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1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H10#define _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H11 12#include <__config>13#include <__exception/exception_ptr.h>14#include <__memory/addressof.h>15#include <__type_traits/decay.h>16#include <__type_traits/enable_if.h>17#include <__type_traits/integral_constant.h>18#include <__type_traits/is_base_of.h>19#include <__type_traits/is_class.h>20#include <__type_traits/is_constructible.h>21#include <__type_traits/is_convertible.h>22#include <__type_traits/is_final.h>23#include <__type_traits/is_polymorphic.h>24#include <__utility/forward.h>25 26#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)27# pragma GCC system_header28#endif29 30_LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD31 32class _LIBCPP_EXPORTED_FROM_ABI nested_exception {33 exception_ptr __ptr_;34 35public:36 nested_exception() _NOEXCEPT;37 _LIBCPP_HIDE_FROM_ABI nested_exception(const nested_exception&) _NOEXCEPT = default;38 _LIBCPP_HIDE_FROM_ABI nested_exception& operator=(const nested_exception&) _NOEXCEPT = default;39 virtual ~nested_exception() _NOEXCEPT;40 41 // access functions42 [[__noreturn__]] void rethrow_nested() const;43 _LIBCPP_HIDE_FROM_ABI exception_ptr nested_ptr() const _NOEXCEPT { return __ptr_; }44};45 46template <class _Tp>47struct __nested : public _Tp, public nested_exception {48 _LIBCPP_HIDE_FROM_ABI explicit __nested(const _Tp& __t) : _Tp(__t) {}49};50 51#if _LIBCPP_HAS_EXCEPTIONS52template <class _Tp, class _Up, bool>53struct __throw_with_nested;54 55template <class _Tp, class _Up>56struct __throw_with_nested<_Tp, _Up, true> {57 [[__noreturn__]] static inline _LIBCPP_HIDE_FROM_ABI void __do_throw(_Tp&& __t) {58 throw __nested<_Up>(std::forward<_Tp>(__t));59 }60};61 62template <class _Tp, class _Up>63struct __throw_with_nested<_Tp, _Up, false> {64 [[__noreturn__]] static inline _LIBCPP_HIDE_FROM_ABI void __do_throw(_Tp&& __t) { throw std::forward<_Tp>(__t); }65};66#endif67 68template <class _Tp>69[[__noreturn__]] _LIBCPP_HIDE_FROM_ABI void throw_with_nested(_Tp&& __t) {70#if _LIBCPP_HAS_EXCEPTIONS71 using _Up = __decay_t<_Tp>;72 static_assert(is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");73 __throw_with_nested<_Tp,74 _Up,75 is_class<_Up>::value && !is_base_of<nested_exception, _Up>::value &&76 !__is_final_v<_Up> >::__do_throw(std::forward<_Tp>(__t));77#else78 ((void)__t);79 // FIXME: Make this abort80#endif81}82 83template <class _From, class _To>84struct __can_dynamic_cast85 : _BoolConstant< is_polymorphic<_From>::value &&86 (!is_base_of<_To, _From>::value || is_convertible<const _From*, const _To*>::value)> {};87 88template <class _Ep, __enable_if_t< __can_dynamic_cast<_Ep, nested_exception>::value, int> = 0>89inline _LIBCPP_HIDE_FROM_ABI void rethrow_if_nested(const _Ep& __e) {90 const nested_exception* __nep = dynamic_cast<const nested_exception*>(std::addressof(__e));91 if (__nep)92 __nep->rethrow_nested();93}94 95template <class _Ep, __enable_if_t<!__can_dynamic_cast<_Ep, nested_exception>::value, int> = 0>96inline _LIBCPP_HIDE_FROM_ABI void rethrow_if_nested(const _Ep&) {}97 98_LIBCPP_END_UNVERSIONED_NAMESPACE_STD99 100#endif // _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H101