xref: /dragonfly/sys/sys/cdefs.h (revision 678e8cc6)
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 $
38  * $DragonFly: src/sys/sys/cdefs.h,v 1.20 2008/11/20 11:27:24 hasso Exp $
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 /*
53  * Macro to test if we are using a specific version of gcc or later.
54  */
55 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
56 #define __GNUC_PREREQ__(ma, mi)	\
57         (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
58 #else
59 #define __GNUC_PREREQ__(ma, mi) 0
60 #endif
61 
62 /*
63  * The __VM_CACHELINE_SIZE macro defines the common cache line alignment
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  */
74 #define	__VM_CACHELINE_SIZE	64
75 #define	__VM_CACHELINE_ALIGN(n)	\
76 			(((n) + __VM_CACHELINE_SIZE - 1) / __VM_CACHELINE_SIZE)
77 
78 /*
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  */
142 #ifdef lint
143 
144 #define __dead2
145 #define	__pure
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 
156 #if !__GNUC_PREREQ__(2, 7)
157 #define __dead2
158 #define __pure2
159 #define __unused
160 #endif
161 
162 #if __GNUC_PREREQ__(2, 7)
163 #define __dead2		__attribute__((__noreturn__))
164 #define __pure2		__attribute__((__const__))
165 #define __unused	__attribute__((__unused__))
166 #define __packed        __attribute__((__packed__))
167 #define __aligned(x)    __attribute__((__aligned__(x)))
168 #define __section(x)    __attribute__((__section__(x)))
169 #endif
170 
171 #if __GNUC_PREREQ__(2, 96)
172 #define	__pure		__attribute__((__pure__))
173 #else
174 #define	__pure		__pure2
175 #endif
176 
177 #if __GNUC_PREREQ__(3, 1)
178 #define __always_inline __attribute__((__always_inline__))
179 #define	__noinline	__attribute__((__noinline__))
180 #else
181 #define __always_inline
182 #define	__noinline
183 #endif
184 
185 #if __GNUC_PREREQ__(3, 3)
186 #define __nonnull(x)    __attribute__((__nonnull__(x)))
187 #define	__used		__attribute__((__used__))
188 #else
189 #define __nonnull(x)
190 #define __used		__unused
191 #endif
192 
193 #endif	/* LINT */
194 
195 #if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION < 199901
196 #define __func__        NULL
197 #endif
198 
199 #if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI)) || \
200     __STDC_VERSION__ >= 199901
201 #define	__LONG_LONG_SUPPORTED
202 #endif
203 
204 /*
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 /*
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
244  * software that is unaware of C99 keywords.
245  */
246 #if !__GNUC_PREREQ__(2, 95)
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).
259  *
260  * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
261  */
262 #if !__GNUC_PREREQ__(2, 7)
263 #define	__printflike(fmtarg, firstvararg)
264 #define	__scanflike(fmtarg, firstvararg)
265 #define	__printf0like(fmtarg, firstvararg)
266 #define	__format_arg(fmtarg)
267 #elif __GNUC_PREREQ__(3, 0)
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)))
275 #define	__format_arg(fmtarg) \
276 	    __attribute__((__format_arg__ (fmtarg)))
277 
278 #else
279 #define	__printflike(fmtarg, firstvararg) \
280 	    __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
281 #define	__printf0like(fmtarg, firstvararg) \
282 	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
283 #define	__scanflike(fmtarg, firstvararg) \
284 	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
285 #define	__format_arg(fmtarg) \
286 	    __attribute__((__format_arg__ (fmtarg)))
287 
288 #endif
289 
290 #if !__GNUC_PREREQ__(3, 0)
291 #define __ARRAY_ZERO	0
292 #else
293 #define __ARRAY_ZERO
294 #endif
295 
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 
306 /*
307  * A convenient constructor macro, GCC 4.3.0 added priority support to
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 /*
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__
346 #define	__cachealign	__attribute__((__aligned__(__VM_CACHELINE_SIZE)))
347 #define	__usereg     	__attribute__((__regparm__(3)))
348 #else
349 #define	__cachealign
350 #define	__usereg
351 #endif
352 
353 #ifdef __GNUC__
354 #define __strong_reference(sym,aliassym)	\
355 	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
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")
363 #endif	/* __GNUC__ */
364 
365 #if defined(__GNUC__)
366 #define	__IDSTRING(name,string)	__asm__(".ident\t\"" string "\"")
367 #endif
368 
369 #ifndef	__RCSID
370 #define	__RCSID(s)	__IDSTRING(rcsid,s)
371 #endif
372 
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 
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 
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
407  *  _POSIX_C_SOURCE == 200809		1003.1-2008
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 
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 
428 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
429 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1
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. */
435 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2
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
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
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
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
469 #define	__POSIX_VISIBLE		200112
470 #define	__ISO_C_VISIBLE		1999
471 #elif (_POSIX_C_SOURCE - 0) >= 199506
472 #define	__POSIX_VISIBLE		199506
473 #define	__ISO_C_VISIBLE		1990
474 #elif (_POSIX_C_SOURCE - 0) >= 199309
475 #define	__POSIX_VISIBLE		199309
476 #define	__ISO_C_VISIBLE		1990
477 #elif (_POSIX_C_SOURCE - 0) >= 199209
478 #define	__POSIX_VISIBLE		199209
479 #define	__ISO_C_VISIBLE		1990
480 #elif (_POSIX_C_SOURCE - 0) >= 199009
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
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
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 
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 
526 #endif /* !_SYS_CDEFS_H_ */
527