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

/* Python interface to finish breakpoints

   Copyright (C) 2011-2015 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"

/* 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);

      /* bpfinishpy_init cannot finish into DUMMY_FRAME (throws an error
         in such case) so it is OK to always pass CTX_SAVER as NULL.  */
      struct value *ret = get_return_value (function, value_type, NULL);

      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;
  int type = bp_breakpoint;
  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 = pid_to_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, 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));
      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))
    {
      PyObject *meth_result;

      meth_result = PyObject_CallMethod (py_obj, outofscope_func, NULL);
      if (meth_result == NULL)
	gdbpy_print_stack ();
      Py_XDECREF (meth_result);
    }

  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;
  struct gdbarch *garch = b->gdbarch ? b->gdbarch : get_current_arch ();

  /* 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)
{
  struct cleanup *cleanup = ensure_python_env (get_current_arch (),
                                               current_language);

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

  do_cleanups (cleanup);
}

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

static void
bpfinishpy_handle_exit (struct inferior *inf)
{
  struct cleanup *cleanup = ensure_python_env (target_gdbarch (),
                                               current_language);

  iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, NULL);

  do_cleanups (cleanup);
}

/* 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
32d0add0	3	Copyright (C) 2011-2015 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"
cc72b2a2	33
cc72b2a2 KP	34	/* Function that is called when a Python finish bp is found out of scope. */
	35	static char * const outofscope_func = "out_of_scope";
	36
	37	/* struct implementing the gdb.FinishBreakpoint object by extending
	38	the gdb.Breakpoint class. */
	39	struct finish_breakpoint_object
	40	{
	41	/* gdb.Breakpoint base class. */
4cb0213d	42	gdbpy_breakpoint_object py_bp;
cc72b2a2 KP	43	/* gdb.Type object of the value return by the breakpointed function.
	44	May be NULL if no debug information was available or return type
	45	was VOID. */
	46	PyObject *return_type;
6a3a010b	47	/* gdb.Value object of the function finished by this breakpoint. Will be
cc72b2a2	48	NULL if return_type is NULL. */
6a3a010b	49	PyObject *function_value;
cc72b2a2 KP	50	/* When stopped at this FinishBreakpoint, gdb.Value object returned by
	51	the function; Py_None if the value is not computable; NULL if GDB is
	52	not stopped at a FinishBreakpoint. */
	53	PyObject *return_value;
	54	};
	55
e36122e9	56	extern PyTypeObject finish_breakpoint_object_type
62eec1a5 TT	57	CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("finish_breakpoint_object");
62eec1a5 TT	58
cc72b2a2 KP	59	/* Python function to get the 'return_value' attribute of
	60	FinishBreakpoint. */
	61
	62	static PyObject *
	63	bpfinishpy_get_returnvalue (PyObject self, void closure)
	64	{
	65	struct finish_breakpoint_object *self_finishbp =
	66	(struct finish_breakpoint_object *) self;
	67
	68	if (!self_finishbp->return_value)
	69	Py_RETURN_NONE;
	70
	71	Py_INCREF (self_finishbp->return_value);
	72	return self_finishbp->return_value;
	73	}
	74
	75	/* Deallocate FinishBreakpoint object. */
	76
	77	static void
	78	bpfinishpy_dealloc (PyObject *self)
	79	{
	80	struct finish_breakpoint_object *self_bpfinish =
	81	(struct finish_breakpoint_object *) self;
	82
6a3a010b	83	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2 KP	84	Py_XDECREF (self_bpfinish->return_type);
	85	Py_XDECREF (self_bpfinish->return_value);
	86	}
	87
	88	/* Triggered when gdbpy_should_stop is about to execute the `stop' callback
	89	of the gdb.FinishBreakpoint object BP_OBJ. Will compute and cache the
	90	`return_value', if possible. */
	91
	92	void
4cb0213d	93	bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2 KP	94	{
	95	struct finish_breakpoint_object *self_finishbp =
	96	(struct finish_breakpoint_object *) bp_obj;
cc72b2a2 KP	97
	98	/* Can compute return_value only once. */
	99	gdb_assert (!self_finishbp->return_value);
	100
	101	if (!self_finishbp->return_type)
	102	return;
	103
492d29ea	104	TRY
cc72b2a2	105	{
6a3a010b MR	106	struct value *function =
	107	value_object_to_value (self_finishbp->function_value);
	108	struct type *value_type =
	109	type_object_to_type (self_finishbp->return_type);
8a6c4031 JK	110
	111	/* bpfinishpy_init cannot finish into DUMMY_FRAME (throws an error
	112	in such case) so it is OK to always pass CTX_SAVER as NULL. */
	113	struct value *ret = get_return_value (function, value_type, NULL);
cc72b2a2 KP	114
	115	if (ret)
	116	{
	117	self_finishbp->return_value = value_to_value_object (ret);
	118	if (!self_finishbp->return_value)
	119	gdbpy_print_stack ();
	120	}
	121	else
	122	{
	123	Py_INCREF (Py_None);
	124	self_finishbp->return_value = Py_None;
	125	}
	126	}
492d29ea	127	CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	128	{
	129	gdbpy_convert_exception (except);
	130	gdbpy_print_stack ();
	131	}
492d29ea	132	END_CATCH
cc72b2a2 KP	133	}
	134
	135	/* Triggered when gdbpy_should_stop has triggered the `stop' callback
	136	of the gdb.FinishBreakpoint object BP_OBJ. */
	137
	138	void
4cb0213d	139	bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2	140	{
cc72b2a2	141
492d29ea	142	TRY
cc72b2a2 KP	143	{
	144	/* Can't delete it here, but it will be removed at the next stop. */
	145	disable_breakpoint (bp_obj->bp);
	146	gdb_assert (bp_obj->bp->disposition == disp_del);
	147	}
492d29ea	148	CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	149	{
	150	gdbpy_convert_exception (except);
	151	gdbpy_print_stack ();
	152	}
492d29ea	153	END_CATCH
cc72b2a2 KP	154	}
	155
	156	/* Python function to create a new breakpoint. */
	157
	158	static int
	159	bpfinishpy_init (PyObject self, PyObject args, PyObject *kwargs)
	160	{
	161	static char *keywords[] = { "frame", "internal", NULL };
	162	struct finish_breakpoint_object *self_bpfinish =
	163	(struct finish_breakpoint_object *) self;
	164	int type = bp_breakpoint;
	165	PyObject *frame_obj = NULL;
	166	int thread;
62d7fb51 DE	167	struct frame_info frame = NULL; / init for gcc -Wall */
62d7fb51 DE	168	struct frame_info *prev_frame = NULL;
cc72b2a2 KP	169	struct frame_id frame_id;
	170	PyObject *internal = NULL;
	171	int internal_bp = 0;
a06efdd6	172	CORE_ADDR pc;
cc72b2a2 KP	173	struct symbol *function;
	174
	175	if (!PyArg_ParseTupleAndKeywords (args, kwargs, "\|OO", keywords,
	176	&frame_obj, &internal))
	177	return -1;
	178
492d29ea	179	TRY
cc72b2a2	180	{
dd5fa3e7 TT	181	/* Default frame to newest frame if necessary. */
	182	if (frame_obj == NULL)
	183	frame = get_current_frame ();
cc72b2a2	184	else
dd5fa3e7 TT	185	frame = frame_object_to_frame_info (frame_obj);
	186
	187	if (frame == NULL)
	188	{
256458bc	189	PyErr_SetString (PyExc_ValueError,
dd5fa3e7 TT	190	_("Invalid ID for the `frame' object."));
	191	}
	192	else
	193	{
	194	prev_frame = get_prev_frame (frame);
	195	if (prev_frame == 0)
	196	{
	197	PyErr_SetString (PyExc_ValueError,
	198	_("\"FinishBreakpoint\" not "
	199	"meaningful in the outermost "
	200	"frame."));
	201	}
	202	else if (get_frame_type (prev_frame) == DUMMY_FRAME)
	203	{
	204	PyErr_SetString (PyExc_ValueError,
	205	_("\"FinishBreakpoint\" cannot "
	206	"be set on a dummy frame."));
	207	}
	208	else
	209	{
	210	frame_id = get_frame_id (prev_frame);
	211	if (frame_id_eq (frame_id, null_frame_id))
	212	PyErr_SetString (PyExc_ValueError,
	213	_("Invalid ID for the `frame' object."));
	214	}
	215	}
cc72b2a2	216	}
492d29ea	217	CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	218	{
	219	gdbpy_convert_exception (except);
	220	return -1;
	221	}
492d29ea PA	222	END_CATCH
	223
	224	if (PyErr_Occurred ())
cc72b2a2 KP	225	return -1;
	226
	227	thread = pid_to_thread_id (inferior_ptid);
	228	if (thread == 0)
	229	{
	230	PyErr_SetString (PyExc_ValueError,
	231	_("No thread currently selected."));
	232	return -1;
	233	}
	234
	235	if (internal)
	236	{
	237	internal_bp = PyObject_IsTrue (internal);
256458bc	238	if (internal_bp == -1)
cc72b2a2	239	{
256458bc	240	PyErr_SetString (PyExc_ValueError,
cc72b2a2 KP	241	_("The value of `internal' must be a boolean."));
	242	return -1;
	243	}
	244	}
	245
	246	/* Find the function we will return from. */
	247	self_bpfinish->return_type = NULL;
6a3a010b	248	self_bpfinish->function_value = NULL;
cc72b2a2	249
492d29ea	250	TRY
cc72b2a2 KP	251	{
	252	if (get_frame_pc_if_available (frame, &pc))
	253	{
	254	function = find_pc_function (pc);
	255	if (function != NULL)
	256	{
	257	struct type *ret_type =
	258	TYPE_TARGET_TYPE (SYMBOL_TYPE (function));
	259
	260	/* Remember only non-void return types. */
	261	if (TYPE_CODE (ret_type) != TYPE_CODE_VOID)
	262	{
6a3a010b MR	263	struct value *func_value;
6a3a010b MR	264
cc72b2a2 KP	265	/* Ignore Python errors at this stage. */
	266	self_bpfinish->return_type = type_to_type_object (ret_type);
	267	PyErr_Clear ();
6a3a010b MR	268	func_value = read_var_value (function, frame);
	269	self_bpfinish->function_value =
	270	value_to_value_object (func_value);
cc72b2a2 KP	271	PyErr_Clear ();
	272	}
	273	}
	274	}
	275	}
492d29ea	276	CATCH (except, RETURN_MASK_ALL)
7556d4a4 PA	277	{
	278	/* Just swallow. Either the return type or the function value
	279	remain NULL. */
	280	}
492d29ea	281	END_CATCH
7556d4a4 PA	282
7556d4a4 PA	283	if (self_bpfinish->return_type == NULL \|\| self_bpfinish->function_value == NULL)
cc72b2a2 KP	284	{
	285	/* Won't be able to compute return value. */
	286	Py_XDECREF (self_bpfinish->return_type);
6a3a010b	287	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2 KP	288
cc72b2a2 KP	289	self_bpfinish->return_type = NULL;
6a3a010b	290	self_bpfinish->function_value = NULL;
cc72b2a2 KP	291	}
	292
	293	bppy_pending_object = &self_bpfinish->py_bp;
	294	bppy_pending_object->number = -1;
	295	bppy_pending_object->bp = NULL;
	296
492d29ea	297	TRY
cc72b2a2	298	{
f00aae0f KS	299	struct event_location *location;
	300	struct cleanup *back_to;
	301
cc72b2a2	302	/* Set a breakpoint on the return address. */
a06efdd6	303	location = new_address_location (get_frame_pc (prev_frame));
f00aae0f	304	back_to = make_cleanup_delete_event_location (location);
cc72b2a2	305	create_breakpoint (python_gdbarch,
f00aae0f	306	location, NULL, thread, NULL,
cc72b2a2 KP	307	0,
	308	1 /temp_flag/,
	309	bp_breakpoint,
	310	0,
	311	AUTO_BOOLEAN_TRUE,
	312	&bkpt_breakpoint_ops,
44f238bb	313	0, 1, internal_bp, 0);
f00aae0f	314	do_cleanups (back_to);
cc72b2a2	315	}
492d29ea PA	316	CATCH (except, RETURN_MASK_ALL)
	317	{
	318	GDB_PY_SET_HANDLE_EXCEPTION (except);
	319	}
	320	END_CATCH
256458bc	321
cc72b2a2 KP	322	self_bpfinish->py_bp.bp->frame_id = frame_id;
cc72b2a2 KP	323	self_bpfinish->py_bp.is_finish_bp = 1;
256458bc	324
cc72b2a2 KP	325	/* Bind the breakpoint with the current program space. */
	326	self_bpfinish->py_bp.bp->pspace = current_program_space;
	327
	328	return 0;
cc72b2a2 KP	329	}
	330
	331	/* Called when GDB notices that the finish breakpoint BP_OBJ is out of
	332	the current callstack. Triggers the method OUT_OF_SCOPE if implemented,
	333	then delete the breakpoint. */
	334
	335	static void
	336	bpfinishpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj)
	337	{
4cb0213d	338	gdbpy_breakpoint_object bp_obj = (gdbpy_breakpoint_object ) bpfinish_obj;
cc72b2a2 KP	339	PyObject py_obj = (PyObject ) bp_obj;
	340
	341	if (bpfinish_obj->py_bp.bp->enable_state == bp_enabled
	342	&& PyObject_HasAttrString (py_obj, outofscope_func))
	343	{
18868860 TT	344	PyObject *meth_result;
	345
	346	meth_result = PyObject_CallMethod (py_obj, outofscope_func, NULL);
	347	if (meth_result == NULL)
	348	gdbpy_print_stack ();
	349	Py_XDECREF (meth_result);
cc72b2a2 KP	350	}
	351
	352	delete_breakpoint (bpfinish_obj->py_bp.bp);
	353	}
	354
	355	/* Callback for `bpfinishpy_detect_out_scope'. Triggers Python's
	356	`B->out_of_scope' function if B is a FinishBreakpoint out of its scope. */
	357
	358	static int
	359	bpfinishpy_detect_out_scope_cb (struct breakpoint b, void args)
	360	{
cc72b2a2 KP	361	struct breakpoint bp_stopped = (struct breakpoint ) args;
	362	PyObject py_bp = (PyObject ) b->py_bp_object;
	363	struct gdbarch *garch = b->gdbarch ? b->gdbarch : get_current_arch ();
256458bc	364
cc72b2a2 KP	365	/* Trigger out_of_scope if this is a FinishBreakpoint and its frame is
	366	not anymore in the current callstack. */
	367	if (py_bp != NULL && b->py_bp_object->is_finish_bp)
	368	{
	369	struct finish_breakpoint_object *finish_bp =
	370	(struct finish_breakpoint_object *) py_bp;
	371
	372	/* Check scope if not currently stopped at the FinishBreakpoint. */
	373	if (b != bp_stopped)
	374	{
492d29ea	375	TRY
cc72b2a2 KP	376	{
	377	if (b->pspace == current_inferior ()->pspace
	378	&& (!target_has_registers
	379	\|\| frame_find_by_id (b->frame_id) == NULL))
	380	bpfinishpy_out_of_scope (finish_bp);
	381	}
492d29ea	382	CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	383	{
	384	gdbpy_convert_exception (except);
	385	gdbpy_print_stack ();
	386	}
492d29ea	387	END_CATCH
cc72b2a2 KP	388	}
	389	}
	390
	391	return 0;
	392	}
	393
	394	/* Attached to `stop' notifications, check if the execution has run
	395	out of the scope of any FinishBreakpoint before it has been hit. */
	396
	397	static void
	398	bpfinishpy_handle_stop (struct bpstats *bs, int print_frame)
	399	{
	400	struct cleanup *cleanup = ensure_python_env (get_current_arch (),
	401	current_language);
	402
	403	iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb,
	404	bs == NULL ? NULL : bs->breakpoint_at);
	405
	406	do_cleanups (cleanup);
	407	}
	408
	409	/* Attached to `exit' notifications, triggers all the necessary out of
	410	scope notifications. */
	411
	412	static void
	413	bpfinishpy_handle_exit (struct inferior *inf)
	414	{
f5656ead	415	struct cleanup *cleanup = ensure_python_env (target_gdbarch (),
cc72b2a2 KP	416	current_language);
	417
	418	iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, NULL);
	419
	420	do_cleanups (cleanup);
	421	}
	422
	423	/* Initialize the Python finish breakpoint code. */
	424
999633ed	425	int
cc72b2a2 KP	426	gdbpy_initialize_finishbreakpoints (void)
	427	{
	428	if (PyType_Ready (&finish_breakpoint_object_type) < 0)
999633ed	429	return -1;
256458bc	430
aa36459a TT	431	if (gdb_pymodule_addobject (gdb_module, "FinishBreakpoint",
aa36459a TT	432	(PyObject *) &finish_breakpoint_object_type) < 0)
999633ed	433	return -1;
256458bc	434
cc72b2a2 KP	435	observer_attach_normal_stop (bpfinishpy_handle_stop);
cc72b2a2 KP	436	observer_attach_inferior_exit (bpfinishpy_handle_exit);
999633ed TT	437
999633ed TT	438	return 0;
cc72b2a2 KP	439	}
	440
	441	static PyGetSetDef finish_breakpoint_object_getset[] = {
	442	{ "return_value", bpfinishpy_get_returnvalue, NULL,
	443	"gdb.Value object representing the return value, if any. \
	444	None otherwise.", NULL },
	445	{ NULL } /* Sentinel. */
	446	};
	447
e36122e9	448	PyTypeObject finish_breakpoint_object_type =
cc72b2a2	449	{
9a27f2c6	450	PyVarObject_HEAD_INIT (NULL, 0)
cc72b2a2 KP	451	"gdb.FinishBreakpoint", /tp_name/
	452	sizeof (struct finish_breakpoint_object), /tp_basicsize/
	453	0, /tp_itemsize/
	454	bpfinishpy_dealloc, /tp_dealloc/
	455	0, /tp_print/
	456	0, /tp_getattr/
	457	0, /tp_setattr/
	458	0, /tp_compare/
	459	0, /tp_repr/
	460	0, /tp_as_number/
	461	0, /tp_as_sequence/
	462	0, /tp_as_mapping/
	463	0, /tp_hash /
	464	0, /tp_call/
	465	0, /tp_str/
	466	0, /tp_getattro/
	467	0, /tp_setattro /
	468	0, /tp_as_buffer/
	469	Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_BASETYPE, /tp_flags/
	470	"GDB finish breakpoint object", /* tp_doc */
	471	0, /* tp_traverse */
	472	0, /* tp_clear */
	473	0, /* tp_richcompare */
	474	0, /* tp_weaklistoffset */
	475	0, /* tp_iter */
	476	0, /* tp_iternext */
	477	0, /* tp_methods */
	478	0, /* tp_members */
	479	finish_breakpoint_object_getset,/* tp_getset */
	480	&breakpoint_object_type, /* tp_base */
	481	0, /* tp_dict */
	482	0, /* tp_descr_get */
	483	0, /* tp_descr_set */
	484	0, /* tp_dictoffset */
	485	bpfinishpy_init, /* tp_init */
	486	0, /* tp_alloc */
	487	0 /* tp_new */
	488	};