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

/* Python interface to finish breakpoints

   Copyright (C) 2011-2022 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.Symbol object of the function finished by this breakpoint.

     nullptr if no debug information was available or return type was VOID.  */
  PyObject *func_symbol;

  /* gdb.Value object of the function finished by this breakpoint.

     nullptr if no debug information was available or return type was VOID.  */
  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->func_symbol);
  Py_XDECREF (self_bpfinish->function_value);
  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->func_symbol == nullptr)
    return;

  try
    {
      struct symbol *func_symbol =
	symbol_object_to_symbol (self_finishbp->func_symbol);
      struct value *function =
	value_object_to_value (self_finishbp->function_value);
      struct value *ret =
	get_return_value (func_symbol, function);

      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);
      bp_obj->bp->disposition = disp_del_at_next_stop;
    }
  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;
  frame_info_ptr frame = NULL; /* init for gcc -Wall */
  frame_info_ptr prev_frame = NULL;
  struct frame_id frame_id;
  PyObject *internal = NULL;
  int internal_bp = 0;
  CORE_ADDR pc;

  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);
	}
    }
  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->func_symbol = nullptr;
  self_bpfinish->function_value = nullptr;

  try
    {
      if (get_frame_pc_if_available (frame, &pc))
	{
	  struct symbol *function = find_pc_function (pc);
	  if (function != nullptr)
	    {
	      struct type *ret_type =
		check_typedef (function->type ()->target_type ());

	      /* Remember only non-void return types.  */
	      if (ret_type->code () != TYPE_CODE_VOID)
		{
		  /* Ignore Python errors at this stage.  */
		  value *func_value = read_var_value (function, NULL, frame);
		  self_bpfinish->function_value
		    = value_to_value_object (func_value);
		  PyErr_Clear ();

		  self_bpfinish->func_symbol
		    = symbol_to_symbol_object (function);
		  PyErr_Clear ();
		}
	    }
	}
    }
  catch (const gdb_exception &except)
    {
      /* Just swallow.  Either the return type or the function value
	 remain NULL.  */
    }

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

      self_bpfinish->func_symbol = nullptr;
      self_bpfinish->function_value = nullptr;
    }

  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.  */
      location_spec_up locspec
	= new_address_location_spec (get_frame_pc (prev_frame), NULL, 0);
      create_breakpoint (gdbpy_enter::get_gdbarch (),
			 locspec.get (), NULL, thread, NULL, false,
			 0,
			 1 /*temp_flag*/,
			 bp_breakpoint,
			 0,
			 AUTO_BOOLEAN_TRUE,
			 &code_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 void
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 ();
	    }
	}
    }
}

/* 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 bpstat *bs, int print_frame)
{
  gdbpy_enter enter_py;

  for (breakpoint *bp : all_breakpoints_safe ())
    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 ());

  for (breakpoint *bp : all_breakpoints_safe ())
    bpfinishpy_detect_out_scope_cb (bp, nullptr);
}

/* Initialize the Python finish breakpoint code.  */

int
gdbpy_initialize_finishbreakpoints (void)
{
  if (!gdbpy_breakpoint_init_breakpoint_type ())
    return -1;

  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,
				      "py-finishbreakpoint");
  gdb::observers::inferior_exit.attach (bpfinishpy_handle_exit,
					"py-finishbreakpoint");

  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
4a94e368	3	Copyright (C) 2011-2022 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;
e6b36367 LS	43
	44	/* gdb.Symbol object of the function finished by this breakpoint.
	45
	46	nullptr if no debug information was available or return type was VOID. */
	47	PyObject *func_symbol;
	48
	49	/* gdb.Value object of the function finished by this breakpoint.
	50
	51	nullptr if no debug information was available or return type was VOID. */
6a3a010b	52	PyObject *function_value;
e6b36367	53
cc72b2a2 KP	54	/* When stopped at this FinishBreakpoint, gdb.Value object returned by
	55	the function; Py_None if the value is not computable; NULL if GDB is
	56	not stopped at a FinishBreakpoint. */
	57	PyObject *return_value;
	58	};
	59
e36122e9	60	extern PyTypeObject finish_breakpoint_object_type
62eec1a5 TT	61	CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("finish_breakpoint_object");
62eec1a5 TT	62
cc72b2a2 KP	63	/* Python function to get the 'return_value' attribute of
	64	FinishBreakpoint. */
	65
	66	static PyObject *
	67	bpfinishpy_get_returnvalue (PyObject self, void closure)
	68	{
	69	struct finish_breakpoint_object *self_finishbp =
	70	(struct finish_breakpoint_object *) self;
	71
	72	if (!self_finishbp->return_value)
	73	Py_RETURN_NONE;
	74
	75	Py_INCREF (self_finishbp->return_value);
	76	return self_finishbp->return_value;
	77	}
	78
	79	/* Deallocate FinishBreakpoint object. */
	80
	81	static void
	82	bpfinishpy_dealloc (PyObject *self)
	83	{
	84	struct finish_breakpoint_object *self_bpfinish =
dda83cd7	85	(struct finish_breakpoint_object *) self;
cc72b2a2	86
e6b36367	87	Py_XDECREF (self_bpfinish->func_symbol);
6a3a010b	88	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2	89	Py_XDECREF (self_bpfinish->return_value);
2e953aca	90	Py_TYPE (self)->tp_free (self);
cc72b2a2 KP	91	}
	92
	93	/* Triggered when gdbpy_should_stop is about to execute the `stop' callback
	94	of the gdb.FinishBreakpoint object BP_OBJ. Will compute and cache the
	95	`return_value', if possible. */
	96
	97	void
4cb0213d	98	bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2 KP	99	{
cc72b2a2 KP	100	struct finish_breakpoint_object *self_finishbp =
dda83cd7	101	(struct finish_breakpoint_object *) bp_obj;
cc72b2a2 KP	102
	103	/* Can compute return_value only once. */
	104	gdb_assert (!self_finishbp->return_value);
	105
e6b36367	106	if (self_finishbp->func_symbol == nullptr)
cc72b2a2 KP	107	return;
cc72b2a2 KP	108
a70b8144	109	try
cc72b2a2	110	{
e6b36367 LS	111	struct symbol *func_symbol =
e6b36367 LS	112	symbol_object_to_symbol (self_finishbp->func_symbol);
6a3a010b	113	struct value *function =
dda83cd7	114	value_object_to_value (self_finishbp->function_value);
e6b36367 LS	115	struct value *ret =
e6b36367 LS	116	get_return_value (func_symbol, function);
cc72b2a2 KP	117
cc72b2a2 KP	118	if (ret)
dda83cd7 SM	119	{
	120	self_finishbp->return_value = value_to_value_object (ret);
	121	if (!self_finishbp->return_value)
	122	gdbpy_print_stack ();
	123	}
cc72b2a2	124	else
dda83cd7 SM	125	{
	126	Py_INCREF (Py_None);
	127	self_finishbp->return_value = Py_None;
	128	}
cc72b2a2	129	}
230d2906	130	catch (const gdb_exception &except)
cc72b2a2 KP	131	{
	132	gdbpy_convert_exception (except);
	133	gdbpy_print_stack ();
	134	}
	135	}
	136
	137	/* Triggered when gdbpy_should_stop has triggered the `stop' callback
	138	of the gdb.FinishBreakpoint object BP_OBJ. */
	139
	140	void
4cb0213d	141	bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2	142	{
cc72b2a2	143
a70b8144	144	try
cc72b2a2 KP	145	{
	146	/* Can't delete it here, but it will be removed at the next stop. */
	147	disable_breakpoint (bp_obj->bp);
6533cbee	148	bp_obj->bp->disposition = disp_del_at_next_stop;
cc72b2a2	149	}
230d2906	150	catch (const gdb_exception &except)
cc72b2a2 KP	151	{
	152	gdbpy_convert_exception (except);
	153	gdbpy_print_stack ();
	154	}
	155	}
	156
	157	/* Python function to create a new breakpoint. */
	158
	159	static int
	160	bpfinishpy_init (PyObject self, PyObject args, PyObject *kwargs)
	161	{
2adadf51	162	static const char *keywords[] = { "frame", "internal", NULL };
cc72b2a2 KP	163	struct finish_breakpoint_object *self_bpfinish =
cc72b2a2 KP	164	(struct finish_breakpoint_object *) self;
cc72b2a2 KP	165	PyObject *frame_obj = NULL;
cc72b2a2 KP	166	int thread;
bd2b40ac TT	167	frame_info_ptr frame = NULL; /* init for gcc -Wall */
bd2b40ac TT	168	frame_info_ptr 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	173
2adadf51 PA	174	if (!gdb_PyArg_ParseTupleAndKeywords (args, kwargs, "\|OO", keywords,
2adadf51 PA	175	&frame_obj, &internal))
cc72b2a2 KP	176	return -1;
cc72b2a2 KP	177
a70b8144	178	try
cc72b2a2	179	{
dd5fa3e7 TT	180	/* Default frame to newest frame if necessary. */
	181	if (frame_obj == NULL)
	182	frame = get_current_frame ();
cc72b2a2	183	else
dd5fa3e7 TT	184	frame = frame_object_to_frame_info (frame_obj);
	185
	186	if (frame == NULL)
	187	{
256458bc	188	PyErr_SetString (PyExc_ValueError,
dd5fa3e7 TT	189	_("Invalid ID for the `frame' object."));
	190	}
	191	else
	192	{
	193	prev_frame = get_prev_frame (frame);
	194	if (prev_frame == 0)
	195	{
	196	PyErr_SetString (PyExc_ValueError,
	197	_("\"FinishBreakpoint\" not "
	198	"meaningful in the outermost "
	199	"frame."));
	200	}
	201	else if (get_frame_type (prev_frame) == DUMMY_FRAME)
	202	{
	203	PyErr_SetString (PyExc_ValueError,
	204	_("\"FinishBreakpoint\" cannot "
	205	"be set on a dummy frame."));
	206	}
	207	else
04ea6b63	208	frame_id = get_frame_id (prev_frame);
dd5fa3e7	209	}
cc72b2a2	210	}
230d2906	211	catch (const gdb_exception &except)
cc72b2a2 KP	212	{
	213	gdbpy_convert_exception (except);
	214	return -1;
	215	}
492d29ea PA	216
492d29ea PA	217	if (PyErr_Occurred ())
cc72b2a2 KP	218	return -1;
cc72b2a2 KP	219
00431a78	220	if (inferior_ptid == null_ptid)
cc72b2a2 KP	221	{
cc72b2a2 KP	222	PyErr_SetString (PyExc_ValueError,
dda83cd7	223	_("No thread currently selected."));
cc72b2a2 KP	224	return -1;
	225	}
	226
00431a78 PA	227	thread = inferior_thread ()->global_num;
00431a78 PA	228
cc72b2a2 KP	229	if (internal)
	230	{
	231	internal_bp = PyObject_IsTrue (internal);
256458bc	232	if (internal_bp == -1)
dda83cd7 SM	233	{
	234	PyErr_SetString (PyExc_ValueError,
	235	_("The value of `internal' must be a boolean."));
	236	return -1;
	237	}
cc72b2a2 KP	238	}
	239
	240	/* Find the function we will return from. */
e6b36367 LS	241	self_bpfinish->func_symbol = nullptr;
e6b36367 LS	242	self_bpfinish->function_value = nullptr;
cc72b2a2	243
a70b8144	244	try
cc72b2a2 KP	245	{
cc72b2a2 KP	246	if (get_frame_pc_if_available (frame, &pc))
dda83cd7	247	{
e6b36367 LS	248	struct symbol *function = find_pc_function (pc);
e6b36367 LS	249	if (function != nullptr)
dda83cd7 SM	250	{
dda83cd7 SM	251	struct type *ret_type =
27710edb	252	check_typedef (function->type ()->target_type ());
cc72b2a2	253
dda83cd7 SM	254	/* Remember only non-void return types. */
	255	if (ret_type->code () != TYPE_CODE_VOID)
	256	{
dda83cd7	257	/* Ignore Python errors at this stage. */
e6b36367 LS	258	value *func_value = read_var_value (function, NULL, frame);
	259	self_bpfinish->function_value
	260	= value_to_value_object (func_value);
dda83cd7	261	PyErr_Clear ();
e6b36367 LS	262
	263	self_bpfinish->func_symbol
	264	= symbol_to_symbol_object (function);
dda83cd7 SM	265	PyErr_Clear ();
	266	}
	267	}
	268	}
cc72b2a2	269	}
230d2906	270	catch (const gdb_exception &except)
7556d4a4 PA	271	{
	272	/* Just swallow. Either the return type or the function value
	273	remain NULL. */
	274	}
	275
e6b36367 LS	276	if (self_bpfinish->func_symbol == nullptr
e6b36367 LS	277	\|\| self_bpfinish->function_value == nullptr)
cc72b2a2 KP	278	{
cc72b2a2 KP	279	/* Won't be able to compute return value. */
e6b36367	280	Py_XDECREF (self_bpfinish->func_symbol);
6a3a010b	281	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2	282
e6b36367 LS	283	self_bpfinish->func_symbol = nullptr;
e6b36367 LS	284	self_bpfinish->function_value = nullptr;
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. */
264f9890 PA	294	location_spec_up locspec
264f9890 PA	295	= new_address_location_spec (get_frame_pc (prev_frame), NULL, 0);
1da5d0e6	296	create_breakpoint (gdbpy_enter::get_gdbarch (),
264f9890	297	locspec.get (), NULL, thread, NULL, false,
dda83cd7 SM	298	0,
	299	1 /temp_flag/,
	300	bp_breakpoint,
	301	0,
	302	AUTO_BOOLEAN_TRUE,
74421c0b	303	&code_breakpoint_ops,
dda83cd7	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
240edef6	345	static void
95da600f CB	346	bpfinishpy_detect_out_scope_cb (struct breakpoint *b,
95da600f CB	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 =
dda83cd7	356	(struct finish_breakpoint_object *) py_bp;
cc72b2a2 KP	357
	358	/* Check scope if not currently stopped at the FinishBreakpoint. */
	359	if (b != bp_stopped)
dda83cd7 SM	360	{
	361	try
	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	}
	368	catch (const gdb_exception &except)
	369	{
	370	gdbpy_convert_exception (except);
	371	gdbpy_print_stack ();
	372	}
	373	}
cc72b2a2	374	}
cc72b2a2 KP	375	}
	376
	377	/* Attached to `stop' notifications, check if the execution has run
	378	out of the scope of any FinishBreakpoint before it has been hit. */
	379
	380	static void
313f3b21	381	bpfinishpy_handle_stop (struct bpstat *bs, int print_frame)
cc72b2a2	382	{
1da5d0e6	383	gdbpy_enter enter_py;
cc72b2a2	384
240edef6 SM	385	for (breakpoint *bp : all_breakpoints_safe ())
240edef6 SM	386	bpfinishpy_detect_out_scope_cb (bp, bs == NULL ? NULL : bs->breakpoint_at);
cc72b2a2 KP	387	}
	388
	389	/* Attached to `exit' notifications, triggers all the necessary out of
	390	scope notifications. */
	391
	392	static void
	393	bpfinishpy_handle_exit (struct inferior *inf)
	394	{
1da5d0e6	395	gdbpy_enter enter_py (target_gdbarch ());
cc72b2a2	396
240edef6 SM	397	for (breakpoint *bp : all_breakpoints_safe ())
240edef6 SM	398	bpfinishpy_detect_out_scope_cb (bp, nullptr);
cc72b2a2 KP	399	}
	400
	401	/* Initialize the Python finish breakpoint code. */
	402
999633ed	403	int
cc72b2a2 KP	404	gdbpy_initialize_finishbreakpoints (void)
cc72b2a2 KP	405	{
8a3b1706 AB	406	if (!gdbpy_breakpoint_init_breakpoint_type ())
	407	return -1;
	408
cc72b2a2	409	if (PyType_Ready (&finish_breakpoint_object_type) < 0)
999633ed	410	return -1;
256458bc	411
aa36459a TT	412	if (gdb_pymodule_addobject (gdb_module, "FinishBreakpoint",
aa36459a TT	413	(PyObject *) &finish_breakpoint_object_type) < 0)
999633ed	414	return -1;
256458bc	415
c90e7d63 SM	416	gdb::observers::normal_stop.attach (bpfinishpy_handle_stop,
	417	"py-finishbreakpoint");
	418	gdb::observers::inferior_exit.attach (bpfinishpy_handle_exit,
	419	"py-finishbreakpoint");
999633ed TT	420
999633ed TT	421	return 0;
cc72b2a2 KP	422	}
cc72b2a2 KP	423
0d1f4ceb	424	static gdb_PyGetSetDef finish_breakpoint_object_getset[] = {
cc72b2a2 KP	425	{ "return_value", bpfinishpy_get_returnvalue, NULL,
	426	"gdb.Value object representing the return value, if any. \
	427	None otherwise.", NULL },
	428	{ NULL } /* Sentinel. */
	429	};
	430
e36122e9	431	PyTypeObject finish_breakpoint_object_type =
cc72b2a2	432	{
9a27f2c6	433	PyVarObject_HEAD_INIT (NULL, 0)
cc72b2a2 KP	434	"gdb.FinishBreakpoint", /tp_name/
	435	sizeof (struct finish_breakpoint_object), /tp_basicsize/
	436	0, /tp_itemsize/
	437	bpfinishpy_dealloc, /tp_dealloc/
	438	0, /tp_print/
	439	0, /tp_getattr/
	440	0, /tp_setattr/
	441	0, /tp_compare/
	442	0, /tp_repr/
	443	0, /tp_as_number/
	444	0, /tp_as_sequence/
	445	0, /tp_as_mapping/
	446	0, /tp_hash /
	447	0, /tp_call/
	448	0, /tp_str/
	449	0, /tp_getattro/
	450	0, /tp_setattro /
	451	0, /tp_as_buffer/
	452	Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_BASETYPE, /tp_flags/
	453	"GDB finish breakpoint object", /* tp_doc */
	454	0, /* tp_traverse */
	455	0, /* tp_clear */
	456	0, /* tp_richcompare */
	457	0, /* tp_weaklistoffset */
	458	0, /* tp_iter */
	459	0, /* tp_iternext */
	460	0, /* tp_methods */
	461	0, /* tp_members */
	462	finish_breakpoint_object_getset,/* tp_getset */
	463	&breakpoint_object_type, /* tp_base */
	464	0, /* tp_dict */
	465	0, /* tp_descr_get */
	466	0, /* tp_descr_set */
	467	0, /* tp_dictoffset */
	468	bpfinishpy_init, /* tp_init */
	469	0, /* tp_alloc */
	470	0 /* tp_new */
	471	};