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cc72b2a2 KP |
1 | /* Python interface to finish breakpoints |
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 */ |
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) |
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; |
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 | |
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 | } |
304 | GDB_PY_SET_HANDLE_EXCEPTION (except); | |
256458bc | 305 | |
cc72b2a2 KP |
306 | self_bpfinish->py_bp.bp->frame_id = frame_id; |
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", |
416 | (PyObject *) &finish_breakpoint_object_type) < 0) | |
999633ed | 417 | return -1; |
256458bc | 418 | |
cc72b2a2 KP |
419 | observer_attach_normal_stop (bpfinishpy_handle_stop); |
420 | observer_attach_inferior_exit (bpfinishpy_handle_exit); | |
999633ed TT |
421 | |
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 | }; |