features.h 15 KB

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  1. /* Copyright (C) 1991-1993,1995-2006,2007,2009 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, see
  13. <http://www.gnu.org/licenses/>. */
  14. #ifndef _FEATURES_H
  15. #define _FEATURES_H 1
  16. /* These are defined by the user (or the compiler)
  17. to specify the desired environment:
  18. __STRICT_ANSI__ ISO Standard C.
  19. _ISOC99_SOURCE Extensions to ISO C89 from ISO C99.
  20. _POSIX_SOURCE IEEE Std 1003.1.
  21. _POSIX_C_SOURCE If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2;
  22. if >=199309L, add IEEE Std 1003.1b-1993;
  23. if >=199506L, add IEEE Std 1003.1c-1995;
  24. if >=200112L, all of IEEE 1003.1-2004
  25. if >=200809L, all of IEEE 1003.1-2008
  26. _XOPEN_SOURCE Includes POSIX and XPG things. Set to 500 if
  27. Single Unix conformance is wanted, to 600 for the
  28. sixth revision, to 700 for the seventh revision.
  29. _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
  30. _LARGEFILE_SOURCE Some more functions for correct standard I/O.
  31. _LARGEFILE64_SOURCE Additional functionality from LFS for large files.
  32. _FILE_OFFSET_BITS=N Select default filesystem interface.
  33. _BSD_SOURCE ISO C, POSIX, and 4.3BSD things.
  34. _SVID_SOURCE ISO C, POSIX, and SVID things.
  35. _ATFILE_SOURCE Additional *at interfaces.
  36. _GNU_SOURCE All of the above, plus GNU extensions.
  37. _REENTRANT Select additionally reentrant object.
  38. _THREAD_SAFE Same as _REENTRANT, often used by other systems.
  39. _FORTIFY_SOURCE If set to numeric value > 0 additional security
  40. measures are defined, according to level.
  41. The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
  42. If none of these are defined, the default is to have _SVID_SOURCE,
  43. _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
  44. 200112L. If more than one of these are defined, they accumulate.
  45. For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
  46. together give you ISO C, 1003.1, and 1003.2, but nothing else.
  47. These are defined by this file and are used by the
  48. header files to decide what to declare or define:
  49. __USE_ISOC99 Define ISO C99 things.
  50. __USE_ISOC95 Define ISO C90 AMD1 (C95) things.
  51. __USE_POSIX Define IEEE Std 1003.1 things.
  52. __USE_POSIX2 Define IEEE Std 1003.2 things.
  53. __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
  54. __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things.
  55. __USE_XOPEN Define XPG things.
  56. __USE_XOPEN_EXTENDED Define X/Open Unix things.
  57. __USE_UNIX98 Define Single Unix V2 things.
  58. __USE_XOPEN2K Define XPG6 things.
  59. __USE_XOPEN2K8 Define XPG7 things.
  60. __USE_LARGEFILE Define correct standard I/O things.
  61. __USE_LARGEFILE64 Define LFS things with separate names.
  62. __USE_FILE_OFFSET64 Define 64bit interface as default.
  63. __USE_BSD Define 4.3BSD things.
  64. __USE_SVID Define SVID things.
  65. __USE_MISC Define things common to BSD and System V Unix.
  66. __USE_ATFILE Define *at interfaces and AT_* constants for them.
  67. __USE_GNU Define GNU extensions.
  68. __USE_REENTRANT Define reentrant/thread-safe *_r functions.
  69. __USE_FORTIFY_LEVEL Additional security measures used, according to level.
  70. __FAVOR_BSD Favor 4.3BSD things in cases of conflict.
  71. The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
  72. defined by this file unconditionally. `__GNU_LIBRARY__' is provided
  73. only for compatibility. All new code should use the other symbols
  74. to test for features.
  75. All macros listed above as possibly being defined by this file are
  76. explicitly undefined if they are not explicitly defined.
  77. Feature-test macros that are not defined by the user or compiler
  78. but are implied by the other feature-test macros defined (or by the
  79. lack of any definitions) are defined by the file. */
  80. /* Undefine everything, so we get a clean slate. */
  81. #undef __USE_ISOC99
  82. #undef __USE_ISOC95
  83. #undef __USE_POSIX
  84. #undef __USE_POSIX2
  85. #undef __USE_POSIX199309
  86. #undef __USE_POSIX199506
  87. #undef __USE_XOPEN
  88. #undef __USE_XOPEN_EXTENDED
  89. #undef __USE_UNIX98
  90. #undef __USE_XOPEN2K
  91. #undef __USE_XOPEN2K8
  92. #undef __USE_LARGEFILE
  93. #undef __USE_LARGEFILE64
  94. #undef __USE_FILE_OFFSET64
  95. #undef __USE_BSD
  96. #undef __USE_SVID
  97. #undef __USE_MISC
  98. #undef __USE_ATFILE
  99. #undef __USE_GNU
  100. #undef __USE_REENTRANT
  101. #undef __USE_FORTIFY_LEVEL
  102. #undef __FAVOR_BSD
  103. #undef __KERNEL_STRICT_NAMES
  104. /* Suppress kernel-name space pollution unless user expressedly asks
  105. for it. */
  106. #ifndef _LOOSE_KERNEL_NAMES
  107. # define __KERNEL_STRICT_NAMES
  108. #endif
  109. /* Always use ISO C things. */
  110. #define __USE_ANSI 1
  111. /* Convenience macros to test the versions of glibc and gcc.
  112. Use them like this:
  113. #if __GNUC_PREREQ (2,8)
  114. ... code requiring gcc 2.8 or later ...
  115. #endif
  116. Note - they won't work for gcc1 or glibc1, since the _MINOR macros
  117. were not defined then. */
  118. #if defined __GNUC__ && defined __GNUC_MINOR__
  119. # define __GNUC_PREREQ(maj, min) \
  120. ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  121. #else
  122. # define __GNUC_PREREQ(maj, min) 0
  123. #endif
  124. /* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
  125. #if defined _BSD_SOURCE && \
  126. !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
  127. defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
  128. defined _GNU_SOURCE || defined _SVID_SOURCE)
  129. # define __FAVOR_BSD 1
  130. #endif
  131. /* If _GNU_SOURCE was defined by the user, turn on all the other features. */
  132. #ifdef _GNU_SOURCE
  133. # undef _ISOC99_SOURCE
  134. # define _ISOC99_SOURCE 1
  135. # undef _POSIX_SOURCE
  136. # define _POSIX_SOURCE 1
  137. # undef _POSIX_C_SOURCE
  138. # define _POSIX_C_SOURCE 200809L
  139. # undef _XOPEN_SOURCE
  140. # define _XOPEN_SOURCE 700
  141. # undef _XOPEN_SOURCE_EXTENDED
  142. # define _XOPEN_SOURCE_EXTENDED 1
  143. # undef _LARGEFILE64_SOURCE
  144. # define _LARGEFILE64_SOURCE 1
  145. # undef _BSD_SOURCE
  146. # define _BSD_SOURCE 1
  147. # undef _SVID_SOURCE
  148. # define _SVID_SOURCE 1
  149. # undef _ATFILE_SOURCE
  150. # define _ATFILE_SOURCE 1
  151. #endif
  152. /* This macro indicates that the installed library is uClibc. Use
  153. * __UCLIBC_MAJOR__ and __UCLIBC_MINOR__ to test for the features in
  154. * specific releases. */
  155. #define __UCLIBC__ 1
  156. #ifdef __UCLIBC__
  157. /* Load up the current set of uClibc supported features along
  158. * with the current uClibc major and minor version numbers.
  159. * For uClibc release 0.9.26, these numbers would be:
  160. * #define __UCLIBC_MAJOR__ 0
  161. * #define __UCLIBC_MINOR__ 9
  162. * #define __UCLIBC_SUBLEVEL__ 26
  163. */
  164. # define __need_uClibc_config_h
  165. # include <bits/uClibc_config.h>
  166. # undef __need_uClibc_config_h
  167. /* For uClibc, always optimize for size -- this should disable
  168. * a lot of expensive inlining...
  169. * TODO: this is wrong! __OPTIMIZE_SIZE__ is an indicator of
  170. * gcc -Os compile. We should not mess with compiler inlines.
  171. * We should instead disable __USE_EXTERN_INLINES unconditionally,
  172. * or maybe actually audit and test uclibc to work correctly
  173. * with __USE_EXTERN_INLINES on.
  174. */
  175. # define __OPTIMIZE_SIZE__ 1
  176. /* disable unsupported features */
  177. # undef __LDBL_COMPAT
  178. # ifndef __UCLIBC_HAS_FORTIFY__
  179. # undef _FORTIFY_SOURCE
  180. # endif
  181. # ifndef __UCLIBC_HAS_THREADS__
  182. # if defined _REENTRANT || defined _THREAD_SAFE
  183. # warning requested reentrant code, but thread support was disabled
  184. # undef _REENTRANT
  185. # undef _THREAD_SAFE
  186. # endif
  187. # endif
  188. # ifndef __UCLIBC_HAS_LFS__
  189. # undef _LARGEFILE64_SOURCE
  190. /* NOTE: This is probably incorrect on a 64-bit arch... */
  191. # if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
  192. # error It appears you have defined _FILE_OFFSET_BITS=64. Unfortunately, \
  193. uClibc was built without large file support enabled.
  194. # endif
  195. # elif defined __BCC__
  196. # error BCC does not support LFS, please disable it
  197. # endif
  198. #endif /* __UCLIBC__ */
  199. /* If nothing (other than _GNU_SOURCE) is defined,
  200. define _BSD_SOURCE and _SVID_SOURCE. */
  201. #if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
  202. !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
  203. !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
  204. !defined _BSD_SOURCE && !defined _SVID_SOURCE)
  205. # define _BSD_SOURCE 1
  206. # define _SVID_SOURCE 1
  207. #endif
  208. /* This is to enable the ISO C99 extension. Also recognize the old macro
  209. which was used prior to the standard acceptance. This macro will
  210. eventually go away and the features enabled by default once the ISO C99
  211. standard is widely adopted. */
  212. #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
  213. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
  214. # define __USE_ISOC99 1
  215. #endif
  216. /* This is to enable the ISO C90 Amendment 1:1995 extension. */
  217. #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
  218. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
  219. # define __USE_ISOC95 1
  220. #endif
  221. /* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
  222. (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
  223. #if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
  224. !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
  225. # define _POSIX_SOURCE 1
  226. # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
  227. # define _POSIX_C_SOURCE 2
  228. # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
  229. # define _POSIX_C_SOURCE 199506L
  230. # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700
  231. # define _POSIX_C_SOURCE 200112L
  232. # else
  233. # define _POSIX_C_SOURCE 200809L
  234. # endif
  235. # define __USE_POSIX_IMPLICITLY 1
  236. #endif
  237. #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
  238. # define __USE_POSIX 1
  239. #endif
  240. #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
  241. # define __USE_POSIX2 1
  242. #endif
  243. #if (_POSIX_C_SOURCE - 0) >= 199309L
  244. # define __USE_POSIX199309 1
  245. #endif
  246. #if (_POSIX_C_SOURCE - 0) >= 199506L
  247. # define __USE_POSIX199506 1
  248. #endif
  249. #if (_POSIX_C_SOURCE - 0) >= 200112L
  250. # define __USE_XOPEN2K 1
  251. # undef __USE_ISOC99
  252. # define __USE_ISOC99 1
  253. #endif
  254. #if (_POSIX_C_SOURCE - 0) >= 200809L
  255. # define __USE_XOPEN2K8 1
  256. # undef _ATFILE_SOURCE
  257. # define _ATFILE_SOURCE 1
  258. #endif
  259. #ifdef _XOPEN_SOURCE
  260. # define __USE_XOPEN 1
  261. # if (_XOPEN_SOURCE - 0) >= 500
  262. # define __USE_XOPEN_EXTENDED 1
  263. # define __USE_UNIX98 1
  264. # undef _LARGEFILE_SOURCE
  265. # define _LARGEFILE_SOURCE 1
  266. # if (_XOPEN_SOURCE - 0) >= 600
  267. # if (_XOPEN_SOURCE - 0) >= 700
  268. # define __USE_XOPEN2K8 1
  269. # endif
  270. # define __USE_XOPEN2K 1
  271. # undef __USE_ISOC99
  272. # define __USE_ISOC99 1
  273. # endif
  274. # else
  275. # ifdef _XOPEN_SOURCE_EXTENDED
  276. # define __USE_XOPEN_EXTENDED 1
  277. # endif
  278. # endif
  279. #endif
  280. #ifdef _LARGEFILE_SOURCE
  281. # define __USE_LARGEFILE 1
  282. #endif
  283. #ifdef _LARGEFILE64_SOURCE
  284. # define __USE_LARGEFILE64 1
  285. #endif
  286. #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
  287. # define __USE_FILE_OFFSET64 1
  288. #endif
  289. #if defined _BSD_SOURCE || defined _SVID_SOURCE
  290. # define __USE_MISC 1
  291. #endif
  292. #ifdef _BSD_SOURCE
  293. # define __USE_BSD 1
  294. #endif
  295. #ifdef _SVID_SOURCE
  296. # define __USE_SVID 1
  297. #endif
  298. #ifdef _ATFILE_SOURCE
  299. # define __USE_ATFILE 1
  300. #endif
  301. #ifdef _GNU_SOURCE
  302. # define __USE_GNU 1
  303. #endif
  304. #if defined _REENTRANT || defined _THREAD_SAFE
  305. # define __USE_REENTRANT 1
  306. #endif
  307. #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 \
  308. && __GNUC_PREREQ (4, 1) && defined __OPTIMIZE__ && __OPTIMIZE__ > 0
  309. # if _FORTIFY_SOURCE > 1
  310. # define __USE_FORTIFY_LEVEL 2
  311. # else
  312. # define __USE_FORTIFY_LEVEL 1
  313. # endif
  314. #else
  315. # define __USE_FORTIFY_LEVEL 0
  316. #endif
  317. /* We do support the IEC 559 math functionality, real and complex. */
  318. #ifdef __UCLIBC_HAS_FLOATS__
  319. #define __STDC_IEC_559__ 1
  320. #define __STDC_IEC_559_COMPLEX__ 1
  321. #endif
  322. #ifdef __UCLIBC_HAS_WCHAR__
  323. /* wchar_t uses ISO 10646-1 (2nd ed., published 2000-09-15) / Unicode 3.1. */
  324. #define __STDC_ISO_10646__ 200009L
  325. #endif
  326. /* There is an unwholesomely huge amount of code out there that depends on the
  327. * presence of GNU libc header files. We have GNU libc header files. So here
  328. * we commit a horrible sin. At this point, we _lie_ and claim to be GNU libc
  329. * to make things like /usr/include/linux/socket.h and lots of apps work as
  330. * their developers intended. This is IMHO, pardonable, since these defines
  331. * are not really intended to check for the presence of a particular library,
  332. * but rather are used to define an _interface_. */
  333. #if !defined __FORCE_NOGLIBC && (!defined _LIBC || defined __FORCE_GLIBC)
  334. /* This macro indicates that the installed library is the GNU C Library.
  335. For historic reasons the value now is 6 and this will stay from now
  336. on. The use of this variable is deprecated. */
  337. /* uClibc WARNING: leave these aligned to the left, don't put a space after '#', else
  338. * broken apps could fail the check. */
  339. #undef __GNU_LIBRARY__
  340. #define __GNU_LIBRARY__ 6
  341. /* Major and minor version number of the GNU C library package. Use
  342. these macros to test for features in specific releases. */
  343. /* Don't do it, if you want to keep uClibc happy. */
  344. #define __GLIBC__ 2
  345. #define __GLIBC_MINOR__ 10
  346. #endif
  347. #define __GLIBC_PREREQ(maj, min) \
  348. ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
  349. #ifndef __UCLIBC__
  350. /* Decide whether a compiler supports the long long datatypes. */
  351. #if defined __GNUC__ \
  352. || (defined __PGI && defined __i386__ ) \
  353. || (defined __INTEL_COMPILER && (defined __i386__ || defined __ia64__)) \
  354. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
  355. # define __GLIBC_HAVE_LONG_LONG 1
  356. #endif
  357. #endif
  358. /* This is here only because every header file already includes this one. */
  359. #ifndef __ASSEMBLER__
  360. # ifndef _SYS_CDEFS_H
  361. # include <sys/cdefs.h>
  362. # endif
  363. /* If we don't have __REDIRECT, prototypes will be missing if
  364. __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
  365. # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
  366. # define __USE_LARGEFILE 1
  367. # ifdef __UCLIBC_HAS_LFS__
  368. # define __USE_LARGEFILE64 1
  369. # endif
  370. # endif
  371. #endif /* !ASSEMBLER */
  372. /* Decide whether we can, and are willing to define extern inline
  373. * functions in headers, even if this results in a slightly bigger
  374. * code for user programs built against uclibc.
  375. * Enabled only in -O2 compiles, not -Os.
  376. * uclibc itself is usually built without __USE_EXTERN_INLINES,
  377. * remove "&& !defined __OPTIMIZE_SIZE__" part to do otherwise.
  378. */
  379. #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
  380. && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
  381. && (defined __extern_inline || defined __GNUC_GNU_INLINE__ || defined __GNUC_STDC_INLINE__)
  382. # define __USE_EXTERN_INLINES 1
  383. #endif
  384. #ifdef _LIBC
  385. # ifdef __UCLIBC_HAS_LFS__
  386. # undef _FILE_OFFSET_BITS
  387. # undef __USE_FILE_OFFSET64
  388. # endif
  389. # include <libc-internal.h>
  390. #endif
  391. #endif /* features.h */