not). For 492 instance, with GCC, -std=gnu11 will have C99-compliant scanf with 493 or without -D_GNU_SOURCE, but -std=c89 -D_GNU_SOURCE will have the 494 old extension. */ 495 #if (defined __USE_GNU \ 496 && (defined __cplusplus \ 497 ? (__cplusplus < 201103L && !defined __GXX_EXPERIMENTAL_CXX0X__) \ 498 : (!defined __STDC_VERSION__ || __STDC_VERSION__ < 199901L))) 499 # define __GLIBC_USE_DEPRECATED_SCANF 1 500 #else 501 # define __GLIBC_USE_DEPRECATED_SCANF 0 502 #endif 503 504 /* ISO C23 added support for a 0b or 0B prefix on binary constants as 505 inputs to strtol-family functions (base 0 or 2). This macro is 506 used to condition redirection in headers to allow that redirection 507 to be disabled when building those functions, despite _GNU_SOURCE 508 being defined. */ 509 #if __GLIBC_USE (ISOC23) 510 # define __GLIBC_USE_C23_STRTOL 1 511 #else 512 # define __GLIBC_USE_C23_STRTOL 0 513 #endif 514 515 /* Get definitions of __STDC_* predefined macros, if the compiler has 516 not preincluded this header automatically. */ 517 #include <stdc-predef.h> 518 519 /* This macro indicates that the installed library is the GNU C Library. 520 For historic reasons the value now is 6 and this will stay from now 521 on. The use of this variable is deprecated. Use __GLIBC__ and 522 __GLIBC_MINOR__ now (see below) when you want to test for a specific 523 GNU C library version and use the values in <gnu/lib-names.h> to get 524 the sonames of the shared libraries. */ 525 #undef __GNU_LIBRARY__ 526 #define __GNU_LIBRARY__ 6 527 528 /* Major and minor version number of the GNU C library package. Use 529 these macros to test for features in specific releases. */ 530 #define __GLIBC__ 2 531 #define __GLIBC_MINOR__ 43 532 533 #define __GLIBC_PREREQ(maj, min) \ 534 ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min)) 535 536 /* This is here only because every header file already includes this one. */ 537 #ifndef __ASSEMBLER__ 538 # ifndef _SYS_CDEFS_H 539 # include <sys/cdefs.h> 540 # endif 541 542 /* If we don't have __REDIRECT, prototypes will be missing if 543 __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */ 544 # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT 545 # define __USE_LARGEFILE 1 546 # define __USE_LARGEFILE64 1 547 # endif 548 549 #endif /* !ASSEMBLER */ 550 551 /* Decide whether we can define 'extern inline' functions in headers. */ 552 #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \ 553 && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \ 554 && defined __extern_inline && !(defined __clang__ && defined _LIBC) 555 # define __USE_EXTERN_INLINES 1 556 #endif 557 558 559 /* This is here only because every header file already includes this one. 560 Get the definitions of all the appropriate `__stub_FUNCTION' symbols. 561 <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub 562 that will always return failure (and set errno to ENOSYS). */ 563 #include <gnu/stubs.h> 564 565 566 #endif /* features.h */
