cdefs.h 26 KB

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  1. /* Copyright (C) 1992-2024 Free Software Foundation, Inc.
  2. Copyright The GNU Toolchain Authors.
  3. This file is part of the GNU C Library.
  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. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, see
  14. <https://www.gnu.org/licenses/>. */
  15. #ifndef _SYS_CDEFS_H
  16. #define _SYS_CDEFS_H 1
  17. /* We are almost always included from features.h. */
  18. #ifndef _FEATURES_H
  19. # include <features.h>
  20. #endif
  21. /* The GNU libc does not support any K&R compilers or the traditional mode
  22. of ISO C compilers anymore. Check for some of the combinations not
  23. supported anymore. */
  24. #if defined __GNUC__ && !defined __STDC__
  25. # error "You need a ISO C conforming compiler to use the glibc headers"
  26. #endif
  27. /* Some user header file might have defined this before. */
  28. #undef __P
  29. #undef __PMT
  30. /* Compilers that lack __has_attribute may object to
  31. #if defined __has_attribute && __has_attribute (...)
  32. even though they do not need to evaluate the right-hand side of the &&.
  33. Similarly for __has_builtin, etc. */
  34. #if (defined __has_attribute \
  35. && (!defined __clang_minor__ \
  36. || (defined __apple_build_version__ \
  37. ? 6000000 <= __apple_build_version__ \
  38. : 3 < __clang_major__ + (5 <= __clang_minor__))))
  39. # define __glibc_has_attribute(attr) __has_attribute (attr)
  40. #else
  41. # define __glibc_has_attribute(attr) 0
  42. #endif
  43. #ifdef __has_builtin
  44. # define __glibc_has_builtin(name) __has_builtin (name)
  45. #else
  46. # define __glibc_has_builtin(name) 0
  47. #endif
  48. #ifdef __has_extension
  49. # define __glibc_has_extension(ext) __has_extension (ext)
  50. #else
  51. # define __glibc_has_extension(ext) 0
  52. #endif
  53. #if defined __GNUC__ || defined __clang__
  54. /* All functions, except those with callbacks or those that
  55. synchronize memory, are leaf functions. */
  56. # if __GNUC_PREREQ (4, 6) && !defined _LIBC
  57. # define __LEAF , __leaf__
  58. # define __LEAF_ATTR __attribute__ ((__leaf__))
  59. # else
  60. # define __LEAF
  61. # define __LEAF_ATTR
  62. # endif
  63. /* GCC can always grok prototypes. For C++ programs we add throw()
  64. to help it optimize the function calls. But this only works with
  65. gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions
  66. as non-throwing using a function attribute since programs can use
  67. the -fexceptions options for C code as well. */
  68. # if !defined __cplusplus \
  69. && (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__))
  70. # define __THROW __attribute__ ((__nothrow__ __LEAF))
  71. # define __THROWNL __attribute__ ((__nothrow__))
  72. # define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
  73. # define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
  74. # else
  75. # if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major >= 4)
  76. # if __cplusplus >= 201103L
  77. # define __THROW noexcept (true)
  78. # else
  79. # define __THROW throw ()
  80. # endif
  81. # define __THROWNL __THROW
  82. # define __NTH(fct) __LEAF_ATTR fct __THROW
  83. # define __NTHNL(fct) fct __THROW
  84. # else
  85. # define __THROW
  86. # define __THROWNL
  87. # define __NTH(fct) fct
  88. # define __NTHNL(fct) fct
  89. # endif
  90. # endif
  91. #else /* Not GCC or clang. */
  92. # if (defined __cplusplus \
  93. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
  94. # define __inline inline
  95. # else
  96. # define __inline /* No inline functions. */
  97. # endif
  98. # define __THROW
  99. # define __THROWNL
  100. # define __NTH(fct) fct
  101. #endif /* GCC || clang. */
  102. /* These two macros are not used in glibc anymore. They are kept here
  103. only because some other projects expect the macros to be defined. */
  104. #define __P(args) args
  105. #define __PMT(args) args
  106. /* For these things, GCC behaves the ANSI way normally,
  107. and the non-ANSI way under -traditional. */
  108. #define __CONCAT(x,y) x ## y
  109. #define __STRING(x) #x
  110. /* This is not a typedef so `const __ptr_t' does the right thing. */
  111. #define __ptr_t void *
  112. /* C++ needs to know that types and declarations are C, not C++. */
  113. #ifdef __cplusplus
  114. # define __BEGIN_DECLS extern "C" {
  115. # define __END_DECLS }
  116. #else
  117. # define __BEGIN_DECLS
  118. # define __END_DECLS
  119. #endif
  120. /* Gnulib avoids these definitions, as they don't work on non-glibc platforms.
  121. In particular, __bos and __bos0 are defined differently in the Android libc.
  122. */
  123. #ifndef __GNULIB_CDEFS
  124. /* Fortify support. */
  125. # define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
  126. # define __bos0(ptr) __builtin_object_size (ptr, 0)
  127. /* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
  128. # if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
  129. || __GNUC_PREREQ (12, 0))
  130. # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
  131. # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
  132. # else
  133. # define __glibc_objsize0(__o) __bos0 (__o)
  134. # define __glibc_objsize(__o) __bos (__o)
  135. # endif
  136. /* Compile time conditions to choose between the regular, _chk and _chk_warn
  137. variants. These conditions should get evaluated to constant and optimized
  138. away. */
  139. # define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
  140. # define __glibc_unsigned_or_positive(__l) \
  141. ((__typeof (__l)) 0 < (__typeof (__l)) -1 \
  142. || (__builtin_constant_p (__l) && (__l) > 0))
  143. /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
  144. condition can be folded to a constant and if it is true, or unknown (-1) */
  145. # define __glibc_safe_or_unknown_len(__l, __s, __osz) \
  146. ((__osz) == (__SIZE_TYPE__) -1 \
  147. || (__glibc_unsigned_or_positive (__l) \
  148. && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
  149. (__s), (__osz))) \
  150. && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz))))
  151. /* Conversely, we know at compile time that the length is unsafe if the
  152. __L * __S <= __OBJSZ condition can be folded to a constant and if it is
  153. false. */
  154. # define __glibc_unsafe_len(__l, __s, __osz) \
  155. (__glibc_unsigned_or_positive (__l) \
  156. && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
  157. __s, __osz)) \
  158. && !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
  159. /* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be
  160. declared. */
  161. # define __glibc_fortify(f, __l, __s, __osz, ...) \
  162. (__glibc_safe_or_unknown_len (__l, __s, __osz) \
  163. ? __ ## f ## _alias (__VA_ARGS__) \
  164. : (__glibc_unsafe_len (__l, __s, __osz) \
  165. ? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \
  166. : __ ## f ## _chk (__VA_ARGS__, __osz))) \
  167. /* Fortify function f, where object size argument passed to f is the number of
  168. elements and not total size. */
  169. # define __glibc_fortify_n(f, __l, __s, __osz, ...) \
  170. (__glibc_safe_or_unknown_len (__l, __s, __osz) \
  171. ? __ ## f ## _alias (__VA_ARGS__) \
  172. : (__glibc_unsafe_len (__l, __s, __osz) \
  173. ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \
  174. : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s)))) \
  175. #endif
  176. #if __GNUC_PREREQ (4,3)
  177. # define __warnattr(msg) __attribute__((__warning__ (msg)))
  178. # define __errordecl(name, msg) \
  179. extern void name (void) __attribute__((__error__ (msg)))
  180. #else
  181. # define __warnattr(msg)
  182. # define __errordecl(name, msg) extern void name (void)
  183. #endif
  184. /* Support for flexible arrays.
  185. Headers that should use flexible arrays only if they're "real"
  186. (e.g. only if they won't affect sizeof()) should test
  187. #if __glibc_c99_flexarr_available. */
  188. #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
  189. # define __flexarr []
  190. # define __glibc_c99_flexarr_available 1
  191. #elif __GNUC_PREREQ (2,97) || defined __clang__
  192. /* GCC 2.97 and clang support C99 flexible array members as an extension,
  193. even when in C89 mode or compiling C++ (any version). */
  194. # define __flexarr []
  195. # define __glibc_c99_flexarr_available 1
  196. #elif defined __GNUC__
  197. /* Pre-2.97 GCC did not support C99 flexible arrays but did have
  198. an equivalent extension with slightly different notation. */
  199. # define __flexarr [0]
  200. # define __glibc_c99_flexarr_available 1
  201. #else
  202. /* Some other non-C99 compiler. Approximate with [1]. */
  203. # define __flexarr [1]
  204. # define __glibc_c99_flexarr_available 0
  205. #endif
  206. /* __asm__ ("xyz") is used throughout the headers to rename functions
  207. at the assembly language level. This is wrapped by the __REDIRECT
  208. macro, in order to support compilers that can do this some other
  209. way. When compilers don't support asm-names at all, we have to do
  210. preprocessor tricks instead (which don't have exactly the right
  211. semantics, but it's the best we can do).
  212. Example:
  213. int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
  214. #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
  215. # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
  216. # ifdef __cplusplus
  217. # define __REDIRECT_NTH(name, proto, alias) \
  218. name proto __THROW __asm__ (__ASMNAME (#alias))
  219. # define __REDIRECT_NTHNL(name, proto, alias) \
  220. name proto __THROWNL __asm__ (__ASMNAME (#alias))
  221. # else
  222. # define __REDIRECT_NTH(name, proto, alias) \
  223. name proto __asm__ (__ASMNAME (#alias)) __THROW
  224. # define __REDIRECT_NTHNL(name, proto, alias) \
  225. name proto __asm__ (__ASMNAME (#alias)) __THROWNL
  226. # endif
  227. # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
  228. # define __ASMNAME2(prefix, cname) __STRING (prefix) cname
  229. /*
  230. #elif __SOME_OTHER_COMPILER__
  231. # define __REDIRECT(name, proto, alias) name proto; \
  232. _Pragma("let " #name " = " #alias)
  233. */
  234. #endif
  235. /* GCC and clang have various useful declarations that can be made with
  236. the '__attribute__' syntax. All of the ways we use this do fine if
  237. they are omitted for compilers that don't understand it. */
  238. #if !(defined __GNUC__ || defined __clang__)
  239. # define __attribute__(xyz) /* Ignore */
  240. #endif
  241. /* At some point during the gcc 2.96 development the `malloc' attribute
  242. for functions was introduced. We don't want to use it unconditionally
  243. (although this would be possible) since it generates warnings. */
  244. #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
  245. # define __attribute_malloc__ __attribute__ ((__malloc__))
  246. #else
  247. # define __attribute_malloc__ /* Ignore */
  248. #endif
  249. /* Tell the compiler which arguments to an allocation function
  250. indicate the size of the allocation. */
  251. #if __GNUC_PREREQ (4, 3)
  252. # define __attribute_alloc_size__(params) \
  253. __attribute__ ((__alloc_size__ params))
  254. #else
  255. # define __attribute_alloc_size__(params) /* Ignore. */
  256. #endif
  257. /* Tell the compiler which argument to an allocation function
  258. indicates the alignment of the allocation. */
  259. #if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__)
  260. # define __attribute_alloc_align__(param) \
  261. __attribute__ ((__alloc_align__ param))
  262. #else
  263. # define __attribute_alloc_align__(param) /* Ignore. */
  264. #endif
  265. /* At some point during the gcc 2.96 development the `pure' attribute
  266. for functions was introduced. We don't want to use it unconditionally
  267. (although this would be possible) since it generates warnings. */
  268. #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
  269. # define __attribute_pure__ __attribute__ ((__pure__))
  270. #else
  271. # define __attribute_pure__ /* Ignore */
  272. #endif
  273. /* This declaration tells the compiler that the value is constant. */
  274. #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
  275. # define __attribute_const__ __attribute__ ((__const__))
  276. #else
  277. # define __attribute_const__ /* Ignore */
  278. #endif
  279. #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
  280. # define __attribute_maybe_unused__ __attribute__ ((__unused__))
  281. #else
  282. # define __attribute_maybe_unused__ /* Ignore */
  283. #endif
  284. /* At some point during the gcc 3.1 development the `used' attribute
  285. for functions was introduced. We don't want to use it unconditionally
  286. (although this would be possible) since it generates warnings. */
  287. #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
  288. # define __attribute_used__ __attribute__ ((__used__))
  289. # define __attribute_noinline__ __attribute__ ((__noinline__))
  290. #else
  291. # define __attribute_used__ __attribute__ ((__unused__))
  292. # define __attribute_noinline__ /* Ignore */
  293. #endif
  294. /* Since version 3.2, gcc allows marking deprecated functions. */
  295. #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
  296. # define __attribute_deprecated__ __attribute__ ((__deprecated__))
  297. #else
  298. # define __attribute_deprecated__ /* Ignore */
  299. #endif
  300. /* Since version 4.5, gcc also allows one to specify the message printed
  301. when a deprecated function is used. clang claims to be gcc 4.2, but
  302. may also support this feature. */
  303. #if __GNUC_PREREQ (4,5) \
  304. || __glibc_has_extension (__attribute_deprecated_with_message__)
  305. # define __attribute_deprecated_msg__(msg) \
  306. __attribute__ ((__deprecated__ (msg)))
  307. #else
  308. # define __attribute_deprecated_msg__(msg) __attribute_deprecated__
  309. #endif
  310. /* At some point during the gcc 2.8 development the `format_arg' attribute
  311. for functions was introduced. We don't want to use it unconditionally
  312. (although this would be possible) since it generates warnings.
  313. If several `format_arg' attributes are given for the same function, in
  314. gcc-3.0 and older, all but the last one are ignored. In newer gccs,
  315. all designated arguments are considered. */
  316. #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
  317. # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
  318. #else
  319. # define __attribute_format_arg__(x) /* Ignore */
  320. #endif
  321. /* At some point during the gcc 2.97 development the `strfmon' format
  322. attribute for functions was introduced. We don't want to use it
  323. unconditionally (although this would be possible) since it
  324. generates warnings. */
  325. #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
  326. # define __attribute_format_strfmon__(a,b) \
  327. __attribute__ ((__format__ (__strfmon__, a, b)))
  328. #else
  329. # define __attribute_format_strfmon__(a,b) /* Ignore */
  330. #endif
  331. /* The nonnull function attribute marks pointer parameters that
  332. must not be NULL. This has the name __nonnull in glibc,
  333. and __attribute_nonnull__ in files shared with Gnulib to avoid
  334. collision with a different __nonnull in DragonFlyBSD 5.9. */
  335. #ifndef __attribute_nonnull__
  336. # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
  337. # define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params))
  338. # else
  339. # define __attribute_nonnull__(params)
  340. # endif
  341. #endif
  342. #ifndef __nonnull
  343. # define __nonnull(params) __attribute_nonnull__ (params)
  344. #endif
  345. /* The returns_nonnull function attribute marks the return type of the function
  346. as always being non-null. */
  347. #ifndef __returns_nonnull
  348. # if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__)
  349. # define __returns_nonnull __attribute__ ((__returns_nonnull__))
  350. # else
  351. # define __returns_nonnull
  352. # endif
  353. #endif
  354. /* If fortification mode, we warn about unused results of certain
  355. function calls which can lead to problems. */
  356. #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
  357. # define __attribute_warn_unused_result__ \
  358. __attribute__ ((__warn_unused_result__))
  359. # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
  360. # define __wur __attribute_warn_unused_result__
  361. # endif
  362. #else
  363. # define __attribute_warn_unused_result__ /* empty */
  364. #endif
  365. #ifndef __wur
  366. # define __wur /* Ignore */
  367. #endif
  368. /* Forces a function to be always inlined. */
  369. #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
  370. /* The Linux kernel defines __always_inline in stddef.h (283d7573), and
  371. it conflicts with this definition. Therefore undefine it first to
  372. allow either header to be included first. */
  373. # undef __always_inline
  374. # define __always_inline __inline __attribute__ ((__always_inline__))
  375. #else
  376. # undef __always_inline
  377. # define __always_inline __inline
  378. #endif
  379. /* Associate error messages with the source location of the call site rather
  380. than with the source location inside the function. */
  381. #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
  382. # define __attribute_artificial__ __attribute__ ((__artificial__))
  383. #else
  384. # define __attribute_artificial__ /* Ignore */
  385. #endif
  386. /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
  387. inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
  388. or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
  389. older than 4.3 may define these macros and still not guarantee GNU inlining
  390. semantics.
  391. clang++ identifies itself as gcc-4.2, but has support for GNU inlining
  392. semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
  393. __GNUC_GNU_INLINE__ macro definitions. */
  394. #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
  395. || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
  396. || defined __GNUC_GNU_INLINE__)))
  397. # if defined __GNUC_STDC_INLINE__ || defined __cplusplus
  398. # define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
  399. # define __extern_always_inline \
  400. extern __always_inline __attribute__ ((__gnu_inline__))
  401. # else
  402. # define __extern_inline extern __inline
  403. # define __extern_always_inline extern __always_inline
  404. # endif
  405. #endif
  406. #ifdef __extern_always_inline
  407. # define __fortify_function __extern_always_inline __attribute_artificial__
  408. #endif
  409. /* GCC 4.3 and above allow passing all anonymous arguments of an
  410. __extern_always_inline function to some other vararg function. */
  411. #if __GNUC_PREREQ (4,3)
  412. # define __va_arg_pack() __builtin_va_arg_pack ()
  413. # define __va_arg_pack_len() __builtin_va_arg_pack_len ()
  414. #endif
  415. /* It is possible to compile containing GCC extensions even if GCC is
  416. run in pedantic mode if the uses are carefully marked using the
  417. `__extension__' keyword. But this is not generally available before
  418. version 2.8. */
  419. #if !(__GNUC_PREREQ (2,8) || defined __clang__)
  420. # define __extension__ /* Ignore */
  421. #endif
  422. /* __restrict is known in EGCS 1.2 and above, and in clang.
  423. It works also in C++ mode (outside of arrays), but only when spelled
  424. as '__restrict', not 'restrict'. */
  425. #if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
  426. # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
  427. # define __restrict restrict
  428. # else
  429. # define __restrict /* Ignore */
  430. # endif
  431. #endif
  432. /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
  433. array_name[restrict]
  434. GCC 3.1 and clang support this.
  435. This syntax is not usable in C++ mode. */
  436. #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
  437. # define __restrict_arr __restrict
  438. #else
  439. # ifdef __GNUC__
  440. # define __restrict_arr /* Not supported in old GCC. */
  441. # else
  442. # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
  443. # define __restrict_arr restrict
  444. # else
  445. /* Some other non-C99 compiler. */
  446. # define __restrict_arr /* Not supported. */
  447. # endif
  448. # endif
  449. #endif
  450. #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
  451. # define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
  452. # define __glibc_likely(cond) __builtin_expect ((cond), 1)
  453. #else
  454. # define __glibc_unlikely(cond) (cond)
  455. # define __glibc_likely(cond) (cond)
  456. #endif
  457. #if (!defined _Noreturn \
  458. && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
  459. && !(__GNUC_PREREQ (4,7) \
  460. || (3 < __clang_major__ + (5 <= __clang_minor__))))
  461. # if __GNUC_PREREQ (2,8)
  462. # define _Noreturn __attribute__ ((__noreturn__))
  463. # else
  464. # define _Noreturn
  465. # endif
  466. #endif
  467. #if __GNUC_PREREQ (8, 0)
  468. /* Describes a char array whose address can safely be passed as the first
  469. argument to strncpy and strncat, as the char array is not necessarily
  470. a NUL-terminated string. */
  471. # define __attribute_nonstring__ __attribute__ ((__nonstring__))
  472. #else
  473. # define __attribute_nonstring__
  474. #endif
  475. /* Undefine (also defined in libc-symbols.h). */
  476. #undef __attribute_copy__
  477. #if __GNUC_PREREQ (9, 0)
  478. /* Copies attributes from the declaration or type referenced by
  479. the argument. */
  480. # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
  481. #else
  482. # define __attribute_copy__(arg)
  483. #endif
  484. #if (!defined _Static_assert && !defined __cplusplus \
  485. && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
  486. && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
  487. || defined __STRICT_ANSI__))
  488. # define _Static_assert(expr, diagnostic) \
  489. extern int (*__Static_assert_function (void)) \
  490. [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
  491. #endif
  492. #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
  493. # ifdef __REDIRECT
  494. /* Alias name defined automatically. */
  495. # define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
  496. # define __LDBL_REDIR_DECL(name) \
  497. extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
  498. /* Alias name defined automatically, with leading underscores. */
  499. # define __LDBL_REDIR2_DECL(name) \
  500. extern __typeof (__##name) __##name \
  501. __asm (__ASMNAME ("__" #name "ieee128"));
  502. /* Alias name defined manually. */
  503. # define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
  504. # define __LDBL_REDIR1_DECL(name, alias) \
  505. extern __typeof (name) name __asm (__ASMNAME (#alias));
  506. # define __LDBL_REDIR1_NTH(name, proto, alias) \
  507. __REDIRECT_NTH (name, proto, alias)
  508. # define __REDIRECT_NTH_LDBL(name, proto, alias) \
  509. __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
  510. /* Unused. */
  511. # define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl
  512. # define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
  513. # else
  514. _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
  515. # endif
  516. #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
  517. # define __LDBL_COMPAT 1
  518. # ifdef __REDIRECT
  519. # define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
  520. # define __LDBL_REDIR(name, proto) \
  521. __LDBL_REDIR1 (name, proto, __nldbl_##name)
  522. # define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
  523. # define __LDBL_REDIR_NTH(name, proto) \
  524. __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
  525. # define __LDBL_REDIR2_DECL(name) \
  526. extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
  527. # define __LDBL_REDIR1_DECL(name, alias) \
  528. extern __typeof (name) name __asm (__ASMNAME (#alias));
  529. # define __LDBL_REDIR_DECL(name) \
  530. extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
  531. # define __REDIRECT_LDBL(name, proto, alias) \
  532. __LDBL_REDIR1 (name, proto, __nldbl_##alias)
  533. # define __REDIRECT_NTH_LDBL(name, proto, alias) \
  534. __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
  535. # endif
  536. #endif
  537. #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
  538. || !defined __REDIRECT
  539. # define __LDBL_REDIR1(name, proto, alias) name proto
  540. # define __LDBL_REDIR(name, proto) name proto
  541. # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
  542. # define __LDBL_REDIR_NTH(name, proto) name proto __THROW
  543. # define __LDBL_REDIR2_DECL(name)
  544. # define __LDBL_REDIR_DECL(name)
  545. # ifdef __REDIRECT
  546. # define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
  547. # define __REDIRECT_NTH_LDBL(name, proto, alias) \
  548. __REDIRECT_NTH (name, proto, alias)
  549. # endif
  550. #endif
  551. /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
  552. intended for use in preprocessor macros.
  553. Note: MESSAGE must be a _single_ string; concatenation of string
  554. literals is not supported. */
  555. #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
  556. # define __glibc_macro_warning1(message) _Pragma (#message)
  557. # define __glibc_macro_warning(message) \
  558. __glibc_macro_warning1 (GCC warning message)
  559. #else
  560. # define __glibc_macro_warning(msg)
  561. #endif
  562. /* Generic selection (ISO C11) is a C-only feature, available in GCC
  563. since version 4.9. Previous versions do not provide generic
  564. selection, even though they might set __STDC_VERSION__ to 201112L,
  565. when in -std=c11 mode. Thus, we must check for !defined __GNUC__
  566. when testing __STDC_VERSION__ for generic selection support.
  567. On the other hand, Clang also defines __GNUC__, so a clang-specific
  568. check is required to enable the use of generic selection. */
  569. #if !defined __cplusplus \
  570. && (__GNUC_PREREQ (4, 9) \
  571. || __glibc_has_extension (c_generic_selections) \
  572. || (!defined __GNUC__ && defined __STDC_VERSION__ \
  573. && __STDC_VERSION__ >= 201112L))
  574. # define __HAVE_GENERIC_SELECTION 1
  575. #else
  576. # define __HAVE_GENERIC_SELECTION 0
  577. #endif
  578. #if __GNUC_PREREQ (10, 0)
  579. /* Designates a 1-based positional argument ref-index of pointer type
  580. that can be used to access size-index elements of the pointed-to
  581. array according to access mode, or at least one element when
  582. size-index is not provided:
  583. access (access-mode, <ref-index> [, <size-index>]) */
  584. # define __attr_access(x) __attribute__ ((__access__ x))
  585. /* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may
  586. use the access attribute to get object sizes from function definition
  587. arguments, so we can't use them on functions we fortify. Drop the object
  588. size hints for such functions. */
  589. # if __USE_FORTIFY_LEVEL == 3
  590. # define __fortified_attr_access(a, o, s) __attribute__ ((__access__ (a, o)))
  591. # else
  592. # define __fortified_attr_access(a, o, s) __attr_access ((a, o, s))
  593. # endif
  594. # if __GNUC_PREREQ (11, 0)
  595. # define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno)))
  596. # else
  597. # define __attr_access_none(argno)
  598. # endif
  599. #else
  600. # define __fortified_attr_access(a, o, s)
  601. # define __attr_access(x)
  602. # define __attr_access_none(argno)
  603. #endif
  604. #if __GNUC_PREREQ (11, 0)
  605. /* Designates dealloc as a function to call to deallocate objects
  606. allocated by the declared function. */
  607. # define __attr_dealloc(dealloc, argno) \
  608. __attribute__ ((__malloc__ (dealloc, argno)))
  609. # define __attr_dealloc_free __attr_dealloc (__builtin_free, 1)
  610. #else
  611. # define __attr_dealloc(dealloc, argno)
  612. # define __attr_dealloc_free
  613. #endif
  614. /* Specify that a function such as setjmp or vfork may return
  615. twice. */
  616. #if __GNUC_PREREQ (4, 1)
  617. # define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
  618. #else
  619. # define __attribute_returns_twice__ /* Ignore. */
  620. #endif
  621. #endif /* sys/cdefs.h */