Add __pure as attribute. A __pure function can only depend on the
[dragonfly.git] / sys / sys / cdefs.h
CommitLineData
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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 $
ceb0d0c4 38 * $DragonFly: src/sys/sys/cdefs.h,v 1.15 2005/02/16 21:50:00 joerg Exp $
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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
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52/*
53 * Macro to test if we are using a specific version of gcc or later.
54 */
55#ifdef __GNUC__
56#define __GNUC_PREREQ__(ma, mi) \
57 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
58#else
59#define __GNUC_PREREQ__(ma, mi) \
60 0
61#endif
62
f754816e 63/*
d9abbdda 64 * The __VM_CACHELINE_SIZE macro defines the common cache line alignment
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65 * size that can be found across most recent and somewhat latest Intel
66 * hardware, i.e. L1 cache sizes etc.
67 *
68 * If needed, this value can be TUNED. Suitable values for this macro
69 * are 32, 64 and 128 bytes. The unit of measurement for this macro is
70 * bytes.
71 *
72 * XXX: This macro and related macros will eventually move to a MD
73 * header, but currently, we do need such a hierarchy.
74 */
d9abbdda 75#define __VM_CACHELINE_SIZE 32
f754816e 76
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77/*
78 * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
79 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
80 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
81 * mode -- there must be no spaces between its arguments, and for nested
82 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also
83 * concatenate double-quoted strings produced by the __STRING macro, but
84 * this only works with ANSI C.
85 *
86 * __XSTRING is like __STRING, but it expands any macros in its argument
87 * first. It is only available with ANSI C.
88 */
89#if defined(__STDC__) || defined(__cplusplus)
90#define __P(protos) protos /* full-blown ANSI C */
91#define __CONCAT1(x,y) x ## y
92#define __CONCAT(x,y) __CONCAT1(x,y)
93#define __STRING(x) #x /* stringify without expanding x */
94#define __XSTRING(x) __STRING(x) /* expand x, then stringify */
95
96#define __const const /* define reserved names to standard */
97#define __signed signed
98#define __volatile volatile
99#if defined(__cplusplus)
100#define __inline inline /* convert to C++ keyword */
101#else
102#ifndef __GNUC__
103#define __inline /* delete GCC keyword */
104#endif /* !__GNUC__ */
105#endif /* !__cplusplus */
106
107#else /* !(__STDC__ || __cplusplus) */
108#define __P(protos) () /* traditional C preprocessor */
109#define __CONCAT(x,y) x/**/y
110#define __STRING(x) "x"
111
112#ifndef __GNUC__
113#define __const /* delete pseudo-ANSI C keywords */
114#define __inline
115#define __signed
116#define __volatile
117/*
118 * In non-ANSI C environments, new programs will want ANSI-only C keywords
119 * deleted from the program and old programs will want them left alone.
120 * When using a compiler other than gcc, programs using the ANSI C keywords
121 * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
122 * When using "gcc -traditional", we assume that this is the intent; if
123 * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
124 */
125#ifndef NO_ANSI_KEYWORDS
126#define const /* delete ANSI C keywords */
127#define inline
128#define signed
129#define volatile
130#endif /* !NO_ANSI_KEYWORDS */
131#endif /* !__GNUC__ */
132#endif /* !(__STDC__ || __cplusplus) */
133
134/*
135 * Compiler-dependent macros to help declare dead (non-returning) and
136 * pure (no side effects) functions, and unused variables. They are
137 * null except for versions of gcc that are known to support the features
138 * properly (old versions of gcc-2 supported the dead and pure features
139 * in a different (wrong) way).
140 */
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141#ifdef lint
142
143#define __dead2
ceb0d0c4 144#define __pure
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145#define __pure2
146#define __unused
147#define __packed
148#define __aligned(x)
149#define __section(x)
150#define __always_inline
151#define __nonnull(x)
152
153#else
154
3d28a533 155#if !__GNUC_PREREQ__(2, 7)
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156#define __dead2
157#define __pure2
158#define __unused
159#endif
dc62b251 160
dc62b251 161#if __GNUC_PREREQ__(2, 7)
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162#define __dead2 __attribute__((__noreturn__))
163#define __pure2 __attribute__((__const__))
164#define __unused __attribute__((__unused__))
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165#define __packed __attribute__((__packed__))
166#define __aligned(x) __attribute__((__aligned__(x)))
167#define __section(x) __attribute__((__section__(x)))
168#endif
169
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170#if __GNUC_PREREQ__(3, 0)
171#define __pure __attribute__((__pure__))
172#else
173#define __pure __pure2
174#endif
175
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176#if __GNUC_PREREQ__(3, 1)
177#define __always_inline __attribute__((__always_inline__))
178#else
179#define __always_inline
180#endif
181
182#if __GNUC_PREREQ__(3, 3)
183#define __nonnull(x) __attribute__((__nonnull__(x)))
efb8080e 184#define __used __attribute__((__used__))
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185#else
186#define __nonnull(x)
efb8080e 187#define __used __unused
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188#endif
189
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190#endif /* LINT */
191
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192#if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION < 199901
193#define __func__ NULL
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194#endif
195
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196#if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI)) || \
197 __STDC_VERSION__ >= 199901
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198#define __LONG_LONG_SUPPORTED
199#endif
200
201/*
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202 * GCC 2.95 and later provides `__restrict' as an extention to C90 to support
203 * the C99-specific `restrict' type qualifier. We happen to use `__restrict'
204 * as a way to define the `restrict' type qualifier without disturbing older
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205 * software that is unaware of C99 keywords.
206 */
3d28a533 207#if !__GNUC_PREREQ__(2, 95)
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208#if __STDC_VERSION__ < 199901
209#define __restrict
210#else
211#define __restrict restrict
212#endif
213#endif
214
215/*
216 * Compiler-dependent macros to declare that functions take printf-like
217 * or scanf-like arguments. They are null except for versions of gcc
218 * that are known to support the features properly (old versions of gcc-2
219 * didn't permit keeping the keywords out of the application namespace).
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220 *
221 * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
984263bc 222 */
3d28a533 223#if !__GNUC_PREREQ__(2, 7)
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224#define __printflike(fmtarg, firstvararg)
225#define __scanflike(fmtarg, firstvararg)
38139e70 226#define __printf0like(fmtarg, firstvararg)
3d28a533 227#elif __GNUC_PREREQ__(3, 0)
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228#define __printflike(fmtarg, firstvararg) \
229 __attribute__((__nonnull__(fmtarg), \
230 __format__ (__printf__, fmtarg, firstvararg)))
231#define __printf0like(fmtarg, firstvararg) \
232 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
233#define __scanflike(fmtarg, firstvararg) \
234 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
235
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236#else
237#define __printflike(fmtarg, firstvararg) \
238 __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
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239#define __printf0like(fmtarg, firstvararg) \
240 __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
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241#define __scanflike(fmtarg, firstvararg) \
242 __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
243#endif
244
3d28a533 245#if !__GNUC_PREREQ__(3, 0)
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246#define __ARRAY_ZERO 0
247#else
248#define __ARRAY_ZERO
249#endif
250
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251/*
252 * Handy GCC based macros:
253 *
254 * __cachealign:
255 *
256 * The __cachealign macro can be used for cache line aligning structures
257 * of small to medium size. It aligns the particular structure or
258 * storage type to a system default cache line alignment, thus giving us
259 * a much more better cache utilization by making the hardware work at
260 * its best burst speeds.
261 *
262 * __usereg:
263 *
264 * The __usereg macro can/should be used when a function contains
265 * arguments not more than 3. It can be very useful to us due to the
266 * message-passing nature of the kernel.
267 *
268 * !!NOTE - USAGE INFORMATION!!
269 *
270 * The __cachealign macro should not be used for data structures that are
271 * as big struct proc, struct vnode, struct thread, and other structs which
272 * are as big as them; simply because it will be useless in that case.
273 *
274 * The __usereg macro should be used whenever possible, i.e., when a function
275 * does not exceed more than 3 arguments, and should not be used for vararg
276 * type functions.
277 *
278 * In other words, AVOID MISUSE OF THESE MACROS. :-)
279 */
280#ifdef __GNUC__
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281#define __cachealign __attribute__((__aligned__(__VM_CACHELINE_SIZE)))
282#define __usereg __attribute__((__regparm__(3)))
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283#else
284#define __cachealign
285#define __usereg
286#endif
287
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288#ifdef __GNUC__
289#define __strong_reference(sym,aliassym) \
290 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
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291#define __weak_reference(sym,alias) \
292 __asm__(".weak " #alias); \
293 __asm__(".equ " #alias ", " #sym)
294#define __warn_references(sym,msg) \
295 __asm__(".section .gnu.warning." #sym); \
296 __asm__(".asciz \"" msg "\""); \
297 __asm__(".previous")
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298#endif /* __GNUC__ */
299
aa8d5dcb 300#if defined(__GNUC__)
984263bc 301#define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
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302#endif
303
304#ifndef __RCSID
305#define __RCSID(s) __IDSTRING(rcsid,s)
306#endif
307
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308#ifndef __RCSID_SOURCE
309#define __RCSID_SOURCE(s) __IDSTRING(rcsid_source,s)
310#endif
311
312#ifndef __COPYRIGHT
313#define __COPYRIGHT(s) __IDSTRING(copyright,s)
314#endif
315
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316#ifndef __DECONST
317#define __DECONST(type, var) ((type)(uintptr_t)(const void *)(var))
318#endif
319
320#ifndef __DEVOLATILE
321#define __DEVOLATILE(type, var) ((type)(uintptr_t)(volatile void *)(var))
322#endif
323
324#ifndef __DEQUALIFY
325#define __DEQUALIFY(type, var) ((type)(uintptr_t)(const volatile void *)(var))
326#endif
327
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328/*-
329 * The following definitions are an extension of the behavior originally
330 * implemented in <sys/_posix.h>, but with a different level of granularity.
331 * POSIX.1 requires that the macros we test be defined before any standard
332 * header file is included.
333 *
334 * Here's a quick run-down of the versions:
335 * defined(_POSIX_SOURCE) 1003.1-1988
336 * _POSIX_C_SOURCE == 1 1003.1-1990
337 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
338 * _POSIX_C_SOURCE == 199309 1003.1b-1993
339 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
340 * and the omnibus ISO/IEC 9945-1: 1996
341 * _POSIX_C_SOURCE == 200112 1003.1-2001
342 *
343 * In addition, the X/Open Portability Guide, which is now the Single UNIX
344 * Specification, defines a feature-test macro which indicates the version of
345 * that specification, and which subsumes _POSIX_C_SOURCE.
346 *
347 * Our macros begin with two underscores to avoid namespace screwage.
348 */
349
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350#if defined(_POSIX_C_SOURCE)
351
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352/* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
353#if _POSIX_C_SOURCE == 1
354#undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
355#define _POSIX_C_SOURCE 199009
356#endif
357
358/* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
359#if _POSIX_C_SOURCE == 2
360#undef _POSIX_C_SOURCE
361#define _POSIX_C_SOURCE 199209
362#endif
363
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364#endif /* _POSIX_C_SOURCE */
365
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366/* Deal with various X/Open Portability Guides and Single UNIX Spec. */
367#ifdef _XOPEN_SOURCE
368#if _XOPEN_SOURCE - 0 >= 600
369#define __XSI_VISIBLE 600
370#undef _POSIX_C_SOURCE
371#define _POSIX_C_SOURCE 200112
372#elif _XOPEN_SOURCE - 0 >= 500
373#define __XSI_VISIBLE 500
374#undef _POSIX_C_SOURCE
375#define _POSIX_C_SOURCE 199506
376#endif
377#endif
378
379/*
380 * Deal with all versions of POSIX. The ordering relative to the tests above is
381 * important.
382 */
383#if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
384#define _POSIX_C_SOURCE 198808
385#endif
386#ifdef _POSIX_C_SOURCE
387#if _POSIX_C_SOURCE >= 200112
388#define __POSIX_VISIBLE 200112
389#define __ISO_C_VISIBLE 1999
390#elif _POSIX_C_SOURCE >= 199506
391#define __POSIX_VISIBLE 199506
392#define __ISO_C_VISIBLE 1990
393#elif _POSIX_C_SOURCE >= 199309
394#define __POSIX_VISIBLE 199309
395#define __ISO_C_VISIBLE 1990
396#elif _POSIX_C_SOURCE >= 199209
397#define __POSIX_VISIBLE 199209
398#define __ISO_C_VISIBLE 1990
399#elif _POSIX_C_SOURCE >= 199009
400#define __POSIX_VISIBLE 199009
401#define __ISO_C_VISIBLE 1990
402#else
403#define __POSIX_VISIBLE 198808
404#define __ISO_C_VISIBLE 0
405#endif /* _POSIX_C_SOURCE */
406#else
407/*-
408 * Deal with _ANSI_SOURCE:
409 * If it is defined, and no other compilation environment is explicitly
410 * requested, then define our internal feature-test macros to zero. This
411 * makes no difference to the preprocessor (undefined symbols in preprocessing
412 * expressions are defined to have value zero), but makes it more convenient for
413 * a test program to print out the values.
414 *
415 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
416 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
417 * environment (and in fact we will never get here).
418 */
419#ifdef _ANSI_SOURCE /* Hide almost everything. */
420#define __POSIX_VISIBLE 0
421#define __XSI_VISIBLE 0
422#define __BSD_VISIBLE 0
423#define __ISO_C_VISIBLE 1990
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424#elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */
425#define __POSIX_VISIBLE 0
426#define __XSI_VISIBLE 0
427#define __BSD_VISIBLE 0
428#define __ISO_C_VISIBLE 1999
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429#else /* Default environment: show everything. */
430#define __POSIX_VISIBLE 200112
431#define __XSI_VISIBLE 600
432#define __BSD_VISIBLE 1
433#define __ISO_C_VISIBLE 1999
434#endif
435#endif
436
437#endif /* !_SYS_CDEFS_H_ */