1 /* Copyright (C) 1992-2022 Free Software Foundation, Inc. 2 Copyright The GNU Toolchain Authors. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #ifndef _SYS_CDEFS_H 20 #define _SYS_CDEFS_H 1 21 22 /* We are almost always included from features.h. */ 23 #ifndef _FEATURES_H 24 # include <features.h> 25 #endif 26 27 /* The GNU libc does not support any K&R compilers or the traditional mode 28 of ISO C compilers anymore. Check for some of the combinations not 29 supported anymore. */ 30 #if defined __GNUC__ && !defined __STDC__ && !defined __cplusplus 31 # error "You need a ISO C or C++ conforming compiler to use the glibc headers" 32 #endif 33 34 /* Some user header file might have defined this before. */ 35 #undef __P 36 #undef __PMT 37 38 /* Compilers that lack __has_attribute may object to 39 #if defined __has_attribute && __has_attribute (...) 40 even though they do not need to evaluate the right-hand side of the &&. 41 Similarly for __has_builtin, etc. */ 42 #if (defined __has_attribute \ 43 && (!defined __clang_minor__ \ 44 || 3 < __clang_major__ + (5 <= __clang_minor__))) 45 # define __glibc_has_attribute(attr) __has_attribute (attr) 46 #else 47 # define __glibc_has_attribute(attr) 0 48 #endif 49 #ifdef __has_builtin 50 # define __glibc_has_builtin(name) __has_builtin (name) 51 #else 52 # define __glibc_has_builtin(name) 0 53 #endif 54 #ifdef __has_extension 55 # define __glibc_has_extension(ext) __has_extension (ext) 56 #else 57 # define __glibc_has_extension(ext) 0 58 #endif 59 60 #if defined __GNUC__ || defined __clang__ 61 62 /* All functions, except those with callbacks or those that 63 synchronize memory, are leaf functions. */ 64 # if __GNUC_PREREQ (4, 6) && !defined _LIBC 65 # define __LEAF , __leaf__ 66 # define __LEAF_ATTR __attribute__ ((__leaf__)) 67 # else 68 # define __LEAF 69 # define __LEAF_ATTR 70 # endif 71 72 /* GCC can always grok prototypes. For C++ programs we add throw() 73 to help it optimize the function calls. But this only works with 74 gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions 75 as non-throwing using a function attribute since programs can use 76 the -fexceptions options for C code as well. */ 77 # if !defined __cplusplus \ 78 && (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__)) 79 # define __THROW __attribute__ ((__nothrow__ __LEAF)) 80 # define __THROWNL __attribute__ ((__nothrow__)) 81 # define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct 82 # define __NTHNL(fct) __attribute__ ((__nothrow__)) fct 83 # else 84 # if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major >= 4) 85 # if __cplusplus >= 201103L 86 # define __THROW noexcept (true) 87 # else 88 # define __THROW throw () 89 # endif 90 # define __THROWNL __THROW 91 # define __NTH(fct) __LEAF_ATTR fct __THROW 92 # define __NTHNL(fct) fct __THROW 93 # else 94 # define __THROW 95 # define __THROWNL 96 # define __NTH(fct) fct 97 # define __NTHNL(fct) fct 98 # endif 99 # endif 100 101 #else /* Not GCC or clang. */ 102 103 # if (defined __cplusplus \ 104 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)) 105 # define __inline inline 106 # else 107 # define __inline /* No inline functions. */ 108 # endif 109 110 # define __THROW 111 # define __THROWNL 112 # define __NTH(fct) fct 113 114 #endif /* GCC || clang. */ 115 116 /* These two macros are not used in glibc anymore. They are kept here 117 only because some other projects expect the macros to be defined. */ 118 #define __P(args) args 119 #define __PMT(args) args 120 121 /* For these things, GCC behaves the ANSI way normally, 122 and the non-ANSI way under -traditional. */ 123 124 #define __CONCAT(x,y) x ## y 125 #define __STRING(x) #x 126 127 /* This is not a typedef so `const __ptr_t' does the right thing. */ 128 #define __ptr_t void * 129 130 131 /* C++ needs to know that types and declarations are C, not C++. */ 132 #ifdef __cplusplus 133 # define __BEGIN_DECLS extern "C" { 134 # define __END_DECLS } 135 #else 136 # define __BEGIN_DECLS 137 # define __END_DECLS 138 #endif 139 140 141 /* Fortify support. */ 142 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1) 143 #define __bos0(ptr) __builtin_object_size (ptr, 0) 144 145 /* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */ 146 #if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \ 147 || __GNUC_PREREQ (12, 0)) 148 # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0) 149 # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1) 150 #else 151 # define __glibc_objsize0(__o) __bos0 (__o) 152 # define __glibc_objsize(__o) __bos (__o) 153 #endif 154 155 /* Compile time conditions to choose between the regular, _chk and _chk_warn 156 variants. These conditions should get evaluated to constant and optimized 157 away. */ 158 159 #define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s)) 160 #define __glibc_unsigned_or_positive(__l) \ 161 ((__typeof (__l)) 0 < (__typeof (__l)) -1 \ 162 || (__builtin_constant_p (__l) && (__l) > 0)) 163 164 /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ 165 condition can be folded to a constant and if it is true, or unknown (-1) */ 166 #define __glibc_safe_or_unknown_len(__l, __s, __osz) \ 167 ((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \ 168 || (__glibc_unsigned_or_positive (__l) \ 169 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \ 170 (__s), (__osz))) \ 171 && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz)))) 172 173 /* Conversely, we know at compile time that the length is unsafe if the 174 __L * __S <= __OBJSZ condition can be folded to a constant and if it is 175 false. */ 176 #define __glibc_unsafe_len(__l, __s, __osz) \ 177 (__glibc_unsigned_or_positive (__l) \ 178 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \ 179 __s, __osz)) \ 180 && !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz)) 181 182 /* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be 183 declared. */ 184 185 #define __glibc_fortify(f, __l, __s, __osz, ...) \ 186 (__glibc_safe_or_unknown_len (__l, __s, __osz) \ 187 ? __ ## f ## _alias (__VA_ARGS__) \ 188 : (__glibc_unsafe_len (__l, __s, __osz) \ 189 ? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \ 190 : __ ## f ## _chk (__VA_ARGS__, __osz))) \ 191 192 /* Fortify function f, where object size argument passed to f is the number of 193 elements and not total size. */ 194 195 #define __glibc_fortify_n(f, __l, __s, __osz, ...) \ 196 (__glibc_safe_or_unknown_len (__l, __s, __osz) \ 197 ? __ ## f ## _alias (__VA_ARGS__) \ 198 : (__glibc_unsafe_len (__l, __s, __osz) \ 199 ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \ 200 : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s)))) \ 201 202 #if __GNUC_PREREQ (4,3) 203 # define __warnattr(msg) __attribute__((__warning__ (msg))) 204 # define __errordecl(name, msg) \ 205 extern void name (void) __attribute__((__error__ (msg))) 206 #else 207 # define __warnattr(msg) 208 # define __errordecl(name, msg) extern void name (void) 209 #endif 210 211 /* Support for flexible arrays. 212 Headers that should use flexible arrays only if they're "real" 213 (e.g. only if they won't affect sizeof()) should test 214 #if __glibc_c99_flexarr_available. */ 215 #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc 216 # define __flexarr [] 217 # define __glibc_c99_flexarr_available 1 218 #elif __GNUC_PREREQ (2,97) || defined __clang__ 219 /* GCC 2.97 and clang support C99 flexible array members as an extension, 220 even when in C89 mode or compiling C++ (any version). */ 221 # define __flexarr [] 222 # define __glibc_c99_flexarr_available 1 223 #elif defined __GNUC__ 224 /* Pre-2.97 GCC did not support C99 flexible arrays but did have 225 an equivalent extension with slightly different notation. */ 226 # define __flexarr [0] 227 # define __glibc_c99_flexarr_available 1 228 #else 229 /* Some other non-C99 compiler. Approximate with [1]. */ 230 # define __flexarr [1] 231 # define __glibc_c99_flexarr_available 0 232 #endif 233 234 235 /* __asm__ ("xyz") is used throughout the headers to rename functions 236 at the assembly language level. This is wrapped by the __REDIRECT 237 macro, in order to support compilers that can do this some other 238 way. When compilers don't support asm-names at all, we have to do 239 preprocessor tricks instead (which don't have exactly the right 240 semantics, but it's the best we can do). 241 242 Example: 243 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */ 244 245 #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4) 246 247 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias)) 248 # ifdef __cplusplus 249 # define __REDIRECT_NTH(name, proto, alias) \ 250 name proto __THROW __asm__ (__ASMNAME (#alias)) 251 # define __REDIRECT_NTHNL(name, proto, alias) \ 252 name proto __THROWNL __asm__ (__ASMNAME (#alias)) 253 # else 254 # define __REDIRECT_NTH(name, proto, alias) \ 255 name proto __asm__ (__ASMNAME (#alias)) __THROW 256 # define __REDIRECT_NTHNL(name, proto, alias) \ 257 name proto __asm__ (__ASMNAME (#alias)) __THROWNL 258 # endif 259 # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname) 260 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname 261 262 /* 263 #elif __SOME_OTHER_COMPILER__ 264 265 # define __REDIRECT(name, proto, alias) name proto; \ 266 _Pragma("let " #name " = " #alias) 267 */ 268 #endif 269 270 /* GCC and clang have various useful declarations that can be made with 271 the '__attribute__' syntax. All of the ways we use this do fine if 272 they are omitted for compilers that don't understand it. */ 273 #if !(defined __GNUC__ || defined __clang__) 274 # define __attribute__(xyz) /* Ignore */ 275 #endif 276 277 /* At some point during the gcc 2.96 development the `malloc' 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 (2,96) || __glibc_has_attribute (__malloc__) 281 # define __attribute_malloc__ __attribute__ ((__malloc__)) 282 #else 283 # define __attribute_malloc__ /* Ignore */ 284 #endif 285 286 /* Tell the compiler which arguments to an allocation function 287 indicate the size of the allocation. */ 288 #if __GNUC_PREREQ (4, 3) 289 # define __attribute_alloc_size__(params) \ 290 __attribute__ ((__alloc_size__ params)) 291 #else 292 # define __attribute_alloc_size__(params) /* Ignore. */ 293 #endif 294 295 /* Tell the compiler which argument to an allocation function 296 indicates the alignment of the allocation. */ 297 #if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__) 298 # define __attribute_alloc_align__(param) \ 299 __attribute__ ((__alloc_align__ param)) 300 #else 301 # define __attribute_alloc_align__(param) /* Ignore. */ 302 #endif 303 304 /* At some point during the gcc 2.96 development the `pure' attribute 305 for functions was introduced. We don't want to use it unconditionally 306 (although this would be possible) since it generates warnings. */ 307 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__) 308 # define __attribute_pure__ __attribute__ ((__pure__)) 309 #else 310 # define __attribute_pure__ /* Ignore */ 311 #endif 312 313 /* This declaration tells the compiler that the value is constant. */ 314 #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__) 315 # define __attribute_const__ __attribute__ ((__const__)) 316 #else 317 # define __attribute_const__ /* Ignore */ 318 #endif 319 320 #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__) 321 # define __attribute_maybe_unused__ __attribute__ ((__unused__)) 322 #else 323 # define __attribute_maybe_unused__ /* Ignore */ 324 #endif 325 326 /* At some point during the gcc 3.1 development the `used' attribute 327 for functions was introduced. We don't want to use it unconditionally 328 (although this would be possible) since it generates warnings. */ 329 #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__) 330 # define __attribute_used__ __attribute__ ((__used__)) 331 # define __attribute_noinline__ __attribute__ ((__noinline__)) 332 #else 333 # define __attribute_used__ __attribute__ ((__unused__)) 334 # define __attribute_noinline__ /* Ignore */ 335 #endif 336 337 /* Since version 3.2, gcc allows marking deprecated functions. */ 338 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__) 339 # define __attribute_deprecated__ __attribute__ ((__deprecated__)) 340 #else 341 # define __attribute_deprecated__ /* Ignore */ 342 #endif 343 344 /* Since version 4.5, gcc also allows one to specify the message printed 345 when a deprecated function is used. clang claims to be gcc 4.2, but 346 may also support this feature. */ 347 #if __GNUC_PREREQ (4,5) \ 348 || __glibc_has_extension (__attribute_deprecated_with_message__) 349 # define __attribute_deprecated_msg__(msg) \ 350 __attribute__ ((__deprecated__ (msg))) 351 #else 352 # define __attribute_deprecated_msg__(msg) __attribute_deprecated__ 353 #endif 354 355 /* At some point during the gcc 2.8 development the `format_arg' attribute 356 for functions was introduced. We don't want to use it unconditionally 357 (although this would be possible) since it generates warnings. 358 If several `format_arg' attributes are given for the same function, in 359 gcc-3.0 and older, all but the last one are ignored. In newer gccs, 360 all designated arguments are considered. */ 361 #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__) 362 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x))) 363 #else 364 # define __attribute_format_arg__(x) /* Ignore */ 365 #endif 366 367 /* At some point during the gcc 2.97 development the `strfmon' format 368 attribute for functions was introduced. We don't want to use it 369 unconditionally (although this would be possible) since it 370 generates warnings. */ 371 #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__) 372 # define __attribute_format_strfmon__(a,b) \ 373 __attribute__ ((__format__ (__strfmon__, a, b))) 374 #else 375 # define __attribute_format_strfmon__(a,b) /* Ignore */ 376 #endif 377 378 /* The nonnull function attribute marks pointer parameters that 379 must not be NULL. This has the name __nonnull in glibc, 380 and __attribute_nonnull__ in files shared with Gnulib to avoid 381 collision with a different __nonnull in DragonFlyBSD 5.9. */ 382 #ifndef __attribute_nonnull__ 383 # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__) 384 # define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params)) 385 # else 386 # define __attribute_nonnull__(params) 387 # endif 388 #endif 389 #ifndef __nonnull 390 # define __nonnull(params) __attribute_nonnull__ (params) 391 #endif 392 393 /* The returns_nonnull function attribute marks the return type of the function 394 as always being non-null. */ 395 #ifndef __returns_nonnull 396 # if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__) 397 # define __returns_nonnull __attribute__ ((__returns_nonnull__)) 398 # else 399 # define __returns_nonnull 400 # endif 401 #endif 402 403 /* If fortification mode, we warn about unused results of certain 404 function calls which can lead to problems. */ 405 #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__) 406 # define __attribute_warn_unused_result__ \ 407 __attribute__ ((__warn_unused_result__)) 408 # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0 409 # define __wur __attribute_warn_unused_result__ 410 # endif 411 #else 412 # define __attribute_warn_unused_result__ /* empty */ 413 #endif 414 #ifndef __wur 415 # define __wur /* Ignore */ 416 #endif 417 418 /* Forces a function to be always inlined. */ 419 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__) 420 /* The Linux kernel defines __always_inline in stddef.h (283d7573), and 421 it conflicts with this definition. Therefore undefine it first to 422 allow either header to be included first. */ 423 # undef __always_inline 424 # define __always_inline __inline __attribute__ ((__always_inline__)) 425 #else 426 # undef __always_inline 427 # define __always_inline __inline 428 #endif 429 430 /* Associate error messages with the source location of the call site rather 431 than with the source location inside the function. */ 432 #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__) 433 # define __attribute_artificial__ __attribute__ ((__artificial__)) 434 #else 435 # define __attribute_artificial__ /* Ignore */ 436 #endif 437 438 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99 439 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__ 440 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions 441 older than 4.3 may define these macros and still not guarantee GNU inlining 442 semantics. 443 444 clang++ identifies itself as gcc-4.2, but has support for GNU inlining 445 semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and 446 __GNUC_GNU_INLINE__ macro definitions. */ 447 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \ 448 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \ 449 || defined __GNUC_GNU_INLINE__))) 450 # if defined __GNUC_STDC_INLINE__ || defined __cplusplus 451 # define __extern_inline extern __inline __attribute__ ((__gnu_inline__)) 452 # define __extern_always_inline \ 453 extern __always_inline __attribute__ ((__gnu_inline__)) 454 # else 455 # define __extern_inline extern __inline 456 # define __extern_always_inline extern __always_inline 457 # endif 458 #endif 459 460 #ifdef __extern_always_inline 461 # define __fortify_function __extern_always_inline __attribute_artificial__ 462 #endif 463 464 /* GCC 4.3 and above allow passing all anonymous arguments of an 465 __extern_always_inline function to some other vararg function. */ 466 #if __GNUC_PREREQ (4,3) 467 # define __va_arg_pack() __builtin_va_arg_pack () 468 # define __va_arg_pack_len() __builtin_va_arg_pack_len () 469 #endif 470 471 /* It is possible to compile containing GCC extensions even if GCC is 472 run in pedantic mode if the uses are carefully marked using the 473 `__extension__' keyword. But this is not generally available before 474 version 2.8. */ 475 #if !(__GNUC_PREREQ (2,8) || defined __clang__) 476 # define __extension__ /* Ignore */ 477 #endif 478 479 /* __restrict is known in EGCS 1.2 and above, and in clang. 480 It works also in C++ mode (outside of arrays), but only when spelled 481 as '__restrict', not 'restrict'. */ 482 #if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3) 483 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 484 # define __restrict restrict 485 # else 486 # define __restrict /* Ignore */ 487 # endif 488 #endif 489 490 /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is 491 array_name[restrict] 492 GCC 3.1 and clang support this. 493 This syntax is not usable in C++ mode. */ 494 #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus 495 # define __restrict_arr __restrict 496 #else 497 # ifdef __GNUC__ 498 # define __restrict_arr /* Not supported in old GCC. */ 499 # else 500 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 501 # define __restrict_arr restrict 502 # else 503 /* Some other non-C99 compiler. */ 504 # define __restrict_arr /* Not supported. */ 505 # endif 506 # endif 507 #endif 508 509 #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect) 510 # define __glibc_unlikely(cond) __builtin_expect ((cond), 0) 511 # define __glibc_likely(cond) __builtin_expect ((cond), 1) 512 #else 513 # define __glibc_unlikely(cond) (cond) 514 # define __glibc_likely(cond) (cond) 515 #endif 516 517 #if (!defined _Noreturn \ 518 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \ 519 && !(__GNUC_PREREQ (4,7) \ 520 || (3 < __clang_major__ + (5 <= __clang_minor__)))) 521 # if __GNUC_PREREQ (2,8) 522 # define _Noreturn __attribute__ ((__noreturn__)) 523 # else 524 # define _Noreturn 525 # endif 526 #endif 527 528 #if __GNUC_PREREQ (8, 0) 529 /* Describes a char array whose address can safely be passed as the first 530 argument to strncpy and strncat, as the char array is not necessarily 531 a NUL-terminated string. */ 532 # define __attribute_nonstring__ __attribute__ ((__nonstring__)) 533 #else 534 # define __attribute_nonstring__ 535 #endif 536 537 /* Undefine (also defined in libc-symbols.h). */ 538 #undef __attribute_copy__ 539 #if __GNUC_PREREQ (9, 0) 540 /* Copies attributes from the declaration or type referenced by 541 the argument. */ 542 # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg))) 543 #else 544 # define __attribute_copy__(arg) 545 #endif 546 547 #if (!defined _Static_assert && !defined __cplusplus \ 548 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \ 549 && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \ 550 || defined __STRICT_ANSI__)) 551 # define _Static_assert(expr, diagnostic) \ 552 extern int (*__Static_assert_function (void)) \ 553 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })] 554 #endif 555 556 /* Gnulib avoids including these, as they don't work on non-glibc or 557 older glibc platforms. */ 558 #ifndef __GNULIB_CDEFS 559 # include <bits/wordsize.h> 560 # include <bits/long-double.h> 561 #endif 562 563 #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1 564 # ifdef __REDIRECT 565 566 /* Alias name defined automatically. */ 567 # define __LDBL_REDIR(name, proto) ... unused__ldbl_redir 568 # define __LDBL_REDIR_DECL(name) \ 569 extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128")); 570 571 /* Alias name defined automatically, with leading underscores. */ 572 # define __LDBL_REDIR2_DECL(name) \ 573 extern __typeof (__##name) __##name \ 574 __asm (__ASMNAME ("__" #name "ieee128")); 575 576 /* Alias name defined manually. */ 577 # define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1 578 # define __LDBL_REDIR1_DECL(name, alias) \ 579 extern __typeof (name) name __asm (__ASMNAME (#alias)); 580 581 # define __LDBL_REDIR1_NTH(name, proto, alias) \ 582 __REDIRECT_NTH (name, proto, alias) 583 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 584 __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128) 585 586 /* Unused. */ 587 # define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl 588 # define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth 589 590 # else 591 _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform"); 592 # endif 593 #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH 594 # define __LDBL_COMPAT 1 595 # ifdef __REDIRECT 596 # define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias) 597 # define __LDBL_REDIR(name, proto) \ 598 __LDBL_REDIR1 (name, proto, __nldbl_##name) 599 # define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias) 600 # define __LDBL_REDIR_NTH(name, proto) \ 601 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name) 602 # define __LDBL_REDIR2_DECL(name) \ 603 extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name)); 604 # define __LDBL_REDIR1_DECL(name, alias) \ 605 extern __typeof (name) name __asm (__ASMNAME (#alias)); 606 # define __LDBL_REDIR_DECL(name) \ 607 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name)); 608 # define __REDIRECT_LDBL(name, proto, alias) \ 609 __LDBL_REDIR1 (name, proto, __nldbl_##alias) 610 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 611 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias) 612 # endif 613 #endif 614 #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \ 615 || !defined __REDIRECT 616 # define __LDBL_REDIR1(name, proto, alias) name proto 617 # define __LDBL_REDIR(name, proto) name proto 618 # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW 619 # define __LDBL_REDIR_NTH(name, proto) name proto __THROW 620 # define __LDBL_REDIR2_DECL(name) 621 # define __LDBL_REDIR_DECL(name) 622 # ifdef __REDIRECT 623 # define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias) 624 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 625 __REDIRECT_NTH (name, proto, alias) 626 # endif 627 #endif 628 629 /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is 630 intended for use in preprocessor macros. 631 632 Note: MESSAGE must be a _single_ string; concatenation of string 633 literals is not supported. */ 634 #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5) 635 # define __glibc_macro_warning1(message) _Pragma (#message) 636 # define __glibc_macro_warning(message) \ 637 __glibc_macro_warning1 (GCC warning message) 638 #else 639 # define __glibc_macro_warning(msg) 640 #endif 641 642 /* Generic selection (ISO C11) is a C-only feature, available in GCC 643 since version 4.9. Previous versions do not provide generic 644 selection, even though they might set __STDC_VERSION__ to 201112L, 645 when in -std=c11 mode. Thus, we must check for !defined __GNUC__ 646 when testing __STDC_VERSION__ for generic selection support. 647 On the other hand, Clang also defines __GNUC__, so a clang-specific 648 check is required to enable the use of generic selection. */ 649 #if !defined __cplusplus \ 650 && (__GNUC_PREREQ (4, 9) \ 651 || __glibc_has_extension (c_generic_selections) \ 652 || (!defined __GNUC__ && defined __STDC_VERSION__ \ 653 && __STDC_VERSION__ >= 201112L)) 654 # define __HAVE_GENERIC_SELECTION 1 655 #else 656 # define __HAVE_GENERIC_SELECTION 0 657 #endif 658 659 #if __GNUC_PREREQ (10, 0) 660 /* Designates a 1-based positional argument ref-index of pointer type 661 that can be used to access size-index elements of the pointed-to 662 array according to access mode, or at least one element when 663 size-index is not provided: 664 access (access-mode, <ref-index> [, <size-index>]) */ 665 # define __attr_access(x) __attribute__ ((__access__ x)) 666 /* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may 667 use the access attribute to get object sizes from function definition 668 arguments, so we can't use them on functions we fortify. Drop the object 669 size hints for such functions. */ 670 # if __USE_FORTIFY_LEVEL == 3 671 # define __fortified_attr_access(a, o, s) __attribute__ ((__access__ (a, o))) 672 # else 673 # define __fortified_attr_access(a, o, s) __attr_access ((a, o, s)) 674 # endif 675 # if __GNUC_PREREQ (11, 0) 676 # define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno))) 677 # else 678 # define __attr_access_none(argno) 679 # endif 680 #else 681 # define __fortified_attr_access(a, o, s) 682 # define __attr_access(x) 683 # define __attr_access_none(argno) 684 #endif 685 686 #if __GNUC_PREREQ (11, 0) 687 /* Designates dealloc as a function to call to deallocate objects 688 allocated by the declared function. */ 689 # define __attr_dealloc(dealloc, argno) \ 690 __attribute__ ((__malloc__ (dealloc, argno))) 691 # define __attr_dealloc_free __attr_dealloc (__builtin_free, 1) 692 #else 693 # define __attr_dealloc(dealloc, argno) 694 # define __attr_dealloc_free 695 #endif 696 697 /* Specify that a function such as setjmp or vfork may return 698 twice. */ 699 #if __GNUC_PREREQ (4, 1) 700 # define __attribute_returns_twice__ __attribute__ ((__returns_twice__)) 701 #else 702 # define __attribute_returns_twice__ /* Ignore. */ 703 #endif 704 705 #endif /* sys/cdefs.h */ 706