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  * $FreeBSD$
36  */
37 
38 #ifndef	_SYS_CDEFS_H_
39 #define	_SYS_CDEFS_H_
40 
41 #if defined(_KERNEL) && defined(_STANDALONE)
42 #error "_KERNEL and _STANDALONE are mutually exclusive"
43 #endif
44 
45 /*
46  * Testing against Clang-specific extensions.
47  */
48 #ifndef	__has_attribute
49 #define	__has_attribute(x)	0
50 #endif
51 #ifndef	__has_extension
52 #define	__has_extension		__has_feature
53 #endif
54 #ifndef	__has_feature
55 #define	__has_feature(x)	0
56 #endif
57 #ifndef	__has_include
58 #define	__has_include(x)	0
59 #endif
60 #ifndef	__has_builtin
61 #define	__has_builtin(x)	0
62 #endif
63 
64 #if defined(__cplusplus)
65 #define	__BEGIN_DECLS	extern "C" {
66 #define	__END_DECLS	}
67 #else
68 #define	__BEGIN_DECLS
69 #define	__END_DECLS
70 #endif
71 
72 /*
73  * This code has been put in place to help reduce the addition of
74  * compiler specific defines in FreeBSD code.  It helps to aid in
75  * having a compiler-agnostic source tree.
76  */
77 
78 #if defined(__GNUC__)
79 
80 #if __GNUC__ >= 3
81 #define	__GNUCLIKE_ASM 3
82 #define	__GNUCLIKE_MATH_BUILTIN_CONSTANTS
83 #else
84 #define	__GNUCLIKE_ASM 2
85 #endif
86 #define	__GNUCLIKE___TYPEOF 1
87 #define	__GNUCLIKE___SECTION 1
88 
89 #define	__GNUCLIKE_CTOR_SECTION_HANDLING 1
90 
91 #define	__GNUCLIKE_BUILTIN_CONSTANT_P 1
92 
93 #if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3)
94 #define	__GNUCLIKE_BUILTIN_VARARGS 1
95 #define	__GNUCLIKE_BUILTIN_STDARG 1
96 #define	__GNUCLIKE_BUILTIN_VAALIST 1
97 #endif
98 
99 #define	__GNUC_VA_LIST_COMPATIBILITY 1
100 
101 /*
102  * Compiler memory barriers, specific to gcc and clang.
103  */
104 #define	__compiler_membar()	__asm __volatile(" " : : : "memory")
105 
106 #define	__GNUCLIKE_BUILTIN_NEXT_ARG 1
107 #define	__GNUCLIKE_MATH_BUILTIN_RELOPS
108 
109 #define	__GNUCLIKE_BUILTIN_MEMCPY 1
110 
111 /* XXX: if __GNUC__ >= 2: not tested everywhere originally, where replaced */
112 #define	__CC_SUPPORTS_INLINE 1
113 #define	__CC_SUPPORTS___INLINE 1
114 #define	__CC_SUPPORTS___INLINE__ 1
115 
116 #define	__CC_SUPPORTS___FUNC__ 1
117 #define	__CC_SUPPORTS_WARNING 1
118 
119 #define	__CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */
120 
121 #define	__CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
122 
123 #endif /* __GNUC__ */
124 
125 /*
126  * Macro to test if we're using a specific version of gcc or later.
127  */
128 #if defined(__GNUC__)
129 #define	__GNUC_PREREQ__(ma, mi)	\
130 	(__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
131 #else
132 #define	__GNUC_PREREQ__(ma, mi)	0
133 #endif
134 
135 /*
136  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
137  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
138  * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
139  * mode -- there must be no spaces between its arguments, and for nested
140  * __CONCAT's, all the __CONCAT's must be at the left.  __CONCAT can also
141  * concatenate double-quoted strings produced by the __STRING macro, but
142  * this only works with ANSI C.
143  *
144  * __XSTRING is like __STRING, but it expands any macros in its argument
145  * first.  It is only available with ANSI C.
146  */
147 #if defined(__STDC__) || defined(__cplusplus)
148 #define	__P(protos)	protos		/* full-blown ANSI C */
149 #define	__CONCAT1(x,y)	x ## y
150 #define	__CONCAT(x,y)	__CONCAT1(x,y)
151 #define	__STRING(x)	#x		/* stringify without expanding x */
152 #define	__XSTRING(x)	__STRING(x)	/* expand x, then stringify */
153 
154 #define	__const		const		/* define reserved names to standard */
155 #define	__signed	signed
156 #define	__volatile	volatile
157 #if defined(__cplusplus)
158 #define	__inline	inline		/* convert to C++ keyword */
159 #else
160 #if !(defined(__CC_SUPPORTS___INLINE))
161 #define	__inline			/* delete GCC keyword */
162 #endif /* ! __CC_SUPPORTS___INLINE */
163 #endif /* !__cplusplus */
164 
165 #else	/* !(__STDC__ || __cplusplus) */
166 #define	__P(protos)	()		/* traditional C preprocessor */
167 #define	__CONCAT(x,y)	x/**/y
168 #define	__STRING(x)	"x"
169 
170 #if !defined(__CC_SUPPORTS___INLINE)
171 #define	__const				/* delete pseudo-ANSI C keywords */
172 #define	__inline
173 #define	__signed
174 #define	__volatile
175 /*
176  * In non-ANSI C environments, new programs will want ANSI-only C keywords
177  * deleted from the program and old programs will want them left alone.
178  * When using a compiler other than gcc, programs using the ANSI C keywords
179  * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
180  * When using "gcc -traditional", we assume that this is the intent; if
181  * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
182  */
183 #ifndef	NO_ANSI_KEYWORDS
184 #define	const				/* delete ANSI C keywords */
185 #define	inline
186 #define	signed
187 #define	volatile
188 #endif	/* !NO_ANSI_KEYWORDS */
189 #endif	/* !__CC_SUPPORTS___INLINE */
190 #endif	/* !(__STDC__ || __cplusplus) */
191 
192 /*
193  * Compiler-dependent macros to help declare dead (non-returning) and
194  * pure (no side effects) functions, and unused variables.  They are
195  * null except for versions of gcc that are known to support the features
196  * properly (old versions of gcc-2 supported the dead and pure features
197  * in a different (wrong) way).  If we do not provide an implementation
198  * for a given compiler, let the compile fail if it is told to use
199  * a feature that we cannot live without.
200  */
201 #define	__weak_symbol	__attribute__((__weak__))
202 #if !__GNUC_PREREQ__(2, 5)
203 #define	__dead2
204 #define	__pure2
205 #define	__unused
206 #endif
207 #if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7
208 #define	__dead2		__attribute__((__noreturn__))
209 #define	__pure2		__attribute__((__const__))
210 #define	__unused
211 /* XXX Find out what to do for __packed, __aligned and __section */
212 #endif
213 #if __GNUC_PREREQ__(2, 7)
214 #define	__dead2		__attribute__((__noreturn__))
215 #define	__pure2		__attribute__((__const__))
216 #define	__unused	__attribute__((__unused__))
217 #define	__used		__attribute__((__used__))
218 #define	__packed	__attribute__((__packed__))
219 #define	__aligned(x)	__attribute__((__aligned__(x)))
220 #define	__section(x)	__attribute__((__section__(x)))
221 #endif
222 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__)
223 #define	__alloc_size(x)	__attribute__((__alloc_size__(x)))
224 #define	__alloc_size2(n, x)	__attribute__((__alloc_size__(n, x)))
225 #else
226 #define	__alloc_size(x)
227 #define	__alloc_size2(n, x)
228 #endif
229 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
230 #define	__alloc_align(x)	__attribute__((__alloc_align__(x)))
231 #else
232 #define	__alloc_align(x)
233 #endif
234 
235 #if !__GNUC_PREREQ__(2, 95)
236 #define	__alignof(x)	__offsetof(struct { char __a; x __b; }, __b)
237 #endif
238 
239 /*
240  * Keywords added in C11.
241  */
242 
243 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
244 
245 #if !__has_extension(c_alignas)
246 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
247     __has_extension(cxx_alignas)
248 #define	_Alignas(x)		alignas(x)
249 #else
250 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
251 #define	_Alignas(x)		__aligned(x)
252 #endif
253 #endif
254 
255 #if defined(__cplusplus) && __cplusplus >= 201103L
256 #define	_Alignof(x)		alignof(x)
257 #else
258 #define	_Alignof(x)		__alignof(x)
259 #endif
260 
261 #if !defined(__cplusplus) && !__has_extension(c_atomic) && \
262 	!__has_extension(cxx_atomic) && !__GNUC_PREREQ__(4, 7)
263 /*
264  * No native support for _Atomic(). Place object in structure to prevent
265  * most forms of direct non-atomic access.
266  */
267 #define	_Atomic(T)		struct { T volatile __val; }
268 #endif
269 
270 #if defined(__cplusplus) && __cplusplus >= 201103L
271 #define	_Noreturn		[[noreturn]]
272 #else
273 #define	_Noreturn		__dead2
274 #endif
275 
276 #if !__has_extension(c_static_assert)
277 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
278     __has_extension(cxx_static_assert)
279 #define	_Static_assert(x, y)	static_assert(x, y)
280 #elif __GNUC_PREREQ__(4,6) && !defined(__cplusplus)
281 /* Nothing, gcc 4.6 and higher has _Static_assert built-in */
282 #elif defined(__COUNTER__)
283 #define	_Static_assert(x, y)	__Static_assert(x, __COUNTER__)
284 #define	__Static_assert(x, y)	___Static_assert(x, y)
285 #define	___Static_assert(x, y)	typedef char __assert_ ## y[(x) ? 1 : -1] \
286 				__unused
287 #else
288 #define	_Static_assert(x, y)	struct __hack
289 #endif
290 #endif
291 
292 #if !__has_extension(c_thread_local)
293 /*
294  * XXX: Some compilers (Clang 3.3, GCC 4.7) falsely announce C++11 mode
295  * without actually supporting the thread_local keyword. Don't check for
296  * the presence of C++11 when defining _Thread_local.
297  */
298 #if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \
299     __has_extension(cxx_thread_local)
300 #define	_Thread_local		thread_local
301 #else
302 #define	_Thread_local		__thread
303 #endif
304 #endif
305 
306 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
307 
308 /*
309  * Emulation of C11 _Generic().  Unlike the previously defined C11
310  * keywords, it is not possible to implement this using exactly the same
311  * syntax.  Therefore implement something similar under the name
312  * __generic().  Unlike _Generic(), this macro can only distinguish
313  * between a single type, so it requires nested invocations to
314  * distinguish multiple cases.
315  */
316 
317 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \
318     __has_extension(c_generic_selections)
319 #define	__generic(expr, t, yes, no)					\
320 	_Generic(expr, t: yes, default: no)
321 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
322 #define	__generic(expr, t, yes, no)					\
323 	__builtin_choose_expr(						\
324 	    __builtin_types_compatible_p(__typeof(expr), t), yes, no)
325 #endif
326 
327 /*
328  * C99 Static array indices in function parameter declarations.  Syntax such as:
329  * void bar(int myArray[static 10]);
330  * is allowed in C99 but not in C++.  Define __min_size appropriately so
331  * headers using it can be compiled in either language.  Use like this:
332  * void bar(int myArray[__min_size(10)]);
333  */
334 #if !defined(__cplusplus) && \
335     (defined(__clang__) || __GNUC_PREREQ__(4, 6)) && \
336     (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901))
337 #define __min_size(x)	static (x)
338 #else
339 #define __min_size(x)	(x)
340 #endif
341 
342 #if __GNUC_PREREQ__(2, 96)
343 #define	__malloc_like	__attribute__((__malloc__))
344 #define	__pure		__attribute__((__pure__))
345 #else
346 #define	__malloc_like
347 #define	__pure
348 #endif
349 
350 #if __GNUC_PREREQ__(3, 1)
351 #define	__always_inline	__attribute__((__always_inline__))
352 #else
353 #define	__always_inline
354 #endif
355 
356 #if __GNUC_PREREQ__(3, 1)
357 #define	__noinline	__attribute__ ((__noinline__))
358 #else
359 #define	__noinline
360 #endif
361 
362 #if __GNUC_PREREQ__(3, 4)
363 #define	__fastcall	__attribute__((__fastcall__))
364 #define	__result_use_check	__attribute__((__warn_unused_result__))
365 #else
366 #define	__fastcall
367 #define	__result_use_check
368 #endif
369 
370 #if __GNUC_PREREQ__(4, 1)
371 #define	__returns_twice	__attribute__((__returns_twice__))
372 #else
373 #define	__returns_twice
374 #endif
375 
376 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
377 #define	__unreachable()	__builtin_unreachable()
378 #else
379 #define	__unreachable()	((void)0)
380 #endif
381 
382 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
383 #if !__GNUC_PREREQ__(2, 7)
384 #define	__func__	NULL
385 #endif
386 
387 #if (defined(__GNUC__) && __GNUC__ >= 2) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
388 #define	__LONG_LONG_SUPPORTED
389 #endif
390 
391 /* C++11 exposes a load of C99 stuff */
392 #if defined(__cplusplus) && __cplusplus >= 201103L
393 #define	__LONG_LONG_SUPPORTED
394 #ifndef	__STDC_LIMIT_MACROS
395 #define	__STDC_LIMIT_MACROS
396 #endif
397 #ifndef	__STDC_CONSTANT_MACROS
398 #define	__STDC_CONSTANT_MACROS
399 #endif
400 #endif
401 
402 /*
403  * GCC 2.95 provides `__restrict' as an extension to C90 to support the
404  * C99-specific `restrict' type qualifier.  We happen to use `__restrict' as
405  * a way to define the `restrict' type qualifier without disturbing older
406  * software that is unaware of C99 keywords.
407  */
408 #if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
409 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901
410 #define	__restrict
411 #else
412 #define	__restrict	restrict
413 #endif
414 #endif
415 
416 /*
417  * GNU C version 2.96 adds explicit branch prediction so that
418  * the CPU back-end can hint the processor and also so that
419  * code blocks can be reordered such that the predicted path
420  * sees a more linear flow, thus improving cache behavior, etc.
421  *
422  * The following two macros provide us with a way to utilize this
423  * compiler feature.  Use __predict_true() if you expect the expression
424  * to evaluate to true, and __predict_false() if you expect the
425  * expression to evaluate to false.
426  *
427  * A few notes about usage:
428  *
429  *	* Generally, __predict_false() error condition checks (unless
430  *	  you have some _strong_ reason to do otherwise, in which case
431  *	  document it), and/or __predict_true() `no-error' condition
432  *	  checks, assuming you want to optimize for the no-error case.
433  *
434  *	* Other than that, if you don't know the likelihood of a test
435  *	  succeeding from empirical or other `hard' evidence, don't
436  *	  make predictions.
437  *
438  *	* These are meant to be used in places that are run `a lot'.
439  *	  It is wasteful to make predictions in code that is run
440  *	  seldomly (e.g. at subsystem initialization time) as the
441  *	  basic block reordering that this affects can often generate
442  *	  larger code.
443  */
444 #if __GNUC_PREREQ__(2, 96)
445 #define	__predict_true(exp)     __builtin_expect((exp), 1)
446 #define	__predict_false(exp)    __builtin_expect((exp), 0)
447 #else
448 #define	__predict_true(exp)     (exp)
449 #define	__predict_false(exp)    (exp)
450 #endif
451 
452 #if __GNUC_PREREQ__(4, 0)
453 #define	__null_sentinel	__attribute__((__sentinel__))
454 #define	__exported	__attribute__((__visibility__("default")))
455 #define	__hidden	__attribute__((__visibility__("hidden")))
456 #else
457 #define	__null_sentinel
458 #define	__exported
459 #define	__hidden
460 #endif
461 
462 /*
463  * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
464  * require it.
465  */
466 #if __GNUC_PREREQ__(4, 1)
467 #define	__offsetof(type, field)	 __builtin_offsetof(type, field)
468 #else
469 #ifndef __cplusplus
470 #define	__offsetof(type, field) \
471 	((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field))
472 #else
473 #define	__offsetof(type, field)					\
474   (__offsetof__ (reinterpret_cast <__size_t>			\
475                  (&reinterpret_cast <const volatile char &>	\
476                   (static_cast<type *> (0)->field))))
477 #endif
478 #endif
479 #define	__rangeof(type, start, end) \
480 	(__offsetof(type, end) - __offsetof(type, start))
481 
482 /*
483  * Given the pointer x to the member m of the struct s, return
484  * a pointer to the containing structure.  When using GCC, we first
485  * assign pointer x to a local variable, to check that its type is
486  * compatible with member m.
487  */
488 #if __GNUC_PREREQ__(3, 1)
489 #define	__containerof(x, s, m) ({					\
490 	const volatile __typeof(((s *)0)->m) *__x = (x);		\
491 	__DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
492 })
493 #else
494 #define	__containerof(x, s, m)						\
495 	__DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
496 #endif
497 
498 /*
499  * Compiler-dependent macros to declare that functions take printf-like
500  * or scanf-like arguments.  They are null except for versions of gcc
501  * that are known to support the features properly (old versions of gcc-2
502  * didn't permit keeping the keywords out of the application namespace).
503  */
504 #if !__GNUC_PREREQ__(2, 7)
505 #define	__printflike(fmtarg, firstvararg)
506 #define	__scanflike(fmtarg, firstvararg)
507 #define	__format_arg(fmtarg)
508 #define	__strfmonlike(fmtarg, firstvararg)
509 #define	__strftimelike(fmtarg, firstvararg)
510 #else
511 #define	__printflike(fmtarg, firstvararg) \
512 	    __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
513 #define	__scanflike(fmtarg, firstvararg) \
514 	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
515 #define	__format_arg(fmtarg)	__attribute__((__format_arg__ (fmtarg)))
516 #define	__strfmonlike(fmtarg, firstvararg) \
517 	    __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
518 #define	__strftimelike(fmtarg, firstvararg) \
519 	    __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
520 #endif
521 
522 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
523 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
524     defined(__GNUC__)
525 #define	__printf0like(fmtarg, firstvararg) \
526 	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
527 #else
528 #define	__printf0like(fmtarg, firstvararg)
529 #endif
530 
531 #if defined(__GNUC__)
532 #define	__strong_reference(sym,aliassym)	\
533 	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
534 #ifdef __STDC__
535 #define	__weak_reference(sym,alias)	\
536 	__asm__(".weak " #alias);	\
537 	__asm__(".equ "  #alias ", " #sym)
538 #define	__warn_references(sym,msg)	\
539 	__asm__(".section .gnu.warning." #sym);	\
540 	__asm__(".asciz \"" msg "\"");	\
541 	__asm__(".previous")
542 #define	__sym_compat(sym,impl,verid)	\
543 	__asm__(".symver " #impl ", " #sym "@" #verid)
544 #define	__sym_default(sym,impl,verid)	\
545 	__asm__(".symver " #impl ", " #sym "@@@" #verid)
546 #else
547 #define	__weak_reference(sym,alias)	\
548 	__asm__(".weak alias");		\
549 	__asm__(".equ alias, sym")
550 #define	__warn_references(sym,msg)	\
551 	__asm__(".section .gnu.warning.sym"); \
552 	__asm__(".asciz \"msg\"");	\
553 	__asm__(".previous")
554 #define	__sym_compat(sym,impl,verid)	\
555 	__asm__(".symver impl, sym@verid")
556 #define	__sym_default(impl,sym,verid)	\
557 	__asm__(".symver impl, sym@@@verid")
558 #endif	/* __STDC__ */
559 #endif	/* __GNUC__ */
560 
561 #define	__GLOBL(sym)	__asm__(".globl " __XSTRING(sym))
562 #define	__WEAK(sym)	__asm__(".weak " __XSTRING(sym))
563 
564 #if defined(__GNUC__)
565 #define	__IDSTRING(name,string)	__asm__(".ident\t\"" string "\"")
566 #else
567 /*
568  * The following definition might not work well if used in header files,
569  * but it should be better than nothing.  If you want a "do nothing"
570  * version, then it should generate some harmless declaration, such as:
571  *    #define	__IDSTRING(name,string)	struct __hack
572  */
573 #define	__IDSTRING(name,string)	static const char name[] __unused = string
574 #endif
575 
576 /*
577  * Embed the rcs id of a source file in the resulting library.  Note that in
578  * more recent ELF binutils, we use .ident allowing the ID to be stripped.
579  * Usage:
580  *	__FBSDID("$FreeBSD$");
581  */
582 #ifndef	__FBSDID
583 #if !defined(STRIP_FBSDID)
584 #define	__FBSDID(s)	__IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
585 #else
586 #define	__FBSDID(s)	struct __hack
587 #endif
588 #endif
589 
590 #ifndef	__RCSID
591 #ifndef	NO__RCSID
592 #define	__RCSID(s)	__IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
593 #else
594 #define	__RCSID(s)	struct __hack
595 #endif
596 #endif
597 
598 #ifndef	__RCSID_SOURCE
599 #ifndef	NO__RCSID_SOURCE
600 #define	__RCSID_SOURCE(s)	__IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
601 #else
602 #define	__RCSID_SOURCE(s)	struct __hack
603 #endif
604 #endif
605 
606 #ifndef	__SCCSID
607 #ifndef	NO__SCCSID
608 #define	__SCCSID(s)	__IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
609 #else
610 #define	__SCCSID(s)	struct __hack
611 #endif
612 #endif
613 
614 #ifndef	__COPYRIGHT
615 #ifndef	NO__COPYRIGHT
616 #define	__COPYRIGHT(s)	__IDSTRING(__CONCAT(__copyright_,__LINE__),s)
617 #else
618 #define	__COPYRIGHT(s)	struct __hack
619 #endif
620 #endif
621 
622 #ifndef	__DECONST
623 #define	__DECONST(type, var)	((type)(__uintptr_t)(const void *)(var))
624 #endif
625 
626 #ifndef	__DEVOLATILE
627 #define	__DEVOLATILE(type, var)	((type)(__uintptr_t)(volatile void *)(var))
628 #endif
629 
630 #ifndef	__DEQUALIFY
631 #define	__DEQUALIFY(type, var)	((type)(__uintptr_t)(const volatile void *)(var))
632 #endif
633 
634 /*-
635  * The following definitions are an extension of the behavior originally
636  * implemented in <sys/_posix.h>, but with a different level of granularity.
637  * POSIX.1 requires that the macros we test be defined before any standard
638  * header file is included.
639  *
640  * Here's a quick run-down of the versions (and some informal names)
641  *  defined(_POSIX_SOURCE)		1003.1-1988
642  *					encoded as 198808 below
643  *  _POSIX_C_SOURCE == 1		1003.1-1990
644  *					encoded as 199009 below
645  *  _POSIX_C_SOURCE == 2		1003.2-1992 C Language Binding Option
646  *					encoded as 199209 below
647  *  _POSIX_C_SOURCE == 199309		1003.1b-1993
648  *					(1003.1 Issue 4, Single Unix Spec v1, Unix 93)
649  *  _POSIX_C_SOURCE == 199506		1003.1c-1995, 1003.1i-1995,
650  *					and the omnibus ISO/IEC 9945-1: 1996
651  *					(1003.1 Issue 5, Single	Unix Spec v2, Unix 95)
652  *  _POSIX_C_SOURCE == 200112		1003.1-2001 (1003.1 Issue 6, Unix 03)
653  *  _POSIX_C_SOURCE == 200809		1003.1-2008 (1003.1 Issue 7)
654  *					IEEE Std 1003.1-2017 (Rev of 1003.1-2008) is
655  *					1003.1-2008 with two TCs applied with
656  *					_POSIX_C_SOURCE=200809 and _XOPEN_SOURCE=700
657  *
658  * In addition, the X/Open Portability Guide, which is now the Single UNIX
659  * Specification, defines a feature-test macro which indicates the version of
660  * that specification, and which subsumes _POSIX_C_SOURCE.
661  *
662  * Our macros begin with two underscores to avoid namespace screwage.
663  */
664 
665 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
666 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
667 #undef _POSIX_C_SOURCE		/* Probably illegal, but beyond caring now. */
668 #define	_POSIX_C_SOURCE		199009
669 #endif
670 
671 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
672 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
673 #undef _POSIX_C_SOURCE
674 #define	_POSIX_C_SOURCE		199209
675 #endif
676 
677 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
678 #ifdef _XOPEN_SOURCE
679 #if _XOPEN_SOURCE - 0 >= 700
680 #define	__XSI_VISIBLE		700
681 #undef _POSIX_C_SOURCE
682 #define	_POSIX_C_SOURCE		200809
683 #elif _XOPEN_SOURCE - 0 >= 600
684 #define	__XSI_VISIBLE		600
685 #undef _POSIX_C_SOURCE
686 #define	_POSIX_C_SOURCE		200112
687 #elif _XOPEN_SOURCE - 0 >= 500
688 #define	__XSI_VISIBLE		500
689 #undef _POSIX_C_SOURCE
690 #define	_POSIX_C_SOURCE		199506
691 #endif
692 #endif
693 
694 /*
695  * Deal with all versions of POSIX.  The ordering relative to the tests above is
696  * important.
697  */
698 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
699 #define	_POSIX_C_SOURCE		198808
700 #endif
701 #ifdef _POSIX_C_SOURCE
702 #if _POSIX_C_SOURCE >= 200809
703 #define	__POSIX_VISIBLE		200809
704 #define	__ISO_C_VISIBLE		1999
705 #elif _POSIX_C_SOURCE >= 200112
706 #define	__POSIX_VISIBLE		200112
707 #define	__ISO_C_VISIBLE		1999
708 #elif _POSIX_C_SOURCE >= 199506
709 #define	__POSIX_VISIBLE		199506
710 #define	__ISO_C_VISIBLE		1990
711 #elif _POSIX_C_SOURCE >= 199309
712 #define	__POSIX_VISIBLE		199309
713 #define	__ISO_C_VISIBLE		1990
714 #elif _POSIX_C_SOURCE >= 199209
715 #define	__POSIX_VISIBLE		199209
716 #define	__ISO_C_VISIBLE		1990
717 #elif _POSIX_C_SOURCE >= 199009
718 #define	__POSIX_VISIBLE		199009
719 #define	__ISO_C_VISIBLE		1990
720 #else
721 #define	__POSIX_VISIBLE		198808
722 #define	__ISO_C_VISIBLE		0
723 #endif /* _POSIX_C_SOURCE */
724 /*
725  * Both glibc and OpenBSD enable c11 features when _ISOC11_SOURCE is defined, or
726  * when compiling with -stdc=c11. A strict reading of the standard would suggest
727  * doing it only for the former. However, a strict reading also requires C99
728  * mode only, so building with C11 is already undefined. Follow glibc's and
729  * OpenBSD's lead for this non-standard configuration for maximum compatibility.
730  */
731 #if _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L)
732 #undef __ISO_C_VISIBLE
733 #define __ISO_C_VISIBLE		2011
734 #endif
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 /*
786  * Old versions of GCC use non-standard ARM arch symbols; acle-compat.h
787  * translates them to __ARM_ARCH and the modern feature symbols defined by ARM.
788  */
789 #if defined(__arm__) && !defined(__ARM_ARCH)
790 #include <machine/acle-compat.h>
791 #endif
792 
793 /*
794  * Nullability qualifiers: currently only supported by Clang.
795  */
796 #if !(defined(__clang__) && __has_feature(nullability))
797 #define	_Nonnull
798 #define	_Nullable
799 #define	_Null_unspecified
800 #define	__NULLABILITY_PRAGMA_PUSH
801 #define	__NULLABILITY_PRAGMA_POP
802 #else
803 #define	__NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push")	\
804 	_Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
805 #define	__NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop")
806 #endif
807 
808 /*
809  * Type Safety Checking
810  *
811  * Clang provides additional attributes to enable checking type safety
812  * properties that cannot be enforced by the C type system.
813  */
814 
815 #if __has_attribute(__argument_with_type_tag__) && \
816     __has_attribute(__type_tag_for_datatype__)
817 #define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
818 	    __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
819 #define	__datatype_type_tag(kind, type) \
820 	    __attribute__((__type_tag_for_datatype__(kind, type)))
821 #else
822 #define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx)
823 #define	__datatype_type_tag(kind, type)
824 #endif
825 
826 /*
827  * Lock annotations.
828  *
829  * Clang provides support for doing basic thread-safety tests at
830  * compile-time, by marking which locks will/should be held when
831  * entering/leaving a functions.
832  *
833  * Furthermore, it is also possible to annotate variables and structure
834  * members to enforce that they are only accessed when certain locks are
835  * held.
836  */
837 
838 #if __has_extension(c_thread_safety_attributes)
839 #define	__lock_annotate(x)	__attribute__((x))
840 #else
841 #define	__lock_annotate(x)
842 #endif
843 
844 /* Structure implements a lock. */
845 #define	__lockable		__lock_annotate(lockable)
846 
847 /* Function acquires an exclusive or shared lock. */
848 #define	__locks_exclusive(...) \
849 	__lock_annotate(exclusive_lock_function(__VA_ARGS__))
850 #define	__locks_shared(...) \
851 	__lock_annotate(shared_lock_function(__VA_ARGS__))
852 
853 /* Function attempts to acquire an exclusive or shared lock. */
854 #define	__trylocks_exclusive(...) \
855 	__lock_annotate(exclusive_trylock_function(__VA_ARGS__))
856 #define	__trylocks_shared(...) \
857 	__lock_annotate(shared_trylock_function(__VA_ARGS__))
858 
859 /* Function releases a lock. */
860 #define	__unlocks(...)		__lock_annotate(unlock_function(__VA_ARGS__))
861 
862 /* Function asserts that an exclusive or shared lock is held. */
863 #define	__asserts_exclusive(...) \
864 	__lock_annotate(assert_exclusive_lock(__VA_ARGS__))
865 #define	__asserts_shared(...) \
866 	__lock_annotate(assert_shared_lock(__VA_ARGS__))
867 
868 /* Function requires that an exclusive or shared lock is or is not held. */
869 #define	__requires_exclusive(...) \
870 	__lock_annotate(exclusive_locks_required(__VA_ARGS__))
871 #define	__requires_shared(...) \
872 	__lock_annotate(shared_locks_required(__VA_ARGS__))
873 #define	__requires_unlocked(...) \
874 	__lock_annotate(locks_excluded(__VA_ARGS__))
875 
876 /* Function should not be analyzed. */
877 #define	__no_lock_analysis	__lock_annotate(no_thread_safety_analysis)
878 
879 /*
880  * Function or variable should not be sanitized, e.g., by AddressSanitizer.
881  * GCC has the nosanitize attribute, but as a function attribute only, and
882  * warns on use as a variable attribute.
883  */
884 #if __has_attribute(no_sanitize) && defined(__clang__)
885 #ifdef _KERNEL
886 #define __nosanitizeaddress	__attribute__((no_sanitize("kernel-address")))
887 #define __nosanitizememory	__attribute__((no_sanitize("kernel-memory")))
888 #else
889 #define __nosanitizeaddress	__attribute__((no_sanitize("address")))
890 #define __nosanitizememory	__attribute__((no_sanitize("memory")))
891 #endif
892 #define __nosanitizethread	__attribute__((no_sanitize("thread")))
893 #else
894 #define __nosanitizeaddress
895 #define __nosanitizememory
896 #define __nosanitizethread
897 #endif
898 
899 /* Guard variables and structure members by lock. */
900 #define	__guarded_by(x)		__lock_annotate(guarded_by(x))
901 #define	__pt_guarded_by(x)	__lock_annotate(pt_guarded_by(x))
902 
903 /* Alignment builtins for better type checking and improved code generation. */
904 /* Provide fallback versions for other compilers (GCC/Clang < 10): */
905 #if !__has_builtin(__builtin_is_aligned)
906 #define __builtin_is_aligned(x, align)	\
907 	(((__uintptr_t)x & ((align) - 1)) == 0)
908 #endif
909 #if !__has_builtin(__builtin_align_up)
910 #define __builtin_align_up(x, align)	\
911 	((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1))))
912 #endif
913 #if !__has_builtin(__builtin_align_down)
914 #define __builtin_align_down(x, align)	\
915 	((__typeof__(x))((x)&(~((align)-1))))
916 #endif
917 
918 #define __align_up(x, y) __builtin_align_up(x, y)
919 #define __align_down(x, y) __builtin_align_down(x, y)
920 #define __is_aligned(x, y) __builtin_is_aligned(x, y)
921 
922 #endif /* !_SYS_CDEFS_H_ */
923