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 1.20 2008/11/20 11:27:24 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     64
  75 #define __VM_CACHELINE_ALIGN(n) \
  76                         (((n) + __VM_CACHELINE_SIZE - 1) / __VM_CACHELINE_SIZE)
  77
  78 /*
  79  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
  80  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
  81  * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
  82  * mode -- there must be no spaces between its arguments, and for nested
  83  * __CONCAT's, all the __CONCAT's must be at the left.  __CONCAT can also
  84  * concatenate double-quoted strings produced by the __STRING macro, but
  85  * this only works with ANSI C.
  86  *
  87  * __XSTRING is like __STRING, but it expands any macros in its argument
  88  * first.  It is only available with ANSI C.
  89  */
  90 #if defined(__STDC__) || defined(__cplusplus)
  91 #define __P(protos)     protos          /* full-blown ANSI C */
  92 #define __CONCAT1(x,y)  x ## y
  93 #define __CONCAT(x,y)   __CONCAT1(x,y)
  94 #define __STRING(x)     #x              /* stringify without expanding x */
  95 #define __XSTRING(x)    __STRING(x)     /* expand x, then stringify */
  96
  97 #define __const         const           /* define reserved names to standard */
  98 #define __signed        signed
  99 #define __volatile      volatile
 100 #if defined(__cplusplus)
 101 #define __inline        inline          /* convert to C++ keyword */
 102 #else
 103 #ifndef __GNUC__
 104 #define __inline                        /* delete GCC keyword */
 105 #endif /* !__GNUC__ */
 106 #endif /* !__cplusplus */
 107
 108 #else   /* !(__STDC__ || __cplusplus) */
 109 #define __P(protos)     ()              /* traditional C preprocessor */
 110 #define __CONCAT(x,y)   x/**/y
 111 #define __STRING(x)     "x"
 112
 113 #ifndef __GNUC__
 114 #define __const                         /* delete pseudo-ANSI C keywords */
 115 #define __inline
 116 #define __signed
 117 #define __volatile
 118 /*
 119  * In non-ANSI C environments, new programs will want ANSI-only C keywords
 120  * deleted from the program and old programs will want them left alone.
 121  * When using a compiler other than gcc, programs using the ANSI C keywords
 122  * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
 123  * When using "gcc -traditional", we assume that this is the intent; if
 124  * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
 125  */
 126 #ifndef NO_ANSI_KEYWORDS
 127 #define const                           /* delete ANSI C keywords */
 128 #define inline
 129 #define signed
 130 #define volatile
 131 #endif  /* !NO_ANSI_KEYWORDS */
 132 #endif  /* !__GNUC__ */
 133 #endif  /* !(__STDC__ || __cplusplus) */
 134
 135 /*
 136  * Compiler-dependent macros to help declare dead (non-returning) and
 137  * pure (no side effects) functions, and unused variables.  They are
 138  * null except for versions of gcc that are known to support the features
 139  * properly (old versions of gcc-2 supported the dead and pure features
 140  * in a different (wrong) way).
 141  */
 142 #ifdef lint
 143
 144 #define __dead2
 145 #define __pure
 146 #define __pure2
 147 #define __unused
 148 #define __packed
 149 #define __aligned(x)
 150 #define __section(x)
 151 #define __always_inline
 152 #define __nonnull(x)
 153
 154 #else
 155
 156 #if !__GNUC_PREREQ__(2, 7)
 157 #define __dead2
 158 #define __pure2
 159 #define __unused
 160 #endif
 161
 162 #if __GNUC_PREREQ__(2, 7)
 163 #define __dead2         __attribute__((__noreturn__))
 164 #define __pure2         __attribute__((__const__))
 165 #define __unused        __attribute__((__unused__))
 166 #define __packed        __attribute__((__packed__))
 167 #define __aligned(x)    __attribute__((__aligned__(x)))
 168 #define __section(x)    __attribute__((__section__(x)))
 169 #endif
 170
 171 #if __GNUC_PREREQ__(2, 96)
 172 #define __pure          __attribute__((__pure__))
 173 #else
 174 #define __pure          __pure2
 175 #endif
 176
 177 #if __GNUC_PREREQ__(3, 1)
 178 #define __always_inline __attribute__((__always_inline__))
 179 #define __noinline      __attribute__((__noinline__))
 180 #else
 181 #define __always_inline
 182 #define __noinline
 183 #endif
 184
 185 #if __GNUC_PREREQ__(3, 3)
 186 #define __nonnull(x)    __attribute__((__nonnull__(x)))
 187 #define __used          __attribute__((__used__))
 188 #else
 189 #define __nonnull(x)
 190 #define __used          __unused
 191 #endif
 192
 193 #endif  /* LINT */
 194
 195 #if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION < 199901
 196 #define __func__        NULL
 197 #endif
 198
 199 #if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI)) || \
 200     __STDC_VERSION__ >= 199901
 201 #define __LONG_LONG_SUPPORTED
 202 #endif
 203
 204 /*
 205  * GNU C version 2.96 adds explicit branch prediction so that
 206  * the CPU back-end can hint the processor and also so that
 207  * code blocks can be reordered such that the predicted path
 208  * sees a more linear flow, thus improving cache behavior, etc.
 209  *
 210  * The following two macros provide us with a way to utilize this
 211  * compiler feature.  Use __predict_true() if you expect the expression
 212  * to evaluate to true, and __predict_false() if you expect the
 213  * expression to evaluate to false.
 214  *
 215  * A few notes about usage:
 216  *
 217  *      * Generally, __predict_false() error condition checks (unless
 218  *        you have some _strong_ reason to do otherwise, in which case
 219  *        document it), and/or __predict_true() `no-error' condition
 220  *        checks, assuming you want to optimize for the no-error case.
 221  *
 222  *      * Other than that, if you don't know the likelihood of a test
 223  *        succeeding from empirical or other `hard' evidence, don't
 224  *        make predictions.
 225  *
 226  *      * These are meant to be used in places that are run `a lot'.
 227  *        It is wasteful to make predictions in code that is run
 228  *        seldomly (e.g. at subsystem initialization time) as the
 229  *        basic block reordering that this affects can often generate
 230  *        larger code.
 231  */
 232 #if __GNUC_PREREQ__(2, 96)
 233 #define __predict_true(exp)     __builtin_expect((exp), 1)
 234 #define __predict_false(exp)    __builtin_expect((exp), 0)
 235 #else
 236 #define __predict_true(exp)     (exp)
 237 #define __predict_false(exp)    (exp)
 238 #endif
 239
 240 /*
 241  * GCC 2.95 and later provides `__restrict' as an extention to C90 to support
 242  * the C99-specific `restrict' type qualifier.  We happen to use `__restrict'
 243  * as a way to define the `restrict' type qualifier without disturbing older
 244  * software that is unaware of C99 keywords.
 245  */
 246 #if !__GNUC_PREREQ__(2, 95)
 247 #if __STDC_VERSION__ < 199901
 248 #define __restrict
 249 #else
 250 #define __restrict      restrict
 251 #endif
 252 #endif
 253
 254 /*
 255  * Compiler-dependent macros to declare that functions take printf-like
 256  * or scanf-like arguments.  They are null except for versions of gcc
 257  * that are known to support the features properly (old versions of gcc-2
 258  * didn't permit keeping the keywords out of the application namespace).
 259  *
 260  * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
 261  */
 262 #if !__GNUC_PREREQ__(2, 7)
 263 #define __printflike(fmtarg, firstvararg)
 264 #define __scanflike(fmtarg, firstvararg)
 265 #define __printf0like(fmtarg, firstvararg)
 266 #define __format_arg(fmtarg)
 267 #elif __GNUC_PREREQ__(3, 0)
 268 #define __printflike(fmtarg, firstvararg) \
 269             __attribute__((__nonnull__(fmtarg), \
 270                           __format__ (__printf__, fmtarg, firstvararg)))
 271 #define __printf0like(fmtarg, firstvararg) \
 272             __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
 273 #define __scanflike(fmtarg, firstvararg) \
 274             __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
 275 #define __format_arg(fmtarg) \
 276             __attribute__((__format_arg__ (fmtarg)))
 277
 278 #else
 279 #define __printflike(fmtarg, firstvararg) \
 280             __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
 281 #define __printf0like(fmtarg, firstvararg) \
 282             __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
 283 #define __scanflike(fmtarg, firstvararg) \
 284             __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
 285 #define __format_arg(fmtarg) \
 286             __attribute__((__format_arg__ (fmtarg)))
 287
 288 #endif
 289
 290 #if !__GNUC_PREREQ__(3, 0)
 291 #define __ARRAY_ZERO    0
 292 #else
 293 #define __ARRAY_ZERO
 294 #endif
 295
 296 /*
 297  * Handy GCC based macros:
 298  *
 299  *      __cachealign:
 300  *
 301  *      The __cachealign macro can be used for cache line aligning structures
 302  *      of small to medium size.  It aligns the particular structure or
 303  *      storage type to a system default cache line alignment, thus giving us
 304  *      a much more better cache utilization by making the hardware work at
 305  *      its best burst speeds.
 306  *
 307  *      __usereg:
 308  *
 309  *      The __usereg macro can/should be used when a function contains
 310  *      arguments not more than 3.  It can be very useful to us due to the
 311  *      message-passing nature of the kernel.
 312  *
 313  * !!NOTE - USAGE INFORMATION!!
 314  *
 315  * The __cachealign macro should not be used for data structures that are
 316  * as big struct proc, struct vnode, struct thread, and other structs which
 317  * are as big as them; simply because it will be useless in that case.
 318  *
 319  * The __usereg macro should be used whenever possible, i.e., when a function
 320  * does not exceed more than 3 arguments, and should not be used for vararg
 321  * type functions.
 322  *
 323  * In other words, AVOID MISUSE OF THESE MACROS. :-)
 324  */
 325 #ifdef __GNUC__
 326 #define __cachealign    __attribute__((__aligned__(__VM_CACHELINE_SIZE)))
 327 #define __usereg        __attribute__((__regparm__(3)))
 328 #else
 329 #define __cachealign
 330 #define __usereg
 331 #endif
 332
 333 #ifdef __GNUC__
 334 #define __strong_reference(sym,aliassym)        \
 335         extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
 336 #define __weak_reference(sym,alias)     \
 337         __asm__(".weak " #alias);       \
 338         __asm__(".equ "  #alias ", " #sym)
 339 #define __warn_references(sym,msg)      \
 340         __asm__(".section .gnu.warning." #sym); \
 341         __asm__(".asciz \"" msg "\"");  \
 342         __asm__(".previous")
 343 #endif  /* __GNUC__ */
 344
 345 #if defined(__GNUC__)
 346 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
 347 #endif
 348
 349 #ifndef __RCSID
 350 #define __RCSID(s)      __IDSTRING(rcsid,s)
 351 #endif
 352
 353 #ifndef __RCSID_SOURCE
 354 #define __RCSID_SOURCE(s) __IDSTRING(rcsid_source,s)
 355 #endif
 356
 357 #ifndef __COPYRIGHT
 358 #define __COPYRIGHT(s)  __IDSTRING(copyright,s)
 359 #endif
 360
 361 #ifndef __DECONST
 362 #define __DECONST(type, var)    ((type)(uintptr_t)(const void *)(var))
 363 #endif
 364
 365 #ifndef __DEVOLATILE
 366 #define __DEVOLATILE(type, var) ((type)(uintptr_t)(volatile void *)(var))
 367 #endif
 368
 369 #ifndef __DEQUALIFY
 370 #define __DEQUALIFY(type, var)  ((type)(uintptr_t)(const volatile void *)(var))
 371 #endif
 372
 373 /*-
 374  * The following definitions are an extension of the behavior originally
 375  * implemented in <sys/_posix.h>, but with a different level of granularity.
 376  * POSIX.1 requires that the macros we test be defined before any standard
 377  * header file is included.
 378  *
 379  * Here's a quick run-down of the versions:
 380  *  defined(_POSIX_SOURCE)              1003.1-1988
 381  *  _POSIX_C_SOURCE == 1                1003.1-1990
 382  *  _POSIX_C_SOURCE == 2                1003.2-1992 C Language Binding Option
 383  *  _POSIX_C_SOURCE == 199309           1003.1b-1993
 384  *  _POSIX_C_SOURCE == 199506           1003.1c-1995, 1003.1i-1995,
 385  *                                      and the omnibus ISO/IEC 9945-1: 1996
 386  *  _POSIX_C_SOURCE == 200112           1003.1-2001
 387  *
 388  * In addition, the X/Open Portability Guide, which is now the Single UNIX
 389  * Specification, defines a feature-test macro which indicates the version of
 390  * that specification, and which subsumes _POSIX_C_SOURCE.
 391  *
 392  * Our macros begin with two underscores to avoid namespace screwage.
 393  */
 394
 395 /*
 396  * If no special macro was specified, make the DragonFly extensions
 397  * available. Also make them available when requested so.
 398  */
 399 #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE) && \
 400     !defined(_ANSI_SOURCE) && !defined(_C99_SOURCE)) || \
 401     defined(_DRAGONFLY_SOURCE) || defined(_NETBSD_SOURCE)
 402 #define __DF_VISIBLE    1
 403 #else
 404 #define __DF_VISIBLE    0
 405 #endif
 406
 407 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
 408 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1
 409 #undef _POSIX_C_SOURCE          /* Probably illegal, but beyond caring now. */
 410 #define _POSIX_C_SOURCE         199009
 411 #endif
 412
 413 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
 414 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2
 415 #undef _POSIX_C_SOURCE
 416 #define _POSIX_C_SOURCE         199209
 417 #endif
 418
 419 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
 420 #ifdef _XOPEN_SOURCE
 421 #if _XOPEN_SOURCE - 0 >= 600
 422 #define __XSI_VISIBLE           600
 423 #undef _POSIX_C_SOURCE
 424 #define _POSIX_C_SOURCE         200112
 425 #elif _XOPEN_SOURCE - 0 >= 500
 426 #define __XSI_VISIBLE           500
 427 #undef _POSIX_C_SOURCE
 428 #define _POSIX_C_SOURCE         199506
 429 #endif
 430 #endif
 431
 432 /*
 433  * Deal with all versions of POSIX.  The ordering relative to the tests above is
 434  * important.
 435  */
 436 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
 437 #define _POSIX_C_SOURCE         198808
 438 #endif
 439 #ifdef _POSIX_C_SOURCE
 440 #if (_POSIX_C_SOURCE - 0) >= 200112
 441 #define __POSIX_VISIBLE         200112
 442 #define __ISO_C_VISIBLE         1999
 443 #elif (_POSIX_C_SOURCE - 0) >= 199506
 444 #define __POSIX_VISIBLE         199506
 445 #define __ISO_C_VISIBLE         1990
 446 #elif (_POSIX_C_SOURCE - 0) >= 199309
 447 #define __POSIX_VISIBLE         199309
 448 #define __ISO_C_VISIBLE         1990
 449 #elif (_POSIX_C_SOURCE - 0) >= 199209
 450 #define __POSIX_VISIBLE         199209
 451 #define __ISO_C_VISIBLE         1990
 452 #elif (_POSIX_C_SOURCE - 0) >= 199009
 453 #define __POSIX_VISIBLE         199009
 454 #define __ISO_C_VISIBLE         1990
 455 #else
 456 #define __POSIX_VISIBLE         198808
 457 #define __ISO_C_VISIBLE         0
 458 #endif /* _POSIX_C_SOURCE */
 459 #else
 460 /*-
 461  * Deal with _ANSI_SOURCE:
 462  * If it is defined, and no other compilation environment is explicitly
 463  * requested, then define our internal feature-test macros to zero.  This
 464  * makes no difference to the preprocessor (undefined symbols in preprocessing
 465  * expressions are defined to have value zero), but makes it more convenient for
 466  * a test program to print out the values.
 467  *
 468  * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
 469  * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
 470  * environment (and in fact we will never get here).
 471  */
 472 #ifdef _ANSI_SOURCE             /* Hide almost everything. */
 473 #define __POSIX_VISIBLE         0
 474 #define __XSI_VISIBLE           0
 475 #define __BSD_VISIBLE           0
 476 #define __ISO_C_VISIBLE         1990
 477 #elif defined(_C99_SOURCE)      /* Localism to specify strict C99 env. */
 478 #define __POSIX_VISIBLE         0
 479 #define __XSI_VISIBLE           0
 480 #define __BSD_VISIBLE           0
 481 #define __ISO_C_VISIBLE         1999
 482 #else                           /* Default environment: show everything. */
 483 #define __POSIX_VISIBLE         200112
 484 #define __XSI_VISIBLE           600
 485 #define __BSD_VISIBLE           1
 486 #define __ISO_C_VISIBLE         1999
 487 #endif
 488 #endif
 489
 490 #endif /* !_SYS_CDEFS_H_ */