eh_throw.cc revision 132720 
1// -*- C++ -*- Exception handling routines for throwing.
2// Copyright (C) 2001, 2003 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 2, 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// You should have received a copy of the GNU General Public License
17// along with GCC; 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
35using namespace __cxxabiv1;
36
37
38static 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
58extern "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 _GLIBCXX_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
83extern "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 _GLIBCXX_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