cppexcept.c

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                   handler, trylevel, last_level, &frame->ebp );
            call_ebp_func( handler, &frame->ebp );
        }
        trylevel = descr->unwind_table[trylevel].prev;
    }
    frame->trylevel = last_level;
}

/* exception frame for nested exceptions in catch block */
struct catch_func_nested_frame
{
    EXCEPTION_REGISTRATION_RECORD frame;     /* standard exception frame */
    EXCEPTION_RECORD             *prev_rec;  /* previous record to restore in thread data */
    cxx_exception_frame          *cxx_frame; /* frame of parent exception */
    cxx_function_descr           *descr;     /* descriptor of parent exception */
    int                           trylevel;  /* current try level */
};

/* handler for exceptions happening while calling a catch function */
static DWORD catch_function_nested_handler( EXCEPTION_RECORD *rec, EXCEPTION_REGISTRATION_RECORD *frame,
                                            CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **dispatcher )
{
    struct catch_func_nested_frame *nested_frame = (struct catch_func_nested_frame *)frame;

    if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
    {
        msvcrt_get_thread_data()->exc_record = nested_frame->prev_rec;
        return ExceptionContinueSearch;
    }
    else
    {
        TRACE( "got nested exception in catch function\n" );
        return cxx_frame_handler( rec, nested_frame->cxx_frame, context,
                                  NULL, nested_frame->descr, &nested_frame->frame,
                                  nested_frame->trylevel );
    }
}

/* find and call the appropriate catch block for an exception */
/* returns the address to continue execution to after the catch block was called */
__inline static void *call_catch_block( PEXCEPTION_RECORD rec, cxx_exception_frame *frame,
                                      cxx_function_descr *descr, int nested_trylevel,
                                      cxx_exception_type *info )
{
    UINT i;
    int j;
    void *addr, *object = (void *)rec->ExceptionInformation[1];
    struct catch_func_nested_frame nested_frame;
    int trylevel = frame->trylevel;
    MSVCRT_thread_data *thread_data = msvcrt_get_thread_data();

    for (i = 0; i < descr->tryblock_count; i++)
    {
        tryblock_info *tryblock = &descr->tryblock[i];

        if (trylevel < tryblock->start_level) continue;
        if (trylevel > tryblock->end_level) continue;

        /* got a try block */
        for (j = 0; j < tryblock->catchblock_count; j++)
        {
            catchblock_info *catchblock = &tryblock->catchblock[j];
            const cxx_type_info *type = find_caught_type( info, catchblock );
            if (!type) continue;

            TRACE( "matched type %p in tryblock %d catchblock %d\n", type, i, j );

            /* copy the exception to its destination on the stack */
            copy_exception( object, frame, catchblock, type );

            /* unwind the stack */
            RtlUnwind( frame, 0, rec, 0 );
            cxx_local_unwind( frame, descr, tryblock->start_level );
            frame->trylevel = tryblock->end_level + 1;

            /* call the catch block */
            TRACE( "calling catch block %p for type %p addr %p ebp %p\n",
                   catchblock, type, catchblock->handler, &frame->ebp );

            /* setup an exception block for nested exceptions */

            //nested_frame.frame.Handler = catch_function_nested_handler;
            nested_frame.frame.Handler = (PEXCEPTION_HANDLER)catch_function_nested_handler;
            nested_frame.prev_rec  = thread_data->exc_record;
            nested_frame.cxx_frame = frame;
            nested_frame.descr     = descr;
            nested_frame.trylevel  = nested_trylevel + 1;

            __wine_push_frame( &nested_frame.frame );
            thread_data->exc_record = rec;
            addr = call_ebp_func( catchblock->handler, &frame->ebp );
            thread_data->exc_record = nested_frame.prev_rec;
            __wine_pop_frame( &nested_frame.frame );

            if (info->destructor) call_dtor( info->destructor, object );
            TRACE( "done, continuing at %p\n", addr );
            return addr;
        }
    }
    return NULL;
}


/*********************************************************************
 *		cxx_frame_handler
 *
 * Implementation of __CxxFrameHandler.
 */
static DWORD cxx_frame_handler( PEXCEPTION_RECORD rec, cxx_exception_frame* frame,
                                PCONTEXT exc_context, EXCEPTION_REGISTRATION_RECORD** dispatch,
                                cxx_function_descr *descr, EXCEPTION_REGISTRATION_RECORD* nested_frame,
                                int nested_trylevel )
{
    cxx_exception_type *exc_type;
    void *next_ip;
    PEXCEPTION_RECORD orig_rec = rec;

    if (descr->magic != CXX_FRAME_MAGIC)
    {
        ERR( "invalid frame magic %x\n", descr->magic );
        return ExceptionContinueSearch;
    }
    if (rec->ExceptionFlags & (EH_UNWINDING|EH_EXIT_UNWIND))
    {
        if (descr->unwind_count && !nested_trylevel) cxx_local_unwind( frame, descr, -1 );
        return ExceptionContinueSearch;
    }
    if (!descr->tryblock_count) return ExceptionContinueSearch;

    exc_type = (cxx_exception_type *)rec->ExceptionInformation[2];
    if (rec->ExceptionCode == CXX_EXCEPTION &&
        rec->ExceptionInformation[0] > CXX_FRAME_MAGIC &&
        exc_type->custom_handler)
    {
        return exc_type->custom_handler( rec, frame, exc_context, dispatch,
                                         descr, nested_trylevel, nested_frame, 0 );
    }

    if (!exc_type)  /* nested exception, fetch info from original exception */
    {
        rec = msvcrt_get_thread_data()->exc_record;
        exc_type = (cxx_exception_type *)rec->ExceptionInformation[2];
    }

    if (TRACE_ON(seh))
    {
        TRACE("handling C++ exception rec %p frame %p trylevel %d descr %p nested_frame %p\n",
              rec, frame, frame->trylevel, descr, nested_frame );
        dump_exception_type( exc_type );
        dump_function_descr( descr, exc_type );
    }

    next_ip = call_catch_block( rec, frame, descr, frame->trylevel, exc_type );

    if (!next_ip) return ExceptionContinueSearch;
    orig_rec->ExceptionFlags &= ~EH_NONCONTINUABLE;
    exc_context->Eip = (DWORD)next_ip;
    exc_context->Ebp = (DWORD)&frame->ebp;
    exc_context->Esp = ((DWORD*)frame)[-1];
    return ExceptionContinueExecution;
}


/*********************************************************************
 *		__CxxFrameHandler (MSVCRT.@)
 */
DWORD __CxxFrameHandler( PEXCEPTION_RECORD rec, EXCEPTION_REGISTRATION_RECORD* frame,
                              PCONTEXT exc_context, EXCEPTION_REGISTRATION_RECORD** dispatch )
{
    cxx_function_descr *descr;

    __asm__ __volatile__("mov %%eax, %0\n" : "=m"(descr));
    return cxx_frame_handler(rec, (cxx_exception_frame *)frame,
                             exc_context, dispatch, descr, NULL, 0 );
}
#endif  /* __i386__ */

/*********************************************************************
 *		_CxxThrowException (MSVCRT.@)
 */
void _CxxThrowException( void *object, const cxx_exception_type *type )
{
    DWORD args[3];

    args[0] = CXX_FRAME_MAGIC;
    args[1] = (DWORD)object;
    args[2] = (DWORD)type;
    RaiseException( CXX_EXCEPTION, EH_NONCONTINUABLE, 3, args );
}

/*********************************************************************
 *		__CxxDetectRethrow (MSVCRT.@)
 */
BOOL __CxxDetectRethrow(PEXCEPTION_POINTERS ptrs)
{
  PEXCEPTION_RECORD rec;

  if (!ptrs)
    return FALSE;

  rec = ptrs->ExceptionRecord;

  if (rec->ExceptionCode == CXX_EXCEPTION &&
      rec->NumberParameters == 3 &&
      rec->ExceptionInformation[0] == CXX_FRAME_MAGIC &&
      rec->ExceptionInformation[2])
  {
    ptrs->ExceptionRecord = msvcrt_get_thread_data()->exc_record;
    return TRUE;
  }
  return (msvcrt_get_thread_data()->exc_record == rec);
}

/*********************************************************************
 *		__CxxQueryExceptionSize (MSVCRT.@)
 */
unsigned int __CxxQueryExceptionSize(void)
{
  return sizeof(cxx_exception_type);
}