zig/lib/libcxx/include/__exception/nested_exception.h
Alex Rønne Petersen 156ab87500
libcxx: Update to Clang 20.
See:

* https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc/77319
* https://discourse.llvm.org/t/rfc-project-hand-in-hand-llvm-libc-libc-code-sharing/77701

We're dropping support for C++03 for Zig due to the first change; it would be
insane to ship 1018 duplicate header files just for this outdated use case.

As a result of the second change, I had to bring in a subset of the headers from
llvm-libc since libc++ now depends on these. Hopefully we can continue to get
away with not copying the entirety of llvm-libc.
2025-04-04 06:08:09 +02:00

101 lines
3.5 KiB
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Vendored

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H
#define _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H
#include <__config>
#include <__exception/exception_ptr.h>
#include <__memory/addressof.h>
#include <__type_traits/decay.h>
#include <__type_traits/enable_if.h>
#include <__type_traits/integral_constant.h>
#include <__type_traits/is_base_of.h>
#include <__type_traits/is_class.h>
#include <__type_traits/is_constructible.h>
#include <__type_traits/is_convertible.h>
#include <__type_traits/is_final.h>
#include <__type_traits/is_polymorphic.h>
#include <__utility/forward.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
namespace std { // purposefully not using versioning namespace
class _LIBCPP_EXPORTED_FROM_ABI nested_exception {
exception_ptr __ptr_;
public:
nested_exception() _NOEXCEPT;
_LIBCPP_HIDE_FROM_ABI nested_exception(const nested_exception&) _NOEXCEPT = default;
_LIBCPP_HIDE_FROM_ABI nested_exception& operator=(const nested_exception&) _NOEXCEPT = default;
virtual ~nested_exception() _NOEXCEPT;
// access functions
[[__noreturn__]] void rethrow_nested() const;
_LIBCPP_HIDE_FROM_ABI exception_ptr nested_ptr() const _NOEXCEPT { return __ptr_; }
};
template <class _Tp>
struct __nested : public _Tp, public nested_exception {
_LIBCPP_HIDE_FROM_ABI explicit __nested(const _Tp& __t) : _Tp(__t) {}
};
#if _LIBCPP_HAS_EXCEPTIONS
template <class _Tp, class _Up, bool>
struct __throw_with_nested;
template <class _Tp, class _Up>
struct __throw_with_nested<_Tp, _Up, true> {
[[__noreturn__]] static inline _LIBCPP_HIDE_FROM_ABI void __do_throw(_Tp&& __t) {
throw __nested<_Up>(std::forward<_Tp>(__t));
}
};
template <class _Tp, class _Up>
struct __throw_with_nested<_Tp, _Up, false> {
[[__noreturn__]] static inline _LIBCPP_HIDE_FROM_ABI void __do_throw(_Tp&& __t) { throw std::forward<_Tp>(__t); }
};
#endif
template <class _Tp>
[[__noreturn__]] _LIBCPP_HIDE_FROM_ABI void throw_with_nested(_Tp&& __t) {
#if _LIBCPP_HAS_EXCEPTIONS
using _Up = __decay_t<_Tp>;
static_assert(is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
__throw_with_nested<_Tp,
_Up,
is_class<_Up>::value && !is_base_of<nested_exception, _Up>::value &&
!__libcpp_is_final<_Up>::value>::__do_throw(std::forward<_Tp>(__t));
#else
((void)__t);
// FIXME: Make this abort
#endif
}
template <class _From, class _To>
struct __can_dynamic_cast
: _BoolConstant< is_polymorphic<_From>::value &&
(!is_base_of<_To, _From>::value || is_convertible<const _From*, const _To*>::value)> {};
template <class _Ep, __enable_if_t< __can_dynamic_cast<_Ep, nested_exception>::value, int> = 0>
inline _LIBCPP_HIDE_FROM_ABI void rethrow_if_nested(const _Ep& __e) {
const nested_exception* __nep = dynamic_cast<const nested_exception*>(std::addressof(__e));
if (__nep)
__nep->rethrow_nested();
}
template <class _Ep, __enable_if_t<!__can_dynamic_cast<_Ep, nested_exception>::value, int> = 0>
inline _LIBCPP_HIDE_FROM_ABI void rethrow_if_nested(const _Ep&) {}
} // namespace std
#endif // _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H