Commit | Line | Data |
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cc72b2a2 KP |
1 | /* Python interface to finish breakpoints |
2 | ||
32d0add0 | 3 | Copyright (C) 2011-2015 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" |
f00aae0f | 32 | #include "location.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 | ||
e36122e9 | 56 | extern PyTypeObject finish_breakpoint_object_type |
62eec1a5 TT |
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; | |
cc72b2a2 KP |
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 | ||
492d29ea | 104 | TRY |
cc72b2a2 | 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); | |
8a6c4031 JK |
110 | |
111 | /* bpfinishpy_init cannot finish into DUMMY_FRAME (throws an error | |
112 | in such case) so it is OK to always pass CTX_SAVER as NULL. */ | |
113 | struct value *ret = get_return_value (function, value_type, NULL); | |
cc72b2a2 KP |
114 | |
115 | if (ret) | |
116 | { | |
117 | self_finishbp->return_value = value_to_value_object (ret); | |
118 | if (!self_finishbp->return_value) | |
119 | gdbpy_print_stack (); | |
120 | } | |
121 | else | |
122 | { | |
123 | Py_INCREF (Py_None); | |
124 | self_finishbp->return_value = Py_None; | |
125 | } | |
126 | } | |
492d29ea | 127 | CATCH (except, RETURN_MASK_ALL) |
cc72b2a2 KP |
128 | { |
129 | gdbpy_convert_exception (except); | |
130 | gdbpy_print_stack (); | |
131 | } | |
492d29ea | 132 | END_CATCH |
cc72b2a2 KP |
133 | } |
134 | ||
135 | /* Triggered when gdbpy_should_stop has triggered the `stop' callback | |
136 | of the gdb.FinishBreakpoint object BP_OBJ. */ | |
137 | ||
138 | void | |
4cb0213d | 139 | bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj) |
cc72b2a2 | 140 | { |
cc72b2a2 | 141 | |
492d29ea | 142 | TRY |
cc72b2a2 KP |
143 | { |
144 | /* Can't delete it here, but it will be removed at the next stop. */ | |
145 | disable_breakpoint (bp_obj->bp); | |
146 | gdb_assert (bp_obj->bp->disposition == disp_del); | |
147 | } | |
492d29ea | 148 | CATCH (except, RETURN_MASK_ALL) |
cc72b2a2 KP |
149 | { |
150 | gdbpy_convert_exception (except); | |
151 | gdbpy_print_stack (); | |
152 | } | |
492d29ea | 153 | END_CATCH |
cc72b2a2 KP |
154 | } |
155 | ||
156 | /* Python function to create a new breakpoint. */ | |
157 | ||
158 | static int | |
159 | bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs) | |
160 | { | |
161 | static char *keywords[] = { "frame", "internal", NULL }; | |
162 | struct finish_breakpoint_object *self_bpfinish = | |
163 | (struct finish_breakpoint_object *) self; | |
164 | int type = bp_breakpoint; | |
165 | PyObject *frame_obj = NULL; | |
166 | int thread; | |
62d7fb51 DE |
167 | struct frame_info *frame = NULL; /* init for gcc -Wall */ |
168 | struct frame_info *prev_frame = NULL; | |
cc72b2a2 KP |
169 | struct frame_id frame_id; |
170 | PyObject *internal = NULL; | |
171 | int internal_bp = 0; | |
172 | CORE_ADDR finish_pc, pc; | |
f00aae0f | 173 | char small_buf[100], *p; |
cc72b2a2 KP |
174 | struct symbol *function; |
175 | ||
176 | if (!PyArg_ParseTupleAndKeywords (args, kwargs, "|OO", keywords, | |
177 | &frame_obj, &internal)) | |
178 | return -1; | |
179 | ||
492d29ea | 180 | TRY |
cc72b2a2 | 181 | { |
dd5fa3e7 TT |
182 | /* Default frame to newest frame if necessary. */ |
183 | if (frame_obj == NULL) | |
184 | frame = get_current_frame (); | |
cc72b2a2 | 185 | else |
dd5fa3e7 TT |
186 | frame = frame_object_to_frame_info (frame_obj); |
187 | ||
188 | if (frame == NULL) | |
189 | { | |
256458bc | 190 | PyErr_SetString (PyExc_ValueError, |
dd5fa3e7 TT |
191 | _("Invalid ID for the `frame' object.")); |
192 | } | |
193 | else | |
194 | { | |
195 | prev_frame = get_prev_frame (frame); | |
196 | if (prev_frame == 0) | |
197 | { | |
198 | PyErr_SetString (PyExc_ValueError, | |
199 | _("\"FinishBreakpoint\" not " | |
200 | "meaningful in the outermost " | |
201 | "frame.")); | |
202 | } | |
203 | else if (get_frame_type (prev_frame) == DUMMY_FRAME) | |
204 | { | |
205 | PyErr_SetString (PyExc_ValueError, | |
206 | _("\"FinishBreakpoint\" cannot " | |
207 | "be set on a dummy frame.")); | |
208 | } | |
209 | else | |
210 | { | |
211 | frame_id = get_frame_id (prev_frame); | |
212 | if (frame_id_eq (frame_id, null_frame_id)) | |
213 | PyErr_SetString (PyExc_ValueError, | |
214 | _("Invalid ID for the `frame' object.")); | |
215 | } | |
216 | } | |
cc72b2a2 | 217 | } |
492d29ea | 218 | CATCH (except, RETURN_MASK_ALL) |
cc72b2a2 KP |
219 | { |
220 | gdbpy_convert_exception (except); | |
221 | return -1; | |
222 | } | |
492d29ea PA |
223 | END_CATCH |
224 | ||
225 | if (PyErr_Occurred ()) | |
cc72b2a2 KP |
226 | return -1; |
227 | ||
228 | thread = pid_to_thread_id (inferior_ptid); | |
229 | if (thread == 0) | |
230 | { | |
231 | PyErr_SetString (PyExc_ValueError, | |
232 | _("No thread currently selected.")); | |
233 | return -1; | |
234 | } | |
235 | ||
236 | if (internal) | |
237 | { | |
238 | internal_bp = PyObject_IsTrue (internal); | |
256458bc | 239 | if (internal_bp == -1) |
cc72b2a2 | 240 | { |
256458bc | 241 | PyErr_SetString (PyExc_ValueError, |
cc72b2a2 KP |
242 | _("The value of `internal' must be a boolean.")); |
243 | return -1; | |
244 | } | |
245 | } | |
246 | ||
247 | /* Find the function we will return from. */ | |
248 | self_bpfinish->return_type = NULL; | |
6a3a010b | 249 | self_bpfinish->function_value = NULL; |
cc72b2a2 | 250 | |
492d29ea | 251 | TRY |
cc72b2a2 KP |
252 | { |
253 | if (get_frame_pc_if_available (frame, &pc)) | |
254 | { | |
255 | function = find_pc_function (pc); | |
256 | if (function != NULL) | |
257 | { | |
258 | struct type *ret_type = | |
259 | TYPE_TARGET_TYPE (SYMBOL_TYPE (function)); | |
260 | ||
261 | /* Remember only non-void return types. */ | |
262 | if (TYPE_CODE (ret_type) != TYPE_CODE_VOID) | |
263 | { | |
6a3a010b MR |
264 | struct value *func_value; |
265 | ||
cc72b2a2 KP |
266 | /* Ignore Python errors at this stage. */ |
267 | self_bpfinish->return_type = type_to_type_object (ret_type); | |
268 | PyErr_Clear (); | |
6a3a010b MR |
269 | func_value = read_var_value (function, frame); |
270 | self_bpfinish->function_value = | |
271 | value_to_value_object (func_value); | |
cc72b2a2 KP |
272 | PyErr_Clear (); |
273 | } | |
274 | } | |
275 | } | |
276 | } | |
492d29ea | 277 | CATCH (except, RETURN_MASK_ALL) |
7556d4a4 PA |
278 | { |
279 | /* Just swallow. Either the return type or the function value | |
280 | remain NULL. */ | |
281 | } | |
492d29ea | 282 | END_CATCH |
7556d4a4 PA |
283 | |
284 | if (self_bpfinish->return_type == NULL || self_bpfinish->function_value == NULL) | |
cc72b2a2 KP |
285 | { |
286 | /* Won't be able to compute return value. */ | |
287 | Py_XDECREF (self_bpfinish->return_type); | |
6a3a010b | 288 | Py_XDECREF (self_bpfinish->function_value); |
cc72b2a2 KP |
289 | |
290 | self_bpfinish->return_type = NULL; | |
6a3a010b | 291 | self_bpfinish->function_value = NULL; |
cc72b2a2 KP |
292 | } |
293 | ||
294 | bppy_pending_object = &self_bpfinish->py_bp; | |
295 | bppy_pending_object->number = -1; | |
296 | bppy_pending_object->bp = NULL; | |
297 | ||
492d29ea | 298 | TRY |
cc72b2a2 | 299 | { |
f00aae0f KS |
300 | struct event_location *location; |
301 | struct cleanup *back_to; | |
302 | ||
cc72b2a2 KP |
303 | /* Set a breakpoint on the return address. */ |
304 | finish_pc = get_frame_pc (prev_frame); | |
41843fe8 | 305 | xsnprintf (small_buf, sizeof (small_buf), "*%s", hex_string (finish_pc)); |
f00aae0f KS |
306 | p = small_buf; |
307 | location = new_linespec_location (&p); | |
308 | back_to = make_cleanup_delete_event_location (location); | |
cc72b2a2 | 309 | create_breakpoint (python_gdbarch, |
f00aae0f | 310 | location, NULL, thread, NULL, |
cc72b2a2 KP |
311 | 0, |
312 | 1 /*temp_flag*/, | |
313 | bp_breakpoint, | |
314 | 0, | |
315 | AUTO_BOOLEAN_TRUE, | |
316 | &bkpt_breakpoint_ops, | |
44f238bb | 317 | 0, 1, internal_bp, 0); |
f00aae0f | 318 | do_cleanups (back_to); |
cc72b2a2 | 319 | } |
492d29ea PA |
320 | CATCH (except, RETURN_MASK_ALL) |
321 | { | |
322 | GDB_PY_SET_HANDLE_EXCEPTION (except); | |
323 | } | |
324 | END_CATCH | |
256458bc | 325 | |
cc72b2a2 KP |
326 | self_bpfinish->py_bp.bp->frame_id = frame_id; |
327 | self_bpfinish->py_bp.is_finish_bp = 1; | |
256458bc | 328 | |
cc72b2a2 KP |
329 | /* Bind the breakpoint with the current program space. */ |
330 | self_bpfinish->py_bp.bp->pspace = current_program_space; | |
331 | ||
332 | return 0; | |
cc72b2a2 KP |
333 | } |
334 | ||
335 | /* Called when GDB notices that the finish breakpoint BP_OBJ is out of | |
336 | the current callstack. Triggers the method OUT_OF_SCOPE if implemented, | |
337 | then delete the breakpoint. */ | |
338 | ||
339 | static void | |
340 | bpfinishpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj) | |
341 | { | |
4cb0213d | 342 | gdbpy_breakpoint_object *bp_obj = (gdbpy_breakpoint_object *) bpfinish_obj; |
cc72b2a2 KP |
343 | PyObject *py_obj = (PyObject *) bp_obj; |
344 | ||
345 | if (bpfinish_obj->py_bp.bp->enable_state == bp_enabled | |
346 | && PyObject_HasAttrString (py_obj, outofscope_func)) | |
347 | { | |
18868860 TT |
348 | PyObject *meth_result; |
349 | ||
350 | meth_result = PyObject_CallMethod (py_obj, outofscope_func, NULL); | |
351 | if (meth_result == NULL) | |
352 | gdbpy_print_stack (); | |
353 | Py_XDECREF (meth_result); | |
cc72b2a2 KP |
354 | } |
355 | ||
356 | delete_breakpoint (bpfinish_obj->py_bp.bp); | |
357 | } | |
358 | ||
359 | /* Callback for `bpfinishpy_detect_out_scope'. Triggers Python's | |
360 | `B->out_of_scope' function if B is a FinishBreakpoint out of its scope. */ | |
361 | ||
362 | static int | |
363 | bpfinishpy_detect_out_scope_cb (struct breakpoint *b, void *args) | |
364 | { | |
cc72b2a2 KP |
365 | struct breakpoint *bp_stopped = (struct breakpoint *) args; |
366 | PyObject *py_bp = (PyObject *) b->py_bp_object; | |
367 | struct gdbarch *garch = b->gdbarch ? b->gdbarch : get_current_arch (); | |
256458bc | 368 | |
cc72b2a2 KP |
369 | /* Trigger out_of_scope if this is a FinishBreakpoint and its frame is |
370 | not anymore in the current callstack. */ | |
371 | if (py_bp != NULL && b->py_bp_object->is_finish_bp) | |
372 | { | |
373 | struct finish_breakpoint_object *finish_bp = | |
374 | (struct finish_breakpoint_object *) py_bp; | |
375 | ||
376 | /* Check scope if not currently stopped at the FinishBreakpoint. */ | |
377 | if (b != bp_stopped) | |
378 | { | |
492d29ea | 379 | TRY |
cc72b2a2 KP |
380 | { |
381 | if (b->pspace == current_inferior ()->pspace | |
382 | && (!target_has_registers | |
383 | || frame_find_by_id (b->frame_id) == NULL)) | |
384 | bpfinishpy_out_of_scope (finish_bp); | |
385 | } | |
492d29ea | 386 | CATCH (except, RETURN_MASK_ALL) |
cc72b2a2 KP |
387 | { |
388 | gdbpy_convert_exception (except); | |
389 | gdbpy_print_stack (); | |
390 | } | |
492d29ea | 391 | END_CATCH |
cc72b2a2 KP |
392 | } |
393 | } | |
394 | ||
395 | return 0; | |
396 | } | |
397 | ||
398 | /* Attached to `stop' notifications, check if the execution has run | |
399 | out of the scope of any FinishBreakpoint before it has been hit. */ | |
400 | ||
401 | static void | |
402 | bpfinishpy_handle_stop (struct bpstats *bs, int print_frame) | |
403 | { | |
404 | struct cleanup *cleanup = ensure_python_env (get_current_arch (), | |
405 | current_language); | |
406 | ||
407 | iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, | |
408 | bs == NULL ? NULL : bs->breakpoint_at); | |
409 | ||
410 | do_cleanups (cleanup); | |
411 | } | |
412 | ||
413 | /* Attached to `exit' notifications, triggers all the necessary out of | |
414 | scope notifications. */ | |
415 | ||
416 | static void | |
417 | bpfinishpy_handle_exit (struct inferior *inf) | |
418 | { | |
f5656ead | 419 | struct cleanup *cleanup = ensure_python_env (target_gdbarch (), |
cc72b2a2 KP |
420 | current_language); |
421 | ||
422 | iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, NULL); | |
423 | ||
424 | do_cleanups (cleanup); | |
425 | } | |
426 | ||
427 | /* Initialize the Python finish breakpoint code. */ | |
428 | ||
999633ed | 429 | int |
cc72b2a2 KP |
430 | gdbpy_initialize_finishbreakpoints (void) |
431 | { | |
432 | if (PyType_Ready (&finish_breakpoint_object_type) < 0) | |
999633ed | 433 | return -1; |
256458bc | 434 | |
aa36459a TT |
435 | if (gdb_pymodule_addobject (gdb_module, "FinishBreakpoint", |
436 | (PyObject *) &finish_breakpoint_object_type) < 0) | |
999633ed | 437 | return -1; |
256458bc | 438 | |
cc72b2a2 KP |
439 | observer_attach_normal_stop (bpfinishpy_handle_stop); |
440 | observer_attach_inferior_exit (bpfinishpy_handle_exit); | |
999633ed TT |
441 | |
442 | return 0; | |
cc72b2a2 KP |
443 | } |
444 | ||
445 | static PyGetSetDef finish_breakpoint_object_getset[] = { | |
446 | { "return_value", bpfinishpy_get_returnvalue, NULL, | |
447 | "gdb.Value object representing the return value, if any. \ | |
448 | None otherwise.", NULL }, | |
449 | { NULL } /* Sentinel. */ | |
450 | }; | |
451 | ||
e36122e9 | 452 | PyTypeObject finish_breakpoint_object_type = |
cc72b2a2 | 453 | { |
9a27f2c6 | 454 | PyVarObject_HEAD_INIT (NULL, 0) |
cc72b2a2 KP |
455 | "gdb.FinishBreakpoint", /*tp_name*/ |
456 | sizeof (struct finish_breakpoint_object), /*tp_basicsize*/ | |
457 | 0, /*tp_itemsize*/ | |
458 | bpfinishpy_dealloc, /*tp_dealloc*/ | |
459 | 0, /*tp_print*/ | |
460 | 0, /*tp_getattr*/ | |
461 | 0, /*tp_setattr*/ | |
462 | 0, /*tp_compare*/ | |
463 | 0, /*tp_repr*/ | |
464 | 0, /*tp_as_number*/ | |
465 | 0, /*tp_as_sequence*/ | |
466 | 0, /*tp_as_mapping*/ | |
467 | 0, /*tp_hash */ | |
468 | 0, /*tp_call*/ | |
469 | 0, /*tp_str*/ | |
470 | 0, /*tp_getattro*/ | |
471 | 0, /*tp_setattro */ | |
472 | 0, /*tp_as_buffer*/ | |
473 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ | |
474 | "GDB finish breakpoint object", /* tp_doc */ | |
475 | 0, /* tp_traverse */ | |
476 | 0, /* tp_clear */ | |
477 | 0, /* tp_richcompare */ | |
478 | 0, /* tp_weaklistoffset */ | |
479 | 0, /* tp_iter */ | |
480 | 0, /* tp_iternext */ | |
481 | 0, /* tp_methods */ | |
482 | 0, /* tp_members */ | |
483 | finish_breakpoint_object_getset,/* tp_getset */ | |
484 | &breakpoint_object_type, /* tp_base */ | |
485 | 0, /* tp_dict */ | |
486 | 0, /* tp_descr_get */ | |
487 | 0, /* tp_descr_set */ | |
488 | 0, /* tp_dictoffset */ | |
489 | bpfinishpy_init, /* tp_init */ | |
490 | 0, /* tp_alloc */ | |
491 | 0 /* tp_new */ | |
492 | }; |