cdefs.h revision 1.52
1/* $NetBSD: cdefs.h,v 1.52 2004/06/07 18:36:24 drochner Exp $ */ 2 3/* 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Berkeley Software Design, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)cdefs.h 8.8 (Berkeley) 1/9/95 35 */ 36 37#ifndef _SYS_CDEFS_H_ 38#define _SYS_CDEFS_H_ 39 40/* 41 * Macro to test if we're using a GNU C compiler of a specific vintage 42 * or later, for e.g. features that appeared in a particular version 43 * of GNU C. Usage: 44 * 45 * #if __GNUC_PREREQ__(major, minor) 46 * ...cool feature... 47 * #else 48 * ...delete feature... 49 * #endif 50 */ 51#ifdef __GNUC__ 52#define __GNUC_PREREQ__(x, y) \ 53 ((__GNUC__ == (x) && __GNUC_MINOR__ >= (y)) || \ 54 (__GNUC__ > (x))) 55#else 56#define __GNUC_PREREQ__(x, y) 0 57#endif 58 59#include <machine/cdefs.h> 60#ifdef __ELF__ 61#include <sys/cdefs_elf.h> 62#else 63#include <sys/cdefs_aout.h> 64#endif 65 66#if defined(__cplusplus) 67#define __BEGIN_DECLS extern "C" { 68#define __END_DECLS } 69#define __static_cast(x,y) static_cast<x>(y) 70#else 71#define __BEGIN_DECLS 72#define __END_DECLS 73#define __static_cast(x,y) (x)y 74#endif 75 76/* 77 * The __CONCAT macro is used to concatenate parts of symbol names, e.g. 78 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. 79 * The __CONCAT macro is a bit tricky -- make sure you don't put spaces 80 * in between its arguments. __CONCAT can also concatenate double-quoted 81 * strings produced by the __STRING macro, but this only works with ANSI C. 82 */ 83 84#define ___STRING(x) __STRING(x) 85#define ___CONCAT(x,y) __CONCAT(x,y) 86 87#if __STDC__ || defined(__cplusplus) 88#define __P(protos) protos /* full-blown ANSI C */ 89#define __CONCAT(x,y) x ## y 90#define __STRING(x) #x 91 92#define __const const /* define reserved names to standard */ 93#define __signed signed 94#define __volatile volatile 95#if defined(__cplusplus) 96#define __inline inline /* convert to C++ keyword */ 97#else 98#if !defined(__GNUC__) && !defined(__lint__) 99#define __inline /* delete GCC keyword */ 100#endif /* !__GNUC__ && !__lint__ */ 101#endif /* !__cplusplus */ 102 103#else /* !(__STDC__ || __cplusplus) */ 104#define __P(protos) () /* traditional C preprocessor */ 105#define __CONCAT(x,y) x/**/y 106#define __STRING(x) "x" 107 108#ifndef __GNUC__ 109#define __const /* delete pseudo-ANSI C keywords */ 110#define __inline 111#define __signed 112#define __volatile 113#endif /* !__GNUC__ */ 114 115/* 116 * In non-ANSI C environments, new programs will want ANSI-only C keywords 117 * deleted from the program and old programs will want them left alone. 118 * Programs using the ANSI C keywords const, inline etc. as normal 119 * identifiers should define -DNO_ANSI_KEYWORDS. 120 */ 121#ifndef NO_ANSI_KEYWORDS 122#define const __const /* convert ANSI C keywords */ 123#define inline __inline 124#define signed __signed 125#define volatile __volatile 126#endif /* !NO_ANSI_KEYWORDS */ 127#endif /* !(__STDC__ || __cplusplus) */ 128 129/* 130 * Used for internal auditing of the NetBSD source tree. 131 */ 132#ifdef __AUDIT__ 133#define __aconst __const 134#else 135#define __aconst 136#endif 137 138/* 139 * GCC2 provides __extension__ to suppress warnings for various GNU C 140 * language extensions under "-ansi -pedantic". 141 */ 142#if !__GNUC_PREREQ__(2, 0) 143#define __extension__ /* delete __extension__ if non-gcc or gcc1 */ 144#endif 145 146/* 147 * GCC1 and some versions of GCC2 declare dead (non-returning) and 148 * pure (no side effects) functions using "volatile" and "const"; 149 * unfortunately, these then cause warnings under "-ansi -pedantic". 150 * GCC2 uses a new, peculiar __attribute__((attrs)) style. All of 151 * these work for GNU C++ (modulo a slight glitch in the C++ grammar 152 * in the distribution version of 2.5.5). 153 */ 154#if !__GNUC_PREREQ__(2, 5) 155#define __attribute__(x) /* delete __attribute__ if non-gcc or gcc1 */ 156#if defined(__GNUC__) && !defined(__STRICT_ANSI__) 157#define __dead __volatile 158#define __pure __const 159#endif 160#endif 161 162/* Delete pseudo-keywords wherever they are not available or needed. */ 163#ifndef __dead 164#define __dead 165#define __pure 166#endif 167 168#if __GNUC_PREREQ__(2, 7) 169#define __unused __attribute__((__unused__)) 170#define __used __attribute__((__used__)) 171#else 172#define __unused /* delete */ 173#define __used /* delete */ 174#endif 175 176#if __GNUC_PREREQ__(2, 7) 177#define __packed __attribute__((__packed__)) 178#define __aligned(x) __attribute__((__aligned__(x))) 179#define __section(x) __attribute__((__section__(x))) 180#elif defined(__lint__) 181#define __packed /* delete */ 182#define __aligned(x) /* delete */ 183#define __section(x) /* delete */ 184#else 185#define __packed error: no __packed for this compiler 186#define __aligned(x) error: no __aligned for this compiler 187#define __section(x) error: no __section for this compiler 188#endif 189 190/* 191 * C99 defines the restrict type qualifier keyword, which was made available 192 * in GCC 2.92. 193 */ 194#if __STDC_VERSION__ >= 199901L 195#define __restrict restrict 196#else 197#if !__GNUC_PREREQ__(2, 92) 198#define __restrict /* delete __restrict when not supported */ 199#endif 200#endif 201 202/* 203 * C99 defines __func__ predefined identifier, which was made available 204 * in GCC 2.95. 205 */ 206#if !(__STDC_VERSION__ >= 199901L) 207#if __GNUC_PREREQ__(2, 6) 208#define __func__ __PRETTY_FUNCTION__ 209#elif __GNUC_PREREQ__(2, 4) 210#define __func__ __FUNCTION__ 211#else 212#define __func__ "" 213#endif 214#endif /* !(__STDC_VERSION__ >= 199901L) */ 215 216#if defined(_KERNEL) 217#if defined(NO_KERNEL_RCSIDS) 218#undef __KERNEL_RCSID 219#define __KERNEL_RCSID(_n, _s) /* nothing */ 220#endif /* NO_KERNEL_RCSIDS */ 221#endif /* _KERNEL */ 222 223#if !defined(_STANDALONE) && !defined(_KERNEL) 224#ifdef __GNUC__ 225#define __RENAME(x) ___RENAME(x) 226#else 227#ifdef __lint__ 228#define __RENAME(x) __symbolrename(x) 229#else 230#error "No function renaming possible" 231#endif /* __lint__ */ 232#endif /* __GNUC__ */ 233#else /* _STANDALONE || _KERNEL */ 234#define __RENAME(x) no renaming in kernel or standalone environment 235#endif 236 237/* 238 * A barrier to stop the optimizer from moving code or assume live 239 * register values. This is gcc specific, the version is more or less 240 * arbitrary, might work with older compilers. 241 */ 242#if __GNUC_PREREQ__(2, 95) 243#define __insn_barrier() __asm __volatile("":::"memory") 244#else 245#define __insn_barrier() /* */ 246#endif 247 248/* 249 * GNU C version 2.96 adds explicit branch prediction so that 250 * the CPU back-end can hint the processor and also so that 251 * code blocks can be reordered such that the predicted path 252 * sees a more linear flow, thus improving cache behavior, etc. 253 * 254 * The following two macros provide us with a way to use this 255 * compiler feature. Use __predict_true() if you expect the expression 256 * to evaluate to true, and __predict_false() if you expect the 257 * expression to evaluate to false. 258 * 259 * A few notes about usage: 260 * 261 * * Generally, __predict_false() error condition checks (unless 262 * you have some _strong_ reason to do otherwise, in which case 263 * document it), and/or __predict_true() `no-error' condition 264 * checks, assuming you want to optimize for the no-error case. 265 * 266 * * Other than that, if you don't know the likelihood of a test 267 * succeeding from empirical or other `hard' evidence, don't 268 * make predictions. 269 * 270 * * These are meant to be used in places that are run `a lot'. 271 * It is wasteful to make predictions in code that is run 272 * seldomly (e.g. at subsystem initialization time) as the 273 * basic block reordering that this affects can often generate 274 * larger code. 275 */ 276#if __GNUC_PREREQ__(2, 96) 277#define __predict_true(exp) __builtin_expect((exp) != 0, 1) 278#define __predict_false(exp) __builtin_expect((exp) != 0, 0) 279#else 280#define __predict_true(exp) (exp) 281#define __predict_false(exp) (exp) 282#endif 283 284/* 285 * Macros for manipulating "link sets". Link sets are arrays of pointers 286 * to objects, which are gathered up by the linker. 287 * 288 * Object format-specific code has provided us with the following macros: 289 * 290 * __link_set_add_text(set, sym) 291 * Add a reference to the .text symbol `sym' to `set'. 292 * 293 * __link_set_add_rodata(set, sym) 294 * Add a reference to the .rodata symbol `sym' to `set'. 295 * 296 * __link_set_add_data(set, sym) 297 * Add a reference to the .data symbol `sym' to `set'. 298 * 299 * __link_set_add_bss(set, sym) 300 * Add a reference to the .bss symbol `sym' to `set'. 301 * 302 * __link_set_decl(set, ptype) 303 * Provide an extern declaration of the set `set', which 304 * contains an array of the pointer type `ptype'. This 305 * macro must be used by any code which wishes to reference 306 * the elements of a link set. 307 * 308 * __link_set_start(set) 309 * This points to the first slot in the link set. 310 * 311 * __link_set_end(set) 312 * This points to the (non-existent) slot after the last 313 * entry in the link set. 314 * 315 * __link_set_count(set) 316 * Count the number of entries in link set `set'. 317 * 318 * In addition, we provide the following macros for accessing link sets: 319 * 320 * __link_set_foreach(pvar, set) 321 * Iterate over the link set `set'. Because a link set is 322 * an array of pointers, pvar must be declared as "type **pvar", 323 * and the actual entry accessed as "*pvar". 324 * 325 * __link_set_entry(set, idx) 326 * Access the link set entry at index `idx' from set `set'. 327 */ 328#define __link_set_foreach(pvar, set) \ 329 for (pvar = __link_set_start(set); pvar < __link_set_end(set); pvar++) 330 331#define __link_set_entry(set, idx) (__link_set_begin(set)[idx]) 332 333#endif /* !_SYS_CDEFS_H_ */ 334