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__ 31 # error "You need a ISO 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 || (defined __apple_build_version__ \ 45 ? 6000000 <= __apple_build_version__ \ 46 : 3 < __clang_major__ + (5 <= __clang_minor__)))) 47 # define __glibc_has_attribute(attr) __has_attribute (attr) 48 #else 49 # define __glibc_has_attribute(attr) 0 50 #endif 51 #ifdef __has_builtin 52 # define __glibc_has_builtin(name) __has_builtin (name) 53 #else 54 # define __glibc_has_builtin(name) 0 55 #endif 56 #ifdef __has_extension 57 # define __glibc_has_extension(ext) __has_extension (ext) 58 #else 59 # define __glibc_has_extension(ext) 0 60 #endif 61 62 #if defined __GNUC__ || defined __clang__ 63 64 /* All functions, except those with callbacks or those that 65 synchronize memory, are leaf functions. */ 66 # if __GNUC_PREREQ (4, 6) && !defined _LIBC 67 # define __LEAF , __leaf__ 68 # define __LEAF_ATTR __attribute__ ((__leaf__)) 69 # else 70 # define __LEAF 71 # define __LEAF_ATTR 72 # endif 73 74 /* GCC can always grok prototypes. For C++ programs we add throw() 75 to help it optimize the function calls. But this only works with 76 gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions 77 as non-throwing using a function attribute since programs can use 78 the -fexceptions options for C code as well. */ 79 # if !defined __cplusplus \ 80 && (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__)) 81 # define __THROW __attribute__ ((__nothrow__ __LEAF)) 82 # define __THROWNL __attribute__ ((__nothrow__)) 83 # define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct 84 # define __NTHNL(fct) __attribute__ ((__nothrow__)) fct 85 # else 86 # if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major >= 4) 87 # if __cplusplus >= 201103L 88 # define __THROW noexcept (true) 89 # else 90 # define __THROW throw () 91 # endif 92 # define __THROWNL __THROW 93 # define __NTH(fct) __LEAF_ATTR fct __THROW 94 # define __NTHNL(fct) fct __THROW 95 # else 96 # define __THROW 97 # define __THROWNL 98 # define __NTH(fct) fct 99 # define __NTHNL(fct) fct 100 # endif 101 # endif 102 103 #else /* Not GCC or clang. */ 104 105 # if (defined __cplusplus \ 106 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)) 107 # define __inline inline 108 # else 109 # define __inline /* No inline functions. */ 110 # endif 111 112 # define __THROW 113 # define __THROWNL 114 # define __NTH(fct) fct 115 116 #endif /* GCC || clang. */ 117 118 /* These two macros are not used in glibc anymore. They are kept here 119 only because some other projects expect the macros to be defined. */ 120 #define __P(args) args 121 #define __PMT(args) args 122 123 /* For these things, GCC behaves the ANSI way normally, 124 and the non-ANSI way under -traditional. */ 125 126 #define __CONCAT(x,y) x ## y 127 #define __STRING(x) #x 128 129 /* This is not a typedef so `const __ptr_t' does the right thing. */ 130 #define __ptr_t void * 131 132 133 /* C++ needs to know that types and declarations are C, not C++. */ 134 #ifdef __cplusplus 135 # define __BEGIN_DECLS extern "C" { 136 # define __END_DECLS } 137 #else 138 # define __BEGIN_DECLS 139 # define __END_DECLS 140 #endif 141 142 143 /* Fortify support. */ 144 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1) 145 #define __bos0(ptr) __builtin_object_size (ptr, 0) 146 147 /* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */ 148 #if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \ 149 || __GNUC_PREREQ (12, 0)) 150 # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0) 151 # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1) 152 #else 153 # define __glibc_objsize0(__o) __bos0 (__o) 154 # define __glibc_objsize(__o) __bos (__o) 155 #endif 156 157 /* Compile time conditions to choose between the regular, _chk and _chk_warn 158 variants. These conditions should get evaluated to constant and optimized 159 away. */ 160 161 #define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s)) 162 #define __glibc_unsigned_or_positive(__l) \ 163 ((__typeof (__l)) 0 < (__typeof (__l)) -1 \ 164 || (__builtin_constant_p (__l) && (__l) > 0)) 165 166 /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ 167 condition can be folded to a constant and if it is true. The -1 check is 168 redundant because since it implies that __glibc_safe_len_cond is true. */ 169 #define __glibc_safe_or_unknown_len(__l, __s, __osz) \ 170 (__glibc_unsigned_or_positive (__l) \ 171 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \ 172 __s, __osz)) \ 173 && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz)) 174 175 /* Conversely, we know at compile time that the length is unsafe if the 176 __L * __S <= __OBJSZ condition can be folded to a constant and if it is 177 false. */ 178 #define __glibc_unsafe_len(__l, __s, __osz) \ 179 (__glibc_unsigned_or_positive (__l) \ 180 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \ 181 __s, __osz)) \ 182 && !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz)) 183 184 /* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be 185 declared. */ 186 187 #define __glibc_fortify(f, __l, __s, __osz, ...) \ 188 (__glibc_safe_or_unknown_len (__l, __s, __osz) \ 189 ? __ ## f ## _alias (__VA_ARGS__) \ 190 : (__glibc_unsafe_len (__l, __s, __osz) \ 191 ? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \ 192 : __ ## f ## _chk (__VA_ARGS__, __osz))) \ 193 194 /* Fortify function f, where object size argument passed to f is the number of 195 elements and not total size. */ 196 197 #define __glibc_fortify_n(f, __l, __s, __osz, ...) \ 198 (__glibc_safe_or_unknown_len (__l, __s, __osz) \ 199 ? __ ## f ## _alias (__VA_ARGS__) \ 200 : (__glibc_unsafe_len (__l, __s, __osz) \ 201 ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \ 202 : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s)))) \ 203 204 #if __GNUC_PREREQ (4,3) 205 # define __warnattr(msg) __attribute__((__warning__ (msg))) 206 # define __errordecl(name, msg) \ 207 extern void name (void) __attribute__((__error__ (msg))) 208 #else 209 # define __warnattr(msg) 210 # define __errordecl(name, msg) extern void name (void) 211 #endif 212 213 /* Support for flexible arrays. 214 Headers that should use flexible arrays only if they're "real" 215 (e.g. only if they won't affect sizeof()) should test 216 #if __glibc_c99_flexarr_available. */ 217 #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc 218 # define __flexarr [] 219 # define __glibc_c99_flexarr_available 1 220 #elif __GNUC_PREREQ (2,97) || defined __clang__ 221 /* GCC 2.97 and clang support C99 flexible array members as an extension, 222 even when in C89 mode or compiling C++ (any version). */ 223 # define __flexarr [] 224 # define __glibc_c99_flexarr_available 1 225 #elif defined __GNUC__ 226 /* Pre-2.97 GCC did not support C99 flexible arrays but did have 227 an equivalent extension with slightly different notation. */ 228 # define __flexarr [0] 229 # define __glibc_c99_flexarr_available 1 230 #else 231 /* Some other non-C99 compiler. Approximate with [1]. */ 232 # define __flexarr [1] 233 # define __glibc_c99_flexarr_available 0 234 #endif 235 236 237 /* __asm__ ("xyz") is used throughout the headers to rename functions 238 at the assembly language level. This is wrapped by the __REDIRECT 239 macro, in order to support compilers that can do this some other 240 way. When compilers don't support asm-names at all, we have to do 241 preprocessor tricks instead (which don't have exactly the right 242 semantics, but it's the best we can do). 243 244 Example: 245 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */ 246 247 #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4) 248 249 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias)) 250 # ifdef __cplusplus 251 # define __REDIRECT_NTH(name, proto, alias) \ 252 name proto __THROW __asm__ (__ASMNAME (#alias)) 253 # define __REDIRECT_NTHNL(name, proto, alias) \ 254 name proto __THROWNL __asm__ (__ASMNAME (#alias)) 255 # else 256 # define __REDIRECT_NTH(name, proto, alias) \ 257 name proto __asm__ (__ASMNAME (#alias)) __THROW 258 # define __REDIRECT_NTHNL(name, proto, alias) \ 259 name proto __asm__ (__ASMNAME (#alias)) __THROWNL 260 # endif 261 # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname) 262 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname 263 264 /* 265 #elif __SOME_OTHER_COMPILER__ 266 267 # define __REDIRECT(name, proto, alias) name proto; \ 268 _Pragma("let " #name " = " #alias) 269 */ 270 #endif 271 272 /* GCC and clang have various useful declarations that can be made with 273 the '__attribute__' syntax. All of the ways we use this do fine if 274 they are omitted for compilers that don't understand it. */ 275 #if !(defined __GNUC__ || defined __clang__) 276 # define __attribute__(xyz) /* Ignore */ 277 #endif 278 279 /* At some point during the gcc 2.96 development the `malloc' attribute 280 for functions was introduced. We don't want to use it unconditionally 281 (although this would be possible) since it generates warnings. */ 282 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__) 283 # define __attribute_malloc__ __attribute__ ((__malloc__)) 284 #else 285 # define __attribute_malloc__ /* Ignore */ 286 #endif 287 288 /* Tell the compiler which arguments to an allocation function 289 indicate the size of the allocation. */ 290 #if __GNUC_PREREQ (4, 3) 291 # define __attribute_alloc_size__(params) \ 292 __attribute__ ((__alloc_size__ params)) 293 #else 294 # define __attribute_alloc_size__(params) /* Ignore. */ 295 #endif 296 297 /* Tell the compiler which argument to an allocation function 298 indicates the alignment of the allocation. */ 299 #if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__) 300 # define __attribute_alloc_align__(param) \ 301 __attribute__ ((__alloc_align__ param)) 302 #else 303 # define __attribute_alloc_align__(param) /* Ignore. */ 304 #endif 305 306 /* At some point during the gcc 2.96 development the `pure' attribute 307 for functions was introduced. We don't want to use it unconditionally 308 (although this would be possible) since it generates warnings. */ 309 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__) 310 # define __attribute_pure__ __attribute__ ((__pure__)) 311 #else 312 # define __attribute_pure__ /* Ignore */ 313 #endif 314 315 /* This declaration tells the compiler that the value is constant. */ 316 #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__) 317 # define __attribute_const__ __attribute__ ((__const__)) 318 #else 319 # define __attribute_const__ /* Ignore */ 320 #endif 321 322 #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__) 323 # define __attribute_maybe_unused__ __attribute__ ((__unused__)) 324 #else 325 # define __attribute_maybe_unused__ /* Ignore */ 326 #endif 327 328 /* At some point during the gcc 3.1 development the `used' attribute 329 for functions was introduced. We don't want to use it unconditionally 330 (although this would be possible) since it generates warnings. */ 331 #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__) 332 # define __attribute_used__ __attribute__ ((__used__)) 333 # define __attribute_noinline__ __attribute__ ((__noinline__)) 334 #else 335 # define __attribute_used__ __attribute__ ((__unused__)) 336 # define __attribute_noinline__ /* Ignore */ 337 #endif 338 339 /* Since version 3.2, gcc allows marking deprecated functions. */ 340 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__) 341 # define __attribute_deprecated__ __attribute__ ((__deprecated__)) 342 #else 343 # define __attribute_deprecated__ /* Ignore */ 344 #endif 345 346 /* Since version 4.5, gcc also allows one to specify the message printed 347 when a deprecated function is used. clang claims to be gcc 4.2, but 348 may also support this feature. */ 349 #if __GNUC_PREREQ (4,5) \ 350 || __glibc_has_extension (__attribute_deprecated_with_message__) 351 # define __attribute_deprecated_msg__(msg) \ 352 __attribute__ ((__deprecated__ (msg))) 353 #else 354 # define __attribute_deprecated_msg__(msg) __attribute_deprecated__ 355 #endif 356 357 /* At some point during the gcc 2.8 development the `format_arg' attribute 358 for functions was introduced. We don't want to use it unconditionally 359 (although this would be possible) since it generates warnings. 360 If several `format_arg' attributes are given for the same function, in 361 gcc-3.0 and older, all but the last one are ignored. In newer gccs, 362 all designated arguments are considered. */ 363 #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__) 364 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x))) 365 #else 366 # define __attribute_format_arg__(x) /* Ignore */ 367 #endif 368 369 /* At some point during the gcc 2.97 development the `strfmon' format 370 attribute for functions was introduced. We don't want to use it 371 unconditionally (although this would be possible) since it 372 generates warnings. */ 373 #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__) 374 # define __attribute_format_strfmon__(a,b) \ 375 __attribute__ ((__format__ (__strfmon__, a, b))) 376 #else 377 # define __attribute_format_strfmon__(a,b) /* Ignore */ 378 #endif 379 380 /* The nonnull function attribute marks pointer parameters that 381 must not be NULL. This has the name __nonnull in glibc, 382 and __attribute_nonnull__ in files shared with Gnulib to avoid 383 collision with a different __nonnull in DragonFlyBSD 5.9. */ 384 #ifndef __attribute_nonnull__ 385 # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__) 386 # define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params)) 387 # else 388 # define __attribute_nonnull__(params) 389 # endif 390 #endif 391 #ifndef __nonnull 392 # define __nonnull(params) __attribute_nonnull__ (params) 393 #endif 394 395 /* The returns_nonnull function attribute marks the return type of the function 396 as always being non-null. */ 397 #ifndef __returns_nonnull 398 # if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__) 399 # define __returns_nonnull __attribute__ ((__returns_nonnull__)) 400 # else 401 # define __returns_nonnull 402 # endif 403 #endif 404 405 /* If fortification mode, we warn about unused results of certain 406 function calls which can lead to problems. */ 407 #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__) 408 # define __attribute_warn_unused_result__ \ 409 __attribute__ ((__warn_unused_result__)) 410 # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0 411 # define __wur __attribute_warn_unused_result__ 412 # endif 413 #else 414 # define __attribute_warn_unused_result__ /* empty */ 415 #endif 416 #ifndef __wur 417 # define __wur /* Ignore */ 418 #endif 419 420 /* Forces a function to be always inlined. */ 421 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__) 422 /* The Linux kernel defines __always_inline in stddef.h (283d7573), and 423 it conflicts with this definition. Therefore undefine it first to 424 allow either header to be included first. */ 425 # undef __always_inline 426 # define __always_inline __inline __attribute__ ((__always_inline__)) 427 #else 428 # undef __always_inline 429 # define __always_inline __inline 430 #endif 431 432 /* Associate error messages with the source location of the call site rather 433 than with the source location inside the function. */ 434 #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__) 435 # define __attribute_artificial__ __attribute__ ((__artificial__)) 436 #else 437 # define __attribute_artificial__ /* Ignore */ 438 #endif 439 440 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99 441 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__ 442 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions 443 older than 4.3 may define these macros and still not guarantee GNU inlining 444 semantics. 445 446 clang++ identifies itself as gcc-4.2, but has support for GNU inlining 447 semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and 448 __GNUC_GNU_INLINE__ macro definitions. */ 449 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \ 450 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \ 451 || defined __GNUC_GNU_INLINE__))) 452 # if defined __GNUC_STDC_INLINE__ || defined __cplusplus 453 # define __extern_inline extern __inline __attribute__ ((__gnu_inline__)) 454 # define __extern_always_inline \ 455 extern __always_inline __attribute__ ((__gnu_inline__)) 456 # else 457 # define __extern_inline extern __inline 458 # define __extern_always_inline extern __always_inline 459 # endif 460 #endif 461 462 #ifdef __extern_always_inline 463 # define __fortify_function __extern_always_inline __attribute_artificial__ 464 #endif 465 466 /* GCC 4.3 and above allow passing all anonymous arguments of an 467 __extern_always_inline function to some other vararg function. */ 468 #if __GNUC_PREREQ (4,3) 469 # define __va_arg_pack() __builtin_va_arg_pack () 470 # define __va_arg_pack_len() __builtin_va_arg_pack_len () 471 #endif 472 473 /* It is possible to compile containing GCC extensions even if GCC is 474 run in pedantic mode if the uses are carefully marked using the 475 `__extension__' keyword. But this is not generally available before 476 version 2.8. */ 477 #if !(__GNUC_PREREQ (2,8) || defined __clang__) 478 # define __extension__ /* Ignore */ 479 #endif 480 481 /* __restrict is known in EGCS 1.2 and above, and in clang. 482 It works also in C++ mode (outside of arrays), but only when spelled 483 as '__restrict', not 'restrict'. */ 484 #if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3) 485 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 486 # define __restrict restrict 487 # else 488 # define __restrict /* Ignore */ 489 # endif 490 #endif 491 492 /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is 493 array_name[restrict] 494 GCC 3.1 and clang support this. 495 This syntax is not usable in C++ mode. */ 496 #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus 497 # define __restrict_arr __restrict 498 #else 499 # ifdef __GNUC__ 500 # define __restrict_arr /* Not supported in old GCC. */ 501 # else 502 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 503 # define __restrict_arr restrict 504 # else 505 /* Some other non-C99 compiler. */ 506 # define __restrict_arr /* Not supported. */ 507 # endif 508 # endif 509 #endif 510 511 #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect) 512 # define __glibc_unlikely(cond) __builtin_expect ((cond), 0) 513 # define __glibc_likely(cond) __builtin_expect ((cond), 1) 514 #else 515 # define __glibc_unlikely(cond) (cond) 516 # define __glibc_likely(cond) (cond) 517 #endif 518 519 #if (!defined _Noreturn \ 520 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \ 521 && !(__GNUC_PREREQ (4,7) \ 522 || (3 < __clang_major__ + (5 <= __clang_minor__)))) 523 # if __GNUC_PREREQ (2,8) 524 # define _Noreturn __attribute__ ((__noreturn__)) 525 # else 526 # define _Noreturn 527 # endif 528 #endif 529 530 #if __GNUC_PREREQ (8, 0) 531 /* Describes a char array whose address can safely be passed as the first 532 argument to strncpy and strncat, as the char array is not necessarily 533 a NUL-terminated string. */ 534 # define __attribute_nonstring__ __attribute__ ((__nonstring__)) 535 #else 536 # define __attribute_nonstring__ 537 #endif 538 539 /* Undefine (also defined in libc-symbols.h). */ 540 #undef __attribute_copy__ 541 #if __GNUC_PREREQ (9, 0) 542 /* Copies attributes from the declaration or type referenced by 543 the argument. */ 544 # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg))) 545 #else 546 # define __attribute_copy__(arg) 547 #endif 548 549 #if (!defined _Static_assert && !defined __cplusplus \ 550 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \ 551 && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \ 552 || defined __STRICT_ANSI__)) 553 # define _Static_assert(expr, diagnostic) \ 554 extern int (*__Static_assert_function (void)) \ 555 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })] 556 #endif 557 558 /* Gnulib avoids including these, as they don't work on non-glibc or 559 older glibc platforms. */ 560 #ifndef __GNULIB_CDEFS 561 # include <bits/wordsize.h> 562 # include <bits/long-double.h> 563 #endif 564 565 #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1 566 # ifdef __REDIRECT 567 568 /* Alias name defined automatically. */ 569 # define __LDBL_REDIR(name, proto) ... unused__ldbl_redir 570 # define __LDBL_REDIR_DECL(name) \ 571 extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128")); 572 573 /* Alias name defined automatically, with leading underscores. */ 574 # define __LDBL_REDIR2_DECL(name) \ 575 extern __typeof (__##name) __##name \ 576 __asm (__ASMNAME ("__" #name "ieee128")); 577 578 /* Alias name defined manually. */ 579 # define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1 580 # define __LDBL_REDIR1_DECL(name, alias) \ 581 extern __typeof (name) name __asm (__ASMNAME (#alias)); 582 583 # define __LDBL_REDIR1_NTH(name, proto, alias) \ 584 __REDIRECT_NTH (name, proto, alias) 585 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 586 __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128) 587 588 /* Unused. */ 589 # define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl 590 # define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth 591 592 # else 593 _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform"); 594 # endif 595 #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH 596 # define __LDBL_COMPAT 1 597 # ifdef __REDIRECT 598 # define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias) 599 # define __LDBL_REDIR(name, proto) \ 600 __LDBL_REDIR1 (name, proto, __nldbl_##name) 601 # define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias) 602 # define __LDBL_REDIR_NTH(name, proto) \ 603 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name) 604 # define __LDBL_REDIR2_DECL(name) \ 605 extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name)); 606 # define __LDBL_REDIR1_DECL(name, alias) \ 607 extern __typeof (name) name __asm (__ASMNAME (#alias)); 608 # define __LDBL_REDIR_DECL(name) \ 609 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name)); 610 # define __REDIRECT_LDBL(name, proto, alias) \ 611 __LDBL_REDIR1 (name, proto, __nldbl_##alias) 612 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 613 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias) 614 # endif 615 #endif 616 #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \ 617 || !defined __REDIRECT 618 # define __LDBL_REDIR1(name, proto, alias) name proto 619 # define __LDBL_REDIR(name, proto) name proto 620 # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW 621 # define __LDBL_REDIR_NTH(name, proto) name proto __THROW 622 # define __LDBL_REDIR2_DECL(name) 623 # define __LDBL_REDIR_DECL(name) 624 # ifdef __REDIRECT 625 # define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias) 626 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 627 __REDIRECT_NTH (name, proto, alias) 628 # endif 629 #endif 630 631 /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is 632 intended for use in preprocessor macros. 633 634 Note: MESSAGE must be a _single_ string; concatenation of string 635 literals is not supported. */ 636 #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5) 637 # define __glibc_macro_warning1(message) _Pragma (#message) 638 # define __glibc_macro_warning(message) \ 639 __glibc_macro_warning1 (GCC warning message) 640 #else 641 # define __glibc_macro_warning(msg) 642 #endif 643 644 /* Generic selection (ISO C11) is a C-only feature, available in GCC 645 since version 4.9. Previous versions do not provide generic 646 selection, even though they might set __STDC_VERSION__ to 201112L, 647 when in -std=c11 mode. Thus, we must check for !defined __GNUC__ 648 when testing __STDC_VERSION__ for generic selection support. 649 On the other hand, Clang also defines __GNUC__, so a clang-specific 650 check is required to enable the use of generic selection. */ 651 #if !defined __cplusplus \ 652 && (__GNUC_PREREQ (4, 9) \ 653 || __glibc_has_extension (c_generic_selections) \ 654 || (!defined __GNUC__ && defined __STDC_VERSION__ \ 655 && __STDC_VERSION__ >= 201112L)) 656 # define __HAVE_GENERIC_SELECTION 1 657 #else 658 # define __HAVE_GENERIC_SELECTION 0 659 #endif 660 661 #if __GNUC_PREREQ (10, 0) 662 /* Designates a 1-based positional argument ref-index of pointer type 663 that can be used to access size-index elements of the pointed-to 664 array according to access mode, or at least one element when 665 size-index is not provided: 666 access (access-mode, <ref-index> [, <size-index>]) */ 667 # define __attr_access(x) __attribute__ ((__access__ x)) 668 /* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may 669 use the access attribute to get object sizes from function definition 670 arguments, so we can't use them on functions we fortify. Drop the object 671 size hints for such functions. */ 672 # if __USE_FORTIFY_LEVEL == 3 673 # define __fortified_attr_access(a, o, s) __attribute__ ((__access__ (a, o))) 674 # else 675 # define __fortified_attr_access(a, o, s) __attr_access ((a, o, s)) 676 # endif 677 # if __GNUC_PREREQ (11, 0) 678 # define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno))) 679 # else 680 # define __attr_access_none(argno) 681 # endif 682 #else 683 # define __fortified_attr_access(a, o, s) 684 # define __attr_access(x) 685 # define __attr_access_none(argno) 686 #endif 687 688 #if __GNUC_PREREQ (11, 0) 689 /* Designates dealloc as a function to call to deallocate objects 690 allocated by the declared function. */ 691 # define __attr_dealloc(dealloc, argno) \ 692 __attribute__ ((__malloc__ (dealloc, argno))) 693 # define __attr_dealloc_free __attr_dealloc (__builtin_free, 1) 694 #else 695 # define __attr_dealloc(dealloc, argno) 696 # define __attr_dealloc_free 697 #endif 698 699 /* Specify that a function such as setjmp or vfork may return 700 twice. */ 701 #if __GNUC_PREREQ (4, 1) 702 # define __attribute_returns_twice__ __attribute__ ((__returns_twice__)) 703 #else 704 # define __attribute_returns_twice__ /* Ignore. */ 705 #endif 706 707 #endif /* sys/cdefs.h */ 708