#include "target-descriptions.h"
#include "target-dcache.h"
#include "terminal.h"
+#include "solist.h"
+#include "event-loop.h"
/* Prototypes for local functions */
static int currently_stepping (struct thread_info *tp);
-static void xdb_handle_command (char *args, int from_tty);
-
void _initialize_infrun (void);
void nullify_last_target_wait_ptid (void);
static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
+static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
+
+/* Asynchronous signal handler registered as event loop source for
+ when we have pending events ready to be passed to the core. */
+static struct async_event_handler *infrun_async_inferior_event_token;
+
+/* Stores whether infrun_async was previously enabled or disabled.
+ Starts off as -1, indicating "never enabled/disabled". */
+static int infrun_is_async = -1;
+
+/* See infrun.h. */
+
+void
+infrun_async (int enable)
+{
+ if (infrun_is_async != enable)
+ {
+ infrun_is_async = enable;
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: infrun_async(%d)\n",
+ enable);
+
+ if (enable)
+ mark_async_event_handler (infrun_async_inferior_event_token);
+ else
+ clear_async_event_handler (infrun_async_inferior_event_token);
+ }
+}
+
/* When set, stop the 'step' command if we enter a function which has
no line number information. The normal behavior is that we step
over such function. */
static struct cmd_list_element *stop_command;
-/* Function inferior was in as of last step command. */
-
-static struct symbol *step_start_function;
-
/* Nonzero if we want to give control to the user when we're notified
of shared library events by the dynamic linker. */
int stop_on_solib_events;
int stop_after_trap;
-/* Save register contents here when executing a "finish" command or are
- about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
- Thus this contains the return value from the called function (assuming
- values are returned in a register). */
-
-struct regcache *stop_registers;
-
/* Nonzero after stop if current stack frame should be printed. */
static int stop_print_frame;
if (info_verbose || debug_infrun)
{
+ /* Ensure that we have a process ptid. */
+ ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
+
target_terminal_ours_for_output ();
fprintf_filtered (gdb_stdlog,
_("Detaching after %s from child %s.\n"),
has_vforked ? "vfork" : "fork",
- target_pid_to_str (child_ptid));
+ target_pid_to_str (process_ptid));
}
}
else
{
if (info_verbose || debug_infrun)
{
+ /* Ensure that we have a process ptid. */
+ ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
+
target_terminal_ours_for_output ();
fprintf_filtered (gdb_stdlog,
_("Detaching after fork from "
"child %s.\n"),
- target_pid_to_str (child_ptid));
+ target_pid_to_str (process_ptid));
}
target_detach (NULL, 0);
switch_to_thread (thread->ptid);
clear_proceed_status (0);
- proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0);
+ proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
}
return 0;
them. Deleting them now rather than at the next user-visible
stop provides a nicer sequence of events for user and MI
notifications. */
- ALL_NON_EXITED_THREADS_SAFE (th, tmp)
+ ALL_THREADS_SAFE (th, tmp)
if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
delete_thread (th->ptid);
breakpoint_init_inferior (inf_execd);
- if (gdb_sysroot && *gdb_sysroot)
+ if (*gdb_sysroot != '\0')
{
- char *name = alloca (strlen (gdb_sysroot)
- + strlen (execd_pathname)
- + 1);
+ char *name = exec_file_find (execd_pathname, NULL);
- strcpy (name, gdb_sysroot);
- strcat (name, execd_pathname);
- execd_pathname = name;
+ execd_pathname = alloca (strlen (name) + 1);
+ strcpy (execd_pathname, name);
+ xfree (name);
}
/* Reset the shared library package. This ensures that we get a
matically get reset there in the new process.). */
}
+/* The queue of threads that need to do a step-over operation to get
+ past e.g., a breakpoint. What technique is used to step over the
+ breakpoint/watchpoint does not matter -- all threads end up in the
+ same queue, to maintain rough temporal order of execution, in order
+ to avoid starvation, otherwise, we could e.g., find ourselves
+ constantly stepping the same couple threads past their breakpoints
+ over and over, if the single-step finish fast enough. */
+struct thread_info *step_over_queue_head;
+
+/* Bit flags indicating what the thread needs to step over. */
+
+enum step_over_what
+ {
+ /* Step over a breakpoint. */
+ STEP_OVER_BREAKPOINT = 1,
+
+ /* Step past a non-continuable watchpoint, in order to let the
+ instruction execute so we can evaluate the watchpoint
+ expression. */
+ STEP_OVER_WATCHPOINT = 2
+ };
+
/* Info about an instruction that is being stepped over. */
struct step_over_info
static void
clear_step_over_info (void)
{
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: clear_step_over_info\n");
step_over_info.aspace = NULL;
step_over_info.address = 0;
step_over_info.nonsteppable_watchpoint_p = 0;
displaced step operation on it. See displaced_step_prepare and
displaced_step_fixup for details. */
-struct displaced_step_request
-{
- ptid_t ptid;
- struct displaced_step_request *next;
-};
-
/* Per-inferior displaced stepping state. */
struct displaced_step_inferior_state
{
/* The process this displaced step state refers to. */
int pid;
- /* A queue of pending displaced stepping requests. One entry per
- thread that needs to do a displaced step. */
- struct displaced_step_request *step_request_queue;
+ /* True if preparing a displaced step ever failed. If so, we won't
+ try displaced stepping for this inferior again. */
+ int failed_before;
/* If this is not null_ptid, this is the thread carrying out a
displaced single-step in process PID. This thread's state will
return NULL;
}
+/* Returns true if any inferior has a thread doing a displaced
+ step. */
+
+static int
+displaced_step_in_progress_any_inferior (void)
+{
+ struct displaced_step_inferior_state *state;
+
+ for (state = displaced_step_inferior_states;
+ state != NULL;
+ state = state->next)
+ if (!ptid_equal (state->step_ptid, null_ptid))
+ return 1;
+
+ return 0;
+}
+
+/* Return true if process PID has a thread doing a displaced step. */
+
+static int
+displaced_step_in_progress (int pid)
+{
+ struct displaced_step_inferior_state *displaced;
+
+ displaced = get_displaced_stepping_state (pid);
+ if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
+ return 1;
+
+ return 0;
+}
+
/* Add a new displaced stepping state for process PID to the displaced
stepping state list, or return a pointer to an already existing
entry, if it already exists. Never returns NULL. */
fprintf_filtered (file,
_("Debugger's willingness to use displaced stepping "
"to step over breakpoints is %s (currently %s).\n"),
- value, non_stop ? "on" : "off");
+ value, target_is_non_stop_p () ? "on" : "off");
else
fprintf_filtered (file,
_("Debugger's willingness to use displaced stepping "
}
/* Return non-zero if displaced stepping can/should be used to step
- over breakpoints. */
+ over breakpoints of thread TP. */
static int
-use_displaced_stepping (struct gdbarch *gdbarch)
+use_displaced_stepping (struct thread_info *tp)
{
- return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
+ struct regcache *regcache = get_thread_regcache (tp->ptid);
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ struct displaced_step_inferior_state *displaced_state;
+
+ displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
+
+ return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
+ && target_is_non_stop_p ())
|| can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
&& gdbarch_displaced_step_copy_insn_p (gdbarch)
- && find_record_target () == NULL);
+ && find_record_target () == NULL
+ && (displaced_state == NULL
+ || !displaced_state->failed_before));
}
/* Clean out any stray displaced stepping state. */
explain how we handle this case instead.
Returns 1 if preparing was successful -- this thread is going to be
- stepped now; or 0 if displaced stepping this thread got queued. */
+ stepped now; 0 if displaced stepping this thread got queued; or -1
+ if this instruction can't be displaced stepped. */
+
static int
-displaced_step_prepare (ptid_t ptid)
+displaced_step_prepare_throw (ptid_t ptid)
{
struct cleanup *old_cleanups, *ignore_cleanups;
struct thread_info *tp = find_thread_ptid (ptid);
support displaced stepping. */
gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
+ /* Nor if the thread isn't meant to step over a breakpoint. */
+ gdb_assert (tp->control.trap_expected);
+
/* Disable range stepping while executing in the scratch pad. We
want a single-step even if executing the displaced instruction in
the scratch buffer lands within the stepping range (e.g., a
{
/* Already waiting for a displaced step to finish. Defer this
request and place in queue. */
- struct displaced_step_request *req, *new_req;
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog,
- "displaced: defering step of %s\n",
+ "displaced: deferring step of %s\n",
target_pid_to_str (ptid));
- new_req = xmalloc (sizeof (*new_req));
- new_req->ptid = ptid;
- new_req->next = NULL;
-
- if (displaced->step_request_queue)
- {
- for (req = displaced->step_request_queue;
- req && req->next;
- req = req->next)
- ;
- req->next = new_req;
- }
- else
- displaced->step_request_queue = new_req;
-
+ thread_step_over_chain_enqueue (tp);
return 0;
}
else
closure = gdbarch_displaced_step_copy_insn (gdbarch,
original, copy, regcache);
-
- /* We don't support the fully-simulated case at present. */
- gdb_assert (closure);
+ if (closure == NULL)
+ {
+ /* The architecture doesn't know how or want to displaced step
+ this instruction or instruction sequence. Fallback to
+ stepping over the breakpoint in-line. */
+ do_cleanups (old_cleanups);
+ return -1;
+ }
/* Save the information we need to fix things up if the step
succeeds. */
return 1;
}
+/* Wrapper for displaced_step_prepare_throw that disabled further
+ attempts at displaced stepping if we get a memory error. */
+
+static int
+displaced_step_prepare (ptid_t ptid)
+{
+ int prepared = -1;
+
+ TRY
+ {
+ prepared = displaced_step_prepare_throw (ptid);
+ }
+ CATCH (ex, RETURN_MASK_ERROR)
+ {
+ struct displaced_step_inferior_state *displaced_state;
+
+ if (ex.error != MEMORY_ERROR)
+ throw_exception (ex);
+
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: disabling displaced stepping: %s\n",
+ ex.message);
+ }
+
+ /* Be verbose if "set displaced-stepping" is "on", silent if
+ "auto". */
+ if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
+ {
+ warning (_("disabling displaced stepping: %s\n"),
+ ex.message);
+ }
+
+ /* Disable further displaced stepping attempts. */
+ displaced_state
+ = get_displaced_stepping_state (ptid_get_pid (ptid));
+ displaced_state->failed_before = 1;
+ }
+ END_CATCH
+
+ return prepared;
+}
+
static void
write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
const gdb_byte *myaddr, int len)
displaced->step_copy));
}
-static void
+/* If we displaced stepped an instruction successfully, adjust
+ registers and memory to yield the same effect the instruction would
+ have had if we had executed it at its original address, and return
+ 1. If the instruction didn't complete, relocate the PC and return
+ -1. If the thread wasn't displaced stepping, return 0. */
+
+static int
displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
{
struct cleanup *old_cleanups;
struct displaced_step_inferior_state *displaced
= get_displaced_stepping_state (ptid_get_pid (event_ptid));
+ int ret;
/* Was any thread of this process doing a displaced step? */
if (displaced == NULL)
- return;
+ return 0;
/* Was this event for the pid we displaced? */
if (ptid_equal (displaced->step_ptid, null_ptid)
|| ! ptid_equal (displaced->step_ptid, event_ptid))
- return;
+ return 0;
old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
displaced_step_restore (displaced, displaced->step_ptid);
+ /* Fixup may need to read memory/registers. Switch to the thread
+ that we're fixing up. Also, target_stopped_by_watchpoint checks
+ the current thread. */
+ switch_to_thread (event_ptid);
+
/* Did the instruction complete successfully? */
- if (signal == GDB_SIGNAL_TRAP)
+ if (signal == GDB_SIGNAL_TRAP
+ && !(target_stopped_by_watchpoint ()
+ && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
+ || target_have_steppable_watchpoint)))
{
- /* Fixup may need to read memory/registers. Switch to the
- thread that we're fixing up. */
- switch_to_thread (event_ptid);
-
/* Fix up the resulting state. */
gdbarch_displaced_step_fixup (displaced->step_gdbarch,
displaced->step_closure,
displaced->step_original,
displaced->step_copy,
get_thread_regcache (displaced->step_ptid));
+ ret = 1;
}
else
{
pc = displaced->step_original + (pc - displaced->step_copy);
regcache_write_pc (regcache, pc);
+ ret = -1;
}
do_cleanups (old_cleanups);
displaced->step_ptid = null_ptid;
- /* Are there any pending displaced stepping requests? If so, run
- one now. Leave the state object around, since we're likely to
- need it again soon. */
- while (displaced->step_request_queue)
- {
- struct displaced_step_request *head;
- ptid_t ptid;
- struct regcache *regcache;
- struct gdbarch *gdbarch;
- CORE_ADDR actual_pc;
- struct address_space *aspace;
+ return ret;
+}
- head = displaced->step_request_queue;
- ptid = head->ptid;
- displaced->step_request_queue = head->next;
- xfree (head);
+/* Data to be passed around while handling an event. This data is
+ discarded between events. */
+struct execution_control_state
+{
+ ptid_t ptid;
+ /* The thread that got the event, if this was a thread event; NULL
+ otherwise. */
+ struct thread_info *event_thread;
- context_switch (ptid);
+ struct target_waitstatus ws;
+ int stop_func_filled_in;
+ CORE_ADDR stop_func_start;
+ CORE_ADDR stop_func_end;
+ const char *stop_func_name;
+ int wait_some_more;
- regcache = get_thread_regcache (ptid);
- actual_pc = regcache_read_pc (regcache);
- aspace = get_regcache_aspace (regcache);
+ /* True if the event thread hit the single-step breakpoint of
+ another thread. Thus the event doesn't cause a stop, the thread
+ needs to be single-stepped past the single-step breakpoint before
+ we can switch back to the original stepping thread. */
+ int hit_singlestep_breakpoint;
+};
- if (breakpoint_here_p (aspace, actual_pc))
- {
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog,
- "displaced: stepping queued %s now\n",
- target_pid_to_str (ptid));
+/* Clear ECS and set it to point at TP. */
- displaced_step_prepare (ptid);
+static void
+reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
+{
+ memset (ecs, 0, sizeof (*ecs));
+ ecs->event_thread = tp;
+ ecs->ptid = tp->ptid;
+}
- gdbarch = get_regcache_arch (regcache);
+static void keep_going_pass_signal (struct execution_control_state *ecs);
+static void prepare_to_wait (struct execution_control_state *ecs);
+static int keep_going_stepped_thread (struct thread_info *tp);
+static int thread_still_needs_step_over (struct thread_info *tp);
+static void stop_all_threads (void);
- if (debug_displaced)
- {
- CORE_ADDR actual_pc = regcache_read_pc (regcache);
- gdb_byte buf[4];
+/* Are there any pending step-over requests? If so, run all we can
+ now and return true. Otherwise, return false. */
- fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
- paddress (gdbarch, actual_pc));
- read_memory (actual_pc, buf, sizeof (buf));
- displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
- }
+static int
+start_step_over (void)
+{
+ struct thread_info *tp, *next;
- if (gdbarch_displaced_step_hw_singlestep (gdbarch,
- displaced->step_closure))
- target_resume (ptid, 1, GDB_SIGNAL_0);
- else
- target_resume (ptid, 0, GDB_SIGNAL_0);
+ /* Don't start a new step-over if we already have an in-line
+ step-over operation ongoing. */
+ if (step_over_info_valid_p ())
+ return 0;
+
+ for (tp = step_over_queue_head; tp != NULL; tp = next)
+ {
+ struct execution_control_state ecss;
+ struct execution_control_state *ecs = &ecss;
+ enum step_over_what step_what;
+ int must_be_in_line;
+
+ next = thread_step_over_chain_next (tp);
+
+ /* If this inferior already has a displaced step in process,
+ don't start a new one. */
+ if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
+ continue;
+
+ step_what = thread_still_needs_step_over (tp);
+ must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
+ || ((step_what & STEP_OVER_BREAKPOINT)
+ && !use_displaced_stepping (tp)));
+
+ /* We currently stop all threads of all processes to step-over
+ in-line. If we need to start a new in-line step-over, let
+ any pending displaced steps finish first. */
+ if (must_be_in_line && displaced_step_in_progress_any_inferior ())
+ return 0;
+
+ thread_step_over_chain_remove (tp);
- /* Done, we're stepping a thread. */
- break;
+ if (step_over_queue_head == NULL)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: step-over queue now empty\n");
}
- else
+
+ if (tp->control.trap_expected
+ || tp->resumed
+ || tp->executing)
{
- int step;
- struct thread_info *tp = inferior_thread ();
+ internal_error (__FILE__, __LINE__,
+ "[%s] has inconsistent state: "
+ "trap_expected=%d, resumed=%d, executing=%d\n",
+ target_pid_to_str (tp->ptid),
+ tp->control.trap_expected,
+ tp->resumed,
+ tp->executing);
+ }
- /* The breakpoint we were sitting under has since been
- removed. */
- tp->control.trap_expected = 0;
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: resuming [%s] for step-over\n",
+ target_pid_to_str (tp->ptid));
+
+ /* keep_going_pass_signal skips the step-over if the breakpoint
+ is no longer inserted. In all-stop, we want to keep looking
+ for a thread that needs a step-over instead of resuming TP,
+ because we wouldn't be able to resume anything else until the
+ target stops again. In non-stop, the resume always resumes
+ only TP, so it's OK to let the thread resume freely. */
+ if (!target_is_non_stop_p () && !step_what)
+ continue;
- /* Go back to what we were trying to do. */
- step = currently_stepping (tp);
+ switch_to_thread (tp->ptid);
+ reset_ecs (ecs, tp);
+ keep_going_pass_signal (ecs);
- if (debug_displaced)
- fprintf_unfiltered (gdb_stdlog,
- "displaced: breakpoint is gone: %s, step(%d)\n",
- target_pid_to_str (tp->ptid), step);
+ if (!ecs->wait_some_more)
+ error (_("Command aborted."));
- target_resume (ptid, step, GDB_SIGNAL_0);
- tp->suspend.stop_signal = GDB_SIGNAL_0;
+ gdb_assert (tp->resumed);
+
+ /* If we started a new in-line step-over, we're done. */
+ if (step_over_info_valid_p ())
+ {
+ gdb_assert (tp->control.trap_expected);
+ return 1;
+ }
- /* This request was discarded. See if there's any other
- thread waiting for its turn. */
+ if (!target_is_non_stop_p ())
+ {
+ /* On all-stop, shouldn't have resumed unless we needed a
+ step over. */
+ gdb_assert (tp->control.trap_expected
+ || tp->step_after_step_resume_breakpoint);
+
+ /* With remote targets (at least), in all-stop, we can't
+ issue any further remote commands until the program stops
+ again. */
+ return 1;
}
+
+ /* Either the thread no longer needed a step-over, or a new
+ displaced stepping sequence started. Even in the latter
+ case, continue looking. Maybe we can also start another
+ displaced step on a thread of other process. */
}
+
+ return 0;
}
/* Update global variables holding ptids to hold NEW_PTID if they were
{
if (ptid_equal (displaced->step_ptid, old_ptid))
displaced->step_ptid = new_ptid;
-
- for (it = displaced->step_request_queue; it; it = it->next)
- if (ptid_equal (it->ptid, old_ptid))
- it->ptid = new_ptid;
}
}
return hw_step;
}
+/* See infrun.h. */
+
ptid_t
user_visible_resume_ptid (int step)
{
- /* By default, resume all threads of all processes. */
- ptid_t resume_ptid = RESUME_ALL;
-
- /* Maybe resume only all threads of the current process. */
- if (!sched_multi && target_supports_multi_process ())
- {
- resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
- }
+ ptid_t resume_ptid;
- /* Maybe resume a single thread after all. */
if (non_stop)
{
/* With non-stop mode on, threads are always handled
else if ((scheduler_mode == schedlock_on)
|| (scheduler_mode == schedlock_step && step))
{
- /* User-settable 'scheduler' mode requires solo thread resume. */
+ /* User-settable 'scheduler' mode requires solo thread
+ resume. */
resume_ptid = inferior_ptid;
}
+ else if (!sched_multi && target_supports_multi_process ())
+ {
+ /* Resume all threads of the current process (and none of other
+ processes). */
+ resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
+ }
+ else
+ {
+ /* Resume all threads of all processes. */
+ resume_ptid = RESUME_ALL;
+ }
- /* We may actually resume fewer threads at first, e.g., if a thread
- is stopped at a breakpoint that needs stepping-off, but that
- should not be visible to the user/frontend, and neither should
- the frontend/user be allowed to proceed any of the threads that
- happen to be stopped for internal run control handling, if a
- previous command wanted them resumed. */
return resume_ptid;
}
+/* Return a ptid representing the set of threads that we will resume,
+ in the perspective of the target, assuming run control handling
+ does not require leaving some threads stopped (e.g., stepping past
+ breakpoint). USER_STEP indicates whether we're about to start the
+ target for a stepping command. */
+
+static ptid_t
+internal_resume_ptid (int user_step)
+{
+ /* In non-stop, we always control threads individually. Note that
+ the target may always work in non-stop mode even with "set
+ non-stop off", in which case user_visible_resume_ptid could
+ return a wildcard ptid. */
+ if (target_is_non_stop_p ())
+ return inferior_ptid;
+ else
+ return user_visible_resume_ptid (user_step);
+}
+
+/* Wrapper for target_resume, that handles infrun-specific
+ bookkeeping. */
+
+static void
+do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
+{
+ struct thread_info *tp = inferior_thread ();
+
+ /* Install inferior's terminal modes. */
+ target_terminal_inferior ();
+
+ /* Avoid confusing the next resume, if the next stop/resume
+ happens to apply to another thread. */
+ tp->suspend.stop_signal = GDB_SIGNAL_0;
+
+ /* Advise target which signals may be handled silently.
+
+ If we have removed breakpoints because we are stepping over one
+ in-line (in any thread), we need to receive all signals to avoid
+ accidentally skipping a breakpoint during execution of a signal
+ handler.
+
+ Likewise if we're displaced stepping, otherwise a trap for a
+ breakpoint in a signal handler might be confused with the
+ displaced step finishing. We don't make the displaced_step_fixup
+ step distinguish the cases instead, because:
+
+ - a backtrace while stopped in the signal handler would show the
+ scratch pad as frame older than the signal handler, instead of
+ the real mainline code.
+
+ - when the thread is later resumed, the signal handler would
+ return to the scratch pad area, which would no longer be
+ valid. */
+ if (step_over_info_valid_p ()
+ || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
+ target_pass_signals (0, NULL);
+ else
+ target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
+
+ target_resume (resume_ptid, step, sig);
+}
+
/* Resume the inferior, but allow a QUIT. This is useful if the user
wants to interrupt some lengthy single-stepping operation
(for child processes, the SIGINT goes to the inferior, and so
we get a SIGINT random_signal, but for remote debugging and perhaps
other targets, that's not true).
- STEP nonzero if we should step (zero to continue instead).
SIG is the signal to give the inferior (zero for none). */
void
-resume (int step, enum gdb_signal sig)
+resume (enum gdb_signal sig)
{
struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
struct regcache *regcache = get_current_regcache ();
CORE_ADDR pc = regcache_read_pc (regcache);
struct address_space *aspace = get_regcache_aspace (regcache);
ptid_t resume_ptid;
- /* From here on, this represents the caller's step vs continue
- request, while STEP represents what we'll actually request the
- target to do. STEP can decay from a step to a continue, if e.g.,
- we need to implement single-stepping with breakpoints (software
- single-step). When deciding whether "set scheduler-locking step"
- applies, it's the callers intention that counts. */
- const int entry_step = step;
+ /* This represents the user's step vs continue request. When
+ deciding whether "set scheduler-locking step" applies, it's the
+ user's intention that counts. */
+ const int user_step = tp->control.stepping_command;
+ /* This represents what we'll actually request the target to do.
+ This can decay from a step to a continue, if e.g., we need to
+ implement single-stepping with breakpoints (software
+ single-step). */
+ int step;
+
+ gdb_assert (!thread_is_in_step_over_chain (tp));
+
+ QUIT;
+
+ if (tp->suspend.waitstatus_pending_p)
+ {
+ if (debug_infrun)
+ {
+ char *statstr;
+
+ statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: resume: thread %s has pending wait status %s "
+ "(currently_stepping=%d).\n",
+ target_pid_to_str (tp->ptid), statstr,
+ currently_stepping (tp));
+ xfree (statstr);
+ }
+
+ tp->resumed = 1;
+
+ /* FIXME: What should we do if we are supposed to resume this
+ thread with a signal? Maybe we should maintain a queue of
+ pending signals to deliver. */
+ if (sig != GDB_SIGNAL_0)
+ {
+ warning (_("Couldn't deliver signal %s to %s.\n"),
+ gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
+ }
+
+ tp->suspend.stop_signal = GDB_SIGNAL_0;
+ discard_cleanups (old_cleanups);
+
+ if (target_can_async_p ())
+ target_async (1);
+ return;
+ }
tp->stepped_breakpoint = 0;
- QUIT;
+ /* Depends on stepped_breakpoint. */
+ step = currently_stepping (tp);
if (current_inferior ()->waiting_for_vfork_done)
{
reported to handle_inferior_event. Set a breakpoint
at the current PC, and run to it. Don't update
prev_pc, because if we end in
- switch_back_to_stepping, we want the "expected thread
- advanced also" branch to be taken. IOW, we don't
- want this thread to step further from PC
+ switch_back_to_stepped_thread, we want the "expected
+ thread advanced also" branch to be taken. IOW, we
+ don't want this thread to step further from PC
(overstep). */
+ gdb_assert (!step_over_info_valid_p ());
insert_single_step_breakpoint (gdbarch, aspace, pc);
insert_breakpoints ();
- tp->suspend.stop_signal = GDB_SIGNAL_0;
- /* We're continuing with all breakpoints inserted. It's
- safe to let the target bypass signals. */
- target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
- /* ... and safe to let other threads run, according to
- schedlock. */
- resume_ptid = user_visible_resume_ptid (entry_step);
- target_resume (resume_ptid, 0, GDB_SIGNAL_0);
+ resume_ptid = internal_resume_ptid (user_step);
+ do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
discard_cleanups (old_cleanups);
+ tp->resumed = 1;
return;
}
}
We can't use displaced stepping when we are waiting for vfork_done
event, displaced stepping breaks the vfork child similarly as single
step software breakpoint. */
- if (use_displaced_stepping (gdbarch)
- && tp->control.trap_expected
+ if (tp->control.trap_expected
+ && use_displaced_stepping (tp)
+ && !step_over_info_valid_p ()
&& sig == GDB_SIGNAL_0
&& !current_inferior ()->waiting_for_vfork_done)
{
- struct displaced_step_inferior_state *displaced;
+ int prepared = displaced_step_prepare (inferior_ptid);
- if (!displaced_step_prepare (inferior_ptid))
+ if (prepared == 0)
{
- /* Got placed in displaced stepping queue. Will be resumed
- later when all the currently queued displaced stepping
- requests finish. The thread is not executing at this
- point, and the call to set_executing will be made later.
- But we need to call set_running here, since from the
- user/frontend's point of view, threads were set running.
- Unless we're calling an inferior function, as in that
- case we pretend the inferior doesn't run at all. */
- if (!tp->control.in_infcall)
- set_running (user_visible_resume_ptid (entry_step), 1);
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "Got placed in step-over queue\n");
+
+ tp->control.trap_expected = 0;
discard_cleanups (old_cleanups);
return;
}
+ else if (prepared < 0)
+ {
+ /* Fallback to stepping over the breakpoint in-line. */
+
+ if (target_is_non_stop_p ())
+ stop_all_threads ();
+
+ set_step_over_info (get_regcache_aspace (regcache),
+ regcache_read_pc (regcache), 0);
+
+ step = maybe_software_singlestep (gdbarch, pc);
+
+ insert_breakpoints ();
+ }
+ else if (prepared > 0)
+ {
+ struct displaced_step_inferior_state *displaced;
- /* Update pc to reflect the new address from which we will execute
- instructions due to displaced stepping. */
- pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
+ /* Update pc to reflect the new address from which we will
+ execute instructions due to displaced stepping. */
+ pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
- displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
- step = gdbarch_displaced_step_hw_singlestep (gdbarch,
- displaced->step_closure);
+ displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
+ step = gdbarch_displaced_step_hw_singlestep (gdbarch,
+ displaced->step_closure);
+ }
}
/* Do we need to do it the hard way, w/temp breakpoints? */
use singlestep breakpoint. */
gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
- /* Decide the set of threads to ask the target to resume. Start
- by assuming everything will be resumed, than narrow the set
- by applying increasingly restricting conditions. */
- resume_ptid = user_visible_resume_ptid (entry_step);
-
- /* Even if RESUME_PTID is a wildcard, and we end up resuming less
- (e.g., we might need to step over a breakpoint), from the
- user/frontend's point of view, all threads in RESUME_PTID are now
- running. Unless we're calling an inferior function, as in that
- case pretend we inferior doesn't run at all. */
- if (!tp->control.in_infcall)
- set_running (resume_ptid, 1);
-
- /* Maybe resume a single thread after all. */
+ /* Decide the set of threads to ask the target to resume. */
if ((step || thread_has_single_step_breakpoints_set (tp))
&& tp->control.trap_expected)
{
breakpoint if allowed to run. */
resume_ptid = inferior_ptid;
}
+ else
+ resume_ptid = internal_resume_ptid (user_step);
if (execution_direction != EXEC_REVERSE
&& step && breakpoint_inserted_here_p (aspace, pc))
{
- /* The only case we currently need to step a breakpoint
- instruction is when we have a signal to deliver. See
- handle_signal_stop where we handle random signals that could
- take out us out of the stepping range. Normally, in that
- case we end up continuing (instead of stepping) over the
+ /* There are two cases where we currently need to step a
+ breakpoint instruction when we have a signal to deliver:
+
+ - See handle_signal_stop where we handle random signals that
+ could take out us out of the stepping range. Normally, in
+ that case we end up continuing (instead of stepping) over the
signal handler with a breakpoint at PC, but there are cases
where we should _always_ single-step, even if we have a
step-resume breakpoint, like when a software watchpoint is
recurses and executes PC again, it'll miss the breakpoint.
So we leave the breakpoint inserted anyway, but we need to
record that we tried to step a breakpoint instruction, so
- that adjust_pc_after_break doesn't end up confused. */
- gdb_assert (sig != GDB_SIGNAL_0);
+ that adjust_pc_after_break doesn't end up confused.
+
+ - In non-stop if we insert a breakpoint (e.g., a step-resume)
+ in one thread after another thread that was stepping had been
+ momentarily paused for a step-over. When we re-resume the
+ stepping thread, it may be resumed from that address with a
+ breakpoint that hasn't trapped yet. Seen with
+ gdb.threads/non-stop-fair-events.exp, on targets that don't
+ do displaced stepping. */
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: resume: [%s] stepped breakpoint\n",
+ target_pid_to_str (tp->ptid));
tp->stepped_breakpoint = 1;
}
if (debug_displaced
- && use_displaced_stepping (gdbarch)
- && tp->control.trap_expected)
+ && tp->control.trap_expected
+ && use_displaced_stepping (tp)
+ && !step_over_info_valid_p ())
{
- struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
+ struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
gdb_byte buf[4];
gdb_assert (pc_in_thread_step_range (pc, tp));
}
- /* Install inferior's terminal modes. */
- target_terminal_inferior ();
-
- /* Avoid confusing the next resume, if the next stop/resume
- happens to apply to another thread. */
- tp->suspend.stop_signal = GDB_SIGNAL_0;
-
- /* Advise target which signals may be handled silently. If we have
- removed breakpoints because we are stepping over one (in any
- thread), we need to receive all signals to avoid accidentally
- skipping a breakpoint during execution of a signal handler. */
- if (step_over_info_valid_p ())
- target_pass_signals (0, NULL);
- else
- target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
-
- target_resume (resume_ptid, step, sig);
-
+ do_target_resume (resume_ptid, step, sig);
+ tp->resumed = 1;
discard_cleanups (old_cleanups);
}
\f
"infrun: clear_proceed_status_thread (%s)\n",
target_pid_to_str (tp->ptid));
+ /* If we're starting a new sequence, then the previous finished
+ single-step is no longer relevant. */
+ if (tp->suspend.waitstatus_pending_p)
+ {
+ if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: clear_proceed_status: pending "
+ "event of %s was a finished step. "
+ "Discarding.\n",
+ target_pid_to_str (tp->ptid));
+
+ tp->suspend.waitstatus_pending_p = 0;
+ tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
+ }
+ else if (debug_infrun)
+ {
+ char *statstr;
+
+ statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: clear_proceed_status_thread: thread %s "
+ "has pending wait status %s "
+ "(currently_stepping=%d).\n",
+ target_pid_to_str (tp->ptid), statstr,
+ currently_stepping (tp));
+ xfree (statstr);
+ }
+ }
+
/* If this signal should not be seen by program, give it zero.
Used for debugging signals. */
if (!signal_pass_state (tp->suspend.stop_signal))
tp->control.step_frame_id = null_frame_id;
tp->control.step_stack_frame_id = null_frame_id;
tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
+ tp->control.step_start_function = NULL;
tp->stop_requested = 0;
tp->control.stop_step = 0;
tp->control.proceed_to_finish = 0;
tp->control.command_interp = NULL;
+ tp->control.stepping_command = 0;
/* Discard any remaining commands or status from previous stop. */
bpstat_clear (&tp->control.stop_bpstat);
stop_after_trap = 0;
- clear_step_over_info ();
-
observer_notify_about_to_proceed ();
-
- if (stop_registers)
- {
- regcache_xfree (stop_registers);
- stop_registers = NULL;
- }
}
/* Returns true if TP is still stopped at a breakpoint that needs
meanwhile, we can skip the whole step-over dance. */
static int
-thread_still_needs_step_over (struct thread_info *tp)
+thread_still_needs_step_over_bp (struct thread_info *tp)
{
if (tp->stepping_over_breakpoint)
{
return 0;
}
-/* Returns true if scheduler locking applies. STEP indicates whether
- we're about to do a step/next-like command to a thread. */
+/* Check whether thread TP still needs to start a step-over in order
+ to make progress when resumed. Returns an bitwise or of enum
+ step_over_what bits, indicating what needs to be stepped over. */
static int
-schedlock_applies (int step)
-{
- return (scheduler_mode == schedlock_on
- || (scheduler_mode == schedlock_step
- && step));
-}
-
-/* Look a thread other than EXCEPT that has previously reported a
- breakpoint event, and thus needs a step-over in order to make
- progress. Returns NULL is none is found. STEP indicates whether
- we're about to step the current thread, in order to decide whether
- "set scheduler-locking step" applies. */
-
-static struct thread_info *
-find_thread_needs_step_over (int step, struct thread_info *except)
+thread_still_needs_step_over (struct thread_info *tp)
{
- struct thread_info *tp, *current;
-
- /* With non-stop mode on, threads are always handled individually. */
- gdb_assert (! non_stop);
-
- current = inferior_thread ();
+ struct inferior *inf = find_inferior_ptid (tp->ptid);
+ int what = 0;
- /* If scheduler locking applies, we can avoid iterating over all
- threads. */
- if (schedlock_applies (step))
- {
- if (except != current
- && thread_still_needs_step_over (current))
- return current;
+ if (thread_still_needs_step_over_bp (tp))
+ what |= STEP_OVER_BREAKPOINT;
- return NULL;
- }
+ if (tp->stepping_over_watchpoint
+ && !target_have_steppable_watchpoint)
+ what |= STEP_OVER_WATCHPOINT;
- ALL_NON_EXITED_THREADS (tp)
- {
- /* Ignore the EXCEPT thread. */
- if (tp == except)
- continue;
- /* Ignore threads of processes we're not resuming. */
- if (!sched_multi
- && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
- continue;
+ return what;
+}
- if (thread_still_needs_step_over (tp))
- return tp;
- }
+/* Returns true if scheduler locking applies. STEP indicates whether
+ we're about to do a step/next-like command to a thread. */
- return NULL;
+static int
+schedlock_applies (struct thread_info *tp)
+{
+ return (scheduler_mode == schedlock_on
+ || (scheduler_mode == schedlock_step
+ && tp->control.stepping_command));
}
/* Basic routine for continuing the program in various fashions.
You should call clear_proceed_status before calling proceed. */
void
-proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
+proceed (CORE_ADDR addr, enum gdb_signal siggnal)
{
struct regcache *regcache;
struct gdbarch *gdbarch;
struct thread_info *tp;
CORE_ADDR pc;
struct address_space *aspace;
+ ptid_t resume_ptid;
+ struct execution_control_state ecss;
+ struct execution_control_state *ecs = &ecss;
+ struct cleanup *old_chain;
+ int started;
/* If we're stopped at a fork/vfork, follow the branch set by the
"set follow-fork-mode" command; otherwise, we'll just proceed
pc = regcache_read_pc (regcache);
tp = inferior_thread ();
- if (step > 0)
- step_start_function = find_pc_function (pc);
- if (step < 0)
- stop_after_trap = 1;
-
/* Fill in with reasonable starting values. */
init_thread_stepping_state (tp);
+ gdb_assert (!thread_is_in_step_over_chain (tp));
+
if (addr == (CORE_ADDR) -1)
{
if (pc == stop_pc
(next/step/etc.), we'll want to print stop event output to the MI
console channel (the stepped-to line, etc.), as if the user
entered the execution command on a real GDB console. */
- inferior_thread ()->control.command_interp = command_interp ();
+ tp->control.command_interp = command_interp ();
+
+ resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
+
+ /* If an exception is thrown from this point on, make sure to
+ propagate GDB's knowledge of the executing state to the
+ frontend/user running state. */
+ old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
+
+ /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
+ threads (e.g., we might need to set threads stepping over
+ breakpoints first), from the user/frontend's point of view, all
+ threads in RESUME_PTID are now running. Unless we're calling an
+ inferior function, as in that case we pretend the inferior
+ doesn't run at all. */
+ if (!tp->control.in_infcall)
+ set_running (resume_ptid, 1);
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
- "infrun: proceed (addr=%s, signal=%s, step=%d)\n",
+ "infrun: proceed (addr=%s, signal=%s)\n",
paddress (gdbarch, addr),
- gdb_signal_to_symbol_string (siggnal), step);
+ gdb_signal_to_symbol_string (siggnal));
- if (non_stop)
- /* In non-stop, each thread is handled individually. The context
- must already be set to the right thread here. */
- ;
- else
+ annotate_starting ();
+
+ /* Make sure that output from GDB appears before output from the
+ inferior. */
+ gdb_flush (gdb_stdout);
+
+ /* In a multi-threaded task we may select another thread and
+ then continue or step.
+
+ But if a thread that we're resuming had stopped at a breakpoint,
+ it will immediately cause another breakpoint stop without any
+ execution (i.e. it will report a breakpoint hit incorrectly). So
+ we must step over it first.
+
+ Look for threads other than the current (TP) that reported a
+ breakpoint hit and haven't been resumed yet since. */
+
+ /* If scheduler locking applies, we can avoid iterating over all
+ threads. */
+ if (!non_stop && !schedlock_applies (tp))
{
- struct thread_info *step_over;
+ struct thread_info *current = tp;
+
+ ALL_NON_EXITED_THREADS (tp)
+ {
+ /* Ignore the current thread here. It's handled
+ afterwards. */
+ if (tp == current)
+ continue;
- /* In a multi-threaded task we may select another thread and
- then continue or step.
+ /* Ignore threads of processes we're not resuming. */
+ if (!ptid_match (tp->ptid, resume_ptid))
+ continue;
- But if the old thread was stopped at a breakpoint, it will
- immediately cause another breakpoint stop without any
- execution (i.e. it will report a breakpoint hit incorrectly).
- So we must step over it first.
+ if (!thread_still_needs_step_over (tp))
+ continue;
+
+ gdb_assert (!thread_is_in_step_over_chain (tp));
- Look for a thread other than the current (TP) that reported a
- breakpoint hit and hasn't been resumed yet since. */
- step_over = find_thread_needs_step_over (step, tp);
- if (step_over != NULL)
- {
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
"infrun: need to step-over [%s] first\n",
- target_pid_to_str (step_over->ptid));
+ target_pid_to_str (tp->ptid));
- /* Store the prev_pc for the stepping thread too, needed by
- switch_back_to_stepping thread. */
- tp->prev_pc = regcache_read_pc (get_current_regcache ());
- switch_to_thread (step_over->ptid);
- tp = step_over;
+ thread_step_over_chain_enqueue (tp);
}
+
+ tp = current;
}
- /* If we need to step over a breakpoint, and we're not using
- displaced stepping to do so, insert all breakpoints (watchpoints,
- etc.) but the one we're stepping over, step one instruction, and
- then re-insert the breakpoint when that step is finished. */
- if (tp->stepping_over_breakpoint && !use_displaced_stepping (gdbarch))
- {
- struct regcache *regcache = get_current_regcache ();
+ /* Enqueue the current thread last, so that we move all other
+ threads over their breakpoints first. */
+ if (tp->stepping_over_breakpoint)
+ thread_step_over_chain_enqueue (tp);
+
+ /* If the thread isn't started, we'll still need to set its prev_pc,
+ so that switch_back_to_stepped_thread knows the thread hasn't
+ advanced. Must do this before resuming any thread, as in
+ all-stop/remote, once we resume we can't send any other packet
+ until the target stops again. */
+ tp->prev_pc = regcache_read_pc (regcache);
+
+ started = start_step_over ();
- set_step_over_info (get_regcache_aspace (regcache),
- regcache_read_pc (regcache), 0);
+ if (step_over_info_valid_p ())
+ {
+ /* Either this thread started a new in-line step over, or some
+ other thread was already doing one. In either case, don't
+ resume anything else until the step-over is finished. */
}
- else
- clear_step_over_info ();
+ else if (started && !target_is_non_stop_p ())
+ {
+ /* A new displaced stepping sequence was started. In all-stop,
+ we can't talk to the target anymore until it next stops. */
+ }
+ else if (!non_stop && target_is_non_stop_p ())
+ {
+ /* In all-stop, but the target is always in non-stop mode.
+ Start all other threads that are implicitly resumed too. */
+ ALL_NON_EXITED_THREADS (tp)
+ {
+ /* Ignore threads of processes we're not resuming. */
+ if (!ptid_match (tp->ptid, resume_ptid))
+ continue;
- insert_breakpoints ();
+ if (tp->resumed)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: proceed: [%s] resumed\n",
+ target_pid_to_str (tp->ptid));
+ gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
+ continue;
+ }
- tp->control.trap_expected = tp->stepping_over_breakpoint;
+ if (thread_is_in_step_over_chain (tp))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: proceed: [%s] needs step-over\n",
+ target_pid_to_str (tp->ptid));
+ continue;
+ }
- annotate_starting ();
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: proceed: resuming %s\n",
+ target_pid_to_str (tp->ptid));
- /* Make sure that output from GDB appears before output from the
- inferior. */
- gdb_flush (gdb_stdout);
+ reset_ecs (ecs, tp);
+ switch_to_thread (tp->ptid);
+ keep_going_pass_signal (ecs);
+ if (!ecs->wait_some_more)
+ error ("Command aborted.");
+ }
+ }
+ else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
+ {
+ /* The thread wasn't started, and isn't queued, run it now. */
+ reset_ecs (ecs, tp);
+ switch_to_thread (tp->ptid);
+ keep_going_pass_signal (ecs);
+ if (!ecs->wait_some_more)
+ error ("Command aborted.");
+ }
- /* Refresh prev_pc value just prior to resuming. This used to be
- done in stop_waiting, however, setting prev_pc there did not handle
- scenarios such as inferior function calls or returning from
- a function via the return command. In those cases, the prev_pc
- value was not set properly for subsequent commands. The prev_pc value
- is used to initialize the starting line number in the ecs. With an
- invalid value, the gdb next command ends up stopping at the position
- represented by the next line table entry past our start position.
- On platforms that generate one line table entry per line, this
- is not a problem. However, on the ia64, the compiler generates
- extraneous line table entries that do not increase the line number.
- When we issue the gdb next command on the ia64 after an inferior call
- or a return command, we often end up a few instructions forward, still
- within the original line we started.
-
- An attempt was made to refresh the prev_pc at the same time the
- execution_control_state is initialized (for instance, just before
- waiting for an inferior event). But this approach did not work
- because of platforms that use ptrace, where the pc register cannot
- be read unless the inferior is stopped. At that point, we are not
- guaranteed the inferior is stopped and so the regcache_read_pc() call
- can fail. Setting the prev_pc value here ensures the value is updated
- correctly when the inferior is stopped. */
- tp->prev_pc = regcache_read_pc (get_current_regcache ());
-
- /* Resume inferior. */
- resume (tp->control.trap_expected || step || bpstat_should_step (),
- tp->suspend.stop_signal);
+ discard_cleanups (old_chain);
/* Wait for it to stop (if not standalone)
and in any case decode why it stopped, and act accordingly. */
}
\f
-/* Data to be passed around while handling an event. This data is
- discarded between events. */
-struct execution_control_state
-{
- ptid_t ptid;
- /* The thread that got the event, if this was a thread event; NULL
- otherwise. */
- struct thread_info *event_thread;
-
- struct target_waitstatus ws;
- int stop_func_filled_in;
- CORE_ADDR stop_func_start;
- CORE_ADDR stop_func_end;
- const char *stop_func_name;
- int wait_some_more;
-
- /* True if the event thread hit the single-step breakpoint of
- another thread. Thus the event doesn't cause a stop, the thread
- needs to be single-stepped past the single-step breakpoint before
- we can switch back to the original stepping thread. */
- int hit_singlestep_breakpoint;
-};
static void handle_inferior_event (struct execution_control_state *ecs);
static void end_stepping_range (struct execution_control_state *ecs);
static void stop_waiting (struct execution_control_state *ecs);
-static void prepare_to_wait (struct execution_control_state *ecs);
static void keep_going (struct execution_control_state *ecs);
static void process_event_stop_test (struct execution_control_state *ecs);
static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
static void
infrun_thread_stop_requested (ptid_t ptid)
{
- struct displaced_step_inferior_state *displaced;
-
- /* PTID was requested to stop. Remove it from the displaced
- stepping queue, so we don't try to resume it automatically. */
-
- for (displaced = displaced_step_inferior_states;
- displaced;
- displaced = displaced->next)
- {
- struct displaced_step_request *it, **prev_next_p;
-
- it = displaced->step_request_queue;
- prev_next_p = &displaced->step_request_queue;
- while (it)
- {
- if (ptid_match (it->ptid, ptid))
- {
- *prev_next_p = it->next;
- it->next = NULL;
- xfree (it);
- }
- else
- {
- prev_next_p = &it->next;
- }
+ struct thread_info *tp;
- it = *prev_next_p;
- }
- }
+ /* PTID was requested to stop. Remove matching threads from the
+ step-over queue, so we don't try to resume them
+ automatically. */
+ ALL_NON_EXITED_THREADS (tp)
+ if (ptid_match (tp->ptid, ptid))
+ {
+ if (thread_is_in_step_over_chain (tp))
+ thread_step_over_chain_remove (tp);
+ }
iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
}
if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
return;
- if (non_stop)
+ if (target_is_non_stop_p ())
{
/* If in non-stop mode, only the current thread stopped. */
func (inferior_thread ());
is set. */
fprintf_unfiltered (tmp_stream,
- "infrun: target_wait (%d", ptid_get_pid (waiton_ptid));
+ "infrun: target_wait (%d.%ld.%ld",
+ ptid_get_pid (waiton_ptid),
+ ptid_get_lwp (waiton_ptid),
+ ptid_get_tid (waiton_ptid));
if (ptid_get_pid (waiton_ptid) != -1)
fprintf_unfiltered (tmp_stream,
" [%s]", target_pid_to_str (waiton_ptid));
fprintf_unfiltered (tmp_stream, ", status) =\n");
fprintf_unfiltered (tmp_stream,
- "infrun: %d [%s],\n",
+ "infrun: %d.%ld.%ld [%s],\n",
ptid_get_pid (result_ptid),
+ ptid_get_lwp (result_ptid),
+ ptid_get_tid (result_ptid),
target_pid_to_str (result_ptid));
fprintf_unfiltered (tmp_stream,
"infrun: %s\n",
ui_file_delete (tmp_stream);
}
+/* Select a thread at random, out of those which are resumed and have
+ had events. */
+
+static struct thread_info *
+random_pending_event_thread (ptid_t waiton_ptid)
+{
+ struct thread_info *event_tp;
+ int num_events = 0;
+ int random_selector;
+
+ /* First see how many events we have. Count only resumed threads
+ that have an event pending. */
+ ALL_NON_EXITED_THREADS (event_tp)
+ if (ptid_match (event_tp->ptid, waiton_ptid)
+ && event_tp->resumed
+ && event_tp->suspend.waitstatus_pending_p)
+ num_events++;
+
+ if (num_events == 0)
+ return NULL;
+
+ /* Now randomly pick a thread out of those that have had events. */
+ random_selector = (int)
+ ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
+
+ if (debug_infrun && num_events > 1)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: Found %d events, selecting #%d\n",
+ num_events, random_selector);
+
+ /* Select the Nth thread that has had an event. */
+ ALL_NON_EXITED_THREADS (event_tp)
+ if (ptid_match (event_tp->ptid, waiton_ptid)
+ && event_tp->resumed
+ && event_tp->suspend.waitstatus_pending_p)
+ if (random_selector-- == 0)
+ break;
+
+ return event_tp;
+}
+
+/* Wrapper for target_wait that first checks whether threads have
+ pending statuses to report before actually asking the target for
+ more events. */
+
+static ptid_t
+do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
+{
+ ptid_t event_ptid;
+ struct thread_info *tp;
+
+ /* First check if there is a resumed thread with a wait status
+ pending. */
+ if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
+ {
+ tp = random_pending_event_thread (ptid);
+ }
+ else
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: Waiting for specific thread %s.\n",
+ target_pid_to_str (ptid));
+
+ /* We have a specific thread to check. */
+ tp = find_thread_ptid (ptid);
+ gdb_assert (tp != NULL);
+ if (!tp->suspend.waitstatus_pending_p)
+ tp = NULL;
+ }
+
+ if (tp != NULL
+ && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
+ || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
+ {
+ struct regcache *regcache = get_thread_regcache (tp->ptid);
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ CORE_ADDR pc;
+ int discard = 0;
+
+ pc = regcache_read_pc (regcache);
+
+ if (pc != tp->suspend.stop_pc)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: PC of %s changed. was=%s, now=%s\n",
+ target_pid_to_str (tp->ptid),
+ paddress (gdbarch, tp->prev_pc),
+ paddress (gdbarch, pc));
+ discard = 1;
+ }
+ else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: previous breakpoint of %s, at %s gone\n",
+ target_pid_to_str (tp->ptid),
+ paddress (gdbarch, pc));
+
+ discard = 1;
+ }
+
+ if (discard)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: pending event of %s cancelled.\n",
+ target_pid_to_str (tp->ptid));
+
+ tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
+ tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
+ }
+ }
+
+ if (tp != NULL)
+ {
+ if (debug_infrun)
+ {
+ char *statstr;
+
+ statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: Using pending wait status %s for %s.\n",
+ statstr,
+ target_pid_to_str (tp->ptid));
+ xfree (statstr);
+ }
+
+ /* Now that we've selected our final event LWP, un-adjust its PC
+ if it was a software breakpoint (and the target doesn't
+ always adjust the PC itself). */
+ if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
+ && !target_supports_stopped_by_sw_breakpoint ())
+ {
+ struct regcache *regcache;
+ struct gdbarch *gdbarch;
+ int decr_pc;
+
+ regcache = get_thread_regcache (tp->ptid);
+ gdbarch = get_regcache_arch (regcache);
+
+ decr_pc = gdbarch_decr_pc_after_break (gdbarch);
+ if (decr_pc != 0)
+ {
+ CORE_ADDR pc;
+
+ pc = regcache_read_pc (regcache);
+ regcache_write_pc (regcache, pc + decr_pc);
+ }
+ }
+
+ tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
+ *status = tp->suspend.waitstatus;
+ tp->suspend.waitstatus_pending_p = 0;
+
+ /* Wake up the event loop again, until all pending events are
+ processed. */
+ if (target_is_async_p ())
+ mark_async_event_handler (infrun_async_inferior_event_token);
+ return tp->ptid;
+ }
+
+ /* But if we don't find one, we'll have to wait. */
+
+ if (deprecated_target_wait_hook)
+ event_ptid = deprecated_target_wait_hook (ptid, status, options);
+ else
+ event_ptid = target_wait (ptid, status, options);
+
+ return event_ptid;
+}
+
/* Prepare and stabilize the inferior for detaching it. E.g.,
detaching while a thread is displaced stepping is a recipe for
crashing it, as nothing would readjust the PC out of the scratch
don't get any event. */
target_dcache_invalidate ();
- if (deprecated_target_wait_hook)
- ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
- else
- ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
+ ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
if (debug_infrun)
print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
wait_for_inferior (void)
{
struct cleanup *old_cleanups;
+ struct cleanup *thread_state_chain;
if (debug_infrun)
fprintf_unfiltered
= make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
NULL);
+ /* If an error happens while handling the event, propagate GDB's
+ knowledge of the executing state to the frontend/user running
+ state. */
+ thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
+
while (1)
{
struct execution_control_state ecss;
struct execution_control_state *ecs = &ecss;
- struct cleanup *old_chain;
ptid_t waiton_ptid = minus_one_ptid;
memset (ecs, 0, sizeof (*ecs));
don't get any event. */
target_dcache_invalidate ();
- if (deprecated_target_wait_hook)
- ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
- else
- ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
+ ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
if (debug_infrun)
print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
- /* If an error happens while handling the event, propagate GDB's
- knowledge of the executing state to the frontend/user running
- state. */
- old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
-
/* Now figure out what to do with the result of the result. */
handle_inferior_event (ecs);
- /* No error, don't finish the state yet. */
- discard_cleanups (old_chain);
-
if (!ecs->wait_some_more)
break;
}
+ /* No error, don't finish the state yet. */
+ discard_cleanups (thread_state_chain);
+
do_cleanups (old_cleanups);
}
make_cleanup_restore_integer (&execution_direction);
execution_direction = target_execution_direction ();
- if (deprecated_target_wait_hook)
- ecs->ptid =
- deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
- else
- ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
+ ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
if (debug_infrun)
print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
/* If an error happens while handling the event, propagate GDB's
knowledge of the executing state to the frontend/user running
state. */
- if (!non_stop)
+ if (!target_is_non_stop_p ())
ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
else
ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
switch_to_thread (ptid);
}
+/* If the target can't tell whether we've hit breakpoints
+ (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
+ check whether that could have been caused by a breakpoint. If so,
+ adjust the PC, per gdbarch_decr_pc_after_break. */
+
static void
-adjust_pc_after_break (struct execution_control_state *ecs)
+adjust_pc_after_break (struct thread_info *thread,
+ struct target_waitstatus *ws)
{
struct regcache *regcache;
struct gdbarch *gdbarch;
target with both of these set in GDB history, and it seems unlikely to be
correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
- if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
+ if (ws->kind != TARGET_WAITKIND_STOPPED)
return;
- if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
+ if (ws->value.sig != GDB_SIGNAL_TRAP)
return;
/* In reverse execution, when a breakpoint is hit, the instruction
if (execution_direction == EXEC_REVERSE)
return;
+ /* If the target can tell whether the thread hit a SW breakpoint,
+ trust it. Targets that can tell also adjust the PC
+ themselves. */
+ if (target_supports_stopped_by_sw_breakpoint ())
+ return;
+
+ /* Note that relying on whether a breakpoint is planted in memory to
+ determine this can fail. E.g,. the breakpoint could have been
+ removed since. Or the thread could have been told to step an
+ instruction the size of a breakpoint instruction, and only
+ _after_ was a breakpoint inserted at its address. */
+
/* If this target does not decrement the PC after breakpoints, then
we have nothing to do. */
- regcache = get_thread_regcache (ecs->ptid);
+ regcache = get_thread_regcache (thread->ptid);
gdbarch = get_regcache_arch (regcache);
- decr_pc = target_decr_pc_after_break (gdbarch);
+ decr_pc = gdbarch_decr_pc_after_break (gdbarch);
if (decr_pc == 0)
return;
breakpoint would be. */
breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
+ /* If the target can't tell whether a software breakpoint triggered,
+ fallback to figuring it out based on breakpoints we think were
+ inserted in the target, and on whether the thread was stepped or
+ continued. */
+
/* Check whether there actually is a software breakpoint inserted at
that location.
removed a breakpoint, but stop events for that breakpoint were
already queued and arrive later. To suppress those spurious
SIGTRAPs, we keep a list of such breakpoint locations for a bit,
- and retire them after a number of stop events are reported. */
+ and retire them after a number of stop events are reported. Note
+ this is an heuristic and can thus get confused. The real fix is
+ to get the "stopped by SW BP and needs adjustment" info out of
+ the target/kernel (and thus never reach here; see above). */
if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
- || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
+ || (target_is_non_stop_p ()
+ && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
{
struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
software breakpoint. In this case (prev_pc == breakpoint_pc),
we also need to back up to the breakpoint address. */
- if (thread_has_single_step_breakpoints_set (ecs->event_thread)
- || !currently_stepping (ecs->event_thread)
- || (ecs->event_thread->stepped_breakpoint
- && ecs->event_thread->prev_pc == breakpoint_pc))
+ if (thread_has_single_step_breakpoints_set (thread)
+ || !currently_stepping (thread)
+ || (thread->stepped_breakpoint
+ && thread->prev_pc == breakpoint_pc))
regcache_write_pc (regcache, breakpoint_pc);
do_cleanups (old_cleanups);
should ignore the event), or 0 if the event deserves to be
processed. */
-static int
-handle_syscall_event (struct execution_control_state *ecs)
+static int
+handle_syscall_event (struct execution_control_state *ecs)
+{
+ struct regcache *regcache;
+ int syscall_number;
+
+ if (!ptid_equal (ecs->ptid, inferior_ptid))
+ context_switch (ecs->ptid);
+
+ regcache = get_thread_regcache (ecs->ptid);
+ syscall_number = ecs->ws.value.syscall_number;
+ stop_pc = regcache_read_pc (regcache);
+
+ if (catch_syscall_enabled () > 0
+ && catching_syscall_number (syscall_number) > 0)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
+ syscall_number);
+
+ ecs->event_thread->control.stop_bpstat
+ = bpstat_stop_status (get_regcache_aspace (regcache),
+ stop_pc, ecs->ptid, &ecs->ws);
+
+ if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
+ {
+ /* Catchpoint hit. */
+ return 0;
+ }
+ }
+
+ /* If no catchpoint triggered for this, then keep going. */
+ keep_going (ecs);
+ return 1;
+}
+
+/* Lazily fill in the execution_control_state's stop_func_* fields. */
+
+static void
+fill_in_stop_func (struct gdbarch *gdbarch,
+ struct execution_control_state *ecs)
+{
+ if (!ecs->stop_func_filled_in)
+ {
+ /* Don't care about return value; stop_func_start and stop_func_name
+ will both be 0 if it doesn't work. */
+ find_pc_partial_function (stop_pc, &ecs->stop_func_name,
+ &ecs->stop_func_start, &ecs->stop_func_end);
+ ecs->stop_func_start
+ += gdbarch_deprecated_function_start_offset (gdbarch);
+
+ if (gdbarch_skip_entrypoint_p (gdbarch))
+ ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
+ ecs->stop_func_start);
+
+ ecs->stop_func_filled_in = 1;
+ }
+}
+
+
+/* Return the STOP_SOON field of the inferior pointed at by PTID. */
+
+static enum stop_kind
+get_inferior_stop_soon (ptid_t ptid)
+{
+ struct inferior *inf = find_inferior_ptid (ptid);
+
+ gdb_assert (inf != NULL);
+ return inf->control.stop_soon;
+}
+
+/* Wait for one event. Store the resulting waitstatus in WS, and
+ return the event ptid. */
+
+static ptid_t
+wait_one (struct target_waitstatus *ws)
+{
+ ptid_t event_ptid;
+ ptid_t wait_ptid = minus_one_ptid;
+
+ overlay_cache_invalid = 1;
+
+ /* Flush target cache before starting to handle each event.
+ Target was running and cache could be stale. This is just a
+ heuristic. Running threads may modify target memory, but we
+ don't get any event. */
+ target_dcache_invalidate ();
+
+ if (deprecated_target_wait_hook)
+ event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
+ else
+ event_ptid = target_wait (wait_ptid, ws, 0);
+
+ if (debug_infrun)
+ print_target_wait_results (wait_ptid, event_ptid, ws);
+
+ return event_ptid;
+}
+
+/* Generate a wrapper for target_stopped_by_REASON that works on PTID
+ instead of the current thread. */
+#define THREAD_STOPPED_BY(REASON) \
+static int \
+thread_stopped_by_ ## REASON (ptid_t ptid) \
+{ \
+ struct cleanup *old_chain; \
+ int res; \
+ \
+ old_chain = save_inferior_ptid (); \
+ inferior_ptid = ptid; \
+ \
+ res = target_stopped_by_ ## REASON (); \
+ \
+ do_cleanups (old_chain); \
+ \
+ return res; \
+}
+
+/* Generate thread_stopped_by_watchpoint. */
+THREAD_STOPPED_BY (watchpoint)
+/* Generate thread_stopped_by_sw_breakpoint. */
+THREAD_STOPPED_BY (sw_breakpoint)
+/* Generate thread_stopped_by_hw_breakpoint. */
+THREAD_STOPPED_BY (hw_breakpoint)
+
+/* Cleanups that switches to the PTID pointed at by PTID_P. */
+
+static void
+switch_to_thread_cleanup (void *ptid_p)
+{
+ ptid_t ptid = *(ptid_t *) ptid_p;
+
+ switch_to_thread (ptid);
+}
+
+/* Save the thread's event and stop reason to process it later. */
+
+static void
+save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
+{
+ struct regcache *regcache;
+ struct address_space *aspace;
+
+ if (debug_infrun)
+ {
+ char *statstr;
+
+ statstr = target_waitstatus_to_string (ws);
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: saving status %s for %d.%ld.%ld\n",
+ statstr,
+ ptid_get_pid (tp->ptid),
+ ptid_get_lwp (tp->ptid),
+ ptid_get_tid (tp->ptid));
+ xfree (statstr);
+ }
+
+ /* Record for later. */
+ tp->suspend.waitstatus = *ws;
+ tp->suspend.waitstatus_pending_p = 1;
+
+ regcache = get_thread_regcache (tp->ptid);
+ aspace = get_regcache_aspace (regcache);
+
+ if (ws->kind == TARGET_WAITKIND_STOPPED
+ && ws->value.sig == GDB_SIGNAL_TRAP)
+ {
+ CORE_ADDR pc = regcache_read_pc (regcache);
+
+ adjust_pc_after_break (tp, &tp->suspend.waitstatus);
+
+ if (thread_stopped_by_watchpoint (tp->ptid))
+ {
+ tp->suspend.stop_reason
+ = TARGET_STOPPED_BY_WATCHPOINT;
+ }
+ else if (target_supports_stopped_by_sw_breakpoint ()
+ && thread_stopped_by_sw_breakpoint (tp->ptid))
+ {
+ tp->suspend.stop_reason
+ = TARGET_STOPPED_BY_SW_BREAKPOINT;
+ }
+ else if (target_supports_stopped_by_hw_breakpoint ()
+ && thread_stopped_by_hw_breakpoint (tp->ptid))
+ {
+ tp->suspend.stop_reason
+ = TARGET_STOPPED_BY_HW_BREAKPOINT;
+ }
+ else if (!target_supports_stopped_by_hw_breakpoint ()
+ && hardware_breakpoint_inserted_here_p (aspace,
+ pc))
+ {
+ tp->suspend.stop_reason
+ = TARGET_STOPPED_BY_HW_BREAKPOINT;
+ }
+ else if (!target_supports_stopped_by_sw_breakpoint ()
+ && software_breakpoint_inserted_here_p (aspace,
+ pc))
+ {
+ tp->suspend.stop_reason
+ = TARGET_STOPPED_BY_SW_BREAKPOINT;
+ }
+ else if (!thread_has_single_step_breakpoints_set (tp)
+ && currently_stepping (tp))
+ {
+ tp->suspend.stop_reason
+ = TARGET_STOPPED_BY_SINGLE_STEP;
+ }
+ }
+}
+
+/* Stop all threads. */
+
+static void
+stop_all_threads (void)
{
- struct regcache *regcache;
- int syscall_number;
+ /* We may need multiple passes to discover all threads. */
+ int pass;
+ int iterations = 0;
+ ptid_t entry_ptid;
+ struct cleanup *old_chain;
- if (!ptid_equal (ecs->ptid, inferior_ptid))
- context_switch (ecs->ptid);
+ gdb_assert (target_is_non_stop_p ());
- regcache = get_thread_regcache (ecs->ptid);
- syscall_number = ecs->ws.value.syscall_number;
- stop_pc = regcache_read_pc (regcache);
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
- if (catch_syscall_enabled () > 0
- && catching_syscall_number (syscall_number) > 0)
+ entry_ptid = inferior_ptid;
+ old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
+
+ /* Request threads to stop, and then wait for the stops. Because
+ threads we already know about can spawn more threads while we're
+ trying to stop them, and we only learn about new threads when we
+ update the thread list, do this in a loop, and keep iterating
+ until two passes find no threads that need to be stopped. */
+ for (pass = 0; pass < 2; pass++, iterations++)
{
if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
- syscall_number);
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: stop_all_threads, pass=%d, "
+ "iterations=%d\n", pass, iterations);
+ while (1)
+ {
+ ptid_t event_ptid;
+ struct target_waitstatus ws;
+ int need_wait = 0;
+ struct thread_info *t;
- ecs->event_thread->control.stop_bpstat
- = bpstat_stop_status (get_regcache_aspace (regcache),
- stop_pc, ecs->ptid, &ecs->ws);
+ update_thread_list ();
- if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
- {
- /* Catchpoint hit. */
- return 0;
- }
- }
+ /* Go through all threads looking for threads that we need
+ to tell the target to stop. */
+ ALL_NON_EXITED_THREADS (t)
+ {
+ if (t->executing)
+ {
+ /* If already stopping, don't request a stop again.
+ We just haven't seen the notification yet. */
+ if (!t->stop_requested)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: %s executing, "
+ "need stop\n",
+ target_pid_to_str (t->ptid));
+ target_stop (t->ptid);
+ t->stop_requested = 1;
+ }
+ else
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: %s executing, "
+ "already stopping\n",
+ target_pid_to_str (t->ptid));
+ }
- /* If no catchpoint triggered for this, then keep going. */
- keep_going (ecs);
- return 1;
-}
+ if (t->stop_requested)
+ need_wait = 1;
+ }
+ else
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: %s not executing\n",
+ target_pid_to_str (t->ptid));
+
+ /* The thread may be not executing, but still be
+ resumed with a pending status to process. */
+ t->resumed = 0;
+ }
+ }
-/* Lazily fill in the execution_control_state's stop_func_* fields. */
+ if (!need_wait)
+ break;
-static void
-fill_in_stop_func (struct gdbarch *gdbarch,
- struct execution_control_state *ecs)
-{
- if (!ecs->stop_func_filled_in)
- {
- /* Don't care about return value; stop_func_start and stop_func_name
- will both be 0 if it doesn't work. */
- find_pc_partial_function (stop_pc, &ecs->stop_func_name,
- &ecs->stop_func_start, &ecs->stop_func_end);
- ecs->stop_func_start
- += gdbarch_deprecated_function_start_offset (gdbarch);
+ /* If we find new threads on the second iteration, restart
+ over. We want to see two iterations in a row with all
+ threads stopped. */
+ if (pass > 0)
+ pass = -1;
- if (gdbarch_skip_entrypoint_p (gdbarch))
- ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
- ecs->stop_func_start);
+ event_ptid = wait_one (&ws);
+ if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
+ {
+ /* All resumed threads exited. */
+ }
+ else if (ws.kind == TARGET_WAITKIND_EXITED
+ || ws.kind == TARGET_WAITKIND_SIGNALLED)
+ {
+ if (debug_infrun)
+ {
+ ptid_t ptid = pid_to_ptid (ws.value.integer);
- ecs->stop_func_filled_in = 1;
- }
-}
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: %s exited while "
+ "stopping threads\n",
+ target_pid_to_str (ptid));
+ }
+ }
+ else
+ {
+ t = find_thread_ptid (event_ptid);
+ if (t == NULL)
+ t = add_thread (event_ptid);
+ t->stop_requested = 0;
+ t->executing = 0;
+ t->resumed = 0;
+ t->control.may_range_step = 0;
-/* Return the STOP_SOON field of the inferior pointed at by PTID. */
+ if (ws.kind == TARGET_WAITKIND_STOPPED
+ && ws.value.sig == GDB_SIGNAL_0)
+ {
+ /* We caught the event that we intended to catch, so
+ there's no event pending. */
+ t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
+ t->suspend.waitstatus_pending_p = 0;
-static enum stop_kind
-get_inferior_stop_soon (ptid_t ptid)
-{
- struct inferior *inf = find_inferior_ptid (ptid);
+ if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
+ {
+ /* Add it back to the step-over queue. */
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: displaced-step of %s "
+ "canceled: adding back to the "
+ "step-over queue\n",
+ target_pid_to_str (t->ptid));
+ }
+ t->control.trap_expected = 0;
+ thread_step_over_chain_enqueue (t);
+ }
+ }
+ else
+ {
+ enum gdb_signal sig;
+ struct regcache *regcache;
+ struct address_space *aspace;
- gdb_assert (inf != NULL);
- return inf->control.stop_soon;
+ if (debug_infrun)
+ {
+ char *statstr;
+
+ statstr = target_waitstatus_to_string (&ws);
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: target_wait %s, saving "
+ "status for %d.%ld.%ld\n",
+ statstr,
+ ptid_get_pid (t->ptid),
+ ptid_get_lwp (t->ptid),
+ ptid_get_tid (t->ptid));
+ xfree (statstr);
+ }
+
+ /* Record for later. */
+ save_waitstatus (t, &ws);
+
+ sig = (ws.kind == TARGET_WAITKIND_STOPPED
+ ? ws.value.sig : GDB_SIGNAL_0);
+
+ if (displaced_step_fixup (t->ptid, sig) < 0)
+ {
+ /* Add it back to the step-over queue. */
+ t->control.trap_expected = 0;
+ thread_step_over_chain_enqueue (t);
+ }
+
+ regcache = get_thread_regcache (t->ptid);
+ t->suspend.stop_pc = regcache_read_pc (regcache);
+
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: saved stop_pc=%s for %s "
+ "(currently_stepping=%d)\n",
+ paddress (target_gdbarch (),
+ t->suspend.stop_pc),
+ target_pid_to_str (t->ptid),
+ currently_stepping (t));
+ }
+ }
+ }
+ }
+ }
+
+ do_cleanups (old_chain);
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
}
/* Given an execution control state that has been freshly filled in by
once). */
static void
-handle_inferior_event (struct execution_control_state *ecs)
+handle_inferior_event_1 (struct execution_control_state *ecs)
{
enum stop_kind stop_soon;
}
/* Dependent on valid ECS->EVENT_THREAD. */
- adjust_pc_after_break (ecs);
+ adjust_pc_after_break (ecs->event_thread, &ecs->ws);
/* Dependent on the current PC value modified by adjust_pc_after_break. */
reinit_frame_cache ();
/* Mark the non-executing threads accordingly. In all-stop, all
threads of all processes are stopped when we get any event
- reported. In non-stop mode, only the event thread stops. If
- we're handling a process exit in non-stop mode, there's nothing
- to do, as threads of the dead process are gone, and threads of
- any other process were left running. */
- if (!non_stop)
- set_executing (minus_one_ptid, 0);
- else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
- && ecs->ws.kind != TARGET_WAITKIND_EXITED)
- set_executing (ecs->ptid, 0);
+ reported. In non-stop mode, only the event thread stops. */
+ {
+ ptid_t mark_ptid;
+
+ if (!target_is_non_stop_p ())
+ mark_ptid = minus_one_ptid;
+ else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
+ || ecs->ws.kind == TARGET_WAITKIND_EXITED)
+ {
+ /* If we're handling a process exit in non-stop mode, even
+ though threads haven't been deleted yet, one would think
+ that there is nothing to do, as threads of the dead process
+ will be soon deleted, and threads of any other process were
+ left running. However, on some targets, threads survive a
+ process exit event. E.g., for the "checkpoint" command,
+ when the current checkpoint/fork exits, linux-fork.c
+ automatically switches to another fork from within
+ target_mourn_inferior, by associating the same
+ inferior/thread to another fork. We haven't mourned yet at
+ this point, but we must mark any threads left in the
+ process as not-executing so that finish_thread_state marks
+ them stopped (in the user's perspective) if/when we present
+ the stop to the user. */
+ mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
+ }
+ else
+ mark_ptid = ecs->ptid;
+
+ set_executing (mark_ptid, 0);
+
+ /* Likewise the resumed flag. */
+ set_resumed (mark_ptid, 0);
+ }
switch (ecs->ws.kind)
{
addresses. Make sure new breakpoints are inserted. */
if (stop_soon == NO_STOP_QUIETLY)
insert_breakpoints ();
- resume (0, GDB_SIGNAL_0);
+ resume (GDB_SIGNAL_0);
prepare_to_wait (ecs);
return;
}
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
if (!ptid_equal (ecs->ptid, inferior_ptid))
context_switch (ecs->ptid);
- resume (0, GDB_SIGNAL_0);
+ resume (GDB_SIGNAL_0);
prepare_to_wait (ecs);
return;
that this operation also cleans up the child process for vfork,
because their pages are shared. */
displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
+ /* Start a new step-over in another thread if there's one
+ that needs it. */
+ start_step_over ();
if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
{
child = ecs->ws.value.related_pid;
/* In non-stop mode, also resume the other branch. */
- if (non_stop && !detach_fork)
+ if (!detach_fork && (non_stop
+ || (sched_multi && target_is_non_stop_p ())))
{
if (follow_child)
switch_to_thread (parent);
}
}
+/* A wrapper around handle_inferior_event_1, which also makes sure
+ that all temporary struct value objects that were created during
+ the handling of the event get deleted at the end. */
+
+static void
+handle_inferior_event (struct execution_control_state *ecs)
+{
+ struct value *mark = value_mark ();
+
+ handle_inferior_event_1 (ecs);
+ /* Purge all temporary values created during the event handling,
+ as it could be a long time before we return to the command level
+ where such values would otherwise be purged. */
+ value_free_to_mark (mark);
+}
+
+/* Restart threads back to what they were trying to do back when we
+ paused them for an in-line step-over. The EVENT_THREAD thread is
+ ignored. */
+
+static void
+restart_threads (struct thread_info *event_thread)
+{
+ struct thread_info *tp;
+ struct thread_info *step_over = NULL;
+
+ /* In case the instruction just stepped spawned a new thread. */
+ update_thread_list ();
+
+ ALL_NON_EXITED_THREADS (tp)
+ {
+ if (tp == event_thread)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: restart threads: "
+ "[%s] is event thread\n",
+ target_pid_to_str (tp->ptid));
+ continue;
+ }
+
+ if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: restart threads: "
+ "[%s] not meant to be running\n",
+ target_pid_to_str (tp->ptid));
+ continue;
+ }
+
+ if (tp->resumed)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: restart threads: [%s] resumed\n",
+ target_pid_to_str (tp->ptid));
+ gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
+ continue;
+ }
+
+ if (thread_is_in_step_over_chain (tp))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: restart threads: "
+ "[%s] needs step-over\n",
+ target_pid_to_str (tp->ptid));
+ gdb_assert (!tp->resumed);
+ continue;
+ }
+
+
+ if (tp->suspend.waitstatus_pending_p)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: restart threads: "
+ "[%s] has pending status\n",
+ target_pid_to_str (tp->ptid));
+ tp->resumed = 1;
+ continue;
+ }
+
+ /* If some thread needs to start a step-over at this point, it
+ should still be in the step-over queue, and thus skipped
+ above. */
+ if (thread_still_needs_step_over (tp))
+ {
+ internal_error (__FILE__, __LINE__,
+ "thread [%s] needs a step-over, but not in "
+ "step-over queue\n",
+ target_pid_to_str (tp->ptid));
+ }
+
+ if (currently_stepping (tp))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: restart threads: [%s] was stepping\n",
+ target_pid_to_str (tp->ptid));
+ keep_going_stepped_thread (tp);
+ }
+ else
+ {
+ struct execution_control_state ecss;
+ struct execution_control_state *ecs = &ecss;
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: restart threads: [%s] continuing\n",
+ target_pid_to_str (tp->ptid));
+ reset_ecs (ecs, tp);
+ switch_to_thread (tp->ptid);
+ keep_going_pass_signal (ecs);
+ }
+ }
+}
+
+/* Callback for iterate_over_threads. Find a resumed thread that has
+ a pending waitstatus. */
+
+static int
+resumed_thread_with_pending_status (struct thread_info *tp,
+ void *arg)
+{
+ return (tp->resumed
+ && tp->suspend.waitstatus_pending_p);
+}
+
+/* Called when we get an event that may finish an in-line or
+ out-of-line (displaced stepping) step-over started previously.
+ Return true if the event is processed and we should go back to the
+ event loop; false if the caller should continue processing the
+ event. */
+
+static int
+finish_step_over (struct execution_control_state *ecs)
+{
+ int had_step_over_info;
+
+ displaced_step_fixup (ecs->ptid,
+ ecs->event_thread->suspend.stop_signal);
+
+ had_step_over_info = step_over_info_valid_p ();
+
+ if (had_step_over_info)
+ {
+ /* If we're stepping over a breakpoint with all threads locked,
+ then only the thread that was stepped should be reporting
+ back an event. */
+ gdb_assert (ecs->event_thread->control.trap_expected);
+
+ if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
+ clear_step_over_info ();
+ }
+
+ if (!target_is_non_stop_p ())
+ return 0;
+
+ /* Start a new step-over in another thread if there's one that
+ needs it. */
+ start_step_over ();
+
+ /* If we were stepping over a breakpoint before, and haven't started
+ a new in-line step-over sequence, then restart all other threads
+ (except the event thread). We can't do this in all-stop, as then
+ e.g., we wouldn't be able to issue any other remote packet until
+ these other threads stop. */
+ if (had_step_over_info && !step_over_info_valid_p ())
+ {
+ struct thread_info *pending;
+
+ /* If we only have threads with pending statuses, the restart
+ below won't restart any thread and so nothing re-inserts the
+ breakpoint we just stepped over. But we need it inserted
+ when we later process the pending events, otherwise if
+ another thread has a pending event for this breakpoint too,
+ we'd discard its event (because the breakpoint that
+ originally caused the event was no longer inserted). */
+ context_switch (ecs->ptid);
+ insert_breakpoints ();
+
+ restart_threads (ecs->event_thread);
+
+ /* If we have events pending, go through handle_inferior_event
+ again, picking up a pending event at random. This avoids
+ thread starvation. */
+
+ /* But not if we just stepped over a watchpoint in order to let
+ the instruction execute so we can evaluate its expression.
+ The set of watchpoints that triggered is recorded in the
+ breakpoint objects themselves (see bp->watchpoint_triggered).
+ If we processed another event first, that other event could
+ clobber this info. */
+ if (ecs->event_thread->stepping_over_watchpoint)
+ return 0;
+
+ pending = iterate_over_threads (resumed_thread_with_pending_status,
+ NULL);
+ if (pending != NULL)
+ {
+ struct thread_info *tp = ecs->event_thread;
+ struct regcache *regcache;
+
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: found resumed threads with "
+ "pending events, saving status\n");
+ }
+
+ gdb_assert (pending != tp);
+
+ /* Record the event thread's event for later. */
+ save_waitstatus (tp, &ecs->ws);
+ /* This was cleared early, by handle_inferior_event. Set it
+ so this pending event is considered by
+ do_target_wait. */
+ tp->resumed = 1;
+
+ gdb_assert (!tp->executing);
+
+ regcache = get_thread_regcache (tp->ptid);
+ tp->suspend.stop_pc = regcache_read_pc (regcache);
+
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: saved stop_pc=%s for %s "
+ "(currently_stepping=%d)\n",
+ paddress (target_gdbarch (),
+ tp->suspend.stop_pc),
+ target_pid_to_str (tp->ptid),
+ currently_stepping (tp));
+ }
+
+ /* This in-line step-over finished; clear this so we won't
+ start a new one. This is what handle_signal_stop would
+ do, if we returned false. */
+ tp->stepping_over_breakpoint = 0;
+
+ /* Wake up the event loop again. */
+ mark_async_event_handler (infrun_async_inferior_event_token);
+
+ prepare_to_wait (ecs);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
/* Come here when the program has stopped with a signal. */
static void
/* Do we need to clean up the state of a thread that has
completed a displaced single-step? (Doing so usually affects
the PC, so do it here, before we set stop_pc.) */
- displaced_step_fixup (ecs->ptid,
- ecs->event_thread->suspend.stop_signal);
+ if (finish_step_over (ecs))
+ return;
/* If we either finished a single-step or hit a breakpoint, but
the user wanted this thread to be stopped, pretend we got a
be necessary for call dummies on a non-executable stack on
SPARC. */
- /* See if the breakpoints module can explain the signal. */
- random_signal
- = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
- ecs->event_thread->suspend.stop_signal);
+ /* See if the breakpoints module can explain the signal. */
+ random_signal
+ = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
+ ecs->event_thread->suspend.stop_signal);
+
+ /* Maybe this was a trap for a software breakpoint that has since
+ been removed. */
+ if (random_signal && target_stopped_by_sw_breakpoint ())
+ {
+ if (program_breakpoint_here_p (gdbarch, stop_pc))
+ {
+ struct regcache *regcache;
+ int decr_pc;
+
+ /* Re-adjust PC to what the program would see if GDB was not
+ debugging it. */
+ regcache = get_thread_regcache (ecs->event_thread->ptid);
+ decr_pc = gdbarch_decr_pc_after_break (gdbarch);
+ if (decr_pc != 0)
+ {
+ struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
+
+ if (record_full_is_used ())
+ record_full_gdb_operation_disable_set ();
+
+ regcache_write_pc (regcache, stop_pc + decr_pc);
+
+ do_cleanups (old_cleanups);
+ }
+ }
+ else
+ {
+ /* A delayed software breakpoint event. Ignore the trap. */
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: delayed software breakpoint "
+ "trap, ignoring\n");
+ random_signal = 0;
+ }
+ }
+
+ /* Maybe this was a trap for a hardware breakpoint/watchpoint that
+ has since been removed. */
+ if (random_signal && target_stopped_by_hw_breakpoint ())
+ {
+ /* A delayed hardware breakpoint event. Ignore the trap. */
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: delayed hardware breakpoint/watchpoint "
+ "trap, ignoring\n");
+ random_signal = 0;
+ }
/* If not, perhaps stepping/nexting can. */
if (random_signal)
&& ecs->event_thread->control.trap_expected
&& ecs->event_thread->control.step_resume_breakpoint == NULL)
{
+ int was_in_line;
+
/* We were just starting a new sequence, attempting to
single-step off of a breakpoint and expecting a SIGTRAP.
Instead this signal arrives. This signal will take us out
"infrun: signal arrived while stepping over "
"breakpoint\n");
+ was_in_line = step_over_info_valid_p ();
+ clear_step_over_info ();
insert_hp_step_resume_breakpoint_at_frame (frame);
ecs->event_thread->step_after_step_resume_breakpoint = 1;
/* Reset trap_expected to ensure breakpoints are re-inserted. */
ecs->event_thread->control.trap_expected = 0;
+ if (target_is_non_stop_p ())
+ {
+ /* Either "set non-stop" is "on", or the target is
+ always in non-stop mode. In this case, we have a bit
+ more work to do. Resume the current thread, and if
+ we had paused all threads, restart them while the
+ signal handler runs. */
+ keep_going (ecs);
+
+ if (was_in_line)
+ {
+ restart_threads (ecs->event_thread);
+ }
+ else if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: no need to restart threads\n");
+ }
+ return;
+ }
+
/* If we were nexting/stepping some other thread, switch to
it, so that we don't continue it, losing control. */
if (!switch_back_to_stepped_thread (ecs))
"infrun: signal may take us out of "
"single-step range\n");
+ clear_step_over_info ();
insert_hp_step_resume_breakpoint_at_frame (frame);
ecs->event_thread->step_after_step_resume_breakpoint = 1;
/* Reset trap_expected to ensure breakpoints are re-inserted. */
struct breakpoint *sr_bp
= ecs->event_thread->control.step_resume_breakpoint;
- if (sr_bp->loc->permanent
+ if (sr_bp != NULL
+ && sr_bp->loc->permanent
&& sr_bp->type == bp_hp_step_resume
&& sr_bp->loc->address == ecs->event_thread->prev_pc)
{
ecs->event_thread->control.step_stack_frame_id)
&& (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
outer_frame_id)
- || step_start_function != find_pc_function (stop_pc))))
+ || (ecs->event_thread->control.step_start_function
+ != find_pc_function (stop_pc)))))
{
CORE_ADDR real_stop_pc;
static int
switch_back_to_stepped_thread (struct execution_control_state *ecs)
{
- if (!non_stop)
+ if (!target_is_non_stop_p ())
{
struct thread_info *tp;
struct thread_info *stepping_thread;
- struct thread_info *step_over;
/* If any thread is blocked on some internal breakpoint, and we
simply need to step over that breakpoint to get it going
return 1;
}
+ /* If this thread needs yet another step-over (e.g., stepping
+ through a delay slot), do it first before moving on to
+ another thread. */
+ if (thread_still_needs_step_over (ecs->event_thread))
+ {
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: thread [%s] still needs step-over\n",
+ target_pid_to_str (ecs->event_thread->ptid));
+ }
+ keep_going (ecs);
+ return 1;
+ }
+
+ /* If scheduler locking applies even if not stepping, there's no
+ need to walk over threads. Above we've checked whether the
+ current thread is stepping. If some other thread not the
+ event thread is stepping, then it must be that scheduler
+ locking is not in effect. */
+ if (schedlock_applies (ecs->event_thread))
+ return 0;
+
/* Otherwise, we no longer expect a trap in the current thread.
Clear the trap_expected flag before switching back -- this is
what keep_going does as well, if we call it. */
if (!signal_program[ecs->event_thread->suspend.stop_signal])
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
- /* If scheduler locking applies even if not stepping, there's no
- need to walk over threads. Above we've checked whether the
- current thread is stepping. If some other thread not the
- event thread is stepping, then it must be that scheduler
- locking is not in effect. */
- if (schedlock_applies (0))
- return 0;
-
- /* Look for the stepping/nexting thread, and check if any other
- thread other than the stepping thread needs to start a
- step-over. Do all step-overs before actually proceeding with
+ /* Do all pending step-overs before actually proceeding with
step/next/etc. */
+ if (start_step_over ())
+ {
+ prepare_to_wait (ecs);
+ return 1;
+ }
+
+ /* Look for the stepping/nexting thread. */
stepping_thread = NULL;
- step_over = NULL;
+
ALL_NON_EXITED_THREADS (tp)
{
- /* Ignore threads of processes we're not resuming. */
+ /* Ignore threads of processes the caller is not
+ resuming. */
if (!sched_multi
- && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
+ && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
continue;
/* When stepping over a breakpoint, we lock all threads
except the one that needs to move past the breakpoint.
If a non-event thread has this set, the "incomplete
step-over" check above should have caught it earlier. */
- gdb_assert (!tp->control.trap_expected);
+ if (tp->control.trap_expected)
+ {
+ internal_error (__FILE__, __LINE__,
+ "[%s] has inconsistent state: "
+ "trap_expected=%d\n",
+ target_pid_to_str (tp->ptid),
+ tp->control.trap_expected);
+ }
/* Did we find the stepping thread? */
if (tp->control.step_range_end)
stepping, then scheduler locking can't be in effect,
otherwise we wouldn't have resumed the current event
thread in the first place. */
- gdb_assert (!schedlock_applies (currently_stepping (tp)));
+ gdb_assert (!schedlock_applies (tp));
stepping_thread = tp;
}
- else if (thread_still_needs_step_over (tp))
- {
- step_over = tp;
-
- /* At the top we've returned early if the event thread
- is stepping. If some other thread not the event
- thread is stepping, then scheduler locking can't be
- in effect, and we can resume this thread. No need to
- keep looking for the stepping thread then. */
- break;
- }
}
- if (step_over != NULL)
+ if (stepping_thread != NULL)
{
- tp = step_over;
if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: switching back to stepped thread\n");
+
+ if (keep_going_stepped_thread (stepping_thread))
{
- fprintf_unfiltered (gdb_stdlog,
- "infrun: need to step-over [%s]\n",
- target_pid_to_str (tp->ptid));
+ prepare_to_wait (ecs);
+ return 1;
}
+ }
+ }
- /* Only the stepping thread should have this set. */
- gdb_assert (tp->control.step_range_end == 0);
+ return 0;
+}
- ecs->ptid = tp->ptid;
- ecs->event_thread = tp;
- switch_to_thread (ecs->ptid);
- keep_going (ecs);
- return 1;
- }
+/* Set a previously stepped thread back to stepping. Returns true on
+ success, false if the resume is not possible (e.g., the thread
+ vanished). */
- if (stepping_thread != NULL)
- {
- struct frame_info *frame;
- struct gdbarch *gdbarch;
+static int
+keep_going_stepped_thread (struct thread_info *tp)
+{
+ struct frame_info *frame;
+ struct gdbarch *gdbarch;
+ struct execution_control_state ecss;
+ struct execution_control_state *ecs = &ecss;
- tp = stepping_thread;
-
- /* If the stepping thread exited, then don't try to switch
- back and resume it, which could fail in several different
- ways depending on the target. Instead, just keep going.
-
- We can find a stepping dead thread in the thread list in
- two cases:
-
- - The target supports thread exit events, and when the
- target tries to delete the thread from the thread list,
- inferior_ptid pointed at the exiting thread. In such
- case, calling delete_thread does not really remove the
- thread from the list; instead, the thread is left listed,
- with 'exited' state.
-
- - The target's debug interface does not support thread
- exit events, and so we have no idea whatsoever if the
- previously stepping thread is still alive. For that
- reason, we need to synchronously query the target
- now. */
- if (is_exited (tp->ptid)
- || !target_thread_alive (tp->ptid))
- {
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog,
- "infrun: not switching back to "
- "stepped thread, it has vanished\n");
+ /* If the stepping thread exited, then don't try to switch back and
+ resume it, which could fail in several different ways depending
+ on the target. Instead, just keep going.
- delete_thread (tp->ptid);
- keep_going (ecs);
- return 1;
- }
+ We can find a stepping dead thread in the thread list in two
+ cases:
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog,
- "infrun: switching back to stepped thread\n");
+ - The target supports thread exit events, and when the target
+ tries to delete the thread from the thread list, inferior_ptid
+ pointed at the exiting thread. In such case, calling
+ delete_thread does not really remove the thread from the list;
+ instead, the thread is left listed, with 'exited' state.
- ecs->event_thread = tp;
- ecs->ptid = tp->ptid;
- context_switch (ecs->ptid);
+ - The target's debug interface does not support thread exit
+ events, and so we have no idea whatsoever if the previously
+ stepping thread is still alive. For that reason, we need to
+ synchronously query the target now. */
- stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
- frame = get_current_frame ();
- gdbarch = get_frame_arch (frame);
+ if (is_exited (tp->ptid)
+ || !target_thread_alive (tp->ptid))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: not resuming previously "
+ "stepped thread, it has vanished\n");
- /* If the PC of the thread we were trying to single-step has
- changed, then that thread has trapped or been signaled,
- but the event has not been reported to GDB yet. Re-poll
- the target looking for this particular thread's event
- (i.e. temporarily enable schedlock) by:
+ delete_thread (tp->ptid);
+ return 0;
+ }
- - setting a break at the current PC
- - resuming that particular thread, only (by setting
- trap expected)
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: resuming previously stepped thread\n");
- This prevents us continuously moving the single-step
- breakpoint forward, one instruction at a time,
- overstepping. */
+ reset_ecs (ecs, tp);
+ switch_to_thread (tp->ptid);
- if (stop_pc != tp->prev_pc)
- {
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog,
- "infrun: expected thread advanced also\n");
-
- /* Clear the info of the previous step-over, as it's no
- longer valid. It's what keep_going would do too, if
- we called it. Must do this before trying to insert
- the sss breakpoint, otherwise if we were previously
- trying to step over this exact address in another
- thread, the breakpoint ends up not installed. */
- clear_step_over_info ();
-
- insert_single_step_breakpoint (get_frame_arch (frame),
- get_frame_address_space (frame),
- stop_pc);
- ecs->event_thread->control.trap_expected = 1;
-
- resume (0, GDB_SIGNAL_0);
- prepare_to_wait (ecs);
- }
- else
- {
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog,
- "infrun: expected thread still "
- "hasn't advanced\n");
- keep_going (ecs);
- }
+ stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
+ frame = get_current_frame ();
+ gdbarch = get_frame_arch (frame);
- return 1;
- }
+ /* If the PC of the thread we were trying to single-step has
+ changed, then that thread has trapped or been signaled, but the
+ event has not been reported to GDB yet. Re-poll the target
+ looking for this particular thread's event (i.e. temporarily
+ enable schedlock) by:
+
+ - setting a break at the current PC
+ - resuming that particular thread, only (by setting trap
+ expected)
+
+ This prevents us continuously moving the single-step breakpoint
+ forward, one instruction at a time, overstepping. */
+
+ if (stop_pc != tp->prev_pc)
+ {
+ ptid_t resume_ptid;
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: expected thread advanced also (%s -> %s)\n",
+ paddress (target_gdbarch (), tp->prev_pc),
+ paddress (target_gdbarch (), stop_pc));
+
+ /* Clear the info of the previous step-over, as it's no longer
+ valid (if the thread was trying to step over a breakpoint, it
+ has already succeeded). It's what keep_going would do too,
+ if we called it. Do this before trying to insert the sss
+ breakpoint, otherwise if we were previously trying to step
+ over this exact address in another thread, the breakpoint is
+ skipped. */
+ clear_step_over_info ();
+ tp->control.trap_expected = 0;
+
+ insert_single_step_breakpoint (get_frame_arch (frame),
+ get_frame_address_space (frame),
+ stop_pc);
+
+ tp->resumed = 1;
+ resume_ptid = internal_resume_ptid (tp->control.stepping_command);
+ do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
}
- return 0;
+ else
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: expected thread still hasn't advanced\n");
+
+ keep_going_pass_signal (ecs);
+ }
+ return 1;
}
-/* Is thread TP in the middle of single-stepping? */
+/* Is thread TP in the middle of (software or hardware)
+ single-stepping? (Note the result of this function must never be
+ passed directly as target_resume's STEP parameter.) */
static int
currently_stepping (struct thread_info *tp)
struct frame_info *frame,
struct symbol *sym)
{
- volatile struct gdb_exception e;
-
- /* We want to ignore errors here. */
- TRY_CATCH (e, RETURN_MASK_ERROR)
+ TRY
{
struct symbol *vsym;
struct value *value;
CORE_ADDR handler;
struct breakpoint *bp;
- vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
+ vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN,
+ NULL).symbol;
value = read_var_value (vsym, frame);
/* If the value was optimized out, revert to the old behavior. */
if (! value_optimized_out (value))
inferior_thread ()->control.exception_resume_breakpoint = bp;
}
}
+ CATCH (e, RETURN_MASK_ERROR)
+ {
+ /* We want to ignore errors here. */
+ }
+ END_CATCH
}
/* A helper for check_exception_resume that sets an
check_exception_resume (struct execution_control_state *ecs,
struct frame_info *frame)
{
- volatile struct gdb_exception e;
struct bound_probe probe;
struct symbol *func;
if (!func)
return;
- TRY_CATCH (e, RETURN_MASK_ERROR)
+ TRY
{
const struct block *b;
struct block_iterator iter;
}
}
}
+ CATCH (e, RETURN_MASK_ERROR)
+ {
+ }
+ END_CATCH
}
static void
/* Let callers know we don't want to wait for the inferior anymore. */
ecs->wait_some_more = 0;
+
+ /* If all-stop, but the target is always in non-stop mode, stop all
+ threads now that we're presenting the stop to the user. */
+ if (!non_stop && target_is_non_stop_p ())
+ stop_all_threads ();
}
-/* Called when we should continue running the inferior, because the
- current event doesn't cause a user visible stop. This does the
- resuming part; waiting for the next event is done elsewhere. */
+/* Like keep_going, but passes the signal to the inferior, even if the
+ signal is set to nopass. */
static void
-keep_going (struct execution_control_state *ecs)
+keep_going_pass_signal (struct execution_control_state *ecs)
{
/* Make sure normal_stop is called if we get a QUIT handled before
reaching resume. */
struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
+ gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
+ gdb_assert (!ecs->event_thread->resumed);
+
/* Save the pc before execution, to compare with pc after stop. */
ecs->event_thread->prev_pc
= regcache_read_pc (get_thread_regcache (ecs->ptid));
- if (ecs->event_thread->control.trap_expected
- && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
+ if (ecs->event_thread->control.trap_expected)
{
+ struct thread_info *tp = ecs->event_thread;
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: %s has trap_expected set, "
+ "resuming to collect trap\n",
+ target_pid_to_str (tp->ptid));
+
/* We haven't yet gotten our trap, and either: intercepted a
non-signal event (e.g., a fork); or took a signal which we
are supposed to pass through to the inferior. Simply
continue. */
discard_cleanups (old_cleanups);
- resume (currently_stepping (ecs->event_thread),
- ecs->event_thread->suspend.stop_signal);
+ resume (ecs->event_thread->suspend.stop_signal);
+ }
+ else if (step_over_info_valid_p ())
+ {
+ /* Another thread is stepping over a breakpoint in-line. If
+ this thread needs a step-over too, queue the request. In
+ either case, this resume must be deferred for later. */
+ struct thread_info *tp = ecs->event_thread;
+
+ if (ecs->hit_singlestep_breakpoint
+ || thread_still_needs_step_over (tp))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: step-over already in progress: "
+ "step-over for %s deferred\n",
+ target_pid_to_str (tp->ptid));
+ thread_step_over_chain_enqueue (tp);
+ }
+ else
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: step-over in progress: "
+ "resume of %s deferred\n",
+ target_pid_to_str (tp->ptid));
+ }
+
+ discard_cleanups (old_cleanups);
}
else
{
- volatile struct gdb_exception e;
struct regcache *regcache = get_current_regcache ();
int remove_bp;
int remove_wps;
+ enum step_over_what step_what;
/* Either the trap was not expected, but we are continuing
anyway (if we got a signal, the user asked it be passed to
instruction, and then re-insert the breakpoint when that step
is finished. */
- remove_bp = (ecs->hit_singlestep_breakpoint
- || thread_still_needs_step_over (ecs->event_thread));
- remove_wps = (ecs->event_thread->stepping_over_watchpoint
- && !target_have_steppable_watchpoint);
+ step_what = thread_still_needs_step_over (ecs->event_thread);
- if (remove_bp && !use_displaced_stepping (get_regcache_arch (regcache)))
+ remove_bp = (ecs->hit_singlestep_breakpoint
+ || (step_what & STEP_OVER_BREAKPOINT));
+ remove_wps = (step_what & STEP_OVER_WATCHPOINT);
+
+ /* We can't use displaced stepping if we need to step past a
+ watchpoint. The instruction copied to the scratch pad would
+ still trigger the watchpoint. */
+ if (remove_bp
+ && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
{
set_step_over_info (get_regcache_aspace (regcache),
regcache_read_pc (regcache), remove_wps);
}
else if (remove_wps)
set_step_over_info (NULL, 0, remove_wps);
- else
- clear_step_over_info ();
+
+ /* If we now need to do an in-line step-over, we need to stop
+ all other threads. Note this must be done before
+ insert_breakpoints below, because that removes the breakpoint
+ we're about to step over, otherwise other threads could miss
+ it. */
+ if (step_over_info_valid_p () && target_is_non_stop_p ())
+ stop_all_threads ();
/* Stop stepping if inserting breakpoints fails. */
- TRY_CATCH (e, RETURN_MASK_ERROR)
+ TRY
{
insert_breakpoints ();
}
- if (e.reason < 0)
+ CATCH (e, RETURN_MASK_ERROR)
{
exception_print (gdb_stderr, e);
stop_waiting (ecs);
+ discard_cleanups (old_cleanups);
return;
}
+ END_CATCH
ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
- /* Do not deliver GDB_SIGNAL_TRAP (except when the user
- explicitly specifies that such a signal should be delivered
- to the target program). Typically, that would occur when a
- user is debugging a target monitor on a simulator: the target
- monitor sets a breakpoint; the simulator encounters this
- breakpoint and halts the simulation handing control to GDB;
- GDB, noting that the stop address doesn't map to any known
- breakpoint, returns control back to the simulator; the
- simulator then delivers the hardware equivalent of a
- GDB_SIGNAL_TRAP to the program being debugged. */
- if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
- && !signal_program[ecs->event_thread->suspend.stop_signal])
- ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
-
discard_cleanups (old_cleanups);
- resume (currently_stepping (ecs->event_thread),
- ecs->event_thread->suspend.stop_signal);
+ resume (ecs->event_thread->suspend.stop_signal);
}
prepare_to_wait (ecs);
}
+/* Called when we should continue running the inferior, because the
+ current event doesn't cause a user visible stop. This does the
+ resuming part; waiting for the next event is done elsewhere. */
+
+static void
+keep_going (struct execution_control_state *ecs)
+{
+ if (ecs->event_thread->control.trap_expected
+ && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
+ ecs->event_thread->control.trap_expected = 0;
+
+ if (!signal_program[ecs->event_thread->suspend.stop_signal])
+ ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
+ keep_going_pass_signal (ecs);
+}
+
/* This function normally comes after a resume, before
handle_inferior_event exits. It takes care of any last bits of
housekeeping, and sets the all-important wait_some_more flag. */
print_stop_event (struct target_waitstatus *ws)
{
int bpstat_ret;
- int source_flag;
+ enum print_what source_flag;
int do_frame_printing = 1;
struct thread_info *tp = inferior_thread ();
if (tp->control.stop_step
&& frame_id_eq (tp->control.step_frame_id,
get_frame_id (get_current_frame ()))
- && step_start_function == find_pc_function (stop_pc))
+ && tp->control.step_start_function == find_pc_function (stop_pc))
{
/* Finished step, just print source line. */
source_flag = SRC_LINE;
struct target_waitstatus last;
ptid_t last_ptid;
struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
+ ptid_t pid_ptid;
get_last_target_status (&last_ptid, &last);
here, so do this before any filtered output. */
if (!non_stop)
make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
- else if (last.kind != TARGET_WAITKIND_SIGNALLED
- && last.kind != TARGET_WAITKIND_EXITED
- && last.kind != TARGET_WAITKIND_NO_RESUMED)
+ else if (last.kind == TARGET_WAITKIND_SIGNALLED
+ || last.kind == TARGET_WAITKIND_EXITED)
+ {
+ /* On some targets, we may still have live threads in the
+ inferior when we get a process exit event. E.g., for
+ "checkpoint", when the current checkpoint/fork exits,
+ linux-fork.c automatically switches to another fork from
+ within target_mourn_inferior. */
+ if (!ptid_equal (inferior_ptid, null_ptid))
+ {
+ pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
+ make_cleanup (finish_thread_state_cleanup, &pid_ptid);
+ }
+ }
+ else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
/* As we're presenting a stop, and potentially removing breakpoints,
if (has_stack_frames () && !stop_stack_dummy)
set_current_sal_from_frame (get_current_frame ());
- /* Let the user/frontend see the threads as stopped, but do nothing
- if the thread was running an infcall. We may be e.g., evaluating
- a breakpoint condition. In that case, the thread had state
- THREAD_RUNNING before the infcall, and shall remain set to
- running, all without informing the user/frontend about state
- transition changes. If this is actually a call command, then the
- thread was originally already stopped, so there's no state to
- finish either. */
- if (target_has_execution && inferior_thread ()->control.in_infcall)
+ /* Let the user/frontend see the threads as stopped, but defer to
+ call_function_by_hand if the thread finished an infcall
+ successfully. We may be e.g., evaluating a breakpoint condition.
+ In that case, the thread had state THREAD_RUNNING before the
+ infcall, and shall remain marked running, all without informing
+ the user/frontend about state transition changes. */
+ if (target_has_execution
+ && inferior_thread ()->control.in_infcall
+ && stop_stack_dummy == STOP_STACK_DUMMY)
discard_cleanups (old_chain);
else
do_cleanups (old_chain);
print_stop_event (&last);
}
- /* Save the function value return registers, if we care.
- We might be about to restore their previous contents. */
- if (inferior_thread ()->control.proceed_to_finish
- && execution_direction != EXEC_REVERSE)
- {
- /* This should not be necessary. */
- if (stop_registers)
- regcache_xfree (stop_registers);
-
- /* NB: The copy goes through to the target picking up the value of
- all the registers. */
- stop_registers = regcache_dup (get_current_regcache ());
- }
-
if (stop_stack_dummy == STOP_STACK_DUMMY)
{
/* Pop the empty frame that contains the stack dummy.
sig_print_header ();
for (; signum < nsigs; signum++)
if (sigs[signum])
- sig_print_info (signum);
+ sig_print_info ((enum gdb_signal) signum);
}
break;
return return_val;
}
-static void
-xdb_handle_command (char *args, int from_tty)
-{
- char **argv;
- struct cleanup *old_chain;
-
- if (args == NULL)
- error_no_arg (_("xdb command"));
-
- /* Break the command line up into args. */
-
- argv = gdb_buildargv (args);
- old_chain = make_cleanup_freeargv (argv);
- if (argv[1] != (char *) NULL)
- {
- char *argBuf;
- int bufLen;
-
- bufLen = strlen (argv[0]) + 20;
- argBuf = (char *) xmalloc (bufLen);
- if (argBuf)
- {
- int validFlag = 1;
- enum gdb_signal oursig;
-
- oursig = gdb_signal_from_name (argv[0]);
- memset (argBuf, 0, bufLen);
- if (strcmp (argv[1], "Q") == 0)
- sprintf (argBuf, "%s %s", argv[0], "noprint");
- else
- {
- if (strcmp (argv[1], "s") == 0)
- {
- if (!signal_stop[oursig])
- sprintf (argBuf, "%s %s", argv[0], "stop");
- else
- sprintf (argBuf, "%s %s", argv[0], "nostop");
- }
- else if (strcmp (argv[1], "i") == 0)
- {
- if (!signal_program[oursig])
- sprintf (argBuf, "%s %s", argv[0], "pass");
- else
- sprintf (argBuf, "%s %s", argv[0], "nopass");
- }
- else if (strcmp (argv[1], "r") == 0)
- {
- if (!signal_print[oursig])
- sprintf (argBuf, "%s %s", argv[0], "print");
- else
- sprintf (argBuf, "%s %s", argv[0], "noprint");
- }
- else
- validFlag = 0;
- }
- if (validFlag)
- handle_command (argBuf, from_tty);
- else
- printf_filtered (_("Invalid signal handling flag.\n"));
- if (argBuf)
- xfree (argBuf);
- }
- }
- do_cleanups (old_chain);
-}
-
enum gdb_signal
gdb_signal_from_command (int num)
{
struct infcall_suspend_state
{
struct thread_suspend_state thread_suspend;
-#if 0 /* Currently unused and empty structures are not valid C. */
- struct inferior_suspend_state inferior_suspend;
-#endif
/* Other fields: */
CORE_ADDR stop_pc;
{
struct infcall_suspend_state *inf_state;
struct thread_info *tp = inferior_thread ();
-#if 0
- struct inferior *inf = current_inferior ();
-#endif
struct regcache *regcache = get_current_regcache ();
struct gdbarch *gdbarch = get_regcache_arch (regcache);
gdb_byte *siginfo_data = NULL;
}
inf_state->thread_suspend = tp->suspend;
-#if 0 /* Currently unused and empty structures are not valid C. */
- inf_state->inferior_suspend = inf->suspend;
-#endif
/* run_inferior_call will not use the signal due to its `proceed' call with
GDB_SIGNAL_0 anyway. */
restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
{
struct thread_info *tp = inferior_thread ();
-#if 0
- struct inferior *inf = current_inferior ();
-#endif
struct regcache *regcache = get_current_regcache ();
struct gdbarch *gdbarch = get_regcache_arch (regcache);
tp->suspend = inf_state->thread_suspend;
-#if 0 /* Currently unused and empty structures are not valid C. */
- inf->suspend = inf_state->inferior_suspend;
-#endif
stop_pc = inf_state->stop_pc;
NULL
};
+/* Callback for infrun's target events source. This is marked when a
+ thread has a pending status to process. */
+
+static void
+infrun_async_inferior_event_handler (gdb_client_data data)
+{
+ /* If the target is closed while this event source is marked, we
+ will reach here without execution, or a target to call
+ target_wait on, which is an error. Instead of tracking whether
+ the target has been popped already, or whether we do have threads
+ with pending statutes, simply ignore the event. */
+ if (!target_is_async_p ())
+ return;
+
+ inferior_event_handler (INF_REG_EVENT, NULL);
+}
+
void
_initialize_infrun (void)
{
int numsigs;
struct cmd_list_element *c;
+ /* Register extra event sources in the event loop. */
+ infrun_async_inferior_event_token
+ = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
+
add_info ("signals", signals_info, _("\
What debugger does when program gets various signals.\n\
Specify a signal as argument to print info on that signal only."));
all signals cumulatively specified."));
set_cmd_completer (c, handle_completer);
- if (xdb_commands)
- {
- add_com ("lz", class_info, signals_info, _("\
-What debugger does when program gets various signals.\n\
-Specify a signal as argument to print info on that signal only."));
- add_com ("z", class_run, xdb_handle_command, _("\
-Specify how to handle a signal.\n\
-Args are signals and actions to apply to those signals.\n\
-Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
-from 1-15 are allowed for compatibility with old versions of GDB.\n\
-Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
-The special arg \"all\" is recognized to mean all signals except those\n\
-used by the debugger, typically SIGTRAP and SIGINT.\n\
-Recognized actions include \"s\" (toggles between stop and nostop),\n\
-\"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
-nopass), \"Q\" (noprint)\n\
-Stop means reenter debugger if this signal happens (implies print).\n\
-Print means print a message if this signal happens.\n\
-Pass means let program see this signal; otherwise program doesn't know.\n\
-Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
-Pass and Stop may be combined."));
- }
-
if (!dbx_commands)
stop_command = add_cmd ("stop", class_obscure,
not_just_help_class_command, _("\
signal_catch[i] = 0;
}
- /* Signals caused by debugger's own actions
- should not be given to the program afterwards. */
+ /* Signals caused by debugger's own actions should not be given to
+ the program afterwards.
+
+ Do not deliver GDB_SIGNAL_TRAP by default, except when the user
+ explicitly specifies that it should be delivered to the target
+ program. Typically, that would occur when a user is debugging a
+ target monitor on a simulator: the target monitor sets a
+ breakpoint; the simulator encounters this breakpoint and halts
+ the simulation handing control to GDB; GDB, noting that the stop
+ address doesn't map to any known breakpoint, returns control back
+ to the simulator; the simulator then delivers the hardware
+ equivalent of a GDB_SIGNAL_TRAP to the program being
+ debugged. */
signal_program[GDB_SIGNAL_TRAP] = 0;
signal_program[GDB_SIGNAL_INT] = 0;
Show mode for locking scheduler during execution."), _("\
off == no locking (threads may preempt at any time)\n\
on == full locking (no thread except the current thread may run)\n\
-step == scheduler locked during every single-step operation.\n\
- In this mode, no other thread may run during a step command.\n\
- Other threads may run while stepping over a function call ('next')."),
+step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
+ In this mode, other threads may run during other commands."),
set_schedlock_func, /* traps on target vector */
show_scheduler_mode,
&setlist, &showlist);
projects / deliverable / binutils-gdb.git / blobdiff