/* Multi-process/thread control defs for GDB, the GNU debugger.
- Copyright (C) 1987-2018 Free Software Foundation, Inc.
+ Copyright (C) 1987-2020 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-gdbthread.h"
+#include "gdbsupport/refcounted-object.h"
+#include "gdbsupport/common-gdbthread.h"
+#include "gdbsupport/forward-scope-exit.h"
+
+struct inferior;
+struct process_stratum_target;
/* 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;
+ 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;
};
/* Base class for target-specific thread data. */
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
+ THREAD_EXITED. (See scoped_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
explicit thread_info (inferior *inf, ptid_t ptid);
~thread_info ();
- bool deletable () const
- {
- /* If this is the current thread, or there's code out there that
- relies on it existing (refcount > 0) we can't delete yet. */
- return (refcount () == 0 && !ptid_equal (ptid, inferior_ptid));
- }
+ bool deletable () const;
/* Mark this thread as running and notify observers. */
void set_running (bool running);
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 = 0;
+ bool executing = false;
/* Non-zero if this thread is resumed from infrun's perspective.
Note that a thread can be marked both as not-executing and
/* State of GDB control of inferior thread execution.
See `struct thread_control_state'. */
- 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'. */
- thread_suspend_state suspend {};
+ thread_suspend_state suspend;
int current_line = 0;
struct symtab *current_symtab = NULL;
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);
+extern struct thread_info *add_thread (process_stratum_target *targ,
+ 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, but does not print a message about new
+ thread. */
+extern struct thread_info *add_thread_silent (process_stratum_target *targ,
+ 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 *);
+extern struct thread_info *add_thread_with_info (process_stratum_target *targ,
+ ptid_t ptid,
+ private_thread_info *);
/* Delete an existing thread list entry. */
extern void delete_thread (struct thread_info *thread);
const char *print_thread_id (struct thread_info *thr);
/* Boolean test for an already-known ptid. */
-extern int in_thread_list (ptid_t ptid);
+extern bool in_thread_list (process_stratum_target *targ, ptid_t ptid);
/* Boolean test for an already-known global thread id (GDB's homegrown
global id, not the system's). */
extern int valid_global_thread_id (int global_id);
+/* Find thread PTID of inferior INF. */
+extern thread_info *find_thread_ptid (inferior *inf, ptid_t ptid);
+
/* Search function to lookup a thread by 'pid'. */
-extern struct thread_info *find_thread_ptid (ptid_t ptid);
+extern struct thread_info *find_thread_ptid (process_stratum_target *targ,
+ 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);
/* Find thread by thread library specific handle in inferior INF. */
-struct thread_info *find_thread_by_handle (struct value *thread_handle,
- struct inferior *inf);
+struct thread_info *find_thread_by_handle
+ (gdb::array_view<const gdb_byte> handle, struct inferior *inf);
/* Finds the first thread of the specified inferior. */
extern struct thread_info *first_thread_of_inferior (inferior *inf);
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);
+void thread_change_ptid (process_stratum_target *targ,
+ 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. */
-#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"
-/* 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 threads, with
+ range-for.
-/* Traverse all threads, except those that have THREAD_EXITED
- state. */
+ Used like this, it walks over all threads of all inferiors of all
+ targets:
-#define ALL_NON_EXITED_THREADS(T) \
- for (T = thread_list; T; T = T->next) \
- if ((T)->state != THREAD_EXITED)
+ for (thread_info *thr : all_threads ())
+ { .... }
-/* 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))
+ FILTER_PTID can be used to filter out threads that don't match.
+ FILTER_PTID can be:
-extern int thread_count (void);
+ - minus_one_ptid, meaning walk all threads of all inferiors of
+ PROC_TARGET. If PROC_TARGET is NULL, then of all targets.
-/* Switch context to thread THR. Also sets the STOP_PC global. */
-extern void switch_to_thread (struct thread_info *thr);
-
-/* Switch context to no thread selected. */
-extern void switch_to_no_thread ();
-
-/* Switch from one thread to another. Does not read registers and
- sets STOP_PC to -1. */
-extern void switch_to_thread_no_regs (struct thread_info *thread);
+ - A process ptid, in which case walk all threads of the specified
+ process. PROC_TARGET must be non-NULL in this case.
-/* Marks or clears thread(s) PTID as resumed. 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. */
-extern void set_resumed (ptid_t ptid, int resumed);
+ - A thread ptid, in which case walk that thread only. PROC_TARGET
+ must be non-NULL in this case.
+*/
-/* 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);
+inline all_matching_threads_range
+all_threads (process_stratum_target *proc_target = nullptr,
+ ptid_t filter_ptid = minus_one_ptid)
+{
+ return all_matching_threads_range (proc_target, filter_ptid);
+}
-/* 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);
+/* Return a range that can be used to walk over all non-exited threads
+ of all inferiors, with range-for. Arguments are like all_threads
+ above. */
-/* 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,
+inline all_non_exited_threads_range
+all_non_exited_threads (process_stratum_target *proc_target = nullptr,
+ ptid_t filter_ptid = minus_one_ptid)
+{
+ return all_non_exited_threads_range (proc_target, filter_ptid);
+}
- use (good):
+/* 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:
- if (is_stopped (ptid))
+ for (thread_info *t : all_threads_safe ())
+ if (some_condition ())
+ delete f;
+*/
- instead of (bad):
+inline all_threads_safe_range
+all_threads_safe ()
+{
+ return {};
+}
- if (!is_running (ptid))
+extern int thread_count (process_stratum_target *proc_target);
- The latter also returns true on exited threads, most likelly not
- what you want. */
+/* Return true if we have any thread in any inferior. */
+extern bool any_thread_p ();
-/* Reports if in the frontend's perpective, thread PTID is running. */
-extern int is_running (ptid_t ptid);
+/* Switch context to thread THR. Also sets the STOP_PC global. */
+extern void switch_to_thread (struct thread_info *thr);
-/* 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);
+/* Switch context to no thread selected. */
+extern void switch_to_no_thread ();
-/* In the frontend's perpective, is this thread stopped? */
-extern int is_stopped (ptid_t ptid);
+/* Switch from one thread to another. Does not read registers. */
+extern void switch_to_thread_no_regs (struct thread_info *thread);
-/* Marks thread PTID as executing, or not. If PTID is minus_one_ptid,
- marks all threads.
+/* Marks or clears thread(s) PTID of TARG as resumed. If PTID is
+ MINUS_ONE_PTID, applies to all threads of TARG. If
+ ptid_is_pid(PTID) is true, applies to all threads of the process
+ pointed at by {TARG,PTID}. */
+extern void set_resumed (process_stratum_target *targ,
+ ptid_t ptid, bool resumed);
+
+/* Marks thread PTID of TARG as running, or as stopped. If PTID is
+ minus_one_ptid, marks all threads of TARG. */
+extern void set_running (process_stratum_target *targ,
+ ptid_t ptid, bool running);
+
+/* Marks or clears thread(s) PTID of TARG as having been requested to
+ stop. If PTID is MINUS_ONE_PTID, applies to all threads of TARG.
+ If ptid_is_pid(PTID) is true, applies to all threads of the process
+ pointed at by {TARG, PTID}. If STOP, then the
+ THREAD_STOP_REQUESTED observer is called with PTID as argument. */
+extern void set_stop_requested (process_stratum_target *targ,
+ ptid_t ptid, bool stop);
+
+/* Marks thread PTID of TARG as executing, or not. If PTID is
+ minus_one_ptid, marks all threads of TARG.
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);
+extern void set_executing (process_stratum_target *targ,
+ ptid_t ptid, bool executing);
-/* True if any (known or unknown) thread is or may be executing. */
-extern int threads_are_executing (void);
+/* True if any (known or unknown) thread of TARG is or may be
+ executing. */
+extern bool threads_are_executing (process_stratum_target *targ);
-/* Merge the executing property of thread PTID over to its thread
- state property (frontend running/stopped view).
+/* Merge the executing property of thread PTID of TARG 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.
+ If PTID is minus_one_ptid, go over all threads of TARG.
Notifications are only emitted if the thread state did change. */
-extern void finish_thread_state (ptid_t ptid);
+extern void finish_thread_state (process_stratum_target *targ, ptid_t ptid);
/* Calls finish_thread_state on scope exit, unless release() is called
to disengage. */
-class scoped_finish_thread_state
-{
-public:
- explicit scoped_finish_thread_state (ptid_t ptid)
- : m_ptid (ptid)
- {}
-
- ~scoped_finish_thread_state ()
- {
- if (!m_released)
- finish_thread_state (m_ptid);
- }
-
- /* Disengage. */
- void release ()
- {
- m_released = true;
- }
-
- DISABLE_COPY_AND_ASSIGN (scoped_finish_thread_state);
-
-private:
- bool m_released = false;
- ptid_t m_ptid;
-};
+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;
/* Print notices on thread events (attach, detach, etc.), set with
`set print thread-events'. */
-extern int print_thread_events;
+extern bool print_thread_events;
/* Prints the list of threads and their details on UIOUT. If
REQUESTED_THREADS, a list of GDB ids/ranges, is not NULL, only
all attached PIDs are printed. If both REQUESTED_THREADS is not
NULL and PID is not -1, then the thread is printed if it belongs to
the specified process. Otherwise, an error is raised. */
-extern void print_thread_info (struct ui_out *uiout, char *requested_threads,
+extern void print_thread_info (struct ui_out *uiout,
+ const char *requested_threads,
int pid);
/* Save/restore current inferior/thread/frame. */
DISABLE_COPY_AND_ASSIGN (scoped_restore_current_thread);
+ /* Cancel restoring on scope exit. */
+ void dont_restore () { m_dont_restore = true; }
+
private:
+ void restore ();
+
+ bool m_dont_restore = false;
/* Use the "class" keyword here, because of a clash with a "thread_info"
function in the Darwin API. */
class thread_info *m_thread;
alive anymore. */
extern void thread_select (const char *tidstr, class thread_info *thr);
-extern struct thread_info *thread_list;
-
#endif /* GDBTHREAD_H */