142 lines · cpp
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// This file implements the default terminate_handler, unexpected_handler and9// new_handler.10//===----------------------------------------------------------------------===//11 12#include <cstdlib> // std::abort13#include <exception>14#include <new>15#include "abort_message.h"16#include "cxxabi.h"17#include "cxa_handlers.h"18#include "cxa_exception.h"19#include "private_typeinfo.h"20#include "include/atomic_support.h" // from libc++21 22#if !defined(LIBCXXABI_SILENT_TERMINATE)23 24static constinit const char* cause = "uncaught";25 26# ifndef _LIBCXXABI_NO_EXCEPTIONS27__attribute__((noreturn))28static void demangling_terminate_handler()29{30 using namespace __cxxabiv1;31 __cxa_eh_globals* globals = __cxa_get_globals_fast();32 33 // If there is no uncaught exception, just note that we're terminating34 if (!globals)35 __abort_message("terminating");36 37 __cxa_exception* exception_header = globals->caughtExceptions;38 if (!exception_header)39 __abort_message("terminating");40 41 _Unwind_Exception* unwind_exception =42 reinterpret_cast<_Unwind_Exception*>(exception_header + 1) - 1;43 44 // If we're terminating due to a foreign exception45 if (!__isOurExceptionClass(unwind_exception))46 __abort_message("terminating due to %s foreign exception", cause);47 48 void* thrown_object =49 __getExceptionClass(unwind_exception) == kOurDependentExceptionClass ?50 ((__cxa_dependent_exception*)exception_header)->primaryException :51 exception_header + 1;52 const __shim_type_info* thrown_type =53 static_cast<const __shim_type_info*>(exception_header->exceptionType);54 55 auto name = [str = thrown_type->name()] {56# ifndef LIBCXXABI_NON_DEMANGLING_TERMINATE57 if (const char* result = __cxxabiv1::__cxa_demangle(str, nullptr, nullptr, nullptr))58 // We're about to abort(), this memory can never be freed; so it's fine59 // to just return a raw pointer60 return result;61# endif62 return str;63 }();64 65 // If the uncaught exception can be caught with std::exception&66 const __shim_type_info* catch_type =67 static_cast<const __shim_type_info*>(&typeid(std::exception));68 if (catch_type->can_catch(thrown_type, thrown_object))69 {70 // Include the what() message from the exception71 const std::exception* e = static_cast<const std::exception*>(thrown_object);72 __abort_message("terminating due to %s exception of type %s: %s", cause, name, e->what());73 }74 else75 {76 // Else just note that we're terminating due to an exception77 __abort_message("terminating due to %s exception of type %s", cause, name);78 }79}80#else // !_LIBCXXABI_NO_EXCEPTIONS81__attribute__((noreturn))82static void demangling_terminate_handler()83{84 __abort_message("terminating");85}86#endif // !_LIBCXXABI_NO_EXCEPTIONS87 88__attribute__((noreturn))89static void demangling_unexpected_handler()90{91 cause = "unexpected";92 std::terminate();93}94 95static constexpr std::terminate_handler default_terminate_handler = demangling_terminate_handler;96static constexpr std::terminate_handler default_unexpected_handler = demangling_unexpected_handler;97#else // !LIBCXXABI_SILENT_TERMINATE98static constexpr std::terminate_handler default_terminate_handler = std::abort;99static constexpr std::terminate_handler default_unexpected_handler = std::terminate;100#endif // !LIBCXXABI_SILENT_TERMINATE101 102//103// Global variables that hold the pointers to the current handler104//105_LIBCXXABI_DATA_VIS106constinit std::terminate_handler __cxa_terminate_handler = default_terminate_handler;107 108_LIBCXXABI_DATA_VIS109constinit std::unexpected_handler __cxa_unexpected_handler = default_unexpected_handler;110 111_LIBCXXABI_DATA_VIS112constinit std::new_handler __cxa_new_handler = nullptr;113 114namespace std115{116 117unexpected_handler118set_unexpected(unexpected_handler func) noexcept119{120 if (func == 0)121 func = default_unexpected_handler;122 return __libcpp_atomic_exchange(&__cxa_unexpected_handler, func,123 _AO_Acq_Rel);124}125 126terminate_handler127set_terminate(terminate_handler func) noexcept128{129 if (func == 0)130 func = default_terminate_handler;131 return __libcpp_atomic_exchange(&__cxa_terminate_handler, func,132 _AO_Acq_Rel);133}134 135new_handler136set_new_handler(new_handler handler) noexcept137{138 return __libcpp_atomic_exchange(&__cxa_new_handler, handler, _AO_Acq_Rel);139}140 141}142