xref: /dragonfly/sys/sys/cdefs.h (revision 3badf6b7)
1 /*
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Berkeley Software Design, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
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.
19  *
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
30  * SUCH DAMAGE.
31  *
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 $
34  */
35 
36 #ifndef	_SYS_CDEFS_H_
37 #define	_SYS_CDEFS_H_
38 
39 /*
40  * Testing against Clang-specific extensions.
41  */
42 
43 #ifndef	__has_extension
44 #define	__has_extension		__has_feature
45 #endif
46 #ifndef	__has_feature
47 #define	__has_feature(x)	0
48 #endif
49 #ifndef	__has_include
50 #define	__has_include(x)	0
51 #endif
52 #ifndef	__has_builtin
53 #define	__has_builtin(x)	0
54 #endif
55 
56 /*
57  * Macro to test if we are using a specific version of gcc or later.
58  */
59 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
60 #define	__GNUC_PREREQ__(ma, mi)	\
61         (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
62 #else
63 #define	__GNUC_PREREQ__(ma, mi) 0
64 #endif
65 
66 #if defined(__cplusplus)
67 #if __GNUC_PREREQ__(4, 0)
68 #define	__BEGIN_DECLS	_Pragma("GCC visibility push(default)") extern "C" {
69 #define	__END_DECLS	} _Pragma("GCC visibility pop")
70 #else
71 #define	__BEGIN_DECLS	extern "C" {
72 #define	__END_DECLS	}
73 #endif
74 #else
75 #define	__BEGIN_DECLS
76 #define	__END_DECLS
77 #endif
78 
79 /*
80  * The __VM_CACHELINE_SIZE macro defines the common cache line alignment
81  * size that can be found across most recent and somewhat latest Intel
82  * hardware, i.e. L1 cache sizes etc.
83  *
84  * If needed, this value can be TUNED.  Suitable values for this macro
85  * are 32, 64 and 128 bytes.  The unit of measurement for this macro is
86  * bytes.
87  *
88  * XXX: This macro and related macros will eventually move to a MD
89  * header, but currently, we do need such a hierarchy.
90  */
91 #define	__VM_CACHELINE_SIZE	64
92 #define	__VM_CACHELINE_MASK	(__VM_CACHELINE_SIZE - 1)
93 #define	__VM_CACHELINE_ALIGN(n)	\
94 	(((n) + __VM_CACHELINE_MASK) & ~__VM_CACHELINE_MASK)
95 
96 /*
97  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
98  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
99  * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
100  * mode -- there must be no spaces between its arguments, and for nested
101  * __CONCAT's, all the __CONCAT's must be at the left.  __CONCAT can also
102  * concatenate double-quoted strings produced by the __STRING macro, but
103  * this only works with ANSI C.
104  *
105  * __XSTRING is like __STRING, but it expands any macros in its argument
106  * first.  It is only available with ANSI C.
107  */
108 #if defined(__STDC__) || defined(__cplusplus)
109 #define	__P(protos)	protos		/* full-blown ANSI C */
110 #define	__CONCAT1(x,y)	x ## y
111 #define	__CONCAT(x,y)	__CONCAT1(x,y)
112 #define	__STRING(x)	#x		/* stringify without expanding x */
113 #define	__XSTRING(x)	__STRING(x)	/* expand x, then stringify */
114 
115 #define	__const		const		/* define reserved names to standard */
116 #define	__signed	signed
117 #define	__volatile	volatile
118 #if defined(__cplusplus)
119 #define	__inline	inline		/* convert to C++ keyword */
120 #else
121 #ifndef __GNUC__
122 #define	__inline			/* delete GCC keyword */
123 #endif /* !__GNUC__ */
124 #endif /* !__cplusplus */
125 
126 #else	/* !(__STDC__ || __cplusplus) */
127 #define	__P(protos)	()		/* traditional C preprocessor */
128 #define	__CONCAT(x,y)	x/**/y
129 #define	__STRING(x)	"x"
130 
131 #ifndef __GNUC__
132 #define	__const				/* delete pseudo-ANSI C keywords */
133 #define	__inline
134 #define	__signed
135 #define	__volatile
136 /*
137  * In non-ANSI C environments, new programs will want ANSI-only C keywords
138  * deleted from the program and old programs will want them left alone.
139  * When using a compiler other than gcc, programs using the ANSI C keywords
140  * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
141  * When using "gcc -traditional", we assume that this is the intent; if
142  * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
143  */
144 #ifndef	NO_ANSI_KEYWORDS
145 #define	const				/* delete ANSI C keywords */
146 #define	inline
147 #define	signed
148 #define	volatile
149 #endif	/* !NO_ANSI_KEYWORDS */
150 #endif	/* !__GNUC__ */
151 #endif	/* !(__STDC__ || __cplusplus) */
152 
153 /*
154  * Compiler-dependent macros to help declare dead (non-returning) and
155  * pure (no side effects) functions, and unused variables.  They are
156  * null except for versions of gcc that are known to support the features
157  * properly (old versions of gcc-2 supported the dead and pure features
158  * in a different (wrong) way).
159  */
160 #ifdef lint
161 
162 #define	__dead2
163 #define	__pure
164 #define	__pure2
165 #define	__unused
166 #define	__packed
167 #define	__aligned(x)
168 #define	__section(x)
169 #define	__always_inline
170 #define	__nonnull(x)
171 #define	__heedresult
172 #define	__returns_twice
173 
174 #else
175 
176 #if __GNUC_PREREQ__(2, 7)
177 #define	__dead2		__attribute__((__noreturn__))
178 #define	__pure2		__attribute__((__const__))
179 #define	__unused	__attribute__((__unused__))
180 #define	__packed        __attribute__((__packed__))
181 #define	__aligned(x)    __attribute__((__aligned__(x)))
182 #define	__section(x)    __attribute__((__section__(x)))
183 #else
184 #define	__dead2
185 #define	__pure2
186 #define	__unused
187 #endif
188 
189 #if __GNUC_PREREQ__(2, 96)
190 #define	__pure		__attribute__((__pure__))
191 #else
192 #define	__pure		__pure2
193 #endif
194 
195 #if __GNUC_PREREQ__(3, 1)
196 #define	__always_inline __attribute__((__always_inline__))
197 #define	__noinline	__attribute__((__noinline__))
198 #else
199 #define	__always_inline
200 #define	__noinline
201 #endif
202 
203 #if __GNUC_PREREQ__(3, 3)
204 #define	__heedresult	__attribute__((__warn_unused_result__))
205 #define	__nonnull(x)    __attribute__((__nonnull__(x)))
206 #define	__used		__attribute__((__used__))
207 #else
208 #define	__heedresult
209 #define	__nonnull(x)
210 #define	__used		__unused
211 #endif
212 
213 #if __GNUC_PREREQ__(4, 1)
214 #define	__returns_twice __attribute__((__returns_twice__))
215 #else
216 #define	__returns_twice
217 #endif
218 
219 #endif	/* LINT */
220 
221 #if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION < 199901
222 #define	__func__        NULL
223 #endif
224 
225 #if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI__)) || \
226     __STDC_VERSION__ >= 199901
227 #define	__LONG_LONG_SUPPORTED
228 #endif
229 
230 /* C++11 exposes a load of C99 stuff */
231 #if defined(__cplusplus) && __cplusplus >= 201103L
232 #define	__LONG_LONG_SUPPORTED
233 #ifndef	__STDC_LIMIT_MACROS
234 #define	__STDC_LIMIT_MACROS
235 #endif
236 #ifndef	__STDC_CONSTANT_MACROS
237 #define	__STDC_CONSTANT_MACROS
238 #endif
239 #endif
240 
241 /*
242  * GNU C version 2.96 adds explicit branch prediction so that
243  * the CPU back-end can hint the processor and also so that
244  * code blocks can be reordered such that the predicted path
245  * sees a more linear flow, thus improving cache behavior, etc.
246  *
247  * The following two macros provide us with a way to utilize this
248  * compiler feature.  Use __predict_true() if you expect the expression
249  * to evaluate to true, and __predict_false() if you expect the
250  * expression to evaluate to false.
251  *
252  * A few notes about usage:
253  *
254  *	* Generally, __predict_false() error condition checks (unless
255  *	  you have some _strong_ reason to do otherwise, in which case
256  *	  document it), and/or __predict_true() `no-error' condition
257  *	  checks, assuming you want to optimize for the no-error case.
258  *
259  *	* Other than that, if you don't know the likelihood of a test
260  *	  succeeding from empirical or other `hard' evidence, don't
261  *	  make predictions.
262  *
263  *	* These are meant to be used in places that are run `a lot'.
264  *	  It is wasteful to make predictions in code that is run
265  *	  seldomly (e.g. at subsystem initialization time) as the
266  *	  basic block reordering that this affects can often generate
267  *	  larger code.
268  */
269 #if __GNUC_PREREQ__(2, 96)
270 #define	__predict_true(exp)     __builtin_expect((exp), 1)
271 #define	__predict_false(exp)    __builtin_expect((exp), 0)
272 #else
273 #define	__predict_true(exp)     (exp)
274 #define	__predict_false(exp)    (exp)
275 #endif
276 
277 /*
278  * GCC 2.95 and later provides `__restrict' as an extention to C90 to support
279  * the C99-specific `restrict' type qualifier.  We happen to use `__restrict'
280  * as a way to define the `restrict' type qualifier without disturbing older
281  * software that is unaware of C99 keywords.
282  */
283 #if !__GNUC_PREREQ__(2, 95)
284 #if __STDC_VERSION__ < 199901
285 #define	__restrict
286 #else
287 #define	__restrict	restrict
288 #endif
289 #endif
290 
291 /*
292  * Compiler-dependent macros to declare that functions take printf-like
293  * or scanf-like arguments.  They are null except for versions of gcc
294  * that are known to support the features properly (old versions of gcc-2
295  * didn't permit keeping the keywords out of the application namespace).
296  *
297  * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
298  */
299 #if !__GNUC_PREREQ__(2, 7)
300 #define	__printflike(fmtarg, firstvararg)
301 #define	__scanflike(fmtarg, firstvararg)
302 #define	__printf0like(fmtarg, firstvararg)
303 #define	__format_arg(fmtarg)
304 #define	__strfmonlike(fmtarg, firstvararg)
305 #define	__strftimelike(fmtarg, firstvararg)
306 
307 #elif __GNUC_PREREQ__(3, 0)
308 #define	__printflike(fmtarg, firstvararg) \
309             __attribute__((__nonnull__(fmtarg), \
310 			  __format__ (__printf__, fmtarg, firstvararg)))
311 #define	__printf0like(fmtarg, firstvararg) \
312             __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
313 #define	__scanflike(fmtarg, firstvararg) \
314 	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
315 #define	__format_arg(fmtarg) \
316 	    __attribute__((__format_arg__ (fmtarg)))
317 #define	__strfmonlike(fmtarg, firstvararg) \
318 	    __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
319 #define	__strftimelike(fmtarg, firstvararg) \
320 	    __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
321 
322 #else
323 #define	__printflike(fmtarg, firstvararg) \
324 	    __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
325 #define	__printf0like(fmtarg, firstvararg) \
326 	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
327 #define	__scanflike(fmtarg, firstvararg) \
328 	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
329 #define	__format_arg(fmtarg) \
330 	    __attribute__((__format_arg__ (fmtarg)))
331 #define	__strfmonlike(fmtarg, firstvararg) \
332 	    __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
333 #define	__strftimelike(fmtarg, firstvararg) \
334 	    __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
335 
336 #endif
337 
338 #if !__GNUC_PREREQ__(3, 0)
339 #define	__ARRAY_ZERO	0
340 #else
341 #define	__ARRAY_ZERO
342 #endif
343 
344 #if __GNUC_PREREQ__(4, 0)
345 #define	__dso_public	__attribute__((__visibility__("default")))
346 #define	__dso_hidden	__attribute__((__visibility__("hidden")))
347 #else
348 #define	__dso_public
349 #define	__dso_hidden
350 #endif
351 
352 /*
353  * A convenient constructor macro, GCC 4.3.0 added priority support to
354  * constructors, provide a compatible interface for both.
355  */
356 #if __GNUC_PREREQ__(4, 3)
357 #define	__constructor(prio) __attribute__((constructor(prio)))
358 #else
359 #define	__constructor(prio) __attribute__((constructor))
360 #endif
361 
362 /*
363  * Handy GCC based macros:
364  *
365  * 	__cachealign:
366  *
367  * 	The __cachealign macro can be used for cache line aligning structures
368  * 	of small to medium size.  It aligns the particular structure or
369  * 	storage type to a system default cache line alignment, thus giving us
370  * 	a much more better cache utilization by making the hardware work at
371  * 	its best burst speeds.
372  *
373  * 	__usereg:
374  *
375  * 	The __usereg macro can/should be used when a function contains
376  * 	arguments not more than 3.  It can be very useful to us due to the
377  * 	message-passing nature of the kernel.
378  *
379  * !!NOTE - USAGE INFORMATION!!
380  *
381  * The __cachealign macro should not be used for data structures that are
382  * as big struct proc, struct vnode, struct thread, and other structs which
383  * are as big as them; simply because it will be useless in that case.
384  *
385  * The __usereg macro should be used whenever possible, i.e., when a function
386  * does not exceed more than 3 arguments, and should not be used for vararg
387  * type functions.
388  *
389  * In other words, AVOID MISUSE OF THESE MACROS. :-)
390  */
391 #ifdef __GNUC__
392 #define	__cachealign	__attribute__((__aligned__(__VM_CACHELINE_SIZE)))
393 #define	__usereg     	__attribute__((__regparm__(3)))
394 #else
395 #define	__cachealign
396 #define	__usereg
397 #endif
398 
399 #ifdef __GNUC__
400 #define	__strong_reference(sym,aliassym)	\
401 	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
402 #define	__weak_reference(sym,alias)	\
403 	__asm__(".weak " #alias);	\
404 	__asm__(".equ "  #alias ", " #sym)
405 #define	__warn_references(sym,msg)	\
406 	__asm__(".section .gnu.warning." #sym);	\
407 	__asm__(".asciz \"" msg "\"");	\
408 	__asm__(".previous")
409 #endif	/* __GNUC__ */
410 
411 #if defined(__GNUC__)
412 #define	__IDSTRING(name,string)	__asm__(".ident\t\"" string "\"")
413 #endif
414 
415 #ifndef	__RCSID
416 #define	__RCSID(s)	__IDSTRING(rcsid,s)
417 #endif
418 
419 #ifndef	__RCSID_SOURCE
420 #define	__RCSID_SOURCE(s) __IDSTRING(rcsid_source,s)
421 #endif
422 
423 #ifndef	__COPYRIGHT
424 #define	__COPYRIGHT(s)	__IDSTRING(copyright,s)
425 #endif
426 
427 #ifndef	__DECONST
428 #define	__DECONST(type, var)	((type)(uintptr_t)(const void *)(var))
429 #endif
430 
431 #ifndef	__DEVOLATILE
432 #define	__DEVOLATILE(type, var)	((type)(uintptr_t)(volatile void *)(var))
433 #endif
434 
435 #ifndef	__DEQUALIFY
436 #define	__DEQUALIFY(type, var)	((type)(uintptr_t)(const volatile void *)(var))
437 #endif
438 
439 /*
440  * Keywords added in C11.
441  */
442 
443 #if !__GNUC_PREREQ__(2, 95)
444 #define	__alignof(x)	__offsetof(struct { char __a; x __b; }, __b)
445 #endif
446 
447 /*
448  * Keywords added in C11.
449  */
450 
451 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
452 
453 #if !__has_extension(c_alignas)
454 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
455     __has_extension(cxx_alignas)
456 #define	_Alignas(x)		alignas(x)
457 #else
458 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
459 #define	_Alignas(x)		__aligned(x)
460 #endif
461 #endif
462 
463 #if defined(__cplusplus) && __cplusplus >= 201103L
464 #define	_Alignof(x)		alignof(x)
465 #else
466 #define	_Alignof(x)		__alignof(x)
467 #endif
468 
469 #define	_Noreturn		__dead2
470 
471 #if !__has_extension(c_static_assert)
472 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
473     __has_extension(cxx_static_assert)
474 #define	_Static_assert(x, y)	static_assert(x, y)
475 #elif !__GNUC_PREREQ__(4, 6)
476 #define	_Static_assert(x, y)	struct __hack
477 #ifdef _KERNEL
478 #define	CTASSERT(x)		_CTASSERT(x, __LINE__)
479 #define	_CTASSERT(x, y)		__CTASSERT(x, y)
480 #define	__CTASSERT(x, y)	typedef char __assert ## y[(x) ? 1 : -1]
481 #endif
482 #endif
483 #endif
484 
485 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
486 
487 #if defined(_KERNEL) && !defined(CTASSERT)
488 #define	CTASSERT(x)		_Static_assert(x, \
489 				    "compile-time assertion failed")
490 #endif
491 
492 /*
493  * Emulation of C11 _Generic().  Unlike the previously defined C11
494  * keywords, it is not possible to implement this using exactly the same
495  * syntax.  Therefore implement something similar under the name
496  * __generic().  Unlike _Generic(), this macro can only distinguish
497  * between a single type, so it requires nested invocations to
498  * distinguish multiple cases.
499  */
500 
501 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
502 #define	__generic(expr, t, yes, no)					\
503 	_Generic(expr, t: yes, default: no)
504 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
505 #define	__generic(expr, t, yes, no)					\
506 	__builtin_choose_expr(						\
507 	    __builtin_types_compatible_p(__typeof(expr), t), yes, no)
508 #endif
509 
510 /*-
511  * POSIX.1 requires that the macros we test be defined before any standard
512  * header file is included.
513  *
514  * Here's a quick run-down of the versions:
515  *  defined(_POSIX_SOURCE)		1003.1-1988
516  *  _POSIX_C_SOURCE == 1		1003.1-1990
517  *  _POSIX_C_SOURCE == 2		1003.2-1992 C Language Binding Option
518  *  _POSIX_C_SOURCE == 199309		1003.1b-1993
519  *  _POSIX_C_SOURCE == 199506		1003.1c-1995, 1003.1i-1995,
520  *					and the omnibus ISO/IEC 9945-1: 1996
521  *  _POSIX_C_SOURCE == 200112		1003.1-2001
522  *  _POSIX_C_SOURCE == 200809		1003.1-2008
523  *
524  * In addition, the X/Open Portability Guide, which is now the Single UNIX
525  * Specification, defines a feature-test macro which indicates the version of
526  * that specification, and which subsumes _POSIX_C_SOURCE.
527  *
528  * Our macros begin with two underscores to avoid namespace screwage.
529  */
530 
531 /*
532  * If no special macro was specified, make the DragonFly extensions
533  * available. Also make them available when requested so.
534  */
535 #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE) && \
536     !defined(_ANSI_SOURCE) && !defined(_C99_SOURCE)) || \
537     defined(_DRAGONFLY_SOURCE) || defined(_NETBSD_SOURCE)
538 #define	__DF_VISIBLE	1
539 #else
540 #define	__DF_VISIBLE	0
541 #endif
542 
543 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
544 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1
545 #undef _POSIX_C_SOURCE		/* Probably illegal, but beyond caring now. */
546 #define	_POSIX_C_SOURCE		199009
547 #endif
548 
549 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
550 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2
551 #undef _POSIX_C_SOURCE
552 #define	_POSIX_C_SOURCE		199209
553 #endif
554 
555 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
556 #ifdef _XOPEN_SOURCE
557 #if _XOPEN_SOURCE - 0 >= 700
558 #define	__XSI_VISIBLE		700
559 #undef _POSIX_C_SOURCE
560 #define	_POSIX_C_SOURCE		200809
561 #elif _XOPEN_SOURCE - 0 >= 600
562 #define	__XSI_VISIBLE		600
563 #undef _POSIX_C_SOURCE
564 #define	_POSIX_C_SOURCE		200112
565 #elif _XOPEN_SOURCE - 0 >= 500
566 #define	__XSI_VISIBLE		500
567 #undef _POSIX_C_SOURCE
568 #define	_POSIX_C_SOURCE		199506
569 #endif
570 #endif
571 
572 /*
573  * Deal with all versions of POSIX.  The ordering relative to the tests above is
574  * important.
575  */
576 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
577 #define	_POSIX_C_SOURCE		198808
578 #endif
579 #ifdef _POSIX_C_SOURCE
580 #if (_POSIX_C_SOURCE - 0) >= 200809
581 #define	__POSIX_VISIBLE		200809
582 #define	__ISO_C_VISIBLE		1999
583 #elif (_POSIX_C_SOURCE - 0) >= 200112
584 #define	__POSIX_VISIBLE		200112
585 #define	__ISO_C_VISIBLE		1999
586 #elif (_POSIX_C_SOURCE - 0) >= 199506
587 #define	__POSIX_VISIBLE		199506
588 #define	__ISO_C_VISIBLE		1990
589 #elif (_POSIX_C_SOURCE - 0) >= 199309
590 #define	__POSIX_VISIBLE		199309
591 #define	__ISO_C_VISIBLE		1990
592 #elif (_POSIX_C_SOURCE - 0) >= 199209
593 #define	__POSIX_VISIBLE		199209
594 #define	__ISO_C_VISIBLE		1990
595 #elif (_POSIX_C_SOURCE - 0) >= 199009
596 #define	__POSIX_VISIBLE		199009
597 #define	__ISO_C_VISIBLE		1990
598 #else
599 #define	__POSIX_VISIBLE		198808
600 #define	__ISO_C_VISIBLE		0
601 #endif /* _POSIX_C_SOURCE */
602 #else
603 /*-
604  * Deal with _ANSI_SOURCE:
605  * If it is defined, and no other compilation environment is explicitly
606  * requested, then define our internal feature-test macros to zero.  This
607  * makes no difference to the preprocessor (undefined symbols in preprocessing
608  * expressions are defined to have value zero), but makes it more convenient for
609  * a test program to print out the values.
610  *
611  * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
612  * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
613  * environment (and in fact we will never get here).
614  */
615 #ifdef _ANSI_SOURCE		/* Hide almost everything. */
616 #define	__POSIX_VISIBLE		0
617 #define	__XSI_VISIBLE		0
618 #define	__BSD_VISIBLE		0
619 #define	__ISO_C_VISIBLE		1990
620 #elif defined(_C99_SOURCE)	/* Localism to specify strict C99 env. */
621 #define	__POSIX_VISIBLE		0
622 #define	__XSI_VISIBLE		0
623 #define	__BSD_VISIBLE		0
624 #define	__ISO_C_VISIBLE		1999
625 #elif defined(_C11_SOURCE)	/* Localism to specify strict C11 env. */
626 #define	__POSIX_VISIBLE		0
627 #define	__XSI_VISIBLE		0
628 #define	__BSD_VISIBLE		0
629 #define	__ISO_C_VISIBLE		2011
630 #else				/* Default environment: show everything. */
631 #define	__POSIX_VISIBLE		200809
632 #define	__XSI_VISIBLE		700
633 #define	__BSD_VISIBLE		1
634 #define	__ISO_C_VISIBLE		2011
635 #endif
636 #endif
637 
638 /*
639  * GLOBL macro exists to preserve __start_set_* and __stop_set_* sections
640  * of kernel modules which are discarded from binutils 2.17.50+ otherwise.
641  */
642 
643 #define	__GLOBL1(sym)	__asm__(".globl " #sym)
644 #define	__GLOBL(sym)	__GLOBL1(sym)
645 
646 /*
647  * Ignore the rcs id of a source file.
648  */
649 
650 #ifndef __FBSDID
651 #define	__FBSDID(s)	struct __hack
652 #endif
653 
654 #ifndef __RCSID
655 #define	__RCSID(s)	struct __hack
656 #endif
657 
658 #ifndef __RCSID_SOURCE
659 #define	__RCSID_SOURCE(s)	struct __hack
660 #endif
661 
662 #ifndef __SCCSID
663 #define	__SCCSID(s)	struct __hack
664 #endif
665 
666 #ifndef __COPYRIGHT
667 #define	__COPYRIGHT(s)  struct __hack
668 #endif
669 
670 #endif /* !_SYS_CDEFS_H_ */
671