1 // -*- C++ -*- Manage the thread-local exception globals. 2 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 3 // Free Software Foundation, Inc. 4 // 5 // This file is part of GCC. 6 // 7 // GCC is free software; you can redistribute it and/or modify 8 // it under the terms of the GNU General Public License as published by 9 // the Free Software Foundation; either version 2, or (at your option) 10 // any later version. 11 // 12 // GCC is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 // 17 // You should have received a copy of the GNU General Public License 18 // along with GCC; see the file COPYING. If not, write to 19 // the Free Software Foundation, 51 Franklin Street, Fifth Floor, 20 // Boston, MA 02110-1301, USA. 21 22 // As a special exception, you may use this file as part of a free software 23 // library without restriction. Specifically, if other files instantiate 24 // templates or use macros or inline functions from this file, or you compile 25 // this file and link it with other files to produce an executable, this 26 // file does not by itself cause the resulting executable to be covered by 27 // the GNU General Public License. This exception does not however 28 // invalidate any other reasons why the executable file might be covered by 29 // the GNU General Public License. 30 31 #include <bits/c++config.h> 32 #include <exception> 33 #include <cstdlib> 34 #include "cxxabi.h" 35 #include "unwind-cxx.h" 36 #include "bits/gthr.h" 37 38 #if _GLIBCXX_HOSTED 39 using std::free; 40 using std::malloc; 41 #else 42 // In a freestanding environment, these functions may not be 43 // available -- but for now, we assume that they are. 44 extern "C" void *malloc (std::size_t); 45 extern "C" void free(void *); 46 #endif 47 48 using namespace __cxxabiv1; 49 50 #if _GLIBCXX_HAVE_TLS 51 52 namespace 53 { 54 abi::__cxa_eh_globals* 55 get_global() throw() 56 { 57 static __thread abi::__cxa_eh_globals global; 58 return &global; 59 } 60 } // anonymous namespace 61 62 extern "C" __cxa_eh_globals* 63 __cxxabiv1::__cxa_get_globals_fast() throw() 64 { return get_global(); } 65 66 extern "C" __cxa_eh_globals* 67 __cxxabiv1::__cxa_get_globals() throw() 68 { return get_global(); } 69 70 71 #else 72 73 // Single-threaded fallback buffer. 74 static __cxa_eh_globals eh_globals; 75 76 #if __GTHREADS 77 78 static void 79 eh_globals_dtor(void* ptr) 80 { 81 if (ptr) 82 { 83 __cxa_eh_globals* g = reinterpret_cast<__cxa_eh_globals*>(ptr); 84 __cxa_exception* exn = g->caughtExceptions; 85 __cxa_exception* next; 86 while (exn) 87 { 88 next = exn->nextException; 89 _Unwind_DeleteException(&exn->unwindHeader); 90 exn = next; 91 } 92 free(ptr); 93 } 94 } 95 96 struct __eh_globals_init 97 { 98 __gthread_key_t _M_key; 99 bool _M_init; 100 101 __eh_globals_init() : _M_init(false) 102 { 103 if (__gthread_active_p()) 104 _M_init = __gthread_key_create(&_M_key, eh_globals_dtor) == 0; 105 } 106 107 ~__eh_globals_init() 108 { 109 if (_M_init) 110 __gthread_key_delete(_M_key); 111 _M_init = false; 112 } 113 }; 114 115 static __eh_globals_init init; 116 117 extern "C" __cxa_eh_globals* 118 __cxxabiv1::__cxa_get_globals_fast() throw() 119 { 120 __cxa_eh_globals* g; 121 if (init._M_init) 122 g = static_cast<__cxa_eh_globals*>(__gthread_getspecific(init._M_key)); 123 else 124 g = &eh_globals; 125 return g; 126 } 127 128 extern "C" __cxa_eh_globals* 129 __cxxabiv1::__cxa_get_globals() throw() 130 { 131 __cxa_eh_globals* g; 132 if (init._M_init) 133 { 134 g = static_cast<__cxa_eh_globals*>(__gthread_getspecific(init._M_key)); 135 if (!g) 136 { 137 void* v = malloc(sizeof(__cxa_eh_globals)); 138 if (v == 0 || __gthread_setspecific(init._M_key, v) != 0) 139 std::terminate(); 140 g = static_cast<__cxa_eh_globals*>(v); 141 g->caughtExceptions = 0; 142 g->uncaughtExceptions = 0; 143 } 144 } 145 else 146 g = &eh_globals; 147 return g; 148 } 149 150 #else 151 152 extern "C" __cxa_eh_globals* 153 __cxxabiv1::__cxa_get_globals_fast() throw() 154 { return &eh_globals; } 155 156 extern "C" __cxa_eh_globals* 157 __cxxabiv1::__cxa_get_globals() throw() 158 { return &eh_globals; } 159 160 #endif 161 162 #endif 163