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8d7b6b4cb2
glibc/misc/sys/cdefs.h
Florian Weimer 8d7b6b4cb2 socket: Use may_alias on sockaddr structs (bug 19622) 
This supports common coding patterns.  The GCC C front end before
version 7 rejects the may_alias attribute on a struct definition
if it was not present in a previous forward declaration, so this
attribute can only be conditionally applied.

This implements the spirit of the change in Austin Group issue 1641.

Suggested-by: Marek Polacek <polacek@redhat.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Sam James <sam@gentoo.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-05-18 09:33:19 +02:00

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/* Copyright (C) 1992-2024 Free Software Foundation, Inc.
Copyright The GNU Toolchain Authors.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _SYS_CDEFS_H
#define _SYS_CDEFS_H 1
/* We are almost always included from features.h. */
#ifndef _FEATURES_H
# include <features.h>
#endif
/* The GNU libc does not support any K&R compilers or the traditional mode
of ISO C compilers anymore. Check for some of the combinations not
supported anymore. */
#if defined __GNUC__ && !defined __STDC__ && !defined __cplusplus
# error "You need a ISO C or C++ conforming compiler to use the glibc headers"
#endif
/* Some user header file might have defined this before. */
#undef __P
#undef __PMT
/* Compilers that lack __has_attribute may object to
#if defined __has_attribute && __has_attribute (...)
even though they do not need to evaluate the right-hand side of the &&.
Similarly for __has_builtin, etc. */
#if (defined __has_attribute \
&& (!defined __clang_minor__ \
|| 3 < __clang_major__ + (5 <= __clang_minor__)))
# define __glibc_has_attribute(attr) __has_attribute (attr)
#else
# define __glibc_has_attribute(attr) 0
#endif
#ifdef __has_builtin
# define __glibc_has_builtin(name) __has_builtin (name)
#else
# define __glibc_has_builtin(name) 0
#endif
#ifdef __has_extension
# define __glibc_has_extension(ext) __has_extension (ext)
#else
# define __glibc_has_extension(ext) 0
#endif
#if defined __GNUC__ || defined __clang__
/* All functions, except those with callbacks or those that
synchronize memory, are leaf functions. */
# if __GNUC_PREREQ (4, 6) && !defined _LIBC
# define __LEAF , __leaf__
# define __LEAF_ATTR __attribute__ ((__leaf__))
# else
# define __LEAF
# define __LEAF_ATTR
# endif
/* GCC can always grok prototypes. For C++ programs we add throw()
to help it optimize the function calls. But this only works with
gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions
as non-throwing using a function attribute since programs can use
the -fexceptions options for C code as well. */
# if !defined __cplusplus \
&& (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__))
# define __THROW __attribute__ ((__nothrow__ __LEAF))
# define __THROWNL __attribute__ ((__nothrow__))
# define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
# define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
# else
# if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major__ >= 4)
# if __cplusplus >= 201103L
# define __THROW noexcept (true)
# else
# define __THROW throw ()
# endif
# define __THROWNL __THROW
# define __NTH(fct) __LEAF_ATTR fct __THROW
# define __NTHNL(fct) fct __THROW
# else
# define __THROW
# define __THROWNL
# define __NTH(fct) fct
# define __NTHNL(fct) fct
# endif
# endif
# if __GNUC_PREREQ (4, 3) || __glibc_has_attribute (__cold__)
# define __COLD __attribute__ ((__cold__))
# else
# define __COLD
# endif
#else /* Not GCC or clang. */
# if (defined __cplusplus \
|| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
# define __inline inline
# else
# define __inline /* No inline functions. */
# endif
# define __THROW
# define __THROWNL
# define __NTH(fct) fct
# define __COLD
#endif /* GCC || clang. */
/* These two macros are not used in glibc anymore. They are kept here
only because some other projects expect the macros to be defined. */
#define __P(args) args
#define __PMT(args) args
/* For these things, GCC behaves the ANSI way normally,
and the non-ANSI way under -traditional. */
#define __CONCAT(x,y) x ## y
#define __STRING(x) #x
/* This is not a typedef so `const __ptr_t' does the right thing. */
#define __ptr_t void *
/* C++ needs to know that types and declarations are C, not C++. */
#ifdef __cplusplus
# define __BEGIN_DECLS extern "C" {
# define __END_DECLS }
#else
# define __BEGIN_DECLS
# define __END_DECLS
#endif
/* The overloadable attribute was added on clang 2.6. */
#if defined __clang_major__ \
&& (__clang_major__ + (__clang_minor__ >= 6) > 2)
# define __attribute_overloadable__ __attribute__((__overloadable__))
#else
# define __attribute_overloadable__
#endif
/* Fortify support. */
#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
#define __bos0(ptr) __builtin_object_size (ptr, 0)
/* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
#if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
|| __GNUC_PREREQ (12, 0))
# define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
# define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
#else
# define __glibc_objsize0(__o) __bos0 (__o)
# define __glibc_objsize(__o) __bos (__o)
#endif
#if __USE_FORTIFY_LEVEL > 0
/* Compile time conditions to choose between the regular, _chk and _chk_warn
variants. These conditions should get evaluated to constant and optimized
away. */
#define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
#define __glibc_unsigned_or_positive(__l) \
((__typeof (__l)) 0 < (__typeof (__l)) -1 \
|| (__builtin_constant_p (__l) && (__l) > 0))
/* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
condition can be folded to a constant and if it is true, or unknown (-1) */
#define __glibc_safe_or_unknown_len(__l, __s, __osz) \
((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \
|| (__glibc_unsigned_or_positive (__l) \
&& __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
(__s), (__osz))) \
&& __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz))))
/* Conversely, we know at compile time that the length is unsafe if the
__L * __S <= __OBJSZ condition can be folded to a constant and if it is
false. */
#define __glibc_unsafe_len(__l, __s, __osz) \
(__glibc_unsigned_or_positive (__l) \
&& __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
__s, __osz)) \
&& !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
/* To correctly instrument the fortify wrapper clang requires the
pass_object_size attribute, and the attribute has the restriction that the
argument needs to be 'const'. Furthermore, to make it usable with C
interfaces, clang provides the overload attribute, which provides a C++
like function overload support. The overloaded fortify wrapper with the
pass_object_size attribute has precedence over the default symbol.
Also, clang does not support __va_arg_pack, so variadic functions are
expanded to issue va_arg implementations. The error function must not have
bodies (address takes are expanded to nonfortified calls), and with
__fortify_function compiler might still create a body with the C++
mangling name (due to the overload attribute). In this case, the function
is defined with __fortify_function_error_function macro instead.
The argument size check is also done with a clang-only attribute,
__attribute__ ((__diagnose_if__ (...))), different than gcc which calls
symbol_chk_warn alias with uses __warnattr attribute.
The pass_object_size was added on clang 4.0, __diagnose_if__ on 5.0,
and pass_dynamic_object_size on 9.0. */
#if defined __clang_major__ && __clang_major__ >= 5
# define __fortify_use_clang 1
# define __fortify_function_error_function static __attribute__((__unused__))
# define __fortify_clang_pass_object_size_n(n) \
__attribute__ ((__pass_object_size__ (n)))
# define __fortify_clang_pass_object_size0 \
__fortify_clang_pass_object_size_n (0)
# define __fortify_clang_pass_object_size \
__fortify_clang_pass_object_size_n (__USE_FORTIFY_LEVEL > 1)
# if __clang_major__ >= 9
# define __fortify_clang_pass_dynamic_object_size_n(n) \
__attribute__ ((__pass_dynamic_object_size__ (n)))
# define __fortify_clang_pass_dynamic_object_size0 \
__fortify_clang_pass_dynamic_object_size_n (0)
# define __fortify_clang_pass_dynamic_object_size \
__fortify_clang_pass_dynamic_object_size_n (1)
# else
# define __fortify_clang_pass_dynamic_object_size_n(n)
# define __fortify_clang_pass_dynamic_object_size0
# define __fortify_clang_pass_dynamic_object_size
# endif
# define __fortify_clang_bos_static_lt_impl(bos_val, n, s) \
((bos_val) != -1ULL && (n) > (bos_val) / (s))
# define __fortify_clang_bos_static_lt2(__n, __e, __s) \
__fortify_clang_bos_static_lt_impl (__bos (__e), __n, __s)
# define __fortify_clang_bos_static_lt(__n, __e) \
__fortify_clang_bos_static_lt2 (__n, __e, 1)
# define __fortify_clang_bos0_static_lt2(__n, __e, __s) \
__fortify_clang_bos_static_lt_impl (__bos0 (__e), __n, __s)
# define __fortify_clang_bos0_static_lt(__n, __e) \
__fortify_clang_bos0_static_lt2 (__n, __e, 1)
# define __fortify_clang_bosn_args(bos_fn, n, buf, div, complaint) \
(__fortify_clang_bos_static_lt_impl (bos_fn (buf), n, div)), (complaint), \
"warning"
# define __fortify_clang_warning(__c, __msg) \
__attribute__ ((__diagnose_if__ ((__c), (__msg), "warning")))
# define __fortify_clang_error(__c, __msg) \
__attribute__ ((__diagnose_if__ ((__c), (__msg), "error")))
# define __fortify_clang_warning_only_if_bos0_lt(n, buf, complaint) \
__attribute__ ((__diagnose_if__ \
(__fortify_clang_bosn_args (__bos0, n, buf, 1, complaint))))
# define __fortify_clang_warning_only_if_bos0_lt2(n, buf, div, complaint) \
__attribute__ ((__diagnose_if__ \
(__fortify_clang_bosn_args (__bos0, n, buf, div, complaint))))
# define __fortify_clang_warning_only_if_bos_lt(n, buf, complaint) \
__attribute__ ((__diagnose_if__ \
(__fortify_clang_bosn_args (__bos, n, buf, 1, complaint))))
# define __fortify_clang_warning_only_if_bos_lt2(n, buf, div, complaint) \
__attribute__ ((__diagnose_if__ \
(__fortify_clang_bosn_args (__bos, n, buf, div, complaint))))
# define __fortify_clang_prefer_this_overload \
__attribute__ ((enable_if (1, "")))
# define __fortify_clang_unavailable(__msg) \
__attribute__ ((unavailable(__msg)))
# if __USE_FORTIFY_LEVEL == 3
# define __fortify_clang_overload_arg(__type, __attr, __name) \
__type __attr const __fortify_clang_pass_dynamic_object_size __name
# define __fortify_clang_overload_arg0(__type, __attr, __name) \
__type __attr const __fortify_clang_pass_dynamic_object_size0 __name
# else
# define __fortify_clang_overload_arg(__type, __attr, __name) \
__type __attr const __fortify_clang_pass_object_size __name
# define __fortify_clang_overload_arg0(__type, __attr, __name) \
__type __attr const __fortify_clang_pass_object_size0 __name
# endif
# define __fortify_clang_mul_may_overflow(size, n) \
((size | n) >= (((size_t)1) << (8 * sizeof (size_t) / 2)))
# define __fortify_clang_size_too_small(__bos, __dest, __len) \
(__bos (__dest) != (size_t) -1 && __bos (__dest) < __len)
# define __fortify_clang_warn_if_src_too_large(__dest, __src) \
__fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize, \
__dest, \
__builtin_strlen (__src) + 1), \
"destination buffer will always be overflown by source")
# define __fortify_clang_warn_if_dest_too_small(__dest, __len) \
__fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize, \
__dest, \
__len), \
"function called with bigger length than the destination buffer")
# define __fortify_clang_warn_if_dest_too_small0(__dest, __len) \
__fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize0, \
__dest, \
__len), \
"function called with bigger length than the destination buffer")
#else
# define __fortify_use_clang 0
# define __fortify_clang_warning(__c, __msg)
# define __fortify_clang_warning_only_if_bos0_lt(__n, __buf, __complaint)
# define __fortify_clang_warning_only_if_bos0_lt2(__n, __buf, __div, complaint)
# define __fortify_clang_warning_only_if_bos_lt(__n, __buf, __complaint)
# define __fortify_clang_warning_only_if_bos_lt2(__n, __buf, div, __complaint)
# define __fortify_clang_overload_arg(__type, __attr, __name) \
__type __attr __name
# define __fortify_clang_overload_arg0(__type, __attr, __name) \
__fortify_clang_overload_arg (__type, __attr, __name)
# define __fortify_clang_warn_if_src_too_large(__dest, __src)
# define __fortify_clang_warn_if_dest_too_small(__dest, __len)
# define __fortify_clang_warn_if_dest_too_small0(__dest, __len)
#endif
/* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be
declared. */
#if !__fortify_use_clang
# define __glibc_fortify(f, __l, __s, __osz, ...) \
(__glibc_safe_or_unknown_len (__l, __s, __osz) \
? __ ## f ## _alias (__VA_ARGS__) \
: (__glibc_unsafe_len (__l, __s, __osz) \
? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \
: __ ## f ## _chk (__VA_ARGS__, __osz)))
#else
# define __glibc_fortify(f, __l, __s, __osz, ...) \
(__osz == (__SIZE_TYPE__) -1) \
? __ ## f ## _alias (__VA_ARGS__) \
: __ ## f ## _chk (__VA_ARGS__, __osz)
#endif
/* Fortify function f, where object size argument passed to f is the number of
elements and not total size. */
#if !__fortify_use_clang
# define __glibc_fortify_n(f, __l, __s, __osz, ...) \
(__glibc_safe_or_unknown_len (__l, __s, __osz) \
? __ ## f ## _alias (__VA_ARGS__) \
: (__glibc_unsafe_len (__l, __s, __osz) \
? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \
: __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))))
# else
# define __glibc_fortify_n(f, __l, __s, __osz, ...) \
(__osz == (__SIZE_TYPE__) -1) \
? __ ## f ## _alias (__VA_ARGS__) \
: __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))
#endif
#endif /* __USE_FORTIFY_LEVEL > 0 */
#if __GNUC_PREREQ (4,3)
# define __warnattr(msg) __attribute__((__warning__ (msg)))
# define __errordecl(name, msg) \
extern void name (void) __attribute__((__error__ (msg)))
#else
# define __warnattr(msg)
# define __errordecl(name, msg) extern void name (void)
#endif
/* Support for flexible arrays.
Headers that should use flexible arrays only if they're "real"
(e.g. only if they won't affect sizeof()) should test
#if __glibc_c99_flexarr_available. */
#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
# define __flexarr []
# define __glibc_c99_flexarr_available 1
#elif __GNUC_PREREQ (2,97) || defined __clang__
/* GCC 2.97 and clang support C99 flexible array members as an extension,
even when in C89 mode or compiling C++ (any version). */
# define __flexarr []
# define __glibc_c99_flexarr_available 1
#elif defined __GNUC__
/* Pre-2.97 GCC did not support C99 flexible arrays but did have
an equivalent extension with slightly different notation. */
# define __flexarr [0]
# define __glibc_c99_flexarr_available 1
#else
/* Some other non-C99 compiler. Approximate with [1]. */
# define __flexarr [1]
# define __glibc_c99_flexarr_available 0
#endif
/* __asm__ ("xyz") is used throughout the headers to rename functions
at the assembly language level. This is wrapped by the __REDIRECT
macro, in order to support compilers that can do this some other
way. When compilers don't support asm-names at all, we have to do
preprocessor tricks instead (which don't have exactly the right
semantics, but it's the best we can do).
Example:
int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
#if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
# ifdef __cplusplus
# define __REDIRECT_NTH(name, proto, alias) \
name proto __THROW __asm__ (__ASMNAME (#alias))
# define __REDIRECT_NTHNL(name, proto, alias) \
name proto __THROWNL __asm__ (__ASMNAME (#alias))
# else
# define __REDIRECT_NTH(name, proto, alias) \
name proto __asm__ (__ASMNAME (#alias)) __THROW
# define __REDIRECT_NTHNL(name, proto, alias) \
name proto __asm__ (__ASMNAME (#alias)) __THROWNL
# endif
# define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
# define __ASMNAME2(prefix, cname) __STRING (prefix) cname
#ifndef __REDIRECT_FORTIFY
#define __REDIRECT_FORTIFY __REDIRECT
#endif
#ifndef __REDIRECT_FORTIFY_NTH
#define __REDIRECT_FORTIFY_NTH __REDIRECT_NTH
#endif
/*
#elif __SOME_OTHER_COMPILER__
# define __REDIRECT(name, proto, alias) name proto; \
_Pragma("let " #name " = " #alias)
*/
#endif
/* GCC and clang have various useful declarations that can be made with
the '__attribute__' syntax. All of the ways we use this do fine if
they are omitted for compilers that don't understand it. */
#if !(defined __GNUC__ || defined __clang__)
# define __attribute__(xyz) /* Ignore */
#endif
/* At some point during the gcc 2.96 development the `malloc' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
#if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
# define __attribute_malloc__ __attribute__ ((__malloc__))
#else
# define __attribute_malloc__ /* Ignore */
#endif
/* Tell the compiler which arguments to an allocation function
indicate the size of the allocation. */
#if __GNUC_PREREQ (4, 3)
# define __attribute_alloc_size__(params) \
__attribute__ ((__alloc_size__ params))
#else
# define __attribute_alloc_size__(params) /* Ignore. */
#endif
/* Tell the compiler which argument to an allocation function
indicates the alignment of the allocation. */
#if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__)
# define __attribute_alloc_align__(param) \
__attribute__ ((__alloc_align__ param))
#else
# define __attribute_alloc_align__(param) /* Ignore. */
#endif
/* At some point during the gcc 2.96 development the `pure' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
#if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
# define __attribute_pure__ __attribute__ ((__pure__))
#else
# define __attribute_pure__ /* Ignore */
#endif
/* This declaration tells the compiler that the value is constant. */
#if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
# define __attribute_const__ __attribute__ ((__const__))
#else
# define __attribute_const__ /* Ignore */
#endif
#if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
# define __attribute_maybe_unused__ __attribute__ ((__unused__))
#else
# define __attribute_maybe_unused__ /* Ignore */
#endif
/* At some point during the gcc 3.1 development the `used' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
#if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
# define __attribute_used__ __attribute__ ((__used__))
# define __attribute_noinline__ __attribute__ ((__noinline__))
#else
# define __attribute_used__ __attribute__ ((__unused__))
# define __attribute_noinline__ /* Ignore */
#endif
/* Since version 3.2, gcc allows marking deprecated functions. */
#if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
# define __attribute_deprecated__ __attribute__ ((__deprecated__))
#else
# define __attribute_deprecated__ /* Ignore */
#endif
/* Since version 4.5, gcc also allows one to specify the message printed
when a deprecated function is used. clang claims to be gcc 4.2, but
may also support this feature. */
#if __GNUC_PREREQ (4,5) \
|| __glibc_has_extension (__attribute_deprecated_with_message__)
# define __attribute_deprecated_msg__(msg) \
__attribute__ ((__deprecated__ (msg)))
#else
# define __attribute_deprecated_msg__(msg) __attribute_deprecated__
#endif
/* At some point during the gcc 2.8 development the `format_arg' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings.
If several `format_arg' attributes are given for the same function, in
gcc-3.0 and older, all but the last one are ignored. In newer gccs,
all designated arguments are considered. */
#if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
# define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
#else
# define __attribute_format_arg__(x) /* Ignore */
#endif
/* At some point during the gcc 2.97 development the `strfmon' format
attribute for functions was introduced. We don't want to use it
unconditionally (although this would be possible) since it
generates warnings. */
#if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
# define __attribute_format_strfmon__(a,b) \
__attribute__ ((__format__ (__strfmon__, a, b)))
#else
# define __attribute_format_strfmon__(a,b) /* Ignore */
#endif
/* The nonnull function attribute marks pointer parameters that
must not be NULL. This has the name __nonnull in glibc,
and __attribute_nonnull__ in files shared with Gnulib to avoid
collision with a different __nonnull in DragonFlyBSD 5.9. */
#ifndef __attribute_nonnull__
# if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
# define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params))
# else
# define __attribute_nonnull__(params)
# endif
#endif
#ifndef __nonnull
# define __nonnull(params) __attribute_nonnull__ (params)
#endif
/* The returns_nonnull function attribute marks the return type of the function
as always being non-null. */
#ifndef __returns_nonnull
# if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__)
# define __returns_nonnull __attribute__ ((__returns_nonnull__))
# else
# define __returns_nonnull
# endif
#endif
/* If fortification mode, we warn about unused results of certain
function calls which can lead to problems. */
#if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
# define __attribute_warn_unused_result__ \
__attribute__ ((__warn_unused_result__))
# if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
# define __wur __attribute_warn_unused_result__
# endif
#else
# define __attribute_warn_unused_result__ /* empty */
#endif
#ifndef __wur
# define __wur /* Ignore */
#endif
/* Forces a function to be always inlined. */
#if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
/* The Linux kernel defines __always_inline in stddef.h (283d7573), and
it conflicts with this definition. Therefore undefine it first to
allow either header to be included first. */
# undef __always_inline
# define __always_inline __inline __attribute__ ((__always_inline__))
#else
# undef __always_inline
# define __always_inline __inline
#endif
/* Associate error messages with the source location of the call site rather
than with the source location inside the function. */
#if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
# define __attribute_artificial__ __attribute__ ((__artificial__))
#else
# define __attribute_artificial__ /* Ignore */
#endif
/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
older than 4.3 may define these macros and still not guarantee GNU inlining
semantics.
clang++ identifies itself as gcc-4.2, but has support for GNU inlining
semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
__GNUC_GNU_INLINE__ macro definitions. */
#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
|| (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
|| defined __GNUC_GNU_INLINE__)))
# if defined __GNUC_STDC_INLINE__ || defined __cplusplus
# define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
# define __extern_always_inline \
extern __always_inline __attribute__ ((__gnu_inline__))
# else
# define __extern_inline extern __inline
# define __extern_always_inline extern __always_inline
# endif
#endif
#ifdef __extern_always_inline
# define __fortify_function __extern_always_inline __attribute_artificial__
#endif
/* GCC 4.3 and above allow passing all anonymous arguments of an
__extern_always_inline function to some other vararg function. */
#if __GNUC_PREREQ (4,3)
# define __va_arg_pack() __builtin_va_arg_pack ()
# define __va_arg_pack_len() __builtin_va_arg_pack_len ()
#endif
/* It is possible to compile containing GCC extensions even if GCC is
run in pedantic mode if the uses are carefully marked using the
`__extension__' keyword. But this is not generally available before
version 2.8. */
#if !(__GNUC_PREREQ (2,8) || defined __clang__)
# define __extension__ /* Ignore */
#endif
/* __restrict is known in EGCS 1.2 and above, and in clang.
It works also in C++ mode (outside of arrays), but only when spelled
as '__restrict', not 'restrict'. */
#if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
# define __restrict restrict
# else
# define __restrict /* Ignore */
# endif
#endif
/* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
array_name[restrict]
GCC 3.1 and clang support this.
This syntax is not usable in C++ mode. */
#if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
# define __restrict_arr __restrict
#else
# ifdef __GNUC__
# define __restrict_arr /* Not supported in old GCC. */
# else
# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
# define __restrict_arr restrict
# else
/* Some other non-C99 compiler. */
# define __restrict_arr /* Not supported. */
# endif
# endif
#endif
#if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
# define __glibc_likely(cond) __builtin_expect ((cond), 1)
#else
# define __glibc_unlikely(cond) (cond)
# define __glibc_likely(cond) (cond)
#endif
#if (!defined _Noreturn \
&& (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
&& !(__GNUC_PREREQ (4,7) \
|| (3 < __clang_major__ + (5 <= __clang_minor__))))
# if __GNUC_PREREQ (2,8)
# define _Noreturn __attribute__ ((__noreturn__))
# else
# define _Noreturn
# endif
#endif
#if __GNUC_PREREQ (8, 0)
/* Describes a char array whose address can safely be passed as the first
argument to strncpy and strncat, as the char array is not necessarily
a NUL-terminated string. */
# define __attribute_nonstring__ __attribute__ ((__nonstring__))
#else
# define __attribute_nonstring__
#endif
/* Undefine (also defined in libc-symbols.h). */
#undef __attribute_copy__
#if __GNUC_PREREQ (9, 0)
/* Copies attributes from the declaration or type referenced by
the argument. */
# define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
#else
# define __attribute_copy__(arg)
#endif
#if (!defined _Static_assert && !defined __cplusplus \
&& (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
&& (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
|| defined __STRICT_ANSI__))
# define _Static_assert(expr, diagnostic) \
extern int (*__Static_assert_function (void)) \
[!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
#endif
/* Gnulib avoids including these, as they don't work on non-glibc or
older glibc platforms. */
#ifndef __GNULIB_CDEFS
# include <bits/wordsize.h>
# include <bits/long-double.h>
#endif
#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
# ifdef __REDIRECT
/* Alias name defined automatically. */
# define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
# define __LDBL_REDIR_DECL(name) \
extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
# define __REDIRECT_LDBL(name, proto, alias) \
name proto __asm (__ASMNAME ("__" #alias "ieee128"))
/* Alias name defined automatically, with leading underscores. */
# define __LDBL_REDIR2_DECL(name) \
extern __typeof (__##name) __##name \
__asm (__ASMNAME ("__" #name "ieee128"));
/* Alias name defined manually. */
# define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
# define __LDBL_REDIR1_DECL(name, alias) \
extern __typeof (name) name __asm (__ASMNAME (#alias));
# define __LDBL_REDIR1_NTH(name, proto, alias) \
__REDIRECT_NTH (name, proto, alias)
# define __REDIRECT_NTH_LDBL(name, proto, alias) \
__LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
/* Unused. */
# define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
# else
_Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
# endif
#elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
# define __LDBL_COMPAT 1
# ifdef __REDIRECT
# define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
# define __LDBL_REDIR(name, proto) \
__LDBL_REDIR1 (name, proto, __nldbl_##name)
# define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
# define __LDBL_REDIR_NTH(name, proto) \
__LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
# define __LDBL_REDIR2_DECL(name) \
extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
# define __LDBL_REDIR1_DECL(name, alias) \
extern __typeof (name) name __asm (__ASMNAME (#alias));
# define __LDBL_REDIR_DECL(name) \
extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
# define __REDIRECT_LDBL(name, proto, alias) \
__LDBL_REDIR1 (name, proto, __nldbl_##alias)
# define __REDIRECT_NTH_LDBL(name, proto, alias) \
__LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
# endif
#endif
#if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
|| !defined __REDIRECT
# define __LDBL_REDIR1(name, proto, alias) name proto
# define __LDBL_REDIR(name, proto) name proto
# define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
# define __LDBL_REDIR_NTH(name, proto) name proto __THROW
# define __LDBL_REDIR2_DECL(name)
# define __LDBL_REDIR_DECL(name)
# ifdef __REDIRECT
# define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
# define __REDIRECT_NTH_LDBL(name, proto, alias) \
__REDIRECT_NTH (name, proto, alias)
# endif
#endif
/* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
intended for use in preprocessor macros.
Note: MESSAGE must be a _single_ string; concatenation of string
literals is not supported. */
#if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
# define __glibc_macro_warning1(message) _Pragma (#message)
# define __glibc_macro_warning(message) \
__glibc_macro_warning1 (GCC warning message)
#else
# define __glibc_macro_warning(msg)
#endif
/* Generic selection (ISO C11) is a C-only feature, available in GCC
since version 4.9. Previous versions do not provide generic
selection, even though they might set __STDC_VERSION__ to 201112L,
when in -std=c11 mode. Thus, we must check for !defined __GNUC__
when testing __STDC_VERSION__ for generic selection support.
On the other hand, Clang also defines __GNUC__, so a clang-specific
check is required to enable the use of generic selection. */
#if !defined __cplusplus \
&& (__GNUC_PREREQ (4, 9) \
|| __glibc_has_extension (c_generic_selections) \
|| (!defined __GNUC__ && defined __STDC_VERSION__ \
&& __STDC_VERSION__ >= 201112L))
# define __HAVE_GENERIC_SELECTION 1
#else
# define __HAVE_GENERIC_SELECTION 0
#endif
#if __GNUC_PREREQ (10, 0)
/* Designates a 1-based positional argument ref-index of pointer type
that can be used to access size-index elements of the pointed-to
array according to access mode, or at least one element when
size-index is not provided:
access (access-mode, <ref-index> [, <size-index>]) */
# define __attr_access(x) __attribute__ ((__access__ x))
/* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may
use the access attribute to get object sizes from function definition
arguments, so we can't use them on functions we fortify. Drop the access
attribute for such functions. */
# if __USE_FORTIFY_LEVEL == 3
# define __fortified_attr_access(a, o, s)
# else
# define __fortified_attr_access(a, o, s) __attr_access ((a, o, s))
# endif
# if __GNUC_PREREQ (11, 0)
# define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno)))
# else
# define __attr_access_none(argno)
# endif
#else
# define __fortified_attr_access(a, o, s)
# define __attr_access(x)
# define __attr_access_none(argno)
#endif
#if __GNUC_PREREQ (11, 0)
/* Designates dealloc as a function to call to deallocate objects
allocated by the declared function. */
# define __attr_dealloc(dealloc, argno) \
__attribute__ ((__malloc__ (dealloc, argno)))
# define __attr_dealloc_free __attr_dealloc (__builtin_free, 1)
#else
# define __attr_dealloc(dealloc, argno)
# define __attr_dealloc_free
#endif
/* Specify that a function such as setjmp or vfork may return
twice. */
#if __GNUC_PREREQ (4, 1)
# define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
#else
# define __attribute_returns_twice__ /* Ignore. */
#endif
/* Mark struct types as aliasable. Restricted to compilers that
support forward declarations of structs in the presence of the
attribute. */
#if __GNUC_PREREQ (7, 1) || defined __clang__
# define __attribute_struct_may_alias__ __attribute__ ((__may_alias__))
#else
# define __attribute_struct_may_alias__
#endif
#endif /* sys/cdefs.h */
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