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

/* Python interface to finish breakpoints

   Copyright (C) 2011-2020 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 "observable.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 const char 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);
  Py_TYPE (self)->tp_free (self);
}

/* 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 (const gdb_exception &except)
    {
      gdbpy_convert_exception (except);
      gdbpy_print_stack ();
    }
}

/* 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 (const gdb_exception &except)
    {
      gdbpy_convert_exception (except);
      gdbpy_print_stack ();
    }
}

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

static int
bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
{
  static const 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 (!gdb_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 (const gdb_exception &except)
    {
      gdbpy_convert_exception (except);
      return -1;
    }

  if (PyErr_Occurred ())
    return -1;

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

  thread = inferior_thread ()->global_num;

  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 =
		check_typedef (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 (const gdb_exception &except)
    {
      /* Just swallow.  Either the return type or the function value
	 remain NULL.  */
    }

  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
    {
      /* Set a breakpoint on the return address.  */
      event_location_up location
	= new_address_location (get_frame_pc (prev_frame), NULL, 0);
      create_breakpoint (python_gdbarch,
                         location.get (), NULL, thread, NULL,
                         0,
                         1 /*temp_flag*/,
                         bp_breakpoint,
                         0,
                         AUTO_BOOLEAN_TRUE,
                         &bkpt_breakpoint_ops,
                         0, 1, internal_bp, 0);
    }
  catch (const gdb_exception &except)
    {
      GDB_PY_SET_HANDLE_EXCEPTION (except);
    }

  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 bool
bpfinishpy_detect_out_scope_cb (struct breakpoint *b,
				struct breakpoint *bp_stopped)
{
  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 (const gdb_exception &except)
            {
              gdbpy_convert_exception (except);
              gdbpy_print_stack ();
            }
        }
    }

  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 ([&] (breakpoint *bp)
    {
      return bpfinishpy_detect_out_scope_cb
	(bp, 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 ([&] (breakpoint *bp)
    {
      return bpfinishpy_detect_out_scope_cb (bp, nullptr);
    });
}

/* 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;

  gdb::observers::normal_stop.attach (bpfinishpy_handle_stop);
  gdb::observers::inferior_exit.attach (bpfinishpy_handle_exit);

  return 0;
}

static gdb_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
b811d2c2	3	Copyright (C) 2011-2020 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"
76727919	29	#include "observable.h"
cc72b2a2	30	#include "inferior.h"
6a3a010b	31	#include "block.h"
f00aae0f	32	#include "location.h"
cc72b2a2	33
cc72b2a2	34	/* Function that is called when a Python finish bp is found out of scope. */
a121b7c1	35	static const char outofscope_func[] = "out_of_scope";
cc72b2a2 KP	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);
cc72b2a2 KP	85	Py_XDECREF (self_bpfinish->return_value);
2e953aca	86	Py_TYPE (self)->tp_free (self);
cc72b2a2 KP	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
a70b8144	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	}
230d2906	125	catch (const gdb_exception &except)
cc72b2a2 KP	126	{
	127	gdbpy_convert_exception (except);
	128	gdbpy_print_stack ();
	129	}
	130	}
	131
	132	/* Triggered when gdbpy_should_stop has triggered the `stop' callback
	133	of the gdb.FinishBreakpoint object BP_OBJ. */
	134
	135	void
4cb0213d	136	bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2	137	{
cc72b2a2	138
a70b8144	139	try
cc72b2a2 KP	140	{
	141	/* Can't delete it here, but it will be removed at the next stop. */
	142	disable_breakpoint (bp_obj->bp);
	143	gdb_assert (bp_obj->bp->disposition == disp_del);
	144	}
230d2906	145	catch (const gdb_exception &except)
cc72b2a2 KP	146	{
	147	gdbpy_convert_exception (except);
	148	gdbpy_print_stack ();
	149	}
	150	}
	151
	152	/* Python function to create a new breakpoint. */
	153
	154	static int
	155	bpfinishpy_init (PyObject self, PyObject args, PyObject *kwargs)
	156	{
2adadf51	157	static const char *keywords[] = { "frame", "internal", NULL };
cc72b2a2 KP	158	struct finish_breakpoint_object *self_bpfinish =
cc72b2a2 KP	159	(struct finish_breakpoint_object *) self;
cc72b2a2 KP	160	PyObject *frame_obj = NULL;
cc72b2a2 KP	161	int thread;
62d7fb51 DE	162	struct frame_info frame = NULL; / init for gcc -Wall */
62d7fb51 DE	163	struct frame_info *prev_frame = NULL;
cc72b2a2 KP	164	struct frame_id frame_id;
	165	PyObject *internal = NULL;
	166	int internal_bp = 0;
a06efdd6	167	CORE_ADDR pc;
cc72b2a2 KP	168	struct symbol *function;
cc72b2a2 KP	169
2adadf51 PA	170	if (!gdb_PyArg_ParseTupleAndKeywords (args, kwargs, "\|OO", keywords,
2adadf51 PA	171	&frame_obj, &internal))
cc72b2a2 KP	172	return -1;
cc72b2a2 KP	173
a70b8144	174	try
cc72b2a2	175	{
dd5fa3e7 TT	176	/* Default frame to newest frame if necessary. */
	177	if (frame_obj == NULL)
	178	frame = get_current_frame ();
cc72b2a2	179	else
dd5fa3e7 TT	180	frame = frame_object_to_frame_info (frame_obj);
	181
	182	if (frame == NULL)
	183	{
256458bc	184	PyErr_SetString (PyExc_ValueError,
dd5fa3e7 TT	185	_("Invalid ID for the `frame' object."));
	186	}
	187	else
	188	{
	189	prev_frame = get_prev_frame (frame);
	190	if (prev_frame == 0)
	191	{
	192	PyErr_SetString (PyExc_ValueError,
	193	_("\"FinishBreakpoint\" not "
	194	"meaningful in the outermost "
	195	"frame."));
	196	}
	197	else if (get_frame_type (prev_frame) == DUMMY_FRAME)
	198	{
	199	PyErr_SetString (PyExc_ValueError,
	200	_("\"FinishBreakpoint\" cannot "
	201	"be set on a dummy frame."));
	202	}
	203	else
	204	{
	205	frame_id = get_frame_id (prev_frame);
	206	if (frame_id_eq (frame_id, null_frame_id))
	207	PyErr_SetString (PyExc_ValueError,
	208	_("Invalid ID for the `frame' object."));
	209	}
	210	}
cc72b2a2	211	}
230d2906	212	catch (const gdb_exception &except)
cc72b2a2 KP	213	{
	214	gdbpy_convert_exception (except);
	215	return -1;
	216	}
492d29ea PA	217
492d29ea PA	218	if (PyErr_Occurred ())
cc72b2a2 KP	219	return -1;
cc72b2a2 KP	220
00431a78	221	if (inferior_ptid == null_ptid)
cc72b2a2 KP	222	{
	223	PyErr_SetString (PyExc_ValueError,
	224	_("No thread currently selected."));
	225	return -1;
	226	}
	227
00431a78 PA	228	thread = inferior_thread ()->global_num;
00431a78 PA	229
cc72b2a2 KP	230	if (internal)
	231	{
	232	internal_bp = PyObject_IsTrue (internal);
256458bc	233	if (internal_bp == -1)
cc72b2a2	234	{
256458bc	235	PyErr_SetString (PyExc_ValueError,
cc72b2a2 KP	236	_("The value of `internal' must be a boolean."));
	237	return -1;
	238	}
	239	}
	240
	241	/* Find the function we will return from. */
	242	self_bpfinish->return_type = NULL;
6a3a010b	243	self_bpfinish->function_value = NULL;
cc72b2a2	244
a70b8144	245	try
cc72b2a2 KP	246	{
	247	if (get_frame_pc_if_available (frame, &pc))
	248	{
	249	function = find_pc_function (pc);
	250	if (function != NULL)
	251	{
	252	struct type *ret_type =
f097f5ad	253	check_typedef (TYPE_TARGET_TYPE (SYMBOL_TYPE (function)));
cc72b2a2 KP	254
	255	/* Remember only non-void return types. */
	256	if (TYPE_CODE (ret_type) != TYPE_CODE_VOID)
	257	{
6a3a010b MR	258	struct value *func_value;
6a3a010b MR	259
cc72b2a2 KP	260	/* Ignore Python errors at this stage. */
	261	self_bpfinish->return_type = type_to_type_object (ret_type);
	262	PyErr_Clear ();
63e43d3a	263	func_value = read_var_value (function, NULL, frame);
6a3a010b MR	264	self_bpfinish->function_value =
6a3a010b MR	265	value_to_value_object (func_value);
cc72b2a2 KP	266	PyErr_Clear ();
	267	}
	268	}
	269	}
	270	}
230d2906	271	catch (const gdb_exception &except)
7556d4a4 PA	272	{
	273	/* Just swallow. Either the return type or the function value
	274	remain NULL. */
	275	}
	276
	277	if (self_bpfinish->return_type == NULL \|\| self_bpfinish->function_value == NULL)
cc72b2a2 KP	278	{
	279	/* Won't be able to compute return value. */
	280	Py_XDECREF (self_bpfinish->return_type);
6a3a010b	281	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2 KP	282
cc72b2a2 KP	283	self_bpfinish->return_type = NULL;
6a3a010b	284	self_bpfinish->function_value = NULL;
cc72b2a2 KP	285	}
	286
	287	bppy_pending_object = &self_bpfinish->py_bp;
	288	bppy_pending_object->number = -1;
	289	bppy_pending_object->bp = NULL;
	290
a70b8144	291	try
cc72b2a2 KP	292	{
cc72b2a2 KP	293	/* Set a breakpoint on the return address. */
ffc2605c TT	294	event_location_up location
ffc2605c TT	295	= new_address_location (get_frame_pc (prev_frame), NULL, 0);
cc72b2a2	296	create_breakpoint (python_gdbarch,
ffc2605c	297	location.get (), NULL, thread, NULL,
cc72b2a2 KP	298	0,
	299	1 /temp_flag/,
	300	bp_breakpoint,
	301	0,
	302	AUTO_BOOLEAN_TRUE,
	303	&bkpt_breakpoint_ops,
44f238bb	304	0, 1, internal_bp, 0);
cc72b2a2	305	}
230d2906	306	catch (const gdb_exception &except)
492d29ea PA	307	{
	308	GDB_PY_SET_HANDLE_EXCEPTION (except);
	309	}
256458bc	310
cc72b2a2 KP	311	self_bpfinish->py_bp.bp->frame_id = frame_id;
cc72b2a2 KP	312	self_bpfinish->py_bp.is_finish_bp = 1;
256458bc	313
cc72b2a2 KP	314	/* Bind the breakpoint with the current program space. */
	315	self_bpfinish->py_bp.bp->pspace = current_program_space;
	316
	317	return 0;
cc72b2a2 KP	318	}
	319
	320	/* Called when GDB notices that the finish breakpoint BP_OBJ is out of
	321	the current callstack. Triggers the method OUT_OF_SCOPE if implemented,
	322	then delete the breakpoint. */
	323
	324	static void
	325	bpfinishpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj)
	326	{
4cb0213d	327	gdbpy_breakpoint_object bp_obj = (gdbpy_breakpoint_object ) bpfinish_obj;
cc72b2a2 KP	328	PyObject py_obj = (PyObject ) bp_obj;
	329
	330	if (bpfinish_obj->py_bp.bp->enable_state == bp_enabled
	331	&& PyObject_HasAttrString (py_obj, outofscope_func))
	332	{
7780f186 TT	333	gdbpy_ref<> meth_result (PyObject_CallMethod (py_obj, outofscope_func,
7780f186 TT	334	NULL));
18868860 TT	335	if (meth_result == NULL)
18868860 TT	336	gdbpy_print_stack ();
cc72b2a2 KP	337	}
	338
	339	delete_breakpoint (bpfinish_obj->py_bp.bp);
	340	}
	341
	342	/* Callback for `bpfinishpy_detect_out_scope'. Triggers Python's
	343	`B->out_of_scope' function if B is a FinishBreakpoint out of its scope. */
	344
95da600f CB	345	static bool
	346	bpfinishpy_detect_out_scope_cb (struct breakpoint *b,
	347	struct breakpoint *bp_stopped)
cc72b2a2	348	{
cc72b2a2	349	PyObject py_bp = (PyObject ) b->py_bp_object;
256458bc	350
cc72b2a2 KP	351	/* Trigger out_of_scope if this is a FinishBreakpoint and its frame is
	352	not anymore in the current callstack. */
	353	if (py_bp != NULL && b->py_bp_object->is_finish_bp)
	354	{
	355	struct finish_breakpoint_object *finish_bp =
	356	(struct finish_breakpoint_object *) py_bp;
	357
	358	/* Check scope if not currently stopped at the FinishBreakpoint. */
	359	if (b != bp_stopped)
	360	{
a70b8144	361	try
cc72b2a2 KP	362	{
	363	if (b->pspace == current_inferior ()->pspace
	364	&& (!target_has_registers
	365	\|\| frame_find_by_id (b->frame_id) == NULL))
	366	bpfinishpy_out_of_scope (finish_bp);
	367	}
230d2906	368	catch (const gdb_exception &except)
cc72b2a2 KP	369	{
	370	gdbpy_convert_exception (except);
	371	gdbpy_print_stack ();
	372	}
	373	}
	374	}
	375
	376	return 0;
	377	}
	378
	379	/* Attached to `stop' notifications, check if the execution has run
	380	out of the scope of any FinishBreakpoint before it has been hit. */
	381
	382	static void
	383	bpfinishpy_handle_stop (struct bpstats *bs, int print_frame)
	384	{
6e7c365e	385	gdbpy_enter enter_py (get_current_arch (), current_language);
cc72b2a2	386
95da600f CB	387	iterate_over_breakpoints ([&] (breakpoint *bp)
	388	{
	389	return bpfinishpy_detect_out_scope_cb
	390	(bp, bs == NULL ? NULL : bs->breakpoint_at);
	391	});
cc72b2a2 KP	392	}
	393
	394	/* Attached to `exit' notifications, triggers all the necessary out of
	395	scope notifications. */
	396
	397	static void
	398	bpfinishpy_handle_exit (struct inferior *inf)
	399	{
6e7c365e	400	gdbpy_enter enter_py (target_gdbarch (), current_language);
cc72b2a2	401
95da600f CB	402	iterate_over_breakpoints ([&] (breakpoint *bp)
	403	{
	404	return bpfinishpy_detect_out_scope_cb (bp, nullptr);
	405	});
cc72b2a2 KP	406	}
	407
	408	/* Initialize the Python finish breakpoint code. */
	409
999633ed	410	int
cc72b2a2 KP	411	gdbpy_initialize_finishbreakpoints (void)
	412	{
	413	if (PyType_Ready (&finish_breakpoint_object_type) < 0)
999633ed	414	return -1;
256458bc	415
aa36459a TT	416	if (gdb_pymodule_addobject (gdb_module, "FinishBreakpoint",
aa36459a TT	417	(PyObject *) &finish_breakpoint_object_type) < 0)
999633ed	418	return -1;
256458bc	419
76727919 TT	420	gdb::observers::normal_stop.attach (bpfinishpy_handle_stop);
76727919 TT	421	gdb::observers::inferior_exit.attach (bpfinishpy_handle_exit);
999633ed TT	422
999633ed TT	423	return 0;
cc72b2a2 KP	424	}
cc72b2a2 KP	425
0d1f4ceb	426	static gdb_PyGetSetDef finish_breakpoint_object_getset[] = {
cc72b2a2 KP	427	{ "return_value", bpfinishpy_get_returnvalue, NULL,
	428	"gdb.Value object representing the return value, if any. \
	429	None otherwise.", NULL },
	430	{ NULL } /* Sentinel. */
	431	};
	432
e36122e9	433	PyTypeObject finish_breakpoint_object_type =
cc72b2a2	434	{
9a27f2c6	435	PyVarObject_HEAD_INIT (NULL, 0)
cc72b2a2 KP	436	"gdb.FinishBreakpoint", /tp_name/
	437	sizeof (struct finish_breakpoint_object), /tp_basicsize/
	438	0, /tp_itemsize/
	439	bpfinishpy_dealloc, /tp_dealloc/
	440	0, /tp_print/
	441	0, /tp_getattr/
	442	0, /tp_setattr/
	443	0, /tp_compare/
	444	0, /tp_repr/
	445	0, /tp_as_number/
	446	0, /tp_as_sequence/
	447	0, /tp_as_mapping/
	448	0, /tp_hash /
	449	0, /tp_call/
	450	0, /tp_str/
	451	0, /tp_getattro/
	452	0, /tp_setattro /
	453	0, /tp_as_buffer/
	454	Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_BASETYPE, /tp_flags/
	455	"GDB finish breakpoint object", /* tp_doc */
	456	0, /* tp_traverse */
	457	0, /* tp_clear */
	458	0, /* tp_richcompare */
	459	0, /* tp_weaklistoffset */
	460	0, /* tp_iter */
	461	0, /* tp_iternext */
	462	0, /* tp_methods */
	463	0, /* tp_members */
	464	finish_breakpoint_object_getset,/* tp_getset */
	465	&breakpoint_object_type, /* tp_base */
	466	0, /* tp_dict */
	467	0, /* tp_descr_get */
	468	0, /* tp_descr_set */
	469	0, /* tp_dictoffset */
	470	bpfinishpy_init, /* tp_init */
	471	0, /* tp_alloc */
	472	0 /* tp_new */
	473	};