cdefs.h

00001 /*
00002  * Copyright (c) 1991, 1993
00003  *      The Regents of the University of California.  All rights reserved.
00004  *
00005  * This code is derived from software contributed to Berkeley by
00006  * Berkeley Software Design, Inc.
00007  *
00008  * Redistribution and use in source and binary forms, with or without
00009  * modification, are permitted provided that the following conditions
00010  * are met:
00011  * 1. Redistributions of source code must retain the above copyright
00012  *    notice, this list of conditions and the following disclaimer.
00013  * 2. Redistributions in binary form must reproduce the above copyright
00014  *    notice, this list of conditions and the following disclaimer in the
00015  *    documentation and/or other materials provided with the distribution.
00016  * 3. All advertising materials mentioning features or use of this software
00017  *    must display the following acknowledgement:
00018  *      This product includes software developed by the University of
00019  *      California, Berkeley and its contributors.
00020  * 4. Neither the name of the University nor the names of its contributors
00021  *    may be used to endorse or promote products derived from this software
00022  *    without specific prior written permission.
00023  *
00024  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00025  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00026  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00027  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00028  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00029  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00030  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00031  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00032  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00033  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00034  * SUCH DAMAGE.
00035  *
00036  *      @(#)cdefs.h     8.8 (Berkeley) 1/9/95
00037  * $FreeBSD: src/sys/sys/cdefs.h,v 1.78 2003/10/01 11:26:20 mux Exp $
00038  */
00039 
00040 #ifndef _SYS_CDEFS_H_
00041 #define _SYS_CDEFS_H_
00042 
00043 #if defined(__cplusplus)
00044 #define __BEGIN_DECLS   extern "C" {
00045 #define __END_DECLS     }
00046 #else
00047 #define __BEGIN_DECLS
00048 #define __END_DECLS
00049 #endif
00050 
00051 /*
00052  * Macro to test if we're using a specific version of gcc or later.
00053  */
00054 #ifdef __GNUC__
00055 #define __GNUC_PREREQ__(ma, mi) \
00056         (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
00057 #else
00058 #define __GNUC_PREREQ__(ma, mi) 0
00059 #endif
00060 
00061 /*
00062  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
00063  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
00064  * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
00065  * mode -- there must be no spaces between its arguments, and for nested
00066  * __CONCAT's, all the __CONCAT's must be at the left.  __CONCAT can also
00067  * concatenate double-quoted strings produced by the __STRING macro, but
00068  * this only works with ANSI C.
00069  *
00070  * __XSTRING is like __STRING, but it expands any macros in its argument
00071  * first.  It is only available with ANSI C.
00072  */
00073 #if defined(__STDC__) || defined(__cplusplus)
00074 #define __P(protos)     protos          /* full-blown ANSI C */
00075 #define __CONCAT1(x,y)  x ## y
00076 #define __CONCAT(x,y)   __CONCAT1(x,y)
00077 #define __STRING(x)     #x              /* stringify without expanding x */
00078 #define __XSTRING(x)    __STRING(x)     /* expand x, then stringify */
00079 
00080 #define __const         const           /* define reserved names to standard */
00081 #define __signed        signed
00082 #define __volatile      volatile
00083 #if defined(__cplusplus)
00084 #define __inline        inline          /* convert to C++ keyword */
00085 #else
00086 #ifndef __GNUC__
00087 #define __inline                        /* delete GCC keyword */
00088 #endif /* !__GNUC__ */
00089 #endif /* !__cplusplus */
00090 
00091 #else   /* !(__STDC__ || __cplusplus) */
00092 #define __P(protos)     ()              /* traditional C preprocessor */
00093 #define __CONCAT(x,y)   xy
00094 #define __STRING(x)     "x"
00095 
00096 #ifndef __GNUC__
00097 #define __const                         /* delete pseudo-ANSI C keywords */
00098 #define __inline
00099 #define __signed
00100 #define __volatile
00101 /*
00102  * In non-ANSI C environments, new programs will want ANSI-only C keywords
00103  * deleted from the program and old programs will want them left alone.
00104  * When using a compiler other than gcc, programs using the ANSI C keywords
00105  * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
00106  * When using "gcc -traditional", we assume that this is the intent; if
00107  * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
00108  */
00109 #ifndef NO_ANSI_KEYWORDS
00110 #define const                           /* delete ANSI C keywords */
00111 #define inline
00112 #define signed
00113 #define volatile
00114 #endif  /* !NO_ANSI_KEYWORDS */
00115 #endif  /* !__GNUC__ */
00116 #endif  /* !(__STDC__ || __cplusplus) */
00117 
00118 /*
00119  * Compiler-dependent macros to help declare dead (non-returning) and
00120  * pure (no side effects) functions, and unused variables.  They are
00121  * null except for versions of gcc that are known to support the features
00122  * properly (old versions of gcc-2 supported the dead and pure features
00123  * in a different (wrong) way).  If we do not provide an implementation
00124  * for a given compiler, let the compile fail if it is told to use
00125  * a feature that we cannot live without.
00126  */
00127 #ifdef lint
00128 #define __dead2
00129 #define __pure2
00130 #define __unused
00131 #define __packed
00132 #define __aligned(x)
00133 #define __section(x)
00134 #else
00135 #if !__GNUC_PREREQ__(2, 5)
00136 #define __dead2
00137 #define __pure2
00138 #define __unused
00139 #endif
00140 #if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7
00141 #define __dead2         __attribute__((__noreturn__))
00142 #define __pure2         __attribute__((__const__))
00143 #define __unused
00144 /* XXX Find out what to do for __packed, __aligned and __section */
00145 #endif
00146 #if __GNUC_PREREQ__(2, 7)
00147 #define __dead2         __attribute__((__noreturn__))
00148 #define __pure2         __attribute__((__const__))
00149 #define __unused        __attribute__((__unused__))
00150 #define __packed        __attribute__((__packed__))
00151 #define __aligned(x)    __attribute__((__aligned__(x)))
00152 #define __section(x)    __attribute__((__section__(x)))
00153 #endif
00154 #endif
00155 
00156 #if __GNUC_PREREQ__(3, 1)
00157 #define __always_inline __attribute__((__always_inline__))
00158 #else
00159 #define __always_inline
00160 #endif
00161 
00162 #if __GNUC_PREREQ__(3, 3)
00163 #define __nonnull(x)    __attribute__((__nonnull__(x)))
00164 #else
00165 #define __nonnull(x)
00166 #endif
00167 
00168 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
00169 #if !__GNUC_PREREQ__(2, 7)
00170 #define __func__        NULL
00171 #endif
00172 
00173 #if __GNUC__ >= 2 && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
00174 #define __LONG_LONG_SUPPORTED
00175 #endif
00176 
00177 /*
00178  * GCC 2.95 provides `__restrict' as an extension to C90 to support the
00179  * C99-specific `restrict' type qualifier.  We happen to use `__restrict' as
00180  * a way to define the `restrict' type qualifier without disturbing older
00181  * software that is unaware of C99 keywords.
00182  */
00183 #if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
00184 #if __STDC_VERSION__ < 199901
00185 #define __restrict
00186 #else
00187 #define __restrict      restrict
00188 #endif
00189 #endif
00190 
00191 /*
00192  * GNU C version 2.96 adds explicit branch prediction so that
00193  * the CPU back-end can hint the processor and also so that
00194  * code blocks can be reordered such that the predicted path
00195  * sees a more linear flow, thus improving cache behavior, etc.
00196  *
00197  * The following two macros provide us with a way to utilize this
00198  * compiler feature.  Use __predict_true() if you expect the expression
00199  * to evaluate to true, and __predict_false() if you expect the
00200  * expression to evaluate to false.
00201  *
00202  * A few notes about usage:
00203  *
00204  *      * Generally, __predict_false() error condition checks (unless
00205  *        you have some _strong_ reason to do otherwise, in which case
00206  *        document it), and/or __predict_true() `no-error' condition
00207  *        checks, assuming you want to optimize for the no-error case.
00208  *
00209  *      * Other than that, if you don't know the likelihood of a test
00210  *        succeeding from empirical or other `hard' evidence, don't
00211  *        make predictions.
00212  *
00213  *      * These are meant to be used in places that are run `a lot'.
00214  *        It is wasteful to make predictions in code that is run
00215  *        seldomly (e.g. at subsystem initialization time) as the
00216  *        basic block reordering that this affects can often generate
00217  *        larger code.
00218  */
00219 #if __GNUC_PREREQ__(2, 96)
00220 #define __predict_true(exp)     __builtin_expect((exp), 1)
00221 #define __predict_false(exp)    __builtin_expect((exp), 0)
00222 #else
00223 #define __predict_true(exp)     (exp)
00224 #define __predict_false(exp)    (exp)
00225 #endif
00226 
00227 /*
00228  * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
00229  * require it.
00230  */
00231 #define __offsetof(type, field) ((size_t)(&((type *)0)->field))
00232 
00233 /*
00234  * Compiler-dependent macros to declare that functions take printf-like
00235  * or scanf-like arguments.  They are null except for versions of gcc
00236  * that are known to support the features properly (old versions of gcc-2
00237  * didn't permit keeping the keywords out of the application namespace).
00238  */
00239 #if !__GNUC_PREREQ__(2, 7)
00240 #define __printflike(fmtarg, firstvararg)
00241 #define __scanflike(fmtarg, firstvararg)
00242 #else
00243 #define __printflike(fmtarg, firstvararg) \
00244             __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
00245 #define __scanflike(fmtarg, firstvararg) \
00246             __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
00247 #endif
00248 
00249 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
00250 #if __FreeBSD_cc_version >= 300001
00251 #define __printf0like(fmtarg, firstvararg) \
00252             __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
00253 #else
00254 #define __printf0like(fmtarg, firstvararg)
00255 #endif
00256 
00257 #ifdef __GNUC__
00258 #define __strong_reference(sym,aliassym)        \
00259         extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
00260 #ifdef __STDC__
00261 #define __weak_reference(sym,alias)     \
00262         __asm__(".weak " #alias);       \
00263         __asm__(".equ "  #alias ", " #sym)
00264 #define __warn_references(sym,msg)      \
00265         __asm__(".section .gnu.warning." #sym); \
00266         __asm__(".asciz \"" msg "\"");  \
00267         __asm__(".previous")
00268 #else
00269 #define __weak_reference(sym,alias)     \
00270         __asm__(".weak alias");         \
00271         __asm__(".equ alias, sym")
00272 #define __warn_references(sym,msg)      \
00273         __asm__(".section .gnu.warning.sym"); \
00274         __asm__(".asciz \"msg\"");      \
00275         __asm__(".previous")
00276 #endif  /* __STDC__ */
00277 #endif  /* __GNUC__ */
00278 
00279 #ifdef __GNUC__
00280 #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
00281 #else
00282 /*
00283  * The following definition might not work well if used in header files,
00284  * but it should be better than nothing.  If you want a "do nothing"
00285  * version, then it should generate some harmless declaration, such as:
00286  *    #define __IDSTRING(name,string)   struct __hack
00287  */
00288 #define __IDSTRING(name,string) static const char name[] __unused = string
00289 #endif
00290 
00291 /*
00292  * Embed the rcs id of a source file in the resulting library.  Note that in
00293  * more recent ELF binutils, we use .ident allowing the ID to be stripped.
00294  * Usage:
00295  *      __FBSDID("$FreeBSD: src/sys/sys/cdefs.h,v 1.78 2003/10/01 11:26:20 mux Exp $");
00296  */
00297 #ifndef __FBSDID
00298 #if !defined(lint) && !defined(STRIP_FBSDID)
00299 #define __FBSDID(s)     __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
00300 #else
00301 #define __FBSDID(s)     struct __hack
00302 #endif
00303 #endif
00304 
00305 #ifndef __RCSID
00306 #ifndef NO__RCSID
00307 #define __RCSID(s)      __IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
00308 #else
00309 #define __RCSID(s)      struct __hack
00310 #endif
00311 #endif
00312 
00313 #ifndef __RCSID_SOURCE
00314 #ifndef NO__RCSID_SOURCE
00315 #define __RCSID_SOURCE(s)       __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
00316 #else
00317 #define __RCSID_SOURCE(s)       struct __hack
00318 #endif
00319 #endif
00320 
00321 #ifndef __SCCSID
00322 #ifndef NO__SCCSID
00323 #define __SCCSID(s)     __IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
00324 #else
00325 #define __SCCSID(s)     struct __hack
00326 #endif
00327 #endif
00328 
00329 #ifndef __COPYRIGHT
00330 #ifndef NO__COPYRIGHT
00331 #define __COPYRIGHT(s)  __IDSTRING(__CONCAT(__copyright_,__LINE__),s)
00332 #else
00333 #define __COPYRIGHT(s)  struct __hack
00334 #endif
00335 #endif
00336 
00337 #ifndef __DECONST
00338 #define __DECONST(type, var)    ((type)(uintptr_t)(const void *)(var))
00339 #endif
00340 
00341 #ifndef __DEVOLATILE
00342 #define __DEVOLATILE(type, var) ((type)(uintptr_t)(volatile void *)(var))
00343 #endif
00344 
00345 #ifndef __DEQUALIFY
00346 #define __DEQUALIFY(type, var)  ((type)(uintptr_t)(const volatile void *)(var))
00347 #endif
00348 
00349 /*-
00350  * The following definitions are an extension of the behavior originally
00351  * implemented in <sys/_posix.h>, but with a different level of granularity.
00352  * POSIX.1 requires that the macros we test be defined before any standard
00353  * header file is included.
00354  *
00355  * Here's a quick run-down of the versions:
00356  *  defined(_POSIX_SOURCE)              1003.1-1988
00357  *  _POSIX_C_SOURCE == 1                1003.1-1990
00358  *  _POSIX_C_SOURCE == 2                1003.2-1992 C Language Binding Option
00359  *  _POSIX_C_SOURCE == 199309           1003.1b-1993
00360  *  _POSIX_C_SOURCE == 199506           1003.1c-1995, 1003.1i-1995,
00361  *                                      and the omnibus ISO/IEC 9945-1: 1996
00362  *  _POSIX_C_SOURCE == 200112           1003.1-2001
00363  *
00364  * In addition, the X/Open Portability Guide, which is now the Single UNIX
00365  * Specification, defines a feature-test macro which indicates the version of
00366  * that specification, and which subsumes _POSIX_C_SOURCE.
00367  *
00368  * Our macros begin with two underscores to avoid namespace screwage.
00369  */
00370 
00371 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
00372 #if _POSIX_C_SOURCE == 1
00373 #undef _POSIX_C_SOURCE          /* Probably illegal, but beyond caring now. */
00374 #define _POSIX_C_SOURCE         199009
00375 #endif
00376 
00377 /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
00378 #if _POSIX_C_SOURCE == 2
00379 #undef _POSIX_C_SOURCE
00380 #define _POSIX_C_SOURCE         199209
00381 #endif
00382 
00383 /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
00384 #ifdef _XOPEN_SOURCE
00385 #if _XOPEN_SOURCE - 0 >= 600
00386 #define __XSI_VISIBLE           600
00387 #undef _POSIX_C_SOURCE
00388 #define _POSIX_C_SOURCE         200112
00389 #elif _XOPEN_SOURCE - 0 >= 500
00390 #define __XSI_VISIBLE           500
00391 #undef _POSIX_C_SOURCE
00392 #define _POSIX_C_SOURCE         199506
00393 #endif
00394 #endif
00395 
00396 /*
00397  * Deal with all versions of POSIX.  The ordering relative to the tests above is
00398  * important.
00399  */
00400 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
00401 #define _POSIX_C_SOURCE         198808
00402 #endif
00403 #ifdef _POSIX_C_SOURCE
00404 #if _POSIX_C_SOURCE >= 200112
00405 #define __POSIX_VISIBLE         200112
00406 #define __ISO_C_VISIBLE         1999
00407 #elif _POSIX_C_SOURCE >= 199506
00408 #define __POSIX_VISIBLE         199506
00409 #define __ISO_C_VISIBLE         1990
00410 #elif _POSIX_C_SOURCE >= 199309
00411 #define __POSIX_VISIBLE         199309
00412 #define __ISO_C_VISIBLE         1990
00413 #elif _POSIX_C_SOURCE >= 199209
00414 #define __POSIX_VISIBLE         199209
00415 #define __ISO_C_VISIBLE         1990
00416 #elif _POSIX_C_SOURCE >= 199009
00417 #define __POSIX_VISIBLE         199009
00418 #define __ISO_C_VISIBLE         1990
00419 #else
00420 #define __POSIX_VISIBLE         198808
00421 #define __ISO_C_VISIBLE         0
00422 #endif /* _POSIX_C_SOURCE */
00423 #else
00424 /*-
00425  * Deal with _ANSI_SOURCE:
00426  * If it is defined, and no other compilation environment is explicitly
00427  * requested, then define our internal feature-test macros to zero.  This
00428  * makes no difference to the preprocessor (undefined symbols in preprocessing
00429  * expressions are defined to have value zero), but makes it more convenient for
00430  * a test program to print out the values.
00431  *
00432  * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
00433  * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
00434  * environment (and in fact we will never get here).
00435  */
00436 #if defined(_ANSI_SOURCE)       /* Hide almost everything. */
00437 #define __POSIX_VISIBLE         0
00438 #define __XSI_VISIBLE           0
00439 #define __BSD_VISIBLE           0
00440 #define __ISO_C_VISIBLE         1990
00441 #elif defined(_C99_SOURCE)      /* Localism to specify strict C99 env. */
00442 #define __POSIX_VISIBLE         0
00443 #define __XSI_VISIBLE           0
00444 #define __BSD_VISIBLE           0
00445 #define __ISO_C_VISIBLE         1999
00446 #else                           /* Default environment: show everything. */
00447 #define __POSIX_VISIBLE         200112
00448 #define __XSI_VISIBLE           600
00449 #define __BSD_VISIBLE           1
00450 #define __ISO_C_VISIBLE         1999
00451 #endif
00452 #endif
00453 
00454 #endif /* !_SYS_CDEFS_H_ */