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 * 3. 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
33 * $FreeBSD: src/sys/sys/cdefs.h,v 1.28.2.8 2002/09/18 04:05:13 mikeh Exp $
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
59 * Macro to test if we are using a specific version of gcc or later.
62 #define __GNUC_PREREQ__(ma, mi) \
63 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
65 #define __GNUC_PREREQ__(ma, mi) 0
68 #if defined(__cplusplus)
69 #define __BEGIN_EXTERN_C extern "C" {
70 #define __END_EXTERN_C }
74 #define __BEGIN_EXTERN_C
75 #define __END_EXTERN_C
78 #if __GNUC_PREREQ__(4, 0)
79 #define __dso_public __attribute__((__visibility__("default")))
80 #define __dso_hidden __attribute__((__visibility__("hidden")))
81 #define __BEGIN_PUBLIC_DECLS \
82 _Pragma("GCC visibility push(default)") __BEGIN_EXTERN_C
83 #define __END_PUBLIC_DECLS \
84 __END_EXTERN_C _Pragma("GCC visibility pop")
85 #define __BEGIN_HIDDEN_DECLS \
86 _Pragma("GCC visibility push(hidden)") __BEGIN_EXTERN_C
87 #define __END_HIDDEN_DECLS \
88 __END_EXTERN_C _Pragma("GCC visibility pop")
92 #define __BEGIN_PUBLIC_DECLS \
94 #define __END_PUBLIC_DECLS \
96 #define __BEGIN_HIDDEN_DECLS \
98 #define __END_HIDDEN_DECLS \
102 #if defined(__cplusplus)
103 #define __BEGIN_DECLS __BEGIN_PUBLIC_DECLS
104 #define __END_DECLS __END_PUBLIC_DECLS
108 * The __VM_CACHELINE_SIZE macro defines the common cache line alignment
109 * size that can be found across most recent and somewhat latest Intel
110 * hardware, i.e. L1 cache sizes etc.
112 * If needed, this value can be TUNED. Suitable values for this macro
113 * are 32, 64 and 128 bytes. The unit of measurement for this macro is
116 * XXX: This macro and related macros will eventually move to a MD
117 * header, but currently, we do need such a hierarchy.
119 #define __VM_CACHELINE_SIZE 64
120 #define __VM_CACHELINE_MASK (__VM_CACHELINE_SIZE - 1)
121 #define __VM_CACHELINE_ALIGN(n) \
122 (((n) + __VM_CACHELINE_MASK) & ~__VM_CACHELINE_MASK)
125 * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
126 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
127 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
128 * mode -- there must be no spaces between its arguments, and for nested
129 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also
130 * concatenate double-quoted strings produced by the __STRING macro, but
131 * this only works with ANSI C.
133 * __XSTRING is like __STRING, but it expands any macros in its argument
134 * first. It is only available with ANSI C.
136 #if defined(__STDC__) || defined(__cplusplus)
137 #define __P(protos) protos /* full-blown ANSI C */
138 #define __CONCAT1(x,y) x ## y
139 #define __CONCAT(x,y) __CONCAT1(x,y)
140 #define __STRING(x) #x /* stringify without expanding x */
141 #define __XSTRING(x) __STRING(x) /* expand x, then stringify */
143 #define __const const /* define reserved names to standard */
144 #define __signed signed
145 #define __volatile volatile
146 #if defined(__cplusplus)
147 #define __inline inline /* convert to C++ keyword */
150 #define __inline /* delete GCC keyword */
151 #endif /* !__GNUC__ */
152 #endif /* !__cplusplus */
154 #else /* !(__STDC__ || __cplusplus) */
155 #define __P(protos) () /* traditional C preprocessor */
156 #define __CONCAT(x,y) x/**/y
157 #define __STRING(x) "x"
160 #define __const /* delete pseudo-ANSI C keywords */
165 * In non-ANSI C environments, new programs will want ANSI-only C keywords
166 * deleted from the program and old programs will want them left alone.
167 * When using a compiler other than gcc, programs using the ANSI C keywords
168 * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
169 * When using "gcc -traditional", we assume that this is the intent; if
170 * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
172 #ifndef NO_ANSI_KEYWORDS
173 #define const /* delete ANSI C keywords */
177 #endif /* !NO_ANSI_KEYWORDS */
178 #endif /* !__GNUC__ */
179 #endif /* __STDC__ || __cplusplus */
182 * Compiler-dependent macros to help declare dead (non-returning) and
183 * pure (no side effects) functions, and unused variables. They are
184 * null except for versions of gcc that are known to support the features
185 * properly (old versions of gcc-2 supported the dead and pure features
186 * in a different (wrong) way).
188 #define __weak_symbol __attribute__((__weak__))
189 #if __GNUC_PREREQ__(2, 7)
190 #define __dead2 __attribute__((__noreturn__))
191 #define __pure2 __attribute__((__const__))
192 #define __unused __attribute__((__unused__))
193 #define __packed __attribute__((__packed__))
194 #define __aligned(x) __attribute__((__aligned__(x)))
195 #define __section(x) __attribute__((__section__(x)))
202 #if __GNUC_PREREQ__(2, 96)
203 #define __malloclike __attribute__((__malloc__))
204 #define __pure __attribute__((__pure__))
207 #define __pure __pure2
210 #if __GNUC_PREREQ__(3, 1)
211 #define __always_inline __attribute__((__always_inline__))
212 #define __noinline __attribute__((__noinline__))
214 #define __always_inline
218 #if __GNUC_PREREQ__(3, 3)
219 #define __nonnull(...) __attribute__((__nonnull__(__VA_ARGS__)))
220 #define __used __attribute__((__used__))
222 #define __nonnull(...)
223 #define __used __unused
226 #if __GNUC_PREREQ__(3, 4)
227 #define __heedresult __attribute__((__warn_unused_result__))
232 #if __GNUC_PREREQ__(4, 1)
233 #define __returns_twice __attribute__((__returns_twice__))
235 #define __returns_twice
238 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
239 #define __unreachable() __builtin_unreachable()
241 #define __unreachable() ((void)0)
244 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__)
245 #define __alloc_size(x) __attribute__((__alloc_size__(x)))
246 #define __alloc_size2(n, x) __attribute__((__alloc_size__(n, x)))
248 #define __alloc_size(x)
249 #define __alloc_size2(n, x)
252 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
253 #define __alloc_align(x) __attribute__((__alloc_align__(x)))
255 #define __alloc_align(x)
258 #if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION__ < 199901
259 #define __func__ NULL
262 #if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI__)) || \
263 __STDC_VERSION__ >= 199901
264 #define __LONG_LONG_SUPPORTED
267 /* C++11 exposes a load of C99 stuff */
268 #if defined(__cplusplus) && __cplusplus >= 201103L
269 #define __LONG_LONG_SUPPORTED
270 #ifndef __STDC_LIMIT_MACROS
271 #define __STDC_LIMIT_MACROS
273 #ifndef __STDC_CONSTANT_MACROS
274 #define __STDC_CONSTANT_MACROS
279 * GCC 2.95 and later provides `__restrict' as an extension to C90 to support
280 * the C99-specific `restrict' type qualifier. We happen to use `__restrict'
281 * as a way to define the `restrict' type qualifier without disturbing older
282 * software that is unaware of C99 keywords.
284 #if !__GNUC_PREREQ__(2, 95)
285 #if __STDC_VERSION__ < 199901
288 #define __restrict restrict
293 * C99 allows to declare arrays as non-overlapping.
295 #if __GNUC_PREREQ__(3, 1) && !defined(__GNUG__)
296 #define __restrict_arr __restrict
299 #define __restrict_arr
301 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901
302 #define __restrict_arr restrict
304 #define __restrict_arr
310 * GNU C version 2.96 adds explicit branch prediction so that
311 * the CPU back-end can hint the processor and also so that
312 * code blocks can be reordered such that the predicted path
313 * sees a more linear flow, thus improving cache behavior, etc.
315 * The following two macros provide us with a way to utilize this
316 * compiler feature. Use __predict_true() if you expect the expression
317 * to evaluate to true, and __predict_false() if you expect the
318 * expression to evaluate to false.
320 * A few notes about usage:
322 * * Generally, __predict_false() error condition checks (unless
323 * you have some _strong_ reason to do otherwise, in which case
324 * document it), and/or __predict_true() `no-error' condition
325 * checks, assuming you want to optimize for the no-error case.
327 * * Other than that, if you don't know the likelihood of a test
328 * succeeding from empirical or other `hard' evidence, don't
331 * * These are meant to be used in places that are run `a lot'.
332 * It is wasteful to make predictions in code that is run
333 * seldomly (e.g. at subsystem initialization time) as the
334 * basic block reordering that this affects can often generate
337 #if __GNUC_PREREQ__(2, 96)
338 #define __predict_true(exp) __builtin_expect((exp), 1)
339 #define __predict_false(exp) __builtin_expect((exp), 0)
341 #define __predict_true(exp) (exp)
342 #define __predict_false(exp) (exp)
346 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
349 #if __GNUC_PREREQ__(4, 1)
350 #define __offsetof(type, field) __builtin_offsetof(type, field)
353 #define __offsetof(type, field) \
354 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
356 #define __offsetof(type, field) \
357 (__offsetof__ (reinterpret_cast <__size_t> \
358 (&reinterpret_cast <const volatile char &> \
359 (static_cast<type *> (0)->field))))
364 * Compiler-dependent macros to declare that functions take printf-like
365 * or scanf-like arguments. They are null except for versions of gcc
366 * that are known to support the features properly (old versions of gcc-2
367 * didn't permit keeping the keywords out of the application namespace).
369 * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
371 #if !__GNUC_PREREQ__(2, 7)
372 #define __printflike(fmtarg, firstvararg)
373 #define __scanflike(fmtarg, firstvararg)
374 #define __printf0like(fmtarg, firstvararg)
375 #define __format_arg(fmtarg)
376 #define __strfmonlike(fmtarg, firstvararg)
377 #define __strftimelike(fmtarg, firstvararg)
379 #elif __GNUC_PREREQ__(3, 0)
380 #define __printflike(fmtarg, firstvararg) \
381 __attribute__((__nonnull__(fmtarg), \
382 __format__ (__printf__, fmtarg, firstvararg)))
383 #define __printf0like(fmtarg, firstvararg) \
384 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
385 #define __scanflike(fmtarg, firstvararg) \
386 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
387 #define __format_arg(fmtarg) \
388 __attribute__((__format_arg__ (fmtarg)))
389 #define __strfmonlike(fmtarg, firstvararg) \
390 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
391 #define __strftimelike(fmtarg, firstvararg) \
392 __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
395 #define __printflike(fmtarg, firstvararg) \
396 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
397 #define __printf0like(fmtarg, firstvararg) \
398 __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
399 #define __scanflike(fmtarg, firstvararg) \
400 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
401 #define __format_arg(fmtarg) \
402 __attribute__((__format_arg__ (fmtarg)))
403 #define __strfmonlike(fmtarg, firstvararg) \
404 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
405 #define __strftimelike(fmtarg, firstvararg) \
406 __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
409 #if !__GNUC_PREREQ__(3, 0)
410 #define __ARRAY_ZERO 0
416 * A convenient constructor macro, GCC 4.3.0 added priority support to
417 * constructors, provide a compatible interface for both.
419 #if __GNUC_PREREQ__(4, 3)
420 #define __constructor(prio) __attribute__((constructor(prio)))
422 #define __constructor(prio) __attribute__((constructor))
426 * Handy GCC based macros:
430 * The __cachealign macro can be used for cache line aligning structures
431 * of small to medium size. It aligns the particular structure or
432 * storage type to a system default cache line alignment, thus giving us
433 * a much more better cache utilization by making the hardware work at
434 * its best burst speeds.
438 * The __usereg macro can/should be used when a function contains
439 * arguments not more than 3. It can be very useful to us due to the
440 * message-passing nature of the kernel.
442 * !!NOTE - USAGE INFORMATION!!
444 * The __cachealign macro should not be used for data structures that are
445 * as big struct proc, struct vnode, struct thread, and other structs which
446 * are as big as them; simply because it will be useless in that case.
448 * The __usereg macro should be used whenever possible, i.e., when a function
449 * does not exceed more than 3 arguments, and should not be used for vararg
452 * In other words, AVOID MISUSE OF THESE MACROS. :-)
455 #define __cachealign __attribute__((__aligned__(__VM_CACHELINE_SIZE)))
456 #define __usereg __attribute__((__regparm__(3)))
463 #define __strong_reference(sym,aliassym) \
464 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
465 #define __weak_reference(sym,aliassym) \
466 __strong_reference(sym,aliassym) __attribute__ ((__weak__))
467 #define __weak_reference_asm(sym,alias) \
468 __asm__(".weak " #alias); \
469 __asm__(".equ " #alias ", " #sym)
470 #define __warn_references(sym,msg) \
471 __asm__(".section .gnu.warning." #sym); \
472 __asm__(".asciz \"" msg "\""); \
474 #define __sym_compat(sym,impl,verid) \
475 __asm__(".symver " #impl ", " #sym "@" #verid)
476 #define __sym_default(sym,impl,verid) \
477 __asm__(".symver " #impl ", " #sym "@@@" #verid)
478 #endif /* __GNUC__ */
480 #if defined(__GNUC__)
481 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
485 #define __RCSID(s) struct __hack
488 #ifndef __RCSID_SOURCE
489 #define __RCSID_SOURCE(s) struct __hack
493 #define __SCCSID(s) struct __hack
497 #define __FBSDID(s) struct __hack
501 #define __COPYRIGHT(s) struct __hack
505 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var))
509 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var))
513 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var))
517 * Keywords added in C11.
520 #if !__GNUC_PREREQ__(2, 95)
521 #define __alignof(x) __offsetof(struct { char __a; x __b; }, __b)
524 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
526 #if !__has_extension(c_alignas)
527 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
528 __has_extension(cxx_alignas)
529 #define _Alignas(x) alignas(x)
531 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
532 #define _Alignas(x) __aligned(x)
536 #if defined(__cplusplus) && __cplusplus >= 201103L
537 #define _Alignof(x) alignof(x)
539 #define _Alignof(x) __alignof(x)
542 #if !defined(_Noreturn)
543 #define _Noreturn __dead2
546 #if !__has_extension(c_static_assert)
547 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
548 __has_extension(cxx_static_assert)
549 #define _Static_assert(x, y) static_assert(x, y)
550 #elif !__GNUC_PREREQ__(4, 6)
551 #define _Static_assert(x, y) struct __hack
553 #define CTASSERT(x) _CTASSERT(x, __LINE__)
554 #define _CTASSERT(x, y) __CTASSERT(x, y)
555 #define __CTASSERT(x, y) typedef char __assert ## y[(x) ? 1 : -1]
560 * GCC 4.7 has -std=c++11 but does not support thread_local.
562 #if !__has_extension(c_thread_local)
563 #if (defined(__cplusplus) && __cplusplus >= 201103L && __GNUC_PREREQ__(4, 8)) || \
564 __has_extension(cxx_thread_local)
565 #define _Thread_local thread_local
567 #define _Thread_local __thread
572 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
574 #if defined(_KERNEL) && !defined(CTASSERT)
575 #define CTASSERT(x) _Static_assert(x, \
576 "compile-time assertion failed")
580 * Emulation of C11 _Generic(). Unlike the previously defined C11
581 * keywords, it is not possible to implement this using exactly the same
582 * syntax. Therefore implement something similar under the name
583 * __generic(). Unlike _Generic(), this macro can only distinguish
584 * between a single type, so it requires nested invocations to
585 * distinguish multiple cases.
588 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
589 #define __generic(expr, t, yes, no) \
590 _Generic(expr, t: yes, default: no)
591 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
592 #define __generic(expr, t, yes, no) \
593 __builtin_choose_expr( \
594 __builtin_types_compatible_p(__typeof(expr), t), yes, no)
598 * POSIX.1 requires that the macros we test be defined before any standard
599 * header file is included.
601 * Here's a quick run-down of the versions:
602 * defined(_POSIX_SOURCE) 1003.1-1988
603 * _POSIX_C_SOURCE == 1 1003.1-1990
604 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
605 * _POSIX_C_SOURCE == 199309 1003.1b-1993
606 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
607 * and the omnibus ISO/IEC 9945-1: 1996
608 * _POSIX_C_SOURCE == 200112 1003.1-2001
609 * _POSIX_C_SOURCE == 200809 1003.1-2008
611 * In addition, the X/Open Portability Guide, which is now the Single UNIX
612 * Specification, defines a feature-test macro which indicates the version of
613 * that specification, and which subsumes _POSIX_C_SOURCE.
615 * Our macros begin with two underscores to avoid namespace screwage.
618 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
619 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1
620 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
621 #define _POSIX_C_SOURCE 199009
624 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
625 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2
626 #undef _POSIX_C_SOURCE
627 #define _POSIX_C_SOURCE 199209
630 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
632 #if _XOPEN_SOURCE - 0 >= 700
633 #define __XSI_VISIBLE 700
634 #undef _POSIX_C_SOURCE
635 #define _POSIX_C_SOURCE 200809
636 #elif _XOPEN_SOURCE - 0 >= 600
637 #define __XSI_VISIBLE 600
638 #undef _POSIX_C_SOURCE
639 #define _POSIX_C_SOURCE 200112
640 #elif _XOPEN_SOURCE - 0 >= 500
641 #define __XSI_VISIBLE 500
642 #undef _POSIX_C_SOURCE
643 #define _POSIX_C_SOURCE 199506
648 * Deal with all versions of POSIX. The ordering relative to the tests above is
651 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
652 #define _POSIX_C_SOURCE 198808
654 #ifdef _POSIX_C_SOURCE
655 #if (_POSIX_C_SOURCE - 0) >= 200809
656 #define __POSIX_VISIBLE 200809
657 #define __ISO_C_VISIBLE 1999
658 #elif (_POSIX_C_SOURCE - 0) >= 200112
659 #define __POSIX_VISIBLE 200112
660 #define __ISO_C_VISIBLE 1999
661 #elif (_POSIX_C_SOURCE - 0) >= 199506
662 #define __POSIX_VISIBLE 199506
663 #define __ISO_C_VISIBLE 1990
664 #elif (_POSIX_C_SOURCE - 0) >= 199309
665 #define __POSIX_VISIBLE 199309
666 #define __ISO_C_VISIBLE 1990
667 #elif (_POSIX_C_SOURCE - 0) >= 199209
668 #define __POSIX_VISIBLE 199209
669 #define __ISO_C_VISIBLE 1990
670 #elif (_POSIX_C_SOURCE - 0) >= 199009
671 #define __POSIX_VISIBLE 199009
672 #define __ISO_C_VISIBLE 1990
674 #define __POSIX_VISIBLE 198808
675 #define __ISO_C_VISIBLE 0
676 #endif /* _POSIX_C_SOURCE */
679 * Deal with _ANSI_SOURCE:
680 * If it is defined, and no other compilation environment is explicitly
681 * requested, then define our internal feature-test macros to zero. This
682 * makes no difference to the preprocessor (undefined symbols in preprocessing
683 * expressions are defined to have value zero), but makes it more convenient for
684 * a test program to print out the values.
686 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
687 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
688 * environment (and in fact we will never get here).
690 #if defined(_ANSI_SOURCE) /* Hide almost everything. */
691 #define __POSIX_VISIBLE 0
692 #define __XSI_VISIBLE 0
693 #define __BSD_VISIBLE 0
694 #define __ISO_C_VISIBLE 1990
695 #define __EXT1_VISIBLE 0
696 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */
697 #define __POSIX_VISIBLE 0
698 #define __XSI_VISIBLE 0
699 #define __BSD_VISIBLE 0
700 #define __ISO_C_VISIBLE 1999
701 #define __EXT1_VISIBLE 0
702 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */
703 #define __POSIX_VISIBLE 0
704 #define __XSI_VISIBLE 0
705 #define __BSD_VISIBLE 0
706 #define __ISO_C_VISIBLE 2011
707 #define __EXT1_VISIBLE 0
708 #else /* Default environment: show everything. */
709 #define __POSIX_VISIBLE 200809
710 #define __XSI_VISIBLE 700
711 #define __BSD_VISIBLE 1
712 #define __ISO_C_VISIBLE 2011
713 #define __EXT1_VISIBLE 1
717 /* User override __EXT1_VISIBLE */
718 #if defined(__STDC_WANT_LIB_EXT1__)
719 #undef __EXT1_VISIBLE
720 #if __STDC_WANT_LIB_EXT1__
721 #define __EXT1_VISIBLE 1
723 #define __EXT1_VISIBLE 0
725 #endif /* __STDC_WANT_LIB_EXT1__ */
727 #ifndef __BSD_VISIBLE
728 #define __BSD_VISIBLE 0
730 #ifndef __EXT1_VISIBLE
731 #define __EXT1_VISIBLE 0
735 * GLOBL macro exists to preserve __start_set_* and __stop_set_* sections
736 * of kernel modules which are discarded from binutils 2.17.50+ otherwise.
739 #define __GLOBL1(sym) __asm__(".globl " #sym)
740 #define __GLOBL(sym) __GLOBL1(sym)
742 #endif /* !_SYS_CDEFS_H_ */