minix/include/sys/cdefs.h

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/* $NetBSD: cdefs.h,v 1.78 2009/10/02 21:05:28 christos Exp $ */
/*
* 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. 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
*/
#ifndef _SYS_CDEFS_H_
#define _SYS_CDEFS_H_
/*
* Macro to test if we're using a GNU C compiler of a specific vintage
* or later, for e.g. features that appeared in a particular version
* of GNU C. Usage:
*
* #if __GNUC_PREREQ__(major, minor)
* ...cool feature...
* #else
* ...delete feature...
* #endif
*/
#ifdef __GNUC__
#define __GNUC_PREREQ__(x, y) \
((__GNUC__ == (x) && __GNUC_MINOR__ >= (y)) || \
(__GNUC__ > (x)))
#else
#define __GNUC_PREREQ__(x, y) 0
#endif
#if 0
#include <machine/cdefs.h>
#ifdef __ELF__
#include <sys/cdefs_elf.h>
#else
#include <sys/cdefs_aout.h>
#endif
#endif
#if defined(__cplusplus)
#define __BEGIN_DECLS extern "C" {
#define __END_DECLS }
#define __static_cast(x,y) static_cast<x>(y)
#else
#define __BEGIN_DECLS
#define __END_DECLS
#define __static_cast(x,y) (x)y
#endif
/*
* 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 -- make sure you don't put spaces
* in between its arguments. __CONCAT can also concatenate double-quoted
* strings produced by the __STRING macro, but this only works with ANSI C.
*/
#define ___STRING(x) __STRING(x)
#define ___CONCAT(x,y) __CONCAT(x,y)
#if __STDC__ || defined(__cplusplus)
#define __P(protos) protos /* full-blown ANSI C */
#define __CONCAT(x,y) x ## y
#define __STRING(x) #x
#define __const const /* define reserved names to standard */
#define __signed signed
#define __volatile volatile
#if defined(__cplusplus) || defined(__PCC__)
#define __inline inline /* convert to C++/C99 keyword */
#else
#if !defined(__GNUC__) && !defined(__lint__)
#define __inline /* delete GCC keyword */
#endif /* !__GNUC__ && !__lint__ */
#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
#endif /* !__GNUC__ */
/*
* 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.
* Programs using the ANSI C keywords const, inline etc. as normal
* identifiers should define -DNO_ANSI_KEYWORDS.
*/
#ifndef NO_ANSI_KEYWORDS
#define const __const /* convert ANSI C keywords */
#define inline __inline
#define signed __signed
#define volatile __volatile
#endif /* !NO_ANSI_KEYWORDS */
#endif /* !(__STDC__ || __cplusplus) */
/*
* Used for internal auditing of the NetBSD source tree.
*/
#ifdef __AUDIT__
#define __aconst __const
#else
#define __aconst
#endif
/*
* The following macro is used to remove const cast-away warnings
* from gcc -Wcast-qual; it should be used with caution because it
* can hide valid errors; in particular most valid uses are in
* situations where the API requires it, not to cast away string
* constants. We don't use *intptr_t on purpose here and we are
* explicit about unsigned long so that we don't have additional
* dependencies.
*/
#define __UNCONST(a) ((void *)(unsigned long)(const void *)(a))
/*
* The following macro is used to remove the volatile cast-away warnings
* from gcc -Wcast-qual; as above it should be used with caution
* because it can hide valid errors or warnings. Valid uses include
* making it possible to pass a volatile pointer to memset().
* For the same reasons as above, we use unsigned long and not intptr_t.
*/
#define __UNVOLATILE(a) ((void *)(unsigned long)(volatile void *)(a))
/*
* GCC2 provides __extension__ to suppress warnings for various GNU C
* language extensions under "-ansi -pedantic".
*/
#if !__GNUC_PREREQ__(2, 0)
#define __extension__ /* delete __extension__ if non-gcc or gcc1 */
#endif
/*
* GCC1 and some versions of GCC2 declare dead (non-returning) and
* pure (no side effects) functions using "volatile" and "const";
* unfortunately, these then cause warnings under "-ansi -pedantic".
* GCC2 uses a new, peculiar __attribute__((attrs)) style. All of
* these work for GNU C++ (modulo a slight glitch in the C++ grammar
* in the distribution version of 2.5.5).
*
* GCC defines a pure function as depending only on its arguments and
* global variables. Typical examples are strlen and sqrt.
*
* GCC defines a const function as depending only on its arguments.
* Therefore calling a const function again with identical arguments
* will always produce the same result.
*
* Rounding modes for floating point operations are considered global
* variables and prevent sqrt from being a const function.
*
* Calls to const functions can be optimised away and moved around
* without limitations.
*/
#if !__GNUC_PREREQ__(2, 0)
#define __attribute__(x)
#endif
#if __GNUC_PREREQ__(2, 5)
#define __dead __attribute__((__noreturn__))
#elif defined(__GNUC__)
#define __dead __volatile
#else
#define __dead
#endif
#if __GNUC_PREREQ__(2, 96)
#define __pure __attribute__((__pure__))
#elif defined(__GNUC__)
#define __pure __const
#else
#define __pure
#endif
#if __GNUC_PREREQ__(2, 5)
#define __constfunc __attribute__((__const__))
#else
#define __constfunc
#endif
#if __GNUC_PREREQ__(3, 0)
#define __noinline __attribute__((__noinline__))
#else
#define __noinline /* nothing */
#endif
#if __GNUC_PREREQ__(2, 7)
#define __unused __attribute__((__unused__))
#else
#define __unused /* delete */
#endif
#if __GNUC_PREREQ__(3, 1)
#define __used __attribute__((__used__))
#else
#define __used __unused
#endif
#if defined(__lint__)
#define __packed __packed
#define __aligned(x) /* delete */
#define __section(x) /* delete */
#elif __GNUC_PREREQ__(2, 7)
#define __packed __attribute__((__packed__))
#define __aligned(x) __attribute__((__aligned__(x)))
#define __section(x) __attribute__((__section__(x)))
#elif defined(__PCC__)
#define __packed _Pragma("packed 1")
#define __aligned(x) _Pragma("aligned " __STRING(x))
#define __section(x) _Pragma("section " ## x)
#else
#define __packed error: no __packed for this compiler
#define __aligned(x) error: no __aligned for this compiler
#define __section(x) error: no __section for this compiler
#endif
/*
* C99 defines the restrict type qualifier keyword, which was made available
* in GCC 2.92.
*/
#if defined(__lint__)
#define __restrict /* delete __restrict when not supported */
#elif __STDC_VERSION__ >= 199901L
#define __restrict restrict
#elif !__GNUC_PREREQ__(2, 92)
#define __restrict /* delete __restrict when not supported */
#endif
/*
* C99 defines __func__ predefined identifier, which was made available
* in GCC 2.95.
*/
#if !(__STDC_VERSION__ >= 199901L)
#if __GNUC_PREREQ__(2, 6)
#define __func__ __PRETTY_FUNCTION__
#elif __GNUC_PREREQ__(2, 4)
#define __func__ __FUNCTION__
#else
#define __func__ ""
#endif
#endif /* !(__STDC_VERSION__ >= 199901L) */
#if defined(_KERNEL)
#if defined(NO_KERNEL_RCSIDS)
#undef __KERNEL_RCSID
#define __KERNEL_RCSID(_n, _s) /* nothing */
#endif /* NO_KERNEL_RCSIDS */
#endif /* _KERNEL */
#if 0
#if !defined(_STANDALONE) && !defined(_KERNEL)
#if defined(__GNUC__) || defined(__PCC__)
#define __RENAME(x) ___RENAME(x)
#else
#ifdef __lint__
#define __RENAME(x) __symbolrename(x)
#else
#error "No function renaming possible"
#endif /* __lint__ */
#endif /* __GNUC__ */
#else /* _STANDALONE || _KERNEL */
#define __RENAME(x) no renaming in kernel or standalone environment
#endif
#endif
/*
* A barrier to stop the optimizer from moving code or assume live
* register values. This is gcc specific, the version is more or less
* arbitrary, might work with older compilers.
*/
#if __GNUC_PREREQ__(2, 95)
#define __insn_barrier() __asm __volatile("":::"memory")
#else
#define __insn_barrier() /* */
#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 use 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) != 0, 1)
#define __predict_false(exp) __builtin_expect((exp) != 0, 0)
#else
#define __predict_true(exp) (exp)
#define __predict_false(exp) (exp)
#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).
*/
#if __GNUC_PREREQ__(2, 7)
#define __printflike(fmtarg, firstvararg) \
__attribute__((__format__ (__printf__, fmtarg, firstvararg)))
#define __scanflike(fmtarg, firstvararg) \
__attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
#define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg)))
#else
#define __printflike(fmtarg, firstvararg) /* nothing */
#define __scanflike(fmtarg, firstvararg) /* nothing */
#define __format_arg(fmtarg) /* nothing */
#endif
/*
* Macros for manipulating "link sets". Link sets are arrays of pointers
* to objects, which are gathered up by the linker.
*
* Object format-specific code has provided us with the following macros:
*
* __link_set_add_text(set, sym)
* Add a reference to the .text symbol `sym' to `set'.
*
* __link_set_add_rodata(set, sym)
* Add a reference to the .rodata symbol `sym' to `set'.
*
* __link_set_add_data(set, sym)
* Add a reference to the .data symbol `sym' to `set'.
*
* __link_set_add_bss(set, sym)
* Add a reference to the .bss symbol `sym' to `set'.
*
* __link_set_decl(set, ptype)
* Provide an extern declaration of the set `set', which
* contains an array of the pointer type `ptype'. This
* macro must be used by any code which wishes to reference
* the elements of a link set.
*
* __link_set_start(set)
* This points to the first slot in the link set.
*
* __link_set_end(set)
* This points to the (non-existent) slot after the last
* entry in the link set.
*
* __link_set_count(set)
* Count the number of entries in link set `set'.
*
* In addition, we provide the following macros for accessing link sets:
*
* __link_set_foreach(pvar, set)
* Iterate over the link set `set'. Because a link set is
* an array of pointers, pvar must be declared as "type **pvar",
* and the actual entry accessed as "*pvar".
*
* __link_set_entry(set, idx)
* Access the link set entry at index `idx' from set `set'.
*/
#define __link_set_foreach(pvar, set) \
for (pvar = __link_set_start(set); pvar < __link_set_end(set); pvar++)
#define __link_set_entry(set, idx) (__link_set_begin(set)[idx])
/*
* Return the number of elements in a statically-allocated array,
* __x.
*/
#define __arraycount(__x) (sizeof(__x) / sizeof(__x[0]))
/* __BIT(n): nth bit, where __BIT(0) == 0x1. */
#define __BIT(__n) \
(((uintmax_t)(__n) >= NBBY * sizeof(uintmax_t)) ? 0 : ((uintmax_t)1 << (uintmax_t)(__n)))
/* __BITS(m, n): bits m through n, m < n. */
#define __BITS(__m, __n) \
((__BIT(MAX((__m), (__n)) + 1) - 1) ^ (__BIT(MIN((__m), (__n))) - 1))
/* find least significant bit that is set */
#define __LOWEST_SET_BIT(__mask) ((((__mask) - 1) & (__mask)) ^ (__mask))
#define __PRIuBIT PRIuMAX
#define __PRIuBITS __PRIuBIT
#define __PRIxBIT PRIxMAX
#define __PRIxBITS __PRIxBIT
#define __SHIFTOUT(__x, __mask) (((__x) & (__mask)) / __LOWEST_SET_BIT(__mask))
#define __SHIFTIN(__x, __mask) ((__x) * __LOWEST_SET_BIT(__mask))
#define __SHIFTOUT_MASK(__mask) __SHIFTOUT((__mask), (__mask))
/*
* Only to be used in other headers that are included from both c or c++
* NOT to be used in code.
*/
#ifdef __cplusplus
#define __CAST(__dt, __st) static_cast<__dt>(__st)
#else
#define __CAST(__dt, __st) ((__dt)(__st))
#endif
#endif /* !_SYS_CDEFS_H_ */