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
34 * @(#)cdefs.h 8.8 (Berkeley) 1/9/95
40 #if defined(_KERNEL) && defined(_STANDALONE)
41 #error "_KERNEL and _STANDALONE are mutually exclusive"
45 * Testing against Clang-specific extensions.
47 #ifndef __has_attribute
48 #define __has_attribute(x) 0
50 #ifndef __has_extension
51 #define __has_extension __has_feature
54 #define __has_feature(x) 0
57 #define __has_include(x) 0
60 #define __has_builtin(x) 0
63 #if defined(__cplusplus)
64 #define __BEGIN_DECLS extern "C" {
72 * This code has been put in place to help reduce the addition of
73 * compiler specific defines in FreeBSD code. It helps to aid in
74 * having a compiler-agnostic source tree.
79 #define __GNUCLIKE___SECTION 1
81 #define __GNUCLIKE_CTOR_SECTION_HANDLING 1
83 #define __GNUCLIKE_BUILTIN_CONSTANT_P 1
85 #if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3)
86 #define __GNUCLIKE_BUILTIN_VARARGS 1
87 #define __GNUCLIKE_BUILTIN_STDARG 1
88 #define __GNUCLIKE_BUILTIN_VAALIST 1
91 #define __GNUC_VA_LIST_COMPATIBILITY 1
94 * Compiler memory barriers, specific to gcc and clang.
96 #define __compiler_membar() __asm __volatile(" " : : : "memory")
98 #define __GNUCLIKE_BUILTIN_NEXT_ARG 1
99 #define __GNUCLIKE_MATH_BUILTIN_RELOPS
101 #define __GNUCLIKE_BUILTIN_MEMCPY 1
103 /* XXX: if __GNUC__ >= 2: not tested everywhere originally, where replaced */
104 #define __CC_SUPPORTS_INLINE 1
105 #define __CC_SUPPORTS___INLINE 1
106 #define __CC_SUPPORTS___INLINE__ 1
108 #define __CC_SUPPORTS___FUNC__ 1
109 #define __CC_SUPPORTS_WARNING 1
111 #define __CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */
113 #define __CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
115 #endif /* __GNUC__ */
118 * Macro to test if we're using a specific version of gcc or later.
120 #if defined(__GNUC__)
121 #define __GNUC_PREREQ__(ma, mi) \
122 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
124 #define __GNUC_PREREQ__(ma, mi) 0
128 * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
129 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
130 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
131 * mode -- there must be no spaces between its arguments, and for nested
132 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also
133 * concatenate double-quoted strings produced by the __STRING macro, but
134 * this only works with ANSI C.
136 * __XSTRING is like __STRING, but it expands any macros in its argument
137 * first. It is only available with ANSI C.
139 #if defined(__STDC__) || defined(__cplusplus)
140 #define __P(protos) protos /* full-blown ANSI C */
141 #define __CONCAT1(x,y) x ## y
142 #define __CONCAT(x,y) __CONCAT1(x,y)
143 #define __STRING(x) #x /* stringify without expanding x */
144 #define __XSTRING(x) __STRING(x) /* expand x, then stringify */
146 #define __const const /* define reserved names to standard */
147 #define __signed signed
148 #define __volatile volatile
149 #if defined(__cplusplus)
150 #define __inline inline /* convert to C++ keyword */
152 #if !(defined(__CC_SUPPORTS___INLINE))
153 #define __inline /* delete GCC keyword */
154 #endif /* ! __CC_SUPPORTS___INLINE */
155 #endif /* !__cplusplus */
157 #else /* !(__STDC__ || __cplusplus) */
158 #define __P(protos) () /* traditional C preprocessor */
159 #define __CONCAT(x,y) x/**/y
160 #define __STRING(x) "x"
162 #if !defined(__CC_SUPPORTS___INLINE)
163 #define __const /* delete pseudo-ANSI C keywords */
168 * In non-ANSI C environments, new programs will want ANSI-only C keywords
169 * deleted from the program and old programs will want them left alone.
170 * When using a compiler other than gcc, programs using the ANSI C keywords
171 * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
172 * When using "gcc -traditional", we assume that this is the intent; if
173 * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
175 #ifndef NO_ANSI_KEYWORDS
176 #define const /* delete ANSI C keywords */
180 #endif /* !NO_ANSI_KEYWORDS */
181 #endif /* !__CC_SUPPORTS___INLINE */
182 #endif /* !(__STDC__ || __cplusplus) */
185 * Compiler-dependent macros to help declare dead (non-returning) and
186 * pure (no side effects) functions, and unused variables. They are
187 * null except for versions of gcc that are known to support the features
188 * properly (old versions of gcc-2 supported the dead and pure features
189 * in a different (wrong) way). If we do not provide an implementation
190 * for a given compiler, let the compile fail if it is told to use
191 * a feature that we cannot live without.
193 #define __weak_symbol __attribute__((__weak__))
194 #if !__GNUC_PREREQ__(2, 5)
199 #if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7
200 #define __dead2 __attribute__((__noreturn__))
201 #define __pure2 __attribute__((__const__))
203 /* XXX Find out what to do for __packed, __aligned and __section */
205 #if __GNUC_PREREQ__(2, 7)
206 #define __dead2 __attribute__((__noreturn__))
207 #define __pure2 __attribute__((__const__))
208 #define __unused __attribute__((__unused__))
209 #define __used __attribute__((__used__))
210 #define __packed __attribute__((__packed__))
211 #define __aligned(x) __attribute__((__aligned__(x)))
212 #define __section(x) __attribute__((__section__(x)))
214 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__)
215 #define __alloc_size(x) __attribute__((__alloc_size__(x)))
216 #define __alloc_size2(n, x) __attribute__((__alloc_size__(n, x)))
218 #define __alloc_size(x)
219 #define __alloc_size2(n, x)
221 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
222 #define __alloc_align(x) __attribute__((__alloc_align__(x)))
224 #define __alloc_align(x)
227 #if !__GNUC_PREREQ__(2, 95)
228 #define __alignof(x) __offsetof(struct { char __a; x __b; }, __b)
232 * Keywords added in C11.
235 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
237 #if !__has_extension(c_alignas)
238 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
239 __has_extension(cxx_alignas)
240 #define _Alignas(x) alignas(x)
242 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
243 #define _Alignas(x) __aligned(x)
247 #if defined(__cplusplus) && __cplusplus >= 201103L
248 #define _Alignof(x) alignof(x)
250 #define _Alignof(x) __alignof(x)
253 #if !defined(__cplusplus) && !__has_extension(c_atomic) && \
254 !__has_extension(cxx_atomic) && !__GNUC_PREREQ__(4, 7)
256 * No native support for _Atomic(). Place object in structure to prevent
257 * most forms of direct non-atomic access.
259 #define _Atomic(T) struct { T volatile __val; }
262 #if defined(__cplusplus) && __cplusplus >= 201103L
263 #define _Noreturn [[noreturn]]
265 #define _Noreturn __dead2
268 #if !__has_extension(c_static_assert)
269 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
270 __has_extension(cxx_static_assert)
271 #define _Static_assert(x, y) static_assert(x, y)
272 #elif __GNUC_PREREQ__(4,6) && !defined(__cplusplus)
273 /* Nothing, gcc 4.6 and higher has _Static_assert built-in */
274 #elif defined(__COUNTER__)
275 #define _Static_assert(x, y) __Static_assert(x, __COUNTER__)
276 #define __Static_assert(x, y) ___Static_assert(x, y)
277 #define ___Static_assert(x, y) typedef char __assert_ ## y[(x) ? 1 : -1] \
280 #define _Static_assert(x, y) struct __hack
284 #if !__has_extension(c_thread_local)
286 * XXX: Some compilers (Clang 3.3, GCC 4.7) falsely announce C++11 mode
287 * without actually supporting the thread_local keyword. Don't check for
288 * the presence of C++11 when defining _Thread_local.
290 #if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \
291 __has_extension(cxx_thread_local)
292 #define _Thread_local thread_local
294 #define _Thread_local __thread
298 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
301 * Emulation of C11 _Generic(). Unlike the previously defined C11
302 * keywords, it is not possible to implement this using exactly the same
303 * syntax. Therefore implement something similar under the name
304 * __generic(). Unlike _Generic(), this macro can only distinguish
305 * between a single type, so it requires nested invocations to
306 * distinguish multiple cases.
308 * Note that the comma operator is used to force expr to decay in
309 * order to match _Generic().
312 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \
313 __has_extension(c_generic_selections)
314 #define __generic(expr, t, yes, no) \
315 _Generic(expr, t: yes, default: no)
316 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
317 #define __generic(expr, t, yes, no) \
318 __builtin_choose_expr( \
319 __builtin_types_compatible_p(__typeof((0, (expr))), t), yes, no)
323 * C99 Static array indices in function parameter declarations. Syntax such as:
324 * void bar(int myArray[static 10]);
325 * is allowed in C99 but not in C++. Define __min_size appropriately so
326 * headers using it can be compiled in either language. Use like this:
327 * void bar(int myArray[__min_size(10)]);
329 #if !defined(__cplusplus) && \
330 (defined(__clang__) || __GNUC_PREREQ__(4, 6)) && \
331 (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901))
332 #define __min_size(x) static (x)
334 #define __min_size(x) (x)
337 #if __GNUC_PREREQ__(2, 96)
338 #define __malloc_like __attribute__((__malloc__))
339 #define __pure __attribute__((__pure__))
341 #define __malloc_like
345 #if __GNUC_PREREQ__(3, 1)
346 #define __always_inline __attribute__((__always_inline__))
348 #define __always_inline
351 #if __GNUC_PREREQ__(3, 1)
352 #define __noinline __attribute__ ((__noinline__))
357 #if __GNUC_PREREQ__(3, 4)
358 #define __fastcall __attribute__((__fastcall__))
359 #define __result_use_check __attribute__((__warn_unused_result__))
362 #define __result_use_check
365 #if __GNUC_PREREQ__(4, 1)
366 #define __returns_twice __attribute__((__returns_twice__))
368 #define __returns_twice
371 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
372 #define __unreachable() __builtin_unreachable()
374 #define __unreachable() ((void)0)
377 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
378 #if !__GNUC_PREREQ__(2, 7)
379 #define __func__ NULL
382 #if (defined(__GNUC__) && __GNUC__ >= 2) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
383 #define __LONG_LONG_SUPPORTED
386 /* C++11 exposes a load of C99 stuff */
387 #if defined(__cplusplus) && __cplusplus >= 201103L
388 #define __LONG_LONG_SUPPORTED
389 #ifndef __STDC_LIMIT_MACROS
390 #define __STDC_LIMIT_MACROS
392 #ifndef __STDC_CONSTANT_MACROS
393 #define __STDC_CONSTANT_MACROS
398 * We use `__restrict' as a way to define the `restrict' type qualifier
399 * without disturbing older software that is unaware of C99 keywords.
400 * GCC also provides `__restrict' as an extension to support C99-style
401 * restricted pointers in other language modes.
403 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901
404 #define __restrict restrict
405 #elif !__GNUC_PREREQ__(2, 95)
410 * GNU C version 2.96 adds explicit branch prediction so that
411 * the CPU back-end can hint the processor and also so that
412 * code blocks can be reordered such that the predicted path
413 * sees a more linear flow, thus improving cache behavior, etc.
415 * The following two macros provide us with a way to utilize this
416 * compiler feature. Use __predict_true() if you expect the expression
417 * to evaluate to true, and __predict_false() if you expect the
418 * expression to evaluate to false.
420 * A few notes about usage:
422 * * Generally, __predict_false() error condition checks (unless
423 * you have some _strong_ reason to do otherwise, in which case
424 * document it), and/or __predict_true() `no-error' condition
425 * checks, assuming you want to optimize for the no-error case.
427 * * Other than that, if you don't know the likelihood of a test
428 * succeeding from empirical or other `hard' evidence, don't
431 * * These are meant to be used in places that are run `a lot'.
432 * It is wasteful to make predictions in code that is run
433 * seldomly (e.g. at subsystem initialization time) as the
434 * basic block reordering that this affects can often generate
437 #if __GNUC_PREREQ__(2, 96)
438 #define __predict_true(exp) __builtin_expect((exp), 1)
439 #define __predict_false(exp) __builtin_expect((exp), 0)
441 #define __predict_true(exp) (exp)
442 #define __predict_false(exp) (exp)
445 #if __GNUC_PREREQ__(4, 0)
446 #define __null_sentinel __attribute__((__sentinel__))
447 #define __exported __attribute__((__visibility__("default")))
448 #define __hidden __attribute__((__visibility__("hidden")))
450 #define __null_sentinel
456 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
459 #if __GNUC_PREREQ__(4, 1)
460 #define __offsetof(type, field) __builtin_offsetof(type, field)
463 #define __offsetof(type, field) \
464 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
466 #define __offsetof(type, field) \
467 (__offsetof__ (reinterpret_cast <__size_t> \
468 (&reinterpret_cast <const volatile char &> \
469 (static_cast<type *> (0)->field))))
472 #define __rangeof(type, start, end) \
473 (__offsetof(type, end) - __offsetof(type, start))
476 * Given the pointer x to the member m of the struct s, return
477 * a pointer to the containing structure. When using GCC, we first
478 * assign pointer x to a local variable, to check that its type is
479 * compatible with member m.
481 #if __GNUC_PREREQ__(3, 1)
482 #define __containerof(x, s, m) ({ \
483 const volatile __typeof(((s *)0)->m) *__x = (x); \
484 __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
487 #define __containerof(x, s, m) \
488 __DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
492 * Compiler-dependent macros to declare that functions take printf-like
493 * or scanf-like arguments. They are null except for versions of gcc
494 * that are known to support the features properly (old versions of gcc-2
495 * didn't permit keeping the keywords out of the application namespace).
497 #if !__GNUC_PREREQ__(2, 7)
498 #define __printflike(fmtarg, firstvararg)
499 #define __scanflike(fmtarg, firstvararg)
500 #define __format_arg(fmtarg)
501 #define __strfmonlike(fmtarg, firstvararg)
502 #define __strftimelike(fmtarg, firstvararg)
504 #define __printflike(fmtarg, firstvararg) \
505 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
506 #define __scanflike(fmtarg, firstvararg) \
507 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
508 #define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg)))
509 #define __strfmonlike(fmtarg, firstvararg) \
510 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
511 #define __strftimelike(fmtarg, firstvararg) \
512 __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
515 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
516 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
518 #define __printf0like(fmtarg, firstvararg) \
519 __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
521 #define __printf0like(fmtarg, firstvararg)
524 #if defined(__GNUC__)
525 #define __strong_reference(sym,aliassym) \
526 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
528 #define __weak_reference(sym,alias) \
529 __asm__(".weak " #alias); \
530 __asm__(".equ " #alias ", " #sym)
531 #define __warn_references(sym,msg) \
532 __asm__(".section .gnu.warning." #sym); \
533 __asm__(".asciz \"" msg "\""); \
535 #define __sym_compat(sym,impl,verid) \
536 __asm__(".symver " #impl ", " #sym "@" #verid)
537 #define __sym_default(sym,impl,verid) \
538 __asm__(".symver " #impl ", " #sym "@@@" #verid)
540 #define __weak_reference(sym,alias) \
541 __asm__(".weak alias"); \
542 __asm__(".equ alias, sym")
543 #define __warn_references(sym,msg) \
544 __asm__(".section .gnu.warning.sym"); \
545 __asm__(".asciz \"msg\""); \
547 #define __sym_compat(sym,impl,verid) \
548 __asm__(".symver impl, sym@verid")
549 #define __sym_default(impl,sym,verid) \
550 __asm__(".symver impl, sym@@@verid")
551 #endif /* __STDC__ */
552 #endif /* __GNUC__ */
554 #define __GLOBL(sym) __asm__(".globl " __XSTRING(sym))
555 #define __WEAK(sym) __asm__(".weak " __XSTRING(sym))
557 #if defined(__GNUC__)
558 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
561 * The following definition might not work well if used in header files,
562 * but it should be better than nothing. If you want a "do nothing"
563 * version, then it should generate some harmless declaration, such as:
564 * #define __IDSTRING(name,string) struct __hack
566 #define __IDSTRING(name,string) static const char name[] __unused = string
570 * Embed the rcs id of a source file in the resulting library. Note that in
571 * more recent ELF binutils, we use .ident allowing the ID to be stripped.
575 #if !defined(STRIP_FBSDID)
576 #define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
578 #define __FBSDID(s) struct __hack
584 #define __RCSID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
586 #define __RCSID(s) struct __hack
590 #ifndef __RCSID_SOURCE
591 #ifndef NO__RCSID_SOURCE
592 #define __RCSID_SOURCE(s) __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
594 #define __RCSID_SOURCE(s) struct __hack
600 #define __SCCSID(s) __IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
602 #define __SCCSID(s) struct __hack
607 #ifndef NO__COPYRIGHT
608 #define __COPYRIGHT(s) __IDSTRING(__CONCAT(__copyright_,__LINE__),s)
610 #define __COPYRIGHT(s) struct __hack
615 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var))
619 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var))
623 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var))
627 * The following definitions are an extension of the behavior originally
628 * implemented in <sys/_posix.h>, but with a different level of granularity.
629 * POSIX.1 requires that the macros we test be defined before any standard
630 * header file is included.
632 * Here's a quick run-down of the versions (and some informal names)
633 * defined(_POSIX_SOURCE) 1003.1-1988
634 * encoded as 198808 below
635 * _POSIX_C_SOURCE == 1 1003.1-1990
636 * encoded as 199009 below
637 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
638 * encoded as 199209 below
639 * _POSIX_C_SOURCE == 199309 1003.1b-1993
640 * (1003.1 Issue 4, Single Unix Spec v1, Unix 93)
641 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
642 * and the omnibus ISO/IEC 9945-1: 1996
643 * (1003.1 Issue 5, Single Unix Spec v2, Unix 95)
644 * _POSIX_C_SOURCE == 200112 1003.1-2001 (1003.1 Issue 6, Unix 03)
645 * _POSIX_C_SOURCE == 200809 1003.1-2008 (1003.1 Issue 7)
646 * IEEE Std 1003.1-2017 (Rev of 1003.1-2008) is
647 * 1003.1-2008 with two TCs applied with
648 * _POSIX_C_SOURCE=200809 and _XOPEN_SOURCE=700
650 * In addition, the X/Open Portability Guide, which is now the Single UNIX
651 * Specification, defines a feature-test macro which indicates the version of
652 * that specification, and which subsumes _POSIX_C_SOURCE.
654 * Our macros begin with two underscores to avoid namespace screwage.
657 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
658 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
659 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
660 #define _POSIX_C_SOURCE 199009
663 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
664 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
665 #undef _POSIX_C_SOURCE
666 #define _POSIX_C_SOURCE 199209
669 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
671 #if _XOPEN_SOURCE - 0 >= 700
672 #define __XSI_VISIBLE 700
673 #undef _POSIX_C_SOURCE
674 #define _POSIX_C_SOURCE 200809
675 #elif _XOPEN_SOURCE - 0 >= 600
676 #define __XSI_VISIBLE 600
677 #undef _POSIX_C_SOURCE
678 #define _POSIX_C_SOURCE 200112
679 #elif _XOPEN_SOURCE - 0 >= 500
680 #define __XSI_VISIBLE 500
681 #undef _POSIX_C_SOURCE
682 #define _POSIX_C_SOURCE 199506
687 * Deal with all versions of POSIX. The ordering relative to the tests above is
690 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
691 #define _POSIX_C_SOURCE 198808
693 #ifdef _POSIX_C_SOURCE
694 #if _POSIX_C_SOURCE >= 200809
695 #define __POSIX_VISIBLE 200809
696 #define __ISO_C_VISIBLE 1999
697 #elif _POSIX_C_SOURCE >= 200112
698 #define __POSIX_VISIBLE 200112
699 #define __ISO_C_VISIBLE 1999
700 #elif _POSIX_C_SOURCE >= 199506
701 #define __POSIX_VISIBLE 199506
702 #define __ISO_C_VISIBLE 1990
703 #elif _POSIX_C_SOURCE >= 199309
704 #define __POSIX_VISIBLE 199309
705 #define __ISO_C_VISIBLE 1990
706 #elif _POSIX_C_SOURCE >= 199209
707 #define __POSIX_VISIBLE 199209
708 #define __ISO_C_VISIBLE 1990
709 #elif _POSIX_C_SOURCE >= 199009
710 #define __POSIX_VISIBLE 199009
711 #define __ISO_C_VISIBLE 1990
713 #define __POSIX_VISIBLE 198808
714 #define __ISO_C_VISIBLE 0
715 #endif /* _POSIX_C_SOURCE */
717 * Both glibc and OpenBSD enable c11 features when _ISOC11_SOURCE is defined, or
718 * when compiling with -stdc=c11. A strict reading of the standard would suggest
719 * doing it only for the former. However, a strict reading also requires C99
720 * mode only, so building with C11 is already undefined. Follow glibc's and
721 * OpenBSD's lead for this non-standard configuration for maximum compatibility.
723 #if _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L)
724 #undef __ISO_C_VISIBLE
725 #define __ISO_C_VISIBLE 2011
729 * Deal with _ANSI_SOURCE:
730 * If it is defined, and no other compilation environment is explicitly
731 * requested, then define our internal feature-test macros to zero. This
732 * makes no difference to the preprocessor (undefined symbols in preprocessing
733 * expressions are defined to have value zero), but makes it more convenient for
734 * a test program to print out the values.
736 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
737 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
738 * environment (and in fact we will never get here).
740 #if defined(_ANSI_SOURCE) /* Hide almost everything. */
741 #define __POSIX_VISIBLE 0
742 #define __XSI_VISIBLE 0
743 #define __BSD_VISIBLE 0
744 #define __ISO_C_VISIBLE 1990
745 #define __EXT1_VISIBLE 0
746 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */
747 #define __POSIX_VISIBLE 0
748 #define __XSI_VISIBLE 0
749 #define __BSD_VISIBLE 0
750 #define __ISO_C_VISIBLE 1999
751 #define __EXT1_VISIBLE 0
752 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */
753 #define __POSIX_VISIBLE 0
754 #define __XSI_VISIBLE 0
755 #define __BSD_VISIBLE 0
756 #define __ISO_C_VISIBLE 2011
757 #define __EXT1_VISIBLE 0
758 #else /* Default environment: show everything. */
759 #define __POSIX_VISIBLE 200809
760 #define __XSI_VISIBLE 700
761 #define __BSD_VISIBLE 1
762 #define __ISO_C_VISIBLE 2011
763 #define __EXT1_VISIBLE 1
767 /* User override __EXT1_VISIBLE */
768 #if defined(__STDC_WANT_LIB_EXT1__)
769 #undef __EXT1_VISIBLE
770 #if __STDC_WANT_LIB_EXT1__
771 #define __EXT1_VISIBLE 1
773 #define __EXT1_VISIBLE 0
775 #endif /* __STDC_WANT_LIB_EXT1__ */
778 * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h
779 * translates them to __ARM_ARCH and the modern feature symbols defined by ARM.
781 #if defined(__arm__) && !defined(__ARM_ARCH)
782 #include <machine/acle-compat.h>
786 * Nullability qualifiers: currently only supported by Clang.
788 #if !(defined(__clang__) && __has_feature(nullability))
791 #define _Null_unspecified
792 #define __NULLABILITY_PRAGMA_PUSH
793 #define __NULLABILITY_PRAGMA_POP
795 #define __NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push") \
796 _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
797 #define __NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop")
801 * Type Safety Checking
803 * Clang provides additional attributes to enable checking type safety
804 * properties that cannot be enforced by the C type system.
807 #if __has_attribute(__argument_with_type_tag__) && \
808 __has_attribute(__type_tag_for_datatype__)
809 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
810 __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
811 #define __datatype_type_tag(kind, type) \
812 __attribute__((__type_tag_for_datatype__(kind, type)))
814 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx)
815 #define __datatype_type_tag(kind, type)
821 * Clang provides support for doing basic thread-safety tests at
822 * compile-time, by marking which locks will/should be held when
823 * entering/leaving a functions.
825 * Furthermore, it is also possible to annotate variables and structure
826 * members to enforce that they are only accessed when certain locks are
830 #if __has_extension(c_thread_safety_attributes)
831 #define __lock_annotate(x) __attribute__((x))
833 #define __lock_annotate(x)
836 /* Structure implements a lock. */
837 #define __lockable __lock_annotate(lockable)
839 /* Function acquires an exclusive or shared lock. */
840 #define __locks_exclusive(...) \
841 __lock_annotate(exclusive_lock_function(__VA_ARGS__))
842 #define __locks_shared(...) \
843 __lock_annotate(shared_lock_function(__VA_ARGS__))
845 /* Function attempts to acquire an exclusive or shared lock. */
846 #define __trylocks_exclusive(...) \
847 __lock_annotate(exclusive_trylock_function(__VA_ARGS__))
848 #define __trylocks_shared(...) \
849 __lock_annotate(shared_trylock_function(__VA_ARGS__))
851 /* Function releases a lock. */
852 #define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__))
854 /* Function asserts that an exclusive or shared lock is held. */
855 #define __asserts_exclusive(...) \
856 __lock_annotate(assert_exclusive_lock(__VA_ARGS__))
857 #define __asserts_shared(...) \
858 __lock_annotate(assert_shared_lock(__VA_ARGS__))
860 /* Function requires that an exclusive or shared lock is or is not held. */
861 #define __requires_exclusive(...) \
862 __lock_annotate(exclusive_locks_required(__VA_ARGS__))
863 #define __requires_shared(...) \
864 __lock_annotate(shared_locks_required(__VA_ARGS__))
865 #define __requires_unlocked(...) \
866 __lock_annotate(locks_excluded(__VA_ARGS__))
868 /* Function should not be analyzed. */
869 #define __no_lock_analysis __lock_annotate(no_thread_safety_analysis)
872 * Function or variable should not be sanitized, e.g., by AddressSanitizer.
873 * GCC has the nosanitize attribute, but as a function attribute only, and
874 * warns on use as a variable attribute.
876 #if __has_attribute(no_sanitize) && defined(__clang__)
878 #define __nosanitizeaddress __attribute__((no_sanitize("kernel-address")))
879 #define __nosanitizememory __attribute__((no_sanitize("kernel-memory")))
881 #define __nosanitizeaddress __attribute__((no_sanitize("address")))
882 #define __nosanitizememory __attribute__((no_sanitize("memory")))
884 #define __nosanitizethread __attribute__((no_sanitize("thread")))
886 #define __nosanitizeaddress
887 #define __nosanitizememory
888 #define __nosanitizethread
892 * Make it possible to opt out of stack smashing protection.
894 #if __has_attribute(no_stack_protector)
895 #define __nostackprotector __attribute__((no_stack_protector))
897 #define __nostackprotector \
898 __attribute__((__optimize__("-fno-stack-protector")))
901 /* Guard variables and structure members by lock. */
902 #define __guarded_by(x) __lock_annotate(guarded_by(x))
903 #define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x))
905 /* Alignment builtins for better type checking and improved code generation. */
906 /* Provide fallback versions for other compilers (GCC/Clang < 10): */
907 #if !__has_builtin(__builtin_is_aligned)
908 #define __builtin_is_aligned(x, align) \
909 (((__uintptr_t)x & ((align) - 1)) == 0)
911 #if !__has_builtin(__builtin_align_up)
912 #define __builtin_align_up(x, align) \
913 ((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1))))
915 #if !__has_builtin(__builtin_align_down)
916 #define __builtin_align_down(x, align) \
917 ((__typeof__(x))((x)&(~((align)-1))))
920 #define __align_up(x, y) __builtin_align_up(x, y)
921 #define __align_down(x, y) __builtin_align_down(x, y)
922 #define __is_aligned(x, y) __builtin_is_aligned(x, y)
924 #endif /* !_SYS_CDEFS_H_ */