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

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