cdefs: Rework and augment visibility attributes
[dragonfly.git] / sys / sys / cdefs.h
CommitLineData
984263bc
MD
1/*
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Berkeley Software Design, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)cdefs.h 8.8 (Berkeley) 1/9/95
37 * $FreeBSD: src/sys/sys/cdefs.h,v 1.28.2.8 2002/09/18 04:05:13 mikeh Exp $
2c292fb2 38 * $DragonFly: src/sys/sys/cdefs.h,v 1.20 2008/11/20 11:27:24 hasso Exp $
984263bc
MD
39 */
40
41#ifndef _SYS_CDEFS_H_
42#define _SYS_CDEFS_H_
43
44#if defined(__cplusplus)
45#define __BEGIN_DECLS extern "C" {
46#define __END_DECLS }
47#else
48#define __BEGIN_DECLS
49#define __END_DECLS
50#endif
51
52/*
dc62b251
MD
53 * Macro to test if we are using a specific version of gcc or later.
54 */
43c9ef94
JR
55#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
56#define __GNUC_PREREQ__(ma, mi) \
dc62b251
MD
57 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
58#else
43c9ef94 59#define __GNUC_PREREQ__(ma, mi) 0
dc62b251
MD
60#endif
61
62/*
d9abbdda 63 * The __VM_CACHELINE_SIZE macro defines the common cache line alignment
f754816e
HP
64 * size that can be found across most recent and somewhat latest Intel
65 * hardware, i.e. L1 cache sizes etc.
66 *
67 * If needed, this value can be TUNED. Suitable values for this macro
68 * are 32, 64 and 128 bytes. The unit of measurement for this macro is
69 * bytes.
70 *
71 * XXX: This macro and related macros will eventually move to a MD
72 * header, but currently, we do need such a hierarchy.
73 */
ddca1582
MD
74#define __VM_CACHELINE_SIZE 64
75#define __VM_CACHELINE_ALIGN(n) \
76 (((n) + __VM_CACHELINE_SIZE - 1) / __VM_CACHELINE_SIZE)
f754816e
HP
77
78/*
984263bc
MD
79 * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
80 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
81 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
82 * mode -- there must be no spaces between its arguments, and for nested
83 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also
84 * concatenate double-quoted strings produced by the __STRING macro, but
85 * this only works with ANSI C.
86 *
87 * __XSTRING is like __STRING, but it expands any macros in its argument
88 * first. It is only available with ANSI C.
89 */
90#if defined(__STDC__) || defined(__cplusplus)
91#define __P(protos) protos /* full-blown ANSI C */
92#define __CONCAT1(x,y) x ## y
93#define __CONCAT(x,y) __CONCAT1(x,y)
94#define __STRING(x) #x /* stringify without expanding x */
95#define __XSTRING(x) __STRING(x) /* expand x, then stringify */
96
97#define __const const /* define reserved names to standard */
98#define __signed signed
99#define __volatile volatile
100#if defined(__cplusplus)
101#define __inline inline /* convert to C++ keyword */
102#else
103#ifndef __GNUC__
104#define __inline /* delete GCC keyword */
105#endif /* !__GNUC__ */
106#endif /* !__cplusplus */
107
108#else /* !(__STDC__ || __cplusplus) */
109#define __P(protos) () /* traditional C preprocessor */
110#define __CONCAT(x,y) x/**/y
111#define __STRING(x) "x"
112
113#ifndef __GNUC__
114#define __const /* delete pseudo-ANSI C keywords */
115#define __inline
116#define __signed
117#define __volatile
118/*
119 * In non-ANSI C environments, new programs will want ANSI-only C keywords
120 * deleted from the program and old programs will want them left alone.
121 * When using a compiler other than gcc, programs using the ANSI C keywords
122 * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
123 * When using "gcc -traditional", we assume that this is the intent; if
124 * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
125 */
126#ifndef NO_ANSI_KEYWORDS
127#define const /* delete ANSI C keywords */
128#define inline
129#define signed
130#define volatile
131#endif /* !NO_ANSI_KEYWORDS */
132#endif /* !__GNUC__ */
133#endif /* !(__STDC__ || __cplusplus) */
134
135/*
136 * Compiler-dependent macros to help declare dead (non-returning) and
137 * pure (no side effects) functions, and unused variables. They are
138 * null except for versions of gcc that are known to support the features
139 * properly (old versions of gcc-2 supported the dead and pure features
140 * in a different (wrong) way).
141 */
dc62b251
MD
142#ifdef lint
143
144#define __dead2
ceb0d0c4 145#define __pure
dc62b251
MD
146#define __pure2
147#define __unused
148#define __packed
149#define __aligned(x)
150#define __section(x)
151#define __always_inline
152#define __nonnull(x)
153
154#else
155
3d28a533 156#if !__GNUC_PREREQ__(2, 7)
984263bc
MD
157#define __dead2
158#define __pure2
159#define __unused
160#endif
dc62b251 161
dc62b251 162#if __GNUC_PREREQ__(2, 7)
984263bc
MD
163#define __dead2 __attribute__((__noreturn__))
164#define __pure2 __attribute__((__const__))
165#define __unused __attribute__((__unused__))
dc62b251
MD
166#define __packed __attribute__((__packed__))
167#define __aligned(x) __attribute__((__aligned__(x)))
168#define __section(x) __attribute__((__section__(x)))
169#endif
170
74c78f9b 171#if __GNUC_PREREQ__(2, 96)
ceb0d0c4
JS
172#define __pure __attribute__((__pure__))
173#else
174#define __pure __pure2
175#endif
176
dc62b251
MD
177#if __GNUC_PREREQ__(3, 1)
178#define __always_inline __attribute__((__always_inline__))
e0f95098 179#define __noinline __attribute__((__noinline__))
dc62b251
MD
180#else
181#define __always_inline
e0f95098 182#define __noinline
dc62b251
MD
183#endif
184
185#if __GNUC_PREREQ__(3, 3)
186#define __nonnull(x) __attribute__((__nonnull__(x)))
efb8080e 187#define __used __attribute__((__used__))
dc62b251
MD
188#else
189#define __nonnull(x)
efb8080e 190#define __used __unused
dc62b251
MD
191#endif
192
dc62b251
MD
193#endif /* LINT */
194
3d28a533
JS
195#if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION < 199901
196#define __func__ NULL
984263bc
MD
197#endif
198
3d28a533
JS
199#if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI)) || \
200 __STDC_VERSION__ >= 199901
984263bc
MD
201#define __LONG_LONG_SUPPORTED
202#endif
203
204/*
ae0ec55c
DX
205 * GNU C version 2.96 adds explicit branch prediction so that
206 * the CPU back-end can hint the processor and also so that
207 * code blocks can be reordered such that the predicted path
208 * sees a more linear flow, thus improving cache behavior, etc.
209 *
210 * The following two macros provide us with a way to utilize this
211 * compiler feature. Use __predict_true() if you expect the expression
212 * to evaluate to true, and __predict_false() if you expect the
213 * expression to evaluate to false.
214 *
215 * A few notes about usage:
216 *
217 * * Generally, __predict_false() error condition checks (unless
218 * you have some _strong_ reason to do otherwise, in which case
219 * document it), and/or __predict_true() `no-error' condition
220 * checks, assuming you want to optimize for the no-error case.
221 *
222 * * Other than that, if you don't know the likelihood of a test
223 * succeeding from empirical or other `hard' evidence, don't
224 * make predictions.
225 *
226 * * These are meant to be used in places that are run `a lot'.
227 * It is wasteful to make predictions in code that is run
228 * seldomly (e.g. at subsystem initialization time) as the
229 * basic block reordering that this affects can often generate
230 * larger code.
231 */
232#if __GNUC_PREREQ__(2, 96)
233#define __predict_true(exp) __builtin_expect((exp), 1)
234#define __predict_false(exp) __builtin_expect((exp), 0)
235#else
236#define __predict_true(exp) (exp)
237#define __predict_false(exp) (exp)
238#endif
239
240/*
3d28a533
JS
241 * GCC 2.95 and later provides `__restrict' as an extention to C90 to support
242 * the C99-specific `restrict' type qualifier. We happen to use `__restrict'
243 * as a way to define the `restrict' type qualifier without disturbing older
984263bc
MD
244 * software that is unaware of C99 keywords.
245 */
3d28a533 246#if !__GNUC_PREREQ__(2, 95)
984263bc
MD
247#if __STDC_VERSION__ < 199901
248#define __restrict
249#else
250#define __restrict restrict
251#endif
252#endif
253
254/*
255 * Compiler-dependent macros to declare that functions take printf-like
256 * or scanf-like arguments. They are null except for versions of gcc
257 * that are known to support the features properly (old versions of gcc-2
258 * didn't permit keeping the keywords out of the application namespace).
38139e70
JS
259 *
260 * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
984263bc 261 */
3d28a533 262#if !__GNUC_PREREQ__(2, 7)
984263bc
MD
263#define __printflike(fmtarg, firstvararg)
264#define __scanflike(fmtarg, firstvararg)
38139e70 265#define __printf0like(fmtarg, firstvararg)
e0f95098 266#define __format_arg(fmtarg)
3d28a533 267#elif __GNUC_PREREQ__(3, 0)
38139e70
JS
268#define __printflike(fmtarg, firstvararg) \
269 __attribute__((__nonnull__(fmtarg), \
270 __format__ (__printf__, fmtarg, firstvararg)))
271#define __printf0like(fmtarg, firstvararg) \
272 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
273#define __scanflike(fmtarg, firstvararg) \
274 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
e0f95098
PA
275#define __format_arg(fmtarg) \
276 __attribute__((__format_arg__ (fmtarg)))
38139e70 277
984263bc
MD
278#else
279#define __printflike(fmtarg, firstvararg) \
280 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
38139e70
JS
281#define __printf0like(fmtarg, firstvararg) \
282 __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
984263bc
MD
283#define __scanflike(fmtarg, firstvararg) \
284 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
e0f95098
PA
285#define __format_arg(fmtarg) \
286 __attribute__((__format_arg__ (fmtarg)))
287
984263bc
MD
288#endif
289
3d28a533 290#if !__GNUC_PREREQ__(3, 0)
18ba5b61
MD
291#define __ARRAY_ZERO 0
292#else
293#define __ARRAY_ZERO
294#endif
295
25fffb38
JM
296#if __GNUC_PREREQ__(4, 0)
297#define __exported __attribute__((__visibility__("default")))
298#define __dso_public __attribute__((__visibility__("default")))
299#define __dso_hidden __attribute__((__visibility__("hidden")))
300#else
301#define __exported
302#define __dso_public
303#define __dso_hidden
304#endif
305
f754816e 306/*
2ea04d5f 307 * A convenient constructor macro, GCC 4.3.0 added priority support to
754d5cac
SG
308 * constructors, provide a compatible interface for both.
309 */
310#if __GNUC_PREREQ__(4, 3)
311#define __constructor(prio) __attribute__((constructor(prio)))
312#else
313#define __constructor(prio) __attribute__((constructor))
314#endif
315
316/*
f754816e
HP
317 * Handy GCC based macros:
318 *
319 * __cachealign:
320 *
321 * The __cachealign macro can be used for cache line aligning structures
322 * of small to medium size. It aligns the particular structure or
323 * storage type to a system default cache line alignment, thus giving us
324 * a much more better cache utilization by making the hardware work at
325 * its best burst speeds.
326 *
327 * __usereg:
328 *
329 * The __usereg macro can/should be used when a function contains
330 * arguments not more than 3. It can be very useful to us due to the
331 * message-passing nature of the kernel.
332 *
333 * !!NOTE - USAGE INFORMATION!!
334 *
335 * The __cachealign macro should not be used for data structures that are
336 * as big struct proc, struct vnode, struct thread, and other structs which
337 * are as big as them; simply because it will be useless in that case.
338 *
339 * The __usereg macro should be used whenever possible, i.e., when a function
340 * does not exceed more than 3 arguments, and should not be used for vararg
341 * type functions.
342 *
343 * In other words, AVOID MISUSE OF THESE MACROS. :-)
344 */
345#ifdef __GNUC__
d9abbdda
JS
346#define __cachealign __attribute__((__aligned__(__VM_CACHELINE_SIZE)))
347#define __usereg __attribute__((__regparm__(3)))
f754816e
HP
348#else
349#define __cachealign
350#define __usereg
351#endif
352
984263bc
MD
353#ifdef __GNUC__
354#define __strong_reference(sym,aliassym) \
355 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
984263bc
MD
356#define __weak_reference(sym,alias) \
357 __asm__(".weak " #alias); \
358 __asm__(".equ " #alias ", " #sym)
359#define __warn_references(sym,msg) \
360 __asm__(".section .gnu.warning." #sym); \
361 __asm__(".asciz \"" msg "\""); \
362 __asm__(".previous")
984263bc
MD
363#endif /* __GNUC__ */
364
aa8d5dcb 365#if defined(__GNUC__)
984263bc 366#define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
984263bc
MD
367#endif
368
369#ifndef __RCSID
370#define __RCSID(s) __IDSTRING(rcsid,s)
371#endif
372
984263bc
MD
373#ifndef __RCSID_SOURCE
374#define __RCSID_SOURCE(s) __IDSTRING(rcsid_source,s)
375#endif
376
377#ifndef __COPYRIGHT
378#define __COPYRIGHT(s) __IDSTRING(copyright,s)
379#endif
380
8a59902d
JS
381#ifndef __DECONST
382#define __DECONST(type, var) ((type)(uintptr_t)(const void *)(var))
383#endif
384
385#ifndef __DEVOLATILE
386#define __DEVOLATILE(type, var) ((type)(uintptr_t)(volatile void *)(var))
387#endif
388
389#ifndef __DEQUALIFY
390#define __DEQUALIFY(type, var) ((type)(uintptr_t)(const volatile void *)(var))
391#endif
392
984263bc
MD
393/*-
394 * The following definitions are an extension of the behavior originally
395 * implemented in <sys/_posix.h>, but with a different level of granularity.
396 * POSIX.1 requires that the macros we test be defined before any standard
397 * header file is included.
398 *
399 * Here's a quick run-down of the versions:
400 * defined(_POSIX_SOURCE) 1003.1-1988
401 * _POSIX_C_SOURCE == 1 1003.1-1990
402 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
403 * _POSIX_C_SOURCE == 199309 1003.1b-1993
404 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
405 * and the omnibus ISO/IEC 9945-1: 1996
406 * _POSIX_C_SOURCE == 200112 1003.1-2001
ae2ee8ee 407 * _POSIX_C_SOURCE == 200809 1003.1-2008
984263bc
MD
408 *
409 * In addition, the X/Open Portability Guide, which is now the Single UNIX
410 * Specification, defines a feature-test macro which indicates the version of
411 * that specification, and which subsumes _POSIX_C_SOURCE.
412 *
413 * Our macros begin with two underscores to avoid namespace screwage.
414 */
415
3c00e9c1
JS
416/*
417 * If no special macro was specified, make the DragonFly extensions
418 * available. Also make them available when requested so.
419 */
420#if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE) && \
421 !defined(_ANSI_SOURCE) && !defined(_C99_SOURCE)) || \
422 defined(_DRAGONFLY_SOURCE) || defined(_NETBSD_SOURCE)
423#define __DF_VISIBLE 1
424#else
425#define __DF_VISIBLE 0
426#endif
427
984263bc 428/* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
2c292fb2 429#if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1
984263bc
MD
430#undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
431#define _POSIX_C_SOURCE 199009
432#endif
433
434/* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
2c292fb2 435#if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2
984263bc
MD
436#undef _POSIX_C_SOURCE
437#define _POSIX_C_SOURCE 199209
438#endif
439
440/* Deal with various X/Open Portability Guides and Single UNIX Spec. */
441#ifdef _XOPEN_SOURCE
ae2ee8ee
SW
442#if _XOPEN_SOURCE - 0 >= 700
443#define __XSI_VISIBLE 700
444#undef _POSIX_C_SOURCE
445#define _POSIX_C_SOURCE 200809
446#elif _XOPEN_SOURCE - 0 >= 600
984263bc
MD
447#define __XSI_VISIBLE 600
448#undef _POSIX_C_SOURCE
449#define _POSIX_C_SOURCE 200112
450#elif _XOPEN_SOURCE - 0 >= 500
451#define __XSI_VISIBLE 500
452#undef _POSIX_C_SOURCE
453#define _POSIX_C_SOURCE 199506
454#endif
455#endif
456
457/*
458 * Deal with all versions of POSIX. The ordering relative to the tests above is
459 * important.
460 */
461#if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
462#define _POSIX_C_SOURCE 198808
463#endif
464#ifdef _POSIX_C_SOURCE
ae2ee8ee
SW
465#if (_POSIX_C_SOURCE - 0) >= 200809
466#define __POSIX_VISIBLE 200809
467#define __ISO_C_VISIBLE 1999
468#elif (_POSIX_C_SOURCE - 0) >= 200112
984263bc
MD
469#define __POSIX_VISIBLE 200112
470#define __ISO_C_VISIBLE 1999
2c292fb2 471#elif (_POSIX_C_SOURCE - 0) >= 199506
984263bc
MD
472#define __POSIX_VISIBLE 199506
473#define __ISO_C_VISIBLE 1990
2c292fb2 474#elif (_POSIX_C_SOURCE - 0) >= 199309
984263bc
MD
475#define __POSIX_VISIBLE 199309
476#define __ISO_C_VISIBLE 1990
2c292fb2 477#elif (_POSIX_C_SOURCE - 0) >= 199209
984263bc
MD
478#define __POSIX_VISIBLE 199209
479#define __ISO_C_VISIBLE 1990
2c292fb2 480#elif (_POSIX_C_SOURCE - 0) >= 199009
984263bc
MD
481#define __POSIX_VISIBLE 199009
482#define __ISO_C_VISIBLE 1990
483#else
484#define __POSIX_VISIBLE 198808
485#define __ISO_C_VISIBLE 0
486#endif /* _POSIX_C_SOURCE */
487#else
488/*-
489 * Deal with _ANSI_SOURCE:
490 * If it is defined, and no other compilation environment is explicitly
491 * requested, then define our internal feature-test macros to zero. This
492 * makes no difference to the preprocessor (undefined symbols in preprocessing
493 * expressions are defined to have value zero), but makes it more convenient for
494 * a test program to print out the values.
495 *
496 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
497 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
498 * environment (and in fact we will never get here).
499 */
500#ifdef _ANSI_SOURCE /* Hide almost everything. */
501#define __POSIX_VISIBLE 0
502#define __XSI_VISIBLE 0
503#define __BSD_VISIBLE 0
504#define __ISO_C_VISIBLE 1990
3d28a533
JS
505#elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */
506#define __POSIX_VISIBLE 0
507#define __XSI_VISIBLE 0
508#define __BSD_VISIBLE 0
509#define __ISO_C_VISIBLE 1999
984263bc
MD
510#else /* Default environment: show everything. */
511#define __POSIX_VISIBLE 200112
512#define __XSI_VISIBLE 600
513#define __BSD_VISIBLE 1
514#define __ISO_C_VISIBLE 1999
515#endif
516#endif
517
c358eb24
JM
518/*
519 * GLOBL macro exists to preserve __start_set_* and __stop_set_* sections
520 * of kernel modules which are discarded from binutils 2.17.50+ otherwise.
521 */
522
523#define __GLOBL1(sym) __asm__(".globl " #sym)
524#define __GLOBL(sym) __GLOBL1(sym)
525
984263bc 526#endif /* !_SYS_CDEFS_H_ */