gdb/python/py-event.c

   1 /* Python interface to inferior events.
   2
   3    Copyright (C) 2009-2016 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program 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 of the License, or
  10    (at your option) any later version.
  11
  12    This program 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    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "py-event.h"
  22
  23 void
  24 evpy_dealloc (PyObject *self)
  25 {
  26   Py_XDECREF (((event_object *) self)->dict);
  27   Py_TYPE (self)->tp_free (self);
  28 }
  29
  30 PyObject *
  31 create_event_object (PyTypeObject *py_type)
  32 {
  33   event_object *event_obj;
  34
  35   event_obj = PyObject_New (event_object, py_type);
  36   if (!event_obj)
  37     goto fail;
  38
  39   event_obj->dict = PyDict_New ();
  40   if (!event_obj->dict)
  41     goto fail;
  42
  43   return (PyObject*) event_obj;
  44
  45  fail:
  46   Py_XDECREF (event_obj);
  47   return NULL;
  48 }
  49
  50 /* Add the attribute ATTR to the event object EVENT.  In
  51    python this attribute will be accessible by the name NAME.
  52    returns 0 if the operation succeeds and -1 otherwise.  This
  53    function acquires a new reference to ATTR.  */
  54
  55 int
  56 evpy_add_attribute (PyObject *event, char *name, PyObject *attr)
  57 {
  58   return PyObject_SetAttrString (event, name, attr);
  59 }
  60
  61 /* Initialize the Python event code.  */
  62
  63 int
  64 gdbpy_initialize_event (void)
  65 {
  66   return gdbpy_initialize_event_generic (&event_object_type,
  67                                          "Event");
  68 }
  69
  70 /* Initialize the given event type.  If BASE is not NULL it will
  71   be set as the types base.
  72   Returns 0 if initialization was successful -1 otherwise.  */
  73
  74 int
  75 gdbpy_initialize_event_generic (PyTypeObject *type,
  76                                 char *name)
  77 {
  78   if (PyType_Ready (type) < 0)
  79     return -1;
  80
  81   return gdb_pymodule_addobject (gdb_module, name, (PyObject *) type);
  82 }
  83
  84
  85 /* Notify the list of listens that the given EVENT has occurred.
  86    returns 0 if emit is successful -1 otherwise.  */
  87
  88 int
  89 evpy_emit_event (PyObject *event,
  90                  eventregistry_object *registry)
  91 {
  92   PyObject *callback_list_copy = NULL;
  93   Py_ssize_t i;
  94
  95   /* Create a copy of call back list and use that for
  96      notifying listeners to avoid skipping callbacks
  97      in the case of a callback being disconnected during
  98      a notification.  */
  99   callback_list_copy = PySequence_List (registry->callbacks);
 100   if (!callback_list_copy)
 101     goto fail;
 102
 103   for (i = 0; i < PyList_Size (callback_list_copy); i++)
 104     {
 105       PyObject *func = PyList_GetItem (callback_list_copy, i);
 106       PyObject *func_result;
 107
 108       if (func == NULL)
 109         goto fail;
 110
 111       func_result = PyObject_CallFunctionObjArgs (func, event, NULL);
 112
 113       if (func_result == NULL)
 114         {
 115           /* Print the trace here, but keep going -- we want to try to
 116              call all of the callbacks even if one is broken.  */
 117           gdbpy_print_stack ();
 118         }
 119       else
 120         {
 121           Py_DECREF (func_result);
 122         }
 123     }
 124
 125   Py_XDECREF (callback_list_copy);
 126   Py_XDECREF (event);
 127   return 0;
 128
 129  fail:
 130   gdbpy_print_stack ();
 131   Py_XDECREF (callback_list_copy);
 132   Py_XDECREF (event);
 133   return -1;
 134 }
 135
 136 static PyGetSetDef event_object_getset[] =
 137 {
 138   { "__dict__", gdb_py_generic_dict, NULL,
 139     "The __dict__ for this event.", &event_object_type },
 140   { NULL }
 141 };
 142
 143 PyTypeObject event_object_type =
 144 {
 145   PyVarObject_HEAD_INIT (NULL, 0)
 146   "gdb.Event",                                /* tp_name */
 147   sizeof (event_object),                      /* tp_basicsize */
 148   0,                                          /* tp_itemsize */
 149   evpy_dealloc,                               /* tp_dealloc */
 150   0,                                          /* tp_print */
 151   0,                                          /* tp_getattr */
 152   0,                                          /* tp_setattr */
 153   0,                                          /* tp_compare */
 154   0,                                          /* tp_repr */
 155   0,                                          /* tp_as_number */
 156   0,                                          /* tp_as_sequence */
 157   0,                                          /* tp_as_mapping */
 158   0,                                          /* tp_hash  */
 159   0,                                          /* tp_call */
 160   0,                                          /* tp_str */
 161   0,                                          /* tp_getattro */
 162   0,                                          /* tp_setattro */
 163   0,                                          /* tp_as_buffer */
 164   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,   /* tp_flags */
 165   "GDB event object",                         /* tp_doc */
 166   0,                                          /* tp_traverse */
 167   0,                                          /* tp_clear */
 168   0,                                          /* tp_richcompare */
 169   0,                                          /* tp_weaklistoffset */
 170   0,                                          /* tp_iter */
 171   0,                                          /* tp_iternext */
 172   0,                                          /* tp_methods */
 173   0,                                          /* tp_members */
 174   event_object_getset,                        /* tp_getset */
 175   0,                                          /* tp_base */
 176   0,                                          /* tp_dict */
 177   0,                                          /* tp_descr_get */
 178   0,                                          /* tp_descr_set */
 179   offsetof (event_object, dict),              /* tp_dictoffset */
 180   0,                                          /* tp_init */
 181   0                                           /* tp_alloc */
 182 };