1 /* Multi-process/thread control defs for GDB, the GNU debugger.
2 Copyright (C) 1987-2015 Free Software Foundation, Inc.
3 Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA.
6 This file is part of GDB.
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.
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.
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/>. */
26 #include "breakpoint.h"
31 #include "common/vec.h"
33 /* Frontend view of the thread state. Possible extensions: stepping,
34 finishing, until(ling),... */
42 /* Inferior thread specific part of `struct infcall_control_state'.
44 Inferior process counterpart is `struct inferior_control_state'. */
46 struct thread_control_state
48 /* User/external stepping state. */
50 /* Step-resume or longjmp-resume breakpoint. */
51 struct breakpoint *step_resume_breakpoint;
53 /* Exception-resume breakpoint. */
54 struct breakpoint *exception_resume_breakpoint;
56 /* Breakpoints used for software single stepping. Plural, because
57 it may have multiple locations. E.g., if stepping over a
58 conditional branch instruction we can't decode the condition for,
59 we'll need to put a breakpoint at the branch destination, and
60 another at the instruction after the branch. */
61 struct breakpoint *single_step_breakpoints;
63 /* Range to single step within.
65 If this is nonzero, respond to a single-step signal by continuing
66 to step if the pc is in this range.
68 If step_range_start and step_range_end are both 1, it means to
69 step for a single instruction (FIXME: it might clean up
70 wait_for_inferior in a minor way if this were changed to the
71 address of the instruction and that address plus one. But maybe
73 CORE_ADDR step_range_start; /* Inclusive */
74 CORE_ADDR step_range_end; /* Exclusive */
76 /* If GDB issues a target step request, and this is nonzero, the
77 target should single-step this thread once, and then continue
78 single-stepping it without GDB core involvement as long as the
79 thread stops in the step range above. If this is zero, the
80 target should ignore the step range, and only issue one single
84 /* Stack frame address as of when stepping command was issued.
85 This is how we know when we step into a subroutine call, and how
86 to set the frame for the breakpoint used to step out. */
87 struct frame_id step_frame_id;
89 /* Similarly, the frame ID of the underlying stack frame (skipping
90 any inlined frames). */
91 struct frame_id step_stack_frame_id;
93 /* Nonzero if we are presently stepping over a breakpoint.
95 If we hit a breakpoint or watchpoint, and then continue, we need
96 to single step the current thread with breakpoints disabled, to
97 avoid hitting the same breakpoint or watchpoint again. And we
98 should step just a single thread and keep other threads stopped,
99 so that other threads don't miss breakpoints while they are
102 So, this variable simultaneously means that we need to single
103 step the current thread, keep other threads stopped, and that
104 breakpoints should be removed while we step.
106 This variable is set either:
107 - in proceed, when we resume inferior on user's explicit request
108 - in keep_going, if handle_inferior_event decides we need to
109 step over breakpoint.
111 The variable is cleared in normal_stop. The proceed calls
112 wait_for_inferior, which calls handle_inferior_event in a loop,
113 and until wait_for_inferior exits, this variable is changed only
117 /* Nonzero if the thread is being proceeded for a "finish" command
118 or a similar situation when stop_registers should be saved. */
119 int proceed_to_finish;
121 /* Nonzero if the thread is being proceeded for an inferior function
125 enum step_over_calls_kind step_over_calls;
127 /* Nonzero if stopped due to a step command. */
130 /* Chain containing status of breakpoint(s) the thread stopped
134 /* The interpreter that issued the execution command. NULL if the
135 thread was resumed as a result of a command applied to some other
136 thread (e.g., "next" with scheduler-locking off). */
137 struct interp *command_interp;
140 /* Inferior thread specific part of `struct infcall_suspend_state'.
142 Inferior process counterpart is `struct inferior_suspend_state'. */
144 struct thread_suspend_state
146 /* Last signal that the inferior received (why it stopped). When
147 the thread is resumed, this signal is delivered. Note: the
148 target should not check whether the signal is in pass state,
149 because the signal may have been explicitly passed with the
150 "signal" command, which overrides "handle nopass". If the signal
151 should be suppressed, the core will take care of clearing this
152 before the target is resumed. */
153 enum gdb_signal stop_signal;
156 typedef struct value *value_ptr;
157 DEF_VEC_P (value_ptr);
158 typedef VEC (value_ptr) value_vec;
162 struct thread_info *next;
163 ptid_t ptid; /* "Actual process id";
164 In fact, this may be overloaded with
165 kernel thread id, etc. */
166 int num; /* Convenient handle (GDB thread id) */
168 /* The name of the thread, as specified by the user. This is NULL
169 if the thread does not have a user-given name. */
172 /* Non-zero means the thread is executing. Note: this is different
173 from saying that there is an active target and we are stopped at
174 a breakpoint, for instance. This is a real indicator whether the
175 thread is off and running. */
178 /* Frontend view of the thread state. Note that the THREAD_RUNNING/
179 THREAD_STOPPED states are different from EXECUTING. When the
180 thread is stopped internally while handling an internal event,
181 like a software single-step breakpoint, EXECUTING will be false,
182 but STATE will still be THREAD_RUNNING. */
183 enum thread_state state;
185 /* If this is > 0, then it means there's code out there that relies
186 on this thread being listed. Don't delete it from the lists even
187 if we detect it exiting. */
190 /* State of GDB control of inferior thread execution.
191 See `struct thread_control_state'. */
192 struct thread_control_state control;
194 /* State of inferior thread to restore after GDB is done with an inferior
195 call. See `struct thread_suspend_state'. */
196 struct thread_suspend_state suspend;
199 struct symtab *current_symtab;
201 /* Internal stepping state. */
203 /* Record the pc of the thread the last time it stopped. This is
204 maintained by proceed and keep_going, and used in
205 adjust_pc_after_break to distinguish a hardware single-step
206 SIGTRAP from a breakpoint SIGTRAP. */
209 /* Did we set the thread stepping a breakpoint instruction? This is
210 used in conjunction with PREV_PC to decide whether to adjust the
212 int stepped_breakpoint;
214 /* Should we step over breakpoint next time keep_going is called? */
215 int stepping_over_breakpoint;
217 /* Should we step over a watchpoint next time keep_going is called?
218 This is needed on targets with non-continuable, non-steppable
220 int stepping_over_watchpoint;
222 /* Set to TRUE if we should finish single-stepping over a breakpoint
223 after hitting the current step-resume breakpoint. The context here
224 is that GDB is to do `next' or `step' while signal arrives.
225 When stepping over a breakpoint and signal arrives, GDB will attempt
226 to skip signal handler, so it inserts a step_resume_breakpoint at the
227 signal return address, and resume inferior.
228 step_after_step_resume_breakpoint is set to TRUE at this moment in
229 order to keep GDB in mind that there is still a breakpoint to step over
230 when GDB gets back SIGTRAP from step_resume_breakpoint. */
231 int step_after_step_resume_breakpoint;
233 /* Per-thread command support. */
235 /* Pointer to what is left to do for an execution command after the
236 target stops. Used only in asynchronous mode, by targets that
237 support async execution. Several execution commands use it. */
238 struct continuation *continuations;
240 /* Similar to the above, but used when a single execution command
241 requires several resume/stop iterations. Used by the step
243 struct continuation *intermediate_continuations;
245 /* If stepping, nonzero means step count is > 1 so don't print frame
246 next time inferior stops if it stops due to stepping. */
249 /* This is used to remember when a fork or vfork event was caught by
250 a catchpoint, and thus the event is to be followed at the next
251 resume of the thread, and not immediately. */
252 struct target_waitstatus pending_follow;
254 /* True if this thread has been explicitly requested to stop. */
257 /* The initiating frame of a nexting operation, used for deciding
258 which exceptions to intercept. If it is null_frame_id no
259 bp_longjmp or bp_exception but longjmp has been caught just for
260 bp_longjmp_call_dummy. */
261 struct frame_id initiating_frame;
263 /* Private data used by the target vector implementation. */
264 struct private_thread_info *priv;
266 /* Function that is called to free PRIVATE. If this is NULL, then
267 xfree will be called on PRIVATE. */
268 void (*private_dtor) (struct private_thread_info *);
270 /* Branch trace information for this thread. */
271 struct btrace_thread_info btrace;
273 /* Flag which indicates that the stack temporaries should be stored while
274 evaluating expressions. */
275 int stack_temporaries_enabled;
277 /* Values that are stored as temporaries on stack while evaluating
279 value_vec *stack_temporaries;
282 /* Create an empty thread list, or empty the existing one. */
283 extern void init_thread_list (void);
285 /* Add a thread to the thread list, print a message
286 that a new thread is found, and return the pointer to
287 the new thread. Caller my use this pointer to
288 initialize the private thread data. */
289 extern struct thread_info *add_thread (ptid_t ptid);
291 /* Same as add_thread, but does not print a message
293 extern struct thread_info *add_thread_silent (ptid_t ptid);
295 /* Same as add_thread, and sets the private info. */
296 extern struct thread_info *add_thread_with_info (ptid_t ptid,
297 struct private_thread_info *);
299 /* Delete an existing thread list entry. */
300 extern void delete_thread (ptid_t);
302 /* Delete an existing thread list entry, and be quiet about it. Used
303 after the process this thread having belonged to having already
304 exited, for example. */
305 extern void delete_thread_silent (ptid_t);
307 /* Delete a step_resume_breakpoint from the thread database. */
308 extern void delete_step_resume_breakpoint (struct thread_info *);
310 /* Delete an exception_resume_breakpoint from the thread database. */
311 extern void delete_exception_resume_breakpoint (struct thread_info *);
313 /* Delete the single-step breakpoints of thread TP, if any. */
314 extern void delete_single_step_breakpoints (struct thread_info *tp);
316 /* Check if the thread has software single stepping breakpoints
318 extern int thread_has_single_step_breakpoints_set (struct thread_info *tp);
320 /* Check whether the thread has software single stepping breakpoints
322 extern int thread_has_single_step_breakpoint_here (struct thread_info *tp,
323 struct address_space *aspace,
326 /* Translate the integer thread id (GDB's homegrown id, not the system's)
327 into a "pid" (which may be overloaded with extra thread information). */
328 extern ptid_t thread_id_to_pid (int);
330 /* Translate a 'pid' (which may be overloaded with extra thread information)
331 into the integer thread id (GDB's homegrown id, not the system's). */
332 extern int pid_to_thread_id (ptid_t ptid);
334 /* Boolean test for an already-known pid (which may be overloaded with
335 extra thread information). */
336 extern int in_thread_list (ptid_t ptid);
338 /* Boolean test for an already-known thread id (GDB's homegrown id,
339 not the system's). */
340 extern int valid_thread_id (int thread);
342 /* Search function to lookup a thread by 'pid'. */
343 extern struct thread_info *find_thread_ptid (ptid_t ptid);
345 /* Find thread by GDB user-visible thread number. */
346 struct thread_info *find_thread_id (int num);
348 /* Finds the first thread of the inferior given by PID. If PID is -1,
349 returns the first thread in the list. */
350 struct thread_info *first_thread_of_process (int pid);
352 /* Returns any thread of process PID, giving preference to the current
354 extern struct thread_info *any_thread_of_process (int pid);
356 /* Returns any non-exited thread of process PID, giving preference to
357 the current thread, and to not executing threads. */
358 extern struct thread_info *any_live_thread_of_process (int pid);
360 /* Change the ptid of thread OLD_PTID to NEW_PTID. */
361 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
363 /* Iterator function to call a user-provided callback function
364 once for each known thread. */
365 typedef int (*thread_callback_func) (struct thread_info *, void *);
366 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
368 /* Traverse all threads, except those that have THREAD_EXITED
371 #define ALL_NON_EXITED_THREADS(T) \
372 for (T = thread_list; T; T = T->next) \
373 if ((T)->state != THREAD_EXITED)
375 /* Like ALL_NON_EXITED_THREADS, but allows deleting the currently
377 #define ALL_NON_EXITED_THREADS_SAFE(T, TMP) \
378 for ((T) = thread_list; \
379 (T) != NULL ? ((TMP) = (T)->next, 1): 0; \
381 if ((T)->state != THREAD_EXITED)
383 extern int thread_count (void);
385 /* Switch from one thread to another. */
386 extern void switch_to_thread (ptid_t ptid);
388 /* Marks thread PTID is running, or stopped.
389 If PTID is minus_one_ptid, marks all threads. */
390 extern void set_running (ptid_t ptid, int running);
392 /* Marks or clears thread(s) PTID as having been requested to stop.
393 If PTID is MINUS_ONE_PTID, applies to all threads. If
394 ptid_is_pid(PTID) is true, applies to all threads of the process
395 pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED
396 observer is called with PTID as argument. */
397 extern void set_stop_requested (ptid_t ptid, int stop);
399 /* NOTE: Since the thread state is not a boolean, most times, you do
400 not want to check it with negation. If you really want to check if
401 the thread is stopped,
405 if (is_stopped (ptid))
409 if (!is_running (ptid))
411 The latter also returns true on exited threads, most likelly not
414 /* Reports if in the frontend's perpective, thread PTID is running. */
415 extern int is_running (ptid_t ptid);
417 /* Is this thread listed, but known to have exited? We keep it listed
418 (but not visible) until it's safe to delete. */
419 extern int is_exited (ptid_t ptid);
421 /* In the frontend's perpective, is this thread stopped? */
422 extern int is_stopped (ptid_t ptid);
424 /* Marks thread PTID as executing, or not. If PTID is minus_one_ptid,
427 Note that this is different from the running state. See the
428 description of state and executing fields of struct
430 extern void set_executing (ptid_t ptid, int executing);
432 /* Reports if thread PTID is executing. */
433 extern int is_executing (ptid_t ptid);
435 /* True if any (known or unknown) thread is or may be executing. */
436 extern int threads_are_executing (void);
438 /* Merge the executing property of thread PTID over to its thread
439 state property (frontend running/stopped view).
441 "not executing" -> "stopped"
442 "executing" -> "running"
445 If PTID is minus_one_ptid, go over all threads.
447 Notifications are only emitted if the thread state did change. */
448 extern void finish_thread_state (ptid_t ptid);
450 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
451 registered as a cleanup. PTID_P points to the ptid_t that is
452 passed to FINISH_THREAD_STATE. */
453 extern void finish_thread_state_cleanup (void *ptid_p);
455 /* Commands with a prefix of `thread'. */
456 extern struct cmd_list_element *thread_cmd_list;
458 extern void thread_command (char *tidstr, int from_tty);
460 /* Print notices on thread events (attach, detach, etc.), set with
461 `set print thread-events'. */
462 extern int print_thread_events;
464 extern void print_thread_info (struct ui_out *uiout, char *threads,
467 extern struct cleanup *make_cleanup_restore_current_thread (void);
469 /* Returns a pointer into the thread_info corresponding to
470 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */
471 extern struct thread_info* inferior_thread (void);
473 extern void update_thread_list (void);
475 /* Delete any thread the target says is no longer alive. */
477 extern void prune_threads (void);
479 /* Return true if PC is in the stepping range of THREAD. */
481 int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);
483 extern struct cleanup *enable_thread_stack_temporaries (ptid_t ptid);
485 extern int thread_stack_temporaries_enabled_p (ptid_t ptid);
487 extern void push_thread_stack_temporary (ptid_t ptid, struct value *v);
489 extern struct value *get_last_thread_stack_temporary (ptid_t);
491 extern int value_in_thread_stack_temporaries (struct value *, ptid_t);
493 extern struct thread_info *thread_list;
495 #endif /* GDBTHREAD_H */