1 /* Python interface to finish breakpoints
3 Copyright (C) 2011-2015 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"
33 /* Function that is called when a Python finish bp is found out of scope. */
34 static char * const outofscope_func
= "out_of_scope";
36 /* struct implementing the gdb.FinishBreakpoint object by extending
37 the gdb.Breakpoint class. */
38 struct finish_breakpoint_object
40 /* gdb.Breakpoint base class. */
41 gdbpy_breakpoint_object py_bp
;
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
45 PyObject
*return_type
;
46 /* gdb.Value object of the function finished by this breakpoint. Will be
47 NULL if return_type is NULL. */
48 PyObject
*function_value
;
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
;
55 extern PyTypeObject finish_breakpoint_object_type
56 CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("finish_breakpoint_object");
58 /* Python function to get the 'return_value' attribute of
62 bpfinishpy_get_returnvalue (PyObject
*self
, void *closure
)
64 struct finish_breakpoint_object
*self_finishbp
=
65 (struct finish_breakpoint_object
*) self
;
67 if (!self_finishbp
->return_value
)
70 Py_INCREF (self_finishbp
->return_value
);
71 return self_finishbp
->return_value
;
74 /* Deallocate FinishBreakpoint object. */
77 bpfinishpy_dealloc (PyObject
*self
)
79 struct finish_breakpoint_object
*self_bpfinish
=
80 (struct finish_breakpoint_object
*) self
;
82 Py_XDECREF (self_bpfinish
->function_value
);
83 Py_XDECREF (self_bpfinish
->return_type
);
84 Py_XDECREF (self_bpfinish
->return_value
);
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. */
92 bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object
*bp_obj
)
94 struct finish_breakpoint_object
*self_finishbp
=
95 (struct finish_breakpoint_object
*) bp_obj
;
96 volatile struct gdb_exception except
;
98 /* Can compute return_value only once. */
99 gdb_assert (!self_finishbp
->return_value
);
101 if (!self_finishbp
->return_type
)
104 TRY_CATCH (except
, RETURN_MASK_ALL
)
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 if (except
.reason
< 0)
126 gdbpy_convert_exception (except
);
127 gdbpy_print_stack ();
131 /* Triggered when gdbpy_should_stop has triggered the `stop' callback
132 of the gdb.FinishBreakpoint object BP_OBJ. */
135 bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object
*bp_obj
)
137 volatile struct gdb_exception except
;
139 TRY_CATCH (except
, RETURN_MASK_ALL
)
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 if (except
.reason
< 0)
147 gdbpy_convert_exception (except
);
148 gdbpy_print_stack ();
152 /* Python function to create a new breakpoint. */
155 bpfinishpy_init (PyObject
*self
, PyObject
*args
, PyObject
*kwargs
)
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
;
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
;
168 CORE_ADDR finish_pc
, pc
;
169 volatile struct gdb_exception except
;
170 char *addr_str
, small_buf
[100];
171 struct symbol
*function
;
173 if (!PyArg_ParseTupleAndKeywords (args
, kwargs
, "|OO", keywords
,
174 &frame_obj
, &internal
))
177 TRY_CATCH (except
, RETURN_MASK_ALL
)
179 /* Default frame to newest frame if necessary. */
180 if (frame_obj
== NULL
)
181 frame
= get_current_frame ();
183 frame
= frame_object_to_frame_info (frame_obj
);
187 PyErr_SetString (PyExc_ValueError
,
188 _("Invalid ID for the `frame' object."));
192 prev_frame
= get_prev_frame (frame
);
195 PyErr_SetString (PyExc_ValueError
,
196 _("\"FinishBreakpoint\" not "
197 "meaningful in the outermost "
200 else if (get_frame_type (prev_frame
) == DUMMY_FRAME
)
202 PyErr_SetString (PyExc_ValueError
,
203 _("\"FinishBreakpoint\" cannot "
204 "be set on a dummy frame."));
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."));
215 if (except
.reason
< 0)
217 gdbpy_convert_exception (except
);
220 else if (PyErr_Occurred ())
223 thread
= pid_to_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
;
246 TRY_CATCH (except
, RETURN_MASK_ALL
)
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
, frame
);
265 self_bpfinish
->function_value
=
266 value_to_value_object (func_value
);
272 if (except
.reason
< 0)
274 /* Just swallow. Either the return type or the function value
278 if (self_bpfinish
->return_type
== NULL
|| self_bpfinish
->function_value
== NULL
)
280 /* Won't be able to compute return value. */
281 Py_XDECREF (self_bpfinish
->return_type
);
282 Py_XDECREF (self_bpfinish
->function_value
);
284 self_bpfinish
->return_type
= NULL
;
285 self_bpfinish
->function_value
= NULL
;
288 bppy_pending_object
= &self_bpfinish
->py_bp
;
289 bppy_pending_object
->number
= -1;
290 bppy_pending_object
->bp
= NULL
;
292 TRY_CATCH (except
, RETURN_MASK_ALL
)
294 /* Set a breakpoint on the return address. */
295 finish_pc
= get_frame_pc (prev_frame
);
296 xsnprintf (small_buf
, sizeof (small_buf
), "*%s", hex_string (finish_pc
));
297 addr_str
= small_buf
;
299 create_breakpoint (python_gdbarch
,
300 addr_str
, NULL
, thread
, NULL
,
306 &bkpt_breakpoint_ops
,
307 0, 1, internal_bp
, 0);
309 GDB_PY_SET_HANDLE_EXCEPTION (except
);
311 self_bpfinish
->py_bp
.bp
->frame_id
= frame_id
;
312 self_bpfinish
->py_bp
.is_finish_bp
= 1;
314 /* Bind the breakpoint with the current program space. */
315 self_bpfinish
->py_bp
.bp
->pspace
= current_program_space
;
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. */
325 bpfinishpy_out_of_scope (struct finish_breakpoint_object
*bpfinish_obj
)
327 gdbpy_breakpoint_object
*bp_obj
= (gdbpy_breakpoint_object
*) bpfinish_obj
;
328 PyObject
*py_obj
= (PyObject
*) bp_obj
;
330 if (bpfinish_obj
->py_bp
.bp
->enable_state
== bp_enabled
331 && PyObject_HasAttrString (py_obj
, outofscope_func
))
333 PyObject
*meth_result
;
335 meth_result
= PyObject_CallMethod (py_obj
, outofscope_func
, NULL
);
336 if (meth_result
== NULL
)
337 gdbpy_print_stack ();
338 Py_XDECREF (meth_result
);
341 delete_breakpoint (bpfinish_obj
->py_bp
.bp
);
344 /* Callback for `bpfinishpy_detect_out_scope'. Triggers Python's
345 `B->out_of_scope' function if B is a FinishBreakpoint out of its scope. */
348 bpfinishpy_detect_out_scope_cb (struct breakpoint
*b
, void *args
)
350 volatile struct gdb_exception except
;
351 struct breakpoint
*bp_stopped
= (struct breakpoint
*) args
;
352 PyObject
*py_bp
= (PyObject
*) b
->py_bp_object
;
353 struct gdbarch
*garch
= b
->gdbarch
? b
->gdbarch
: get_current_arch ();
355 /* Trigger out_of_scope if this is a FinishBreakpoint and its frame is
356 not anymore in the current callstack. */
357 if (py_bp
!= NULL
&& b
->py_bp_object
->is_finish_bp
)
359 struct finish_breakpoint_object
*finish_bp
=
360 (struct finish_breakpoint_object
*) py_bp
;
362 /* Check scope if not currently stopped at the FinishBreakpoint. */
365 TRY_CATCH (except
, RETURN_MASK_ALL
)
367 if (b
->pspace
== current_inferior ()->pspace
368 && (!target_has_registers
369 || frame_find_by_id (b
->frame_id
) == NULL
))
370 bpfinishpy_out_of_scope (finish_bp
);
372 if (except
.reason
< 0)
374 gdbpy_convert_exception (except
);
375 gdbpy_print_stack ();
383 /* Attached to `stop' notifications, check if the execution has run
384 out of the scope of any FinishBreakpoint before it has been hit. */
387 bpfinishpy_handle_stop (struct bpstats
*bs
, int print_frame
)
389 struct cleanup
*cleanup
= ensure_python_env (get_current_arch (),
392 iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb
,
393 bs
== NULL
? NULL
: bs
->breakpoint_at
);
395 do_cleanups (cleanup
);
398 /* Attached to `exit' notifications, triggers all the necessary out of
399 scope notifications. */
402 bpfinishpy_handle_exit (struct inferior
*inf
)
404 struct cleanup
*cleanup
= ensure_python_env (target_gdbarch (),
407 iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb
, NULL
);
409 do_cleanups (cleanup
);
412 /* Initialize the Python finish breakpoint code. */
415 gdbpy_initialize_finishbreakpoints (void)
417 if (PyType_Ready (&finish_breakpoint_object_type
) < 0)
420 if (gdb_pymodule_addobject (gdb_module
, "FinishBreakpoint",
421 (PyObject
*) &finish_breakpoint_object_type
) < 0)
424 observer_attach_normal_stop (bpfinishpy_handle_stop
);
425 observer_attach_inferior_exit (bpfinishpy_handle_exit
);
430 static PyGetSetDef finish_breakpoint_object_getset
[] = {
431 { "return_value", bpfinishpy_get_returnvalue
, NULL
,
432 "gdb.Value object representing the return value, if any. \
433 None otherwise.", NULL
},
434 { NULL
} /* Sentinel. */
437 PyTypeObject finish_breakpoint_object_type
=
439 PyVarObject_HEAD_INIT (NULL
, 0)
440 "gdb.FinishBreakpoint", /*tp_name*/
441 sizeof (struct finish_breakpoint_object
), /*tp_basicsize*/
443 bpfinishpy_dealloc
, /*tp_dealloc*/
450 0, /*tp_as_sequence*/
458 Py_TPFLAGS_DEFAULT
| Py_TPFLAGS_BASETYPE
, /*tp_flags*/
459 "GDB finish breakpoint object", /* tp_doc */
462 0, /* tp_richcompare */
463 0, /* tp_weaklistoffset */
468 finish_breakpoint_object_getset
,/* tp_getset */
469 &breakpoint_object_type
, /* tp_base */
471 0, /* tp_descr_get */
472 0, /* tp_descr_set */
473 0, /* tp_dictoffset */
474 bpfinishpy_init
, /* tp_init */