1 /* Copyright (C) 1992-2021 Free Software Foundation, Inc. 2 This file is part of the GNU C Library. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU General Public 6 License as published by the Free Software Foundation; either 7 version 3 of the License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 General Public License for more details. 13 14 You should have received a copy of the GNU General Public 15 License along with the GNU C Library; if not, see 16 <https://www.gnu.org/licenses/>. */ 17 18 #ifndef _SYS_CDEFS_H 19 #define _SYS_CDEFS_H 1 20 21 /* We are almost always included from features.h. */ 22 #ifndef _FEATURES_H 23 # include <features.h> 24 #endif 25 26 /* The GNU libc does not support any K&R compilers or the traditional mode 27 of ISO C compilers anymore. Check for some of the combinations not 28 supported anymore. */ 29 #if defined __GNUC__ && !defined __STDC__ 30 # error "You need a ISO C conforming compiler to use the glibc headers" 31 #endif 32 33 /* Some user header file might have defined this before. */ 34 #undef __P 35 #undef __PMT 36 37 /* Compilers that lack __has_attribute may object to 38 #if defined __has_attribute && __has_attribute (...) 39 even though they do not need to evaluate the right-hand side of the &&. 40 Similarly for __has_builtin, etc. */ 41 #if (defined __has_attribute \ 42 && (!defined __clang_minor__ \ 43 || 3 < __clang_major__ + (5 <= __clang_minor__))) 44 # define __glibc_has_attribute(attr) __has_attribute (attr) 45 #else 46 # define __glibc_has_attribute(attr) 0 47 #endif 48 #ifdef __has_builtin 49 # define __glibc_has_builtin(name) __has_builtin (name) 50 #else 51 # define __glibc_has_builtin(name) 0 52 #endif 53 #ifdef __has_extension 54 # define __glibc_has_extension(ext) __has_extension (ext) 55 #else 56 # define __glibc_has_extension(ext) 0 57 #endif 58 59 #if defined __GNUC__ || defined __clang__ 60 61 /* All functions, except those with callbacks or those that 62 synchronize memory, are leaf functions. */ 63 # if __GNUC_PREREQ (4, 6) && !defined _LIBC 64 # define __LEAF , __leaf__ 65 # define __LEAF_ATTR __attribute__ ((__leaf__)) 66 # else 67 # define __LEAF 68 # define __LEAF_ATTR 69 # endif 70 71 /* GCC can always grok prototypes. For C++ programs we add throw() 72 to help it optimize the function calls. But this only works with 73 gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions 74 as non-throwing using a function attribute since programs can use 75 the -fexceptions options for C code as well. */ 76 # if !defined __cplusplus \ 77 && (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__)) 78 # define __THROW __attribute__ ((__nothrow__ __LEAF)) 79 # define __THROWNL __attribute__ ((__nothrow__)) 80 # define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct 81 # define __NTHNL(fct) __attribute__ ((__nothrow__)) fct 82 # else 83 # if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major >= 4) 84 # if __cplusplus >= 201103L 85 # define __THROW noexcept (true) 86 # else 87 # define __THROW throw () 88 # endif 89 # define __THROWNL __THROW 90 # define __NTH(fct) __LEAF_ATTR fct __THROW 91 # define __NTHNL(fct) fct __THROW 92 # else 93 # define __THROW 94 # define __THROWNL 95 # define __NTH(fct) fct 96 # define __NTHNL(fct) fct 97 # endif 98 # endif 99 100 #else /* Not GCC or clang. */ 101 102 # if (defined __cplusplus \ 103 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)) 104 # define __inline inline 105 # else 106 # define __inline /* No inline functions. */ 107 # endif 108 109 # define __THROW 110 # define __THROWNL 111 # define __NTH(fct) fct 112 113 #endif /* GCC || clang. */ 114 115 /* These two macros are not used in glibc anymore. They are kept here 116 only because some other projects expect the macros to be defined. */ 117 #define __P(args) args 118 #define __PMT(args) args 119 120 /* For these things, GCC behaves the ANSI way normally, 121 and the non-ANSI way under -traditional. */ 122 123 #define __CONCAT(x,y) x ## y 124 #define __STRING(x) #x 125 126 /* This is not a typedef so `const __ptr_t' does the right thing. */ 127 #define __ptr_t void * 128 129 130 /* C++ needs to know that types and declarations are C, not C++. */ 131 #ifdef __cplusplus 132 # define __BEGIN_DECLS extern "C" { 133 # define __END_DECLS } 134 #else 135 # define __BEGIN_DECLS 136 # define __END_DECLS 137 #endif 138 139 140 /* Fortify support. */ 141 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1) 142 #define __bos0(ptr) __builtin_object_size (ptr, 0) 143 144 /* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */ 145 #if __USE_FORTIFY_LEVEL == 3 && __glibc_clang_prereq (9, 0) 146 # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0) 147 # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1) 148 #else 149 # define __glibc_objsize0(__o) __bos0 (__o) 150 # define __glibc_objsize(__o) __bos (__o) 151 #endif 152 153 #if __GNUC_PREREQ (4,3) 154 # define __warnattr(msg) __attribute__((__warning__ (msg))) 155 # define __errordecl(name, msg) \ 156 extern void name (void) __attribute__((__error__ (msg))) 157 #else 158 # define __warnattr(msg) 159 # define __errordecl(name, msg) extern void name (void) 160 #endif 161 162 /* Support for flexible arrays. 163 Headers that should use flexible arrays only if they're "real" 164 (e.g. only if they won't affect sizeof()) should test 165 #if __glibc_c99_flexarr_available. */ 166 #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc 167 # define __flexarr [] 168 # define __glibc_c99_flexarr_available 1 169 #elif __GNUC_PREREQ (2,97) || defined __clang__ 170 /* GCC 2.97 and clang support C99 flexible array members as an extension, 171 even when in C89 mode or compiling C++ (any version). */ 172 # define __flexarr [] 173 # define __glibc_c99_flexarr_available 1 174 #elif defined __GNUC__ 175 /* Pre-2.97 GCC did not support C99 flexible arrays but did have 176 an equivalent extension with slightly different notation. */ 177 # define __flexarr [0] 178 # define __glibc_c99_flexarr_available 1 179 #else 180 /* Some other non-C99 compiler. Approximate with [1]. */ 181 # define __flexarr [1] 182 # define __glibc_c99_flexarr_available 0 183 #endif 184 185 186 /* __asm__ ("xyz") is used throughout the headers to rename functions 187 at the assembly language level. This is wrapped by the __REDIRECT 188 macro, in order to support compilers that can do this some other 189 way. When compilers don't support asm-names at all, we have to do 190 preprocessor tricks instead (which don't have exactly the right 191 semantics, but it's the best we can do). 192 193 Example: 194 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */ 195 196 #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4) 197 198 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias)) 199 # ifdef __cplusplus 200 # define __REDIRECT_NTH(name, proto, alias) \ 201 name proto __THROW __asm__ (__ASMNAME (#alias)) 202 # define __REDIRECT_NTHNL(name, proto, alias) \ 203 name proto __THROWNL __asm__ (__ASMNAME (#alias)) 204 # else 205 # define __REDIRECT_NTH(name, proto, alias) \ 206 name proto __asm__ (__ASMNAME (#alias)) __THROW 207 # define __REDIRECT_NTHNL(name, proto, alias) \ 208 name proto __asm__ (__ASMNAME (#alias)) __THROWNL 209 # endif 210 # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname) 211 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname 212 213 /* 214 #elif __SOME_OTHER_COMPILER__ 215 216 # define __REDIRECT(name, proto, alias) name proto; \ 217 _Pragma("let " #name " = " #alias) 218 */ 219 #endif 220 221 /* GCC and clang have various useful declarations that can be made with 222 the '__attribute__' syntax. All of the ways we use this do fine if 223 they are omitted for compilers that don't understand it. */ 224 #if !(defined __GNUC__ || defined __clang__) 225 # define __attribute__(xyz) /* Ignore */ 226 #endif 227 228 /* At some point during the gcc 2.96 development the `malloc' attribute 229 for functions was introduced. We don't want to use it unconditionally 230 (although this would be possible) since it generates warnings. */ 231 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__) 232 # define __attribute_malloc__ __attribute__ ((__malloc__)) 233 #else 234 # define __attribute_malloc__ /* Ignore */ 235 #endif 236 237 /* Tell the compiler which arguments to an allocation function 238 indicate the size of the allocation. */ 239 #if __GNUC_PREREQ (4, 3) 240 # define __attribute_alloc_size__(params) \ 241 __attribute__ ((__alloc_size__ params)) 242 #else 243 # define __attribute_alloc_size__(params) /* Ignore. */ 244 #endif 245 246 /* At some point during the gcc 2.96 development the `pure' attribute 247 for functions was introduced. We don't want to use it unconditionally 248 (although this would be possible) since it generates warnings. */ 249 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__) 250 # define __attribute_pure__ __attribute__ ((__pure__)) 251 #else 252 # define __attribute_pure__ /* Ignore */ 253 #endif 254 255 /* This declaration tells the compiler that the value is constant. */ 256 #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__) 257 # define __attribute_const__ __attribute__ ((__const__)) 258 #else 259 # define __attribute_const__ /* Ignore */ 260 #endif 261 262 #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__) 263 # define __attribute_maybe_unused__ __attribute__ ((__unused__)) 264 /* Once the next version of the C standard comes out, we can 265 do something like the following here: 266 #elif defined __STDC_VERSION__ && 202???L <= __STDC_VERSION__ 267 # define __attribute_maybe_unused__ [[__maybe_unused__]] */ 268 #else 269 # define __attribute_maybe_unused__ /* Ignore */ 270 #endif 271 272 /* At some point during the gcc 3.1 development the `used' attribute 273 for functions was introduced. We don't want to use it unconditionally 274 (although this would be possible) since it generates warnings. */ 275 #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__) 276 # define __attribute_used__ __attribute__ ((__used__)) 277 # define __attribute_noinline__ __attribute__ ((__noinline__)) 278 #else 279 # define __attribute_used__ __attribute__ ((__unused__)) 280 # define __attribute_noinline__ /* Ignore */ 281 #endif 282 283 /* Since version 3.2, gcc allows marking deprecated functions. */ 284 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__) 285 # define __attribute_deprecated__ __attribute__ ((__deprecated__)) 286 #else 287 # define __attribute_deprecated__ /* Ignore */ 288 #endif 289 290 /* Since version 4.5, gcc also allows one to specify the message printed 291 when a deprecated function is used. clang claims to be gcc 4.2, but 292 may also support this feature. */ 293 #if __GNUC_PREREQ (4,5) \ 294 || __glibc_has_extension (__attribute_deprecated_with_message__) 295 # define __attribute_deprecated_msg__(msg) \ 296 __attribute__ ((__deprecated__ (msg))) 297 #else 298 # define __attribute_deprecated_msg__(msg) __attribute_deprecated__ 299 #endif 300 301 /* At some point during the gcc 2.8 development the `format_arg' attribute 302 for functions was introduced. We don't want to use it unconditionally 303 (although this would be possible) since it generates warnings. 304 If several `format_arg' attributes are given for the same function, in 305 gcc-3.0 and older, all but the last one are ignored. In newer gccs, 306 all designated arguments are considered. */ 307 #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__) 308 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x))) 309 #else 310 # define __attribute_format_arg__(x) /* Ignore */ 311 #endif 312 313 /* At some point during the gcc 2.97 development the `strfmon' format 314 attribute for functions was introduced. We don't want to use it 315 unconditionally (although this would be possible) since it 316 generates warnings. */ 317 #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__) 318 # define __attribute_format_strfmon__(a,b) \ 319 __attribute__ ((__format__ (__strfmon__, a, b))) 320 #else 321 # define __attribute_format_strfmon__(a,b) /* Ignore */ 322 #endif 323 324 /* 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 338 339 /* If fortification mode, we warn about unused results of certain 340 function calls which can lead to problems. */ 341 #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__) 342 # define __attribute_warn_unused_result__ \ 343 __attribute__ ((__warn_unused_result__)) 344 # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0 345 # define __wur __attribute_warn_unused_result__ 346 # endif 347 #else 348 # define __attribute_warn_unused_result__ /* empty */ 349 #endif 350 #ifndef __wur 351 # define __wur /* Ignore */ 352 #endif 353 354 /* Forces a function to be always inlined. */ 355 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__) 356 /* The Linux kernel defines __always_inline in stddef.h (283d7573), and 357 it conflicts with this definition. Therefore undefine it first to 358 allow either header to be included first. */ 359 # undef __always_inline 360 # define __always_inline __inline __attribute__ ((__always_inline__)) 361 #else 362 # undef __always_inline 363 # define __always_inline __inline 364 #endif 365 366 /* Associate error messages with the source location of the call site rather 367 than with the source location inside the function. */ 368 #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__) 369 # define __attribute_artificial__ __attribute__ ((__artificial__)) 370 #else 371 # define __attribute_artificial__ /* Ignore */ 372 #endif 373 374 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99 375 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__ 376 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions 377 older than 4.3 may define these macros and still not guarantee GNU inlining 378 semantics. 379 380 clang++ identifies itself as gcc-4.2, but has support for GNU inlining 381 semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and 382 __GNUC_GNU_INLINE__ macro definitions. */ 383 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \ 384 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \ 385 || defined __GNUC_GNU_INLINE__))) 386 # if defined __GNUC_STDC_INLINE__ || defined __cplusplus 387 # define __extern_inline extern __inline __attribute__ ((__gnu_inline__)) 388 # define __extern_always_inline \ 389 extern __always_inline __attribute__ ((__gnu_inline__)) 390 # else 391 # define __extern_inline extern __inline 392 # define __extern_always_inline extern __always_inline 393 # endif 394 #endif 395 396 #ifdef __extern_always_inline 397 # define __fortify_function __extern_always_inline __attribute_artificial__ 398 #endif 399 400 /* GCC 4.3 and above allow passing all anonymous arguments of an 401 __extern_always_inline function to some other vararg function. */ 402 #if __GNUC_PREREQ (4,3) 403 # define __va_arg_pack() __builtin_va_arg_pack () 404 # define __va_arg_pack_len() __builtin_va_arg_pack_len () 405 #endif 406 407 /* It is possible to compile containing GCC extensions even if GCC is 408 run in pedantic mode if the uses are carefully marked using the 409 `__extension__' keyword. But this is not generally available before 410 version 2.8. */ 411 #if !(__GNUC_PREREQ (2,8) || defined __clang__) 412 # define __extension__ /* Ignore */ 413 #endif 414 415 /* __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 425 426 /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is 427 array_name[restrict] 428 GCC 3.1 and clang support this. 429 This syntax is not usable in C++ mode. */ 430 #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus 431 # define __restrict_arr __restrict 432 #else 433 # ifdef __GNUC__ 434 # define __restrict_arr /* Not supported in old GCC. */ 435 # else 436 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 437 # define __restrict_arr restrict 438 # else 439 /* Some other non-C99 compiler. */ 440 # define __restrict_arr /* Not supported. */ 441 # endif 442 # endif 443 #endif 444 445 #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect) 446 # define __glibc_unlikely(cond) __builtin_expect ((cond), 0) 447 # define __glibc_likely(cond) __builtin_expect ((cond), 1) 448 #else 449 # define __glibc_unlikely(cond) (cond) 450 # define __glibc_likely(cond) (cond) 451 #endif 452 453 #if (!defined _Noreturn \ 454 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \ 455 && !(__GNUC_PREREQ (4,7) \ 456 || (3 < __clang_major__ + (5 <= __clang_minor__)))) 457 # if __GNUC_PREREQ (2,8) 458 # define _Noreturn __attribute__ ((__noreturn__)) 459 # else 460 # define _Noreturn 461 # endif 462 #endif 463 464 #if __GNUC_PREREQ (8, 0) 465 /* Describes a char array whose address can safely be passed as the first 466 argument to strncpy and strncat, as the char array is not necessarily 467 a NUL-terminated string. */ 468 # define __attribute_nonstring__ __attribute__ ((__nonstring__)) 469 #else 470 # define __attribute_nonstring__ 471 #endif 472 473 /* Undefine (also defined in libc-symbols.h). */ 474 #undef __attribute_copy__ 475 #if __GNUC_PREREQ (9, 0) 476 /* Copies attributes from the declaration or type referenced by 477 the argument. */ 478 # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg))) 479 #else 480 # define __attribute_copy__(arg) 481 #endif 482 483 #if (!defined _Static_assert && !defined __cplusplus \ 484 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \ 485 && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \ 486 || defined __STRICT_ANSI__)) 487 # define _Static_assert(expr, diagnostic) \ 488 extern int (*__Static_assert_function (void)) \ 489 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })] 490 #endif 491 492 /* Gnulib avoids including these, as they don't work on non-glibc or 493 older glibc platforms. */ 494 #ifndef __GNULIB_CDEFS 495 # include <bits/wordsize.h> 496 # include <bits/long-double.h> 497 #endif 498 499 #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1 500 # ifdef __REDIRECT 501 502 /* Alias name defined automatically. */ 503 # define __LDBL_REDIR(name, proto) ... unused__ldbl_redir 504 # define __LDBL_REDIR_DECL(name) \ 505 extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128")); 506 507 /* Alias name defined automatically, with leading underscores. */ 508 # define __LDBL_REDIR2_DECL(name) \ 509 extern __typeof (__##name) __##name \ 510 __asm (__ASMNAME ("__" #name "ieee128")); 511 512 /* Alias name defined manually. */ 513 # define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1 514 # define __LDBL_REDIR1_DECL(name, alias) \ 515 extern __typeof (name) name __asm (__ASMNAME (#alias)); 516 517 # define __LDBL_REDIR1_NTH(name, proto, alias) \ 518 __REDIRECT_NTH (name, proto, alias) 519 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 520 __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128) 521 522 /* Unused. */ 523 # define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl 524 # define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth 525 526 # else 527 _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform"); 528 # endif 529 #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH 530 # define __LDBL_COMPAT 1 531 # ifdef __REDIRECT 532 # define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias) 533 # define __LDBL_REDIR(name, proto) \ 534 __LDBL_REDIR1 (name, proto, __nldbl_##name) 535 # define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias) 536 # define __LDBL_REDIR_NTH(name, proto) \ 537 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name) 538 # define __LDBL_REDIR2_DECL(name) \ 539 extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name)); 540 # define __LDBL_REDIR1_DECL(name, alias) \ 541 extern __typeof (name) name __asm (__ASMNAME (#alias)); 542 # define __LDBL_REDIR_DECL(name) \ 543 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name)); 544 # define __REDIRECT_LDBL(name, proto, alias) \ 545 __LDBL_REDIR1 (name, proto, __nldbl_##alias) 546 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 547 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias) 548 # endif 549 #endif 550 #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \ 551 || !defined __REDIRECT 552 # define __LDBL_REDIR1(name, proto, alias) name proto 553 # define __LDBL_REDIR(name, proto) name proto 554 # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW 555 # define __LDBL_REDIR_NTH(name, proto) name proto __THROW 556 # define __LDBL_REDIR2_DECL(name) 557 # define __LDBL_REDIR_DECL(name) 558 # ifdef __REDIRECT 559 # define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias) 560 # define __REDIRECT_NTH_LDBL(name, proto, alias) \ 561 __REDIRECT_NTH (name, proto, alias) 562 # endif 563 #endif 564 565 /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is 566 intended for use in preprocessor macros. 567 568 Note: MESSAGE must be a _single_ string; concatenation of string 569 literals is not supported. */ 570 #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5) 571 # define __glibc_macro_warning1(message) _Pragma (#message) 572 # define __glibc_macro_warning(message) \ 573 __glibc_macro_warning1 (GCC warning message) 574 #else 575 # define __glibc_macro_warning(msg) 576 #endif 577 578 /* Generic selection (ISO C11) is a C-only feature, available in GCC 579 since version 4.9. Previous versions do not provide generic 580 selection, even though they might set __STDC_VERSION__ to 201112L, 581 when in -std=c11 mode. Thus, we must check for !defined __GNUC__ 582 when testing __STDC_VERSION__ for generic selection support. 583 On the other hand, Clang also defines __GNUC__, so a clang-specific 584 check is required to enable the use of generic selection. */ 585 #if !defined __cplusplus \ 586 && (__GNUC_PREREQ (4, 9) \ 587 || __glibc_has_extension (c_generic_selections) \ 588 || (!defined __GNUC__ && defined __STDC_VERSION__ \ 589 && __STDC_VERSION__ >= 201112L)) 590 # define __HAVE_GENERIC_SELECTION 1 591 #else 592 # define __HAVE_GENERIC_SELECTION 0 593 #endif 594 595 #if __GNUC_PREREQ (10, 0) 596 /* Designates a 1-based positional argument ref-index of pointer type 597 that can be used to access size-index elements of the pointed-to 598 array according to access mode, or at least one element when 599 size-index is not provided: 600 access (access-mode, <ref-index> [, <size-index>]) */ 601 #define __attr_access(x) __attribute__ ((__access__ x)) 602 #else 603 # define __attr_access(x) 604 #endif 605 606 /* Specify that a function such as setjmp or vfork may return 607 twice. */ 608 #if __GNUC_PREREQ (4, 1) 609 # define __attribute_returns_twice__ __attribute__ ((__returns_twice__)) 610 #else 611 # define __attribute_returns_twice__ /* Ignore. */ 612 #endif 613 614 #endif /* sys/cdefs.h */ 615