/* Multi-process/thread control defs for GDB, the GNU debugger.
- Copyright (C) 1987-2018 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-gdbthread.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;
+ 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. */
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);
struct thread_info *next = NULL;
ptid_t ptid; /* "Actual process id";
/* 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;
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 *);
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);
struct thread_info *find_thread_by_handle (struct value *thread_handle,
struct inferior *inf);
-/* 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);
+/* Finds the first thread of the specified inferior. */
+extern struct thread_info *first_thread_of_inferior (inferior *inf);
-/* Returns any thread of process PID, giving preference to the current
- thread. */
-extern struct thread_info *any_thread_of_process (int pid);
+/* 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 process PID, giving preference to
+/* 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. Does not read registers and
- sets STOP_PC to -1. */
+/* 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 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);
/* 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;
int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);
-/* Enable storing stack temporaries for thread with id PTID and
- disable and clear the stack temporaries on destruction. */
+/* 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 (ptid_t ptid)
- : m_ptid (ptid)
+ explicit enable_thread_stack_temporaries (struct thread_info *thr)
+ : m_thr (thr)
{
- struct thread_info *tp = find_thread_ptid (ptid);
+ gdb_assert (m_thr != NULL);
- gdb_assert (tp != NULL);
- tp->stack_temporaries_enabled = true;
- tp->stack_temporaries.clear ();
+ m_thr->incref ();
+
+ m_thr->stack_temporaries_enabled = true;
+ m_thr->stack_temporaries.clear ();
}
~enable_thread_stack_temporaries ()
{
- struct thread_info *tp = find_thread_ptid (m_ptid);
+ m_thr->stack_temporaries_enabled = false;
+ m_thr->stack_temporaries.clear ();
- if (tp != NULL)
- {
- tp->stack_temporaries_enabled = false;
- tp->stack_temporaries.clear ();
- }
+ m_thr->decref ();
}
DISABLE_COPY_AND_ASSIGN (enable_thread_stack_temporaries);
private:
- ptid_t m_ptid;
+ struct thread_info *m_thr;
};
-extern bool thread_stack_temporaries_enabled_p (ptid_t ptid);
+extern bool thread_stack_temporaries_enabled_p (struct thread_info *tp);
-extern void push_thread_stack_temporary (ptid_t ptid, struct value *v);
+extern void push_thread_stack_temporary (struct thread_info *tp, struct value *v);
-extern struct value *get_last_thread_stack_temporary (ptid_t);
+extern value *get_last_thread_stack_temporary (struct thread_info *tp);
-extern bool value_in_thread_stack_temporaries (struct value *, ptid_t);
+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);
-/* Check whether it makes sense to access a register of PTID at this point.
+/* 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_ptid (ptid_t ptid);
+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
alive anymore. */
extern void thread_select (const char *tidstr, class thread_info *thr);
-extern struct thread_info *thread_list;
-
#endif /* GDBTHREAD_H */