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

/* Written 2000 by Werner Almesberger */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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
 * $FreeBSD$
 */

#ifndef	_SYS_CDEFS_H_
#define	_SYS_CDEFS_H_

#include <sys/config.h>
#include <machine/_default_types.h>

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

#ifdef __GNUC__
# define __ASMNAME(cname)  __XSTRING (__USER_LABEL_PREFIX__) cname
# define _ASMNAME(cname)   __asm__(__ASMNAME(cname))
#else
# define _ASMNAME(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_attribute
#define	__has_attribute(x)	0
#endif
#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

/*  ISO C++.  */

#ifdef __cplusplus
#if !(defined(_BEGIN_STD_C) && defined(_END_STD_C))
#ifdef _HAVE_STD_CXX
#define _BEGIN_STD_C namespace std { extern "C" {
#define _END_STD_C  } }
#else
#define _BEGIN_STD_C extern "C" {
#define _END_STD_C  }
#endif
#if __GNUC_PREREQ (3, 3)
#define _NOTHROW __attribute__ ((__nothrow__))
#else
#define _NOTHROW throw()
#endif
#endif
#else
#define _BEGIN_STD_C
#define _END_STD_C
#if __GNUC_PREREQ (3, 3)
#define _NOTHROW __attribute__ ((__nothrow__))
#else
#define _NOTHROW
#endif
#endif

/**
 * Not all compilers offer __builtin_expect (e.g. CompCert does
 * not have it). In that case, transparently replace all
 * occurences of that builtin with just the condition:
 */
#ifndef _HAVE_BUILTIN_EXPECT
#define __builtin_expect(cond, exp) (cond)
#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__)

#if __GNUC__ >= 3
#define	__GNUCLIKE_ASM 3
#define	__GNUCLIKE_MATH_BUILTIN_CONSTANTS
#else
#define	__GNUCLIKE_ASM 2
#endif
#define	__GNUCLIKE___TYPEOF 1
#define	__GNUCLIKE___SECTION 1

#define	__GNUCLIKE_CTOR_SECTION_HANDLING 1

#define	__GNUCLIKE_BUILTIN_CONSTANT_P 1

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

#define	__GNUC_VA_LIST_COMPATIBILITY 1

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

#define	__GNUCLIKE_BUILTIN_NEXT_ARG 1
#define	__GNUCLIKE_MATH_BUILTIN_RELOPS

#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__ */

/*
 * 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.
 */
#define	__weak_symbol	__attribute__((__weak__))
#if !__GNUC_PREREQ__(2, 5)
#define	__dead2
#define	__pure2
#define	__unused
#endif
#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7
#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

#ifdef _HAVE_ALLOC_SIZE
#define	__alloc_size(x)	__attribute__((__alloc_size__(x)))
#define	__alloc_size2(n, x)	__attribute__((__alloc_size__(n, x)))
#else
#define	__alloc_size(x)
#define	__alloc_size2(n, x)
#endif
#if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
#define	__alloc_align(x)	__attribute__((__alloc_align__(x)))
#else
#define	__alloc_align(x)
#endif

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

#if __GNUC_PREREQ__(4,5) || defined(__clang__)
#define __picolibc_deprecated(m) __attribute__((__deprecated__(m)))
#else
#define __picolibc_deprecated(m) _ATTRIBUTE(__deprecated__)
#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 !defined(__cplusplus) && !__has_extension(c_atomic) && \
	!__has_extension(cxx_atomic) && !__GNUC_PREREQ__(4, 7)
/*
 * 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 !__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) && !defined(__cplusplus)
/* Nothing, gcc 4.6 and higher has _Static_assert built-in */
#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] \
				__unused
#else
#define	_Static_assert(x, y)	struct __hack
#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.
 *
 * Note that the comma operator is used to force expr to decay in
 * order to match _Generic().
 */

#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \
    __has_extension(c_generic_selections)
#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((0, (expr))), t), yes, no)
#endif

/*
 * C99 Static array indices in function parameter declarations.  Syntax such as:
 * void bar(int myArray[static 10]);
 * is allowed in C99 but not in C++.  Define __min_size appropriately so
 * headers using it can be compiled in either language.  Use like this:
 * void bar(int myArray[__min_size(10)]);
 */
#if !defined(__cplusplus) && \
    (defined(__clang__) || __GNUC_PREREQ__(4, 6)) && \
    (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901))
#define __min_size(x)	static (x)
#else
#define __min_size(x)	(x)
#endif

#if __GNUC_PREREQ__(2, 96)
# if __GNUC_PREREQ__(11, 0)
#  define       __malloc_like_with_free(_f,_a) __attribute__((__malloc__, __malloc__(_f,_a)))
# else
#  define       __malloc_like_with_free(_f,_a) __attribute__((__malloc__))
# endif
# define	__pure		__attribute__((__pure__))
#else
#define __malloc_like_with_free(free,free_arg)
#define	__pure
#endif

#define	__malloc_like __malloc_like_with_free(free, 1)

#ifndef __always_inline
#if __GNUC_PREREQ__(3, 1)
#define	__always_inline	__inline__ __attribute__((__always_inline__))
#else
#define	__always_inline
#endif
#endif

#ifndef __noinline
#if __GNUC_PREREQ__(3, 1)
#define	__noinline	__attribute__ ((__noinline__))
#else
#define	__noinline
#endif
#endif

#if defined(_HAVE_ATTRIBUTE_ALWAYS_INLINE) && defined(_HAVE_ATTRIBUTE_GNU_INLINE)
/*
 * When this macro is defined, use it to declare inline versions of extern functions.
 */
#define __declare_extern_inline(type) extern __inline type __attribute((gnu_inline, always_inline))
#endif

#if defined(__clang__) && defined(__nonnull)
/* Clang has a builtin macro __nonnull for the _Nonnull qualifier */
#undef __nonnull
#endif
#if __GNUC_PREREQ__(3, 3)
#define	__nonnull(x)	__attribute__((__nonnull__ x))
#define	__nonnull_all	__attribute__((__nonnull__))
#else
#define	__nonnull(x)
#define	__nonnull_all
#endif

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

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

#if __GNUC_PREREQ__(4, 6) || __has_builtin(__builtin_unreachable)
#define	__unreachable()	__builtin_unreachable()
#else
#define	__unreachable()	((void)0)
#endif

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

/*
 * We use `__restrict' as a way to define the `restrict' type qualifier
 * without disturbing older software that is unaware of C99 keywords.
 * GCC also provides `__restrict' as an extension to support C99-style
 * restricted pointers in other language modes.
 */
#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901
#define	__restrict	restrict
#elif !__GNUC_PREREQ__(2, 95)
#define	__restrict
#endif

/*
 * Additionally, we allow to use `__restrict_arr' for declaring arrays as
 * non-overlapping per C99.  That's supported since gcc 3.1, but it's not
 * allowed in C++.
 */
#if defined(__cplusplus) || !__GNUC_PREREQ__(3, 1)
#define __restrict_arr
#elif defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
#define __restrict_arr       restrict
#else
#define __restrict_arr
#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, 0)
#define	__null_sentinel	__attribute__((__sentinel__))
#define	__exported	__attribute__((__visibility__("default")))
/* Only default visibility is supported on PE/COFF targets. */
#define	__hidden	__attribute__((__visibility__("hidden")))
#else
#define	__null_sentinel
#define	__exported
#define	__hidden
#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)
#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__)
#define	__printf0like(fmtarg, firstvararg) \
	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
#else
#define	__printf0like(fmtarg, firstvararg)
#endif

#if defined(_HAVE_ALIAS_ATTRIBUTE)
#define	__strong_reference(sym,aliassym)	\
    extern __typeof (sym) aliassym __attribute__ ((__alias__ (__STRING(sym))))
#endif

#if defined(_HAVE_WEAK_ATTRIBUTE) && defined(_HAVE_ALIAS_ATTRIBUTE)
#define	__weak_reference(sym,aliassym)	\
    extern __typeof (sym) aliassym __attribute__ ((__weak__, __alias__ (__STRING(sym))))
#endif

/*
   Taken from glibc:
   Add the compiler optimization to inhibit loop transformation to library
   calls.  This is used to avoid recursive calls in memset and memmove
   default implementations.
*/
#if defined(_HAVE_CC_INHIBIT_LOOP_TO_LIBCALL)
# define __inhibit_loop_to_libcall \
  __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
#elif defined(_HAVE_NO_BUILTIN_ATTRIBUTE)
# define __inhibit_loop_to_libcall \
    __attribute__((no_builtin))
#else
# define __inhibit_loop_to_libcall
#endif

/*
 * Tell optimizer to not add new builtin calls when optimizing a
 * function body.
 */
#if defined(_HAVE_NO_BUILTIN_ATTRIBUTE)
# define __inhibit_new_builtin_calls \
    __attribute__((no_builtin))
#else
#define __inhibit_new_builtin_calls
#endif

#if defined(__GNUC__)
#ifndef __weak_reference
#ifdef __ELF__
#ifdef __STDC__
#define	__weak_reference(sym,alias)	\
	__asm__(".weak " #alias);	\
	__asm__(".equ "  #alias ", " #sym)
#else
#define	__weak_reference(sym,alias)	\
	__asm__(".weak alias");		\
	__asm__(".equ alias, sym")
#endif
#elif __clang__
#ifdef __MACH__
/* Macos prefixes all C symbols with an underscore, this needs to be done manually in asm */

/* So far I have not been able to create on Macos an exported symbol that itself
 * is weak but aliases a strong symbol. A workaround is to make the original
 * symbol weak and the alias symbol will automatically become weak too. */
/* Hint: use `nm -m obj.o` to check the symbols weak/strong on Mac */
#define __weak_reference(sym,alias) \
	__asm__(".weak_definition _" #sym); \
	__asm__(".globl _" #alias); \
	__asm__(".set _" #alias ", _" #sym)
#elif defined(__STDC__)
#define __weak_reference(sym,alias) \
	__asm__(".weak_reference " #alias); \
	__asm__(".globl " #alias); \
	__asm__(".set " #alias ", " #sym)
#else
#define __weak_reference(sym,alias) \
	__asm__(".weak_reference alias");\
	__asm__(".set alias, sym")
#endif
#else	/* !__ELF__ && !__clang__ */
#ifdef __STDC__
#define	__weak_reference(sym,alias)	\
	__asm__(".stabs \"_" #alias "\",11,0,0,0");	\
	__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")
#endif
#endif
#endif

#endif	/* __GNUC__ */

#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

/*
 * Nullability qualifiers: currently only supported by Clang.
 */
#if !(defined(__clang__) && __has_feature(nullability))
#define	_Nonnull
#define	_Nullable
#define	_Null_unspecified
#define	__NULLABILITY_PRAGMA_PUSH
#define	__NULLABILITY_PRAGMA_POP
#else
#define	__NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push")	\
	_Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
#define	__NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop")
#endif

/*
 * Type Safety Checking
 *
 * Clang provides additional attributes to enable checking type safety
 * properties that cannot be enforced by the C type system. 
 */

#if __has_attribute(__argument_with_type_tag__) && \
    __has_attribute(__type_tag_for_datatype__)
#define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
	    __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
#define	__datatype_type_tag(kind, type) \
	    __attribute__((__type_tag_for_datatype__(kind, type)))
#else
#define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx)
#define	__datatype_type_tag(kind, type)
#endif

/*
 * Lock annotations.
 *
 * Clang provides support for doing basic thread-safety tests at
 * compile-time, by marking which locks will/should be held when
 * entering/leaving a functions.
 *
 * Furthermore, it is also possible to annotate variables and structure
 * members to enforce that they are only accessed when certain locks are
 * held.
 */

#if __has_extension(c_thread_safety_attributes)
#define	__lock_annotate(x)	__attribute__((x))
#else
#define	__lock_annotate(x)
#endif

/* Structure implements a lock. */
/* FIXME: Use __lockable__, etc. to avoid colliding with user namespace macros,
 * once clang is fixed: https://bugs.llvm.org/show_bug.cgi?id=34319 */
#define	__lockable		__lock_annotate(lockable)

/* Function acquires an exclusive or shared lock. */
#define	__locks_exclusive(...) \
	__lock_annotate(exclusive_lock_function(__VA_ARGS__))
#define	__locks_shared(...) \
	__lock_annotate(shared_lock_function(__VA_ARGS__))

/* Function attempts to acquire an exclusive or shared lock. */
#define	__trylocks_exclusive(...) \
	__lock_annotate(exclusive_trylock_function(__VA_ARGS__))
#define	__trylocks_shared(...) \
	__lock_annotate(shared_trylock_function(__VA_ARGS__))

/* Function releases a lock. */
#define	__unlocks(...)		__lock_annotate(unlock_function(__VA_ARGS__))

/* Function asserts that an exclusive or shared lock is held. */
#define	__asserts_exclusive(...) \
	__lock_annotate(assert_exclusive_lock(__VA_ARGS__))
#define	__asserts_shared(...) \
	__lock_annotate(assert_shared_lock(__VA_ARGS__))

/* Function requires that an exclusive or shared lock is or is not held. */
#define	__requires_exclusive(...) \
	__lock_annotate(exclusive_locks_required(__VA_ARGS__))
#define	__requires_shared(...) \
	__lock_annotate(shared_locks_required(__VA_ARGS__))
#define	__requires_unlocked(...) \
	__lock_annotate(locks_excluded(__VA_ARGS__))

/* Function should not be analyzed. */
#define	__no_lock_analysis	__lock_annotate(no_thread_safety_analysis)

/*
 * Function or variable should not be sanitized, e.g., by AddressSanitizer.
 * GCC has the nosanitize attribute, but as a function attribute only, and
 * warns on use as a variable attribute.
 */
#if __has_attribute(no_sanitize) && defined(__clang__)
#ifdef _KERNEL
#define __nosanitizeaddress	__attribute__((no_sanitize("kernel-address")))
#define __nosanitizememory	__attribute__((no_sanitize("kernel-memory")))
#else
#define __nosanitizeaddress	__attribute__((no_sanitize("address")))
#define __nosanitizememory	__attribute__((no_sanitize("memory")))
#endif
#define __nosanitizethread	__attribute__((no_sanitize("thread")))
#else
#define __nosanitizeaddress
#define __nosanitizememory
#define __nosanitizethread
#endif

/*
 * fall-through case statement annotations
 */
#if __cplusplus >= 201703L || __STDC_VERSION__ > 201710L
/* Standard C++17/C23 attribute */
#define __PICOLIBC_FALLTHROUGH [[fallthrough]]
#elif __has_attribute(fallthrough)
/* Non-standard but supported by at least gcc and clang */
#define __PICOLIBC_FALLTHROUGH __attribute__((fallthrough))
#else
#define __PICOLIBC_FALLTHROUGH do { } while(0)
#endif

/* Guard variables and structure members by lock. */
#define	__guarded_by(x)		__lock_annotate(guarded_by(x))
#define	__pt_guarded_by(x)	__lock_annotate(pt_guarded_by(x))

/* Alignment builtins for better type checking and improved code generation. */
/* Provide fallback versions for other compilers (GCC/Clang < 10): */
#if !__has_builtin(__builtin_is_aligned)
#define __builtin_is_aligned(x, align)	\
	(((__uintptr_t)x & ((align) - 1)) == 0)
#endif
#if !__has_builtin(__builtin_align_up)
#define __builtin_align_up(x, align)	\
	((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1))))
#endif
#if !__has_builtin(__builtin_align_down)
#define __builtin_align_down(x, align)	\
	((__typeof__(x))((x)&(~((align)-1))))
#endif

#define __align_up(x, y) __builtin_align_up(x, y)
#define __align_down(x, y) __builtin_align_down(x, y)
#define __is_aligned(x, y) __builtin_is_aligned(x, y)

#ifndef _LONG_DOUBLE
#define _LONG_DOUBLE long double
#endif

/* Support gcc's __attribute__ facility.  */

#ifdef __GNUC__
#define _ATTRIBUTE(attrs) __attribute__ (attrs)
#else
#define _ATTRIBUTE(attrs)
#endif

/*  The traditional meaning of 'extern inline' for GCC is not
  to emit the function body unless the address is explicitly
  taken.  However this behaviour is changing to match the C99
  standard, which uses 'extern inline' to indicate that the
  function body *must* be emitted.  Likewise, a function declared
  without either 'extern' or 'static' defaults to extern linkage
  (C99 6.2.2p5), and the compiler may choose whether to use the
  inline version or call the extern linkage version (6.7.4p6).
  If we are using GCC, but do not have the new behaviour, we need
  to use extern inline; if we are using a new GCC with the
  C99-compatible behaviour, or a non-GCC compiler (which we will
  have to hope is C99, since there is no other way to achieve the
  effect of omitting the function if it isn't referenced) we use
  'static inline', which c99 defines to mean more-or-less the same
  as the Gnu C 'extern inline'.  */
#if defined(__GNUC__) && !defined(__GNUC_STDC_INLINE__)
/* We're using GCC, but without the new C99-compatible behaviour.  */
#define _ELIDABLE_INLINE extern __inline__ _ATTRIBUTE ((__always_inline__))
#else
/* We're using GCC in C99 mode, or an unknown compiler which
  we just have to hope obeys the C99 semantics of inline.  */
#define _ELIDABLE_INLINE static __inline__
#endif

#if __GNUC_PREREQ (3, 1)
#define _NOINLINE		__attribute__ ((__noinline__))
#define _NOINLINE_STATIC	_NOINLINE static
#else
/* On non-GNU compilers and GCC prior to version 3.1 the compiler can't be
   trusted not to inline if it is static. */
#define _NOINLINE
#define _NOINLINE_STATIC
#endif

#endif /* !_SYS_CDEFS_H_ */
