Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
- 2008 Free Software Foundation, Inc.
+ 2008, 2009 Free Software Foundation, Inc.
This file is part of GDB.
static int currently_stepping (struct thread_info *tp);
+static int currently_stepping_callback (struct thread_info *tp, void *data);
+
static void xdb_handle_command (char *args, int from_tty);
static int prepare_to_proceed (int);
int stop_after_trap;
-/* Save register contents here when about to pop a stack dummy frame,
- if-and-only-if proceed_to_finish is set.
+/* 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). */
/* Saved contents of copy area. */
static gdb_byte *displaced_step_saved_copy;
-/* When this is non-zero, we are allowed to use displaced stepping, if
- the architecture supports it. When this is zero, we use
- traditional the hold-and-step approach. */
-int can_use_displaced_stepping = 1;
+/* Enum strings for "set|show displaced-stepping". */
+
+static const char can_use_displaced_stepping_auto[] = "auto";
+static const char can_use_displaced_stepping_on[] = "on";
+static const char can_use_displaced_stepping_off[] = "off";
+static const char *can_use_displaced_stepping_enum[] =
+{
+ can_use_displaced_stepping_auto,
+ can_use_displaced_stepping_on,
+ can_use_displaced_stepping_off,
+ NULL,
+};
+
+/* If ON, and the architecture supports it, GDB will use displaced
+ stepping to step over breakpoints. If OFF, or if the architecture
+ doesn't support it, GDB will instead use the traditional
+ hold-and-step approach. If AUTO (which is the default), GDB will
+ decide which technique to use to step over breakpoints depending on
+ which of all-stop or non-stop mode is active --- displaced stepping
+ in non-stop mode; hold-and-step in all-stop mode. */
+
+static const char *can_use_displaced_stepping =
+ can_use_displaced_stepping_auto;
+
static void
show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
struct cmd_list_element *c,
const char *value)
{
- fprintf_filtered (file, _("\
-Debugger's willingness to use displaced stepping to step over "
-"breakpoints is %s.\n"), value);
+ if (can_use_displaced_stepping == can_use_displaced_stepping_auto)
+ fprintf_filtered (file, _("\
+Debugger's willingness to use displaced stepping to step over \
+breakpoints is %s (currently %s).\n"),
+ value, non_stop ? "on" : "off");
+ else
+ fprintf_filtered (file, _("\
+Debugger's willingness to use displaced stepping to step over \
+breakpoints is %s.\n"), value);
}
-/* Return non-zero if displaced stepping is enabled, and can be used
- with GDBARCH. */
+/* Return non-zero if displaced stepping can/should be used to step
+ over breakpoints. */
+
static int
use_displaced_stepping (struct gdbarch *gdbarch)
{
- return (can_use_displaced_stepping
+ return (((can_use_displaced_stepping == can_use_displaced_stepping_auto
+ && non_stop)
+ || can_use_displaced_stepping == can_use_displaced_stepping_on)
&& gdbarch_displaced_step_copy_insn_p (gdbarch));
}
{
int should_resume = 1;
struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
+
+ /* Note that these must be reset if we follow a fork below. */
struct regcache *regcache = get_current_regcache ();
struct gdbarch *gdbarch = get_regcache_arch (regcache);
struct thread_info *tp = inferior_thread ();
CORE_ADDR pc = regcache_read_pc (regcache);
+
QUIT;
if (debug_infrun)
pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
if (follow_fork ())
should_resume = 0;
+
+ /* Following a child fork will change our notion of current
+ thread. */
+ tp = inferior_thread ();
+ regcache = get_current_regcache ();
+ gdbarch = get_regcache_arch (regcache);
+ pc = regcache_read_pc (regcache);
break;
case TARGET_WAITKIND_EXECD:
displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
}
- target_resume (resume_ptid, step, sig);
-
/* Avoid confusing the next resume, if the next stop/resume
happens to apply to another thread. */
tp->stop_signal = TARGET_SIGNAL_0;
+
+ target_resume (resume_ptid, step, sig);
}
discard_cleanups (old_cleanups);
/* Clear out all variables saying what to do when inferior is continued.
First do this, then set the ones you want, then call `proceed'. */
-void
-clear_proceed_status (void)
+static void
+clear_proceed_status_thread (struct thread_info *tp)
{
- if (!ptid_equal (inferior_ptid, null_ptid))
- {
- struct thread_info *tp;
- struct inferior *inferior;
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: clear_proceed_status_thread (%s)\n",
+ target_pid_to_str (tp->ptid));
- tp = inferior_thread ();
+ tp->trap_expected = 0;
+ tp->step_range_start = 0;
+ tp->step_range_end = 0;
+ tp->step_frame_id = null_frame_id;
+ tp->step_over_calls = STEP_OVER_UNDEBUGGABLE;
+ tp->stop_requested = 0;
- tp->trap_expected = 0;
- tp->step_range_start = 0;
- tp->step_range_end = 0;
- tp->step_frame_id = null_frame_id;
- tp->step_over_calls = STEP_OVER_UNDEBUGGABLE;
+ tp->stop_step = 0;
- tp->stop_step = 0;
+ tp->proceed_to_finish = 0;
- tp->proceed_to_finish = 0;
+ /* Discard any remaining commands or status from previous stop. */
+ bpstat_clear (&tp->stop_bpstat);
+}
- /* Discard any remaining commands or status from previous
- stop. */
- bpstat_clear (&tp->stop_bpstat);
+static int
+clear_proceed_status_callback (struct thread_info *tp, void *data)
+{
+ if (is_exited (tp->ptid))
+ return 0;
+ clear_proceed_status_thread (tp);
+ return 0;
+}
+
+void
+clear_proceed_status (void)
+{
+ if (!ptid_equal (inferior_ptid, null_ptid))
+ {
+ struct inferior *inferior;
+
+ if (non_stop)
+ {
+ /* If in non-stop mode, only delete the per-thread status
+ of the current thread. */
+ clear_proceed_status_thread (inferior_thread ());
+ }
+ else
+ {
+ /* In all-stop mode, delete the per-thread status of
+ *all* threads. */
+ iterate_over_threads (clear_proceed_status_callback, NULL);
+ }
+
inferior = current_inferior ();
inferior->stop_soon = NO_STOP_QUIETLY;
}
struct thread_info *tp;
CORE_ADDR pc = regcache_read_pc (regcache);
int oneproc = 0;
- enum target_signal stop_signal;
if (step > 0)
step_start_function = find_pc_function (pc);
if (addr == (CORE_ADDR) -1)
{
- if (pc == stop_pc && breakpoint_here_p (pc))
+ if (pc == stop_pc && breakpoint_here_p (pc)
+ && execution_direction != EXEC_REVERSE)
/* There is a breakpoint at the address we will resume at,
step one instruction before inserting breakpoints so that
we do not stop right away (and report a second hit at this
- breakpoint). */
+ breakpoint).
+
+ Note, we don't do this in reverse, because we won't
+ actually be executing the breakpoint insn anyway.
+ We'll be (un-)executing the previous instruction. */
+
oneproc = 1;
else if (gdbarch_single_step_through_delay_p (gdbarch)
&& gdbarch_single_step_through_delay (gdbarch,
/* Inferior exited. */
EXITED,
/* Inferior received signal, and user asked to be notified. */
- SIGNAL_RECEIVED
+ SIGNAL_RECEIVED,
+ /* Reverse execution -- target ran out of history info. */
+ NO_HISTORY
};
/* The PTID we'll do a target_wait on.*/
void handle_inferior_event (struct execution_control_state *ecs);
-static void step_into_function (struct execution_control_state *ecs);
+static void handle_step_into_function (struct execution_control_state *ecs);
+static void handle_step_into_function_backward (struct execution_control_state *ecs);
static void insert_step_resume_breakpoint_at_frame (struct frame_info *step_frame);
static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
static void insert_step_resume_breakpoint_at_sal (struct symtab_and_line sr_sal,
static void print_stop_reason (enum inferior_stop_reason stop_reason,
int stop_info);
+/* Callback for iterate over threads. If the thread is stopped, but
+ the user/frontend doesn't know about that yet, go through
+ normal_stop, as if the thread had just stopped now. ARG points at
+ a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
+ ptid_is_pid(PTID) is true, applies to all threads of the process
+ pointed at by PTID. Otherwise, apply only to the thread pointed by
+ PTID. */
+
+static int
+infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
+{
+ ptid_t ptid = * (ptid_t *) arg;
+
+ if ((ptid_equal (info->ptid, ptid)
+ || ptid_equal (minus_one_ptid, ptid)
+ || (ptid_is_pid (ptid)
+ && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
+ && is_running (info->ptid)
+ && !is_executing (info->ptid))
+ {
+ struct cleanup *old_chain;
+ struct execution_control_state ecss;
+ struct execution_control_state *ecs = &ecss;
+
+ memset (ecs, 0, sizeof (*ecs));
+
+ old_chain = make_cleanup_restore_current_thread ();
+
+ switch_to_thread (info->ptid);
+
+ /* Go through handle_inferior_event/normal_stop, so we always
+ have consistent output as if the stop event had been
+ reported. */
+ ecs->ptid = info->ptid;
+ ecs->event_thread = find_thread_pid (info->ptid);
+ ecs->ws.kind = TARGET_WAITKIND_STOPPED;
+ ecs->ws.value.sig = TARGET_SIGNAL_0;
+
+ handle_inferior_event (ecs);
+
+ if (!ecs->wait_some_more)
+ {
+ struct thread_info *tp;
+
+ normal_stop ();
+
+ /* Finish off the continuations. The continations
+ themselves are responsible for realising the thread
+ didn't finish what it was supposed to do. */
+ tp = inferior_thread ();
+ do_all_intermediate_continuations_thread (tp);
+ do_all_continuations_thread (tp);
+ }
+
+ do_cleanups (old_chain);
+ }
+
+ return 0;
+}
+
+/* This function is attached as a "thread_stop_requested" observer.
+ Cleanup local state that assumed the PTID was to be resumed, and
+ report the stop to the frontend. */
+
+void
+infrun_thread_stop_requested (ptid_t ptid)
+{
+ struct displaced_step_request *it, *next, *prev = NULL;
+
+ /* PTID was requested to stop. Remove it from the displaced
+ stepping queue, so we don't try to resume it automatically. */
+ for (it = displaced_step_request_queue; it; it = next)
+ {
+ next = it->next;
+
+ if (ptid_equal (it->ptid, ptid)
+ || ptid_equal (minus_one_ptid, ptid)
+ || (ptid_is_pid (ptid)
+ && ptid_get_pid (ptid) == ptid_get_pid (it->ptid)))
+ {
+ if (displaced_step_request_queue == it)
+ displaced_step_request_queue = it->next;
+ else
+ prev->next = it->next;
+
+ xfree (it);
+ }
+ else
+ prev = it;
+ }
+
+ iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
+}
+
/* Callback for iterate_over_threads. */
static int
if (ecs->ws.value.sig != TARGET_SIGNAL_TRAP)
return;
+ /* In reverse execution, when a breakpoint is hit, the instruction
+ under it has already been de-executed. The reported PC always
+ points at the breakpoint address, so adjusting it further would
+ be wrong. E.g., consider this case on a decr_pc_after_break == 1
+ architecture:
+
+ B1 0x08000000 : INSN1
+ B2 0x08000001 : INSN2
+ 0x08000002 : INSN3
+ PC -> 0x08000003 : INSN4
+
+ Say you're stopped at 0x08000003 as above. Reverse continuing
+ from that point should hit B2 as below. Reading the PC when the
+ SIGTRAP is reported should read 0x08000001 and INSN2 should have
+ been de-executed already.
+
+ B1 0x08000000 : INSN1
+ B2 PC -> 0x08000001 : INSN2
+ 0x08000002 : INSN3
+ 0x08000003 : INSN4
+
+ We can't apply the same logic as for forward execution, because
+ we would wrongly adjust the PC to 0x08000000, since there's a
+ breakpoint at PC - 1. We'd then report a hit on B1, although
+ INSN1 hadn't been de-executed yet. Doing nothing is the correct
+ behaviour. */
+ if (execution_direction == EXEC_REVERSE)
+ return;
+
/* If this target does not decrement the PC after breakpoints, then
we have nothing to do. */
regcache = get_thread_regcache (ecs->ptid);
{
breakpoint_retire_moribund ();
- /* Mark the non-executing threads accordingly. */
- if (!non_stop
- || ecs->ws.kind == TARGET_WAITKIND_EXITED
- || ecs->ws.kind == TARGET_WAITKIND_SIGNALLED)
- set_executing (pid_to_ptid (-1), 0);
- else
- set_executing (ecs->ptid, 0);
+ /* 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 (inferior_ptid, 0);
}
switch (infwait_state)
case TARGET_WAITKIND_EXITED:
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXITED\n");
+ inferior_ptid = ecs->ptid;
target_terminal_ours (); /* Must do this before mourn anyway */
print_stop_reason (EXITED, ecs->ws.value.integer);
case TARGET_WAITKIND_SIGNALLED:
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SIGNALLED\n");
+ inferior_ptid = ecs->ptid;
stop_print_frame = 0;
target_terminal_ours (); /* Must do this before mourn anyway */
ecs->event_thread->stop_signal = ecs->ws.value.sig;
break;
+ case TARGET_WAITKIND_NO_HISTORY:
+ /* Reverse execution: target ran out of history info. */
+ stop_pc = read_pc ();
+ print_stop_reason (NO_HISTORY, 0);
+ stop_stepping (ecs);
+ return;
+
/* We had an event in the inferior, but we are not interested
in handling it at this level. The lower layers have already
done what needs to be done, if anything.
return;
}
- /* 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.) */
if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
- displaced_step_fixup (ecs->ptid, ecs->event_thread->stop_signal);
+ {
+ /* 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->stop_signal);
+
+ /* If we either finished a single-step or hit a breakpoint, but
+ the user wanted this thread to be stopped, pretend we got a
+ SIG0 (generic unsignaled stop). */
+
+ if (ecs->event_thread->stop_requested
+ && ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
+ ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
+ }
stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
}
}
- stepping_past_singlestep_breakpoint = 0;
-
if (!ptid_equal (deferred_step_ptid, null_ptid))
{
/* In non-stop mode, there's never a deferred_step_ptid set. */
the fact that we were supposed to switch back. */
if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
{
- struct thread_info *tp;
-
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
"infrun: handling deferred step\n");
SIGTRAP. Some systems (e.g. Windows), and stubs supporting
target extended-remote report it instead of a SIGSTOP
(e.g. gdbserver). We already rely on SIGTRAP being our
- signal, so this is no exception. */
+ signal, so this is no exception.
+
+ Also consider that the attach is complete when we see a
+ TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell
+ the target to stop all threads of the inferior, in case the
+ low level attach operation doesn't stop them implicitly. If
+ they weren't stopped implicitly, then the stub will report a
+ TARGET_SIGNAL_0, meaning: stopped for no particular reason
+ other than GDB's request. */
if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
&& (ecs->event_thread->stop_signal == TARGET_SIGNAL_STOP
- || ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP))
+ || ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
+ || ecs->event_thread->stop_signal == TARGET_SIGNAL_0))
{
stop_stepping (ecs);
ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
target_terminal_ours_for_output ();
print_stop_reason (SIGNAL_RECEIVED, ecs->event_thread->stop_signal);
}
- /* Always stop on signals if we're just gaining control of the
- program. */
+ /* Always stop on signals if we're either just gaining control
+ of the program, or the user explicitly requested this thread
+ to remain stopped. */
if (stop_soon != NO_STOP_QUIETLY
+ || ecs->event_thread->stop_requested
|| signal_stop_state (ecs->event_thread->stop_signal))
{
stop_stepping (ecs);
keep_going (ecs);
return;
}
+ if (stop_pc == ecs->stop_func_start
+ && execution_direction == EXEC_REVERSE)
+ {
+ /* We are stepping over a function call in reverse, and
+ just hit the step-resume breakpoint at the start
+ address of the function. Go back to single-stepping,
+ which should take us back to the function call. */
+ ecs->event_thread->stepping_over_breakpoint = 1;
+ keep_going (ecs);
+ return;
+ }
break;
case BPSTAT_WHAT_CHECK_SHLIBS:
- case BPSTAT_WHAT_CHECK_SHLIBS_RESUME_FROM_HOOK:
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CHECK_SHLIBS\n");
stop_stepping (ecs);
return;
}
-
- /* If we stopped due to an explicit catchpoint, then the
- (see above) call to SOLIB_ADD pulled in any symbols
- from a newly-loaded library, if appropriate.
-
- We do want the inferior to stop, but not where it is
- now, which is in the dynamic linker callback. Rather,
- we would like it stop in the user's program, just after
- the call that caused this catchpoint to trigger. That
- gives the user a more useful vantage from which to
- examine their program's state. */
- else if (what.main_action
- == BPSTAT_WHAT_CHECK_SHLIBS_RESUME_FROM_HOOK)
- {
- /* ??rehrauer: If I could figure out how to get the
- right return PC from here, we could just set a temp
- breakpoint and resume. I'm not sure we can without
- cracking open the dld's shared libraries and sniffing
- their unwind tables and text/data ranges, and that's
- not a terribly portable notion.
-
- Until that time, we must step the inferior out of the
- dld callback, and also out of the dld itself (and any
- code or stubs in libdld.sl, such as "shl_load" and
- friends) until we reach non-dld code. At that point,
- we can stop stepping. */
- bpstat_get_triggered_catchpoints (ecs->event_thread->stop_bpstat,
- &ecs->
- event_thread->
- stepping_through_solib_catchpoints);
- ecs->event_thread->stepping_through_solib_after_catch = 1;
-
- /* Be sure to lift all breakpoints, so the inferior does
- actually step past this point... */
- ecs->event_thread->stepping_over_breakpoint = 1;
- break;
- }
else
{
/* We want to step over this breakpoint, then keep going. */
test for stepping. But, if not stepping,
do not stop. */
+ /* In all-stop mode, if we're currently stepping but have stopped in
+ some other thread, we need to switch back to the stepped thread. */
+ if (!non_stop)
+ {
+ struct thread_info *tp;
+ tp = iterate_over_threads (currently_stepping_callback,
+ ecs->event_thread);
+ if (tp)
+ {
+ /* However, if the current thread is blocked on some internal
+ breakpoint, and we simply need to step over that breakpoint
+ to get it going again, do that first. */
+ if ((ecs->event_thread->trap_expected
+ && ecs->event_thread->stop_signal != TARGET_SIGNAL_TRAP)
+ || ecs->event_thread->stepping_over_breakpoint)
+ {
+ keep_going (ecs);
+ return;
+ }
+
+ /* Otherwise, we no longer expect a trap in the current thread.
+ Clear the trap_expected flag before switching back -- this is
+ what keep_going would do as well, if we called it. */
+ ecs->event_thread->trap_expected = 0;
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: switching back to stepped thread\n");
+
+ ecs->event_thread = tp;
+ ecs->ptid = tp->ptid;
+ context_switch (ecs->ptid);
+ keep_going (ecs);
+ return;
+ }
+ }
+
/* Are we stepping to get the inferior out of the dynamic linker's
hook (and possibly the dld itself) after catching a shlib
event? */
&& stop_pc < ecs->event_thread->step_range_end)
{
if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: stepping inside range [0x%s-0x%s]\n",
+ fprintf_unfiltered (gdb_stdlog, "infrun: stepping inside range [0x%s-0x%s]\n",
paddr_nz (ecs->event_thread->step_range_start),
paddr_nz (ecs->event_thread->step_range_end));
- keep_going (ecs);
+
+ /* When stepping backward, stop at beginning of line range
+ (unless it's the function entry point, in which case
+ keep going back to the call point). */
+ if (stop_pc == ecs->event_thread->step_range_start
+ && stop_pc != ecs->stop_func_start
+ && execution_direction == EXEC_REVERSE)
+ {
+ ecs->event_thread->stop_step = 1;
+ print_stop_reason (END_STEPPING_RANGE, 0);
+ stop_stepping (ecs);
+ }
+ else
+ keep_going (ecs);
+
return;
}
previous frame must have valid frame IDs. */
if (!frame_id_eq (get_frame_id (get_current_frame ()),
ecs->event_thread->step_frame_id)
- && frame_id_eq (frame_unwind_id (get_current_frame ()),
- ecs->event_thread->step_frame_id))
+ && (frame_id_eq (frame_unwind_id (get_current_frame ()),
+ ecs->event_thread->step_frame_id)
+ || execution_direction == EXEC_REVERSE))
{
CORE_ADDR real_stop_pc;
if (ecs->event_thread->step_over_calls == STEP_OVER_ALL)
{
- /* We're doing a "next", set a breakpoint at callee's return
- address (the address at which the caller will
- resume). */
- insert_step_resume_breakpoint_at_caller (get_current_frame ());
+ /* We're doing a "next".
+
+ Normal (forward) execution: set a breakpoint at the
+ callee's return address (the address at which the caller
+ will resume).
+
+ Reverse (backward) execution. set the step-resume
+ breakpoint at the start of the function that we just
+ stepped into (backwards), and continue to there. When we
+ get there, we'll need to single-step back to the caller. */
+
+ if (execution_direction == EXEC_REVERSE)
+ {
+ struct symtab_and_line sr_sal;
+
+ if (ecs->stop_func_start == 0
+ && in_solib_dynsym_resolve_code (stop_pc))
+ {
+ /* Stepped into runtime loader dynamic symbol
+ resolution code. Since we're in reverse,
+ we have already backed up through the runtime
+ loader and the dynamic function. This is just
+ the trampoline (jump table).
+
+ Just keep stepping, we'll soon be home.
+ */
+ keep_going (ecs);
+ return;
+ }
+ /* Normal (staticly linked) function call return. */
+ init_sal (&sr_sal);
+ sr_sal.pc = ecs->stop_func_start;
+ insert_step_resume_breakpoint_at_sal (sr_sal, null_frame_id);
+ }
+ else
+ insert_step_resume_breakpoint_at_caller (get_current_frame ());
+
keep_going (ecs);
return;
}
tmp_sal = find_pc_line (ecs->stop_func_start, 0);
if (tmp_sal.line != 0)
{
- step_into_function (ecs);
+ if (execution_direction == EXEC_REVERSE)
+ handle_step_into_function_backward (ecs);
+ else
+ handle_step_into_function (ecs);
return;
}
}
return;
}
- /* Set a breakpoint at callee's return address (the address at
- which the caller will resume). */
- insert_step_resume_breakpoint_at_caller (get_current_frame ());
+ if (execution_direction == EXEC_REVERSE)
+ {
+ /* Set a breakpoint at callee's start address.
+ From there we can step once and be back in the caller. */
+ struct symtab_and_line sr_sal;
+ init_sal (&sr_sal);
+ sr_sal.pc = ecs->stop_func_start;
+ insert_step_resume_breakpoint_at_sal (sr_sal, null_frame_id);
+ }
+ else
+ /* Set a breakpoint at callee's return address (the address
+ at which the caller will resume). */
+ insert_step_resume_breakpoint_at_caller (get_current_frame ());
+
keep_going (ecs);
return;
}
/* Are we in the middle of stepping? */
+static int
+currently_stepping_thread (struct thread_info *tp)
+{
+ return (tp->step_range_end && tp->step_resume_breakpoint == NULL)
+ || tp->trap_expected
+ || tp->stepping_through_solib_after_catch;
+}
+
+static int
+currently_stepping_callback (struct thread_info *tp, void *data)
+{
+ /* Return true if any thread *but* the one passed in "data" is
+ in the middle of stepping. */
+ return tp != data && currently_stepping_thread (tp);
+}
+
static int
currently_stepping (struct thread_info *tp)
{
- return (((tp->step_range_end && tp->step_resume_breakpoint == NULL)
- || tp->trap_expected)
- || tp->stepping_through_solib_after_catch
- || bpstat_should_step ());
+ return currently_stepping_thread (tp) || bpstat_should_step ();
}
-/* Subroutine call with source code we should not step over. Do step
- to the first line of code in it. */
+/* Inferior has stepped into a subroutine call with source code that
+ we should not step over. Do step to the first line of code in
+ it. */
static void
-step_into_function (struct execution_control_state *ecs)
+handle_step_into_function (struct execution_control_state *ecs)
{
struct symtab *s;
struct symtab_and_line stop_func_sal, sr_sal;
s = find_pc_symtab (stop_pc);
if (s && s->language != language_asm)
- ecs->stop_func_start = gdbarch_skip_prologue
- (current_gdbarch, ecs->stop_func_start);
+ ecs->stop_func_start = gdbarch_skip_prologue (current_gdbarch,
+ ecs->stop_func_start);
stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
/* Use the step_resume_break to step until the end of the prologue,
keep_going (ecs);
}
+/* Inferior has stepped backward into a subroutine call with source
+ code that we should not step over. Do step to the beginning of the
+ last line of code in it. */
+
+static void
+handle_step_into_function_backward (struct execution_control_state *ecs)
+{
+ struct symtab *s;
+ struct symtab_and_line stop_func_sal, sr_sal;
+
+ s = find_pc_symtab (stop_pc);
+ if (s && s->language != language_asm)
+ ecs->stop_func_start = gdbarch_skip_prologue (current_gdbarch,
+ ecs->stop_func_start);
+
+ stop_func_sal = find_pc_line (stop_pc, 0);
+
+ /* OK, we're just going to keep stepping here. */
+ if (stop_func_sal.pc == stop_pc)
+ {
+ /* We're there already. Just stop stepping now. */
+ ecs->event_thread->stop_step = 1;
+ print_stop_reason (END_STEPPING_RANGE, 0);
+ stop_stepping (ecs);
+ }
+ else
+ {
+ /* Else just reset the step range and keep going.
+ No step-resume breakpoint, they don't work for
+ epilogues, which can have multiple entry paths. */
+ ecs->event_thread->step_range_start = stop_func_sal.pc;
+ ecs->event_thread->step_range_end = stop_func_sal.end;
+ keep_going (ecs);
+ }
+ return;
+}
+
/* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
This is used to both functions and to skip over code. */
return_child_result_value = stop_info;
break;
case SIGNAL_RECEIVED:
- /* Signal received. The signal table tells us to print about
- it. */
+ /* Signal received. The signal table tells us to print about
+ it. */
annotate_signal ();
- ui_out_text (uiout, "\nProgram received signal ");
- annotate_signal_name ();
- if (ui_out_is_mi_like_p (uiout))
- ui_out_field_string
- (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
- ui_out_field_string (uiout, "signal-name",
- target_signal_to_name (stop_info));
- annotate_signal_name_end ();
- ui_out_text (uiout, ", ");
- annotate_signal_string ();
- ui_out_field_string (uiout, "signal-meaning",
- target_signal_to_string (stop_info));
- annotate_signal_string_end ();
+
+ if (stop_info == TARGET_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
+ {
+ struct thread_info *t = inferior_thread ();
+
+ ui_out_text (uiout, "\n[");
+ ui_out_field_string (uiout, "thread-name",
+ target_pid_to_str (t->ptid));
+ ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
+ ui_out_text (uiout, " stopped");
+ }
+ else
+ {
+ ui_out_text (uiout, "\nProgram received signal ");
+ annotate_signal_name ();
+ if (ui_out_is_mi_like_p (uiout))
+ ui_out_field_string
+ (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
+ ui_out_field_string (uiout, "signal-name",
+ target_signal_to_name (stop_info));
+ annotate_signal_name_end ();
+ ui_out_text (uiout, ", ");
+ annotate_signal_string ();
+ ui_out_field_string (uiout, "signal-meaning",
+ target_signal_to_string (stop_info));
+ annotate_signal_string_end ();
+ }
ui_out_text (uiout, ".\n");
break;
+ case NO_HISTORY:
+ /* Reverse execution: target ran out of history info. */
+ ui_out_text (uiout, "\nNo more reverse-execution history.\n");
+ break;
default:
internal_error (__FILE__, __LINE__,
_("print_stop_reason: unrecognized enum value"));
else
observer_notify_normal_stop (NULL);
}
- if (target_has_execution
- && last.kind != TARGET_WAITKIND_SIGNALLED
- && last.kind != TARGET_WAITKIND_EXITED)
- {
- /* Delete the breakpoint we stopped at, if it wants to be deleted.
- Delete any breakpoint that is to be deleted at the next stop. */
- breakpoint_auto_delete (inferior_thread ()->stop_bpstat);
+ if (target_has_execution)
+ {
+ if (last.kind != TARGET_WAITKIND_SIGNALLED
+ && last.kind != TARGET_WAITKIND_EXITED)
+ /* Delete the breakpoint we stopped at, if it wants to be deleted.
+ Delete any breakpoint that is to be deleted at the next stop. */
+ breakpoint_auto_delete (inferior_thread ()->stop_bpstat);
+
+ /* Mark the stopped 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_running (pid_to_ptid (-1), 0);
- else
+ set_running (minus_one_ptid, 0);
+ else if (last.kind != TARGET_WAITKIND_SIGNALLED
+ && last.kind != TARGET_WAITKIND_EXITED)
set_running (inferior_ptid, 0);
}
argv++;
}
- target_notice_signals (inferior_ptid);
+ for (signum = 0; signum < nsigs; signum++)
+ if (sigs[signum])
+ {
+ target_notice_signals (inferior_ptid);
- if (from_tty)
- {
- /* Show the results. */
- sig_print_header ();
- for (signum = 0; signum < nsigs; signum++)
- {
- if (sigs[signum])
- {
- sig_print_info (signum);
- }
- }
- }
+ if (from_tty)
+ {
+ /* Show the results. */
+ sig_print_header ();
+ for (; signum < nsigs; signum++)
+ if (sigs[signum])
+ sig_print_info (signum);
+ }
+
+ break;
+ }
do_cleanups (old_chain);
}
int proceed_to_finish;
};
-void
-write_inferior_status_register (struct inferior_status *inf_status, int regno,
- LONGEST val)
-{
- int size = register_size (current_gdbarch, regno);
- void *buf = alloca (size);
- store_signed_integer (buf, size, val);
- regcache_raw_write (inf_status->registers, regno, buf);
-}
-
/* Save all of the information associated with the inferior<==>gdb
connection. INF_STATUS is a pointer to a "struct inferior_status"
(defined in inferior.h). */
&& ptid1.tid == ptid2.tid);
}
+/* Returns true if PTID represents a process. */
+
+int
+ptid_is_pid (ptid_t ptid)
+{
+ if (ptid_equal (minus_one_ptid, ptid))
+ return 0;
+ if (ptid_equal (null_ptid, ptid))
+ return 0;
+
+ return (ptid_get_lwp (ptid) == 0 && ptid_get_tid (ptid) == 0);
+}
+
/* restore_inferior_ptid() will be used by the cleanup machinery
to restore the inferior_ptid value saved in a call to
save_inferior_ptid(). */
}
\f
+/* User interface for reverse debugging:
+ Set exec-direction / show exec-direction commands
+ (returns error unless target implements to_set_exec_direction method). */
+
+enum exec_direction_kind execution_direction = EXEC_FORWARD;
+static const char exec_forward[] = "forward";
+static const char exec_reverse[] = "reverse";
+static const char *exec_direction = exec_forward;
+static const char *exec_direction_names[] = {
+ exec_forward,
+ exec_reverse,
+ NULL
+};
+
+static void
+set_exec_direction_func (char *args, int from_tty,
+ struct cmd_list_element *cmd)
+{
+ if (target_can_execute_reverse)
+ {
+ if (!strcmp (exec_direction, exec_forward))
+ execution_direction = EXEC_FORWARD;
+ else if (!strcmp (exec_direction, exec_reverse))
+ execution_direction = EXEC_REVERSE;
+ }
+}
+
+static void
+show_exec_direction_func (struct ui_file *out, int from_tty,
+ struct cmd_list_element *cmd, const char *value)
+{
+ switch (execution_direction) {
+ case EXEC_FORWARD:
+ fprintf_filtered (out, _("Forward.\n"));
+ break;
+ case EXEC_REVERSE:
+ fprintf_filtered (out, _("Reverse.\n"));
+ break;
+ case EXEC_ERROR:
+ default:
+ fprintf_filtered (out,
+ _("Forward (target `%s' does not support exec-direction).\n"),
+ target_shortname);
+ break;
+ }
+}
+
+/* User interface for non-stop mode. */
+
int non_stop = 0;
static int non_stop_1 = 0;
show_step_stop_if_no_debug,
&setlist, &showlist);
- add_setshow_boolean_cmd ("can-use-displaced-stepping", class_maintenance,
- &can_use_displaced_stepping, _("\
+ add_setshow_enum_cmd ("displaced-stepping", class_run,
+ can_use_displaced_stepping_enum,
+ &can_use_displaced_stepping, _("\
Set debugger's willingness to use displaced stepping."), _("\
Show debugger's willingness to use displaced stepping."), _("\
-If zero, gdb will not use displaced stepping to step over\n\
-breakpoints, even if such is supported by the target."),
- NULL,
- show_can_use_displaced_stepping,
- &maintenance_set_cmdlist,
- &maintenance_show_cmdlist);
+If on, gdb will use displaced stepping to step over breakpoints if it is\n\
+supported by the target architecture. If off, gdb will not use displaced\n\
+stepping to step over breakpoints, even if such is supported by the target\n\
+architecture. If auto (which is the default), gdb will use displaced stepping\n\
+if the target architecture supports it and non-stop mode is active, but will not\n\
+use it in all-stop mode (see help set non-stop)."),
+ NULL,
+ show_can_use_displaced_stepping,
+ &setlist, &showlist);
+
+ add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
+ &exec_direction, _("Set direction of execution.\n\
+Options are 'forward' or 'reverse'."),
+ _("Show direction of execution (forward/reverse)."),
+ _("Tells gdb whether to execute forward or backward."),
+ set_exec_direction_func, show_exec_direction_func,
+ &setlist, &showlist);
/* ptid initializations */
null_ptid = ptid_build (0, 0, 0);
displaced_step_ptid = null_ptid;
observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
+ observer_attach_thread_stop_requested (infrun_thread_stop_requested);
}