1 // -*- C++ -*- Exception handling routines for throwing.
2 // Copyright (C) 2001, 2003 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 <bits/c++config.h>
32 #include "unwind-cxx.h"
33 
34 
35 using namespace __cxxabiv1;
36 
37 
38 static void
39 __gxx_exception_cleanup (_Unwind_Reason_Code code, _Unwind_Exception *exc)
40 {
41   __cxa_exception *header = __get_exception_header_from_ue (exc);
42 
43   // If we haven't been caught by a foreign handler, then this is
44   // some sort of unwind error.  In that case just die immediately.
45   // _Unwind_DeleteException in the HP-UX IA64 libunwind library
46   //  returns _URC_NO_REASON and not _URC_FOREIGN_EXCEPTION_CAUGHT
47   // like the GCC _Unwind_DeleteException function does.
48   if (code != _URC_FOREIGN_EXCEPTION_CAUGHT && code != _URC_NO_REASON)
49     __terminate (header->terminateHandler);
50 
51   if (header->exceptionDestructor)
52     header->exceptionDestructor (header + 1);
53 
54   __cxa_free_exception (header + 1);
55 }
56 
57 
58 extern "C" void
59 __cxa_throw (void *obj, std::type_info *tinfo, void (*dest) (void *))
60 {
61   __cxa_exception *header = __get_exception_header_from_obj (obj);
62   header->exceptionType = tinfo;
63   header->exceptionDestructor = dest;
64   header->unexpectedHandler = __unexpected_handler;
65   header->terminateHandler = __terminate_handler;
66   header->unwindHeader.exception_class = __gxx_exception_class;
67   header->unwindHeader.exception_cleanup = __gxx_exception_cleanup;
68 
69   __cxa_eh_globals *globals = __cxa_get_globals ();
70   globals->uncaughtExceptions += 1;
71 
72 #ifdef _GLIBCPP_SJLJ_EXCEPTIONS
73   _Unwind_SjLj_RaiseException (&header->unwindHeader);
74 #else
75   _Unwind_RaiseException (&header->unwindHeader);
76 #endif
77 
78   // Some sort of unwinding error.  Note that terminate is a handler.
79   __cxa_begin_catch (&header->unwindHeader);
80   std::terminate ();
81 }
82 
83 extern "C" void
84 __cxa_rethrow ()
85 {
86   __cxa_eh_globals *globals = __cxa_get_globals ();
87   __cxa_exception *header = globals->caughtExceptions;
88 
89   // Watch for luser rethrowing with no active exception.
90   if (header)
91     {
92       // Tell __cxa_end_catch this is a rethrow.
93       if (header->unwindHeader.exception_class != __gxx_exception_class)
94 	globals->caughtExceptions = 0;
95       else
96 	header->handlerCount = -header->handlerCount;
97 
98 #ifdef _GLIBCPP_SJLJ_EXCEPTIONS
99       _Unwind_SjLj_Resume_or_Rethrow (&header->unwindHeader);
100 #else
101 #ifdef _LIBUNWIND_STD_ABI
102       _Unwind_RaiseException (&header->unwindHeader);
103 #else
104       _Unwind_Resume_or_Rethrow (&header->unwindHeader);
105 #endif
106 #endif
107 
108       // Some sort of unwinding error.  Note that terminate is a handler.
109       __cxa_begin_catch (&header->unwindHeader);
110     }
111   std::terminate ();
112 }
113