/* Multi-process/thread control defs for GDB, the GNU debugger.
- Copyright (C) 1987-2016 Free Software Foundation, Inc.
+ Copyright (C) 1987-2019 Free Software Foundation, Inc.
Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA.
#include "breakpoint.h"
#include "frame.h"
#include "ui-out.h"
-#include "inferior.h"
#include "btrace.h"
#include "common/vec.h"
#include "target/waitstatus.h"
#include "cli/cli-utils.h"
+#include "common/refcounted-object.h"
+#include "common/common-gdbthread.h"
+#include "common/forward-scope-exit.h"
+
+struct inferior;
/* Frontend view of the thread state. Possible extensions: stepping,
- finishing, until(ling),... */
+ finishing, until(ling),...
+
+ 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 (tp->state == THREAD_STOPPED)
+
+ instead of (bad):
+
+ if (tp->state != THREAD_RUNNING)
+
+ The latter is also true for exited threads, most likely not what
+ you want. */
enum thread_state
{
+ /* In the frontend's perpective, the thread is stopped. */
THREAD_STOPPED,
+
+ /* In the frontend's perpective, the thread is running. */
THREAD_RUNNING,
+
+ /* The thread is listed, but known to have exited. We keep it
+ listed (but not visible) until it's safe to delete it. */
THREAD_EXITED,
};
+/* STEP_OVER_ALL means step over all subroutine calls.
+ STEP_OVER_UNDEBUGGABLE means step over calls to undebuggable functions.
+ STEP_OVER_NONE means don't step over any subroutine calls. */
+
+enum step_over_calls_kind
+ {
+ STEP_OVER_NONE,
+ STEP_OVER_ALL,
+ STEP_OVER_UNDEBUGGABLE
+ };
+
/* Inferior thread specific part of `struct infcall_control_state'.
Inferior process counterpart is `struct inferior_control_state'. */
/* User/external stepping state. */
/* Step-resume or longjmp-resume breakpoint. */
- struct breakpoint *step_resume_breakpoint;
+ struct breakpoint *step_resume_breakpoint = nullptr;
/* Exception-resume breakpoint. */
- struct breakpoint *exception_resume_breakpoint;
+ struct breakpoint *exception_resume_breakpoint = nullptr;
/* 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;
+ struct breakpoint *single_step_breakpoints = nullptr;
/* Range to single step within.
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 */
+ CORE_ADDR step_range_start = 0; /* Inclusive */
+ CORE_ADDR step_range_end = 0; /* Exclusive */
/* Function the thread was in as of last it started stepping. */
- struct symbol *step_start_function;
+ struct symbol *step_start_function = nullptr;
/* If GDB issues a target step request, and this is nonzero, the
target should single-step this thread once, and then continue
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;
+ int may_range_step = 0;
/* 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;
+ 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;
+ struct frame_id step_stack_frame_id {};
/* Nonzero if we are presently stepping over a breakpoint.
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;
+ int trap_expected = 0;
/* 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;
+ int proceed_to_finish = 0;
/* Nonzero if the thread is being proceeded for an inferior function
call. */
- int in_infcall;
+ int in_infcall = 0;
- enum step_over_calls_kind step_over_calls;
+ enum step_over_calls_kind step_over_calls = STEP_OVER_NONE;
/* Nonzero if stopped due to a step command. */
- int stop_step;
+ int stop_step = 0;
/* 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;
+ bpstat stop_bpstat = nullptr;
/* 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;
+ int stepping_command = 0;
};
/* Inferior thread specific part of `struct infcall_suspend_state'. */
"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;
+ enum gdb_signal stop_signal = GDB_SIGNAL_0;
/* The reason the thread last stopped, if we need to track it
(breakpoint, watchpoint, etc.) */
- enum target_stop_reason stop_reason;
+ enum target_stop_reason stop_reason = TARGET_STOPPED_BY_NO_REASON;
/* The waitstatus for this thread's last event. */
- struct target_waitstatus waitstatus;
+ struct target_waitstatus waitstatus {};
/* If true WAITSTATUS hasn't been handled yet. */
- int waitstatus_pending_p;
+ int waitstatus_pending_p = 0;
/* Record the pc of the thread the last time it stopped. (This is
not the current thread's PC as that may have changed since the
- last stop, e.g., "return" command, or "p $pc = 0xf000"). This is
- used in coordination with stop_reason and waitstatus_pending_p:
- if the thread's PC is changed since it last stopped, a pending
- breakpoint waitstatus is discarded. */
- CORE_ADDR stop_pc;
+ last stop, e.g., "return" command, or "p $pc = 0xf000").
+
+ - If the thread's PC has not changed since the thread last
+ stopped, then proceed skips a breakpoint at the current PC,
+ otherwise we let the thread run into the breakpoint.
+
+ - If the thread has an unprocessed event pending, as indicated by
+ waitstatus_pending_p, this is used in coordination with
+ stop_reason: if the thread's PC has changed since the thread
+ last stopped, a pending breakpoint waitstatus is discarded.
+
+ - If the thread is running, this is set to -1, to avoid leaving
+ it with a stale value, to make it easier to catch bugs. */
+ CORE_ADDR stop_pc = 0;
};
-typedef struct value *value_ptr;
-DEF_VEC_P (value_ptr);
-typedef VEC (value_ptr) value_vec;
+/* Base class for target-specific thread data. */
+struct private_thread_info
+{
+ virtual ~private_thread_info () = 0;
+};
-struct thread_info
+/* Threads are intrusively refcounted objects. Being the
+ user-selected thread is normally considered an implicit strong
+ reference and is thus not accounted in the refcount, unlike
+ inferior objects. This is necessary, because there's no "current
+ thread" pointer. Instead the current thread is inferred from the
+ inferior_ptid global. However, when GDB needs to remember the
+ selected thread to later restore it, GDB bumps the thread object's
+ refcount, to prevent something deleting the thread object before
+ reverting back (e.g., due to a "kill" command). If the thread
+ meanwhile exits before being re-selected, then the thread object is
+ left listed in the thread list, but marked with state
+ THREAD_EXITED. (See make_cleanup_restore_current_thread and
+ delete_thread). All other thread references are considered weak
+ references. Placing a thread in the thread list is an implicit
+ strong reference, and is thus not accounted for in the thread's
+ refcount. */
+
+class thread_info : public refcounted_object
{
- struct thread_info *next;
+public:
+ explicit thread_info (inferior *inf, ptid_t ptid);
+ ~thread_info ();
+
+ bool deletable () const;
+
+ /* Mark this thread as running and notify observers. */
+ void set_running (bool running);
+
+ struct thread_info *next = NULL;
ptid_t ptid; /* "Actual process id";
In fact, this may be overloaded with
kernel thread id, etc. */
/* 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;
+ char *name = NULL;
/* 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;
+ int executing = 0;
/* Non-zero if this thread is resumed from infrun's perspective.
Note that a thread can be marked both as not-executing and
thread really run until that wait status has been processed, but
we should not process that wait status if we didn't try to let
the thread run. */
- int resumed;
+ int resumed = 0;
/* 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;
+ enum thread_state state = THREAD_STOPPED;
/* State of GDB control of inferior thread execution.
See `struct thread_control_state'. */
- struct thread_control_state control;
+ 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;
+ thread_suspend_state suspend;
- int current_line;
- struct symtab *current_symtab;
+ int current_line = 0;
+ struct symtab *current_symtab = NULL;
/* Internal stepping state. */
by proceed and keep_going, and among other things, it's used in
adjust_pc_after_break to distinguish a hardware single-step
SIGTRAP from a breakpoint SIGTRAP. */
- CORE_ADDR prev_pc;
+ CORE_ADDR prev_pc = 0;
/* 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;
+ int stepped_breakpoint = 0;
/* Should we step over breakpoint next time keep_going is called? */
- int stepping_over_breakpoint;
+ int stepping_over_breakpoint = 0;
/* 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;
+ int stepping_over_watchpoint = 0;
/* Set to TRUE if we should finish single-stepping over a breakpoint
after hitting the current step-resume breakpoint. The context here
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;
+ int step_after_step_resume_breakpoint = 0;
/* Pointer to the state machine manager object that handles what is
left to do for the thread's execution command after the target
stops. Several execution commands use it. */
- struct thread_fsm *thread_fsm;
+ struct thread_fsm *thread_fsm = NULL;
/* 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
struct target_waitstatus pending_follow;
/* True if this thread has been explicitly requested to stop. */
- int stop_requested;
+ int stop_requested = 0;
/* 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;
+ struct frame_id initiating_frame = null_frame_id;
/* 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 *);
+ std::unique_ptr<private_thread_info> priv;
/* Branch trace information for this thread. */
- struct btrace_thread_info btrace;
+ struct btrace_thread_info btrace {};
/* Flag which indicates that the stack temporaries should be stored while
evaluating expressions. */
- int stack_temporaries_enabled;
+ bool stack_temporaries_enabled = false;
/* Values that are stored as temporaries on stack while evaluating
expressions. */
- value_vec *stack_temporaries;
+ std::vector<struct value *> stack_temporaries;
/* Step-over chain. A thread is in the step-over queue if these are
non-NULL. If only a single thread is in the chain, then these
fields point to self. */
- struct thread_info *step_over_prev;
- struct thread_info *step_over_next;
+ struct thread_info *step_over_prev = NULL;
+ struct thread_info *step_over_next = NULL;
};
+/* A gdb::ref_ptr pointer to a thread_info. */
+
+using thread_info_ref
+ = gdb::ref_ptr<struct thread_info, refcounted_object_ref_policy>;
+
/* Create an empty thread list, or empty the existing one. */
extern void init_thread_list (void);
struct private_thread_info *);
/* Delete an existing thread list entry. */
-extern void delete_thread (ptid_t);
+extern void delete_thread (struct thread_info *thread);
/* 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);
+extern void delete_thread_silent (struct thread_info *thread);
/* Delete a step_resume_breakpoint from the thread database. */
extern void delete_step_resume_breakpoint (struct thread_info *);
/* 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,
+ const address_space *aspace,
CORE_ADDR addr);
-/* Translate the global 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 global_thread_id_to_ptid (int num);
-
-/* Translate a 'pid' (which may be overloaded with extra thread
- information) into the global integer thread id (GDB's homegrown id,
- not the system's). */
-extern int ptid_to_global_thread_id (ptid_t ptid);
-
/* Returns whether to show inferior-qualified thread IDs, or plain
thread numbers. Inferior-qualified IDs are shown whenever we have
multiple inferiors, or the only inferior left has number > 1. */
circular static buffer, NUMCELLS deep. */
const char *print_thread_id (struct thread_info *thr);
-/* Boolean test for an already-known pid (which may be overloaded with
- extra thread information). */
+/* Boolean test for an already-known ptid. */
extern int in_thread_list (ptid_t ptid);
/* Boolean test for an already-known global thread id (GDB's homegrown
/* Search function to lookup a thread by 'pid'. */
extern struct thread_info *find_thread_ptid (ptid_t ptid);
+/* Search function to lookup a thread by 'ptid'. Only searches in
+ threads of INF. */
+extern struct thread_info *find_thread_ptid (inferior *inf, ptid_t ptid);
+
/* Find thread by GDB global thread ID. */
struct thread_info *find_thread_global_id (int global_id);
-/* 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);
+/* Find thread by thread library specific handle in inferior INF. */
+struct thread_info *find_thread_by_handle (struct value *thread_handle,
+ struct inferior *inf);
-/* Returns any thread of process PID, giving preference to the current
- thread. */
-extern struct thread_info *any_thread_of_process (int pid);
+/* Finds the first thread of the specified inferior. */
+extern struct thread_info *first_thread_of_inferior (inferior *inf);
-/* Returns any non-exited thread of process PID, giving preference to
+/* Returns any thread of inferior INF, giving preference to the
+ current thread. */
+extern struct thread_info *any_thread_of_inferior (inferior *inf);
+
+/* Returns any non-exited thread of inferior INF, giving preference to
the current thread, and to not executing threads. */
-extern struct thread_info *any_live_thread_of_process (int pid);
+extern struct thread_info *any_live_thread_of_inferior (inferior *inf);
/* Change the ptid of thread OLD_PTID to NEW_PTID. */
void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
typedef int (*thread_callback_func) (struct thread_info *, void *);
extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
-/* Traverse all threads. */
-#define ALL_THREADS(T) \
- for (T = thread_list; T; T = T->next) \
+/* Pull in the internals of the inferiors/threads ranges and
+ iterators. Must be done after struct thread_info is defined. */
+#include "thread-iter.h"
+
+/* Return a range that can be used to walk over all threads of all
+ inferiors, with range-for. Used like this:
+
+ for (thread_info *thr : all_threads ())
+ { .... }
+*/
+inline all_threads_range
+all_threads ()
+{
+ return {};
+}
+
+/* Likewise, but accept a filter PTID. */
+
+inline all_matching_threads_range
+all_threads (ptid_t filter_ptid)
+{
+ return all_matching_threads_range (filter_ptid);
+}
-/* Traverse over all threads, sorted by inferior. */
-#define ALL_THREADS_BY_INFERIOR(inf, tp) \
- ALL_INFERIORS (inf) \
- ALL_THREADS (tp) \
- if (inf == tp->inf)
+/* Return a range that can be used to walk over all non-exited threads
+ of all inferiors, with range-for. FILTER_PTID can be used to
+ filter out thread that don't match. */
-/* Traverse all threads, except those that have THREAD_EXITED
- state. */
+inline all_non_exited_threads_range
+all_non_exited_threads (ptid_t filter_ptid = minus_one_ptid)
+{
+ return all_non_exited_threads_range (filter_ptid);
+}
-#define ALL_NON_EXITED_THREADS(T) \
- for (T = thread_list; T; T = T->next) \
- if ((T)->state != THREAD_EXITED)
+/* Return a range that can be used to walk over all threads of all
+ inferiors, with range-for, safely. I.e., it is safe to delete the
+ currently-iterated thread. When combined with range-for, this
+ allow convenient patterns like this:
-/* 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))
+ for (thread_info *t : all_threads_safe ())
+ if (some_condition ())
+ delete f;
+*/
+
+inline all_threads_safe_range
+all_threads_safe ()
+{
+ return all_threads_safe_range ();
+}
extern int thread_count (void);
-/* Switch from one thread to another. Also sets the STOP_PC
- global. */
-extern void switch_to_thread (ptid_t ptid);
+/* Return true if we have any thread in any inferior. */
+extern bool any_thread_p ();
+
+/* Switch context to thread THR. Also sets the STOP_PC global. */
+extern void switch_to_thread (struct thread_info *thr);
-/* Switch from one thread to another. Does not read registers and
- sets STOP_PC to -1. */
+/* Switch context to no thread selected. */
+extern void switch_to_no_thread ();
+
+/* Switch from one thread to another. Does not read registers. */
extern void switch_to_thread_no_regs (struct thread_info *thread);
/* Marks or clears thread(s) PTID as resumed. If PTID is
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.
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);
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);
+/* Calls finish_thread_state on scope exit, unless release() is called
+ to disengage. */
+using scoped_finish_thread_state
+ = FORWARD_SCOPE_EXIT (finish_thread_state);
/* Commands with a prefix of `thread'. */
extern struct cmd_list_element *thread_cmd_list;
-extern void thread_command (char *tidstr, int from_tty);
+extern void thread_command (const char *tidstr, int from_tty);
/* Print notices on thread events (attach, detach, etc.), set with
`set print thread-events'. */
extern void print_thread_info (struct ui_out *uiout, char *requested_threads,
int pid);
-extern struct cleanup *make_cleanup_restore_current_thread (void);
+/* Save/restore current inferior/thread/frame. */
+
+class scoped_restore_current_thread
+{
+public:
+ scoped_restore_current_thread ();
+ ~scoped_restore_current_thread ();
+
+ DISABLE_COPY_AND_ASSIGN (scoped_restore_current_thread);
+
+private:
+ /* Use the "class" keyword here, because of a clash with a "thread_info"
+ function in the Darwin API. */
+ class thread_info *m_thread;
+ inferior *m_inf;
+ frame_id m_selected_frame_id;
+ int m_selected_frame_level;
+ bool m_was_stopped;
+};
/* Returns a pointer into the thread_info corresponding to
INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */
int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);
-extern struct cleanup *enable_thread_stack_temporaries (ptid_t ptid);
+/* Enable storing stack temporaries for thread THR and disable and
+ clear the stack temporaries on destruction. Holds a strong
+ reference to THR. */
+
+class enable_thread_stack_temporaries
+{
+public:
+
+ explicit enable_thread_stack_temporaries (struct thread_info *thr)
+ : m_thr (thr)
+ {
+ gdb_assert (m_thr != NULL);
+
+ m_thr->incref ();
+
+ m_thr->stack_temporaries_enabled = true;
+ m_thr->stack_temporaries.clear ();
+ }
-extern int thread_stack_temporaries_enabled_p (ptid_t ptid);
+ ~enable_thread_stack_temporaries ()
+ {
+ m_thr->stack_temporaries_enabled = false;
+ m_thr->stack_temporaries.clear ();
-extern void push_thread_stack_temporary (ptid_t ptid, struct value *v);
+ m_thr->decref ();
+ }
-extern struct value *get_last_thread_stack_temporary (ptid_t);
+ DISABLE_COPY_AND_ASSIGN (enable_thread_stack_temporaries);
-extern int value_in_thread_stack_temporaries (struct value *, ptid_t);
+private:
+
+ struct thread_info *m_thr;
+};
+
+extern bool thread_stack_temporaries_enabled_p (struct thread_info *tp);
+
+extern void push_thread_stack_temporary (struct thread_info *tp, struct value *v);
+
+extern value *get_last_thread_stack_temporary (struct thread_info *tp);
+
+extern bool value_in_thread_stack_temporaries (struct value *,
+ struct thread_info *thr);
/* Add TP to the end of its inferior's pending step-over chain. */
executing). */
extern void validate_registers_access (void);
-extern struct thread_info *thread_list;
+/* Check whether it makes sense to access a register of THREAD at this point.
+ Returns true if registers may be accessed; false otherwise. */
+extern bool can_access_registers_thread (struct thread_info *thread);
+
+/* Returns whether to show which thread hit the breakpoint, received a
+ signal, etc. and ended up causing a user-visible stop. This is
+ true iff we ever detected multiple threads. */
+extern int show_thread_that_caused_stop (void);
+
+/* Print the message for a thread or/and frame selected. */
+extern void print_selected_thread_frame (struct ui_out *uiout,
+ user_selected_what selection);
+
+/* Helper for the CLI's "thread" command and for MI's -thread-select.
+ Selects thread THR. TIDSTR is the original string the thread ID
+ was parsed from. This is used in the error message if THR is not
+ alive anymore. */
+extern void thread_select (const char *tidstr, class thread_info *thr);
#endif /* GDBTHREAD_H */