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 * Testing against Clang-specific extensions. 44 */ 45#ifndef __has_attribute 46#define __has_attribute(x) 0 47#endif 48#ifndef __has_extension 49#define __has_extension __has_feature 50#endif 51#ifndef __has_feature 52#define __has_feature(x) 0 53#endif 54#ifndef __has_include 55#define __has_include(x) 0 56#endif 57#ifndef __has_builtin 58#define __has_builtin(x) 0 59#endif 60 61#if defined(__cplusplus) 62#define __BEGIN_DECLS extern "C" { 63#define __END_DECLS } 64#else 65#define __BEGIN_DECLS 66#define __END_DECLS 67#endif 68 69/* 70 * This code has been put in place to help reduce the addition of 71 * compiler specific defines in FreeBSD code. It helps to aid in 72 * having a compiler-agnostic source tree. 73 */ 74 75/* 76 * Macro to test if we're using a specific version of gcc or later. 77 */ 78#if defined(__GNUC__) 79#define __GNUC_PREREQ__(ma, mi) \ 80 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi)) 81#else 82#define __GNUC_PREREQ__(ma, mi) 0 83#endif 84 85#if defined(__GNUC__) 86 87/* 88 * Compiler memory barriers, specific to gcc and clang. 89 */ 90#define __compiler_membar() __asm __volatile(" " : : : "memory") 91 92#define __CC_SUPPORTS___INLINE 1 93 94#endif /* __GNUC__ */ 95 96/* 97 * The __CONCAT macro is used to concatenate parts of symbol names, e.g. 98 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. 99 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI 100 * mode -- there must be no spaces between its arguments, and for nested 101 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also 102 * concatenate double-quoted strings produced by the __STRING macro, but 103 * this only works with ANSI C. 104 * 105 * __XSTRING is like __STRING, but it expands any macros in its argument 106 * first. It is only available with ANSI C. 107 */ 108#if defined(__STDC__) || defined(__cplusplus) 109#define __P(protos) protos /* full-blown ANSI C */ 110#define __CONCAT1(x,y) x ## y 111#define __CONCAT(x,y) __CONCAT1(x,y) 112#define __STRING(x) #x /* stringify without expanding x */ 113#define __XSTRING(x) __STRING(x) /* expand x, then stringify */ 114 115#define __const const /* define reserved names to standard */ 116#define __signed signed 117#define __volatile volatile 118#if defined(__cplusplus) 119#define __inline inline /* convert to C++ keyword */ 120#else 121#if !(defined(__CC_SUPPORTS___INLINE)) 122#define __inline /* delete GCC keyword */ 123#endif /* ! __CC_SUPPORTS___INLINE */ 124#endif /* !__cplusplus */ 125 126#else /* !(__STDC__ || __cplusplus) */ 127#define __P(protos) () /* traditional C preprocessor */ 128#define __CONCAT(x,y) x/**/y 129#define __STRING(x) "x" 130 131#if !defined(__CC_SUPPORTS___INLINE) 132#define __const /* delete pseudo-ANSI C keywords */ 133#define __inline 134#define __signed 135#define __volatile 136/* 137 * In non-ANSI C environments, new programs will want ANSI-only C keywords 138 * deleted from the program and old programs will want them left alone. 139 * When using a compiler other than gcc, programs using the ANSI C keywords 140 * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS. 141 * When using "gcc -traditional", we assume that this is the intent; if 142 * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone. 143 */ 144#ifndef NO_ANSI_KEYWORDS 145#define const /* delete ANSI C keywords */ 146#define inline 147#define signed 148#define volatile 149#endif /* !NO_ANSI_KEYWORDS */ 150#endif /* !__CC_SUPPORTS___INLINE */ 151#endif /* !(__STDC__ || __cplusplus) */ 152 153/* 154 * Compiler-dependent macros to help declare dead (non-returning) and 155 * pure (no side effects) functions, and unused variables. They are 156 * null except for versions of gcc that are known to support the features 157 * properly (old versions of gcc-2 supported the dead and pure features 158 * in a different (wrong) way). If we do not provide an implementation 159 * for a given compiler, let the compile fail if it is told to use 160 * a feature that we cannot live without. 161 */ 162#define __weak_symbol __attribute__((__weak__)) 163#if !__GNUC_PREREQ__(2, 5) 164#define __dead2 165#define __pure2 166#define __unused 167#endif 168#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 169#define __dead2 __attribute__((__noreturn__)) 170#define __pure2 __attribute__((__const__)) 171#define __unused 172/* XXX Find out what to do for __packed, __aligned and __section */ 173#endif 174#if __GNUC_PREREQ__(2, 7) 175#define __dead2 __attribute__((__noreturn__)) 176#define __pure2 __attribute__((__const__)) 177#define __unused __attribute__((__unused__)) 178#define __used __attribute__((__used__)) 179#define __packed __attribute__((__packed__)) 180#define __aligned(x) __attribute__((__aligned__(x))) 181#define __section(x) __attribute__((__section__(x))) 182#endif 183#if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__) 184#define __alloc_size(x) __attribute__((__alloc_size__(x))) 185#define __alloc_size2(n, x) __attribute__((__alloc_size__(n, x))) 186#else 187#define __alloc_size(x) 188#define __alloc_size2(n, x) 189#endif 190#if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__) 191#define __alloc_align(x) __attribute__((__alloc_align__(x))) 192#else 193#define __alloc_align(x) 194#endif 195 196#if !__GNUC_PREREQ__(2, 95) 197#define __alignof(x) __offsetof(struct { char __a; x __b; }, __b) 198#endif 199 200/* 201 * Keywords added in C11. 202 */ 203 204#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L 205 206#if !__has_extension(c_alignas) 207#if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 208 __has_extension(cxx_alignas) 209#define _Alignas(x) alignas(x) 210#else 211/* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */ 212#define _Alignas(x) __aligned(x) 213#endif 214#endif 215 216#if defined(__cplusplus) && __cplusplus >= 201103L 217#define _Alignof(x) alignof(x) 218#else 219#define _Alignof(x) __alignof(x) 220#endif 221 222#if !defined(__cplusplus) && !__has_extension(c_atomic) && \ 223 !__has_extension(cxx_atomic) && !__GNUC_PREREQ__(4, 7) 224/* 225 * No native support for _Atomic(). Place object in structure to prevent 226 * most forms of direct non-atomic access. 227 */ 228#define _Atomic(T) struct { T volatile __val; } 229#endif 230 231#if defined(__cplusplus) && __cplusplus >= 201103L 232#define _Noreturn [[noreturn]] 233#else 234#define _Noreturn __dead2 235#endif 236 237#if !__has_extension(c_static_assert) 238#if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 239 __has_extension(cxx_static_assert) 240#define _Static_assert(x, y) static_assert(x, y) 241#elif __GNUC_PREREQ__(4,6) && !defined(__cplusplus) 242/* Nothing, gcc 4.6 and higher has _Static_assert built-in */ 243#elif defined(__COUNTER__) 244#define _Static_assert(x, y) __Static_assert(x, __COUNTER__) 245#define __Static_assert(x, y) ___Static_assert(x, y) 246#define ___Static_assert(x, y) typedef char __assert_ ## y[(x) ? 1 : -1] \ 247 __unused 248#else 249#define _Static_assert(x, y) struct __hack 250#endif 251#endif 252 253#if !__has_extension(c_thread_local) 254/* 255 * XXX: Some compilers (Clang 3.3, GCC 4.7) falsely announce C++11 mode 256 * without actually supporting the thread_local keyword. Don't check for 257 * the presence of C++11 when defining _Thread_local. 258 */ 259#if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \ 260 __has_extension(cxx_thread_local) 261#define _Thread_local thread_local 262#else 263#define _Thread_local __thread 264#endif 265#endif 266 267#endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */ 268 269/* 270 * Emulation of C11 _Generic(). Unlike the previously defined C11 271 * keywords, it is not possible to implement this using exactly the same 272 * syntax. Therefore implement something similar under the name 273 * __generic(). Unlike _Generic(), this macro can only distinguish 274 * between a single type, so it requires nested invocations to 275 * distinguish multiple cases. 276 * 277 * Note that the comma operator is used to force expr to decay in 278 * order to match _Generic(). 279 */ 280 281#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \ 282 __has_extension(c_generic_selections) 283#define __generic(expr, t, yes, no) \ 284 _Generic(expr, t: yes, default: no) 285#elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus) 286#define __generic(expr, t, yes, no) \ 287 __builtin_choose_expr( \ 288 __builtin_types_compatible_p(__typeof((0, (expr))), t), yes, no) 289#endif 290 291/* 292 * C99 Static array indices in function parameter declarations. Syntax such as: 293 * void bar(int myArray[static 10]); 294 * is allowed in C99 but not in C++. Define __min_size appropriately so 295 * headers using it can be compiled in either language. Use like this: 296 * void bar(int myArray[__min_size(10)]); 297 */ 298#if !defined(__cplusplus) && \ 299 (defined(__clang__) || __GNUC_PREREQ__(4, 6)) && \ 300 (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901)) 301#define __min_size(x) static (x) 302#else 303#define __min_size(x) (x) 304#endif 305 306#if __GNUC_PREREQ__(2, 96) 307#define __malloc_like __attribute__((__malloc__)) 308#define __pure __attribute__((__pure__)) 309#else 310#define __malloc_like 311#define __pure 312#endif 313 314#if __GNUC_PREREQ__(3, 1) 315#define __always_inline __attribute__((__always_inline__)) 316#else 317#define __always_inline 318#endif 319 320#if __GNUC_PREREQ__(3, 1) 321#define __noinline __attribute__ ((__noinline__)) 322#else 323#define __noinline 324#endif 325 326#if __GNUC_PREREQ__(3, 4) 327#define __fastcall __attribute__((__fastcall__)) 328#define __result_use_check __attribute__((__warn_unused_result__)) 329#ifdef __clang__ 330/* 331 * clang and gcc have different semantics for __warn_unused_result__: the latter 332 * does not permit the use of a void cast to suppress the warning. Use 333 * __result_use_or_ignore_check in places where a void cast is acceptable. 334 * This can be implemented by [[nodiscard]] from C23. 335 */ 336#define __result_use_or_ignore_check __result_use_check 337#else 338#define __result_use_or_ignore_check 339#endif /* !__clang__ */ 340#else 341#define __fastcall 342#define __result_use_check 343#endif 344 345#if __GNUC_PREREQ__(4, 1) 346#define __returns_twice __attribute__((__returns_twice__)) 347#else 348#define __returns_twice 349#endif 350 351#if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable) 352#define __unreachable() __builtin_unreachable() 353#else 354#define __unreachable() ((void)0) 355#endif 356 357#if (defined(__GNUC__) && __GNUC__ >= 2) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901 358#define __LONG_LONG_SUPPORTED 359#endif 360 361/* C++11 exposes a load of C99 stuff */ 362#if defined(__cplusplus) && __cplusplus >= 201103L 363#define __LONG_LONG_SUPPORTED 364#ifndef __STDC_LIMIT_MACROS 365#define __STDC_LIMIT_MACROS 366#endif 367#ifndef __STDC_CONSTANT_MACROS 368#define __STDC_CONSTANT_MACROS 369#endif 370#endif 371 372/* 373 * noexcept keyword added in C++11. 374 */ 375#if defined(__cplusplus) && __cplusplus >= 201103L 376#define __noexcept noexcept 377#define __noexcept_if(__c) noexcept(__c) 378#else 379#define __noexcept 380#define __noexcept_if(__c) 381#endif 382 383/* 384 * We use `__restrict' as a way to define the `restrict' type qualifier 385 * without disturbing older software that is unaware of C99 keywords. 386 * GCC also provides `__restrict' as an extension to support C99-style 387 * restricted pointers in other language modes. 388 */ 389#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901 390#define __restrict restrict 391#elif !__GNUC_PREREQ__(2, 95) 392#define __restrict 393#endif 394 395/* 396 * GNU C version 2.96 adds explicit branch prediction so that 397 * the CPU back-end can hint the processor and also so that 398 * code blocks can be reordered such that the predicted path 399 * sees a more linear flow, thus improving cache behavior, etc. 400 * 401 * The following two macros provide us with a way to utilize this 402 * compiler feature. Use __predict_true() if you expect the expression 403 * to evaluate to true, and __predict_false() if you expect the 404 * expression to evaluate to false. 405 * 406 * A few notes about usage: 407 * 408 * * Generally, __predict_false() error condition checks (unless 409 * you have some _strong_ reason to do otherwise, in which case 410 * document it), and/or __predict_true() `no-error' condition 411 * checks, assuming you want to optimize for the no-error case. 412 * 413 * * Other than that, if you don't know the likelihood of a test 414 * succeeding from empirical or other `hard' evidence, don't 415 * make predictions. 416 * 417 * * These are meant to be used in places that are run `a lot'. 418 * It is wasteful to make predictions in code that is run 419 * seldomly (e.g. at subsystem initialization time) as the 420 * basic block reordering that this affects can often generate 421 * larger code. 422 */ 423#if __GNUC_PREREQ__(2, 96) 424#define __predict_true(exp) __builtin_expect((exp), 1) 425#define __predict_false(exp) __builtin_expect((exp), 0) 426#else 427#define __predict_true(exp) (exp) 428#define __predict_false(exp) (exp) 429#endif 430 431#if __GNUC_PREREQ__(4, 0) 432#define __null_sentinel __attribute__((__sentinel__)) 433#define __exported __attribute__((__visibility__("default"))) 434#define __hidden __attribute__((__visibility__("hidden"))) 435#else 436#define __null_sentinel 437#define __exported 438#define __hidden 439#endif 440 441/* 442 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h> 443 * require it. 444 */ 445#if __GNUC_PREREQ__(4, 1) 446#define __offsetof(type, field) __builtin_offsetof(type, field) 447#else 448#ifndef __cplusplus 449#define __offsetof(type, field) \ 450 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field)) 451#else 452#define __offsetof(type, field) \ 453 (__offsetof__ (reinterpret_cast <__size_t> \ 454 (&reinterpret_cast <const volatile char &> \ 455 (static_cast<type *> (0)->field)))) 456#endif 457#endif 458#define __rangeof(type, start, end) \ 459 (__offsetof(type, end) - __offsetof(type, start)) 460 461/* 462 * Given the pointer x to the member m of the struct s, return 463 * a pointer to the containing structure. When using GCC, we first 464 * assign pointer x to a local variable, to check that its type is 465 * compatible with member m. 466 */ 467#if __GNUC_PREREQ__(3, 1) 468#define __containerof(x, s, m) ({ \ 469 const volatile __typeof(((s *)0)->m) *__x = (x); \ 470 __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\ 471}) 472#else 473#define __containerof(x, s, m) \ 474 __DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m)) 475#endif 476 477/* 478 * Compiler-dependent macros to declare that functions take printf-like 479 * or scanf-like arguments. They are null except for versions of gcc 480 * that are known to support the features properly (old versions of gcc-2 481 * didn't permit keeping the keywords out of the application namespace). 482 */ 483#if !__GNUC_PREREQ__(2, 7) 484#define __printflike(fmtarg, firstvararg) 485#define __scanflike(fmtarg, firstvararg) 486#define __format_arg(fmtarg) 487#define __strfmonlike(fmtarg, firstvararg) 488#define __strftimelike(fmtarg, firstvararg) 489#else 490#define __printflike(fmtarg, firstvararg) \ 491 __attribute__((__format__ (__printf__, fmtarg, firstvararg))) 492#define __scanflike(fmtarg, firstvararg) \ 493 __attribute__((__format__ (__scanf__, fmtarg, firstvararg))) 494#define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg))) 495#define __strfmonlike(fmtarg, firstvararg) \ 496 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg))) 497#define __strftimelike(fmtarg, firstvararg) \ 498 __attribute__((__format__ (__strftime__, fmtarg, firstvararg))) 499#endif 500 501/* Compiler-dependent macros that rely on FreeBSD-specific extensions. */ 502#if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \ 503 defined(__GNUC__) 504#define __printf0like(fmtarg, firstvararg) \ 505 __attribute__((__format__ (__printf0__, fmtarg, firstvararg))) 506#else 507#define __printf0like(fmtarg, firstvararg) 508#endif 509 510#if defined(__GNUC__) 511#define __strong_reference(sym,aliassym) \ 512 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym))) 513#ifdef __STDC__ 514#define __weak_reference(sym,alias) \ 515 __asm__(".weak " #alias); \ 516 __asm__(".equ " #alias ", " #sym) 517#define __warn_references(sym,msg) \ 518 __asm__(".section .gnu.warning." #sym); \ 519 __asm__(".asciz \"" msg "\""); \ 520 __asm__(".previous") 521#define __sym_compat(sym,impl,verid) \ 522 __asm__(".symver " #impl ", " #sym "@" #verid) 523#define __sym_default(sym,impl,verid) \ 524 __asm__(".symver " #impl ", " #sym "@@@" #verid) 525#else 526#define __weak_reference(sym,alias) \ 527 __asm__(".weak alias"); \ 528 __asm__(".equ alias, sym") 529#define __warn_references(sym,msg) \ 530 __asm__(".section .gnu.warning.sym"); \ 531 __asm__(".asciz \"msg\""); \ 532 __asm__(".previous") 533#define __sym_compat(sym,impl,verid) \ 534 __asm__(".symver impl, sym@verid") 535#define __sym_default(impl,sym,verid) \ 536 __asm__(".symver impl, sym@@@verid") 537#endif /* __STDC__ */ 538#endif /* __GNUC__ */ 539 540#define __GLOBL(sym) __asm__(".globl " __XSTRING(sym)) 541#define __WEAK(sym) __asm__(".weak " __XSTRING(sym)) 542 543#if defined(__GNUC__) 544#define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"") 545#else 546/* 547 * The following definition might not work well if used in header files, 548 * but it should be better than nothing. If you want a "do nothing" 549 * version, then it should generate some harmless declaration, such as: 550 * #define __IDSTRING(name,string) struct __hack 551 */ 552#define __IDSTRING(name,string) static const char name[] __unused = string 553#endif 554 555/* 556 * Embed the rcs id of a source file in the resulting library. Note that in 557 * more recent ELF binutils, we use .ident allowing the ID to be stripped. 558 * Usage: 559 */ 560#ifndef __FBSDID 561#if !defined(STRIP_FBSDID) 562#define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s) 563#else 564#define __FBSDID(s) struct __hack 565#endif 566#endif 567 568#ifndef __RCSID 569#ifndef NO__RCSID 570#define __RCSID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s) 571#else 572#define __RCSID(s) struct __hack 573#endif 574#endif 575 576#ifndef __RCSID_SOURCE 577#ifndef NO__RCSID_SOURCE 578#define __RCSID_SOURCE(s) __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s) 579#else 580#define __RCSID_SOURCE(s) struct __hack 581#endif 582#endif 583 584#ifndef __SCCSID 585#ifndef NO__SCCSID 586#define __SCCSID(s) __IDSTRING(__CONCAT(__sccsid_,__LINE__),s) 587#else 588#define __SCCSID(s) struct __hack 589#endif 590#endif 591 592#ifndef __COPYRIGHT 593#ifndef NO__COPYRIGHT 594#define __COPYRIGHT(s) __IDSTRING(__CONCAT(__copyright_,__LINE__),s) 595#else 596#define __COPYRIGHT(s) struct __hack 597#endif 598#endif 599 600#ifndef __DECONST 601#define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var)) 602#endif 603 604#ifndef __DEVOLATILE 605#define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var)) 606#endif 607 608#ifndef __DEQUALIFY 609#define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var)) 610#endif 611 612#if !defined(_STANDALONE) && !defined(_KERNEL) 613#if defined(__GNUC__) || defined(__PCC__) 614#define __RENAME(x) __asm(__STRING(x)) 615#else 616#define __RENAME(x) no renaming support for compiler in use 617#endif /* __GNUC__ */ 618#else /* _STANDALONE || _KERNEL */ 619#define __RENAME(x) no renaming in kernel/standalone environment 620#endif 621 622/*- 623 * The following definitions are an extension of the behavior originally 624 * implemented in <sys/_posix.h>, but with a different level of granularity. 625 * POSIX.1 requires that the macros we test be defined before any standard 626 * header file is included. 627 * 628 * Here's a quick run-down of the versions (and some informal names) 629 * defined(_POSIX_SOURCE) 1003.1-1988 630 * encoded as 198808 below 631 * _POSIX_C_SOURCE == 1 1003.1-1990 632 * encoded as 199009 below 633 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option 634 * encoded as 199209 below 635 * _POSIX_C_SOURCE == 199309 1003.1b-1993 636 * (1003.1 Issue 4, Single Unix Spec v1, Unix 93) 637 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995, 638 * and the omnibus ISO/IEC 9945-1: 1996 639 * (1003.1 Issue 5, Single Unix Spec v2, Unix 95) 640 * _POSIX_C_SOURCE == 200112 1003.1-2001 (1003.1 Issue 6, Unix 03) 641 * _POSIX_C_SOURCE == 200809 1003.1-2008 (1003.1 Issue 7) 642 * IEEE Std 1003.1-2017 (Rev of 1003.1-2008) is 643 * 1003.1-2008 with two TCs applied with 644 * _POSIX_C_SOURCE=200809 and _XOPEN_SOURCE=700 645 * 646 * In addition, the X/Open Portability Guide, which is now the Single UNIX 647 * Specification, defines a feature-test macro which indicates the version of 648 * that specification, and which subsumes _POSIX_C_SOURCE. 649 * 650 * Our macros begin with two underscores to avoid namespace screwage. 651 */ 652 653/* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */ 654#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1 655#undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */ 656#define _POSIX_C_SOURCE 199009 657#endif 658 659/* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */ 660#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2 661#undef _POSIX_C_SOURCE 662#define _POSIX_C_SOURCE 199209 663#endif 664 665/* Deal with various X/Open Portability Guides and Single UNIX Spec. */ 666#ifdef _XOPEN_SOURCE 667#if _XOPEN_SOURCE - 0 >= 700 668#define __XSI_VISIBLE 700 669#undef _POSIX_C_SOURCE 670#define _POSIX_C_SOURCE 200809 671#elif _XOPEN_SOURCE - 0 >= 600 672#define __XSI_VISIBLE 600 673#undef _POSIX_C_SOURCE 674#define _POSIX_C_SOURCE 200112 675#elif _XOPEN_SOURCE - 0 >= 500 676#define __XSI_VISIBLE 500 677#undef _POSIX_C_SOURCE 678#define _POSIX_C_SOURCE 199506 679#endif 680#endif 681 682/* 683 * Deal with all versions of POSIX. The ordering relative to the tests above is 684 * important. 685 */ 686#if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE) 687#define _POSIX_C_SOURCE 198808 688#endif 689#ifdef _POSIX_C_SOURCE 690#if _POSIX_C_SOURCE >= 200809 691#define __POSIX_VISIBLE 200809 692#define __ISO_C_VISIBLE 1999 693#elif _POSIX_C_SOURCE >= 200112 694#define __POSIX_VISIBLE 200112 695#define __ISO_C_VISIBLE 1999 696#elif _POSIX_C_SOURCE >= 199506 697#define __POSIX_VISIBLE 199506 698#define __ISO_C_VISIBLE 1990 699#elif _POSIX_C_SOURCE >= 199309 700#define __POSIX_VISIBLE 199309 701#define __ISO_C_VISIBLE 1990 702#elif _POSIX_C_SOURCE >= 199209 703#define __POSIX_VISIBLE 199209 704#define __ISO_C_VISIBLE 1990 705#elif _POSIX_C_SOURCE >= 199009 706#define __POSIX_VISIBLE 199009 707#define __ISO_C_VISIBLE 1990 708#else 709#define __POSIX_VISIBLE 198808 710#define __ISO_C_VISIBLE 0 711#endif /* _POSIX_C_SOURCE */ 712/* 713 * Both glibc and OpenBSD enable c11 features when _ISOC11_SOURCE is defined, or 714 * when compiling with -stdc=c11. A strict reading of the standard would suggest 715 * doing it only for the former. However, a strict reading also requires C99 716 * mode only, so building with C11 is already undefined. Follow glibc's and 717 * OpenBSD's lead for this non-standard configuration for maximum compatibility. 718 */ 719#if _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) 720#undef __ISO_C_VISIBLE 721#define __ISO_C_VISIBLE 2011 722#endif 723#else 724/*- 725 * Deal with _ANSI_SOURCE: 726 * If it is defined, and no other compilation environment is explicitly 727 * requested, then define our internal feature-test macros to zero. This 728 * makes no difference to the preprocessor (undefined symbols in preprocessing 729 * expressions are defined to have value zero), but makes it more convenient for 730 * a test program to print out the values. 731 * 732 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as 733 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation 734 * environment (and in fact we will never get here). 735 */ 736#if defined(_ANSI_SOURCE) /* Hide almost everything. */ 737#define __POSIX_VISIBLE 0 738#define __XSI_VISIBLE 0 739#define __BSD_VISIBLE 0 740#define __ISO_C_VISIBLE 1990 741#define __EXT1_VISIBLE 0 742#elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */ 743#define __POSIX_VISIBLE 0 744#define __XSI_VISIBLE 0 745#define __BSD_VISIBLE 0 746#define __ISO_C_VISIBLE 1999 747#define __EXT1_VISIBLE 0 748#elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */ 749#define __POSIX_VISIBLE 0 750#define __XSI_VISIBLE 0 751#define __BSD_VISIBLE 0 752#define __ISO_C_VISIBLE 2011 753#define __EXT1_VISIBLE 0 754#else /* Default environment: show everything. */ 755#define __POSIX_VISIBLE 200809 756#define __XSI_VISIBLE 700 757#define __BSD_VISIBLE 1 758#define __ISO_C_VISIBLE 2011 759#define __EXT1_VISIBLE 1 760#endif 761#endif 762 763/* User override __EXT1_VISIBLE */ 764#if defined(__STDC_WANT_LIB_EXT1__) 765#undef __EXT1_VISIBLE 766#if __STDC_WANT_LIB_EXT1__ 767#define __EXT1_VISIBLE 1 768#else 769#define __EXT1_VISIBLE 0 770#endif 771#endif /* __STDC_WANT_LIB_EXT1__ */ 772 773/* 774 * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h 775 * translates them to __ARM_ARCH and the modern feature symbols defined by ARM. 776 */ 777#if defined(__arm__) && !defined(__ARM_ARCH) 778#include <machine/acle-compat.h> 779#endif 780 781/* 782 * Nullability qualifiers: currently only supported by Clang. 783 */ 784#if !(defined(__clang__) && __has_feature(nullability)) 785#define _Nonnull 786#define _Nullable 787#define _Null_unspecified 788#define __NULLABILITY_PRAGMA_PUSH 789#define __NULLABILITY_PRAGMA_POP 790#else 791#define __NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push") \ 792 _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"") 793#define __NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop") 794#endif 795 796/* 797 * Type Safety Checking 798 * 799 * Clang provides additional attributes to enable checking type safety 800 * properties that cannot be enforced by the C type system. 801 */ 802 803#if __has_attribute(__argument_with_type_tag__) && \ 804 __has_attribute(__type_tag_for_datatype__) 805#define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) \ 806 __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx))) 807#define __datatype_type_tag(kind, type) \ 808 __attribute__((__type_tag_for_datatype__(kind, type))) 809#else 810#define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) 811#define __datatype_type_tag(kind, type) 812#endif 813 814/* 815 * Lock annotations. 816 * 817 * Clang provides support for doing basic thread-safety tests at 818 * compile-time, by marking which locks will/should be held when 819 * entering/leaving a functions. 820 * 821 * Furthermore, it is also possible to annotate variables and structure 822 * members to enforce that they are only accessed when certain locks are 823 * held. 824 */ 825 826#if __has_extension(c_thread_safety_attributes) 827#define __lock_annotate(x) __attribute__((x)) 828#else 829#define __lock_annotate(x) 830#endif 831 832/* Structure implements a lock. */ 833#define __lockable __lock_annotate(lockable) 834 835/* Function acquires an exclusive or shared lock. */ 836#define __locks_exclusive(...) \ 837 __lock_annotate(exclusive_lock_function(__VA_ARGS__)) 838#define __locks_shared(...) \ 839 __lock_annotate(shared_lock_function(__VA_ARGS__)) 840 841/* Function attempts to acquire an exclusive or shared lock. */ 842#define __trylocks_exclusive(...) \ 843 __lock_annotate(exclusive_trylock_function(__VA_ARGS__)) 844#define __trylocks_shared(...) \ 845 __lock_annotate(shared_trylock_function(__VA_ARGS__)) 846 847/* Function releases a lock. */ 848#define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__)) 849 850/* Function asserts that an exclusive or shared lock is held. */ 851#define __asserts_exclusive(...) \ 852 __lock_annotate(assert_exclusive_lock(__VA_ARGS__)) 853#define __asserts_shared(...) \ 854 __lock_annotate(assert_shared_lock(__VA_ARGS__)) 855 856/* Function requires that an exclusive or shared lock is or is not held. */ 857#define __requires_exclusive(...) \ 858 __lock_annotate(exclusive_locks_required(__VA_ARGS__)) 859#define __requires_shared(...) \ 860 __lock_annotate(shared_locks_required(__VA_ARGS__)) 861#define __requires_unlocked(...) \ 862 __lock_annotate(locks_excluded(__VA_ARGS__)) 863 864/* Function should not be analyzed. */ 865#define __no_lock_analysis __lock_annotate(no_thread_safety_analysis) 866 867/* 868 * Function or variable should not be sanitized, e.g., by AddressSanitizer. 869 * GCC has the nosanitize attribute, but as a function attribute only, and 870 * warns on use as a variable attribute. 871 */ 872#if __has_attribute(no_sanitize) && defined(__clang__) 873#ifdef _KERNEL 874#define __nosanitizeaddress __attribute__((no_sanitize("kernel-address"))) 875#define __nosanitizememory __attribute__((no_sanitize("kernel-memory"))) 876#else 877#define __nosanitizeaddress __attribute__((no_sanitize("address"))) 878#define __nosanitizememory __attribute__((no_sanitize("memory"))) 879#endif 880#define __nosanitizethread __attribute__((no_sanitize("thread"))) 881#else 882#define __nosanitizeaddress 883#define __nosanitizememory 884#define __nosanitizethread 885#endif 886 887/* 888 * Make it possible to opt out of stack smashing protection. 889 */ 890#if __has_attribute(no_stack_protector) 891#define __nostackprotector __attribute__((no_stack_protector)) 892#else 893#define __nostackprotector \ 894 __attribute__((__optimize__("-fno-stack-protector"))) 895#endif 896 897/* Guard variables and structure members by lock. */ 898#define __guarded_by(x) __lock_annotate(guarded_by(x)) 899#define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x)) 900 901/* Alignment builtins for better type checking and improved code generation. */ 902/* Provide fallback versions for other compilers (GCC/Clang < 10): */ 903#if !__has_builtin(__builtin_is_aligned) 904#define __builtin_is_aligned(x, align) \ 905 (((__uintptr_t)(x) & ((align) - 1)) == 0) 906#endif 907#if !__has_builtin(__builtin_align_up) 908#define __builtin_align_up(x, align) \ 909 ((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1)))) 910#endif 911#if !__has_builtin(__builtin_align_down) 912#define __builtin_align_down(x, align) \ 913 ((__typeof__(x))((x)&(~((align)-1)))) 914#endif 915 916#define __align_up(x, y) __builtin_align_up(x, y) 917#define __align_down(x, y) __builtin_align_down(x, y) 918#define __is_aligned(x, y) __builtin_is_aligned(x, y) 919 920#endif /* !_SYS_CDEFS_H_ */ 921