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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_EXCEPTION_PTR_H10#define _LIBCPP___EXCEPTION_EXCEPTION_PTR_H11 12#include <__config>13#include <__cstddef/nullptr_t.h>14#include <__cstddef/size_t.h>15#include <__exception/operations.h>16#include <__memory/addressof.h>17#include <__memory/construct_at.h>18#include <__type_traits/decay.h>19#include <__type_traits/is_pointer.h>20#include <__utility/move.h>21#include <__utility/swap.h>22#include <__verbose_abort>23#include <typeinfo>24 25#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)26# pragma GCC system_header27#endif28 29_LIBCPP_PUSH_MACROS30#include <__undef_macros>31 32#ifndef _LIBCPP_ABI_MICROSOFT33 34# if _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION35 36namespace __cxxabiv1 {37 38extern "C" {39_LIBCPP_OVERRIDABLE_FUNC_VIS void* __cxa_allocate_exception(std::size_t) throw();40_LIBCPP_OVERRIDABLE_FUNC_VIS void __cxa_free_exception(void*) throw();41 42struct __cxa_exception;43_LIBCPP_OVERRIDABLE_FUNC_VIS __cxa_exception* __cxa_init_primary_exception(44 void*,45 std::type_info*,46# if defined(_WIN32)47 void(__thiscall*)(void*)) throw();48# elif defined(__wasm__)49 // In Wasm, a destructor returns its argument50 void* (*)(void*)) throw();51# else52 void (*)(void*)) throw();53# endif54}55 56} // namespace __cxxabiv157 58# endif59 60#endif61 62_LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD63 64#ifndef _LIBCPP_ABI_MICROSOFT65 66inline _LIBCPP_HIDE_FROM_ABI void swap(exception_ptr& __x, exception_ptr& __y) _NOEXCEPT;67 68class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {69 void* __ptr_;70 71 static exception_ptr __from_native_exception_pointer(void*) _NOEXCEPT;72 73 template <class _Ep>74 friend _LIBCPP_HIDE_FROM_ABI exception_ptr __make_exception_ptr_explicit(_Ep&) _NOEXCEPT;75 76public:77 // exception_ptr is basically a COW string so it is trivially relocatable.78 using __trivially_relocatable _LIBCPP_NODEBUG = exception_ptr;79 80 _LIBCPP_HIDE_FROM_ABI exception_ptr() _NOEXCEPT : __ptr_() {}81 _LIBCPP_HIDE_FROM_ABI exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}82 83 exception_ptr(const exception_ptr&) _NOEXCEPT;84 _LIBCPP_HIDE_FROM_ABI exception_ptr(exception_ptr&& __other) _NOEXCEPT : __ptr_(__other.__ptr_) {85 __other.__ptr_ = nullptr;86 }87 exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;88 _LIBCPP_HIDE_FROM_ABI exception_ptr& operator=(exception_ptr&& __other) _NOEXCEPT {89 exception_ptr __tmp(std::move(__other));90 std::swap(__tmp, *this);91 return *this;92 }93 ~exception_ptr() _NOEXCEPT;94 95 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return __ptr_ != nullptr; }96 97 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {98 return __x.__ptr_ == __y.__ptr_;99 }100 101 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {102 return !(__x == __y);103 }104 105 friend _LIBCPP_HIDE_FROM_ABI void swap(exception_ptr& __x, exception_ptr& __y) _NOEXCEPT;106 107 friend _LIBCPP_EXPORTED_FROM_ABI exception_ptr current_exception() _NOEXCEPT;108 friend _LIBCPP_EXPORTED_FROM_ABI void rethrow_exception(exception_ptr);109};110 111inline _LIBCPP_HIDE_FROM_ABI void swap(exception_ptr& __x, exception_ptr& __y) _NOEXCEPT {112 std::swap(__x.__ptr_, __y.__ptr_);113}114 115# if _LIBCPP_HAS_EXCEPTIONS116# if _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION117template <class _Ep>118_LIBCPP_HIDE_FROM_ABI exception_ptr __make_exception_ptr_explicit(_Ep& __e) _NOEXCEPT {119 using _Ep2 = __decay_t<_Ep>;120 void* __ex = __cxxabiv1::__cxa_allocate_exception(sizeof(_Ep));121# ifdef __wasm__122 auto __cleanup = [](void* __p) -> void* {123 std::__destroy_at(static_cast<_Ep2*>(__p));124 return __p;125 };126# else127 auto __cleanup = [](void* __p) { std::__destroy_at(static_cast<_Ep2*>(__p)); };128# endif129 (void)__cxxabiv1::__cxa_init_primary_exception(__ex, const_cast<std::type_info*>(&typeid(_Ep)), __cleanup);130 131 try {132 ::new (__ex) _Ep2(__e);133 return exception_ptr::__from_native_exception_pointer(__ex);134 } catch (...) {135 __cxxabiv1::__cxa_free_exception(__ex);136 return current_exception();137 }138}139# endif140 141template <class _Ep>142_LIBCPP_HIDE_FROM_ABI exception_ptr __make_exception_ptr_via_throw(_Ep& __e) _NOEXCEPT {143 try {144 throw __e;145 } catch (...) {146 return current_exception();147 }148}149 150template <class _Ep>151_LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {152 // Objective-C exceptions are thrown via pointer. When throwing an Objective-C exception,153 // Clang generates a call to `objc_exception_throw` instead of the usual `__cxa_throw`.154 // That function creates an exception with a special Objective-C typeinfo instead of155 // the usual C++ typeinfo, since that is needed to implement the behavior documented156 // at [1]).157 //158 // Because of this special behavior, we can't create an exception via `__cxa_init_primary_exception`159 // for Objective-C exceptions, otherwise we'd bypass `objc_exception_throw`. See https://llvm.org/PR135089.160 //161 // [1]:162 // https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Exceptions/Articles/Exceptions64Bit.html163 if _LIBCPP_CONSTEXPR (is_pointer<_Ep>::value) {164 return std::__make_exception_ptr_via_throw(__e);165 }166 167# if _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION && !defined(_LIBCPP_CXX03_LANG)168 return std::__make_exception_ptr_explicit(__e);169# else170 return std::__make_exception_ptr_via_throw(__e);171# endif172}173# else // !_LIBCPP_HAS_EXCEPTIONS174template <class _Ep>175_LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep) _NOEXCEPT {176 _LIBCPP_VERBOSE_ABORT("make_exception_ptr was called in -fno-exceptions mode");177}178# endif // _LIBCPP_HAS_EXCEPTIONS179 180#else // _LIBCPP_ABI_MICROSOFT181 182class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {183 _LIBCPP_DIAGNOSTIC_PUSH184 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-private-field")185 void* __ptr1_;186 void* __ptr2_;187 _LIBCPP_DIAGNOSTIC_POP188 189public:190 exception_ptr() _NOEXCEPT;191 exception_ptr(nullptr_t) _NOEXCEPT;192 exception_ptr(const exception_ptr& __other) _NOEXCEPT;193 exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;194 exception_ptr& operator=(nullptr_t) _NOEXCEPT;195 ~exception_ptr() _NOEXCEPT;196 explicit operator bool() const _NOEXCEPT;197};198 199_LIBCPP_EXPORTED_FROM_ABI bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;200 201inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {202 return !(__x == __y);203}204 205_LIBCPP_EXPORTED_FROM_ABI void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;206 207_LIBCPP_EXPORTED_FROM_ABI exception_ptr __copy_exception_ptr(void* __except, const void* __ptr);208_LIBCPP_EXPORTED_FROM_ABI exception_ptr current_exception() _NOEXCEPT;209[[__noreturn__]] _LIBCPP_EXPORTED_FROM_ABI void rethrow_exception(exception_ptr);210 211// This is a built-in template function which automagically extracts the required212// information.213template <class _E>214void* __GetExceptionInfo(_E);215 216template <class _Ep>217_LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {218 return __copy_exception_ptr(std::addressof(__e), __GetExceptionInfo(__e));219}220 221#endif // _LIBCPP_ABI_MICROSOFT222_LIBCPP_END_UNVERSIONED_NAMESPACE_STD223 224_LIBCPP_POP_MACROS225 226#endif // _LIBCPP___EXCEPTION_EXCEPTION_PTR_H227