xref: /freebsd/sys/sys/cdefs.h (revision 0e6acb26)
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  * $FreeBSD$
34  */
35 
36 #ifndef	_SYS_CDEFS_H_
37 #define	_SYS_CDEFS_H_
38 
39 /*
40  * Testing against Clang-specific extensions.
41  */
42 #ifndef	__has_attribute
43 #define	__has_attribute(x)	0
44 #endif
45 #ifndef	__has_extension
46 #define	__has_extension		__has_feature
47 #endif
48 #ifndef	__has_feature
49 #define	__has_feature(x)	0
50 #endif
51 #ifndef	__has_include
52 #define	__has_include(x)	0
53 #endif
54 #ifndef	__has_builtin
55 #define	__has_builtin(x)	0
56 #endif
57 
58 #if defined(__cplusplus)
59 #define	__BEGIN_DECLS	extern "C" {
60 #define	__END_DECLS	}
61 #else
62 #define	__BEGIN_DECLS
63 #define	__END_DECLS
64 #endif
65 
66 /*
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.
70  */
71 
72 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
73 
74 #if __GNUC__ >= 3 || defined(__INTEL_COMPILER)
75 #define	__GNUCLIKE_ASM 3
76 #define	__GNUCLIKE_MATH_BUILTIN_CONSTANTS
77 #else
78 #define	__GNUCLIKE_ASM 2
79 #endif
80 #define	__GNUCLIKE___TYPEOF 1
81 #define	__GNUCLIKE___OFFSETOF 1
82 #define	__GNUCLIKE___SECTION 1
83 
84 #ifndef __INTEL_COMPILER
85 #define	__GNUCLIKE_CTOR_SECTION_HANDLING 1
86 #endif
87 
88 #define	__GNUCLIKE_BUILTIN_CONSTANT_P 1
89 #if defined(__INTEL_COMPILER) && defined(__cplusplus) && \
90    __INTEL_COMPILER < 800
91 #undef __GNUCLIKE_BUILTIN_CONSTANT_P
92 #endif
93 
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
98 #endif
99 
100 #if defined(__GNUC__)
101 #define	__GNUC_VA_LIST_COMPATIBILITY 1
102 #endif
103 
104 /*
105  * Compiler memory barriers, specific to gcc and clang.
106  */
107 #if defined(__GNUC__)
108 #define	__compiler_membar()	__asm __volatile(" " : : : "memory")
109 #endif
110 
111 #ifndef __INTEL_COMPILER
112 #define	__GNUCLIKE_BUILTIN_NEXT_ARG 1
113 #define	__GNUCLIKE_MATH_BUILTIN_RELOPS
114 #endif
115 
116 #define	__GNUCLIKE_BUILTIN_MEMCPY 1
117 
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
122 
123 #define	__CC_SUPPORTS___FUNC__ 1
124 #define	__CC_SUPPORTS_WARNING 1
125 
126 #define	__CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */
127 
128 #define	__CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
129 
130 #endif /* __GNUC__ || __INTEL_COMPILER */
131 
132 /*
133  * Macro to test if we're using a specific version of gcc or later.
134  */
135 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
136 #define	__GNUC_PREREQ__(ma, mi)	\
137 	(__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
138 #else
139 #define	__GNUC_PREREQ__(ma, mi)	0
140 #endif
141 
142 /*
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.
150  *
151  * __XSTRING is like __STRING, but it expands any macros in its argument
152  * first.  It is only available with ANSI C.
153  */
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 */
160 
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 */
166 #else
167 #if !(defined(__CC_SUPPORTS___INLINE))
168 #define	__inline			/* delete GCC keyword */
169 #endif /* ! __CC_SUPPORTS___INLINE */
170 #endif /* !__cplusplus */
171 
172 #else	/* !(__STDC__ || __cplusplus) */
173 #define	__P(protos)	()		/* traditional C preprocessor */
174 #define	__CONCAT(x,y)	x/**/y
175 #define	__STRING(x)	"x"
176 
177 #if !defined(__CC_SUPPORTS___INLINE)
178 #define	__const				/* delete pseudo-ANSI C keywords */
179 #define	__inline
180 #define	__signed
181 #define	__volatile
182 /*
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.
189  */
190 #ifndef	NO_ANSI_KEYWORDS
191 #define	const				/* delete ANSI C keywords */
192 #define	inline
193 #define	signed
194 #define	volatile
195 #endif	/* !NO_ANSI_KEYWORDS */
196 #endif	/* !__CC_SUPPORTS___INLINE */
197 #endif	/* !(__STDC__ || __cplusplus) */
198 
199 /*
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.
207  */
208 #ifdef lint
209 #define	__dead2
210 #define	__pure2
211 #define	__unused
212 #define	__packed
213 #define	__aligned(x)
214 #define	__alloc_align(x)
215 #define	__alloc_size(x)
216 #define	__section(x)
217 #define	__weak_symbol
218 #else
219 #define	__weak_symbol	__attribute__((__weak__))
220 #if !__GNUC_PREREQ__(2, 5) && !defined(__INTEL_COMPILER)
221 #define	__dead2
222 #define	__pure2
223 #define	__unused
224 #endif
225 #if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 && !defined(__INTEL_COMPILER)
226 #define	__dead2		__attribute__((__noreturn__))
227 #define	__pure2		__attribute__((__const__))
228 #define	__unused
229 /* XXX Find out what to do for __packed, __aligned and __section */
230 #endif
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)))
239 #endif
240 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__)
241 #define	__alloc_size(x)	__attribute__((__alloc_size__(x)))
242 #else
243 #define	__alloc_size(x)
244 #endif
245 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
246 #define	__alloc_align(x)	__attribute__((__alloc_align__(x)))
247 #else
248 #define	__alloc_align(x)
249 #endif
250 #endif /* lint */
251 
252 #if !__GNUC_PREREQ__(2, 95)
253 #define	__alignof(x)	__offsetof(struct { char __a; x __b; }, __b)
254 #endif
255 
256 /*
257  * Keywords added in C11.
258  */
259 
260 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L || defined(lint)
261 
262 #if !__has_extension(c_alignas)
263 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
264     __has_extension(cxx_alignas)
265 #define	_Alignas(x)		alignas(x)
266 #else
267 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
268 #define	_Alignas(x)		__aligned(x)
269 #endif
270 #endif
271 
272 #if defined(__cplusplus) && __cplusplus >= 201103L
273 #define	_Alignof(x)		alignof(x)
274 #else
275 #define	_Alignof(x)		__alignof(x)
276 #endif
277 
278 #if !defined(__cplusplus) && !__has_extension(c_atomic) && \
279     !__has_extension(cxx_atomic)
280 /*
281  * No native support for _Atomic(). Place object in structure to prevent
282  * most forms of direct non-atomic access.
283  */
284 #define	_Atomic(T)		struct { T volatile __val; }
285 #endif
286 
287 #if defined(__cplusplus) && __cplusplus >= 201103L
288 #define	_Noreturn		[[noreturn]]
289 #else
290 #define	_Noreturn		__dead2
291 #endif
292 
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] \
303 				__unused
304 #else
305 #define	_Static_assert(x, y)	struct __hack
306 #endif
307 #endif
308 
309 #if !__has_extension(c_thread_local)
310 /*
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.
314  */
315 #if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \
316     __has_extension(cxx_thread_local)
317 #define	_Thread_local		thread_local
318 #else
319 #define	_Thread_local		__thread
320 #endif
321 #endif
322 
323 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
324 
325 /*
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.
332  */
333 
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)
342 #endif
343 
344 /*
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)]);
350  */
351 #if !defined(__cplusplus) && \
352     (defined(__clang__) || __GNUC_PREREQ__(4, 6)) && \
353     (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901))
354 #define __min_size(x)	static (x)
355 #else
356 #define __min_size(x)	(x)
357 #endif
358 
359 #if __GNUC_PREREQ__(2, 96)
360 #define	__malloc_like	__attribute__((__malloc__))
361 #define	__pure		__attribute__((__pure__))
362 #else
363 #define	__malloc_like
364 #define	__pure
365 #endif
366 
367 #if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
368 #define	__always_inline	__attribute__((__always_inline__))
369 #else
370 #define	__always_inline
371 #endif
372 
373 #if __GNUC_PREREQ__(3, 1)
374 #define	__noinline	__attribute__ ((__noinline__))
375 #else
376 #define	__noinline
377 #endif
378 
379 #if __GNUC_PREREQ__(3, 4)
380 #define	__fastcall	__attribute__((__fastcall__))
381 #define	__result_use_check	__attribute__((__warn_unused_result__))
382 #else
383 #define	__fastcall
384 #define	__result_use_check
385 #endif
386 
387 #if __GNUC_PREREQ__(4, 1)
388 #define	__returns_twice	__attribute__((__returns_twice__))
389 #else
390 #define	__returns_twice
391 #endif
392 
393 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
394 #define	__unreachable()	__builtin_unreachable()
395 #else
396 #define	__unreachable()	((void)0)
397 #endif
398 
399 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
400 #if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
401 #define	__func__	NULL
402 #endif
403 
404 #if (defined(__INTEL_COMPILER) || (defined(__GNUC__) && __GNUC__ >= 2)) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
405 #define	__LONG_LONG_SUPPORTED
406 #endif
407 
408 /* C++11 exposes a load of C99 stuff */
409 #if defined(__cplusplus) && __cplusplus >= 201103L
410 #define	__LONG_LONG_SUPPORTED
411 #ifndef	__STDC_LIMIT_MACROS
412 #define	__STDC_LIMIT_MACROS
413 #endif
414 #ifndef	__STDC_CONSTANT_MACROS
415 #define	__STDC_CONSTANT_MACROS
416 #endif
417 #endif
418 
419 /*
420  * GCC 2.95 provides `__restrict' as an extension to C90 to support the
421  * C99-specific `restrict' type qualifier.  We happen to use `__restrict' as
422  * a way to define the `restrict' type qualifier without disturbing older
423  * software that is unaware of C99 keywords.
424  */
425 #if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
426 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901 || defined(lint)
427 #define	__restrict
428 #else
429 #define	__restrict	restrict
430 #endif
431 #endif
432 
433 /*
434  * GNU C version 2.96 adds explicit branch prediction so that
435  * the CPU back-end can hint the processor and also so that
436  * code blocks can be reordered such that the predicted path
437  * sees a more linear flow, thus improving cache behavior, etc.
438  *
439  * The following two macros provide us with a way to utilize this
440  * compiler feature.  Use __predict_true() if you expect the expression
441  * to evaluate to true, and __predict_false() if you expect the
442  * expression to evaluate to false.
443  *
444  * A few notes about usage:
445  *
446  *	* Generally, __predict_false() error condition checks (unless
447  *	  you have some _strong_ reason to do otherwise, in which case
448  *	  document it), and/or __predict_true() `no-error' condition
449  *	  checks, assuming you want to optimize for the no-error case.
450  *
451  *	* Other than that, if you don't know the likelihood of a test
452  *	  succeeding from empirical or other `hard' evidence, don't
453  *	  make predictions.
454  *
455  *	* These are meant to be used in places that are run `a lot'.
456  *	  It is wasteful to make predictions in code that is run
457  *	  seldomly (e.g. at subsystem initialization time) as the
458  *	  basic block reordering that this affects can often generate
459  *	  larger code.
460  */
461 #if __GNUC_PREREQ__(2, 96)
462 #define	__predict_true(exp)     __builtin_expect((exp), 1)
463 #define	__predict_false(exp)    __builtin_expect((exp), 0)
464 #else
465 #define	__predict_true(exp)     (exp)
466 #define	__predict_false(exp)    (exp)
467 #endif
468 
469 #if __GNUC_PREREQ__(4, 0)
470 #define	__null_sentinel	__attribute__((__sentinel__))
471 #define	__exported	__attribute__((__visibility__("default")))
472 #define	__hidden	__attribute__((__visibility__("hidden")))
473 #else
474 #define	__null_sentinel
475 #define	__exported
476 #define	__hidden
477 #endif
478 
479 /*
480  * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
481  * require it.
482  */
483 #if __GNUC_PREREQ__(4, 1)
484 #define	__offsetof(type, field)	 __builtin_offsetof(type, field)
485 #else
486 #ifndef __cplusplus
487 #define	__offsetof(type, field) \
488 	((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
489 #else
490 #define	__offsetof(type, field)					\
491   (__offsetof__ (reinterpret_cast <__size_t>			\
492                  (&reinterpret_cast <const volatile char &>	\
493                   (static_cast<type *> (0)->field))))
494 #endif
495 #endif
496 #define	__rangeof(type, start, end) \
497 	(__offsetof(type, end) - __offsetof(type, start))
498 
499 /*
500  * Given the pointer x to the member m of the struct s, return
501  * a pointer to the containing structure.  When using GCC, we first
502  * assign pointer x to a local variable, to check that its type is
503  * compatible with member m.
504  */
505 #if __GNUC_PREREQ__(3, 1)
506 #define	__containerof(x, s, m) ({					\
507 	const volatile __typeof(((s *)0)->m) *__x = (x);		\
508 	__DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
509 })
510 #else
511 #define	__containerof(x, s, m)						\
512 	__DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
513 #endif
514 
515 /*
516  * Compiler-dependent macros to declare that functions take printf-like
517  * or scanf-like arguments.  They are null except for versions of gcc
518  * that are known to support the features properly (old versions of gcc-2
519  * didn't permit keeping the keywords out of the application namespace).
520  */
521 #if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
522 #define	__printflike(fmtarg, firstvararg)
523 #define	__scanflike(fmtarg, firstvararg)
524 #define	__format_arg(fmtarg)
525 #define	__strfmonlike(fmtarg, firstvararg)
526 #define	__strftimelike(fmtarg, firstvararg)
527 #else
528 #define	__printflike(fmtarg, firstvararg) \
529 	    __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
530 #define	__scanflike(fmtarg, firstvararg) \
531 	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
532 #define	__format_arg(fmtarg)	__attribute__((__format_arg__ (fmtarg)))
533 #define	__strfmonlike(fmtarg, firstvararg) \
534 	    __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
535 #define	__strftimelike(fmtarg, firstvararg) \
536 	    __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
537 #endif
538 
539 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
540 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
541     defined(__GNUC__) && !defined(__INTEL_COMPILER)
542 #define	__printf0like(fmtarg, firstvararg) \
543 	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
544 #else
545 #define	__printf0like(fmtarg, firstvararg)
546 #endif
547 
548 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
549 #ifndef __INTEL_COMPILER
550 #define	__strong_reference(sym,aliassym)	\
551 	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
552 #endif
553 #ifdef __STDC__
554 #define	__weak_reference(sym,alias)	\
555 	__asm__(".weak " #alias);	\
556 	__asm__(".equ "  #alias ", " #sym)
557 #define	__warn_references(sym,msg)	\
558 	__asm__(".section .gnu.warning." #sym);	\
559 	__asm__(".asciz \"" msg "\"");	\
560 	__asm__(".previous")
561 #define	__sym_compat(sym,impl,verid)	\
562 	__asm__(".symver " #impl ", " #sym "@" #verid)
563 #define	__sym_default(sym,impl,verid)	\
564 	__asm__(".symver " #impl ", " #sym "@@" #verid)
565 #else
566 #define	__weak_reference(sym,alias)	\
567 	__asm__(".weak alias");		\
568 	__asm__(".equ alias, sym")
569 #define	__warn_references(sym,msg)	\
570 	__asm__(".section .gnu.warning.sym"); \
571 	__asm__(".asciz \"msg\"");	\
572 	__asm__(".previous")
573 #define	__sym_compat(sym,impl,verid)	\
574 	__asm__(".symver impl, sym@verid")
575 #define	__sym_default(impl,sym,verid)	\
576 	__asm__(".symver impl, sym@@verid")
577 #endif	/* __STDC__ */
578 #endif	/* __GNUC__ || __INTEL_COMPILER */
579 
580 #define	__GLOBL1(sym)	__asm__(".globl " #sym)
581 #define	__GLOBL(sym)	__GLOBL1(sym)
582 
583 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
584 #define	__IDSTRING(name,string)	__asm__(".ident\t\"" string "\"")
585 #else
586 /*
587  * The following definition might not work well if used in header files,
588  * but it should be better than nothing.  If you want a "do nothing"
589  * version, then it should generate some harmless declaration, such as:
590  *    #define	__IDSTRING(name,string)	struct __hack
591  */
592 #define	__IDSTRING(name,string)	static const char name[] __unused = string
593 #endif
594 
595 /*
596  * Embed the rcs id of a source file in the resulting library.  Note that in
597  * more recent ELF binutils, we use .ident allowing the ID to be stripped.
598  * Usage:
599  *	__FBSDID("$FreeBSD$");
600  */
601 #ifndef	__FBSDID
602 #if !defined(lint) && !defined(STRIP_FBSDID)
603 #define	__FBSDID(s)	__IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
604 #else
605 #define	__FBSDID(s)	struct __hack
606 #endif
607 #endif
608 
609 #ifndef	__RCSID
610 #ifndef	NO__RCSID
611 #define	__RCSID(s)	__IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
612 #else
613 #define	__RCSID(s)	struct __hack
614 #endif
615 #endif
616 
617 #ifndef	__RCSID_SOURCE
618 #ifndef	NO__RCSID_SOURCE
619 #define	__RCSID_SOURCE(s)	__IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
620 #else
621 #define	__RCSID_SOURCE(s)	struct __hack
622 #endif
623 #endif
624 
625 #ifndef	__SCCSID
626 #ifndef	NO__SCCSID
627 #define	__SCCSID(s)	__IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
628 #else
629 #define	__SCCSID(s)	struct __hack
630 #endif
631 #endif
632 
633 #ifndef	__COPYRIGHT
634 #ifndef	NO__COPYRIGHT
635 #define	__COPYRIGHT(s)	__IDSTRING(__CONCAT(__copyright_,__LINE__),s)
636 #else
637 #define	__COPYRIGHT(s)	struct __hack
638 #endif
639 #endif
640 
641 #ifndef	__DECONST
642 #define	__DECONST(type, var)	((type)(__uintptr_t)(const void *)(var))
643 #endif
644 
645 #ifndef	__DEVOLATILE
646 #define	__DEVOLATILE(type, var)	((type)(__uintptr_t)(volatile void *)(var))
647 #endif
648 
649 #ifndef	__DEQUALIFY
650 #define	__DEQUALIFY(type, var)	((type)(__uintptr_t)(const volatile void *)(var))
651 #endif
652 
653 /*-
654  * The following definitions are an extension of the behavior originally
655  * implemented in <sys/_posix.h>, but with a different level of granularity.
656  * POSIX.1 requires that the macros we test be defined before any standard
657  * header file is included.
658  *
659  * Here's a quick run-down of the versions:
660  *  defined(_POSIX_SOURCE)		1003.1-1988
661  *  _POSIX_C_SOURCE == 1		1003.1-1990
662  *  _POSIX_C_SOURCE == 2		1003.2-1992 C Language Binding Option
663  *  _POSIX_C_SOURCE == 199309		1003.1b-1993
664  *  _POSIX_C_SOURCE == 199506		1003.1c-1995, 1003.1i-1995,
665  *					and the omnibus ISO/IEC 9945-1: 1996
666  *  _POSIX_C_SOURCE == 200112		1003.1-2001
667  *  _POSIX_C_SOURCE == 200809		1003.1-2008
668  *
669  * In addition, the X/Open Portability Guide, which is now the Single UNIX
670  * Specification, defines a feature-test macro which indicates the version of
671  * that specification, and which subsumes _POSIX_C_SOURCE.
672  *
673  * Our macros begin with two underscores to avoid namespace screwage.
674  */
675 
676 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
677 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
678 #undef _POSIX_C_SOURCE		/* Probably illegal, but beyond caring now. */
679 #define	_POSIX_C_SOURCE		199009
680 #endif
681 
682 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
683 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
684 #undef _POSIX_C_SOURCE
685 #define	_POSIX_C_SOURCE		199209
686 #endif
687 
688 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
689 #ifdef _XOPEN_SOURCE
690 #if _XOPEN_SOURCE - 0 >= 700
691 #define	__XSI_VISIBLE		700
692 #undef _POSIX_C_SOURCE
693 #define	_POSIX_C_SOURCE		200809
694 #elif _XOPEN_SOURCE - 0 >= 600
695 #define	__XSI_VISIBLE		600
696 #undef _POSIX_C_SOURCE
697 #define	_POSIX_C_SOURCE		200112
698 #elif _XOPEN_SOURCE - 0 >= 500
699 #define	__XSI_VISIBLE		500
700 #undef _POSIX_C_SOURCE
701 #define	_POSIX_C_SOURCE		199506
702 #endif
703 #endif
704 
705 /*
706  * Deal with all versions of POSIX.  The ordering relative to the tests above is
707  * important.
708  */
709 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
710 #define	_POSIX_C_SOURCE		198808
711 #endif
712 #ifdef _POSIX_C_SOURCE
713 #if _POSIX_C_SOURCE >= 200809
714 #define	__POSIX_VISIBLE		200809
715 #define	__ISO_C_VISIBLE		1999
716 #elif _POSIX_C_SOURCE >= 200112
717 #define	__POSIX_VISIBLE		200112
718 #define	__ISO_C_VISIBLE		1999
719 #elif _POSIX_C_SOURCE >= 199506
720 #define	__POSIX_VISIBLE		199506
721 #define	__ISO_C_VISIBLE		1990
722 #elif _POSIX_C_SOURCE >= 199309
723 #define	__POSIX_VISIBLE		199309
724 #define	__ISO_C_VISIBLE		1990
725 #elif _POSIX_C_SOURCE >= 199209
726 #define	__POSIX_VISIBLE		199209
727 #define	__ISO_C_VISIBLE		1990
728 #elif _POSIX_C_SOURCE >= 199009
729 #define	__POSIX_VISIBLE		199009
730 #define	__ISO_C_VISIBLE		1990
731 #else
732 #define	__POSIX_VISIBLE		198808
733 #define	__ISO_C_VISIBLE		0
734 #endif /* _POSIX_C_SOURCE */
735 #else
736 /*-
737  * Deal with _ANSI_SOURCE:
738  * If it is defined, and no other compilation environment is explicitly
739  * requested, then define our internal feature-test macros to zero.  This
740  * makes no difference to the preprocessor (undefined symbols in preprocessing
741  * expressions are defined to have value zero), but makes it more convenient for
742  * a test program to print out the values.
743  *
744  * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
745  * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
746  * environment (and in fact we will never get here).
747  */
748 #if defined(_ANSI_SOURCE)	/* Hide almost everything. */
749 #define	__POSIX_VISIBLE		0
750 #define	__XSI_VISIBLE		0
751 #define	__BSD_VISIBLE		0
752 #define	__ISO_C_VISIBLE		1990
753 #define	__EXT1_VISIBLE		0
754 #elif defined(_C99_SOURCE)	/* Localism to specify strict C99 env. */
755 #define	__POSIX_VISIBLE		0
756 #define	__XSI_VISIBLE		0
757 #define	__BSD_VISIBLE		0
758 #define	__ISO_C_VISIBLE		1999
759 #define	__EXT1_VISIBLE		0
760 #elif defined(_C11_SOURCE)	/* Localism to specify strict C11 env. */
761 #define	__POSIX_VISIBLE		0
762 #define	__XSI_VISIBLE		0
763 #define	__BSD_VISIBLE		0
764 #define	__ISO_C_VISIBLE		2011
765 #define	__EXT1_VISIBLE		0
766 #else				/* Default environment: show everything. */
767 #define	__POSIX_VISIBLE		200809
768 #define	__XSI_VISIBLE		700
769 #define	__BSD_VISIBLE		1
770 #define	__ISO_C_VISIBLE		2011
771 #define	__EXT1_VISIBLE		1
772 #endif
773 #endif
774 
775 /* User override __EXT1_VISIBLE */
776 #if defined(__STDC_WANT_LIB_EXT1__)
777 #undef	__EXT1_VISIBLE
778 #if __STDC_WANT_LIB_EXT1__
779 #define	__EXT1_VISIBLE		1
780 #else
781 #define	__EXT1_VISIBLE		0
782 #endif
783 #endif /* __STDC_WANT_LIB_EXT1__ */
784 
785 #if defined(__mips) || defined(__powerpc64__) || defined(__riscv__)
786 #define	__NO_TLS 1
787 #endif
788 
789 /*
790  * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h
791  * translates them to __ARM_ARCH and the modern feature symbols defined by ARM.
792  */
793 #if defined(__arm__) && !defined(__ARM_ARCH)
794 #include <machine/acle-compat.h>
795 #endif
796 
797 /*
798  * Nullability qualifiers: currently only supported by Clang.
799  */
800 #if !(defined(__clang__) && __has_feature(nullability))
801 #define	_Nonnull
802 #define	_Nullable
803 #define	_Null_unspecified
804 #define	__NULLABILITY_PRAGMA_PUSH
805 #define	__NULLABILITY_PRAGMA_POP
806 #else
807 #define	__NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push")	\
808 	_Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
809 #define	__NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop")
810 #endif
811 
812 /*
813  * Type Safety Checking
814  *
815  * Clang provides additional attributes to enable checking type safety
816  * properties that cannot be enforced by the C type system.
817  */
818 
819 #if __has_attribute(__argument_with_type_tag__) && \
820     __has_attribute(__type_tag_for_datatype__) && !defined(lint)
821 #define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
822 	    __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
823 #define	__datatype_type_tag(kind, type) \
824 	    __attribute__((__type_tag_for_datatype__(kind, type)))
825 #else
826 #define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx)
827 #define	__datatype_type_tag(kind, type)
828 #endif
829 
830 /*
831  * Lock annotations.
832  *
833  * Clang provides support for doing basic thread-safety tests at
834  * compile-time, by marking which locks will/should be held when
835  * entering/leaving a functions.
836  *
837  * Furthermore, it is also possible to annotate variables and structure
838  * members to enforce that they are only accessed when certain locks are
839  * held.
840  */
841 
842 #if __has_extension(c_thread_safety_attributes)
843 #define	__lock_annotate(x)	__attribute__((x))
844 #else
845 #define	__lock_annotate(x)
846 #endif
847 
848 /* Structure implements a lock. */
849 #define	__lockable		__lock_annotate(lockable)
850 
851 /* Function acquires an exclusive or shared lock. */
852 #define	__locks_exclusive(...) \
853 	__lock_annotate(exclusive_lock_function(__VA_ARGS__))
854 #define	__locks_shared(...) \
855 	__lock_annotate(shared_lock_function(__VA_ARGS__))
856 
857 /* Function attempts to acquire an exclusive or shared lock. */
858 #define	__trylocks_exclusive(...) \
859 	__lock_annotate(exclusive_trylock_function(__VA_ARGS__))
860 #define	__trylocks_shared(...) \
861 	__lock_annotate(shared_trylock_function(__VA_ARGS__))
862 
863 /* Function releases a lock. */
864 #define	__unlocks(...)		__lock_annotate(unlock_function(__VA_ARGS__))
865 
866 /* Function asserts that an exclusive or shared lock is held. */
867 #define	__asserts_exclusive(...) \
868 	__lock_annotate(assert_exclusive_lock(__VA_ARGS__))
869 #define	__asserts_shared(...) \
870 	__lock_annotate(assert_shared_lock(__VA_ARGS__))
871 
872 /* Function requires that an exclusive or shared lock is or is not held. */
873 #define	__requires_exclusive(...) \
874 	__lock_annotate(exclusive_locks_required(__VA_ARGS__))
875 #define	__requires_shared(...) \
876 	__lock_annotate(shared_locks_required(__VA_ARGS__))
877 #define	__requires_unlocked(...) \
878 	__lock_annotate(locks_excluded(__VA_ARGS__))
879 
880 /* Function should not be analyzed. */
881 #define	__no_lock_analysis	__lock_annotate(no_thread_safety_analysis)
882 
883 /* Guard variables and structure members by lock. */
884 #define	__guarded_by(x)		__lock_annotate(guarded_by(x))
885 #define	__pt_guarded_by(x)	__lock_annotate(pt_guarded_by(x))
886 
887 #endif /* !_SYS_CDEFS_H_ */
888