1// -*- C++ -*- 2//===----------------------------------------------------------------------===// 3// 4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5// See https://llvm.org/LICENSE.txt for license information. 6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7// 8//===----------------------------------------------------------------------===// 9 10// libsupc++ does not implement the dependent EH ABI and the functionality 11// it uses to implement std::exception_ptr (which it declares as an alias of 12// std::__exception_ptr::exception_ptr) is not directly exported to clients. So 13// we have little choice but to hijack std::__exception_ptr::exception_ptr's 14// (which fortunately has the same layout as our std::exception_ptr) copy 15// constructor, assignment operator and destructor (which are part of its 16// stable ABI), and its rethrow_exception(std::__exception_ptr::exception_ptr) 17// function. 18 19namespace std { 20 21namespace __exception_ptr { 22 23struct exception_ptr { 24 void* __ptr_; 25 26 explicit exception_ptr(void*) noexcept; 27 exception_ptr(const exception_ptr&) noexcept; 28 exception_ptr& operator=(const exception_ptr&) noexcept; 29 ~exception_ptr() noexcept; 30}; 31 32} // namespace __exception_ptr 33 34_LIBCPP_NORETURN void rethrow_exception(__exception_ptr::exception_ptr); 35 36exception_ptr::~exception_ptr() noexcept { reinterpret_cast<__exception_ptr::exception_ptr*>(this)->~exception_ptr(); } 37 38exception_ptr::exception_ptr(const exception_ptr& other) noexcept : __ptr_(other.__ptr_) { 39 new (reinterpret_cast<void*>(this)) 40 __exception_ptr::exception_ptr(reinterpret_cast<const __exception_ptr::exception_ptr&>(other)); 41} 42 43exception_ptr& exception_ptr::operator=(const exception_ptr& other) noexcept { 44 *reinterpret_cast<__exception_ptr::exception_ptr*>(this) = 45 reinterpret_cast<const __exception_ptr::exception_ptr&>(other); 46 return *this; 47} 48 49exception_ptr exception_ptr::__from_native_exception_pointer(void* __e) noexcept { 50 exception_ptr ptr{}; 51 new (reinterpret_cast<void*>(&ptr)) __exception_ptr::exception_ptr(__e); 52 53 return ptr; 54} 55 56nested_exception::nested_exception() noexcept : __ptr_(current_exception()) {} 57 58_LIBCPP_NORETURN void nested_exception::rethrow_nested() const { 59 if (__ptr_ == nullptr) 60 terminate(); 61 rethrow_exception(__ptr_); 62} 63 64_LIBCPP_NORETURN void rethrow_exception(exception_ptr p) { 65 rethrow_exception(reinterpret_cast<__exception_ptr::exception_ptr&>(p)); 66} 67 68} // namespace std 69