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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)cdefs.h 8.8 (Berkeley) 1/9/95 33 * $FreeBSD: src/sys/sys/cdefs.h,v 1.28.2.8 2002/09/18 04:05:13 mikeh Exp $ 34 */ 35 36 #ifndef _SYS_CDEFS_H_ 37 #define _SYS_CDEFS_H_ 38 39 /* 40 * Testing against Clang-specific extensions. 41 */ 42 #ifndef __has_attribute 43 #define __has_attribute(x) 0 44 #endif 45 #ifndef __has_extension 46 #define __has_extension __has_feature 47 #endif 48 #ifndef __has_feature 49 #define __has_feature(x) 0 50 #endif 51 #ifndef __has_include 52 #define __has_include(x) 0 53 #endif 54 #ifndef __has_builtin 55 #define __has_builtin(x) 0 56 #endif 57 58 /* 59 * Macro to test if we are using a specific version of gcc or later. 60 */ 61 #if defined(__GNUC__) 62 #define __GNUC_PREREQ__(ma, mi) \ 63 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi)) 64 #else 65 #define __GNUC_PREREQ__(ma, mi) 0 66 #endif 67 68 #if defined(__cplusplus) 69 #define __BEGIN_EXTERN_C extern "C" { 70 #define __END_EXTERN_C } 71 #else 72 #define __BEGIN_DECLS 73 #define __END_DECLS 74 #define __BEGIN_EXTERN_C 75 #define __END_EXTERN_C 76 #endif 77 78 #if __GNUC_PREREQ__(4, 0) 79 #define __dso_public __attribute__((__visibility__("default"))) 80 #define __dso_hidden __attribute__((__visibility__("hidden"))) 81 #define __BEGIN_PUBLIC_DECLS \ 82 _Pragma("GCC visibility push(default)") __BEGIN_EXTERN_C 83 #define __END_PUBLIC_DECLS \ 84 __END_EXTERN_C _Pragma("GCC visibility pop") 85 #define __BEGIN_HIDDEN_DECLS \ 86 _Pragma("GCC visibility push(hidden)") __BEGIN_EXTERN_C 87 #define __END_HIDDEN_DECLS \ 88 __END_EXTERN_C _Pragma("GCC visibility pop") 89 #else 90 #define __dso_public 91 #define __dso_hidden 92 #define __BEGIN_PUBLIC_DECLS \ 93 __BEGIN_EXTERN_C 94 #define __END_PUBLIC_DECLS \ 95 __END_EXTERN_C 96 #define __BEGIN_HIDDEN_DECLS \ 97 __BEGIN_EXTERN_C 98 #define __END_HIDDEN_DECLS \ 99 __END_EXTERN_C 100 #endif 101 102 #if defined(__cplusplus) 103 #define __BEGIN_DECLS __BEGIN_PUBLIC_DECLS 104 #define __END_DECLS __END_PUBLIC_DECLS 105 #endif 106 107 /* 108 * The __VM_CACHELINE_SIZE macro defines the common cache line alignment 109 * size that can be found across most recent and somewhat latest Intel 110 * hardware, i.e. L1 cache sizes etc. 111 * 112 * If needed, this value can be TUNED. Suitable values for this macro 113 * are 32, 64 and 128 bytes. The unit of measurement for this macro is 114 * bytes. 115 * 116 * XXX: This macro and related macros will eventually move to a MD 117 * header, but currently, we do need such a hierarchy. 118 */ 119 #define __VM_CACHELINE_SIZE 64 120 #define __VM_CACHELINE_MASK (__VM_CACHELINE_SIZE - 1) 121 #define __VM_CACHELINE_ALIGN(n) \ 122 (((n) + __VM_CACHELINE_MASK) & ~__VM_CACHELINE_MASK) 123 124 /* 125 * The __CONCAT macro is used to concatenate parts of symbol names, e.g. 126 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. 127 * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI 128 * mode -- there must be no spaces between its arguments, and for nested 129 * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also 130 * concatenate double-quoted strings produced by the __STRING macro, but 131 * this only works with ANSI C. 132 * 133 * __XSTRING is like __STRING, but it expands any macros in its argument 134 * first. It is only available with ANSI C. 135 */ 136 #if defined(__STDC__) || defined(__cplusplus) 137 #define __P(protos) protos /* full-blown ANSI C */ 138 #define __CONCAT1(x,y) x ## y 139 #define __CONCAT(x,y) __CONCAT1(x,y) 140 #define __STRING(x) #x /* stringify without expanding x */ 141 #define __XSTRING(x) __STRING(x) /* expand x, then stringify */ 142 143 #define __const const /* define reserved names to standard */ 144 #define __signed signed 145 #define __volatile volatile 146 #if defined(__cplusplus) 147 #define __inline inline /* convert to C++ keyword */ 148 #else 149 #ifndef __GNUC__ 150 #define __inline /* delete GCC keyword */ 151 #endif /* !__GNUC__ */ 152 #endif /* !__cplusplus */ 153 154 #else /* !(__STDC__ || __cplusplus) */ 155 #define __P(protos) () /* traditional C preprocessor */ 156 #define __CONCAT(x,y) x/**/y 157 #define __STRING(x) "x" 158 159 #ifndef __GNUC__ 160 #define __const /* delete pseudo-ANSI C keywords */ 161 #define __inline 162 #define __signed 163 #define __volatile 164 /* 165 * In non-ANSI C environments, new programs will want ANSI-only C keywords 166 * deleted from the program and old programs will want them left alone. 167 * When using a compiler other than gcc, programs using the ANSI C keywords 168 * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS. 169 * When using "gcc -traditional", we assume that this is the intent; if 170 * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone. 171 */ 172 #ifndef NO_ANSI_KEYWORDS 173 #define const /* delete ANSI C keywords */ 174 #define inline 175 #define signed 176 #define volatile 177 #endif /* !NO_ANSI_KEYWORDS */ 178 #endif /* !__GNUC__ */ 179 #endif /* __STDC__ || __cplusplus */ 180 181 /* 182 * Compiler-dependent macros to help declare dead (non-returning) and 183 * pure (no side effects) functions, and unused variables. They are 184 * null except for versions of gcc that are known to support the features 185 * properly (old versions of gcc-2 supported the dead and pure features 186 * in a different (wrong) way). 187 */ 188 #define __weak_symbol __attribute__((__weak__)) 189 #if __GNUC_PREREQ__(2, 7) 190 #define __dead2 __attribute__((__noreturn__)) 191 #define __pure2 __attribute__((__const__)) 192 #define __unused __attribute__((__unused__)) 193 #define __packed __attribute__((__packed__)) 194 #define __aligned(x) __attribute__((__aligned__(x))) 195 #define __section(x) __attribute__((__section__(x))) 196 #else 197 #define __dead2 198 #define __pure2 199 #define __unused 200 #endif 201 202 #if __GNUC_PREREQ__(2, 96) 203 #define __malloclike __attribute__((__malloc__)) 204 #define __pure __attribute__((__pure__)) 205 #else 206 #define __malloclike 207 #define __pure __pure2 208 #endif 209 210 #if __GNUC_PREREQ__(3, 1) 211 #define __always_inline __attribute__((__always_inline__)) 212 #define __noinline __attribute__((__noinline__)) 213 #else 214 #define __always_inline 215 #define __noinline 216 #endif 217 218 #if __GNUC_PREREQ__(3, 3) 219 #define __nonnull(...) __attribute__((__nonnull__(__VA_ARGS__))) 220 #define __used __attribute__((__used__)) 221 #else 222 #define __nonnull(...) 223 #define __used __unused 224 #endif 225 226 #if __GNUC_PREREQ__(3, 4) 227 #define __heedresult __attribute__((__warn_unused_result__)) 228 #else 229 #define __heedresult 230 #endif 231 232 #if __GNUC_PREREQ__(4, 1) 233 #define __returns_twice __attribute__((__returns_twice__)) 234 #else 235 #define __returns_twice 236 #endif 237 238 #if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable) 239 #define __unreachable() __builtin_unreachable() 240 #else 241 #define __unreachable() ((void)0) 242 #endif 243 244 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__) 245 #define __alloc_size(x) __attribute__((__alloc_size__(x))) 246 #define __alloc_size2(n, x) __attribute__((__alloc_size__(n, x))) 247 #else 248 #define __alloc_size(x) 249 #define __alloc_size2(n, x) 250 #endif 251 252 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__) 253 #define __alloc_align(x) __attribute__((__alloc_align__(x))) 254 #else 255 #define __alloc_align(x) 256 #endif 257 258 #if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION__ < 199901 259 #define __func__ NULL 260 #endif 261 262 #if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI__)) || \ 263 __STDC_VERSION__ >= 199901 264 #define __LONG_LONG_SUPPORTED 265 #endif 266 267 /* C++11 exposes a load of C99 stuff */ 268 #if defined(__cplusplus) && __cplusplus >= 201103L 269 #define __LONG_LONG_SUPPORTED 270 #ifndef __STDC_LIMIT_MACROS 271 #define __STDC_LIMIT_MACROS 272 #endif 273 #ifndef __STDC_CONSTANT_MACROS 274 #define __STDC_CONSTANT_MACROS 275 #endif 276 #endif 277 278 /* 279 * GCC 2.95 and later provides `__restrict' as an extension to C90 to support 280 * the C99-specific `restrict' type qualifier. We happen to use `__restrict' 281 * as a way to define the `restrict' type qualifier without disturbing older 282 * software that is unaware of C99 keywords. 283 */ 284 #if !__GNUC_PREREQ__(2, 95) 285 #if __STDC_VERSION__ < 199901 286 #define __restrict 287 #else 288 #define __restrict restrict 289 #endif 290 #endif 291 292 /* 293 * C99 allows to declare arrays as non-overlapping. 294 */ 295 #if __GNUC_PREREQ__(3, 1) && !defined(__GNUG__) 296 #define __restrict_arr __restrict 297 #else 298 #ifdef __GNUC__ 299 #define __restrict_arr 300 #else 301 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901 302 #define __restrict_arr restrict 303 #else 304 #define __restrict_arr 305 #endif 306 #endif 307 #endif 308 309 /* 310 * GNU C version 2.96 adds explicit branch prediction so that 311 * the CPU back-end can hint the processor and also so that 312 * code blocks can be reordered such that the predicted path 313 * sees a more linear flow, thus improving cache behavior, etc. 314 * 315 * The following two macros provide us with a way to utilize this 316 * compiler feature. Use __predict_true() if you expect the expression 317 * to evaluate to true, and __predict_false() if you expect the 318 * expression to evaluate to false. 319 * 320 * A few notes about usage: 321 * 322 * * Generally, __predict_false() error condition checks (unless 323 * you have some _strong_ reason to do otherwise, in which case 324 * document it), and/or __predict_true() `no-error' condition 325 * checks, assuming you want to optimize for the no-error case. 326 * 327 * * Other than that, if you don't know the likelihood of a test 328 * succeeding from empirical or other `hard' evidence, don't 329 * make predictions. 330 * 331 * * These are meant to be used in places that are run `a lot'. 332 * It is wasteful to make predictions in code that is run 333 * seldomly (e.g. at subsystem initialization time) as the 334 * basic block reordering that this affects can often generate 335 * larger code. 336 */ 337 #if __GNUC_PREREQ__(2, 96) 338 #define __predict_true(exp) __builtin_expect((exp), 1) 339 #define __predict_false(exp) __builtin_expect((exp), 0) 340 #else 341 #define __predict_true(exp) (exp) 342 #define __predict_false(exp) (exp) 343 #endif 344 345 /* 346 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h> 347 * require it. 348 */ 349 #if __GNUC_PREREQ__(4, 1) 350 #define __offsetof(type, field) __builtin_offsetof(type, field) 351 #else 352 #ifndef __cplusplus 353 #define __offsetof(type, field) \ 354 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field)) 355 #else 356 #define __offsetof(type, field) \ 357 (__offsetof__ (reinterpret_cast <__size_t> \ 358 (&reinterpret_cast <const volatile char &> \ 359 (static_cast<type *> (0)->field)))) 360 #endif 361 #endif 362 363 /* 364 * Compiler-dependent macros to declare that functions take printf-like 365 * or scanf-like arguments. They are null except for versions of gcc 366 * that are known to support the features properly (old versions of gcc-2 367 * didn't permit keeping the keywords out of the application namespace). 368 * 369 * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions. 370 */ 371 #if !__GNUC_PREREQ__(2, 7) 372 #define __printflike(fmtarg, firstvararg) 373 #define __scanflike(fmtarg, firstvararg) 374 #define __printf0like(fmtarg, firstvararg) 375 #define __format_arg(fmtarg) 376 #define __strfmonlike(fmtarg, firstvararg) 377 #define __strftimelike(fmtarg, firstvararg) 378 379 #elif __GNUC_PREREQ__(3, 0) 380 #define __printflike(fmtarg, firstvararg) \ 381 __attribute__((__nonnull__(fmtarg), \ 382 __format__ (__printf__, fmtarg, firstvararg))) 383 #define __printf0like(fmtarg, firstvararg) \ 384 __attribute__((__format__ (__printf__, fmtarg, firstvararg))) 385 #define __scanflike(fmtarg, firstvararg) \ 386 __attribute__((__format__ (__scanf__, fmtarg, firstvararg))) 387 #define __format_arg(fmtarg) \ 388 __attribute__((__format_arg__ (fmtarg))) 389 #define __strfmonlike(fmtarg, firstvararg) \ 390 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg))) 391 #define __strftimelike(fmtarg, firstvararg) \ 392 __attribute__((__format__ (__strftime__, fmtarg, firstvararg))) 393 394 #else 395 #define __printflike(fmtarg, firstvararg) \ 396 __attribute__((__format__ (__printf__, fmtarg, firstvararg))) 397 #define __printf0like(fmtarg, firstvararg) \ 398 __attribute__((__format__ (__printf0__, fmtarg, firstvararg))) 399 #define __scanflike(fmtarg, firstvararg) \ 400 __attribute__((__format__ (__scanf__, fmtarg, firstvararg))) 401 #define __format_arg(fmtarg) \ 402 __attribute__((__format_arg__ (fmtarg))) 403 #define __strfmonlike(fmtarg, firstvararg) \ 404 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg))) 405 #define __strftimelike(fmtarg, firstvararg) \ 406 __attribute__((__format__ (__strftime__, fmtarg, firstvararg))) 407 #endif 408 409 #if !__GNUC_PREREQ__(3, 0) 410 #define __ARRAY_ZERO 0 411 #else 412 #define __ARRAY_ZERO 413 #endif 414 415 /* 416 * A convenient constructor macro, GCC 4.3.0 added priority support to 417 * constructors, provide a compatible interface for both. 418 */ 419 #if __GNUC_PREREQ__(4, 3) 420 #define __constructor(prio) __attribute__((constructor(prio))) 421 #else 422 #define __constructor(prio) __attribute__((constructor)) 423 #endif 424 425 /* 426 * Handy GCC based macros: 427 * 428 * __cachealign: 429 * 430 * The __cachealign macro can be used for cache line aligning structures 431 * of small to medium size. It aligns the particular structure or 432 * storage type to a system default cache line alignment, thus giving us 433 * a much more better cache utilization by making the hardware work at 434 * its best burst speeds. 435 * 436 * __usereg: 437 * 438 * The __usereg macro can/should be used when a function contains 439 * arguments not more than 3. It can be very useful to us due to the 440 * message-passing nature of the kernel. 441 * 442 * !!NOTE - USAGE INFORMATION!! 443 * 444 * The __cachealign macro should not be used for data structures that are 445 * as big struct proc, struct vnode, struct thread, and other structs which 446 * are as big as them; simply because it will be useless in that case. 447 * 448 * The __usereg macro should be used whenever possible, i.e., when a function 449 * does not exceed more than 3 arguments, and should not be used for vararg 450 * type functions. 451 * 452 * In other words, AVOID MISUSE OF THESE MACROS. :-) 453 */ 454 #ifdef __GNUC__ 455 #define __cachealign __attribute__((__aligned__(__VM_CACHELINE_SIZE))) 456 #define __usereg __attribute__((__regparm__(3))) 457 #else 458 #define __cachealign 459 #define __usereg 460 #endif 461 462 #ifdef __GNUC__ 463 #define __strong_reference(sym,aliassym) \ 464 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym))) 465 #define __weak_reference(sym,aliassym) \ 466 __strong_reference(sym,aliassym) __attribute__ ((__weak__)) 467 #define __weak_reference_asm(sym,alias) \ 468 __asm__(".weak " #alias); \ 469 __asm__(".equ " #alias ", " #sym) 470 #define __warn_references(sym,msg) \ 471 __asm__(".section .gnu.warning." #sym); \ 472 __asm__(".asciz \"" msg "\""); \ 473 __asm__(".previous") 474 #define __sym_compat(sym,impl,verid) \ 475 __asm__(".symver " #impl ", " #sym "@" #verid) 476 #define __sym_default(sym,impl,verid) \ 477 __asm__(".symver " #impl ", " #sym "@@@" #verid) 478 #endif /* __GNUC__ */ 479 480 #if defined(__GNUC__) 481 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"") 482 #endif 483 484 #ifndef __RCSID 485 #define __RCSID(s) struct __hack 486 #endif 487 488 #ifndef __RCSID_SOURCE 489 #define __RCSID_SOURCE(s) struct __hack 490 #endif 491 492 #ifndef __SCCSID 493 #define __SCCSID(s) struct __hack 494 #endif 495 496 #ifndef __FBSDID 497 #define __FBSDID(s) struct __hack 498 #endif 499 500 #ifndef __COPYRIGHT 501 #define __COPYRIGHT(s) struct __hack 502 #endif 503 504 #ifndef __DECONST 505 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var)) 506 #endif 507 508 #ifndef __DEVOLATILE 509 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var)) 510 #endif 511 512 #ifndef __DEQUALIFY 513 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var)) 514 #endif 515 516 /* 517 * Keywords added in C11. 518 */ 519 520 #if !__GNUC_PREREQ__(2, 95) 521 #define __alignof(x) __offsetof(struct { char __a; x __b; }, __b) 522 #endif 523 524 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L 525 526 #if !__has_extension(c_alignas) 527 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 528 __has_extension(cxx_alignas) 529 #define _Alignas(x) alignas(x) 530 #else 531 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */ 532 #define _Alignas(x) __aligned(x) 533 #endif 534 #endif 535 536 #if defined(__cplusplus) && __cplusplus >= 201103L 537 #define _Alignof(x) alignof(x) 538 #else 539 #define _Alignof(x) __alignof(x) 540 #endif 541 542 #if !defined(_Noreturn) 543 #define _Noreturn __dead2 544 #endif 545 546 #if !__has_extension(c_static_assert) 547 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 548 __has_extension(cxx_static_assert) 549 #define _Static_assert(x, y) static_assert(x, y) 550 #elif !__GNUC_PREREQ__(4, 6) 551 #define _Static_assert(x, y) struct __hack 552 #ifdef _KERNEL 553 #define CTASSERT(x) _CTASSERT(x, __LINE__) 554 #define _CTASSERT(x, y) __CTASSERT(x, y) 555 #define __CTASSERT(x, y) typedef char __assert ## y[(x) ? 1 : -1] 556 #endif 557 #endif 558 559 /* 560 * GCC 4.7 has -std=c++11 but does not support thread_local. 561 */ 562 #if !__has_extension(c_thread_local) 563 #if (defined(__cplusplus) && __cplusplus >= 201103L && __GNUC_PREREQ__(4, 8)) || \ 564 __has_extension(cxx_thread_local) 565 #define _Thread_local thread_local 566 #else 567 #define _Thread_local __thread 568 #endif 569 #endif 570 #endif 571 572 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */ 573 574 #if defined(_KERNEL) && !defined(CTASSERT) 575 #define CTASSERT(x) _Static_assert(x, \ 576 "compile-time assertion failed") 577 #endif 578 579 /* 580 * Emulation of C11 _Generic(). Unlike the previously defined C11 581 * keywords, it is not possible to implement this using exactly the same 582 * syntax. Therefore implement something similar under the name 583 * __generic(). Unlike _Generic(), this macro can only distinguish 584 * between a single type, so it requires nested invocations to 585 * distinguish multiple cases. 586 */ 587 588 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L 589 #define __generic(expr, t, yes, no) \ 590 _Generic(expr, t: yes, default: no) 591 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus) 592 #define __generic(expr, t, yes, no) \ 593 __builtin_choose_expr( \ 594 __builtin_types_compatible_p(__typeof(expr), t), yes, no) 595 #endif 596 597 /*- 598 * POSIX.1 requires that the macros we test be defined before any standard 599 * header file is included. 600 * 601 * Here's a quick run-down of the versions: 602 * defined(_POSIX_SOURCE) 1003.1-1988 603 * _POSIX_C_SOURCE == 1 1003.1-1990 604 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option 605 * _POSIX_C_SOURCE == 199309 1003.1b-1993 606 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995, 607 * and the omnibus ISO/IEC 9945-1: 1996 608 * _POSIX_C_SOURCE == 200112 1003.1-2001 609 * _POSIX_C_SOURCE == 200809 1003.1-2008 610 * 611 * In addition, the X/Open Portability Guide, which is now the Single UNIX 612 * Specification, defines a feature-test macro which indicates the version of 613 * that specification, and which subsumes _POSIX_C_SOURCE. 614 * 615 * Our macros begin with two underscores to avoid namespace screwage. 616 */ 617 618 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */ 619 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1 620 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */ 621 #define _POSIX_C_SOURCE 199009 622 #endif 623 624 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */ 625 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2 626 #undef _POSIX_C_SOURCE 627 #define _POSIX_C_SOURCE 199209 628 #endif 629 630 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */ 631 #ifdef _XOPEN_SOURCE 632 #if _XOPEN_SOURCE - 0 >= 700 633 #define __XSI_VISIBLE 700 634 #undef _POSIX_C_SOURCE 635 #define _POSIX_C_SOURCE 200809 636 #elif _XOPEN_SOURCE - 0 >= 600 637 #define __XSI_VISIBLE 600 638 #undef _POSIX_C_SOURCE 639 #define _POSIX_C_SOURCE 200112 640 #elif _XOPEN_SOURCE - 0 >= 500 641 #define __XSI_VISIBLE 500 642 #undef _POSIX_C_SOURCE 643 #define _POSIX_C_SOURCE 199506 644 #endif 645 #endif 646 647 /* 648 * Deal with all versions of POSIX. The ordering relative to the tests above is 649 * important. 650 */ 651 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE) 652 #define _POSIX_C_SOURCE 198808 653 #endif 654 #ifdef _POSIX_C_SOURCE 655 #if (_POSIX_C_SOURCE - 0) >= 200809 656 #define __POSIX_VISIBLE 200809 657 #define __ISO_C_VISIBLE 1999 658 #elif (_POSIX_C_SOURCE - 0) >= 200112 659 #define __POSIX_VISIBLE 200112 660 #define __ISO_C_VISIBLE 1999 661 #elif (_POSIX_C_SOURCE - 0) >= 199506 662 #define __POSIX_VISIBLE 199506 663 #define __ISO_C_VISIBLE 1990 664 #elif (_POSIX_C_SOURCE - 0) >= 199309 665 #define __POSIX_VISIBLE 199309 666 #define __ISO_C_VISIBLE 1990 667 #elif (_POSIX_C_SOURCE - 0) >= 199209 668 #define __POSIX_VISIBLE 199209 669 #define __ISO_C_VISIBLE 1990 670 #elif (_POSIX_C_SOURCE - 0) >= 199009 671 #define __POSIX_VISIBLE 199009 672 #define __ISO_C_VISIBLE 1990 673 #else 674 #define __POSIX_VISIBLE 198808 675 #define __ISO_C_VISIBLE 0 676 #endif /* _POSIX_C_SOURCE */ 677 #else 678 /*- 679 * Deal with _ANSI_SOURCE: 680 * If it is defined, and no other compilation environment is explicitly 681 * requested, then define our internal feature-test macros to zero. This 682 * makes no difference to the preprocessor (undefined symbols in preprocessing 683 * expressions are defined to have value zero), but makes it more convenient for 684 * a test program to print out the values. 685 * 686 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as 687 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation 688 * environment (and in fact we will never get here). 689 */ 690 #if defined(_ANSI_SOURCE) /* Hide almost everything. */ 691 #define __POSIX_VISIBLE 0 692 #define __XSI_VISIBLE 0 693 #define __BSD_VISIBLE 0 694 #define __ISO_C_VISIBLE 1990 695 #define __EXT1_VISIBLE 0 696 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */ 697 #define __POSIX_VISIBLE 0 698 #define __XSI_VISIBLE 0 699 #define __BSD_VISIBLE 0 700 #define __ISO_C_VISIBLE 1999 701 #define __EXT1_VISIBLE 0 702 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */ 703 #define __POSIX_VISIBLE 0 704 #define __XSI_VISIBLE 0 705 #define __BSD_VISIBLE 0 706 #define __ISO_C_VISIBLE 2011 707 #define __EXT1_VISIBLE 0 708 #else /* Default environment: show everything. */ 709 #define __POSIX_VISIBLE 200809 710 #define __XSI_VISIBLE 700 711 #define __BSD_VISIBLE 1 712 #define __ISO_C_VISIBLE 2011 713 #define __EXT1_VISIBLE 1 714 #endif 715 #endif 716 717 /* User override __EXT1_VISIBLE */ 718 #if defined(__STDC_WANT_LIB_EXT1__) 719 #undef __EXT1_VISIBLE 720 #if __STDC_WANT_LIB_EXT1__ 721 #define __EXT1_VISIBLE 1 722 #else 723 #define __EXT1_VISIBLE 0 724 #endif 725 #endif /* __STDC_WANT_LIB_EXT1__ */ 726 727 #ifndef __BSD_VISIBLE 728 #define __BSD_VISIBLE 0 729 #endif 730 #ifndef __EXT1_VISIBLE 731 #define __EXT1_VISIBLE 0 732 #endif 733 734 /* 735 * GLOBL macro exists to preserve __start_set_* and __stop_set_* sections 736 * of kernel modules which are discarded from binutils 2.17.50+ otherwise. 737 */ 738 739 #define __GLOBL1(sym) __asm__(".globl " #sym) 740 #define __GLOBL(sym) __GLOBL1(sym) 741 742 #endif /* !_SYS_CDEFS_H_ */ 743