cdefs.h revision 1.107
1/* $NetBSD: cdefs.h,v 1.107 2013/05/29 19:02:30 martin 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#ifdef __GNUC__ 67#define __strict_weak_alias(alias,sym) \ 68 __unused static __typeof__(alias) *__weak_alias_##alias = &sym; \ 69 __weak_alias(alias,sym) 70#else 71#define __strict_weak_alias(alias,sym) __weak_alias(alias,sym) 72#endif 73 74/* 75 * Optional marker for size-optimised MD calling convention. 76 */ 77#ifndef __compactcall 78#define __compactcall 79#endif 80 81/* 82 * The __CONCAT macro is used to concatenate parts of symbol names, e.g. 83 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. 84 * The __CONCAT macro is a bit tricky -- make sure you don't put spaces 85 * in between its arguments. __CONCAT can also concatenate double-quoted 86 * strings produced by the __STRING macro, but this only works with ANSI C. 87 */ 88 89#define ___STRING(x) __STRING(x) 90#define ___CONCAT(x,y) __CONCAT(x,y) 91 92#if __STDC__ || defined(__cplusplus) 93#define __P(protos) protos /* full-blown ANSI C */ 94#define __CONCAT(x,y) x ## y 95#define __STRING(x) #x 96 97#define __const const /* define reserved names to standard */ 98#define __signed signed 99#define __volatile volatile 100#if defined(__cplusplus) || defined(__PCC__) 101#define __inline inline /* convert to C++/C99 keyword */ 102#else 103#if !defined(__GNUC__) && !defined(__lint__) 104#define __inline /* delete GCC keyword */ 105#endif /* !__GNUC__ && !__lint__ */ 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#endif /* !__GNUC__ */ 119 120/* 121 * In non-ANSI C environments, new programs will want ANSI-only C keywords 122 * deleted from the program and old programs will want them left alone. 123 * Programs using the ANSI C keywords const, inline etc. as normal 124 * identifiers should define -DNO_ANSI_KEYWORDS. 125 */ 126#ifndef NO_ANSI_KEYWORDS 127#define const __const /* convert ANSI C keywords */ 128#define inline __inline 129#define signed __signed 130#define volatile __volatile 131#endif /* !NO_ANSI_KEYWORDS */ 132#endif /* !(__STDC__ || __cplusplus) */ 133 134/* 135 * Used for internal auditing of the NetBSD source tree. 136 */ 137#ifdef __AUDIT__ 138#define __aconst __const 139#else 140#define __aconst 141#endif 142 143/* 144 * Compile Time Assertion. 145 */ 146#ifdef __COUNTER__ 147#define __CTASSERT(x) __CTASSERT0(x, __ctassert, __COUNTER__) 148#else 149#define __CTASSERT(x) __CTASSERT0(x, __ctassert, __LINE__) 150#endif 151#define __CTASSERT0(x, y, z) __CTASSERT1(x, y, z) 152#define __CTASSERT1(x, y, z) typedef char y ## z[/*CONSTCOND*/(x) ? 1 : -1] 153 154/* 155 * The following macro is used to remove const cast-away warnings 156 * from gcc -Wcast-qual; it should be used with caution because it 157 * can hide valid errors; in particular most valid uses are in 158 * situations where the API requires it, not to cast away string 159 * constants. We don't use *intptr_t on purpose here and we are 160 * explicit about unsigned long so that we don't have additional 161 * dependencies. 162 */ 163#define __UNCONST(a) ((void *)(unsigned long)(const void *)(a)) 164 165/* 166 * The following macro is used to remove the volatile cast-away warnings 167 * from gcc -Wcast-qual; as above it should be used with caution 168 * because it can hide valid errors or warnings. Valid uses include 169 * making it possible to pass a volatile pointer to memset(). 170 * For the same reasons as above, we use unsigned long and not intptr_t. 171 */ 172#define __UNVOLATILE(a) ((void *)(unsigned long)(volatile void *)(a)) 173 174/* 175 * GCC2 provides __extension__ to suppress warnings for various GNU C 176 * language extensions under "-ansi -pedantic". 177 */ 178#if !__GNUC_PREREQ__(2, 0) 179#define __extension__ /* delete __extension__ if non-gcc or gcc1 */ 180#endif 181 182/* 183 * GCC1 and some versions of GCC2 declare dead (non-returning) and 184 * pure (no side effects) functions using "volatile" and "const"; 185 * unfortunately, these then cause warnings under "-ansi -pedantic". 186 * GCC2 uses a new, peculiar __attribute__((attrs)) style. All of 187 * these work for GNU C++ (modulo a slight glitch in the C++ grammar 188 * in the distribution version of 2.5.5). 189 * 190 * GCC defines a pure function as depending only on its arguments and 191 * global variables. Typical examples are strlen and sqrt. 192 * 193 * GCC defines a const function as depending only on its arguments. 194 * Therefore calling a const function again with identical arguments 195 * will always produce the same result. 196 * 197 * Rounding modes for floating point operations are considered global 198 * variables and prevent sqrt from being a const function. 199 * 200 * Calls to const functions can be optimised away and moved around 201 * without limitations. 202 */ 203#if !__GNUC_PREREQ__(2, 0) 204#define __attribute__(x) 205#endif 206 207#if __GNUC_PREREQ__(2, 5) 208#define __dead __attribute__((__noreturn__)) 209#elif defined(__GNUC__) 210#define __dead __volatile 211#else 212#define __dead 213#endif 214 215#if __GNUC_PREREQ__(2, 96) 216#define __pure __attribute__((__pure__)) 217#elif defined(__GNUC__) 218#define __pure __const 219#else 220#define __pure 221#endif 222 223#if __GNUC_PREREQ__(2, 5) 224#define __constfunc __attribute__((__const__)) 225#else 226#define __constfunc 227#endif 228 229#if __GNUC_PREREQ__(3, 0) 230#define __noinline __attribute__((__noinline__)) 231#else 232#define __noinline /* nothing */ 233#endif 234 235#if __GNUC_PREREQ__(3, 0) 236#define __always_inline __attribute__((__always_inline__)) 237#else 238#define __always_inline /* nothing */ 239#endif 240 241#if __GNUC_PREREQ__(4, 1) 242#define __returns_twice __attribute__((__returns_twice__)) 243#else 244#define __returns_twice /* nothing */ 245#endif 246 247#if __GNUC_PREREQ__(4, 5) 248#define __noclone __attribute__((__noclone__)) 249#else 250#define __noclone /* nothing */ 251#endif 252 253#if __GNUC_PREREQ__(2, 7) 254#define __unused __attribute__((__unused__)) 255#else 256#define __unused /* delete */ 257#endif 258 259#if __GNUC_PREREQ__(3, 1) 260#define __used __attribute__((__used__)) 261#else 262#define __used __unused 263#endif 264 265#if __GNUC_PREREQ__(3, 1) 266#define __noprofile __attribute__((__no_instrument_function__)) 267#else 268#define __noprofile /* nothing */ 269#endif 270 271#if defined(__cplusplus) 272#define __BEGIN_EXTERN_C extern "C" { 273#define __END_EXTERN_C } 274#define __static_cast(x,y) static_cast<x>(y) 275#else 276#define __BEGIN_EXTERN_C 277#define __END_EXTERN_C 278#define __static_cast(x,y) (x)y 279#endif 280 281#if __GNUC_PREREQ__(4, 0) 282# define __dso_public __attribute__((__visibility__("default"))) 283# define __dso_hidden __attribute__((__visibility__("hidden"))) 284# define __BEGIN_PUBLIC_DECLS \ 285 _Pragma("GCC visibility push(default)") __BEGIN_EXTERN_C 286# define __END_PUBLIC_DECLS __END_EXTERN_C _Pragma("GCC visibility pop") 287# define __BEGIN_HIDDEN_DECLS \ 288 _Pragma("GCC visibility push(hidden)") __BEGIN_EXTERN_C 289# define __END_HIDDEN_DECLS __END_EXTERN_C _Pragma("GCC visibility pop") 290#else 291# define __dso_public 292# define __dso_hidden 293# define __BEGIN_PUBLIC_DECLS __BEGIN_EXTERN_C 294# define __END_PUBLIC_DECLS __END_EXTERN_C 295# define __BEGIN_HIDDEN_DECLS __BEGIN_EXTERN_C 296# define __END_HIDDEN_DECLS __END_EXTERN_C 297#endif 298#if __GNUC_PREREQ__(4, 2) 299# define __dso_protected __attribute__((__visibility__("protected"))) 300#else 301# define __dso_protected 302#endif 303 304#define __BEGIN_DECLS __BEGIN_PUBLIC_DECLS 305#define __END_DECLS __END_PUBLIC_DECLS 306 307/* 308 * Non-static C99 inline functions are optional bodies. They don't 309 * create global symbols if not used, but can be replaced if desirable. 310 * This differs from the behavior of GCC before version 4.3. The nearest 311 * equivalent for older GCC is `extern inline'. For newer GCC, use the 312 * gnu_inline attribute additionally to get the old behavior. 313 * 314 * For C99 compilers other than GCC, the C99 behavior is expected. 315 */ 316#if defined(__GNUC__) && defined(__GNUC_STDC_INLINE__) 317#define __c99inline extern __attribute__((__gnu_inline__)) __inline 318#elif defined(__GNUC__) 319#define __c99inline extern __inline 320#elif defined(__STDC_VERSION__) 321#define __c99inline __inline 322#endif 323 324#if defined(__lint__) 325#define __packed __packed 326#define __aligned(x) /* delete */ 327#define __section(x) /* delete */ 328#elif __GNUC_PREREQ__(2, 7) 329#define __packed __attribute__((__packed__)) 330#define __aligned(x) __attribute__((__aligned__(x))) 331#define __section(x) __attribute__((__section__(x))) 332#elif defined(__PCC__) 333#define __packed _Pragma("packed 1") 334#define __aligned(x) _Pragma("aligned " __STRING(x)) 335#define __section(x) _Pragma("section " ## x) 336#elif defined(_MSC_VER) 337#define __packed /* ignore */ 338#else 339#define __packed error: no __packed for this compiler 340#define __aligned(x) error: no __aligned for this compiler 341#define __section(x) error: no __section for this compiler 342#endif 343 344/* 345 * C99 defines the restrict type qualifier keyword, which was made available 346 * in GCC 2.92. 347 */ 348#if defined(__lint__) 349#define __restrict /* delete __restrict when not supported */ 350#elif __STDC_VERSION__ >= 199901L 351#define __restrict restrict 352#elif __GNUC_PREREQ__(2, 92) 353#define __restrict __restrict__ 354#else 355#define __restrict /* delete __restrict when not supported */ 356#endif 357 358/* 359 * C99 defines __func__ predefined identifier, which was made available 360 * in GCC 2.95. 361 */ 362#if !(__STDC_VERSION__ >= 199901L) 363#if __GNUC_PREREQ__(2, 6) 364#define __func__ __PRETTY_FUNCTION__ 365#elif __GNUC_PREREQ__(2, 4) 366#define __func__ __FUNCTION__ 367#else 368#define __func__ "" 369#endif 370#endif /* !(__STDC_VERSION__ >= 199901L) */ 371 372#if defined(_KERNEL) 373#if defined(NO_KERNEL_RCSIDS) 374#undef __KERNEL_RCSID 375#define __KERNEL_RCSID(_n, _s) /* nothing */ 376#endif /* NO_KERNEL_RCSIDS */ 377#endif /* _KERNEL */ 378 379#if !defined(_STANDALONE) && !defined(_KERNEL) 380#if defined(__GNUC__) || defined(__PCC__) 381#define __RENAME(x) ___RENAME(x) 382#elif defined(__lint__) 383#define __RENAME(x) __symbolrename(x) 384#else 385#error "No function renaming possible" 386#endif /* __GNUC__ */ 387#else /* _STANDALONE || _KERNEL */ 388#define __RENAME(x) no renaming in kernel or standalone environment 389#endif 390 391/* 392 * A barrier to stop the optimizer from moving code or assume live 393 * register values. This is gcc specific, the version is more or less 394 * arbitrary, might work with older compilers. 395 */ 396#if __GNUC_PREREQ__(2, 95) 397#define __insn_barrier() __asm __volatile("":::"memory") 398#else 399#define __insn_barrier() /* */ 400#endif 401 402/* 403 * GNU C version 2.96 adds explicit branch prediction so that 404 * the CPU back-end can hint the processor and also so that 405 * code blocks can be reordered such that the predicted path 406 * sees a more linear flow, thus improving cache behavior, etc. 407 * 408 * The following two macros provide us with a way to use this 409 * compiler feature. Use __predict_true() if you expect the expression 410 * to evaluate to true, and __predict_false() if you expect the 411 * expression to evaluate to false. 412 * 413 * A few notes about usage: 414 * 415 * * Generally, __predict_false() error condition checks (unless 416 * you have some _strong_ reason to do otherwise, in which case 417 * document it), and/or __predict_true() `no-error' condition 418 * checks, assuming you want to optimize for the no-error case. 419 * 420 * * Other than that, if you don't know the likelihood of a test 421 * succeeding from empirical or other `hard' evidence, don't 422 * make predictions. 423 * 424 * * These are meant to be used in places that are run `a lot'. 425 * It is wasteful to make predictions in code that is run 426 * seldomly (e.g. at subsystem initialization time) as the 427 * basic block reordering that this affects can often generate 428 * larger code. 429 */ 430#if __GNUC_PREREQ__(2, 96) 431#define __predict_true(exp) __builtin_expect((exp) != 0, 1) 432#define __predict_false(exp) __builtin_expect((exp) != 0, 0) 433#else 434#define __predict_true(exp) (exp) 435#define __predict_false(exp) (exp) 436#endif 437 438/* 439 * Compiler-dependent macros to declare that functions take printf-like 440 * or scanf-like arguments. They are null except for versions of gcc 441 * that are known to support the features properly (old versions of gcc-2 442 * didn't permit keeping the keywords out of the application namespace). 443 */ 444#if __GNUC_PREREQ__(2, 7) 445#define __printflike(fmtarg, firstvararg) \ 446 __attribute__((__format__ (__printf__, fmtarg, firstvararg))) 447#define __scanflike(fmtarg, firstvararg) \ 448 __attribute__((__format__ (__scanf__, fmtarg, firstvararg))) 449#define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg))) 450#else 451#define __printflike(fmtarg, firstvararg) /* nothing */ 452#define __scanflike(fmtarg, firstvararg) /* nothing */ 453#define __format_arg(fmtarg) /* nothing */ 454#endif 455 456/* 457 * Macros for manipulating "link sets". Link sets are arrays of pointers 458 * to objects, which are gathered up by the linker. 459 * 460 * Object format-specific code has provided us with the following macros: 461 * 462 * __link_set_add_text(set, sym) 463 * Add a reference to the .text symbol `sym' to `set'. 464 * 465 * __link_set_add_rodata(set, sym) 466 * Add a reference to the .rodata symbol `sym' to `set'. 467 * 468 * __link_set_add_data(set, sym) 469 * Add a reference to the .data symbol `sym' to `set'. 470 * 471 * __link_set_add_bss(set, sym) 472 * Add a reference to the .bss symbol `sym' to `set'. 473 * 474 * __link_set_decl(set, ptype) 475 * Provide an extern declaration of the set `set', which 476 * contains an array of pointers to type `ptype'. This 477 * macro must be used by any code which wishes to reference 478 * the elements of a link set. 479 * 480 * __link_set_start(set) 481 * This points to the first slot in the link set. 482 * 483 * __link_set_end(set) 484 * This points to the (non-existent) slot after the last 485 * entry in the link set. 486 * 487 * __link_set_count(set) 488 * Count the number of entries in link set `set'. 489 * 490 * In addition, we provide the following macros for accessing link sets: 491 * 492 * __link_set_foreach(pvar, set) 493 * Iterate over the link set `set'. Because a link set is 494 * an array of pointers, pvar must be declared as "type **pvar", 495 * and the actual entry accessed as "*pvar". 496 * 497 * __link_set_entry(set, idx) 498 * Access the link set entry at index `idx' from set `set'. 499 */ 500#define __link_set_foreach(pvar, set) \ 501 for (pvar = __link_set_start(set); pvar < __link_set_end(set); pvar++) 502 503#define __link_set_entry(set, idx) (__link_set_start(set)[idx]) 504 505/* 506 * Return the natural alignment in bytes for the given type 507 */ 508#if __GNUC_PREREQ__(4, 1) 509#define __alignof(__t) __alignof__(__t) 510#else 511#define __alignof(__t) (sizeof(struct { char __x; __t __y; }) - sizeof(__t)) 512#endif 513 514/* 515 * Return the number of elements in a statically-allocated array, 516 * __x. 517 */ 518#define __arraycount(__x) (sizeof(__x) / sizeof(__x[0])) 519 520#ifndef __ASSEMBLER__ 521/* __BIT(n): nth bit, where __BIT(0) == 0x1. */ 522#define __BIT(__n) \ 523 (((uintmax_t)(__n) >= NBBY * sizeof(uintmax_t)) ? 0 : ((uintmax_t)1 << (uintmax_t)(__n))) 524 525/* __BITS(m, n): bits m through n, m < n. */ 526#define __BITS(__m, __n) \ 527 ((__BIT(MAX((__m), (__n)) + 1) - 1) ^ (__BIT(MIN((__m), (__n))) - 1)) 528#endif /* !__ASSEMBLER__ */ 529 530/* find least significant bit that is set */ 531#define __LOWEST_SET_BIT(__mask) ((((__mask) - 1) & (__mask)) ^ (__mask)) 532 533#define __PRIuBIT PRIuMAX 534#define __PRIuBITS __PRIuBIT 535 536#define __PRIxBIT PRIxMAX 537#define __PRIxBITS __PRIxBIT 538 539#define __SHIFTOUT(__x, __mask) (((__x) & (__mask)) / __LOWEST_SET_BIT(__mask)) 540#define __SHIFTIN(__x, __mask) ((__x) * __LOWEST_SET_BIT(__mask)) 541#define __SHIFTOUT_MASK(__mask) __SHIFTOUT((__mask), (__mask)) 542 543/* 544 * Only to be used in other headers that are included from both c or c++ 545 * NOT to be used in code. 546 */ 547#ifdef __cplusplus 548#define __CAST(__dt, __st) static_cast<__dt>(__st) 549#else 550#define __CAST(__dt, __st) ((__dt)(__st)) 551#endif 552 553#define __type_mask(t) (/*LINTED*/sizeof(t) < sizeof(intmax_t) ? \ 554 (~((1ULL << (sizeof(t) * NBBY)) - 1)) : 0ULL) 555 556#ifndef __ASSEMBLER__ 557static __inline long long __zeroll(void) { return 0; } 558static __inline int __negative_p(double x) { return x < 0; } 559#else 560#define __zeroll() (0LL) 561#define __negative_p(x) ((x) < 0) 562#endif 563 564#define __type_min_s(t) ((t)((1ULL << (sizeof(t) * NBBY - 1)))) 565#define __type_max_s(t) ((t)~((1ULL << (sizeof(t) * NBBY - 1)))) 566#define __type_min_u(t) ((t)0ULL) 567#define __type_max_u(t) ((t)~0ULL) 568#define __type_is_signed(t) (/*LINTED*/__type_min_s(t) + (t)1 < (t)1) 569#define __type_min(t) (__type_is_signed(t) ? __type_min_s(t) : __type_min_u(t)) 570#define __type_max(t) (__type_is_signed(t) ? __type_max_s(t) : __type_max_u(t)) 571 572 573#define __type_fit_u(t, a) (/*LINTED*/sizeof(t) < sizeof(intmax_t) ? \ 574 (((a) & __type_mask(t)) == 0) : !__negative_p(a)) 575 576#define __type_fit_s(t, a) (/*LINTED*/__negative_p(a) ? \ 577 ((intmax_t)((a) + __zeroll()) >= (intmax_t)__type_min_s(t)) : \ 578 ((intmax_t)((a) + __zeroll()) <= (intmax_t)__type_max_s(t))) 579 580/* 581 * return true if value 'a' fits in type 't' 582 */ 583#define __type_fit(t, a) (__type_is_signed(t) ? \ 584 __type_fit_s(t, a) : __type_fit_u(t, a)) 585 586#endif /* !_SYS_CDEFS_H_ */ 587