gdb/python/py-event.c

   1 /* Python interface to inferior events.
   2
   3    Copyright (C) 2009-2018 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 gdbpy_ref<>
  31 create_event_object (PyTypeObject *py_type)
  32 {
  33   gdbpy_ref<event_object> event_obj (PyObject_New (event_object, py_type));
  34   if (event_obj == NULL)
  35     return NULL;
  36
  37   event_obj->dict = PyDict_New ();
  38   if (!event_obj->dict)
  39     return NULL;
  40
  41   return gdbpy_ref<> ((PyObject *) event_obj.release ());
  42 }
  43
  44 /* Add the attribute ATTR to the event object EVENT.  In
  45    python this attribute will be accessible by the name NAME.
  46    returns 0 if the operation succeeds and -1 otherwise.  This
  47    function acquires a new reference to ATTR.  */
  48
  49 int
  50 evpy_add_attribute (PyObject *event, const char *name, PyObject *attr)
  51 {
  52   return PyObject_SetAttrString (event, name, attr);
  53 }
  54
  55 /* Initialize the Python event code.  */
  56
  57 int
  58 gdbpy_initialize_event (void)
  59 {
  60   return gdbpy_initialize_event_generic (&event_object_type,
  61                                          "Event");
  62 }
  63
  64 /* Initialize the given event type.  If BASE is not NULL it will
  65   be set as the types base.
  66   Returns 0 if initialization was successful -1 otherwise.  */
  67
  68 int
  69 gdbpy_initialize_event_generic (PyTypeObject *type,
  70                                 const char *name)
  71 {
  72   if (PyType_Ready (type) < 0)
  73     return -1;
  74
  75   return gdb_pymodule_addobject (gdb_module, name, (PyObject *) type);
  76 }
  77
  78
  79 /* Notify the list of listens that the given EVENT has occurred.
  80    returns 0 if emit is successful -1 otherwise.  */
  81
  82 int
  83 evpy_emit_event (PyObject *event,
  84                  eventregistry_object *registry)
  85 {
  86   Py_ssize_t i;
  87
  88   /* Create a copy of call back list and use that for
  89      notifying listeners to avoid skipping callbacks
  90      in the case of a callback being disconnected during
  91      a notification.  */
  92   gdbpy_ref<> callback_list_copy (PySequence_List (registry->callbacks));
  93   if (callback_list_copy == NULL)
  94     return -1;
  95
  96   for (i = 0; i < PyList_Size (callback_list_copy.get ()); i++)
  97     {
  98       PyObject *func = PyList_GetItem (callback_list_copy.get (), i);
  99
 100       if (func == NULL)
 101         return -1;
 102
 103       gdbpy_ref<> func_result (PyObject_CallFunctionObjArgs (func, event,
 104                                                              NULL));
 105
 106       if (func_result == NULL)
 107         {
 108           /* Print the trace here, but keep going -- we want to try to
 109              call all of the callbacks even if one is broken.  */
 110           gdbpy_print_stack ();
 111         }
 112     }
 113
 114   return 0;
 115 }
 116
 117 static gdb_PyGetSetDef event_object_getset[] =
 118 {
 119   { "__dict__", gdb_py_generic_dict, NULL,
 120     "The __dict__ for this event.", &event_object_type },
 121   { NULL }
 122 };
 123
 124 PyTypeObject event_object_type =
 125 {
 126   PyVarObject_HEAD_INIT (NULL, 0)
 127   "gdb.Event",                                /* tp_name */
 128   sizeof (event_object),                      /* tp_basicsize */
 129   0,                                          /* tp_itemsize */
 130   evpy_dealloc,                               /* tp_dealloc */
 131   0,                                          /* tp_print */
 132   0,                                          /* tp_getattr */
 133   0,                                          /* tp_setattr */
 134   0,                                          /* tp_compare */
 135   0,                                          /* tp_repr */
 136   0,                                          /* tp_as_number */
 137   0,                                          /* tp_as_sequence */
 138   0,                                          /* tp_as_mapping */
 139   0,                                          /* tp_hash  */
 140   0,                                          /* tp_call */
 141   0,                                          /* tp_str */
 142   0,                                          /* tp_getattro */
 143   0,                                          /* tp_setattro */
 144   0,                                          /* tp_as_buffer */
 145   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,   /* tp_flags */
 146   "GDB event object",                         /* tp_doc */
 147   0,                                          /* tp_traverse */
 148   0,                                          /* tp_clear */
 149   0,                                          /* tp_richcompare */
 150   0,                                          /* tp_weaklistoffset */
 151   0,                                          /* tp_iter */
 152   0,                                          /* tp_iternext */
 153   0,                                          /* tp_methods */
 154   0,                                          /* tp_members */
 155   event_object_getset,                        /* tp_getset */
 156   0,                                          /* tp_base */
 157   0,                                          /* tp_dict */
 158   0,                                          /* tp_descr_get */
 159   0,                                          /* tp_descr_set */
 160   offsetof (event_object, dict),              /* tp_dictoffset */
 161   0,                                          /* tp_init */
 162   0                                           /* tp_alloc */
 163 };