Annotation of sys/sys/cdefs.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: cdefs.h,v 1.25 2007/06/26 10:30:05 tom Exp $ */
! 2: /* $NetBSD: cdefs.h,v 1.16 1996/04/03 20:46:39 christos Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1991, 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: *
! 8: * This code is derived from software contributed to Berkeley by
! 9: * Berkeley Software Design, Inc.
! 10: *
! 11: * Redistribution and use in source and binary forms, with or without
! 12: * modification, are permitted provided that the following conditions
! 13: * are met:
! 14: * 1. Redistributions of source code must retain the above copyright
! 15: * notice, this list of conditions and the following disclaimer.
! 16: * 2. Redistributions in binary form must reproduce the above copyright
! 17: * notice, this list of conditions and the following disclaimer in the
! 18: * documentation and/or other materials provided with the distribution.
! 19: * 3. Neither the name of the University nor the names of its contributors
! 20: * may be used to endorse or promote products derived from this software
! 21: * without specific prior written permission.
! 22: *
! 23: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 24: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 25: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 26: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 27: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 28: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 29: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 30: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 31: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 32: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 33: * SUCH DAMAGE.
! 34: *
! 35: * @(#)cdefs.h 8.7 (Berkeley) 1/21/94
! 36: */
! 37:
! 38: #ifndef _SYS_CDEFS_H_
! 39: #define _SYS_CDEFS_H_
! 40:
! 41: #include <machine/cdefs.h>
! 42:
! 43: #if defined(__cplusplus)
! 44: #define __BEGIN_DECLS extern "C" {
! 45: #define __END_DECLS }
! 46: #else
! 47: #define __BEGIN_DECLS
! 48: #define __END_DECLS
! 49: #endif
! 50:
! 51: /*
! 52: * Macro to test if we're using a specific version of gcc or later.
! 53: */
! 54: #ifdef __GNUC__
! 55: #define __GNUC_PREREQ__(ma, mi) \
! 56: ((__GNUC__ > (ma)) || (__GNUC__ == (ma) && __GNUC_MINOR__ >= (mi)))
! 57: #else
! 58: #define __GNUC_PREREQ__(ma, mi) 0
! 59: #endif
! 60:
! 61: /*
! 62: * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
! 63: * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
! 64: * The __CONCAT macro is a bit tricky -- make sure you don't put spaces
! 65: * in between its arguments. __CONCAT can also concatenate double-quoted
! 66: * strings produced by the __STRING macro, but this only works with ANSI C.
! 67: */
! 68: #if defined(__STDC__) || defined(__cplusplus)
! 69: #define __P(protos) protos /* full-blown ANSI C */
! 70: #define __CONCAT(x,y) x ## y
! 71: #define __STRING(x) #x
! 72:
! 73: #define __const const /* define reserved names to standard */
! 74: #define __signed signed
! 75: #define __volatile volatile
! 76: #if defined(__cplusplus)
! 77: #define __inline inline /* convert to C++ keyword */
! 78: #else
! 79: #if !defined(__GNUC__) && !defined(lint)
! 80: #define __inline /* delete GCC keyword */
! 81: #endif /* !__GNUC__ && !lint */
! 82: #endif /* !__cplusplus */
! 83:
! 84: #else /* !(__STDC__ || __cplusplus) */
! 85: #define __P(protos) () /* traditional C preprocessor */
! 86: #define __CONCAT(x,y) x/**/y
! 87: #define __STRING(x) "x"
! 88:
! 89: #if !defined(__GNUC__) && !defined(lint)
! 90: #define __const /* delete pseudo-ANSI C keywords */
! 91: #define __inline
! 92: #define __signed
! 93: #define __volatile
! 94: #endif /* !__GNUC__ && !lint */
! 95:
! 96: /*
! 97: * In non-ANSI C environments, new programs will want ANSI-only C keywords
! 98: * deleted from the program and old programs will want them left alone.
! 99: * Programs using the ANSI C keywords const, inline etc. as normal
! 100: * identifiers should define -DNO_ANSI_KEYWORDS.
! 101: */
! 102: #ifndef NO_ANSI_KEYWORDS
! 103: #define const __const /* convert ANSI C keywords */
! 104: #define inline __inline
! 105: #define signed __signed
! 106: #define volatile __volatile
! 107: #endif /* !NO_ANSI_KEYWORDS */
! 108: #endif /* !(__STDC__ || __cplusplus) */
! 109:
! 110: /*
! 111: * GCC1 and some versions of GCC2 declare dead (non-returning) and
! 112: * pure (no side effects) functions using "volatile" and "const";
! 113: * unfortunately, these then cause warnings under "-ansi -pedantic".
! 114: * GCC >= 2.5 uses the __attribute__((attrs)) style. All of these
! 115: * work for GNU C++ (modulo a slight glitch in the C++ grammar in
! 116: * the distribution version of 2.5.5).
! 117: */
! 118:
! 119: #if !__GNUC_PREREQ__(2, 5)
! 120: #define __attribute__(x) /* delete __attribute__ if non-gcc or gcc1 */
! 121: #if defined(__GNUC__) && !defined(__STRICT_ANSI__)
! 122: #define __dead __volatile
! 123: #define __pure __const
! 124: #elif defined(lint)
! 125: #define __dead /* NORETURN */
! 126: #endif
! 127: #elif !defined(__STRICT_ANSI__)
! 128: #define __dead __attribute__((__noreturn__))
! 129: #define __pure __attribute__((__const__))
! 130: #endif
! 131:
! 132: /*
! 133: * GNU C version 2.96 adds explicit branch prediction so that
! 134: * the CPU back-end can hint the processor and also so that
! 135: * code blocks can be reordered such that the predicted path
! 136: * sees a more linear flow, thus improving cache behavior, etc.
! 137: *
! 138: * The following two macros provide us with a way to utilize this
! 139: * compiler feature. Use __predict_true() if you expect the expression
! 140: * to evaluate to true, and __predict_false() if you expect the
! 141: * expression to evaluate to false.
! 142: *
! 143: * A few notes about usage:
! 144: *
! 145: * * Generally, __predict_false() error condition checks (unless
! 146: * you have some _strong_ reason to do otherwise, in which case
! 147: * document it), and/or __predict_true() `no-error' condition
! 148: * checks, assuming you want to optimize for the no-error case.
! 149: *
! 150: * * Other than that, if you don't know the likelihood of a test
! 151: * succeeding from empirical or other `hard' evidence, don't
! 152: * make predictions.
! 153: *
! 154: * * These are meant to be used in places that are run `a lot'.
! 155: * It is wasteful to make predictions in code that is run
! 156: * seldomly (e.g. at subsystem initialization time) as the
! 157: * basic block reordering that this affects can often generate
! 158: * larger code.
! 159: */
! 160: #if __GNUC_PREREQ__(2, 96)
! 161: #define __predict_true(exp) __builtin_expect(((exp) != 0), 1)
! 162: #define __predict_false(exp) __builtin_expect(((exp) != 0), 0)
! 163: #else
! 164: #define __predict_true(exp) ((exp) != 0)
! 165: #define __predict_false(exp) ((exp) != 0)
! 166: #endif
! 167:
! 168: /* Delete pseudo-keywords wherever they are not available or needed. */
! 169: #ifndef __dead
! 170: #define __dead
! 171: #define __pure
! 172: #endif
! 173:
! 174: #if __GNUC_PREREQ__(2, 7)
! 175: #define __packed __attribute__((__packed__))
! 176: #elif defined(lint)
! 177: #define __packed
! 178: #endif
! 179:
! 180: #if !__GNUC_PREREQ__(2, 8)
! 181: #define __extension__
! 182: #endif
! 183:
! 184: #if __GNUC_PREREQ__(2, 8)
! 185: #define __statement(x) __extension__(x)
! 186: #elif defined(lint)
! 187: #define __statement(x) (0)
! 188: #else
! 189: #define __statement(x) (x)
! 190: #endif
! 191:
! 192: #if __GNUC_PREREQ__(3, 0)
! 193: #define __malloc __attribute__((__malloc__))
! 194: #else
! 195: #define __malloc
! 196: #endif
! 197:
! 198: /*
! 199: * "The nice thing about standards is that there are so many to choose from."
! 200: * There are a number of "feature test macros" specified by (different)
! 201: * standards that determine which interfaces and types the header files
! 202: * should expose.
! 203: *
! 204: * Because of inconsistencies in these macros, we define our own
! 205: * set in the private name space that end in _VISIBLE. These are
! 206: * always defined and so headers can test their values easily.
! 207: * Things can get tricky when multiple feature macros are defined.
! 208: * We try to take the union of all the features requested.
! 209: *
! 210: * The following macros are guaranteed to have a value after cdefs.h
! 211: * has been included:
! 212: * __POSIX_VISIBLE
! 213: * __XPG_VISIBLE
! 214: * __ISO_C_VISIBLE
! 215: * __BSD_VISIBLE
! 216: */
! 217:
! 218: /*
! 219: * X/Open Portability Guides and Single Unix Specifications.
! 220: * _XOPEN_SOURCE XPG3
! 221: * _XOPEN_SOURCE && _XOPEN_VERSION = 4 XPG4
! 222: * _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED = 1 XPG4v2
! 223: * _XOPEN_SOURCE == 500 XPG5
! 224: * _XOPEN_SOURCE == 520 XPG5v2
! 225: * _XOPEN_SOURCE == 600 POSIX 1003.1-2001 with XSI
! 226: *
! 227: * The XPG spec implies a specific value for _POSIX_C_SOURCE.
! 228: */
! 229: #ifdef _XOPEN_SOURCE
! 230: # if (_XOPEN_SOURCE - 0 >= 600)
! 231: # define __XPG_VISIBLE 600
! 232: # undef _POSIX_C_SOURCE
! 233: # define _POSIX_C_SOURCE 200112L
! 234: # elif (_XOPEN_SOURCE - 0 >= 520)
! 235: # define __XPG_VISIBLE 520
! 236: # undef _POSIX_C_SOURCE
! 237: # define _POSIX_C_SOURCE 199506L
! 238: # elif (_XOPEN_SOURCE - 0 >= 500)
! 239: # define __XPG_VISIBLE 500
! 240: # undef _POSIX_C_SOURCE
! 241: # define _POSIX_C_SOURCE 199506L
! 242: # elif (_XOPEN_SOURCE_EXTENDED - 0 == 1)
! 243: # define __XPG_VISIBLE 420
! 244: # elif (_XOPEN_VERSION - 0 >= 4)
! 245: # define __XPG_VISIBLE 400
! 246: # else
! 247: # define __XPG_VISIBLE 300
! 248: # endif
! 249: #endif
! 250:
! 251: /*
! 252: * POSIX macros, these checks must follow the XOPEN ones above.
! 253: *
! 254: * _POSIX_SOURCE == 1 1003.1-1988 (superseded by _POSIX_C_SOURCE)
! 255: * _POSIX_C_SOURCE == 1 1003.1-1990
! 256: * _POSIX_C_SOURCE == 2 1003.2-1992
! 257: * _POSIX_C_SOURCE == 199309L 1003.1b-1993
! 258: * _POSIX_C_SOURCE == 199506L 1003.1c-1995, 1003.1i-1995,
! 259: * and the omnibus ISO/IEC 9945-1:1996
! 260: * _POSIX_C_SOURCE == 200112L 1003.1-2001
! 261: *
! 262: * The POSIX spec implies a specific value for __ISO_C_VISIBLE, though
! 263: * this may be overridden by the _ISOC99_SOURCE macro later.
! 264: */
! 265: #ifdef _POSIX_C_SOURCE
! 266: # if (_POSIX_C_SOURCE - 0 >= 200112)
! 267: # define __POSIX_VISIBLE 200112
! 268: # define __ISO_C_VISIBLE 1999
! 269: # elif (_POSIX_C_SOURCE - 0 >= 199506)
! 270: # define __POSIX_VISIBLE 199506
! 271: # define __ISO_C_VISIBLE 1990
! 272: # elif (_POSIX_C_SOURCE - 0 >= 199309)
! 273: # define __POSIX_VISIBLE 199309
! 274: # define __ISO_C_VISIBLE 1990
! 275: # elif (_POSIX_C_SOURCE - 0 >= 2)
! 276: # define __POSIX_VISIBLE 199209
! 277: # define __ISO_C_VISIBLE 1990
! 278: # else
! 279: # define __POSIX_VISIBLE 199009
! 280: # define __ISO_C_VISIBLE 1990
! 281: # endif
! 282: #elif defined(_POSIX_SOURCE)
! 283: # define __POSIX_VISIBLE 198808
! 284: # define __ISO_C_VISIBLE 0
! 285: #endif
! 286:
! 287: /*
! 288: * _ANSI_SOURCE means to expose ANSI C89 interfaces only.
! 289: * If the user defines it in addition to one of the POSIX or XOPEN
! 290: * macros, assume the POSIX/XOPEN macro(s) should take precedence.
! 291: */
! 292: #if defined(_ANSI_SOURCE) && !defined(__POSIX_VISIBLE) && \
! 293: !defined(__XPG_VISIBLE)
! 294: # define __POSIX_VISIBLE 0
! 295: # define __XPG_VISIBLE 0
! 296: # define __ISO_C_VISIBLE 1990
! 297: #endif
! 298:
! 299: /*
! 300: * _ISOC99_SOURCE and __STDC_VERSION__ override any of the other macros since
! 301: * they are non-exclusive.
! 302: */
! 303: #if defined(_ISOC99_SOURCE) || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901)
! 304: # undef __ISO_C_VISIBLE
! 305: # define __ISO_C_VISIBLE 1999
! 306: #endif
! 307:
! 308: /*
! 309: * Finally deal with BSD-specific interfaces that are not covered
! 310: * by any standards. We expose these when one of the POSIX or XPG
! 311: * macros is defined or if the user explicitly asks for them.
! 312: */
! 313: #if !defined(_BSD_SOURCE) && \
! 314: (defined(_ANSI_SOURCE) || defined(__XPG_VISIBLE) || defined(__POSIX_VISIBLE))
! 315: # define __BSD_VISIBLE 0
! 316: #endif
! 317:
! 318: /*
! 319: * Default values.
! 320: */
! 321: #ifndef __XPG_VISIBLE
! 322: # define __XPG_VISIBLE 600
! 323: #endif
! 324: #ifndef __POSIX_VISIBLE
! 325: # define __POSIX_VISIBLE 200112
! 326: #endif
! 327: #ifndef __ISO_C_VISIBLE
! 328: # define __ISO_C_VISIBLE 1999
! 329: #endif
! 330: #ifndef __BSD_VISIBLE
! 331: # define __BSD_VISIBLE 1
! 332: #endif
! 333:
! 334: #endif /* !_SYS_CDEFS_H_ */
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