1 /* Multi-process/thread control defs for GDB, the GNU debugger.
2 Copyright (C) 1987-2021 Free Software Foundation, Inc.
3 Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA.
4
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20
21 #ifndef GDBTHREAD_H
22 #define GDBTHREAD_H
23
24 struct symtab;
25
26 #include "breakpoint.h"
27 #include "frame.h"
28 #include "ui-out.h"
29 #include "btrace.h"
30 #include "target/waitstatus.h"
31 #include "cli/cli-utils.h"
32 #include "gdbsupport/refcounted-object.h"
33 #include "gdbsupport/common-gdbthread.h"
34 #include "gdbsupport/forward-scope-exit.h"
35 #include "displaced-stepping.h"
36
37 struct inferior;
38 struct process_stratum_target;
39
40 /* Frontend view of the thread state. Possible extensions: stepping,
41 finishing, until(ling),...
42
43 NOTE: Since the thread state is not a boolean, most times, you do
44 not want to check it with negation. If you really want to check if
45 the thread is stopped,
46
47 use (good):
48
49 if (tp->state == THREAD_STOPPED)
50
51 instead of (bad):
52
53 if (tp->state != THREAD_RUNNING)
54
55 The latter is also true for exited threads, most likely not what
56 you want. */
57 enum thread_state
58 {
59 /* In the frontend's perpective, the thread is stopped. */
60 THREAD_STOPPED,
61
62 /* In the frontend's perpective, the thread is running. */
63 THREAD_RUNNING,
64
65 /* The thread is listed, but known to have exited. We keep it
66 listed (but not visible) until it's safe to delete it. */
67 THREAD_EXITED,
68 };
69
70 /* STEP_OVER_ALL means step over all subroutine calls.
71 STEP_OVER_UNDEBUGGABLE means step over calls to undebuggable functions.
72 STEP_OVER_NONE means don't step over any subroutine calls. */
73
74 enum step_over_calls_kind
75 {
76 STEP_OVER_NONE,
77 STEP_OVER_ALL,
78 STEP_OVER_UNDEBUGGABLE
79 };
80
81 /* Inferior thread specific part of `struct infcall_control_state'.
82
83 Inferior process counterpart is `struct inferior_control_state'. */
84
85 struct thread_control_state
86 {
87 /* User/external stepping state. */
88
89 /* Step-resume or longjmp-resume breakpoint. */
90 struct breakpoint *step_resume_breakpoint = nullptr;
91
92 /* Exception-resume breakpoint. */
93 struct breakpoint *exception_resume_breakpoint = nullptr;
94
95 /* Breakpoints used for software single stepping. Plural, because
96 it may have multiple locations. E.g., if stepping over a
97 conditional branch instruction we can't decode the condition for,
98 we'll need to put a breakpoint at the branch destination, and
99 another at the instruction after the branch. */
100 struct breakpoint *single_step_breakpoints = nullptr;
101
102 /* Range to single step within.
103
104 If this is nonzero, respond to a single-step signal by continuing
105 to step if the pc is in this range.
106
107 If step_range_start and step_range_end are both 1, it means to
108 step for a single instruction (FIXME: it might clean up
109 wait_for_inferior in a minor way if this were changed to the
110 address of the instruction and that address plus one. But maybe
111 not). */
112 CORE_ADDR step_range_start = 0; /* Inclusive */
113 CORE_ADDR step_range_end = 0; /* Exclusive */
114
115 /* Function the thread was in as of last it started stepping. */
116 struct symbol *step_start_function = nullptr;
117
118 /* If GDB issues a target step request, and this is nonzero, the
119 target should single-step this thread once, and then continue
120 single-stepping it without GDB core involvement as long as the
121 thread stops in the step range above. If this is zero, the
122 target should ignore the step range, and only issue one single
123 step. */
124 int may_range_step = 0;
125
126 /* Stack frame address as of when stepping command was issued.
127 This is how we know when we step into a subroutine call, and how
128 to set the frame for the breakpoint used to step out. */
129 struct frame_id step_frame_id {};
130
131 /* Similarly, the frame ID of the underlying stack frame (skipping
132 any inlined frames). */
133 struct frame_id step_stack_frame_id {};
134
135 /* True if the the thread is presently stepping over a breakpoint or
136 a watchpoint, either with an inline step over or a displaced (out
137 of line) step, and we're now expecting it to report a trap for
138 the finished single step. */
139 int trap_expected = 0;
140
141 /* Nonzero if the thread is being proceeded for a "finish" command
142 or a similar situation when return value should be printed. */
143 int proceed_to_finish = 0;
144
145 /* Nonzero if the thread is being proceeded for an inferior function
146 call. */
147 int in_infcall = 0;
148
149 enum step_over_calls_kind step_over_calls = STEP_OVER_NONE;
150
151 /* Nonzero if stopped due to a step command. */
152 int stop_step = 0;
153
154 /* Chain containing status of breakpoint(s) the thread stopped
155 at. */
156 bpstat stop_bpstat = nullptr;
157
158 /* Whether the command that started the thread was a stepping
159 command. This is used to decide whether "set scheduler-locking
160 step" behaves like "on" or "off". */
161 int stepping_command = 0;
162 };
163
164 /* Inferior thread specific part of `struct infcall_suspend_state'. */
165
166 struct thread_suspend_state
167 {
168 /* Last signal that the inferior received (why it stopped). When
169 the thread is resumed, this signal is delivered. Note: the
170 target should not check whether the signal is in pass state,
171 because the signal may have been explicitly passed with the
172 "signal" command, which overrides "handle nopass". If the signal
173 should be suppressed, the core will take care of clearing this
174 before the target is resumed. */
175 enum gdb_signal stop_signal = GDB_SIGNAL_0;
176
177 /* The reason the thread last stopped, if we need to track it
178 (breakpoint, watchpoint, etc.) */
179 enum target_stop_reason stop_reason = TARGET_STOPPED_BY_NO_REASON;
180
181 /* The waitstatus for this thread's last event. */
182 struct target_waitstatus waitstatus {};
183 /* If true WAITSTATUS hasn't been handled yet. */
184 int waitstatus_pending_p = 0;
185
186 /* Record the pc of the thread the last time it stopped. (This is
187 not the current thread's PC as that may have changed since the
188 last stop, e.g., "return" command, or "p $pc = 0xf000").
189
190 - If the thread's PC has not changed since the thread last
191 stopped, then proceed skips a breakpoint at the current PC,
192 otherwise we let the thread run into the breakpoint.
193
194 - If the thread has an unprocessed event pending, as indicated by
195 waitstatus_pending_p, this is used in coordination with
196 stop_reason: if the thread's PC has changed since the thread
197 last stopped, a pending breakpoint waitstatus is discarded.
198
199 - If the thread is running, this is set to -1, to avoid leaving
200 it with a stale value, to make it easier to catch bugs. */
201 CORE_ADDR stop_pc = 0;
202 };
203
204 /* Base class for target-specific thread data. */
205 struct private_thread_info
206 {
207 virtual ~private_thread_info () = 0;
208 };
209
210 /* Threads are intrusively refcounted objects. Being the
211 user-selected thread is normally considered an implicit strong
212 reference and is thus not accounted in the refcount, unlike
213 inferior objects. This is necessary, because there's no "current
214 thread" pointer. Instead the current thread is inferred from the
215 inferior_ptid global. However, when GDB needs to remember the
216 selected thread to later restore it, GDB bumps the thread object's
217 refcount, to prevent something deleting the thread object before
218 reverting back (e.g., due to a "kill" command). If the thread
219 meanwhile exits before being re-selected, then the thread object is
220 left listed in the thread list, but marked with state
221 THREAD_EXITED. (See scoped_restore_current_thread and
222 delete_thread). All other thread references are considered weak
223 references. Placing a thread in the thread list is an implicit
224 strong reference, and is thus not accounted for in the thread's
225 refcount. */
226
227 class thread_info : public refcounted_object
228 {
229 public:
230 explicit thread_info (inferior *inf, ptid_t ptid);
231 ~thread_info ();
232
233 bool deletable () const;
234
235 /* Mark this thread as running and notify observers. */
236 void set_running (bool running);
237
238 struct thread_info *next = NULL;
239 ptid_t ptid; /* "Actual process id";
240 In fact, this may be overloaded with
241 kernel thread id, etc. */
242
243 /* Each thread has two GDB IDs.
244
245 a) The thread ID (Id). This consists of the pair of:
246
247 - the number of the thread's inferior and,
248
249 - the thread's thread number in its inferior, aka, the
250 per-inferior thread number. This number is unique in the
251 inferior but not unique between inferiors.
252
253 b) The global ID (GId). This is a a single integer unique
254 between all inferiors.
255
256 E.g.:
257
258 (gdb) info threads -gid
259 Id GId Target Id Frame
260 * 1.1 1 Thread A 0x16a09237 in foo () at foo.c:10
261 1.2 3 Thread B 0x15ebc6ed in bar () at foo.c:20
262 1.3 5 Thread C 0x15ebc6ed in bar () at foo.c:20
263 2.1 2 Thread A 0x16a09237 in foo () at foo.c:10
264 2.2 4 Thread B 0x15ebc6ed in bar () at foo.c:20
265 2.3 6 Thread C 0x15ebc6ed in bar () at foo.c:20
266
267 Above, both inferiors 1 and 2 have threads numbered 1-3, but each
268 thread has its own unique global ID. */
269
270 /* The thread's global GDB thread number. This is exposed to MI,
271 Python/Scheme, visible with "info threads -gid", and is also what
272 the $_gthread convenience variable is bound to. */
273 int global_num;
274
275 /* The per-inferior thread number. This is unique in the inferior
276 the thread belongs to, but not unique between inferiors. This is
277 what the $_thread convenience variable is bound to. */
278 int per_inf_num;
279
280 /* The inferior this thread belongs to. */
281 struct inferior *inf;
282
283 /* The name of the thread, as specified by the user. This is NULL
284 if the thread does not have a user-given name. */
285 char *name = NULL;
286
287 /* True means the thread is executing. Note: this is different
288 from saying that there is an active target and we are stopped at
289 a breakpoint, for instance. This is a real indicator whether the
290 thread is off and running. */
291 bool executing = false;
292
293 /* True if this thread is resumed from infrun's perspective.
294 Note that a thread can be marked both as not-executing and
295 resumed at the same time. This happens if we try to resume a
296 thread that has a wait status pending. We shouldn't let the
297 thread really run until that wait status has been processed, but
298 we should not process that wait status if we didn't try to let
299 the thread run. */
300 bool resumed = false;
301
302 /* Frontend view of the thread state. Note that the THREAD_RUNNING/
303 THREAD_STOPPED states are different from EXECUTING. When the
304 thread is stopped internally while handling an internal event,
305 like a software single-step breakpoint, EXECUTING will be false,
306 but STATE will still be THREAD_RUNNING. */
307 enum thread_state state = THREAD_STOPPED;
308
309 /* State of GDB control of inferior thread execution.
310 See `struct thread_control_state'. */
311 thread_control_state control;
312
313 /* State of inferior thread to restore after GDB is done with an inferior
314 call. See `struct thread_suspend_state'. */
315 thread_suspend_state suspend;
316
317 int current_line = 0;
318 struct symtab *current_symtab = NULL;
319
320 /* Internal stepping state. */
321
322 /* Record the pc of the thread the last time it was resumed. (It
323 can't be done on stop as the PC may change since the last stop,
324 e.g., "return" command, or "p $pc = 0xf000"). This is maintained
325 by proceed and keep_going, and among other things, it's used in
326 adjust_pc_after_break to distinguish a hardware single-step
327 SIGTRAP from a breakpoint SIGTRAP. */
328 CORE_ADDR prev_pc = 0;
329
330 /* Did we set the thread stepping a breakpoint instruction? This is
331 used in conjunction with PREV_PC to decide whether to adjust the
332 PC. */
333 int stepped_breakpoint = 0;
334
335 /* Should we step over breakpoint next time keep_going is called? */
336 int stepping_over_breakpoint = 0;
337
338 /* Should we step over a watchpoint next time keep_going is called?
339 This is needed on targets with non-continuable, non-steppable
340 watchpoints. */
341 int stepping_over_watchpoint = 0;
342
343 /* Set to TRUE if we should finish single-stepping over a breakpoint
344 after hitting the current step-resume breakpoint. The context here
345 is that GDB is to do `next' or `step' while signal arrives.
346 When stepping over a breakpoint and signal arrives, GDB will attempt
347 to skip signal handler, so it inserts a step_resume_breakpoint at the
348 signal return address, and resume inferior.
349 step_after_step_resume_breakpoint is set to TRUE at this moment in
350 order to keep GDB in mind that there is still a breakpoint to step over
351 when GDB gets back SIGTRAP from step_resume_breakpoint. */
352 int step_after_step_resume_breakpoint = 0;
353
354 /* Pointer to the state machine manager object that handles what is
355 left to do for the thread's execution command after the target
356 stops. Several execution commands use it. */
357 struct thread_fsm *thread_fsm = NULL;
358
359 /* This is used to remember when a fork or vfork event was caught by
360 a catchpoint, and thus the event is to be followed at the next
361 resume of the thread, and not immediately. */
362 struct target_waitstatus pending_follow;
363
364 /* True if this thread has been explicitly requested to stop. */
365 int stop_requested = 0;
366
367 /* The initiating frame of a nexting operation, used for deciding
368 which exceptions to intercept. If it is null_frame_id no
369 bp_longjmp or bp_exception but longjmp has been caught just for
370 bp_longjmp_call_dummy. */
371 struct frame_id initiating_frame = null_frame_id;
372
373 /* Private data used by the target vector implementation. */
374 std::unique_ptr<private_thread_info> priv;
375
376 /* Branch trace information for this thread. */
377 struct btrace_thread_info btrace {};
378
379 /* Flag which indicates that the stack temporaries should be stored while
380 evaluating expressions. */
381 bool stack_temporaries_enabled = false;
382
383 /* Values that are stored as temporaries on stack while evaluating
384 expressions. */
385 std::vector<struct value *> stack_temporaries;
386
387 /* Step-over chain. A thread is in the step-over queue if these are
388 non-NULL. If only a single thread is in the chain, then these
389 fields point to self. */
390 struct thread_info *step_over_prev = NULL;
391 struct thread_info *step_over_next = NULL;
392
393 /* Displaced-step state for this thread. */
394 displaced_step_thread_state displaced_step_state;
395 };
396
397 /* A gdb::ref_ptr pointer to a thread_info. */
398
399 using thread_info_ref
400 = gdb::ref_ptr<struct thread_info, refcounted_object_ref_policy>;
401
402 /* A gdb::ref_ptr pointer to an inferior. This would ideally be in
403 inferior.h, but it can't due to header dependencies (inferior.h
404 includes gdbthread.h). */
405
406 using inferior_ref
407 = gdb::ref_ptr<struct inferior, refcounted_object_ref_policy>;
408
409 /* Create an empty thread list, or empty the existing one. */
410 extern void init_thread_list (void);
411
412 /* Add a thread to the thread list, print a message
413 that a new thread is found, and return the pointer to
414 the new thread. Caller my use this pointer to
415 initialize the private thread data. */
416 extern struct thread_info *add_thread (process_stratum_target *targ,
417 ptid_t ptid);
418
419 /* Same as add_thread, but does not print a message about new
420 thread. */
421 extern struct thread_info *add_thread_silent (process_stratum_target *targ,
422 ptid_t ptid);
423
424 /* Same as add_thread, and sets the private info. */
425 extern struct thread_info *add_thread_with_info (process_stratum_target *targ,
426 ptid_t ptid,
427 private_thread_info *);
428
429 /* Delete thread THREAD and notify of thread exit. If the thread is
430 currently not deletable, don't actually delete it but still tag it
431 as exited and do the notification. */
432 extern void delete_thread (struct thread_info *thread);
433
434 /* Like delete_thread, but be quiet about it. Used when the process
435 this thread belonged to has already exited, for example. */
436 extern void delete_thread_silent (struct thread_info *thread);
437
438 /* Delete a step_resume_breakpoint from the thread database. */
439 extern void delete_step_resume_breakpoint (struct thread_info *);
440
441 /* Delete an exception_resume_breakpoint from the thread database. */
442 extern void delete_exception_resume_breakpoint (struct thread_info *);
443
444 /* Delete the single-step breakpoints of thread TP, if any. */
445 extern void delete_single_step_breakpoints (struct thread_info *tp);
446
447 /* Check if the thread has software single stepping breakpoints
448 set. */
449 extern int thread_has_single_step_breakpoints_set (struct thread_info *tp);
450
451 /* Check whether the thread has software single stepping breakpoints
452 set at PC. */
453 extern int thread_has_single_step_breakpoint_here (struct thread_info *tp,
454 const address_space *aspace,
455 CORE_ADDR addr);
456
457 /* Returns whether to show inferior-qualified thread IDs, or plain
458 thread numbers. Inferior-qualified IDs are shown whenever we have
459 multiple inferiors, or the only inferior left has number > 1. */
460 extern int show_inferior_qualified_tids (void);
461
462 /* Return a string version of THR's thread ID. If there are multiple
463 inferiors, then this prints the inferior-qualifier form, otherwise
464 it only prints the thread number. The result is stored in a
465 circular static buffer, NUMCELLS deep. */
466 const char *print_thread_id (struct thread_info *thr);
467
468 /* Boolean test for an already-known ptid. */
469 extern bool in_thread_list (process_stratum_target *targ, ptid_t ptid);
470
471 /* Boolean test for an already-known global thread id (GDB's homegrown
472 global id, not the system's). */
473 extern int valid_global_thread_id (int global_id);
474
475 /* Find (non-exited) thread PTID of inferior INF. */
476 extern thread_info *find_thread_ptid (inferior *inf, ptid_t ptid);
477
478 /* Search function to lookup a (non-exited) thread by 'ptid'. */
479 extern struct thread_info *find_thread_ptid (process_stratum_target *targ,
480 ptid_t ptid);
481
482 /* Find thread by GDB global thread ID. */
483 struct thread_info *find_thread_global_id (int global_id);
484
485 /* Find thread by thread library specific handle in inferior INF. */
486 struct thread_info *find_thread_by_handle
487 (gdb::array_view<const gdb_byte> handle, struct inferior *inf);
488
489 /* Finds the first thread of the specified inferior. */
490 extern struct thread_info *first_thread_of_inferior (inferior *inf);
491
492 /* Returns any thread of inferior INF, giving preference to the
493 current thread. */
494 extern struct thread_info *any_thread_of_inferior (inferior *inf);
495
496 /* Returns any non-exited thread of inferior INF, giving preference to
497 the current thread, and to not executing threads. */
498 extern struct thread_info *any_live_thread_of_inferior (inferior *inf);
499
500 /* Change the ptid of thread OLD_PTID to NEW_PTID. */
501 void thread_change_ptid (process_stratum_target *targ,
502 ptid_t old_ptid, ptid_t new_ptid);
503
504 /* Iterator function to call a user-provided callback function
505 once for each known thread. */
506 typedef int (*thread_callback_func) (struct thread_info *, void *);
507 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
508
509 /* Pull in the internals of the inferiors/threads ranges and
510 iterators. Must be done after struct thread_info is defined. */
511 #include "thread-iter.h"
512
513 /* Return a range that can be used to walk over threads, with
514 range-for.
515
516 Used like this, it walks over all threads of all inferiors of all
517 targets:
518
519 for (thread_info *thr : all_threads ())
520 { .... }
521
522 FILTER_PTID can be used to filter out threads that don't match.
523 FILTER_PTID can be:
524
525 - minus_one_ptid, meaning walk all threads of all inferiors of
526 PROC_TARGET. If PROC_TARGET is NULL, then of all targets.
527
528 - A process ptid, in which case walk all threads of the specified
529 process. PROC_TARGET must be non-NULL in this case.
530
531 - A thread ptid, in which case walk that thread only. PROC_TARGET
532 must be non-NULL in this case.
533 */
534
535 inline all_matching_threads_range
536 all_threads (process_stratum_target *proc_target = nullptr,
537 ptid_t filter_ptid = minus_one_ptid)
538 {
539 return all_matching_threads_range (proc_target, filter_ptid);
540 }
541
542 /* Return a range that can be used to walk over all non-exited threads
543 of all inferiors, with range-for. Arguments are like all_threads
544 above. */
545
546 inline all_non_exited_threads_range
547 all_non_exited_threads (process_stratum_target *proc_target = nullptr,
548 ptid_t filter_ptid = minus_one_ptid)
549 {
550 return all_non_exited_threads_range (proc_target, filter_ptid);
551 }
552
553 /* Return a range that can be used to walk over all threads of all
554 inferiors, with range-for, safely. I.e., it is safe to delete the
555 currently-iterated thread. When combined with range-for, this
556 allow convenient patterns like this:
557
558 for (thread_info *t : all_threads_safe ())
559 if (some_condition ())
560 delete f;
561 */
562
563 inline all_threads_safe_range
all_threads_safe()564 all_threads_safe ()
565 {
566 return {};
567 }
568
569 extern int thread_count (process_stratum_target *proc_target);
570
571 /* Return true if we have any thread in any inferior. */
572 extern bool any_thread_p ();
573
574 /* Switch context to thread THR. Also sets the STOP_PC global. */
575 extern void switch_to_thread (struct thread_info *thr);
576
577 /* Switch context to no thread selected. */
578 extern void switch_to_no_thread ();
579
580 /* Switch from one thread to another. Does not read registers. */
581 extern void switch_to_thread_no_regs (struct thread_info *thread);
582
583 /* Marks or clears thread(s) PTID of TARG as resumed. If PTID is
584 MINUS_ONE_PTID, applies to all threads of TARG. If
585 ptid_is_pid(PTID) is true, applies to all threads of the process
586 pointed at by {TARG,PTID}. */
587 extern void set_resumed (process_stratum_target *targ,
588 ptid_t ptid, bool resumed);
589
590 /* Marks thread PTID of TARG as running, or as stopped. If PTID is
591 minus_one_ptid, marks all threads of TARG. */
592 extern void set_running (process_stratum_target *targ,
593 ptid_t ptid, bool running);
594
595 /* Marks or clears thread(s) PTID of TARG as having been requested to
596 stop. If PTID is MINUS_ONE_PTID, applies to all threads of TARG.
597 If ptid_is_pid(PTID) is true, applies to all threads of the process
598 pointed at by {TARG, PTID}. If STOP, then the
599 THREAD_STOP_REQUESTED observer is called with PTID as argument. */
600 extern void set_stop_requested (process_stratum_target *targ,
601 ptid_t ptid, bool stop);
602
603 /* Marks thread PTID of TARG as executing, or not. If PTID is
604 minus_one_ptid, marks all threads of TARG.
605
606 Note that this is different from the running state. See the
607 description of state and executing fields of struct
608 thread_info. */
609 extern void set_executing (process_stratum_target *targ,
610 ptid_t ptid, bool executing);
611
612 /* True if any (known or unknown) thread of TARG is or may be
613 executing. */
614 extern bool threads_are_executing (process_stratum_target *targ);
615
616 /* Merge the executing property of thread PTID of TARG over to its
617 thread state property (frontend running/stopped view).
618
619 "not executing" -> "stopped"
620 "executing" -> "running"
621 "exited" -> "exited"
622
623 If PTID is minus_one_ptid, go over all threads of TARG.
624
625 Notifications are only emitted if the thread state did change. */
626 extern void finish_thread_state (process_stratum_target *targ, ptid_t ptid);
627
628 /* Calls finish_thread_state on scope exit, unless release() is called
629 to disengage. */
630 using scoped_finish_thread_state
631 = FORWARD_SCOPE_EXIT (finish_thread_state);
632
633 /* Commands with a prefix of `thread'. */
634 extern struct cmd_list_element *thread_cmd_list;
635
636 extern void thread_command (const char *tidstr, int from_tty);
637
638 /* Print notices on thread events (attach, detach, etc.), set with
639 `set print thread-events'. */
640 extern bool print_thread_events;
641
642 /* Prints the list of threads and their details on UIOUT. If
643 REQUESTED_THREADS, a list of GDB ids/ranges, is not NULL, only
644 print threads whose ID is included in the list. If PID is not -1,
645 only print threads from the process PID. Otherwise, threads from
646 all attached PIDs are printed. If both REQUESTED_THREADS is not
647 NULL and PID is not -1, then the thread is printed if it belongs to
648 the specified process. Otherwise, an error is raised. */
649 extern void print_thread_info (struct ui_out *uiout,
650 const char *requested_threads,
651 int pid);
652
653 /* Save/restore current inferior/thread/frame. */
654
655 class scoped_restore_current_thread
656 {
657 public:
658 scoped_restore_current_thread ();
659 ~scoped_restore_current_thread ();
660
661 DISABLE_COPY_AND_ASSIGN (scoped_restore_current_thread);
662
663 /* Cancel restoring on scope exit. */
dont_restore()664 void dont_restore () { m_dont_restore = true; }
665
666 private:
667 void restore ();
668
669 bool m_dont_restore = false;
670 thread_info_ref m_thread;
671 inferior_ref m_inf;
672
673 frame_id m_selected_frame_id;
674 int m_selected_frame_level;
675 bool m_was_stopped;
676 /* Save/restore the language as well, because selecting a frame
677 changes the current language to the frame's language if "set
678 language auto". */
679 enum language m_lang;
680 };
681
682 /* Returns a pointer into the thread_info corresponding to
683 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */
684 extern struct thread_info* inferior_thread (void);
685
686 extern void update_thread_list (void);
687
688 /* Delete any thread the target says is no longer alive. */
689
690 extern void prune_threads (void);
691
692 /* Delete threads marked THREAD_EXITED. Unlike prune_threads, this
693 does not consult the target about whether the thread is alive right
694 now. */
695 extern void delete_exited_threads (void);
696
697 /* Return true if PC is in the stepping range of THREAD. */
698
699 int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);
700
701 /* Enable storing stack temporaries for thread THR and disable and
702 clear the stack temporaries on destruction. Holds a strong
703 reference to THR. */
704
705 class enable_thread_stack_temporaries
706 {
707 public:
708
enable_thread_stack_temporaries(struct thread_info * thr)709 explicit enable_thread_stack_temporaries (struct thread_info *thr)
710 : m_thr (thread_info_ref::new_reference (thr))
711 {
712 m_thr->stack_temporaries_enabled = true;
713 m_thr->stack_temporaries.clear ();
714 }
715
~enable_thread_stack_temporaries()716 ~enable_thread_stack_temporaries ()
717 {
718 m_thr->stack_temporaries_enabled = false;
719 m_thr->stack_temporaries.clear ();
720 }
721
722 DISABLE_COPY_AND_ASSIGN (enable_thread_stack_temporaries);
723
724 private:
725
726 thread_info_ref m_thr;
727 };
728
729 extern bool thread_stack_temporaries_enabled_p (struct thread_info *tp);
730
731 extern void push_thread_stack_temporary (struct thread_info *tp, struct value *v);
732
733 extern value *get_last_thread_stack_temporary (struct thread_info *tp);
734
735 extern bool value_in_thread_stack_temporaries (struct value *,
736 struct thread_info *thr);
737
738 /* Add TP to the end of the global pending step-over chain. */
739
740 extern void global_thread_step_over_chain_enqueue (thread_info *tp);
741
742 /* Append the thread step over chain CHAIN_HEAD to the global thread step over
743 chain. */
744
745 extern void global_thread_step_over_chain_enqueue_chain
746 (thread_info *chain_head);
747
748 /* Remove TP from step-over chain LIST_P. */
749
750 extern void thread_step_over_chain_remove (thread_info **list_p,
751 thread_info *tp);
752
753 /* Remove TP from the global pending step-over chain. */
754
755 extern void global_thread_step_over_chain_remove (thread_info *tp);
756
757 /* Return the thread following TP in the step-over chain whose head is
758 CHAIN_HEAD. Return NULL if TP is the last entry in the chain. */
759
760 extern thread_info *thread_step_over_chain_next (thread_info *chain_head,
761 thread_info *tp);
762
763 /* Return the thread following TP in the global step-over chain, or NULL if TP
764 is the last entry in the chain. */
765
766 extern thread_info *global_thread_step_over_chain_next (thread_info *tp);
767
768 /* Return true if TP is in any step-over chain. */
769
770 extern int thread_is_in_step_over_chain (struct thread_info *tp);
771
772 /* Return the length of the the step over chain TP is in.
773
774 If TP is non-nullptr, the thread must be in a step over chain.
775 TP may be nullptr, in which case it denotes an empty list, so a length of
776 0. */
777
778 extern int thread_step_over_chain_length (thread_info *tp);
779
780 /* Cancel any ongoing execution command. */
781
782 extern void thread_cancel_execution_command (struct thread_info *thr);
783
784 /* Check whether it makes sense to access a register of the current
785 thread at this point. If not, throw an error (e.g., the thread is
786 executing). */
787 extern void validate_registers_access (void);
788
789 /* Check whether it makes sense to access a register of THREAD at this point.
790 Returns true if registers may be accessed; false otherwise. */
791 extern bool can_access_registers_thread (struct thread_info *thread);
792
793 /* Returns whether to show which thread hit the breakpoint, received a
794 signal, etc. and ended up causing a user-visible stop. This is
795 true iff we ever detected multiple threads. */
796 extern int show_thread_that_caused_stop (void);
797
798 /* Print the message for a thread or/and frame selected. */
799 extern void print_selected_thread_frame (struct ui_out *uiout,
800 user_selected_what selection);
801
802 /* Helper for the CLI's "thread" command and for MI's -thread-select.
803 Selects thread THR. TIDSTR is the original string the thread ID
804 was parsed from. This is used in the error message if THR is not
805 alive anymore. */
806 extern void thread_select (const char *tidstr, class thread_info *thr);
807
808 #endif /* GDBTHREAD_H */
809