1 // -*- C++ -*- Exception handling routines for throwing.
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 "unwind-cxx.h"
27
28 using namespace __cxxabiv1;
29
30
31 static void
__gxx_exception_cleanup(_Unwind_Reason_Code code,_Unwind_Exception * exc)32 __gxx_exception_cleanup (_Unwind_Reason_Code code, _Unwind_Exception *exc)
33 {
34 // This cleanup is set only for primaries.
35 __cxa_refcounted_exception *header
36 = __get_refcounted_exception_header_from_ue (exc);
37
38 // We only want to be called through _Unwind_DeleteException.
39 // _Unwind_DeleteException in the HP-UX IA64 libunwind library
40 // returns _URC_NO_REASON and not _URC_FOREIGN_EXCEPTION_CAUGHT
41 // like the GCC _Unwind_DeleteException function does.
42 if (code != _URC_FOREIGN_EXCEPTION_CAUGHT && code != _URC_NO_REASON)
43 __terminate (header->exc.terminateHandler);
44
45 #if ATOMIC_INT_LOCK_FREE > 1
46 if (__atomic_sub_fetch (&header->referenceCount, 1, __ATOMIC_ACQ_REL) == 0)
47 {
48 #endif
49 if (header->exc.exceptionDestructor)
50 header->exc.exceptionDestructor (header + 1);
51
52 __cxa_free_exception (header + 1);
53 #if ATOMIC_INT_LOCK_FREE > 1
54 }
55 #endif
56 }
57
58
59 extern "C" void
__cxa_throw(void * obj,std::type_info * tinfo,void (_GLIBCXX_CDTOR_CALLABI * dest)(void *))60 __cxxabiv1::__cxa_throw (void *obj, std::type_info *tinfo,
61 void (_GLIBCXX_CDTOR_CALLABI *dest) (void *))
62 {
63 PROBE2 (throw, obj, tinfo);
64
65 __cxa_eh_globals *globals = __cxa_get_globals ();
66 globals->uncaughtExceptions += 1;
67
68 // Definitely a primary.
69 __cxa_refcounted_exception *header
70 = __get_refcounted_exception_header_from_obj (obj);
71 header->referenceCount = 1;
72 header->exc.exceptionType = tinfo;
73 header->exc.exceptionDestructor = dest;
74 header->exc.unexpectedHandler = std::get_unexpected ();
75 header->exc.terminateHandler = std::get_terminate ();
76 __GXX_INIT_PRIMARY_EXCEPTION_CLASS(header->exc.unwindHeader.exception_class);
77 header->exc.unwindHeader.exception_cleanup = __gxx_exception_cleanup;
78
79 #ifdef __USING_SJLJ_EXCEPTIONS__
80 _Unwind_SjLj_RaiseException (&header->exc.unwindHeader);
81 #else
82 _Unwind_RaiseException (&header->exc.unwindHeader);
83 #endif
84
85 // Some sort of unwinding error. Note that terminate is a handler.
86 __cxa_begin_catch (&header->exc.unwindHeader);
87 std::terminate ();
88 }
89
90 extern "C" void
__cxa_rethrow()91 __cxxabiv1::__cxa_rethrow ()
92 {
93 __cxa_eh_globals *globals = __cxa_get_globals ();
94 __cxa_exception *header = globals->caughtExceptions;
95
96 globals->uncaughtExceptions += 1;
97
98 // Watch for luser rethrowing with no active exception.
99 if (header)
100 {
101 // Tell __cxa_end_catch this is a rethrow.
102 if (!__is_gxx_exception_class(header->unwindHeader.exception_class))
103 globals->caughtExceptions = 0;
104 else
105 {
106 header->handlerCount = -header->handlerCount;
107 // Only notify probe for C++ exceptions.
108 PROBE2 (rethrow, __get_object_from_ambiguous_exception(header),
109 header->exceptionType);
110 }
111
112 #ifdef __USING_SJLJ_EXCEPTIONS__
113 _Unwind_SjLj_Resume_or_Rethrow (&header->unwindHeader);
114 #else
115 #if defined(_LIBUNWIND_STD_ABI)
116 _Unwind_RaiseException (&header->unwindHeader);
117 #else
118 _Unwind_Resume_or_Rethrow (&header->unwindHeader);
119 #endif
120 #endif
121
122 // Some sort of unwinding error. Note that terminate is a handler.
123 __cxa_begin_catch (&header->unwindHeader);
124 }
125 std::terminate ();
126 }
127