binutils-gdb/gdb/python/py-stopevent.c

/* Python interface to inferior stop events.

   Copyright (C) 2009-2016 Free Software Foundation, Inc.

   This file is part of GDB.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "py-stopevent.h"

PyObject *
create_stop_event_object (PyTypeObject *py_type)
{
  PyObject *stop_event_obj = create_thread_event_object (py_type);

  if (!stop_event_obj)
    goto fail;

  return stop_event_obj;

  fail:
   Py_XDECREF (stop_event_obj);
   return NULL;
}

/* Callback observers when a stop event occurs.  This function will create a
   new Python stop event object.  If only a specific thread is stopped the
   thread object of the event will be set to that thread.  Otherwise, if all
   threads are stopped thread object will be set to None.
   return 0 if the event was created and emitted successfully otherwise
   returns -1.  */

int
emit_stop_event (struct bpstats *bs, enum gdb_signal stop_signal)
{
  PyObject *stop_event_obj = NULL; /* Appease GCC warning.  */
  PyObject *list = NULL;
  PyObject *first_bp = NULL;
  struct bpstats *current_bs;

  if (evregpy_no_listeners_p (gdb_py_events.stop))
    return 0;

  /* Add any breakpoint set at this location to the list.  */
  for (current_bs = bs; current_bs != NULL; current_bs = current_bs->next)
    {
      if (current_bs->breakpoint_at
          && current_bs->breakpoint_at->py_bp_object)
        {
          PyObject *current_py_bp =
              (PyObject *) current_bs->breakpoint_at->py_bp_object;

          if (list == NULL)
            {
              list = PyList_New (0);
              if (!list)
                goto fail;
            }

          if (PyList_Append (list, current_py_bp))
            goto fail;

          if (first_bp == NULL)
            first_bp = current_py_bp;
        }
    }

  if (list != NULL)
    {
      stop_event_obj = create_breakpoint_event_object (list, first_bp);
      if (!stop_event_obj)
        goto fail;
      Py_DECREF (list);
    }

  /* Check if the signal is "Signal 0" or "Trace/breakpoint trap".  */
  if (stop_signal != GDB_SIGNAL_0
      && stop_signal != GDB_SIGNAL_TRAP)
    {
      stop_event_obj =
	  create_signal_event_object (stop_signal);
      if (!stop_event_obj)
	goto fail;
    }

  /* If all fails emit an unknown stop event.  All event types should
     be known and this should eventually be unused.  */
  if (!stop_event_obj)
    {
      stop_event_obj = create_stop_event_object (&stop_event_object_type);
      if (!stop_event_obj)
        goto fail;
    }

  return evpy_emit_event (stop_event_obj, gdb_py_events.stop);

 fail:
  Py_XDECREF (list);
  return -1;
}

GDBPY_NEW_EVENT_TYPE (stop,
                      "gdb.StopEvent",
                      "StopEvent",
                      "GDB stop event object",
                      thread_event_object_type);