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// -*- C++ -*- ARM specific Exception handling support routines.

// Copyright (C) 2004, 2005, 2008, 2009 Free Software Foundation, Inc.

//

// This file is part of GCC.

//

// GCC is free software; you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation; either version 3, or (at your option)

// any later version.

//

// GCC is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// Under Section 7 of GPL version 3, you are granted additional

// permissions described in the GCC Runtime Library Exception, version

// 3.1, as published by the Free Software Foundation.

//

// You should have received a copy of the GNU General Public License and

// a copy of the GCC Runtime Library Exception along with this program;

// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

// <http://www.gnu.org/licenses/>.

#include <cxxabi.h>

#include "unwind-cxx.h"

#ifdef __ARM_EABI_UNWINDER__

using namespace __cxxabiv1;

// Given the thrown type THROW_TYPE, pointer to a variable containing a

// pointer to the exception object THROWN_PTR_P and a type CATCH_TYPE to

// compare against, return whether or not there is a match and if so,

// update *THROWN_PTR_P.

extern "C" __cxa_type_match_result

__cxa_type_match(_Unwind_Exception* ue_header,

                 const std::type_info* catch_type,

                 bool is_reference __attribute__((__unused__)),

                 void** thrown_ptr_p)

{

  bool forced_unwind = __is_gxx_forced_unwind_class(ue_header->exception_class);

  bool foreign_exception = !forced_unwind && !__is_gxx_exception_class(ue_header->exception_class);

  bool dependent_exception =

    __is_dependent_exception(ue_header->exception_class);

  __cxa_exception* xh = __get_exception_header_from_ue(ue_header);

  __cxa_dependent_exception *dx = __get_dependent_exception_from_ue(ue_header);

  const std::type_info* throw_type;

  if (forced_unwind)

    throw_type = &typeid(abi::__forced_unwind);

  else if (foreign_exception)

    throw_type = &typeid(abi::__foreign_exception);

  else if (dependent_exception)

    throw_type = __get_exception_header_from_obj

      (dx->primaryException)->exceptionType;

  else

    throw_type = xh->exceptionType;

  void* thrown_ptr = *thrown_ptr_p;

  // Pointer types need to adjust the actual pointer, not

  // the pointer to pointer that is the exception object.

  // This also has the effect of passing pointer types

  // "by value" through the __cxa_begin_catch return value.

  if (throw_type->__is_pointer_p())

    thrown_ptr = *(void**) thrown_ptr;

  if (catch_type->__do_catch(throw_type, &thrown_ptr, 1))

    {

      *thrown_ptr_p = thrown_ptr;

      if (typeid(*catch_type) == typeid (typeid(void*)))

        {

          const __pointer_type_info *catch_pointer_type =

            static_cast<const __pointer_type_info *> (catch_type);

          const __pointer_type_info *throw_pointer_type =

            static_cast<const __pointer_type_info *> (throw_type);

          if (typeid (*catch_pointer_type->__pointee) != typeid (void)

              && (*catch_pointer_type->__pointee !=

                  *throw_pointer_type->__pointee))

            return ctm_succeeded_with_ptr_to_base;

        }

      return ctm_succeeded;

    }

  return ctm_failed;

}

// ABI defined routine called at the start of a cleanup handler.

extern "C" bool

__cxa_begin_cleanup(_Unwind_Exception* ue_header)

{

  __cxa_eh_globals *globals = __cxa_get_globals();

  __cxa_exception *header = __get_exception_header_from_ue(ue_header);

  bool native = __is_gxx_exception_class(header->unwindHeader.exception_class);

  if (native)

    {

      header->propagationCount++;

      // Add it to the chain if this is the first time we've seen this

      // exception.

      if (header->propagationCount == 1)

        {

          header->nextPropagatingException = globals->propagatingExceptions;

          globals->propagatingExceptions = header;

        }

    }

  else

    {

      // Remember the exception object, so end_cleanup can return it.

      // These cannot be stacked, so we must abort if we already have

      // a propagating exception.

      if (globals->propagatingExceptions)

        std::terminate ();

      globals->propagatingExceptions = header;

    }

  return true;

}

// Do the work for __cxa_end_cleanup.  Returns the currently propagating

// exception object.

extern "C" _Unwind_Exception *

__gnu_end_cleanup(void)

{

  __cxa_exception *header;

  __cxa_eh_globals *globals = __cxa_get_globals();

  header = globals->propagatingExceptions;

  // Check something hasn't gone horribly wrong.

  if (!header)

    std::terminate();

  if (__is_gxx_exception_class(header->unwindHeader.exception_class))

    {

      header->propagationCount--;

      if (header->propagationCount == 0)

        {

          // Remove exception from chain.

          globals->propagatingExceptions = header->nextPropagatingException;

          header->nextPropagatingException = NULL;

        }

    }

  else

    globals->propagatingExceptions = NULL;

  return &header->unwindHeader;

}

// Assembly wrapper to call __gnu_end_cleanup without clobbering r1-r3.

// Also push r4 to preserve stack alignment.

#ifdef __thumb__

asm (".global __cxa_end_cleanup\n"

"       .type __cxa_end_cleanup, \"function\"\n"

"       .thumb_func\n"

"__cxa_end_cleanup:\n"

"       push\t{r1, r2, r3, r4}\n"

"       bl\t__gnu_end_cleanup\n"

"       pop\t{r1, r2, r3, r4}\n"

"       bl\t_Unwind_Resume @ Never returns\n");

#else

asm (".global __cxa_end_cleanup\n"

"       .type __cxa_end_cleanup, \"function\"\n"

"__cxa_end_cleanup:\n"

"       stmfd\tsp!, {r1, r2, r3, r4}\n"

"       bl\t__gnu_end_cleanup\n"

"       ldmfd\tsp!, {r1, r2, r3, r4}\n"

"       bl\t_Unwind_Resume @ Never returns\n");

#endif

#endif