2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * Berkeley Software Design, Inc.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
38 #if defined(_KERNEL) && defined(_STANDALONE)
39 #error "_KERNEL and _STANDALONE are mutually exclusive"
43 * Testing against Clang-specific extensions.
45 #ifndef __has_attribute
46 #define __has_attribute(x) 0
48 #ifndef __has_extension
49 #define __has_extension __has_feature
52 #define __has_feature(x) 0
55 #define __has_include(x) 0
58 #define __has_builtin(x) 0
61 #if defined(__cplusplus)
62 #define __BEGIN_DECLS extern "C" {
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.
76 * Macro to test if we're using a specific version of gcc or later.
79 #define __GNUC_PREREQ__(ma, mi) \
80 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
82 #define __GNUC_PREREQ__(ma, mi) 0
88 * Compiler memory barriers, specific to gcc and clang.
90 #define __compiler_membar() __asm __volatile(" " : : : "memory")
92 #define __CC_SUPPORTS___INLINE 1
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.
105 * __XSTRING is like __STRING, but it expands any macros in its argument
106 * first. It is only available with ANSI C.
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 */
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 */
121 #if !(defined(__CC_SUPPORTS___INLINE))
122 #define __inline /* delete GCC keyword */
123 #endif /* ! __CC_SUPPORTS___INLINE */
124 #endif /* !__cplusplus */
126 #else /* !(__STDC__ || __cplusplus) */
127 #define __P(protos) () /* traditional C preprocessor */
128 #define __CONCAT(x,y) x/**/y
129 #define __STRING(x) "x"
131 #if !defined(__CC_SUPPORTS___INLINE)
132 #define __const /* delete pseudo-ANSI C keywords */
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.
144 #ifndef NO_ANSI_KEYWORDS
145 #define const /* delete ANSI C keywords */
149 #endif /* !NO_ANSI_KEYWORDS */
150 #endif /* !__CC_SUPPORTS___INLINE */
151 #endif /* !(__STDC__ || __cplusplus) */
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.
162 #define __weak_symbol __attribute__((__weak__))
163 #if !__GNUC_PREREQ__(2, 5)
168 #if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7
169 #define __dead2 __attribute__((__noreturn__))
170 #define __pure2 __attribute__((__const__))
172 /* XXX Find out what to do for __packed, __aligned and __section */
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)))
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)))
187 #define __alloc_size(x)
188 #define __alloc_size2(n, x)
190 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
191 #define __alloc_align(x) __attribute__((__alloc_align__(x)))
193 #define __alloc_align(x)
196 #if !__GNUC_PREREQ__(2, 95)
197 #define __alignof(x) __offsetof(struct { char __a; x __b; }, __b)
201 * Keywords added in C11.
204 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
206 #if !__has_extension(c_alignas)
207 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
208 __has_extension(cxx_alignas)
209 #define _Alignas(x) alignas(x)
211 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
212 #define _Alignas(x) __aligned(x)
216 #if defined(__cplusplus) && __cplusplus >= 201103L
217 #define _Alignof(x) alignof(x)
219 #define _Alignof(x) __alignof(x)
222 #if !defined(__cplusplus) && !__has_extension(c_atomic) && \
223 !__has_extension(cxx_atomic) && !__GNUC_PREREQ__(4, 7)
225 * No native support for _Atomic(). Place object in structure to prevent
226 * most forms of direct non-atomic access.
228 #define _Atomic(T) struct { T volatile __val; }
231 #if defined(__cplusplus) && __cplusplus >= 201103L
232 #define _Noreturn [[noreturn]]
234 #define _Noreturn __dead2
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] \
249 #define _Static_assert(x, y) struct __hack
253 #if !__has_extension(c_thread_local)
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.
259 #if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \
260 __has_extension(cxx_thread_local)
261 #define _Thread_local thread_local
263 #define _Thread_local __thread
267 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
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.
277 * Note that the comma operator is used to force expr to decay in
278 * order to match _Generic().
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)
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)]);
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)
303 #define __min_size(x) (x)
306 #if __GNUC_PREREQ__(2, 96)
307 #define __malloc_like __attribute__((__malloc__))
308 #define __pure __attribute__((__pure__))
310 #define __malloc_like
314 #if __GNUC_PREREQ__(3, 1)
315 #define __always_inline __attribute__((__always_inline__))
317 #define __always_inline
320 #if __GNUC_PREREQ__(3, 1)
321 #define __noinline __attribute__ ((__noinline__))
326 #if __GNUC_PREREQ__(3, 4)
327 #define __fastcall __attribute__((__fastcall__))
328 #define __result_use_check __attribute__((__warn_unused_result__))
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.
336 #define __result_use_or_ignore_check __result_use_check
338 #define __result_use_or_ignore_check
339 #endif /* !__clang__ */
342 #define __result_use_check
345 #if __GNUC_PREREQ__(4, 1)
346 #define __returns_twice __attribute__((__returns_twice__))
348 #define __returns_twice
351 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
352 #define __unreachable() __builtin_unreachable()
354 #define __unreachable() ((void)0)
357 #if (defined(__GNUC__) && __GNUC__ >= 2) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
358 #define __LONG_LONG_SUPPORTED
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
367 #ifndef __STDC_CONSTANT_MACROS
368 #define __STDC_CONSTANT_MACROS
373 * noexcept keyword added in C++11.
375 #if defined(__cplusplus) && __cplusplus >= 201103L
376 #define __noexcept noexcept
377 #define __noexcept_if(__c) noexcept(__c)
380 #define __noexcept_if(__c)
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.
389 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901
390 #define __restrict restrict
391 #elif !__GNUC_PREREQ__(2, 95)
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.
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.
406 * A few notes about usage:
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.
413 * * Other than that, if you don't know the likelihood of a test
414 * succeeding from empirical or other `hard' evidence, don't
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
423 #if __GNUC_PREREQ__(2, 96)
424 #define __predict_true(exp) __builtin_expect((exp), 1)
425 #define __predict_false(exp) __builtin_expect((exp), 0)
427 #define __predict_true(exp) (exp)
428 #define __predict_false(exp) (exp)
431 #if __GNUC_PREREQ__(4, 0)
432 #define __null_sentinel __attribute__((__sentinel__))
433 #define __exported __attribute__((__visibility__("default")))
434 #define __hidden __attribute__((__visibility__("hidden")))
436 #define __null_sentinel
442 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
445 #if __GNUC_PREREQ__(4, 1)
446 #define __offsetof(type, field) __builtin_offsetof(type, field)
449 #define __offsetof(type, field) \
450 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
452 #define __offsetof(type, field) \
453 (__offsetof__ (reinterpret_cast <__size_t> \
454 (&reinterpret_cast <const volatile char &> \
455 (static_cast<type *> (0)->field))))
458 #define __rangeof(type, start, end) \
459 (__offsetof(type, end) - __offsetof(type, start))
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.
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));\
473 #define __containerof(x, s, m) \
474 __DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
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).
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)
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)))
501 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
502 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
504 #define __printf0like(fmtarg, firstvararg) \
505 __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
507 #define __printf0like(fmtarg, firstvararg)
510 #if defined(__GNUC__)
511 #define __strong_reference(sym,aliassym) \
512 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
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 "\""); \
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)
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\""); \
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__ */
540 #define __GLOBL(sym) __asm__(".globl " __XSTRING(sym))
541 #define __WEAK(sym) __asm__(".weak " __XSTRING(sym))
543 #if defined(__GNUC__)
544 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
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
552 #define __IDSTRING(name,string) static const char name[] __unused = string
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.
561 #if !defined(STRIP_FBSDID)
562 #define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
564 #define __FBSDID(s) struct __hack
570 #define __RCSID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
572 #define __RCSID(s) struct __hack
576 #ifndef __RCSID_SOURCE
577 #ifndef NO__RCSID_SOURCE
578 #define __RCSID_SOURCE(s) __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
580 #define __RCSID_SOURCE(s) struct __hack
586 #define __SCCSID(s) __IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
588 #define __SCCSID(s) struct __hack
593 #ifndef NO__COPYRIGHT
594 #define __COPYRIGHT(s) __IDSTRING(__CONCAT(__copyright_,__LINE__),s)
596 #define __COPYRIGHT(s) struct __hack
601 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var))
605 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var))
609 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var))
613 * The following definitions are an extension of the behavior originally
614 * implemented in <sys/_posix.h>, but with a different level of granularity.
615 * POSIX.1 requires that the macros we test be defined before any standard
616 * header file is included.
618 * Here's a quick run-down of the versions (and some informal names)
619 * defined(_POSIX_SOURCE) 1003.1-1988
620 * encoded as 198808 below
621 * _POSIX_C_SOURCE == 1 1003.1-1990
622 * encoded as 199009 below
623 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
624 * encoded as 199209 below
625 * _POSIX_C_SOURCE == 199309 1003.1b-1993
626 * (1003.1 Issue 4, Single Unix Spec v1, Unix 93)
627 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
628 * and the omnibus ISO/IEC 9945-1: 1996
629 * (1003.1 Issue 5, Single Unix Spec v2, Unix 95)
630 * _POSIX_C_SOURCE == 200112 1003.1-2001 (1003.1 Issue 6, Unix 03)
631 * _POSIX_C_SOURCE == 200809 1003.1-2008 (1003.1 Issue 7)
632 * IEEE Std 1003.1-2017 (Rev of 1003.1-2008) is
633 * 1003.1-2008 with two TCs applied with
634 * _POSIX_C_SOURCE=200809 and _XOPEN_SOURCE=700
636 * In addition, the X/Open Portability Guide, which is now the Single UNIX
637 * Specification, defines a feature-test macro which indicates the version of
638 * that specification, and which subsumes _POSIX_C_SOURCE.
640 * Our macros begin with two underscores to avoid namespace screwage.
643 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
644 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
645 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
646 #define _POSIX_C_SOURCE 199009
649 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
650 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
651 #undef _POSIX_C_SOURCE
652 #define _POSIX_C_SOURCE 199209
655 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
657 #if _XOPEN_SOURCE - 0 >= 700
658 #define __XSI_VISIBLE 700
659 #undef _POSIX_C_SOURCE
660 #define _POSIX_C_SOURCE 200809
661 #elif _XOPEN_SOURCE - 0 >= 600
662 #define __XSI_VISIBLE 600
663 #undef _POSIX_C_SOURCE
664 #define _POSIX_C_SOURCE 200112
665 #elif _XOPEN_SOURCE - 0 >= 500
666 #define __XSI_VISIBLE 500
667 #undef _POSIX_C_SOURCE
668 #define _POSIX_C_SOURCE 199506
673 * Deal with all versions of POSIX. The ordering relative to the tests above is
676 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
677 #define _POSIX_C_SOURCE 198808
679 #ifdef _POSIX_C_SOURCE
680 #if _POSIX_C_SOURCE >= 200809
681 #define __POSIX_VISIBLE 200809
682 #define __ISO_C_VISIBLE 1999
683 #elif _POSIX_C_SOURCE >= 200112
684 #define __POSIX_VISIBLE 200112
685 #define __ISO_C_VISIBLE 1999
686 #elif _POSIX_C_SOURCE >= 199506
687 #define __POSIX_VISIBLE 199506
688 #define __ISO_C_VISIBLE 1990
689 #elif _POSIX_C_SOURCE >= 199309
690 #define __POSIX_VISIBLE 199309
691 #define __ISO_C_VISIBLE 1990
692 #elif _POSIX_C_SOURCE >= 199209
693 #define __POSIX_VISIBLE 199209
694 #define __ISO_C_VISIBLE 1990
695 #elif _POSIX_C_SOURCE >= 199009
696 #define __POSIX_VISIBLE 199009
697 #define __ISO_C_VISIBLE 1990
699 #define __POSIX_VISIBLE 198808
700 #define __ISO_C_VISIBLE 0
701 #endif /* _POSIX_C_SOURCE */
703 * Both glibc and OpenBSD enable c11 features when _ISOC11_SOURCE is defined, or
704 * when compiling with -stdc=c11. A strict reading of the standard would suggest
705 * doing it only for the former. However, a strict reading also requires C99
706 * mode only, so building with C11 is already undefined. Follow glibc's and
707 * OpenBSD's lead for this non-standard configuration for maximum compatibility.
709 #if _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L)
710 #undef __ISO_C_VISIBLE
711 #define __ISO_C_VISIBLE 2011
715 * Deal with _ANSI_SOURCE:
716 * If it is defined, and no other compilation environment is explicitly
717 * requested, then define our internal feature-test macros to zero. This
718 * makes no difference to the preprocessor (undefined symbols in preprocessing
719 * expressions are defined to have value zero), but makes it more convenient for
720 * a test program to print out the values.
722 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
723 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
724 * environment (and in fact we will never get here).
726 #if defined(_ANSI_SOURCE) /* Hide almost everything. */
727 #define __POSIX_VISIBLE 0
728 #define __XSI_VISIBLE 0
729 #define __BSD_VISIBLE 0
730 #define __ISO_C_VISIBLE 1990
731 #define __EXT1_VISIBLE 0
732 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */
733 #define __POSIX_VISIBLE 0
734 #define __XSI_VISIBLE 0
735 #define __BSD_VISIBLE 0
736 #define __ISO_C_VISIBLE 1999
737 #define __EXT1_VISIBLE 0
738 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */
739 #define __POSIX_VISIBLE 0
740 #define __XSI_VISIBLE 0
741 #define __BSD_VISIBLE 0
742 #define __ISO_C_VISIBLE 2011
743 #define __EXT1_VISIBLE 0
744 #else /* Default environment: show everything. */
745 #define __POSIX_VISIBLE 200809
746 #define __XSI_VISIBLE 700
747 #define __BSD_VISIBLE 1
748 #define __ISO_C_VISIBLE 2011
749 #define __EXT1_VISIBLE 1
753 /* User override __EXT1_VISIBLE */
754 #if defined(__STDC_WANT_LIB_EXT1__)
755 #undef __EXT1_VISIBLE
756 #if __STDC_WANT_LIB_EXT1__
757 #define __EXT1_VISIBLE 1
759 #define __EXT1_VISIBLE 0
761 #endif /* __STDC_WANT_LIB_EXT1__ */
764 * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h
765 * translates them to __ARM_ARCH and the modern feature symbols defined by ARM.
767 #if defined(__arm__) && !defined(__ARM_ARCH)
768 #include <machine/acle-compat.h>
772 * Nullability qualifiers: currently only supported by Clang.
774 #if !(defined(__clang__) && __has_feature(nullability))
777 #define _Null_unspecified
778 #define __NULLABILITY_PRAGMA_PUSH
779 #define __NULLABILITY_PRAGMA_POP
781 #define __NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push") \
782 _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
783 #define __NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop")
787 * Type Safety Checking
789 * Clang provides additional attributes to enable checking type safety
790 * properties that cannot be enforced by the C type system.
793 #if __has_attribute(__argument_with_type_tag__) && \
794 __has_attribute(__type_tag_for_datatype__)
795 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
796 __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
797 #define __datatype_type_tag(kind, type) \
798 __attribute__((__type_tag_for_datatype__(kind, type)))
800 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx)
801 #define __datatype_type_tag(kind, type)
807 * Clang provides support for doing basic thread-safety tests at
808 * compile-time, by marking which locks will/should be held when
809 * entering/leaving a functions.
811 * Furthermore, it is also possible to annotate variables and structure
812 * members to enforce that they are only accessed when certain locks are
816 #if __has_extension(c_thread_safety_attributes)
817 #define __lock_annotate(x) __attribute__((x))
819 #define __lock_annotate(x)
822 /* Structure implements a lock. */
823 #define __lockable __lock_annotate(lockable)
825 /* Function acquires an exclusive or shared lock. */
826 #define __locks_exclusive(...) \
827 __lock_annotate(exclusive_lock_function(__VA_ARGS__))
828 #define __locks_shared(...) \
829 __lock_annotate(shared_lock_function(__VA_ARGS__))
831 /* Function attempts to acquire an exclusive or shared lock. */
832 #define __trylocks_exclusive(...) \
833 __lock_annotate(exclusive_trylock_function(__VA_ARGS__))
834 #define __trylocks_shared(...) \
835 __lock_annotate(shared_trylock_function(__VA_ARGS__))
837 /* Function releases a lock. */
838 #define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__))
840 /* Function asserts that an exclusive or shared lock is held. */
841 #define __asserts_exclusive(...) \
842 __lock_annotate(assert_exclusive_lock(__VA_ARGS__))
843 #define __asserts_shared(...) \
844 __lock_annotate(assert_shared_lock(__VA_ARGS__))
846 /* Function requires that an exclusive or shared lock is or is not held. */
847 #define __requires_exclusive(...) \
848 __lock_annotate(exclusive_locks_required(__VA_ARGS__))
849 #define __requires_shared(...) \
850 __lock_annotate(shared_locks_required(__VA_ARGS__))
851 #define __requires_unlocked(...) \
852 __lock_annotate(locks_excluded(__VA_ARGS__))
854 /* Function should not be analyzed. */
855 #define __no_lock_analysis __lock_annotate(no_thread_safety_analysis)
858 * Function or variable should not be sanitized, e.g., by AddressSanitizer.
859 * GCC has the nosanitize attribute, but as a function attribute only, and
860 * warns on use as a variable attribute.
862 #if __has_attribute(no_sanitize) && defined(__clang__)
864 #define __nosanitizeaddress __attribute__((no_sanitize("kernel-address")))
865 #define __nosanitizememory __attribute__((no_sanitize("kernel-memory")))
867 #define __nosanitizeaddress __attribute__((no_sanitize("address")))
868 #define __nosanitizememory __attribute__((no_sanitize("memory")))
870 #define __nosanitizethread __attribute__((no_sanitize("thread")))
872 #define __nosanitizeaddress
873 #define __nosanitizememory
874 #define __nosanitizethread
878 * Make it possible to opt out of stack smashing protection.
880 #if __has_attribute(no_stack_protector)
881 #define __nostackprotector __attribute__((no_stack_protector))
883 #define __nostackprotector \
884 __attribute__((__optimize__("-fno-stack-protector")))
887 /* Guard variables and structure members by lock. */
888 #define __guarded_by(x) __lock_annotate(guarded_by(x))
889 #define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x))
891 /* Alignment builtins for better type checking and improved code generation. */
892 /* Provide fallback versions for other compilers (GCC/Clang < 10): */
893 #if !__has_builtin(__builtin_is_aligned)
894 #define __builtin_is_aligned(x, align) \
895 (((__uintptr_t)x & ((align) - 1)) == 0)
897 #if !__has_builtin(__builtin_align_up)
898 #define __builtin_align_up(x, align) \
899 ((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1))))
901 #if !__has_builtin(__builtin_align_down)
902 #define __builtin_align_down(x, align) \
903 ((__typeof__(x))((x)&(~((align)-1))))
906 #define __align_up(x, y) __builtin_align_up(x, y)
907 #define __align_down(x, y) __builtin_align_down(x, y)
908 #define __is_aligned(x, y) __builtin_is_aligned(x, y)
910 #endif /* !_SYS_CDEFS_H_ */