1 /* $OpenBSD: cdefs.h,v 1.7 2001/08/07 21:33:03 millert 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. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)cdefs.h 8.7 (Berkeley) 1/21/94 40 */ 41 42 #ifndef _CDEFS_H_ 43 #define _CDEFS_H_ 44 45 /* 46 * Gratuitous NetBSD gcc extensions we can do without. 47 */ 48 49 #ifdef __KPRINTF_ATTRIBUTE__ 50 #undef __KPRINTF_ATTRIBUTE__ 51 #endif 52 53 #include <machine/cdefs.h> 54 55 #if defined(__cplusplus) 56 #define __BEGIN_DECLS extern "C" { 57 #define __END_DECLS }; 58 #else 59 #define __BEGIN_DECLS 60 #define __END_DECLS 61 #endif 62 63 /* 64 * Macro to test if we're using a specific version of gcc or later. 65 */ 66 #ifdef __GNUC__ 67 #define __GNUC_PREREQ__(ma, mi) \ 68 ((__GNUC__ > (ma)) || (__GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))) 69 #else 70 #define __GNUC_PREREQ__(ma, mi) 0 71 #endif 72 73 /* 74 * The __CONCAT macro is used to concatenate parts of symbol names, e.g. 75 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. 76 * The __CONCAT macro is a bit tricky -- make sure you don't put spaces 77 * in between its arguments. __CONCAT can also concatenate double-quoted 78 * strings produced by the __STRING macro, but this only works with ANSI C. 79 */ 80 #if defined(__STDC__) || defined(__cplusplus) 81 #define __P(protos) protos /* full-blown ANSI C */ 82 #define __CONCAT(x,y) x ## y 83 #define __STRING(x) #x 84 85 #define __const const /* define reserved names to standard */ 86 #define __signed signed 87 #define __volatile volatile 88 #if defined(__cplusplus) 89 #define __inline inline /* convert to C++ keyword */ 90 #else 91 #if !defined(__GNUC__) && !defined(lint) 92 #define __inline /* delete GCC keyword */ 93 #endif /* !__GNUC__ && !lint */ 94 #endif /* !__cplusplus */ 95 96 #else /* !(__STDC__ || __cplusplus) */ 97 #define __P(protos) () /* traditional C preprocessor */ 98 #define __CONCAT(x,y) x/**/y 99 #define __STRING(x) "x" 100 101 #if !defined(__GNUC__) && !defined(lint) 102 #define __const /* delete pseudo-ANSI C keywords */ 103 #define __inline 104 #define __signed 105 #define __volatile 106 #endif /* !__GNUC__ && !lint */ 107 108 /* 109 * In non-ANSI C environments, new programs will want ANSI-only C keywords 110 * deleted from the program and old programs will want them left alone. 111 * Programs using the ANSI C keywords const, inline etc. as normal 112 * identifiers should define -DNO_ANSI_KEYWORDS. 113 */ 114 #ifndef NO_ANSI_KEYWORDS 115 #define const __const /* convert ANSI C keywords */ 116 #define inline __inline 117 #define signed __signed 118 #define volatile __volatile 119 #endif /* !NO_ANSI_KEYWORDS */ 120 #endif /* !(__STDC__ || __cplusplus) */ 121 122 /* 123 * GCC1 and some versions of GCC2 declare dead (non-returning) and 124 * pure (no side effects) functions using "volatile" and "const"; 125 * unfortunately, these then cause warnings under "-ansi -pedantic". 126 * GCC >= 2.5 uses the __attribute__((attrs)) style. All of these 127 * work for GNU C++ (modulo a slight glitch in the C++ grammar in 128 * the distribution version of 2.5.5). 129 */ 130 131 #if !__GNUC_PREREQ__(2, 5) 132 #define __attribute__(x) /* delete __attribute__ if non-gcc or gcc1 */ 133 #if defined(__GNUC__) && !defined(__STRICT_ANSI__) 134 #define __dead __volatile 135 #define __pure __const 136 #endif 137 #elif !defined(__STRICT_ANSI__) 138 #define __dead __attribute__((__noreturn__)) 139 #define __pure __attribute__((__const__)) 140 #endif 141 142 /* 143 * GNU C version 2.96 adds explicit branch prediction so that 144 * the CPU back-end can hint the processor and also so that 145 * code blocks can be reordered such that the predicted path 146 * sees a more linear flow, thus improving cache behavior, etc. 147 * 148 * The following two macros provide us with a way to utilize this 149 * compiler feature. Use __predict_true() if you expect the expression 150 * to evaluate to true, and __predict_false() if you expect the 151 * expression to evaluate to false. 152 * 153 * A few notes about usage: 154 * 155 * * Generally, __predict_false() error condition checks (unless 156 * you have some _strong_ reason to do otherwise, in which case 157 * document it), and/or __predict_true() `no-error' condition 158 * checks, assuming you want to optimize for the no-error case. 159 * 160 * * Other than that, if you don't know the likelihood of a test 161 * succeeding from empirical or other `hard' evidence, don't 162 * make predictions. 163 * 164 * * These are meant to be used in places that are run `a lot'. 165 * It is wasteful to make predictions in code that is run 166 * seldomly (e.g. at subsystem initialization time) as the 167 * basic block reordering that this affects can often generate 168 * larger code. 169 */ 170 #if __GNUC_PREREQ__(2, 96) 171 #define __predict_true(exp) __builtin_expect(((exp) != 0), 1) 172 #define __predict_false(exp) __builtin_expect(((exp) != 0), 0) 173 #else 174 #define __predict_true(exp) ((exp) != 0) 175 #define __predict_false(exp) ((exp) != 0) 176 #endif 177 178 #ifdef __KPRINTF_ATTRIBUTE__ 179 #define __kprintf_attribute__(a) __attribute__(a) 180 #else 181 #define __kprintf_attribute__(a) 182 #endif 183 184 /* Delete pseudo-keywords wherever they are not available or needed. */ 185 #ifndef __dead 186 #define __dead 187 #define __pure 188 #endif 189 190 #endif /* !_CDEFS_H_ */ 191