1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Berkeley Software Design, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef _SYS_CDEFS_H_ 36 #define _SYS_CDEFS_H_ 37 38 #if defined(_KERNEL) && defined(_STANDALONE) 39 #error "_KERNEL and _STANDALONE are mutually exclusive" 40 #endif 41 42 /* 43 * Provide clang-compatible testing macros. All supported versions of gcc (10+) 44 * provide all of these except has_feature and has_extension which are new in 45 * gcc 14. Keep the older ifndefs, though, for non-gcc compilers that may lack 46 * them like tcc and pcc. 47 */ 48 #ifndef __has_attribute 49 #define __has_attribute(x) 0 50 #endif 51 #ifndef __has_extension 52 #define __has_extension __has_feature 53 #endif 54 #ifndef __has_feature 55 #define __has_feature(x) 0 56 #endif 57 #ifndef __has_include 58 #define __has_include(x) 0 59 #endif 60 #ifndef __has_builtin 61 #define __has_builtin(x) 0 62 #endif 63 64 #if defined(__cplusplus) 65 #define __BEGIN_DECLS extern "C" { 66 #define __END_DECLS } 67 #else 68 #define __BEGIN_DECLS 69 #define __END_DECLS 70 #endif 71 72 /* 73 * This code has been put in place to help reduce the addition of 74 * compiler specific defines in FreeBSD code. It helps to aid in 75 * having a compiler-agnostic source tree. 76 */ 77 78 /* 79 * Macro to test if we're using a specific version of gcc or later. 80 */ 81 #if defined(__GNUC__) 82 #define __GNUC_PREREQ__(ma, mi) \ 83 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi)) 84 #else 85 #define __GNUC_PREREQ__(ma, mi) 0 86 #endif 87 88 #if defined(__GNUC__) 89 90 /* 91 * Compiler memory barriers, specific to gcc and clang. 92 */ 93 #define __compiler_membar() __asm __volatile(" " : : : "memory") 94 95 #define __CC_SUPPORTS___INLINE 1 96 #define __CC_SUPPORTS_SYMVER 1 97 98 #endif /* __GNUC__ */ 99 100 /* 101 * TinyC pretends to be gcc 9.3. This is generally good enough to support 102 * everything FreeBSD... except for the .symver assembler directive. 103 */ 104 #ifdef __TINYC__ 105 #undef __CC_SUPPORTS_SYMVER 106 #endif 107 108 /* 109 * The __CONCAT macro is used to concatenate parts of symbol names, e.g. 110 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. 111 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI 112 * mode -- there must be no spaces between its arguments, and for nested 113 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also 114 * concatenate double-quoted strings produced by the __STRING macro, but 115 * this only works with ANSI C. 116 * 117 * __XSTRING is like __STRING, but it expands any macros in its argument 118 * first. It is only available with ANSI C. 119 */ 120 #if defined(__STDC__) || defined(__cplusplus) 121 #define __P(protos) protos /* full-blown ANSI C */ 122 #define __CONCAT1(x,y) x ## y 123 #define __CONCAT(x,y) __CONCAT1(x,y) 124 #define __STRING(x) #x /* stringify without expanding x */ 125 #define __XSTRING(x) __STRING(x) /* expand x, then stringify */ 126 127 #define __volatile volatile 128 #if defined(__cplusplus) 129 #define __inline inline /* convert to C++ keyword */ 130 #else 131 #if !(defined(__CC_SUPPORTS___INLINE)) 132 #define __inline /* delete GCC keyword */ 133 #endif /* ! __CC_SUPPORTS___INLINE */ 134 #endif /* !__cplusplus */ 135 136 #else /* !(__STDC__ || __cplusplus) */ 137 #define __P(protos) () /* traditional C preprocessor */ 138 #define __CONCAT(x,y) x/**/y 139 #define __STRING(x) "x" 140 #if !defined(__CC_SUPPORTS___INLINE) 141 /* Just delete these in a K&R environment */ 142 #define __inline 143 #define __volatile 144 #endif /* !__CC_SUPPORTS___INLINE */ 145 #endif /* !(__STDC__ || __cplusplus) */ 146 147 /* 148 * Compiler-dependent macros to help declare dead (non-returning) and pure (no 149 * side effects) functions, and unused variables. These attributes are supported 150 * by all current compilers, even pcc. 151 */ 152 #define __weak_symbol __attribute__((__weak__)) 153 #define __dead2 __attribute__((__noreturn__)) 154 #define __pure2 __attribute__((__const__)) 155 #define __unused __attribute__((__unused__)) 156 #define __used __attribute__((__used__)) 157 #define __deprecated __attribute__((__deprecated__)) 158 #define __packed __attribute__((__packed__)) 159 #define __aligned(x) __attribute__((__aligned__(x))) 160 #define __section(x) __attribute__((__section__(x))) 161 #define __writeonly __unused 162 #define __alloc_size(x) __attribute__((__alloc_size__(x))) 163 #define __alloc_size2(n, x) __attribute__((__alloc_size__(n, x))) 164 #define __alloc_align(x) __attribute__((__alloc_align__(x))) 165 166 /* 167 * Keywords added in C11. 168 */ 169 170 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L 171 172 #if !__has_extension(c_alignas) 173 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 174 __has_extension(cxx_alignas) 175 #define _Alignas(x) alignas(x) 176 #else 177 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */ 178 #define _Alignas(x) __aligned(x) 179 #endif 180 #endif 181 182 #if defined(__cplusplus) && __cplusplus >= 201103L 183 #define _Alignof(x) alignof(x) 184 #else 185 #define _Alignof(x) __alignof(x) 186 #endif 187 188 #if defined(__cplusplus) && __cplusplus >= 201103L 189 #define _Noreturn [[noreturn]] 190 #else 191 #define _Noreturn __dead2 192 #endif 193 194 #if !__has_extension(c_static_assert) 195 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 196 __has_extension(cxx_static_assert) 197 #define _Static_assert(x, y) static_assert(x, y) 198 #endif 199 #endif 200 201 #if !__has_extension(c_thread_local) 202 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 203 __has_extension(cxx_thread_local) 204 #define _Thread_local thread_local 205 #else 206 #define _Thread_local __thread 207 #endif 208 #endif 209 210 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */ 211 212 /* 213 * Emulation of C11 _Generic(). Unlike the previously defined C11 214 * keywords, it is not possible to implement this using exactly the same 215 * syntax. Therefore implement something similar under the name 216 * __generic(). Unlike _Generic(), this macro can only distinguish 217 * between a single type, so it requires nested invocations to 218 * distinguish multiple cases. 219 * 220 * Note that the comma operator is used to force expr to decay in 221 * order to match _Generic(). 222 */ 223 224 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \ 225 __has_extension(c_generic_selections) 226 #define __generic(expr, t, yes, no) \ 227 _Generic(expr, t: yes, default: no) 228 #elif !defined(__cplusplus) 229 #define __generic(expr, t, yes, no) \ 230 __builtin_choose_expr(__builtin_types_compatible_p( \ 231 __typeof(((void)0, (expr))), t), yes, no) 232 #endif 233 234 /* 235 * C99 Static array indices in function parameter declarations. Syntax such as: 236 * void bar(int myArray[static 10]); 237 * is allowed in C99 but not in C++. Define __min_size appropriately so 238 * headers using it can be compiled in either language. Use like this: 239 * void bar(int myArray[__min_size(10)]); 240 */ 241 #if !defined(__cplusplus) && \ 242 (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901)) 243 #define __min_size(x) static (x) 244 #else 245 #define __min_size(x) (x) 246 #endif 247 248 #define __malloc_like __attribute__((__malloc__)) 249 #define __pure __attribute__((__pure__)) 250 251 #define __always_inline __inline __attribute__((__always_inline__)) 252 #define __noinline __attribute__ ((__noinline__)) 253 #define __fastcall __attribute__((__fastcall__)) 254 #define __result_use_check __attribute__((__warn_unused_result__)) 255 #ifdef __clang__ 256 /* 257 * clang and gcc have different semantics for __warn_unused_result__: the latter 258 * does not permit the use of a void cast to suppress the warning. Use 259 * __result_use_or_ignore_check in places where a void cast is acceptable. 260 * This can be implemented by [[nodiscard]] from C23. 261 */ 262 #define __result_use_or_ignore_check __result_use_check 263 #else 264 #define __result_use_or_ignore_check 265 #endif /* !__clang__ */ 266 267 #define __returns_twice __attribute__((__returns_twice__)) 268 269 #define __unreachable() __builtin_unreachable() 270 271 #if !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901 272 #define __LONG_LONG_SUPPORTED 273 #endif 274 275 /* C++11 exposes a load of C99 stuff */ 276 #if defined(__cplusplus) && __cplusplus >= 201103L 277 #define __LONG_LONG_SUPPORTED 278 #ifndef __STDC_LIMIT_MACROS 279 #define __STDC_LIMIT_MACROS 280 #endif 281 #ifndef __STDC_CONSTANT_MACROS 282 #define __STDC_CONSTANT_MACROS 283 #endif 284 #endif 285 286 /* 287 * noexcept keyword added in C++11. 288 */ 289 #if defined(__cplusplus) && __cplusplus >= 201103L 290 #define __noexcept noexcept 291 #define __noexcept_if(__c) noexcept(__c) 292 #else 293 #define __noexcept 294 #define __noexcept_if(__c) 295 #endif 296 297 /* 298 * We use `__restrict' as a way to define the `restrict' type qualifier 299 * without disturbing older software that is unaware of C99 keywords. 300 * GCC also provides `__restrict' as an extension to support C99-style 301 * restricted pointers in other language modes. 302 */ 303 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901 304 #define __restrict restrict 305 #endif 306 307 /* 308 * All modern compilers have explicit branch prediction so that the CPU back-end 309 * can hint to the processor and also so that code blocks can be reordered such 310 * that the predicted path sees a more linear flow, thus improving cache 311 * behavior, etc. Use sparingly, except in performance critical code where 312 * they make things measurably faster. 313 */ 314 #define __predict_true(exp) __builtin_expect((exp), 1) 315 #define __predict_false(exp) __builtin_expect((exp), 0) 316 317 #define __null_sentinel __attribute__((__sentinel__)) 318 #define __exported __attribute__((__visibility__("default"))) 319 #define __hidden __attribute__((__visibility__("hidden"))) 320 321 /* 322 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h> 323 * require it. 324 */ 325 #define __offsetof(type, field) __builtin_offsetof(type, field) 326 #define __rangeof(type, start, end) \ 327 (__offsetof(type, end) - __offsetof(type, start)) 328 329 /* 330 * Given the pointer x to the member m of the struct s, return 331 * a pointer to the containing structure. When using GCC, we first 332 * assign pointer x to a local variable, to check that its type is 333 * compatible with member m. 334 */ 335 #define __containerof(x, s, m) ({ \ 336 const volatile __typeof(((s *)0)->m) *__x = (x); \ 337 __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\ 338 }) 339 340 /* 341 * Compiler-dependent macros to declare that functions take printf-like 342 * or scanf-like arguments. 343 */ 344 #define __printflike(fmtarg, firstvararg) \ 345 __attribute__((__format__ (__printf__, fmtarg, firstvararg))) 346 #define __scanflike(fmtarg, firstvararg) \ 347 __attribute__((__format__ (__scanf__, fmtarg, firstvararg))) 348 #define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg))) 349 #define __strfmonlike(fmtarg, firstvararg) \ 350 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg))) 351 #define __strftimelike(fmtarg, firstvararg) \ 352 __attribute__((__format__ (__strftime__, fmtarg, firstvararg))) 353 354 /* 355 * Like __printflike, but allows fmtarg to be NULL. FreeBSD invented 'printf0' 356 * for this because older versions of gcc issued warnings for NULL first args. 357 * Clang has always had printf and printf0 as aliases. gcc 11.0 now follows 358 * clang. So now this is an alias for __printflike, or nothing. In the future 359 * _Nullable or _Nonnull will replace this. 360 * XXX Except that doesn't work, so for now revert to printf0 for clang and 361 * the FreeBSD gcc until I can work this out. 362 */ 363 #if defined(__clang__) || (defined(__GNUC__) && defined (__FreeBSD_cc_version)) 364 #define __printf0like(fmtarg, firstvararg) \ 365 __attribute__((__format__ (__printf0__, fmtarg, firstvararg))) 366 #else 367 #define __printf0like(fmtarg, firstvararg) 368 #endif 369 370 #define __strong_reference(sym,aliassym) \ 371 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym))) 372 #ifdef __STDC__ 373 #define __weak_reference(sym,alias) \ 374 __asm__(".weak " #alias); \ 375 __asm__(".equ " #alias ", " #sym) 376 #define __warn_references(sym,msg) \ 377 __asm__(".section .gnu.warning." #sym); \ 378 __asm__(".asciz \"" msg "\""); \ 379 __asm__(".previous") 380 #ifdef __CC_SUPPORTS_SYMVER 381 #define __sym_compat(sym,impl,verid) \ 382 __asm__(".symver " #impl ", " #sym "@" #verid) 383 #define __sym_default(sym,impl,verid) \ 384 __asm__(".symver " #impl ", " #sym "@@@" #verid) 385 #endif 386 #else 387 #define __weak_reference(sym,alias) \ 388 __asm__(".weak alias"); \ 389 __asm__(".equ alias, sym") 390 #define __warn_references(sym,msg) \ 391 __asm__(".section .gnu.warning.sym"); \ 392 __asm__(".asciz \"msg\""); \ 393 __asm__(".previous") 394 #ifdef __CC_SUPPORTS_SYMVER 395 #define __sym_compat(sym,impl,verid) \ 396 __asm__(".symver impl, sym@verid") 397 #define __sym_default(impl,sym,verid) \ 398 __asm__(".symver impl, sym@@@verid") 399 #endif 400 #endif /* __STDC__ */ 401 402 #define __GLOBL(sym) __asm__(".globl " __XSTRING(sym)) 403 #define __WEAK(sym) __asm__(".weak " __XSTRING(sym)) 404 405 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"") 406 407 /* 408 * Embed the rcs id of a source file in the resulting library. Note that in 409 * more recent ELF binutils, we use .ident allowing the ID to be stripped. 410 * Usage: 411 */ 412 #ifndef __FBSDID 413 #if !defined(STRIP_FBSDID) 414 #define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s) 415 #else 416 #define __FBSDID(s) struct __hack 417 #endif 418 #endif 419 420 #ifndef __RCSID 421 #ifndef NO__RCSID 422 #define __RCSID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s) 423 #else 424 #define __RCSID(s) struct __hack 425 #endif 426 #endif 427 428 #ifndef __RCSID_SOURCE 429 #ifndef NO__RCSID_SOURCE 430 #define __RCSID_SOURCE(s) __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s) 431 #else 432 #define __RCSID_SOURCE(s) struct __hack 433 #endif 434 #endif 435 436 #ifndef __SCCSID 437 #ifndef NO__SCCSID 438 #define __SCCSID(s) __IDSTRING(__CONCAT(__sccsid_,__LINE__),s) 439 #else 440 #define __SCCSID(s) struct __hack 441 #endif 442 #endif 443 444 #ifndef __COPYRIGHT 445 #ifndef NO__COPYRIGHT 446 #define __COPYRIGHT(s) __IDSTRING(__CONCAT(__copyright_,__LINE__),s) 447 #else 448 #define __COPYRIGHT(s) struct __hack 449 #endif 450 #endif 451 452 #ifndef __DECONST 453 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var)) 454 #endif 455 456 #ifndef __DEVOLATILE 457 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var)) 458 #endif 459 460 #ifndef __DEQUALIFY 461 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var)) 462 #endif 463 464 #if !defined(_STANDALONE) && !defined(_KERNEL) 465 #define __RENAME(x) __asm(__STRING(x)) 466 #else /* _STANDALONE || _KERNEL */ 467 #define __RENAME(x) no renaming in kernel/standalone environment 468 #endif 469 470 /*- 471 * The following definitions are an extension of the behavior originally 472 * implemented in <sys/_posix.h>, but with a different level of granularity. 473 * POSIX.1 requires that the macros we test be defined before any standard 474 * header file is included. 475 * 476 * Here's a quick run-down of the versions (and some informal names) 477 * defined(_POSIX_SOURCE) 1003.1-1988 478 * encoded as 198808 below 479 * _POSIX_C_SOURCE == 1 1003.1-1990 480 * encoded as 199009 below 481 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option 482 * encoded as 199209 below 483 * _POSIX_C_SOURCE == 199309 1003.1b-1993 484 * (1003.1 Issue 4, Single Unix Spec v1, Unix 93) 485 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995, 486 * and the omnibus ISO/IEC 9945-1: 1996 487 * (1003.1 Issue 5, Single Unix Spec v2, Unix 95) 488 * _POSIX_C_SOURCE == 200112 1003.1-2001 (1003.1 Issue 6, Unix 03) 489 * with _XOPEN_SOURCE=600 490 * _POSIX_C_SOURCE == 200809 1003.1-2008 (1003.1 Issue 7) 491 * IEEE Std 1003.1-2017 (Rev of 1003.1-2008) is 492 * 1003.1-2008 with two TCs applied and 493 * _XOPEN_SOURCE=700 494 * _POSIX_C_SOURCE == 202405 1003.1-2004 (1003.1 Issue 8), IEEE Std 1003.1-2024 495 * with _XOPEN_SOURCE=800 496 * 497 * In addition, the X/Open Portability Guide, which is now the Single UNIX 498 * Specification, defines a feature-test macro which indicates the version of 499 * that specification, and which subsumes _POSIX_C_SOURCE. 500 * 501 * Our macros begin with two underscores to avoid namespace screwage. 502 */ 503 504 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */ 505 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1 506 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */ 507 #define _POSIX_C_SOURCE 199009 508 #endif 509 510 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */ 511 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2 512 #undef _POSIX_C_SOURCE 513 #define _POSIX_C_SOURCE 199209 514 #endif 515 516 /* 517 * Deal with various X/Open Portability Guides and Single UNIX Spec. We use the 518 * '- 0' construct so software that defines _XOPEN_SOURCE to nothing doesn't 519 * cause errors. X/Open CAE Specification, August 1994, System Interfaces and 520 * Headers, Issue 4, Version 2 section 2.2 states an empty definition means the 521 * same thing as _POSIX_C_SOURCE == 2. This broadly mirrors "System V Interface 522 * Definition, Fourth Edition", but earlier editions suggest some ambiguity. 523 * However, FreeBSD has histoically implemented this as a NOP, so we just 524 * document what it should be for now to not break ports gratuitously. 525 */ 526 #ifdef _XOPEN_SOURCE 527 #if _XOPEN_SOURCE - 0 >= 800 528 #define __XSI_VISIBLE 800 529 #undef _POSIX_C_SOURCE 530 #define _POSIX_C_SOURCE 202405 531 #elif _XOPEN_SOURCE - 0 >= 700 532 #define __XSI_VISIBLE 700 533 #undef _POSIX_C_SOURCE 534 #define _POSIX_C_SOURCE 200809 535 #elif _XOPEN_SOURCE - 0 >= 600 536 #define __XSI_VISIBLE 600 537 #undef _POSIX_C_SOURCE 538 #define _POSIX_C_SOURCE 200112 539 #elif _XOPEN_SOURCE - 0 >= 500 540 #define __XSI_VISIBLE 500 541 #undef _POSIX_C_SOURCE 542 #define _POSIX_C_SOURCE 199506 543 #else 544 /* #define _POSIX_C_SOURCE 199209 */ 545 #endif 546 #endif 547 548 /* 549 * Deal with all versions of POSIX. The ordering relative to the tests above is 550 * important. 551 */ 552 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE) 553 #define _POSIX_C_SOURCE 198808 554 #endif 555 #ifdef _POSIX_C_SOURCE 556 #if _POSIX_C_SOURCE >= 202405 557 #define __POSIX_VISIBLE 202405 558 #define __ISO_C_VISIBLE 2017 559 #elif _POSIX_C_SOURCE >= 200809 560 #define __POSIX_VISIBLE 200809 561 #define __ISO_C_VISIBLE 1999 562 #elif _POSIX_C_SOURCE >= 200112 563 #define __POSIX_VISIBLE 200112 564 #define __ISO_C_VISIBLE 1999 565 #elif _POSIX_C_SOURCE >= 199506 566 #define __POSIX_VISIBLE 199506 567 #define __ISO_C_VISIBLE 1990 568 #elif _POSIX_C_SOURCE >= 199309 569 #define __POSIX_VISIBLE 199309 570 #define __ISO_C_VISIBLE 1990 571 #elif _POSIX_C_SOURCE >= 199209 572 #define __POSIX_VISIBLE 199209 573 #define __ISO_C_VISIBLE 1990 574 #elif _POSIX_C_SOURCE >= 199009 575 #define __POSIX_VISIBLE 199009 576 #define __ISO_C_VISIBLE 1990 577 #else 578 #define __POSIX_VISIBLE 198808 579 #define __ISO_C_VISIBLE 0 580 #endif /* _POSIX_C_SOURCE */ 581 582 /* 583 * When we've explicitly asked for a newer C version, make the C variable 584 * visible by default. Also honor the glibc _ISOC{11,23}_SOURCE macros 585 * extensions. Both glibc and OpenBSD do this, even when a more strict 586 * _POSIX_C_SOURCE has been requested, and it makes good sense (especially for 587 * pre POSIX 2024, since C11 is much nicer than the old C99 base). Continue the 588 * practice with C23, though don't do older standards. Also, GLIBC doesn't have 589 * a _ISOC17_SOURCE, so it's not implemented here. glibc has earlier ISOCxx defines, 590 * but we don't implement those as they are not relevant enough. 591 */ 592 #if _ISOC23_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L) 593 #undef __ISO_C_VISIBLE 594 #define __ISO_C_VISIBLE 2023 595 #elif _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) 596 #undef __ISO_C_VISIBLE 597 #define __ISO_C_VISIBLE 2011 598 #endif 599 #else /* _POSIX_C_SOURCE */ 600 /*- 601 * Deal with _ANSI_SOURCE: 602 * If it is defined, and no other compilation environment is explicitly 603 * requested, then define our internal feature-test macros to zero. This 604 * makes no difference to the preprocessor (undefined symbols in preprocessing 605 * expressions are defined to have value zero), but makes it more convenient for 606 * a test program to print out the values. 607 * 608 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as 609 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation 610 * environment (and in fact we will never get here). 611 */ 612 #if defined(_ANSI_SOURCE) /* Hide almost everything. */ 613 #define __POSIX_VISIBLE 0 614 #define __XSI_VISIBLE 0 615 #define __BSD_VISIBLE 0 616 #define __ISO_C_VISIBLE 1990 617 #define __EXT1_VISIBLE 0 618 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */ 619 #define __POSIX_VISIBLE 0 620 #define __XSI_VISIBLE 0 621 #define __BSD_VISIBLE 0 622 #define __ISO_C_VISIBLE 1999 623 #define __EXT1_VISIBLE 0 624 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */ 625 #define __POSIX_VISIBLE 0 626 #define __XSI_VISIBLE 0 627 #define __BSD_VISIBLE 0 628 #define __ISO_C_VISIBLE 2011 629 #define __EXT1_VISIBLE 0 630 #elif defined(_C23_SOURCE) /* Localism to specify strict C23 env. */ 631 #define __POSIX_VISIBLE 0 632 #define __XSI_VISIBLE 0 633 #define __BSD_VISIBLE 0 634 #define __ISO_C_VISIBLE 2023 635 #define __EXT1_VISIBLE 0 636 #else /* Default environment: show everything. */ 637 #define __POSIX_VISIBLE 202405 638 #define __XSI_VISIBLE 800 639 #define __BSD_VISIBLE 1 640 #define __ISO_C_VISIBLE 2023 641 #define __EXT1_VISIBLE 1 642 #endif 643 #endif /* _POSIX_C_SOURCE */ 644 645 /* User override __EXT1_VISIBLE */ 646 #if defined(__STDC_WANT_LIB_EXT1__) 647 #undef __EXT1_VISIBLE 648 #if __STDC_WANT_LIB_EXT1__ 649 #define __EXT1_VISIBLE 1 650 #else 651 #define __EXT1_VISIBLE 0 652 #endif 653 #endif /* __STDC_WANT_LIB_EXT1__ */ 654 655 /* 656 * Nullability qualifiers: currently only supported by Clang. 657 */ 658 #if !(defined(__clang__) && __has_feature(nullability)) 659 #define _Nonnull 660 #define _Nullable 661 #define _Null_unspecified 662 #define __NULLABILITY_PRAGMA_PUSH 663 #define __NULLABILITY_PRAGMA_POP 664 #else 665 #define __NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push") \ 666 _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"") 667 #define __NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop") 668 #endif 669 670 /* 671 * Type Safety Checking 672 * 673 * Clang provides additional attributes to enable checking type safety 674 * properties that cannot be enforced by the C type system. 675 */ 676 677 #if __has_attribute(__argument_with_type_tag__) && \ 678 __has_attribute(__type_tag_for_datatype__) 679 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) \ 680 __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx))) 681 #define __datatype_type_tag(kind, type) \ 682 __attribute__((__type_tag_for_datatype__(kind, type))) 683 #else 684 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) 685 #define __datatype_type_tag(kind, type) 686 #endif 687 688 /* 689 * Lock annotations. 690 * 691 * Clang provides support for doing basic thread-safety tests at 692 * compile-time, by marking which locks will/should be held when 693 * entering/leaving a functions. 694 * 695 * Furthermore, it is also possible to annotate variables and structure 696 * members to enforce that they are only accessed when certain locks are 697 * held. 698 */ 699 700 #if __has_extension(c_thread_safety_attributes) 701 #define __lock_annotate(x) __attribute__((x)) 702 #else 703 #define __lock_annotate(x) 704 #endif 705 706 /* Structure implements a lock. */ 707 #define __lockable __lock_annotate(lockable) 708 709 /* Function acquires an exclusive or shared lock. */ 710 #define __locks_exclusive(...) \ 711 __lock_annotate(exclusive_lock_function(__VA_ARGS__)) 712 #define __locks_shared(...) \ 713 __lock_annotate(shared_lock_function(__VA_ARGS__)) 714 715 /* Function attempts to acquire an exclusive or shared lock. */ 716 #define __trylocks_exclusive(...) \ 717 __lock_annotate(exclusive_trylock_function(__VA_ARGS__)) 718 #define __trylocks_shared(...) \ 719 __lock_annotate(shared_trylock_function(__VA_ARGS__)) 720 721 /* Function releases a lock. */ 722 #define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__)) 723 724 /* Function asserts that an exclusive or shared lock is held. */ 725 #define __asserts_exclusive(...) \ 726 __lock_annotate(assert_exclusive_lock(__VA_ARGS__)) 727 #define __asserts_shared(...) \ 728 __lock_annotate(assert_shared_lock(__VA_ARGS__)) 729 730 /* Function requires that an exclusive or shared lock is or is not held. */ 731 #define __requires_exclusive(...) \ 732 __lock_annotate(exclusive_locks_required(__VA_ARGS__)) 733 #define __requires_shared(...) \ 734 __lock_annotate(shared_locks_required(__VA_ARGS__)) 735 #define __requires_unlocked(...) \ 736 __lock_annotate(locks_excluded(__VA_ARGS__)) 737 738 /* Function should not be analyzed. */ 739 #define __no_lock_analysis __lock_annotate(no_thread_safety_analysis) 740 741 /* 742 * Function or variable should not be sanitized, e.g., by AddressSanitizer. 743 * GCC has the nosanitize attribute, but as a function attribute only, and 744 * warns on use as a variable attribute. 745 */ 746 #if __has_feature(address_sanitizer) && defined(__clang__) 747 #ifdef _KERNEL 748 #define __nosanitizeaddress __attribute__((no_sanitize("kernel-address"))) 749 #else 750 #define __nosanitizeaddress __attribute__((no_sanitize("address"))) 751 #endif 752 #else 753 #define __nosanitizeaddress 754 #endif 755 #if __has_feature(coverage_sanitizer) && defined(__clang__) 756 #define __nosanitizecoverage __attribute__((no_sanitize("coverage"))) 757 #else 758 #define __nosanitizecoverage 759 #endif 760 #if __has_feature(memory_sanitizer) && defined(__clang__) 761 #ifdef _KERNEL 762 #define __nosanitizememory __attribute__((no_sanitize("kernel-memory"))) 763 #else 764 #define __nosanitizememory __attribute__((no_sanitize("memory"))) 765 #endif 766 #else 767 #define __nosanitizememory 768 #endif 769 #if __has_feature(thread_sanitizer) && defined(__clang__) 770 #define __nosanitizethread __attribute__((no_sanitize("thread"))) 771 #else 772 #define __nosanitizethread 773 #endif 774 775 /* 776 * Make it possible to opt out of stack smashing protection. 777 */ 778 #if __has_attribute(no_stack_protector) 779 #define __nostackprotector __attribute__((no_stack_protector)) 780 #else 781 #define __nostackprotector \ 782 __attribute__((__optimize__("-fno-stack-protector"))) 783 #endif 784 785 /* Guard variables and structure members by lock. */ 786 #define __guarded_by(x) __lock_annotate(guarded_by(x)) 787 #define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x)) 788 789 /* Alignment builtins for better type checking and improved code generation. */ 790 /* Provide fallback versions for other compilers (GCC/Clang < 10): */ 791 #if !__has_builtin(__builtin_is_aligned) 792 #define __builtin_is_aligned(x, align) \ 793 (((__uintptr_t)(x) & ((align) - 1)) == 0) 794 #endif 795 #if !__has_builtin(__builtin_align_up) 796 #define __builtin_align_up(x, align) \ 797 ((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1)))) 798 #endif 799 #if !__has_builtin(__builtin_align_down) 800 #define __builtin_align_down(x, align) \ 801 ((__typeof__(x))((x)&(~((align)-1)))) 802 #endif 803 804 #define __align_up(x, y) __builtin_align_up(x, y) 805 #define __align_down(x, y) __builtin_align_down(x, y) 806 #define __is_aligned(x, y) __builtin_is_aligned(x, y) 807 808 #endif /* !_SYS_CDEFS_H_ */ 809