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

   1 // -*- C++ -*- Exception handling routines for throwing.
   2 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   3 // Free Software Foundation, Inc.
   4 //
   5 // This file is part of GCC.
   6 //
   7 // GCC is free software; you can redistribute it and/or modify
   8 // it under the terms of the GNU General Public License as published by
   9 // the Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11 //
  12 // GCC is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16 //
  17 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 #include <bits/c++config.h>
  27 #include "unwind-cxx.h"
  28
  29 using namespace __cxxabiv1;
  30
  31
  32 static void
  33 __gxx_exception_cleanup (_Unwind_Reason_Code code, _Unwind_Exception *exc)
  34 {
  35   // This cleanup is set only for primaries.
  36   __cxa_refcounted_exception *header
  37     = __get_refcounted_exception_header_from_ue (exc);
  38
  39   // We only want to be called through _Unwind_DeleteException.
  40   // _Unwind_DeleteException in the HP-UX IA64 libunwind library
  41   // returns _URC_NO_REASON and not _URC_FOREIGN_EXCEPTION_CAUGHT
  42   // like the GCC _Unwind_DeleteException function does.
  43   if (code != _URC_FOREIGN_EXCEPTION_CAUGHT && code != _URC_NO_REASON)
  44     __terminate (header->exc.terminateHandler);
  45
  46 #ifdef _GLIBCXX_ATOMIC_BUILTINS_4
  47   if (__sync_sub_and_fetch (&header->referenceCount, 1) == 0)
  48     {
  49 #endif
  50       if (header->exc.exceptionDestructor)
  51         header->exc.exceptionDestructor (header + 1);
  52
  53       __cxa_free_exception (header + 1);
  54 #ifdef _GLIBCXX_ATOMIC_BUILTINS_4
  55     }
  56 #endif
  57 }
  58
  59
  60 extern "C" void
  61 __cxxabiv1::__cxa_throw (void *obj, std::type_info *tinfo,
  62                          void (*dest) (void *))
  63 {
  64   // Definitely a primary.
  65   __cxa_refcounted_exception *header
  66     = __get_refcounted_exception_header_from_obj (obj);
  67   header->referenceCount = 1;
  68   header->exc.exceptionType = tinfo;
  69   header->exc.exceptionDestructor = dest;
  70   header->exc.unexpectedHandler = __unexpected_handler;
  71   header->exc.terminateHandler = __terminate_handler;
  72   __GXX_INIT_PRIMARY_EXCEPTION_CLASS(header->exc.unwindHeader.exception_class);
  73   header->exc.unwindHeader.exception_cleanup = __gxx_exception_cleanup;
  74
  75 #ifdef _GLIBCXX_SJLJ_EXCEPTIONS
  76   _Unwind_SjLj_RaiseException (&header->exc.unwindHeader);
  77 #else
  78   _Unwind_RaiseException (&header->exc.unwindHeader);
  79 #endif
  80
  81   // Some sort of unwinding error.  Note that terminate is a handler.
  82   __cxa_begin_catch (&header->exc.unwindHeader);
  83   std::terminate ();
  84 }
  85
  86 extern "C" void
  87 __cxxabiv1::__cxa_rethrow ()
  88 {
  89   __cxa_eh_globals *globals = __cxa_get_globals ();
  90   __cxa_exception *header = globals->caughtExceptions;
  91
  92   globals->uncaughtExceptions += 1;
  93
  94   // Watch for luser rethrowing with no active exception.
  95   if (header)
  96     {
  97       // Tell __cxa_end_catch this is a rethrow.
  98       if (!__is_gxx_exception_class(header->unwindHeader.exception_class))
  99         globals->caughtExceptions = 0;
 100       else
 101         header->handlerCount = -header->handlerCount;
 102
 103 #ifdef _GLIBCXX_SJLJ_EXCEPTIONS
 104       _Unwind_SjLj_Resume_or_Rethrow (&header->unwindHeader);
 105 #else
 106 #if defined(_LIBUNWIND_STD_ABI)
 107       _Unwind_RaiseException (&header->unwindHeader);
 108 #else
 109       _Unwind_Resume_or_Rethrow (&header->unwindHeader);
 110 #endif
 111 #endif
 112
 113       // Some sort of unwinding error.  Note that terminate is a handler.
 114       __cxa_begin_catch (&header->unwindHeader);
 115     }
 116   std::terminate ();
 117 }