1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Berkeley Software Design, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)cdefs.h	8.8 (Berkeley) 1/9/95
35  * $FreeBSD: stable/12/sys/sys/cdefs.h 371167 2021-12-06 15:56:59Z imp $
36  */
37 
38 #ifndef	_SYS_CDEFS_H_
39 #define	_SYS_CDEFS_H_
40 
41 /*
42  * Testing against Clang-specific extensions.
43  */
44 #ifndef	__has_attribute
45 #define	__has_attribute(x)	0
46 #endif
47 #ifndef	__has_extension
48 #define	__has_extension		__has_feature
49 #endif
50 #ifndef	__has_feature
51 #define	__has_feature(x)	0
52 #endif
53 #ifndef	__has_include
54 #define	__has_include(x)	0
55 #endif
56 #ifndef	__has_builtin
57 #define	__has_builtin(x)	0
58 #endif
59 
60 #if defined(__cplusplus)
61 #define	__BEGIN_DECLS	extern "C" {
62 #define	__END_DECLS	}
63 #else
64 #define	__BEGIN_DECLS
65 #define	__END_DECLS
66 #endif
67 
68 /*
69  * This code has been put in place to help reduce the addition of
70  * compiler specific defines in FreeBSD code.  It helps to aid in
71  * having a compiler-agnostic source tree.
72  */
73 
74 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
75 
76 #if __GNUC__ >= 3 || defined(__INTEL_COMPILER)
77 #define	__GNUCLIKE_ASM 3
78 #define	__GNUCLIKE_MATH_BUILTIN_CONSTANTS
79 #else
80 #define	__GNUCLIKE_ASM 2
81 #endif
82 #define	__GNUCLIKE___TYPEOF 1
83 #define	__GNUCLIKE___OFFSETOF 1
84 #define	__GNUCLIKE___SECTION 1
85 
86 #ifndef __INTEL_COMPILER
87 #define	__GNUCLIKE_CTOR_SECTION_HANDLING 1
88 #endif
89 
90 #define	__GNUCLIKE_BUILTIN_CONSTANT_P 1
91 #if defined(__INTEL_COMPILER) && defined(__cplusplus) && \
92    __INTEL_COMPILER < 800
93 #undef __GNUCLIKE_BUILTIN_CONSTANT_P
94 #endif
95 
96 #if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3)
97 #define	__GNUCLIKE_BUILTIN_VARARGS 1
98 #define	__GNUCLIKE_BUILTIN_STDARG 1
99 #define	__GNUCLIKE_BUILTIN_VAALIST 1
100 #endif
101 
102 #define	__GNUC_VA_LIST_COMPATIBILITY 1
103 
104 /*
105  * Compiler memory barriers, specific to gcc and clang.
106  */
107 #define	__compiler_membar()	__asm __volatile(" " : : : "memory")
108 
109 #ifndef __INTEL_COMPILER
110 #define	__GNUCLIKE_BUILTIN_NEXT_ARG 1
111 #define	__GNUCLIKE_MATH_BUILTIN_RELOPS
112 #endif
113 
114 #define	__GNUCLIKE_BUILTIN_MEMCPY 1
115 
116 /* XXX: if __GNUC__ >= 2: not tested everywhere originally, where replaced */
117 #define	__CC_SUPPORTS_INLINE 1
118 #define	__CC_SUPPORTS___INLINE 1
119 #define	__CC_SUPPORTS___INLINE__ 1
120 
121 #define	__CC_SUPPORTS___FUNC__ 1
122 #define	__CC_SUPPORTS_WARNING 1
123 
124 #define	__CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */
125 
126 #define	__CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
127 
128 #endif /* __GNUC__ || __INTEL_COMPILER */
129 
130 /*
131  * Macro to test if we're using a specific version of gcc or later.
132  */
133 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
134 #define	__GNUC_PREREQ__(ma, mi)	\
135 	(__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
136 #else
137 #define	__GNUC_PREREQ__(ma, mi)	0
138 #endif
139 
140 /*
141  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
142  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
143  * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
144  * mode -- there must be no spaces between its arguments, and for nested
145  * __CONCAT's, all the __CONCAT's must be at the left.  __CONCAT can also
146  * concatenate double-quoted strings produced by the __STRING macro, but
147  * this only works with ANSI C.
148  *
149  * __XSTRING is like __STRING, but it expands any macros in its argument
150  * first.  It is only available with ANSI C.
151  */
152 #if defined(__STDC__) || defined(__cplusplus)
153 #define	__P(protos)	protos		/* full-blown ANSI C */
154 #define	__CONCAT1(x,y)	x ## y
155 #define	__CONCAT(x,y)	__CONCAT1(x,y)
156 #define	__STRING(x)	#x		/* stringify without expanding x */
157 #define	__XSTRING(x)	__STRING(x)	/* expand x, then stringify */
158 
159 #define	__const		const		/* define reserved names to standard */
160 #define	__signed	signed
161 #define	__volatile	volatile
162 #if defined(__cplusplus)
163 #define	__inline	inline		/* convert to C++ keyword */
164 #else
165 #if !(defined(__CC_SUPPORTS___INLINE))
166 #define	__inline			/* delete GCC keyword */
167 #endif /* ! __CC_SUPPORTS___INLINE */
168 #endif /* !__cplusplus */
169 
170 #else	/* !(__STDC__ || __cplusplus) */
171 #define	__P(protos)	()		/* traditional C preprocessor */
172 #define	__CONCAT(x,y)	x/**/y
173 #define	__STRING(x)	"x"
174 
175 #if !defined(__CC_SUPPORTS___INLINE)
176 #define	__const				/* delete pseudo-ANSI C keywords */
177 #define	__inline
178 #define	__signed
179 #define	__volatile
180 /*
181  * In non-ANSI C environments, new programs will want ANSI-only C keywords
182  * deleted from the program and old programs will want them left alone.
183  * When using a compiler other than gcc, programs using the ANSI C keywords
184  * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
185  * When using "gcc -traditional", we assume that this is the intent; if
186  * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
187  */
188 #ifndef	NO_ANSI_KEYWORDS
189 #define	const				/* delete ANSI C keywords */
190 #define	inline
191 #define	signed
192 #define	volatile
193 #endif	/* !NO_ANSI_KEYWORDS */
194 #endif	/* !__CC_SUPPORTS___INLINE */
195 #endif	/* !(__STDC__ || __cplusplus) */
196 
197 /*
198  * Compiler-dependent macros to help declare dead (non-returning) and
199  * pure (no side effects) functions, and unused variables.  They are
200  * null except for versions of gcc that are known to support the features
201  * properly (old versions of gcc-2 supported the dead and pure features
202  * in a different (wrong) way).  If we do not provide an implementation
203  * for a given compiler, let the compile fail if it is told to use
204  * a feature that we cannot live without.
205  */
206 #define	__weak_symbol	__attribute__((__weak__))
207 #if !__GNUC_PREREQ__(2, 5) && !defined(__INTEL_COMPILER)
208 #define	__dead2
209 #define	__pure2
210 #define	__unused
211 #endif
212 #if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 && !defined(__INTEL_COMPILER)
213 #define	__dead2		__attribute__((__noreturn__))
214 #define	__pure2		__attribute__((__const__))
215 #define	__unused
216 /* XXX Find out what to do for __packed, __aligned and __section */
217 #endif
218 #if __GNUC_PREREQ__(2, 7) || defined(__INTEL_COMPILER)
219 #define	__dead2		__attribute__((__noreturn__))
220 #define	__pure2		__attribute__((__const__))
221 #define	__unused	__attribute__((__unused__))
222 #define	__used		__attribute__((__used__))
223 #define	__packed	__attribute__((__packed__))
224 #define	__aligned(x)	__attribute__((__aligned__(x)))
225 #define	__section(x)	__attribute__((__section__(x)))
226 #endif
227 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__)
228 #define	__alloc_size(x)	__attribute__((__alloc_size__(x)))
229 #define	__alloc_size2(n, x)	__attribute__((__alloc_size__(n, x)))
230 #else
231 #define	__alloc_size(x)
232 #define	__alloc_size2(n, x)
233 #endif
234 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
235 #define	__alloc_align(x)	__attribute__((__alloc_align__(x)))
236 #else
237 #define	__alloc_align(x)
238 #endif
239 
240 #if !__GNUC_PREREQ__(2, 95)
241 #define	__alignof(x)	__offsetof(struct { char __a; x __b; }, __b)
242 #endif
243 
244 /*
245  * Keywords added in C11.
246  */
247 
248 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
249 
250 #if !__has_extension(c_alignas)
251 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
252     __has_extension(cxx_alignas)
253 #define	_Alignas(x)		alignas(x)
254 #else
255 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
256 #define	_Alignas(x)		__aligned(x)
257 #endif
258 #endif
259 
260 #if defined(__cplusplus) && __cplusplus >= 201103L
261 #define	_Alignof(x)		alignof(x)
262 #else
263 #define	_Alignof(x)		__alignof(x)
264 #endif
265 
266 #if !defined(__cplusplus) && !__has_extension(c_atomic) && \
267 	!__has_extension(cxx_atomic) && !__GNUC_PREREQ__(4, 7)
268 /*
269  * No native support for _Atomic(). Place object in structure to prevent
270  * most forms of direct non-atomic access.
271  */
272 #define	_Atomic(T)		struct { T volatile __val; }
273 #endif
274 
275 #if defined(__cplusplus) && __cplusplus >= 201103L
276 #define	_Noreturn		[[noreturn]]
277 #else
278 #define	_Noreturn		__dead2
279 #endif
280 
281 #if !__has_extension(c_static_assert)
282 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
283     __has_extension(cxx_static_assert)
284 #define	_Static_assert(x, y)	static_assert(x, y)
285 #elif __GNUC_PREREQ__(4,6) && !defined(__cplusplus)
286 /* Nothing, gcc 4.6 and higher has _Static_assert built-in */
287 #elif defined(__COUNTER__)
288 #define	_Static_assert(x, y)	__Static_assert(x, __COUNTER__)
289 #define	__Static_assert(x, y)	___Static_assert(x, y)
290 #define	___Static_assert(x, y)	typedef char __assert_ ## y[(x) ? 1 : -1] \
291 				__unused
292 #else
293 #define	_Static_assert(x, y)	struct __hack
294 #endif
295 #endif
296 
297 #if !__has_extension(c_thread_local)
298 /*
299  * XXX: Some compilers (Clang 3.3, GCC 4.7) falsely announce C++11 mode
300  * without actually supporting the thread_local keyword. Don't check for
301  * the presence of C++11 when defining _Thread_local.
302  */
303 #if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \
304     __has_extension(cxx_thread_local)
305 #define	_Thread_local		thread_local
306 #else
307 #define	_Thread_local		__thread
308 #endif
309 #endif
310 
311 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
312 
313 /*
314  * Emulation of C11 _Generic().  Unlike the previously defined C11
315  * keywords, it is not possible to implement this using exactly the same
316  * syntax.  Therefore implement something similar under the name
317  * __generic().  Unlike _Generic(), this macro can only distinguish
318  * between a single type, so it requires nested invocations to
319  * distinguish multiple cases.
320  */
321 
322 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \
323     __has_extension(c_generic_selections)
324 #define	__generic(expr, t, yes, no)					\
325 	_Generic(expr, t: yes, default: no)
326 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
327 #define	__generic(expr, t, yes, no)					\
328 	__builtin_choose_expr(						\
329 	    __builtin_types_compatible_p(__typeof(expr), t), yes, no)
330 #endif
331 
332 /*
333  * C99 Static array indices in function parameter declarations.  Syntax such as:
334  * void bar(int myArray[static 10]);
335  * is allowed in C99 but not in C++.  Define __min_size appropriately so
336  * headers using it can be compiled in either language.  Use like this:
337  * void bar(int myArray[__min_size(10)]);
338  */
339 #if !defined(__cplusplus) && \
340     (defined(__clang__) || __GNUC_PREREQ__(4, 6)) && \
341     (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901))
342 #define __min_size(x)	static (x)
343 #else
344 #define __min_size(x)	(x)
345 #endif
346 
347 #if __GNUC_PREREQ__(2, 96)
348 #define	__malloc_like	__attribute__((__malloc__))
349 #define	__pure		__attribute__((__pure__))
350 #else
351 #define	__malloc_like
352 #define	__pure
353 #endif
354 
355 #if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
356 #define	__always_inline	__attribute__((__always_inline__))
357 #else
358 #define	__always_inline
359 #endif
360 
361 #if __GNUC_PREREQ__(3, 1)
362 #define	__noinline	__attribute__ ((__noinline__))
363 #else
364 #define	__noinline
365 #endif
366 
367 #if __GNUC_PREREQ__(3, 4)
368 #define	__fastcall	__attribute__((__fastcall__))
369 #define	__result_use_check	__attribute__((__warn_unused_result__))
370 #else
371 #define	__fastcall
372 #define	__result_use_check
373 #endif
374 
375 #if __GNUC_PREREQ__(4, 1)
376 #define	__returns_twice	__attribute__((__returns_twice__))
377 #else
378 #define	__returns_twice
379 #endif
380 
381 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
382 #define	__unreachable()	__builtin_unreachable()
383 #else
384 #define	__unreachable()	((void)0)
385 #endif
386 
387 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
388 #if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
389 #define	__func__	NULL
390 #endif
391 
392 #if (defined(__INTEL_COMPILER) || (defined(__GNUC__) && __GNUC__ >= 2)) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
393 #define	__LONG_LONG_SUPPORTED
394 #endif
395 
396 /* C++11 exposes a load of C99 stuff */
397 #if defined(__cplusplus) && __cplusplus >= 201103L
398 #define	__LONG_LONG_SUPPORTED
399 #ifndef	__STDC_LIMIT_MACROS
400 #define	__STDC_LIMIT_MACROS
401 #endif
402 #ifndef	__STDC_CONSTANT_MACROS
403 #define	__STDC_CONSTANT_MACROS
404 #endif
405 #endif
406 
407 /*
408  * GCC 2.95 provides `__restrict' as an extension to C90 to support the
409  * C99-specific `restrict' type qualifier.  We happen to use `__restrict' as
410  * a way to define the `restrict' type qualifier without disturbing older
411  * software that is unaware of C99 keywords.
412  */
413 #if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
414 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901
415 #define	__restrict
416 #else
417 #define	__restrict	restrict
418 #endif
419 #endif
420 
421 /*
422  * GNU C version 2.96 adds explicit branch prediction so that
423  * the CPU back-end can hint the processor and also so that
424  * code blocks can be reordered such that the predicted path
425  * sees a more linear flow, thus improving cache behavior, etc.
426  *
427  * The following two macros provide us with a way to utilize this
428  * compiler feature.  Use __predict_true() if you expect the expression
429  * to evaluate to true, and __predict_false() if you expect the
430  * expression to evaluate to false.
431  *
432  * A few notes about usage:
433  *
434  *	* Generally, __predict_false() error condition checks (unless
435  *	  you have some _strong_ reason to do otherwise, in which case
436  *	  document it), and/or __predict_true() `no-error' condition
437  *	  checks, assuming you want to optimize for the no-error case.
438  *
439  *	* Other than that, if you don't know the likelihood of a test
440  *	  succeeding from empirical or other `hard' evidence, don't
441  *	  make predictions.
442  *
443  *	* These are meant to be used in places that are run `a lot'.
444  *	  It is wasteful to make predictions in code that is run
445  *	  seldomly (e.g. at subsystem initialization time) as the
446  *	  basic block reordering that this affects can often generate
447  *	  larger code.
448  */
449 #if __GNUC_PREREQ__(2, 96)
450 #define	__predict_true(exp)     __builtin_expect((exp), 1)
451 #define	__predict_false(exp)    __builtin_expect((exp), 0)
452 #else
453 #define	__predict_true(exp)     (exp)
454 #define	__predict_false(exp)    (exp)
455 #endif
456 
457 #if __GNUC_PREREQ__(4, 0)
458 #define	__null_sentinel	__attribute__((__sentinel__))
459 #define	__exported	__attribute__((__visibility__("default")))
460 #define	__hidden	__attribute__((__visibility__("hidden")))
461 #else
462 #define	__null_sentinel
463 #define	__exported
464 #define	__hidden
465 #endif
466 
467 /*
468  * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
469  * require it.
470  */
471 #if __GNUC_PREREQ__(4, 1)
472 #define	__offsetof(type, field)	 __builtin_offsetof(type, field)
473 #else
474 #ifndef __cplusplus
475 #define	__offsetof(type, field) \
476 	((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
477 #else
478 #define	__offsetof(type, field)					\
479   (__offsetof__ (reinterpret_cast <__size_t>			\
480                  (&reinterpret_cast <const volatile char &>	\
481                   (static_cast<type *> (0)->field))))
482 #endif
483 #endif
484 #define	__rangeof(type, start, end) \
485 	(__offsetof(type, end) - __offsetof(type, start))
486 
487 /*
488  * Given the pointer x to the member m of the struct s, return
489  * a pointer to the containing structure.  When using GCC, we first
490  * assign pointer x to a local variable, to check that its type is
491  * compatible with member m.
492  */
493 #if __GNUC_PREREQ__(3, 1)
494 #define	__containerof(x, s, m) ({					\
495 	const volatile __typeof(((s *)0)->m) *__x = (x);		\
496 	__DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
497 })
498 #else
499 #define	__containerof(x, s, m)						\
500 	__DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
501 #endif
502 
503 /*
504  * Compiler-dependent macros to declare that functions take printf-like
505  * or scanf-like arguments.  They are null except for versions of gcc
506  * that are known to support the features properly (old versions of gcc-2
507  * didn't permit keeping the keywords out of the application namespace).
508  */
509 #if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
510 #define	__printflike(fmtarg, firstvararg)
511 #define	__scanflike(fmtarg, firstvararg)
512 #define	__format_arg(fmtarg)
513 #define	__strfmonlike(fmtarg, firstvararg)
514 #define	__strftimelike(fmtarg, firstvararg)
515 #else
516 #define	__printflike(fmtarg, firstvararg) \
517 	    __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
518 #define	__scanflike(fmtarg, firstvararg) \
519 	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
520 #define	__format_arg(fmtarg)	__attribute__((__format_arg__ (fmtarg)))
521 #define	__strfmonlike(fmtarg, firstvararg) \
522 	    __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
523 #define	__strftimelike(fmtarg, firstvararg) \
524 	    __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
525 #endif
526 
527 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
528 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
529     defined(__GNUC__) && !defined(__INTEL_COMPILER)
530 #define	__printf0like(fmtarg, firstvararg) \
531 	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
532 #else
533 #define	__printf0like(fmtarg, firstvararg)
534 #endif
535 
536 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
537 #ifndef __INTEL_COMPILER
538 #define	__strong_reference(sym,aliassym)	\
539 	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
540 #endif
541 #ifdef __STDC__
542 #define	__weak_reference(sym,alias)	\
543 	__asm__(".weak " #alias);	\
544 	__asm__(".equ "  #alias ", " #sym)
545 #define	__warn_references(sym,msg)	\
546 	__asm__(".section .gnu.warning." #sym);	\
547 	__asm__(".asciz \"" msg "\"");	\
548 	__asm__(".previous")
549 #define	__sym_compat(sym,impl,verid)	\
550 	__asm__(".symver " #impl ", " #sym "@" #verid)
551 #define	__sym_default(sym,impl,verid)	\
552 	__asm__(".symver " #impl ", " #sym "@@@" #verid)
553 #else
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(impl,sym,verid)	\
564 	__asm__(".symver impl, sym@@@verid")
565 #endif	/* __STDC__ */
566 #endif	/* __GNUC__ || __INTEL_COMPILER */
567 
568 #define	__GLOBL(sym)	__asm__(".globl " __XSTRING(sym))
569 #define	__WEAK(sym)	__asm__(".weak " __XSTRING(sym))
570 
571 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
572 #define	__IDSTRING(name,string)	__asm__(".ident\t\"" string "\"")
573 #else
574 /*
575  * The following definition might not work well if used in header files,
576  * but it should be better than nothing.  If you want a "do nothing"
577  * version, then it should generate some harmless declaration, such as:
578  *    #define	__IDSTRING(name,string)	struct __hack
579  */
580 #define	__IDSTRING(name,string)	static const char name[] __unused = string
581 #endif
582 
583 /*
584  * Embed the rcs id of a source file in the resulting library.  Note that in
585  * more recent ELF binutils, we use .ident allowing the ID to be stripped.
586  * Usage:
587  *	__FBSDID("$FreeBSD: stable/12/sys/sys/cdefs.h 371167 2021-12-06 15:56:59Z imp $");
588  */
589 #ifndef	__FBSDID
590 #if !defined(STRIP_FBSDID)
591 #define	__FBSDID(s)	__IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
592 #else
593 #define	__FBSDID(s)	struct __hack
594 #endif
595 #endif
596 
597 #ifndef	__RCSID
598 #ifndef	NO__RCSID
599 #define	__RCSID(s)	__IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
600 #else
601 #define	__RCSID(s)	struct __hack
602 #endif
603 #endif
604 
605 #ifndef	__RCSID_SOURCE
606 #ifndef	NO__RCSID_SOURCE
607 #define	__RCSID_SOURCE(s)	__IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
608 #else
609 #define	__RCSID_SOURCE(s)	struct __hack
610 #endif
611 #endif
612 
613 #ifndef	__SCCSID
614 #ifndef	NO__SCCSID
615 #define	__SCCSID(s)	__IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
616 #else
617 #define	__SCCSID(s)	struct __hack
618 #endif
619 #endif
620 
621 #ifndef	__COPYRIGHT
622 #ifndef	NO__COPYRIGHT
623 #define	__COPYRIGHT(s)	__IDSTRING(__CONCAT(__copyright_,__LINE__),s)
624 #else
625 #define	__COPYRIGHT(s)	struct __hack
626 #endif
627 #endif
628 
629 #ifndef	__DECONST
630 #define	__DECONST(type, var)	((type)(__uintptr_t)(const void *)(var))
631 #endif
632 
633 #ifndef	__DEVOLATILE
634 #define	__DEVOLATILE(type, var)	((type)(__uintptr_t)(volatile void *)(var))
635 #endif
636 
637 #ifndef	__DEQUALIFY
638 #define	__DEQUALIFY(type, var)	((type)(__uintptr_t)(const volatile void *)(var))
639 #endif
640 
641 /*-
642  * The following definitions are an extension of the behavior originally
643  * implemented in <sys/_posix.h>, but with a different level of granularity.
644  * POSIX.1 requires that the macros we test be defined before any standard
645  * header file is included.
646  *
647  * Here's a quick run-down of the versions:
648  *  defined(_POSIX_SOURCE)		1003.1-1988
649  *  _POSIX_C_SOURCE == 1		1003.1-1990
650  *  _POSIX_C_SOURCE == 2		1003.2-1992 C Language Binding Option
651  *  _POSIX_C_SOURCE == 199309		1003.1b-1993
652  *  _POSIX_C_SOURCE == 199506		1003.1c-1995, 1003.1i-1995,
653  *					and the omnibus ISO/IEC 9945-1: 1996
654  *  _POSIX_C_SOURCE == 200112		1003.1-2001
655  *  _POSIX_C_SOURCE == 200809		1003.1-2008
656  *
657  * In addition, the X/Open Portability Guide, which is now the Single UNIX
658  * Specification, defines a feature-test macro which indicates the version of
659  * that specification, and which subsumes _POSIX_C_SOURCE.
660  *
661  * Our macros begin with two underscores to avoid namespace screwage.
662  */
663 
664 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
665 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
666 #undef _POSIX_C_SOURCE		/* Probably illegal, but beyond caring now. */
667 #define	_POSIX_C_SOURCE		199009
668 #endif
669 
670 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
671 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
672 #undef _POSIX_C_SOURCE
673 #define	_POSIX_C_SOURCE		199209
674 #endif
675 
676 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
677 #ifdef _XOPEN_SOURCE
678 #if _XOPEN_SOURCE - 0 >= 700
679 #define	__XSI_VISIBLE		700
680 #undef _POSIX_C_SOURCE
681 #define	_POSIX_C_SOURCE		200809
682 #elif _XOPEN_SOURCE - 0 >= 600
683 #define	__XSI_VISIBLE		600
684 #undef _POSIX_C_SOURCE
685 #define	_POSIX_C_SOURCE		200112
686 #elif _XOPEN_SOURCE - 0 >= 500
687 #define	__XSI_VISIBLE		500
688 #undef _POSIX_C_SOURCE
689 #define	_POSIX_C_SOURCE		199506
690 #endif
691 #endif
692 
693 /*
694  * Deal with all versions of POSIX.  The ordering relative to the tests above is
695  * important.
696  */
697 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
698 #define	_POSIX_C_SOURCE		198808
699 #endif
700 #ifdef _POSIX_C_SOURCE
701 #if _POSIX_C_SOURCE >= 200809
702 #define	__POSIX_VISIBLE		200809
703 #define	__ISO_C_VISIBLE		1999
704 #elif _POSIX_C_SOURCE >= 200112
705 #define	__POSIX_VISIBLE		200112
706 #define	__ISO_C_VISIBLE		1999
707 #elif _POSIX_C_SOURCE >= 199506
708 #define	__POSIX_VISIBLE		199506
709 #define	__ISO_C_VISIBLE		1990
710 #elif _POSIX_C_SOURCE >= 199309
711 #define	__POSIX_VISIBLE		199309
712 #define	__ISO_C_VISIBLE		1990
713 #elif _POSIX_C_SOURCE >= 199209
714 #define	__POSIX_VISIBLE		199209
715 #define	__ISO_C_VISIBLE		1990
716 #elif _POSIX_C_SOURCE >= 199009
717 #define	__POSIX_VISIBLE		199009
718 #define	__ISO_C_VISIBLE		1990
719 #else
720 #define	__POSIX_VISIBLE		198808
721 #define	__ISO_C_VISIBLE		0
722 #endif /* _POSIX_C_SOURCE */
723 /*
724  * Both glibc and OpenBSD enable c11 features when _ISOC11_SOURCE is defined, or
725  * when compiling with -stdc=c11. A strict reading of the standard would suggest
726  * doing it only for the former. However, a strict reading also requires C99
727  * mode only, so building with C11 is already undefined. Follow glibc's and
728  * OpenBSD's lead for this non-standard configuration for maximum compatibility.
729  */
730 #if _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L)
731 #undef __ISO_C_VISIBLE
732 #define __ISO_C_VISIBLE		2011
733 #endif
734 #else
735 /*-
736  * Deal with _ANSI_SOURCE:
737  * If it is defined, and no other compilation environment is explicitly
738  * requested, then define our internal feature-test macros to zero.  This
739  * makes no difference to the preprocessor (undefined symbols in preprocessing
740  * expressions are defined to have value zero), but makes it more convenient for
741  * a test program to print out the values.
742  *
743  * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
744  * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
745  * environment (and in fact we will never get here).
746  */
747 #if defined(_ANSI_SOURCE)	/* Hide almost everything. */
748 #define	__POSIX_VISIBLE		0
749 #define	__XSI_VISIBLE		0
750 #define	__BSD_VISIBLE		0
751 #define	__ISO_C_VISIBLE		1990
752 #define	__EXT1_VISIBLE		0
753 #elif defined(_C99_SOURCE)	/* Localism to specify strict C99 env. */
754 #define	__POSIX_VISIBLE		0
755 #define	__XSI_VISIBLE		0
756 #define	__BSD_VISIBLE		0
757 #define	__ISO_C_VISIBLE		1999
758 #define	__EXT1_VISIBLE		0
759 #elif defined(_C11_SOURCE)	/* Localism to specify strict C11 env. */
760 #define	__POSIX_VISIBLE		0
761 #define	__XSI_VISIBLE		0
762 #define	__BSD_VISIBLE		0
763 #define	__ISO_C_VISIBLE		2011
764 #define	__EXT1_VISIBLE		0
765 #else				/* Default environment: show everything. */
766 #define	__POSIX_VISIBLE		200809
767 #define	__XSI_VISIBLE		700
768 #define	__BSD_VISIBLE		1
769 #define	__ISO_C_VISIBLE		2011
770 #define	__EXT1_VISIBLE		1
771 #endif
772 #endif
773 
774 /* User override __EXT1_VISIBLE */
775 #if defined(__STDC_WANT_LIB_EXT1__)
776 #undef	__EXT1_VISIBLE
777 #if __STDC_WANT_LIB_EXT1__
778 #define	__EXT1_VISIBLE		1
779 #else
780 #define	__EXT1_VISIBLE		0
781 #endif
782 #endif /* __STDC_WANT_LIB_EXT1__ */
783 
784 #if defined(__mips) || defined(__powerpc64__) || defined(__riscv)
785 #define	__NO_TLS 1
786 #endif
787 
788 /*
789  * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h
790  * translates them to __ARM_ARCH and the modern feature symbols defined by ARM.
791  */
792 #if defined(__arm__) && !defined(__ARM_ARCH)
793 #include <machine/acle-compat.h>
794 #endif
795 
796 /*
797  * Nullability qualifiers: currently only supported by Clang.
798  */
799 #if !(defined(__clang__) && __has_feature(nullability))
800 #define	_Nonnull
801 #define	_Nullable
802 #define	_Null_unspecified
803 #define	__NULLABILITY_PRAGMA_PUSH
804 #define	__NULLABILITY_PRAGMA_POP
805 #else
806 #define	__NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push")	\
807 	_Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
808 #define	__NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop")
809 #endif
810 
811 /*
812  * Type Safety Checking
813  *
814  * Clang provides additional attributes to enable checking type safety
815  * properties that cannot be enforced by the C type system.
816  */
817 
818 #if __has_attribute(__argument_with_type_tag__) && \
819     __has_attribute(__type_tag_for_datatype__)
820 #define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
821 	    __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
822 #define	__datatype_type_tag(kind, type) \
823 	    __attribute__((__type_tag_for_datatype__(kind, type)))
824 #else
825 #define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx)
826 #define	__datatype_type_tag(kind, type)
827 #endif
828 
829 /*
830  * Lock annotations.
831  *
832  * Clang provides support for doing basic thread-safety tests at
833  * compile-time, by marking which locks will/should be held when
834  * entering/leaving a functions.
835  *
836  * Furthermore, it is also possible to annotate variables and structure
837  * members to enforce that they are only accessed when certain locks are
838  * held.
839  */
840 
841 #if __has_extension(c_thread_safety_attributes)
842 #define	__lock_annotate(x)	__attribute__((x))
843 #else
844 #define	__lock_annotate(x)
845 #endif
846 
847 /* Structure implements a lock. */
848 #define	__lockable		__lock_annotate(lockable)
849 
850 /* Function acquires an exclusive or shared lock. */
851 #define	__locks_exclusive(...) \
852 	__lock_annotate(exclusive_lock_function(__VA_ARGS__))
853 #define	__locks_shared(...) \
854 	__lock_annotate(shared_lock_function(__VA_ARGS__))
855 
856 /* Function attempts to acquire an exclusive or shared lock. */
857 #define	__trylocks_exclusive(...) \
858 	__lock_annotate(exclusive_trylock_function(__VA_ARGS__))
859 #define	__trylocks_shared(...) \
860 	__lock_annotate(shared_trylock_function(__VA_ARGS__))
861 
862 /* Function releases a lock. */
863 #define	__unlocks(...)		__lock_annotate(unlock_function(__VA_ARGS__))
864 
865 /* Function asserts that an exclusive or shared lock is held. */
866 #define	__asserts_exclusive(...) \
867 	__lock_annotate(assert_exclusive_lock(__VA_ARGS__))
868 #define	__asserts_shared(...) \
869 	__lock_annotate(assert_shared_lock(__VA_ARGS__))
870 
871 /* Function requires that an exclusive or shared lock is or is not held. */
872 #define	__requires_exclusive(...) \
873 	__lock_annotate(exclusive_locks_required(__VA_ARGS__))
874 #define	__requires_shared(...) \
875 	__lock_annotate(shared_locks_required(__VA_ARGS__))
876 #define	__requires_unlocked(...) \
877 	__lock_annotate(locks_excluded(__VA_ARGS__))
878 
879 /* Function should not be analyzed. */
880 #define	__no_lock_analysis	__lock_annotate(no_thread_safety_analysis)
881 
882 /* Guard variables and structure members by lock. */
883 #define	__guarded_by(x)		__lock_annotate(guarded_by(x))
884 #define	__pt_guarded_by(x)	__lock_annotate(pt_guarded_by(x))
885 
886 /* Alignment builtins for better type checking and improved code generation. */
887 /* Provide fallback versions for other compilers (GCC/Clang < 10): */
888 #if !__has_builtin(__builtin_is_aligned)
889 #define __builtin_is_aligned(x, align)	\
890 	(((__uintptr_t)x & ((align) - 1)) == 0)
891 #endif
892 #if !__has_builtin(__builtin_align_up)
893 #define __builtin_align_up(x, align)	\
894 	((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1))))
895 #endif
896 #if !__has_builtin(__builtin_align_down)
897 #define __builtin_align_down(x, align)	\
898 	((__typeof__(x))((x)&(~((align)-1))))
899 #endif
900 
901 #define __align_up(x, y) __builtin_align_up(x, y)
902 #define __align_down(x, y) __builtin_align_down(x, y)
903 #define __is_aligned(x, y) __builtin_is_aligned(x, y)
904 
905 #endif /* !_SYS_CDEFS_H_ */
906