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 exception_ptr(const exception_ptr&) noexcept; 27 exception_ptr& operator=(const exception_ptr&) noexcept; 28 ~exception_ptr() noexcept; 29}; 30 31} // namespace __exception_ptr 32 33_LIBCPP_NORETURN void rethrow_exception(__exception_ptr::exception_ptr); 34 35exception_ptr::~exception_ptr() noexcept { reinterpret_cast<__exception_ptr::exception_ptr*>(this)->~exception_ptr(); } 36 37exception_ptr::exception_ptr(const exception_ptr& other) noexcept : __ptr_(other.__ptr_) { 38 new (reinterpret_cast<void*>(this)) 39 __exception_ptr::exception_ptr(reinterpret_cast<const __exception_ptr::exception_ptr&>(other)); 40} 41 42exception_ptr& exception_ptr::operator=(const exception_ptr& other) noexcept { 43 *reinterpret_cast<__exception_ptr::exception_ptr*>(this) = 44 reinterpret_cast<const __exception_ptr::exception_ptr&>(other); 45 return *this; 46} 47 48nested_exception::nested_exception() noexcept : __ptr_(current_exception()) {} 49 50_LIBCPP_NORETURN void nested_exception::rethrow_nested() const { 51 if (__ptr_ == nullptr) 52 terminate(); 53 rethrow_exception(__ptr_); 54} 55 56_LIBCPP_NORETURN void rethrow_exception(exception_ptr p) { 57 rethrow_exception(reinterpret_cast<__exception_ptr::exception_ptr&>(p)); 58} 59 60} // namespace std 61