[deliverable/binutils-gdb.git] / gdb / python / py-finishbreakpoint.c

/* Python interface to finish breakpoints

   Copyright (C) 2011-2017 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 "python-internal.h"
#include "breakpoint.h"
#include "frame.h"
#include "gdbthread.h"
#include "arch-utils.h"
#include "language.h"
#include "observer.h"
#include "inferior.h"
#include "block.h"
#include "location.h"
#include "py-ref.h"

/* Function that is called when a Python finish bp is found out of scope.  */
static char * const outofscope_func = "out_of_scope";

/* struct implementing the gdb.FinishBreakpoint object by extending
   the gdb.Breakpoint class.  */
struct finish_breakpoint_object
{
  /* gdb.Breakpoint base class.  */
  gdbpy_breakpoint_object py_bp;
  /* gdb.Type object of the value return by the breakpointed function.
     May be NULL if no debug information was available or return type
     was VOID.  */
  PyObject *return_type;
  /* gdb.Value object of the function finished by this breakpoint.  Will be
     NULL if return_type is NULL.  */
  PyObject *function_value;
  /* When stopped at this FinishBreakpoint, gdb.Value object returned by
     the function; Py_None if the value is not computable; NULL if GDB is
     not stopped at a FinishBreakpoint.  */
  PyObject *return_value;
};

extern PyTypeObject finish_breakpoint_object_type
    CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("finish_breakpoint_object");

/* Python function to get the 'return_value' attribute of
   FinishBreakpoint.  */

static PyObject *
bpfinishpy_get_returnvalue (PyObject *self, void *closure)
{
  struct finish_breakpoint_object *self_finishbp =
      (struct finish_breakpoint_object *) self;

  if (!self_finishbp->return_value)
    Py_RETURN_NONE;

  Py_INCREF (self_finishbp->return_value);
  return self_finishbp->return_value;
}

/* Deallocate FinishBreakpoint object.  */

static void
bpfinishpy_dealloc (PyObject *self)
{
  struct finish_breakpoint_object *self_bpfinish =
        (struct finish_breakpoint_object *) self;

  Py_XDECREF (self_bpfinish->function_value);
  Py_XDECREF (self_bpfinish->return_type);
  Py_XDECREF (self_bpfinish->return_value);
}

/* Triggered when gdbpy_should_stop is about to execute the `stop' callback
   of the gdb.FinishBreakpoint object BP_OBJ.  Will compute and cache the
   `return_value', if possible.  */

void
bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
{
  struct finish_breakpoint_object *self_finishbp =
        (struct finish_breakpoint_object *) bp_obj;

  /* Can compute return_value only once.  */
  gdb_assert (!self_finishbp->return_value);

  if (!self_finishbp->return_type)
    return;

  TRY
    {
      struct value *function =
        value_object_to_value (self_finishbp->function_value);
      struct type *value_type =
        type_object_to_type (self_finishbp->return_type);
      struct value *ret = get_return_value (function, value_type);

      if (ret)
        {
          self_finishbp->return_value = value_to_value_object (ret);
          if (!self_finishbp->return_value)
              gdbpy_print_stack ();
        }
      else
        {
          Py_INCREF (Py_None);
          self_finishbp->return_value = Py_None;
        }
    }
  CATCH (except, RETURN_MASK_ALL)
    {
      gdbpy_convert_exception (except);
      gdbpy_print_stack ();
    }
  END_CATCH
}

/* Triggered when gdbpy_should_stop has triggered the `stop' callback
   of the gdb.FinishBreakpoint object BP_OBJ.  */

void
bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
{

  TRY
    {
      /* Can't delete it here, but it will be removed at the next stop.  */
      disable_breakpoint (bp_obj->bp);
      gdb_assert (bp_obj->bp->disposition == disp_del);
    }
  CATCH (except, RETURN_MASK_ALL)
    {
      gdbpy_convert_exception (except);
      gdbpy_print_stack ();
    }
  END_CATCH
}

/* Python function to create a new breakpoint.  */

static int
bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
{
  static char *keywords[] = { "frame", "internal", NULL };
  struct finish_breakpoint_object *self_bpfinish =
      (struct finish_breakpoint_object *) self;
  PyObject *frame_obj = NULL;
  int thread;
  struct frame_info *frame = NULL; /* init for gcc -Wall */
  struct frame_info *prev_frame = NULL;
  struct frame_id frame_id;
  PyObject *internal = NULL;
  int internal_bp = 0;
  CORE_ADDR pc;
  struct symbol *function;

  if (!PyArg_ParseTupleAndKeywords (args, kwargs, "|OO", keywords,
                                    &frame_obj, &internal))
    return -1;

  TRY
    {
      /* Default frame to newest frame if necessary.  */
      if (frame_obj == NULL)
	frame = get_current_frame ();
      else
	frame = frame_object_to_frame_info (frame_obj);

      if (frame == NULL)
	{
	  PyErr_SetString (PyExc_ValueError,
			   _("Invalid ID for the `frame' object."));
	}
      else
	{
	  prev_frame = get_prev_frame (frame);
	  if (prev_frame == 0)
	    {
	      PyErr_SetString (PyExc_ValueError,
			       _("\"FinishBreakpoint\" not "
				 "meaningful in the outermost "
				 "frame."));
	    }
	  else if (get_frame_type (prev_frame) == DUMMY_FRAME)
	    {
	      PyErr_SetString (PyExc_ValueError,
			       _("\"FinishBreakpoint\" cannot "
				 "be set on a dummy frame."));
	    }
	  else
	    {
	      frame_id = get_frame_id (prev_frame);
	      if (frame_id_eq (frame_id, null_frame_id))
		PyErr_SetString (PyExc_ValueError,
				 _("Invalid ID for the `frame' object."));
	    }
	}
    }
  CATCH (except, RETURN_MASK_ALL)
    {
      gdbpy_convert_exception (except);
      return -1;
    }
  END_CATCH

  if (PyErr_Occurred ())
    return -1;

  thread = ptid_to_global_thread_id (inferior_ptid);
  if (thread == 0)
    {
      PyErr_SetString (PyExc_ValueError,
                       _("No thread currently selected."));
      return -1;
    }

  if (internal)
    {
      internal_bp = PyObject_IsTrue (internal);
      if (internal_bp == -1)
        {
          PyErr_SetString (PyExc_ValueError,
                           _("The value of `internal' must be a boolean."));
          return -1;
        }
    }

  /* Find the function we will return from.  */
  self_bpfinish->return_type = NULL;
  self_bpfinish->function_value = NULL;

  TRY
    {
      if (get_frame_pc_if_available (frame, &pc))
        {
          function = find_pc_function (pc);
          if (function != NULL)
            {
              struct type *ret_type =
                  TYPE_TARGET_TYPE (SYMBOL_TYPE (function));

              /* Remember only non-void return types.  */
              if (TYPE_CODE (ret_type) != TYPE_CODE_VOID)
                {
                  struct value *func_value;

                  /* Ignore Python errors at this stage.  */
                  self_bpfinish->return_type = type_to_type_object (ret_type);
                  PyErr_Clear ();
                  func_value = read_var_value (function, NULL, frame);
                  self_bpfinish->function_value =
                      value_to_value_object (func_value);
                  PyErr_Clear ();
                }
            }
        }
    }
  CATCH (except, RETURN_MASK_ALL)
    {
      /* Just swallow.  Either the return type or the function value
	 remain NULL.  */
    }
  END_CATCH

  if (self_bpfinish->return_type == NULL || self_bpfinish->function_value == NULL)
    {
      /* Won't be able to compute return value.  */
      Py_XDECREF (self_bpfinish->return_type);
      Py_XDECREF (self_bpfinish->function_value);

      self_bpfinish->return_type = NULL;
      self_bpfinish->function_value = NULL;
    }

  bppy_pending_object = &self_bpfinish->py_bp;
  bppy_pending_object->number = -1;
  bppy_pending_object->bp = NULL;

  TRY
    {
      struct event_location *location;
      struct cleanup *back_to;

      /* Set a breakpoint on the return address.  */
      location = new_address_location (get_frame_pc (prev_frame), NULL, 0);
      back_to = make_cleanup_delete_event_location (location);
      create_breakpoint (python_gdbarch,
                         location, NULL, thread, NULL,
                         0,
                         1 /*temp_flag*/,
                         bp_breakpoint,
                         0,
                         AUTO_BOOLEAN_TRUE,
                         &bkpt_breakpoint_ops,
                         0, 1, internal_bp, 0);
      do_cleanups (back_to);
    }
  CATCH (except, RETURN_MASK_ALL)
    {
      GDB_PY_SET_HANDLE_EXCEPTION (except);
    }
  END_CATCH

  self_bpfinish->py_bp.bp->frame_id = frame_id;
  self_bpfinish->py_bp.is_finish_bp = 1;

  /* Bind the breakpoint with the current program space.  */
  self_bpfinish->py_bp.bp->pspace = current_program_space;

  return 0;
}

/* Called when GDB notices that the finish breakpoint BP_OBJ is out of
   the current callstack.  Triggers the method OUT_OF_SCOPE if implemented,
   then delete the breakpoint.  */

static void
bpfinishpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj)
{
  gdbpy_breakpoint_object *bp_obj = (gdbpy_breakpoint_object *) bpfinish_obj;
  PyObject *py_obj = (PyObject *) bp_obj;

  if (bpfinish_obj->py_bp.bp->enable_state == bp_enabled
      && PyObject_HasAttrString (py_obj, outofscope_func))
    {
      gdbpy_ref<> meth_result (PyObject_CallMethod (py_obj, outofscope_func,
						    NULL));
      if (meth_result == NULL)
	gdbpy_print_stack ();
    }

  delete_breakpoint (bpfinish_obj->py_bp.bp);
}

/* Callback for `bpfinishpy_detect_out_scope'.  Triggers Python's
   `B->out_of_scope' function if B is a FinishBreakpoint out of its scope.  */

static int
bpfinishpy_detect_out_scope_cb (struct breakpoint *b, void *args)
{
  struct breakpoint *bp_stopped = (struct breakpoint *) args;
  PyObject *py_bp = (PyObject *) b->py_bp_object;

  /* Trigger out_of_scope if this is a FinishBreakpoint and its frame is
     not anymore in the current callstack.  */
  if (py_bp != NULL && b->py_bp_object->is_finish_bp)
    {
      struct finish_breakpoint_object *finish_bp =
          (struct finish_breakpoint_object *) py_bp;

      /* Check scope if not currently stopped at the FinishBreakpoint.  */
      if (b != bp_stopped)
        {
          TRY
            {
              if (b->pspace == current_inferior ()->pspace
                  && (!target_has_registers
                      || frame_find_by_id (b->frame_id) == NULL))
                bpfinishpy_out_of_scope (finish_bp);
            }
          CATCH (except, RETURN_MASK_ALL)
            {
              gdbpy_convert_exception (except);
              gdbpy_print_stack ();
            }
	  END_CATCH
        }
    }

  return 0;
}

/* Attached to `stop' notifications, check if the execution has run
   out of the scope of any FinishBreakpoint before it has been hit.  */

static void
bpfinishpy_handle_stop (struct bpstats *bs, int print_frame)
{
  gdbpy_enter enter_py (get_current_arch (), current_language);

  iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb,
                            bs == NULL ? NULL : bs->breakpoint_at);
}

/* Attached to `exit' notifications, triggers all the necessary out of
   scope notifications.  */

static void
bpfinishpy_handle_exit (struct inferior *inf)
{
  gdbpy_enter enter_py (target_gdbarch (), current_language);

  iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, NULL);
}

/* Initialize the Python finish breakpoint code.  */

int
gdbpy_initialize_finishbreakpoints (void)
{
  if (PyType_Ready (&finish_breakpoint_object_type) < 0)
    return -1;

  if (gdb_pymodule_addobject (gdb_module, "FinishBreakpoint",
			      (PyObject *) &finish_breakpoint_object_type) < 0)
    return -1;

  observer_attach_normal_stop (bpfinishpy_handle_stop);
  observer_attach_inferior_exit (bpfinishpy_handle_exit);

  return 0;
}

static PyGetSetDef finish_breakpoint_object_getset[] = {
  { "return_value", bpfinishpy_get_returnvalue, NULL,
  "gdb.Value object representing the return value, if any. \
None otherwise.", NULL },
    { NULL }  /* Sentinel.  */
};

PyTypeObject finish_breakpoint_object_type =
{
  PyVarObject_HEAD_INIT (NULL, 0)
  "gdb.FinishBreakpoint",         /*tp_name*/
  sizeof (struct finish_breakpoint_object),  /*tp_basicsize*/
  0,                              /*tp_itemsize*/
  bpfinishpy_dealloc,             /*tp_dealloc*/
  0,                              /*tp_print*/
  0,                              /*tp_getattr*/
  0,                              /*tp_setattr*/
  0,                              /*tp_compare*/
  0,                              /*tp_repr*/
  0,                              /*tp_as_number*/
  0,                              /*tp_as_sequence*/
  0,                              /*tp_as_mapping*/
  0,                              /*tp_hash */
  0,                              /*tp_call*/
  0,                              /*tp_str*/
  0,                              /*tp_getattro*/
  0,                              /*tp_setattro */
  0,                              /*tp_as_buffer*/
  Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
  "GDB finish breakpoint object", /* tp_doc */
  0,                              /* tp_traverse */
  0,                              /* tp_clear */
  0,                              /* tp_richcompare */
  0,                              /* tp_weaklistoffset */
  0,                              /* tp_iter */
  0,                              /* tp_iternext */
  0,                              /* tp_methods */
  0,                              /* tp_members */
  finish_breakpoint_object_getset,/* tp_getset */
  &breakpoint_object_type,        /* tp_base */
  0,                              /* tp_dict */
  0,                              /* tp_descr_get */
  0,                              /* tp_descr_set */
  0,                              /* tp_dictoffset */
  bpfinishpy_init,                /* tp_init */
  0,                              /* tp_alloc */
  0                               /* tp_new */
};
Commit	Line	Data
cc72b2a2 KP	1	/* Python interface to finish breakpoints
cc72b2a2 KP	2
61baf725	3	Copyright (C) 2011-2017 Free Software Foundation, Inc.
cc72b2a2 KP	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
	21
	22	#include "defs.h"
cc72b2a2 KP	23	#include "python-internal.h"
	24	#include "breakpoint.h"
	25	#include "frame.h"
	26	#include "gdbthread.h"
	27	#include "arch-utils.h"
	28	#include "language.h"
	29	#include "observer.h"
	30	#include "inferior.h"
6a3a010b	31	#include "block.h"
f00aae0f	32	#include "location.h"
16361ffb	33	#include "py-ref.h"
cc72b2a2	34
cc72b2a2 KP	35	/* Function that is called when a Python finish bp is found out of scope. */
	36	static char * const outofscope_func = "out_of_scope";
	37
	38	/* struct implementing the gdb.FinishBreakpoint object by extending
	39	the gdb.Breakpoint class. */
	40	struct finish_breakpoint_object
	41	{
	42	/* gdb.Breakpoint base class. */
4cb0213d	43	gdbpy_breakpoint_object py_bp;
cc72b2a2 KP	44	/* gdb.Type object of the value return by the breakpointed function.
	45	May be NULL if no debug information was available or return type
	46	was VOID. */
	47	PyObject *return_type;
6a3a010b	48	/* gdb.Value object of the function finished by this breakpoint. Will be
cc72b2a2	49	NULL if return_type is NULL. */
6a3a010b	50	PyObject *function_value;
cc72b2a2 KP	51	/* When stopped at this FinishBreakpoint, gdb.Value object returned by
	52	the function; Py_None if the value is not computable; NULL if GDB is
	53	not stopped at a FinishBreakpoint. */
	54	PyObject *return_value;
	55	};
	56
e36122e9	57	extern PyTypeObject finish_breakpoint_object_type
62eec1a5 TT	58	CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("finish_breakpoint_object");
62eec1a5 TT	59
cc72b2a2 KP	60	/* Python function to get the 'return_value' attribute of
	61	FinishBreakpoint. */
	62
	63	static PyObject *
	64	bpfinishpy_get_returnvalue (PyObject self, void closure)
	65	{
	66	struct finish_breakpoint_object *self_finishbp =
	67	(struct finish_breakpoint_object *) self;
	68
	69	if (!self_finishbp->return_value)
	70	Py_RETURN_NONE;
	71
	72	Py_INCREF (self_finishbp->return_value);
	73	return self_finishbp->return_value;
	74	}
	75
	76	/* Deallocate FinishBreakpoint object. */
	77
	78	static void
	79	bpfinishpy_dealloc (PyObject *self)
	80	{
	81	struct finish_breakpoint_object *self_bpfinish =
	82	(struct finish_breakpoint_object *) self;
	83
6a3a010b	84	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2 KP	85	Py_XDECREF (self_bpfinish->return_type);
	86	Py_XDECREF (self_bpfinish->return_value);
	87	}
	88
	89	/* Triggered when gdbpy_should_stop is about to execute the `stop' callback
	90	of the gdb.FinishBreakpoint object BP_OBJ. Will compute and cache the
	91	`return_value', if possible. */
	92
	93	void
4cb0213d	94	bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2 KP	95	{
	96	struct finish_breakpoint_object *self_finishbp =
	97	(struct finish_breakpoint_object *) bp_obj;
cc72b2a2 KP	98
	99	/* Can compute return_value only once. */
	100	gdb_assert (!self_finishbp->return_value);
	101
	102	if (!self_finishbp->return_type)
	103	return;
	104
492d29ea	105	TRY
cc72b2a2	106	{
6a3a010b MR	107	struct value *function =
	108	value_object_to_value (self_finishbp->function_value);
	109	struct type *value_type =
	110	type_object_to_type (self_finishbp->return_type);
0700e23e	111	struct value *ret = get_return_value (function, value_type);
cc72b2a2 KP	112
	113	if (ret)
	114	{
	115	self_finishbp->return_value = value_to_value_object (ret);
	116	if (!self_finishbp->return_value)
	117	gdbpy_print_stack ();
	118	}
	119	else
	120	{
	121	Py_INCREF (Py_None);
	122	self_finishbp->return_value = Py_None;
	123	}
	124	}
492d29ea	125	CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	126	{
	127	gdbpy_convert_exception (except);
	128	gdbpy_print_stack ();
	129	}
492d29ea	130	END_CATCH
cc72b2a2 KP	131	}
	132
	133	/* Triggered when gdbpy_should_stop has triggered the `stop' callback
	134	of the gdb.FinishBreakpoint object BP_OBJ. */
	135
	136	void
4cb0213d	137	bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2	138	{
cc72b2a2	139
492d29ea	140	TRY
cc72b2a2 KP	141	{
	142	/* Can't delete it here, but it will be removed at the next stop. */
	143	disable_breakpoint (bp_obj->bp);
	144	gdb_assert (bp_obj->bp->disposition == disp_del);
	145	}
492d29ea	146	CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	147	{
	148	gdbpy_convert_exception (except);
	149	gdbpy_print_stack ();
	150	}
492d29ea	151	END_CATCH
cc72b2a2 KP	152	}
	153
	154	/* Python function to create a new breakpoint. */
	155
	156	static int
	157	bpfinishpy_init (PyObject self, PyObject args, PyObject *kwargs)
	158	{
	159	static char *keywords[] = { "frame", "internal", NULL };
	160	struct finish_breakpoint_object *self_bpfinish =
	161	(struct finish_breakpoint_object *) self;
cc72b2a2 KP	162	PyObject *frame_obj = NULL;
cc72b2a2 KP	163	int thread;
62d7fb51 DE	164	struct frame_info frame = NULL; / init for gcc -Wall */
62d7fb51 DE	165	struct frame_info *prev_frame = NULL;
cc72b2a2 KP	166	struct frame_id frame_id;
	167	PyObject *internal = NULL;
	168	int internal_bp = 0;
a06efdd6	169	CORE_ADDR pc;
cc72b2a2 KP	170	struct symbol *function;
	171
	172	if (!PyArg_ParseTupleAndKeywords (args, kwargs, "\|OO", keywords,
	173	&frame_obj, &internal))
	174	return -1;
	175
492d29ea	176	TRY
cc72b2a2	177	{
dd5fa3e7 TT	178	/* Default frame to newest frame if necessary. */
	179	if (frame_obj == NULL)
	180	frame = get_current_frame ();
cc72b2a2	181	else
dd5fa3e7 TT	182	frame = frame_object_to_frame_info (frame_obj);
	183
	184	if (frame == NULL)
	185	{
256458bc	186	PyErr_SetString (PyExc_ValueError,
dd5fa3e7 TT	187	_("Invalid ID for the `frame' object."));
	188	}
	189	else
	190	{
	191	prev_frame = get_prev_frame (frame);
	192	if (prev_frame == 0)
	193	{
	194	PyErr_SetString (PyExc_ValueError,
	195	_("\"FinishBreakpoint\" not "
	196	"meaningful in the outermost "
	197	"frame."));
	198	}
	199	else if (get_frame_type (prev_frame) == DUMMY_FRAME)
	200	{
	201	PyErr_SetString (PyExc_ValueError,
	202	_("\"FinishBreakpoint\" cannot "
	203	"be set on a dummy frame."));
	204	}
	205	else
	206	{
	207	frame_id = get_frame_id (prev_frame);
	208	if (frame_id_eq (frame_id, null_frame_id))
	209	PyErr_SetString (PyExc_ValueError,
	210	_("Invalid ID for the `frame' object."));
	211	}
	212	}
cc72b2a2	213	}
492d29ea	214	CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	215	{
	216	gdbpy_convert_exception (except);
	217	return -1;
	218	}
492d29ea PA	219	END_CATCH
	220
	221	if (PyErr_Occurred ())
cc72b2a2 KP	222	return -1;
cc72b2a2 KP	223
5d5658a1	224	thread = ptid_to_global_thread_id (inferior_ptid);
cc72b2a2 KP	225	if (thread == 0)
	226	{
	227	PyErr_SetString (PyExc_ValueError,
	228	_("No thread currently selected."));
	229	return -1;
	230	}
	231
	232	if (internal)
	233	{
	234	internal_bp = PyObject_IsTrue (internal);
256458bc	235	if (internal_bp == -1)
cc72b2a2	236	{
256458bc	237	PyErr_SetString (PyExc_ValueError,
cc72b2a2 KP	238	_("The value of `internal' must be a boolean."));
	239	return -1;
	240	}
	241	}
	242
	243	/* Find the function we will return from. */
	244	self_bpfinish->return_type = NULL;
6a3a010b	245	self_bpfinish->function_value = NULL;
cc72b2a2	246
492d29ea	247	TRY
cc72b2a2 KP	248	{
	249	if (get_frame_pc_if_available (frame, &pc))
	250	{
	251	function = find_pc_function (pc);
	252	if (function != NULL)
	253	{
	254	struct type *ret_type =
	255	TYPE_TARGET_TYPE (SYMBOL_TYPE (function));
	256
	257	/* Remember only non-void return types. */
	258	if (TYPE_CODE (ret_type) != TYPE_CODE_VOID)
	259	{
6a3a010b MR	260	struct value *func_value;
6a3a010b MR	261
cc72b2a2 KP	262	/* Ignore Python errors at this stage. */
	263	self_bpfinish->return_type = type_to_type_object (ret_type);
	264	PyErr_Clear ();
63e43d3a	265	func_value = read_var_value (function, NULL, frame);
6a3a010b MR	266	self_bpfinish->function_value =
6a3a010b MR	267	value_to_value_object (func_value);
cc72b2a2 KP	268	PyErr_Clear ();
	269	}
	270	}
	271	}
	272	}
492d29ea	273	CATCH (except, RETURN_MASK_ALL)
7556d4a4 PA	274	{
	275	/* Just swallow. Either the return type or the function value
	276	remain NULL. */
	277	}
492d29ea	278	END_CATCH
7556d4a4 PA	279
7556d4a4 PA	280	if (self_bpfinish->return_type == NULL \|\| self_bpfinish->function_value == NULL)
cc72b2a2 KP	281	{
	282	/* Won't be able to compute return value. */
	283	Py_XDECREF (self_bpfinish->return_type);
6a3a010b	284	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2 KP	285
cc72b2a2 KP	286	self_bpfinish->return_type = NULL;
6a3a010b	287	self_bpfinish->function_value = NULL;
cc72b2a2 KP	288	}
	289
	290	bppy_pending_object = &self_bpfinish->py_bp;
	291	bppy_pending_object->number = -1;
	292	bppy_pending_object->bp = NULL;
	293
492d29ea	294	TRY
cc72b2a2	295	{
f00aae0f KS	296	struct event_location *location;
	297	struct cleanup *back_to;
	298
cc72b2a2	299	/* Set a breakpoint on the return address. */
305e13e6	300	location = new_address_location (get_frame_pc (prev_frame), NULL, 0);
f00aae0f	301	back_to = make_cleanup_delete_event_location (location);
cc72b2a2	302	create_breakpoint (python_gdbarch,
f00aae0f	303	location, NULL, thread, NULL,
cc72b2a2 KP	304	0,
	305	1 /temp_flag/,
	306	bp_breakpoint,
	307	0,
	308	AUTO_BOOLEAN_TRUE,
	309	&bkpt_breakpoint_ops,
44f238bb	310	0, 1, internal_bp, 0);
f00aae0f	311	do_cleanups (back_to);
cc72b2a2	312	}
492d29ea PA	313	CATCH (except, RETURN_MASK_ALL)
	314	{
	315	GDB_PY_SET_HANDLE_EXCEPTION (except);
	316	}
	317	END_CATCH
256458bc	318
cc72b2a2 KP	319	self_bpfinish->py_bp.bp->frame_id = frame_id;
cc72b2a2 KP	320	self_bpfinish->py_bp.is_finish_bp = 1;
256458bc	321
cc72b2a2 KP	322	/* Bind the breakpoint with the current program space. */
	323	self_bpfinish->py_bp.bp->pspace = current_program_space;
	324
	325	return 0;
cc72b2a2 KP	326	}
	327
	328	/* Called when GDB notices that the finish breakpoint BP_OBJ is out of
	329	the current callstack. Triggers the method OUT_OF_SCOPE if implemented,
	330	then delete the breakpoint. */
	331
	332	static void
	333	bpfinishpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj)
	334	{
4cb0213d	335	gdbpy_breakpoint_object bp_obj = (gdbpy_breakpoint_object ) bpfinish_obj;
cc72b2a2 KP	336	PyObject py_obj = (PyObject ) bp_obj;
	337
	338	if (bpfinish_obj->py_bp.bp->enable_state == bp_enabled
	339	&& PyObject_HasAttrString (py_obj, outofscope_func))
	340	{
7780f186 TT	341	gdbpy_ref<> meth_result (PyObject_CallMethod (py_obj, outofscope_func,
7780f186 TT	342	NULL));
18868860 TT	343	if (meth_result == NULL)
18868860 TT	344	gdbpy_print_stack ();
cc72b2a2 KP	345	}
	346
	347	delete_breakpoint (bpfinish_obj->py_bp.bp);
	348	}
	349
	350	/* Callback for `bpfinishpy_detect_out_scope'. Triggers Python's
	351	`B->out_of_scope' function if B is a FinishBreakpoint out of its scope. */
	352
	353	static int
	354	bpfinishpy_detect_out_scope_cb (struct breakpoint b, void args)
	355	{
cc72b2a2 KP	356	struct breakpoint bp_stopped = (struct breakpoint ) args;
cc72b2a2 KP	357	PyObject py_bp = (PyObject ) b->py_bp_object;
256458bc	358
cc72b2a2 KP	359	/* Trigger out_of_scope if this is a FinishBreakpoint and its frame is
	360	not anymore in the current callstack. */
	361	if (py_bp != NULL && b->py_bp_object->is_finish_bp)
	362	{
	363	struct finish_breakpoint_object *finish_bp =
	364	(struct finish_breakpoint_object *) py_bp;
	365
	366	/* Check scope if not currently stopped at the FinishBreakpoint. */
	367	if (b != bp_stopped)
	368	{
492d29ea	369	TRY
cc72b2a2 KP	370	{
	371	if (b->pspace == current_inferior ()->pspace
	372	&& (!target_has_registers
	373	\|\| frame_find_by_id (b->frame_id) == NULL))
	374	bpfinishpy_out_of_scope (finish_bp);
	375	}
492d29ea	376	CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	377	{
	378	gdbpy_convert_exception (except);
	379	gdbpy_print_stack ();
	380	}
492d29ea	381	END_CATCH
cc72b2a2 KP	382	}
	383	}
	384
	385	return 0;
	386	}
	387
	388	/* Attached to `stop' notifications, check if the execution has run
	389	out of the scope of any FinishBreakpoint before it has been hit. */
	390
	391	static void
	392	bpfinishpy_handle_stop (struct bpstats *bs, int print_frame)
	393	{
6e7c365e	394	gdbpy_enter enter_py (get_current_arch (), current_language);
cc72b2a2 KP	395
	396	iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb,
	397	bs == NULL ? NULL : bs->breakpoint_at);
cc72b2a2 KP	398	}
	399
	400	/* Attached to `exit' notifications, triggers all the necessary out of
	401	scope notifications. */
	402
	403	static void
	404	bpfinishpy_handle_exit (struct inferior *inf)
	405	{
6e7c365e	406	gdbpy_enter enter_py (target_gdbarch (), current_language);
cc72b2a2 KP	407
cc72b2a2 KP	408	iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, NULL);
cc72b2a2 KP	409	}
	410
	411	/* Initialize the Python finish breakpoint code. */
	412
999633ed	413	int
cc72b2a2 KP	414	gdbpy_initialize_finishbreakpoints (void)
	415	{
	416	if (PyType_Ready (&finish_breakpoint_object_type) < 0)
999633ed	417	return -1;
256458bc	418
aa36459a TT	419	if (gdb_pymodule_addobject (gdb_module, "FinishBreakpoint",
aa36459a TT	420	(PyObject *) &finish_breakpoint_object_type) < 0)
999633ed	421	return -1;
256458bc	422
cc72b2a2 KP	423	observer_attach_normal_stop (bpfinishpy_handle_stop);
cc72b2a2 KP	424	observer_attach_inferior_exit (bpfinishpy_handle_exit);
999633ed TT	425
999633ed TT	426	return 0;
cc72b2a2 KP	427	}
	428
	429	static PyGetSetDef finish_breakpoint_object_getset[] = {
	430	{ "return_value", bpfinishpy_get_returnvalue, NULL,
	431	"gdb.Value object representing the return value, if any. \
	432	None otherwise.", NULL },
	433	{ NULL } /* Sentinel. */
	434	};
	435
e36122e9	436	PyTypeObject finish_breakpoint_object_type =
cc72b2a2	437	{
9a27f2c6	438	PyVarObject_HEAD_INIT (NULL, 0)
cc72b2a2 KP	439	"gdb.FinishBreakpoint", /tp_name/
	440	sizeof (struct finish_breakpoint_object), /tp_basicsize/
	441	0, /tp_itemsize/
	442	bpfinishpy_dealloc, /tp_dealloc/
	443	0, /tp_print/
	444	0, /tp_getattr/
	445	0, /tp_setattr/
	446	0, /tp_compare/
	447	0, /tp_repr/
	448	0, /tp_as_number/
	449	0, /tp_as_sequence/
	450	0, /tp_as_mapping/
	451	0, /tp_hash /
	452	0, /tp_call/
	453	0, /tp_str/
	454	0, /tp_getattro/
	455	0, /tp_setattro /
	456	0, /tp_as_buffer/
	457	Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_BASETYPE, /tp_flags/
	458	"GDB finish breakpoint object", /* tp_doc */
	459	0, /* tp_traverse */
	460	0, /* tp_clear */
	461	0, /* tp_richcompare */
	462	0, /* tp_weaklistoffset */
	463	0, /* tp_iter */
	464	0, /* tp_iternext */
	465	0, /* tp_methods */
	466	0, /* tp_members */
	467	finish_breakpoint_object_getset,/* tp_getset */
	468	&breakpoint_object_type, /* tp_base */
	469	0, /* tp_dict */
	470	0, /* tp_descr_get */
	471	0, /* tp_descr_set */
	472	0, /* tp_dictoffset */
	473	bpfinishpy_init, /* tp_init */
	474	0, /* tp_alloc */
	475	0 /* tp_new */
	476	};