/* libc/sys/linux/sys/cdefs.h - Helper macros for K&R vs. ANSI C compat. */

/* Written 2000 by Werner Almesberger */

/*-
 * 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
 * $FreeBSD$
 */

#ifndef _SYS_CDEFS_H_
#define _SYS_CDEFS_H_

#include <machine/_default_types.h>
#include <sys/features.h>
#include <stddef.h>

#define __PMT(args) args
#define __DOTS , ...
#define __THROW

#ifdef __GNUC__
#define __ASMNAME(cname) __XSTRING(__USER_LABEL_PREFIX__) \
cname
#endif

#define __ptr_t void *
#define __long_double_t long double

#define __attribute_malloc__
#define __attribute_pure__
#define __attribute_format_strfmon__(a, b)
#define __flexarr [0]

#ifndef __BOUNDED_POINTERS__
#define __bounded   /* nothing */
#define __unbounded /* nothing */
#define __ptrvalue  /* nothing */
#endif

/*
 * 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

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

/*
 * This code has been put in place to help reduce the addition of
 * compiler specific defines in FreeBSD code.  It helps to aid in
 * having a compiler-agnostic source tree.
 */

#if defined(__GNUC__) || defined(__INTEL_COMPILER)

#if __GNUC__ >= 3 || defined(__INTEL_COMPILER)
#define __GNUCLIKE_ASM 3
#define __GNUCLIKE_MATH_BUILTIN_CONSTANTS
#else
#define __GNUCLIKE_ASM 2
#endif
#define __GNUCLIKE___TYPEOF 1
#define __GNUCLIKE___OFFSETOF 1
#define __GNUCLIKE___SECTION 1

#ifndef __INTEL_COMPILER
#define __GNUCLIKE_CTOR_SECTION_HANDLING 1
#endif

#define __GNUCLIKE_BUILTIN_CONSTANT_P 1
#if defined(__INTEL_COMPILER) && defined(__cplusplus) && __INTEL_COMPILER < 800
#undef __GNUCLIKE_BUILTIN_CONSTANT_P
#endif

#if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3) && !defined(__INTEL_COMPILER)
#define __GNUCLIKE_BUILTIN_VARARGS 1
#define __GNUCLIKE_BUILTIN_STDARG 1
#define __GNUCLIKE_BUILTIN_VAALIST 1
#endif

#if defined(__GNUC__)
#define __GNUC_VA_LIST_COMPATIBILITY 1
#endif

/*
 * Compiler memory barriers, specific to gcc and clang.
 */
#if defined(__GNUC__)
#define __compiler_membar() __asm __volatile(" " \
											 :   \
											 :   \
											 : "memory")
#endif

#ifndef __INTEL_COMPILER
#define __GNUCLIKE_BUILTIN_NEXT_ARG 1
#define __GNUCLIKE_MATH_BUILTIN_RELOPS
#endif

#define __GNUCLIKE_BUILTIN_MEMCPY 1

/* XXX: if __GNUC__ >= 2: not tested everywhere originally, where replaced */
#define __CC_SUPPORTS_INLINE 1
#define __CC_SUPPORTS___INLINE 1
#define __CC_SUPPORTS___INLINE__ 1

#define __CC_SUPPORTS___FUNC__ 1
#define __CC_SUPPORTS_WARNING 1

#define __CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */

#define __CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1

#endif /* __GNUC__ || __INTEL_COMPILER */

/*
 * 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(__CC_SUPPORTS___INLINE))
#define __inline /* delete GCC keyword */
#endif			 /* ! __CC_SUPPORTS___INLINE */
#endif			 /* !__cplusplus */

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

#if !defined(__CC_SUPPORTS___INLINE)
#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 /* !__CC_SUPPORTS___INLINE */
#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 __used __attribute__((__used__))
#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 __used __attribute__((__used__))
#define __packed __attribute__((__packed__))
#define __aligned(x) __attribute__((__aligned__(x)))
#define __section(x) __attribute__((__section__(x)))
#endif
#endif

#if !__GNUC_PREREQ__(2, 95)
#define __alignof(x) __offsetof(struct {char __a; x __b; }, __b)
#endif

/*
 * Keywords added in C11.
 */

#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L

#if !__has_extension(c_alignas)
#if (defined(__cplusplus) && __cplusplus >= 201103L) || \
	__has_extension(cxx_alignas)
#define _Alignas(x) alignas(x)
#else
/* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */
#define _Alignas(x) __aligned(x)
#endif
#endif

#if defined(__cplusplus) && __cplusplus >= 201103L
#define _Alignof(x) alignof(x)
#else
#define _Alignof(x) __alignof(x)
#endif

#if !__has_extension(c_atomic) && !__has_extension(cxx_atomic)
/*
 * No native support for _Atomic(). Place object in structure to prevent
 * most forms of direct non-atomic access.
 */
#define _Atomic(T) struct {T volatile __val; }
#endif

#if defined(__cplusplus) && __cplusplus >= 201103L
#define _Noreturn[[noreturn]]
#else
#define _Noreturn __dead2
#endif

#if __GNUC_PREREQ__(4, 6) && !defined(__cplusplus)
/*  Do nothing: _Static_assert() works as per C11 */
#elif !__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 defined(__COUNTER__)
#define _Static_assert(x, y) __Static_assert(x, __COUNTER__)
#define __Static_assert(x, y) ___Static_assert(x, y)
#define ___Static_assert(x, y) typedef char __assert_##y[(x) ? 1 : -1]
#else
#define _Static_assert(x, y) struct __hack
#endif
#endif

#if !__has_extension(c_thread_local)
/* XXX: Change this to test against C++11 when clang in base supports it. */
#if /* (defined(__cplusplus) && __cplusplus >= 201103L) || */ \
	__has_extension(cxx_thread_local)
#define _Thread_local thread_local
#else
#define _Thread_local __thread
#endif
#endif

#endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */

/*
 * 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

#if __GNUC_PREREQ__(2, 96)
#define __malloc_like __attribute__((__malloc__))
#define __pure __attribute__((__pure__))
#else
#define __malloc_like
#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, 1)
#define __noinline __attribute__((__noinline__))
#else
#define __noinline
#endif

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

#if __GNUC_PREREQ__(3, 4)
#define __fastcall __attribute__((__fastcall__))
#else
#define __fastcall
#endif

#if __GNUC_PREREQ__(4, 1)
#define __returns_twice __attribute__((__returns_twice__))
#else
#define __returns_twice
#endif

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

#if __GNUC_PREREQ__(4, 2)
#define __hidden __attribute__((__visibility__("hidden")))
#define __exported __attribute__((__visibility__("default")))
#else
#define __hidden
#define __exported
#endif

#define __offsetof(type, field) offsetof(type, field)
#define __rangeof(type, start, end) \
	(__offsetof(type, end) - __offsetof(type, start))

/*
 * Given the pointer x to the member m of the struct s, return
 * a pointer to the containing structure.  When using GCC, we first
 * assign pointer x to a local variable, to check that its type is
 * compatible with member m.
 */
#if __GNUC_PREREQ__(3, 1)
#define __containerof(x, s, m) ({                                    \
	const volatile __typeof__(((s *)0)->m) *__x = (x);               \
	__DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m)); \
})
#else
#define __containerof(x, s, m) \
	__DEQUALIFY(s *, (const volatile char *)(x)-__offsetof(s, m))
#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) && !defined(__INTEL_COMPILER)
#define __printflike(fmtarg, firstvararg)
#define __scanflike(fmtarg, firstvararg)
#define __format_arg(fmtarg)
#define __strfmonlike(fmtarg, firstvararg)
#define __strftimelike(fmtarg, firstvararg)
#else
#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)))
#define __strfmonlike(fmtarg, firstvararg) \
	__attribute__((__format__(__strfmon__, fmtarg, firstvararg)))
#define __strftimelike(fmtarg, firstvararg) \
	__attribute__((__format__(__strftime__, fmtarg, firstvararg)))
#endif

/* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
#if defined(__FreeBSD_cc_version) && __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 __ELF__
#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")
#define __sym_compat(sym, impl, verid) \
	__asm__(".symver " #impl ", " #sym "@" #verid)
#define __sym_default(sym, impl, verid) \
	__asm__(".symver " #impl ", " #sym "@@" #verid)
#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")
#define __sym_compat(sym, impl, verid) \
	__asm__(".symver impl, sym@verid")
#define __sym_default(impl, sym, verid) \
	__asm__(".symver impl, sym@@verid")
#endif /* __STDC__ */
#else  /* !__ELF__ */
#ifdef __STDC__
#define __weak_reference(sym, alias)            \
	__asm__(".stabs \"_" #alias "\",11,0,0,0"); \
	__asm__(".stabs \"_" #sym "\",1,0,0,0")
#define __warn_references(sym, msg)         \
	__asm__(".stabs \"" msg "\",30,0,0,0"); \
	__asm__(".stabs \"_" #sym "\",1,0,0,0")
#else
#define __weak_reference(sym, alias)           \
	__asm__(".stabs \"_/**/alias\",11,0,0,0"); \
	__asm__(".stabs \"_/**/sym\",1,0,0,0")
#define __warn_references(sym, msg) \
	__asm__(".stabs msg,30,0,0,0"); \
	__asm__(".stabs \"_/**/sym\",1,0,0,0")
#endif /* __STDC__ */
#endif /* __ELF__ */
#endif /* __GNUC__ || __INTEL_COMPILER */

#ifndef __FBSDID
#define __FBSDID(s) struct __hack
#endif

#ifndef __RCSID
#define __RCSID(s) struct __hack
#endif

#ifndef __RCSID_SOURCE
#define __RCSID_SOURCE(s) struct __hack
#endif

#ifndef __SCCSID
#define __SCCSID(s) struct __hack
#endif

#ifndef __COPYRIGHT
#define __COPYRIGHT(s) struct __hack
#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
 *  _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.
 */

/* 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 >= 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 >= 200809
#define __POSIX_VISIBLE 200809
#define __ISO_C_VISIBLE 1999
#elif _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
#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
#elif defined(_GNU_SOURCE) /* Everything and the kitchen sink. */
#define __POSIX_VISIBLE 200809
#define __XSI_VISIBLE 700
#define __BSD_VISIBLE 1
#define __ISO_C_VISIBLE 2011
#define __GNU_VISIBLE 1
#else /* Default: everything except __GNU_VISIBLE. */
#define __POSIX_VISIBLE 200809
#define __XSI_VISIBLE 700
#define __BSD_VISIBLE 1
#define __ISO_C_VISIBLE 2011
#endif
#endif

#endif /* !_SYS_CDEFS_H_ */
