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8d7b6b4cb2
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>
887 lines
34 KiB
C
887 lines
34 KiB
C
/* Copyright (C) 1992-2024 Free Software Foundation, Inc.
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Copyright The GNU Toolchain Authors.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#ifndef _SYS_CDEFS_H
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#define _SYS_CDEFS_H 1
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/* We are almost always included from features.h. */
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#ifndef _FEATURES_H
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# include <features.h>
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#endif
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/* The GNU libc does not support any K&R compilers or the traditional mode
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of ISO C compilers anymore. Check for some of the combinations not
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supported anymore. */
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#if defined __GNUC__ && !defined __STDC__ && !defined __cplusplus
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# error "You need a ISO C or C++ conforming compiler to use the glibc headers"
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#endif
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/* Some user header file might have defined this before. */
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#undef __P
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#undef __PMT
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/* Compilers that lack __has_attribute may object to
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#if defined __has_attribute && __has_attribute (...)
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even though they do not need to evaluate the right-hand side of the &&.
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Similarly for __has_builtin, etc. */
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#if (defined __has_attribute \
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&& (!defined __clang_minor__ \
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|| 3 < __clang_major__ + (5 <= __clang_minor__)))
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# define __glibc_has_attribute(attr) __has_attribute (attr)
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#else
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# define __glibc_has_attribute(attr) 0
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#endif
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#ifdef __has_builtin
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# define __glibc_has_builtin(name) __has_builtin (name)
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#else
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# define __glibc_has_builtin(name) 0
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#endif
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#ifdef __has_extension
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# define __glibc_has_extension(ext) __has_extension (ext)
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#else
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# define __glibc_has_extension(ext) 0
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#endif
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#if defined __GNUC__ || defined __clang__
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/* All functions, except those with callbacks or those that
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synchronize memory, are leaf functions. */
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# if __GNUC_PREREQ (4, 6) && !defined _LIBC
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# define __LEAF , __leaf__
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# define __LEAF_ATTR __attribute__ ((__leaf__))
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# else
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# define __LEAF
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# define __LEAF_ATTR
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# endif
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/* GCC can always grok prototypes. For C++ programs we add throw()
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to help it optimize the function calls. But this only works with
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gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions
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as non-throwing using a function attribute since programs can use
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the -fexceptions options for C code as well. */
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# if !defined __cplusplus \
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&& (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__))
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# define __THROW __attribute__ ((__nothrow__ __LEAF))
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# define __THROWNL __attribute__ ((__nothrow__))
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# define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
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# define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
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# else
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# if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major__ >= 4)
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# if __cplusplus >= 201103L
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# define __THROW noexcept (true)
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# else
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# define __THROW throw ()
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# endif
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# define __THROWNL __THROW
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# define __NTH(fct) __LEAF_ATTR fct __THROW
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# define __NTHNL(fct) fct __THROW
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# else
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# define __THROW
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# define __THROWNL
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# define __NTH(fct) fct
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# define __NTHNL(fct) fct
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# endif
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# endif
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# if __GNUC_PREREQ (4, 3) || __glibc_has_attribute (__cold__)
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# define __COLD __attribute__ ((__cold__))
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# else
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# define __COLD
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# endif
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#else /* Not GCC or clang. */
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# if (defined __cplusplus \
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|| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
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# define __inline inline
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# else
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# define __inline /* No inline functions. */
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# endif
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# define __THROW
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# define __THROWNL
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# define __NTH(fct) fct
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# define __COLD
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#endif /* GCC || clang. */
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/* These two macros are not used in glibc anymore. They are kept here
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only because some other projects expect the macros to be defined. */
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#define __P(args) args
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#define __PMT(args) args
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/* For these things, GCC behaves the ANSI way normally,
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and the non-ANSI way under -traditional. */
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#define __CONCAT(x,y) x ## y
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#define __STRING(x) #x
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/* This is not a typedef so `const __ptr_t' does the right thing. */
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#define __ptr_t void *
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/* C++ needs to know that types and declarations are C, not C++. */
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#ifdef __cplusplus
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# define __BEGIN_DECLS extern "C" {
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# define __END_DECLS }
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#else
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# define __BEGIN_DECLS
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# define __END_DECLS
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#endif
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/* The overloadable attribute was added on clang 2.6. */
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#if defined __clang_major__ \
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&& (__clang_major__ + (__clang_minor__ >= 6) > 2)
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# define __attribute_overloadable__ __attribute__((__overloadable__))
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#else
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# define __attribute_overloadable__
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#endif
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/* Fortify support. */
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#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
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#define __bos0(ptr) __builtin_object_size (ptr, 0)
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/* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
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#if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
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|| __GNUC_PREREQ (12, 0))
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# define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
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# define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
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#else
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# define __glibc_objsize0(__o) __bos0 (__o)
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# define __glibc_objsize(__o) __bos (__o)
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#endif
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#if __USE_FORTIFY_LEVEL > 0
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/* Compile time conditions to choose between the regular, _chk and _chk_warn
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variants. These conditions should get evaluated to constant and optimized
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away. */
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#define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
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#define __glibc_unsigned_or_positive(__l) \
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((__typeof (__l)) 0 < (__typeof (__l)) -1 \
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|| (__builtin_constant_p (__l) && (__l) > 0))
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/* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
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condition can be folded to a constant and if it is true, or unknown (-1) */
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#define __glibc_safe_or_unknown_len(__l, __s, __osz) \
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((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \
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|| (__glibc_unsigned_or_positive (__l) \
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&& __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
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(__s), (__osz))) \
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&& __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz))))
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/* Conversely, we know at compile time that the length is unsafe if the
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__L * __S <= __OBJSZ condition can be folded to a constant and if it is
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false. */
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#define __glibc_unsafe_len(__l, __s, __osz) \
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(__glibc_unsigned_or_positive (__l) \
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&& __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
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__s, __osz)) \
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&& !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
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/* To correctly instrument the fortify wrapper clang requires the
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pass_object_size attribute, and the attribute has the restriction that the
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argument needs to be 'const'. Furthermore, to make it usable with C
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interfaces, clang provides the overload attribute, which provides a C++
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like function overload support. The overloaded fortify wrapper with the
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pass_object_size attribute has precedence over the default symbol.
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Also, clang does not support __va_arg_pack, so variadic functions are
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expanded to issue va_arg implementations. The error function must not have
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bodies (address takes are expanded to nonfortified calls), and with
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__fortify_function compiler might still create a body with the C++
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mangling name (due to the overload attribute). In this case, the function
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is defined with __fortify_function_error_function macro instead.
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The argument size check is also done with a clang-only attribute,
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__attribute__ ((__diagnose_if__ (...))), different than gcc which calls
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symbol_chk_warn alias with uses __warnattr attribute.
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The pass_object_size was added on clang 4.0, __diagnose_if__ on 5.0,
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and pass_dynamic_object_size on 9.0. */
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#if defined __clang_major__ && __clang_major__ >= 5
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# define __fortify_use_clang 1
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# define __fortify_function_error_function static __attribute__((__unused__))
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# define __fortify_clang_pass_object_size_n(n) \
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__attribute__ ((__pass_object_size__ (n)))
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# define __fortify_clang_pass_object_size0 \
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__fortify_clang_pass_object_size_n (0)
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# define __fortify_clang_pass_object_size \
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__fortify_clang_pass_object_size_n (__USE_FORTIFY_LEVEL > 1)
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# if __clang_major__ >= 9
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# define __fortify_clang_pass_dynamic_object_size_n(n) \
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__attribute__ ((__pass_dynamic_object_size__ (n)))
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# define __fortify_clang_pass_dynamic_object_size0 \
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__fortify_clang_pass_dynamic_object_size_n (0)
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# define __fortify_clang_pass_dynamic_object_size \
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__fortify_clang_pass_dynamic_object_size_n (1)
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# else
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# define __fortify_clang_pass_dynamic_object_size_n(n)
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# define __fortify_clang_pass_dynamic_object_size0
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# define __fortify_clang_pass_dynamic_object_size
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# endif
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# define __fortify_clang_bos_static_lt_impl(bos_val, n, s) \
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((bos_val) != -1ULL && (n) > (bos_val) / (s))
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# define __fortify_clang_bos_static_lt2(__n, __e, __s) \
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__fortify_clang_bos_static_lt_impl (__bos (__e), __n, __s)
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# define __fortify_clang_bos_static_lt(__n, __e) \
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__fortify_clang_bos_static_lt2 (__n, __e, 1)
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# define __fortify_clang_bos0_static_lt2(__n, __e, __s) \
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__fortify_clang_bos_static_lt_impl (__bos0 (__e), __n, __s)
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# define __fortify_clang_bos0_static_lt(__n, __e) \
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__fortify_clang_bos0_static_lt2 (__n, __e, 1)
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# define __fortify_clang_bosn_args(bos_fn, n, buf, div, complaint) \
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(__fortify_clang_bos_static_lt_impl (bos_fn (buf), n, div)), (complaint), \
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"warning"
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# define __fortify_clang_warning(__c, __msg) \
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__attribute__ ((__diagnose_if__ ((__c), (__msg), "warning")))
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# define __fortify_clang_error(__c, __msg) \
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__attribute__ ((__diagnose_if__ ((__c), (__msg), "error")))
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# define __fortify_clang_warning_only_if_bos0_lt(n, buf, complaint) \
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__attribute__ ((__diagnose_if__ \
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(__fortify_clang_bosn_args (__bos0, n, buf, 1, complaint))))
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# define __fortify_clang_warning_only_if_bos0_lt2(n, buf, div, complaint) \
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__attribute__ ((__diagnose_if__ \
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(__fortify_clang_bosn_args (__bos0, n, buf, div, complaint))))
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# define __fortify_clang_warning_only_if_bos_lt(n, buf, complaint) \
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__attribute__ ((__diagnose_if__ \
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(__fortify_clang_bosn_args (__bos, n, buf, 1, complaint))))
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# define __fortify_clang_warning_only_if_bos_lt2(n, buf, div, complaint) \
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__attribute__ ((__diagnose_if__ \
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(__fortify_clang_bosn_args (__bos, n, buf, div, complaint))))
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# define __fortify_clang_prefer_this_overload \
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__attribute__ ((enable_if (1, "")))
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# define __fortify_clang_unavailable(__msg) \
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__attribute__ ((unavailable(__msg)))
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# if __USE_FORTIFY_LEVEL == 3
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# define __fortify_clang_overload_arg(__type, __attr, __name) \
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__type __attr const __fortify_clang_pass_dynamic_object_size __name
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# define __fortify_clang_overload_arg0(__type, __attr, __name) \
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__type __attr const __fortify_clang_pass_dynamic_object_size0 __name
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# else
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# define __fortify_clang_overload_arg(__type, __attr, __name) \
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__type __attr const __fortify_clang_pass_object_size __name
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# define __fortify_clang_overload_arg0(__type, __attr, __name) \
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__type __attr const __fortify_clang_pass_object_size0 __name
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# endif
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# define __fortify_clang_mul_may_overflow(size, n) \
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((size | n) >= (((size_t)1) << (8 * sizeof (size_t) / 2)))
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# define __fortify_clang_size_too_small(__bos, __dest, __len) \
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(__bos (__dest) != (size_t) -1 && __bos (__dest) < __len)
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# define __fortify_clang_warn_if_src_too_large(__dest, __src) \
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__fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize, \
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__dest, \
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__builtin_strlen (__src) + 1), \
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"destination buffer will always be overflown by source")
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# define __fortify_clang_warn_if_dest_too_small(__dest, __len) \
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__fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize, \
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__dest, \
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__len), \
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"function called with bigger length than the destination buffer")
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# define __fortify_clang_warn_if_dest_too_small0(__dest, __len) \
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__fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize0, \
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__dest, \
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__len), \
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"function called with bigger length than the destination buffer")
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#else
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# define __fortify_use_clang 0
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# define __fortify_clang_warning(__c, __msg)
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# define __fortify_clang_warning_only_if_bos0_lt(__n, __buf, __complaint)
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# define __fortify_clang_warning_only_if_bos0_lt2(__n, __buf, __div, complaint)
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# define __fortify_clang_warning_only_if_bos_lt(__n, __buf, __complaint)
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# define __fortify_clang_warning_only_if_bos_lt2(__n, __buf, div, __complaint)
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# define __fortify_clang_overload_arg(__type, __attr, __name) \
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__type __attr __name
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# define __fortify_clang_overload_arg0(__type, __attr, __name) \
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__fortify_clang_overload_arg (__type, __attr, __name)
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# define __fortify_clang_warn_if_src_too_large(__dest, __src)
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# define __fortify_clang_warn_if_dest_too_small(__dest, __len)
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# define __fortify_clang_warn_if_dest_too_small0(__dest, __len)
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#endif
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/* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be
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declared. */
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#if !__fortify_use_clang
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# define __glibc_fortify(f, __l, __s, __osz, ...) \
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(__glibc_safe_or_unknown_len (__l, __s, __osz) \
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? __ ## f ## _alias (__VA_ARGS__) \
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: (__glibc_unsafe_len (__l, __s, __osz) \
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? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \
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: __ ## f ## _chk (__VA_ARGS__, __osz)))
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#else
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# define __glibc_fortify(f, __l, __s, __osz, ...) \
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(__osz == (__SIZE_TYPE__) -1) \
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? __ ## f ## _alias (__VA_ARGS__) \
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: __ ## f ## _chk (__VA_ARGS__, __osz)
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#endif
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/* Fortify function f, where object size argument passed to f is the number of
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elements and not total size. */
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#if !__fortify_use_clang
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# define __glibc_fortify_n(f, __l, __s, __osz, ...) \
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(__glibc_safe_or_unknown_len (__l, __s, __osz) \
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? __ ## f ## _alias (__VA_ARGS__) \
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: (__glibc_unsafe_len (__l, __s, __osz) \
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? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \
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: __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))))
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# else
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# define __glibc_fortify_n(f, __l, __s, __osz, ...) \
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(__osz == (__SIZE_TYPE__) -1) \
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? __ ## f ## _alias (__VA_ARGS__) \
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: __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))
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#endif
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#endif /* __USE_FORTIFY_LEVEL > 0 */
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#if __GNUC_PREREQ (4,3)
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# define __warnattr(msg) __attribute__((__warning__ (msg)))
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# define __errordecl(name, msg) \
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extern void name (void) __attribute__((__error__ (msg)))
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#else
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# define __warnattr(msg)
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# define __errordecl(name, msg) extern void name (void)
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#endif
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/* Support for flexible arrays.
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Headers that should use flexible arrays only if they're "real"
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(e.g. only if they won't affect sizeof()) should test
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#if __glibc_c99_flexarr_available. */
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#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
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# define __flexarr []
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# define __glibc_c99_flexarr_available 1
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#elif __GNUC_PREREQ (2,97) || defined __clang__
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/* GCC 2.97 and clang support C99 flexible array members as an extension,
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even when in C89 mode or compiling C++ (any version). */
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# define __flexarr []
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# define __glibc_c99_flexarr_available 1
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#elif defined __GNUC__
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/* Pre-2.97 GCC did not support C99 flexible arrays but did have
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an equivalent extension with slightly different notation. */
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# define __flexarr [0]
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# define __glibc_c99_flexarr_available 1
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#else
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/* 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 */
|