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
42 * Testing against Clang-specific extensions.
44 #ifndef __has_attribute
45 #define __has_attribute(x) 0
47 #ifndef __has_extension
48 #define __has_extension __has_feature
51 #define __has_feature(x) 0
54 #define __has_include(x) 0
57 #define __has_builtin(x) 0
60 #if defined(__cplusplus)
61 #define __BEGIN_DECLS extern "C" {
69 * This code has been put in place to help reduce the addition of
70 * compiler specific defines in FreeBSD code. It helps to aid in
71 * having a compiler-agnostic source tree.
74 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
76 #if __GNUC__ >= 3 || defined(__INTEL_COMPILER)
77 #define __GNUCLIKE_ASM 3
78 #define __GNUCLIKE_MATH_BUILTIN_CONSTANTS
80 #define __GNUCLIKE_ASM 2
82 #define __GNUCLIKE___TYPEOF 1
83 #define __GNUCLIKE___OFFSETOF 1
84 #define __GNUCLIKE___SECTION 1
86 #ifndef __INTEL_COMPILER
87 #define __GNUCLIKE_CTOR_SECTION_HANDLING 1
90 #define __GNUCLIKE_BUILTIN_CONSTANT_P 1
91 #if defined(__INTEL_COMPILER) && defined(__cplusplus) && \
92 __INTEL_COMPILER < 800
93 #undef __GNUCLIKE_BUILTIN_CONSTANT_P
96 #if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3)
97 #define __GNUCLIKE_BUILTIN_VARARGS 1
98 #define __GNUCLIKE_BUILTIN_STDARG 1
99 #define __GNUCLIKE_BUILTIN_VAALIST 1
102 #if defined(__GNUC__)
103 #define __GNUC_VA_LIST_COMPATIBILITY 1
107 * Compiler memory barriers, specific to gcc and clang.
109 #if defined(__GNUC__)
110 #define __compiler_membar() __asm __volatile(" " : : : "memory")
113 #ifndef __INTEL_COMPILER
114 #define __GNUCLIKE_BUILTIN_NEXT_ARG 1
115 #define __GNUCLIKE_MATH_BUILTIN_RELOPS
118 #define __GNUCLIKE_BUILTIN_MEMCPY 1
120 /* XXX: if __GNUC__ >= 2: not tested everywhere originally, where replaced */
121 #define __CC_SUPPORTS_INLINE 1
122 #define __CC_SUPPORTS___INLINE 1
123 #define __CC_SUPPORTS___INLINE__ 1
125 #define __CC_SUPPORTS___FUNC__ 1
126 #define __CC_SUPPORTS_WARNING 1
128 #define __CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */
130 #define __CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
132 #endif /* __GNUC__ || __INTEL_COMPILER */
135 * Macro to test if we're using a specific version of gcc or later.
137 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
138 #define __GNUC_PREREQ__(ma, mi) \
139 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
141 #define __GNUC_PREREQ__(ma, mi) 0
145 * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
146 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
147 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
148 * mode -- there must be no spaces between its arguments, and for nested
149 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also
150 * concatenate double-quoted strings produced by the __STRING macro, but
151 * this only works with ANSI C.
153 * __XSTRING is like __STRING, but it expands any macros in its argument
154 * first. It is only available with ANSI C.
156 #if defined(__STDC__) || defined(__cplusplus)
157 #define __P(protos) protos /* full-blown ANSI C */
158 #define __CONCAT1(x,y) x ## y
159 #define __CONCAT(x,y) __CONCAT1(x,y)
160 #define __STRING(x) #x /* stringify without expanding x */
161 #define __XSTRING(x) __STRING(x) /* expand x, then stringify */
163 #define __const const /* define reserved names to standard */
164 #define __signed signed
165 #define __volatile volatile
166 #if defined(__cplusplus)
167 #define __inline inline /* convert to C++ keyword */
169 #if !(defined(__CC_SUPPORTS___INLINE))
170 #define __inline /* delete GCC keyword */
171 #endif /* ! __CC_SUPPORTS___INLINE */
172 #endif /* !__cplusplus */
174 #else /* !(__STDC__ || __cplusplus) */
175 #define __P(protos) () /* traditional C preprocessor */
176 #define __CONCAT(x,y) x/**/y
177 #define __STRING(x) "x"
179 #if !defined(__CC_SUPPORTS___INLINE)
180 #define __const /* delete pseudo-ANSI C keywords */
185 * In non-ANSI C environments, new programs will want ANSI-only C keywords
186 * deleted from the program and old programs will want them left alone.
187 * When using a compiler other than gcc, programs using the ANSI C keywords
188 * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
189 * When using "gcc -traditional", we assume that this is the intent; if
190 * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
192 #ifndef NO_ANSI_KEYWORDS
193 #define const /* delete ANSI C keywords */
197 #endif /* !NO_ANSI_KEYWORDS */
198 #endif /* !__CC_SUPPORTS___INLINE */
199 #endif /* !(__STDC__ || __cplusplus) */
202 * Compiler-dependent macros to help declare dead (non-returning) and
203 * pure (no side effects) functions, and unused variables. They are
204 * null except for versions of gcc that are known to support the features
205 * properly (old versions of gcc-2 supported the dead and pure features
206 * in a different (wrong) way). If we do not provide an implementation
207 * for a given compiler, let the compile fail if it is told to use
208 * a feature that we cannot live without.
210 #define __weak_symbol __attribute__((__weak__))
211 #if !__GNUC_PREREQ__(2, 5) && !defined(__INTEL_COMPILER)
216 #if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 && !defined(__INTEL_COMPILER)
217 #define __dead2 __attribute__((__noreturn__))
218 #define __pure2 __attribute__((__const__))
220 /* XXX Find out what to do for __packed, __aligned and __section */
222 #if __GNUC_PREREQ__(2, 7) || defined(__INTEL_COMPILER)
223 #define __dead2 __attribute__((__noreturn__))
224 #define __pure2 __attribute__((__const__))
225 #define __unused __attribute__((__unused__))
226 #define __used __attribute__((__used__))
227 #define __packed __attribute__((__packed__))
228 #define __aligned(x) __attribute__((__aligned__(x)))
229 #define __section(x) __attribute__((__section__(x)))
231 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__)
232 #define __alloc_size(x) __attribute__((__alloc_size__(x)))
233 #define __alloc_size2(n, x) __attribute__((__alloc_size__(n, x)))
235 #define __alloc_size(x)
236 #define __alloc_size2(n, x)
238 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
239 #define __alloc_align(x) __attribute__((__alloc_align__(x)))
241 #define __alloc_align(x)
244 #if !__GNUC_PREREQ__(2, 95)
245 #define __alignof(x) __offsetof(struct { char __a; x __b; }, __b)
249 * Keywords added in C11.
252 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
254 #if !__has_extension(c_alignas)
255 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
256 __has_extension(cxx_alignas)
257 #define _Alignas(x) alignas(x)
259 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
260 #define _Alignas(x) __aligned(x)
264 #if defined(__cplusplus) && __cplusplus >= 201103L
265 #define _Alignof(x) alignof(x)
267 #define _Alignof(x) __alignof(x)
270 #if !defined(__cplusplus) && !__has_extension(c_atomic) && \
271 !__has_extension(cxx_atomic) && !__GNUC_PREREQ__(4, 7)
273 * No native support for _Atomic(). Place object in structure to prevent
274 * most forms of direct non-atomic access.
276 #define _Atomic(T) struct { T volatile __val; }
279 #if defined(__cplusplus) && __cplusplus >= 201103L
280 #define _Noreturn [[noreturn]]
282 #define _Noreturn __dead2
285 #if !__has_extension(c_static_assert)
286 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
287 __has_extension(cxx_static_assert)
288 #define _Static_assert(x, y) static_assert(x, y)
289 #elif __GNUC_PREREQ__(4,6) && !defined(__cplusplus)
290 /* Nothing, gcc 4.6 and higher has _Static_assert built-in */
291 #elif defined(__COUNTER__)
292 #define _Static_assert(x, y) __Static_assert(x, __COUNTER__)
293 #define __Static_assert(x, y) ___Static_assert(x, y)
294 #define ___Static_assert(x, y) typedef char __assert_ ## y[(x) ? 1 : -1] \
297 #define _Static_assert(x, y) struct __hack
301 #if !__has_extension(c_thread_local)
303 * XXX: Some compilers (Clang 3.3, GCC 4.7) falsely announce C++11 mode
304 * without actually supporting the thread_local keyword. Don't check for
305 * the presence of C++11 when defining _Thread_local.
307 #if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \
308 __has_extension(cxx_thread_local)
309 #define _Thread_local thread_local
311 #define _Thread_local __thread
315 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
318 * Emulation of C11 _Generic(). Unlike the previously defined C11
319 * keywords, it is not possible to implement this using exactly the same
320 * syntax. Therefore implement something similar under the name
321 * __generic(). Unlike _Generic(), this macro can only distinguish
322 * between a single type, so it requires nested invocations to
323 * distinguish multiple cases.
326 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \
327 __has_extension(c_generic_selections)
328 #define __generic(expr, t, yes, no) \
329 _Generic(expr, t: yes, default: no)
330 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
331 #define __generic(expr, t, yes, no) \
332 __builtin_choose_expr( \
333 __builtin_types_compatible_p(__typeof(expr), t), yes, no)
337 * C99 Static array indices in function parameter declarations. Syntax such as:
338 * void bar(int myArray[static 10]);
339 * is allowed in C99 but not in C++. Define __min_size appropriately so
340 * headers using it can be compiled in either language. Use like this:
341 * void bar(int myArray[__min_size(10)]);
343 #if !defined(__cplusplus) && \
344 (defined(__clang__) || __GNUC_PREREQ__(4, 6)) && \
345 (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901))
346 #define __min_size(x) static (x)
348 #define __min_size(x) (x)
351 #if __GNUC_PREREQ__(2, 96)
352 #define __malloc_like __attribute__((__malloc__))
353 #define __pure __attribute__((__pure__))
355 #define __malloc_like
359 #if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
360 #define __always_inline __attribute__((__always_inline__))
362 #define __always_inline
365 #if __GNUC_PREREQ__(3, 1)
366 #define __noinline __attribute__ ((__noinline__))
371 #if __GNUC_PREREQ__(3, 4)
372 #define __fastcall __attribute__((__fastcall__))
373 #define __result_use_check __attribute__((__warn_unused_result__))
376 #define __result_use_check
379 #if __GNUC_PREREQ__(4, 1)
380 #define __returns_twice __attribute__((__returns_twice__))
382 #define __returns_twice
385 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
386 #define __unreachable() __builtin_unreachable()
388 #define __unreachable() ((void)0)
391 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
392 #if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
393 #define __func__ NULL
396 #if (defined(__INTEL_COMPILER) || (defined(__GNUC__) && __GNUC__ >= 2)) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
397 #define __LONG_LONG_SUPPORTED
400 /* C++11 exposes a load of C99 stuff */
401 #if defined(__cplusplus) && __cplusplus >= 201103L
402 #define __LONG_LONG_SUPPORTED
403 #ifndef __STDC_LIMIT_MACROS
404 #define __STDC_LIMIT_MACROS
406 #ifndef __STDC_CONSTANT_MACROS
407 #define __STDC_CONSTANT_MACROS
412 * GCC 2.95 provides `__restrict' as an extension to C90 to support the
413 * C99-specific `restrict' type qualifier. We happen to use `__restrict' as
414 * a way to define the `restrict' type qualifier without disturbing older
415 * software that is unaware of C99 keywords.
417 #if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
418 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901
421 #define __restrict restrict
426 * GNU C version 2.96 adds explicit branch prediction so that
427 * the CPU back-end can hint the processor and also so that
428 * code blocks can be reordered such that the predicted path
429 * sees a more linear flow, thus improving cache behavior, etc.
431 * The following two macros provide us with a way to utilize this
432 * compiler feature. Use __predict_true() if you expect the expression
433 * to evaluate to true, and __predict_false() if you expect the
434 * expression to evaluate to false.
436 * A few notes about usage:
438 * * Generally, __predict_false() error condition checks (unless
439 * you have some _strong_ reason to do otherwise, in which case
440 * document it), and/or __predict_true() `no-error' condition
441 * checks, assuming you want to optimize for the no-error case.
443 * * Other than that, if you don't know the likelihood of a test
444 * succeeding from empirical or other `hard' evidence, don't
447 * * These are meant to be used in places that are run `a lot'.
448 * It is wasteful to make predictions in code that is run
449 * seldomly (e.g. at subsystem initialization time) as the
450 * basic block reordering that this affects can often generate
453 #if __GNUC_PREREQ__(2, 96)
454 #define __predict_true(exp) __builtin_expect((exp), 1)
455 #define __predict_false(exp) __builtin_expect((exp), 0)
457 #define __predict_true(exp) (exp)
458 #define __predict_false(exp) (exp)
461 #if __GNUC_PREREQ__(4, 0)
462 #define __null_sentinel __attribute__((__sentinel__))
463 #define __exported __attribute__((__visibility__("default")))
464 #define __hidden __attribute__((__visibility__("hidden")))
466 #define __null_sentinel
472 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
475 #if __GNUC_PREREQ__(4, 1)
476 #define __offsetof(type, field) __builtin_offsetof(type, field)
479 #define __offsetof(type, field) \
480 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
482 #define __offsetof(type, field) \
483 (__offsetof__ (reinterpret_cast <__size_t> \
484 (&reinterpret_cast <const volatile char &> \
485 (static_cast<type *> (0)->field))))
488 #define __rangeof(type, start, end) \
489 (__offsetof(type, end) - __offsetof(type, start))
492 * Given the pointer x to the member m of the struct s, return
493 * a pointer to the containing structure. When using GCC, we first
494 * assign pointer x to a local variable, to check that its type is
495 * compatible with member m.
497 #if __GNUC_PREREQ__(3, 1)
498 #define __containerof(x, s, m) ({ \
499 const volatile __typeof(((s *)0)->m) *__x = (x); \
500 __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
503 #define __containerof(x, s, m) \
504 __DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
508 * Compiler-dependent macros to declare that functions take printf-like
509 * or scanf-like arguments. They are null except for versions of gcc
510 * that are known to support the features properly (old versions of gcc-2
511 * didn't permit keeping the keywords out of the application namespace).
513 #if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
514 #define __printflike(fmtarg, firstvararg)
515 #define __scanflike(fmtarg, firstvararg)
516 #define __format_arg(fmtarg)
517 #define __strfmonlike(fmtarg, firstvararg)
518 #define __strftimelike(fmtarg, firstvararg)
520 #define __printflike(fmtarg, firstvararg) \
521 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
522 #define __scanflike(fmtarg, firstvararg) \
523 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
524 #define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg)))
525 #define __strfmonlike(fmtarg, firstvararg) \
526 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
527 #define __strftimelike(fmtarg, firstvararg) \
528 __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
531 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
532 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
533 defined(__GNUC__) && !defined(__INTEL_COMPILER)
534 #define __printf0like(fmtarg, firstvararg) \
535 __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
537 #define __printf0like(fmtarg, firstvararg)
540 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
541 #ifndef __INTEL_COMPILER
542 #define __strong_reference(sym,aliassym) \
543 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
546 #define __weak_reference(sym,alias) \
547 __asm__(".weak " #alias); \
548 __asm__(".equ " #alias ", " #sym)
549 #define __warn_references(sym,msg) \
550 __asm__(".section .gnu.warning." #sym); \
551 __asm__(".asciz \"" msg "\""); \
553 #define __sym_compat(sym,impl,verid) \
554 __asm__(".symver " #impl ", " #sym "@" #verid)
555 #define __sym_default(sym,impl,verid) \
556 __asm__(".symver " #impl ", " #sym "@@@" #verid)
558 #define __weak_reference(sym,alias) \
559 __asm__(".weak alias"); \
560 __asm__(".equ alias, sym")
561 #define __warn_references(sym,msg) \
562 __asm__(".section .gnu.warning.sym"); \
563 __asm__(".asciz \"msg\""); \
565 #define __sym_compat(sym,impl,verid) \
566 __asm__(".symver impl, sym@verid")
567 #define __sym_default(impl,sym,verid) \
568 __asm__(".symver impl, sym@@@verid")
569 #endif /* __STDC__ */
570 #endif /* __GNUC__ || __INTEL_COMPILER */
572 #define __GLOBL1(sym) __asm__(".globl " #sym)
573 #define __GLOBL(sym) __GLOBL1(sym)
575 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
576 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
579 * The following definition might not work well if used in header files,
580 * but it should be better than nothing. If you want a "do nothing"
581 * version, then it should generate some harmless declaration, such as:
582 * #define __IDSTRING(name,string) struct __hack
584 #define __IDSTRING(name,string) static const char name[] __unused = string
588 * Embed the rcs id of a source file in the resulting library. Note that in
589 * more recent ELF binutils, we use .ident allowing the ID to be stripped.
591 * __FBSDID("$FreeBSD$");
594 #if !defined(STRIP_FBSDID)
595 #define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
597 #define __FBSDID(s) struct __hack
603 #define __RCSID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
605 #define __RCSID(s) struct __hack
609 #ifndef __RCSID_SOURCE
610 #ifndef NO__RCSID_SOURCE
611 #define __RCSID_SOURCE(s) __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
613 #define __RCSID_SOURCE(s) struct __hack
619 #define __SCCSID(s) __IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
621 #define __SCCSID(s) struct __hack
626 #ifndef NO__COPYRIGHT
627 #define __COPYRIGHT(s) __IDSTRING(__CONCAT(__copyright_,__LINE__),s)
629 #define __COPYRIGHT(s) struct __hack
634 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var))
638 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var))
642 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var))
646 * The following definitions are an extension of the behavior originally
647 * implemented in <sys/_posix.h>, but with a different level of granularity.
648 * POSIX.1 requires that the macros we test be defined before any standard
649 * header file is included.
651 * Here's a quick run-down of the versions:
652 * defined(_POSIX_SOURCE) 1003.1-1988
653 * _POSIX_C_SOURCE == 1 1003.1-1990
654 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
655 * _POSIX_C_SOURCE == 199309 1003.1b-1993
656 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
657 * and the omnibus ISO/IEC 9945-1: 1996
658 * _POSIX_C_SOURCE == 200112 1003.1-2001
659 * _POSIX_C_SOURCE == 200809 1003.1-2008
661 * In addition, the X/Open Portability Guide, which is now the Single UNIX
662 * Specification, defines a feature-test macro which indicates the version of
663 * that specification, and which subsumes _POSIX_C_SOURCE.
665 * Our macros begin with two underscores to avoid namespace screwage.
668 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
669 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
670 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
671 #define _POSIX_C_SOURCE 199009
674 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
675 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
676 #undef _POSIX_C_SOURCE
677 #define _POSIX_C_SOURCE 199209
680 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
682 #if _XOPEN_SOURCE - 0 >= 700
683 #define __XSI_VISIBLE 700
684 #undef _POSIX_C_SOURCE
685 #define _POSIX_C_SOURCE 200809
686 #elif _XOPEN_SOURCE - 0 >= 600
687 #define __XSI_VISIBLE 600
688 #undef _POSIX_C_SOURCE
689 #define _POSIX_C_SOURCE 200112
690 #elif _XOPEN_SOURCE - 0 >= 500
691 #define __XSI_VISIBLE 500
692 #undef _POSIX_C_SOURCE
693 #define _POSIX_C_SOURCE 199506
698 * Deal with all versions of POSIX. The ordering relative to the tests above is
701 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
702 #define _POSIX_C_SOURCE 198808
704 #ifdef _POSIX_C_SOURCE
705 #if _POSIX_C_SOURCE >= 200809
706 #define __POSIX_VISIBLE 200809
707 #define __ISO_C_VISIBLE 1999
708 #elif _POSIX_C_SOURCE >= 200112
709 #define __POSIX_VISIBLE 200112
710 #define __ISO_C_VISIBLE 1999
711 #elif _POSIX_C_SOURCE >= 199506
712 #define __POSIX_VISIBLE 199506
713 #define __ISO_C_VISIBLE 1990
714 #elif _POSIX_C_SOURCE >= 199309
715 #define __POSIX_VISIBLE 199309
716 #define __ISO_C_VISIBLE 1990
717 #elif _POSIX_C_SOURCE >= 199209
718 #define __POSIX_VISIBLE 199209
719 #define __ISO_C_VISIBLE 1990
720 #elif _POSIX_C_SOURCE >= 199009
721 #define __POSIX_VISIBLE 199009
722 #define __ISO_C_VISIBLE 1990
724 #define __POSIX_VISIBLE 198808
725 #define __ISO_C_VISIBLE 0
726 #endif /* _POSIX_C_SOURCE */
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__ */
777 #if defined(__mips) || defined(__powerpc64__) || defined(__riscv)
782 * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h
783 * translates them to __ARM_ARCH and the modern feature symbols defined by ARM.
785 #if defined(__arm__) && !defined(__ARM_ARCH)
786 #include <machine/acle-compat.h>
790 * Nullability qualifiers: currently only supported by Clang.
792 #if !(defined(__clang__) && __has_feature(nullability))
795 #define _Null_unspecified
796 #define __NULLABILITY_PRAGMA_PUSH
797 #define __NULLABILITY_PRAGMA_POP
799 #define __NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push") \
800 _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
801 #define __NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop")
805 * Type Safety Checking
807 * Clang provides additional attributes to enable checking type safety
808 * properties that cannot be enforced by the C type system.
811 #if __has_attribute(__argument_with_type_tag__) && \
812 __has_attribute(__type_tag_for_datatype__)
813 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
814 __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
815 #define __datatype_type_tag(kind, type) \
816 __attribute__((__type_tag_for_datatype__(kind, type)))
818 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx)
819 #define __datatype_type_tag(kind, type)
825 * Clang provides support for doing basic thread-safety tests at
826 * compile-time, by marking which locks will/should be held when
827 * entering/leaving a functions.
829 * Furthermore, it is also possible to annotate variables and structure
830 * members to enforce that they are only accessed when certain locks are
834 #if __has_extension(c_thread_safety_attributes)
835 #define __lock_annotate(x) __attribute__((x))
837 #define __lock_annotate(x)
840 /* Structure implements a lock. */
841 #define __lockable __lock_annotate(lockable)
843 /* Function acquires an exclusive or shared lock. */
844 #define __locks_exclusive(...) \
845 __lock_annotate(exclusive_lock_function(__VA_ARGS__))
846 #define __locks_shared(...) \
847 __lock_annotate(shared_lock_function(__VA_ARGS__))
849 /* Function attempts to acquire an exclusive or shared lock. */
850 #define __trylocks_exclusive(...) \
851 __lock_annotate(exclusive_trylock_function(__VA_ARGS__))
852 #define __trylocks_shared(...) \
853 __lock_annotate(shared_trylock_function(__VA_ARGS__))
855 /* Function releases a lock. */
856 #define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__))
858 /* Function asserts that an exclusive or shared lock is held. */
859 #define __asserts_exclusive(...) \
860 __lock_annotate(assert_exclusive_lock(__VA_ARGS__))
861 #define __asserts_shared(...) \
862 __lock_annotate(assert_shared_lock(__VA_ARGS__))
864 /* Function requires that an exclusive or shared lock is or is not held. */
865 #define __requires_exclusive(...) \
866 __lock_annotate(exclusive_locks_required(__VA_ARGS__))
867 #define __requires_shared(...) \
868 __lock_annotate(shared_locks_required(__VA_ARGS__))
869 #define __requires_unlocked(...) \
870 __lock_annotate(locks_excluded(__VA_ARGS__))
872 /* Function should not be analyzed. */
873 #define __no_lock_analysis __lock_annotate(no_thread_safety_analysis)
875 /* Guard variables and structure members by lock. */
876 #define __guarded_by(x) __lock_annotate(guarded_by(x))
877 #define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x))
879 #endif /* !_SYS_CDEFS_H_ */