xref: /freebsd-10.1-release/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.
 * 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: head/sys/sys/cdefs.h 132538 2004-07-22 09:20:51Z tjr $
 */

#ifndef	_SYS_CDEFS_H_
#define	_SYS_CDEFS_H_

#if defined(__cplusplus)
#define	__BEGIN_DECLS	extern "C" {
#define	__END_DECLS	}
#else
#define	__BEGIN_DECLS
#define	__END_DECLS
#endif

/*
 * Macro to test if we're 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

/*
 * 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
#if !(defined(__GNUC__) || defined(__INTEL_COMPILER))
#define	__inline			/* delete GCC keyword */
#endif /* !(__GNUC__ || __INTEL_COMPILER) */
#endif /* !__cplusplus */

#else	/* !(__STDC__ || __cplusplus) */
#define	__P(protos)	()		/* traditional C preprocessor */
#define	__CONCAT(x,y)	x/**/y
#define	__STRING(x)	"x"

#if !(defined(__GNUC__) || defined(__INTEL_COMPILER))
#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__ || __INTEL_COMPILER) */
#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).  If we do not provide an implementation
 * for a given compiler, let the compile fail if it is told to use
 * a feature that we cannot live without.
 */
#ifdef lint
#define	__dead2
#define	__pure2
#define	__unused
#define	__packed
#define	__aligned(x)
#define	__section(x)
#else
#if !__GNUC_PREREQ__(2, 5) && !defined(__INTEL_COMPILER)
#define	__dead2
#define	__pure2
#define	__unused
#endif
#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 && !defined(__INTEL_COMPILER)
#define	__dead2		__attribute__((__noreturn__))
#define	__pure2		__attribute__((__const__))
#define	__unused
/* XXX Find out what to do for __packed, __aligned and __section */
#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 defined(__INTEL_COMPILER)
#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
#endif

#if __GNUC_PREREQ__(2, 96)
#define	__pure		__attribute__((__pure__))
#else
#define	__pure
#endif

#if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
#define	__always_inline	__attribute__((__always_inline__))
#else
#define	__always_inline
#endif

#if __GNUC_PREREQ__(3, 3)
#define __nonnull(x)	__attribute__((__nonnull__(x)))
#else
#define __nonnull(x)
#endif

/* XXX: should use `#if __STDC_VERSION__ < 199901'. */
#if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
#define	__func__	NULL
#endif

#if (defined(__INTEL_COMPILER) || (defined(__GNUC__) && __GNUC__ >= 2)) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
#define	__LONG_LONG_SUPPORTED
#endif

/*
 * GCC 2.95 provides `__restrict' as an extension 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__ == 2 && __GNUC_MINOR__ == 95)
#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901
#define	__restrict
#else
#define	__restrict	restrict
#endif
#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

/*
 * We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
 * require it.
 */
#define	__offsetof(type, field)	((size_t)(&((type *)0)->field))

/*
 * 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) && !defined(__INTEL_COMPILER)
#define	__printflike(fmtarg, firstvararg)
#define	__scanflike(fmtarg, firstvararg)
#else
#define	__printflike(fmtarg, firstvararg) \
	    __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
#define	__scanflike(fmtarg, firstvararg) \
	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
#endif

/* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
#if __FreeBSD_cc_version >= 300001 && defined(__GNUC__) && !defined(__INTEL_COMPILER)
#define	__printf0like(fmtarg, firstvararg) \
	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
#else
#define	__printf0like(fmtarg, firstvararg)
#endif

#if defined(__GNUC__) || defined(__INTEL_COMPILER)
#ifndef __INTEL_COMPILER
#define	__strong_reference(sym,aliassym)	\
	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
#endif
#ifdef __STDC__
#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")
#else
#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	/* __STDC__ */
#endif	/* __GNUC__ || __INTEL_COMPILER */

#if defined(__GNUC__) || defined(__INTEL_COMPILER)
#define	__IDSTRING(name,string)	__asm__(".ident\t\"" string "\"")
#else
/*
 * The following definition might not work well if used in header files,
 * but it should be better than nothing.  If you want a "do nothing"
 * version, then it should generate some harmless declaration, such as:
 *    #define __IDSTRING(name,string)	struct __hack
 */
#define	__IDSTRING(name,string)	static const char name[] __unused = string
#endif

/*
 * Embed the rcs id of a source file in the resulting library.  Note that in
 * more recent ELF binutils, we use .ident allowing the ID to be stripped.
 * Usage:
 *	__FBSDID("$FreeBSD: head/sys/sys/cdefs.h 132538 2004-07-22 09:20:51Z tjr $");
 */
#ifndef	__FBSDID
#if !defined(lint) && !defined(STRIP_FBSDID)
#define	__FBSDID(s)	__IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
#else
#define	__FBSDID(s)	struct __hack
#endif
#endif

#ifndef	__RCSID
#ifndef	NO__RCSID
#define	__RCSID(s)	__IDSTRING(__CONCAT(__rcsid_,__LINE__),s)
#else
#define	__RCSID(s)	struct __hack
#endif
#endif

#ifndef	__RCSID_SOURCE
#ifndef	NO__RCSID_SOURCE
#define	__RCSID_SOURCE(s)	__IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s)
#else
#define	__RCSID_SOURCE(s)	struct __hack
#endif
#endif

#ifndef	__SCCSID
#ifndef	NO__SCCSID
#define	__SCCSID(s)	__IDSTRING(__CONCAT(__sccsid_,__LINE__),s)
#else
#define	__SCCSID(s)	struct __hack
#endif
#endif

#ifndef	__COPYRIGHT
#ifndef	NO__COPYRIGHT
#define	__COPYRIGHT(s)	__IDSTRING(__CONCAT(__copyright_,__LINE__),s)
#else
#define	__COPYRIGHT(s)	struct __hack
#endif
#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

/*-
 * 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
 *
 * 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.
 */

/* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 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 == 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 >= 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 >= 200112
#define	__POSIX_VISIBLE		200112
#define	__ISO_C_VISIBLE		1999
#elif _POSIX_C_SOURCE >= 199506
#define	__POSIX_VISIBLE		199506
#define	__ISO_C_VISIBLE		1990
#elif _POSIX_C_SOURCE >= 199309
#define	__POSIX_VISIBLE		199309
#define	__ISO_C_VISIBLE		1990
#elif _POSIX_C_SOURCE >= 199209
#define	__POSIX_VISIBLE		199209
#define	__ISO_C_VISIBLE		1990
#elif _POSIX_C_SOURCE >= 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).
 */
#if defined(_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
#else				/* Default environment: show everything. */
#define	__POSIX_VISIBLE		200112
#define	__XSI_VISIBLE		600
#define	__BSD_VISIBLE		1
#define	__ISO_C_VISIBLE		1999
#endif
#endif

#endif /* !_SYS_CDEFS_H_ */