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

/* Python interface to finish breakpoints

   Copyright (C) 2011-2014 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"

/* 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;
};

static 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;
  volatile struct gdb_exception except;

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

  if (!self_finishbp->return_type)
    return;

  TRY_CATCH (except, RETURN_MASK_ALL)
    {
      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;
        }
    }
  if (except.reason < 0)
    {
      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)
{
  volatile struct gdb_exception except;

  TRY_CATCH (except, RETURN_MASK_ALL)
    {
      /* 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);
    }
  if (except.reason < 0)
    {
      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 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 finish_pc, pc;
  volatile struct gdb_exception except;
  char *addr_str, small_buf[100];
  struct symbol *function;

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

  TRY_CATCH (except, RETURN_MASK_ALL)
    {
      /* 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."));
	    }
	}
    }
  if (except.reason < 0)
    {
      gdbpy_convert_exception (except);
      return -1;
    }
  else 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_CATCH (except, RETURN_MASK_ALL)
    {
      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 ();
                }
            }
        }
    }
  if (except.reason < 0
      || !self_bpfinish->return_type || !self_bpfinish->function_value)
    {
      /* 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_CATCH (except, RETURN_MASK_ALL)
    {
      /* Set a breakpoint on the return address.  */
      finish_pc = get_frame_pc (prev_frame);
      xsnprintf (small_buf, sizeof (small_buf), "*%s", hex_string (finish_pc));
      addr_str = small_buf;

      create_breakpoint (python_gdbarch,
                         addr_str, NULL, thread, NULL,
                         0,
                         1 /*temp_flag*/,
                         bp_breakpoint,
                         0,
                         AUTO_BOOLEAN_TRUE,
                         &bkpt_breakpoint_ops,
                         0, 1, internal_bp, 0);
    }
  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))
    {
      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)
{
  volatile struct gdb_exception except;
  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_CATCH (except, RETURN_MASK_ALL)
            {
              if (b->pspace == current_inferior ()->pspace
                  && (!target_has_registers
                      || frame_find_by_id (b->frame_id) == NULL))
                bpfinishpy_out_of_scope (finish_bp);
            }
          if (except.reason < 0)
            {
              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)
{
  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.  */
};

static 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
ecd75fc8	3	Copyright (C) 2011-2014 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"
cc72b2a2	32
cc72b2a2 KP	33	/* Function that is called when a Python finish bp is found out of scope. */
	34	static char * const outofscope_func = "out_of_scope";
	35
	36	/* struct implementing the gdb.FinishBreakpoint object by extending
	37	the gdb.Breakpoint class. */
	38	struct finish_breakpoint_object
	39	{
	40	/* gdb.Breakpoint base class. */
4cb0213d	41	gdbpy_breakpoint_object py_bp;
cc72b2a2 KP	42	/* gdb.Type object of the value return by the breakpointed function.
	43	May be NULL if no debug information was available or return type
	44	was VOID. */
	45	PyObject *return_type;
6a3a010b	46	/* gdb.Value object of the function finished by this breakpoint. Will be
cc72b2a2	47	NULL if return_type is NULL. */
6a3a010b	48	PyObject *function_value;
cc72b2a2 KP	49	/* When stopped at this FinishBreakpoint, gdb.Value object returned by
	50	the function; Py_None if the value is not computable; NULL if GDB is
	51	not stopped at a FinishBreakpoint. */
	52	PyObject *return_value;
	53	};
	54
62eec1a5 TT	55	static PyTypeObject finish_breakpoint_object_type
	56	CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("finish_breakpoint_object");
	57
cc72b2a2 KP	58	/* Python function to get the 'return_value' attribute of
	59	FinishBreakpoint. */
	60
	61	static PyObject *
	62	bpfinishpy_get_returnvalue (PyObject self, void closure)
	63	{
	64	struct finish_breakpoint_object *self_finishbp =
	65	(struct finish_breakpoint_object *) self;
	66
	67	if (!self_finishbp->return_value)
	68	Py_RETURN_NONE;
	69
	70	Py_INCREF (self_finishbp->return_value);
	71	return self_finishbp->return_value;
	72	}
	73
	74	/* Deallocate FinishBreakpoint object. */
	75
	76	static void
	77	bpfinishpy_dealloc (PyObject *self)
	78	{
	79	struct finish_breakpoint_object *self_bpfinish =
	80	(struct finish_breakpoint_object *) self;
	81
6a3a010b	82	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2 KP	83	Py_XDECREF (self_bpfinish->return_type);
	84	Py_XDECREF (self_bpfinish->return_value);
	85	}
	86
	87	/* Triggered when gdbpy_should_stop is about to execute the `stop' callback
	88	of the gdb.FinishBreakpoint object BP_OBJ. Will compute and cache the
	89	`return_value', if possible. */
	90
	91	void
4cb0213d	92	bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2 KP	93	{
	94	struct finish_breakpoint_object *self_finishbp =
	95	(struct finish_breakpoint_object *) bp_obj;
	96	volatile struct gdb_exception except;
	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
	104	TRY_CATCH (except, RETURN_MASK_ALL)
	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);
	110	struct value *ret = get_return_value (function, value_type);
cc72b2a2 KP	111
	112	if (ret)
	113	{
	114	self_finishbp->return_value = value_to_value_object (ret);
	115	if (!self_finishbp->return_value)
	116	gdbpy_print_stack ();
	117	}
	118	else
	119	{
	120	Py_INCREF (Py_None);
	121	self_finishbp->return_value = Py_None;
	122	}
	123	}
	124	if (except.reason < 0)
	125	{
	126	gdbpy_convert_exception (except);
	127	gdbpy_print_stack ();
	128	}
	129	}
	130
	131	/* Triggered when gdbpy_should_stop has triggered the `stop' callback
	132	of the gdb.FinishBreakpoint object BP_OBJ. */
	133
	134	void
4cb0213d	135	bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
cc72b2a2 KP	136	{
	137	volatile struct gdb_exception except;
	138
	139	TRY_CATCH (except, RETURN_MASK_ALL)
	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	}
	145	if (except.reason < 0)
	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	{
	157	static char *keywords[] = { "frame", "internal", NULL };
	158	struct finish_breakpoint_object *self_bpfinish =
	159	(struct finish_breakpoint_object *) self;
	160	int type = bp_breakpoint;
	161	PyObject *frame_obj = NULL;
	162	int thread;
62d7fb51 DE	163	struct frame_info frame = NULL; / init for gcc -Wall */
62d7fb51 DE	164	struct frame_info *prev_frame = NULL;
cc72b2a2 KP	165	struct frame_id frame_id;
	166	PyObject *internal = NULL;
	167	int internal_bp = 0;
	168	CORE_ADDR finish_pc, pc;
	169	volatile struct gdb_exception except;
	170	char *addr_str, small_buf[100];
	171	struct symbol *function;
	172
	173	if (!PyArg_ParseTupleAndKeywords (args, kwargs, "\|OO", keywords,
	174	&frame_obj, &internal))
	175	return -1;
	176
cc72b2a2 KP	177	TRY_CATCH (except, RETURN_MASK_ALL)
cc72b2a2 KP	178	{
dd5fa3e7 TT	179	/* Default frame to newest frame if necessary. */
	180	if (frame_obj == NULL)
	181	frame = get_current_frame ();
cc72b2a2	182	else
dd5fa3e7 TT	183	frame = frame_object_to_frame_info (frame_obj);
	184
	185	if (frame == NULL)
	186	{
256458bc	187	PyErr_SetString (PyExc_ValueError,
dd5fa3e7 TT	188	_("Invalid ID for the `frame' object."));
	189	}
	190	else
	191	{
	192	prev_frame = get_prev_frame (frame);
	193	if (prev_frame == 0)
	194	{
	195	PyErr_SetString (PyExc_ValueError,
	196	_("\"FinishBreakpoint\" not "
	197	"meaningful in the outermost "
	198	"frame."));
	199	}
	200	else if (get_frame_type (prev_frame) == DUMMY_FRAME)
	201	{
	202	PyErr_SetString (PyExc_ValueError,
	203	_("\"FinishBreakpoint\" cannot "
	204	"be set on a dummy frame."));
	205	}
	206	else
	207	{
	208	frame_id = get_frame_id (prev_frame);
	209	if (frame_id_eq (frame_id, null_frame_id))
	210	PyErr_SetString (PyExc_ValueError,
	211	_("Invalid ID for the `frame' object."));
	212	}
	213	}
cc72b2a2 KP	214	}
	215	if (except.reason < 0)
	216	{
	217	gdbpy_convert_exception (except);
	218	return -1;
	219	}
	220	else if (PyErr_Occurred ())
	221	return -1;
	222
	223	thread = pid_to_thread_id (inferior_ptid);
	224	if (thread == 0)
	225	{
	226	PyErr_SetString (PyExc_ValueError,
	227	_("No thread currently selected."));
	228	return -1;
	229	}
	230
	231	if (internal)
	232	{
	233	internal_bp = PyObject_IsTrue (internal);
256458bc	234	if (internal_bp == -1)
cc72b2a2	235	{
256458bc	236	PyErr_SetString (PyExc_ValueError,
cc72b2a2 KP	237	_("The value of `internal' must be a boolean."));
	238	return -1;
	239	}
	240	}
	241
	242	/* Find the function we will return from. */
	243	self_bpfinish->return_type = NULL;
6a3a010b	244	self_bpfinish->function_value = NULL;
cc72b2a2 KP	245
	246	TRY_CATCH (except, RETURN_MASK_ALL)
	247	{
	248	if (get_frame_pc_if_available (frame, &pc))
	249	{
	250	function = find_pc_function (pc);
	251	if (function != NULL)
	252	{
	253	struct type *ret_type =
	254	TYPE_TARGET_TYPE (SYMBOL_TYPE (function));
	255
	256	/* Remember only non-void return types. */
	257	if (TYPE_CODE (ret_type) != TYPE_CODE_VOID)
	258	{
6a3a010b MR	259	struct value *func_value;
6a3a010b MR	260
cc72b2a2 KP	261	/* Ignore Python errors at this stage. */
	262	self_bpfinish->return_type = type_to_type_object (ret_type);
	263	PyErr_Clear ();
6a3a010b MR	264	func_value = read_var_value (function, frame);
	265	self_bpfinish->function_value =
	266	value_to_value_object (func_value);
cc72b2a2 KP	267	PyErr_Clear ();
	268	}
	269	}
	270	}
	271	}
	272	if (except.reason < 0
6a3a010b	273	\|\| !self_bpfinish->return_type \|\| !self_bpfinish->function_value)
cc72b2a2 KP	274	{
	275	/* Won't be able to compute return value. */
	276	Py_XDECREF (self_bpfinish->return_type);
6a3a010b	277	Py_XDECREF (self_bpfinish->function_value);
cc72b2a2 KP	278
cc72b2a2 KP	279	self_bpfinish->return_type = NULL;
6a3a010b	280	self_bpfinish->function_value = NULL;
cc72b2a2 KP	281	}
	282
	283	bppy_pending_object = &self_bpfinish->py_bp;
	284	bppy_pending_object->number = -1;
	285	bppy_pending_object->bp = NULL;
	286
	287	TRY_CATCH (except, RETURN_MASK_ALL)
	288	{
	289	/* Set a breakpoint on the return address. */
	290	finish_pc = get_frame_pc (prev_frame);
41843fe8	291	xsnprintf (small_buf, sizeof (small_buf), "*%s", hex_string (finish_pc));
cc72b2a2 KP	292	addr_str = small_buf;
	293
	294	create_breakpoint (python_gdbarch,
e7e0cddf	295	addr_str, NULL, thread, NULL,
cc72b2a2 KP	296	0,
	297	1 /temp_flag/,
	298	bp_breakpoint,
	299	0,
	300	AUTO_BOOLEAN_TRUE,
	301	&bkpt_breakpoint_ops,
44f238bb	302	0, 1, internal_bp, 0);
cc72b2a2 KP	303	}
cc72b2a2 KP	304	GDB_PY_SET_HANDLE_EXCEPTION (except);
256458bc	305
cc72b2a2 KP	306	self_bpfinish->py_bp.bp->frame_id = frame_id;
cc72b2a2 KP	307	self_bpfinish->py_bp.is_finish_bp = 1;
256458bc	308
cc72b2a2 KP	309	/* Bind the breakpoint with the current program space. */
	310	self_bpfinish->py_bp.bp->pspace = current_program_space;
	311
	312	return 0;
cc72b2a2 KP	313	}
	314
	315	/* Called when GDB notices that the finish breakpoint BP_OBJ is out of
	316	the current callstack. Triggers the method OUT_OF_SCOPE if implemented,
	317	then delete the breakpoint. */
	318
	319	static void
	320	bpfinishpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj)
	321	{
4cb0213d	322	gdbpy_breakpoint_object bp_obj = (gdbpy_breakpoint_object ) bpfinish_obj;
cc72b2a2 KP	323	PyObject py_obj = (PyObject ) bp_obj;
	324
	325	if (bpfinish_obj->py_bp.bp->enable_state == bp_enabled
	326	&& PyObject_HasAttrString (py_obj, outofscope_func))
	327	{
18868860 TT	328	PyObject *meth_result;
	329
	330	meth_result = PyObject_CallMethod (py_obj, outofscope_func, NULL);
	331	if (meth_result == NULL)
	332	gdbpy_print_stack ();
	333	Py_XDECREF (meth_result);
cc72b2a2 KP	334	}
	335
	336	delete_breakpoint (bpfinish_obj->py_bp.bp);
	337	}
	338
	339	/* Callback for `bpfinishpy_detect_out_scope'. Triggers Python's
	340	`B->out_of_scope' function if B is a FinishBreakpoint out of its scope. */
	341
	342	static int
	343	bpfinishpy_detect_out_scope_cb (struct breakpoint b, void args)
	344	{
	345	volatile struct gdb_exception except;
	346	struct breakpoint bp_stopped = (struct breakpoint ) args;
	347	PyObject py_bp = (PyObject ) b->py_bp_object;
	348	struct gdbarch *garch = b->gdbarch ? b->gdbarch : get_current_arch ();
256458bc	349
cc72b2a2 KP	350	/* Trigger out_of_scope if this is a FinishBreakpoint and its frame is
	351	not anymore in the current callstack. */
	352	if (py_bp != NULL && b->py_bp_object->is_finish_bp)
	353	{
	354	struct finish_breakpoint_object *finish_bp =
	355	(struct finish_breakpoint_object *) py_bp;
	356
	357	/* Check scope if not currently stopped at the FinishBreakpoint. */
	358	if (b != bp_stopped)
	359	{
	360	TRY_CATCH (except, RETURN_MASK_ALL)
	361	{
	362	if (b->pspace == current_inferior ()->pspace
	363	&& (!target_has_registers
	364	\|\| frame_find_by_id (b->frame_id) == NULL))
	365	bpfinishpy_out_of_scope (finish_bp);
	366	}
	367	if (except.reason < 0)
	368	{
	369	gdbpy_convert_exception (except);
	370	gdbpy_print_stack ();
	371	}
	372	}
	373	}
	374
	375	return 0;
	376	}
	377
	378	/* Attached to `stop' notifications, check if the execution has run
	379	out of the scope of any FinishBreakpoint before it has been hit. */
	380
	381	static void
	382	bpfinishpy_handle_stop (struct bpstats *bs, int print_frame)
	383	{
	384	struct cleanup *cleanup = ensure_python_env (get_current_arch (),
	385	current_language);
	386
	387	iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb,
	388	bs == NULL ? NULL : bs->breakpoint_at);
	389
	390	do_cleanups (cleanup);
	391	}
	392
	393	/* Attached to `exit' notifications, triggers all the necessary out of
	394	scope notifications. */
	395
	396	static void
	397	bpfinishpy_handle_exit (struct inferior *inf)
	398	{
f5656ead	399	struct cleanup *cleanup = ensure_python_env (target_gdbarch (),
cc72b2a2 KP	400	current_language);
	401
	402	iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, NULL);
	403
	404	do_cleanups (cleanup);
	405	}
	406
	407	/* Initialize the Python finish breakpoint code. */
	408
999633ed	409	int
cc72b2a2 KP	410	gdbpy_initialize_finishbreakpoints (void)
	411	{
	412	if (PyType_Ready (&finish_breakpoint_object_type) < 0)
999633ed	413	return -1;
256458bc	414
aa36459a TT	415	if (gdb_pymodule_addobject (gdb_module, "FinishBreakpoint",
aa36459a TT	416	(PyObject *) &finish_breakpoint_object_type) < 0)
999633ed	417	return -1;
256458bc	418
cc72b2a2 KP	419	observer_attach_normal_stop (bpfinishpy_handle_stop);
cc72b2a2 KP	420	observer_attach_inferior_exit (bpfinishpy_handle_exit);
999633ed TT	421
999633ed TT	422	return 0;
cc72b2a2 KP	423	}
	424
	425	static PyGetSetDef finish_breakpoint_object_getset[] = {
	426	{ "return_value", bpfinishpy_get_returnvalue, NULL,
	427	"gdb.Value object representing the return value, if any. \
	428	None otherwise.", NULL },
	429	{ NULL } /* Sentinel. */
	430	};
	431
	432	static PyTypeObject finish_breakpoint_object_type =
	433	{
9a27f2c6	434	PyVarObject_HEAD_INIT (NULL, 0)
cc72b2a2 KP	435	"gdb.FinishBreakpoint", /tp_name/
	436	sizeof (struct finish_breakpoint_object), /tp_basicsize/
	437	0, /tp_itemsize/
	438	bpfinishpy_dealloc, /tp_dealloc/
	439	0, /tp_print/
	440	0, /tp_getattr/
	441	0, /tp_setattr/
	442	0, /tp_compare/
	443	0, /tp_repr/
	444	0, /tp_as_number/
	445	0, /tp_as_sequence/
	446	0, /tp_as_mapping/
	447	0, /tp_hash /
	448	0, /tp_call/
	449	0, /tp_str/
	450	0, /tp_getattro/
	451	0, /tp_setattro /
	452	0, /tp_as_buffer/
	453	Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_BASETYPE, /tp_flags/
	454	"GDB finish breakpoint object", /* tp_doc */
	455	0, /* tp_traverse */
	456	0, /* tp_clear */
	457	0, /* tp_richcompare */
	458	0, /* tp_weaklistoffset */
	459	0, /* tp_iter */
	460	0, /* tp_iternext */
	461	0, /* tp_methods */
	462	0, /* tp_members */
	463	finish_breakpoint_object_getset,/* tp_getset */
	464	&breakpoint_object_type, /* tp_base */
	465	0, /* tp_dict */
	466	0, /* tp_descr_get */
	467	0, /* tp_descr_set */
	468	0, /* tp_dictoffset */
	469	bpfinishpy_init, /* tp_init */
	470	0, /* tp_alloc */
	471	0 /* tp_new */
	472	};