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1 | /* Cache and manage frames for GDB, the GNU debugger. | |
2 | ||
3 | Copyright (C) 1986-2023 Free Software Foundation, Inc. | |
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 | #include "defs.h" | |
21 | #include "frame.h" | |
22 | #include "target.h" | |
23 | #include "value.h" | |
24 | #include "inferior.h" | |
25 | #include "regcache.h" | |
26 | #include "user-regs.h" | |
27 | #include "gdbsupport/gdb_obstack.h" | |
28 | #include "dummy-frame.h" | |
29 | #include "sentinel-frame.h" | |
30 | #include "gdbcore.h" | |
31 | #include "annotate.h" | |
32 | #include "language.h" | |
33 | #include "frame-unwind.h" | |
34 | #include "frame-base.h" | |
35 | #include "command.h" | |
36 | #include "gdbcmd.h" | |
37 | #include "observable.h" | |
38 | #include "objfiles.h" | |
39 | #include "gdbthread.h" | |
40 | #include "block.h" | |
41 | #include "inline-frame.h" | |
42 | #include "tracepoint.h" | |
43 | #include "hashtab.h" | |
44 | #include "valprint.h" | |
45 | #include "cli/cli-option.h" | |
46 | #include "dwarf2/loc.h" | |
47 | ||
48 | /* The sentinel frame terminates the innermost end of the frame chain. | |
49 | If unwound, it returns the information needed to construct an | |
50 | innermost frame. | |
51 | ||
52 | The current frame, which is the innermost frame, can be found at | |
53 | sentinel_frame->prev. | |
54 | ||
55 | This is an optimization to be able to find the sentinel frame quickly, | |
56 | it could otherwise be found in the frame cache. */ | |
57 | ||
58 | static frame_info *sentinel_frame; | |
59 | ||
60 | /* Number of calls to reinit_frame_cache. */ | |
61 | static unsigned int frame_cache_generation = 0; | |
62 | ||
63 | /* See frame.h. */ | |
64 | ||
65 | unsigned int | |
66 | get_frame_cache_generation () | |
67 | { | |
68 | return frame_cache_generation; | |
69 | } | |
70 | ||
71 | /* The values behind the global "set backtrace ..." settings. */ | |
72 | set_backtrace_options user_set_backtrace_options; | |
73 | ||
74 | static frame_info_ptr get_prev_frame_raw (frame_info_ptr this_frame); | |
75 | static const char *frame_stop_reason_symbol_string (enum unwind_stop_reason reason); | |
76 | static frame_info_ptr create_new_frame (frame_id id); | |
77 | ||
78 | /* Status of some values cached in the frame_info object. */ | |
79 | ||
80 | enum cached_copy_status | |
81 | { | |
82 | /* Value is unknown. */ | |
83 | CC_UNKNOWN, | |
84 | ||
85 | /* We have a value. */ | |
86 | CC_VALUE, | |
87 | ||
88 | /* Value was not saved. */ | |
89 | CC_NOT_SAVED, | |
90 | ||
91 | /* Value is unavailable. */ | |
92 | CC_UNAVAILABLE | |
93 | }; | |
94 | ||
95 | enum class frame_id_status | |
96 | { | |
97 | /* Frame id is not computed. */ | |
98 | NOT_COMPUTED = 0, | |
99 | ||
100 | /* Frame id is being computed (compute_frame_id is active). */ | |
101 | COMPUTING, | |
102 | ||
103 | /* Frame id has been computed. */ | |
104 | COMPUTED, | |
105 | }; | |
106 | ||
107 | /* We keep a cache of stack frames, each of which is a "struct | |
108 | frame_info". The innermost one gets allocated (in | |
109 | wait_for_inferior) each time the inferior stops; sentinel_frame | |
110 | points to it. Additional frames get allocated (in get_prev_frame) | |
111 | as needed, and are chained through the next and prev fields. Any | |
112 | time that the frame cache becomes invalid (most notably when we | |
113 | execute something, but also if we change how we interpret the | |
114 | frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything | |
115 | which reads new symbols)), we should call reinit_frame_cache. */ | |
116 | ||
117 | struct frame_info | |
118 | { | |
119 | /* Return a string representation of this frame. */ | |
120 | std::string to_string () const; | |
121 | ||
122 | /* Level of this frame. The inner-most (youngest) frame is at level | |
123 | 0. As you move towards the outer-most (oldest) frame, the level | |
124 | increases. This is a cached value. It could just as easily be | |
125 | computed by counting back from the selected frame to the inner | |
126 | most frame. */ | |
127 | /* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be | |
128 | reserved to indicate a bogus frame - one that has been created | |
129 | just to keep GDB happy (GDB always needs a frame). For the | |
130 | moment leave this as speculation. */ | |
131 | int level; | |
132 | ||
133 | /* The frame's program space. */ | |
134 | struct program_space *pspace; | |
135 | ||
136 | /* The frame's address space. */ | |
137 | const address_space *aspace; | |
138 | ||
139 | /* The frame's low-level unwinder and corresponding cache. The | |
140 | low-level unwinder is responsible for unwinding register values | |
141 | for the previous frame. The low-level unwind methods are | |
142 | selected based on the presence, or otherwise, of register unwind | |
143 | information such as CFI. */ | |
144 | void *prologue_cache; | |
145 | const struct frame_unwind *unwind; | |
146 | ||
147 | /* Cached copy of the previous frame's architecture. */ | |
148 | struct | |
149 | { | |
150 | bool p; | |
151 | struct gdbarch *arch; | |
152 | } prev_arch; | |
153 | ||
154 | /* Cached copy of the previous frame's resume address. */ | |
155 | struct { | |
156 | cached_copy_status status; | |
157 | /* Did VALUE require unmasking when being read. */ | |
158 | bool masked; | |
159 | CORE_ADDR value; | |
160 | } prev_pc; | |
161 | ||
162 | /* Cached copy of the previous frame's function address. */ | |
163 | struct | |
164 | { | |
165 | CORE_ADDR addr; | |
166 | cached_copy_status status; | |
167 | } prev_func; | |
168 | ||
169 | /* This frame's ID. */ | |
170 | struct | |
171 | { | |
172 | frame_id_status p; | |
173 | struct frame_id value; | |
174 | } this_id; | |
175 | ||
176 | /* The frame's high-level base methods, and corresponding cache. | |
177 | The high level base methods are selected based on the frame's | |
178 | debug info. */ | |
179 | const struct frame_base *base; | |
180 | void *base_cache; | |
181 | ||
182 | /* Pointers to the next (down, inner, younger) and previous (up, | |
183 | outer, older) frame_info's in the frame cache. */ | |
184 | struct frame_info *next; /* down, inner, younger */ | |
185 | bool prev_p; | |
186 | struct frame_info *prev; /* up, outer, older */ | |
187 | ||
188 | /* The reason why we could not set PREV, or UNWIND_NO_REASON if we | |
189 | could. Only valid when PREV_P is set. */ | |
190 | enum unwind_stop_reason stop_reason; | |
191 | ||
192 | /* A frame specific string describing the STOP_REASON in more detail. | |
193 | Only valid when PREV_P is set, but even then may still be NULL. */ | |
194 | const char *stop_string; | |
195 | }; | |
196 | ||
197 | /* See frame.h. */ | |
198 | ||
199 | void | |
200 | set_frame_previous_pc_masked (frame_info_ptr frame) | |
201 | { | |
202 | frame->prev_pc.masked = true; | |
203 | } | |
204 | ||
205 | /* See frame.h. */ | |
206 | ||
207 | bool | |
208 | get_frame_pc_masked (frame_info_ptr frame) | |
209 | { | |
210 | gdb_assert (frame->next != nullptr); | |
211 | gdb_assert (frame->next->prev_pc.status == CC_VALUE); | |
212 | ||
213 | return frame->next->prev_pc.masked; | |
214 | } | |
215 | ||
216 | /* A frame stash used to speed up frame lookups. Create a hash table | |
217 | to stash frames previously accessed from the frame cache for | |
218 | quicker subsequent retrieval. The hash table is emptied whenever | |
219 | the frame cache is invalidated. */ | |
220 | ||
221 | static htab_t frame_stash; | |
222 | ||
223 | /* Internal function to calculate a hash from the frame_id addresses, | |
224 | using as many valid addresses as possible. Frames below level 0 | |
225 | are not stored in the hash table. */ | |
226 | ||
227 | static hashval_t | |
228 | frame_addr_hash (const void *ap) | |
229 | { | |
230 | const frame_info *frame = (const frame_info *) ap; | |
231 | const struct frame_id f_id = frame->this_id.value; | |
232 | hashval_t hash = 0; | |
233 | ||
234 | gdb_assert (f_id.stack_status != FID_STACK_INVALID | |
235 | || f_id.code_addr_p | |
236 | || f_id.special_addr_p); | |
237 | ||
238 | if (f_id.stack_status == FID_STACK_VALID) | |
239 | hash = iterative_hash (&f_id.stack_addr, | |
240 | sizeof (f_id.stack_addr), hash); | |
241 | if (f_id.code_addr_p) | |
242 | hash = iterative_hash (&f_id.code_addr, | |
243 | sizeof (f_id.code_addr), hash); | |
244 | if (f_id.special_addr_p) | |
245 | hash = iterative_hash (&f_id.special_addr, | |
246 | sizeof (f_id.special_addr), hash); | |
247 | ||
248 | char user_created_p = f_id.user_created_p; | |
249 | hash = iterative_hash (&user_created_p, sizeof (user_created_p), hash); | |
250 | ||
251 | return hash; | |
252 | } | |
253 | ||
254 | /* Internal equality function for the hash table. This function | |
255 | defers equality operations to frame_id::operator==. */ | |
256 | ||
257 | static int | |
258 | frame_addr_hash_eq (const void *a, const void *b) | |
259 | { | |
260 | const frame_info *f_entry = (const frame_info *) a; | |
261 | const frame_info *f_element = (const frame_info *) b; | |
262 | ||
263 | return f_entry->this_id.value == f_element->this_id.value; | |
264 | } | |
265 | ||
266 | /* Deletion function for the frame cache hash table. */ | |
267 | ||
268 | static void | |
269 | frame_info_del (frame_info *frame) | |
270 | { | |
271 | if (frame->prologue_cache != nullptr | |
272 | && frame->unwind->dealloc_cache != nullptr) | |
273 | frame->unwind->dealloc_cache (frame, frame->prologue_cache); | |
274 | ||
275 | if (frame->base_cache != nullptr | |
276 | && frame->base->unwind->dealloc_cache != nullptr) | |
277 | frame->base->unwind->dealloc_cache (frame, frame->base_cache); | |
278 | } | |
279 | ||
280 | /* Internal function to create the frame_stash hash table. 100 seems | |
281 | to be a good compromise to start the hash table at. */ | |
282 | ||
283 | static void | |
284 | frame_stash_create (void) | |
285 | { | |
286 | frame_stash = htab_create | |
287 | (100, frame_addr_hash, frame_addr_hash_eq, | |
288 | [] (void *p) | |
289 | { | |
290 | auto frame = static_cast<frame_info *> (p); | |
291 | frame_info_del (frame); | |
292 | }); | |
293 | } | |
294 | ||
295 | /* Internal function to add a frame to the frame_stash hash table. | |
296 | Returns false if a frame with the same ID was already stashed, true | |
297 | otherwise. */ | |
298 | ||
299 | static bool | |
300 | frame_stash_add (frame_info *frame) | |
301 | { | |
302 | /* Valid frame levels are -1 (sentinel frames) and above. */ | |
303 | gdb_assert (frame->level >= -1); | |
304 | ||
305 | frame_info **slot = (frame_info **) htab_find_slot (frame_stash, | |
306 | frame, INSERT); | |
307 | ||
308 | /* If we already have a frame in the stack with the same id, we | |
309 | either have a stack cycle (corrupted stack?), or some bug | |
310 | elsewhere in GDB. In any case, ignore the duplicate and return | |
311 | an indication to the caller. */ | |
312 | if (*slot != nullptr) | |
313 | return false; | |
314 | ||
315 | *slot = frame; | |
316 | return true; | |
317 | } | |
318 | ||
319 | /* Internal function to search the frame stash for an entry with the | |
320 | given frame ID. If found, return that frame. Otherwise return | |
321 | NULL. */ | |
322 | ||
323 | static frame_info_ptr | |
324 | frame_stash_find (struct frame_id id) | |
325 | { | |
326 | struct frame_info dummy; | |
327 | frame_info *frame; | |
328 | ||
329 | dummy.this_id.value = id; | |
330 | frame = (frame_info *) htab_find (frame_stash, &dummy); | |
331 | return frame_info_ptr (frame); | |
332 | } | |
333 | ||
334 | /* Internal function to invalidate the frame stash by removing all | |
335 | entries in it. This only occurs when the frame cache is | |
336 | invalidated. */ | |
337 | ||
338 | static void | |
339 | frame_stash_invalidate (void) | |
340 | { | |
341 | htab_empty (frame_stash); | |
342 | } | |
343 | ||
344 | /* See frame.h */ | |
345 | scoped_restore_selected_frame::scoped_restore_selected_frame () | |
346 | { | |
347 | m_lang = current_language->la_language; | |
348 | save_selected_frame (&m_fid, &m_level); | |
349 | } | |
350 | ||
351 | /* See frame.h */ | |
352 | scoped_restore_selected_frame::~scoped_restore_selected_frame () | |
353 | { | |
354 | restore_selected_frame (m_fid, m_level); | |
355 | set_language (m_lang); | |
356 | } | |
357 | ||
358 | /* Flag to control debugging. */ | |
359 | ||
360 | bool frame_debug; | |
361 | ||
362 | static void | |
363 | show_frame_debug (struct ui_file *file, int from_tty, | |
364 | struct cmd_list_element *c, const char *value) | |
365 | { | |
366 | gdb_printf (file, _("Frame debugging is %s.\n"), value); | |
367 | } | |
368 | ||
369 | /* Implementation of "show backtrace past-main". */ | |
370 | ||
371 | static void | |
372 | show_backtrace_past_main (struct ui_file *file, int from_tty, | |
373 | struct cmd_list_element *c, const char *value) | |
374 | { | |
375 | gdb_printf (file, | |
376 | _("Whether backtraces should " | |
377 | "continue past \"main\" is %s.\n"), | |
378 | value); | |
379 | } | |
380 | ||
381 | /* Implementation of "show backtrace past-entry". */ | |
382 | ||
383 | static void | |
384 | show_backtrace_past_entry (struct ui_file *file, int from_tty, | |
385 | struct cmd_list_element *c, const char *value) | |
386 | { | |
387 | gdb_printf (file, _("Whether backtraces should continue past the " | |
388 | "entry point of a program is %s.\n"), | |
389 | value); | |
390 | } | |
391 | ||
392 | /* Implementation of "show backtrace limit". */ | |
393 | ||
394 | static void | |
395 | show_backtrace_limit (struct ui_file *file, int from_tty, | |
396 | struct cmd_list_element *c, const char *value) | |
397 | { | |
398 | gdb_printf (file, | |
399 | _("An upper bound on the number " | |
400 | "of backtrace levels is %s.\n"), | |
401 | value); | |
402 | } | |
403 | ||
404 | /* See frame.h. */ | |
405 | ||
406 | std::string | |
407 | frame_id::to_string () const | |
408 | { | |
409 | const struct frame_id &id = *this; | |
410 | ||
411 | std::string res = "{"; | |
412 | ||
413 | if (id.stack_status == FID_STACK_INVALID) | |
414 | res += "!stack"; | |
415 | else if (id.stack_status == FID_STACK_UNAVAILABLE) | |
416 | res += "stack=<unavailable>"; | |
417 | else if (id.stack_status == FID_STACK_SENTINEL) | |
418 | res += "stack=<sentinel>"; | |
419 | else if (id.stack_status == FID_STACK_OUTER) | |
420 | res += "stack=<outer>"; | |
421 | else | |
422 | res += std::string ("stack=") + hex_string (id.stack_addr); | |
423 | ||
424 | /* Helper function to format 'N=A' if P is true, otherwise '!N'. */ | |
425 | auto field_to_string = [] (const char *n, bool p, CORE_ADDR a) -> std::string | |
426 | { | |
427 | if (p) | |
428 | return std::string (n) + "=" + core_addr_to_string (a); | |
429 | else | |
430 | return std::string ("!") + std::string (n); | |
431 | }; | |
432 | ||
433 | res += (std::string (",") | |
434 | + field_to_string ("code", id.code_addr_p, id.code_addr) | |
435 | + std::string (",") | |
436 | + field_to_string ("special", id.special_addr_p, id.special_addr)); | |
437 | ||
438 | if (id.artificial_depth) | |
439 | res += ",artificial=" + std::to_string (id.artificial_depth); | |
440 | res += "}"; | |
441 | return res; | |
442 | } | |
443 | ||
444 | /* See frame.h. */ | |
445 | ||
446 | const char * | |
447 | frame_type_str (frame_type type) | |
448 | { | |
449 | switch (type) | |
450 | { | |
451 | case NORMAL_FRAME: | |
452 | return "NORMAL_FRAME"; | |
453 | ||
454 | case DUMMY_FRAME: | |
455 | return "DUMMY_FRAME"; | |
456 | ||
457 | case INLINE_FRAME: | |
458 | return "INLINE_FRAME"; | |
459 | ||
460 | case TAILCALL_FRAME: | |
461 | return "TAILCALL_FRAME"; | |
462 | ||
463 | case SIGTRAMP_FRAME: | |
464 | return "SIGTRAMP_FRAME"; | |
465 | ||
466 | case ARCH_FRAME: | |
467 | return "ARCH_FRAME"; | |
468 | ||
469 | case SENTINEL_FRAME: | |
470 | return "SENTINEL_FRAME"; | |
471 | ||
472 | default: | |
473 | return "<unknown type>"; | |
474 | }; | |
475 | } | |
476 | ||
477 | /* See struct frame_info. */ | |
478 | ||
479 | std::string | |
480 | frame_info::to_string () const | |
481 | { | |
482 | const frame_info *fi = this; | |
483 | ||
484 | std::string res; | |
485 | ||
486 | res += string_printf ("{level=%d,", fi->level); | |
487 | ||
488 | if (fi->unwind != NULL) | |
489 | res += string_printf ("type=%s,", frame_type_str (fi->unwind->type)); | |
490 | else | |
491 | res += "type=<unknown>,"; | |
492 | ||
493 | if (fi->unwind != NULL) | |
494 | res += string_printf ("unwinder=\"%s\",", fi->unwind->name); | |
495 | else | |
496 | res += "unwinder=<unknown>,"; | |
497 | ||
498 | if (fi->next == NULL || fi->next->prev_pc.status == CC_UNKNOWN) | |
499 | res += "pc=<unknown>,"; | |
500 | else if (fi->next->prev_pc.status == CC_VALUE) | |
501 | res += string_printf ("pc=%s%s,", hex_string (fi->next->prev_pc.value), | |
502 | fi->next->prev_pc.masked ? "[PAC]" : ""); | |
503 | else if (fi->next->prev_pc.status == CC_NOT_SAVED) | |
504 | res += "pc=<not saved>,"; | |
505 | else if (fi->next->prev_pc.status == CC_UNAVAILABLE) | |
506 | res += "pc=<unavailable>,"; | |
507 | ||
508 | if (fi->this_id.p == frame_id_status::NOT_COMPUTED) | |
509 | res += "id=<not computed>,"; | |
510 | else if (fi->this_id.p == frame_id_status::COMPUTING) | |
511 | res += "id=<computing>,"; | |
512 | else | |
513 | res += string_printf ("id=%s,", fi->this_id.value.to_string ().c_str ()); | |
514 | ||
515 | if (fi->next != NULL && fi->next->prev_func.status == CC_VALUE) | |
516 | res += string_printf ("func=%s", hex_string (fi->next->prev_func.addr)); | |
517 | else | |
518 | res += "func=<unknown>"; | |
519 | ||
520 | res += "}"; | |
521 | ||
522 | return res; | |
523 | } | |
524 | ||
525 | /* Given FRAME, return the enclosing frame as found in real frames read-in from | |
526 | inferior memory. Skip any previous frames which were made up by GDB. | |
527 | Return FRAME if FRAME is a non-artificial frame. | |
528 | Return NULL if FRAME is the start of an artificial-only chain. */ | |
529 | ||
530 | static frame_info_ptr | |
531 | skip_artificial_frames (frame_info_ptr frame) | |
532 | { | |
533 | /* Note we use get_prev_frame_always, and not get_prev_frame. The | |
534 | latter will truncate the frame chain, leading to this function | |
535 | unintentionally returning a null_frame_id (e.g., when the user | |
536 | sets a backtrace limit). | |
537 | ||
538 | Note that for record targets we may get a frame chain that consists | |
539 | of artificial frames only. */ | |
540 | while (get_frame_type (frame) == INLINE_FRAME | |
541 | || get_frame_type (frame) == TAILCALL_FRAME) | |
542 | { | |
543 | frame = get_prev_frame_always (frame); | |
544 | if (frame == NULL) | |
545 | break; | |
546 | } | |
547 | ||
548 | return frame; | |
549 | } | |
550 | ||
551 | frame_info_ptr | |
552 | skip_unwritable_frames (frame_info_ptr frame) | |
553 | { | |
554 | while (gdbarch_code_of_frame_writable (get_frame_arch (frame), frame) == 0) | |
555 | { | |
556 | frame = get_prev_frame (frame); | |
557 | if (frame == NULL) | |
558 | break; | |
559 | } | |
560 | ||
561 | return frame; | |
562 | } | |
563 | ||
564 | /* See frame.h. */ | |
565 | ||
566 | frame_info_ptr | |
567 | skip_tailcall_frames (frame_info_ptr frame) | |
568 | { | |
569 | while (get_frame_type (frame) == TAILCALL_FRAME) | |
570 | { | |
571 | /* Note that for record targets we may get a frame chain that consists of | |
572 | tailcall frames only. */ | |
573 | frame = get_prev_frame (frame); | |
574 | if (frame == NULL) | |
575 | break; | |
576 | } | |
577 | ||
578 | return frame; | |
579 | } | |
580 | ||
581 | /* Compute the frame's uniq ID that can be used to, later, re-find the | |
582 | frame. */ | |
583 | ||
584 | static void | |
585 | compute_frame_id (frame_info_ptr fi) | |
586 | { | |
587 | FRAME_SCOPED_DEBUG_ENTER_EXIT; | |
588 | ||
589 | gdb_assert (fi->this_id.p == frame_id_status::NOT_COMPUTED); | |
590 | ||
591 | unsigned int entry_generation = get_frame_cache_generation (); | |
592 | ||
593 | try | |
594 | { | |
595 | /* Mark this frame's id as "being computed. */ | |
596 | fi->this_id.p = frame_id_status::COMPUTING; | |
597 | ||
598 | frame_debug_printf ("fi=%d", fi->level); | |
599 | ||
600 | /* Find the unwinder. */ | |
601 | if (fi->unwind == NULL) | |
602 | frame_unwind_find_by_frame (fi, &fi->prologue_cache); | |
603 | ||
604 | /* Find THIS frame's ID. */ | |
605 | /* Default to outermost if no ID is found. */ | |
606 | fi->this_id.value = outer_frame_id; | |
607 | fi->unwind->this_id (fi, &fi->prologue_cache, &fi->this_id.value); | |
608 | gdb_assert (frame_id_p (fi->this_id.value)); | |
609 | ||
610 | /* Mark this frame's id as "computed". */ | |
611 | fi->this_id.p = frame_id_status::COMPUTED; | |
612 | ||
613 | frame_debug_printf (" -> %s", fi->this_id.value.to_string ().c_str ()); | |
614 | } | |
615 | catch (const gdb_exception &ex) | |
616 | { | |
617 | /* On error, revert the frame id status to not computed. If the frame | |
618 | cache generation changed, the frame object doesn't exist anymore, so | |
619 | don't touch it. */ | |
620 | if (get_frame_cache_generation () == entry_generation) | |
621 | fi->this_id.p = frame_id_status::NOT_COMPUTED; | |
622 | ||
623 | throw; | |
624 | } | |
625 | } | |
626 | ||
627 | /* Return a frame uniq ID that can be used to, later, re-find the | |
628 | frame. */ | |
629 | ||
630 | struct frame_id | |
631 | get_frame_id (frame_info_ptr fi) | |
632 | { | |
633 | if (fi == NULL) | |
634 | return null_frame_id; | |
635 | ||
636 | /* It's always invalid to try to get a frame's id while it is being | |
637 | computed. */ | |
638 | gdb_assert (fi->this_id.p != frame_id_status::COMPUTING); | |
639 | ||
640 | if (fi->this_id.p == frame_id_status::NOT_COMPUTED) | |
641 | { | |
642 | /* If we haven't computed the frame id yet, then it must be that | |
643 | this is the current frame. Compute it now, and stash the | |
644 | result. The IDs of other frames are computed as soon as | |
645 | they're created, in order to detect cycles. See | |
646 | get_prev_frame_if_no_cycle. */ | |
647 | gdb_assert (fi->level == 0); | |
648 | ||
649 | /* Compute. */ | |
650 | compute_frame_id (fi); | |
651 | ||
652 | /* Since this is the first frame in the chain, this should | |
653 | always succeed. */ | |
654 | bool stashed = frame_stash_add (fi.get ()); | |
655 | gdb_assert (stashed); | |
656 | } | |
657 | ||
658 | return fi->this_id.value; | |
659 | } | |
660 | ||
661 | struct frame_id | |
662 | get_stack_frame_id (frame_info_ptr next_frame) | |
663 | { | |
664 | return get_frame_id (skip_artificial_frames (next_frame)); | |
665 | } | |
666 | ||
667 | struct frame_id | |
668 | frame_unwind_caller_id (frame_info_ptr next_frame) | |
669 | { | |
670 | frame_info_ptr this_frame; | |
671 | ||
672 | /* Use get_prev_frame_always, and not get_prev_frame. The latter | |
673 | will truncate the frame chain, leading to this function | |
674 | unintentionally returning a null_frame_id (e.g., when a caller | |
675 | requests the frame ID of "main()"s caller. */ | |
676 | ||
677 | next_frame = skip_artificial_frames (next_frame); | |
678 | if (next_frame == NULL) | |
679 | return null_frame_id; | |
680 | ||
681 | this_frame = get_prev_frame_always (next_frame); | |
682 | if (this_frame) | |
683 | return get_frame_id (skip_artificial_frames (this_frame)); | |
684 | else | |
685 | return null_frame_id; | |
686 | } | |
687 | ||
688 | const struct frame_id null_frame_id = { 0 }; /* All zeros. */ | |
689 | const struct frame_id outer_frame_id = { 0, 0, 0, FID_STACK_OUTER, 0, 1, 0 }; | |
690 | ||
691 | struct frame_id | |
692 | frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr, | |
693 | CORE_ADDR special_addr) | |
694 | { | |
695 | struct frame_id id = null_frame_id; | |
696 | ||
697 | id.stack_addr = stack_addr; | |
698 | id.stack_status = FID_STACK_VALID; | |
699 | id.code_addr = code_addr; | |
700 | id.code_addr_p = true; | |
701 | id.special_addr = special_addr; | |
702 | id.special_addr_p = true; | |
703 | return id; | |
704 | } | |
705 | ||
706 | /* See frame.h. */ | |
707 | ||
708 | struct frame_id | |
709 | frame_id_build_unavailable_stack (CORE_ADDR code_addr) | |
710 | { | |
711 | struct frame_id id = null_frame_id; | |
712 | ||
713 | id.stack_status = FID_STACK_UNAVAILABLE; | |
714 | id.code_addr = code_addr; | |
715 | id.code_addr_p = true; | |
716 | return id; | |
717 | } | |
718 | ||
719 | /* See frame.h. */ | |
720 | ||
721 | struct frame_id | |
722 | frame_id_build_unavailable_stack_special (CORE_ADDR code_addr, | |
723 | CORE_ADDR special_addr) | |
724 | { | |
725 | struct frame_id id = null_frame_id; | |
726 | ||
727 | id.stack_status = FID_STACK_UNAVAILABLE; | |
728 | id.code_addr = code_addr; | |
729 | id.code_addr_p = true; | |
730 | id.special_addr = special_addr; | |
731 | id.special_addr_p = true; | |
732 | return id; | |
733 | } | |
734 | ||
735 | struct frame_id | |
736 | frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr) | |
737 | { | |
738 | struct frame_id id = null_frame_id; | |
739 | ||
740 | id.stack_addr = stack_addr; | |
741 | id.stack_status = FID_STACK_VALID; | |
742 | id.code_addr = code_addr; | |
743 | id.code_addr_p = true; | |
744 | return id; | |
745 | } | |
746 | ||
747 | struct frame_id | |
748 | frame_id_build_wild (CORE_ADDR stack_addr) | |
749 | { | |
750 | struct frame_id id = null_frame_id; | |
751 | ||
752 | id.stack_addr = stack_addr; | |
753 | id.stack_status = FID_STACK_VALID; | |
754 | return id; | |
755 | } | |
756 | ||
757 | /* See frame.h. */ | |
758 | ||
759 | frame_id | |
760 | frame_id_build_sentinel (CORE_ADDR stack_addr, CORE_ADDR code_addr) | |
761 | { | |
762 | frame_id id = null_frame_id; | |
763 | ||
764 | id.stack_status = FID_STACK_SENTINEL; | |
765 | id.special_addr_p = 1; | |
766 | ||
767 | if (stack_addr != 0 || code_addr != 0) | |
768 | { | |
769 | /* The purpose of saving these in the sentinel frame ID is to be able to | |
770 | differentiate the IDs of several sentinel frames that could exist | |
771 | simultaneously in the frame cache. */ | |
772 | id.stack_addr = stack_addr; | |
773 | id.code_addr = code_addr; | |
774 | id.code_addr_p = 1; | |
775 | } | |
776 | ||
777 | return id; | |
778 | } | |
779 | ||
780 | bool | |
781 | frame_id_p (frame_id l) | |
782 | { | |
783 | /* The frame is valid iff it has a valid stack address. */ | |
784 | bool p = l.stack_status != FID_STACK_INVALID; | |
785 | ||
786 | frame_debug_printf ("l=%s -> %d", l.to_string ().c_str (), p); | |
787 | ||
788 | return p; | |
789 | } | |
790 | ||
791 | bool | |
792 | frame_id_artificial_p (frame_id l) | |
793 | { | |
794 | if (!frame_id_p (l)) | |
795 | return false; | |
796 | ||
797 | return l.artificial_depth != 0; | |
798 | } | |
799 | ||
800 | bool | |
801 | frame_id::operator== (const frame_id &r) const | |
802 | { | |
803 | bool eq; | |
804 | ||
805 | if (stack_status == FID_STACK_INVALID | |
806 | || r.stack_status == FID_STACK_INVALID) | |
807 | /* Like a NaN, if either ID is invalid, the result is false. | |
808 | Note that a frame ID is invalid iff it is the null frame ID. */ | |
809 | eq = false; | |
810 | else if (stack_status != r.stack_status || stack_addr != r.stack_addr) | |
811 | /* If .stack addresses are different, the frames are different. */ | |
812 | eq = false; | |
813 | else if (code_addr_p && r.code_addr_p && code_addr != r.code_addr) | |
814 | /* An invalid code addr is a wild card. If .code addresses are | |
815 | different, the frames are different. */ | |
816 | eq = false; | |
817 | else if (special_addr_p && r.special_addr_p | |
818 | && special_addr != r.special_addr) | |
819 | /* An invalid special addr is a wild card (or unused). Otherwise | |
820 | if special addresses are different, the frames are different. */ | |
821 | eq = false; | |
822 | else if (artificial_depth != r.artificial_depth) | |
823 | /* If artificial depths are different, the frames must be different. */ | |
824 | eq = false; | |
825 | else if (user_created_p != r.user_created_p) | |
826 | eq = false; | |
827 | else | |
828 | /* Frames are equal. */ | |
829 | eq = true; | |
830 | ||
831 | frame_debug_printf ("l=%s, r=%s -> %d", | |
832 | to_string ().c_str (), r.to_string ().c_str (), eq); | |
833 | ||
834 | return eq; | |
835 | } | |
836 | ||
837 | /* Safety net to check whether frame ID L should be inner to | |
838 | frame ID R, according to their stack addresses. | |
839 | ||
840 | This method cannot be used to compare arbitrary frames, as the | |
841 | ranges of valid stack addresses may be discontiguous (e.g. due | |
842 | to sigaltstack). | |
843 | ||
844 | However, it can be used as safety net to discover invalid frame | |
845 | IDs in certain circumstances. Assuming that NEXT is the immediate | |
846 | inner frame to THIS and that NEXT and THIS are both NORMAL frames: | |
847 | ||
848 | * The stack address of NEXT must be inner-than-or-equal to the stack | |
849 | address of THIS. | |
850 | ||
851 | Therefore, if frame_id_inner (THIS, NEXT) holds, some unwind | |
852 | error has occurred. | |
853 | ||
854 | * If NEXT and THIS have different stack addresses, no other frame | |
855 | in the frame chain may have a stack address in between. | |
856 | ||
857 | Therefore, if frame_id_inner (TEST, THIS) holds, but | |
858 | frame_id_inner (TEST, NEXT) does not hold, TEST cannot refer | |
859 | to a valid frame in the frame chain. | |
860 | ||
861 | The sanity checks above cannot be performed when a SIGTRAMP frame | |
862 | is involved, because signal handlers might be executed on a different | |
863 | stack than the stack used by the routine that caused the signal | |
864 | to be raised. This can happen for instance when a thread exceeds | |
865 | its maximum stack size. In this case, certain compilers implement | |
866 | a stack overflow strategy that cause the handler to be run on a | |
867 | different stack. */ | |
868 | ||
869 | static bool | |
870 | frame_id_inner (struct gdbarch *gdbarch, struct frame_id l, struct frame_id r) | |
871 | { | |
872 | bool inner; | |
873 | ||
874 | if (l.stack_status != FID_STACK_VALID || r.stack_status != FID_STACK_VALID) | |
875 | /* Like NaN, any operation involving an invalid ID always fails. | |
876 | Likewise if either ID has an unavailable stack address. */ | |
877 | inner = false; | |
878 | else if (l.artificial_depth > r.artificial_depth | |
879 | && l.stack_addr == r.stack_addr | |
880 | && l.code_addr_p == r.code_addr_p | |
881 | && l.special_addr_p == r.special_addr_p | |
882 | && l.special_addr == r.special_addr) | |
883 | { | |
884 | /* Same function, different inlined functions. */ | |
885 | const struct block *lb, *rb; | |
886 | ||
887 | gdb_assert (l.code_addr_p && r.code_addr_p); | |
888 | ||
889 | lb = block_for_pc (l.code_addr); | |
890 | rb = block_for_pc (r.code_addr); | |
891 | ||
892 | if (lb == NULL || rb == NULL) | |
893 | /* Something's gone wrong. */ | |
894 | inner = false; | |
895 | else | |
896 | /* This will return true if LB and RB are the same block, or | |
897 | if the block with the smaller depth lexically encloses the | |
898 | block with the greater depth. */ | |
899 | inner = rb->contains (lb); | |
900 | } | |
901 | else | |
902 | /* Only return non-zero when strictly inner than. Note that, per | |
903 | comment in "frame.h", there is some fuzz here. Frameless | |
904 | functions are not strictly inner than (same .stack but | |
905 | different .code and/or .special address). */ | |
906 | inner = gdbarch_inner_than (gdbarch, l.stack_addr, r.stack_addr); | |
907 | ||
908 | frame_debug_printf ("is l=%s inner than r=%s? %d", | |
909 | l.to_string ().c_str (), r.to_string ().c_str (), | |
910 | inner); | |
911 | ||
912 | return inner; | |
913 | } | |
914 | ||
915 | frame_info_ptr | |
916 | frame_find_by_id (struct frame_id id) | |
917 | { | |
918 | frame_info_ptr frame, prev_frame; | |
919 | ||
920 | /* ZERO denotes the null frame, let the caller decide what to do | |
921 | about it. Should it instead return get_current_frame()? */ | |
922 | if (!frame_id_p (id)) | |
923 | return NULL; | |
924 | ||
925 | /* Check for the sentinel frame. */ | |
926 | if (id == frame_id_build_sentinel (0, 0)) | |
927 | return frame_info_ptr (sentinel_frame); | |
928 | ||
929 | /* Try using the frame stash first. Finding it there removes the need | |
930 | to perform the search by looping over all frames, which can be very | |
931 | CPU-intensive if the number of frames is very high (the loop is O(n) | |
932 | and get_prev_frame performs a series of checks that are relatively | |
933 | expensive). This optimization is particularly useful when this function | |
934 | is called from another function (such as value_fetch_lazy, case | |
935 | val->lval () == lval_register) which already loops over all frames, | |
936 | making the overall behavior O(n^2). */ | |
937 | frame = frame_stash_find (id); | |
938 | if (frame) | |
939 | return frame; | |
940 | ||
941 | for (frame = get_current_frame (); ; frame = prev_frame) | |
942 | { | |
943 | struct frame_id self = get_frame_id (frame); | |
944 | ||
945 | if (id == self) | |
946 | /* An exact match. */ | |
947 | return frame; | |
948 | ||
949 | prev_frame = get_prev_frame (frame); | |
950 | if (!prev_frame) | |
951 | return NULL; | |
952 | ||
953 | /* As a safety net to avoid unnecessary backtracing while trying | |
954 | to find an invalid ID, we check for a common situation where | |
955 | we can detect from comparing stack addresses that no other | |
956 | frame in the current frame chain can have this ID. See the | |
957 | comment at frame_id_inner for details. */ | |
958 | if (get_frame_type (frame) == NORMAL_FRAME | |
959 | && !frame_id_inner (get_frame_arch (frame), id, self) | |
960 | && frame_id_inner (get_frame_arch (prev_frame), id, | |
961 | get_frame_id (prev_frame))) | |
962 | return NULL; | |
963 | } | |
964 | return NULL; | |
965 | } | |
966 | ||
967 | static CORE_ADDR | |
968 | frame_unwind_pc (frame_info_ptr this_frame) | |
969 | { | |
970 | if (this_frame->prev_pc.status == CC_UNKNOWN) | |
971 | { | |
972 | struct gdbarch *prev_gdbarch; | |
973 | CORE_ADDR pc = 0; | |
974 | bool pc_p = false; | |
975 | ||
976 | /* The right way. The `pure' way. The one true way. This | |
977 | method depends solely on the register-unwind code to | |
978 | determine the value of registers in THIS frame, and hence | |
979 | the value of this frame's PC (resume address). A typical | |
980 | implementation is no more than: | |
981 | ||
982 | frame_unwind_register (this_frame, ISA_PC_REGNUM, buf); | |
983 | return extract_unsigned_integer (buf, size of ISA_PC_REGNUM); | |
984 | ||
985 | Note: this method is very heavily dependent on a correct | |
986 | register-unwind implementation, it pays to fix that | |
987 | method first; this method is frame type agnostic, since | |
988 | it only deals with register values, it works with any | |
989 | frame. This is all in stark contrast to the old | |
990 | FRAME_SAVED_PC which would try to directly handle all the | |
991 | different ways that a PC could be unwound. */ | |
992 | prev_gdbarch = frame_unwind_arch (this_frame); | |
993 | ||
994 | try | |
995 | { | |
996 | pc = gdbarch_unwind_pc (prev_gdbarch, this_frame); | |
997 | pc_p = true; | |
998 | } | |
999 | catch (const gdb_exception_error &ex) | |
1000 | { | |
1001 | if (ex.error == NOT_AVAILABLE_ERROR) | |
1002 | { | |
1003 | this_frame->prev_pc.status = CC_UNAVAILABLE; | |
1004 | ||
1005 | frame_debug_printf ("this_frame=%d -> <unavailable>", | |
1006 | this_frame->level); | |
1007 | } | |
1008 | else if (ex.error == OPTIMIZED_OUT_ERROR) | |
1009 | { | |
1010 | this_frame->prev_pc.status = CC_NOT_SAVED; | |
1011 | ||
1012 | frame_debug_printf ("this_frame=%d -> <not saved>", | |
1013 | this_frame->level); | |
1014 | } | |
1015 | else | |
1016 | throw; | |
1017 | } | |
1018 | ||
1019 | if (pc_p) | |
1020 | { | |
1021 | this_frame->prev_pc.value = pc; | |
1022 | this_frame->prev_pc.status = CC_VALUE; | |
1023 | ||
1024 | frame_debug_printf ("this_frame=%d -> %s", | |
1025 | this_frame->level, | |
1026 | hex_string (this_frame->prev_pc.value)); | |
1027 | } | |
1028 | } | |
1029 | ||
1030 | if (this_frame->prev_pc.status == CC_VALUE) | |
1031 | return this_frame->prev_pc.value; | |
1032 | else if (this_frame->prev_pc.status == CC_UNAVAILABLE) | |
1033 | throw_error (NOT_AVAILABLE_ERROR, _("PC not available")); | |
1034 | else if (this_frame->prev_pc.status == CC_NOT_SAVED) | |
1035 | throw_error (OPTIMIZED_OUT_ERROR, _("PC not saved")); | |
1036 | else | |
1037 | internal_error ("unexpected prev_pc status: %d", | |
1038 | (int) this_frame->prev_pc.status); | |
1039 | } | |
1040 | ||
1041 | CORE_ADDR | |
1042 | frame_unwind_caller_pc (frame_info_ptr this_frame) | |
1043 | { | |
1044 | this_frame = skip_artificial_frames (this_frame); | |
1045 | ||
1046 | /* We must have a non-artificial frame. The caller is supposed to check | |
1047 | the result of frame_unwind_caller_id (), which returns NULL_FRAME_ID | |
1048 | in this case. */ | |
1049 | gdb_assert (this_frame != NULL); | |
1050 | ||
1051 | return frame_unwind_pc (this_frame); | |
1052 | } | |
1053 | ||
1054 | bool | |
1055 | get_frame_func_if_available (frame_info_ptr this_frame, CORE_ADDR *pc) | |
1056 | { | |
1057 | frame_info *next_frame = this_frame->next; | |
1058 | ||
1059 | if (next_frame->prev_func.status == CC_UNKNOWN) | |
1060 | { | |
1061 | CORE_ADDR addr_in_block; | |
1062 | ||
1063 | /* Make certain that this, and not the adjacent, function is | |
1064 | found. */ | |
1065 | if (!get_frame_address_in_block_if_available (this_frame, &addr_in_block)) | |
1066 | { | |
1067 | next_frame->prev_func.status = CC_UNAVAILABLE; | |
1068 | ||
1069 | frame_debug_printf ("this_frame=%d -> unavailable", | |
1070 | this_frame->level); | |
1071 | } | |
1072 | else | |
1073 | { | |
1074 | next_frame->prev_func.status = CC_VALUE; | |
1075 | next_frame->prev_func.addr = get_pc_function_start (addr_in_block); | |
1076 | ||
1077 | frame_debug_printf ("this_frame=%d -> %s", | |
1078 | this_frame->level, | |
1079 | hex_string (next_frame->prev_func.addr)); | |
1080 | } | |
1081 | } | |
1082 | ||
1083 | if (next_frame->prev_func.status == CC_UNAVAILABLE) | |
1084 | { | |
1085 | *pc = -1; | |
1086 | return false; | |
1087 | } | |
1088 | else | |
1089 | { | |
1090 | gdb_assert (next_frame->prev_func.status == CC_VALUE); | |
1091 | ||
1092 | *pc = next_frame->prev_func.addr; | |
1093 | return true; | |
1094 | } | |
1095 | } | |
1096 | ||
1097 | CORE_ADDR | |
1098 | get_frame_func (frame_info_ptr this_frame) | |
1099 | { | |
1100 | CORE_ADDR pc; | |
1101 | ||
1102 | if (!get_frame_func_if_available (this_frame, &pc)) | |
1103 | throw_error (NOT_AVAILABLE_ERROR, _("PC not available")); | |
1104 | ||
1105 | return pc; | |
1106 | } | |
1107 | ||
1108 | std::unique_ptr<readonly_detached_regcache> | |
1109 | frame_save_as_regcache (frame_info_ptr this_frame) | |
1110 | { | |
1111 | auto cooked_read = [this_frame] (int regnum, gdb_byte *buf) | |
1112 | { | |
1113 | if (!deprecated_frame_register_read (this_frame, regnum, buf)) | |
1114 | return REG_UNAVAILABLE; | |
1115 | else | |
1116 | return REG_VALID; | |
1117 | }; | |
1118 | ||
1119 | std::unique_ptr<readonly_detached_regcache> regcache | |
1120 | (new readonly_detached_regcache (get_frame_arch (this_frame), cooked_read)); | |
1121 | ||
1122 | return regcache; | |
1123 | } | |
1124 | ||
1125 | void | |
1126 | frame_pop (frame_info_ptr this_frame) | |
1127 | { | |
1128 | frame_info_ptr prev_frame; | |
1129 | ||
1130 | if (get_frame_type (this_frame) == DUMMY_FRAME) | |
1131 | { | |
1132 | /* Popping a dummy frame involves restoring more than just registers. | |
1133 | dummy_frame_pop does all the work. */ | |
1134 | dummy_frame_pop (get_frame_id (this_frame), inferior_thread ()); | |
1135 | return; | |
1136 | } | |
1137 | ||
1138 | /* Ensure that we have a frame to pop to. */ | |
1139 | prev_frame = get_prev_frame_always (this_frame); | |
1140 | ||
1141 | if (!prev_frame) | |
1142 | error (_("Cannot pop the initial frame.")); | |
1143 | ||
1144 | /* Ignore TAILCALL_FRAME type frames, they were executed already before | |
1145 | entering THISFRAME. */ | |
1146 | prev_frame = skip_tailcall_frames (prev_frame); | |
1147 | ||
1148 | if (prev_frame == NULL) | |
1149 | error (_("Cannot find the caller frame.")); | |
1150 | ||
1151 | /* Make a copy of all the register values unwound from this frame. | |
1152 | Save them in a scratch buffer so that there isn't a race between | |
1153 | trying to extract the old values from the current regcache while | |
1154 | at the same time writing new values into that same cache. */ | |
1155 | std::unique_ptr<readonly_detached_regcache> scratch | |
1156 | = frame_save_as_regcache (prev_frame); | |
1157 | ||
1158 | /* FIXME: cagney/2003-03-16: It should be possible to tell the | |
1159 | target's register cache that it is about to be hit with a burst | |
1160 | register transfer and that the sequence of register writes should | |
1161 | be batched. The pair target_prepare_to_store() and | |
1162 | target_store_registers() kind of suggest this functionality. | |
1163 | Unfortunately, they don't implement it. Their lack of a formal | |
1164 | definition can lead to targets writing back bogus values | |
1165 | (arguably a bug in the target code mind). */ | |
1166 | /* Now copy those saved registers into the current regcache. */ | |
1167 | get_thread_regcache (inferior_thread ())->restore (scratch.get ()); | |
1168 | ||
1169 | /* We've made right mess of GDB's local state, just discard | |
1170 | everything. */ | |
1171 | reinit_frame_cache (); | |
1172 | } | |
1173 | ||
1174 | void | |
1175 | frame_register_unwind (frame_info_ptr next_frame, int regnum, | |
1176 | int *optimizedp, int *unavailablep, | |
1177 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
1178 | int *realnump, gdb_byte *bufferp) | |
1179 | { | |
1180 | struct value *value; | |
1181 | ||
1182 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates | |
1183 | that the value proper does not need to be fetched. */ | |
1184 | gdb_assert (optimizedp != NULL); | |
1185 | gdb_assert (lvalp != NULL); | |
1186 | gdb_assert (addrp != NULL); | |
1187 | gdb_assert (realnump != NULL); | |
1188 | /* gdb_assert (bufferp != NULL); */ | |
1189 | ||
1190 | value = frame_unwind_register_value (next_frame, regnum); | |
1191 | ||
1192 | gdb_assert (value != NULL); | |
1193 | ||
1194 | *optimizedp = value->optimized_out (); | |
1195 | *unavailablep = !value->entirely_available (); | |
1196 | *lvalp = value->lval (); | |
1197 | *addrp = value->address (); | |
1198 | if (*lvalp == lval_register) | |
1199 | *realnump = VALUE_REGNUM (value); | |
1200 | else | |
1201 | *realnump = -1; | |
1202 | ||
1203 | if (bufferp) | |
1204 | { | |
1205 | if (!*optimizedp && !*unavailablep) | |
1206 | memcpy (bufferp, value->contents_all ().data (), | |
1207 | value->type ()->length ()); | |
1208 | else | |
1209 | memset (bufferp, 0, value->type ()->length ()); | |
1210 | } | |
1211 | ||
1212 | /* Dispose of the new value. This prevents watchpoints from | |
1213 | trying to watch the saved frame pointer. */ | |
1214 | release_value (value); | |
1215 | } | |
1216 | ||
1217 | /* Get the value of the register that belongs to this FRAME. This | |
1218 | function is a wrapper to the call sequence ``frame_register_unwind | |
1219 | (get_next_frame (FRAME))''. As per frame_register_unwind(), if | |
1220 | VALUEP is NULL, the registers value is not fetched/computed. */ | |
1221 | ||
1222 | static void | |
1223 | frame_register (frame_info_ptr frame, int regnum, | |
1224 | int *optimizedp, int *unavailablep, enum lval_type *lvalp, | |
1225 | CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp) | |
1226 | { | |
1227 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates | |
1228 | that the value proper does not need to be fetched. */ | |
1229 | gdb_assert (optimizedp != NULL); | |
1230 | gdb_assert (lvalp != NULL); | |
1231 | gdb_assert (addrp != NULL); | |
1232 | gdb_assert (realnump != NULL); | |
1233 | /* gdb_assert (bufferp != NULL); */ | |
1234 | ||
1235 | /* Obtain the register value by unwinding the register from the next | |
1236 | (more inner frame). */ | |
1237 | gdb_assert (frame != NULL && frame->next != NULL); | |
1238 | frame_register_unwind (frame_info_ptr (frame->next), regnum, optimizedp, | |
1239 | unavailablep, lvalp, addrp, realnump, bufferp); | |
1240 | } | |
1241 | ||
1242 | void | |
1243 | frame_unwind_register (frame_info_ptr next_frame, int regnum, gdb_byte *buf) | |
1244 | { | |
1245 | int optimized; | |
1246 | int unavailable; | |
1247 | CORE_ADDR addr; | |
1248 | int realnum; | |
1249 | enum lval_type lval; | |
1250 | ||
1251 | frame_register_unwind (next_frame, regnum, &optimized, &unavailable, | |
1252 | &lval, &addr, &realnum, buf); | |
1253 | ||
1254 | if (optimized) | |
1255 | throw_error (OPTIMIZED_OUT_ERROR, | |
1256 | _("Register %d was not saved"), regnum); | |
1257 | if (unavailable) | |
1258 | throw_error (NOT_AVAILABLE_ERROR, | |
1259 | _("Register %d is not available"), regnum); | |
1260 | } | |
1261 | ||
1262 | void | |
1263 | get_frame_register (frame_info_ptr frame, | |
1264 | int regnum, gdb_byte *buf) | |
1265 | { | |
1266 | frame_unwind_register (frame_info_ptr (frame->next), regnum, buf); | |
1267 | } | |
1268 | ||
1269 | struct value * | |
1270 | frame_unwind_register_value (frame_info_ptr next_frame, int regnum) | |
1271 | { | |
1272 | FRAME_SCOPED_DEBUG_ENTER_EXIT; | |
1273 | ||
1274 | gdb_assert (next_frame != NULL); | |
1275 | gdbarch *gdbarch = frame_unwind_arch (next_frame); | |
1276 | frame_debug_printf ("frame=%d, regnum=%d(%s)", | |
1277 | next_frame->level, regnum, | |
1278 | user_reg_map_regnum_to_name (gdbarch, regnum)); | |
1279 | ||
1280 | /* Find the unwinder. */ | |
1281 | if (next_frame->unwind == NULL) | |
1282 | frame_unwind_find_by_frame (next_frame, &next_frame->prologue_cache); | |
1283 | ||
1284 | /* Ask this frame to unwind its register. */ | |
1285 | value *value = next_frame->unwind->prev_register (next_frame, | |
1286 | &next_frame->prologue_cache, | |
1287 | regnum); | |
1288 | ||
1289 | if (frame_debug) | |
1290 | { | |
1291 | string_file debug_file; | |
1292 | ||
1293 | gdb_printf (&debug_file, " ->"); | |
1294 | if (value->optimized_out ()) | |
1295 | { | |
1296 | gdb_printf (&debug_file, " "); | |
1297 | val_print_not_saved (&debug_file); | |
1298 | } | |
1299 | else | |
1300 | { | |
1301 | if (value->lval () == lval_register) | |
1302 | gdb_printf (&debug_file, " register=%d", | |
1303 | VALUE_REGNUM (value)); | |
1304 | else if (value->lval () == lval_memory) | |
1305 | gdb_printf (&debug_file, " address=%s", | |
1306 | paddress (gdbarch, | |
1307 | value->address ())); | |
1308 | else | |
1309 | gdb_printf (&debug_file, " computed"); | |
1310 | ||
1311 | if (value->lazy ()) | |
1312 | gdb_printf (&debug_file, " lazy"); | |
1313 | else | |
1314 | { | |
1315 | int i; | |
1316 | gdb::array_view<const gdb_byte> buf = value->contents (); | |
1317 | ||
1318 | gdb_printf (&debug_file, " bytes="); | |
1319 | gdb_printf (&debug_file, "["); | |
1320 | for (i = 0; i < register_size (gdbarch, regnum); i++) | |
1321 | gdb_printf (&debug_file, "%02x", buf[i]); | |
1322 | gdb_printf (&debug_file, "]"); | |
1323 | } | |
1324 | } | |
1325 | ||
1326 | frame_debug_printf ("%s", debug_file.c_str ()); | |
1327 | } | |
1328 | ||
1329 | return value; | |
1330 | } | |
1331 | ||
1332 | struct value * | |
1333 | get_frame_register_value (frame_info_ptr frame, int regnum) | |
1334 | { | |
1335 | return frame_unwind_register_value (frame_info_ptr (frame->next), regnum); | |
1336 | } | |
1337 | ||
1338 | LONGEST | |
1339 | frame_unwind_register_signed (frame_info_ptr next_frame, int regnum) | |
1340 | { | |
1341 | struct gdbarch *gdbarch = frame_unwind_arch (next_frame); | |
1342 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
1343 | struct value *value = frame_unwind_register_value (next_frame, regnum); | |
1344 | ||
1345 | gdb_assert (value != NULL); | |
1346 | ||
1347 | if (value->optimized_out ()) | |
1348 | { | |
1349 | throw_error (OPTIMIZED_OUT_ERROR, | |
1350 | _("Register %d was not saved"), regnum); | |
1351 | } | |
1352 | if (!value->entirely_available ()) | |
1353 | { | |
1354 | throw_error (NOT_AVAILABLE_ERROR, | |
1355 | _("Register %d is not available"), regnum); | |
1356 | } | |
1357 | ||
1358 | LONGEST r = extract_signed_integer (value->contents_all (), byte_order); | |
1359 | ||
1360 | release_value (value); | |
1361 | return r; | |
1362 | } | |
1363 | ||
1364 | LONGEST | |
1365 | get_frame_register_signed (frame_info_ptr frame, int regnum) | |
1366 | { | |
1367 | return frame_unwind_register_signed (frame_info_ptr (frame->next), regnum); | |
1368 | } | |
1369 | ||
1370 | ULONGEST | |
1371 | frame_unwind_register_unsigned (frame_info_ptr next_frame, int regnum) | |
1372 | { | |
1373 | struct gdbarch *gdbarch = frame_unwind_arch (next_frame); | |
1374 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
1375 | int size = register_size (gdbarch, regnum); | |
1376 | struct value *value = frame_unwind_register_value (next_frame, regnum); | |
1377 | ||
1378 | gdb_assert (value != NULL); | |
1379 | ||
1380 | if (value->optimized_out ()) | |
1381 | { | |
1382 | throw_error (OPTIMIZED_OUT_ERROR, | |
1383 | _("Register %d was not saved"), regnum); | |
1384 | } | |
1385 | if (!value->entirely_available ()) | |
1386 | { | |
1387 | throw_error (NOT_AVAILABLE_ERROR, | |
1388 | _("Register %d is not available"), regnum); | |
1389 | } | |
1390 | ||
1391 | ULONGEST r = extract_unsigned_integer (value->contents_all ().data (), | |
1392 | size, byte_order); | |
1393 | ||
1394 | release_value (value); | |
1395 | return r; | |
1396 | } | |
1397 | ||
1398 | ULONGEST | |
1399 | get_frame_register_unsigned (frame_info_ptr frame, int regnum) | |
1400 | { | |
1401 | return frame_unwind_register_unsigned (frame_info_ptr (frame->next), regnum); | |
1402 | } | |
1403 | ||
1404 | bool | |
1405 | read_frame_register_unsigned (frame_info_ptr frame, int regnum, | |
1406 | ULONGEST *val) | |
1407 | { | |
1408 | struct value *regval = get_frame_register_value (frame, regnum); | |
1409 | ||
1410 | if (!regval->optimized_out () | |
1411 | && regval->entirely_available ()) | |
1412 | { | |
1413 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
1414 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
1415 | int size = register_size (gdbarch, VALUE_REGNUM (regval)); | |
1416 | ||
1417 | *val = extract_unsigned_integer (regval->contents ().data (), size, | |
1418 | byte_order); | |
1419 | return true; | |
1420 | } | |
1421 | ||
1422 | return false; | |
1423 | } | |
1424 | ||
1425 | void | |
1426 | put_frame_register (frame_info_ptr frame, int regnum, | |
1427 | const gdb_byte *buf) | |
1428 | { | |
1429 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
1430 | int realnum; | |
1431 | int optim; | |
1432 | int unavail; | |
1433 | enum lval_type lval; | |
1434 | CORE_ADDR addr; | |
1435 | ||
1436 | frame_register (frame, regnum, &optim, &unavail, | |
1437 | &lval, &addr, &realnum, NULL); | |
1438 | if (optim) | |
1439 | error (_("Attempt to assign to a register that was not saved.")); | |
1440 | switch (lval) | |
1441 | { | |
1442 | case lval_memory: | |
1443 | { | |
1444 | write_memory (addr, buf, register_size (gdbarch, regnum)); | |
1445 | break; | |
1446 | } | |
1447 | case lval_register: | |
1448 | get_thread_regcache (inferior_thread ())->cooked_write (realnum, buf); | |
1449 | break; | |
1450 | default: | |
1451 | error (_("Attempt to assign to an unmodifiable value.")); | |
1452 | } | |
1453 | } | |
1454 | ||
1455 | /* This function is deprecated. Use get_frame_register_value instead, | |
1456 | which provides more accurate information. | |
1457 | ||
1458 | Find and return the value of REGNUM for the specified stack frame. | |
1459 | The number of bytes copied is REGISTER_SIZE (REGNUM). | |
1460 | ||
1461 | Returns 0 if the register value could not be found. */ | |
1462 | ||
1463 | bool | |
1464 | deprecated_frame_register_read (frame_info_ptr frame, int regnum, | |
1465 | gdb_byte *myaddr) | |
1466 | { | |
1467 | int optimized; | |
1468 | int unavailable; | |
1469 | enum lval_type lval; | |
1470 | CORE_ADDR addr; | |
1471 | int realnum; | |
1472 | ||
1473 | frame_register (frame, regnum, &optimized, &unavailable, | |
1474 | &lval, &addr, &realnum, myaddr); | |
1475 | ||
1476 | return !optimized && !unavailable; | |
1477 | } | |
1478 | ||
1479 | bool | |
1480 | get_frame_register_bytes (frame_info_ptr frame, int regnum, | |
1481 | CORE_ADDR offset, | |
1482 | gdb::array_view<gdb_byte> buffer, | |
1483 | int *optimizedp, int *unavailablep) | |
1484 | { | |
1485 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
1486 | int i; | |
1487 | int maxsize; | |
1488 | int numregs; | |
1489 | ||
1490 | /* Skip registers wholly inside of OFFSET. */ | |
1491 | while (offset >= register_size (gdbarch, regnum)) | |
1492 | { | |
1493 | offset -= register_size (gdbarch, regnum); | |
1494 | regnum++; | |
1495 | } | |
1496 | ||
1497 | /* Ensure that we will not read beyond the end of the register file. | |
1498 | This can only ever happen if the debug information is bad. */ | |
1499 | maxsize = -offset; | |
1500 | numregs = gdbarch_num_cooked_regs (gdbarch); | |
1501 | for (i = regnum; i < numregs; i++) | |
1502 | { | |
1503 | int thissize = register_size (gdbarch, i); | |
1504 | ||
1505 | if (thissize == 0) | |
1506 | break; /* This register is not available on this architecture. */ | |
1507 | maxsize += thissize; | |
1508 | } | |
1509 | ||
1510 | int len = buffer.size (); | |
1511 | if (len > maxsize) | |
1512 | error (_("Bad debug information detected: " | |
1513 | "Attempt to read %d bytes from registers."), len); | |
1514 | ||
1515 | /* Copy the data. */ | |
1516 | while (len > 0) | |
1517 | { | |
1518 | int curr_len = register_size (gdbarch, regnum) - offset; | |
1519 | ||
1520 | if (curr_len > len) | |
1521 | curr_len = len; | |
1522 | ||
1523 | gdb_byte *myaddr = buffer.data (); | |
1524 | ||
1525 | if (curr_len == register_size (gdbarch, regnum)) | |
1526 | { | |
1527 | enum lval_type lval; | |
1528 | CORE_ADDR addr; | |
1529 | int realnum; | |
1530 | ||
1531 | frame_register (frame, regnum, optimizedp, unavailablep, | |
1532 | &lval, &addr, &realnum, myaddr); | |
1533 | if (*optimizedp || *unavailablep) | |
1534 | return false; | |
1535 | } | |
1536 | else | |
1537 | { | |
1538 | struct value *value | |
1539 | = frame_unwind_register_value (frame_info_ptr (frame->next), | |
1540 | regnum); | |
1541 | gdb_assert (value != NULL); | |
1542 | *optimizedp = value->optimized_out (); | |
1543 | *unavailablep = !value->entirely_available (); | |
1544 | ||
1545 | if (*optimizedp || *unavailablep) | |
1546 | { | |
1547 | release_value (value); | |
1548 | return false; | |
1549 | } | |
1550 | ||
1551 | memcpy (myaddr, value->contents_all ().data () + offset, | |
1552 | curr_len); | |
1553 | release_value (value); | |
1554 | } | |
1555 | ||
1556 | myaddr += curr_len; | |
1557 | len -= curr_len; | |
1558 | offset = 0; | |
1559 | regnum++; | |
1560 | } | |
1561 | ||
1562 | *optimizedp = 0; | |
1563 | *unavailablep = 0; | |
1564 | ||
1565 | return true; | |
1566 | } | |
1567 | ||
1568 | void | |
1569 | put_frame_register_bytes (frame_info_ptr frame, int regnum, | |
1570 | CORE_ADDR offset, | |
1571 | gdb::array_view<const gdb_byte> buffer) | |
1572 | { | |
1573 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
1574 | ||
1575 | /* Skip registers wholly inside of OFFSET. */ | |
1576 | while (offset >= register_size (gdbarch, regnum)) | |
1577 | { | |
1578 | offset -= register_size (gdbarch, regnum); | |
1579 | regnum++; | |
1580 | } | |
1581 | ||
1582 | int len = buffer.size (); | |
1583 | /* Copy the data. */ | |
1584 | while (len > 0) | |
1585 | { | |
1586 | int curr_len = register_size (gdbarch, regnum) - offset; | |
1587 | ||
1588 | if (curr_len > len) | |
1589 | curr_len = len; | |
1590 | ||
1591 | const gdb_byte *myaddr = buffer.data (); | |
1592 | if (curr_len == register_size (gdbarch, regnum)) | |
1593 | { | |
1594 | put_frame_register (frame, regnum, myaddr); | |
1595 | } | |
1596 | else | |
1597 | { | |
1598 | struct value *value | |
1599 | = frame_unwind_register_value (frame_info_ptr (frame->next), | |
1600 | regnum); | |
1601 | gdb_assert (value != NULL); | |
1602 | ||
1603 | memcpy ((char *) value->contents_writeable ().data () + offset, | |
1604 | myaddr, curr_len); | |
1605 | put_frame_register (frame, regnum, | |
1606 | value->contents_raw ().data ()); | |
1607 | release_value (value); | |
1608 | } | |
1609 | ||
1610 | myaddr += curr_len; | |
1611 | len -= curr_len; | |
1612 | offset = 0; | |
1613 | regnum++; | |
1614 | } | |
1615 | } | |
1616 | ||
1617 | /* Create a sentinel frame. | |
1618 | ||
1619 | See frame_id_build_sentinel for the description of STACK_ADDR and | |
1620 | CODE_ADDR. */ | |
1621 | ||
1622 | static frame_info_ptr | |
1623 | create_sentinel_frame (program_space *pspace, address_space *aspace, | |
1624 | regcache *regcache, CORE_ADDR stack_addr, | |
1625 | CORE_ADDR code_addr) | |
1626 | { | |
1627 | frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
1628 | ||
1629 | frame->level = -1; | |
1630 | frame->pspace = pspace; | |
1631 | frame->aspace = aspace; | |
1632 | /* Explicitly initialize the sentinel frame's cache. Provide it | |
1633 | with the underlying regcache. In the future additional | |
1634 | information, such as the frame's thread will be added. */ | |
1635 | frame->prologue_cache = sentinel_frame_cache (regcache); | |
1636 | /* For the moment there is only one sentinel frame implementation. */ | |
1637 | frame->unwind = &sentinel_frame_unwind; | |
1638 | /* Link this frame back to itself. The frame is self referential | |
1639 | (the unwound PC is the same as the pc), so make it so. */ | |
1640 | frame->next = frame; | |
1641 | /* The sentinel frame has a special ID. */ | |
1642 | frame->this_id.p = frame_id_status::COMPUTED; | |
1643 | frame->this_id.value = frame_id_build_sentinel (stack_addr, code_addr); | |
1644 | ||
1645 | bool added = frame_stash_add (frame); | |
1646 | gdb_assert (added); | |
1647 | ||
1648 | frame_debug_printf (" -> %s", frame->to_string ().c_str ()); | |
1649 | ||
1650 | return frame_info_ptr (frame); | |
1651 | } | |
1652 | ||
1653 | /* Cache for frame addresses already read by gdb. Valid only while | |
1654 | inferior is stopped. Control variables for the frame cache should | |
1655 | be local to this module. */ | |
1656 | ||
1657 | static struct obstack frame_cache_obstack; | |
1658 | ||
1659 | void * | |
1660 | frame_obstack_zalloc (unsigned long size) | |
1661 | { | |
1662 | void *data = obstack_alloc (&frame_cache_obstack, size); | |
1663 | ||
1664 | memset (data, 0, size); | |
1665 | return data; | |
1666 | } | |
1667 | ||
1668 | static frame_info_ptr get_prev_frame_always_1 (frame_info_ptr this_frame); | |
1669 | ||
1670 | frame_info_ptr | |
1671 | get_current_frame (void) | |
1672 | { | |
1673 | frame_info_ptr current_frame; | |
1674 | ||
1675 | /* First check, and report, the lack of registers. Having GDB | |
1676 | report "No stack!" or "No memory" when the target doesn't even | |
1677 | have registers is very confusing. Besides, "printcmd.exp" | |
1678 | explicitly checks that ``print $pc'' with no registers prints "No | |
1679 | registers". */ | |
1680 | if (!target_has_registers ()) | |
1681 | error (_("No registers.")); | |
1682 | if (!target_has_stack ()) | |
1683 | error (_("No stack.")); | |
1684 | if (!target_has_memory ()) | |
1685 | error (_("No memory.")); | |
1686 | /* Traceframes are effectively a substitute for the live inferior. */ | |
1687 | if (get_traceframe_number () < 0) | |
1688 | validate_registers_access (); | |
1689 | ||
1690 | if (sentinel_frame == NULL) | |
1691 | sentinel_frame = | |
1692 | create_sentinel_frame (current_program_space, | |
1693 | current_inferior ()->aspace.get (), | |
1694 | get_thread_regcache (inferior_thread ()), | |
1695 | 0, 0).get (); | |
1696 | ||
1697 | /* Set the current frame before computing the frame id, to avoid | |
1698 | recursion inside compute_frame_id, in case the frame's | |
1699 | unwinder decides to do a symbol lookup (which depends on the | |
1700 | selected frame's block). | |
1701 | ||
1702 | This call must always succeed. In particular, nothing inside | |
1703 | get_prev_frame_always_1 should try to unwind from the | |
1704 | sentinel frame, because that could fail/throw, and we always | |
1705 | want to leave with the current frame created and linked in -- | |
1706 | we should never end up with the sentinel frame as outermost | |
1707 | frame. */ | |
1708 | current_frame = get_prev_frame_always_1 (frame_info_ptr (sentinel_frame)); | |
1709 | gdb_assert (current_frame != NULL); | |
1710 | ||
1711 | return current_frame; | |
1712 | } | |
1713 | ||
1714 | /* The "selected" stack frame is used by default for local and arg | |
1715 | access. | |
1716 | ||
1717 | The "single source of truth" for the selected frame is the | |
1718 | SELECTED_FRAME_ID / SELECTED_FRAME_LEVEL pair. | |
1719 | ||
1720 | Frame IDs can be saved/restored across reinitializing the frame | |
1721 | cache, while frame_info pointers can't (frame_info objects are | |
1722 | invalidated). If we know the corresponding frame_info object, it | |
1723 | is cached in SELECTED_FRAME. | |
1724 | ||
1725 | If SELECTED_FRAME_ID / SELECTED_FRAME_LEVEL are null_frame_id / -1, | |
1726 | and the target has stack and is stopped, the selected frame is the | |
1727 | current (innermost) target frame. SELECTED_FRAME_ID is never the ID | |
1728 | of the current (innermost) target frame. SELECTED_FRAME_LEVEL may | |
1729 | only be 0 if the selected frame is a user-created one (created and | |
1730 | selected through the "select-frame view" command), in which case | |
1731 | SELECTED_FRAME_ID is the frame id derived from the user-provided | |
1732 | addresses. | |
1733 | ||
1734 | If SELECTED_FRAME_ID / SELECTED_FRAME_LEVEL are null_frame_id / -1, | |
1735 | and the target has no stack or is executing, then there's no | |
1736 | selected frame. */ | |
1737 | static frame_id selected_frame_id = null_frame_id; | |
1738 | static int selected_frame_level = -1; | |
1739 | ||
1740 | /* See frame.h. This definition should come before any definition of a static | |
1741 | frame_info_ptr, to ensure that frame_list is destroyed after any static | |
1742 | frame_info_ptr. This is necessary because the destructor of frame_info_ptr | |
1743 | uses frame_list. */ | |
1744 | ||
1745 | intrusive_list<frame_info_ptr> frame_info_ptr::frame_list; | |
1746 | ||
1747 | /* The cached frame_info object pointing to the selected frame. | |
1748 | Looked up on demand by get_selected_frame. */ | |
1749 | static frame_info_ptr selected_frame; | |
1750 | ||
1751 | /* See frame.h. */ | |
1752 | ||
1753 | void | |
1754 | save_selected_frame (frame_id *frame_id, int *frame_level) | |
1755 | noexcept | |
1756 | { | |
1757 | *frame_id = selected_frame_id; | |
1758 | *frame_level = selected_frame_level; | |
1759 | } | |
1760 | ||
1761 | /* See frame.h. */ | |
1762 | ||
1763 | void | |
1764 | restore_selected_frame (frame_id frame_id, int frame_level) | |
1765 | noexcept | |
1766 | { | |
1767 | /* Unless it is a user-created frame, save_selected_frame never returns | |
1768 | level == 0, so we shouldn't see it here either. */ | |
1769 | gdb_assert (frame_level != 0 || frame_id.user_created_p); | |
1770 | ||
1771 | /* FRAME_ID can be null_frame_id only IFF frame_level is -1. */ | |
1772 | gdb_assert ((frame_level == -1 && !frame_id_p (frame_id)) | |
1773 | || (frame_level != -1 && frame_id_p (frame_id))); | |
1774 | ||
1775 | selected_frame_id = frame_id; | |
1776 | selected_frame_level = frame_level; | |
1777 | ||
1778 | /* Will be looked up later by get_selected_frame. */ | |
1779 | selected_frame = nullptr; | |
1780 | } | |
1781 | ||
1782 | /* Lookup the frame_info object for the selected frame FRAME_ID / | |
1783 | FRAME_LEVEL and cache the result. | |
1784 | ||
1785 | If FRAME_LEVEL > 0 and the originally selected frame isn't found, | |
1786 | warn and select the innermost (current) frame. */ | |
1787 | ||
1788 | static void | |
1789 | lookup_selected_frame (struct frame_id a_frame_id, int frame_level) | |
1790 | { | |
1791 | frame_info_ptr frame = NULL; | |
1792 | int count; | |
1793 | ||
1794 | /* This either means there was no selected frame, or the selected | |
1795 | frame was the current frame. In either case, select the current | |
1796 | frame. */ | |
1797 | if (frame_level == -1) | |
1798 | { | |
1799 | select_frame (get_current_frame ()); | |
1800 | return; | |
1801 | } | |
1802 | ||
1803 | /* This means the selected frame was a user-created one. Create a new one | |
1804 | using the user-provided addresses, which happen to be in the frame id. */ | |
1805 | if (frame_level == 0) | |
1806 | { | |
1807 | gdb_assert (a_frame_id.user_created_p); | |
1808 | select_frame (create_new_frame (a_frame_id)); | |
1809 | return; | |
1810 | } | |
1811 | ||
1812 | /* select_frame never saves 0 in SELECTED_FRAME_LEVEL, so we | |
1813 | shouldn't see it here. */ | |
1814 | gdb_assert (frame_level > 0); | |
1815 | ||
1816 | /* Restore by level first, check if the frame id is the same as | |
1817 | expected. If that fails, try restoring by frame id. If that | |
1818 | fails, nothing to do, just warn the user. */ | |
1819 | ||
1820 | count = frame_level; | |
1821 | frame = find_relative_frame (get_current_frame (), &count); | |
1822 | if (count == 0 | |
1823 | && frame != NULL | |
1824 | /* The frame ids must match - either both valid or both | |
1825 | outer_frame_id. The latter case is not failsafe, but since | |
1826 | it's highly unlikely the search by level finds the wrong | |
1827 | frame, it's 99.9(9)% of the time (for all practical purposes) | |
1828 | safe. */ | |
1829 | && get_frame_id (frame) == a_frame_id) | |
1830 | { | |
1831 | /* Cool, all is fine. */ | |
1832 | select_frame (frame); | |
1833 | return; | |
1834 | } | |
1835 | ||
1836 | frame = frame_find_by_id (a_frame_id); | |
1837 | if (frame != NULL) | |
1838 | { | |
1839 | /* Cool, refound it. */ | |
1840 | select_frame (frame); | |
1841 | return; | |
1842 | } | |
1843 | ||
1844 | /* Nothing else to do, the frame layout really changed. Select the | |
1845 | innermost stack frame. */ | |
1846 | select_frame (get_current_frame ()); | |
1847 | ||
1848 | /* Warn the user. */ | |
1849 | if (frame_level > 0 && !current_uiout->is_mi_like_p ()) | |
1850 | { | |
1851 | warning (_("Couldn't restore frame #%d in " | |
1852 | "current thread. Bottom (innermost) frame selected:"), | |
1853 | frame_level); | |
1854 | /* For MI, we should probably have a notification about current | |
1855 | frame change. But this error is not very likely, so don't | |
1856 | bother for now. */ | |
1857 | print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); | |
1858 | } | |
1859 | } | |
1860 | ||
1861 | bool | |
1862 | has_stack_frames () | |
1863 | { | |
1864 | if (!target_has_registers () || !target_has_stack () | |
1865 | || !target_has_memory ()) | |
1866 | return false; | |
1867 | ||
1868 | /* Traceframes are effectively a substitute for the live inferior. */ | |
1869 | if (get_traceframe_number () < 0) | |
1870 | { | |
1871 | /* No current inferior, no frame. */ | |
1872 | if (inferior_ptid == null_ptid) | |
1873 | return false; | |
1874 | ||
1875 | thread_info *tp = inferior_thread (); | |
1876 | /* Don't try to read from a dead thread. */ | |
1877 | if (tp->state == THREAD_EXITED) | |
1878 | return false; | |
1879 | ||
1880 | /* ... or from a spinning thread. */ | |
1881 | if (tp->executing ()) | |
1882 | return false; | |
1883 | } | |
1884 | ||
1885 | return true; | |
1886 | } | |
1887 | ||
1888 | /* See frame.h. */ | |
1889 | ||
1890 | frame_info_ptr | |
1891 | get_selected_frame (const char *message) | |
1892 | { | |
1893 | if (selected_frame == NULL) | |
1894 | { | |
1895 | if (message != NULL && !has_stack_frames ()) | |
1896 | error (("%s"), message); | |
1897 | ||
1898 | lookup_selected_frame (selected_frame_id, selected_frame_level); | |
1899 | } | |
1900 | /* There is always a frame. */ | |
1901 | gdb_assert (selected_frame != NULL); | |
1902 | return selected_frame; | |
1903 | } | |
1904 | ||
1905 | /* This is a variant of get_selected_frame() which can be called when | |
1906 | the inferior does not have a frame; in that case it will return | |
1907 | NULL instead of calling error(). */ | |
1908 | ||
1909 | frame_info_ptr | |
1910 | deprecated_safe_get_selected_frame (void) | |
1911 | { | |
1912 | if (!has_stack_frames ()) | |
1913 | return NULL; | |
1914 | return get_selected_frame (NULL); | |
1915 | } | |
1916 | ||
1917 | /* Invalidate the selected frame. */ | |
1918 | ||
1919 | static void | |
1920 | invalidate_selected_frame () | |
1921 | { | |
1922 | selected_frame = nullptr; | |
1923 | selected_frame_level = -1; | |
1924 | selected_frame_id = null_frame_id; | |
1925 | } | |
1926 | ||
1927 | /* See frame.h. */ | |
1928 | ||
1929 | void | |
1930 | select_frame (frame_info_ptr fi) | |
1931 | { | |
1932 | gdb_assert (fi != nullptr); | |
1933 | ||
1934 | selected_frame = fi; | |
1935 | selected_frame_level = frame_relative_level (fi); | |
1936 | ||
1937 | /* If the frame is a user-created one, save its level and frame id just like | |
1938 | any other non-level-0 frame. */ | |
1939 | if (selected_frame_level == 0 && !fi->this_id.value.user_created_p) | |
1940 | { | |
1941 | /* Treat the current frame especially -- we want to always | |
1942 | save/restore it without warning, even if the frame ID changes | |
1943 | (see lookup_selected_frame). E.g.: | |
1944 | ||
1945 | // The current frame is selected, the target had just stopped. | |
1946 | { | |
1947 | scoped_restore_selected_frame restore_frame; | |
1948 | some_operation_that_changes_the_stack (); | |
1949 | } | |
1950 | // scoped_restore_selected_frame's dtor runs, but the | |
1951 | // original frame_id can't be found. No matter whether it | |
1952 | // is found or not, we still end up with the now-current | |
1953 | // frame selected. Warning in lookup_selected_frame in this | |
1954 | // case seems pointless. | |
1955 | ||
1956 | Also get_frame_id may access the target's registers/memory, | |
1957 | and thus skipping get_frame_id optimizes the common case. | |
1958 | ||
1959 | Saving the selected frame this way makes get_selected_frame | |
1960 | and restore_current_frame return/re-select whatever frame is | |
1961 | the innermost (current) then. */ | |
1962 | selected_frame_level = -1; | |
1963 | selected_frame_id = null_frame_id; | |
1964 | } | |
1965 | else | |
1966 | selected_frame_id = get_frame_id (fi); | |
1967 | ||
1968 | /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the | |
1969 | frame is being invalidated. */ | |
1970 | ||
1971 | /* FIXME: kseitz/2002-08-28: It would be nice to call | |
1972 | selected_frame_level_changed_event() right here, but due to limitations | |
1973 | in the current interfaces, we would end up flooding UIs with events | |
1974 | because select_frame() is used extensively internally. | |
1975 | ||
1976 | Once we have frame-parameterized frame (and frame-related) commands, | |
1977 | the event notification can be moved here, since this function will only | |
1978 | be called when the user's selected frame is being changed. */ | |
1979 | ||
1980 | /* Ensure that symbols for this frame are read in. Also, determine the | |
1981 | source language of this frame, and switch to it if desired. */ | |
1982 | if (fi) | |
1983 | { | |
1984 | CORE_ADDR pc; | |
1985 | ||
1986 | /* We retrieve the frame's symtab by using the frame PC. | |
1987 | However we cannot use the frame PC as-is, because it usually | |
1988 | points to the instruction following the "call", which is | |
1989 | sometimes the first instruction of another function. So we | |
1990 | rely on get_frame_address_in_block() which provides us with a | |
1991 | PC which is guaranteed to be inside the frame's code | |
1992 | block. */ | |
1993 | if (get_frame_address_in_block_if_available (fi, &pc)) | |
1994 | { | |
1995 | struct compunit_symtab *cust = find_pc_compunit_symtab (pc); | |
1996 | ||
1997 | if (cust != NULL | |
1998 | && cust->language () != current_language->la_language | |
1999 | && cust->language () != language_unknown | |
2000 | && language_mode == language_mode_auto) | |
2001 | set_language (cust->language ()); | |
2002 | } | |
2003 | } | |
2004 | } | |
2005 | ||
2006 | /* Create an arbitrary (i.e. address specified by user) or innermost frame. | |
2007 | Always returns a non-NULL value. */ | |
2008 | ||
2009 | static frame_info_ptr | |
2010 | create_new_frame (frame_id id) | |
2011 | { | |
2012 | gdb_assert (id.user_created_p); | |
2013 | gdb_assert (id.stack_status == frame_id_stack_status::FID_STACK_VALID); | |
2014 | gdb_assert (id.code_addr_p); | |
2015 | ||
2016 | frame_debug_printf ("stack_addr=%s, core_addr=%s", | |
2017 | hex_string (id.stack_addr), hex_string (id.code_addr)); | |
2018 | ||
2019 | /* Avoid creating duplicate frames, search for an existing frame with that id | |
2020 | in the stash. */ | |
2021 | frame_info_ptr frame = frame_stash_find (id); | |
2022 | if (frame != nullptr) | |
2023 | return frame; | |
2024 | ||
2025 | frame_info *fi = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
2026 | ||
2027 | fi->next = create_sentinel_frame (current_program_space, | |
2028 | current_inferior ()->aspace.get (), | |
2029 | get_thread_regcache (inferior_thread ()), | |
2030 | id.stack_addr, id.code_addr).get (); | |
2031 | ||
2032 | /* Set/update this frame's cached PC value, found in the next frame. | |
2033 | Do this before looking for this frame's unwinder. A sniffer is | |
2034 | very likely to read this, and the corresponding unwinder is | |
2035 | entitled to rely that the PC doesn't magically change. */ | |
2036 | fi->next->prev_pc.value = id.code_addr; | |
2037 | fi->next->prev_pc.status = CC_VALUE; | |
2038 | ||
2039 | /* We currently assume that frame chain's can't cross spaces. */ | |
2040 | fi->pspace = fi->next->pspace; | |
2041 | fi->aspace = fi->next->aspace; | |
2042 | ||
2043 | /* Select/initialize both the unwind function and the frame's type | |
2044 | based on the PC. */ | |
2045 | frame_unwind_find_by_frame (frame_info_ptr (fi), &fi->prologue_cache); | |
2046 | ||
2047 | fi->this_id.p = frame_id_status::COMPUTED; | |
2048 | fi->this_id.value = id; | |
2049 | ||
2050 | bool added = frame_stash_add (fi); | |
2051 | gdb_assert (added); | |
2052 | ||
2053 | frame_debug_printf (" -> %s", fi->to_string ().c_str ()); | |
2054 | ||
2055 | return frame_info_ptr (fi); | |
2056 | } | |
2057 | ||
2058 | frame_info_ptr | |
2059 | create_new_frame (CORE_ADDR stack, CORE_ADDR pc) | |
2060 | { | |
2061 | frame_id id = frame_id_build (stack, pc); | |
2062 | id.user_created_p = 1; | |
2063 | ||
2064 | return create_new_frame (id); | |
2065 | } | |
2066 | ||
2067 | /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the | |
2068 | innermost frame). Be careful to not fall off the bottom of the | |
2069 | frame chain and onto the sentinel frame. */ | |
2070 | ||
2071 | frame_info_ptr | |
2072 | get_next_frame (frame_info_ptr this_frame) | |
2073 | { | |
2074 | if (this_frame->level > 0) | |
2075 | return frame_info_ptr (this_frame->next); | |
2076 | else | |
2077 | return NULL; | |
2078 | } | |
2079 | ||
2080 | /* Return the frame that THIS_FRAME calls. If THIS_FRAME is the | |
2081 | innermost (i.e. current) frame, return the sentinel frame. Thus, | |
2082 | unlike get_next_frame(), NULL will never be returned. */ | |
2083 | ||
2084 | frame_info_ptr | |
2085 | get_next_frame_sentinel_okay (frame_info_ptr this_frame) | |
2086 | { | |
2087 | gdb_assert (this_frame != NULL); | |
2088 | ||
2089 | /* Note that, due to the manner in which the sentinel frame is | |
2090 | constructed, this_frame->next still works even when this_frame | |
2091 | is the sentinel frame. But we disallow it here anyway because | |
2092 | calling get_next_frame_sentinel_okay() on the sentinel frame | |
2093 | is likely a coding error. */ | |
2094 | if (this_frame->this_id.p == frame_id_status::COMPUTED) | |
2095 | gdb_assert (!is_sentinel_frame_id (this_frame->this_id.value)); | |
2096 | ||
2097 | return frame_info_ptr (this_frame->next); | |
2098 | } | |
2099 | ||
2100 | /* Observer for the target_changed event. */ | |
2101 | ||
2102 | static void | |
2103 | frame_observer_target_changed (struct target_ops *target) | |
2104 | { | |
2105 | reinit_frame_cache (); | |
2106 | } | |
2107 | ||
2108 | /* Flush the entire frame cache. */ | |
2109 | ||
2110 | void | |
2111 | reinit_frame_cache (void) | |
2112 | { | |
2113 | ++frame_cache_generation; | |
2114 | ||
2115 | if (htab_elements (frame_stash) > 0) | |
2116 | annotate_frames_invalid (); | |
2117 | ||
2118 | invalidate_selected_frame (); | |
2119 | ||
2120 | /* Invalidate cache. */ | |
2121 | if (sentinel_frame != nullptr) | |
2122 | { | |
2123 | /* If frame 0's id is not computed, it is not in the frame stash, so its | |
2124 | dealloc functions will not be called when emptying the frame stash. | |
2125 | Call frame_info_del manually in that case. */ | |
2126 | frame_info *current_frame = sentinel_frame->prev; | |
2127 | if (current_frame != nullptr | |
2128 | && current_frame->this_id.p == frame_id_status::NOT_COMPUTED) | |
2129 | frame_info_del (current_frame); | |
2130 | ||
2131 | sentinel_frame = nullptr; | |
2132 | } | |
2133 | ||
2134 | frame_stash_invalidate (); | |
2135 | ||
2136 | /* Since we can't really be sure what the first object allocated was. */ | |
2137 | obstack_free (&frame_cache_obstack, 0); | |
2138 | obstack_init (&frame_cache_obstack); | |
2139 | ||
2140 | for (frame_info_ptr &iter : frame_info_ptr::frame_list) | |
2141 | iter.invalidate (); | |
2142 | ||
2143 | frame_debug_printf ("generation=%d", frame_cache_generation); | |
2144 | } | |
2145 | ||
2146 | /* Find where a register is saved (in memory or another register). | |
2147 | The result of frame_register_unwind is just where it is saved | |
2148 | relative to this particular frame. */ | |
2149 | ||
2150 | static void | |
2151 | frame_register_unwind_location (frame_info_ptr this_frame, int regnum, | |
2152 | int *optimizedp, enum lval_type *lvalp, | |
2153 | CORE_ADDR *addrp, int *realnump) | |
2154 | { | |
2155 | gdb_assert (this_frame == NULL || this_frame->level >= 0); | |
2156 | ||
2157 | while (this_frame != NULL) | |
2158 | { | |
2159 | int unavailable; | |
2160 | ||
2161 | frame_register_unwind (this_frame, regnum, optimizedp, &unavailable, | |
2162 | lvalp, addrp, realnump, NULL); | |
2163 | ||
2164 | if (*optimizedp) | |
2165 | break; | |
2166 | ||
2167 | if (*lvalp != lval_register) | |
2168 | break; | |
2169 | ||
2170 | regnum = *realnump; | |
2171 | this_frame = get_next_frame (this_frame); | |
2172 | } | |
2173 | } | |
2174 | ||
2175 | /* Get the previous raw frame, and check that it is not identical to | |
2176 | same other frame frame already in the chain. If it is, there is | |
2177 | most likely a stack cycle, so we discard it, and mark THIS_FRAME as | |
2178 | outermost, with UNWIND_SAME_ID stop reason. Unlike the other | |
2179 | validity tests, that compare THIS_FRAME and the next frame, we do | |
2180 | this right after creating the previous frame, to avoid ever ending | |
2181 | up with two frames with the same id in the frame chain. | |
2182 | ||
2183 | There is however, one case where this cycle detection is not desirable, | |
2184 | when asking for the previous frame of an inline frame, in this case, if | |
2185 | the previous frame is a duplicate and we return nullptr then we will be | |
2186 | unable to calculate the frame_id of the inline frame, this in turn | |
2187 | causes inline_frame_this_id() to fail. So for inline frames (and only | |
2188 | for inline frames), the previous frame will always be returned, even when it | |
2189 | has a duplicate frame_id. We're not worried about cycles in the frame | |
2190 | chain as, if the previous frame returned here has a duplicate frame_id, | |
2191 | then the frame_id of the inline frame, calculated based off the frame_id | |
2192 | of the previous frame, should also be a duplicate. */ | |
2193 | ||
2194 | static frame_info_ptr | |
2195 | get_prev_frame_maybe_check_cycle (frame_info_ptr this_frame) | |
2196 | { | |
2197 | frame_info_ptr prev_frame = get_prev_frame_raw (this_frame); | |
2198 | ||
2199 | /* Don't compute the frame id of the current frame yet. Unwinding | |
2200 | the sentinel frame can fail (e.g., if the thread is gone and we | |
2201 | can't thus read its registers). If we let the cycle detection | |
2202 | code below try to compute a frame ID, then an error thrown from | |
2203 | within the frame ID computation would result in the sentinel | |
2204 | frame as outermost frame, which is bogus. Instead, we'll compute | |
2205 | the current frame's ID lazily in get_frame_id. Note that there's | |
2206 | no point in doing cycle detection when there's only one frame, so | |
2207 | nothing is lost here. */ | |
2208 | if (prev_frame->level == 0) | |
2209 | return prev_frame; | |
2210 | ||
2211 | unsigned int entry_generation = get_frame_cache_generation (); | |
2212 | ||
2213 | try | |
2214 | { | |
2215 | compute_frame_id (prev_frame); | |
2216 | ||
2217 | bool cycle_detection_p = get_frame_type (this_frame) != INLINE_FRAME; | |
2218 | ||
2219 | /* This assert checks GDB's state with respect to calculating the | |
2220 | frame-id of THIS_FRAME, in the case where THIS_FRAME is an inline | |
2221 | frame. | |
2222 | ||
2223 | If THIS_FRAME is frame #0, and is an inline frame, then we put off | |
2224 | calculating the frame_id until we specifically make a call to | |
2225 | get_frame_id(). As a result we can enter this function in two | |
2226 | possible states. If GDB asked for the previous frame of frame #0 | |
2227 | then THIS_FRAME will be frame #0 (an inline frame), and the | |
2228 | frame_id will be in the NOT_COMPUTED state. However, if GDB asked | |
2229 | for the frame_id of frame #0, then, as getting the frame_id of an | |
2230 | inline frame requires us to get the frame_id of the previous | |
2231 | frame, we will still end up in here, and the frame_id status will | |
2232 | be COMPUTING. | |
2233 | ||
2234 | If, instead, THIS_FRAME is at a level greater than #0 then things | |
2235 | are simpler. For these frames we immediately compute the frame_id | |
2236 | when the frame is initially created, and so, for those frames, we | |
2237 | will always enter this function with the frame_id status of | |
2238 | COMPUTING. */ | |
2239 | gdb_assert (cycle_detection_p | |
2240 | || (this_frame->level > 0 | |
2241 | && (this_frame->this_id.p | |
2242 | == frame_id_status::COMPUTING)) | |
2243 | || (this_frame->level == 0 | |
2244 | && (this_frame->this_id.p | |
2245 | != frame_id_status::COMPUTED))); | |
2246 | ||
2247 | /* We must do the CYCLE_DETECTION_P check after attempting to add | |
2248 | PREV_FRAME into the cache; if PREV_FRAME is unique then we do want | |
2249 | it in the cache, but if it is a duplicate and CYCLE_DETECTION_P is | |
2250 | false, then we don't want to unlink it. */ | |
2251 | if (!frame_stash_add (prev_frame.get ()) && cycle_detection_p) | |
2252 | { | |
2253 | /* Another frame with the same id was already in the stash. We just | |
2254 | detected a cycle. */ | |
2255 | frame_debug_printf (" -> nullptr // this frame has same ID"); | |
2256 | ||
2257 | this_frame->stop_reason = UNWIND_SAME_ID; | |
2258 | /* Unlink. */ | |
2259 | prev_frame->next = NULL; | |
2260 | this_frame->prev = NULL; | |
2261 | prev_frame = NULL; | |
2262 | } | |
2263 | } | |
2264 | catch (const gdb_exception &ex) | |
2265 | { | |
2266 | if (get_frame_cache_generation () == entry_generation) | |
2267 | { | |
2268 | prev_frame->next = NULL; | |
2269 | this_frame->prev = NULL; | |
2270 | } | |
2271 | ||
2272 | throw; | |
2273 | } | |
2274 | ||
2275 | return prev_frame; | |
2276 | } | |
2277 | ||
2278 | /* Helper function for get_prev_frame_always, this is called inside a | |
2279 | TRY_CATCH block. Return the frame that called THIS_FRAME or NULL if | |
2280 | there is no such frame. This may throw an exception. */ | |
2281 | ||
2282 | static frame_info_ptr | |
2283 | get_prev_frame_always_1 (frame_info_ptr this_frame) | |
2284 | { | |
2285 | FRAME_SCOPED_DEBUG_ENTER_EXIT; | |
2286 | ||
2287 | gdb_assert (this_frame != NULL); | |
2288 | ||
2289 | if (frame_debug) | |
2290 | { | |
2291 | if (this_frame != NULL) | |
2292 | frame_debug_printf ("this_frame=%d", this_frame->level); | |
2293 | else | |
2294 | frame_debug_printf ("this_frame=nullptr"); | |
2295 | } | |
2296 | ||
2297 | struct gdbarch *gdbarch = get_frame_arch (this_frame); | |
2298 | ||
2299 | /* Only try to do the unwind once. */ | |
2300 | if (this_frame->prev_p) | |
2301 | { | |
2302 | if (this_frame->prev != nullptr) | |
2303 | frame_debug_printf (" -> %s // cached", | |
2304 | this_frame->prev->to_string ().c_str ()); | |
2305 | else | |
2306 | frame_debug_printf | |
2307 | (" -> nullptr // %s // cached", | |
2308 | frame_stop_reason_symbol_string (this_frame->stop_reason)); | |
2309 | return frame_info_ptr (this_frame->prev); | |
2310 | } | |
2311 | ||
2312 | /* If the frame unwinder hasn't been selected yet, we must do so | |
2313 | before setting prev_p; otherwise the check for misbehaved | |
2314 | sniffers will think that this frame's sniffer tried to unwind | |
2315 | further (see frame_cleanup_after_sniffer). */ | |
2316 | if (this_frame->unwind == NULL) | |
2317 | frame_unwind_find_by_frame (this_frame, &this_frame->prologue_cache); | |
2318 | ||
2319 | this_frame->prev_p = true; | |
2320 | this_frame->stop_reason = UNWIND_NO_REASON; | |
2321 | ||
2322 | /* If we are unwinding from an inline frame, all of the below tests | |
2323 | were already performed when we unwound from the next non-inline | |
2324 | frame. We must skip them, since we can not get THIS_FRAME's ID | |
2325 | until we have unwound all the way down to the previous non-inline | |
2326 | frame. */ | |
2327 | if (get_frame_type (this_frame) == INLINE_FRAME) | |
2328 | return get_prev_frame_maybe_check_cycle (this_frame); | |
2329 | ||
2330 | /* If this_frame is the current frame, then compute and stash its | |
2331 | frame id prior to fetching and computing the frame id of the | |
2332 | previous frame. Otherwise, the cycle detection code in | |
2333 | get_prev_frame_if_no_cycle() will not work correctly. When | |
2334 | get_frame_id() is called later on, an assertion error will be | |
2335 | triggered in the event of a cycle between the current frame and | |
2336 | its previous frame. | |
2337 | ||
2338 | Note we do this after the INLINE_FRAME check above. That is | |
2339 | because the inline frame's frame id computation needs to fetch | |
2340 | the frame id of its previous real stack frame. I.e., we need to | |
2341 | avoid recursion in that case. This is OK since we're sure the | |
2342 | inline frame won't create a cycle with the real stack frame. See | |
2343 | inline_frame_this_id. */ | |
2344 | if (this_frame->level == 0) | |
2345 | get_frame_id (this_frame); | |
2346 | ||
2347 | /* Check that this frame is unwindable. If it isn't, don't try to | |
2348 | unwind to the prev frame. */ | |
2349 | this_frame->stop_reason | |
2350 | = this_frame->unwind->stop_reason (this_frame, | |
2351 | &this_frame->prologue_cache); | |
2352 | ||
2353 | if (this_frame->stop_reason != UNWIND_NO_REASON) | |
2354 | { | |
2355 | frame_debug_printf | |
2356 | (" -> nullptr // %s", | |
2357 | frame_stop_reason_symbol_string (this_frame->stop_reason)); | |
2358 | return NULL; | |
2359 | } | |
2360 | ||
2361 | /* Check that this frame's ID isn't inner to (younger, below, next) | |
2362 | the next frame. This happens when a frame unwind goes backwards. | |
2363 | This check is valid only if this frame and the next frame are NORMAL. | |
2364 | See the comment at frame_id_inner for details. */ | |
2365 | if (get_frame_type (this_frame) == NORMAL_FRAME | |
2366 | && this_frame->next->unwind->type == NORMAL_FRAME | |
2367 | && frame_id_inner (get_frame_arch (frame_info_ptr (this_frame->next)), | |
2368 | get_frame_id (this_frame), | |
2369 | get_frame_id (frame_info_ptr (this_frame->next)))) | |
2370 | { | |
2371 | CORE_ADDR this_pc_in_block; | |
2372 | struct minimal_symbol *morestack_msym; | |
2373 | const char *morestack_name = NULL; | |
2374 | ||
2375 | /* gcc -fsplit-stack __morestack can continue the stack anywhere. */ | |
2376 | this_pc_in_block = get_frame_address_in_block (this_frame); | |
2377 | morestack_msym = lookup_minimal_symbol_by_pc (this_pc_in_block).minsym; | |
2378 | if (morestack_msym) | |
2379 | morestack_name = morestack_msym->linkage_name (); | |
2380 | if (!morestack_name || strcmp (morestack_name, "__morestack") != 0) | |
2381 | { | |
2382 | frame_debug_printf (" -> nullptr // this frame ID is inner"); | |
2383 | this_frame->stop_reason = UNWIND_INNER_ID; | |
2384 | return NULL; | |
2385 | } | |
2386 | } | |
2387 | ||
2388 | /* Check that this and the next frame do not unwind the PC register | |
2389 | to the same memory location. If they do, then even though they | |
2390 | have different frame IDs, the new frame will be bogus; two | |
2391 | functions can't share a register save slot for the PC. This can | |
2392 | happen when the prologue analyzer finds a stack adjustment, but | |
2393 | no PC save. | |
2394 | ||
2395 | This check does assume that the "PC register" is roughly a | |
2396 | traditional PC, even if the gdbarch_unwind_pc method adjusts | |
2397 | it (we do not rely on the value, only on the unwound PC being | |
2398 | dependent on this value). A potential improvement would be | |
2399 | to have the frame prev_pc method and the gdbarch unwind_pc | |
2400 | method set the same lval and location information as | |
2401 | frame_register_unwind. */ | |
2402 | if (this_frame->level > 0 | |
2403 | && gdbarch_pc_regnum (gdbarch) >= 0 | |
2404 | && get_frame_type (this_frame) == NORMAL_FRAME | |
2405 | && (get_frame_type (frame_info_ptr (this_frame->next)) == NORMAL_FRAME | |
2406 | || get_frame_type (frame_info_ptr (this_frame->next)) == INLINE_FRAME)) | |
2407 | { | |
2408 | int optimized, realnum, nrealnum; | |
2409 | enum lval_type lval, nlval; | |
2410 | CORE_ADDR addr, naddr; | |
2411 | ||
2412 | frame_register_unwind_location (this_frame, | |
2413 | gdbarch_pc_regnum (gdbarch), | |
2414 | &optimized, &lval, &addr, &realnum); | |
2415 | frame_register_unwind_location (get_next_frame (this_frame), | |
2416 | gdbarch_pc_regnum (gdbarch), | |
2417 | &optimized, &nlval, &naddr, &nrealnum); | |
2418 | ||
2419 | if ((lval == lval_memory && lval == nlval && addr == naddr) | |
2420 | || (lval == lval_register && lval == nlval && realnum == nrealnum)) | |
2421 | { | |
2422 | frame_debug_printf (" -> nullptr // no saved PC"); | |
2423 | this_frame->stop_reason = UNWIND_NO_SAVED_PC; | |
2424 | this_frame->prev = NULL; | |
2425 | return NULL; | |
2426 | } | |
2427 | } | |
2428 | ||
2429 | return get_prev_frame_maybe_check_cycle (this_frame); | |
2430 | } | |
2431 | ||
2432 | /* Return a "struct frame_info" corresponding to the frame that called | |
2433 | THIS_FRAME. Returns NULL if there is no such frame. | |
2434 | ||
2435 | Unlike get_prev_frame, this function always tries to unwind the | |
2436 | frame. */ | |
2437 | ||
2438 | frame_info_ptr | |
2439 | get_prev_frame_always (frame_info_ptr this_frame) | |
2440 | { | |
2441 | frame_info_ptr prev_frame = NULL; | |
2442 | ||
2443 | try | |
2444 | { | |
2445 | prev_frame = get_prev_frame_always_1 (this_frame); | |
2446 | } | |
2447 | catch (const gdb_exception_error &ex) | |
2448 | { | |
2449 | if (ex.error == MEMORY_ERROR) | |
2450 | { | |
2451 | this_frame->stop_reason = UNWIND_MEMORY_ERROR; | |
2452 | if (ex.message != NULL) | |
2453 | { | |
2454 | char *stop_string; | |
2455 | size_t size; | |
2456 | ||
2457 | /* The error needs to live as long as the frame does. | |
2458 | Allocate using stack local STOP_STRING then assign the | |
2459 | pointer to the frame, this allows the STOP_STRING on the | |
2460 | frame to be of type 'const char *'. */ | |
2461 | size = ex.message->size () + 1; | |
2462 | stop_string = (char *) frame_obstack_zalloc (size); | |
2463 | memcpy (stop_string, ex.what (), size); | |
2464 | this_frame->stop_string = stop_string; | |
2465 | } | |
2466 | prev_frame = NULL; | |
2467 | } | |
2468 | else | |
2469 | throw; | |
2470 | } | |
2471 | ||
2472 | return prev_frame; | |
2473 | } | |
2474 | ||
2475 | /* Construct a new "struct frame_info" and link it previous to | |
2476 | this_frame. */ | |
2477 | ||
2478 | static frame_info_ptr | |
2479 | get_prev_frame_raw (frame_info_ptr this_frame) | |
2480 | { | |
2481 | frame_info *prev_frame; | |
2482 | ||
2483 | /* Allocate the new frame but do not wire it in to the frame chain. | |
2484 | Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along | |
2485 | frame->next to pull some fancy tricks (of course such code is, by | |
2486 | definition, recursive). Try to prevent it. | |
2487 | ||
2488 | There is no reason to worry about memory leaks, should the | |
2489 | remainder of the function fail. The allocated memory will be | |
2490 | quickly reclaimed when the frame cache is flushed, and the `we've | |
2491 | been here before' check above will stop repeated memory | |
2492 | allocation calls. */ | |
2493 | prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info); | |
2494 | prev_frame->level = this_frame->level + 1; | |
2495 | ||
2496 | /* For now, assume we don't have frame chains crossing address | |
2497 | spaces. */ | |
2498 | prev_frame->pspace = this_frame->pspace; | |
2499 | prev_frame->aspace = this_frame->aspace; | |
2500 | ||
2501 | /* Don't yet compute ->unwind (and hence ->type). It is computed | |
2502 | on-demand in get_frame_type, frame_register_unwind, and | |
2503 | get_frame_id. */ | |
2504 | ||
2505 | /* Don't yet compute the frame's ID. It is computed on-demand by | |
2506 | get_frame_id(). */ | |
2507 | ||
2508 | /* The unwound frame ID is validate at the start of this function, | |
2509 | as part of the logic to decide if that frame should be further | |
2510 | unwound, and not here while the prev frame is being created. | |
2511 | Doing this makes it possible for the user to examine a frame that | |
2512 | has an invalid frame ID. | |
2513 | ||
2514 | Some very old VAX code noted: [...] For the sake of argument, | |
2515 | suppose that the stack is somewhat trashed (which is one reason | |
2516 | that "info frame" exists). So, return 0 (indicating we don't | |
2517 | know the address of the arglist) if we don't know what frame this | |
2518 | frame calls. */ | |
2519 | ||
2520 | /* Link it in. */ | |
2521 | this_frame->prev = prev_frame; | |
2522 | prev_frame->next = this_frame.get (); | |
2523 | ||
2524 | frame_debug_printf (" -> %s", prev_frame->to_string ().c_str ()); | |
2525 | ||
2526 | return frame_info_ptr (prev_frame); | |
2527 | } | |
2528 | ||
2529 | /* Debug routine to print a NULL frame being returned. */ | |
2530 | ||
2531 | static void | |
2532 | frame_debug_got_null_frame (frame_info_ptr this_frame, | |
2533 | const char *reason) | |
2534 | { | |
2535 | if (frame_debug) | |
2536 | { | |
2537 | if (this_frame != NULL) | |
2538 | frame_debug_printf ("this_frame=%d -> %s", this_frame->level, reason); | |
2539 | else | |
2540 | frame_debug_printf ("this_frame=nullptr -> %s", reason); | |
2541 | } | |
2542 | } | |
2543 | ||
2544 | /* Is this (non-sentinel) frame in the "main"() function? */ | |
2545 | ||
2546 | static bool | |
2547 | inside_main_func (frame_info_ptr this_frame) | |
2548 | { | |
2549 | if (current_program_space->symfile_object_file == nullptr) | |
2550 | return false; | |
2551 | ||
2552 | CORE_ADDR sym_addr = 0; | |
2553 | const char *name = main_name (); | |
2554 | bound_minimal_symbol msymbol | |
2555 | = lookup_minimal_symbol (name, NULL, | |
2556 | current_program_space->symfile_object_file); | |
2557 | ||
2558 | if (msymbol.minsym != nullptr) | |
2559 | sym_addr = msymbol.value_address (); | |
2560 | ||
2561 | /* Favor a full symbol in Fortran, for the case where the Fortran main | |
2562 | is also called "main". */ | |
2563 | if (msymbol.minsym == nullptr | |
2564 | || get_frame_language (this_frame) == language_fortran) | |
2565 | { | |
2566 | /* In some language (for example Fortran) there will be no minimal | |
2567 | symbol with the name of the main function. In this case we should | |
2568 | search the full symbols to see if we can find a match. */ | |
2569 | struct block_symbol bs = lookup_symbol (name, NULL, VAR_DOMAIN, 0); | |
2570 | ||
2571 | /* We might have found some unrelated symbol. For example, the | |
2572 | Rust compiler can emit both a subprogram and a namespace with | |
2573 | the same name in the same scope; and due to how gdb's symbol | |
2574 | tables currently work, we can't request the one we'd | |
2575 | prefer. */ | |
2576 | if (bs.symbol != nullptr && bs.symbol->aclass () == LOC_BLOCK) | |
2577 | { | |
2578 | const struct block *block = bs.symbol->value_block (); | |
2579 | gdb_assert (block != nullptr); | |
2580 | sym_addr = block->start (); | |
2581 | } | |
2582 | else if (msymbol.minsym == nullptr) | |
2583 | return false; | |
2584 | } | |
2585 | ||
2586 | /* Convert any function descriptor addresses into the actual function | |
2587 | code address. */ | |
2588 | sym_addr = (gdbarch_convert_from_func_ptr_addr | |
2589 | (get_frame_arch (this_frame), sym_addr, | |
2590 | current_inferior ()->top_target ())); | |
2591 | ||
2592 | return sym_addr == get_frame_func (this_frame); | |
2593 | } | |
2594 | ||
2595 | /* Test whether THIS_FRAME is inside the process entry point function. */ | |
2596 | ||
2597 | static bool | |
2598 | inside_entry_func (frame_info_ptr this_frame) | |
2599 | { | |
2600 | CORE_ADDR entry_point; | |
2601 | ||
2602 | if (!entry_point_address_query (&entry_point)) | |
2603 | return false; | |
2604 | ||
2605 | return get_frame_func (this_frame) == entry_point; | |
2606 | } | |
2607 | ||
2608 | /* Return a structure containing various interesting information about | |
2609 | the frame that called THIS_FRAME. Returns NULL if there is either | |
2610 | no such frame or the frame fails any of a set of target-independent | |
2611 | condition that should terminate the frame chain (e.g., as unwinding | |
2612 | past main()). | |
2613 | ||
2614 | This function should not contain target-dependent tests, such as | |
2615 | checking whether the program-counter is zero. */ | |
2616 | ||
2617 | frame_info_ptr | |
2618 | get_prev_frame (frame_info_ptr this_frame) | |
2619 | { | |
2620 | FRAME_SCOPED_DEBUG_ENTER_EXIT; | |
2621 | ||
2622 | CORE_ADDR frame_pc; | |
2623 | int frame_pc_p; | |
2624 | ||
2625 | /* There is always a frame. If this assertion fails, suspect that | |
2626 | something should be calling get_selected_frame() or | |
2627 | get_current_frame(). */ | |
2628 | gdb_assert (this_frame != NULL); | |
2629 | ||
2630 | frame_pc_p = get_frame_pc_if_available (this_frame, &frame_pc); | |
2631 | ||
2632 | /* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much | |
2633 | sense to stop unwinding at a dummy frame. One place where a dummy | |
2634 | frame may have an address "inside_main_func" is on HPUX. On HPUX, the | |
2635 | pcsqh register (space register for the instruction at the head of the | |
2636 | instruction queue) cannot be written directly; the only way to set it | |
2637 | is to branch to code that is in the target space. In order to implement | |
2638 | frame dummies on HPUX, the called function is made to jump back to where | |
2639 | the inferior was when the user function was called. If gdb was inside | |
2640 | the main function when we created the dummy frame, the dummy frame will | |
2641 | point inside the main function. */ | |
2642 | if (this_frame->level >= 0 | |
2643 | && get_frame_type (this_frame) == NORMAL_FRAME | |
2644 | && !user_set_backtrace_options.backtrace_past_main | |
2645 | && frame_pc_p | |
2646 | && inside_main_func (this_frame)) | |
2647 | /* Don't unwind past main(). Note, this is done _before_ the | |
2648 | frame has been marked as previously unwound. That way if the | |
2649 | user later decides to enable unwinds past main(), that will | |
2650 | automatically happen. */ | |
2651 | { | |
2652 | frame_debug_got_null_frame (this_frame, "inside main func"); | |
2653 | return NULL; | |
2654 | } | |
2655 | ||
2656 | /* If the user's backtrace limit has been exceeded, stop. We must | |
2657 | add two to the current level; one of those accounts for backtrace_limit | |
2658 | being 1-based and the level being 0-based, and the other accounts for | |
2659 | the level of the new frame instead of the level of the current | |
2660 | frame. */ | |
2661 | if (this_frame->level + 2 > user_set_backtrace_options.backtrace_limit) | |
2662 | { | |
2663 | frame_debug_got_null_frame (this_frame, "backtrace limit exceeded"); | |
2664 | return NULL; | |
2665 | } | |
2666 | ||
2667 | /* If we're already inside the entry function for the main objfile, | |
2668 | then it isn't valid. Don't apply this test to a dummy frame - | |
2669 | dummy frame PCs typically land in the entry func. Don't apply | |
2670 | this test to the sentinel frame. Sentinel frames should always | |
2671 | be allowed to unwind. */ | |
2672 | /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() - | |
2673 | wasn't checking for "main" in the minimal symbols. With that | |
2674 | fixed asm-source tests now stop in "main" instead of halting the | |
2675 | backtrace in weird and wonderful ways somewhere inside the entry | |
2676 | file. Suspect that tests for inside the entry file/func were | |
2677 | added to work around that (now fixed) case. */ | |
2678 | /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right) | |
2679 | suggested having the inside_entry_func test use the | |
2680 | inside_main_func() msymbol trick (along with entry_point_address() | |
2681 | I guess) to determine the address range of the start function. | |
2682 | That should provide a far better stopper than the current | |
2683 | heuristics. */ | |
2684 | /* NOTE: tausq/2004-10-09: this is needed if, for example, the compiler | |
2685 | applied tail-call optimizations to main so that a function called | |
2686 | from main returns directly to the caller of main. Since we don't | |
2687 | stop at main, we should at least stop at the entry point of the | |
2688 | application. */ | |
2689 | if (this_frame->level >= 0 | |
2690 | && get_frame_type (this_frame) == NORMAL_FRAME | |
2691 | && !user_set_backtrace_options.backtrace_past_entry | |
2692 | && frame_pc_p | |
2693 | && inside_entry_func (this_frame)) | |
2694 | { | |
2695 | frame_debug_got_null_frame (this_frame, "inside entry func"); | |
2696 | return NULL; | |
2697 | } | |
2698 | ||
2699 | /* Assume that the only way to get a zero PC is through something | |
2700 | like a SIGSEGV or a dummy frame, and hence that NORMAL frames | |
2701 | will never unwind a zero PC. */ | |
2702 | if (this_frame->level > 0 | |
2703 | && (get_frame_type (this_frame) == NORMAL_FRAME | |
2704 | || get_frame_type (this_frame) == INLINE_FRAME) | |
2705 | && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME | |
2706 | && frame_pc_p && frame_pc == 0) | |
2707 | { | |
2708 | frame_debug_got_null_frame (this_frame, "zero PC"); | |
2709 | return NULL; | |
2710 | } | |
2711 | ||
2712 | return get_prev_frame_always (this_frame); | |
2713 | } | |
2714 | ||
2715 | CORE_ADDR | |
2716 | get_frame_pc (frame_info_ptr frame) | |
2717 | { | |
2718 | gdb_assert (frame->next != NULL); | |
2719 | return frame_unwind_pc (frame_info_ptr (frame->next)); | |
2720 | } | |
2721 | ||
2722 | bool | |
2723 | get_frame_pc_if_available (frame_info_ptr frame, CORE_ADDR *pc) | |
2724 | { | |
2725 | ||
2726 | gdb_assert (frame->next != NULL); | |
2727 | ||
2728 | try | |
2729 | { | |
2730 | *pc = frame_unwind_pc (frame_info_ptr (frame->next)); | |
2731 | } | |
2732 | catch (const gdb_exception_error &ex) | |
2733 | { | |
2734 | if (ex.error == NOT_AVAILABLE_ERROR) | |
2735 | return false; | |
2736 | else | |
2737 | throw; | |
2738 | } | |
2739 | ||
2740 | return true; | |
2741 | } | |
2742 | ||
2743 | /* Return an address that falls within THIS_FRAME's code block. */ | |
2744 | ||
2745 | CORE_ADDR | |
2746 | get_frame_address_in_block (frame_info_ptr this_frame) | |
2747 | { | |
2748 | /* A draft address. */ | |
2749 | CORE_ADDR pc = get_frame_pc (this_frame); | |
2750 | ||
2751 | frame_info_ptr next_frame (this_frame->next); | |
2752 | ||
2753 | /* Calling get_frame_pc returns the resume address for THIS_FRAME. | |
2754 | Normally the resume address is inside the body of the function | |
2755 | associated with THIS_FRAME, but there is a special case: when | |
2756 | calling a function which the compiler knows will never return | |
2757 | (for instance abort), the call may be the very last instruction | |
2758 | in the calling function. The resume address will point after the | |
2759 | call and may be at the beginning of a different function | |
2760 | entirely. | |
2761 | ||
2762 | If THIS_FRAME is a signal frame or dummy frame, then we should | |
2763 | not adjust the unwound PC. For a dummy frame, GDB pushed the | |
2764 | resume address manually onto the stack. For a signal frame, the | |
2765 | OS may have pushed the resume address manually and invoked the | |
2766 | handler (e.g. GNU/Linux), or invoked the trampoline which called | |
2767 | the signal handler - but in either case the signal handler is | |
2768 | expected to return to the trampoline. So in both of these | |
2769 | cases we know that the resume address is executable and | |
2770 | related. So we only need to adjust the PC if THIS_FRAME | |
2771 | is a normal function. | |
2772 | ||
2773 | If the program has been interrupted while THIS_FRAME is current, | |
2774 | then clearly the resume address is inside the associated | |
2775 | function. There are three kinds of interruption: debugger stop | |
2776 | (next frame will be SENTINEL_FRAME), operating system | |
2777 | signal or exception (next frame will be SIGTRAMP_FRAME), | |
2778 | or debugger-induced function call (next frame will be | |
2779 | DUMMY_FRAME). So we only need to adjust the PC if | |
2780 | NEXT_FRAME is a normal function. | |
2781 | ||
2782 | We check the type of NEXT_FRAME first, since it is already | |
2783 | known; frame type is determined by the unwinder, and since | |
2784 | we have THIS_FRAME we've already selected an unwinder for | |
2785 | NEXT_FRAME. | |
2786 | ||
2787 | If the next frame is inlined, we need to keep going until we find | |
2788 | the real function - for instance, if a signal handler is invoked | |
2789 | while in an inlined function, then the code address of the | |
2790 | "calling" normal function should not be adjusted either. */ | |
2791 | ||
2792 | while (get_frame_type (next_frame) == INLINE_FRAME) | |
2793 | next_frame = frame_info_ptr (next_frame->next); | |
2794 | ||
2795 | if ((get_frame_type (next_frame) == NORMAL_FRAME | |
2796 | || get_frame_type (next_frame) == TAILCALL_FRAME) | |
2797 | && (get_frame_type (this_frame) == NORMAL_FRAME | |
2798 | || get_frame_type (this_frame) == TAILCALL_FRAME | |
2799 | || get_frame_type (this_frame) == INLINE_FRAME)) | |
2800 | return pc - 1; | |
2801 | ||
2802 | return pc; | |
2803 | } | |
2804 | ||
2805 | bool | |
2806 | get_frame_address_in_block_if_available (frame_info_ptr this_frame, | |
2807 | CORE_ADDR *pc) | |
2808 | { | |
2809 | ||
2810 | try | |
2811 | { | |
2812 | *pc = get_frame_address_in_block (this_frame); | |
2813 | } | |
2814 | catch (const gdb_exception_error &ex) | |
2815 | { | |
2816 | if (ex.error == NOT_AVAILABLE_ERROR) | |
2817 | return false; | |
2818 | throw; | |
2819 | } | |
2820 | ||
2821 | return true; | |
2822 | } | |
2823 | ||
2824 | symtab_and_line | |
2825 | find_frame_sal (frame_info_ptr frame) | |
2826 | { | |
2827 | frame_info_ptr next_frame; | |
2828 | int notcurrent; | |
2829 | CORE_ADDR pc; | |
2830 | ||
2831 | if (frame_inlined_callees (frame) > 0) | |
2832 | { | |
2833 | struct symbol *sym; | |
2834 | ||
2835 | /* If the current frame has some inlined callees, and we have a next | |
2836 | frame, then that frame must be an inlined frame. In this case | |
2837 | this frame's sal is the "call site" of the next frame's inlined | |
2838 | function, which can not be inferred from get_frame_pc. */ | |
2839 | next_frame = get_next_frame (frame); | |
2840 | if (next_frame) | |
2841 | sym = get_frame_function (next_frame); | |
2842 | else | |
2843 | sym = inline_skipped_symbol (inferior_thread ()); | |
2844 | ||
2845 | /* If frame is inline, it certainly has symbols. */ | |
2846 | gdb_assert (sym); | |
2847 | ||
2848 | symtab_and_line sal; | |
2849 | if (sym->line () != 0) | |
2850 | { | |
2851 | sal.symtab = sym->symtab (); | |
2852 | sal.line = sym->line (); | |
2853 | } | |
2854 | else | |
2855 | /* If the symbol does not have a location, we don't know where | |
2856 | the call site is. Do not pretend to. This is jarring, but | |
2857 | we can't do much better. */ | |
2858 | sal.pc = get_frame_pc (frame); | |
2859 | ||
2860 | sal.pspace = get_frame_program_space (frame); | |
2861 | return sal; | |
2862 | } | |
2863 | ||
2864 | /* If FRAME is not the innermost frame, that normally means that | |
2865 | FRAME->pc points at the return instruction (which is *after* the | |
2866 | call instruction), and we want to get the line containing the | |
2867 | call (because the call is where the user thinks the program is). | |
2868 | However, if the next frame is either a SIGTRAMP_FRAME or a | |
2869 | DUMMY_FRAME, then the next frame will contain a saved interrupt | |
2870 | PC and such a PC indicates the current (rather than next) | |
2871 | instruction/line, consequently, for such cases, want to get the | |
2872 | line containing fi->pc. */ | |
2873 | if (!get_frame_pc_if_available (frame, &pc)) | |
2874 | return {}; | |
2875 | ||
2876 | notcurrent = (pc != get_frame_address_in_block (frame)); | |
2877 | return find_pc_line (pc, notcurrent); | |
2878 | } | |
2879 | ||
2880 | /* Per "frame.h", return the ``address'' of the frame. Code should | |
2881 | really be using get_frame_id(). */ | |
2882 | CORE_ADDR | |
2883 | get_frame_base (frame_info_ptr fi) | |
2884 | { | |
2885 | return get_frame_id (fi).stack_addr; | |
2886 | } | |
2887 | ||
2888 | /* High-level offsets into the frame. Used by the debug info. */ | |
2889 | ||
2890 | CORE_ADDR | |
2891 | get_frame_base_address (frame_info_ptr fi) | |
2892 | { | |
2893 | if (get_frame_type (fi) != NORMAL_FRAME) | |
2894 | return 0; | |
2895 | if (fi->base == NULL) | |
2896 | fi->base = frame_base_find_by_frame (fi); | |
2897 | /* Sneaky: If the low-level unwind and high-level base code share a | |
2898 | common unwinder, let them share the prologue cache. */ | |
2899 | if (fi->base->unwind == fi->unwind) | |
2900 | return fi->base->this_base (fi, &fi->prologue_cache); | |
2901 | return fi->base->this_base (fi, &fi->base_cache); | |
2902 | } | |
2903 | ||
2904 | CORE_ADDR | |
2905 | get_frame_locals_address (frame_info_ptr fi) | |
2906 | { | |
2907 | if (get_frame_type (fi) != NORMAL_FRAME) | |
2908 | return 0; | |
2909 | /* If there isn't a frame address method, find it. */ | |
2910 | if (fi->base == NULL) | |
2911 | fi->base = frame_base_find_by_frame (fi); | |
2912 | /* Sneaky: If the low-level unwind and high-level base code share a | |
2913 | common unwinder, let them share the prologue cache. */ | |
2914 | if (fi->base->unwind == fi->unwind) | |
2915 | return fi->base->this_locals (fi, &fi->prologue_cache); | |
2916 | return fi->base->this_locals (fi, &fi->base_cache); | |
2917 | } | |
2918 | ||
2919 | CORE_ADDR | |
2920 | get_frame_args_address (frame_info_ptr fi) | |
2921 | { | |
2922 | if (get_frame_type (fi) != NORMAL_FRAME) | |
2923 | return 0; | |
2924 | /* If there isn't a frame address method, find it. */ | |
2925 | if (fi->base == NULL) | |
2926 | fi->base = frame_base_find_by_frame (fi); | |
2927 | /* Sneaky: If the low-level unwind and high-level base code share a | |
2928 | common unwinder, let them share the prologue cache. */ | |
2929 | if (fi->base->unwind == fi->unwind) | |
2930 | return fi->base->this_args (fi, &fi->prologue_cache); | |
2931 | return fi->base->this_args (fi, &fi->base_cache); | |
2932 | } | |
2933 | ||
2934 | /* Return true if the frame unwinder for frame FI is UNWINDER; false | |
2935 | otherwise. */ | |
2936 | ||
2937 | bool | |
2938 | frame_unwinder_is (frame_info_ptr fi, const frame_unwind *unwinder) | |
2939 | { | |
2940 | if (fi->unwind == nullptr) | |
2941 | frame_unwind_find_by_frame (fi, &fi->prologue_cache); | |
2942 | ||
2943 | return fi->unwind == unwinder; | |
2944 | } | |
2945 | ||
2946 | /* Level of the selected frame: 0 for innermost, 1 for its caller, ... | |
2947 | or -1 for a NULL frame. */ | |
2948 | ||
2949 | int | |
2950 | frame_relative_level (frame_info_ptr fi) | |
2951 | { | |
2952 | if (fi == NULL) | |
2953 | return -1; | |
2954 | else | |
2955 | return fi->level; | |
2956 | } | |
2957 | ||
2958 | enum frame_type | |
2959 | get_frame_type (frame_info_ptr frame) | |
2960 | { | |
2961 | if (frame->unwind == NULL) | |
2962 | /* Initialize the frame's unwinder because that's what | |
2963 | provides the frame's type. */ | |
2964 | frame_unwind_find_by_frame (frame, &frame->prologue_cache); | |
2965 | return frame->unwind->type; | |
2966 | } | |
2967 | ||
2968 | struct program_space * | |
2969 | get_frame_program_space (frame_info_ptr frame) | |
2970 | { | |
2971 | return frame->pspace; | |
2972 | } | |
2973 | ||
2974 | struct program_space * | |
2975 | frame_unwind_program_space (frame_info_ptr this_frame) | |
2976 | { | |
2977 | gdb_assert (this_frame); | |
2978 | ||
2979 | /* This is really a placeholder to keep the API consistent --- we | |
2980 | assume for now that we don't have frame chains crossing | |
2981 | spaces. */ | |
2982 | return this_frame->pspace; | |
2983 | } | |
2984 | ||
2985 | const address_space * | |
2986 | get_frame_address_space (frame_info_ptr frame) | |
2987 | { | |
2988 | return frame->aspace; | |
2989 | } | |
2990 | ||
2991 | /* Memory access methods. */ | |
2992 | ||
2993 | void | |
2994 | get_frame_memory (frame_info_ptr this_frame, CORE_ADDR addr, | |
2995 | gdb::array_view<gdb_byte> buffer) | |
2996 | { | |
2997 | read_memory (addr, buffer.data (), buffer.size ()); | |
2998 | } | |
2999 | ||
3000 | LONGEST | |
3001 | get_frame_memory_signed (frame_info_ptr this_frame, CORE_ADDR addr, | |
3002 | int len) | |
3003 | { | |
3004 | struct gdbarch *gdbarch = get_frame_arch (this_frame); | |
3005 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
3006 | ||
3007 | return read_memory_integer (addr, len, byte_order); | |
3008 | } | |
3009 | ||
3010 | ULONGEST | |
3011 | get_frame_memory_unsigned (frame_info_ptr this_frame, CORE_ADDR addr, | |
3012 | int len) | |
3013 | { | |
3014 | struct gdbarch *gdbarch = get_frame_arch (this_frame); | |
3015 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
3016 | ||
3017 | return read_memory_unsigned_integer (addr, len, byte_order); | |
3018 | } | |
3019 | ||
3020 | bool | |
3021 | safe_frame_unwind_memory (frame_info_ptr this_frame, | |
3022 | CORE_ADDR addr, gdb::array_view<gdb_byte> buffer) | |
3023 | { | |
3024 | /* NOTE: target_read_memory returns zero on success! */ | |
3025 | return target_read_memory (addr, buffer.data (), buffer.size ()) == 0; | |
3026 | } | |
3027 | ||
3028 | /* Architecture methods. */ | |
3029 | ||
3030 | struct gdbarch * | |
3031 | get_frame_arch (frame_info_ptr this_frame) | |
3032 | { | |
3033 | return frame_unwind_arch (frame_info_ptr (this_frame->next)); | |
3034 | } | |
3035 | ||
3036 | struct gdbarch * | |
3037 | frame_unwind_arch (frame_info_ptr next_frame) | |
3038 | { | |
3039 | if (!next_frame->prev_arch.p) | |
3040 | { | |
3041 | struct gdbarch *arch; | |
3042 | ||
3043 | if (next_frame->unwind == NULL) | |
3044 | frame_unwind_find_by_frame (next_frame, &next_frame->prologue_cache); | |
3045 | ||
3046 | if (next_frame->unwind->prev_arch != NULL) | |
3047 | arch = next_frame->unwind->prev_arch (next_frame, | |
3048 | &next_frame->prologue_cache); | |
3049 | else | |
3050 | arch = get_frame_arch (next_frame); | |
3051 | ||
3052 | next_frame->prev_arch.arch = arch; | |
3053 | next_frame->prev_arch.p = true; | |
3054 | frame_debug_printf ("next_frame=%d -> %s", | |
3055 | next_frame->level, | |
3056 | gdbarch_bfd_arch_info (arch)->printable_name); | |
3057 | } | |
3058 | ||
3059 | return next_frame->prev_arch.arch; | |
3060 | } | |
3061 | ||
3062 | struct gdbarch * | |
3063 | frame_unwind_caller_arch (frame_info_ptr next_frame) | |
3064 | { | |
3065 | next_frame = skip_artificial_frames (next_frame); | |
3066 | ||
3067 | /* We must have a non-artificial frame. The caller is supposed to check | |
3068 | the result of frame_unwind_caller_id (), which returns NULL_FRAME_ID | |
3069 | in this case. */ | |
3070 | gdb_assert (next_frame != NULL); | |
3071 | ||
3072 | return frame_unwind_arch (next_frame); | |
3073 | } | |
3074 | ||
3075 | /* Gets the language of FRAME. */ | |
3076 | ||
3077 | enum language | |
3078 | get_frame_language (frame_info_ptr frame) | |
3079 | { | |
3080 | CORE_ADDR pc = 0; | |
3081 | bool pc_p = false; | |
3082 | ||
3083 | gdb_assert (frame!= NULL); | |
3084 | ||
3085 | /* We determine the current frame language by looking up its | |
3086 | associated symtab. To retrieve this symtab, we use the frame | |
3087 | PC. However we cannot use the frame PC as is, because it | |
3088 | usually points to the instruction following the "call", which | |
3089 | is sometimes the first instruction of another function. So | |
3090 | we rely on get_frame_address_in_block(), it provides us with | |
3091 | a PC that is guaranteed to be inside the frame's code | |
3092 | block. */ | |
3093 | ||
3094 | try | |
3095 | { | |
3096 | pc = get_frame_address_in_block (frame); | |
3097 | pc_p = true; | |
3098 | } | |
3099 | catch (const gdb_exception_error &ex) | |
3100 | { | |
3101 | if (ex.error != NOT_AVAILABLE_ERROR) | |
3102 | throw; | |
3103 | } | |
3104 | ||
3105 | if (pc_p) | |
3106 | { | |
3107 | struct compunit_symtab *cust = find_pc_compunit_symtab (pc); | |
3108 | ||
3109 | if (cust != NULL) | |
3110 | return cust->language (); | |
3111 | } | |
3112 | ||
3113 | return language_unknown; | |
3114 | } | |
3115 | ||
3116 | /* Stack pointer methods. */ | |
3117 | ||
3118 | CORE_ADDR | |
3119 | get_frame_sp (frame_info_ptr this_frame) | |
3120 | { | |
3121 | struct gdbarch *gdbarch = get_frame_arch (this_frame); | |
3122 | ||
3123 | /* NOTE drow/2008-06-28: gdbarch_unwind_sp could be converted to | |
3124 | operate on THIS_FRAME now. */ | |
3125 | return gdbarch_unwind_sp (gdbarch, frame_info_ptr (this_frame->next)); | |
3126 | } | |
3127 | ||
3128 | /* See frame.h. */ | |
3129 | ||
3130 | frame_info_ptr | |
3131 | frame_follow_static_link (frame_info_ptr frame) | |
3132 | { | |
3133 | const block *frame_block = get_frame_block (frame, nullptr); | |
3134 | frame_block = frame_block->function_block (); | |
3135 | ||
3136 | const struct dynamic_prop *static_link = frame_block->static_link (); | |
3137 | if (static_link == nullptr) | |
3138 | return {}; | |
3139 | ||
3140 | CORE_ADDR upper_frame_base; | |
3141 | ||
3142 | if (!dwarf2_evaluate_property (static_link, frame, NULL, &upper_frame_base)) | |
3143 | return {}; | |
3144 | ||
3145 | /* Now climb up the stack frame until we reach the frame we are interested | |
3146 | in. */ | |
3147 | for (; frame != nullptr; frame = get_prev_frame (frame)) | |
3148 | { | |
3149 | struct symbol *framefunc = get_frame_function (frame); | |
3150 | ||
3151 | /* Stacks can be quite deep: give the user a chance to stop this. */ | |
3152 | QUIT; | |
3153 | ||
3154 | /* If we don't know how to compute FRAME's base address, don't give up: | |
3155 | maybe the frame we are looking for is upper in the stack frame. */ | |
3156 | if (framefunc != NULL | |
3157 | && SYMBOL_BLOCK_OPS (framefunc) != NULL | |
3158 | && SYMBOL_BLOCK_OPS (framefunc)->get_frame_base != NULL | |
3159 | && (SYMBOL_BLOCK_OPS (framefunc)->get_frame_base (framefunc, frame) | |
3160 | == upper_frame_base)) | |
3161 | break; | |
3162 | } | |
3163 | ||
3164 | return frame; | |
3165 | } | |
3166 | ||
3167 | /* Return the reason why we can't unwind past FRAME. */ | |
3168 | ||
3169 | enum unwind_stop_reason | |
3170 | get_frame_unwind_stop_reason (frame_info_ptr frame) | |
3171 | { | |
3172 | /* Fill-in STOP_REASON. */ | |
3173 | get_prev_frame_always (frame); | |
3174 | gdb_assert (frame->prev_p); | |
3175 | ||
3176 | return frame->stop_reason; | |
3177 | } | |
3178 | ||
3179 | /* Return a string explaining REASON. */ | |
3180 | ||
3181 | const char * | |
3182 | unwind_stop_reason_to_string (enum unwind_stop_reason reason) | |
3183 | { | |
3184 | switch (reason) | |
3185 | { | |
3186 | #define SET(name, description) \ | |
3187 | case name: return _(description); | |
3188 | #include "unwind_stop_reasons.def" | |
3189 | #undef SET | |
3190 | ||
3191 | default: | |
3192 | internal_error ("Invalid frame stop reason"); | |
3193 | } | |
3194 | } | |
3195 | ||
3196 | const char * | |
3197 | frame_stop_reason_string (frame_info_ptr fi) | |
3198 | { | |
3199 | gdb_assert (fi->prev_p); | |
3200 | gdb_assert (fi->prev == NULL); | |
3201 | ||
3202 | /* Return the specific string if we have one. */ | |
3203 | if (fi->stop_string != NULL) | |
3204 | return fi->stop_string; | |
3205 | ||
3206 | /* Return the generic string if we have nothing better. */ | |
3207 | return unwind_stop_reason_to_string (fi->stop_reason); | |
3208 | } | |
3209 | ||
3210 | /* Return the enum symbol name of REASON as a string, to use in debug | |
3211 | output. */ | |
3212 | ||
3213 | static const char * | |
3214 | frame_stop_reason_symbol_string (enum unwind_stop_reason reason) | |
3215 | { | |
3216 | switch (reason) | |
3217 | { | |
3218 | #define SET(name, description) \ | |
3219 | case name: return #name; | |
3220 | #include "unwind_stop_reasons.def" | |
3221 | #undef SET | |
3222 | ||
3223 | default: | |
3224 | internal_error ("Invalid frame stop reason"); | |
3225 | } | |
3226 | } | |
3227 | ||
3228 | /* Clean up after a failed (wrong unwinder) attempt to unwind past | |
3229 | FRAME. */ | |
3230 | ||
3231 | void | |
3232 | frame_cleanup_after_sniffer (frame_info_ptr frame) | |
3233 | { | |
3234 | /* The sniffer should not allocate a prologue cache if it did not | |
3235 | match this frame. */ | |
3236 | gdb_assert (frame->prologue_cache == NULL); | |
3237 | ||
3238 | /* No sniffer should extend the frame chain; sniff based on what is | |
3239 | already certain. */ | |
3240 | gdb_assert (!frame->prev_p); | |
3241 | ||
3242 | /* The sniffer should not check the frame's ID; that's circular. */ | |
3243 | gdb_assert (frame->this_id.p != frame_id_status::COMPUTED); | |
3244 | ||
3245 | /* Clear cached fields dependent on the unwinder. | |
3246 | ||
3247 | The previous PC is independent of the unwinder, but the previous | |
3248 | function is not (see get_frame_address_in_block). */ | |
3249 | frame->prev_func.status = CC_UNKNOWN; | |
3250 | frame->prev_func.addr = 0; | |
3251 | ||
3252 | /* Discard the unwinder last, so that we can easily find it if an assertion | |
3253 | in this function triggers. */ | |
3254 | frame->unwind = NULL; | |
3255 | } | |
3256 | ||
3257 | /* Set FRAME's unwinder temporarily, so that we can call a sniffer. | |
3258 | If sniffing fails, the caller should be sure to call | |
3259 | frame_cleanup_after_sniffer. */ | |
3260 | ||
3261 | void | |
3262 | frame_prepare_for_sniffer (frame_info_ptr frame, | |
3263 | const struct frame_unwind *unwind) | |
3264 | { | |
3265 | gdb_assert (frame->unwind == NULL); | |
3266 | frame->unwind = unwind; | |
3267 | } | |
3268 | ||
3269 | static struct cmd_list_element *set_backtrace_cmdlist; | |
3270 | static struct cmd_list_element *show_backtrace_cmdlist; | |
3271 | ||
3272 | /* Definition of the "set backtrace" settings that are exposed as | |
3273 | "backtrace" command options. */ | |
3274 | ||
3275 | using boolean_option_def | |
3276 | = gdb::option::boolean_option_def<set_backtrace_options>; | |
3277 | ||
3278 | const gdb::option::option_def set_backtrace_option_defs[] = { | |
3279 | ||
3280 | boolean_option_def { | |
3281 | "past-main", | |
3282 | [] (set_backtrace_options *opt) { return &opt->backtrace_past_main; }, | |
3283 | show_backtrace_past_main, /* show_cmd_cb */ | |
3284 | N_("Set whether backtraces should continue past \"main\"."), | |
3285 | N_("Show whether backtraces should continue past \"main\"."), | |
3286 | N_("Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ | |
3287 | the backtrace at \"main\". Set this if you need to see the rest\n\ | |
3288 | of the stack trace."), | |
3289 | }, | |
3290 | ||
3291 | boolean_option_def { | |
3292 | "past-entry", | |
3293 | [] (set_backtrace_options *opt) { return &opt->backtrace_past_entry; }, | |
3294 | show_backtrace_past_entry, /* show_cmd_cb */ | |
3295 | N_("Set whether backtraces should continue past the entry point of a program."), | |
3296 | N_("Show whether backtraces should continue past the entry point of a program."), | |
3297 | N_("Normally there are no callers beyond the entry point of a program, so GDB\n\ | |
3298 | will terminate the backtrace there. Set this if you need to see\n\ | |
3299 | the rest of the stack trace."), | |
3300 | }, | |
3301 | }; | |
3302 | ||
3303 | /* Implement the 'maintenance print frame-id' command. */ | |
3304 | ||
3305 | static void | |
3306 | maintenance_print_frame_id (const char *args, int from_tty) | |
3307 | { | |
3308 | frame_info_ptr frame; | |
3309 | ||
3310 | /* Use the currently selected frame, or select a frame based on the level | |
3311 | number passed by the user. */ | |
3312 | if (args == nullptr) | |
3313 | frame = get_selected_frame ("No frame selected"); | |
3314 | else | |
3315 | { | |
3316 | int level = value_as_long (parse_and_eval (args)); | |
3317 | frame = find_relative_frame (get_current_frame (), &level); | |
3318 | } | |
3319 | ||
3320 | /* Print the frame-id. */ | |
3321 | gdb_assert (frame != nullptr); | |
3322 | gdb_printf ("frame-id for frame #%d: %s\n", | |
3323 | frame_relative_level (frame), | |
3324 | get_frame_id (frame).to_string ().c_str ()); | |
3325 | } | |
3326 | ||
3327 | /* See frame-info-ptr.h. */ | |
3328 | ||
3329 | frame_info_ptr::frame_info_ptr (struct frame_info *ptr) | |
3330 | : m_ptr (ptr) | |
3331 | { | |
3332 | frame_list.push_back (*this); | |
3333 | ||
3334 | if (m_ptr == nullptr) | |
3335 | return; | |
3336 | ||
3337 | m_cached_level = ptr->level; | |
3338 | ||
3339 | if (m_cached_level != 0 || m_ptr->this_id.value.user_created_p) | |
3340 | m_cached_id = m_ptr->this_id.value; | |
3341 | } | |
3342 | ||
3343 | /* See frame-info-ptr.h. */ | |
3344 | ||
3345 | frame_info * | |
3346 | frame_info_ptr::reinflate () const | |
3347 | { | |
3348 | /* Ensure we have a valid frame level (sentinel frame or above). */ | |
3349 | gdb_assert (m_cached_level >= -1); | |
3350 | ||
3351 | if (m_ptr != nullptr) | |
3352 | { | |
3353 | /* The frame_info wasn't invalidated, no need to reinflate. */ | |
3354 | return m_ptr; | |
3355 | } | |
3356 | ||
3357 | if (m_cached_id.user_created_p) | |
3358 | m_ptr = create_new_frame (m_cached_id).get (); | |
3359 | else | |
3360 | { | |
3361 | /* Frame #0 needs special handling, see comment in select_frame. */ | |
3362 | if (m_cached_level == 0) | |
3363 | m_ptr = get_current_frame ().get (); | |
3364 | else | |
3365 | { | |
3366 | /* If we reach here without a valid frame id, it means we are trying | |
3367 | to reinflate a frame whose id was not know at construction time. | |
3368 | We're probably trying to reinflate a frame while computing its id | |
3369 | which is not possible, and would indicate a problem with GDB. */ | |
3370 | gdb_assert (frame_id_p (m_cached_id)); | |
3371 | m_ptr = frame_find_by_id (m_cached_id).get (); | |
3372 | } | |
3373 | } | |
3374 | ||
3375 | gdb_assert (m_ptr != nullptr); | |
3376 | return m_ptr; | |
3377 | } | |
3378 | ||
3379 | void _initialize_frame (); | |
3380 | void | |
3381 | _initialize_frame () | |
3382 | { | |
3383 | obstack_init (&frame_cache_obstack); | |
3384 | ||
3385 | frame_stash_create (); | |
3386 | ||
3387 | gdb::observers::target_changed.attach (frame_observer_target_changed, | |
3388 | "frame"); | |
3389 | ||
3390 | add_setshow_prefix_cmd ("backtrace", class_maintenance, | |
3391 | _("\ | |
3392 | Set backtrace specific variables.\n\ | |
3393 | Configure backtrace variables such as the backtrace limit"), | |
3394 | _("\ | |
3395 | Show backtrace specific variables.\n\ | |
3396 | Show backtrace variables such as the backtrace limit."), | |
3397 | &set_backtrace_cmdlist, &show_backtrace_cmdlist, | |
3398 | &setlist, &showlist); | |
3399 | ||
3400 | add_setshow_uinteger_cmd ("limit", class_obscure, | |
3401 | &user_set_backtrace_options.backtrace_limit, _("\ | |
3402 | Set an upper bound on the number of backtrace levels."), _("\ | |
3403 | Show the upper bound on the number of backtrace levels."), _("\ | |
3404 | No more than the specified number of frames can be displayed or examined.\n\ | |
3405 | Literal \"unlimited\" or zero means no limit."), | |
3406 | NULL, | |
3407 | show_backtrace_limit, | |
3408 | &set_backtrace_cmdlist, | |
3409 | &show_backtrace_cmdlist); | |
3410 | ||
3411 | gdb::option::add_setshow_cmds_for_options | |
3412 | (class_stack, &user_set_backtrace_options, | |
3413 | set_backtrace_option_defs, &set_backtrace_cmdlist, &show_backtrace_cmdlist); | |
3414 | ||
3415 | /* Debug this files internals. */ | |
3416 | add_setshow_boolean_cmd ("frame", class_maintenance, &frame_debug, _("\ | |
3417 | Set frame debugging."), _("\ | |
3418 | Show frame debugging."), _("\ | |
3419 | When non-zero, frame specific internal debugging is enabled."), | |
3420 | NULL, | |
3421 | show_frame_debug, | |
3422 | &setdebuglist, &showdebuglist); | |
3423 | ||
3424 | add_cmd ("frame-id", class_maintenance, maintenance_print_frame_id, | |
3425 | _("Print the current frame-id."), | |
3426 | &maintenanceprintlist); | |
3427 | } |