FreeBSD/Linux Kernel Cross Reference
sys/sys/cdefs.h

     /*
      * Copyright (c) 1991, 1993
      *      The Regents of the University of California.  All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
      * Berkeley Software Design, Inc.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the University of
     *      California, Berkeley and its contributors.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)cdefs.h     8.8 (Berkeley) 1/9/95
     * $FreeBSD: src/sys/sys/cdefs.h,v 1.28.2.8 2002/09/18 04:05:13 mikeh Exp $
     */
    
    #ifndef _SYS_CDEFS_H_
    #define _SYS_CDEFS_H_
    
    /*
     * Testing against Clang-specific extensions.
     */
    
    #ifndef __has_extension
    #define __has_extension         __has_feature
    #endif
    #ifndef __has_feature
    #define __has_feature(x)        0
    #endif
    #ifndef __has_include
    #define __has_include(x)        0
    #endif
    #ifndef __has_builtin
    #define __has_builtin(x)        0
    #endif
    
    /*
     * Macro to test if we are using a specific version of gcc or later.
     */
    #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
    #define __GNUC_PREREQ__(ma, mi) \
            (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
    #else
    #define __GNUC_PREREQ__(ma, mi) 0
    #endif
    
    #if defined(__cplusplus)
    #if __GNUC_PREREQ__(4, 0)
    #define __BEGIN_DECLS   _Pragma("GCC visibility push(default)") extern "C" {
    #define __END_DECLS     } _Pragma("GCC visibility pop")
    #else
    #define __BEGIN_DECLS   extern "C" {
    #define __END_DECLS     }
    #endif
    #else
    #define __BEGIN_DECLS
    #define __END_DECLS
    #endif
    
    /*
     * The __VM_CACHELINE_SIZE macro defines the common cache line alignment
     * size that can be found across most recent and somewhat latest Intel
     * hardware, i.e. L1 cache sizes etc.
     *
     * If needed, this value can be TUNED.  Suitable values for this macro
     * are 32, 64 and 128 bytes.  The unit of measurement for this macro is
     * bytes.
     * 
     * XXX: This macro and related macros will eventually move to a MD
     * header, but currently, we do need such a hierarchy.
     */
    #define __VM_CACHELINE_SIZE     64
    #define __VM_CACHELINE_MASK     (__VM_CACHELINE_SIZE - 1)
    #define __VM_CACHELINE_ALIGN(n) \
            (((n) + __VM_CACHELINE_MASK) & ~__VM_CACHELINE_MASK)
    
   /*
    * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
    * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
    * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
    * mode -- there must be no spaces between its arguments, and for nested
    * __CONCAT's, all the __CONCAT's must be at the left.  __CONCAT can also
    * concatenate double-quoted strings produced by the __STRING macro, but
    * this only works with ANSI C.
    *
    * __XSTRING is like __STRING, but it expands any macros in its argument
    * first.  It is only available with ANSI C.
    */
   #if defined(__STDC__) || defined(__cplusplus)
   #define __P(protos)     protos          /* full-blown ANSI C */
   #define __CONCAT1(x,y)  x ## y
   #define __CONCAT(x,y)   __CONCAT1(x,y)
   #define __STRING(x)     #x              /* stringify without expanding x */
   #define __XSTRING(x)    __STRING(x)     /* expand x, then stringify */
   
   #define __const         const           /* define reserved names to standard */
   #define __signed        signed
   #define __volatile      volatile
   #if defined(__cplusplus)
   #define __inline        inline          /* convert to C++ keyword */
   #else
   #ifndef __GNUC__
   #define __inline                        /* delete GCC keyword */
   #endif /* !__GNUC__ */
   #endif /* !__cplusplus */
   
   #else   /* !(__STDC__ || __cplusplus) */
   #define __P(protos)     ()              /* traditional C preprocessor */
   #define __CONCAT(x,y)   x/**/y
   #define __STRING(x)     "x"
   
   #ifndef __GNUC__
   #define __const                         /* delete pseudo-ANSI C keywords */
   #define __inline
   #define __signed
   #define __volatile
   /*
    * In non-ANSI C environments, new programs will want ANSI-only C keywords
    * deleted from the program and old programs will want them left alone.
    * When using a compiler other than gcc, programs using the ANSI C keywords
    * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
    * When using "gcc -traditional", we assume that this is the intent; if
    * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
    */
   #ifndef NO_ANSI_KEYWORDS
   #define const                           /* delete ANSI C keywords */
   #define inline
   #define signed
   #define volatile
   #endif  /* !NO_ANSI_KEYWORDS */
   #endif  /* !__GNUC__ */
   #endif  /* !(__STDC__ || __cplusplus) */
   
   /*
    * Compiler-dependent macros to help declare dead (non-returning) and
    * pure (no side effects) functions, and unused variables.  They are
    * null except for versions of gcc that are known to support the features
    * properly (old versions of gcc-2 supported the dead and pure features
    * in a different (wrong) way).
    */
   #ifdef lint
   
   #define __dead2
   #define __pure
   #define __pure2
   #define __unused
   #define __packed
   #define __aligned(x)
   #define __section(x)
   #define __always_inline
   #define __nonnull(x)
   
   #else
   
   #if !__GNUC_PREREQ__(2, 7)
   #define __dead2
   #define __pure2
   #define __unused
   #endif
   
   #if __GNUC_PREREQ__(2, 7)
   #define __dead2         __attribute__((__noreturn__))
   #define __pure2         __attribute__((__const__))
   #define __unused        __attribute__((__unused__))
   #define __packed        __attribute__((__packed__))
   #define __aligned(x)    __attribute__((__aligned__(x)))
   #define __section(x)    __attribute__((__section__(x)))
   #endif
   
   #if __GNUC_PREREQ__(2, 96)
   #define __pure          __attribute__((__pure__))
   #else
   #define __pure          __pure2
   #endif
   
   #if __GNUC_PREREQ__(3, 1)
   #define __always_inline __attribute__((__always_inline__))
   #define __noinline      __attribute__((__noinline__))
   #else
   #define __always_inline
   #define __noinline
   #endif
   
   #if __GNUC_PREREQ__(3, 3)
   #define __nonnull(x)    __attribute__((__nonnull__(x)))
   #define __used          __attribute__((__used__))
   #else
   #define __nonnull(x)
   #define __used          __unused
   #endif
   
   #endif  /* LINT */
   
   #if !__GNUC_PREREQ__(2, 7) && __STDC_VERSION < 199901
   #define __func__        NULL
   #endif
   
   #if (__GNUC_PREREQ__(2, 0) && !defined(__STRICT_ANSI)) || \
       __STDC_VERSION__ >= 199901
   #define __LONG_LONG_SUPPORTED
   #endif
   
   /*
    * GNU C version 2.96 adds explicit branch prediction so that
    * the CPU back-end can hint the processor and also so that
    * code blocks can be reordered such that the predicted path
    * sees a more linear flow, thus improving cache behavior, etc.
    *
    * The following two macros provide us with a way to utilize this
    * compiler feature.  Use __predict_true() if you expect the expression
    * to evaluate to true, and __predict_false() if you expect the
    * expression to evaluate to false.
    *
    * A few notes about usage:
    *
    *      * Generally, __predict_false() error condition checks (unless
    *        you have some _strong_ reason to do otherwise, in which case
    *        document it), and/or __predict_true() `no-error' condition
    *        checks, assuming you want to optimize for the no-error case.
    *
    *      * Other than that, if you don't know the likelihood of a test
    *        succeeding from empirical or other `hard' evidence, don't
    *        make predictions.
    *
    *      * These are meant to be used in places that are run `a lot'.
    *        It is wasteful to make predictions in code that is run
    *        seldomly (e.g. at subsystem initialization time) as the
    *        basic block reordering that this affects can often generate
    *        larger code.
    */
   #if __GNUC_PREREQ__(2, 96)
   #define __predict_true(exp)     __builtin_expect((exp), 1)
   #define __predict_false(exp)    __builtin_expect((exp), 0)
   #else
   #define __predict_true(exp)     (exp)
   #define __predict_false(exp)    (exp)
   #endif
   
   /*
    * GCC 2.95 and later provides `__restrict' as an extention to C90 to support
    * the C99-specific `restrict' type qualifier.  We happen to use `__restrict'
    * as a way to define the `restrict' type qualifier without disturbing older
    * software that is unaware of C99 keywords.
    */
   #if !__GNUC_PREREQ__(2, 95)
   #if __STDC_VERSION__ < 199901
   #define __restrict
   #else
   #define __restrict      restrict
   #endif
   #endif
   
   /*
    * Compiler-dependent macros to declare that functions take printf-like
    * or scanf-like arguments.  They are null except for versions of gcc
    * that are known to support the features properly (old versions of gcc-2
    * didn't permit keeping the keywords out of the application namespace).
    *
    * The printf0like macro for GCC 2 uses DragonFly specific compiler extensions.
    */
   #if !__GNUC_PREREQ__(2, 7)
   #define __printflike(fmtarg, firstvararg)
   #define __scanflike(fmtarg, firstvararg)
   #define __printf0like(fmtarg, firstvararg)
   #define __format_arg(fmtarg)
   #define __strfmonlike(fmtarg, firstvararg)
   #define __strftimelike(fmtarg, firstvararg)
   
   #elif __GNUC_PREREQ__(3, 0)
   #define __printflike(fmtarg, firstvararg) \
               __attribute__((__nonnull__(fmtarg), \
                             __format__ (__printf__, fmtarg, firstvararg)))
   #define __printf0like(fmtarg, firstvararg) \
               __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
   #define __scanflike(fmtarg, firstvararg) \
               __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
   #define __format_arg(fmtarg) \
               __attribute__((__format_arg__ (fmtarg)))
   #define __strfmonlike(fmtarg, firstvararg) \
               __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
   #define __strftimelike(fmtarg, firstvararg) \
               __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
   
   #else
   #define __printflike(fmtarg, firstvararg) \
               __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
   #define __printf0like(fmtarg, firstvararg) \
               __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
   #define __scanflike(fmtarg, firstvararg) \
               __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
   #define __format_arg(fmtarg) \
               __attribute__((__format_arg__ (fmtarg)))
   #define __strfmonlike(fmtarg, firstvararg) \
               __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
   #define __strftimelike(fmtarg, firstvararg) \
               __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
   
   #endif
   
   #if !__GNUC_PREREQ__(3, 0)
   #define __ARRAY_ZERO    0
   #else
   #define __ARRAY_ZERO
   #endif
   
   #if __GNUC_PREREQ__(4, 0)
   #define __dso_public    __attribute__((__visibility__("default")))
   #define __dso_hidden    __attribute__((__visibility__("hidden")))
   #else
   #define __dso_public
   #define __dso_hidden
   #endif
   
   /*
    * A convenient constructor macro, GCC 4.3.0 added priority support to
    * constructors, provide a compatible interface for both.
    */
   #if __GNUC_PREREQ__(4, 3)
   #define __constructor(prio) __attribute__((constructor(prio)))
   #else
   #define __constructor(prio) __attribute__((constructor))
   #endif
   
   /*
    * Handy GCC based macros:
    *
    *      __cachealign:
    *      
    *      The __cachealign macro can be used for cache line aligning structures
    *      of small to medium size.  It aligns the particular structure or
    *      storage type to a system default cache line alignment, thus giving us
    *      a much more better cache utilization by making the hardware work at
    *      its best burst speeds.
    *
    *      __usereg:
    *      
    *      The __usereg macro can/should be used when a function contains
    *      arguments not more than 3.  It can be very useful to us due to the
    *      message-passing nature of the kernel.
    *
    * !!NOTE - USAGE INFORMATION!!
    *
    * The __cachealign macro should not be used for data structures that are
    * as big struct proc, struct vnode, struct thread, and other structs which
    * are as big as them; simply because it will be useless in that case.
    *
    * The __usereg macro should be used whenever possible, i.e., when a function
    * does not exceed more than 3 arguments, and should not be used for vararg
    * type functions.
    *
    * In other words, AVOID MISUSE OF THESE MACROS. :-)
    */
   #ifdef __GNUC__
   #define __cachealign    __attribute__((__aligned__(__VM_CACHELINE_SIZE)))
   #define __usereg        __attribute__((__regparm__(3)))
   #else
   #define __cachealign
   #define __usereg
   #endif
   
   #ifdef __GNUC__
   #define __strong_reference(sym,aliassym)        \
           extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
   #define __weak_reference(sym,alias)     \
           __asm__(".weak " #alias);       \
           __asm__(".equ "  #alias ", " #sym)
   #define __warn_references(sym,msg)      \
           __asm__(".section .gnu.warning." #sym); \
           __asm__(".asciz \"" msg "\"");  \
           __asm__(".previous")
   #endif  /* __GNUC__ */
   
   #if defined(__GNUC__)
   #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"")
   #endif
   
   #ifndef __RCSID
   #define __RCSID(s)      __IDSTRING(rcsid,s)
   #endif
   
   #ifndef __RCSID_SOURCE
   #define __RCSID_SOURCE(s) __IDSTRING(rcsid_source,s)
   #endif
   
   #ifndef __COPYRIGHT
   #define __COPYRIGHT(s)  __IDSTRING(copyright,s)
   #endif
   
   #ifndef __DECONST
   #define __DECONST(type, var)    ((type)(uintptr_t)(const void *)(var))
   #endif
   
   #ifndef __DEVOLATILE
   #define __DEVOLATILE(type, var) ((type)(uintptr_t)(volatile void *)(var))
   #endif
   
   #ifndef __DEQUALIFY
   #define __DEQUALIFY(type, var)  ((type)(uintptr_t)(const volatile void *)(var))
   #endif
   
   /*
    * Keywords added in C11.
    */
   
   #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
   
   #define _Noreturn               __dead2
   
   #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */
   
   #if !__has_extension(c_static_assert)
   #if (defined(__cplusplus) && __cplusplus >= 201103L) || \
       __has_extension(cxx_static_assert)
   #define _Static_assert(x, y)    static_assert(x, y)
   #elif !__GNUC_PREREQ__(4, 6)
   #define _Static_assert(x, y)    struct __hack
   #endif
   #endif
   
   /*
    * Emulation of C11 _Generic().  Unlike the previously defined C11
    * keywords, it is not possible to implement this using exactly the same
    * syntax.  Therefore implement something similar under the name
    * __generic().  Unlike _Generic(), this macro can only distinguish
    * between a single type, so it requires nested invocations to
    * distinguish multiple cases.
    */
   
   #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
   #define __generic(expr, t, yes, no)                                     \
           _Generic(expr, t: yes, default: no)
   #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
   #define __generic(expr, t, yes, no)                                     \
           __builtin_choose_expr(                                          \
               __builtin_types_compatible_p(__typeof(expr), t), yes, no)
   #endif
   
   /*-
    * The following definitions are an extension of the behavior originally
    * implemented in <sys/_posix.h>, but with a different level of granularity.
    * POSIX.1 requires that the macros we test be defined before any standard
    * header file is included.
    *
    * Here's a quick run-down of the versions:
    *  defined(_POSIX_SOURCE)              1003.1-1988
    *  _POSIX_C_SOURCE == 1                1003.1-1990
    *  _POSIX_C_SOURCE == 2                1003.2-1992 C Language Binding Option
    *  _POSIX_C_SOURCE == 199309           1003.1b-1993
    *  _POSIX_C_SOURCE == 199506           1003.1c-1995, 1003.1i-1995,
    *                                      and the omnibus ISO/IEC 9945-1: 1996
    *  _POSIX_C_SOURCE == 200112           1003.1-2001
    *  _POSIX_C_SOURCE == 200809           1003.1-2008
    *
    * In addition, the X/Open Portability Guide, which is now the Single UNIX
    * Specification, defines a feature-test macro which indicates the version of
    * that specification, and which subsumes _POSIX_C_SOURCE.
    *
    * Our macros begin with two underscores to avoid namespace screwage.
    */
   
   /*
    * If no special macro was specified, make the DragonFly extensions
    * available. Also make them available when requested so.
    */
   #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE) && \
       !defined(_ANSI_SOURCE) && !defined(_C99_SOURCE)) || \
       defined(_DRAGONFLY_SOURCE) || defined(_NETBSD_SOURCE)
   #define __DF_VISIBLE    1
   #else
   #define __DF_VISIBLE    0
   #endif
   
   /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
   #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 1
   #undef _POSIX_C_SOURCE          /* Probably illegal, but beyond caring now. */
   #define _POSIX_C_SOURCE         199009
   #endif
   
   /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
   #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0) == 2
   #undef _POSIX_C_SOURCE
   #define _POSIX_C_SOURCE         199209
   #endif
   
   /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
   #ifdef _XOPEN_SOURCE
   #if _XOPEN_SOURCE - 0 >= 700
   #define __XSI_VISIBLE           700
   #undef _POSIX_C_SOURCE
   #define _POSIX_C_SOURCE         200809
   #elif _XOPEN_SOURCE - 0 >= 600
   #define __XSI_VISIBLE           600
   #undef _POSIX_C_SOURCE
   #define _POSIX_C_SOURCE         200112
   #elif _XOPEN_SOURCE - 0 >= 500
   #define __XSI_VISIBLE           500
   #undef _POSIX_C_SOURCE
   #define _POSIX_C_SOURCE         199506
   #endif
   #endif
   
   /*
    * Deal with all versions of POSIX.  The ordering relative to the tests above is
    * important.
    */
   #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
   #define _POSIX_C_SOURCE         198808
   #endif
   #ifdef _POSIX_C_SOURCE
   #if (_POSIX_C_SOURCE - 0) >= 200809
   #define __POSIX_VISIBLE         200809
   #define __ISO_C_VISIBLE         1999
   #elif (_POSIX_C_SOURCE - 0) >= 200112
   #define __POSIX_VISIBLE         200112
   #define __ISO_C_VISIBLE         1999
   #elif (_POSIX_C_SOURCE - 0) >= 199506
   #define __POSIX_VISIBLE         199506
   #define __ISO_C_VISIBLE         1990
   #elif (_POSIX_C_SOURCE - 0) >= 199309
   #define __POSIX_VISIBLE         199309
   #define __ISO_C_VISIBLE         1990
   #elif (_POSIX_C_SOURCE - 0) >= 199209
   #define __POSIX_VISIBLE         199209
   #define __ISO_C_VISIBLE         1990
   #elif (_POSIX_C_SOURCE - 0) >= 199009
   #define __POSIX_VISIBLE         199009
   #define __ISO_C_VISIBLE         1990
   #else
   #define __POSIX_VISIBLE         198808
   #define __ISO_C_VISIBLE         0
   #endif /* _POSIX_C_SOURCE */
   #else
   /*-
    * Deal with _ANSI_SOURCE:
    * If it is defined, and no other compilation environment is explicitly
    * requested, then define our internal feature-test macros to zero.  This
    * makes no difference to the preprocessor (undefined symbols in preprocessing
    * expressions are defined to have value zero), but makes it more convenient for
    * a test program to print out the values.
    *
    * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
    * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
    * environment (and in fact we will never get here).
    */
   #ifdef _ANSI_SOURCE             /* Hide almost everything. */
   #define __POSIX_VISIBLE         0
   #define __XSI_VISIBLE           0
   #define __BSD_VISIBLE           0
   #define __ISO_C_VISIBLE         1990
   #elif defined(_C99_SOURCE)      /* Localism to specify strict C99 env. */
   #define __POSIX_VISIBLE         0
   #define __XSI_VISIBLE           0
   #define __BSD_VISIBLE           0
   #define __ISO_C_VISIBLE         1999
   #elif defined(_C11_SOURCE)      /* Localism to specify strict C11 env. */
   #define __POSIX_VISIBLE         0
   #define __XSI_VISIBLE           0
   #define __BSD_VISIBLE           0
   #define __ISO_C_VISIBLE         2011
   #else                           /* Default environment: show everything. */
   #define __POSIX_VISIBLE         200809
   #define __XSI_VISIBLE           700
   #define __BSD_VISIBLE           1
   #define __ISO_C_VISIBLE         2011
   #endif
   #endif
   
   /*
    * GLOBL macro exists to preserve __start_set_* and __stop_set_* sections
    * of kernel modules which are discarded from binutils 2.17.50+ otherwise.
    */
   
   #define __GLOBL1(sym)   __asm__(".globl " #sym)
   #define __GLOBL(sym)    __GLOBL1(sym)
   
   #endif /* !_SYS_CDEFS_H_ */

Cache object: f97f4ce40d7a64ced33215e256f31075