unwind-cxx.h revision 132720
1// -*- C++ -*- Exception handling and frame unwind runtime interface routines. 2// Copyright (C) 2001 Free Software Foundation, Inc. 3// 4// This file is part of GCC. 5// 6// GCC is free software; you can redistribute it and/or modify 7// it under the terms of the GNU General Public License as published by 8// the Free Software Foundation; either version 2, or (at your option) 9// any later version. 10// 11// GCC is distributed in the hope that it will be useful, 12// but WITHOUT ANY WARRANTY; without even the implied warranty of 13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14// GNU General Public License for more details. 15// 16// You should have received a copy of the GNU General Public License 17// along with GCC; see the file COPYING. If not, write to 18// the Free Software Foundation, 59 Temple Place - Suite 330, 19// Boston, MA 02111-1307, USA. 20 21// As a special exception, you may use this file as part of a free software 22// library without restriction. Specifically, if other files instantiate 23// templates or use macros or inline functions from this file, or you compile 24// this file and link it with other files to produce an executable, this 25// file does not by itself cause the resulting executable to be covered by 26// the GNU General Public License. This exception does not however 27// invalidate any other reasons why the executable file might be covered by 28// the GNU General Public License. 29 30// This is derived from the C++ ABI for IA-64. Where we diverge 31// for cross-architecture compatibility are noted with "@@@". 32 33#ifndef _UNWIND_CXX_H 34#define _UNWIND_CXX_H 1 35 36// Level 2: C++ ABI 37 38#include <typeinfo> 39#include <exception> 40#include <cstddef> 41#include "unwind.h" 42 43namespace __cxxabiv1 44{ 45 46// A C++ exception object consists of a header, which is a wrapper around 47// an unwind object header with additional C++ specific information, 48// followed by the exception object itself. 49 50struct __cxa_exception 51{ 52 // Manage the exception object itself. 53 std::type_info *exceptionType; 54 void (*exceptionDestructor)(void *); 55 56 // The C++ standard has entertaining rules wrt calling set_terminate 57 // and set_unexpected in the middle of the exception cleanup process. 58 std::unexpected_handler unexpectedHandler; 59 std::terminate_handler terminateHandler; 60 61 // The caught exception stack threads through here. 62 __cxa_exception *nextException; 63 64 // How many nested handlers have caught this exception. A negated 65 // value is a signal that this object has been rethrown. 66 int handlerCount; 67 68 // Cache parsed handler data from the personality routine Phase 1 69 // for Phase 2 and __cxa_call_unexpected. 70 int handlerSwitchValue; 71 const unsigned char *actionRecord; 72 const unsigned char *languageSpecificData; 73 _Unwind_Ptr catchTemp; 74 void *adjustedPtr; 75 76 // The generic exception header. Must be last. 77 _Unwind_Exception unwindHeader; 78}; 79 80// Each thread in a C++ program has access to a __cxa_eh_globals object. 81struct __cxa_eh_globals 82{ 83 __cxa_exception *caughtExceptions; 84 unsigned int uncaughtExceptions; 85}; 86 87 88// The __cxa_eh_globals for the current thread can be obtained by using 89// either of the following functions. The "fast" version assumes at least 90// one prior call of __cxa_get_globals has been made from the current 91// thread, so no initialization is necessary. 92extern "C" __cxa_eh_globals *__cxa_get_globals () throw(); 93extern "C" __cxa_eh_globals *__cxa_get_globals_fast () throw(); 94 95// Allocate memory for the exception plus the thown object. 96extern "C" void *__cxa_allocate_exception(std::size_t thrown_size) throw(); 97 98// Free the space allocated for the exception. 99extern "C" void __cxa_free_exception(void *thrown_exception) throw(); 100 101// Throw the exception. 102extern "C" void __cxa_throw (void *thrown_exception, 103 std::type_info *tinfo, 104 void (*dest) (void *)) 105 __attribute__((noreturn)); 106 107// Used to implement exception handlers. 108extern "C" void *__cxa_begin_catch (void *) throw(); 109extern "C" void __cxa_end_catch (); 110extern "C" void __cxa_rethrow () __attribute__((noreturn)); 111 112// These facilitate code generation for recurring situations. 113extern "C" void __cxa_bad_cast (); 114extern "C" void __cxa_bad_typeid (); 115 116// @@@ These are not directly specified by the IA-64 C++ ABI. 117 118// Handles re-checking the exception specification if unexpectedHandler 119// throws, and if bad_exception needs to be thrown. Called from the 120// compiler. 121extern "C" void __cxa_call_unexpected (void *) __attribute__((noreturn)); 122 123// Invokes given handler, dying appropriately if the user handler was 124// so inconsiderate as to return. 125extern void __terminate(std::terminate_handler) __attribute__((noreturn)); 126extern void __unexpected(std::unexpected_handler) __attribute__((noreturn)); 127 128// The current installed user handlers. 129extern std::terminate_handler __terminate_handler; 130extern std::unexpected_handler __unexpected_handler; 131 132// These are explicitly GNU C++ specific. 133 134// This is the exception class we report -- "GNUCC++\0". 135const _Unwind_Exception_Class __gxx_exception_class 136= ((((((((_Unwind_Exception_Class) 'G' 137 << 8 | (_Unwind_Exception_Class) 'N') 138 << 8 | (_Unwind_Exception_Class) 'U') 139 << 8 | (_Unwind_Exception_Class) 'C') 140 << 8 | (_Unwind_Exception_Class) 'C') 141 << 8 | (_Unwind_Exception_Class) '+') 142 << 8 | (_Unwind_Exception_Class) '+') 143 << 8 | (_Unwind_Exception_Class) '\0'); 144 145// GNU C++ personality routine, Version 0. 146extern "C" _Unwind_Reason_Code __gxx_personality_v0 147 (int, _Unwind_Action, _Unwind_Exception_Class, 148 struct _Unwind_Exception *, struct _Unwind_Context *); 149 150// GNU C++ sjlj personality routine, Version 0. 151extern "C" _Unwind_Reason_Code __gxx_personality_sj0 152 (int, _Unwind_Action, _Unwind_Exception_Class, 153 struct _Unwind_Exception *, struct _Unwind_Context *); 154 155// Acquire the C++ exception header from the C++ object. 156static inline __cxa_exception * 157__get_exception_header_from_obj (void *ptr) 158{ 159 return reinterpret_cast<__cxa_exception *>(ptr) - 1; 160} 161 162// Acquire the C++ exception header from the generic exception header. 163static inline __cxa_exception * 164__get_exception_header_from_ue (_Unwind_Exception *exc) 165{ 166 return reinterpret_cast<__cxa_exception *>(exc + 1) - 1; 167} 168 169} /* namespace __cxxabiv1 */ 170 171#endif // _UNWIND_CXX_H 172