1 // -*- C++ -*- std::terminate, std::unexpected and friends.
2 // Copyright (C) 1994-2019 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 "typeinfo"
26 #include "exception"
27 #include <cstdlib>
28 #include "unwind-cxx.h"
29 #include "eh_term_handler.h"
30 #include <bits/exception_defines.h>
31 #include <bits/atomic_lockfree_defines.h>
32 
33 #if ATOMIC_POINTER_LOCK_FREE < 2
34 #include <ext/concurrence.h>
35 namespace
36 {
37   __gnu_cxx::__mutex mx;
38 }
39 #endif
40 
41 using namespace __cxxabiv1;
42 
43 void
__terminate(std::terminate_handler handler)44 __cxxabiv1::__terminate (std::terminate_handler handler) throw ()
45 {
46   __try
47     {
48       handler ();
49       std::abort ();
50     }
51   __catch(...)
52     { std::abort (); }
53 }
54 
55 void
terminate()56 std::terminate () throw()
57 {
58   __terminate (get_terminate ());
59 }
60 
61 void
__unexpected(std::unexpected_handler handler)62 __cxxabiv1::__unexpected (std::unexpected_handler handler)
63 {
64   handler();
65   std::terminate ();
66 }
67 
68 void
unexpected()69 std::unexpected ()
70 {
71   __unexpected (get_unexpected ());
72 }
73 
74 std::terminate_handler
set_terminate(std::terminate_handler func)75 std::set_terminate (std::terminate_handler func) throw()
76 {
77   if (!func)
78     func = _GLIBCXX_DEFAULT_TERM_HANDLER;
79 
80   std::terminate_handler old;
81 #if ATOMIC_POINTER_LOCK_FREE > 1
82   __atomic_exchange (&__terminate_handler, &func, &old, __ATOMIC_ACQ_REL);
83 #else
84   __gnu_cxx::__scoped_lock l(mx);
85   old = __terminate_handler;
86   __terminate_handler = func;
87 #endif
88   return old;
89 }
90 
91 std::terminate_handler
get_terminate()92 std::get_terminate () noexcept
93 {
94   std::terminate_handler func;
95 #if ATOMIC_POINTER_LOCK_FREE > 1
96   __atomic_load (&__terminate_handler, &func, __ATOMIC_ACQUIRE);
97 #else
98   __gnu_cxx::__scoped_lock l(mx);
99   func = __terminate_handler;
100 #endif
101   return func;
102 }
103 
104 std::unexpected_handler
set_unexpected(std::unexpected_handler func)105 std::set_unexpected (std::unexpected_handler func) throw()
106 {
107   if (!func)
108     func = std::terminate;
109 
110   std::unexpected_handler old;
111 #if ATOMIC_POINTER_LOCK_FREE > 1
112   __atomic_exchange (&__unexpected_handler, &func, &old, __ATOMIC_ACQ_REL);
113 #else
114   __gnu_cxx::__scoped_lock l(mx);
115   old = __unexpected_handler;
116   __unexpected_handler = func;
117 #endif
118   return old;
119 }
120 
121 std::unexpected_handler
get_unexpected()122 std::get_unexpected () noexcept
123 {
124   std::unexpected_handler func;
125 #if ATOMIC_POINTER_LOCK_FREE > 1
126   __atomic_load (&__unexpected_handler, &func, __ATOMIC_ACQUIRE);
127 #else
128   __gnu_cxx::__scoped_lock l(mx);
129   func = __unexpected_handler;
130 #endif
131   return func;
132 }
133