summaryrefslogtreecommitdiff
path: root/gdb/gdbthread.h
blob: 0926f5f1c13b2970de0518d7d2b80d0d9ec3e9c2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
/* Multi-process/thread control defs for GDB, the GNU debugger.
   Copyright (C) 1987-2015 Free Software Foundation, Inc.
   Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.
   

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef GDBTHREAD_H
#define GDBTHREAD_H

struct symtab;

#include "breakpoint.h"
#include "frame.h"
#include "ui-out.h"
#include "inferior.h"
#include "btrace.h"
#include "common/vec.h"

/* Frontend view of the thread state.  Possible extensions: stepping,
   finishing, until(ling),...  */
enum thread_state
{
  THREAD_STOPPED,
  THREAD_RUNNING,
  THREAD_EXITED,
};

/* Inferior thread specific part of `struct infcall_control_state'.

   Inferior process counterpart is `struct inferior_control_state'.  */

struct thread_control_state
{
  /* User/external stepping state.  */

  /* Step-resume or longjmp-resume breakpoint.  */
  struct breakpoint *step_resume_breakpoint;

  /* Exception-resume breakpoint.  */
  struct breakpoint *exception_resume_breakpoint;

  /* Breakpoints used for software single stepping.  Plural, because
     it may have multiple locations.  E.g., if stepping over a
     conditional branch instruction we can't decode the condition for,
     we'll need to put a breakpoint at the branch destination, and
     another at the instruction after the branch.  */
  struct breakpoint *single_step_breakpoints;

  /* Range to single step within.

     If this is nonzero, respond to a single-step signal by continuing
     to step if the pc is in this range.

     If step_range_start and step_range_end are both 1, it means to
     step for a single instruction (FIXME: it might clean up
     wait_for_inferior in a minor way if this were changed to the
     address of the instruction and that address plus one.  But maybe
     not).  */
  CORE_ADDR step_range_start;	/* Inclusive */
  CORE_ADDR step_range_end;	/* Exclusive */

  /* Function the thread was in as of last it started stepping.  */
  struct symbol *step_start_function;

  /* If GDB issues a target step request, and this is nonzero, the
     target should single-step this thread once, and then continue
     single-stepping it without GDB core involvement as long as the
     thread stops in the step range above.  If this is zero, the
     target should ignore the step range, and only issue one single
     step.  */
  int may_range_step;

  /* Stack frame address as of when stepping command was issued.
     This is how we know when we step into a subroutine call, and how
     to set the frame for the breakpoint used to step out.  */
  struct frame_id step_frame_id;

  /* Similarly, the frame ID of the underlying stack frame (skipping
     any inlined frames).  */
  struct frame_id step_stack_frame_id;

  /* Nonzero if we are presently stepping over a breakpoint.

     If we hit a breakpoint or watchpoint, and then continue, we need
     to single step the current thread with breakpoints disabled, to
     avoid hitting the same breakpoint or watchpoint again.  And we
     should step just a single thread and keep other threads stopped,
     so that other threads don't miss breakpoints while they are
     removed.

     So, this variable simultaneously means that we need to single
     step the current thread, keep other threads stopped, and that
     breakpoints should be removed while we step.

     This variable is set either:
     - in proceed, when we resume inferior on user's explicit request
     - in keep_going, if handle_inferior_event decides we need to
     step over breakpoint.

     The variable is cleared in normal_stop.  The proceed calls
     wait_for_inferior, which calls handle_inferior_event in a loop,
     and until wait_for_inferior exits, this variable is changed only
     by keep_going.  */
  int trap_expected;

  /* Nonzero if the thread is being proceeded for a "finish" command
     or a similar situation when return value should be printed.  */
  int proceed_to_finish;

  /* Nonzero if the thread is being proceeded for an inferior function
     call.  */
  int in_infcall;

  enum step_over_calls_kind step_over_calls;

  /* Nonzero if stopped due to a step command.  */
  int stop_step;

  /* Chain containing status of breakpoint(s) the thread stopped
     at.  */
  bpstat stop_bpstat;

  /* The interpreter that issued the execution command.  NULL if the
     thread was resumed as a result of a command applied to some other
     thread (e.g., "next" with scheduler-locking off).  */
  struct interp *command_interp;

  /* Whether the command that started the thread was a stepping
     command.  This is used to decide whether "set scheduler-locking
     step" behaves like "on" or "off".  */
  int stepping_command;
};

/* Inferior thread specific part of `struct infcall_suspend_state'.

   Inferior process counterpart is `struct inferior_suspend_state'.  */

struct thread_suspend_state
{
  /* Last signal that the inferior received (why it stopped).  When
     the thread is resumed, this signal is delivered.  Note: the
     target should not check whether the signal is in pass state,
     because the signal may have been explicitly passed with the
     "signal" command, which overrides "handle nopass".  If the signal
     should be suppressed, the core will take care of clearing this
     before the target is resumed.  */
  enum gdb_signal stop_signal;
};

typedef struct value *value_ptr;
DEF_VEC_P (value_ptr);
typedef VEC (value_ptr) value_vec;

struct thread_info
{
  struct thread_info *next;
  ptid_t ptid;			/* "Actual process id";
				    In fact, this may be overloaded with 
				    kernel thread id, etc.  */
  int num;			/* Convenient handle (GDB thread id) */

  /* The name of the thread, as specified by the user.  This is NULL
     if the thread does not have a user-given name.  */
  char *name;

  /* Non-zero means the thread is executing.  Note: this is different
     from saying that there is an active target and we are stopped at
     a breakpoint, for instance.  This is a real indicator whether the
     thread is off and running.  */
  int executing;

  /* Frontend view of the thread state.  Note that the THREAD_RUNNING/
     THREAD_STOPPED states are different from EXECUTING.  When the
     thread is stopped internally while handling an internal event,
     like a software single-step breakpoint, EXECUTING will be false,
     but STATE will still be THREAD_RUNNING.  */
  enum thread_state state;

  /* If this is > 0, then it means there's code out there that relies
     on this thread being listed.  Don't delete it from the lists even
     if we detect it exiting.  */
  int refcount;

  /* State of GDB control of inferior thread execution.
     See `struct thread_control_state'.  */
  struct thread_control_state control;

  /* State of inferior thread to restore after GDB is done with an inferior
     call.  See `struct thread_suspend_state'.  */
  struct thread_suspend_state suspend;

  int current_line;
  struct symtab *current_symtab;

  /* Internal stepping state.  */

  /* Record the pc of the thread the last time it stopped.  This is
     maintained by proceed and keep_going, and used in
     adjust_pc_after_break to distinguish a hardware single-step
     SIGTRAP from a breakpoint SIGTRAP.  */
  CORE_ADDR prev_pc;

  /* Did we set the thread stepping a breakpoint instruction?  This is
     used in conjunction with PREV_PC to decide whether to adjust the
     PC.  */
  int stepped_breakpoint;

  /* Should we step over breakpoint next time keep_going is called?  */
  int stepping_over_breakpoint;

  /* Should we step over a watchpoint next time keep_going is called?
     This is needed on targets with non-continuable, non-steppable
     watchpoints.  */
  int stepping_over_watchpoint;

  /* Set to TRUE if we should finish single-stepping over a breakpoint
     after hitting the current step-resume breakpoint.  The context here
     is that GDB is to do `next' or `step' while signal arrives.
     When stepping over a breakpoint and signal arrives, GDB will attempt
     to skip signal handler, so it inserts a step_resume_breakpoint at the
     signal return address, and resume inferior.
     step_after_step_resume_breakpoint is set to TRUE at this moment in
     order to keep GDB in mind that there is still a breakpoint to step over
     when GDB gets back SIGTRAP from step_resume_breakpoint.  */
  int step_after_step_resume_breakpoint;

  /* Per-thread command support.  */

  /* Pointer to what is left to do for an execution command after the
     target stops.  Used only in asynchronous mode, by targets that
     support async execution.  Several execution commands use it.  */
  struct continuation *continuations;

  /* Similar to the above, but used when a single execution command
     requires several resume/stop iterations.  Used by the step
     command.  */
  struct continuation *intermediate_continuations;

  /* If stepping, nonzero means step count is > 1 so don't print frame
     next time inferior stops if it stops due to stepping.  */
  int step_multi;

  /* This is used to remember when a fork or vfork event was caught by
     a catchpoint, and thus the event is to be followed at the next
     resume of the thread, and not immediately.  */
  struct target_waitstatus pending_follow;

  /* True if this thread has been explicitly requested to stop.  */
  int stop_requested;

  /* The initiating frame of a nexting operation, used for deciding
     which exceptions to intercept.  If it is null_frame_id no
     bp_longjmp or bp_exception but longjmp has been caught just for
     bp_longjmp_call_dummy.  */
  struct frame_id initiating_frame;

  /* Private data used by the target vector implementation.  */
  struct private_thread_info *priv;

  /* Function that is called to free PRIVATE.  If this is NULL, then
     xfree will be called on PRIVATE.  */
  void (*private_dtor) (struct private_thread_info *);

  /* Branch trace information for this thread.  */
  struct btrace_thread_info btrace;

  /* Flag which indicates that the stack temporaries should be stored while
     evaluating expressions.  */
  int stack_temporaries_enabled;

  /* Values that are stored as temporaries on stack while evaluating
     expressions.  */
  value_vec *stack_temporaries;
};

/* Create an empty thread list, or empty the existing one.  */
extern void init_thread_list (void);

/* Add a thread to the thread list, print a message
   that a new thread is found, and return the pointer to
   the new thread.  Caller my use this pointer to 
   initialize the private thread data.  */
extern struct thread_info *add_thread (ptid_t ptid);

/* Same as add_thread, but does not print a message
   about new thread.  */
extern struct thread_info *add_thread_silent (ptid_t ptid);

/* Same as add_thread, and sets the private info.  */
extern struct thread_info *add_thread_with_info (ptid_t ptid,
						 struct private_thread_info *);

/* Delete an existing thread list entry.  */
extern void delete_thread (ptid_t);

/* Delete an existing thread list entry, and be quiet about it.  Used
   after the process this thread having belonged to having already
   exited, for example.  */
extern void delete_thread_silent (ptid_t);

/* Delete a step_resume_breakpoint from the thread database.  */
extern void delete_step_resume_breakpoint (struct thread_info *);

/* Delete an exception_resume_breakpoint from the thread database.  */
extern void delete_exception_resume_breakpoint (struct thread_info *);

/* Delete the single-step breakpoints of thread TP, if any.  */
extern void delete_single_step_breakpoints (struct thread_info *tp);

/* Check if the thread has software single stepping breakpoints
   set.  */
extern int thread_has_single_step_breakpoints_set (struct thread_info *tp);

/* Check whether the thread has software single stepping breakpoints
   set at PC.  */
extern int thread_has_single_step_breakpoint_here (struct thread_info *tp,
						   struct address_space *aspace,
						   CORE_ADDR addr);

/* Translate the integer thread id (GDB's homegrown id, not the system's)
   into a "pid" (which may be overloaded with extra thread information).  */
extern ptid_t thread_id_to_pid (int);

/* Translate a 'pid' (which may be overloaded with extra thread information) 
   into the integer thread id (GDB's homegrown id, not the system's).  */
extern int pid_to_thread_id (ptid_t ptid);

/* Boolean test for an already-known pid (which may be overloaded with
   extra thread information).  */
extern int in_thread_list (ptid_t ptid);

/* Boolean test for an already-known thread id (GDB's homegrown id, 
   not the system's).  */
extern int valid_thread_id (int thread);

/* Search function to lookup a thread by 'pid'.  */
extern struct thread_info *find_thread_ptid (ptid_t ptid);

/* Find thread by GDB user-visible thread number.  */
struct thread_info *find_thread_id (int num);

/* Finds the first thread of the inferior given by PID.  If PID is -1,
   returns the first thread in the list.  */
struct thread_info *first_thread_of_process (int pid);

/* Returns any thread of process PID, giving preference to the current
   thread.  */
extern struct thread_info *any_thread_of_process (int pid);

/* Returns any non-exited thread of process PID, giving preference to
   the current thread, and to not executing threads.  */
extern struct thread_info *any_live_thread_of_process (int pid);

/* Change the ptid of thread OLD_PTID to NEW_PTID.  */
void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);

/* Iterator function to call a user-provided callback function
   once for each known thread.  */
typedef int (*thread_callback_func) (struct thread_info *, void *);
extern struct thread_info *iterate_over_threads (thread_callback_func, void *);

/* Traverse all threads, except those that have THREAD_EXITED
   state.  */

#define ALL_NON_EXITED_THREADS(T)				\
  for (T = thread_list; T; T = T->next) \
    if ((T)->state != THREAD_EXITED)

/* Traverse all threads, including those that have THREAD_EXITED
   state.  Allows deleting the currently iterated thread.  */
#define ALL_THREADS_SAFE(T, TMP)	\
  for ((T) = thread_list;			\
       (T) != NULL ? ((TMP) = (T)->next, 1): 0;	\
       (T) = (TMP))

extern int thread_count (void);

/* Switch from one thread to another.  */
extern void switch_to_thread (ptid_t ptid);

/* Marks thread PTID is running, or stopped. 
   If PTID is minus_one_ptid, marks all threads.  */
extern void set_running (ptid_t ptid, int running);

/* Marks or clears thread(s) PTID as having been requested to stop.
   If PTID is MINUS_ONE_PTID, applies to all threads.  If
   ptid_is_pid(PTID) is true, applies to all threads of the process
   pointed at by PTID.  If STOP, then the THREAD_STOP_REQUESTED
   observer is called with PTID as argument.  */
extern void set_stop_requested (ptid_t ptid, int stop);

/* NOTE: Since the thread state is not a boolean, most times, you do
   not want to check it with negation.  If you really want to check if
   the thread is stopped,

    use (good):

     if (is_stopped (ptid))

    instead of (bad):

     if (!is_running (ptid))

   The latter also returns true on exited threads, most likelly not
   what you want.  */

/* Reports if in the frontend's perpective, thread PTID is running.  */
extern int is_running (ptid_t ptid);

/* Is this thread listed, but known to have exited?  We keep it listed
   (but not visible) until it's safe to delete.  */
extern int is_exited (ptid_t ptid);

/* In the frontend's perpective, is this thread stopped?  */
extern int is_stopped (ptid_t ptid);

/* Marks thread PTID as executing, or not.  If PTID is minus_one_ptid,
   marks all threads.

   Note that this is different from the running state.  See the
   description of state and executing fields of struct
   thread_info.  */
extern void set_executing (ptid_t ptid, int executing);

/* Reports if thread PTID is executing.  */
extern int is_executing (ptid_t ptid);

/* True if any (known or unknown) thread is or may be executing.  */
extern int threads_are_executing (void);

/* Merge the executing property of thread PTID over to its thread
   state property (frontend running/stopped view).

   "not executing" -> "stopped"
   "executing"     -> "running"
   "exited"        -> "exited"

   If PTID is minus_one_ptid, go over all threads.

   Notifications are only emitted if the thread state did change.  */
extern void finish_thread_state (ptid_t ptid);

/* Same as FINISH_THREAD_STATE, but with an interface suitable to be
   registered as a cleanup.  PTID_P points to the ptid_t that is
   passed to FINISH_THREAD_STATE.  */
extern void finish_thread_state_cleanup (void *ptid_p);

/* Commands with a prefix of `thread'.  */
extern struct cmd_list_element *thread_cmd_list;

extern void thread_command (char *tidstr, int from_tty);

/* Print notices on thread events (attach, detach, etc.), set with
   `set print thread-events'.  */
extern int print_thread_events;

extern void print_thread_info (struct ui_out *uiout, char *threads,
			       int pid);

extern struct cleanup *make_cleanup_restore_current_thread (void);

/* Returns a pointer into the thread_info corresponding to
   INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
extern struct thread_info* inferior_thread (void);

extern void update_thread_list (void);

/* Delete any thread the target says is no longer alive.  */

extern void prune_threads (void);

/* Delete threads marked THREAD_EXITED.  Unlike prune_threads, this
   does not consult the target about whether the thread is alive right
   now.  */
extern void delete_exited_threads (void);

/* Return true if PC is in the stepping range of THREAD.  */

int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);

extern struct cleanup *enable_thread_stack_temporaries (ptid_t ptid);

extern int thread_stack_temporaries_enabled_p (ptid_t ptid);

extern void push_thread_stack_temporary (ptid_t ptid, struct value *v);

extern struct value *get_last_thread_stack_temporary (ptid_t);

extern int value_in_thread_stack_temporaries (struct value *, ptid_t);

extern struct thread_info *thread_list;

#endif /* GDBTHREAD_H */