xref: /dragonfly/sys/sys/cdefs.h (revision bd611623)
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  */
39 
40 #ifndef	_SYS_CDEFS_H_
41 #define	_SYS_CDEFS_H_
42 
43 /*
44  * Macro to test if we are using a specific version of gcc or later.
45  */
46 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
47 #define __GNUC_PREREQ__(ma, mi)	\
48         (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
49 #else
50 #define __GNUC_PREREQ__(ma, mi) 0
51 #endif
52 
53 #if defined(__cplusplus)
54 #if __GNUC_PREREQ__(4, 0)
55 #define	__BEGIN_DECLS	_Pragma("GCC visibility push(default)") extern "C" {
56 #define	__END_DECLS	} _Pragma("GCC visibility pop")
57 #else
58 #define	__BEGIN_DECLS	extern "C" {
59 #define	__END_DECLS	}
60 #endif
61 #else
62 #define	__BEGIN_DECLS
63 #define	__END_DECLS
64 #endif
65 
66 /*
67  * The __VM_CACHELINE_SIZE macro defines the common cache line alignment
68  * size that can be found across most recent and somewhat latest Intel
69  * hardware, i.e. L1 cache sizes etc.
70  *
71  * If needed, this value can be TUNED.  Suitable values for this macro
72  * are 32, 64 and 128 bytes.  The unit of measurement for this macro is
73  * bytes.
74  *
75  * XXX: This macro and related macros will eventually move to a MD
76  * header, but currently, we do need such a hierarchy.
77  */
78 #define	__VM_CACHELINE_SIZE	64
79 #define __VM_CACHELINE_MASK	(__VM_CACHELINE_SIZE - 1)
80 #define	__VM_CACHELINE_ALIGN(n)	\
81 	(((n) + __VM_CACHELINE_MASK) & ~__VM_CACHELINE_MASK)
82 
83 /*
84  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
85  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
86  * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
87  * mode -- there must be no spaces between its arguments, and for nested
88  * __CONCAT's, all the __CONCAT's must be at the left.  __CONCAT can also
89  * concatenate double-quoted strings produced by the __STRING macro, but
90  * this only works with ANSI C.
91  *
92  * __XSTRING is like __STRING, but it expands any macros in its argument
93  * first.  It is only available with ANSI C.
94  */
95 #if defined(__STDC__) || defined(__cplusplus)
96 #define	__P(protos)	protos		/* full-blown ANSI C */
97 #define	__CONCAT1(x,y)	x ## y
98 #define	__CONCAT(x,y)	__CONCAT1(x,y)
99 #define	__STRING(x)	#x		/* stringify without expanding x */
100 #define	__XSTRING(x)	__STRING(x)	/* expand x, then stringify */
101 
102 #define	__const		const		/* define reserved names to standard */
103 #define	__signed	signed
104 #define	__volatile	volatile
105 #if defined(__cplusplus)
106 #define	__inline	inline		/* convert to C++ keyword */
107 #else
108 #ifndef __GNUC__
109 #define	__inline			/* delete GCC keyword */
110 #endif /* !__GNUC__ */
111 #endif /* !__cplusplus */
112 
113 #else	/* !(__STDC__ || __cplusplus) */
114 #define	__P(protos)	()		/* traditional C preprocessor */
115 #define	__CONCAT(x,y)	x/**/y
116 #define	__STRING(x)	"x"
117 
118 #ifndef __GNUC__
119 #define	__const				/* delete pseudo-ANSI C keywords */
120 #define	__inline
121 #define	__signed
122 #define	__volatile
123 /*
124  * In non-ANSI C environments, new programs will want ANSI-only C keywords
125  * deleted from the program and old programs will want them left alone.
126  * When using a compiler other than gcc, programs using the ANSI C keywords
127  * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
128  * When using "gcc -traditional", we assume that this is the intent; if
129  * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
130  */
131 #ifndef	NO_ANSI_KEYWORDS
132 #define	const				/* delete ANSI C keywords */
133 #define	inline
134 #define	signed
135 #define	volatile
136 #endif	/* !NO_ANSI_KEYWORDS */
137 #endif	/* !__GNUC__ */
138 #endif	/* !(__STDC__ || __cplusplus) */
139 
140 /*
141  * Compiler-dependent macros to help declare dead (non-returning) and
142  * pure (no side effects) functions, and unused variables.  They are
143  * null except for versions of gcc that are known to support the features
144  * properly (old versions of gcc-2 supported the dead and pure features
145  * in a different (wrong) way).
146  */
147 #ifdef lint
148 
149 #define __dead2
150 #define	__pure
151 #define __pure2
152 #define __unused
153 #define __packed
154 #define __aligned(x)
155 #define __section(x)
156 #define __always_inline
157 #define __nonnull(x)
158 
159 #else
160 
161 #if !__GNUC_PREREQ__(2, 7)
162 #define __dead2
163 #define __pure2
164 #define __unused
165 #endif
166 
167 #if __GNUC_PREREQ__(2, 7)
168 #define __dead2		__attribute__((__noreturn__))
169 #define __pure2		__attribute__((__const__))
170 #define __unused	__attribute__((__unused__))
171 #define __packed        __attribute__((__packed__))
172 #define __aligned(x)    __attribute__((__aligned__(x)))
173 #define __section(x)    __attribute__((__section__(x)))
174 #endif
175 
176 #if __GNUC_PREREQ__(2, 96)
177 #define	__pure		__attribute__((__pure__))
178 #else
179 #define	__pure		__pure2
180 #endif
181 
182 #if __GNUC_PREREQ__(3, 1)
183 #define __always_inline __attribute__((__always_inline__))
184 #define	__noinline	__attribute__((__noinline__))
185 #else
186 #define __always_inline
187 #define	__noinline
188 #endif
189 
190 #if __GNUC_PREREQ__(3, 3)
191 #define __nonnull(x)    __attribute__((__nonnull__(x)))
192 #define	__used		__attribute__((__used__))
193 #else
194 #define __nonnull(x)
195 #define __used		__unused
196 #endif
197 
198 #endif	/* LINT */
199 
200 #if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION < 199901
201 #define __func__        NULL
202 #endif
203 
204 #if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI)) || \
205     __STDC_VERSION__ >= 199901
206 #define	__LONG_LONG_SUPPORTED
207 #endif
208 
209 /*
210  * GNU C version 2.96 adds explicit branch prediction so that
211  * the CPU back-end can hint the processor and also so that
212  * code blocks can be reordered such that the predicted path
213  * sees a more linear flow, thus improving cache behavior, etc.
214  *
215  * The following two macros provide us with a way to utilize this
216  * compiler feature.  Use __predict_true() if you expect the expression
217  * to evaluate to true, and __predict_false() if you expect the
218  * expression to evaluate to false.
219  *
220  * A few notes about usage:
221  *
222  *	* Generally, __predict_false() error condition checks (unless
223  *	  you have some _strong_ reason to do otherwise, in which case
224  *	  document it), and/or __predict_true() `no-error' condition
225  *	  checks, assuming you want to optimize for the no-error case.
226  *
227  *	* Other than that, if you don't know the likelihood of a test
228  *	  succeeding from empirical or other `hard' evidence, don't
229  *	  make predictions.
230  *
231  *	* These are meant to be used in places that are run `a lot'.
232  *	  It is wasteful to make predictions in code that is run
233  *	  seldomly (e.g. at subsystem initialization time) as the
234  *	  basic block reordering that this affects can often generate
235  *	  larger code.
236  */
237 #if __GNUC_PREREQ__(2, 96)
238 #define __predict_true(exp)     __builtin_expect((exp), 1)
239 #define __predict_false(exp)    __builtin_expect((exp), 0)
240 #else
241 #define __predict_true(exp)     (exp)
242 #define __predict_false(exp)    (exp)
243 #endif
244 
245 /*
246  * GCC 2.95 and later provides `__restrict' as an extention to C90 to support
247  * the C99-specific `restrict' type qualifier.  We happen to use `__restrict'
248  * as a way to define the `restrict' type qualifier without disturbing older
249  * software that is unaware of C99 keywords.
250  */
251 #if !__GNUC_PREREQ__(2, 95)
252 #if __STDC_VERSION__ < 199901
253 #define	__restrict
254 #else
255 #define	__restrict	restrict
256 #endif
257 #endif
258 
259 /*
260  * Compiler-dependent macros to declare that functions take printf-like
261  * or scanf-like arguments.  They are null except for versions of gcc
262  * that are known to support the features properly (old versions of gcc-2
263  * didn't permit keeping the keywords out of the application namespace).
264  *
265  * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
266  */
267 #if !__GNUC_PREREQ__(2, 7)
268 #define	__printflike(fmtarg, firstvararg)
269 #define	__scanflike(fmtarg, firstvararg)
270 #define	__printf0like(fmtarg, firstvararg)
271 #define	__format_arg(fmtarg)
272 #elif __GNUC_PREREQ__(3, 0)
273 #define	__printflike(fmtarg, firstvararg) \
274             __attribute__((__nonnull__(fmtarg), \
275 			  __format__ (__printf__, fmtarg, firstvararg)))
276 #define	__printf0like(fmtarg, firstvararg) \
277             __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
278 #define	__scanflike(fmtarg, firstvararg) \
279 	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
280 #define	__format_arg(fmtarg) \
281 	    __attribute__((__format_arg__ (fmtarg)))
282 
283 #else
284 #define	__printflike(fmtarg, firstvararg) \
285 	    __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
286 #define	__printf0like(fmtarg, firstvararg) \
287 	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
288 #define	__scanflike(fmtarg, firstvararg) \
289 	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
290 #define	__format_arg(fmtarg) \
291 	    __attribute__((__format_arg__ (fmtarg)))
292 
293 #endif
294 
295 #if !__GNUC_PREREQ__(3, 0)
296 #define __ARRAY_ZERO	0
297 #else
298 #define __ARRAY_ZERO
299 #endif
300 
301 #if __GNUC_PREREQ__(4, 0)
302 #define __dso_public	__attribute__((__visibility__("default")))
303 #define __dso_hidden	__attribute__((__visibility__("hidden")))
304 #else
305 #define __dso_public
306 #define __dso_hidden
307 #endif
308 
309 /*
310  * A convenient constructor macro, GCC 4.3.0 added priority support to
311  * constructors, provide a compatible interface for both.
312  */
313 #if __GNUC_PREREQ__(4, 3)
314 #define	__constructor(prio) __attribute__((constructor(prio)))
315 #else
316 #define	__constructor(prio) __attribute__((constructor))
317 #endif
318 
319 /*
320  * Handy GCC based macros:
321  *
322  * 	__cachealign:
323  *
324  * 	The __cachealign macro can be used for cache line aligning structures
325  * 	of small to medium size.  It aligns the particular structure or
326  * 	storage type to a system default cache line alignment, thus giving us
327  * 	a much more better cache utilization by making the hardware work at
328  * 	its best burst speeds.
329  *
330  * 	__usereg:
331  *
332  * 	The __usereg macro can/should be used when a function contains
333  * 	arguments not more than 3.  It can be very useful to us due to the
334  * 	message-passing nature of the kernel.
335  *
336  * !!NOTE - USAGE INFORMATION!!
337  *
338  * The __cachealign macro should not be used for data structures that are
339  * as big struct proc, struct vnode, struct thread, and other structs which
340  * are as big as them; simply because it will be useless in that case.
341  *
342  * The __usereg macro should be used whenever possible, i.e., when a function
343  * does not exceed more than 3 arguments, and should not be used for vararg
344  * type functions.
345  *
346  * In other words, AVOID MISUSE OF THESE MACROS. :-)
347  */
348 #ifdef __GNUC__
349 #define	__cachealign	__attribute__((__aligned__(__VM_CACHELINE_SIZE)))
350 #define	__usereg     	__attribute__((__regparm__(3)))
351 #else
352 #define	__cachealign
353 #define	__usereg
354 #endif
355 
356 #ifdef __GNUC__
357 #define __strong_reference(sym,aliassym)	\
358 	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
359 #define	__weak_reference(sym,alias)	\
360 	__asm__(".weak " #alias);	\
361 	__asm__(".equ "  #alias ", " #sym)
362 #define	__warn_references(sym,msg)	\
363 	__asm__(".section .gnu.warning." #sym);	\
364 	__asm__(".asciz \"" msg "\"");	\
365 	__asm__(".previous")
366 #endif	/* __GNUC__ */
367 
368 #if defined(__GNUC__)
369 #define	__IDSTRING(name,string)	__asm__(".ident\t\"" string "\"")
370 #endif
371 
372 #ifndef	__RCSID
373 #define	__RCSID(s)	__IDSTRING(rcsid,s)
374 #endif
375 
376 #ifndef	__RCSID_SOURCE
377 #define	__RCSID_SOURCE(s) __IDSTRING(rcsid_source,s)
378 #endif
379 
380 #ifndef	__COPYRIGHT
381 #define	__COPYRIGHT(s)	__IDSTRING(copyright,s)
382 #endif
383 
384 #ifndef	__DECONST
385 #define	__DECONST(type, var)	((type)(uintptr_t)(const void *)(var))
386 #endif
387 
388 #ifndef	__DEVOLATILE
389 #define	__DEVOLATILE(type, var)	((type)(uintptr_t)(volatile void *)(var))
390 #endif
391 
392 #ifndef	__DEQUALIFY
393 #define	__DEQUALIFY(type, var)	((type)(uintptr_t)(const volatile void *)(var))
394 #endif
395 
396 /*-
397  * The following definitions are an extension of the behavior originally
398  * implemented in <sys/_posix.h>, but with a different level of granularity.
399  * POSIX.1 requires that the macros we test be defined before any standard
400  * header file is included.
401  *
402  * Here's a quick run-down of the versions:
403  *  defined(_POSIX_SOURCE)		1003.1-1988
404  *  _POSIX_C_SOURCE == 1		1003.1-1990
405  *  _POSIX_C_SOURCE == 2		1003.2-1992 C Language Binding Option
406  *  _POSIX_C_SOURCE == 199309		1003.1b-1993
407  *  _POSIX_C_SOURCE == 199506		1003.1c-1995, 1003.1i-1995,
408  *					and the omnibus ISO/IEC 9945-1: 1996
409  *  _POSIX_C_SOURCE == 200112		1003.1-2001
410  *  _POSIX_C_SOURCE == 200809		1003.1-2008
411  *
412  * In addition, the X/Open Portability Guide, which is now the Single UNIX
413  * Specification, defines a feature-test macro which indicates the version of
414  * that specification, and which subsumes _POSIX_C_SOURCE.
415  *
416  * Our macros begin with two underscores to avoid namespace screwage.
417  */
418 
419 /*
420  * If no special macro was specified, make the DragonFly extensions
421  * available. Also make them available when requested so.
422  */
423 #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE) && \
424     !defined(_ANSI_SOURCE) && !defined(_C99_SOURCE)) || \
425     defined(_DRAGONFLY_SOURCE) || defined(_NETBSD_SOURCE)
426 #define __DF_VISIBLE	1
427 #else
428 #define __DF_VISIBLE	0
429 #endif
430 
431 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
432 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1
433 #undef _POSIX_C_SOURCE		/* Probably illegal, but beyond caring now. */
434 #define	_POSIX_C_SOURCE		199009
435 #endif
436 
437 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
438 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2
439 #undef _POSIX_C_SOURCE
440 #define	_POSIX_C_SOURCE		199209
441 #endif
442 
443 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
444 #ifdef _XOPEN_SOURCE
445 #if _XOPEN_SOURCE - 0 >= 700
446 #define	__XSI_VISIBLE		700
447 #undef _POSIX_C_SOURCE
448 #define	_POSIX_C_SOURCE		200809
449 #elif _XOPEN_SOURCE - 0 >= 600
450 #define	__XSI_VISIBLE		600
451 #undef _POSIX_C_SOURCE
452 #define	_POSIX_C_SOURCE		200112
453 #elif _XOPEN_SOURCE - 0 >= 500
454 #define	__XSI_VISIBLE		500
455 #undef _POSIX_C_SOURCE
456 #define	_POSIX_C_SOURCE		199506
457 #endif
458 #endif
459 
460 /*
461  * Deal with all versions of POSIX.  The ordering relative to the tests above is
462  * important.
463  */
464 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
465 #define	_POSIX_C_SOURCE		198808
466 #endif
467 #ifdef _POSIX_C_SOURCE
468 #if (_POSIX_C_SOURCE - 0) >= 200809
469 #define	__POSIX_VISIBLE		200809
470 #define	__ISO_C_VISIBLE		1999
471 #elif (_POSIX_C_SOURCE - 0) >= 200112
472 #define	__POSIX_VISIBLE		200112
473 #define	__ISO_C_VISIBLE		1999
474 #elif (_POSIX_C_SOURCE - 0) >= 199506
475 #define	__POSIX_VISIBLE		199506
476 #define	__ISO_C_VISIBLE		1990
477 #elif (_POSIX_C_SOURCE - 0) >= 199309
478 #define	__POSIX_VISIBLE		199309
479 #define	__ISO_C_VISIBLE		1990
480 #elif (_POSIX_C_SOURCE - 0) >= 199209
481 #define	__POSIX_VISIBLE		199209
482 #define	__ISO_C_VISIBLE		1990
483 #elif (_POSIX_C_SOURCE - 0) >= 199009
484 #define	__POSIX_VISIBLE		199009
485 #define	__ISO_C_VISIBLE		1990
486 #else
487 #define	__POSIX_VISIBLE		198808
488 #define	__ISO_C_VISIBLE		0
489 #endif /* _POSIX_C_SOURCE */
490 #else
491 /*-
492  * Deal with _ANSI_SOURCE:
493  * If it is defined, and no other compilation environment is explicitly
494  * requested, then define our internal feature-test macros to zero.  This
495  * makes no difference to the preprocessor (undefined symbols in preprocessing
496  * expressions are defined to have value zero), but makes it more convenient for
497  * a test program to print out the values.
498  *
499  * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
500  * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
501  * environment (and in fact we will never get here).
502  */
503 #ifdef _ANSI_SOURCE		/* Hide almost everything. */
504 #define	__POSIX_VISIBLE		0
505 #define	__XSI_VISIBLE		0
506 #define	__BSD_VISIBLE		0
507 #define	__ISO_C_VISIBLE		1990
508 #elif defined(_C99_SOURCE)	/* Localism to specify strict C99 env. */
509 #define	__POSIX_VISIBLE		0
510 #define	__XSI_VISIBLE		0
511 #define	__BSD_VISIBLE		0
512 #define	__ISO_C_VISIBLE		1999
513 #else				/* Default environment: show everything. */
514 #define	__POSIX_VISIBLE		200112
515 #define	__XSI_VISIBLE		600
516 #define	__BSD_VISIBLE		1
517 #define	__ISO_C_VISIBLE		1999
518 #endif
519 #endif
520 
521 /*
522  * GLOBL macro exists to preserve __start_set_* and __stop_set_* sections
523  * of kernel modules which are discarded from binutils 2.17.50+ otherwise.
524  */
525 
526 #define	__GLOBL1(sym)	__asm__(".globl " #sym)
527 #define	__GLOBL(sym)	__GLOBL1(sym)
528 
529 #endif /* !_SYS_CDEFS_H_ */
530