1 /* Python interface to finish breakpoints
3 Copyright (C) 2011-2017 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
23 #include "python-internal.h"
24 #include "breakpoint.h"
26 #include "gdbthread.h"
27 #include "arch-utils.h"
34 /* Function that is called when a Python finish bp is found out of scope. */
35 static char * const outofscope_func
= "out_of_scope";
37 /* struct implementing the gdb.FinishBreakpoint object by extending
38 the gdb.Breakpoint class. */
39 struct finish_breakpoint_object
41 /* gdb.Breakpoint base class. */
42 gdbpy_breakpoint_object py_bp
;
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
46 PyObject
*return_type
;
47 /* gdb.Value object of the function finished by this breakpoint. Will be
48 NULL if return_type is NULL. */
49 PyObject
*function_value
;
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
;
56 extern PyTypeObject finish_breakpoint_object_type
57 CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("finish_breakpoint_object");
59 /* Python function to get the 'return_value' attribute of
63 bpfinishpy_get_returnvalue (PyObject
*self
, void *closure
)
65 struct finish_breakpoint_object
*self_finishbp
=
66 (struct finish_breakpoint_object
*) self
;
68 if (!self_finishbp
->return_value
)
71 Py_INCREF (self_finishbp
->return_value
);
72 return self_finishbp
->return_value
;
75 /* Deallocate FinishBreakpoint object. */
78 bpfinishpy_dealloc (PyObject
*self
)
80 struct finish_breakpoint_object
*self_bpfinish
=
81 (struct finish_breakpoint_object
*) self
;
83 Py_XDECREF (self_bpfinish
->function_value
);
84 Py_XDECREF (self_bpfinish
->return_type
);
85 Py_XDECREF (self_bpfinish
->return_value
);
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. */
93 bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object
*bp_obj
)
95 struct finish_breakpoint_object
*self_finishbp
=
96 (struct finish_breakpoint_object
*) bp_obj
;
98 /* Can compute return_value only once. */
99 gdb_assert (!self_finishbp
->return_value
);
101 if (!self_finishbp
->return_type
)
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
);
114 self_finishbp
->return_value
= value_to_value_object (ret
);
115 if (!self_finishbp
->return_value
)
116 gdbpy_print_stack ();
121 self_finishbp
->return_value
= Py_None
;
124 CATCH (except
, RETURN_MASK_ALL
)
126 gdbpy_convert_exception (except
);
127 gdbpy_print_stack ();
132 /* Triggered when gdbpy_should_stop has triggered the `stop' callback
133 of the gdb.FinishBreakpoint object BP_OBJ. */
136 bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object
*bp_obj
)
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
);
145 CATCH (except
, RETURN_MASK_ALL
)
147 gdbpy_convert_exception (except
);
148 gdbpy_print_stack ();
153 /* Python function to create a new breakpoint. */
156 bpfinishpy_init (PyObject
*self
, PyObject
*args
, PyObject
*kwargs
)
158 static char *keywords
[] = { "frame", "internal", NULL
};
159 struct finish_breakpoint_object
*self_bpfinish
=
160 (struct finish_breakpoint_object
*) self
;
161 PyObject
*frame_obj
= NULL
;
163 struct frame_info
*frame
= NULL
; /* init for gcc -Wall */
164 struct frame_info
*prev_frame
= NULL
;
165 struct frame_id frame_id
;
166 PyObject
*internal
= NULL
;
169 struct symbol
*function
;
171 if (!PyArg_ParseTupleAndKeywords (args
, kwargs
, "|OO", keywords
,
172 &frame_obj
, &internal
))
177 /* Default frame to newest frame if necessary. */
178 if (frame_obj
== NULL
)
179 frame
= get_current_frame ();
181 frame
= frame_object_to_frame_info (frame_obj
);
185 PyErr_SetString (PyExc_ValueError
,
186 _("Invalid ID for the `frame' object."));
190 prev_frame
= get_prev_frame (frame
);
193 PyErr_SetString (PyExc_ValueError
,
194 _("\"FinishBreakpoint\" not "
195 "meaningful in the outermost "
198 else if (get_frame_type (prev_frame
) == DUMMY_FRAME
)
200 PyErr_SetString (PyExc_ValueError
,
201 _("\"FinishBreakpoint\" cannot "
202 "be set on a dummy frame."));
206 frame_id
= get_frame_id (prev_frame
);
207 if (frame_id_eq (frame_id
, null_frame_id
))
208 PyErr_SetString (PyExc_ValueError
,
209 _("Invalid ID for the `frame' object."));
213 CATCH (except
, RETURN_MASK_ALL
)
215 gdbpy_convert_exception (except
);
220 if (PyErr_Occurred ())
223 thread
= ptid_to_global_thread_id (inferior_ptid
);
226 PyErr_SetString (PyExc_ValueError
,
227 _("No thread currently selected."));
233 internal_bp
= PyObject_IsTrue (internal
);
234 if (internal_bp
== -1)
236 PyErr_SetString (PyExc_ValueError
,
237 _("The value of `internal' must be a boolean."));
242 /* Find the function we will return from. */
243 self_bpfinish
->return_type
= NULL
;
244 self_bpfinish
->function_value
= NULL
;
248 if (get_frame_pc_if_available (frame
, &pc
))
250 function
= find_pc_function (pc
);
251 if (function
!= NULL
)
253 struct type
*ret_type
=
254 TYPE_TARGET_TYPE (SYMBOL_TYPE (function
));
256 /* Remember only non-void return types. */
257 if (TYPE_CODE (ret_type
) != TYPE_CODE_VOID
)
259 struct value
*func_value
;
261 /* Ignore Python errors at this stage. */
262 self_bpfinish
->return_type
= type_to_type_object (ret_type
);
264 func_value
= read_var_value (function
, NULL
, frame
);
265 self_bpfinish
->function_value
=
266 value_to_value_object (func_value
);
272 CATCH (except
, RETURN_MASK_ALL
)
274 /* Just swallow. Either the return type or the function value
279 if (self_bpfinish
->return_type
== NULL
|| self_bpfinish
->function_value
== NULL
)
281 /* Won't be able to compute return value. */
282 Py_XDECREF (self_bpfinish
->return_type
);
283 Py_XDECREF (self_bpfinish
->function_value
);
285 self_bpfinish
->return_type
= NULL
;
286 self_bpfinish
->function_value
= NULL
;
289 bppy_pending_object
= &self_bpfinish
->py_bp
;
290 bppy_pending_object
->number
= -1;
291 bppy_pending_object
->bp
= NULL
;
295 struct event_location
*location
;
296 struct cleanup
*back_to
;
298 /* Set a breakpoint on the return address. */
299 location
= new_address_location (get_frame_pc (prev_frame
), NULL
, 0);
300 back_to
= make_cleanup_delete_event_location (location
);
301 create_breakpoint (python_gdbarch
,
302 location
, NULL
, thread
, NULL
,
308 &bkpt_breakpoint_ops
,
309 0, 1, internal_bp
, 0);
310 do_cleanups (back_to
);
312 CATCH (except
, RETURN_MASK_ALL
)
314 GDB_PY_SET_HANDLE_EXCEPTION (except
);
318 self_bpfinish
->py_bp
.bp
->frame_id
= frame_id
;
319 self_bpfinish
->py_bp
.is_finish_bp
= 1;
321 /* Bind the breakpoint with the current program space. */
322 self_bpfinish
->py_bp
.bp
->pspace
= current_program_space
;
327 /* Called when GDB notices that the finish breakpoint BP_OBJ is out of
328 the current callstack. Triggers the method OUT_OF_SCOPE if implemented,
329 then delete the breakpoint. */
332 bpfinishpy_out_of_scope (struct finish_breakpoint_object
*bpfinish_obj
)
334 gdbpy_breakpoint_object
*bp_obj
= (gdbpy_breakpoint_object
*) bpfinish_obj
;
335 PyObject
*py_obj
= (PyObject
*) bp_obj
;
337 if (bpfinish_obj
->py_bp
.bp
->enable_state
== bp_enabled
338 && PyObject_HasAttrString (py_obj
, outofscope_func
))
340 PyObject
*meth_result
;
342 meth_result
= PyObject_CallMethod (py_obj
, outofscope_func
, NULL
);
343 if (meth_result
== NULL
)
344 gdbpy_print_stack ();
345 Py_XDECREF (meth_result
);
348 delete_breakpoint (bpfinish_obj
->py_bp
.bp
);
351 /* Callback for `bpfinishpy_detect_out_scope'. Triggers Python's
352 `B->out_of_scope' function if B is a FinishBreakpoint out of its scope. */
355 bpfinishpy_detect_out_scope_cb (struct breakpoint
*b
, void *args
)
357 struct breakpoint
*bp_stopped
= (struct breakpoint
*) args
;
358 PyObject
*py_bp
= (PyObject
*) b
->py_bp_object
;
360 /* Trigger out_of_scope if this is a FinishBreakpoint and its frame is
361 not anymore in the current callstack. */
362 if (py_bp
!= NULL
&& b
->py_bp_object
->is_finish_bp
)
364 struct finish_breakpoint_object
*finish_bp
=
365 (struct finish_breakpoint_object
*) py_bp
;
367 /* Check scope if not currently stopped at the FinishBreakpoint. */
372 if (b
->pspace
== current_inferior ()->pspace
373 && (!target_has_registers
374 || frame_find_by_id (b
->frame_id
) == NULL
))
375 bpfinishpy_out_of_scope (finish_bp
);
377 CATCH (except
, RETURN_MASK_ALL
)
379 gdbpy_convert_exception (except
);
380 gdbpy_print_stack ();
389 /* Attached to `stop' notifications, check if the execution has run
390 out of the scope of any FinishBreakpoint before it has been hit. */
393 bpfinishpy_handle_stop (struct bpstats
*bs
, int print_frame
)
395 struct cleanup
*cleanup
= ensure_python_env (get_current_arch (),
398 iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb
,
399 bs
== NULL
? NULL
: bs
->breakpoint_at
);
401 do_cleanups (cleanup
);
404 /* Attached to `exit' notifications, triggers all the necessary out of
405 scope notifications. */
408 bpfinishpy_handle_exit (struct inferior
*inf
)
410 struct cleanup
*cleanup
= ensure_python_env (target_gdbarch (),
413 iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb
, NULL
);
415 do_cleanups (cleanup
);
418 /* Initialize the Python finish breakpoint code. */
421 gdbpy_initialize_finishbreakpoints (void)
423 if (PyType_Ready (&finish_breakpoint_object_type
) < 0)
426 if (gdb_pymodule_addobject (gdb_module
, "FinishBreakpoint",
427 (PyObject
*) &finish_breakpoint_object_type
) < 0)
430 observer_attach_normal_stop (bpfinishpy_handle_stop
);
431 observer_attach_inferior_exit (bpfinishpy_handle_exit
);
436 static PyGetSetDef finish_breakpoint_object_getset
[] = {
437 { "return_value", bpfinishpy_get_returnvalue
, NULL
,
438 "gdb.Value object representing the return value, if any. \
439 None otherwise.", NULL
},
440 { NULL
} /* Sentinel. */
443 PyTypeObject finish_breakpoint_object_type
=
445 PyVarObject_HEAD_INIT (NULL
, 0)
446 "gdb.FinishBreakpoint", /*tp_name*/
447 sizeof (struct finish_breakpoint_object
), /*tp_basicsize*/
449 bpfinishpy_dealloc
, /*tp_dealloc*/
456 0, /*tp_as_sequence*/
464 Py_TPFLAGS_DEFAULT
| Py_TPFLAGS_BASETYPE
, /*tp_flags*/
465 "GDB finish breakpoint object", /* tp_doc */
468 0, /* tp_richcompare */
469 0, /* tp_weaklistoffset */
474 finish_breakpoint_object_getset
,/* tp_getset */
475 &breakpoint_object_type
, /* tp_base */
477 0, /* tp_descr_get */
478 0, /* tp_descr_set */
479 0, /* tp_dictoffset */
480 bpfinishpy_init
, /* tp_init */