/* Multi-process/thread control defs for GDB, the GNU debugger.
- Copyright (C) 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1997, 1998, 1999,
- 2000, 2007, 2008 Free Software Foundation, Inc.
+ Copyright (C) 1987-2016 Free Software Foundation, Inc.
Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA.
#ifndef GDBTHREAD_H
#define GDBTHREAD_H
-struct breakpoint;
-struct frame_id;
struct symtab;
-/* For bpstat */
#include "breakpoint.h"
-
-/* For struct frame_id. */
#include "frame.h"
-
#include "ui-out.h"
+#include "inferior.h"
+#include "btrace.h"
+#include "common/vec.h"
+#include "target/waitstatus.h"
+
+/* Frontend view of the thread state. Possible extensions: stepping,
+ finishing, until(ling),... */
+enum thread_state
+{
+ THREAD_STOPPED,
+ THREAD_RUNNING,
+ THREAD_EXITED,
+};
+
+/* Inferior thread specific part of `struct infcall_control_state'.
+
+ Inferior process counterpart is `struct inferior_control_state'. */
+
+struct thread_control_state
+{
+ /* User/external stepping state. */
+
+ /* Step-resume or longjmp-resume breakpoint. */
+ struct breakpoint *step_resume_breakpoint;
+
+ /* Exception-resume breakpoint. */
+ struct breakpoint *exception_resume_breakpoint;
+
+ /* 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;
+
+ /* Range to single step within.
+
+ If this is nonzero, respond to a single-step signal by continuing
+ to step if the pc is in this range.
+
+ If step_range_start and step_range_end are both 1, it means to
+ step for a single instruction (FIXME: it might clean up
+ 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 */
+
+ /* Function the thread was in as of last it started stepping. */
+ struct symbol *step_start_function;
+
+ /* If GDB issues a target step request, and this is nonzero, the
+ target should single-step this thread once, and then continue
+ single-stepping it without GDB core involvement as long as the
+ 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;
+
+ /* 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;
+
+ /* Similarly, the frame ID of the underlying stack frame (skipping
+ any inlined frames). */
+ struct frame_id step_stack_frame_id;
+
+ /* Nonzero if we are presently stepping over a breakpoint.
+
+ If we hit a breakpoint or watchpoint, and then continue, we need
+ to single step the current thread with breakpoints disabled, to
+ avoid hitting the same breakpoint or watchpoint again. And we
+ should step just a single thread and keep other threads stopped,
+ so that other threads don't miss breakpoints while they are
+ removed.
+
+ So, this variable simultaneously means that we need to single
+ step the current thread, keep other threads stopped, and that
+ breakpoints should be removed while we step.
+
+ This variable is set either:
+ - in proceed, when we resume inferior on user's explicit request
+ - in keep_going, if handle_inferior_event decides we need to
+ step over breakpoint.
+
+ The variable is cleared in normal_stop. The proceed calls
+ 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;
+
+ /* 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;
+
+ /* Nonzero if the thread is being proceeded for an inferior function
+ call. */
+ int in_infcall;
+
+ enum step_over_calls_kind step_over_calls;
+
+ /* Nonzero if stopped due to a step command. */
+ int stop_step;
+
+ /* 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;
+
+ /* 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;
+};
+
+/* Inferior thread specific part of `struct infcall_suspend_state'. */
+
+struct thread_suspend_state
+{
+ /* Last signal that the inferior received (why it stopped). When
+ the thread is resumed, this signal is delivered. Note: the
+ target should not check whether the signal is in pass state,
+ because the signal may have been explicitly passed with the
+ "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;
+
+ /* The reason the thread last stopped, if we need to track it
+ (breakpoint, watchpoint, etc.) */
+ enum target_stop_reason stop_reason;
+
+ /* The waitstatus for this thread's last event. */
+ struct target_waitstatus waitstatus;
+ /* If true WAITSTATUS hasn't been handled yet. */
+ int waitstatus_pending_p;
+
+ /* 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;
+};
+
+typedef struct value *value_ptr;
+DEF_VEC_P (value_ptr);
+typedef VEC (value_ptr) value_vec;
struct thread_info
{
In fact, this may be overloaded with
kernel thread id, etc. */
int num; /* Convenient handle (GDB thread id) */
- /* State from wait_for_inferior */
- CORE_ADDR prev_pc;
- struct breakpoint *step_resume_breakpoint;
- CORE_ADDR step_range_start;
- CORE_ADDR step_range_end;
- struct frame_id step_frame_id;
+
+ /* 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;
+
+ /* 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;
+
+ /* Non-zero if this thread is resumed from infrun's perspective.
+ Note that a thread can be marked both as not-executing and
+ resumed at the same time. This happens if we try to resume a
+ thread that has a wait status pending. We shouldn't let the
+ 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;
+
+ /* 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;
+
+ /* State of GDB control of inferior thread execution.
+ See `struct thread_control_state'. */
+ struct 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;
+
int current_line;
struct symtab *current_symtab;
- int trap_expected;
- int handling_longjmp;
- int stepping_over_breakpoint;
- /* This is set TRUE when a catchpoint of a shared library event
- triggers. Since we don't wish to leave the inferior in the
- solib hook when we report the event, we step the inferior
- back to user code before stopping and reporting the event. */
- int stepping_through_solib_after_catch;
+ /* Internal stepping state. */
+
+ /* Record the pc of the thread the last time it was resumed. (It
+ can't be done on stop as the PC may change since the last stop,
+ e.g., "return" command, or "p $pc = 0xf000"). This is maintained
+ 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;
+
+ /* 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;
- /* When stepping_through_solib_after_catch is TRUE, this is a
- list of the catchpoints that should be reported as triggering
- when we finally do stop stepping. */
- bpstat stepping_through_solib_catchpoints;
+ /* Should we step over breakpoint next time keep_going is called? */
+ int stepping_over_breakpoint;
+
+ /* 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;
+
+ /* Set to TRUE if we should finish single-stepping over a breakpoint
+ after hitting the current step-resume breakpoint. The context here
+ is that GDB is to do `next' or `step' while signal arrives.
+ When stepping over a breakpoint and signal arrives, GDB will attempt
+ to skip signal handler, so it inserts a step_resume_breakpoint at the
+ signal return address, and resume inferior.
+ 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;
+
+ /* 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;
+
+ /* 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
+ resume of the thread, and not immediately. */
+ struct target_waitstatus pending_follow;
+
+ /* True if this thread has been explicitly requested to stop. */
+ int stop_requested;
+
+ /* 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;
/* Private data used by the target vector implementation. */
- struct private_thread_info *private;
+ 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 *);
+
+ /* Branch trace information for this thread. */
+ struct btrace_thread_info btrace;
+
+ /* Flag which indicates that the stack temporaries should be stored while
+ evaluating expressions. */
+ int stack_temporaries_enabled;
+
+ /* Values that are stored as temporaries on stack while evaluating
+ expressions. */
+ value_vec *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;
};
/* Create an empty thread list, or empty the existing one. */
/* Delete an existing thread list entry. */
extern void delete_thread (ptid_t);
-/* Delete a step_resume_breakpoint from the thread database. */
-extern void delete_step_resume_breakpoint (void *);
+/* 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);
+
+/* Delete a step_resume_breakpoint from the thread database. */
+extern void delete_step_resume_breakpoint (struct thread_info *);
+
+/* Delete an exception_resume_breakpoint from the thread database. */
+extern void delete_exception_resume_breakpoint (struct thread_info *);
+
+/* Delete the single-step breakpoints of thread TP, if any. */
+extern void delete_single_step_breakpoints (struct thread_info *tp);
+
+/* Check if the thread has software single stepping breakpoints
+ set. */
+extern int thread_has_single_step_breakpoints_set (struct thread_info *tp);
+
+/* 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,
+ CORE_ADDR addr);
/* Translate the integer thread id (GDB's homegrown id, not the system's)
into a "pid" (which may be overloaded with extra thread information). */
into the integer thread id (GDB's homegrown id, not the system's). */
extern int pid_to_thread_id (ptid_t ptid);
+/* Return a string version of THR's thread ID. The result is stored
+ in a 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). */
extern int in_thread_list (ptid_t ptid);
extern int valid_thread_id (int thread);
/* Search function to lookup a thread by 'pid'. */
-extern struct thread_info *find_thread_pid (ptid_t ptid);
+extern struct thread_info *find_thread_ptid (ptid_t ptid);
+
+/* Find thread by GDB user-visible thread number. */
+struct thread_info *find_thread_id (int num);
+
+/* 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);
+
+/* Returns any thread of process PID, giving preference to the current
+ thread. */
+extern struct thread_info *any_thread_of_process (int pid);
+
+/* Returns any non-exited thread of process PID, giving preference to
+ the current thread, and to not executing threads. */
+extern struct thread_info *any_live_thread_of_process (int pid);
+
+/* Change the ptid of thread OLD_PTID to NEW_PTID. */
+void thread_change_ptid (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 *);
-/* infrun context switch: save the debugger state for the given thread. */
-extern void save_infrun_state (ptid_t ptid,
- CORE_ADDR prev_pc,
- int trap_expected,
- struct breakpoint *step_resume_breakpoint,
- CORE_ADDR step_range_start,
- CORE_ADDR step_range_end,
- const struct frame_id *step_frame_id,
- int handling_longjmp,
- int another_trap,
- int stepping_through_solib_after_catch,
- bpstat stepping_through_solib_catchpoints,
- int current_line,
- struct symtab *current_symtab);
-
-/* infrun context switch: load the debugger state previously saved
- for the given thread. */
-extern void load_infrun_state (ptid_t ptid,
- CORE_ADDR *prev_pc,
- int *trap_expected,
- struct breakpoint **step_resume_breakpoint,
- CORE_ADDR *step_range_start,
- CORE_ADDR *step_range_end,
- struct frame_id *step_frame_id,
- int *handling_longjmp,
- int *another_trap,
- int *stepping_through_solib_affter_catch,
- bpstat *stepping_through_solib_catchpoints,
- int *current_line,
- struct symtab **current_symtab);
-
-/* Switch from one thread to another. */
+/* Traverse all threads, except those that have THREAD_EXITED
+ state. */
+
+#define ALL_NON_EXITED_THREADS(T) \
+ for (T = thread_list; T; T = T->next) \
+ if ((T)->state != THREAD_EXITED)
+
+/* 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))
+
+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);
+/* 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);
+
+/* 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);
+
+/* 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);
+
+/* 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);
+
+/* 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.
+
+ 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);
+
+/* 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);
+
+/* Merge the executing property of thread PTID 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.
+
+ 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);
+
/* Commands with a prefix of `thread'. */
extern struct cmd_list_element *thread_cmd_list;
+extern void thread_command (char *tidstr, int from_tty);
+
/* Print notices on thread events (attach, detach, etc.), set with
`set print thread-events'. */
extern int print_thread_events;
-extern void print_thread_info (struct ui_out *uiout, int thread);
+extern void print_thread_info (struct ui_out *uiout, char *threads,
+ int pid);
+
+extern struct cleanup *make_cleanup_restore_current_thread (void);
+
+/* Returns a pointer into the thread_info corresponding to
+ INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */
+extern struct thread_info* inferior_thread (void);
+
+extern void update_thread_list (void);
+
+/* Delete any thread the target says is no longer alive. */
+
+extern void prune_threads (void);
+
+/* Delete threads marked THREAD_EXITED. Unlike prune_threads, this
+ does not consult the target about whether the thread is alive right
+ now. */
+extern void delete_exited_threads (void);
+
+/* Return true if PC is in the stepping range of THREAD. */
+
+int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);
+
+extern struct cleanup *enable_thread_stack_temporaries (ptid_t ptid);
+
+extern int thread_stack_temporaries_enabled_p (ptid_t ptid);
+
+extern void push_thread_stack_temporary (ptid_t ptid, struct value *v);
+
+extern struct value *get_last_thread_stack_temporary (ptid_t);
+
+extern int value_in_thread_stack_temporaries (struct value *, ptid_t);
+
+/* Add TP to the end of its inferior's pending step-over chain. */
+
+extern void thread_step_over_chain_enqueue (struct thread_info *tp);
+
+/* Remove TP from its inferior's pending step-over chain. */
+
+extern void thread_step_over_chain_remove (struct thread_info *tp);
+
+/* Return the next thread in the step-over chain starting at TP. NULL
+ if TP is the last entry in the chain. */
+
+extern struct thread_info *thread_step_over_chain_next (struct thread_info *tp);
+
+/* Return true if TP is in the step-over chain. */
+
+extern int thread_is_in_step_over_chain (struct thread_info *tp);
+
+/* Cancel any ongoing execution command. */
+
+extern void thread_cancel_execution_command (struct thread_info *thr);
+
+/* Check whether it makes sense to access a register of the current
+ thread at this point. If not, throw an error (e.g., the thread is
+ executing). */
+extern void validate_registers_access (void);
+
+extern struct thread_info *thread_list;
#endif /* GDBTHREAD_H */