2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Berkeley Software Design, Inc.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * @(#)cdefs.h 8.8 (Berkeley) 1/9/95
40 * Testing against Clang-specific extensions.
42 #ifndef __has_attribute
43 #define __has_attribute(x) 0
45 #ifndef __has_extension
46 #define __has_extension __has_feature
49 #define __has_feature(x) 0
52 #define __has_include(x) 0
55 #define __has_builtin(x) 0
58 #if defined(__cplusplus)
59 #define __BEGIN_DECLS extern "C" {
67 * This code has been put in place to help reduce the addition of
68 * compiler specific defines in FreeBSD code. It helps to aid in
69 * having a compiler-agnostic source tree.
72 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
74 #if __GNUC__ >= 3 || defined(__INTEL_COMPILER)
75 #define __GNUCLIKE_ASM 3
76 #define __GNUCLIKE_MATH_BUILTIN_CONSTANTS
78 #define __GNUCLIKE_ASM 2
80 #define __GNUCLIKE___TYPEOF 1
81 #define __GNUCLIKE___OFFSETOF 1
82 #define __GNUCLIKE___SECTION 1
84 #ifndef __INTEL_COMPILER
85 #define __GNUCLIKE_CTOR_SECTION_HANDLING 1
88 #define __GNUCLIKE_BUILTIN_CONSTANT_P 1
89 #if defined(__INTEL_COMPILER) && defined(__cplusplus) && \
90 __INTEL_COMPILER < 800
91 #undef __GNUCLIKE_BUILTIN_CONSTANT_P
94 #if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3)
95 #define __GNUCLIKE_BUILTIN_VARARGS 1
96 #define __GNUCLIKE_BUILTIN_STDARG 1
97 #define __GNUCLIKE_BUILTIN_VAALIST 1
100 #if defined(__GNUC__)
101 #define __GNUC_VA_LIST_COMPATIBILITY 1
105 * Compiler memory barriers, specific to gcc and clang.
107 #if defined(__GNUC__)
108 #define __compiler_membar() __asm __volatile(" " : : : "memory")
111 #ifndef __INTEL_COMPILER
112 #define __GNUCLIKE_BUILTIN_NEXT_ARG 1
113 #define __GNUCLIKE_MATH_BUILTIN_RELOPS
116 #define __GNUCLIKE_BUILTIN_MEMCPY 1
118 /* XXX: if __GNUC__ >= 2: not tested everywhere originally, where replaced */
119 #define __CC_SUPPORTS_INLINE 1
120 #define __CC_SUPPORTS___INLINE 1
121 #define __CC_SUPPORTS___INLINE__ 1
123 #define __CC_SUPPORTS___FUNC__ 1
124 #define __CC_SUPPORTS_WARNING 1
126 #define __CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */
128 #define __CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
130 #endif /* __GNUC__ || __INTEL_COMPILER */
133 * Macro to test if we're using a specific version of gcc or later.
135 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
136 #define __GNUC_PREREQ__(ma, mi) \
137 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
139 #define __GNUC_PREREQ__(ma, mi) 0
143 * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
144 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
145 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
146 * mode -- there must be no spaces between its arguments, and for nested
147 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also
148 * concatenate double-quoted strings produced by the __STRING macro, but
149 * this only works with ANSI C.
151 * __XSTRING is like __STRING, but it expands any macros in its argument
152 * first. It is only available with ANSI C.
154 #if defined(__STDC__) || defined(__cplusplus)
155 #define __P(protos) protos /* full-blown ANSI C */
156 #define __CONCAT1(x,y) x ## y
157 #define __CONCAT(x,y) __CONCAT1(x,y)
158 #define __STRING(x) #x /* stringify without expanding x */
159 #define __XSTRING(x) __STRING(x) /* expand x, then stringify */
161 #define __const const /* define reserved names to standard */
162 #define __signed signed
163 #define __volatile volatile
164 #if defined(__cplusplus)
165 #define __inline inline /* convert to C++ keyword */
167 #if !(defined(__CC_SUPPORTS___INLINE))
168 #define __inline /* delete GCC keyword */
169 #endif /* ! __CC_SUPPORTS___INLINE */
170 #endif /* !__cplusplus */
172 #else /* !(__STDC__ || __cplusplus) */
173 #define __P(protos) () /* traditional C preprocessor */
174 #define __CONCAT(x,y) x/**/y
175 #define __STRING(x) "x"
177 #if !defined(__CC_SUPPORTS___INLINE)
178 #define __const /* delete pseudo-ANSI C keywords */
183 * In non-ANSI C environments, new programs will want ANSI-only C keywords
184 * deleted from the program and old programs will want them left alone.
185 * When using a compiler other than gcc, programs using the ANSI C keywords
186 * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
187 * When using "gcc -traditional", we assume that this is the intent; if
188 * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
190 #ifndef NO_ANSI_KEYWORDS
191 #define const /* delete ANSI C keywords */
195 #endif /* !NO_ANSI_KEYWORDS */
196 #endif /* !__CC_SUPPORTS___INLINE */
197 #endif /* !(__STDC__ || __cplusplus) */
200 * Compiler-dependent macros to help declare dead (non-returning) and
201 * pure (no side effects) functions, and unused variables. They are
202 * null except for versions of gcc that are known to support the features
203 * properly (old versions of gcc-2 supported the dead and pure features
204 * in a different (wrong) way). If we do not provide an implementation
205 * for a given compiler, let the compile fail if it is told to use
206 * a feature that we cannot live without.
214 #define __alloc_align(x)
215 #define __alloc_size(x)
217 #define __weak_symbol
219 #define __weak_symbol __attribute__((__weak__))
220 #if !__GNUC_PREREQ__(2, 5) && !defined(__INTEL_COMPILER)
225 #if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 && !defined(__INTEL_COMPILER)
226 #define __dead2 __attribute__((__noreturn__))
227 #define __pure2 __attribute__((__const__))
229 /* XXX Find out what to do for __packed, __aligned and __section */
231 #if __GNUC_PREREQ__(2, 7) || defined(__INTEL_COMPILER)
232 #define __dead2 __attribute__((__noreturn__))
233 #define __pure2 __attribute__((__const__))
234 #define __unused __attribute__((__unused__))
235 #define __used __attribute__((__used__))
236 #define __packed __attribute__((__packed__))
237 #define __aligned(x) __attribute__((__aligned__(x)))
238 #define __section(x) __attribute__((__section__(x)))
240 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__)
241 #define __alloc_size(x) __attribute__((__alloc_size__(x)))
243 #define __alloc_size(x)
245 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
246 #define __alloc_align(x) __attribute__((__alloc_align__(x)))
248 #define __alloc_align(x)
252 #if !__GNUC_PREREQ__(2, 95)
253 #define __alignof(x) __offsetof(struct { char __a; x __b; }, __b)
257 * Keywords added in C11.
260 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L || defined(lint)
262 #if !__has_extension(c_alignas)
263 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
264 __has_extension(cxx_alignas)
265 #define _Alignas(x) alignas(x)
267 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
268 #define _Alignas(x) __aligned(x)
272 #if defined(__cplusplus) && __cplusplus >= 201103L
273 #define _Alignof(x) alignof(x)
275 #define _Alignof(x) __alignof(x)
278 #if !defined(__cplusplus) && !__has_extension(c_atomic) && \
279 !__has_extension(cxx_atomic)
281 * No native support for _Atomic(). Place object in structure to prevent
282 * most forms of direct non-atomic access.
284 #define _Atomic(T) struct { T volatile __val; }
287 #if defined(__cplusplus) && __cplusplus >= 201103L
288 #define _Noreturn [[noreturn]]
290 #define _Noreturn __dead2
293 #if !__has_extension(c_static_assert)
294 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
295 __has_extension(cxx_static_assert)
296 #define _Static_assert(x, y) static_assert(x, y)
297 #elif __GNUC_PREREQ__(4,6)
298 /* Nothing, gcc 4.6 and higher has _Static_assert built-in */
299 #elif defined(__COUNTER__)
300 #define _Static_assert(x, y) __Static_assert(x, __COUNTER__)
301 #define __Static_assert(x, y) ___Static_assert(x, y)
302 #define ___Static_assert(x, y) typedef char __assert_ ## y[(x) ? 1 : -1] \
305 #define _Static_assert(x, y) struct __hack
309 #if !__has_extension(c_thread_local)
311 * XXX: Some compilers (Clang 3.3, GCC 4.7) falsely announce C++11 mode
312 * without actually supporting the thread_local keyword. Don't check for
313 * the presence of C++11 when defining _Thread_local.
315 #if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \
316 __has_extension(cxx_thread_local)
317 #define _Thread_local thread_local
319 #define _Thread_local __thread
323 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
326 * Emulation of C11 _Generic(). Unlike the previously defined C11
327 * keywords, it is not possible to implement this using exactly the same
328 * syntax. Therefore implement something similar under the name
329 * __generic(). Unlike _Generic(), this macro can only distinguish
330 * between a single type, so it requires nested invocations to
331 * distinguish multiple cases.
334 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \
335 __has_extension(c_generic_selections)
336 #define __generic(expr, t, yes, no) \
337 _Generic(expr, t: yes, default: no)
338 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
339 #define __generic(expr, t, yes, no) \
340 __builtin_choose_expr( \
341 __builtin_types_compatible_p(__typeof(expr), t), yes, no)
345 * C99 Static array indices in function parameter declarations. Syntax such as:
346 * void bar(int myArray[static 10]);
347 * is allowed in C99 but not in C++. Define __min_size appropriately so
348 * headers using it can be compiled in either language. Use like this:
349 * void bar(int myArray[__min_size(10)]);
351 #if !defined(__cplusplus) && \
352 (!defined(__STDC_VERSION) || (__STDC_VERSION__ >= 199901))
353 #define __min_size(x) static (x)
355 #define __min_size(x) (x)
358 #if __GNUC_PREREQ__(2, 96)
359 #define __malloc_like __attribute__((__malloc__))
360 #define __pure __attribute__((__pure__))
362 #define __malloc_like
366 #if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
367 #define __always_inline __attribute__((__always_inline__))
369 #define __always_inline
372 #if __GNUC_PREREQ__(3, 1)
373 #define __noinline __attribute__ ((__noinline__))
378 #if __GNUC_PREREQ__(3, 3)
379 #define __nonnull(x) __attribute__((__nonnull__(x)))
380 #define __nonnull_all __attribute__((__nonnull__))
383 #define __nonnull_all
386 #if __GNUC_PREREQ__(3, 4)
387 #define __fastcall __attribute__((__fastcall__))
388 #define __result_use_check __attribute__((__warn_unused_result__))
391 #define __result_use_check
394 #if __GNUC_PREREQ__(4, 1)
395 #define __returns_twice __attribute__((__returns_twice__))
397 #define __returns_twice
400 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
401 #define __unreachable() __builtin_unreachable()
403 #define __unreachable() ((void)0)
406 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
407 #if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
408 #define __func__ NULL
411 #if (defined(__INTEL_COMPILER) || (defined(__GNUC__) && __GNUC__ >= 2)) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
412 #define __LONG_LONG_SUPPORTED
415 /* C++11 exposes a load of C99 stuff */
416 #if defined(__cplusplus) && __cplusplus >= 201103L
417 #define __LONG_LONG_SUPPORTED
418 #ifndef __STDC_LIMIT_MACROS
419 #define __STDC_LIMIT_MACROS
421 #ifndef __STDC_CONSTANT_MACROS
422 #define __STDC_CONSTANT_MACROS
427 * GCC 2.95 provides `__restrict' as an extension to C90 to support the
428 * C99-specific `restrict' type qualifier. We happen to use `__restrict' as
429 * a way to define the `restrict' type qualifier without disturbing older
430 * software that is unaware of C99 keywords.
432 #if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
433 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901 || defined(lint)
436 #define __restrict restrict
441 * GNU C version 2.96 adds explicit branch prediction so that
442 * the CPU back-end can hint the processor and also so that
443 * code blocks can be reordered such that the predicted path
444 * sees a more linear flow, thus improving cache behavior, etc.
446 * The following two macros provide us with a way to utilize this
447 * compiler feature. Use __predict_true() if you expect the expression
448 * to evaluate to true, and __predict_false() if you expect the
449 * expression to evaluate to false.
451 * A few notes about usage:
453 * * Generally, __predict_false() error condition checks (unless
454 * you have some _strong_ reason to do otherwise, in which case
455 * document it), and/or __predict_true() `no-error' condition
456 * checks, assuming you want to optimize for the no-error case.
458 * * Other than that, if you don't know the likelihood of a test
459 * succeeding from empirical or other `hard' evidence, don't
462 * * These are meant to be used in places that are run `a lot'.
463 * It is wasteful to make predictions in code that is run
464 * seldomly (e.g. at subsystem initialization time) as the
465 * basic block reordering that this affects can often generate
468 #if __GNUC_PREREQ__(2, 96)
469 #define __predict_true(exp) __builtin_expect((exp), 1)
470 #define __predict_false(exp) __builtin_expect((exp), 0)
472 #define __predict_true(exp) (exp)
473 #define __predict_false(exp) (exp)
476 #if __GNUC_PREREQ__(4, 0)
477 #define __null_sentinel __attribute__((__sentinel__))
478 #define __exported __attribute__((__visibility__("default")))
479 #define __hidden __attribute__((__visibility__("hidden")))
481 #define __null_sentinel
487 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
490 #if __GNUC_PREREQ__(4, 1)
491 #define __offsetof(type, field) __builtin_offsetof(type, field)
494 #define __offsetof(type, field) \
495 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
497 #define __offsetof(type, field) \
498 (__offsetof__ (reinterpret_cast <__size_t> \
499 (&reinterpret_cast <const volatile char &> \
500 (static_cast<type *> (0)->field))))
503 #define __rangeof(type, start, end) \
504 (__offsetof(type, end) - __offsetof(type, start))
507 * Given the pointer x to the member m of the struct s, return
508 * a pointer to the containing structure. When using GCC, we first
509 * assign pointer x to a local variable, to check that its type is
510 * compatible with member m.
512 #if __GNUC_PREREQ__(3, 1)
513 #define __containerof(x, s, m) ({ \
514 const volatile __typeof(((s *)0)->m) *__x = (x); \
515 __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
518 #define __containerof(x, s, m) \
519 __DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
523 * Compiler-dependent macros to declare that functions take printf-like
524 * or scanf-like arguments. They are null except for versions of gcc
525 * that are known to support the features properly (old versions of gcc-2
526 * didn't permit keeping the keywords out of the application namespace).
528 #if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
529 #define __printflike(fmtarg, firstvararg)
530 #define __scanflike(fmtarg, firstvararg)
531 #define __format_arg(fmtarg)
532 #define __strfmonlike(fmtarg, firstvararg)
533 #define __strftimelike(fmtarg, firstvararg)
535 #define __printflike(fmtarg, firstvararg) \
536 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
537 #define __scanflike(fmtarg, firstvararg) \
538 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
539 #define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg)))
540 #define __strfmonlike(fmtarg, firstvararg) \
541 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
542 #define __strftimelike(fmtarg, firstvararg) \
543 __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
546 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
547 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
548 defined(__GNUC__) && !defined(__INTEL_COMPILER)
549 #define __printf0like(fmtarg, firstvararg) \
550 __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
552 #define __printf0like(fmtarg, firstvararg)
555 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
556 #ifndef __INTEL_COMPILER
557 #define __strong_reference(sym,aliassym) \
558 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
561 #define __weak_reference(sym,alias) \
562 __asm__(".weak " #alias); \
563 __asm__(".equ " #alias ", " #sym)
564 #define __warn_references(sym,msg) \
565 __asm__(".section .gnu.warning." #sym); \
566 __asm__(".asciz \"" msg "\""); \
568 #define __sym_compat(sym,impl,verid) \
569 __asm__(".symver " #impl ", " #sym "@" #verid)
570 #define __sym_default(sym,impl,verid) \
571 __asm__(".symver " #impl ", " #sym "@@" #verid)
573 #define __weak_reference(sym,alias) \
574 __asm__(".weak alias"); \
575 __asm__(".equ alias, sym")
576 #define __warn_references(sym,msg) \
577 __asm__(".section .gnu.warning.sym"); \
578 __asm__(".asciz \"msg\""); \
580 #define __sym_compat(sym,impl,verid) \
581 __asm__(".symver impl, sym@verid")
582 #define __sym_default(impl,sym,verid) \
583 __asm__(".symver impl, sym@@verid")
584 #endif /* __STDC__ */
585 #endif /* __GNUC__ || __INTEL_COMPILER */
587 #define __GLOBL1(sym) __asm__(".globl " #sym)
588 #define __GLOBL(sym) __GLOBL1(sym)
590 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
591 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
594 * The following definition might not work well if used in header files,
595 * but it should be better than nothing. If you want a "do nothing"
596 * version, then it should generate some harmless declaration, such as:
597 * #define __IDSTRING(name,string) struct __hack
599 #define __IDSTRING(name,string) static const char name[] __unused = string
603 * Embed the rcs id of a source file in the resulting library. Note that in
604 * more recent ELF binutils, we use .ident allowing the ID to be stripped.
606 * __FBSDID("$FreeBSD$");
609 #if !defined(lint) && !defined(STRIP_FBSDID)
610 #define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
612 #define __FBSDID(s) struct __hack
618 #define __RCSID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
620 #define __RCSID(s) struct __hack
624 #ifndef __RCSID_SOURCE
625 #ifndef NO__RCSID_SOURCE
626 #define __RCSID_SOURCE(s) __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
628 #define __RCSID_SOURCE(s) struct __hack
634 #define __SCCSID(s) __IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
636 #define __SCCSID(s) struct __hack
641 #ifndef NO__COPYRIGHT
642 #define __COPYRIGHT(s) __IDSTRING(__CONCAT(__copyright_,__LINE__),s)
644 #define __COPYRIGHT(s) struct __hack
649 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var))
653 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var))
657 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var))
661 * The following definitions are an extension of the behavior originally
662 * implemented in <sys/_posix.h>, but with a different level of granularity.
663 * POSIX.1 requires that the macros we test be defined before any standard
664 * header file is included.
666 * Here's a quick run-down of the versions:
667 * defined(_POSIX_SOURCE) 1003.1-1988
668 * _POSIX_C_SOURCE == 1 1003.1-1990
669 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
670 * _POSIX_C_SOURCE == 199309 1003.1b-1993
671 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
672 * and the omnibus ISO/IEC 9945-1: 1996
673 * _POSIX_C_SOURCE == 200112 1003.1-2001
674 * _POSIX_C_SOURCE == 200809 1003.1-2008
676 * In addition, the X/Open Portability Guide, which is now the Single UNIX
677 * Specification, defines a feature-test macro which indicates the version of
678 * that specification, and which subsumes _POSIX_C_SOURCE.
680 * Our macros begin with two underscores to avoid namespace screwage.
683 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
684 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
685 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
686 #define _POSIX_C_SOURCE 199009
689 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
690 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
691 #undef _POSIX_C_SOURCE
692 #define _POSIX_C_SOURCE 199209
695 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
697 #if _XOPEN_SOURCE - 0 >= 700
698 #define __XSI_VISIBLE 700
699 #undef _POSIX_C_SOURCE
700 #define _POSIX_C_SOURCE 200809
701 #elif _XOPEN_SOURCE - 0 >= 600
702 #define __XSI_VISIBLE 600
703 #undef _POSIX_C_SOURCE
704 #define _POSIX_C_SOURCE 200112
705 #elif _XOPEN_SOURCE - 0 >= 500
706 #define __XSI_VISIBLE 500
707 #undef _POSIX_C_SOURCE
708 #define _POSIX_C_SOURCE 199506
713 * Deal with all versions of POSIX. The ordering relative to the tests above is
716 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
717 #define _POSIX_C_SOURCE 198808
719 #ifdef _POSIX_C_SOURCE
720 #if _POSIX_C_SOURCE >= 200809
721 #define __POSIX_VISIBLE 200809
722 #define __ISO_C_VISIBLE 1999
723 #elif _POSIX_C_SOURCE >= 200112
724 #define __POSIX_VISIBLE 200112
725 #define __ISO_C_VISIBLE 1999
726 #elif _POSIX_C_SOURCE >= 199506
727 #define __POSIX_VISIBLE 199506
728 #define __ISO_C_VISIBLE 1990
729 #elif _POSIX_C_SOURCE >= 199309
730 #define __POSIX_VISIBLE 199309
731 #define __ISO_C_VISIBLE 1990
732 #elif _POSIX_C_SOURCE >= 199209
733 #define __POSIX_VISIBLE 199209
734 #define __ISO_C_VISIBLE 1990
735 #elif _POSIX_C_SOURCE >= 199009
736 #define __POSIX_VISIBLE 199009
737 #define __ISO_C_VISIBLE 1990
739 #define __POSIX_VISIBLE 198808
740 #define __ISO_C_VISIBLE 0
741 #endif /* _POSIX_C_SOURCE */
744 * Deal with _ANSI_SOURCE:
745 * If it is defined, and no other compilation environment is explicitly
746 * requested, then define our internal feature-test macros to zero. This
747 * makes no difference to the preprocessor (undefined symbols in preprocessing
748 * expressions are defined to have value zero), but makes it more convenient for
749 * a test program to print out the values.
751 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
752 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
753 * environment (and in fact we will never get here).
755 #if defined(_ANSI_SOURCE) /* Hide almost everything. */
756 #define __POSIX_VISIBLE 0
757 #define __XSI_VISIBLE 0
758 #define __BSD_VISIBLE 0
759 #define __ISO_C_VISIBLE 1990
760 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */
761 #define __POSIX_VISIBLE 0
762 #define __XSI_VISIBLE 0
763 #define __BSD_VISIBLE 0
764 #define __ISO_C_VISIBLE 1999
765 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */
766 #define __POSIX_VISIBLE 0
767 #define __XSI_VISIBLE 0
768 #define __BSD_VISIBLE 0
769 #define __ISO_C_VISIBLE 2011
770 #else /* Default environment: show everything. */
771 #define __POSIX_VISIBLE 200809
772 #define __XSI_VISIBLE 700
773 #define __BSD_VISIBLE 1
774 #define __ISO_C_VISIBLE 2011
778 #if defined(__mips) || defined(__powerpc64__) || defined(__riscv__)
783 * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h
784 * translates them to __ARM_ARCH and the modern feature symbols defined by ARM.
786 #if defined(__arm__) && !defined(__ARM_ARCH)
787 #include <machine/acle-compat.h>
791 * Nullability qualifiers: currently only supported by Clang.
793 #if !(defined(__clang__) && __has_feature(nullability))
799 * Type Safety Checking
801 * Clang provides additional attributes to enable checking type safety
802 * properties that cannot be enforced by the C type system.
805 #if __has_attribute(__argument_with_type_tag__) && \
806 __has_attribute(__type_tag_for_datatype__) && !defined(lint)
807 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
808 __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
809 #define __datatype_type_tag(kind, type) \
810 __attribute__((__type_tag_for_datatype__(kind, type)))
812 #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx)
813 #define __datatype_type_tag(kind, type)
819 * Clang provides support for doing basic thread-safety tests at
820 * compile-time, by marking which locks will/should be held when
821 * entering/leaving a functions.
823 * Furthermore, it is also possible to annotate variables and structure
824 * members to enforce that they are only accessed when certain locks are
828 #if __has_extension(c_thread_safety_attributes)
829 #define __lock_annotate(x) __attribute__((x))
831 #define __lock_annotate(x)
834 /* Structure implements a lock. */
835 #define __lockable __lock_annotate(lockable)
837 /* Function acquires an exclusive or shared lock. */
838 #define __locks_exclusive(...) \
839 __lock_annotate(exclusive_lock_function(__VA_ARGS__))
840 #define __locks_shared(...) \
841 __lock_annotate(shared_lock_function(__VA_ARGS__))
843 /* Function attempts to acquire an exclusive or shared lock. */
844 #define __trylocks_exclusive(...) \
845 __lock_annotate(exclusive_trylock_function(__VA_ARGS__))
846 #define __trylocks_shared(...) \
847 __lock_annotate(shared_trylock_function(__VA_ARGS__))
849 /* Function releases a lock. */
850 #define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__))
852 /* Function asserts that an exclusive or shared lock is held. */
853 #define __asserts_exclusive(...) \
854 __lock_annotate(assert_exclusive_lock(__VA_ARGS__))
855 #define __asserts_shared(...) \
856 __lock_annotate(assert_shared_lock(__VA_ARGS__))
858 /* Function requires that an exclusive or shared lock is or is not held. */
859 #define __requires_exclusive(...) \
860 __lock_annotate(exclusive_locks_required(__VA_ARGS__))
861 #define __requires_shared(...) \
862 __lock_annotate(shared_locks_required(__VA_ARGS__))
863 #define __requires_unlocked(...) \
864 __lock_annotate(locks_excluded(__VA_ARGS__))
866 /* Function should not be analyzed. */
867 #define __no_lock_analysis __lock_annotate(no_thread_safety_analysis)
869 /* Guard variables and structure members by lock. */
870 #define __guarded_by(x) __lock_annotate(guarded_by(x))
871 #define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x))
873 #endif /* !_SYS_CDEFS_H_ */