libstdc++-v3/libsupc++/eh_throw.cc

   1 // -*- C++ -*- Exception handling routines for throwing.
   2 // Copyright (C) 2001, 2003, 2008 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, 51 Franklin Street, Fifth Floor,
  19 // Boston, MA 02110-1301, 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 #include <bits/c++config.h>
  31 #include "unwind-cxx.h"
  32
  33 using namespace __cxxabiv1;
  34
  35
  36 static void
  37 __gxx_exception_cleanup (_Unwind_Reason_Code code, _Unwind_Exception *exc)
  38 {
  39   // This cleanup is set only for primaries.
  40   __cxa_exception *header = __get_exception_header_from_ue (exc);
  41
  42   // We only want to be called through _Unwind_DeleteException.
  43   // _Unwind_DeleteException in the HP-UX IA64 libunwind library
  44   // returns _URC_NO_REASON and not _URC_FOREIGN_EXCEPTION_CAUGHT
  45   // like the GCC _Unwind_DeleteException function does.
  46   if (code != _URC_FOREIGN_EXCEPTION_CAUGHT && code != _URC_NO_REASON)
  47     __terminate (header->terminateHandler);
  48
  49   if (__gnu_cxx::__exchange_and_add_dispatch (&header->referenceCount, -1) == 0)
  50     {
  51       if (header->exceptionDestructor)
  52         header->exceptionDestructor (header + 1);
  53
  54       __cxa_free_exception (header + 1);
  55     }
  56 }
  57
  58
  59 extern "C" void
  60 __cxxabiv1::__cxa_throw (void *obj, std::type_info *tinfo,
  61                          void (*dest) (void *))
  62 {
  63   // Definitely a primary.
  64   __cxa_exception *header = __get_exception_header_from_obj (obj);
  65   header->referenceCount = 0;
  66   header->exceptionType = tinfo;
  67   header->exceptionDestructor = dest;
  68   header->unexpectedHandler = __unexpected_handler;
  69   header->terminateHandler = __terminate_handler;
  70   __GXX_INIT_PRIMARY_EXCEPTION_CLASS(header->unwindHeader.exception_class);
  71   header->unwindHeader.exception_cleanup = __gxx_exception_cleanup;
  72
  73 #ifdef _GLIBCXX_SJLJ_EXCEPTIONS
  74   _Unwind_SjLj_RaiseException (&header->unwindHeader);
  75 #else
  76   _Unwind_RaiseException (&header->unwindHeader);
  77 #endif
  78
  79   // Some sort of unwinding error.  Note that terminate is a handler.
  80   __cxa_begin_catch (&header->unwindHeader);
  81   std::terminate ();
  82 }
  83
  84 extern "C" void
  85 __cxxabiv1::__cxa_rethrow ()
  86 {
  87   __cxa_eh_globals *globals = __cxa_get_globals ();
  88   __cxa_exception *header = globals->caughtExceptions;
  89
  90   globals->uncaughtExceptions += 1;
  91
  92   // Watch for luser rethrowing with no active exception.
  93   if (header)
  94     {
  95       // Tell __cxa_end_catch this is a rethrow.
  96       if (!__is_gxx_exception_class(header->unwindHeader.exception_class))
  97         globals->caughtExceptions = 0;
  98       else
  99         header->handlerCount = -header->handlerCount;
 100
 101 #ifdef _GLIBCXX_SJLJ_EXCEPTIONS
 102       _Unwind_SjLj_Resume_or_Rethrow (&header->unwindHeader);
 103 #else
 104 #if defined(_LIBUNWIND_STD_ABI)
 105       _Unwind_RaiseException (&header->unwindHeader);
 106 #else
 107       _Unwind_Resume_or_Rethrow (&header->unwindHeader);
 108 #endif
 109 #endif
 110
 111       // Some sort of unwinding error.  Note that terminate is a handler.
 112       __cxa_begin_catch (&header->unwindHeader);
 113     }
 114   std::terminate ();
 115 }