Commit | Line | Data |
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cc72b2a2 KP |
1 | /* Python interface to finish breakpoints |
2 | ||
28e7fd62 | 3 | Copyright (C) 2011-2013 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" | |
23 | #include "exceptions.h" | |
24 | #include "python-internal.h" | |
25 | #include "breakpoint.h" | |
26 | #include "frame.h" | |
27 | #include "gdbthread.h" | |
28 | #include "arch-utils.h" | |
29 | #include "language.h" | |
30 | #include "observer.h" | |
31 | #include "inferior.h" | |
6a3a010b | 32 | #include "block.h" |
cc72b2a2 | 33 | |
cc72b2a2 KP |
34 | /* Function that is called when a Python finish bp is found out of scope. */ |
35 | static char * const outofscope_func = "out_of_scope"; | |
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; |
cc72b2a2 KP |
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 | |
45 | was VOID. */ | |
46 | PyObject *return_type; | |
6a3a010b | 47 | /* gdb.Value object of the function finished by this breakpoint. Will be |
cc72b2a2 | 48 | NULL if return_type is NULL. */ |
6a3a010b | 49 | PyObject *function_value; |
cc72b2a2 KP |
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; | |
54 | }; | |
55 | ||
62eec1a5 TT |
56 | static PyTypeObject finish_breakpoint_object_type |
57 | CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("finish_breakpoint_object"); | |
58 | ||
cc72b2a2 KP |
59 | /* Python function to get the 'return_value' attribute of |
60 | FinishBreakpoint. */ | |
61 | ||
62 | static PyObject * | |
63 | bpfinishpy_get_returnvalue (PyObject *self, void *closure) | |
64 | { | |
65 | struct finish_breakpoint_object *self_finishbp = | |
66 | (struct finish_breakpoint_object *) self; | |
67 | ||
68 | if (!self_finishbp->return_value) | |
69 | Py_RETURN_NONE; | |
70 | ||
71 | Py_INCREF (self_finishbp->return_value); | |
72 | return self_finishbp->return_value; | |
73 | } | |
74 | ||
75 | /* Deallocate FinishBreakpoint object. */ | |
76 | ||
77 | static void | |
78 | bpfinishpy_dealloc (PyObject *self) | |
79 | { | |
80 | struct finish_breakpoint_object *self_bpfinish = | |
81 | (struct finish_breakpoint_object *) self; | |
82 | ||
6a3a010b | 83 | Py_XDECREF (self_bpfinish->function_value); |
cc72b2a2 KP |
84 | Py_XDECREF (self_bpfinish->return_type); |
85 | Py_XDECREF (self_bpfinish->return_value); | |
86 | } | |
87 | ||
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. */ | |
91 | ||
92 | void | |
4cb0213d | 93 | bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object *bp_obj) |
cc72b2a2 KP |
94 | { |
95 | struct finish_breakpoint_object *self_finishbp = | |
96 | (struct finish_breakpoint_object *) bp_obj; | |
97 | volatile struct gdb_exception except; | |
98 | ||
99 | /* Can compute return_value only once. */ | |
100 | gdb_assert (!self_finishbp->return_value); | |
101 | ||
102 | if (!self_finishbp->return_type) | |
103 | return; | |
104 | ||
105 | TRY_CATCH (except, RETURN_MASK_ALL) | |
106 | { | |
6a3a010b MR |
107 | struct value *function = |
108 | value_object_to_value (self_finishbp->function_value); | |
109 | struct type *value_type = | |
110 | type_object_to_type (self_finishbp->return_type); | |
111 | struct value *ret = get_return_value (function, value_type); | |
cc72b2a2 KP |
112 | |
113 | if (ret) | |
114 | { | |
115 | self_finishbp->return_value = value_to_value_object (ret); | |
116 | if (!self_finishbp->return_value) | |
117 | gdbpy_print_stack (); | |
118 | } | |
119 | else | |
120 | { | |
121 | Py_INCREF (Py_None); | |
122 | self_finishbp->return_value = Py_None; | |
123 | } | |
124 | } | |
125 | if (except.reason < 0) | |
126 | { | |
127 | gdbpy_convert_exception (except); | |
128 | gdbpy_print_stack (); | |
129 | } | |
130 | } | |
131 | ||
132 | /* Triggered when gdbpy_should_stop has triggered the `stop' callback | |
133 | of the gdb.FinishBreakpoint object BP_OBJ. */ | |
134 | ||
135 | void | |
4cb0213d | 136 | bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj) |
cc72b2a2 KP |
137 | { |
138 | volatile struct gdb_exception except; | |
139 | ||
140 | TRY_CATCH (except, RETURN_MASK_ALL) | |
141 | { | |
142 | /* Can't delete it here, but it will be removed at the next stop. */ | |
143 | disable_breakpoint (bp_obj->bp); | |
144 | gdb_assert (bp_obj->bp->disposition == disp_del); | |
145 | } | |
146 | if (except.reason < 0) | |
147 | { | |
148 | gdbpy_convert_exception (except); | |
149 | gdbpy_print_stack (); | |
150 | } | |
151 | } | |
152 | ||
153 | /* Python function to create a new breakpoint. */ | |
154 | ||
155 | static int | |
156 | bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs) | |
157 | { | |
158 | static char *keywords[] = { "frame", "internal", NULL }; | |
159 | struct finish_breakpoint_object *self_bpfinish = | |
160 | (struct finish_breakpoint_object *) self; | |
161 | int type = bp_breakpoint; | |
162 | PyObject *frame_obj = NULL; | |
163 | int thread; | |
62d7fb51 DE |
164 | struct frame_info *frame = NULL; /* init for gcc -Wall */ |
165 | struct frame_info *prev_frame = NULL; | |
cc72b2a2 KP |
166 | struct frame_id frame_id; |
167 | PyObject *internal = NULL; | |
168 | int internal_bp = 0; | |
169 | CORE_ADDR finish_pc, pc; | |
170 | volatile struct gdb_exception except; | |
171 | char *addr_str, small_buf[100]; | |
172 | struct symbol *function; | |
173 | ||
174 | if (!PyArg_ParseTupleAndKeywords (args, kwargs, "|OO", keywords, | |
175 | &frame_obj, &internal)) | |
176 | return -1; | |
177 | ||
cc72b2a2 KP |
178 | TRY_CATCH (except, RETURN_MASK_ALL) |
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 | |
208 | { | |
209 | frame_id = get_frame_id (prev_frame); | |
210 | if (frame_id_eq (frame_id, null_frame_id)) | |
211 | PyErr_SetString (PyExc_ValueError, | |
212 | _("Invalid ID for the `frame' object.")); | |
213 | } | |
214 | } | |
cc72b2a2 KP |
215 | } |
216 | if (except.reason < 0) | |
217 | { | |
218 | gdbpy_convert_exception (except); | |
219 | return -1; | |
220 | } | |
221 | else if (PyErr_Occurred ()) | |
222 | return -1; | |
223 | ||
224 | thread = pid_to_thread_id (inferior_ptid); | |
225 | if (thread == 0) | |
226 | { | |
227 | PyErr_SetString (PyExc_ValueError, | |
228 | _("No thread currently selected.")); | |
229 | return -1; | |
230 | } | |
231 | ||
232 | if (internal) | |
233 | { | |
234 | internal_bp = PyObject_IsTrue (internal); | |
256458bc | 235 | if (internal_bp == -1) |
cc72b2a2 | 236 | { |
256458bc | 237 | PyErr_SetString (PyExc_ValueError, |
cc72b2a2 KP |
238 | _("The value of `internal' must be a boolean.")); |
239 | return -1; | |
240 | } | |
241 | } | |
242 | ||
243 | /* Find the function we will return from. */ | |
244 | self_bpfinish->return_type = NULL; | |
6a3a010b | 245 | self_bpfinish->function_value = NULL; |
cc72b2a2 KP |
246 | |
247 | TRY_CATCH (except, RETURN_MASK_ALL) | |
248 | { | |
249 | if (get_frame_pc_if_available (frame, &pc)) | |
250 | { | |
251 | function = find_pc_function (pc); | |
252 | if (function != NULL) | |
253 | { | |
254 | struct type *ret_type = | |
255 | TYPE_TARGET_TYPE (SYMBOL_TYPE (function)); | |
256 | ||
257 | /* Remember only non-void return types. */ | |
258 | if (TYPE_CODE (ret_type) != TYPE_CODE_VOID) | |
259 | { | |
6a3a010b MR |
260 | struct value *func_value; |
261 | ||
cc72b2a2 KP |
262 | /* Ignore Python errors at this stage. */ |
263 | self_bpfinish->return_type = type_to_type_object (ret_type); | |
264 | PyErr_Clear (); | |
6a3a010b MR |
265 | func_value = read_var_value (function, frame); |
266 | self_bpfinish->function_value = | |
267 | value_to_value_object (func_value); | |
cc72b2a2 KP |
268 | PyErr_Clear (); |
269 | } | |
270 | } | |
271 | } | |
272 | } | |
273 | if (except.reason < 0 | |
6a3a010b | 274 | || !self_bpfinish->return_type || !self_bpfinish->function_value) |
cc72b2a2 KP |
275 | { |
276 | /* Won't be able to compute return value. */ | |
277 | Py_XDECREF (self_bpfinish->return_type); | |
6a3a010b | 278 | Py_XDECREF (self_bpfinish->function_value); |
cc72b2a2 KP |
279 | |
280 | self_bpfinish->return_type = NULL; | |
6a3a010b | 281 | self_bpfinish->function_value = NULL; |
cc72b2a2 KP |
282 | } |
283 | ||
284 | bppy_pending_object = &self_bpfinish->py_bp; | |
285 | bppy_pending_object->number = -1; | |
286 | bppy_pending_object->bp = NULL; | |
287 | ||
288 | TRY_CATCH (except, RETURN_MASK_ALL) | |
289 | { | |
290 | /* Set a breakpoint on the return address. */ | |
291 | finish_pc = get_frame_pc (prev_frame); | |
41843fe8 | 292 | xsnprintf (small_buf, sizeof (small_buf), "*%s", hex_string (finish_pc)); |
cc72b2a2 KP |
293 | addr_str = small_buf; |
294 | ||
295 | create_breakpoint (python_gdbarch, | |
e7e0cddf | 296 | addr_str, NULL, thread, NULL, |
cc72b2a2 KP |
297 | 0, |
298 | 1 /*temp_flag*/, | |
299 | bp_breakpoint, | |
300 | 0, | |
301 | AUTO_BOOLEAN_TRUE, | |
302 | &bkpt_breakpoint_ops, | |
44f238bb | 303 | 0, 1, internal_bp, 0); |
cc72b2a2 KP |
304 | } |
305 | GDB_PY_SET_HANDLE_EXCEPTION (except); | |
256458bc | 306 | |
cc72b2a2 KP |
307 | self_bpfinish->py_bp.bp->frame_id = frame_id; |
308 | self_bpfinish->py_bp.is_finish_bp = 1; | |
256458bc | 309 | |
cc72b2a2 KP |
310 | /* Bind the breakpoint with the current program space. */ |
311 | self_bpfinish->py_bp.bp->pspace = current_program_space; | |
312 | ||
313 | return 0; | |
cc72b2a2 KP |
314 | } |
315 | ||
316 | /* Called when GDB notices that the finish breakpoint BP_OBJ is out of | |
317 | the current callstack. Triggers the method OUT_OF_SCOPE if implemented, | |
318 | then delete the breakpoint. */ | |
319 | ||
320 | static void | |
321 | bpfinishpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj) | |
322 | { | |
4cb0213d | 323 | gdbpy_breakpoint_object *bp_obj = (gdbpy_breakpoint_object *) bpfinish_obj; |
cc72b2a2 KP |
324 | PyObject *py_obj = (PyObject *) bp_obj; |
325 | ||
326 | if (bpfinish_obj->py_bp.bp->enable_state == bp_enabled | |
327 | && PyObject_HasAttrString (py_obj, outofscope_func)) | |
328 | { | |
18868860 TT |
329 | PyObject *meth_result; |
330 | ||
331 | meth_result = PyObject_CallMethod (py_obj, outofscope_func, NULL); | |
332 | if (meth_result == NULL) | |
333 | gdbpy_print_stack (); | |
334 | Py_XDECREF (meth_result); | |
cc72b2a2 KP |
335 | } |
336 | ||
337 | delete_breakpoint (bpfinish_obj->py_bp.bp); | |
338 | } | |
339 | ||
340 | /* Callback for `bpfinishpy_detect_out_scope'. Triggers Python's | |
341 | `B->out_of_scope' function if B is a FinishBreakpoint out of its scope. */ | |
342 | ||
343 | static int | |
344 | bpfinishpy_detect_out_scope_cb (struct breakpoint *b, void *args) | |
345 | { | |
346 | volatile struct gdb_exception except; | |
347 | struct breakpoint *bp_stopped = (struct breakpoint *) args; | |
348 | PyObject *py_bp = (PyObject *) b->py_bp_object; | |
349 | struct gdbarch *garch = b->gdbarch ? b->gdbarch : get_current_arch (); | |
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 = | |
356 | (struct finish_breakpoint_object *) py_bp; | |
357 | ||
358 | /* Check scope if not currently stopped at the FinishBreakpoint. */ | |
359 | if (b != bp_stopped) | |
360 | { | |
361 | TRY_CATCH (except, RETURN_MASK_ALL) | |
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 | if (except.reason < 0) | |
369 | { | |
370 | gdbpy_convert_exception (except); | |
371 | gdbpy_print_stack (); | |
372 | } | |
373 | } | |
374 | } | |
375 | ||
376 | return 0; | |
377 | } | |
378 | ||
379 | /* Attached to `stop' notifications, check if the execution has run | |
380 | out of the scope of any FinishBreakpoint before it has been hit. */ | |
381 | ||
382 | static void | |
383 | bpfinishpy_handle_stop (struct bpstats *bs, int print_frame) | |
384 | { | |
385 | struct cleanup *cleanup = ensure_python_env (get_current_arch (), | |
386 | current_language); | |
387 | ||
388 | iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, | |
389 | bs == NULL ? NULL : bs->breakpoint_at); | |
390 | ||
391 | do_cleanups (cleanup); | |
392 | } | |
393 | ||
394 | /* Attached to `exit' notifications, triggers all the necessary out of | |
395 | scope notifications. */ | |
396 | ||
397 | static void | |
398 | bpfinishpy_handle_exit (struct inferior *inf) | |
399 | { | |
f5656ead | 400 | struct cleanup *cleanup = ensure_python_env (target_gdbarch (), |
cc72b2a2 KP |
401 | current_language); |
402 | ||
403 | iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, NULL); | |
404 | ||
405 | do_cleanups (cleanup); | |
406 | } | |
407 | ||
408 | /* Initialize the Python finish breakpoint code. */ | |
409 | ||
999633ed | 410 | int |
cc72b2a2 KP |
411 | gdbpy_initialize_finishbreakpoints (void) |
412 | { | |
413 | if (PyType_Ready (&finish_breakpoint_object_type) < 0) | |
999633ed | 414 | return -1; |
256458bc | 415 | |
aa36459a TT |
416 | if (gdb_pymodule_addobject (gdb_module, "FinishBreakpoint", |
417 | (PyObject *) &finish_breakpoint_object_type) < 0) | |
999633ed | 418 | return -1; |
256458bc | 419 | |
cc72b2a2 KP |
420 | observer_attach_normal_stop (bpfinishpy_handle_stop); |
421 | observer_attach_inferior_exit (bpfinishpy_handle_exit); | |
999633ed TT |
422 | |
423 | return 0; | |
cc72b2a2 KP |
424 | } |
425 | ||
426 | static PyGetSetDef finish_breakpoint_object_getset[] = { | |
427 | { "return_value", bpfinishpy_get_returnvalue, NULL, | |
428 | "gdb.Value object representing the return value, if any. \ | |
429 | None otherwise.", NULL }, | |
430 | { NULL } /* Sentinel. */ | |
431 | }; | |
432 | ||
433 | static PyTypeObject finish_breakpoint_object_type = | |
434 | { | |
9a27f2c6 | 435 | PyVarObject_HEAD_INIT (NULL, 0) |
cc72b2a2 KP |
436 | "gdb.FinishBreakpoint", /*tp_name*/ |
437 | sizeof (struct finish_breakpoint_object), /*tp_basicsize*/ | |
438 | 0, /*tp_itemsize*/ | |
439 | bpfinishpy_dealloc, /*tp_dealloc*/ | |
440 | 0, /*tp_print*/ | |
441 | 0, /*tp_getattr*/ | |
442 | 0, /*tp_setattr*/ | |
443 | 0, /*tp_compare*/ | |
444 | 0, /*tp_repr*/ | |
445 | 0, /*tp_as_number*/ | |
446 | 0, /*tp_as_sequence*/ | |
447 | 0, /*tp_as_mapping*/ | |
448 | 0, /*tp_hash */ | |
449 | 0, /*tp_call*/ | |
450 | 0, /*tp_str*/ | |
451 | 0, /*tp_getattro*/ | |
452 | 0, /*tp_setattro */ | |
453 | 0, /*tp_as_buffer*/ | |
454 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ | |
455 | "GDB finish breakpoint object", /* tp_doc */ | |
456 | 0, /* tp_traverse */ | |
457 | 0, /* tp_clear */ | |
458 | 0, /* tp_richcompare */ | |
459 | 0, /* tp_weaklistoffset */ | |
460 | 0, /* tp_iter */ | |
461 | 0, /* tp_iternext */ | |
462 | 0, /* tp_methods */ | |
463 | 0, /* tp_members */ | |
464 | finish_breakpoint_object_getset,/* tp_getset */ | |
465 | &breakpoint_object_type, /* tp_base */ | |
466 | 0, /* tp_dict */ | |
467 | 0, /* tp_descr_get */ | |
468 | 0, /* tp_descr_set */ | |
469 | 0, /* tp_dictoffset */ | |
470 | bpfinishpy_init, /* tp_init */ | |
471 | 0, /* tp_alloc */ | |
472 | 0 /* tp_new */ | |
473 | }; |