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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// This file implements the "Exception Handling APIs"9// https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html10//11//===----------------------------------------------------------------------===//12 13#ifndef _CXA_EXCEPTION_H14#define _CXA_EXCEPTION_H15 16#include <exception> // for std::unexpected_handler and std::terminate_handler17#include "cxxabi.h"18#include "unwind.h"19 20namespace __cxxabiv1 {21 22static const uint64_t kOurExceptionClass = 0x434C4E47432B2B00; // CLNGC++\023static const uint64_t kOurDependentExceptionClass = 0x434C4E47432B2B01; // CLNGC++\124static const uint64_t get_vendor_and_language = 0xFFFFFFFFFFFFFF00; // mask for CLNGC++25 26_LIBCXXABI_HIDDEN uint64_t __getExceptionClass (const _Unwind_Exception*);27_LIBCXXABI_HIDDEN void __setExceptionClass ( _Unwind_Exception*, uint64_t);28_LIBCXXABI_HIDDEN bool __isOurExceptionClass(const _Unwind_Exception*);29 30struct _LIBCXXABI_HIDDEN __cxa_exception {31#if defined(__LP64__) || defined(_WIN64) || defined(_LIBCXXABI_ARM_EHABI)32 // Now _Unwind_Exception is marked with __attribute__((aligned)),33 // which implies __cxa_exception is also aligned. Insert padding34 // in the beginning of the struct, rather than before unwindHeader.35 void *reserve;36 37 // This is a new field to support C++11 exception_ptr.38 // For binary compatibility it is at the start of this39 // struct which is prepended to the object thrown in40 // __cxa_allocate_exception.41 size_t referenceCount;42#endif43 44 // Manage the exception object itself.45 std::type_info *exceptionType;46#ifdef __wasm__47 // In Wasm, a destructor returns its argument48 void *(_LIBCXXABI_DTOR_FUNC *exceptionDestructor)(void *);49#else50 void (_LIBCXXABI_DTOR_FUNC *__ptrauth_cxxabi_exception_destructor exceptionDestructor)(void *);51#endif52 std::unexpected_handler __ptrauth_cxxabi_unexpected_handler unexpectedHandler;53 std::terminate_handler __ptrauth_cxxabi_terminate_handler terminateHandler;54 55 __cxa_exception *nextException;56 57 int handlerCount;58 59#if defined(_LIBCXXABI_ARM_EHABI)60 __cxa_exception* nextPropagatingException;61 int propagationCount;62#else63 int handlerSwitchValue;64 const unsigned char *__ptrauth_cxxabi_action_record actionRecord;65 const unsigned char *__ptrauth_cxxabi_lsd languageSpecificData;66 void *__ptrauth_cxxabi_catch_temp catchTemp;67 void *__ptrauth_cxxabi_adjusted_ptr adjustedPtr;68#endif69 70#if !defined(__LP64__) && !defined(_WIN64) && !defined(_LIBCXXABI_ARM_EHABI)71 // This is a new field to support C++11 exception_ptr.72 // For binary compatibility it is placed where the compiler73 // previously added padding to 64-bit align unwindHeader.74 size_t referenceCount;75#endif76 _Unwind_Exception unwindHeader;77};78 79// http://sourcery.mentor.com/archives/cxx-abi-dev/msg01924.html80// The layout of this structure MUST match the layout of __cxa_exception, with81// primaryException instead of referenceCount.82// The pointer authentication schemas specified here must also match those of83// the corresponding members in __cxa_exception.84struct _LIBCXXABI_HIDDEN __cxa_dependent_exception {85#if defined(__LP64__) || defined(_WIN64) || defined(_LIBCXXABI_ARM_EHABI)86 void* reserve; // padding.87 void* primaryException;88#endif89 90 std::type_info *exceptionType;91 void (_LIBCXXABI_DTOR_FUNC *__ptrauth_cxxabi_exception_destructor exceptionDestructor)(void *);92 std::unexpected_handler __ptrauth_cxxabi_unexpected_handler unexpectedHandler;93 std::terminate_handler __ptrauth_cxxabi_terminate_handler terminateHandler;94 95 __cxa_exception *nextException;96 97 int handlerCount;98 99#if defined(_LIBCXXABI_ARM_EHABI)100 __cxa_exception* nextPropagatingException;101 int propagationCount;102#else103 int handlerSwitchValue;104 const unsigned char *__ptrauth_cxxabi_action_record actionRecord;105 const unsigned char *__ptrauth_cxxabi_lsd languageSpecificData;106 void *__ptrauth_cxxabi_catch_temp catchTemp;107 void *__ptrauth_cxxabi_adjusted_ptr adjustedPtr;108#endif109 110#if !defined(__LP64__) && !defined(_WIN64) && !defined(_LIBCXXABI_ARM_EHABI)111 void* primaryException;112#endif113 _Unwind_Exception unwindHeader;114};115 116// Verify the negative offsets of different fields.117static_assert(sizeof(_Unwind_Exception) +118 offsetof(__cxa_exception, unwindHeader) ==119 sizeof(__cxa_exception),120 "unwindHeader has wrong negative offsets");121static_assert(sizeof(_Unwind_Exception) +122 offsetof(__cxa_dependent_exception, unwindHeader) ==123 sizeof(__cxa_dependent_exception),124 "unwindHeader has wrong negative offsets");125 126#if defined(_LIBCXXABI_ARM_EHABI)127static_assert(offsetof(__cxa_exception, propagationCount) +128 sizeof(_Unwind_Exception) + sizeof(void*) ==129 sizeof(__cxa_exception),130 "propagationCount has wrong negative offset");131static_assert(offsetof(__cxa_dependent_exception, propagationCount) +132 sizeof(_Unwind_Exception) + sizeof(void*) ==133 sizeof(__cxa_dependent_exception),134 "propagationCount has wrong negative offset");135#elif defined(__LP64__) || defined(_WIN64)136static_assert(offsetof(__cxa_exception, adjustedPtr) +137 sizeof(_Unwind_Exception) + sizeof(void*) ==138 sizeof(__cxa_exception),139 "adjustedPtr has wrong negative offset");140static_assert(offsetof(__cxa_dependent_exception, adjustedPtr) +141 sizeof(_Unwind_Exception) + sizeof(void*) ==142 sizeof(__cxa_dependent_exception),143 "adjustedPtr has wrong negative offset");144#else145static_assert(offsetof(__cxa_exception, referenceCount) +146 sizeof(_Unwind_Exception) + sizeof(void*) ==147 sizeof(__cxa_exception),148 "referenceCount has wrong negative offset");149static_assert(offsetof(__cxa_dependent_exception, primaryException) +150 sizeof(_Unwind_Exception) + sizeof(void*) ==151 sizeof(__cxa_dependent_exception),152 "primaryException has wrong negative offset");153#endif154 155struct _LIBCXXABI_HIDDEN __cxa_eh_globals {156 __cxa_exception * caughtExceptions;157 unsigned int uncaughtExceptions;158#if defined(_LIBCXXABI_ARM_EHABI)159 __cxa_exception* propagatingExceptions;160#endif161};162 163extern "C" _LIBCXXABI_FUNC_VIS __cxa_eh_globals * __cxa_get_globals ();164extern "C" _LIBCXXABI_FUNC_VIS __cxa_eh_globals * __cxa_get_globals_fast ();165 166extern "C" _LIBCXXABI_FUNC_VIS void * __cxa_allocate_dependent_exception ();167extern "C" _LIBCXXABI_FUNC_VIS void __cxa_free_dependent_exception (void * dependent_exception);168 169} // namespace __cxxabiv1170 171#endif // _CXA_EXCEPTION_H172