1 /* Copyright (C) 1992-2021 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 || 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 # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0) 148 # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1) 149 #else 150 # define __glibc_objsize0(__o) __bos0 (__o) 151 # define __glibc_objsize(__o) __bos (__o) 152 #endif 153 154 /* Compile time conditions to choose between the regular, _chk and _chk_warn 155 variants. These conditions should get evaluated to constant and optimized 156 away. */ 157 158 #define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s)) 159 #define __glibc_unsigned_or_positive(__l) \ 160 ((__typeof (__l)) 0 < (__typeof (__l)) -1 \ 161 || (__builtin_constant_p (__l) && (__l) > 0)) 162 163 /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ 164 condition can be folded to a constant and if it is true. The -1 check is 165 redundant because since it implies that __glibc_safe_len_cond is true. */ 166 #define __glibc_safe_or_unknown_len(__l, __s, __osz) \ 167 (__glibc_unsigned_or_positive (__l) \ 168 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \ 169 __s, __osz)) \ 170 && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz)) 171 172 /* Conversely, we know at compile time that the length is safe if the 173 __L * __S <= __OBJSZ condition can be folded to a constant and if it is 174 false. */ 175 #define __glibc_unsafe_len(__l, __s, __osz) \ 176 (__glibc_unsigned_or_positive (__l) \ 177 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \ 178 __s, __osz)) \ 179 && !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz)) 180 181 /* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be 182 declared. */ 183 184 #define __glibc_fortify(f, __l, __s, __osz, ...) \ 185 (__glibc_safe_or_unknown_len (__l, __s, __osz) \ 186 ? __ ## f ## _alias (__VA_ARGS__) \ 187 : (__glibc_unsafe_len (__l, __s, __osz) \ 188 ? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \ 189 : __ ## f ## _chk (__VA_ARGS__, __osz))) \ 190 191 /* Fortify function f, where object size argument passed to f is the number of 192 elements and not total size. */ 193 194 #define __glibc_fortify_n(f, __l, __s, __osz, ...) \ 195 (__glibc_safe_or_unknown_len (__l, __s, __osz) \ 196 ? __ ## f ## _alias (__VA_ARGS__) \ 197 : (__glibc_unsafe_len (__l, __s, __osz) \ 198 ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \ 199 : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s)))) \ 200 201 #if __GNUC_PREREQ (4,3) 202 # define __warnattr(msg) __attribute__((__warning__ (msg))) 203 # define __errordecl(name, msg) \ 204 extern void name (void) __attribute__((__error__ (msg))) 205 #else 206 # define __warnattr(msg) 207 # define __errordecl(name, msg) extern void name (void) 208 #endif 209 210 /* Support for flexible arrays. 211 Headers that should use flexible arrays only if they're "real" 212 (e.g. only if they won't affect sizeof()) should test 213 #if __glibc_c99_flexarr_available. */ 214 #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc 215 # define __flexarr [] 216 # define __glibc_c99_flexarr_available 1 217 #elif __GNUC_PREREQ (2,97) || defined __clang__ 218 /* GCC 2.97 and clang support C99 flexible array members as an extension, 219 even when in C89 mode or compiling C++ (any version). */ 220 # define __flexarr [] 221 # define __glibc_c99_flexarr_available 1 222 #elif defined __GNUC__ 223 /* Pre-2.97 GCC did not support C99 flexible arrays but did have 224 an equivalent extension with slightly different notation. */ 225 # define __flexarr [0] 226 # define __glibc_c99_flexarr_available 1 227 #else 228 /* Some other non-C99 compiler. Approximate with [1]. */ 229 # define __flexarr [1] 230 # define __glibc_c99_flexarr_available 0 231 #endif 232 233 234 /* __asm__ ("xyz") is used throughout the headers to rename functions 235 at the assembly language level. This is wrapped by the __REDIRECT 236 macro, in order to support compilers that can do this some other 237 way. When compilers don't support asm-names at all, we have to do 238 preprocessor tricks instead (which don't have exactly the right 239 semantics, but it's the best we can do). 240 241 Example: 242 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */ 243 244 #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4) 245 246 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias)) 247 # ifdef __cplusplus 248 # define __REDIRECT_NTH(name, proto, alias) \ 249 name proto __THROW __asm__ (__ASMNAME (#alias)) 250 # define __REDIRECT_NTHNL(name, proto, alias) \ 251 name proto __THROWNL __asm__ (__ASMNAME (#alias)) 252 # else 253 # define __REDIRECT_NTH(name, proto, alias) \ 254 name proto __asm__ (__ASMNAME (#alias)) __THROW 255 # define __REDIRECT_NTHNL(name, proto, alias) \ 256 name proto __asm__ (__ASMNAME (#alias)) __THROWNL 257 # endif 258 # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname) 259 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname 260 261 /* 262 #elif __SOME_OTHER_COMPILER__ 263 264 # define __REDIRECT(name, proto, alias) name proto; \ 265 _Pragma("let " #name " = " #alias) 266 */ 267 #endif 268 269 /* GCC and clang have various useful declarations that can be made with 270 the '__attribute__' syntax. All of the ways we use this do fine if 271 they are omitted for compilers that don't understand it. */ 272 #if !(defined __GNUC__ || defined __clang__) 273 # define __attribute__(xyz) /* Ignore */ 274 #endif 275 276 /* At some point during the gcc 2.96 development the `malloc' attribute 277 for functions was introduced. We don't want to use it unconditionally 278 (although this would be possible) since it generates warnings. */ 279 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__) 280 # define __attribute_malloc__ __attribute__ ((__malloc__)) 281 #else 282 # define __attribute_malloc__ /* Ignore */ 283 #endif 284 285 /* Tell the compiler which arguments to an allocation function 286 indicate the size of the allocation. */ 287 #if __GNUC_PREREQ (4, 3) 288 # define __attribute_alloc_size__(params) \ 289 __attribute__ ((__alloc_size__ params)) 290 #else 291 # define __attribute_alloc_size__(params) /* Ignore. */ 292 #endif 293 294 /* Tell the compiler which argument to an allocation function 295 indicates the alignment of the allocation. */ 296 #if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__) 297 # define __attribute_alloc_align__(param) \ 298 __attribute__ ((__alloc_align__ param)) 299 #else 300 # define __attribute_alloc_align__(param) /* Ignore. */ 301 #endif 302 303 /* At some point during the gcc 2.96 development the `pure' 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 __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__) 307 # define __attribute_pure__ __attribute__ ((__pure__)) 308 #else 309 # define __attribute_pure__ /* Ignore */ 310 #endif 311 312 /* This declaration tells the compiler that the value is constant. */ 313 #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__) 314 # define __attribute_const__ __attribute__ ((__const__)) 315 #else 316 # define __attribute_const__ /* Ignore */ 317 #endif 318 319 #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__) 320 # define __attribute_maybe_unused__ __attribute__ ((__unused__)) 321 #else 322 # define __attribute_maybe_unused__ /* Ignore */ 323 #endif 324 325 /* At some point during the gcc 3.1 development the `used' attribute 326 for functions was introduced. We don't want to use it unconditionally 327 (although this would be possible) since it generates warnings. */ 328 #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__) 329 # define __attribute_used__ __attribute__ ((__used__)) 330 # define __attribute_noinline__ __attribute__ ((__noinline__)) 331 #else 332 # define __attribute_used__ __attribute__ ((__unused__)) 333 # define __attribute_noinline__ /* Ignore */ 334 #endif 335 336 /* Since version 3.2, gcc allows marking deprecated functions. */ 337 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__) 338 # define __attribute_deprecated__ __attribute__ ((__deprecated__)) 339 #else 340 # define __attribute_deprecated__ /* Ignore */ 341 #endif 342 343 /* Since version 4.5, gcc also allows one to specify the message printed 344 when a deprecated function is used. clang claims to be gcc 4.2, but 345 may also support this feature. */ 346 #if __GNUC_PREREQ (4,5) \ 347 || __glibc_has_extension (__attribute_deprecated_with_message__) 348 # define __attribute_deprecated_msg__(msg) \ 349 __attribute__ ((__deprecated__ (msg))) 350 #else 351 # define __attribute_deprecated_msg__(msg) __attribute_deprecated__ 352 #endif 353 354 /* At some point during the gcc 2.8 development the `format_arg' attribute 355 for functions was introduced. We don't want to use it unconditionally 356 (although this would be possible) since it generates warnings. 357 If several `format_arg' attributes are given for the same function, in 358 gcc-3.0 and older, all but the last one are ignored. In newer gccs, 359 all designated arguments are considered. */ 360 #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__) 361 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x))) 362 #else 363 # define __attribute_format_arg__(x) /* Ignore */ 364 #endif 365 366 /* At some point during the gcc 2.97 development the `strfmon' format 367 attribute for functions was introduced. We don't want to use it 368 unconditionally (although this would be possible) since it 369 generates warnings. */ 370 #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__) 371 # define __attribute_format_strfmon__(a,b) \ 372 __attribute__ ((__format__ (__strfmon__, a, b))) 373 #else 374 # define __attribute_format_strfmon__(a,b) /* Ignore */ 375 #endif 376 377 /* The nonnull function attribute marks pointer parameters that 378 must not be NULL. This has the name __nonnull in glibc, 379 and __attribute_nonnull__ in files shared with Gnulib to avoid 380 collision with a different __nonnull in DragonFlyBSD 5.9. */ 381 #ifndef __attribute_nonnull__ 382 # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__) 383 # define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params)) 384 # else 385 # define __attribute_nonnull__(params) 386 # endif 387 #endif 388 #ifndef __nonnull 389 # define __nonnull(params) __attribute_nonnull__ (params) 390 #endif 391 392 /* The returns_nonnull function attribute marks the return type of the function 393 as always being non-null. */ 394 #ifndef __returns_nonnull 395 # if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__) 396 # define __returns_nonnull __attribute__ ((__returns_nonnull__)) 397 # else 398 # define __returns_nonnull 399 # endif 400 #endif 401 402 /* If fortification mode, we warn about unused results of certain 403 function calls which can lead to problems. */ 404 #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__) 405 # define __attribute_warn_unused_result__ \ 406 __attribute__ ((__warn_unused_result__)) 407 # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0 408 # define __wur __attribute_warn_unused_result__ 409 # endif 410 #else 411 # define __attribute_warn_unused_result__ /* empty */ 412 #endif 413 #ifndef __wur 414 # define __wur /* Ignore */ 415 #endif 416 417 /* Forces a function to be always inlined. */ 418 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__) 419 /* The Linux kernel defines __always_inline in stddef.h (283d7573), and 420 it conflicts with this definition. Therefore undefine it first to 421 allow either header to be included first. */ 422 # undef __always_inline 423 # define __always_inline __inline __attribute__ ((__always_inline__)) 424 #else 425 # undef __always_inline 426 # define __always_inline __inline 427 #endif 428 429 /* Associate error messages with the source location of the call site rather 430 than with the source location inside the function. */ 431 #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__) 432 # define __attribute_artificial__ __attribute__ ((__artificial__)) 433 #else 434 # define __attribute_artificial__ /* Ignore */ 435 #endif 436 437 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99 438 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__ 439 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions 440 older than 4.3 may define these macros and still not guarantee GNU inlining 441 semantics. 442 443 clang++ identifies itself as gcc-4.2, but has support for GNU inlining 444 semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and 445 __GNUC_GNU_INLINE__ macro definitions. */ 446 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \ 447 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \ 448 || defined __GNUC_GNU_INLINE__))) 449 # if defined __GNUC_STDC_INLINE__ || defined __cplusplus 450 # define __extern_inline extern __inline __attribute__ ((__gnu_inline__)) 451 # define __extern_always_inline \ 452 extern __always_inline __attribute__ ((__gnu_inline__)) 453 # else 454 # define __extern_inline extern __inline 455 # define __extern_always_inline extern __always_inline 456 # endif 457 #endif 458 459 #ifdef __extern_always_inline 460 # define __fortify_function __extern_always_inline __attribute_artificial__ 461 #endif 462 463 /* GCC 4.3 and above allow passing all anonymous arguments of an 464 __extern_always_inline function to some other vararg function. */ 465 #if __GNUC_PREREQ (4,3) 466 # define __va_arg_pack() __builtin_va_arg_pack () 467 # define __va_arg_pack_len() __builtin_va_arg_pack_len () 468 #endif 469 470 /* It is possible to compile containing GCC extensions even if GCC is 471 run in pedantic mode if the uses are carefully marked using the 472 `__extension__' keyword. But this is not generally available before 473 version 2.8. */ 474 #if !(__GNUC_PREREQ (2,8) || defined __clang__) 475 # define __extension__ /* Ignore */ 476 #endif 477 478 /* __restrict is known in EGCS 1.2 and above, and in clang. 479 It works also in C++ mode (outside of arrays), but only when spelled 480 as '__restrict', not 'restrict'. */ 481 #if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3) 482 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 483 # define __restrict restrict 484 # else 485 # define __restrict /* Ignore */ 486 # endif 487 #endif 488 489 /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is 490 array_name[restrict] 491 GCC 3.1 and clang support this. 492 This syntax is not usable in C++ mode. */ 493 #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus 494 # define __restrict_arr __restrict 495 #else 496 # ifdef __GNUC__ 497 # define __restrict_arr /* Not supported in old GCC. */ 498 # else 499 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 500 # define __restrict_arr restrict 501 # else 502 /* Some other non-C99 compiler. */ 503 # define __restrict_arr /* Not supported. */ 504 # endif 505 # endif 506 #endif 507 508 #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect) 509 # define __glibc_unlikely(cond) __builtin_expect ((cond), 0) 510 # define __glibc_likely(cond) __builtin_expect ((cond), 1) 511 #else 512 # define __glibc_unlikely(cond) (cond) 513 # define __glibc_likely(cond) (cond) 514 #endif 515 516 #if (!defined _Noreturn \ 517 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \ 518 && !(__GNUC_PREREQ (4,7) \ 519 || (3 < __clang_major__ + (5 <= __clang_minor__)))) 520 # if __GNUC_PREREQ (2,8) 521 # define _Noreturn __attribute__ ((__noreturn__)) 522 # else 523 # define _Noreturn 524 # endif 525 #endif 526 527 #if __GNUC_PREREQ (8, 0) 528 /* Describes a char array whose address can safely be passed as the first 529 argument to strncpy and strncat, as the char array is not necessarily 530 a NUL-terminated string. */ 531 # define __attribute_nonstring__ __attribute__ ((__nonstring__)) 532 #else 533 # define __attribute_nonstring__ 534 #endif 535 536 /* Undefine (also defined in libc-symbols.h). */ 537 #undef __attribute_copy__ 538 #if __GNUC_PREREQ (9, 0) 539 /* Copies attributes from the declaration or type referenced by 540 the argument. */ 541 # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg))) 542 #else 543 # define __attribute_copy__(arg) 544 #endif 545 546 #if (!defined _Static_assert && !defined __cplusplus \ 547 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \ 548 && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \ 549 || defined __STRICT_ANSI__)) 550 # define _Static_assert(expr, diagnostic) \ 551 extern int (*__Static_assert_function (void)) \ 552 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })] 553 #endif 554 555 /* Gnulib avoids including these, as they don't work on non-glibc or 556 older glibc platforms. */ 557 #ifndef __GNULIB_CDEFS 558 # include <bits/wordsize.h> 559 # include <bits/long-double.h> 560 #endif 561 562 #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1 563 # ifdef __REDIRECT 564 565 /* Alias name defined automatically. */ 566 # define __LDBL_REDIR(name, proto) ... unused__ldbl_redir 567 # define __LDBL_REDIR_DECL(name) \ 568 extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128")); 569 570 /* Alias name defined automatically, with leading underscores. */ 571 # define __LDBL_REDIR2_DECL(name) \ 572 extern __typeof (__##name) __##name \ 573 __asm (__ASMNAME ("__" #name "ieee128")); 574 575 /* Alias name defined manually. */ 576 # define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1 577 # define __LDBL_REDIR1_DECL(name, alias) \ 578 extern __typeof (name) name __asm (__ASMNAME (#alias)); 579 580 # define __LDBL_REDIR1_NTH(name, proto, alias) \ 581 __REDIRECT_NTH (name, proto, alias) 582 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 583 __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128) 584 585 /* Unused. */ 586 # define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl 587 # define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth 588 589 # else 590 _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform"); 591 # endif 592 #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH 593 # define __LDBL_COMPAT 1 594 # ifdef __REDIRECT 595 # define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias) 596 # define __LDBL_REDIR(name, proto) \ 597 __LDBL_REDIR1 (name, proto, __nldbl_##name) 598 # define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias) 599 # define __LDBL_REDIR_NTH(name, proto) \ 600 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name) 601 # define __LDBL_REDIR2_DECL(name) \ 602 extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name)); 603 # define __LDBL_REDIR1_DECL(name, alias) \ 604 extern __typeof (name) name __asm (__ASMNAME (#alias)); 605 # define __LDBL_REDIR_DECL(name) \ 606 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name)); 607 # define __REDIRECT_LDBL(name, proto, alias) \ 608 __LDBL_REDIR1 (name, proto, __nldbl_##alias) 609 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 610 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias) 611 # endif 612 #endif 613 #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \ 614 || !defined __REDIRECT 615 # define __LDBL_REDIR1(name, proto, alias) name proto 616 # define __LDBL_REDIR(name, proto) name proto 617 # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW 618 # define __LDBL_REDIR_NTH(name, proto) name proto __THROW 619 # define __LDBL_REDIR2_DECL(name) 620 # define __LDBL_REDIR_DECL(name) 621 # ifdef __REDIRECT 622 # define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias) 623 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 624 __REDIRECT_NTH (name, proto, alias) 625 # endif 626 #endif 627 628 /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is 629 intended for use in preprocessor macros. 630 631 Note: MESSAGE must be a _single_ string; concatenation of string 632 literals is not supported. */ 633 #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5) 634 # define __glibc_macro_warning1(message) _Pragma (#message) 635 # define __glibc_macro_warning(message) \ 636 __glibc_macro_warning1 (GCC warning message) 637 #else 638 # define __glibc_macro_warning(msg) 639 #endif 640 641 /* Generic selection (ISO C11) is a C-only feature, available in GCC 642 since version 4.9. Previous versions do not provide generic 643 selection, even though they might set __STDC_VERSION__ to 201112L, 644 when in -std=c11 mode. Thus, we must check for !defined __GNUC__ 645 when testing __STDC_VERSION__ for generic selection support. 646 On the other hand, Clang also defines __GNUC__, so a clang-specific 647 check is required to enable the use of generic selection. */ 648 #if !defined __cplusplus \ 649 && (__GNUC_PREREQ (4, 9) \ 650 || __glibc_has_extension (c_generic_selections) \ 651 || (!defined __GNUC__ && defined __STDC_VERSION__ \ 652 && __STDC_VERSION__ >= 201112L)) 653 # define __HAVE_GENERIC_SELECTION 1 654 #else 655 # define __HAVE_GENERIC_SELECTION 0 656 #endif 657 658 #if __GNUC_PREREQ (10, 0) 659 /* Designates a 1-based positional argument ref-index of pointer type 660 that can be used to access size-index elements of the pointed-to 661 array according to access mode, or at least one element when 662 size-index is not provided: 663 access (access-mode, <ref-index> [, <size-index>]) */ 664 # define __attr_access(x) __attribute__ ((__access__ x)) 665 /* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may 666 use the access attribute to get object sizes from function definition 667 arguments, so we can't use them on functions we fortify. Drop the object 668 size hints for such functions. */ 669 # if __USE_FORTIFY_LEVEL == 3 670 # define __fortified_attr_access(a, o, s) __attribute__ ((__access__ (a, o))) 671 # else 672 # define __fortified_attr_access(a, o, s) __attr_access ((a, o, s)) 673 # endif 674 # if __GNUC_PREREQ (11, 0) 675 # define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno))) 676 # else 677 # define __attr_access_none(argno) 678 # endif 679 #else 680 # define __fortified_attr_access(a, o, s) 681 # define __attr_access(x) 682 # define __attr_access_none(argno) 683 #endif 684 685 #if __GNUC_PREREQ (11, 0) 686 /* Designates dealloc as a function to call to deallocate objects 687 allocated by the declared function. */ 688 # define __attr_dealloc(dealloc, argno) \ 689 __attribute__ ((__malloc__ (dealloc, argno))) 690 # define __attr_dealloc_free __attr_dealloc (__builtin_free, 1) 691 #else 692 # define __attr_dealloc(dealloc, argno) 693 # define __attr_dealloc_free 694 #endif 695 696 /* Specify that a function such as setjmp or vfork may return 697 twice. */ 698 #if __GNUC_PREREQ (4, 1) 699 # define __attribute_returns_twice__ __attribute__ ((__returns_twice__)) 700 #else 701 # define __attribute_returns_twice__ /* Ignore. */ 702 #endif 703 704 #endif /* sys/cdefs.h */ 705