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 * C99 allows the 'static' keyword in array declarators of function 311 * parameter lists, such as: 312 * void bar(int myArray[static 10]); 313 * However, this is allowed in C++, so define this __min_size() macro 314 * to make headers usable in both languages. 315 */ 316 #if !defined(__cplusplus) && \ 317 (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901) 318 #define __min_size(x) static (x) 319 #else 320 #define __min_size(x) (x) 321 #endif 322 323 /* 324 * GNU C version 2.96 adds explicit branch prediction so that 325 * the CPU back-end can hint the processor and also so that 326 * code blocks can be reordered such that the predicted path 327 * sees a more linear flow, thus improving cache behavior, etc. 328 * 329 * The following two macros provide us with a way to utilize this 330 * compiler feature. Use __predict_true() if you expect the expression 331 * to evaluate to true, and __predict_false() if you expect the 332 * expression to evaluate to false. 333 * 334 * A few notes about usage: 335 * 336 * * Generally, __predict_false() error condition checks (unless 337 * you have some _strong_ reason to do otherwise, in which case 338 * document it), and/or __predict_true() `no-error' condition 339 * checks, assuming you want to optimize for the no-error case. 340 * 341 * * Other than that, if you don't know the likelihood of a test 342 * succeeding from empirical or other `hard' evidence, don't 343 * make predictions. 344 * 345 * * These are meant to be used in places that are run `a lot'. 346 * It is wasteful to make predictions in code that is run 347 * seldomly (e.g. at subsystem initialization time) as the 348 * basic block reordering that this affects can often generate 349 * larger code. 350 */ 351 #if __GNUC_PREREQ__(2, 96) 352 #define __predict_true(exp) __builtin_expect((exp), 1) 353 #define __predict_false(exp) __builtin_expect((exp), 0) 354 #else 355 #define __predict_true(exp) (exp) 356 #define __predict_false(exp) (exp) 357 #endif 358 359 /* 360 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h> 361 * require it. 362 */ 363 #if __GNUC_PREREQ__(4, 1) 364 #define __offsetof(type, field) __builtin_offsetof(type, field) 365 #else 366 #ifndef __cplusplus 367 #define __offsetof(type, field) \ 368 ((__size_t)(__uintptr_t)((const volatile void *)&((type *)0)->field)) 369 #else 370 #define __offsetof(type, field) \ 371 (__offsetof__ (reinterpret_cast <__size_t> \ 372 (&reinterpret_cast <const volatile char &> \ 373 (static_cast<type *> (0)->field)))) 374 #endif 375 #endif 376 377 /* 378 * Given the pointer x to the member m of the struct s, return a pointer to 379 * the containing structure. When using GCC, we first assign pointer x to 380 * a local variable, to check that its type is compatible with member m. 381 */ 382 #if __GNUC_PREREQ__(3, 1) 383 #define __containerof(x, s, m) ({ \ 384 const volatile __typeof(((s *)NULL)->m) *__x = (x); \ 385 __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m)); \ 386 }) 387 #else 388 #define __containerof(x, s, m) \ 389 __DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m)) 390 #endif 391 392 /* 393 * Compiler-dependent macros to declare that functions take printf-like 394 * or scanf-like arguments. They are null except for versions of gcc 395 * that are known to support the features properly (old versions of gcc-2 396 * didn't permit keeping the keywords out of the application namespace). 397 * 398 * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions. 399 */ 400 #if !__GNUC_PREREQ__(2, 7) 401 #define __printflike(fmtarg, firstvararg) 402 #define __scanflike(fmtarg, firstvararg) 403 #define __printf0like(fmtarg, firstvararg) 404 #define __format_arg(fmtarg) 405 #define __strfmonlike(fmtarg, firstvararg) 406 #define __strftimelike(fmtarg, firstvararg) 407 408 #elif __GNUC_PREREQ__(3, 0) 409 #define __printflike(fmtarg, firstvararg) \ 410 __attribute__((__nonnull__(fmtarg), \ 411 __format__ (__printf__, fmtarg, firstvararg))) 412 #define __printf0like(fmtarg, firstvararg) \ 413 __attribute__((__format__ (__printf__, fmtarg, firstvararg))) 414 #define __scanflike(fmtarg, firstvararg) \ 415 __attribute__((__format__ (__scanf__, fmtarg, firstvararg))) 416 #define __format_arg(fmtarg) \ 417 __attribute__((__format_arg__ (fmtarg))) 418 #define __strfmonlike(fmtarg, firstvararg) \ 419 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg))) 420 #define __strftimelike(fmtarg, firstvararg) \ 421 __attribute__((__format__ (__strftime__, fmtarg, firstvararg))) 422 423 #else 424 #define __printflike(fmtarg, firstvararg) \ 425 __attribute__((__format__ (__printf__, fmtarg, firstvararg))) 426 #define __printf0like(fmtarg, firstvararg) \ 427 __attribute__((__format__ (__printf0__, fmtarg, firstvararg))) 428 #define __scanflike(fmtarg, firstvararg) \ 429 __attribute__((__format__ (__scanf__, fmtarg, firstvararg))) 430 #define __format_arg(fmtarg) \ 431 __attribute__((__format_arg__ (fmtarg))) 432 #define __strfmonlike(fmtarg, firstvararg) \ 433 __attribute__((__format__ (__strfmon__, fmtarg, firstvararg))) 434 #define __strftimelike(fmtarg, firstvararg) \ 435 __attribute__((__format__ (__strftime__, fmtarg, firstvararg))) 436 #endif 437 438 #if !__GNUC_PREREQ__(3, 0) 439 #define __ARRAY_ZERO 0 440 #else 441 #define __ARRAY_ZERO 442 #endif 443 444 /* 445 * A convenient constructor macro, GCC 4.3.0 added priority support to 446 * constructors, provide a compatible interface for both. 447 */ 448 #if __GNUC_PREREQ__(4, 3) 449 #define __constructor(prio) __attribute__((constructor(prio))) 450 #else 451 #define __constructor(prio) __attribute__((constructor)) 452 #endif 453 454 /* 455 * Handy GCC based macros: 456 * 457 * __cachealign: 458 * 459 * The __cachealign macro can be used for cache line aligning structures 460 * of small to medium size. It aligns the particular structure or 461 * storage type to a system default cache line alignment, thus giving us 462 * a much more better cache utilization by making the hardware work at 463 * its best burst speeds. 464 * 465 * __usereg: 466 * 467 * The __usereg macro can/should be used when a function contains 468 * arguments not more than 3. It can be very useful to us due to the 469 * message-passing nature of the kernel. 470 * 471 * !!NOTE - USAGE INFORMATION!! 472 * 473 * The __cachealign macro should not be used for data structures that are 474 * as big struct proc, struct vnode, struct thread, and other structs which 475 * are as big as them; simply because it will be useless in that case. 476 * 477 * The __usereg macro should be used whenever possible, i.e., when a function 478 * does not exceed more than 3 arguments, and should not be used for vararg 479 * type functions. 480 * 481 * In other words, AVOID MISUSE OF THESE MACROS. :-) 482 */ 483 #ifdef __GNUC__ 484 #define __cachealign __attribute__((__aligned__(__VM_CACHELINE_SIZE))) 485 #define __usereg __attribute__((__regparm__(3))) 486 #else 487 #define __cachealign 488 #define __usereg 489 #endif 490 491 #ifdef __GNUC__ 492 #define __strong_reference(sym,aliassym) \ 493 extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym))) 494 #define __weak_reference(sym,aliassym) \ 495 __strong_reference(sym,aliassym) __attribute__ ((__weak__)) 496 #define __weak_reference_asm(sym,alias) \ 497 __asm__(".weak " #alias); \ 498 __asm__(".equ " #alias ", " #sym) 499 #define __warn_references(sym,msg) \ 500 __asm__(".section .gnu.warning." #sym); \ 501 __asm__(".asciz \"" msg "\""); \ 502 __asm__(".previous") 503 #define __sym_compat(sym,impl,verid) \ 504 __asm__(".symver " #impl ", " #sym "@" #verid) 505 #define __sym_default(sym,impl,verid) \ 506 __asm__(".symver " #impl ", " #sym "@@@" #verid) 507 #endif /* __GNUC__ */ 508 509 #if defined(__GNUC__) 510 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"") 511 #endif 512 513 #ifndef __RCSID 514 #define __RCSID(s) struct __hack 515 #endif 516 517 #ifndef __RCSID_SOURCE 518 #define __RCSID_SOURCE(s) struct __hack 519 #endif 520 521 #ifndef __SCCSID 522 #define __SCCSID(s) struct __hack 523 #endif 524 525 #ifndef __FBSDID 526 #define __FBSDID(s) struct __hack 527 #endif 528 529 #ifndef __COPYRIGHT 530 #define __COPYRIGHT(s) struct __hack 531 #endif 532 533 #ifndef __DECONST 534 #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var)) 535 #endif 536 537 #ifndef __DEVOLATILE 538 #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var)) 539 #endif 540 541 #ifndef __DEQUALIFY 542 #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var)) 543 #endif 544 545 /* 546 * Keywords added in C11. 547 */ 548 549 #if !__GNUC_PREREQ__(2, 95) 550 #define __alignof(x) __offsetof(struct { char __a; x __b; }, __b) 551 #endif 552 553 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L 554 555 #if !__has_extension(c_alignas) 556 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 557 __has_extension(cxx_alignas) 558 #define _Alignas(x) alignas(x) 559 #else 560 /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */ 561 #define _Alignas(x) __aligned(x) 562 #endif 563 #endif 564 565 #if defined(__cplusplus) && __cplusplus >= 201103L 566 #define _Alignof(x) alignof(x) 567 #else 568 #define _Alignof(x) __alignof(x) 569 #endif 570 571 #if !defined(_Noreturn) 572 #define _Noreturn __dead2 573 #endif 574 575 #if !__has_extension(c_static_assert) 576 #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ 577 __has_extension(cxx_static_assert) 578 #define _Static_assert(x, y) static_assert(x, y) 579 #elif !__GNUC_PREREQ__(4, 6) 580 #define _Static_assert(x, y) struct __hack 581 #ifdef _KERNEL 582 #define CTASSERT(x) _CTASSERT(x, __LINE__) 583 #define _CTASSERT(x, y) __CTASSERT(x, y) 584 #define __CTASSERT(x, y) typedef char __assert ## y[(x) ? 1 : -1] 585 #endif 586 #endif 587 588 /* 589 * GCC 4.7 has -std=c++11 but does not support thread_local. 590 */ 591 #if !__has_extension(c_thread_local) 592 #if (defined(__cplusplus) && __cplusplus >= 201103L && __GNUC_PREREQ__(4, 8)) || \ 593 __has_extension(cxx_thread_local) 594 #define _Thread_local thread_local 595 #else 596 #define _Thread_local __thread 597 #endif 598 #endif 599 #endif 600 601 #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */ 602 603 #if defined(_KERNEL) && !defined(CTASSERT) 604 #define CTASSERT(x) _Static_assert(x, \ 605 "compile-time assertion failed") 606 #endif 607 608 /* 609 * Emulation of C11 _Generic(). Unlike the previously defined C11 610 * keywords, it is not possible to implement this using exactly the same 611 * syntax. Therefore implement something similar under the name 612 * __generic(). Unlike _Generic(), this macro can only distinguish 613 * between a single type, so it requires nested invocations to 614 * distinguish multiple cases. 615 */ 616 617 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L 618 #define __generic(expr, t, yes, no) \ 619 _Generic(expr, t: yes, default: no) 620 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus) 621 #define __generic(expr, t, yes, no) \ 622 __builtin_choose_expr( \ 623 __builtin_types_compatible_p(__typeof(expr), t), yes, no) 624 #endif 625 626 /*- 627 * POSIX.1 requires that the macros we test be defined before any standard 628 * header file is included. 629 * 630 * Here's a quick run-down of the versions: 631 * defined(_POSIX_SOURCE) 1003.1-1988 632 * _POSIX_C_SOURCE == 1 1003.1-1990 633 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option 634 * _POSIX_C_SOURCE == 199309 1003.1b-1993 635 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995, 636 * and the omnibus ISO/IEC 9945-1: 1996 637 * _POSIX_C_SOURCE == 200112 1003.1-2001 638 * _POSIX_C_SOURCE == 200809 1003.1-2008 639 * 640 * In addition, the X/Open Portability Guide, which is now the Single UNIX 641 * Specification, defines a feature-test macro which indicates the version of 642 * that specification, and which subsumes _POSIX_C_SOURCE. 643 * 644 * Our macros begin with two underscores to avoid namespace screwage. 645 */ 646 647 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */ 648 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1 649 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */ 650 #define _POSIX_C_SOURCE 199009 651 #endif 652 653 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */ 654 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2 655 #undef _POSIX_C_SOURCE 656 #define _POSIX_C_SOURCE 199209 657 #endif 658 659 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */ 660 #ifdef _XOPEN_SOURCE 661 #if _XOPEN_SOURCE - 0 >= 700 662 #define __XSI_VISIBLE 700 663 #undef _POSIX_C_SOURCE 664 #define _POSIX_C_SOURCE 200809 665 #elif _XOPEN_SOURCE - 0 >= 600 666 #define __XSI_VISIBLE 600 667 #undef _POSIX_C_SOURCE 668 #define _POSIX_C_SOURCE 200112 669 #elif _XOPEN_SOURCE - 0 >= 500 670 #define __XSI_VISIBLE 500 671 #undef _POSIX_C_SOURCE 672 #define _POSIX_C_SOURCE 199506 673 #endif 674 #endif 675 676 /* 677 * Deal with all versions of POSIX. The ordering relative to the tests above is 678 * important. 679 */ 680 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE) 681 #define _POSIX_C_SOURCE 198808 682 #endif 683 #ifdef _POSIX_C_SOURCE 684 #if (_POSIX_C_SOURCE - 0) >= 200809 685 #define __POSIX_VISIBLE 200809 686 #define __ISO_C_VISIBLE 1999 687 #elif (_POSIX_C_SOURCE - 0) >= 200112 688 #define __POSIX_VISIBLE 200112 689 #define __ISO_C_VISIBLE 1999 690 #elif (_POSIX_C_SOURCE - 0) >= 199506 691 #define __POSIX_VISIBLE 199506 692 #define __ISO_C_VISIBLE 1990 693 #elif (_POSIX_C_SOURCE - 0) >= 199309 694 #define __POSIX_VISIBLE 199309 695 #define __ISO_C_VISIBLE 1990 696 #elif (_POSIX_C_SOURCE - 0) >= 199209 697 #define __POSIX_VISIBLE 199209 698 #define __ISO_C_VISIBLE 1990 699 #elif (_POSIX_C_SOURCE - 0) >= 199009 700 #define __POSIX_VISIBLE 199009 701 #define __ISO_C_VISIBLE 1990 702 #else 703 #define __POSIX_VISIBLE 198808 704 #define __ISO_C_VISIBLE 0 705 #endif /* _POSIX_C_SOURCE */ 706 #else 707 /*- 708 * Deal with _ANSI_SOURCE: 709 * If it is defined, and no other compilation environment is explicitly 710 * requested, then define our internal feature-test macros to zero. This 711 * makes no difference to the preprocessor (undefined symbols in preprocessing 712 * expressions are defined to have value zero), but makes it more convenient for 713 * a test program to print out the values. 714 * 715 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as 716 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation 717 * environment (and in fact we will never get here). 718 */ 719 #if defined(_ANSI_SOURCE) /* Hide almost everything. */ 720 #define __POSIX_VISIBLE 0 721 #define __XSI_VISIBLE 0 722 #define __BSD_VISIBLE 0 723 #define __ISO_C_VISIBLE 1990 724 #define __EXT1_VISIBLE 0 725 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */ 726 #define __POSIX_VISIBLE 0 727 #define __XSI_VISIBLE 0 728 #define __BSD_VISIBLE 0 729 #define __ISO_C_VISIBLE 1999 730 #define __EXT1_VISIBLE 0 731 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */ 732 #define __POSIX_VISIBLE 0 733 #define __XSI_VISIBLE 0 734 #define __BSD_VISIBLE 0 735 #define __ISO_C_VISIBLE 2011 736 #define __EXT1_VISIBLE 0 737 #else /* Default environment: show everything. */ 738 #define __POSIX_VISIBLE 200809 739 #define __XSI_VISIBLE 700 740 #define __BSD_VISIBLE 1 741 #define __ISO_C_VISIBLE 2011 742 #define __EXT1_VISIBLE 1 743 #endif 744 #endif 745 746 /* User override __EXT1_VISIBLE */ 747 #if defined(__STDC_WANT_LIB_EXT1__) 748 #undef __EXT1_VISIBLE 749 #if __STDC_WANT_LIB_EXT1__ 750 #define __EXT1_VISIBLE 1 751 #else 752 #define __EXT1_VISIBLE 0 753 #endif 754 #endif /* __STDC_WANT_LIB_EXT1__ */ 755 756 #ifndef __BSD_VISIBLE 757 #define __BSD_VISIBLE 0 758 #endif 759 #ifndef __EXT1_VISIBLE 760 #define __EXT1_VISIBLE 0 761 #endif 762 763 /* 764 * GLOBL macro exists to preserve __start_set_* and __stop_set_* sections 765 * of kernel modules which are discarded from binutils 2.17.50+ otherwise. 766 */ 767 768 #define __GLOBL1(sym) __asm__(".globl " #sym) 769 #define __GLOBL(sym) __GLOBL1(sym) 770 771 #endif /* !_SYS_CDEFS_H_ */ 772