1 // -*- C++ -*- Exception handling routines for catching. 2 // Copyright (C) 2001 Free Software Foundation, Inc. 3 // 4 // This file is part of GNU CC. 5 // 6 // GNU CC 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 // GNU CC 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 GNU CC; 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 31 #include <cstdlib> 32 #include "unwind-cxx.h" 33 34 using namespace __cxxabiv1; 35 36 37 extern "C" void * 38 __cxa_begin_catch (void *exc_obj_in) 39 { 40 _Unwind_Exception *exceptionObject 41 = reinterpret_cast <_Unwind_Exception *>(exc_obj_in); 42 43 // ??? Foreign exceptions can't be stacked here, and there doesn't 44 // appear to be any place to store for __cxa_end_catch to destroy. 45 46 __cxa_exception *header = __get_exception_header_from_ue (exceptionObject); 47 __cxa_eh_globals *globals = __cxa_get_globals (); 48 __cxa_exception *prev = globals->caughtExceptions; 49 int count = header->handlerCount; 50 51 if (count < 0) 52 // This exception was rethrown from an immediately enclosing region. 53 count = -count + 1; 54 else 55 count += 1; 56 header->handlerCount = count; 57 58 globals->uncaughtExceptions -= 1; 59 if (header != prev) 60 { 61 header->nextException = prev; 62 globals->caughtExceptions = header; 63 } 64 65 return header->adjustedPtr; 66 } 67 68 69 extern "C" void 70 __cxa_end_catch () 71 { 72 __cxa_eh_globals *globals = __cxa_get_globals_fast (); 73 __cxa_exception *header = globals->caughtExceptions; 74 int count = header->handlerCount; 75 76 if (count < 0) 77 { 78 // This exception was rethrown. Decrement the (inverted) catch 79 // count and remove it from the chain when it reaches zero. 80 if (++count == 0) 81 { 82 globals->uncaughtExceptions += 1; 83 globals->caughtExceptions = header->nextException; 84 } 85 } 86 else if (--count == 0) 87 { 88 // Handling for this exception is complete. Destroy the object. 89 globals->caughtExceptions = header->nextException; 90 _Unwind_DeleteException (&header->unwindHeader); 91 return; 92 } 93 else if (count < 0) 94 // A bug in the exception handling library or compiler. 95 std::abort (); 96 97 header->handlerCount = count; 98 } 99 100 101 bool 102 std::uncaught_exception() throw() 103 { 104 __cxa_eh_globals *globals = __cxa_get_globals (); 105 return globals->uncaughtExceptions != 0; 106 } 107