X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Fgdbthread.h;h=09ea5baf23ac95a5145ab5d51dc3291059827237;hb=64cc34d87089ff24b43e0a8760be132b7afa6f34;hp=ca529831aaa6a9462cd7c9ceac7d9871fc8167de;hpb=f6e29b6ec0a4fd410ddaaddacf045c4cb4e890f2;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h index ca529831aa..09ea5baf23 100644 --- a/gdb/gdbthread.h +++ b/gdb/gdbthread.h @@ -1,5 +1,5 @@ /* Multi-process/thread control defs for GDB, the GNU debugger. - Copyright (C) 1987-2014 Free Software Foundation, Inc. + Copyright (C) 1987-2018 Free Software Foundation, Inc. Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA. @@ -28,6 +28,11 @@ struct symtab; #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" /* Frontend view of the thread state. Possible extensions: stepping, finishing, until(ling),... */ @@ -52,6 +57,13 @@ struct thread_control_state /* 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 @@ -65,6 +77,9 @@ struct thread_control_state 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 @@ -107,7 +122,7 @@ struct thread_control_state int trap_expected; /* Nonzero if the thread is being proceeded for a "finish" command - or a similar situation when stop_registers should be saved. */ + 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 @@ -123,73 +138,183 @@ struct thread_control_state 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'. - - Inferior process counterpart is `struct inferior_suspend_state'. */ +/* Inferior thread specific part of `struct infcall_suspend_state'. */ struct thread_suspend_state { - /* Last signal that the inferior received (why it stopped). */ + /* 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; }; -struct thread_info +/* Base class for target-specific thread data. */ +struct private_thread_info { - struct thread_info *next; + virtual ~private_thread_info () = 0; +}; + +/* 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 +{ +public: + 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)); + } + + struct thread_info *next = NULL; ptid_t ptid; /* "Actual process id"; In fact, this may be overloaded with kernel thread id, etc. */ - int num; /* Convenient handle (GDB thread id) */ + + /* Each thread has two GDB IDs. + + a) The thread ID (Id). This consists of the pair of: + + - the number of the thread's inferior and, + + - the thread's thread number in its inferior, aka, the + per-inferior thread number. This number is unique in the + inferior but not unique between inferiors. + + b) The global ID (GId). This is a a single integer unique + between all inferiors. + + E.g.: + + (gdb) info threads -gid + Id GId Target Id Frame + * 1.1 1 Thread A 0x16a09237 in foo () at foo.c:10 + 1.2 3 Thread B 0x15ebc6ed in bar () at foo.c:20 + 1.3 5 Thread C 0x15ebc6ed in bar () at foo.c:20 + 2.1 2 Thread A 0x16a09237 in foo () at foo.c:10 + 2.2 4 Thread B 0x15ebc6ed in bar () at foo.c:20 + 2.3 6 Thread C 0x15ebc6ed in bar () at foo.c:20 + + Above, both inferiors 1 and 2 have threads numbered 1-3, but each + thread has its own unique global ID. */ + + /* The thread's global GDB thread number. This is exposed to MI, + Python/Scheme, visible with "info threads -gid", and is also what + the $_gthread convenience variable is bound to. */ + int global_num; + + /* The per-inferior thread number. This is unique in the inferior + the thread belongs to, but not unique between inferiors. This is + what the $_thread convenience variable is bound to. */ + int per_inf_num; + + /* The inferior this thread belongs to. */ + struct inferior *inf; /* 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 + 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 = 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. */ - /* Record the pc of the thread the last time it stopped. This is - maintained by proceed and keep_going, and used in + /* 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; + 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 = 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 = 0; /* Set to TRUE if we should finish single-stepping over a breakpoint after hitting the current step-resume breakpoint. The context here @@ -200,23 +325,12 @@ struct thread_info 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; - - /* Per-thread command support. */ - - /* Pointer to what is left to do for an execution command after the - target stops. Used only in asynchronous mode, by targets that - support async execution. Several execution commands use it. */ - struct continuation *continuations; + int step_after_step_resume_breakpoint = 0; - /* Similar to the above, but used when a single execution command - requires several resume/stop iterations. Used by the step - command. */ - struct continuation *intermediate_continuations; - - /* If stepping, nonzero means step count is > 1 so don't print frame - next time inferior stops if it stops due to stepping. */ - int step_multi; + /* 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 = 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 @@ -224,23 +338,33 @@ struct thread_info 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 *private; - - /* 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 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. */ + bool stack_temporaries_enabled = false; + + /* Values that are stored as temporaries on stack while evaluating + expressions. */ + std::vector 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 = NULL; + struct thread_info *step_over_next = NULL; }; /* Create an empty thread list, or empty the existing one. */ @@ -274,37 +398,68 @@ 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 *); -/* Translate the 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 thread_id_to_pid (int); +/* 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, + const address_space *aspace, + CORE_ADDR addr); -/* Translate 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); +/* 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. */ +extern int show_inferior_qualified_tids (void); + +/* Return a string version of THR's thread ID. If there are multiple + inferiors, then this prints the inferior-qualifier form, otherwise + it only prints the thread number. 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); -/* Boolean test for an already-known thread id (GDB's homegrown id, - not the system's). */ -extern int valid_thread_id (int thread); +/* 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); /* Search function to lookup a thread by 'pid'. */ 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); +/* 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); /* 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. */ +/* 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 for - not executing threads. */ +/* 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. */ @@ -315,6 +470,16 @@ 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) \ + +/* Traverse over all threads, sorted by inferior. */ +#define ALL_THREADS_BY_INFERIOR(inf, tp) \ + ALL_INFERIORS (inf) \ + ALL_THREADS (tp) \ + if (inf == tp->inf) + /* Traverse all threads, except those that have THREAD_EXITED state. */ @@ -322,13 +487,26 @@ extern struct thread_info *iterate_over_threads (thread_callback_func, void *); 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. */ -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_get_pid (PTID) is -1, marks all threads. */ + 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. @@ -363,10 +541,7 @@ extern int is_exited (ptid_t ptid); /* In the frontend's perpective, is this thread stopped? */ extern int is_stopped (ptid_t ptid); -/* In the frontend's perpective is there any thread running? */ -extern int any_running (void); - -/* Marks thread PTID as executing, or not. If ptid_get_pid (PTID) is -1, +/* 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 @@ -377,6 +552,9 @@ 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). @@ -384,27 +562,77 @@ extern int is_executing (ptid_t ptid); "executing" -> "running" "exited" -> "exited" - If ptid_get_pid (PTID) is -1, go over all threads. + 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); +/* 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; +}; /* Commands with a prefix of `thread'. */ extern struct cmd_list_element *thread_cmd_list; +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 int print_thread_events; -extern void print_thread_info (struct ui_out *uiout, char *threads, +/* Prints the list of threads and their details on UIOUT. If + REQUESTED_THREADS, a list of GDB ids/ranges, is not NULL, only + print threads whose ID is included in the list. If PID is not -1, + only print threads from the process PID. Otherwise, threads from + 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, 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. */ @@ -412,10 +640,107 @@ 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); +/* Enable storing stack temporaries for thread with id PTID and + disable and clear the stack temporaries on destruction. */ + +class enable_thread_stack_temporaries +{ +public: + + explicit enable_thread_stack_temporaries (ptid_t ptid) + : m_ptid (ptid) + { + struct thread_info *tp = find_thread_ptid (ptid); + + gdb_assert (tp != NULL); + tp->stack_temporaries_enabled = true; + tp->stack_temporaries.clear (); + } + + ~enable_thread_stack_temporaries () + { + struct thread_info *tp = find_thread_ptid (m_ptid); + + if (tp != NULL) + { + tp->stack_temporaries_enabled = false; + tp->stack_temporaries.clear (); + } + } + + DISABLE_COPY_AND_ASSIGN (enable_thread_stack_temporaries); + +private: + + ptid_t m_ptid; +}; + +extern bool 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 bool 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); + +/* Check whether it makes sense to access a register of PTID at this point. + Returns true if registers may be accessed; false otherwise. */ +extern bool can_access_registers_ptid (ptid_t ptid); + +/* 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); + extern struct thread_info *thread_list; #endif /* GDBTHREAD_H */