1 // -*- C++ -*- Manage the thread-local exception globals.
2 // Copyright (C) 2001-2016 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24
25 #include <bits/c++config.h>
26 #include <exception>
27 #include <cstdlib>
28 #include "cxxabi.h"
29 #include "unwind-cxx.h"
30 #include "bits/gthr.h"
31
32 #if _GLIBCXX_HOSTED
33 using std::free;
34 using std::malloc;
35 #else
36 // In a freestanding environment, these functions may not be
37 // available -- but for now, we assume that they are.
38 extern "C" void *malloc (std::size_t);
39 extern "C" void free(void *);
40 #endif
41
42 using namespace __cxxabiv1;
43
44 #if _GLIBCXX_HAVE_TLS
45
46 namespace
47 {
48 abi::__cxa_eh_globals*
get_global()49 get_global() _GLIBCXX_NOTHROW
50 {
51 static __thread abi::__cxa_eh_globals global;
52 return &global;
53 }
54 } // anonymous namespace
55
56 extern "C" __cxa_eh_globals*
__cxa_get_globals_fast()57 __cxxabiv1::__cxa_get_globals_fast() _GLIBCXX_NOTHROW
58 { return get_global(); }
59
60 extern "C" __cxa_eh_globals*
__cxa_get_globals()61 __cxxabiv1::__cxa_get_globals() _GLIBCXX_NOTHROW
62 { return get_global(); }
63
64
65 #else
66
67 // Single-threaded fallback buffer.
68 static __cxa_eh_globals eh_globals;
69
70 #if __GTHREADS
71
72 static void
eh_globals_dtor(void * ptr)73 eh_globals_dtor(void* ptr)
74 {
75 if (ptr)
76 {
77 __cxa_eh_globals* g = reinterpret_cast<__cxa_eh_globals*>(ptr);
78 __cxa_exception* exn = g->caughtExceptions;
79 __cxa_exception* next;
80 while (exn)
81 {
82 next = exn->nextException;
83 _Unwind_DeleteException(&exn->unwindHeader);
84 exn = next;
85 }
86 free(ptr);
87 }
88 }
89
90 struct __eh_globals_init
91 {
92 __gthread_key_t _M_key;
93 bool _M_init;
94
__eh_globals_init__eh_globals_init95 __eh_globals_init() : _M_init(false)
96 {
97 if (__gthread_active_p())
98 _M_init = __gthread_key_create(&_M_key, eh_globals_dtor) == 0;
99 }
100
~__eh_globals_init__eh_globals_init101 ~__eh_globals_init()
102 {
103 if (_M_init)
104 __gthread_key_delete(_M_key);
105 _M_init = false;
106 }
107 };
108
109 static __eh_globals_init init;
110
111 extern "C" __cxa_eh_globals*
__cxa_get_globals_fast()112 __cxxabiv1::__cxa_get_globals_fast() _GLIBCXX_NOTHROW
113 {
114 __cxa_eh_globals* g;
115 if (init._M_init)
116 g = static_cast<__cxa_eh_globals*>(__gthread_getspecific(init._M_key));
117 else
118 g = &eh_globals;
119 return g;
120 }
121
122 extern "C" __cxa_eh_globals*
__cxa_get_globals()123 __cxxabiv1::__cxa_get_globals() _GLIBCXX_NOTHROW
124 {
125 __cxa_eh_globals* g;
126 if (init._M_init)
127 {
128 g = static_cast<__cxa_eh_globals*>(__gthread_getspecific(init._M_key));
129 if (!g)
130 {
131 void* v = malloc(sizeof(__cxa_eh_globals));
132 if (v == 0 || __gthread_setspecific(init._M_key, v) != 0)
133 std::terminate();
134 g = static_cast<__cxa_eh_globals*>(v);
135 g->caughtExceptions = 0;
136 g->uncaughtExceptions = 0;
137 #ifdef __ARM_EABI_UNWINDER__
138 g->propagatingExceptions = 0;
139 #endif
140 }
141 }
142 else
143 g = &eh_globals;
144 return g;
145 }
146
147 #else
148
149 extern "C" __cxa_eh_globals*
__cxa_get_globals_fast()150 __cxxabiv1::__cxa_get_globals_fast() _GLIBCXX_NOTHROW
151 { return &eh_globals; }
152
153 extern "C" __cxa_eh_globals*
__cxa_get_globals()154 __cxxabiv1::__cxa_get_globals() _GLIBCXX_NOTHROW
155 { return &eh_globals; }
156
157 #endif
158
159 #endif
160