1 /* Multi-process/thread control defs for GDB, the GNU debugger.
2 Copyright (C) 1987-2014 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"
32 /* Frontend view of the thread state. Possible extensions: stepping,
33 finishing, until(ling),... */
41 /* Inferior thread specific part of `struct infcall_control_state'.
43 Inferior process counterpart is `struct inferior_control_state'. */
45 struct thread_control_state
47 /* User/external stepping state. */
49 /* Step-resume or longjmp-resume breakpoint. */
50 struct breakpoint *step_resume_breakpoint;
52 /* Exception-resume breakpoint. */
53 struct breakpoint *exception_resume_breakpoint;
55 /* Breakpoints used for software single stepping. Plural, because
56 it may have multiple locations. E.g., if stepping over a
57 conditional branch instruction we can't decode the condition for,
58 we'll need to put a breakpoint at the branch destination, and
59 another at the instruction after the branch. */
60 struct breakpoint *single_step_breakpoints;
62 /* Range to single step within.
64 If this is nonzero, respond to a single-step signal by continuing
65 to step if the pc is in this range.
67 If step_range_start and step_range_end are both 1, it means to
68 step for a single instruction (FIXME: it might clean up
69 wait_for_inferior in a minor way if this were changed to the
70 address of the instruction and that address plus one. But maybe
72 CORE_ADDR step_range_start; /* Inclusive */
73 CORE_ADDR step_range_end; /* Exclusive */
75 /* If GDB issues a target step request, and this is nonzero, the
76 target should single-step this thread once, and then continue
77 single-stepping it without GDB core involvement as long as the
78 thread stops in the step range above. If this is zero, the
79 target should ignore the step range, and only issue one single
83 /* Stack frame address as of when stepping command was issued.
84 This is how we know when we step into a subroutine call, and how
85 to set the frame for the breakpoint used to step out. */
86 struct frame_id step_frame_id;
88 /* Similarly, the frame ID of the underlying stack frame (skipping
89 any inlined frames). */
90 struct frame_id step_stack_frame_id;
92 /* Nonzero if we are presently stepping over a breakpoint.
94 If we hit a breakpoint or watchpoint, and then continue, we need
95 to single step the current thread with breakpoints disabled, to
96 avoid hitting the same breakpoint or watchpoint again. And we
97 should step just a single thread and keep other threads stopped,
98 so that other threads don't miss breakpoints while they are
101 So, this variable simultaneously means that we need to single
102 step the current thread, keep other threads stopped, and that
103 breakpoints should be removed while we step.
105 This variable is set either:
106 - in proceed, when we resume inferior on user's explicit request
107 - in keep_going, if handle_inferior_event decides we need to
108 step over breakpoint.
110 The variable is cleared in normal_stop. The proceed calls
111 wait_for_inferior, which calls handle_inferior_event in a loop,
112 and until wait_for_inferior exits, this variable is changed only
116 /* Nonzero if the thread is being proceeded for a "finish" command
117 or a similar situation when stop_registers should be saved. */
118 int proceed_to_finish;
120 /* Nonzero if the thread is being proceeded for an inferior function
124 enum step_over_calls_kind step_over_calls;
126 /* Nonzero if stopped due to a step command. */
129 /* Chain containing status of breakpoint(s) the thread stopped
133 /* The interpreter that issued the execution command. NULL if the
134 thread was resumed as a result of a command applied to some other
135 thread (e.g., "next" with scheduler-locking off). */
136 struct interp *command_interp;
139 /* Inferior thread specific part of `struct infcall_suspend_state'.
141 Inferior process counterpart is `struct inferior_suspend_state'. */
143 struct thread_suspend_state
145 /* Last signal that the inferior received (why it stopped). When
146 the thread is resumed, this signal is delivered. Note: the
147 target should not check whether the signal is in pass state,
148 because the signal may have been explicitly passed with the
149 "signal" command, which overrides "handle nopass". If the signal
150 should be suppressed, the core will take care of clearing this
151 before the target is resumed. */
152 enum gdb_signal stop_signal;
157 struct thread_info *next;
158 ptid_t ptid; /* "Actual process id";
159 In fact, this may be overloaded with
160 kernel thread id, etc. */
161 int num; /* Convenient handle (GDB thread id) */
163 /* The name of the thread, as specified by the user. This is NULL
164 if the thread does not have a user-given name. */
167 /* Non-zero means the thread is executing. Note: this is different
168 from saying that there is an active target and we are stopped at
169 a breakpoint, for instance. This is a real indicator whether the
170 thread is off and running. */
173 /* Frontend view of the thread state. Note that the THREAD_RUNNING/
174 THREAD_STOPPED states are different from EXECUTING. When the
175 thread is stopped internally while handling an internal event,
176 like a software single-step breakpoint, EXECUTING will be false,
177 but STATE will still be THREAD_RUNNING. */
178 enum thread_state state;
180 /* If this is > 0, then it means there's code out there that relies
181 on this thread being listed. Don't delete it from the lists even
182 if we detect it exiting. */
185 /* State of GDB control of inferior thread execution.
186 See `struct thread_control_state'. */
187 struct thread_control_state control;
189 /* State of inferior thread to restore after GDB is done with an inferior
190 call. See `struct thread_suspend_state'. */
191 struct thread_suspend_state suspend;
194 struct symtab *current_symtab;
196 /* Internal stepping state. */
198 /* Record the pc of the thread the last time it stopped. This is
199 maintained by proceed and keep_going, and used in
200 adjust_pc_after_break to distinguish a hardware single-step
201 SIGTRAP from a breakpoint SIGTRAP. */
204 /* Should we step over breakpoint next time keep_going is called? */
205 int stepping_over_breakpoint;
207 /* Should we step over a watchpoint next time keep_going is called?
208 This is needed on targets with non-continuable, non-steppable
210 int stepping_over_watchpoint;
212 /* Set to TRUE if we should finish single-stepping over a breakpoint
213 after hitting the current step-resume breakpoint. The context here
214 is that GDB is to do `next' or `step' while signal arrives.
215 When stepping over a breakpoint and signal arrives, GDB will attempt
216 to skip signal handler, so it inserts a step_resume_breakpoint at the
217 signal return address, and resume inferior.
218 step_after_step_resume_breakpoint is set to TRUE at this moment in
219 order to keep GDB in mind that there is still a breakpoint to step over
220 when GDB gets back SIGTRAP from step_resume_breakpoint. */
221 int step_after_step_resume_breakpoint;
223 /* Per-thread command support. */
225 /* Pointer to what is left to do for an execution command after the
226 target stops. Used only in asynchronous mode, by targets that
227 support async execution. Several execution commands use it. */
228 struct continuation *continuations;
230 /* Similar to the above, but used when a single execution command
231 requires several resume/stop iterations. Used by the step
233 struct continuation *intermediate_continuations;
235 /* If stepping, nonzero means step count is > 1 so don't print frame
236 next time inferior stops if it stops due to stepping. */
239 /* This is used to remember when a fork or vfork event was caught by
240 a catchpoint, and thus the event is to be followed at the next
241 resume of the thread, and not immediately. */
242 struct target_waitstatus pending_follow;
244 /* True if this thread has been explicitly requested to stop. */
247 /* The initiating frame of a nexting operation, used for deciding
248 which exceptions to intercept. If it is null_frame_id no
249 bp_longjmp or bp_exception but longjmp has been caught just for
250 bp_longjmp_call_dummy. */
251 struct frame_id initiating_frame;
253 /* Private data used by the target vector implementation. */
254 struct private_thread_info *private;
256 /* Function that is called to free PRIVATE. If this is NULL, then
257 xfree will be called on PRIVATE. */
258 void (*private_dtor) (struct private_thread_info *);
260 /* Branch trace information for this thread. */
261 struct btrace_thread_info btrace;
264 /* Create an empty thread list, or empty the existing one. */
265 extern void init_thread_list (void);
267 /* Add a thread to the thread list, print a message
268 that a new thread is found, and return the pointer to
269 the new thread. Caller my use this pointer to
270 initialize the private thread data. */
271 extern struct thread_info *add_thread (ptid_t ptid);
273 /* Same as add_thread, but does not print a message
275 extern struct thread_info *add_thread_silent (ptid_t ptid);
277 /* Same as add_thread, and sets the private info. */
278 extern struct thread_info *add_thread_with_info (ptid_t ptid,
279 struct private_thread_info *);
281 /* Delete an existing thread list entry. */
282 extern void delete_thread (ptid_t);
284 /* Delete an existing thread list entry, and be quiet about it. Used
285 after the process this thread having belonged to having already
286 exited, for example. */
287 extern void delete_thread_silent (ptid_t);
289 /* Delete a step_resume_breakpoint from the thread database. */
290 extern void delete_step_resume_breakpoint (struct thread_info *);
292 /* Delete an exception_resume_breakpoint from the thread database. */
293 extern void delete_exception_resume_breakpoint (struct thread_info *);
295 /* Delete the single-step breakpoints of thread TP, if any. */
296 extern void delete_single_step_breakpoints (struct thread_info *tp);
298 /* Check if the thread has software single stepping breakpoints
300 extern int thread_has_single_step_breakpoints_set (struct thread_info *tp);
302 /* Check whether the thread has software single stepping breakpoints
304 extern int thread_has_single_step_breakpoint_here (struct thread_info *tp,
305 struct address_space *aspace,
308 /* Translate the integer thread id (GDB's homegrown id, not the system's)
309 into a "pid" (which may be overloaded with extra thread information). */
310 extern ptid_t thread_id_to_pid (int);
312 /* Translate a 'pid' (which may be overloaded with extra thread information)
313 into the integer thread id (GDB's homegrown id, not the system's). */
314 extern int pid_to_thread_id (ptid_t ptid);
316 /* Boolean test for an already-known pid (which may be overloaded with
317 extra thread information). */
318 extern int in_thread_list (ptid_t ptid);
320 /* Boolean test for an already-known thread id (GDB's homegrown id,
321 not the system's). */
322 extern int valid_thread_id (int thread);
324 /* Search function to lookup a thread by 'pid'. */
325 extern struct thread_info *find_thread_ptid (ptid_t ptid);
327 /* Find thread by GDB user-visible thread number. */
328 struct thread_info *find_thread_id (int num);
330 /* Finds the first thread of the inferior given by PID. If PID is -1,
331 returns the first thread in the list. */
332 struct thread_info *first_thread_of_process (int pid);
334 /* Returns any thread of process PID, giving preference to the current
336 extern struct thread_info *any_thread_of_process (int pid);
338 /* Returns any non-exited thread of process PID, giving preference to
339 the current thread, and to not executing threads. */
340 extern struct thread_info *any_live_thread_of_process (int pid);
342 /* Change the ptid of thread OLD_PTID to NEW_PTID. */
343 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
345 /* Iterator function to call a user-provided callback function
346 once for each known thread. */
347 typedef int (*thread_callback_func) (struct thread_info *, void *);
348 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
350 /* Traverse all threads, except those that have THREAD_EXITED
353 #define ALL_NON_EXITED_THREADS(T) \
354 for (T = thread_list; T; T = T->next) \
355 if ((T)->state != THREAD_EXITED)
357 extern int thread_count (void);
359 /* Switch from one thread to another. */
360 extern void switch_to_thread (ptid_t ptid);
362 /* Marks thread PTID is running, or stopped.
363 If ptid_get_pid (PTID) is -1, marks all threads. */
364 extern void set_running (ptid_t ptid, int running);
366 /* Marks or clears thread(s) PTID as having been requested to stop.
367 If PTID is MINUS_ONE_PTID, applies to all threads. If
368 ptid_is_pid(PTID) is true, applies to all threads of the process
369 pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED
370 observer is called with PTID as argument. */
371 extern void set_stop_requested (ptid_t ptid, int stop);
373 /* NOTE: Since the thread state is not a boolean, most times, you do
374 not want to check it with negation. If you really want to check if
375 the thread is stopped,
379 if (is_stopped (ptid))
383 if (!is_running (ptid))
385 The latter also returns true on exited threads, most likelly not
388 /* Reports if in the frontend's perpective, thread PTID is running. */
389 extern int is_running (ptid_t ptid);
391 /* Is this thread listed, but known to have exited? We keep it listed
392 (but not visible) until it's safe to delete. */
393 extern int is_exited (ptid_t ptid);
395 /* In the frontend's perpective, is this thread stopped? */
396 extern int is_stopped (ptid_t ptid);
398 /* Marks thread PTID as executing, or not. If ptid_get_pid (PTID) is -1,
401 Note that this is different from the running state. See the
402 description of state and executing fields of struct
404 extern void set_executing (ptid_t ptid, int executing);
406 /* Reports if thread PTID is executing. */
407 extern int is_executing (ptid_t ptid);
409 /* True if any (known or unknown) thread is or may be executing. */
410 extern int threads_are_executing (void);
412 /* Merge the executing property of thread PTID over to its thread
413 state property (frontend running/stopped view).
415 "not executing" -> "stopped"
416 "executing" -> "running"
419 If ptid_get_pid (PTID) is -1, go over all threads.
421 Notifications are only emitted if the thread state did change. */
422 extern void finish_thread_state (ptid_t ptid);
424 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
425 registered as a cleanup. PTID_P points to the ptid_t that is
426 passed to FINISH_THREAD_STATE. */
427 extern void finish_thread_state_cleanup (void *ptid_p);
429 /* Commands with a prefix of `thread'. */
430 extern struct cmd_list_element *thread_cmd_list;
432 /* Print notices on thread events (attach, detach, etc.), set with
433 `set print thread-events'. */
434 extern int print_thread_events;
436 extern void print_thread_info (struct ui_out *uiout, char *threads,
439 extern struct cleanup *make_cleanup_restore_current_thread (void);
441 /* Returns a pointer into the thread_info corresponding to
442 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */
443 extern struct thread_info* inferior_thread (void);
445 extern void update_thread_list (void);
447 /* Return true if PC is in the stepping range of THREAD. */
449 int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);
451 extern struct thread_info *thread_list;
453 #endif /* GDBTHREAD_H */