sys/sys/cdefs.h

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