cdefs.h 26 KB

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  1. /* Copyright (C) 1992-2023 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__ && !defined __cplusplus
  25. # error "You need a ISO C or 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. || 3 < __clang_major__ + (5 <= __clang_minor__)))
  37. # define __glibc_has_attribute(attr) __has_attribute (attr)
  38. #else
  39. # define __glibc_has_attribute(attr) 0
  40. #endif
  41. #ifdef __has_builtin
  42. # define __glibc_has_builtin(name) __has_builtin (name)
  43. #else
  44. # define __glibc_has_builtin(name) 0
  45. #endif
  46. #ifdef __has_extension
  47. # define __glibc_has_extension(ext) __has_extension (ext)
  48. #else
  49. # define __glibc_has_extension(ext) 0
  50. #endif
  51. #if defined __GNUC__ || defined __clang__
  52. /* All functions, except those with callbacks or those that
  53. synchronize memory, are leaf functions. */
  54. # if __GNUC_PREREQ (4, 6) && !defined _LIBC
  55. # define __LEAF , __leaf__
  56. # define __LEAF_ATTR __attribute__ ((__leaf__))
  57. # else
  58. # define __LEAF
  59. # define __LEAF_ATTR
  60. # endif
  61. /* GCC can always grok prototypes. For C++ programs we add throw()
  62. to help it optimize the function calls. But this only works with
  63. gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions
  64. as non-throwing using a function attribute since programs can use
  65. the -fexceptions options for C code as well. */
  66. # if !defined __cplusplus \
  67. && (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__))
  68. # define __THROW __attribute__ ((__nothrow__ __LEAF))
  69. # define __THROWNL __attribute__ ((__nothrow__))
  70. # define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
  71. # define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
  72. # else
  73. # if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major >= 4)
  74. # if __cplusplus >= 201103L
  75. # define __THROW noexcept (true)
  76. # else
  77. # define __THROW throw ()
  78. # endif
  79. # define __THROWNL __THROW
  80. # define __NTH(fct) __LEAF_ATTR fct __THROW
  81. # define __NTHNL(fct) fct __THROW
  82. # else
  83. # define __THROW
  84. # define __THROWNL
  85. # define __NTH(fct) fct
  86. # define __NTHNL(fct) fct
  87. # endif
  88. # endif
  89. #else /* Not GCC or clang. */
  90. # if (defined __cplusplus \
  91. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
  92. # define __inline inline
  93. # else
  94. # define __inline /* No inline functions. */
  95. # endif
  96. # define __THROW
  97. # define __THROWNL
  98. # define __NTH(fct) fct
  99. #endif /* GCC || clang. */
  100. /* These two macros are not used in glibc anymore. They are kept here
  101. only because some other projects expect the macros to be defined. */
  102. #define __P(args) args
  103. #define __PMT(args) args
  104. /* For these things, GCC behaves the ANSI way normally,
  105. and the non-ANSI way under -traditional. */
  106. #define __CONCAT(x,y) x ## y
  107. #define __STRING(x) #x
  108. /* This is not a typedef so `const __ptr_t' does the right thing. */
  109. #define __ptr_t void *
  110. /* C++ needs to know that types and declarations are C, not C++. */
  111. #ifdef __cplusplus
  112. # define __BEGIN_DECLS extern "C" {
  113. # define __END_DECLS }
  114. #else
  115. # define __BEGIN_DECLS
  116. # define __END_DECLS
  117. #endif
  118. /* Fortify support. */
  119. #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
  120. #define __bos0(ptr) __builtin_object_size (ptr, 0)
  121. /* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
  122. #if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
  123. || __GNUC_PREREQ (12, 0))
  124. # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
  125. # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
  126. #else
  127. # define __glibc_objsize0(__o) __bos0 (__o)
  128. # define __glibc_objsize(__o) __bos (__o)
  129. #endif
  130. /* Compile time conditions to choose between the regular, _chk and _chk_warn
  131. variants. These conditions should get evaluated to constant and optimized
  132. away. */
  133. #define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
  134. #define __glibc_unsigned_or_positive(__l) \
  135. ((__typeof (__l)) 0 < (__typeof (__l)) -1 \
  136. || (__builtin_constant_p (__l) && (__l) > 0))
  137. /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
  138. condition can be folded to a constant and if it is true, or unknown (-1) */
  139. #define __glibc_safe_or_unknown_len(__l, __s, __osz) \
  140. ((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \
  141. || (__glibc_unsigned_or_positive (__l) \
  142. && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
  143. (__s), (__osz))) \
  144. && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz))))
  145. /* Conversely, we know at compile time that the length is unsafe if the
  146. __L * __S <= __OBJSZ condition can be folded to a constant and if it is
  147. false. */
  148. #define __glibc_unsafe_len(__l, __s, __osz) \
  149. (__glibc_unsigned_or_positive (__l) \
  150. && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
  151. __s, __osz)) \
  152. && !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
  153. /* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be
  154. declared. */
  155. #define __glibc_fortify(f, __l, __s, __osz, ...) \
  156. (__glibc_safe_or_unknown_len (__l, __s, __osz) \
  157. ? __ ## f ## _alias (__VA_ARGS__) \
  158. : (__glibc_unsafe_len (__l, __s, __osz) \
  159. ? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \
  160. : __ ## f ## _chk (__VA_ARGS__, __osz))) \
  161. /* Fortify function f, where object size argument passed to f is the number of
  162. elements and not total size. */
  163. #define __glibc_fortify_n(f, __l, __s, __osz, ...) \
  164. (__glibc_safe_or_unknown_len (__l, __s, __osz) \
  165. ? __ ## f ## _alias (__VA_ARGS__) \
  166. : (__glibc_unsafe_len (__l, __s, __osz) \
  167. ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \
  168. : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s)))) \
  169. #if __GNUC_PREREQ (4,3)
  170. # define __warnattr(msg) __attribute__((__warning__ (msg)))
  171. # define __errordecl(name, msg) \
  172. extern void name (void) __attribute__((__error__ (msg)))
  173. #else
  174. # define __warnattr(msg)
  175. # define __errordecl(name, msg) extern void name (void)
  176. #endif
  177. /* Support for flexible arrays.
  178. Headers that should use flexible arrays only if they're "real"
  179. (e.g. only if they won't affect sizeof()) should test
  180. #if __glibc_c99_flexarr_available. */
  181. #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
  182. # define __flexarr []
  183. # define __glibc_c99_flexarr_available 1
  184. #elif __GNUC_PREREQ (2,97) || defined __clang__
  185. /* GCC 2.97 and clang support C99 flexible array members as an extension,
  186. even when in C89 mode or compiling C++ (any version). */
  187. # define __flexarr []
  188. # define __glibc_c99_flexarr_available 1
  189. #elif defined __GNUC__
  190. /* Pre-2.97 GCC did not support C99 flexible arrays but did have
  191. an equivalent extension with slightly different notation. */
  192. # define __flexarr [0]
  193. # define __glibc_c99_flexarr_available 1
  194. #else
  195. /* Some other non-C99 compiler. Approximate with [1]. */
  196. # define __flexarr [1]
  197. # define __glibc_c99_flexarr_available 0
  198. #endif
  199. /* __asm__ ("xyz") is used throughout the headers to rename functions
  200. at the assembly language level. This is wrapped by the __REDIRECT
  201. macro, in order to support compilers that can do this some other
  202. way. When compilers don't support asm-names at all, we have to do
  203. preprocessor tricks instead (which don't have exactly the right
  204. semantics, but it's the best we can do).
  205. Example:
  206. int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
  207. #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
  208. # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
  209. # ifdef __cplusplus
  210. # define __REDIRECT_NTH(name, proto, alias) \
  211. name proto __THROW __asm__ (__ASMNAME (#alias))
  212. # define __REDIRECT_NTHNL(name, proto, alias) \
  213. name proto __THROWNL __asm__ (__ASMNAME (#alias))
  214. # else
  215. # define __REDIRECT_NTH(name, proto, alias) \
  216. name proto __asm__ (__ASMNAME (#alias)) __THROW
  217. # define __REDIRECT_NTHNL(name, proto, alias) \
  218. name proto __asm__ (__ASMNAME (#alias)) __THROWNL
  219. # endif
  220. # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
  221. # define __ASMNAME2(prefix, cname) __STRING (prefix) cname
  222. /*
  223. #elif __SOME_OTHER_COMPILER__
  224. # define __REDIRECT(name, proto, alias) name proto; \
  225. _Pragma("let " #name " = " #alias)
  226. */
  227. #endif
  228. /* GCC and clang have various useful declarations that can be made with
  229. the '__attribute__' syntax. All of the ways we use this do fine if
  230. they are omitted for compilers that don't understand it. */
  231. #if !(defined __GNUC__ || defined __clang__)
  232. # define __attribute__(xyz) /* Ignore */
  233. #endif
  234. /* At some point during the gcc 2.96 development the `malloc' attribute
  235. for functions was introduced. We don't want to use it unconditionally
  236. (although this would be possible) since it generates warnings. */
  237. #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
  238. # define __attribute_malloc__ __attribute__ ((__malloc__))
  239. #else
  240. # define __attribute_malloc__ /* Ignore */
  241. #endif
  242. /* Tell the compiler which arguments to an allocation function
  243. indicate the size of the allocation. */
  244. #if __GNUC_PREREQ (4, 3)
  245. # define __attribute_alloc_size__(params) \
  246. __attribute__ ((__alloc_size__ params))
  247. #else
  248. # define __attribute_alloc_size__(params) /* Ignore. */
  249. #endif
  250. /* Tell the compiler which argument to an allocation function
  251. indicates the alignment of the allocation. */
  252. #if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__)
  253. # define __attribute_alloc_align__(param) \
  254. __attribute__ ((__alloc_align__ param))
  255. #else
  256. # define __attribute_alloc_align__(param) /* Ignore. */
  257. #endif
  258. /* At some point during the gcc 2.96 development the `pure' attribute
  259. for functions was introduced. We don't want to use it unconditionally
  260. (although this would be possible) since it generates warnings. */
  261. #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
  262. # define __attribute_pure__ __attribute__ ((__pure__))
  263. #else
  264. # define __attribute_pure__ /* Ignore */
  265. #endif
  266. /* This declaration tells the compiler that the value is constant. */
  267. #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
  268. # define __attribute_const__ __attribute__ ((__const__))
  269. #else
  270. # define __attribute_const__ /* Ignore */
  271. #endif
  272. #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
  273. # define __attribute_maybe_unused__ __attribute__ ((__unused__))
  274. #else
  275. # define __attribute_maybe_unused__ /* Ignore */
  276. #endif
  277. /* At some point during the gcc 3.1 development the `used' attribute
  278. for functions was introduced. We don't want to use it unconditionally
  279. (although this would be possible) since it generates warnings. */
  280. #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
  281. # define __attribute_used__ __attribute__ ((__used__))
  282. # define __attribute_noinline__ __attribute__ ((__noinline__))
  283. #else
  284. # define __attribute_used__ __attribute__ ((__unused__))
  285. # define __attribute_noinline__ /* Ignore */
  286. #endif
  287. /* Since version 3.2, gcc allows marking deprecated functions. */
  288. #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
  289. # define __attribute_deprecated__ __attribute__ ((__deprecated__))
  290. #else
  291. # define __attribute_deprecated__ /* Ignore */
  292. #endif
  293. /* Since version 4.5, gcc also allows one to specify the message printed
  294. when a deprecated function is used. clang claims to be gcc 4.2, but
  295. may also support this feature. */
  296. #if __GNUC_PREREQ (4,5) \
  297. || __glibc_has_extension (__attribute_deprecated_with_message__)
  298. # define __attribute_deprecated_msg__(msg) \
  299. __attribute__ ((__deprecated__ (msg)))
  300. #else
  301. # define __attribute_deprecated_msg__(msg) __attribute_deprecated__
  302. #endif
  303. /* At some point during the gcc 2.8 development the `format_arg' attribute
  304. for functions was introduced. We don't want to use it unconditionally
  305. (although this would be possible) since it generates warnings.
  306. If several `format_arg' attributes are given for the same function, in
  307. gcc-3.0 and older, all but the last one are ignored. In newer gccs,
  308. all designated arguments are considered. */
  309. #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
  310. # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
  311. #else
  312. # define __attribute_format_arg__(x) /* Ignore */
  313. #endif
  314. /* At some point during the gcc 2.97 development the `strfmon' format
  315. attribute for functions was introduced. We don't want to use it
  316. unconditionally (although this would be possible) since it
  317. generates warnings. */
  318. #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
  319. # define __attribute_format_strfmon__(a,b) \
  320. __attribute__ ((__format__ (__strfmon__, a, b)))
  321. #else
  322. # define __attribute_format_strfmon__(a,b) /* Ignore */
  323. #endif
  324. /* The nonnull function attribute marks pointer parameters that
  325. must not be NULL. This has the name __nonnull in glibc,
  326. and __attribute_nonnull__ in files shared with Gnulib to avoid
  327. collision with a different __nonnull in DragonFlyBSD 5.9. */
  328. #ifndef __attribute_nonnull__
  329. # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
  330. # define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params))
  331. # else
  332. # define __attribute_nonnull__(params)
  333. # endif
  334. #endif
  335. #ifndef __nonnull
  336. # define __nonnull(params) __attribute_nonnull__ (params)
  337. #endif
  338. /* The returns_nonnull function attribute marks the return type of the function
  339. as always being non-null. */
  340. #ifndef __returns_nonnull
  341. # if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__)
  342. # define __returns_nonnull __attribute__ ((__returns_nonnull__))
  343. # else
  344. # define __returns_nonnull
  345. # endif
  346. #endif
  347. /* If fortification mode, we warn about unused results of certain
  348. function calls which can lead to problems. */
  349. #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
  350. # define __attribute_warn_unused_result__ \
  351. __attribute__ ((__warn_unused_result__))
  352. # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
  353. # define __wur __attribute_warn_unused_result__
  354. # endif
  355. #else
  356. # define __attribute_warn_unused_result__ /* empty */
  357. #endif
  358. #ifndef __wur
  359. # define __wur /* Ignore */
  360. #endif
  361. /* Forces a function to be always inlined. */
  362. #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
  363. /* The Linux kernel defines __always_inline in stddef.h (283d7573), and
  364. it conflicts with this definition. Therefore undefine it first to
  365. allow either header to be included first. */
  366. # undef __always_inline
  367. # define __always_inline __inline __attribute__ ((__always_inline__))
  368. #else
  369. # undef __always_inline
  370. # define __always_inline __inline
  371. #endif
  372. /* Associate error messages with the source location of the call site rather
  373. than with the source location inside the function. */
  374. #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
  375. # define __attribute_artificial__ __attribute__ ((__artificial__))
  376. #else
  377. # define __attribute_artificial__ /* Ignore */
  378. #endif
  379. /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
  380. inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
  381. or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
  382. older than 4.3 may define these macros and still not guarantee GNU inlining
  383. semantics.
  384. clang++ identifies itself as gcc-4.2, but has support for GNU inlining
  385. semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
  386. __GNUC_GNU_INLINE__ macro definitions. */
  387. #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
  388. || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
  389. || defined __GNUC_GNU_INLINE__)))
  390. # if defined __GNUC_STDC_INLINE__ || defined __cplusplus
  391. # define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
  392. # define __extern_always_inline \
  393. extern __always_inline __attribute__ ((__gnu_inline__))
  394. # else
  395. # define __extern_inline extern __inline
  396. # define __extern_always_inline extern __always_inline
  397. # endif
  398. #endif
  399. #ifdef __extern_always_inline
  400. # define __fortify_function __extern_always_inline __attribute_artificial__
  401. #endif
  402. /* GCC 4.3 and above allow passing all anonymous arguments of an
  403. __extern_always_inline function to some other vararg function. */
  404. #if __GNUC_PREREQ (4,3)
  405. # define __va_arg_pack() __builtin_va_arg_pack ()
  406. # define __va_arg_pack_len() __builtin_va_arg_pack_len ()
  407. #endif
  408. /* It is possible to compile containing GCC extensions even if GCC is
  409. run in pedantic mode if the uses are carefully marked using the
  410. `__extension__' keyword. But this is not generally available before
  411. version 2.8. */
  412. #if !(__GNUC_PREREQ (2,8) || defined __clang__)
  413. # define __extension__ /* Ignore */
  414. #endif
  415. /* __restrict is known in EGCS 1.2 and above, and in clang.
  416. It works also in C++ mode (outside of arrays), but only when spelled
  417. as '__restrict', not 'restrict'. */
  418. #if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
  419. # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
  420. # define __restrict restrict
  421. # else
  422. # define __restrict /* Ignore */
  423. # endif
  424. #endif
  425. /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
  426. array_name[restrict]
  427. GCC 3.1 and clang support this.
  428. This syntax is not usable in C++ mode. */
  429. #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
  430. # define __restrict_arr __restrict
  431. #else
  432. # ifdef __GNUC__
  433. # define __restrict_arr /* Not supported in old GCC. */
  434. # else
  435. # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
  436. # define __restrict_arr restrict
  437. # else
  438. /* Some other non-C99 compiler. */
  439. # define __restrict_arr /* Not supported. */
  440. # endif
  441. # endif
  442. #endif
  443. #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
  444. # define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
  445. # define __glibc_likely(cond) __builtin_expect ((cond), 1)
  446. #else
  447. # define __glibc_unlikely(cond) (cond)
  448. # define __glibc_likely(cond) (cond)
  449. #endif
  450. #if (!defined _Noreturn \
  451. && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
  452. && !(__GNUC_PREREQ (4,7) \
  453. || (3 < __clang_major__ + (5 <= __clang_minor__))))
  454. # if __GNUC_PREREQ (2,8)
  455. # define _Noreturn __attribute__ ((__noreturn__))
  456. # else
  457. # define _Noreturn
  458. # endif
  459. #endif
  460. #if __GNUC_PREREQ (8, 0)
  461. /* Describes a char array whose address can safely be passed as the first
  462. argument to strncpy and strncat, as the char array is not necessarily
  463. a NUL-terminated string. */
  464. # define __attribute_nonstring__ __attribute__ ((__nonstring__))
  465. #else
  466. # define __attribute_nonstring__
  467. #endif
  468. /* Undefine (also defined in libc-symbols.h). */
  469. #undef __attribute_copy__
  470. #if __GNUC_PREREQ (9, 0)
  471. /* Copies attributes from the declaration or type referenced by
  472. the argument. */
  473. # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
  474. #else
  475. # define __attribute_copy__(arg)
  476. #endif
  477. #if (!defined _Static_assert && !defined __cplusplus \
  478. && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
  479. && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
  480. || defined __STRICT_ANSI__))
  481. # define _Static_assert(expr, diagnostic) \
  482. extern int (*__Static_assert_function (void)) \
  483. [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
  484. #endif
  485. /* Gnulib avoids including these, as they don't work on non-glibc or
  486. older glibc platforms. */
  487. #ifndef __GNULIB_CDEFS
  488. # include <bits/wordsize.h>
  489. # include <bits/long-double.h>
  490. #endif
  491. #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
  492. # ifdef __REDIRECT
  493. /* Alias name defined automatically. */
  494. # define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
  495. # define __LDBL_REDIR_DECL(name) \
  496. extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
  497. /* Alias name defined automatically, with leading underscores. */
  498. # define __LDBL_REDIR2_DECL(name) \
  499. extern __typeof (__##name) __##name \
  500. __asm (__ASMNAME ("__" #name "ieee128"));
  501. /* Alias name defined manually. */
  502. # define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
  503. # define __LDBL_REDIR1_DECL(name, alias) \
  504. extern __typeof (name) name __asm (__ASMNAME (#alias));
  505. # define __LDBL_REDIR1_NTH(name, proto, alias) \
  506. __REDIRECT_NTH (name, proto, alias)
  507. # define __REDIRECT_NTH_LDBL(name, proto, alias) \
  508. __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
  509. /* Unused. */
  510. # define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl
  511. # define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
  512. # else
  513. _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
  514. # endif
  515. #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
  516. # define __LDBL_COMPAT 1
  517. # ifdef __REDIRECT
  518. # define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
  519. # define __LDBL_REDIR(name, proto) \
  520. __LDBL_REDIR1 (name, proto, __nldbl_##name)
  521. # define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
  522. # define __LDBL_REDIR_NTH(name, proto) \
  523. __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
  524. # define __LDBL_REDIR2_DECL(name) \
  525. extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
  526. # define __LDBL_REDIR1_DECL(name, alias) \
  527. extern __typeof (name) name __asm (__ASMNAME (#alias));
  528. # define __LDBL_REDIR_DECL(name) \
  529. extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
  530. # define __REDIRECT_LDBL(name, proto, alias) \
  531. __LDBL_REDIR1 (name, proto, __nldbl_##alias)
  532. # define __REDIRECT_NTH_LDBL(name, proto, alias) \
  533. __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
  534. # endif
  535. #endif
  536. #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
  537. || !defined __REDIRECT
  538. # define __LDBL_REDIR1(name, proto, alias) name proto
  539. # define __LDBL_REDIR(name, proto) name proto
  540. # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
  541. # define __LDBL_REDIR_NTH(name, proto) name proto __THROW
  542. # define __LDBL_REDIR2_DECL(name)
  543. # define __LDBL_REDIR_DECL(name)
  544. # ifdef __REDIRECT
  545. # define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
  546. # define __REDIRECT_NTH_LDBL(name, proto, alias) \
  547. __REDIRECT_NTH (name, proto, alias)
  548. # endif
  549. #endif
  550. /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
  551. intended for use in preprocessor macros.
  552. Note: MESSAGE must be a _single_ string; concatenation of string
  553. literals is not supported. */
  554. #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
  555. # define __glibc_macro_warning1(message) _Pragma (#message)
  556. # define __glibc_macro_warning(message) \
  557. __glibc_macro_warning1 (GCC warning message)
  558. #else
  559. # define __glibc_macro_warning(msg)
  560. #endif
  561. /* Generic selection (ISO C11) is a C-only feature, available in GCC
  562. since version 4.9. Previous versions do not provide generic
  563. selection, even though they might set __STDC_VERSION__ to 201112L,
  564. when in -std=c11 mode. Thus, we must check for !defined __GNUC__
  565. when testing __STDC_VERSION__ for generic selection support.
  566. On the other hand, Clang also defines __GNUC__, so a clang-specific
  567. check is required to enable the use of generic selection. */
  568. #if !defined __cplusplus \
  569. && (__GNUC_PREREQ (4, 9) \
  570. || __glibc_has_extension (c_generic_selections) \
  571. || (!defined __GNUC__ && defined __STDC_VERSION__ \
  572. && __STDC_VERSION__ >= 201112L))
  573. # define __HAVE_GENERIC_SELECTION 1
  574. #else
  575. # define __HAVE_GENERIC_SELECTION 0
  576. #endif
  577. #if __GNUC_PREREQ (10, 0)
  578. /* Designates a 1-based positional argument ref-index of pointer type
  579. that can be used to access size-index elements of the pointed-to
  580. array according to access mode, or at least one element when
  581. size-index is not provided:
  582. access (access-mode, <ref-index> [, <size-index>]) */
  583. # define __attr_access(x) __attribute__ ((__access__ x))
  584. /* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may
  585. use the access attribute to get object sizes from function definition
  586. arguments, so we can't use them on functions we fortify. Drop the object
  587. size hints for such functions. */
  588. # if __USE_FORTIFY_LEVEL == 3
  589. # define __fortified_attr_access(a, o, s) __attribute__ ((__access__ (a, o)))
  590. # else
  591. # define __fortified_attr_access(a, o, s) __attr_access ((a, o, s))
  592. # endif
  593. # if __GNUC_PREREQ (11, 0)
  594. # define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno)))
  595. # else
  596. # define __attr_access_none(argno)
  597. # endif
  598. #else
  599. # define __fortified_attr_access(a, o, s)
  600. # define __attr_access(x)
  601. # define __attr_access_none(argno)
  602. #endif
  603. #if __GNUC_PREREQ (11, 0)
  604. /* Designates dealloc as a function to call to deallocate objects
  605. allocated by the declared function. */
  606. # define __attr_dealloc(dealloc, argno) \
  607. __attribute__ ((__malloc__ (dealloc, argno)))
  608. # define __attr_dealloc_free __attr_dealloc (__builtin_free, 1)
  609. #else
  610. # define __attr_dealloc(dealloc, argno)
  611. # define __attr_dealloc_free
  612. #endif
  613. /* Specify that a function such as setjmp or vfork may return
  614. twice. */
  615. #if __GNUC_PREREQ (4, 1)
  616. # define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
  617. #else
  618. # define __attribute_returns_twice__ /* Ignore. */
  619. #endif
  620. #endif /* sys/cdefs.h */