1/* $NetBSD: cdefs.h,v 1.166 2025/04/06 22:43:08 rillig Exp $ */
2
3/* * Copyright (c) 1991, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Berkeley Software Design, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)cdefs.h 8.8 (Berkeley) 1/9/95
34 */
35
36#ifndef _SYS_CDEFS_H_
37#define _SYS_CDEFS_H_
38
39/*
40 * Macro to test if we're using a GNU C compiler of a specific vintage
41 * or later, for e.g. features that appeared in a particular version
42 * of GNU C. Usage:
43 *
44 * #if __GNUC_PREREQ__(major, minor)
45 * ...cool feature...
46 * #else
47 * ...delete feature...
48 * #endif
49 */
50#ifdef __GNUC__
51#define __GNUC_PREREQ__(x, y) \
52 ((__GNUC__ == (x) && __GNUC_MINOR__ >= (y)) || \
53 (__GNUC__ > (x)))
54#else
55#define __GNUC_PREREQ__(x, y) 0
56#endif
57
58/*
59 * Macros to test Clang/LLVM features.
60 * Usage:
61 *
62 * #if __has_feature(safe_stack)
63 * ...SafeStack specific code...
64 * #else
65 * ..regular code...
66 * #endif
67 */
68#ifndef __has_feature
69#define __has_feature(x) 0
70#endif
71
72#ifndef __has_extension
73#define __has_extension __has_feature /* Compat with pre-3.0 Clang */
74#endif
75
76#include <machine/cdefs.h>
77#ifdef __ELF__
78#include <sys/cdefs_elf.h>
79#else
80#include <sys/cdefs_aout.h>
81#endif
82
83#ifdef __GNUC__
84#define __strict_weak_alias(alias,sym) \
85 __unused static __typeof__(alias) *__weak_alias_##alias = &sym; \
86 __weak_alias(alias,sym)
87#else
88#define __strict_weak_alias(alias,sym) __weak_alias(alias,sym)
89#endif
90
91/*
92 * Optional marker for size-optimised MD calling convention.
93 */
94#ifndef __compactcall
95#define __compactcall
96#endif
97
98/*
99 * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
100 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
101 * The __CONCAT macro is a bit tricky -- make sure you don't put spaces
102 * in between its arguments. __CONCAT can also concatenate double-quoted
103 * strings produced by the __STRING macro, but this only works with ANSI C.
104 */
105
106#define ___STRING(x) __STRING(x)
107#define ___CONCAT(x,y) __CONCAT(x,y)
108
109#if __STDC__ || defined(__cplusplus)
110#define __P(protos) protos /* full-blown ANSI C */
111#define __CONCAT(x,y) x ## y
112#define __STRING(x) #x
113
114#define __const const /* define reserved names to standard */
115#define __signed signed
116#define __volatile volatile
117
118#define __CONCAT3(a,b,c) a ## b ## c
119#define __CONCAT4(a,b,c,d) a ## b ## c ## d
120#define __CONCAT5(a,b,c,d,e) a ## b ## c ## d ## e
121#define __CONCAT6(a,b,c,d,e,f) a ## b ## c ## d ## e ## f
122#define __CONCAT7(a,b,c,d,e,f,g) a ## b ## c ## d ## e ## f ## g
123#define __CONCAT8(a,b,c,d,e,f,g,h) a ## b ## c ## d ## e ## f ## g ## h
124
125#if defined(__cplusplus) || defined(__PCC__)
126#define __inline inline /* convert to C++/C99 keyword */
127#else
128#if !defined(__GNUC__) && !defined(__lint__)
129#define __inline /* delete GCC keyword */
130#endif /* !__GNUC__ && !__lint__ */
131#endif /* !__cplusplus */
132
133#else /* !(__STDC__ || __cplusplus) */
134#define __P(protos) () /* traditional C preprocessor */
135#define __CONCAT(x,y) x/**/y
136#define __STRING(x) "x"
137
138#ifndef __GNUC__
139#define __const /* delete pseudo-ANSI C keywords */
140#define __inline
141#define __signed
142#define __volatile
143#endif /* !__GNUC__ */
144
145/*
146 * In non-ANSI C environments, new programs will want ANSI-only C keywords
147 * deleted from the program and old programs will want them left alone.
148 * Programs using the ANSI C keywords const, inline etc. as normal
149 * identifiers should define -DNO_ANSI_KEYWORDS.
150 */
151#ifndef NO_ANSI_KEYWORDS
152#define const __const /* convert ANSI C keywords */
153#define inline __inline
154#define signed __signed
155#define volatile __volatile
156#endif /* !NO_ANSI_KEYWORDS */
157#endif /* !(__STDC__ || __cplusplus) */
158
159/*
160 * Used for internal auditing of the NetBSD source tree.
161 */
162#ifdef __AUDIT__
163#define __aconst __const
164#else
165#define __aconst
166#endif
167
168/*
169 * Compile Time Assertion.
170 */
171#ifdef __COUNTER__
172#define __CTASSERT(x) __CTASSERT0(x, __ctassert, __COUNTER__)
173#else
174#define __CTASSERT(x) __CTASSERT99(x, __INCLUDE_LEVEL__, __LINE__)
175#define __CTASSERT99(x, a, b) __CTASSERT0(x, __CONCAT(__ctassert,a), \
176 __CONCAT(_,b))
177#endif
178#define __CTASSERT0(x, y, z) __CTASSERT1(x, y, z)
179#define __CTASSERT1(x, y, z) \
180 struct y ## z ## _struct { \
181 unsigned int y ## z : /*CONSTCOND*/(x) ? 1 : -1; \
182 }
183
184/*
185 * The following macro is used to remove const cast-away warnings
186 * from gcc -Wcast-qual; it should be used with caution because it
187 * can hide valid errors; in particular most valid uses are in
188 * situations where the API requires it, not to cast away string
189 * constants. We don't use *intptr_t on purpose here and we are
190 * explicit about unsigned long so that we don't have additional
191 * dependencies.
192 */
193#define __UNCONST(a) ((void *)(unsigned long)(const void *)(a))
194
195/*
196 * The following macro is used to remove the volatile cast-away warnings
197 * from gcc -Wcast-qual; as above it should be used with caution
198 * because it can hide valid errors or warnings. Valid uses include
199 * making it possible to pass a volatile pointer to memset().
200 * For the same reasons as above, we use unsigned long and not intptr_t.
201 */
202#define __UNVOLATILE(a) ((void *)(unsigned long)(volatile void *)(a))
203
204/*
205 * The following macro is used to remove the the function type cast warnings
206 * from gcc -Wcast-function-type and as above should be used with caution.
207 */
208#define __FPTRCAST(t, f) ((t)(void *)(f))
209
210/*
211 * GCC2 provides __extension__ to suppress warnings for various GNU C
212 * language extensions under "-ansi -pedantic".
213 */
214#if !__GNUC_PREREQ__(2, 0)
215#define __extension__ /* delete __extension__ if non-gcc or gcc1 */
216#endif
217
218/*
219 * GCC1 and some versions of GCC2 declare dead (non-returning) and
220 * pure (no side effects) functions using "volatile" and "const";
221 * unfortunately, these then cause warnings under "-ansi -pedantic".
222 * GCC2 uses a new, peculiar __attribute__((attrs)) style. All of
223 * these work for GNU C++ (modulo a slight glitch in the C++ grammar
224 * in the distribution version of 2.5.5).
225 *
226 * GCC defines a pure function as depending only on its arguments and
227 * global variables. Typical examples are strlen and sqrt.
228 *
229 * GCC defines a const function as depending only on its arguments.
230 * Therefore calling a const function again with identical arguments
231 * will always produce the same result.
232 *
233 * Rounding modes for floating point operations are considered global
234 * variables and prevent sqrt from being a const function.
235 *
236 * Calls to const functions can be optimised away and moved around
237 * without limitations.
238 */
239#if !__GNUC_PREREQ__(2, 0) && !defined(__lint__)
240#define __attribute__(x)
241#endif
242
243#if __GNUC_PREREQ__(2, 5) || defined(__lint__)
244#define __dead __attribute__((__noreturn__))
245#elif defined(__GNUC__)
246#define __dead __volatile
247#else
248#define __dead
249#endif
250
251#if __GNUC_PREREQ__(2, 96) || defined(__lint__)
252#define __pure __attribute__((__pure__))
253#elif defined(__GNUC__)
254#define __pure __const
255#else
256#define __pure
257#endif
258
259#if __GNUC_PREREQ__(2, 5) || defined(__lint__)
260#define __constfunc __attribute__((__const__))
261#else
262#define __constfunc
263#endif
264
265#if __GNUC_PREREQ__(3, 0) || defined(__lint__)
266#define __noinline __attribute__((__noinline__))
267#else
268#define __noinline /* nothing */
269#endif
270
271#if __GNUC_PREREQ__(3, 0) || defined(__lint__)
272#define __always_inline __attribute__((__always_inline__))
273#else
274#define __always_inline /* nothing */
275#endif
276
277#if __GNUC_PREREQ__(4, 0) || defined(__lint__)
278#define __null_sentinel __attribute__((__sentinel__))
279#else
280#define __null_sentinel /* nothing */
281#endif
282
283#if __GNUC_PREREQ__(4, 1) || defined(__lint__)
284#define __returns_twice __attribute__((__returns_twice__))
285#else
286#define __returns_twice /* nothing */
287#endif
288
289#if __GNUC_PREREQ__(4, 5) || defined(__lint__)
290#define __noclone __attribute__((__noclone__))
291#else
292#define __noclone /* nothing */
293#endif
294
295/*
296 * __unused: Note that item or function might be unused.
297 */
298#if __GNUC_PREREQ__(2, 7) || defined(__lint__)
299#define __unused __attribute__((__unused__))
300#else
301#define __unused /* delete */
302#endif
303
304/*
305 * __used: Note that item is needed, even if it appears to be unused.
306 */
307#if __GNUC_PREREQ__(3, 1) || defined(__lint__)
308#define __used __attribute__((__used__))
309#else
310#define __used __unused
311#endif
312
313/*
314 * __diagused: Note that item is used in diagnostic code, but may be
315 * unused in non-diagnostic code.
316 */
317#if (defined(_KERNEL) && defined(DIAGNOSTIC)) \
318 || (!defined(_KERNEL) && !defined(NDEBUG))
319#define __diagused /* empty */
320#else
321#define __diagused __unused
322#endif
323
324/*
325 * __debugused: Note that item is used in debug code, but may be
326 * unused in non-debug code.
327 */
328#if defined(DEBUG)
329#define __debugused /* empty */
330#else
331#define __debugused __unused
332#endif
333
334#if __GNUC_PREREQ__(3, 1) || defined(__lint__)
335#define __noprofile __attribute__((__no_instrument_function__))
336#else
337#define __noprofile /* nothing */
338#endif
339
340#if __GNUC_PREREQ__(4, 6) || defined(__clang__) || defined(__lint__)
341#define __unreachable() __builtin_unreachable()
342#else
343#define __unreachable() do {} while (0)
344#endif
345
346#if defined(_KERNEL) || defined(_RUMPKERNEL)
347#if defined(__clang__) && __has_feature(address_sanitizer)
348#define __noasan __attribute__((no_sanitize("kernel-address", "address")))
349#elif __GNUC_PREREQ__(4, 9) && defined(__SANITIZE_ADDRESS__)
350#define __noasan __attribute__((no_sanitize_address))
351#else
352#define __noasan /* nothing */
353#endif
354
355#if defined(__clang__) && __has_feature(thread_sanitizer)
356#define __nocsan __attribute__((no_sanitize("thread")))
357#elif __GNUC_PREREQ__(4, 9) && defined(__SANITIZE_THREAD__)
358#define __nocsan __attribute__((no_sanitize_thread))
359#else
360#define __nocsan /* nothing */
361#endif
362
363#if defined(__clang__) && __has_feature(memory_sanitizer)
364#define __nomsan __attribute__((no_sanitize("kernel-memory", "memory")))
365#else
366#define __nomsan /* nothing */
367#endif
368
369#if defined(__clang__) && __has_feature(undefined_behavior_sanitizer)
370#define __noubsan __attribute__((no_sanitize("undefined")))
371#elif __GNUC_PREREQ__(4, 9) && defined(__SANITIZE_UNDEFINED__)
372#define __noubsan __attribute__((no_sanitize_undefined))
373#else
374#define __noubsan /* nothing */
375#endif
376#endif
377
378#if defined(__COVERITY__) || \
379 __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__) ||\
380 __has_feature(leak_sanitizer) || defined(__SANITIZE_LEAK__)
381#define __NO_LEAKS
382#endif
383
384/*
385 * To be used when an empty body is required like:
386 *
387 * #ifdef DEBUG
388 * # define dprintf(a) printf(a)
389 * #else
390 * # define dprintf(a) __nothing
391 * #endif
392 *
393 * We use ((void)0) instead of do {} while (0) so that it
394 * works on , expressions.
395 */
396#define __nothing (/*LINTED*/(void)0)
397
398#if defined(__cplusplus)
399#define __BEGIN_EXTERN_C extern "C" {
400#define __END_EXTERN_C }
401#define __static_cast(x,y) static_cast<x>(y)
402#else
403#define __BEGIN_EXTERN_C
404#define __END_EXTERN_C
405#define __static_cast(x,y) (x)y
406#endif
407
408#if __GNUC_PREREQ__(4, 0) || defined(__lint__)
409# define __dso_public __attribute__((__visibility__("default")))
410# define __dso_hidden __attribute__((__visibility__("hidden")))
411# define __BEGIN_PUBLIC_DECLS \
412 _Pragma("GCC visibility push(default)") __BEGIN_EXTERN_C
413# define __END_PUBLIC_DECLS __END_EXTERN_C _Pragma("GCC visibility pop")
414# define __BEGIN_HIDDEN_DECLS \
415 _Pragma("GCC visibility push(hidden)") __BEGIN_EXTERN_C
416# define __END_HIDDEN_DECLS __END_EXTERN_C _Pragma("GCC visibility pop")
417#else
418# define __dso_public
419# define __dso_hidden
420# define __BEGIN_PUBLIC_DECLS __BEGIN_EXTERN_C
421# define __END_PUBLIC_DECLS __END_EXTERN_C
422# define __BEGIN_HIDDEN_DECLS __BEGIN_EXTERN_C
423# define __END_HIDDEN_DECLS __END_EXTERN_C
424#endif
425#if __GNUC_PREREQ__(4, 2) || defined(__lint__)
426# define __dso_protected __attribute__((__visibility__("protected")))
427#else
428# define __dso_protected
429#endif
430
431#define __BEGIN_DECLS __BEGIN_PUBLIC_DECLS
432#define __END_DECLS __END_PUBLIC_DECLS
433
434/*
435 * Non-static C99 inline functions are optional bodies. They don't
436 * create global symbols if not used, but can be replaced if desirable.
437 * This differs from the behavior of GCC before version 4.3. The nearest
438 * equivalent for older GCC is `extern inline'. For newer GCC, use the
439 * gnu_inline attribute additionally to get the old behavior.
440 *
441 * For C99 compilers other than GCC, the C99 behavior is expected.
442 */
443#if defined(__GNUC__) && defined(__GNUC_STDC_INLINE__)
444#define __c99inline extern __attribute__((__gnu_inline__)) __inline
445#elif defined(__GNUC__)
446#define __c99inline extern __inline
447#elif defined(__STDC_VERSION__) || defined(__lint__)
448#define __c99inline __inline
449#endif
450
451#if defined(__lint__)
452#define __thread /* delete */
453#define __packed __packed
454#define __aligned(x) _Alignas((x))
455#define __section(x) /* delete */
456#elif __GNUC_PREREQ__(2, 7) || defined(__PCC__) || defined(__lint__)
457#define __packed __attribute__((__packed__))
458#define __aligned(x) __attribute__((__aligned__(x)))
459#define __section(x) __attribute__((__section__(x)))
460#elif defined(_MSC_VER)
461#define __packed /* ignore */
462#else
463#define __packed error: no __packed for this compiler
464#define __aligned(x) error: no __aligned for this compiler
465#define __section(x) error: no __section for this compiler
466#endif
467
468/*
469 * C99 defines the restrict type qualifier keyword, which was made available
470 * in GCC 2.92.
471 */
472#if __STDC_VERSION__ >= 199901L
473#define __restrict restrict
474#elif __GNUC_PREREQ__(2, 92)
475#define __restrict __restrict__
476#else
477#define __restrict /* delete __restrict when not supported */
478#endif
479
480/*
481 * C99 and C++11 define __func__ predefined identifier, which was made
482 * available in GCC 2.95.
483 */
484#if !(__STDC_VERSION__ >= 199901L) && !(__cplusplus - 0 >= 201103L)
485#if __GNUC_PREREQ__(2, 4) || defined(__lint__)
486#define __func__ __FUNCTION__
487#else
488#define __func__ ""
489#endif
490#endif /* !(__STDC_VERSION__ >= 199901L) && !(__cplusplus - 0 >= 201103L) */
491
492#if defined(_KERNEL) && defined(NO_KERNEL_RCSIDS)
493#undef __KERNEL_RCSID
494#define __KERNEL_RCSID(_n, _s) /* nothing */
495#undef __RCSID
496#define __RCSID(_s) /* nothing */
497#endif
498
499#if !defined(_STANDALONE) && !defined(_KERNEL)
500#if defined(__GNUC__) || defined(__PCC__)
501#define __RENAME(x) ___RENAME(x)
502#elif defined(__lint__)
503#define __RENAME(x) __symbolrename(x)
504#else
505#error "No function renaming possible"
506#endif /* __GNUC__ */
507#else /* _STANDALONE || _KERNEL */
508#define __RENAME(x) no renaming in kernel/standalone environment
509#endif
510
511/*
512 * A barrier to stop the optimizer from moving code or assume live
513 * register values. This is gcc specific, the version is more or less
514 * arbitrary, might work with older compilers.
515 */
516#if __GNUC_PREREQ__(2, 95) || defined(__lint__)
517#define __insn_barrier() __asm __volatile("":::"memory")
518#else
519#define __insn_barrier() /* */
520#endif
521
522/*
523 * GNU C version 2.96 adds explicit branch prediction so that
524 * the CPU back-end can hint the processor and also so that
525 * code blocks can be reordered such that the predicted path
526 * sees a more linear flow, thus improving cache behavior, etc.
527 *
528 * The following two macros provide us with a way to use this
529 * compiler feature. Use __predict_true() if you expect the expression
530 * to evaluate to true, and __predict_false() if you expect the
531 * expression to evaluate to false.
532 *
533 * A few notes about usage:
534 *
535 * * Generally, __predict_false() error condition checks (unless
536 * you have some _strong_ reason to do otherwise, in which case
537 * document it), and/or __predict_true() `no-error' condition
538 * checks, assuming you want to optimize for the no-error case.
539 *
540 * * Other than that, if you don't know the likelihood of a test
541 * succeeding from empirical or other `hard' evidence, don't
542 * make predictions.
543 *
544 * * These are meant to be used in places that are run `a lot'.
545 * It is wasteful to make predictions in code that is run
546 * seldomly (e.g. at subsystem initialization time) as the
547 * basic block reordering that this affects can often generate
548 * larger code.
549 *
550 * We use an explicit ternary operator to map any value to exactly 0 or
551 * 1 so that (a) we can specify one value to expect, and (b) the given
552 * expression occurs only in the position of a conditional so that C++
553 * classes with conversion to bool work as if this were a conditional.
554 * In contrast, say, `(exp) != 0' would require the type of exp to
555 * support conversion to integer as well.
556 */
557#if __GNUC_PREREQ__(2, 96) || defined(__lint__)
558#define __predict_true(exp) __builtin_expect((exp) ? 1 : 0, 1)
559#define __predict_false(exp) __builtin_expect((exp) ? 1 : 0, 0)
560#else
561#define __predict_true(exp) (exp)
562#define __predict_false(exp) (exp)
563#endif
564
565/*
566 * Compiler-dependent macros to declare that functions take printf-like
567 * or scanf-like arguments. They are null except for versions of gcc
568 * that are known to support the features properly (old versions of gcc-2
569 * didn't permit keeping the keywords out of the application namespace).
570 */
571#if __GNUC_PREREQ__(2, 7) || defined(__lint__)
572#define __printflike(fmtarg, firstvararg) \
573 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
574#ifndef __syslog_attribute__
575#define __syslog__ __printf__
576#endif
577#define __sysloglike(fmtarg, firstvararg) \
578 __attribute__((__format__ (__syslog__, fmtarg, firstvararg)))
579#define __scanflike(fmtarg, firstvararg) \
580 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
581#define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg)))
582#else
583#define __printflike(fmtarg, firstvararg) /* nothing */
584#define __scanflike(fmtarg, firstvararg) /* nothing */
585#define __sysloglike(fmtarg, firstvararg) /* nothing */
586#define __format_arg(fmtarg) /* nothing */
587#endif
588
589/*
590 * Macros for manipulating "link sets". Link sets are arrays of pointers
591 * to objects, which are gathered up by the linker.
592 *
593 * Object format-specific code has provided us with the following macros:
594 *
595 * __link_set_add_text(set, sym)
596 * Add a reference to the .text symbol `sym' to `set'.
597 *
598 * __link_set_add_rodata(set, sym)
599 * Add a reference to the .rodata symbol `sym' to `set'.
600 *
601 * __link_set_add_data(set, sym)
602 * Add a reference to the .data symbol `sym' to `set'.
603 *
604 * __link_set_add_bss(set, sym)
605 * Add a reference to the .bss symbol `sym' to `set'.
606 *
607 * __link_set_decl(set, ptype)
608 * Provide an extern declaration of the set `set', which
609 * contains an array of pointers to type `ptype'. This
610 * macro must be used by any code which wishes to reference
611 * the elements of a link set.
612 *
613 * __link_set_start(set)
614 * This points to the first slot in the link set.
615 *
616 * __link_set_end(set)
617 * This points to the (non-existent) slot after the last
618 * entry in the link set.
619 *
620 * __link_set_count(set)
621 * Count the number of entries in link set `set'.
622 *
623 * In addition, we provide the following macros for accessing link sets:
624 *
625 * __link_set_foreach(pvar, set)
626 * Iterate over the link set `set'. Because a link set is
627 * an array of pointers, pvar must be declared as "type **pvar",
628 * and the actual entry accessed as "*pvar".
629 *
630 * __link_set_entry(set, idx)
631 * Access the link set entry at index `idx' from set `set'.
632 */
633#define __link_set_foreach(pvar, set) \
634 for (pvar = __link_set_start(set); pvar < __link_set_end(set); pvar++)
635
636#define __link_set_entry(set, idx) (__link_set_start(set)[idx])
637
638/*
639 * Return the natural alignment in bytes for the given type
640 */
641#if __GNUC_PREREQ__(4, 1) || defined(__lint__)
642#define __alignof(__t) __alignof__(__t)
643#else
644#define __alignof(__t) (sizeof(struct { char __x; __t __y; }) - sizeof(__t))
645#endif
646
647/*
648 * Return the number of elements in a statically-allocated array,
649 * __x.
650 */
651#define __arraycount(__x) (sizeof(__x) / sizeof(__x[0]))
652
653#ifndef __ASSEMBLER__
654/* __BIT(n): nth bit, where __BIT(0) == 0x1. */
655#define __BIT(__n) \
656 (((__UINTMAX_TYPE__)(__n) >= __CHAR_BIT__ * sizeof(__UINTMAX_TYPE__)) \
657 ? 0 \
658 : ((__UINTMAX_TYPE__)1 << \
659 (__UINTMAX_TYPE__)((__n) & \
660 (__CHAR_BIT__ * sizeof(__UINTMAX_TYPE__) - 1))))
661
662/* __MASK(n): first n bits all set, where __MASK(4) == 0b1111. */
663#define __MASK(__n) (__BIT(__n) - 1)
664
665/* Macros for min/max. */
666#define __MIN(a,b) ((/*CONSTCOND*/(a)<=(b))?(a):(b))
667#define __MAX(a,b) ((/*CONSTCOND*/(a)>(b))?(a):(b))
668
669/* __BITS(m, n): bits m through n, m < n. */
670#define __BITS(__m, __n) \
671 ((__BIT(__MAX((__m), (__n)) + 1) - 1) ^ (__BIT(__MIN((__m), (__n))) - 1))
672#endif /* !__ASSEMBLER__ */
673
674/* find least significant bit that is set */
675#define __LOWEST_SET_BIT(__mask) ((((__mask) - 1) & (__mask)) ^ (__mask))
676
677#define __PRIuBIT PRIuMAX
678#define __PRIuBITS __PRIuBIT
679
680#define __PRIxBIT PRIxMAX
681#define __PRIxBITS __PRIxBIT
682
683#define __SHIFTOUT(__x, __mask) (((__x) & (__mask)) / __LOWEST_SET_BIT(__mask))
684#define __SHIFTIN(__x, __mask) ((__x) * __LOWEST_SET_BIT(__mask))
685#define __SHIFTOUT_MASK(__mask) __SHIFTOUT((__mask), (__mask))
686
687/*
688 * Only to be used in other headers that are included from both c or c++
689 * NOT to be used in code.
690 */
691#ifdef __cplusplus
692#define __CAST(__dt, __st) static_cast<__dt>(__st)
693#else
694#define __CAST(__dt, __st) ((__dt)(__st))
695#endif
696
697#define __CASTV(__dt, __st) __CAST(__dt, __CAST(void *, __st))
698#define __CASTCV(__dt, __st) __CAST(__dt, __CAST(const void *, __st))
699
700/*
701 * Suppresses `variable set but not used' warnings.
702 *
703 * Typically for #ifdefs, where one branch of the #ifdef uses a
704 * variable but the other does not. Useful in patching external code
705 * to keep the patches narrowly scoped.
706 *
707 * Limitation: Only for variables, and only non-volatile variables.
708 *
709 * (Abusing this for anything else may lead to side effects. Pointers
710 * to volatile objects are OK, as in `volatile int *a', as long as the
711 * pointer itself is not volatile, as in `int *volatile a'.)
712 */
713#define __USE(a) (/*LINTED*/(void)(a))
714
715/*
716 * Verifies the expression e compiles, but does not evaluate it. Safe
717 * when e has side effects.
718 *
719 * Typically used for the arguments to macros with conditional
720 * definitions like DIAGNOSTIC or KDTRACE_HOOKS: when enabled, the
721 * macro uses the argument; when disabled, the macro passes the
722 * argument to __MACROUSE but doesn't otherwise use it. Cast to long
723 * in case the argument is a bit field, which is forbidden in sizeof.
724 *
725 * Limitation: Doesn't work for expressions of aggregate (struct/union)
726 * types.
727 *
728 * (If you find a way to handle both bit fields and aggregate types,
729 * you could unify __USE and __MACROUSE.)
730 */
731#define __MACROUSE(e) (/*LINTED*/(void)sizeof((long)(e)))
732
733#define __type_mask(t) (/*LINTED*/sizeof(t) < sizeof(__INTMAX_TYPE__) ? \
734 (~((1ULL << (sizeof(t) * __CHAR_BIT__)) - 1)) : 0ULL)
735
736#ifndef __ASSEMBLER__
737static __inline long long __zeroll(void) { return 0; }
738static __inline unsigned long long __zeroull(void) { return 0; }
739#else
740#define __zeroll() (0LL)
741#define __zeroull() (0ULL)
742#endif
743
744#define __negative_p(x) (!((x) > 0) && ((x) != 0))
745
746#define __type_min_s(t) ((t)((1ULL << (sizeof(t) * __CHAR_BIT__ - 1))))
747#define __type_max_s(t) ((t)~((1ULL << (sizeof(t) * __CHAR_BIT__ - 1))))
748#define __type_min_u(t) ((t)0ULL)
749#define __type_max_u(t) ((t)~0ULL)
750#define __type_is_signed(t) (/*LINTED*/__type_min_s(t) + (t)1 < (t)1)
751#define __type_min(t) (__type_is_signed(t) ? __type_min_s(t) : __type_min_u(t))
752#define __type_max(t) (__type_is_signed(t) ? __type_max_s(t) : __type_max_u(t))
753
754
755#define __type_fit_u(t, a) \
756 (/*LINTED*/!__negative_p(a) && \
757 ((__UINTMAX_TYPE__)((a) + __zeroull()) <= \
758 (__UINTMAX_TYPE__)__type_max_u(t)))
759
760#define __type_fit_s(t, a) \
761 (/*LINTED*/__negative_p(a) \
762 ? ((__INTMAX_TYPE__)((a) + __zeroll()) >= \
763 (__INTMAX_TYPE__)__type_min_s(t)) \
764 : ((__INTMAX_TYPE__)((a) + __zeroll()) >= (__INTMAX_TYPE__)0 && \
765 ((__INTMAX_TYPE__)((a) + __zeroll()) <= \
766 (__INTMAX_TYPE__)__type_max_s(t))))
767
768/*
769 * return true if value 'a' fits in type 't'
770 */
771#define __type_fit(t, a) (__type_is_signed(t) ? \
772 __type_fit_s(t, a) : __type_fit_u(t, a))
773
774#endif /* !_SYS_CDEFS_H_ */