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 #define __result_use_check
334 #if __GNUC_PREREQ__(4, 1)
335 #define __returns_twice __attribute__((__returns_twice__))
337 #define __returns_twice
340 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
341 #define __unreachable() __builtin_unreachable()
343 #define __unreachable() ((void)0)
346 #if (defined(__GNUC__) && __GNUC__ >= 2) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
347 #define __LONG_LONG_SUPPORTED
350 /* C++11 exposes a load of C99 stuff */
351 #if defined(__cplusplus) && __cplusplus >= 201103L
352 #define __LONG_LONG_SUPPORTED
353 #ifndef __STDC_LIMIT_MACROS
354 #define __STDC_LIMIT_MACROS
356 #ifndef __STDC_CONSTANT_MACROS
357 #define __STDC_CONSTANT_MACROS
362 * We use `__restrict' as a way to define the `restrict' type qualifier
363 * without disturbing older software that is unaware of C99 keywords.
364 * GCC also provides `__restrict' as an extension to support C99-style
365 * restricted pointers in other language modes.
367 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901
368 #define __restrict restrict
369 #elif !__GNUC_PREREQ__(2, 95)
374 * GNU C version 2.96 adds explicit branch prediction so that
375 * the CPU back-end can hint the processor and also so that
376 * code blocks can be reordered such that the predicted path
377 * sees a more linear flow, thus improving cache behavior, etc.
379 * The following two macros provide us with a way to utilize this
380 * compiler feature. Use __predict_true() if you expect the expression
381 * to evaluate to true, and __predict_false() if you expect the
382 * expression to evaluate to false.
384 * A few notes about usage:
386 * * Generally, __predict_false() error condition checks (unless
387 * you have some _strong_ reason to do otherwise, in which case
388 * document it), and/or __predict_true() `no-error' condition
389 * checks, assuming you want to optimize for the no-error case.
391 * * Other than that, if you don't know the likelihood of a test
392 * succeeding from empirical or other `hard' evidence, don't
395 * * These are meant to be used in places that are run `a lot'.
396 * It is wasteful to make predictions in code that is run
397 * seldomly (e.g. at subsystem initialization time) as the
398 * basic block reordering that this affects can often generate
401 #if __GNUC_PREREQ__(2, 96)
402 #define __predict_true(exp) __builtin_expect((exp), 1)
403 #define __predict_false(exp) __builtin_expect((exp), 0)
405 #define __predict_true(exp) (exp)
406 #define __predict_false(exp) (exp)
409 #if __GNUC_PREREQ__(4, 0)
410 #define __null_sentinel __attribute__((__sentinel__))
411 #define __exported __attribute__((__visibility__("default")))
412 #define __hidden __attribute__((__visibility__("hidden")))
414 #define __null_sentinel
420 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
423 #if __GNUC_PREREQ__(4, 1)
424 #define __offsetof(type, field) __builtin_offsetof(type, field)
427 #define __offsetof(type, field) \
428 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
430 #define __offsetof(type, field) \
431 (__offsetof__ (reinterpret_cast <__size_t> \
432 (&reinterpret_cast <const volatile char &> \
433 (static_cast<type *> (0)->field))))
436 #define __rangeof(type, start, end) \
437 (__offsetof(type, end) - __offsetof(type, start))
440 * Given the pointer x to the member m of the struct s, return
441 * a pointer to the containing structure. When using GCC, we first
442 * assign pointer x to a local variable, to check that its type is
443 * compatible with member m.
445 #if __GNUC_PREREQ__(3, 1)
446 #define __containerof(x, s, m) ({ \
447 const volatile __typeof(((s *)0)->m) *__x = (x); \
448 __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
451 #define __containerof(x, s, m) \
452 __DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
456 * Compiler-dependent macros to declare that functions take printf-like
457 * or scanf-like arguments. They are null except for versions of gcc
458 * that are known to support the features properly (old versions of gcc-2
459 * didn't permit keeping the keywords out of the application namespace).
461 #if !__GNUC_PREREQ__(2, 7)
462 #define __printflike(fmtarg, firstvararg)
463 #define __scanflike(fmtarg, firstvararg)
464 #define __format_arg(fmtarg)
465 #define __strfmonlike(fmtarg, firstvararg)
466 #define __strftimelike(fmtarg, firstvararg)
468 #define __printflike(fmtarg, firstvararg) \
469 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
470 #define __scanflike(fmtarg, firstvararg) \
471 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
472 #define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg)))
473 #define __strfmonlike(fmtarg, firstvararg) \
474 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
475 #define __strftimelike(fmtarg, firstvararg) \
476 __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
479 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
480 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
482 #define __printf0like(fmtarg, firstvararg) \
483 __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
485 #define __printf0like(fmtarg, firstvararg)
488 #if defined(__GNUC__)
489 #define __strong_reference(sym,aliassym) \
490 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
492 #define __weak_reference(sym,alias) \
493 __asm__(".weak " #alias); \
494 __asm__(".equ " #alias ", " #sym)
495 #define __warn_references(sym,msg) \
496 __asm__(".section .gnu.warning." #sym); \
497 __asm__(".asciz \"" msg "\""); \
499 #define __sym_compat(sym,impl,verid) \
500 __asm__(".symver " #impl ", " #sym "@" #verid)
501 #define __sym_default(sym,impl,verid) \
502 __asm__(".symver " #impl ", " #sym "@@@" #verid)
504 #define __weak_reference(sym,alias) \
505 __asm__(".weak alias"); \
506 __asm__(".equ alias, sym")
507 #define __warn_references(sym,msg) \
508 __asm__(".section .gnu.warning.sym"); \
509 __asm__(".asciz \"msg\""); \
511 #define __sym_compat(sym,impl,verid) \
512 __asm__(".symver impl, sym@verid")
513 #define __sym_default(impl,sym,verid) \
514 __asm__(".symver impl, sym@@@verid")
515 #endif /* __STDC__ */
516 #endif /* __GNUC__ */
518 #define __GLOBL(sym) __asm__(".globl " __XSTRING(sym))
519 #define __WEAK(sym) __asm__(".weak " __XSTRING(sym))
521 #if defined(__GNUC__)
522 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
525 * The following definition might not work well if used in header files,
526 * but it should be better than nothing. If you want a "do nothing"
527 * version, then it should generate some harmless declaration, such as:
528 * #define __IDSTRING(name,string) struct __hack
530 #define __IDSTRING(name,string) static const char name[] __unused = string
534 * Embed the rcs id of a source file in the resulting library. Note that in
535 * more recent ELF binutils, we use .ident allowing the ID to be stripped.
539 #if !defined(STRIP_FBSDID)
540 #define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
542 #define __FBSDID(s) struct __hack
548 #define __RCSID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
550 #define __RCSID(s) struct __hack
554 #ifndef __RCSID_SOURCE
555 #ifndef NO__RCSID_SOURCE
556 #define __RCSID_SOURCE(s) __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
558 #define __RCSID_SOURCE(s) struct __hack
564 #define __SCCSID(s) __IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
566 #define __SCCSID(s) struct __hack
571 #ifndef NO__COPYRIGHT
572 #define __COPYRIGHT(s) __IDSTRING(__CONCAT(__copyright_,__LINE__),s)
574 #define __COPYRIGHT(s) struct __hack
579 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var))
583 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var))
587 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var))
591 * The following definitions are an extension of the behavior originally
592 * implemented in <sys/_posix.h>, but with a different level of granularity.
593 * POSIX.1 requires that the macros we test be defined before any standard
594 * header file is included.
596 * Here's a quick run-down of the versions (and some informal names)
597 * defined(_POSIX_SOURCE) 1003.1-1988
598 * encoded as 198808 below
599 * _POSIX_C_SOURCE == 1 1003.1-1990
600 * encoded as 199009 below
601 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
602 * encoded as 199209 below
603 * _POSIX_C_SOURCE == 199309 1003.1b-1993
604 * (1003.1 Issue 4, Single Unix Spec v1, Unix 93)
605 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
606 * and the omnibus ISO/IEC 9945-1: 1996
607 * (1003.1 Issue 5, Single Unix Spec v2, Unix 95)
608 * _POSIX_C_SOURCE == 200112 1003.1-2001 (1003.1 Issue 6, Unix 03)
609 * _POSIX_C_SOURCE == 200809 1003.1-2008 (1003.1 Issue 7)
610 * IEEE Std 1003.1-2017 (Rev of 1003.1-2008) is
611 * 1003.1-2008 with two TCs applied with
612 * _POSIX_C_SOURCE=200809 and _XOPEN_SOURCE=700
614 * In addition, the X/Open Portability Guide, which is now the Single UNIX
615 * Specification, defines a feature-test macro which indicates the version of
616 * that specification, and which subsumes _POSIX_C_SOURCE.
618 * Our macros begin with two underscores to avoid namespace screwage.
621 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
622 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
623 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
624 #define _POSIX_C_SOURCE 199009
627 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
628 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
629 #undef _POSIX_C_SOURCE
630 #define _POSIX_C_SOURCE 199209
633 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
635 #if _XOPEN_SOURCE - 0 >= 700
636 #define __XSI_VISIBLE 700
637 #undef _POSIX_C_SOURCE
638 #define _POSIX_C_SOURCE 200809
639 #elif _XOPEN_SOURCE - 0 >= 600
640 #define __XSI_VISIBLE 600
641 #undef _POSIX_C_SOURCE
642 #define _POSIX_C_SOURCE 200112
643 #elif _XOPEN_SOURCE - 0 >= 500
644 #define __XSI_VISIBLE 500
645 #undef _POSIX_C_SOURCE
646 #define _POSIX_C_SOURCE 199506
651 * Deal with all versions of POSIX. The ordering relative to the tests above is
654 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
655 #define _POSIX_C_SOURCE 198808
657 #ifdef _POSIX_C_SOURCE
658 #if _POSIX_C_SOURCE >= 200809
659 #define __POSIX_VISIBLE 200809
660 #define __ISO_C_VISIBLE 1999
661 #elif _POSIX_C_SOURCE >= 200112
662 #define __POSIX_VISIBLE 200112
663 #define __ISO_C_VISIBLE 1999
664 #elif _POSIX_C_SOURCE >= 199506
665 #define __POSIX_VISIBLE 199506
666 #define __ISO_C_VISIBLE 1990
667 #elif _POSIX_C_SOURCE >= 199309
668 #define __POSIX_VISIBLE 199309
669 #define __ISO_C_VISIBLE 1990
670 #elif _POSIX_C_SOURCE >= 199209
671 #define __POSIX_VISIBLE 199209
672 #define __ISO_C_VISIBLE 1990
673 #elif _POSIX_C_SOURCE >= 199009
674 #define __POSIX_VISIBLE 199009
675 #define __ISO_C_VISIBLE 1990
677 #define __POSIX_VISIBLE 198808
678 #define __ISO_C_VISIBLE 0
679 #endif /* _POSIX_C_SOURCE */
681 * Both glibc and OpenBSD enable c11 features when _ISOC11_SOURCE is defined, or
682 * when compiling with -stdc=c11. A strict reading of the standard would suggest
683 * doing it only for the former. However, a strict reading also requires C99
684 * mode only, so building with C11 is already undefined. Follow glibc's and
685 * OpenBSD's lead for this non-standard configuration for maximum compatibility.
687 #if _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L)
688 #undef __ISO_C_VISIBLE
689 #define __ISO_C_VISIBLE 2011
693 * Deal with _ANSI_SOURCE:
694 * If it is defined, and no other compilation environment is explicitly
695 * requested, then define our internal feature-test macros to zero. This
696 * makes no difference to the preprocessor (undefined symbols in preprocessing
697 * expressions are defined to have value zero), but makes it more convenient for
698 * a test program to print out the values.
700 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
701 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
702 * environment (and in fact we will never get here).
704 #if defined(_ANSI_SOURCE) /* Hide almost everything. */
705 #define __POSIX_VISIBLE 0
706 #define __XSI_VISIBLE 0
707 #define __BSD_VISIBLE 0
708 #define __ISO_C_VISIBLE 1990
709 #define __EXT1_VISIBLE 0
710 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */
711 #define __POSIX_VISIBLE 0
712 #define __XSI_VISIBLE 0
713 #define __BSD_VISIBLE 0
714 #define __ISO_C_VISIBLE 1999
715 #define __EXT1_VISIBLE 0
716 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */
717 #define __POSIX_VISIBLE 0
718 #define __XSI_VISIBLE 0
719 #define __BSD_VISIBLE 0
720 #define __ISO_C_VISIBLE 2011
721 #define __EXT1_VISIBLE 0
722 #else /* Default environment: show everything. */
723 #define __POSIX_VISIBLE 200809
724 #define __XSI_VISIBLE 700
725 #define __BSD_VISIBLE 1
726 #define __ISO_C_VISIBLE 2011
727 #define __EXT1_VISIBLE 1
731 /* User override __EXT1_VISIBLE */
732 #if defined(__STDC_WANT_LIB_EXT1__)
733 #undef __EXT1_VISIBLE
734 #if __STDC_WANT_LIB_EXT1__
735 #define __EXT1_VISIBLE 1
737 #define __EXT1_VISIBLE 0
739 #endif /* __STDC_WANT_LIB_EXT1__ */
742 * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h
743 * translates them to __ARM_ARCH and the modern feature symbols defined by ARM.
745 #if defined(__arm__) && !defined(__ARM_ARCH)
746 #include <machine/acle-compat.h>
750 * Nullability qualifiers: currently only supported by Clang.
752 #if !(defined(__clang__) && __has_feature(nullability))
755 #define _Null_unspecified
756 #define __NULLABILITY_PRAGMA_PUSH
757 #define __NULLABILITY_PRAGMA_POP
759 #define __NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push") \
760 _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
761 #define __NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop")
765 * Type Safety Checking
767 * Clang provides additional attributes to enable checking type safety
768 * properties that cannot be enforced by the C type system.
771 #if __has_attribute(__argument_with_type_tag__) && \
772 __has_attribute(__type_tag_for_datatype__)
773 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
774 __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
775 #define __datatype_type_tag(kind, type) \
776 __attribute__((__type_tag_for_datatype__(kind, type)))
778 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx)
779 #define __datatype_type_tag(kind, type)
785 * Clang provides support for doing basic thread-safety tests at
786 * compile-time, by marking which locks will/should be held when
787 * entering/leaving a functions.
789 * Furthermore, it is also possible to annotate variables and structure
790 * members to enforce that they are only accessed when certain locks are
794 #if __has_extension(c_thread_safety_attributes)
795 #define __lock_annotate(x) __attribute__((x))
797 #define __lock_annotate(x)
800 /* Structure implements a lock. */
801 #define __lockable __lock_annotate(lockable)
803 /* Function acquires an exclusive or shared lock. */
804 #define __locks_exclusive(...) \
805 __lock_annotate(exclusive_lock_function(__VA_ARGS__))
806 #define __locks_shared(...) \
807 __lock_annotate(shared_lock_function(__VA_ARGS__))
809 /* Function attempts to acquire an exclusive or shared lock. */
810 #define __trylocks_exclusive(...) \
811 __lock_annotate(exclusive_trylock_function(__VA_ARGS__))
812 #define __trylocks_shared(...) \
813 __lock_annotate(shared_trylock_function(__VA_ARGS__))
815 /* Function releases a lock. */
816 #define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__))
818 /* Function asserts that an exclusive or shared lock is held. */
819 #define __asserts_exclusive(...) \
820 __lock_annotate(assert_exclusive_lock(__VA_ARGS__))
821 #define __asserts_shared(...) \
822 __lock_annotate(assert_shared_lock(__VA_ARGS__))
824 /* Function requires that an exclusive or shared lock is or is not held. */
825 #define __requires_exclusive(...) \
826 __lock_annotate(exclusive_locks_required(__VA_ARGS__))
827 #define __requires_shared(...) \
828 __lock_annotate(shared_locks_required(__VA_ARGS__))
829 #define __requires_unlocked(...) \
830 __lock_annotate(locks_excluded(__VA_ARGS__))
832 /* Function should not be analyzed. */
833 #define __no_lock_analysis __lock_annotate(no_thread_safety_analysis)
836 * Function or variable should not be sanitized, e.g., by AddressSanitizer.
837 * GCC has the nosanitize attribute, but as a function attribute only, and
838 * warns on use as a variable attribute.
840 #if __has_attribute(no_sanitize) && defined(__clang__)
842 #define __nosanitizeaddress __attribute__((no_sanitize("kernel-address")))
843 #define __nosanitizememory __attribute__((no_sanitize("kernel-memory")))
845 #define __nosanitizeaddress __attribute__((no_sanitize("address")))
846 #define __nosanitizememory __attribute__((no_sanitize("memory")))
848 #define __nosanitizethread __attribute__((no_sanitize("thread")))
850 #define __nosanitizeaddress
851 #define __nosanitizememory
852 #define __nosanitizethread
856 * Make it possible to opt out of stack smashing protection.
858 #if __has_attribute(no_stack_protector)
859 #define __nostackprotector __attribute__((no_stack_protector))
861 #define __nostackprotector \
862 __attribute__((__optimize__("-fno-stack-protector")))
865 /* Guard variables and structure members by lock. */
866 #define __guarded_by(x) __lock_annotate(guarded_by(x))
867 #define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x))
869 /* Alignment builtins for better type checking and improved code generation. */
870 /* Provide fallback versions for other compilers (GCC/Clang < 10): */
871 #if !__has_builtin(__builtin_is_aligned)
872 #define __builtin_is_aligned(x, align) \
873 (((__uintptr_t)x & ((align) - 1)) == 0)
875 #if !__has_builtin(__builtin_align_up)
876 #define __builtin_align_up(x, align) \
877 ((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1))))
879 #if !__has_builtin(__builtin_align_down)
880 #define __builtin_align_down(x, align) \
881 ((__typeof__(x))((x)&(~((align)-1))))
884 #define __align_up(x, y) __builtin_align_up(x, y)
885 #define __align_down(x, y) __builtin_align_down(x, y)
886 #define __is_aligned(x, y) __builtin_is_aligned(x, y)
888 #endif /* !_SYS_CDEFS_H_ */