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. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *      @(#)cdefs.h     8.8 (Berkeley) 1/9/95
  37  * $FreeBSD: src/sys/sys/cdefs.h,v 1.28.2.8 2002/09/18 04:05:13 mikeh Exp $
  38  * $DragonFly: src/sys/sys/cdefs.h,v 1.19.10.1 2008/11/20 11:56:50 hasso Exp $
  39  */
  40
  41 #ifndef _SYS_CDEFS_H_
  42 #define _SYS_CDEFS_H_
  43
  44 #if defined(__cplusplus)
  45 #define __BEGIN_DECLS   extern "C" {
  46 #define __END_DECLS     }
  47 #else
  48 #define __BEGIN_DECLS
  49 #define __END_DECLS
  50 #endif
  51
  52 /*
  53  * Macro to test if we are using a specific version of gcc or later.
  54  */
  55 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
  56 #define __GNUC_PREREQ__(ma, mi) \
  57         (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
  58 #else
  59 #define __GNUC_PREREQ__(ma, mi) 0
  60 #endif
  61
  62 /*
  63  * The __VM_CACHELINE_SIZE macro defines the common cache line alignment
  64  * size that can be found across most recent and somewhat latest Intel
  65  * hardware, i.e. L1 cache sizes etc.
  66  *
  67  * If needed, this value can be TUNED.  Suitable values for this macro
  68  * are 32, 64 and 128 bytes.  The unit of measurement for this macro is
  69  * bytes.
  70  *
  71  * XXX: This macro and related macros will eventually move to a MD
  72  * header, but currently, we do need such a hierarchy.
  73  */
  74 #define __VM_CACHELINE_SIZE     32
  75
  76 /*
  77  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
  78  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
  79  * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
  80  * mode -- there must be no spaces between its arguments, and for nested
  81  * __CONCAT's, all the __CONCAT's must be at the left.  __CONCAT can also
  82  * concatenate double-quoted strings produced by the __STRING macro, but
  83  * this only works with ANSI C.
  84  *
  85  * __XSTRING is like __STRING, but it expands any macros in its argument
  86  * first.  It is only available with ANSI C.
  87  */
  88 #if defined(__STDC__) || defined(__cplusplus)
  89 #define __P(protos)     protos          /* full-blown ANSI C */
  90 #define __CONCAT1(x,y)  x ## y
  91 #define __CONCAT(x,y)   __CONCAT1(x,y)
  92 #define __STRING(x)     #x              /* stringify without expanding x */
  93 #define __XSTRING(x)    __STRING(x)     /* expand x, then stringify */
  94
  95 #define __const         const           /* define reserved names to standard */
  96 #define __signed        signed
  97 #define __volatile      volatile
  98 #if defined(__cplusplus)
  99 #define __inline        inline          /* convert to C++ keyword */
 100 #else
 101 #ifndef __GNUC__
 102 #define __inline                        /* delete GCC keyword */
 103 #endif /* !__GNUC__ */
 104 #endif /* !__cplusplus */
 105
 106 #else   /* !(__STDC__ || __cplusplus) */
 107 #define __P(protos)     ()              /* traditional C preprocessor */
 108 #define __CONCAT(x,y)   x/**/y
 109 #define __STRING(x)     "x"
 110
 111 #ifndef __GNUC__
 112 #define __const                         /* delete pseudo-ANSI C keywords */
 113 #define __inline
 114 #define __signed
 115 #define __volatile
 116 /*
 117  * In non-ANSI C environments, new programs will want ANSI-only C keywords
 118  * deleted from the program and old programs will want them left alone.
 119  * When using a compiler other than gcc, programs using the ANSI C keywords
 120  * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
 121  * When using "gcc -traditional", we assume that this is the intent; if
 122  * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
 123  */
 124 #ifndef NO_ANSI_KEYWORDS
 125 #define const                           /* delete ANSI C keywords */
 126 #define inline
 127 #define signed
 128 #define volatile
 129 #endif  /* !NO_ANSI_KEYWORDS */
 130 #endif  /* !__GNUC__ */
 131 #endif  /* !(__STDC__ || __cplusplus) */
 132
 133 /*
 134  * Compiler-dependent macros to help declare dead (non-returning) and
 135  * pure (no side effects) functions, and unused variables.  They are
 136  * null except for versions of gcc that are known to support the features
 137  * properly (old versions of gcc-2 supported the dead and pure features
 138  * in a different (wrong) way).
 139  */
 140 #ifdef lint
 141
 142 #define __dead2
 143 #define __pure
 144 #define __pure2
 145 #define __unused
 146 #define __packed
 147 #define __aligned(x)
 148 #define __section(x)
 149 #define __always_inline
 150 #define __nonnull(x)
 151
 152 #else
 153
 154 #if !__GNUC_PREREQ__(2, 7)
 155 #define __dead2
 156 #define __pure2
 157 #define __unused
 158 #endif
 159
 160 #if __GNUC_PREREQ__(2, 7)
 161 #define __dead2         __attribute__((__noreturn__))
 162 #define __pure2         __attribute__((__const__))
 163 #define __unused        __attribute__((__unused__))
 164 #define __packed        __attribute__((__packed__))
 165 #define __aligned(x)    __attribute__((__aligned__(x)))
 166 #define __section(x)    __attribute__((__section__(x)))
 167 #endif
 168
 169 #if __GNUC_PREREQ__(2, 96)
 170 #define __pure          __attribute__((__pure__))
 171 #else
 172 #define __pure          __pure2
 173 #endif
 174
 175 #if __GNUC_PREREQ__(3, 1)
 176 #define __always_inline __attribute__((__always_inline__))
 177 #else
 178 #define __always_inline
 179 #endif
 180
 181 #if __GNUC_PREREQ__(3, 3)
 182 #define __nonnull(x)    __attribute__((__nonnull__(x)))
 183 #define __used          __attribute__((__used__))
 184 #else
 185 #define __nonnull(x)
 186 #define __used          __unused
 187 #endif
 188
 189 #endif  /* LINT */
 190
 191 #if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION < 199901
 192 #define __func__        NULL
 193 #endif
 194
 195 #if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI)) || \
 196     __STDC_VERSION__ >= 199901
 197 #define __LONG_LONG_SUPPORTED
 198 #endif
 199
 200 /*
 201  * GNU C version 2.96 adds explicit branch prediction so that
 202  * the CPU back-end can hint the processor and also so that
 203  * code blocks can be reordered such that the predicted path
 204  * sees a more linear flow, thus improving cache behavior, etc.
 205  *
 206  * The following two macros provide us with a way to utilize this
 207  * compiler feature.  Use __predict_true() if you expect the expression
 208  * to evaluate to true, and __predict_false() if you expect the
 209  * expression to evaluate to false.
 210  *
 211  * A few notes about usage:
 212  *
 213  *      * Generally, __predict_false() error condition checks (unless
 214  *        you have some _strong_ reason to do otherwise, in which case
 215  *        document it), and/or __predict_true() `no-error' condition
 216  *        checks, assuming you want to optimize for the no-error case.
 217  *
 218  *      * Other than that, if you don't know the likelihood of a test
 219  *        succeeding from empirical or other `hard' evidence, don't
 220  *        make predictions.
 221  *
 222  *      * These are meant to be used in places that are run `a lot'.
 223  *        It is wasteful to make predictions in code that is run
 224  *        seldomly (e.g. at subsystem initialization time) as the
 225  *        basic block reordering that this affects can often generate
 226  *        larger code.
 227  */
 228 #if __GNUC_PREREQ__(2, 96)
 229 #define __predict_true(exp)     __builtin_expect((exp), 1)
 230 #define __predict_false(exp)    __builtin_expect((exp), 0)
 231 #else
 232 #define __predict_true(exp)     (exp)
 233 #define __predict_false(exp)    (exp)
 234 #endif
 235
 236 /*
 237  * GCC 2.95 and later provides `__restrict' as an extention to C90 to support
 238  * the C99-specific `restrict' type qualifier.  We happen to use `__restrict'
 239  * as a way to define the `restrict' type qualifier without disturbing older
 240  * software that is unaware of C99 keywords.
 241  */
 242 #if !__GNUC_PREREQ__(2, 95)
 243 #if __STDC_VERSION__ < 199901
 244 #define __restrict
 245 #else
 246 #define __restrict      restrict
 247 #endif
 248 #endif
 249
 250 /*
 251  * Compiler-dependent macros to declare that functions take printf-like
 252  * or scanf-like arguments.  They are null except for versions of gcc
 253  * that are known to support the features properly (old versions of gcc-2
 254  * didn't permit keeping the keywords out of the application namespace).
 255  *
 256  * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
 257  */
 258 #if !__GNUC_PREREQ__(2, 7)
 259 #define __printflike(fmtarg, firstvararg)
 260 #define __scanflike(fmtarg, firstvararg)
 261 #define __printf0like(fmtarg, firstvararg)
 262 #elif __GNUC_PREREQ__(3, 0)
 263 #define __printflike(fmtarg, firstvararg) \
 264             __attribute__((__nonnull__(fmtarg), \
 265                           __format__ (__printf__, fmtarg, firstvararg)))
 266 #define __printf0like(fmtarg, firstvararg) \
 267             __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
 268 #define __scanflike(fmtarg, firstvararg) \
 269             __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
 270
 271 #else
 272 #define __printflike(fmtarg, firstvararg) \
 273             __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
 274 #define __printf0like(fmtarg, firstvararg) \
 275             __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
 276 #define __scanflike(fmtarg, firstvararg) \
 277             __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
 278 #endif
 279
 280 #if !__GNUC_PREREQ__(3, 0)
 281 #define __ARRAY_ZERO    0
 282 #else
 283 #define __ARRAY_ZERO
 284 #endif
 285
 286 /*
 287  * Handy GCC based macros:
 288  *
 289  *      __cachealign:
 290  *
 291  *      The __cachealign macro can be used for cache line aligning structures
 292  *      of small to medium size.  It aligns the particular structure or
 293  *      storage type to a system default cache line alignment, thus giving us
 294  *      a much more better cache utilization by making the hardware work at
 295  *      its best burst speeds.
 296  *
 297  *      __usereg:
 298  *
 299  *      The __usereg macro can/should be used when a function contains
 300  *      arguments not more than 3.  It can be very useful to us due to the
 301  *      message-passing nature of the kernel.
 302  *
 303  * !!NOTE - USAGE INFORMATION!!
 304  *
 305  * The __cachealign macro should not be used for data structures that are
 306  * as big struct proc, struct vnode, struct thread, and other structs which
 307  * are as big as them; simply because it will be useless in that case.
 308  *
 309  * The __usereg macro should be used whenever possible, i.e., when a function
 310  * does not exceed more than 3 arguments, and should not be used for vararg
 311  * type functions.
 312  *
 313  * In other words, AVOID MISUSE OF THESE MACROS. :-)
 314  */
 315 #ifdef __GNUC__
 316 #define __cachealign    __attribute__((__aligned__(__VM_CACHELINE_SIZE)))
 317 #define __usereg        __attribute__((__regparm__(3)))
 318 #else
 319 #define __cachealign
 320 #define __usereg
 321 #endif
 322
 323 #ifdef __GNUC__
 324 #define __strong_reference(sym,aliassym)        \
 325         extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
 326 #define __weak_reference(sym,alias)     \
 327         __asm__(".weak " #alias);       \
 328         __asm__(".equ "  #alias ", " #sym)
 329 #define __warn_references(sym,msg)      \
 330         __asm__(".section .gnu.warning." #sym); \
 331         __asm__(".asciz \"" msg "\"");  \
 332         __asm__(".previous")
 333 #endif  /* __GNUC__ */
 334
 335 #if defined(__GNUC__)
 336 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
 337 #endif
 338
 339 #ifndef __RCSID
 340 #define __RCSID(s)      __IDSTRING(rcsid,s)
 341 #endif
 342
 343 #ifndef __RCSID_SOURCE
 344 #define __RCSID_SOURCE(s) __IDSTRING(rcsid_source,s)
 345 #endif
 346
 347 #ifndef __COPYRIGHT
 348 #define __COPYRIGHT(s)  __IDSTRING(copyright,s)
 349 #endif
 350
 351 #ifndef __DECONST
 352 #define __DECONST(type, var)    ((type)(uintptr_t)(const void *)(var))
 353 #endif
 354
 355 #ifndef __DEVOLATILE
 356 #define __DEVOLATILE(type, var) ((type)(uintptr_t)(volatile void *)(var))
 357 #endif
 358
 359 #ifndef __DEQUALIFY
 360 #define __DEQUALIFY(type, var)  ((type)(uintptr_t)(const volatile void *)(var))
 361 #endif
 362
 363 /*-
 364  * The following definitions are an extension of the behavior originally
 365  * implemented in <sys/_posix.h>, but with a different level of granularity.
 366  * POSIX.1 requires that the macros we test be defined before any standard
 367  * header file is included.
 368  *
 369  * Here's a quick run-down of the versions:
 370  *  defined(_POSIX_SOURCE)              1003.1-1988
 371  *  _POSIX_C_SOURCE == 1                1003.1-1990
 372  *  _POSIX_C_SOURCE == 2                1003.2-1992 C Language Binding Option
 373  *  _POSIX_C_SOURCE == 199309           1003.1b-1993
 374  *  _POSIX_C_SOURCE == 199506           1003.1c-1995, 1003.1i-1995,
 375  *                                      and the omnibus ISO/IEC 9945-1: 1996
 376  *  _POSIX_C_SOURCE == 200112           1003.1-2001
 377  *
 378  * In addition, the X/Open Portability Guide, which is now the Single UNIX
 379  * Specification, defines a feature-test macro which indicates the version of
 380  * that specification, and which subsumes _POSIX_C_SOURCE.
 381  *
 382  * Our macros begin with two underscores to avoid namespace screwage.
 383  */
 384
 385 /*
 386  * If no special macro was specified, make the DragonFly extensions
 387  * available. Also make them available when requested so.
 388  */
 389 #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE) && \
 390     !defined(_ANSI_SOURCE) && !defined(_C99_SOURCE)) || \
 391     defined(_DRAGONFLY_SOURCE) || defined(_NETBSD_SOURCE)
 392 #define __DF_VISIBLE    1
 393 #else
 394 #define __DF_VISIBLE    0
 395 #endif
 396
 397 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
 398 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1
 399 #undef _POSIX_C_SOURCE          /* Probably illegal, but beyond caring now. */
 400 #define _POSIX_C_SOURCE         199009
 401 #endif
 402
 403 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
 404 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2
 405 #undef _POSIX_C_SOURCE
 406 #define _POSIX_C_SOURCE         199209
 407 #endif
 408
 409 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
 410 #ifdef _XOPEN_SOURCE
 411 #if _XOPEN_SOURCE - 0 >= 600
 412 #define __XSI_VISIBLE           600
 413 #undef _POSIX_C_SOURCE
 414 #define _POSIX_C_SOURCE         200112
 415 #elif _XOPEN_SOURCE - 0 >= 500
 416 #define __XSI_VISIBLE           500
 417 #undef _POSIX_C_SOURCE
 418 #define _POSIX_C_SOURCE         199506
 419 #endif
 420 #endif
 421
 422 /*
 423  * Deal with all versions of POSIX.  The ordering relative to the tests above is
 424  * important.
 425  */
 426 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
 427 #define _POSIX_C_SOURCE         198808
 428 #endif
 429 #ifdef _POSIX_C_SOURCE
 430 #if (_POSIX_C_SOURCE - 0) >= 200112
 431 #define __POSIX_VISIBLE         200112
 432 #define __ISO_C_VISIBLE         1999
 433 #elif (_POSIX_C_SOURCE - 0) >= 199506
 434 #define __POSIX_VISIBLE         199506
 435 #define __ISO_C_VISIBLE         1990
 436 #elif (_POSIX_C_SOURCE - 0) >= 199309
 437 #define __POSIX_VISIBLE         199309
 438 #define __ISO_C_VISIBLE         1990
 439 #elif (_POSIX_C_SOURCE - 0) >= 199209
 440 #define __POSIX_VISIBLE         199209
 441 #define __ISO_C_VISIBLE         1990
 442 #elif (_POSIX_C_SOURCE - 0) >= 199009
 443 #define __POSIX_VISIBLE         199009
 444 #define __ISO_C_VISIBLE         1990
 445 #else
 446 #define __POSIX_VISIBLE         198808
 447 #define __ISO_C_VISIBLE         0
 448 #endif /* _POSIX_C_SOURCE */
 449 #else
 450 /*-
 451  * Deal with _ANSI_SOURCE:
 452  * If it is defined, and no other compilation environment is explicitly
 453  * requested, then define our internal feature-test macros to zero.  This
 454  * makes no difference to the preprocessor (undefined symbols in preprocessing
 455  * expressions are defined to have value zero), but makes it more convenient for
 456  * a test program to print out the values.
 457  *
 458  * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
 459  * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
 460  * environment (and in fact we will never get here).
 461  */
 462 #ifdef _ANSI_SOURCE             /* Hide almost everything. */
 463 #define __POSIX_VISIBLE         0
 464 #define __XSI_VISIBLE           0
 465 #define __BSD_VISIBLE           0
 466 #define __ISO_C_VISIBLE         1990
 467 #elif defined(_C99_SOURCE)      /* Localism to specify strict C99 env. */
 468 #define __POSIX_VISIBLE         0
 469 #define __XSI_VISIBLE           0
 470 #define __BSD_VISIBLE           0
 471 #define __ISO_C_VISIBLE         1999
 472 #else                           /* Default environment: show everything. */
 473 #define __POSIX_VISIBLE         200112
 474 #define __XSI_VISIBLE           600
 475 #define __BSD_VISIBLE           1
 476 #define __ISO_C_VISIBLE         1999
 477 #endif
 478 #endif
 479
 480 #endif /* !_SYS_CDEFS_H_ */