]>
Commit | Line | Data |
---|---|---|
9c1412c1 AC |
1 | /* Code dealing with dummy stack frames, for GDB, the GNU debugger. |
2 | ||
1d506c26 | 3 | Copyright (C) 1986-2024 Free Software Foundation, Inc. |
9c1412c1 AC |
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 | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
9c1412c1 AC |
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 | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
9c1412c1 AC |
19 | |
20 | ||
9c1412c1 | 21 | #include "dummy-frame.h" |
4de283e4 | 22 | #include "regcache.h" |
d55e5aa6 | 23 | #include "frame.h" |
4de283e4 TT |
24 | #include "inferior.h" |
25 | #include "frame-unwind.h" | |
26 | #include "command.h" | |
5b9707eb | 27 | #include "cli/cli-cmds.h" |
4de283e4 | 28 | #include "observable.h" |
e2e4d78b | 29 | #include "gdbthread.h" |
5e970501 | 30 | #include "infcall.h" |
0d12e84c | 31 | #include "gdbarch.h" |
9c1412c1 | 32 | |
b67a2c6f YQ |
33 | struct dummy_frame_id |
34 | { | |
35 | /* This frame's ID. Must match the value returned by | |
36 | gdbarch_dummy_id. */ | |
37 | struct frame_id id; | |
38 | ||
39 | /* The thread this dummy_frame relates to. */ | |
00431a78 | 40 | thread_info *thread; |
b67a2c6f YQ |
41 | }; |
42 | ||
43 | /* Return whether dummy_frame_id *ID1 and *ID2 are equal. */ | |
44 | ||
45 | static int | |
46 | dummy_frame_id_eq (struct dummy_frame_id *id1, | |
47 | struct dummy_frame_id *id2) | |
48 | { | |
a0cbd650 | 49 | return id1->id == id2->id && id1->thread == id2->thread; |
b67a2c6f YQ |
50 | } |
51 | ||
10989690 JK |
52 | /* List of dummy_frame destructors. */ |
53 | ||
54 | struct dummy_frame_dtor_list | |
55 | { | |
56 | /* Next element in the list or NULL if this is the last element. */ | |
57 | struct dummy_frame_dtor_list *next; | |
58 | ||
59 | /* If non-NULL, a destructor that is run when this dummy frame is freed. */ | |
60 | dummy_frame_dtor_ftype *dtor; | |
61 | ||
62 | /* Arbitrary data that is passed to DTOR. */ | |
63 | void *dtor_data; | |
64 | }; | |
65 | ||
9c1412c1 AC |
66 | /* Dummy frame. This saves the processor state just prior to setting |
67 | up the inferior function call. Older targets save the registers | |
68 | on the target stack (but that really slows down function calls). */ | |
69 | ||
70 | struct dummy_frame | |
71 | { | |
72 | struct dummy_frame *next; | |
b67a2c6f YQ |
73 | |
74 | /* An id represents a dummy frame. */ | |
75 | struct dummy_frame_id id; | |
76 | ||
b89667eb | 77 | /* The caller's state prior to the call. */ |
16c381f0 | 78 | struct infcall_suspend_state *caller_state; |
233a8fb3 | 79 | |
10989690 JK |
80 | /* First element of destructors list or NULL if there are no |
81 | destructors registered for this dummy_frame. */ | |
82 | struct dummy_frame_dtor_list *dtor_list; | |
9c1412c1 AC |
83 | }; |
84 | ||
85 | static struct dummy_frame *dummy_frame_stack = NULL; | |
86 | ||
b89667eb | 87 | /* Push the caller's state, along with the dummy frame info, onto the |
96860204 | 88 | dummy-frame stack. */ |
9c1412c1 AC |
89 | |
90 | void | |
16c381f0 | 91 | dummy_frame_push (struct infcall_suspend_state *caller_state, |
00431a78 | 92 | const frame_id *dummy_id, thread_info *thread) |
9c1412c1 AC |
93 | { |
94 | struct dummy_frame *dummy_frame; | |
9c1412c1 | 95 | |
41bf6aca | 96 | dummy_frame = XCNEW (struct dummy_frame); |
b89667eb | 97 | dummy_frame->caller_state = caller_state; |
b67a2c6f | 98 | dummy_frame->id.id = (*dummy_id); |
00431a78 | 99 | dummy_frame->id.thread = thread; |
9c1412c1 AC |
100 | dummy_frame->next = dummy_frame_stack; |
101 | dummy_frame_stack = dummy_frame; | |
102 | } | |
103 | ||
b89667eb | 104 | /* Remove *DUMMY_PTR from the dummy frame stack. */ |
a45ae3ed | 105 | |
b89667eb DE |
106 | static void |
107 | remove_dummy_frame (struct dummy_frame **dummy_ptr) | |
a45ae3ed | 108 | { |
b89667eb | 109 | struct dummy_frame *dummy = *dummy_ptr; |
a45ae3ed | 110 | |
10989690 JK |
111 | while (dummy->dtor_list != NULL) |
112 | { | |
113 | struct dummy_frame_dtor_list *list = dummy->dtor_list; | |
114 | ||
115 | dummy->dtor_list = list->next; | |
116 | list->dtor (list->dtor_data, 0); | |
117 | xfree (list); | |
118 | } | |
5e970501 | 119 | |
b89667eb | 120 | *dummy_ptr = dummy->next; |
16c381f0 | 121 | discard_infcall_suspend_state (dummy->caller_state); |
b89667eb | 122 | xfree (dummy); |
a45ae3ed UW |
123 | } |
124 | ||
e2e4d78b JK |
125 | /* Delete any breakpoint B which is a momentary breakpoint for return from |
126 | inferior call matching DUMMY_VOIDP. */ | |
127 | ||
95da600f CB |
128 | static bool |
129 | pop_dummy_frame_bpt (struct breakpoint *b, struct dummy_frame *dummy) | |
e2e4d78b | 130 | { |
00431a78 | 131 | if (b->thread == dummy->id.thread->global_num |
a0cbd650 | 132 | && b->disposition == disp_del && b->frame_id == dummy->id.id) |
e2e4d78b JK |
133 | { |
134 | while (b->related_breakpoint != b) | |
135 | delete_breakpoint (b->related_breakpoint); | |
136 | ||
137 | delete_breakpoint (b); | |
138 | ||
139 | /* Stop the traversal. */ | |
95da600f | 140 | return true; |
e2e4d78b JK |
141 | } |
142 | ||
143 | /* Continue the traversal. */ | |
95da600f | 144 | return false; |
e2e4d78b JK |
145 | } |
146 | ||
b89667eb DE |
147 | /* Pop *DUMMY_PTR, restoring program state to that before the |
148 | frame was created. */ | |
a45ae3ed UW |
149 | |
150 | static void | |
b89667eb | 151 | pop_dummy_frame (struct dummy_frame **dummy_ptr) |
a45ae3ed | 152 | { |
e2e4d78b JK |
153 | struct dummy_frame *dummy = *dummy_ptr; |
154 | ||
00431a78 | 155 | gdb_assert (dummy->id.thread == inferior_thread ()); |
233a8fb3 | 156 | |
10989690 JK |
157 | while (dummy->dtor_list != NULL) |
158 | { | |
159 | struct dummy_frame_dtor_list *list = dummy->dtor_list; | |
160 | ||
161 | dummy->dtor_list = list->next; | |
162 | list->dtor (list->dtor_data, 1); | |
163 | xfree (list); | |
164 | } | |
233a8fb3 | 165 | |
e2e4d78b | 166 | restore_infcall_suspend_state (dummy->caller_state); |
a45ae3ed | 167 | |
a1decfc1 SM |
168 | for (breakpoint &bp : all_breakpoints_safe ()) |
169 | if (pop_dummy_frame_bpt (&bp, dummy)) | |
240edef6 | 170 | break; |
b89667eb | 171 | |
16c381f0 | 172 | /* restore_infcall_control_state frees inf_state, |
0963b4bd | 173 | all that remains is to pop *dummy_ptr. */ |
b89667eb DE |
174 | *dummy_ptr = dummy->next; |
175 | xfree (dummy); | |
176 | ||
177 | /* We've made right mess of GDB's local state, just discard | |
178 | everything. */ | |
179 | reinit_frame_cache (); | |
180 | } | |
181 | ||
182 | /* Look up DUMMY_ID. | |
183 | Return NULL if not found. */ | |
184 | ||
185 | static struct dummy_frame ** | |
b67a2c6f | 186 | lookup_dummy_frame (struct dummy_frame_id *dummy_id) |
b89667eb DE |
187 | { |
188 | struct dummy_frame **dp; | |
189 | ||
190 | for (dp = &dummy_frame_stack; *dp != NULL; dp = &(*dp)->next) | |
a45ae3ed | 191 | { |
b67a2c6f | 192 | if (dummy_frame_id_eq (&(*dp)->id, dummy_id)) |
b89667eb | 193 | return dp; |
a45ae3ed UW |
194 | } |
195 | ||
b89667eb DE |
196 | return NULL; |
197 | } | |
198 | ||
00431a78 | 199 | /* Find the dummy frame by DUMMY_ID and THREAD, and pop it, restoring |
b67a2c6f | 200 | program state to that before the frame was created. |
b89667eb | 201 | On return reinit_frame_cache has been called. |
b67a2c6f | 202 | If the frame isn't found, flag an internal error. */ |
b89667eb DE |
203 | |
204 | void | |
00431a78 | 205 | dummy_frame_pop (frame_id dummy_id, thread_info *thread) |
b89667eb DE |
206 | { |
207 | struct dummy_frame **dp; | |
00431a78 | 208 | struct dummy_frame_id id = { dummy_id, thread }; |
b89667eb | 209 | |
b67a2c6f | 210 | dp = lookup_dummy_frame (&id); |
b89667eb DE |
211 | gdb_assert (dp != NULL); |
212 | ||
213 | pop_dummy_frame (dp); | |
214 | } | |
215 | ||
b67a2c6f YQ |
216 | /* Find the dummy frame by DUMMY_ID and PTID and drop it. Do nothing |
217 | if it is not found. Do not restore its state into inferior, just | |
218 | free its memory. */ | |
e2e4d78b JK |
219 | |
220 | void | |
00431a78 | 221 | dummy_frame_discard (struct frame_id dummy_id, thread_info *thread) |
e2e4d78b JK |
222 | { |
223 | struct dummy_frame **dp; | |
00431a78 | 224 | struct dummy_frame_id id = { dummy_id, thread }; |
e2e4d78b | 225 | |
b67a2c6f | 226 | dp = lookup_dummy_frame (&id); |
e2e4d78b JK |
227 | if (dp) |
228 | remove_dummy_frame (dp); | |
229 | } | |
230 | ||
233a8fb3 JK |
231 | /* See dummy-frame.h. */ |
232 | ||
233 | void | |
00431a78 | 234 | register_dummy_frame_dtor (frame_id dummy_id, thread_info *thread, |
233a8fb3 JK |
235 | dummy_frame_dtor_ftype *dtor, void *dtor_data) |
236 | { | |
00431a78 | 237 | struct dummy_frame_id id = { dummy_id, thread }; |
233a8fb3 | 238 | struct dummy_frame **dp, *d; |
10989690 | 239 | struct dummy_frame_dtor_list *list; |
233a8fb3 JK |
240 | |
241 | dp = lookup_dummy_frame (&id); | |
242 | gdb_assert (dp != NULL); | |
243 | d = *dp; | |
8d749320 | 244 | list = XNEW (struct dummy_frame_dtor_list); |
10989690 JK |
245 | list->next = d->dtor_list; |
246 | d->dtor_list = list; | |
247 | list->dtor = dtor; | |
248 | list->dtor_data = dtor_data; | |
233a8fb3 JK |
249 | } |
250 | ||
251 | /* See dummy-frame.h. */ | |
252 | ||
253 | int | |
254 | find_dummy_frame_dtor (dummy_frame_dtor_ftype *dtor, void *dtor_data) | |
255 | { | |
256 | struct dummy_frame *d; | |
257 | ||
258 | for (d = dummy_frame_stack; d != NULL; d = d->next) | |
10989690 JK |
259 | { |
260 | struct dummy_frame_dtor_list *list; | |
261 | ||
262 | for (list = d->dtor_list; list != NULL; list = list->next) | |
263 | if (list->dtor == dtor && list->dtor_data == dtor_data) | |
264 | return 1; | |
265 | } | |
233a8fb3 JK |
266 | return 0; |
267 | } | |
268 | ||
e2e4d78b JK |
269 | /* There may be stale dummy frames, perhaps left over from when an uncaught |
270 | longjmp took us out of a function that was called by the debugger. Clean | |
271 | them up at least once whenever we start a new inferior. */ | |
b89667eb DE |
272 | |
273 | static void | |
a0ff652f | 274 | cleanup_dummy_frames (inferior *inf) |
b89667eb DE |
275 | { |
276 | while (dummy_frame_stack != NULL) | |
277 | remove_dummy_frame (&dummy_frame_stack); | |
a45ae3ed UW |
278 | } |
279 | ||
d67ec5db AC |
280 | /* Return the dummy frame cache, it contains both the ID, and a |
281 | pointer to the regcache. */ | |
282 | struct dummy_frame_cache | |
283 | { | |
284 | struct frame_id this_id; | |
daf6667d | 285 | readonly_detached_regcache *prev_regcache; |
d67ec5db AC |
286 | }; |
287 | ||
b89667eb | 288 | static int |
d67ec5db | 289 | dummy_frame_sniffer (const struct frame_unwind *self, |
8480a37e | 290 | const frame_info_ptr &this_frame, |
d67ec5db AC |
291 | void **this_prologue_cache) |
292 | { | |
d67ec5db AC |
293 | /* When unwinding a normal frame, the stack structure is determined |
294 | by analyzing the frame's function's code (be it using brute force | |
295 | prologue analysis, or the dwarf2 CFI). In the case of a dummy | |
296 | frame, that simply isn't possible. The PC is either the program | |
297 | entry point, or some random address on the stack. Trying to use | |
298 | that PC to apply standard frame ID unwind techniques is just | |
299 | asking for trouble. */ | |
0c98cc2b | 300 | |
b89667eb | 301 | /* Don't bother unless there is at least one dummy frame. */ |
0c98cc2b | 302 | if (dummy_frame_stack != NULL) |
d67ec5db | 303 | { |
efc889c1 | 304 | struct dummy_frame *dummyframe; |
669fac23 DJ |
305 | /* Use an architecture specific method to extract this frame's |
306 | dummy ID, assuming it is a dummy frame. */ | |
efc889c1 YQ |
307 | struct frame_id this_id |
308 | = gdbarch_dummy_id (get_frame_arch (this_frame), this_frame); | |
00431a78 | 309 | struct dummy_frame_id dummy_id = { this_id, inferior_thread () }; |
0c98cc2b MS |
310 | |
311 | /* Use that ID to find the corresponding cache entry. */ | |
312 | for (dummyframe = dummy_frame_stack; | |
313 | dummyframe != NULL; | |
314 | dummyframe = dummyframe->next) | |
3c109c8b | 315 | { |
b67a2c6f | 316 | if (dummy_frame_id_eq (&dummyframe->id, &dummy_id)) |
0c98cc2b MS |
317 | { |
318 | struct dummy_frame_cache *cache; | |
9a619af0 | 319 | |
0c98cc2b | 320 | cache = FRAME_OBSTACK_ZALLOC (struct dummy_frame_cache); |
16c381f0 JK |
321 | cache->prev_regcache = get_infcall_suspend_state_regcache |
322 | (dummyframe->caller_state); | |
0c98cc2b MS |
323 | cache->this_id = this_id; |
324 | (*this_prologue_cache) = cache; | |
325 | return 1; | |
326 | } | |
3c109c8b | 327 | } |
d67ec5db AC |
328 | } |
329 | return 0; | |
330 | } | |
331 | ||
9c1412c1 AC |
332 | /* Given a call-dummy dummy-frame, return the registers. Here the |
333 | register value is taken from the local copy of the register buffer. */ | |
334 | ||
669fac23 | 335 | static struct value * |
8480a37e | 336 | dummy_frame_prev_register (const frame_info_ptr &this_frame, |
6dc42492 | 337 | void **this_prologue_cache, |
669fac23 | 338 | int regnum) |
9c1412c1 | 339 | { |
9a3c8263 SM |
340 | struct dummy_frame_cache *cache |
341 | = (struct dummy_frame_cache *) *this_prologue_cache; | |
669fac23 DJ |
342 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
343 | struct value *reg_val; | |
344 | ||
345 | /* The dummy-frame sniffer always fills in the cache. */ | |
d67ec5db | 346 | gdb_assert (cache != NULL); |
9c1412c1 AC |
347 | |
348 | /* Describe the register's location. Generic dummy frames always | |
349 | have the register value in an ``expression''. */ | |
ee7bb294 | 350 | reg_val = value::zero (register_type (gdbarch, regnum), not_lval); |
669fac23 DJ |
351 | |
352 | /* Use the regcache_cooked_read() method so that it, on the fly, | |
353 | constructs either a raw or pseudo register from the raw | |
354 | register cache. */ | |
50888e42 | 355 | cache->prev_regcache->cooked_read |
bbe912ba | 356 | (regnum, reg_val->contents_writeable ().data ()); |
669fac23 | 357 | return reg_val; |
9c1412c1 AC |
358 | } |
359 | ||
b89667eb | 360 | /* Assuming that THIS_FRAME is a dummy, return its ID. That ID is |
6dc42492 | 361 | determined by examining the NEXT frame's unwound registers using |
669fac23 | 362 | the method dummy_id(). As a side effect, THIS dummy frame's |
7a9dd1b2 | 363 | dummy cache is located and saved in THIS_PROLOGUE_CACHE. */ |
494cca16 AC |
364 | |
365 | static void | |
8480a37e | 366 | dummy_frame_this_id (const frame_info_ptr &this_frame, |
6dc42492 AC |
367 | void **this_prologue_cache, |
368 | struct frame_id *this_id) | |
c689142b | 369 | { |
d67ec5db | 370 | /* The dummy-frame sniffer always fills in the cache. */ |
9a3c8263 SM |
371 | struct dummy_frame_cache *cache |
372 | = (struct dummy_frame_cache *) *this_prologue_cache; | |
9a619af0 | 373 | |
d67ec5db AC |
374 | gdb_assert (cache != NULL); |
375 | (*this_id) = cache->this_id; | |
c689142b AC |
376 | } |
377 | ||
39d7b0e2 | 378 | const struct frame_unwind dummy_frame_unwind = |
494cca16 | 379 | { |
a154d838 | 380 | "dummy", |
7df05f2b | 381 | DUMMY_FRAME, |
8fbca658 | 382 | default_frame_unwind_stop_reason, |
6dc42492 | 383 | dummy_frame_this_id, |
d67ec5db AC |
384 | dummy_frame_prev_register, |
385 | NULL, | |
386 | dummy_frame_sniffer, | |
494cca16 AC |
387 | }; |
388 | ||
8bcb5208 AB |
389 | /* See dummy-frame.h. */ |
390 | ||
391 | struct frame_id | |
8480a37e | 392 | default_dummy_id (struct gdbarch *gdbarch, const frame_info_ptr &this_frame) |
8bcb5208 AB |
393 | { |
394 | CORE_ADDR sp, pc; | |
395 | ||
396 | sp = get_frame_sp (this_frame); | |
397 | pc = get_frame_pc (this_frame); | |
398 | return frame_id_build (sp, pc); | |
399 | } | |
400 | ||
00905d52 AC |
401 | static void |
402 | fprint_dummy_frames (struct ui_file *file) | |
403 | { | |
404 | struct dummy_frame *s; | |
9a619af0 | 405 | |
00905d52 | 406 | for (s = dummy_frame_stack; s != NULL; s = s->next) |
6cb06a8c TT |
407 | gdb_printf (file, "%s: id=%s, ptid=%s\n", |
408 | host_address_to_string (s), | |
409 | s->id.id.to_string ().c_str (), | |
410 | s->id.thread->ptid.to_string ().c_str ()); | |
00905d52 AC |
411 | } |
412 | ||
413 | static void | |
31d56ade | 414 | maintenance_print_dummy_frames (const char *args, int from_tty) |
00905d52 AC |
415 | { |
416 | if (args == NULL) | |
417 | fprint_dummy_frames (gdb_stdout); | |
418 | else | |
419 | { | |
d7e74731 | 420 | stdio_file file; |
9a619af0 | 421 | |
d7e74731 | 422 | if (!file.open (args, "w")) |
e2e0b3e5 | 423 | perror_with_name (_("maintenance print dummy-frames")); |
d7e74731 | 424 | fprint_dummy_frames (&file); |
00905d52 AC |
425 | } |
426 | } | |
427 | ||
6c265988 | 428 | void _initialize_dummy_frame (); |
00905d52 | 429 | void |
6c265988 | 430 | _initialize_dummy_frame () |
00905d52 AC |
431 | { |
432 | add_cmd ("dummy-frames", class_maintenance, maintenance_print_dummy_frames, | |
1a966eab | 433 | _("Print the contents of the internal dummy-frame stack."), |
00905d52 AC |
434 | &maintenanceprintlist); |
435 | ||
c90e7d63 | 436 | gdb::observers::inferior_created.attach (cleanup_dummy_frames, "dummy-frame"); |
00905d52 | 437 | } |