705096250d
Currently, GDB can pass a signal to the wrong thread in several
different but related scenarios.
E.g., if thread 1 stops for signal SIGFOO, the user switches to thread
2, and then issues "continue", SIGFOO is actually delivered to thread
2, not thread 1. This obviously messes up programs that use
pthread_kill to send signals to specific threads.
This has been a known issue for a long while. Back in 2008 when I
made stop_signal be per-thread (2020b7ab), I kept the behavior -- see
code in 'proceed' being removed -- wanting to come back to it later.
The time has finally come now.
The patch fixes this -- on resumption, intercepted signals are always
delivered to the thread that had intercepted them.
Another example: if thread 1 stops for a breakpoint, the user switches
to thread 2, and then issues "signal SIGFOO", SIGFOO is actually
delivered to thread 1, not thread 2, because 'proceed' first switches
to thread 1 to step over its breakpoint... If the user deletes the
breakpoint before issuing "signal FOO", then the signal is delivered
to thread 2 (the current thread).
"signal SIGFOO" can be used for two things: inject a signal in the
program while the program/thread had stopped for none, bypassing
"handle nopass"; or changing/suppressing a signal the program had
stopped for. These scenarios are really two faces of the same coin,
and GDB can't really guess what the user is trying to do. GDB might
have intercepted signals in more than one thread even (see the new
signal-command-multiple-signals-pending.exp test). At least in the
inject case, it's obviously clear to me that the user means to deliver
the signal to the currently selected thread, so best is to make the
command's behavior consistent and easy to explain.
Then, if the user is trying to suppress/change a signal the program
had stopped for instead of injecting a new signal, but, the user had
changed threads meanwhile, then she will be surprised that with:
(gdb) continue
Thread 1 stopped for signal SIGFOO.
(gdb) thread 2
(gdb) signal SIGBAR
... GDB actually delivers SIGFOO to thread 1, and SIGBAR to thread 2
(with scheduler-locking off, which is the default, because then
"signal" or any other resumption command resumes all threads).
So the patch makes GDB detect that, and ask for confirmation:
(gdb) thread 1
[Switching to thread 1 (Thread 10979)]
(gdb) signal SIGUSR2
Note:
Thread 3 previously stopped with signal SIGUSR2, User defined signal 2.
Thread 2 previously stopped with signal SIGUSR1, User defined signal 1.
Continuing thread 1 (the current thread) with specified signal will
still deliver the signals noted above to their respective threads.
Continue anyway? (y or n)
All these scenarios are covered by the new tests.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-07-25 Pedro Alves <palves@redhat.com>
* NEWS: Mention signal passing and "signal" command changes.
* gdbthread.h (struct thread_suspend_state) <stop_signal>: Extend
comment.
* breakpoint.c (until_break_command): Adjust clear_proceed_status
call.
* infcall.c (run_inferior_call): Adjust clear_proceed_status call.
* infcmd.c (proceed_thread_callback, continue_1, step_once)
(jump_command): Adjust clear_proceed_status call.
(signal_command): Warn if other thread that are resumed have
signals that will be delivered. Adjust clear_proceed_status call.
(until_next_command, finish_command)
(proceed_after_attach_callback, attach_command_post_wait)
(attach_command): Adjust clear_proceed_status call.
* infrun.c (proceed_after_vfork_done): Likewise.
(proceed_after_attach_callback): Adjust comment.
(clear_proceed_status_thread): Clear stop_signal if not in pass
state.
(clear_proceed_status_callback): Delete.
(clear_proceed_status): New 'step' parameter. Only clear the
proceed status of threads the command being prepared is about to
resume.
(proceed): If passed in an explicit signal, override stop_signal
with it. Don't pass the last stop signal to the thread we're
resuming.
(init_wait_for_inferior): Adjust clear_proceed_status call.
(switch_back_to_stepped_thread): Clear the signal if it should not
be passed.
* infrun.h (clear_proceed_status): New 'step' parameter.
(user_visible_resume_ptid): Add comment.
* linux-nat.c (linux_nat_resume_callback): Don't check whether the
signal is in pass state.
* remote.c (append_pending_thread_resumptions): Likewise.
* mi/mi-main.c (proceed_thread): Adjust clear_proceed_status call.
gdb/doc/
2014-07-25 Pedro Alves <palves@redhat.com>
Eli Zaretskii <eliz@gnu.org>
* gdb.texinfo (Signaling) <signal command>: Explain what happens
with multi-threaded programs.
gdb/testsuite/
2014-07-25 Pedro Alves <palves@redhat.com>
* gdb.threads/signal-command-handle-nopass.c: New file.
* gdb.threads/signal-command-handle-nopass.exp: New file.
* gdb.threads/signal-command-multiple-signals-pending.c: New file.
* gdb.threads/signal-command-multiple-signals-pending.exp: New file.
* gdb.threads/signal-delivered-right-thread.c: New file.
* gdb.threads/signal-delivered-right-thread.exp: New file.
7523 lines
243 KiB
C
7523 lines
243 KiB
C
/* Target-struct-independent code to start (run) and stop an inferior
|
||
process.
|
||
|
||
Copyright (C) 1986-2014 Free Software Foundation, Inc.
|
||
|
||
This file is part of GDB.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 3 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||
|
||
#include "defs.h"
|
||
#include "infrun.h"
|
||
#include <string.h>
|
||
#include <ctype.h>
|
||
#include "symtab.h"
|
||
#include "frame.h"
|
||
#include "inferior.h"
|
||
#include "exceptions.h"
|
||
#include "breakpoint.h"
|
||
#include "gdb_wait.h"
|
||
#include "gdbcore.h"
|
||
#include "gdbcmd.h"
|
||
#include "cli/cli-script.h"
|
||
#include "target.h"
|
||
#include "gdbthread.h"
|
||
#include "annotate.h"
|
||
#include "symfile.h"
|
||
#include "top.h"
|
||
#include <signal.h>
|
||
#include "inf-loop.h"
|
||
#include "regcache.h"
|
||
#include "value.h"
|
||
#include "observer.h"
|
||
#include "language.h"
|
||
#include "solib.h"
|
||
#include "main.h"
|
||
#include "dictionary.h"
|
||
#include "block.h"
|
||
#include "gdb_assert.h"
|
||
#include "mi/mi-common.h"
|
||
#include "event-top.h"
|
||
#include "record.h"
|
||
#include "record-full.h"
|
||
#include "inline-frame.h"
|
||
#include "jit.h"
|
||
#include "tracepoint.h"
|
||
#include "continuations.h"
|
||
#include "interps.h"
|
||
#include "skip.h"
|
||
#include "probe.h"
|
||
#include "objfiles.h"
|
||
#include "completer.h"
|
||
#include "target-descriptions.h"
|
||
#include "target-dcache.h"
|
||
|
||
/* Prototypes for local functions */
|
||
|
||
static void signals_info (char *, int);
|
||
|
||
static void handle_command (char *, int);
|
||
|
||
static void sig_print_info (enum gdb_signal);
|
||
|
||
static void sig_print_header (void);
|
||
|
||
static void resume_cleanups (void *);
|
||
|
||
static int hook_stop_stub (void *);
|
||
|
||
static int restore_selected_frame (void *);
|
||
|
||
static int follow_fork (void);
|
||
|
||
static void set_schedlock_func (char *args, int from_tty,
|
||
struct cmd_list_element *c);
|
||
|
||
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_hp_step_resume_breakpoint_at_frame (struct frame_info *);
|
||
|
||
static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
|
||
|
||
static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
|
||
|
||
/* 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. */
|
||
int step_stop_if_no_debug = 0;
|
||
static void
|
||
show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
|
||
}
|
||
|
||
/* In asynchronous mode, but simulating synchronous execution. */
|
||
|
||
int sync_execution = 0;
|
||
|
||
/* proceed and normal_stop use this to notify the user when the
|
||
inferior stopped in a different thread than it had been running
|
||
in. */
|
||
|
||
static ptid_t previous_inferior_ptid;
|
||
|
||
/* If set (default for legacy reasons), when following a fork, GDB
|
||
will detach from one of the fork branches, child or parent.
|
||
Exactly which branch is detached depends on 'set follow-fork-mode'
|
||
setting. */
|
||
|
||
static int detach_fork = 1;
|
||
|
||
int debug_displaced = 0;
|
||
static void
|
||
show_debug_displaced (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
|
||
}
|
||
|
||
unsigned int debug_infrun = 0;
|
||
static void
|
||
show_debug_infrun (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
|
||
}
|
||
|
||
|
||
/* Support for disabling address space randomization. */
|
||
|
||
int disable_randomization = 1;
|
||
|
||
static void
|
||
show_disable_randomization (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
if (target_supports_disable_randomization ())
|
||
fprintf_filtered (file,
|
||
_("Disabling randomization of debuggee's "
|
||
"virtual address space is %s.\n"),
|
||
value);
|
||
else
|
||
fputs_filtered (_("Disabling randomization of debuggee's "
|
||
"virtual address space is unsupported on\n"
|
||
"this platform.\n"), file);
|
||
}
|
||
|
||
static void
|
||
set_disable_randomization (char *args, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
if (!target_supports_disable_randomization ())
|
||
error (_("Disabling randomization of debuggee's "
|
||
"virtual address space is unsupported on\n"
|
||
"this platform."));
|
||
}
|
||
|
||
/* User interface for non-stop mode. */
|
||
|
||
int non_stop = 0;
|
||
static int non_stop_1 = 0;
|
||
|
||
static void
|
||
set_non_stop (char *args, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
if (target_has_execution)
|
||
{
|
||
non_stop_1 = non_stop;
|
||
error (_("Cannot change this setting while the inferior is running."));
|
||
}
|
||
|
||
non_stop = non_stop_1;
|
||
}
|
||
|
||
static void
|
||
show_non_stop (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file,
|
||
_("Controlling the inferior in non-stop mode is %s.\n"),
|
||
value);
|
||
}
|
||
|
||
/* "Observer mode" is somewhat like a more extreme version of
|
||
non-stop, in which all GDB operations that might affect the
|
||
target's execution have been disabled. */
|
||
|
||
int observer_mode = 0;
|
||
static int observer_mode_1 = 0;
|
||
|
||
static void
|
||
set_observer_mode (char *args, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
if (target_has_execution)
|
||
{
|
||
observer_mode_1 = observer_mode;
|
||
error (_("Cannot change this setting while the inferior is running."));
|
||
}
|
||
|
||
observer_mode = observer_mode_1;
|
||
|
||
may_write_registers = !observer_mode;
|
||
may_write_memory = !observer_mode;
|
||
may_insert_breakpoints = !observer_mode;
|
||
may_insert_tracepoints = !observer_mode;
|
||
/* We can insert fast tracepoints in or out of observer mode,
|
||
but enable them if we're going into this mode. */
|
||
if (observer_mode)
|
||
may_insert_fast_tracepoints = 1;
|
||
may_stop = !observer_mode;
|
||
update_target_permissions ();
|
||
|
||
/* Going *into* observer mode we must force non-stop, then
|
||
going out we leave it that way. */
|
||
if (observer_mode)
|
||
{
|
||
pagination_enabled = 0;
|
||
non_stop = non_stop_1 = 1;
|
||
}
|
||
|
||
if (from_tty)
|
||
printf_filtered (_("Observer mode is now %s.\n"),
|
||
(observer_mode ? "on" : "off"));
|
||
}
|
||
|
||
static void
|
||
show_observer_mode (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Observer mode is %s.\n"), value);
|
||
}
|
||
|
||
/* This updates the value of observer mode based on changes in
|
||
permissions. Note that we are deliberately ignoring the values of
|
||
may-write-registers and may-write-memory, since the user may have
|
||
reason to enable these during a session, for instance to turn on a
|
||
debugging-related global. */
|
||
|
||
void
|
||
update_observer_mode (void)
|
||
{
|
||
int newval;
|
||
|
||
newval = (!may_insert_breakpoints
|
||
&& !may_insert_tracepoints
|
||
&& may_insert_fast_tracepoints
|
||
&& !may_stop
|
||
&& non_stop);
|
||
|
||
/* Let the user know if things change. */
|
||
if (newval != observer_mode)
|
||
printf_filtered (_("Observer mode is now %s.\n"),
|
||
(newval ? "on" : "off"));
|
||
|
||
observer_mode = observer_mode_1 = newval;
|
||
}
|
||
|
||
/* Tables of how to react to signals; the user sets them. */
|
||
|
||
static unsigned char *signal_stop;
|
||
static unsigned char *signal_print;
|
||
static unsigned char *signal_program;
|
||
|
||
/* Table of signals that are registered with "catch signal". A
|
||
non-zero entry indicates that the signal is caught by some "catch
|
||
signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
|
||
signals. */
|
||
static unsigned char *signal_catch;
|
||
|
||
/* Table of signals that the target may silently handle.
|
||
This is automatically determined from the flags above,
|
||
and simply cached here. */
|
||
static unsigned char *signal_pass;
|
||
|
||
#define SET_SIGS(nsigs,sigs,flags) \
|
||
do { \
|
||
int signum = (nsigs); \
|
||
while (signum-- > 0) \
|
||
if ((sigs)[signum]) \
|
||
(flags)[signum] = 1; \
|
||
} while (0)
|
||
|
||
#define UNSET_SIGS(nsigs,sigs,flags) \
|
||
do { \
|
||
int signum = (nsigs); \
|
||
while (signum-- > 0) \
|
||
if ((sigs)[signum]) \
|
||
(flags)[signum] = 0; \
|
||
} while (0)
|
||
|
||
/* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
|
||
this function is to avoid exporting `signal_program'. */
|
||
|
||
void
|
||
update_signals_program_target (void)
|
||
{
|
||
target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
|
||
}
|
||
|
||
/* Value to pass to target_resume() to cause all threads to resume. */
|
||
|
||
#define RESUME_ALL minus_one_ptid
|
||
|
||
/* Command list pointer for the "stop" placeholder. */
|
||
|
||
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;
|
||
|
||
/* Enable or disable optional shared library event breakpoints
|
||
as appropriate when the above flag is changed. */
|
||
|
||
static void
|
||
set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
|
||
{
|
||
update_solib_breakpoints ();
|
||
}
|
||
|
||
static void
|
||
show_stop_on_solib_events (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
|
||
value);
|
||
}
|
||
|
||
/* Nonzero means expecting a trace trap
|
||
and should stop the inferior and return silently when it happens. */
|
||
|
||
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;
|
||
|
||
/* This is a cached copy of the pid/waitstatus of the last event
|
||
returned by target_wait()/deprecated_target_wait_hook(). This
|
||
information is returned by get_last_target_status(). */
|
||
static ptid_t target_last_wait_ptid;
|
||
static struct target_waitstatus target_last_waitstatus;
|
||
|
||
static void context_switch (ptid_t ptid);
|
||
|
||
void init_thread_stepping_state (struct thread_info *tss);
|
||
|
||
static void init_infwait_state (void);
|
||
|
||
static const char follow_fork_mode_child[] = "child";
|
||
static const char follow_fork_mode_parent[] = "parent";
|
||
|
||
static const char *const follow_fork_mode_kind_names[] = {
|
||
follow_fork_mode_child,
|
||
follow_fork_mode_parent,
|
||
NULL
|
||
};
|
||
|
||
static const char *follow_fork_mode_string = follow_fork_mode_parent;
|
||
static void
|
||
show_follow_fork_mode_string (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file,
|
||
_("Debugger response to a program "
|
||
"call of fork or vfork is \"%s\".\n"),
|
||
value);
|
||
}
|
||
|
||
|
||
/* Tell the target to follow the fork we're stopped at. Returns true
|
||
if the inferior should be resumed; false, if the target for some
|
||
reason decided it's best not to resume. */
|
||
|
||
static int
|
||
follow_fork (void)
|
||
{
|
||
int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
|
||
int should_resume = 1;
|
||
struct thread_info *tp;
|
||
|
||
/* Copy user stepping state to the new inferior thread. FIXME: the
|
||
followed fork child thread should have a copy of most of the
|
||
parent thread structure's run control related fields, not just these.
|
||
Initialized to avoid "may be used uninitialized" warnings from gcc. */
|
||
struct breakpoint *step_resume_breakpoint = NULL;
|
||
struct breakpoint *exception_resume_breakpoint = NULL;
|
||
CORE_ADDR step_range_start = 0;
|
||
CORE_ADDR step_range_end = 0;
|
||
struct frame_id step_frame_id = { 0 };
|
||
struct interp *command_interp = NULL;
|
||
|
||
if (!non_stop)
|
||
{
|
||
ptid_t wait_ptid;
|
||
struct target_waitstatus wait_status;
|
||
|
||
/* Get the last target status returned by target_wait(). */
|
||
get_last_target_status (&wait_ptid, &wait_status);
|
||
|
||
/* If not stopped at a fork event, then there's nothing else to
|
||
do. */
|
||
if (wait_status.kind != TARGET_WAITKIND_FORKED
|
||
&& wait_status.kind != TARGET_WAITKIND_VFORKED)
|
||
return 1;
|
||
|
||
/* Check if we switched over from WAIT_PTID, since the event was
|
||
reported. */
|
||
if (!ptid_equal (wait_ptid, minus_one_ptid)
|
||
&& !ptid_equal (inferior_ptid, wait_ptid))
|
||
{
|
||
/* We did. Switch back to WAIT_PTID thread, to tell the
|
||
target to follow it (in either direction). We'll
|
||
afterwards refuse to resume, and inform the user what
|
||
happened. */
|
||
switch_to_thread (wait_ptid);
|
||
should_resume = 0;
|
||
}
|
||
}
|
||
|
||
tp = inferior_thread ();
|
||
|
||
/* If there were any forks/vforks that were caught and are now to be
|
||
followed, then do so now. */
|
||
switch (tp->pending_follow.kind)
|
||
{
|
||
case TARGET_WAITKIND_FORKED:
|
||
case TARGET_WAITKIND_VFORKED:
|
||
{
|
||
ptid_t parent, child;
|
||
|
||
/* If the user did a next/step, etc, over a fork call,
|
||
preserve the stepping state in the fork child. */
|
||
if (follow_child && should_resume)
|
||
{
|
||
step_resume_breakpoint = clone_momentary_breakpoint
|
||
(tp->control.step_resume_breakpoint);
|
||
step_range_start = tp->control.step_range_start;
|
||
step_range_end = tp->control.step_range_end;
|
||
step_frame_id = tp->control.step_frame_id;
|
||
exception_resume_breakpoint
|
||
= clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
|
||
command_interp = tp->control.command_interp;
|
||
|
||
/* For now, delete the parent's sr breakpoint, otherwise,
|
||
parent/child sr breakpoints are considered duplicates,
|
||
and the child version will not be installed. Remove
|
||
this when the breakpoints module becomes aware of
|
||
inferiors and address spaces. */
|
||
delete_step_resume_breakpoint (tp);
|
||
tp->control.step_range_start = 0;
|
||
tp->control.step_range_end = 0;
|
||
tp->control.step_frame_id = null_frame_id;
|
||
delete_exception_resume_breakpoint (tp);
|
||
tp->control.command_interp = NULL;
|
||
}
|
||
|
||
parent = inferior_ptid;
|
||
child = tp->pending_follow.value.related_pid;
|
||
|
||
/* Tell the target to do whatever is necessary to follow
|
||
either parent or child. */
|
||
if (target_follow_fork (follow_child, detach_fork))
|
||
{
|
||
/* Target refused to follow, or there's some other reason
|
||
we shouldn't resume. */
|
||
should_resume = 0;
|
||
}
|
||
else
|
||
{
|
||
/* This pending follow fork event is now handled, one way
|
||
or another. The previous selected thread may be gone
|
||
from the lists by now, but if it is still around, need
|
||
to clear the pending follow request. */
|
||
tp = find_thread_ptid (parent);
|
||
if (tp)
|
||
tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
|
||
|
||
/* This makes sure we don't try to apply the "Switched
|
||
over from WAIT_PID" logic above. */
|
||
nullify_last_target_wait_ptid ();
|
||
|
||
/* If we followed the child, switch to it... */
|
||
if (follow_child)
|
||
{
|
||
switch_to_thread (child);
|
||
|
||
/* ... and preserve the stepping state, in case the
|
||
user was stepping over the fork call. */
|
||
if (should_resume)
|
||
{
|
||
tp = inferior_thread ();
|
||
tp->control.step_resume_breakpoint
|
||
= step_resume_breakpoint;
|
||
tp->control.step_range_start = step_range_start;
|
||
tp->control.step_range_end = step_range_end;
|
||
tp->control.step_frame_id = step_frame_id;
|
||
tp->control.exception_resume_breakpoint
|
||
= exception_resume_breakpoint;
|
||
tp->control.command_interp = command_interp;
|
||
}
|
||
else
|
||
{
|
||
/* If we get here, it was because we're trying to
|
||
resume from a fork catchpoint, but, the user
|
||
has switched threads away from the thread that
|
||
forked. In that case, the resume command
|
||
issued is most likely not applicable to the
|
||
child, so just warn, and refuse to resume. */
|
||
warning (_("Not resuming: switched threads "
|
||
"before following fork child.\n"));
|
||
}
|
||
|
||
/* Reset breakpoints in the child as appropriate. */
|
||
follow_inferior_reset_breakpoints ();
|
||
}
|
||
else
|
||
switch_to_thread (parent);
|
||
}
|
||
}
|
||
break;
|
||
case TARGET_WAITKIND_SPURIOUS:
|
||
/* Nothing to follow. */
|
||
break;
|
||
default:
|
||
internal_error (__FILE__, __LINE__,
|
||
"Unexpected pending_follow.kind %d\n",
|
||
tp->pending_follow.kind);
|
||
break;
|
||
}
|
||
|
||
return should_resume;
|
||
}
|
||
|
||
void
|
||
follow_inferior_reset_breakpoints (void)
|
||
{
|
||
struct thread_info *tp = inferior_thread ();
|
||
|
||
/* Was there a step_resume breakpoint? (There was if the user
|
||
did a "next" at the fork() call.) If so, explicitly reset its
|
||
thread number. Cloned step_resume breakpoints are disabled on
|
||
creation, so enable it here now that it is associated with the
|
||
correct thread.
|
||
|
||
step_resumes are a form of bp that are made to be per-thread.
|
||
Since we created the step_resume bp when the parent process
|
||
was being debugged, and now are switching to the child process,
|
||
from the breakpoint package's viewpoint, that's a switch of
|
||
"threads". We must update the bp's notion of which thread
|
||
it is for, or it'll be ignored when it triggers. */
|
||
|
||
if (tp->control.step_resume_breakpoint)
|
||
{
|
||
breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
|
||
tp->control.step_resume_breakpoint->loc->enabled = 1;
|
||
}
|
||
|
||
/* Treat exception_resume breakpoints like step_resume breakpoints. */
|
||
if (tp->control.exception_resume_breakpoint)
|
||
{
|
||
breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
|
||
tp->control.exception_resume_breakpoint->loc->enabled = 1;
|
||
}
|
||
|
||
/* Reinsert all breakpoints in the child. The user may have set
|
||
breakpoints after catching the fork, in which case those
|
||
were never set in the child, but only in the parent. This makes
|
||
sure the inserted breakpoints match the breakpoint list. */
|
||
|
||
breakpoint_re_set ();
|
||
insert_breakpoints ();
|
||
}
|
||
|
||
/* The child has exited or execed: resume threads of the parent the
|
||
user wanted to be executing. */
|
||
|
||
static int
|
||
proceed_after_vfork_done (struct thread_info *thread,
|
||
void *arg)
|
||
{
|
||
int pid = * (int *) arg;
|
||
|
||
if (ptid_get_pid (thread->ptid) == pid
|
||
&& is_running (thread->ptid)
|
||
&& !is_executing (thread->ptid)
|
||
&& !thread->stop_requested
|
||
&& thread->suspend.stop_signal == GDB_SIGNAL_0)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: resuming vfork parent thread %s\n",
|
||
target_pid_to_str (thread->ptid));
|
||
|
||
switch_to_thread (thread->ptid);
|
||
clear_proceed_status (0);
|
||
proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0);
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Called whenever we notice an exec or exit event, to handle
|
||
detaching or resuming a vfork parent. */
|
||
|
||
static void
|
||
handle_vfork_child_exec_or_exit (int exec)
|
||
{
|
||
struct inferior *inf = current_inferior ();
|
||
|
||
if (inf->vfork_parent)
|
||
{
|
||
int resume_parent = -1;
|
||
|
||
/* This exec or exit marks the end of the shared memory region
|
||
between the parent and the child. If the user wanted to
|
||
detach from the parent, now is the time. */
|
||
|
||
if (inf->vfork_parent->pending_detach)
|
||
{
|
||
struct thread_info *tp;
|
||
struct cleanup *old_chain;
|
||
struct program_space *pspace;
|
||
struct address_space *aspace;
|
||
|
||
/* follow-fork child, detach-on-fork on. */
|
||
|
||
inf->vfork_parent->pending_detach = 0;
|
||
|
||
if (!exec)
|
||
{
|
||
/* If we're handling a child exit, then inferior_ptid
|
||
points at the inferior's pid, not to a thread. */
|
||
old_chain = save_inferior_ptid ();
|
||
save_current_program_space ();
|
||
save_current_inferior ();
|
||
}
|
||
else
|
||
old_chain = save_current_space_and_thread ();
|
||
|
||
/* We're letting loose of the parent. */
|
||
tp = any_live_thread_of_process (inf->vfork_parent->pid);
|
||
switch_to_thread (tp->ptid);
|
||
|
||
/* We're about to detach from the parent, which implicitly
|
||
removes breakpoints from its address space. There's a
|
||
catch here: we want to reuse the spaces for the child,
|
||
but, parent/child are still sharing the pspace at this
|
||
point, although the exec in reality makes the kernel give
|
||
the child a fresh set of new pages. The problem here is
|
||
that the breakpoints module being unaware of this, would
|
||
likely chose the child process to write to the parent
|
||
address space. Swapping the child temporarily away from
|
||
the spaces has the desired effect. Yes, this is "sort
|
||
of" a hack. */
|
||
|
||
pspace = inf->pspace;
|
||
aspace = inf->aspace;
|
||
inf->aspace = NULL;
|
||
inf->pspace = NULL;
|
||
|
||
if (debug_infrun || info_verbose)
|
||
{
|
||
target_terminal_ours ();
|
||
|
||
if (exec)
|
||
fprintf_filtered (gdb_stdlog,
|
||
"Detaching vfork parent process "
|
||
"%d after child exec.\n",
|
||
inf->vfork_parent->pid);
|
||
else
|
||
fprintf_filtered (gdb_stdlog,
|
||
"Detaching vfork parent process "
|
||
"%d after child exit.\n",
|
||
inf->vfork_parent->pid);
|
||
}
|
||
|
||
target_detach (NULL, 0);
|
||
|
||
/* Put it back. */
|
||
inf->pspace = pspace;
|
||
inf->aspace = aspace;
|
||
|
||
do_cleanups (old_chain);
|
||
}
|
||
else if (exec)
|
||
{
|
||
/* We're staying attached to the parent, so, really give the
|
||
child a new address space. */
|
||
inf->pspace = add_program_space (maybe_new_address_space ());
|
||
inf->aspace = inf->pspace->aspace;
|
||
inf->removable = 1;
|
||
set_current_program_space (inf->pspace);
|
||
|
||
resume_parent = inf->vfork_parent->pid;
|
||
|
||
/* Break the bonds. */
|
||
inf->vfork_parent->vfork_child = NULL;
|
||
}
|
||
else
|
||
{
|
||
struct cleanup *old_chain;
|
||
struct program_space *pspace;
|
||
|
||
/* If this is a vfork child exiting, then the pspace and
|
||
aspaces were shared with the parent. Since we're
|
||
reporting the process exit, we'll be mourning all that is
|
||
found in the address space, and switching to null_ptid,
|
||
preparing to start a new inferior. But, since we don't
|
||
want to clobber the parent's address/program spaces, we
|
||
go ahead and create a new one for this exiting
|
||
inferior. */
|
||
|
||
/* Switch to null_ptid, so that clone_program_space doesn't want
|
||
to read the selected frame of a dead process. */
|
||
old_chain = save_inferior_ptid ();
|
||
inferior_ptid = null_ptid;
|
||
|
||
/* This inferior is dead, so avoid giving the breakpoints
|
||
module the option to write through to it (cloning a
|
||
program space resets breakpoints). */
|
||
inf->aspace = NULL;
|
||
inf->pspace = NULL;
|
||
pspace = add_program_space (maybe_new_address_space ());
|
||
set_current_program_space (pspace);
|
||
inf->removable = 1;
|
||
inf->symfile_flags = SYMFILE_NO_READ;
|
||
clone_program_space (pspace, inf->vfork_parent->pspace);
|
||
inf->pspace = pspace;
|
||
inf->aspace = pspace->aspace;
|
||
|
||
/* Put back inferior_ptid. We'll continue mourning this
|
||
inferior. */
|
||
do_cleanups (old_chain);
|
||
|
||
resume_parent = inf->vfork_parent->pid;
|
||
/* Break the bonds. */
|
||
inf->vfork_parent->vfork_child = NULL;
|
||
}
|
||
|
||
inf->vfork_parent = NULL;
|
||
|
||
gdb_assert (current_program_space == inf->pspace);
|
||
|
||
if (non_stop && resume_parent != -1)
|
||
{
|
||
/* If the user wanted the parent to be running, let it go
|
||
free now. */
|
||
struct cleanup *old_chain = make_cleanup_restore_current_thread ();
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: resuming vfork parent process %d\n",
|
||
resume_parent);
|
||
|
||
iterate_over_threads (proceed_after_vfork_done, &resume_parent);
|
||
|
||
do_cleanups (old_chain);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Enum strings for "set|show follow-exec-mode". */
|
||
|
||
static const char follow_exec_mode_new[] = "new";
|
||
static const char follow_exec_mode_same[] = "same";
|
||
static const char *const follow_exec_mode_names[] =
|
||
{
|
||
follow_exec_mode_new,
|
||
follow_exec_mode_same,
|
||
NULL,
|
||
};
|
||
|
||
static const char *follow_exec_mode_string = follow_exec_mode_same;
|
||
static void
|
||
show_follow_exec_mode_string (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
|
||
}
|
||
|
||
/* EXECD_PATHNAME is assumed to be non-NULL. */
|
||
|
||
static void
|
||
follow_exec (ptid_t pid, char *execd_pathname)
|
||
{
|
||
struct thread_info *th = inferior_thread ();
|
||
struct inferior *inf = current_inferior ();
|
||
|
||
/* This is an exec event that we actually wish to pay attention to.
|
||
Refresh our symbol table to the newly exec'd program, remove any
|
||
momentary bp's, etc.
|
||
|
||
If there are breakpoints, they aren't really inserted now,
|
||
since the exec() transformed our inferior into a fresh set
|
||
of instructions.
|
||
|
||
We want to preserve symbolic breakpoints on the list, since
|
||
we have hopes that they can be reset after the new a.out's
|
||
symbol table is read.
|
||
|
||
However, any "raw" breakpoints must be removed from the list
|
||
(e.g., the solib bp's), since their address is probably invalid
|
||
now.
|
||
|
||
And, we DON'T want to call delete_breakpoints() here, since
|
||
that may write the bp's "shadow contents" (the instruction
|
||
value that was overwritten witha TRAP instruction). Since
|
||
we now have a new a.out, those shadow contents aren't valid. */
|
||
|
||
mark_breakpoints_out ();
|
||
|
||
update_breakpoints_after_exec ();
|
||
|
||
/* If there was one, it's gone now. We cannot truly step-to-next
|
||
statement through an exec(). */
|
||
th->control.step_resume_breakpoint = NULL;
|
||
th->control.exception_resume_breakpoint = NULL;
|
||
th->control.step_range_start = 0;
|
||
th->control.step_range_end = 0;
|
||
|
||
/* The target reports the exec event to the main thread, even if
|
||
some other thread does the exec, and even if the main thread was
|
||
already stopped --- if debugging in non-stop mode, it's possible
|
||
the user had the main thread held stopped in the previous image
|
||
--- release it now. This is the same behavior as step-over-exec
|
||
with scheduler-locking on in all-stop mode. */
|
||
th->stop_requested = 0;
|
||
|
||
/* What is this a.out's name? */
|
||
printf_unfiltered (_("%s is executing new program: %s\n"),
|
||
target_pid_to_str (inferior_ptid),
|
||
execd_pathname);
|
||
|
||
/* We've followed the inferior through an exec. Therefore, the
|
||
inferior has essentially been killed & reborn. */
|
||
|
||
gdb_flush (gdb_stdout);
|
||
|
||
breakpoint_init_inferior (inf_execd);
|
||
|
||
if (gdb_sysroot && *gdb_sysroot)
|
||
{
|
||
char *name = alloca (strlen (gdb_sysroot)
|
||
+ strlen (execd_pathname)
|
||
+ 1);
|
||
|
||
strcpy (name, gdb_sysroot);
|
||
strcat (name, execd_pathname);
|
||
execd_pathname = name;
|
||
}
|
||
|
||
/* Reset the shared library package. This ensures that we get a
|
||
shlib event when the child reaches "_start", at which point the
|
||
dld will have had a chance to initialize the child. */
|
||
/* Also, loading a symbol file below may trigger symbol lookups, and
|
||
we don't want those to be satisfied by the libraries of the
|
||
previous incarnation of this process. */
|
||
no_shared_libraries (NULL, 0);
|
||
|
||
if (follow_exec_mode_string == follow_exec_mode_new)
|
||
{
|
||
struct program_space *pspace;
|
||
|
||
/* The user wants to keep the old inferior and program spaces
|
||
around. Create a new fresh one, and switch to it. */
|
||
|
||
inf = add_inferior (current_inferior ()->pid);
|
||
pspace = add_program_space (maybe_new_address_space ());
|
||
inf->pspace = pspace;
|
||
inf->aspace = pspace->aspace;
|
||
|
||
exit_inferior_num_silent (current_inferior ()->num);
|
||
|
||
set_current_inferior (inf);
|
||
set_current_program_space (pspace);
|
||
}
|
||
else
|
||
{
|
||
/* The old description may no longer be fit for the new image.
|
||
E.g, a 64-bit process exec'ed a 32-bit process. Clear the
|
||
old description; we'll read a new one below. No need to do
|
||
this on "follow-exec-mode new", as the old inferior stays
|
||
around (its description is later cleared/refetched on
|
||
restart). */
|
||
target_clear_description ();
|
||
}
|
||
|
||
gdb_assert (current_program_space == inf->pspace);
|
||
|
||
/* That a.out is now the one to use. */
|
||
exec_file_attach (execd_pathname, 0);
|
||
|
||
/* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
|
||
(Position Independent Executable) main symbol file will get applied by
|
||
solib_create_inferior_hook below. breakpoint_re_set would fail to insert
|
||
the breakpoints with the zero displacement. */
|
||
|
||
symbol_file_add (execd_pathname,
|
||
(inf->symfile_flags
|
||
| SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
|
||
NULL, 0);
|
||
|
||
if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
|
||
set_initial_language ();
|
||
|
||
/* If the target can specify a description, read it. Must do this
|
||
after flipping to the new executable (because the target supplied
|
||
description must be compatible with the executable's
|
||
architecture, and the old executable may e.g., be 32-bit, while
|
||
the new one 64-bit), and before anything involving memory or
|
||
registers. */
|
||
target_find_description ();
|
||
|
||
solib_create_inferior_hook (0);
|
||
|
||
jit_inferior_created_hook ();
|
||
|
||
breakpoint_re_set ();
|
||
|
||
/* Reinsert all breakpoints. (Those which were symbolic have
|
||
been reset to the proper address in the new a.out, thanks
|
||
to symbol_file_command...). */
|
||
insert_breakpoints ();
|
||
|
||
/* The next resume of this inferior should bring it to the shlib
|
||
startup breakpoints. (If the user had also set bp's on
|
||
"main" from the old (parent) process, then they'll auto-
|
||
matically get reset there in the new process.). */
|
||
}
|
||
|
||
/* Non-zero if we just simulating a single-step. This is needed
|
||
because we cannot remove the breakpoints in the inferior process
|
||
until after the `wait' in `wait_for_inferior'. */
|
||
static int singlestep_breakpoints_inserted_p = 0;
|
||
|
||
/* The thread we inserted single-step breakpoints for. */
|
||
static ptid_t singlestep_ptid;
|
||
|
||
/* PC when we started this single-step. */
|
||
static CORE_ADDR singlestep_pc;
|
||
|
||
/* Info about an instruction that is being stepped over. Invalid if
|
||
ASPACE is NULL. */
|
||
|
||
struct step_over_info
|
||
{
|
||
/* The instruction's address space. */
|
||
struct address_space *aspace;
|
||
|
||
/* The instruction's address. */
|
||
CORE_ADDR address;
|
||
};
|
||
|
||
/* The step-over info of the location that is being stepped over.
|
||
|
||
Note that with async/breakpoint always-inserted mode, a user might
|
||
set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
|
||
being stepped over. As setting a new breakpoint inserts all
|
||
breakpoints, we need to make sure the breakpoint being stepped over
|
||
isn't inserted then. We do that by only clearing the step-over
|
||
info when the step-over is actually finished (or aborted).
|
||
|
||
Presently GDB can only step over one breakpoint at any given time.
|
||
Given threads that can't run code in the same address space as the
|
||
breakpoint's can't really miss the breakpoint, GDB could be taught
|
||
to step-over at most one breakpoint per address space (so this info
|
||
could move to the address space object if/when GDB is extended).
|
||
The set of breakpoints being stepped over will normally be much
|
||
smaller than the set of all breakpoints, so a flag in the
|
||
breakpoint location structure would be wasteful. A separate list
|
||
also saves complexity and run-time, as otherwise we'd have to go
|
||
through all breakpoint locations clearing their flag whenever we
|
||
start a new sequence. Similar considerations weigh against storing
|
||
this info in the thread object. Plus, not all step overs actually
|
||
have breakpoint locations -- e.g., stepping past a single-step
|
||
breakpoint, or stepping to complete a non-continuable
|
||
watchpoint. */
|
||
static struct step_over_info step_over_info;
|
||
|
||
/* Record the address of the breakpoint/instruction we're currently
|
||
stepping over. */
|
||
|
||
static void
|
||
set_step_over_info (struct address_space *aspace, CORE_ADDR address)
|
||
{
|
||
step_over_info.aspace = aspace;
|
||
step_over_info.address = address;
|
||
}
|
||
|
||
/* Called when we're not longer stepping over a breakpoint / an
|
||
instruction, so all breakpoints are free to be (re)inserted. */
|
||
|
||
static void
|
||
clear_step_over_info (void)
|
||
{
|
||
step_over_info.aspace = NULL;
|
||
step_over_info.address = 0;
|
||
}
|
||
|
||
/* See inferior.h. */
|
||
|
||
int
|
||
stepping_past_instruction_at (struct address_space *aspace,
|
||
CORE_ADDR address)
|
||
{
|
||
return (step_over_info.aspace != NULL
|
||
&& breakpoint_address_match (aspace, address,
|
||
step_over_info.aspace,
|
||
step_over_info.address));
|
||
}
|
||
|
||
|
||
/* Displaced stepping. */
|
||
|
||
/* In non-stop debugging mode, we must take special care to manage
|
||
breakpoints properly; in particular, the traditional strategy for
|
||
stepping a thread past a breakpoint it has hit is unsuitable.
|
||
'Displaced stepping' is a tactic for stepping one thread past a
|
||
breakpoint it has hit while ensuring that other threads running
|
||
concurrently will hit the breakpoint as they should.
|
||
|
||
The traditional way to step a thread T off a breakpoint in a
|
||
multi-threaded program in all-stop mode is as follows:
|
||
|
||
a0) Initially, all threads are stopped, and breakpoints are not
|
||
inserted.
|
||
a1) We single-step T, leaving breakpoints uninserted.
|
||
a2) We insert breakpoints, and resume all threads.
|
||
|
||
In non-stop debugging, however, this strategy is unsuitable: we
|
||
don't want to have to stop all threads in the system in order to
|
||
continue or step T past a breakpoint. Instead, we use displaced
|
||
stepping:
|
||
|
||
n0) Initially, T is stopped, other threads are running, and
|
||
breakpoints are inserted.
|
||
n1) We copy the instruction "under" the breakpoint to a separate
|
||
location, outside the main code stream, making any adjustments
|
||
to the instruction, register, and memory state as directed by
|
||
T's architecture.
|
||
n2) We single-step T over the instruction at its new location.
|
||
n3) We adjust the resulting register and memory state as directed
|
||
by T's architecture. This includes resetting T's PC to point
|
||
back into the main instruction stream.
|
||
n4) We resume T.
|
||
|
||
This approach depends on the following gdbarch methods:
|
||
|
||
- gdbarch_max_insn_length and gdbarch_displaced_step_location
|
||
indicate where to copy the instruction, and how much space must
|
||
be reserved there. We use these in step n1.
|
||
|
||
- gdbarch_displaced_step_copy_insn copies a instruction to a new
|
||
address, and makes any necessary adjustments to the instruction,
|
||
register contents, and memory. We use this in step n1.
|
||
|
||
- gdbarch_displaced_step_fixup adjusts registers and memory after
|
||
we have successfuly single-stepped the instruction, to yield the
|
||
same effect the instruction would have had if we had executed it
|
||
at its original address. We use this in step n3.
|
||
|
||
- gdbarch_displaced_step_free_closure provides cleanup.
|
||
|
||
The gdbarch_displaced_step_copy_insn and
|
||
gdbarch_displaced_step_fixup functions must be written so that
|
||
copying an instruction with gdbarch_displaced_step_copy_insn,
|
||
single-stepping across the copied instruction, and then applying
|
||
gdbarch_displaced_insn_fixup should have the same effects on the
|
||
thread's memory and registers as stepping the instruction in place
|
||
would have. Exactly which responsibilities fall to the copy and
|
||
which fall to the fixup is up to the author of those functions.
|
||
|
||
See the comments in gdbarch.sh for details.
|
||
|
||
Note that displaced stepping and software single-step cannot
|
||
currently be used in combination, although with some care I think
|
||
they could be made to. Software single-step works by placing
|
||
breakpoints on all possible subsequent instructions; if the
|
||
displaced instruction is a PC-relative jump, those breakpoints
|
||
could fall in very strange places --- on pages that aren't
|
||
executable, or at addresses that are not proper instruction
|
||
boundaries. (We do generally let other threads run while we wait
|
||
to hit the software single-step breakpoint, and they might
|
||
encounter such a corrupted instruction.) One way to work around
|
||
this would be to have gdbarch_displaced_step_copy_insn fully
|
||
simulate the effect of PC-relative instructions (and return NULL)
|
||
on architectures that use software single-stepping.
|
||
|
||
In non-stop mode, we can have independent and simultaneous step
|
||
requests, so more than one thread may need to simultaneously step
|
||
over a breakpoint. The current implementation assumes there is
|
||
only one scratch space per process. In this case, we have to
|
||
serialize access to the scratch space. If thread A wants to step
|
||
over a breakpoint, but we are currently waiting for some other
|
||
thread to complete a displaced step, we leave thread A stopped and
|
||
place it in the displaced_step_request_queue. Whenever a displaced
|
||
step finishes, we pick the next thread in the queue and start a new
|
||
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
|
||
{
|
||
/* Pointer to next in linked list. */
|
||
struct displaced_step_inferior_state *next;
|
||
|
||
/* 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;
|
||
|
||
/* If this is not null_ptid, this is the thread carrying out a
|
||
displaced single-step in process PID. This thread's state will
|
||
require fixing up once it has completed its step. */
|
||
ptid_t step_ptid;
|
||
|
||
/* The architecture the thread had when we stepped it. */
|
||
struct gdbarch *step_gdbarch;
|
||
|
||
/* The closure provided gdbarch_displaced_step_copy_insn, to be used
|
||
for post-step cleanup. */
|
||
struct displaced_step_closure *step_closure;
|
||
|
||
/* The address of the original instruction, and the copy we
|
||
made. */
|
||
CORE_ADDR step_original, step_copy;
|
||
|
||
/* Saved contents of copy area. */
|
||
gdb_byte *step_saved_copy;
|
||
};
|
||
|
||
/* The list of states of processes involved in displaced stepping
|
||
presently. */
|
||
static struct displaced_step_inferior_state *displaced_step_inferior_states;
|
||
|
||
/* Get the displaced stepping state of process PID. */
|
||
|
||
static struct displaced_step_inferior_state *
|
||
get_displaced_stepping_state (int pid)
|
||
{
|
||
struct displaced_step_inferior_state *state;
|
||
|
||
for (state = displaced_step_inferior_states;
|
||
state != NULL;
|
||
state = state->next)
|
||
if (state->pid == pid)
|
||
return state;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
static struct displaced_step_inferior_state *
|
||
add_displaced_stepping_state (int pid)
|
||
{
|
||
struct displaced_step_inferior_state *state;
|
||
|
||
for (state = displaced_step_inferior_states;
|
||
state != NULL;
|
||
state = state->next)
|
||
if (state->pid == pid)
|
||
return state;
|
||
|
||
state = xcalloc (1, sizeof (*state));
|
||
state->pid = pid;
|
||
state->next = displaced_step_inferior_states;
|
||
displaced_step_inferior_states = state;
|
||
|
||
return state;
|
||
}
|
||
|
||
/* If inferior is in displaced stepping, and ADDR equals to starting address
|
||
of copy area, return corresponding displaced_step_closure. Otherwise,
|
||
return NULL. */
|
||
|
||
struct displaced_step_closure*
|
||
get_displaced_step_closure_by_addr (CORE_ADDR addr)
|
||
{
|
||
struct displaced_step_inferior_state *displaced
|
||
= get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
|
||
|
||
/* If checking the mode of displaced instruction in copy area. */
|
||
if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
|
||
&& (displaced->step_copy == addr))
|
||
return displaced->step_closure;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Remove the displaced stepping state of process PID. */
|
||
|
||
static void
|
||
remove_displaced_stepping_state (int pid)
|
||
{
|
||
struct displaced_step_inferior_state *it, **prev_next_p;
|
||
|
||
gdb_assert (pid != 0);
|
||
|
||
it = displaced_step_inferior_states;
|
||
prev_next_p = &displaced_step_inferior_states;
|
||
while (it)
|
||
{
|
||
if (it->pid == pid)
|
||
{
|
||
*prev_next_p = it->next;
|
||
xfree (it);
|
||
return;
|
||
}
|
||
|
||
prev_next_p = &it->next;
|
||
it = *prev_next_p;
|
||
}
|
||
}
|
||
|
||
static void
|
||
infrun_inferior_exit (struct inferior *inf)
|
||
{
|
||
remove_displaced_stepping_state (inf->pid);
|
||
}
|
||
|
||
/* 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 enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
|
||
|
||
static void
|
||
show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c,
|
||
const char *value)
|
||
{
|
||
if (can_use_displaced_stepping == AUTO_BOOLEAN_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 can/should be used to step
|
||
over breakpoints. */
|
||
|
||
static int
|
||
use_displaced_stepping (struct gdbarch *gdbarch)
|
||
{
|
||
return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
|
||
|| can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
|
||
&& gdbarch_displaced_step_copy_insn_p (gdbarch)
|
||
&& find_record_target () == NULL);
|
||
}
|
||
|
||
/* Clean out any stray displaced stepping state. */
|
||
static void
|
||
displaced_step_clear (struct displaced_step_inferior_state *displaced)
|
||
{
|
||
/* Indicate that there is no cleanup pending. */
|
||
displaced->step_ptid = null_ptid;
|
||
|
||
if (displaced->step_closure)
|
||
{
|
||
gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
|
||
displaced->step_closure);
|
||
displaced->step_closure = NULL;
|
||
}
|
||
}
|
||
|
||
static void
|
||
displaced_step_clear_cleanup (void *arg)
|
||
{
|
||
struct displaced_step_inferior_state *state = arg;
|
||
|
||
displaced_step_clear (state);
|
||
}
|
||
|
||
/* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
|
||
void
|
||
displaced_step_dump_bytes (struct ui_file *file,
|
||
const gdb_byte *buf,
|
||
size_t len)
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < len; i++)
|
||
fprintf_unfiltered (file, "%02x ", buf[i]);
|
||
fputs_unfiltered ("\n", file);
|
||
}
|
||
|
||
/* Prepare to single-step, using displaced stepping.
|
||
|
||
Note that we cannot use displaced stepping when we have a signal to
|
||
deliver. If we have a signal to deliver and an instruction to step
|
||
over, then after the step, there will be no indication from the
|
||
target whether the thread entered a signal handler or ignored the
|
||
signal and stepped over the instruction successfully --- both cases
|
||
result in a simple SIGTRAP. In the first case we mustn't do a
|
||
fixup, and in the second case we must --- but we can't tell which.
|
||
Comments in the code for 'random signals' in handle_inferior_event
|
||
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. */
|
||
static int
|
||
displaced_step_prepare (ptid_t ptid)
|
||
{
|
||
struct cleanup *old_cleanups, *ignore_cleanups;
|
||
struct thread_info *tp = find_thread_ptid (ptid);
|
||
struct regcache *regcache = get_thread_regcache (ptid);
|
||
struct gdbarch *gdbarch = get_regcache_arch (regcache);
|
||
CORE_ADDR original, copy;
|
||
ULONGEST len;
|
||
struct displaced_step_closure *closure;
|
||
struct displaced_step_inferior_state *displaced;
|
||
int status;
|
||
|
||
/* We should never reach this function if the architecture does not
|
||
support displaced stepping. */
|
||
gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
|
||
|
||
/* 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
|
||
jump/branch). */
|
||
tp->control.may_range_step = 0;
|
||
|
||
/* We have to displaced step one thread at a time, as we only have
|
||
access to a single scratch space per inferior. */
|
||
|
||
displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
|
||
|
||
if (!ptid_equal (displaced->step_ptid, null_ptid))
|
||
{
|
||
/* 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",
|
||
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;
|
||
|
||
return 0;
|
||
}
|
||
else
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"displaced: stepping %s now\n",
|
||
target_pid_to_str (ptid));
|
||
}
|
||
|
||
displaced_step_clear (displaced);
|
||
|
||
old_cleanups = save_inferior_ptid ();
|
||
inferior_ptid = ptid;
|
||
|
||
original = regcache_read_pc (regcache);
|
||
|
||
copy = gdbarch_displaced_step_location (gdbarch);
|
||
len = gdbarch_max_insn_length (gdbarch);
|
||
|
||
/* Save the original contents of the copy area. */
|
||
displaced->step_saved_copy = xmalloc (len);
|
||
ignore_cleanups = make_cleanup (free_current_contents,
|
||
&displaced->step_saved_copy);
|
||
status = target_read_memory (copy, displaced->step_saved_copy, len);
|
||
if (status != 0)
|
||
throw_error (MEMORY_ERROR,
|
||
_("Error accessing memory address %s (%s) for "
|
||
"displaced-stepping scratch space."),
|
||
paddress (gdbarch, copy), safe_strerror (status));
|
||
if (debug_displaced)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
|
||
paddress (gdbarch, copy));
|
||
displaced_step_dump_bytes (gdb_stdlog,
|
||
displaced->step_saved_copy,
|
||
len);
|
||
};
|
||
|
||
closure = gdbarch_displaced_step_copy_insn (gdbarch,
|
||
original, copy, regcache);
|
||
|
||
/* We don't support the fully-simulated case at present. */
|
||
gdb_assert (closure);
|
||
|
||
/* Save the information we need to fix things up if the step
|
||
succeeds. */
|
||
displaced->step_ptid = ptid;
|
||
displaced->step_gdbarch = gdbarch;
|
||
displaced->step_closure = closure;
|
||
displaced->step_original = original;
|
||
displaced->step_copy = copy;
|
||
|
||
make_cleanup (displaced_step_clear_cleanup, displaced);
|
||
|
||
/* Resume execution at the copy. */
|
||
regcache_write_pc (regcache, copy);
|
||
|
||
discard_cleanups (ignore_cleanups);
|
||
|
||
do_cleanups (old_cleanups);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
|
||
paddress (gdbarch, copy));
|
||
|
||
return 1;
|
||
}
|
||
|
||
static void
|
||
write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
|
||
const gdb_byte *myaddr, int len)
|
||
{
|
||
struct cleanup *ptid_cleanup = save_inferior_ptid ();
|
||
|
||
inferior_ptid = ptid;
|
||
write_memory (memaddr, myaddr, len);
|
||
do_cleanups (ptid_cleanup);
|
||
}
|
||
|
||
/* Restore the contents of the copy area for thread PTID. */
|
||
|
||
static void
|
||
displaced_step_restore (struct displaced_step_inferior_state *displaced,
|
||
ptid_t ptid)
|
||
{
|
||
ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
|
||
|
||
write_memory_ptid (ptid, displaced->step_copy,
|
||
displaced->step_saved_copy, len);
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
|
||
target_pid_to_str (ptid),
|
||
paddress (displaced->step_gdbarch,
|
||
displaced->step_copy));
|
||
}
|
||
|
||
static void
|
||
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));
|
||
|
||
/* Was any thread of this process doing a displaced step? */
|
||
if (displaced == NULL)
|
||
return;
|
||
|
||
/* Was this event for the pid we displaced? */
|
||
if (ptid_equal (displaced->step_ptid, null_ptid)
|
||
|| ! ptid_equal (displaced->step_ptid, event_ptid))
|
||
return;
|
||
|
||
old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
|
||
|
||
displaced_step_restore (displaced, displaced->step_ptid);
|
||
|
||
/* Did the instruction complete successfully? */
|
||
if (signal == GDB_SIGNAL_TRAP)
|
||
{
|
||
/* 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));
|
||
}
|
||
else
|
||
{
|
||
/* Since the instruction didn't complete, all we can do is
|
||
relocate the PC. */
|
||
struct regcache *regcache = get_thread_regcache (event_ptid);
|
||
CORE_ADDR pc = regcache_read_pc (regcache);
|
||
|
||
pc = displaced->step_original + (pc - displaced->step_copy);
|
||
regcache_write_pc (regcache, pc);
|
||
}
|
||
|
||
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;
|
||
|
||
head = displaced->step_request_queue;
|
||
ptid = head->ptid;
|
||
displaced->step_request_queue = head->next;
|
||
xfree (head);
|
||
|
||
context_switch (ptid);
|
||
|
||
regcache = get_thread_regcache (ptid);
|
||
actual_pc = regcache_read_pc (regcache);
|
||
aspace = get_regcache_aspace (regcache);
|
||
|
||
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));
|
||
|
||
displaced_step_prepare (ptid);
|
||
|
||
gdbarch = get_regcache_arch (regcache);
|
||
|
||
if (debug_displaced)
|
||
{
|
||
CORE_ADDR actual_pc = regcache_read_pc (regcache);
|
||
gdb_byte buf[4];
|
||
|
||
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));
|
||
}
|
||
|
||
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);
|
||
|
||
/* Done, we're stepping a thread. */
|
||
break;
|
||
}
|
||
else
|
||
{
|
||
int step;
|
||
struct thread_info *tp = inferior_thread ();
|
||
|
||
/* The breakpoint we were sitting under has since been
|
||
removed. */
|
||
tp->control.trap_expected = 0;
|
||
|
||
/* Go back to what we were trying to do. */
|
||
step = currently_stepping (tp);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"displaced: breakpoint is gone: %s, step(%d)\n",
|
||
target_pid_to_str (tp->ptid), step);
|
||
|
||
target_resume (ptid, step, GDB_SIGNAL_0);
|
||
tp->suspend.stop_signal = GDB_SIGNAL_0;
|
||
|
||
/* This request was discarded. See if there's any other
|
||
thread waiting for its turn. */
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Update global variables holding ptids to hold NEW_PTID if they were
|
||
holding OLD_PTID. */
|
||
static void
|
||
infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
|
||
{
|
||
struct displaced_step_request *it;
|
||
struct displaced_step_inferior_state *displaced;
|
||
|
||
if (ptid_equal (inferior_ptid, old_ptid))
|
||
inferior_ptid = new_ptid;
|
||
|
||
if (ptid_equal (singlestep_ptid, old_ptid))
|
||
singlestep_ptid = new_ptid;
|
||
|
||
for (displaced = displaced_step_inferior_states;
|
||
displaced;
|
||
displaced = displaced->next)
|
||
{
|
||
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;
|
||
}
|
||
}
|
||
|
||
|
||
/* Resuming. */
|
||
|
||
/* Things to clean up if we QUIT out of resume (). */
|
||
static void
|
||
resume_cleanups (void *ignore)
|
||
{
|
||
normal_stop ();
|
||
}
|
||
|
||
static const char schedlock_off[] = "off";
|
||
static const char schedlock_on[] = "on";
|
||
static const char schedlock_step[] = "step";
|
||
static const char *const scheduler_enums[] = {
|
||
schedlock_off,
|
||
schedlock_on,
|
||
schedlock_step,
|
||
NULL
|
||
};
|
||
static const char *scheduler_mode = schedlock_off;
|
||
static void
|
||
show_scheduler_mode (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file,
|
||
_("Mode for locking scheduler "
|
||
"during execution is \"%s\".\n"),
|
||
value);
|
||
}
|
||
|
||
static void
|
||
set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
|
||
{
|
||
if (!target_can_lock_scheduler)
|
||
{
|
||
scheduler_mode = schedlock_off;
|
||
error (_("Target '%s' cannot support this command."), target_shortname);
|
||
}
|
||
}
|
||
|
||
/* True if execution commands resume all threads of all processes by
|
||
default; otherwise, resume only threads of the current inferior
|
||
process. */
|
||
int sched_multi = 0;
|
||
|
||
/* Try to setup for software single stepping over the specified location.
|
||
Return 1 if target_resume() should use hardware single step.
|
||
|
||
GDBARCH the current gdbarch.
|
||
PC the location to step over. */
|
||
|
||
static int
|
||
maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
|
||
{
|
||
int hw_step = 1;
|
||
|
||
if (execution_direction == EXEC_FORWARD
|
||
&& gdbarch_software_single_step_p (gdbarch)
|
||
&& gdbarch_software_single_step (gdbarch, get_current_frame ()))
|
||
{
|
||
hw_step = 0;
|
||
/* Do not pull these breakpoints until after a `wait' in
|
||
`wait_for_inferior'. */
|
||
singlestep_breakpoints_inserted_p = 1;
|
||
singlestep_ptid = inferior_ptid;
|
||
singlestep_pc = pc;
|
||
}
|
||
return hw_step;
|
||
}
|
||
|
||
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));
|
||
}
|
||
|
||
/* Maybe resume a single thread after all. */
|
||
if (non_stop)
|
||
{
|
||
/* With non-stop mode on, threads are always handled
|
||
individually. */
|
||
resume_ptid = inferior_ptid;
|
||
}
|
||
else if ((scheduler_mode == schedlock_on)
|
||
|| (scheduler_mode == schedlock_step
|
||
&& (step || singlestep_breakpoints_inserted_p)))
|
||
{
|
||
/* User-settable 'scheduler' mode requires solo thread resume. */
|
||
resume_ptid = inferior_ptid;
|
||
}
|
||
|
||
/* 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;
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
|
||
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);
|
||
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;
|
||
|
||
QUIT;
|
||
|
||
if (current_inferior ()->waiting_for_vfork_done)
|
||
{
|
||
/* Don't try to single-step a vfork parent that is waiting for
|
||
the child to get out of the shared memory region (by exec'ing
|
||
or exiting). This is particularly important on software
|
||
single-step archs, as the child process would trip on the
|
||
software single step breakpoint inserted for the parent
|
||
process. Since the parent will not actually execute any
|
||
instruction until the child is out of the shared region (such
|
||
are vfork's semantics), it is safe to simply continue it.
|
||
Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
|
||
the parent, and tell it to `keep_going', which automatically
|
||
re-sets it stepping. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: resume : clear step\n");
|
||
step = 0;
|
||
}
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: resume (step=%d, signal=%s), "
|
||
"trap_expected=%d, current thread [%s] at %s\n",
|
||
step, gdb_signal_to_symbol_string (sig),
|
||
tp->control.trap_expected,
|
||
target_pid_to_str (inferior_ptid),
|
||
paddress (gdbarch, pc));
|
||
|
||
/* Normally, by the time we reach `resume', the breakpoints are either
|
||
removed or inserted, as appropriate. The exception is if we're sitting
|
||
at a permanent breakpoint; we need to step over it, but permanent
|
||
breakpoints can't be removed. So we have to test for it here. */
|
||
if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
|
||
{
|
||
if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
|
||
gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
|
||
else
|
||
error (_("\
|
||
The program is stopped at a permanent breakpoint, but GDB does not know\n\
|
||
how to step past a permanent breakpoint on this architecture. Try using\n\
|
||
a command like `return' or `jump' to continue execution."));
|
||
}
|
||
|
||
/* If we have a breakpoint to step over, make sure to do a single
|
||
step only. Same if we have software watchpoints. */
|
||
if (tp->control.trap_expected || bpstat_should_step ())
|
||
tp->control.may_range_step = 0;
|
||
|
||
/* If enabled, step over breakpoints by executing a copy of the
|
||
instruction at a different address.
|
||
|
||
We can't use displaced stepping when we have a signal to deliver;
|
||
the comments for displaced_step_prepare explain why. The
|
||
comments in the handle_inferior event for dealing with 'random
|
||
signals' explain what we do instead.
|
||
|
||
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
|
||
|| (step && gdbarch_software_single_step_p (gdbarch)))
|
||
&& sig == GDB_SIGNAL_0
|
||
&& !current_inferior ()->waiting_for_vfork_done)
|
||
{
|
||
struct displaced_step_inferior_state *displaced;
|
||
|
||
if (!displaced_step_prepare (inferior_ptid))
|
||
{
|
||
/* 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);
|
||
discard_cleanups (old_cleanups);
|
||
return;
|
||
}
|
||
|
||
/* 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);
|
||
}
|
||
|
||
/* Do we need to do it the hard way, w/temp breakpoints? */
|
||
else if (step)
|
||
step = maybe_software_singlestep (gdbarch, pc);
|
||
|
||
/* Currently, our software single-step implementation leads to different
|
||
results than hardware single-stepping in one situation: when stepping
|
||
into delivering a signal which has an associated signal handler,
|
||
hardware single-step will stop at the first instruction of the handler,
|
||
while software single-step will simply skip execution of the handler.
|
||
|
||
For now, this difference in behavior is accepted since there is no
|
||
easy way to actually implement single-stepping into a signal handler
|
||
without kernel support.
|
||
|
||
However, there is one scenario where this difference leads to follow-on
|
||
problems: if we're stepping off a breakpoint by removing all breakpoints
|
||
and then single-stepping. In this case, the software single-step
|
||
behavior means that even if there is a *breakpoint* in the signal
|
||
handler, GDB still would not stop.
|
||
|
||
Fortunately, we can at least fix this particular issue. We detect
|
||
here the case where we are about to deliver a signal while software
|
||
single-stepping with breakpoints removed. In this situation, we
|
||
revert the decisions to remove all breakpoints and insert single-
|
||
step breakpoints, and instead we install a step-resume breakpoint
|
||
at the current address, deliver the signal without stepping, and
|
||
once we arrive back at the step-resume breakpoint, actually step
|
||
over the breakpoint we originally wanted to step over. */
|
||
if (singlestep_breakpoints_inserted_p
|
||
&& tp->control.trap_expected && sig != GDB_SIGNAL_0)
|
||
{
|
||
/* If we have nested signals or a pending signal is delivered
|
||
immediately after a handler returns, might might already have
|
||
a step-resume breakpoint set on the earlier handler. We cannot
|
||
set another step-resume breakpoint; just continue on until the
|
||
original breakpoint is hit. */
|
||
if (tp->control.step_resume_breakpoint == NULL)
|
||
{
|
||
insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
|
||
tp->step_after_step_resume_breakpoint = 1;
|
||
}
|
||
|
||
remove_single_step_breakpoints ();
|
||
singlestep_breakpoints_inserted_p = 0;
|
||
|
||
clear_step_over_info ();
|
||
tp->control.trap_expected = 0;
|
||
|
||
insert_breakpoints ();
|
||
}
|
||
|
||
/* If STEP is set, it's a request to use hardware stepping
|
||
facilities. But in that case, we should never
|
||
use singlestep breakpoint. */
|
||
gdb_assert (!(singlestep_breakpoints_inserted_p && 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. */
|
||
if ((step || singlestep_breakpoints_inserted_p)
|
||
&& tp->control.trap_expected)
|
||
{
|
||
/* We're allowing a thread to run past a breakpoint it has
|
||
hit, by single-stepping the thread with the breakpoint
|
||
removed. In which case, we need to single-step only this
|
||
thread, and keep others stopped, as they can miss this
|
||
breakpoint if allowed to run. */
|
||
resume_ptid = inferior_ptid;
|
||
}
|
||
|
||
if (gdbarch_cannot_step_breakpoint (gdbarch))
|
||
{
|
||
/* Most targets can step a breakpoint instruction, thus
|
||
executing it normally. But if this one cannot, just
|
||
continue and we will hit it anyway. */
|
||
if (step && breakpoint_inserted_here_p (aspace, pc))
|
||
step = 0;
|
||
}
|
||
|
||
if (debug_displaced
|
||
&& use_displaced_stepping (gdbarch)
|
||
&& tp->control.trap_expected)
|
||
{
|
||
struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
|
||
struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
|
||
CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
|
||
gdb_byte buf[4];
|
||
|
||
fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
|
||
paddress (resume_gdbarch, actual_pc));
|
||
read_memory (actual_pc, buf, sizeof (buf));
|
||
displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
|
||
}
|
||
|
||
if (tp->control.may_range_step)
|
||
{
|
||
/* If we're resuming a thread with the PC out of the step
|
||
range, then we're doing some nested/finer run control
|
||
operation, like stepping the thread out of the dynamic
|
||
linker or the displaced stepping scratch pad. We
|
||
shouldn't have allowed a range step then. */
|
||
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 (which can
|
||
happen only if we are not using displaced stepping), we need to
|
||
receive all signals to avoid accidentally skipping a breakpoint
|
||
during execution of a signal handler. */
|
||
if ((step || singlestep_breakpoints_inserted_p)
|
||
&& tp->control.trap_expected
|
||
&& !use_displaced_stepping (gdbarch))
|
||
target_pass_signals (0, NULL);
|
||
else
|
||
target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
|
||
|
||
target_resume (resume_ptid, step, sig);
|
||
|
||
discard_cleanups (old_cleanups);
|
||
}
|
||
|
||
/* Proceeding. */
|
||
|
||
/* Clear out all variables saying what to do when inferior is continued.
|
||
First do this, then set the ones you want, then call `proceed'. */
|
||
|
||
static void
|
||
clear_proceed_status_thread (struct thread_info *tp)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: clear_proceed_status_thread (%s)\n",
|
||
target_pid_to_str (tp->ptid));
|
||
|
||
/* 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->suspend.stop_signal = GDB_SIGNAL_0;
|
||
|
||
tp->control.trap_expected = 0;
|
||
tp->control.step_range_start = 0;
|
||
tp->control.step_range_end = 0;
|
||
tp->control.may_range_step = 0;
|
||
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->stop_requested = 0;
|
||
|
||
tp->control.stop_step = 0;
|
||
|
||
tp->control.proceed_to_finish = 0;
|
||
|
||
tp->control.command_interp = NULL;
|
||
|
||
/* Discard any remaining commands or status from previous stop. */
|
||
bpstat_clear (&tp->control.stop_bpstat);
|
||
}
|
||
|
||
void
|
||
clear_proceed_status (int step)
|
||
{
|
||
if (!non_stop)
|
||
{
|
||
struct thread_info *tp;
|
||
ptid_t resume_ptid;
|
||
|
||
resume_ptid = user_visible_resume_ptid (step);
|
||
|
||
/* In all-stop mode, delete the per-thread status of all threads
|
||
we're about to resume, implicitly and explicitly. */
|
||
ALL_NON_EXITED_THREADS (tp)
|
||
{
|
||
if (!ptid_match (tp->ptid, resume_ptid))
|
||
continue;
|
||
clear_proceed_status_thread (tp);
|
||
}
|
||
}
|
||
|
||
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 ());
|
||
}
|
||
|
||
inferior = current_inferior ();
|
||
inferior->control.stop_soon = NO_STOP_QUIETLY;
|
||
}
|
||
|
||
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
|
||
stepping-over in order to make progress. If the breakpoint is gone
|
||
meanwhile, we can skip the whole step-over dance. */
|
||
|
||
static int
|
||
thread_still_needs_step_over (struct thread_info *tp)
|
||
{
|
||
if (tp->stepping_over_breakpoint)
|
||
{
|
||
struct regcache *regcache = get_thread_regcache (tp->ptid);
|
||
|
||
if (breakpoint_here_p (get_regcache_aspace (regcache),
|
||
regcache_read_pc (regcache)))
|
||
return 1;
|
||
|
||
tp->stepping_over_breakpoint = 0;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Returns true if scheduler locking applies. STEP indicates whether
|
||
we're about to do a step/next-like command to a thread. */
|
||
|
||
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)
|
||
{
|
||
struct thread_info *tp, *current;
|
||
|
||
/* With non-stop mode on, threads are always handled individually. */
|
||
gdb_assert (! non_stop);
|
||
|
||
current = inferior_thread ();
|
||
|
||
/* 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;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
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;
|
||
|
||
if (thread_still_needs_step_over (tp))
|
||
return tp;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Basic routine for continuing the program in various fashions.
|
||
|
||
ADDR is the address to resume at, or -1 for resume where stopped.
|
||
SIGGNAL is the signal to give it, or 0 for none,
|
||
or -1 for act according to how it stopped.
|
||
STEP is nonzero if should trap after one instruction.
|
||
-1 means return after that and print nothing.
|
||
You should probably set various step_... variables
|
||
before calling here, if you are stepping.
|
||
|
||
You should call clear_proceed_status before calling proceed. */
|
||
|
||
void
|
||
proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
|
||
{
|
||
struct regcache *regcache;
|
||
struct gdbarch *gdbarch;
|
||
struct thread_info *tp;
|
||
CORE_ADDR pc;
|
||
struct address_space *aspace;
|
||
|
||
/* If we're stopped at a fork/vfork, follow the branch set by the
|
||
"set follow-fork-mode" command; otherwise, we'll just proceed
|
||
resuming the current thread. */
|
||
if (!follow_fork ())
|
||
{
|
||
/* The target for some reason decided not to resume. */
|
||
normal_stop ();
|
||
if (target_can_async_p ())
|
||
inferior_event_handler (INF_EXEC_COMPLETE, NULL);
|
||
return;
|
||
}
|
||
|
||
/* We'll update this if & when we switch to a new thread. */
|
||
previous_inferior_ptid = inferior_ptid;
|
||
|
||
regcache = get_current_regcache ();
|
||
gdbarch = get_regcache_arch (regcache);
|
||
aspace = get_regcache_aspace (regcache);
|
||
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);
|
||
|
||
if (addr == (CORE_ADDR) -1)
|
||
{
|
||
if (pc == stop_pc && breakpoint_here_p (aspace, 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).
|
||
|
||
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. */
|
||
tp->stepping_over_breakpoint = 1;
|
||
else if (gdbarch_single_step_through_delay_p (gdbarch)
|
||
&& gdbarch_single_step_through_delay (gdbarch,
|
||
get_current_frame ()))
|
||
/* We stepped onto an instruction that needs to be stepped
|
||
again before re-inserting the breakpoint, do so. */
|
||
tp->stepping_over_breakpoint = 1;
|
||
}
|
||
else
|
||
{
|
||
regcache_write_pc (regcache, addr);
|
||
}
|
||
|
||
if (siggnal != GDB_SIGNAL_DEFAULT)
|
||
tp->suspend.stop_signal = siggnal;
|
||
|
||
/* Record the interpreter that issued the execution command that
|
||
caused this thread to resume. If the top level interpreter is
|
||
MI/async, and the execution command was a CLI command
|
||
(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 ();
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: proceed (addr=%s, signal=%s, step=%d)\n",
|
||
paddress (gdbarch, addr),
|
||
gdb_signal_to_symbol_string (siggnal), step);
|
||
|
||
if (non_stop)
|
||
/* In non-stop, each thread is handled individually. The context
|
||
must already be set to the right thread here. */
|
||
;
|
||
else
|
||
{
|
||
struct thread_info *step_over;
|
||
|
||
/* In a multi-threaded task we may select another thread and
|
||
then continue or step.
|
||
|
||
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.
|
||
|
||
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));
|
||
|
||
/* 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;
|
||
}
|
||
}
|
||
|
||
/* 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 ();
|
||
|
||
set_step_over_info (get_regcache_aspace (regcache),
|
||
regcache_read_pc (regcache));
|
||
}
|
||
else
|
||
clear_step_over_info ();
|
||
|
||
insert_breakpoints ();
|
||
|
||
tp->control.trap_expected = tp->stepping_over_breakpoint;
|
||
|
||
annotate_starting ();
|
||
|
||
/* Make sure that output from GDB appears before output from the
|
||
inferior. */
|
||
gdb_flush (gdb_stdout);
|
||
|
||
/* 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 ());
|
||
|
||
/* Reset to normal state. */
|
||
init_infwait_state ();
|
||
|
||
/* Resume inferior. */
|
||
resume (tp->control.trap_expected || step || bpstat_should_step (),
|
||
tp->suspend.stop_signal);
|
||
|
||
/* Wait for it to stop (if not standalone)
|
||
and in any case decode why it stopped, and act accordingly. */
|
||
/* Do this only if we are not using the event loop, or if the target
|
||
does not support asynchronous execution. */
|
||
if (!target_can_async_p ())
|
||
{
|
||
wait_for_inferior ();
|
||
normal_stop ();
|
||
}
|
||
}
|
||
|
||
|
||
/* Start remote-debugging of a machine over a serial link. */
|
||
|
||
void
|
||
start_remote (int from_tty)
|
||
{
|
||
struct inferior *inferior;
|
||
|
||
inferior = current_inferior ();
|
||
inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
|
||
|
||
/* Always go on waiting for the target, regardless of the mode. */
|
||
/* FIXME: cagney/1999-09-23: At present it isn't possible to
|
||
indicate to wait_for_inferior that a target should timeout if
|
||
nothing is returned (instead of just blocking). Because of this,
|
||
targets expecting an immediate response need to, internally, set
|
||
things up so that the target_wait() is forced to eventually
|
||
timeout. */
|
||
/* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
|
||
differentiate to its caller what the state of the target is after
|
||
the initial open has been performed. Here we're assuming that
|
||
the target has stopped. It should be possible to eventually have
|
||
target_open() return to the caller an indication that the target
|
||
is currently running and GDB state should be set to the same as
|
||
for an async run. */
|
||
wait_for_inferior ();
|
||
|
||
/* Now that the inferior has stopped, do any bookkeeping like
|
||
loading shared libraries. We want to do this before normal_stop,
|
||
so that the displayed frame is up to date. */
|
||
post_create_inferior (¤t_target, from_tty);
|
||
|
||
normal_stop ();
|
||
}
|
||
|
||
/* Initialize static vars when a new inferior begins. */
|
||
|
||
void
|
||
init_wait_for_inferior (void)
|
||
{
|
||
/* These are meaningless until the first time through wait_for_inferior. */
|
||
|
||
breakpoint_init_inferior (inf_starting);
|
||
|
||
clear_proceed_status (0);
|
||
|
||
target_last_wait_ptid = minus_one_ptid;
|
||
|
||
previous_inferior_ptid = inferior_ptid;
|
||
init_infwait_state ();
|
||
|
||
/* Discard any skipped inlined frames. */
|
||
clear_inline_frame_state (minus_one_ptid);
|
||
|
||
singlestep_ptid = null_ptid;
|
||
singlestep_pc = 0;
|
||
}
|
||
|
||
|
||
/* This enum encodes possible reasons for doing a target_wait, so that
|
||
wfi can call target_wait in one place. (Ultimately the call will be
|
||
moved out of the infinite loop entirely.) */
|
||
|
||
enum infwait_states
|
||
{
|
||
infwait_normal_state,
|
||
infwait_step_watch_state,
|
||
infwait_nonstep_watch_state
|
||
};
|
||
|
||
/* The PTID we'll do a target_wait on.*/
|
||
ptid_t waiton_ptid;
|
||
|
||
/* Current inferior wait state. */
|
||
static enum infwait_states infwait_state;
|
||
|
||
/* 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;
|
||
|
||
/* We were in infwait_step_watch_state or
|
||
infwait_nonstep_watch_state state, and the thread reported an
|
||
event. */
|
||
int stepped_after_stopped_by_watchpoint;
|
||
|
||
/* 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 handle_step_into_function (struct gdbarch *gdbarch,
|
||
struct execution_control_state *ecs);
|
||
static void handle_step_into_function_backward (struct gdbarch *gdbarch,
|
||
struct execution_control_state *ecs);
|
||
static void handle_signal_stop (struct execution_control_state *ecs);
|
||
static void check_exception_resume (struct execution_control_state *,
|
||
struct frame_info *);
|
||
|
||
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);
|
||
|
||
/* 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 ();
|
||
|
||
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 ();
|
||
|
||
/* 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_ptid (info->ptid);
|
||
ecs->ws.kind = TARGET_WAITKIND_STOPPED;
|
||
ecs->ws.value.sig = GDB_SIGNAL_0;
|
||
|
||
handle_inferior_event (ecs);
|
||
|
||
if (!ecs->wait_some_more)
|
||
{
|
||
struct thread_info *tp;
|
||
|
||
normal_stop ();
|
||
|
||
/* Finish off the continuations. */
|
||
tp = inferior_thread ();
|
||
do_all_intermediate_continuations_thread (tp, 1);
|
||
do_all_continuations_thread (tp, 1);
|
||
}
|
||
|
||
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. */
|
||
|
||
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;
|
||
}
|
||
|
||
it = *prev_next_p;
|
||
}
|
||
}
|
||
|
||
iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
|
||
}
|
||
|
||
static void
|
||
infrun_thread_thread_exit (struct thread_info *tp, int silent)
|
||
{
|
||
if (ptid_equal (target_last_wait_ptid, tp->ptid))
|
||
nullify_last_target_wait_ptid ();
|
||
}
|
||
|
||
/* Callback for iterate_over_threads. */
|
||
|
||
static int
|
||
delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
|
||
{
|
||
if (is_exited (info->ptid))
|
||
return 0;
|
||
|
||
delete_step_resume_breakpoint (info);
|
||
delete_exception_resume_breakpoint (info);
|
||
return 0;
|
||
}
|
||
|
||
/* In all-stop, delete the step resume breakpoint of any thread that
|
||
had one. In non-stop, delete the step resume breakpoint of the
|
||
thread that just stopped. */
|
||
|
||
static void
|
||
delete_step_thread_step_resume_breakpoint (void)
|
||
{
|
||
if (!target_has_execution
|
||
|| ptid_equal (inferior_ptid, null_ptid))
|
||
/* If the inferior has exited, we have already deleted the step
|
||
resume breakpoints out of GDB's lists. */
|
||
return;
|
||
|
||
if (non_stop)
|
||
{
|
||
/* If in non-stop mode, only delete the step-resume or
|
||
longjmp-resume breakpoint of the thread that just stopped
|
||
stepping. */
|
||
struct thread_info *tp = inferior_thread ();
|
||
|
||
delete_step_resume_breakpoint (tp);
|
||
delete_exception_resume_breakpoint (tp);
|
||
}
|
||
else
|
||
/* In all-stop mode, delete all step-resume and longjmp-resume
|
||
breakpoints of any thread that had them. */
|
||
iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
|
||
}
|
||
|
||
/* A cleanup wrapper. */
|
||
|
||
static void
|
||
delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
|
||
{
|
||
delete_step_thread_step_resume_breakpoint ();
|
||
}
|
||
|
||
/* Pretty print the results of target_wait, for debugging purposes. */
|
||
|
||
static void
|
||
print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
|
||
const struct target_waitstatus *ws)
|
||
{
|
||
char *status_string = target_waitstatus_to_string (ws);
|
||
struct ui_file *tmp_stream = mem_fileopen ();
|
||
char *text;
|
||
|
||
/* The text is split over several lines because it was getting too long.
|
||
Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
|
||
output as a unit; we want only one timestamp printed if debug_timestamp
|
||
is set. */
|
||
|
||
fprintf_unfiltered (tmp_stream,
|
||
"infrun: target_wait (%d", ptid_get_pid (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",
|
||
ptid_get_pid (result_ptid),
|
||
target_pid_to_str (result_ptid));
|
||
fprintf_unfiltered (tmp_stream,
|
||
"infrun: %s\n",
|
||
status_string);
|
||
|
||
text = ui_file_xstrdup (tmp_stream, NULL);
|
||
|
||
/* This uses %s in part to handle %'s in the text, but also to avoid
|
||
a gcc error: the format attribute requires a string literal. */
|
||
fprintf_unfiltered (gdb_stdlog, "%s", text);
|
||
|
||
xfree (status_string);
|
||
xfree (text);
|
||
ui_file_delete (tmp_stream);
|
||
}
|
||
|
||
/* 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
|
||
pad. */
|
||
|
||
void
|
||
prepare_for_detach (void)
|
||
{
|
||
struct inferior *inf = current_inferior ();
|
||
ptid_t pid_ptid = pid_to_ptid (inf->pid);
|
||
struct cleanup *old_chain_1;
|
||
struct displaced_step_inferior_state *displaced;
|
||
|
||
displaced = get_displaced_stepping_state (inf->pid);
|
||
|
||
/* Is any thread of this process displaced stepping? If not,
|
||
there's nothing else to do. */
|
||
if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
|
||
return;
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"displaced-stepping in-process while detaching");
|
||
|
||
old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
|
||
inf->detaching = 1;
|
||
|
||
while (!ptid_equal (displaced->step_ptid, null_ptid))
|
||
{
|
||
struct cleanup *old_chain_2;
|
||
struct execution_control_state ecss;
|
||
struct execution_control_state *ecs;
|
||
|
||
ecs = &ecss;
|
||
memset (ecs, 0, sizeof (*ecs));
|
||
|
||
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)
|
||
ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
|
||
else
|
||
ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
|
||
|
||
if (debug_infrun)
|
||
print_target_wait_results (pid_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_2 = 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_2);
|
||
|
||
/* Breakpoints and watchpoints are not installed on the target
|
||
at this point, and signals are passed directly to the
|
||
inferior, so this must mean the process is gone. */
|
||
if (!ecs->wait_some_more)
|
||
{
|
||
discard_cleanups (old_chain_1);
|
||
error (_("Program exited while detaching"));
|
||
}
|
||
}
|
||
|
||
discard_cleanups (old_chain_1);
|
||
}
|
||
|
||
/* Wait for control to return from inferior to debugger.
|
||
|
||
If inferior gets a signal, we may decide to start it up again
|
||
instead of returning. That is why there is a loop in this function.
|
||
When this function actually returns it means the inferior
|
||
should be left stopped and GDB should read more commands. */
|
||
|
||
void
|
||
wait_for_inferior (void)
|
||
{
|
||
struct cleanup *old_cleanups;
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered
|
||
(gdb_stdlog, "infrun: wait_for_inferior ()\n");
|
||
|
||
old_cleanups =
|
||
make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
|
||
|
||
while (1)
|
||
{
|
||
struct execution_control_state ecss;
|
||
struct execution_control_state *ecs = &ecss;
|
||
struct cleanup *old_chain;
|
||
|
||
memset (ecs, 0, sizeof (*ecs));
|
||
|
||
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)
|
||
ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
|
||
else
|
||
ecs->ptid = 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;
|
||
}
|
||
|
||
do_cleanups (old_cleanups);
|
||
}
|
||
|
||
/* Asynchronous version of wait_for_inferior. It is called by the
|
||
event loop whenever a change of state is detected on the file
|
||
descriptor corresponding to the target. It can be called more than
|
||
once to complete a single execution command. In such cases we need
|
||
to keep the state in a global variable ECSS. If it is the last time
|
||
that this function is called for a single execution command, then
|
||
report to the user that the inferior has stopped, and do the
|
||
necessary cleanups. */
|
||
|
||
void
|
||
fetch_inferior_event (void *client_data)
|
||
{
|
||
struct execution_control_state ecss;
|
||
struct execution_control_state *ecs = &ecss;
|
||
struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
|
||
struct cleanup *ts_old_chain;
|
||
int was_sync = sync_execution;
|
||
int cmd_done = 0;
|
||
|
||
memset (ecs, 0, sizeof (*ecs));
|
||
|
||
/* We're handling a live event, so make sure we're doing live
|
||
debugging. If we're looking at traceframes while the target is
|
||
running, we're going to need to get back to that mode after
|
||
handling the event. */
|
||
if (non_stop)
|
||
{
|
||
make_cleanup_restore_current_traceframe ();
|
||
set_current_traceframe (-1);
|
||
}
|
||
|
||
if (non_stop)
|
||
/* In non-stop mode, the user/frontend should not notice a thread
|
||
switch due to internal events. Make sure we reverse to the
|
||
user selected thread and frame after handling the event and
|
||
running any breakpoint commands. */
|
||
make_cleanup_restore_current_thread ();
|
||
|
||
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 ();
|
||
|
||
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);
|
||
|
||
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)
|
||
ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
|
||
else
|
||
ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
|
||
|
||
/* Get executed before make_cleanup_restore_current_thread above to apply
|
||
still for the thread which has thrown the exception. */
|
||
make_bpstat_clear_actions_cleanup ();
|
||
|
||
/* Now figure out what to do with the result of the result. */
|
||
handle_inferior_event (ecs);
|
||
|
||
if (!ecs->wait_some_more)
|
||
{
|
||
struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
|
||
|
||
delete_step_thread_step_resume_breakpoint ();
|
||
|
||
/* We may not find an inferior if this was a process exit. */
|
||
if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
|
||
normal_stop ();
|
||
|
||
if (target_has_execution
|
||
&& ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
|
||
&& ecs->ws.kind != TARGET_WAITKIND_EXITED
|
||
&& ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
|
||
&& ecs->event_thread->step_multi
|
||
&& ecs->event_thread->control.stop_step)
|
||
inferior_event_handler (INF_EXEC_CONTINUE, NULL);
|
||
else
|
||
{
|
||
inferior_event_handler (INF_EXEC_COMPLETE, NULL);
|
||
cmd_done = 1;
|
||
}
|
||
}
|
||
|
||
/* No error, don't finish the thread states yet. */
|
||
discard_cleanups (ts_old_chain);
|
||
|
||
/* Revert thread and frame. */
|
||
do_cleanups (old_chain);
|
||
|
||
/* If the inferior was in sync execution mode, and now isn't,
|
||
restore the prompt (a synchronous execution command has finished,
|
||
and we're ready for input). */
|
||
if (interpreter_async && was_sync && !sync_execution)
|
||
observer_notify_sync_execution_done ();
|
||
|
||
if (cmd_done
|
||
&& !was_sync
|
||
&& exec_done_display_p
|
||
&& (ptid_equal (inferior_ptid, null_ptid)
|
||
|| !is_running (inferior_ptid)))
|
||
printf_unfiltered (_("completed.\n"));
|
||
}
|
||
|
||
/* Record the frame and location we're currently stepping through. */
|
||
void
|
||
set_step_info (struct frame_info *frame, struct symtab_and_line sal)
|
||
{
|
||
struct thread_info *tp = inferior_thread ();
|
||
|
||
tp->control.step_frame_id = get_frame_id (frame);
|
||
tp->control.step_stack_frame_id = get_stack_frame_id (frame);
|
||
|
||
tp->current_symtab = sal.symtab;
|
||
tp->current_line = sal.line;
|
||
}
|
||
|
||
/* Clear context switchable stepping state. */
|
||
|
||
void
|
||
init_thread_stepping_state (struct thread_info *tss)
|
||
{
|
||
tss->stepping_over_breakpoint = 0;
|
||
tss->step_after_step_resume_breakpoint = 0;
|
||
}
|
||
|
||
/* Set the cached copy of the last ptid/waitstatus. */
|
||
|
||
static void
|
||
set_last_target_status (ptid_t ptid, struct target_waitstatus status)
|
||
{
|
||
target_last_wait_ptid = ptid;
|
||
target_last_waitstatus = status;
|
||
}
|
||
|
||
/* Return the cached copy of the last pid/waitstatus returned by
|
||
target_wait()/deprecated_target_wait_hook(). The data is actually
|
||
cached by handle_inferior_event(), which gets called immediately
|
||
after target_wait()/deprecated_target_wait_hook(). */
|
||
|
||
void
|
||
get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
|
||
{
|
||
*ptidp = target_last_wait_ptid;
|
||
*status = target_last_waitstatus;
|
||
}
|
||
|
||
void
|
||
nullify_last_target_wait_ptid (void)
|
||
{
|
||
target_last_wait_ptid = minus_one_ptid;
|
||
}
|
||
|
||
/* Switch thread contexts. */
|
||
|
||
static void
|
||
context_switch (ptid_t ptid)
|
||
{
|
||
if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
|
||
target_pid_to_str (inferior_ptid));
|
||
fprintf_unfiltered (gdb_stdlog, "to %s\n",
|
||
target_pid_to_str (ptid));
|
||
}
|
||
|
||
switch_to_thread (ptid);
|
||
}
|
||
|
||
static void
|
||
adjust_pc_after_break (struct execution_control_state *ecs)
|
||
{
|
||
struct regcache *regcache;
|
||
struct gdbarch *gdbarch;
|
||
struct address_space *aspace;
|
||
CORE_ADDR breakpoint_pc, decr_pc;
|
||
|
||
/* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
|
||
we aren't, just return.
|
||
|
||
We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
|
||
affected by gdbarch_decr_pc_after_break. Other waitkinds which are
|
||
implemented by software breakpoints should be handled through the normal
|
||
breakpoint layer.
|
||
|
||
NOTE drow/2004-01-31: On some targets, breakpoints may generate
|
||
different signals (SIGILL or SIGEMT for instance), but it is less
|
||
clear where the PC is pointing afterwards. It may not match
|
||
gdbarch_decr_pc_after_break. I don't know any specific target that
|
||
generates these signals at breakpoints (the code has been in GDB since at
|
||
least 1992) so I can not guess how to handle them here.
|
||
|
||
In earlier versions of GDB, a target with
|
||
gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
|
||
watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
|
||
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)
|
||
return;
|
||
|
||
if (ecs->ws.value.sig != GDB_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);
|
||
gdbarch = get_regcache_arch (regcache);
|
||
|
||
decr_pc = target_decr_pc_after_break (gdbarch);
|
||
if (decr_pc == 0)
|
||
return;
|
||
|
||
aspace = get_regcache_aspace (regcache);
|
||
|
||
/* Find the location where (if we've hit a breakpoint) the
|
||
breakpoint would be. */
|
||
breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
|
||
|
||
/* Check whether there actually is a software breakpoint inserted at
|
||
that location.
|
||
|
||
If in non-stop mode, a race condition is possible where we've
|
||
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. */
|
||
if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
|
||
|| (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
|
||
{
|
||
struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
|
||
|
||
if (record_full_is_used ())
|
||
record_full_gdb_operation_disable_set ();
|
||
|
||
/* When using hardware single-step, a SIGTRAP is reported for both
|
||
a completed single-step and a software breakpoint. Need to
|
||
differentiate between the two, as the latter needs adjusting
|
||
but the former does not.
|
||
|
||
The SIGTRAP can be due to a completed hardware single-step only if
|
||
- we didn't insert software single-step breakpoints
|
||
- the thread to be examined is still the current thread
|
||
- this thread is currently being stepped
|
||
|
||
If any of these events did not occur, we must have stopped due
|
||
to hitting a software breakpoint, and have to back up to the
|
||
breakpoint address.
|
||
|
||
As a special case, we could have hardware single-stepped a
|
||
software breakpoint. In this case (prev_pc == breakpoint_pc),
|
||
we also need to back up to the breakpoint address. */
|
||
|
||
if (singlestep_breakpoints_inserted_p
|
||
|| !ptid_equal (ecs->ptid, inferior_ptid)
|
||
|| !currently_stepping (ecs->event_thread)
|
||
|| ecs->event_thread->prev_pc == breakpoint_pc)
|
||
regcache_write_pc (regcache, breakpoint_pc);
|
||
|
||
do_cleanups (old_cleanups);
|
||
}
|
||
}
|
||
|
||
static void
|
||
init_infwait_state (void)
|
||
{
|
||
waiton_ptid = pid_to_ptid (-1);
|
||
infwait_state = infwait_normal_state;
|
||
}
|
||
|
||
static int
|
||
stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
|
||
{
|
||
for (frame = get_prev_frame (frame);
|
||
frame != NULL;
|
||
frame = get_prev_frame (frame))
|
||
{
|
||
if (frame_id_eq (get_frame_id (frame), step_frame_id))
|
||
return 1;
|
||
if (get_frame_type (frame) != INLINE_FRAME)
|
||
break;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Auxiliary function that handles syscall entry/return events.
|
||
It returns 1 if the inferior should keep going (and GDB
|
||
should ignore the event), or 0 if the event deserves to be
|
||
processed. */
|
||
|
||
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_pid (ptid_get_pid (ptid));
|
||
|
||
gdb_assert (inf != NULL);
|
||
return inf->control.stop_soon;
|
||
}
|
||
|
||
/* Given an execution control state that has been freshly filled in by
|
||
an event from the inferior, figure out what it means and take
|
||
appropriate action.
|
||
|
||
The alternatives are:
|
||
|
||
1) stop_waiting and return; to really stop and return to the
|
||
debugger.
|
||
|
||
2) keep_going and return; to wait for the next event (set
|
||
ecs->event_thread->stepping_over_breakpoint to 1 to single step
|
||
once). */
|
||
|
||
static void
|
||
handle_inferior_event (struct execution_control_state *ecs)
|
||
{
|
||
enum stop_kind stop_soon;
|
||
|
||
if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
|
||
{
|
||
/* 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.
|
||
|
||
One of the possible circumstances for this is when the
|
||
inferior produces output for the console. The inferior has
|
||
not stopped, and we are ignoring the event. Another possible
|
||
circumstance is any event which the lower level knows will be
|
||
reported multiple times without an intervening resume. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
|
||
prepare_to_wait (ecs);
|
||
return;
|
||
}
|
||
|
||
if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
|
||
&& target_can_async_p () && !sync_execution)
|
||
{
|
||
/* There were no unwaited-for children left in the target, but,
|
||
we're not synchronously waiting for events either. Just
|
||
ignore. Otherwise, if we were running a synchronous
|
||
execution command, we need to cancel it and give the user
|
||
back the terminal. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
|
||
prepare_to_wait (ecs);
|
||
return;
|
||
}
|
||
|
||
/* Cache the last pid/waitstatus. */
|
||
set_last_target_status (ecs->ptid, ecs->ws);
|
||
|
||
/* Always clear state belonging to the previous time we stopped. */
|
||
stop_stack_dummy = STOP_NONE;
|
||
|
||
if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
|
||
{
|
||
/* No unwaited-for children left. IOW, all resumed children
|
||
have exited. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
|
||
|
||
stop_print_frame = 0;
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
|
||
if (ecs->ws.kind != TARGET_WAITKIND_EXITED
|
||
&& ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
|
||
{
|
||
ecs->event_thread = find_thread_ptid (ecs->ptid);
|
||
/* If it's a new thread, add it to the thread database. */
|
||
if (ecs->event_thread == NULL)
|
||
ecs->event_thread = add_thread (ecs->ptid);
|
||
|
||
/* Disable range stepping. If the next step request could use a
|
||
range, this will be end up re-enabled then. */
|
||
ecs->event_thread->control.may_range_step = 0;
|
||
}
|
||
|
||
/* Dependent on valid ECS->EVENT_THREAD. */
|
||
adjust_pc_after_break (ecs);
|
||
|
||
/* Dependent on the current PC value modified by adjust_pc_after_break. */
|
||
reinit_frame_cache ();
|
||
|
||
breakpoint_retire_moribund ();
|
||
|
||
/* First, distinguish signals caused by the debugger from signals
|
||
that have to do with the program's own actions. Note that
|
||
breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
|
||
on the operating system version. Here we detect when a SIGILL or
|
||
SIGEMT is really a breakpoint and change it to SIGTRAP. We do
|
||
something similar for SIGSEGV, since a SIGSEGV will be generated
|
||
when we're trying to execute a breakpoint instruction on a
|
||
non-executable stack. This happens for call dummy breakpoints
|
||
for architectures like SPARC that place call dummies on the
|
||
stack. */
|
||
if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
|
||
&& (ecs->ws.value.sig == GDB_SIGNAL_ILL
|
||
|| ecs->ws.value.sig == GDB_SIGNAL_SEGV
|
||
|| ecs->ws.value.sig == GDB_SIGNAL_EMT))
|
||
{
|
||
struct regcache *regcache = get_thread_regcache (ecs->ptid);
|
||
|
||
if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
|
||
regcache_read_pc (regcache)))
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: Treating signal as SIGTRAP\n");
|
||
ecs->ws.value.sig = GDB_SIGNAL_TRAP;
|
||
}
|
||
}
|
||
|
||
/* 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);
|
||
|
||
switch (infwait_state)
|
||
{
|
||
case infwait_normal_state:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
|
||
break;
|
||
|
||
case infwait_step_watch_state:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: infwait_step_watch_state\n");
|
||
|
||
ecs->stepped_after_stopped_by_watchpoint = 1;
|
||
break;
|
||
|
||
case infwait_nonstep_watch_state:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: infwait_nonstep_watch_state\n");
|
||
insert_breakpoints ();
|
||
|
||
/* FIXME-maybe: is this cleaner than setting a flag? Does it
|
||
handle things like signals arriving and other things happening
|
||
in combination correctly? */
|
||
ecs->stepped_after_stopped_by_watchpoint = 1;
|
||
break;
|
||
|
||
default:
|
||
internal_error (__FILE__, __LINE__, _("bad switch"));
|
||
}
|
||
|
||
infwait_state = infwait_normal_state;
|
||
waiton_ptid = pid_to_ptid (-1);
|
||
|
||
switch (ecs->ws.kind)
|
||
{
|
||
case TARGET_WAITKIND_LOADED:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
|
||
if (!ptid_equal (ecs->ptid, inferior_ptid))
|
||
context_switch (ecs->ptid);
|
||
/* Ignore gracefully during startup of the inferior, as it might
|
||
be the shell which has just loaded some objects, otherwise
|
||
add the symbols for the newly loaded objects. Also ignore at
|
||
the beginning of an attach or remote session; we will query
|
||
the full list of libraries once the connection is
|
||
established. */
|
||
|
||
stop_soon = get_inferior_stop_soon (ecs->ptid);
|
||
if (stop_soon == NO_STOP_QUIETLY)
|
||
{
|
||
struct regcache *regcache;
|
||
|
||
regcache = get_thread_regcache (ecs->ptid);
|
||
|
||
handle_solib_event ();
|
||
|
||
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))
|
||
{
|
||
/* A catchpoint triggered. */
|
||
process_event_stop_test (ecs);
|
||
return;
|
||
}
|
||
|
||
/* If requested, stop when the dynamic linker notifies
|
||
gdb of events. This allows the user to get control
|
||
and place breakpoints in initializer routines for
|
||
dynamically loaded objects (among other things). */
|
||
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
|
||
if (stop_on_solib_events)
|
||
{
|
||
/* Make sure we print "Stopped due to solib-event" in
|
||
normal_stop. */
|
||
stop_print_frame = 1;
|
||
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* If we are skipping through a shell, or through shared library
|
||
loading that we aren't interested in, resume the program. If
|
||
we're running the program normally, also resume. */
|
||
if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
|
||
{
|
||
/* Loading of shared libraries might have changed breakpoint
|
||
addresses. Make sure new breakpoints are inserted. */
|
||
if (stop_soon == NO_STOP_QUIETLY
|
||
&& !breakpoints_always_inserted_mode ())
|
||
insert_breakpoints ();
|
||
resume (0, GDB_SIGNAL_0);
|
||
prepare_to_wait (ecs);
|
||
return;
|
||
}
|
||
|
||
/* But stop if we're attaching or setting up a remote
|
||
connection. */
|
||
if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
|
||
|| stop_soon == STOP_QUIETLY_REMOTE)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
|
||
internal_error (__FILE__, __LINE__,
|
||
_("unhandled stop_soon: %d"), (int) stop_soon);
|
||
|
||
case TARGET_WAITKIND_SPURIOUS:
|
||
if (debug_infrun)
|
||
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);
|
||
prepare_to_wait (ecs);
|
||
return;
|
||
|
||
case TARGET_WAITKIND_EXITED:
|
||
case TARGET_WAITKIND_SIGNALLED:
|
||
if (debug_infrun)
|
||
{
|
||
if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: TARGET_WAITKIND_EXITED\n");
|
||
else
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: TARGET_WAITKIND_SIGNALLED\n");
|
||
}
|
||
|
||
inferior_ptid = ecs->ptid;
|
||
set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
|
||
set_current_program_space (current_inferior ()->pspace);
|
||
handle_vfork_child_exec_or_exit (0);
|
||
target_terminal_ours (); /* Must do this before mourn anyway. */
|
||
|
||
/* Clearing any previous state of convenience variables. */
|
||
clear_exit_convenience_vars ();
|
||
|
||
if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
|
||
{
|
||
/* Record the exit code in the convenience variable $_exitcode, so
|
||
that the user can inspect this again later. */
|
||
set_internalvar_integer (lookup_internalvar ("_exitcode"),
|
||
(LONGEST) ecs->ws.value.integer);
|
||
|
||
/* Also record this in the inferior itself. */
|
||
current_inferior ()->has_exit_code = 1;
|
||
current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
|
||
|
||
/* Support the --return-child-result option. */
|
||
return_child_result_value = ecs->ws.value.integer;
|
||
|
||
observer_notify_exited (ecs->ws.value.integer);
|
||
}
|
||
else
|
||
{
|
||
struct regcache *regcache = get_thread_regcache (ecs->ptid);
|
||
struct gdbarch *gdbarch = get_regcache_arch (regcache);
|
||
|
||
if (gdbarch_gdb_signal_to_target_p (gdbarch))
|
||
{
|
||
/* Set the value of the internal variable $_exitsignal,
|
||
which holds the signal uncaught by the inferior. */
|
||
set_internalvar_integer (lookup_internalvar ("_exitsignal"),
|
||
gdbarch_gdb_signal_to_target (gdbarch,
|
||
ecs->ws.value.sig));
|
||
}
|
||
else
|
||
{
|
||
/* We don't have access to the target's method used for
|
||
converting between signal numbers (GDB's internal
|
||
representation <-> target's representation).
|
||
Therefore, we cannot do a good job at displaying this
|
||
information to the user. It's better to just warn
|
||
her about it (if infrun debugging is enabled), and
|
||
give up. */
|
||
if (debug_infrun)
|
||
fprintf_filtered (gdb_stdlog, _("\
|
||
Cannot fill $_exitsignal with the correct signal number.\n"));
|
||
}
|
||
|
||
observer_notify_signal_exited (ecs->ws.value.sig);
|
||
}
|
||
|
||
gdb_flush (gdb_stdout);
|
||
target_mourn_inferior ();
|
||
singlestep_breakpoints_inserted_p = 0;
|
||
cancel_single_step_breakpoints ();
|
||
stop_print_frame = 0;
|
||
stop_waiting (ecs);
|
||
return;
|
||
|
||
/* The following are the only cases in which we keep going;
|
||
the above cases end in a continue or goto. */
|
||
case TARGET_WAITKIND_FORKED:
|
||
case TARGET_WAITKIND_VFORKED:
|
||
if (debug_infrun)
|
||
{
|
||
if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
|
||
else
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
|
||
}
|
||
|
||
/* Check whether the inferior is displaced stepping. */
|
||
{
|
||
struct regcache *regcache = get_thread_regcache (ecs->ptid);
|
||
struct gdbarch *gdbarch = get_regcache_arch (regcache);
|
||
struct displaced_step_inferior_state *displaced
|
||
= get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
|
||
|
||
/* If checking displaced stepping is supported, and thread
|
||
ecs->ptid is displaced stepping. */
|
||
if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
|
||
{
|
||
struct inferior *parent_inf
|
||
= find_inferior_pid (ptid_get_pid (ecs->ptid));
|
||
struct regcache *child_regcache;
|
||
CORE_ADDR parent_pc;
|
||
|
||
/* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
|
||
indicating that the displaced stepping of syscall instruction
|
||
has been done. Perform cleanup for parent process here. Note
|
||
that this operation also cleans up the child process for vfork,
|
||
because their pages are shared. */
|
||
displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
|
||
|
||
if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
|
||
{
|
||
/* Restore scratch pad for child process. */
|
||
displaced_step_restore (displaced, ecs->ws.value.related_pid);
|
||
}
|
||
|
||
/* Since the vfork/fork syscall instruction was executed in the scratchpad,
|
||
the child's PC is also within the scratchpad. Set the child's PC
|
||
to the parent's PC value, which has already been fixed up.
|
||
FIXME: we use the parent's aspace here, although we're touching
|
||
the child, because the child hasn't been added to the inferior
|
||
list yet at this point. */
|
||
|
||
child_regcache
|
||
= get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
|
||
gdbarch,
|
||
parent_inf->aspace);
|
||
/* Read PC value of parent process. */
|
||
parent_pc = regcache_read_pc (regcache);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"displaced: write child pc from %s to %s\n",
|
||
paddress (gdbarch,
|
||
regcache_read_pc (child_regcache)),
|
||
paddress (gdbarch, parent_pc));
|
||
|
||
regcache_write_pc (child_regcache, parent_pc);
|
||
}
|
||
}
|
||
|
||
if (!ptid_equal (ecs->ptid, inferior_ptid))
|
||
context_switch (ecs->ptid);
|
||
|
||
/* Immediately detach breakpoints from the child before there's
|
||
any chance of letting the user delete breakpoints from the
|
||
breakpoint lists. If we don't do this early, it's easy to
|
||
leave left over traps in the child, vis: "break foo; catch
|
||
fork; c; <fork>; del; c; <child calls foo>". We only follow
|
||
the fork on the last `continue', and by that time the
|
||
breakpoint at "foo" is long gone from the breakpoint table.
|
||
If we vforked, then we don't need to unpatch here, since both
|
||
parent and child are sharing the same memory pages; we'll
|
||
need to unpatch at follow/detach time instead to be certain
|
||
that new breakpoints added between catchpoint hit time and
|
||
vfork follow are detached. */
|
||
if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
|
||
{
|
||
/* This won't actually modify the breakpoint list, but will
|
||
physically remove the breakpoints from the child. */
|
||
detach_breakpoints (ecs->ws.value.related_pid);
|
||
}
|
||
|
||
if (singlestep_breakpoints_inserted_p)
|
||
{
|
||
/* Pull the single step breakpoints out of the target. */
|
||
remove_single_step_breakpoints ();
|
||
singlestep_breakpoints_inserted_p = 0;
|
||
}
|
||
|
||
/* In case the event is caught by a catchpoint, remember that
|
||
the event is to be followed at the next resume of the thread,
|
||
and not immediately. */
|
||
ecs->event_thread->pending_follow = ecs->ws;
|
||
|
||
stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
|
||
|
||
ecs->event_thread->control.stop_bpstat
|
||
= bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
|
||
stop_pc, ecs->ptid, &ecs->ws);
|
||
|
||
/* If no catchpoint triggered for this, then keep going. Note
|
||
that we're interested in knowing the bpstat actually causes a
|
||
stop, not just if it may explain the signal. Software
|
||
watchpoints, for example, always appear in the bpstat. */
|
||
if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
|
||
{
|
||
ptid_t parent;
|
||
ptid_t child;
|
||
int should_resume;
|
||
int follow_child
|
||
= (follow_fork_mode_string == follow_fork_mode_child);
|
||
|
||
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
|
||
|
||
should_resume = follow_fork ();
|
||
|
||
parent = ecs->ptid;
|
||
child = ecs->ws.value.related_pid;
|
||
|
||
/* In non-stop mode, also resume the other branch. */
|
||
if (non_stop && !detach_fork)
|
||
{
|
||
if (follow_child)
|
||
switch_to_thread (parent);
|
||
else
|
||
switch_to_thread (child);
|
||
|
||
ecs->event_thread = inferior_thread ();
|
||
ecs->ptid = inferior_ptid;
|
||
keep_going (ecs);
|
||
}
|
||
|
||
if (follow_child)
|
||
switch_to_thread (child);
|
||
else
|
||
switch_to_thread (parent);
|
||
|
||
ecs->event_thread = inferior_thread ();
|
||
ecs->ptid = inferior_ptid;
|
||
|
||
if (should_resume)
|
||
keep_going (ecs);
|
||
else
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
process_event_stop_test (ecs);
|
||
return;
|
||
|
||
case TARGET_WAITKIND_VFORK_DONE:
|
||
/* Done with the shared memory region. Re-insert breakpoints in
|
||
the parent, and keep going. */
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: TARGET_WAITKIND_VFORK_DONE\n");
|
||
|
||
if (!ptid_equal (ecs->ptid, inferior_ptid))
|
||
context_switch (ecs->ptid);
|
||
|
||
current_inferior ()->waiting_for_vfork_done = 0;
|
||
current_inferior ()->pspace->breakpoints_not_allowed = 0;
|
||
/* This also takes care of reinserting breakpoints in the
|
||
previously locked inferior. */
|
||
keep_going (ecs);
|
||
return;
|
||
|
||
case TARGET_WAITKIND_EXECD:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
|
||
|
||
if (!ptid_equal (ecs->ptid, inferior_ptid))
|
||
context_switch (ecs->ptid);
|
||
|
||
singlestep_breakpoints_inserted_p = 0;
|
||
cancel_single_step_breakpoints ();
|
||
|
||
stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
|
||
|
||
/* Do whatever is necessary to the parent branch of the vfork. */
|
||
handle_vfork_child_exec_or_exit (1);
|
||
|
||
/* This causes the eventpoints and symbol table to be reset.
|
||
Must do this now, before trying to determine whether to
|
||
stop. */
|
||
follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
|
||
|
||
ecs->event_thread->control.stop_bpstat
|
||
= bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
|
||
stop_pc, ecs->ptid, &ecs->ws);
|
||
|
||
/* Note that this may be referenced from inside
|
||
bpstat_stop_status above, through inferior_has_execd. */
|
||
xfree (ecs->ws.value.execd_pathname);
|
||
ecs->ws.value.execd_pathname = NULL;
|
||
|
||
/* If no catchpoint triggered for this, then keep going. */
|
||
if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
|
||
{
|
||
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
process_event_stop_test (ecs);
|
||
return;
|
||
|
||
/* Be careful not to try to gather much state about a thread
|
||
that's in a syscall. It's frequently a losing proposition. */
|
||
case TARGET_WAITKIND_SYSCALL_ENTRY:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
|
||
/* Getting the current syscall number. */
|
||
if (handle_syscall_event (ecs) == 0)
|
||
process_event_stop_test (ecs);
|
||
return;
|
||
|
||
/* Before examining the threads further, step this thread to
|
||
get it entirely out of the syscall. (We get notice of the
|
||
event when the thread is just on the verge of exiting a
|
||
syscall. Stepping one instruction seems to get it back
|
||
into user code.) */
|
||
case TARGET_WAITKIND_SYSCALL_RETURN:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
|
||
if (handle_syscall_event (ecs) == 0)
|
||
process_event_stop_test (ecs);
|
||
return;
|
||
|
||
case TARGET_WAITKIND_STOPPED:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
|
||
ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
|
||
handle_signal_stop (ecs);
|
||
return;
|
||
|
||
case TARGET_WAITKIND_NO_HISTORY:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
|
||
/* Reverse execution: target ran out of history info. */
|
||
|
||
/* Pull the single step breakpoints out of the target. */
|
||
if (singlestep_breakpoints_inserted_p)
|
||
{
|
||
if (!ptid_equal (ecs->ptid, inferior_ptid))
|
||
context_switch (ecs->ptid);
|
||
remove_single_step_breakpoints ();
|
||
singlestep_breakpoints_inserted_p = 0;
|
||
}
|
||
stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
|
||
observer_notify_no_history ();
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* Come here when the program has stopped with a signal. */
|
||
|
||
static void
|
||
handle_signal_stop (struct execution_control_state *ecs)
|
||
{
|
||
struct frame_info *frame;
|
||
struct gdbarch *gdbarch;
|
||
int stopped_by_watchpoint;
|
||
enum stop_kind stop_soon;
|
||
int random_signal;
|
||
|
||
gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
|
||
|
||
/* 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 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->suspend.stop_signal == GDB_SIGNAL_TRAP)
|
||
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
|
||
|
||
stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
|
||
|
||
if (debug_infrun)
|
||
{
|
||
struct regcache *regcache = get_thread_regcache (ecs->ptid);
|
||
struct gdbarch *gdbarch = get_regcache_arch (regcache);
|
||
struct cleanup *old_chain = save_inferior_ptid ();
|
||
|
||
inferior_ptid = ecs->ptid;
|
||
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
|
||
paddress (gdbarch, stop_pc));
|
||
if (target_stopped_by_watchpoint ())
|
||
{
|
||
CORE_ADDR addr;
|
||
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
|
||
|
||
if (target_stopped_data_address (¤t_target, &addr))
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stopped data address = %s\n",
|
||
paddress (gdbarch, addr));
|
||
else
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: (no data address available)\n");
|
||
}
|
||
|
||
do_cleanups (old_chain);
|
||
}
|
||
|
||
/* This is originated from start_remote(), start_inferior() and
|
||
shared libraries hook functions. */
|
||
stop_soon = get_inferior_stop_soon (ecs->ptid);
|
||
if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
|
||
{
|
||
if (!ptid_equal (ecs->ptid, inferior_ptid))
|
||
context_switch (ecs->ptid);
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
|
||
stop_print_frame = 1;
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
|
||
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
|
||
&& stop_after_trap)
|
||
{
|
||
if (!ptid_equal (ecs->ptid, inferior_ptid))
|
||
context_switch (ecs->ptid);
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
|
||
stop_print_frame = 0;
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
|
||
/* This originates from attach_command(). We need to overwrite
|
||
the stop_signal here, because some kernels don't ignore a
|
||
SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
|
||
See more comments in inferior.h. On the other hand, if we
|
||
get a non-SIGSTOP, report it to the user - assume the backend
|
||
will handle the SIGSTOP if it should show up later.
|
||
|
||
Also consider that the attach is complete when we see a
|
||
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.
|
||
|
||
Also consider that the attach is complete when we see a
|
||
GDB_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
|
||
GDB_SIGNAL_0, meaning: stopped for no particular reason
|
||
other than GDB's request. */
|
||
if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
|
||
&& (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
|
||
|| ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
|
||
|| ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
|
||
{
|
||
stop_print_frame = 1;
|
||
stop_waiting (ecs);
|
||
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
|
||
return;
|
||
}
|
||
|
||
/* See if something interesting happened to the non-current thread. If
|
||
so, then switch to that thread. */
|
||
if (!ptid_equal (ecs->ptid, inferior_ptid))
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
|
||
|
||
context_switch (ecs->ptid);
|
||
|
||
if (deprecated_context_hook)
|
||
deprecated_context_hook (pid_to_thread_id (ecs->ptid));
|
||
}
|
||
|
||
/* At this point, get hold of the now-current thread's frame. */
|
||
frame = get_current_frame ();
|
||
gdbarch = get_frame_arch (frame);
|
||
|
||
/* Pull the single step breakpoints out of the target. */
|
||
if (singlestep_breakpoints_inserted_p)
|
||
{
|
||
/* However, before doing so, if this single-step breakpoint was
|
||
actually for another thread, set this thread up for moving
|
||
past it. */
|
||
if (!ptid_equal (ecs->ptid, singlestep_ptid)
|
||
&& ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
|
||
{
|
||
struct regcache *regcache;
|
||
struct address_space *aspace;
|
||
CORE_ADDR pc;
|
||
|
||
regcache = get_thread_regcache (ecs->ptid);
|
||
aspace = get_regcache_aspace (regcache);
|
||
pc = regcache_read_pc (regcache);
|
||
if (single_step_breakpoint_inserted_here_p (aspace, pc))
|
||
{
|
||
if (debug_infrun)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: [%s] hit step over single-step"
|
||
" breakpoint of [%s]\n",
|
||
target_pid_to_str (ecs->ptid),
|
||
target_pid_to_str (singlestep_ptid));
|
||
}
|
||
ecs->hit_singlestep_breakpoint = 1;
|
||
}
|
||
}
|
||
|
||
remove_single_step_breakpoints ();
|
||
singlestep_breakpoints_inserted_p = 0;
|
||
}
|
||
|
||
if (ecs->stepped_after_stopped_by_watchpoint)
|
||
stopped_by_watchpoint = 0;
|
||
else
|
||
stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
|
||
|
||
/* If necessary, step over this watchpoint. We'll be back to display
|
||
it in a moment. */
|
||
if (stopped_by_watchpoint
|
||
&& (target_have_steppable_watchpoint
|
||
|| gdbarch_have_nonsteppable_watchpoint (gdbarch)))
|
||
{
|
||
/* At this point, we are stopped at an instruction which has
|
||
attempted to write to a piece of memory under control of
|
||
a watchpoint. The instruction hasn't actually executed
|
||
yet. If we were to evaluate the watchpoint expression
|
||
now, we would get the old value, and therefore no change
|
||
would seem to have occurred.
|
||
|
||
In order to make watchpoints work `right', we really need
|
||
to complete the memory write, and then evaluate the
|
||
watchpoint expression. We do this by single-stepping the
|
||
target.
|
||
|
||
It may not be necessary to disable the watchpoint to stop over
|
||
it. For example, the PA can (with some kernel cooperation)
|
||
single step over a watchpoint without disabling the watchpoint.
|
||
|
||
It is far more common to need to disable a watchpoint to step
|
||
the inferior over it. If we have non-steppable watchpoints,
|
||
we must disable the current watchpoint; it's simplest to
|
||
disable all watchpoints and breakpoints. */
|
||
int hw_step = 1;
|
||
|
||
if (!target_have_steppable_watchpoint)
|
||
{
|
||
remove_breakpoints ();
|
||
/* See comment in resume why we need to stop bypassing signals
|
||
while breakpoints have been removed. */
|
||
target_pass_signals (0, NULL);
|
||
}
|
||
/* Single step */
|
||
hw_step = maybe_software_singlestep (gdbarch, stop_pc);
|
||
target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0);
|
||
waiton_ptid = ecs->ptid;
|
||
if (target_have_steppable_watchpoint)
|
||
infwait_state = infwait_step_watch_state;
|
||
else
|
||
infwait_state = infwait_nonstep_watch_state;
|
||
prepare_to_wait (ecs);
|
||
return;
|
||
}
|
||
|
||
ecs->event_thread->stepping_over_breakpoint = 0;
|
||
bpstat_clear (&ecs->event_thread->control.stop_bpstat);
|
||
ecs->event_thread->control.stop_step = 0;
|
||
stop_print_frame = 1;
|
||
stopped_by_random_signal = 0;
|
||
|
||
/* Hide inlined functions starting here, unless we just performed stepi or
|
||
nexti. After stepi and nexti, always show the innermost frame (not any
|
||
inline function call sites). */
|
||
if (ecs->event_thread->control.step_range_end != 1)
|
||
{
|
||
struct address_space *aspace =
|
||
get_regcache_aspace (get_thread_regcache (ecs->ptid));
|
||
|
||
/* skip_inline_frames is expensive, so we avoid it if we can
|
||
determine that the address is one where functions cannot have
|
||
been inlined. This improves performance with inferiors that
|
||
load a lot of shared libraries, because the solib event
|
||
breakpoint is defined as the address of a function (i.e. not
|
||
inline). Note that we have to check the previous PC as well
|
||
as the current one to catch cases when we have just
|
||
single-stepped off a breakpoint prior to reinstating it.
|
||
Note that we're assuming that the code we single-step to is
|
||
not inline, but that's not definitive: there's nothing
|
||
preventing the event breakpoint function from containing
|
||
inlined code, and the single-step ending up there. If the
|
||
user had set a breakpoint on that inlined code, the missing
|
||
skip_inline_frames call would break things. Fortunately
|
||
that's an extremely unlikely scenario. */
|
||
if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
|
||
&& !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
|
||
&& ecs->event_thread->control.trap_expected
|
||
&& pc_at_non_inline_function (aspace,
|
||
ecs->event_thread->prev_pc,
|
||
&ecs->ws)))
|
||
{
|
||
skip_inline_frames (ecs->ptid);
|
||
|
||
/* Re-fetch current thread's frame in case that invalidated
|
||
the frame cache. */
|
||
frame = get_current_frame ();
|
||
gdbarch = get_frame_arch (frame);
|
||
}
|
||
}
|
||
|
||
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
|
||
&& ecs->event_thread->control.trap_expected
|
||
&& gdbarch_single_step_through_delay_p (gdbarch)
|
||
&& currently_stepping (ecs->event_thread))
|
||
{
|
||
/* We're trying to step off a breakpoint. Turns out that we're
|
||
also on an instruction that needs to be stepped multiple
|
||
times before it's been fully executing. E.g., architectures
|
||
with a delay slot. It needs to be stepped twice, once for
|
||
the instruction and once for the delay slot. */
|
||
int step_through_delay
|
||
= gdbarch_single_step_through_delay (gdbarch, frame);
|
||
|
||
if (debug_infrun && step_through_delay)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
|
||
if (ecs->event_thread->control.step_range_end == 0
|
||
&& step_through_delay)
|
||
{
|
||
/* The user issued a continue when stopped at a breakpoint.
|
||
Set up for another trap and get out of here. */
|
||
ecs->event_thread->stepping_over_breakpoint = 1;
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
else if (step_through_delay)
|
||
{
|
||
/* The user issued a step when stopped at a breakpoint.
|
||
Maybe we should stop, maybe we should not - the delay
|
||
slot *might* correspond to a line of source. In any
|
||
case, don't decide that here, just set
|
||
ecs->stepping_over_breakpoint, making sure we
|
||
single-step again before breakpoints are re-inserted. */
|
||
ecs->event_thread->stepping_over_breakpoint = 1;
|
||
}
|
||
}
|
||
|
||
/* See if there is a breakpoint/watchpoint/catchpoint/etc. that
|
||
handles this event. */
|
||
ecs->event_thread->control.stop_bpstat
|
||
= bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
|
||
stop_pc, ecs->ptid, &ecs->ws);
|
||
|
||
/* Following in case break condition called a
|
||
function. */
|
||
stop_print_frame = 1;
|
||
|
||
/* This is where we handle "moribund" watchpoints. Unlike
|
||
software breakpoints traps, hardware watchpoint traps are
|
||
always distinguishable from random traps. If no high-level
|
||
watchpoint is associated with the reported stop data address
|
||
anymore, then the bpstat does not explain the signal ---
|
||
simply make sure to ignore it if `stopped_by_watchpoint' is
|
||
set. */
|
||
|
||
if (debug_infrun
|
||
&& ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
|
||
&& !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
|
||
GDB_SIGNAL_TRAP)
|
||
&& stopped_by_watchpoint)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: no user watchpoint explains "
|
||
"watchpoint SIGTRAP, ignoring\n");
|
||
|
||
/* NOTE: cagney/2003-03-29: These checks for a random signal
|
||
at one stage in the past included checks for an inferior
|
||
function call's call dummy's return breakpoint. The original
|
||
comment, that went with the test, read:
|
||
|
||
``End of a stack dummy. Some systems (e.g. Sony news) give
|
||
another signal besides SIGTRAP, so check here as well as
|
||
above.''
|
||
|
||
If someone ever tries to get call dummys on a
|
||
non-executable stack to work (where the target would stop
|
||
with something like a SIGSEGV), then those tests might need
|
||
to be re-instated. Given, however, that the tests were only
|
||
enabled when momentary breakpoints were not being used, I
|
||
suspect that it won't be the case.
|
||
|
||
NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
|
||
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);
|
||
|
||
/* If not, perhaps stepping/nexting can. */
|
||
if (random_signal)
|
||
random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
|
||
&& currently_stepping (ecs->event_thread));
|
||
|
||
/* Perhaps the thread hit a single-step breakpoint of _another_
|
||
thread. Single-step breakpoints are transparent to the
|
||
breakpoints module. */
|
||
if (random_signal)
|
||
random_signal = !ecs->hit_singlestep_breakpoint;
|
||
|
||
/* No? Perhaps we got a moribund watchpoint. */
|
||
if (random_signal)
|
||
random_signal = !stopped_by_watchpoint;
|
||
|
||
/* For the program's own signals, act according to
|
||
the signal handling tables. */
|
||
|
||
if (random_signal)
|
||
{
|
||
/* Signal not for debugging purposes. */
|
||
int printed = 0;
|
||
struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
|
||
enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
|
||
gdb_signal_to_symbol_string (stop_signal));
|
||
|
||
stopped_by_random_signal = 1;
|
||
|
||
if (signal_print[ecs->event_thread->suspend.stop_signal])
|
||
{
|
||
/* The signal table tells us to print about this signal. */
|
||
printed = 1;
|
||
target_terminal_ours_for_output ();
|
||
observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
|
||
}
|
||
/* 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
|
||
|| (!inf->detaching
|
||
&& signal_stop_state (ecs->event_thread->suspend.stop_signal)))
|
||
{
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
/* If not going to stop, give terminal back
|
||
if we took it away. */
|
||
else if (printed)
|
||
target_terminal_inferior ();
|
||
|
||
/* Clear the signal if it should not be passed. */
|
||
if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
|
||
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
|
||
|
||
if (ecs->event_thread->prev_pc == stop_pc
|
||
&& ecs->event_thread->control.trap_expected
|
||
&& ecs->event_thread->control.step_resume_breakpoint == NULL)
|
||
{
|
||
/* 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
|
||
of the stepping range so GDB needs to remember to, when
|
||
the signal handler returns, resume stepping off that
|
||
breakpoint. */
|
||
/* To simplify things, "continue" is forced to use the same
|
||
code paths as single-step - set a breakpoint at the
|
||
signal return address and then, once hit, step off that
|
||
breakpoint. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: signal arrived while stepping over "
|
||
"breakpoint\n");
|
||
|
||
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 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))
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
if (ecs->event_thread->control.step_range_end != 0
|
||
&& ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
|
||
&& pc_in_thread_step_range (stop_pc, ecs->event_thread)
|
||
&& frame_id_eq (get_stack_frame_id (frame),
|
||
ecs->event_thread->control.step_stack_frame_id)
|
||
&& ecs->event_thread->control.step_resume_breakpoint == NULL)
|
||
{
|
||
/* The inferior is about to take a signal that will take it
|
||
out of the single step range. Set a breakpoint at the
|
||
current PC (which is presumably where the signal handler
|
||
will eventually return) and then allow the inferior to
|
||
run free.
|
||
|
||
Note that this is only needed for a signal delivered
|
||
while in the single-step range. Nested signals aren't a
|
||
problem as they eventually all return. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: signal may take us out of "
|
||
"single-step range\n");
|
||
|
||
insert_hp_step_resume_breakpoint_at_frame (frame);
|
||
/* Reset trap_expected to ensure breakpoints are re-inserted. */
|
||
ecs->event_thread->control.trap_expected = 0;
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
/* Note: step_resume_breakpoint may be non-NULL. This occures
|
||
when either there's a nested signal, or when there's a
|
||
pending signal enabled just as the signal handler returns
|
||
(leaving the inferior at the step-resume-breakpoint without
|
||
actually executing it). Either way continue until the
|
||
breakpoint is really hit. */
|
||
|
||
if (!switch_back_to_stepped_thread (ecs))
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: random signal, keep going\n");
|
||
|
||
keep_going (ecs);
|
||
}
|
||
return;
|
||
}
|
||
|
||
process_event_stop_test (ecs);
|
||
}
|
||
|
||
/* Come here when we've got some debug event / signal we can explain
|
||
(IOW, not a random signal), and test whether it should cause a
|
||
stop, or whether we should resume the inferior (transparently).
|
||
E.g., could be a breakpoint whose condition evaluates false; we
|
||
could be still stepping within the line; etc. */
|
||
|
||
static void
|
||
process_event_stop_test (struct execution_control_state *ecs)
|
||
{
|
||
struct symtab_and_line stop_pc_sal;
|
||
struct frame_info *frame;
|
||
struct gdbarch *gdbarch;
|
||
CORE_ADDR jmp_buf_pc;
|
||
struct bpstat_what what;
|
||
|
||
/* Handle cases caused by hitting a breakpoint. */
|
||
|
||
frame = get_current_frame ();
|
||
gdbarch = get_frame_arch (frame);
|
||
|
||
what = bpstat_what (ecs->event_thread->control.stop_bpstat);
|
||
|
||
if (what.call_dummy)
|
||
{
|
||
stop_stack_dummy = what.call_dummy;
|
||
}
|
||
|
||
/* If we hit an internal event that triggers symbol changes, the
|
||
current frame will be invalidated within bpstat_what (e.g., if we
|
||
hit an internal solib event). Re-fetch it. */
|
||
frame = get_current_frame ();
|
||
gdbarch = get_frame_arch (frame);
|
||
|
||
switch (what.main_action)
|
||
{
|
||
case BPSTAT_WHAT_SET_LONGJMP_RESUME:
|
||
/* If we hit the breakpoint at longjmp while stepping, we
|
||
install a momentary breakpoint at the target of the
|
||
jmp_buf. */
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
|
||
|
||
ecs->event_thread->stepping_over_breakpoint = 1;
|
||
|
||
if (what.is_longjmp)
|
||
{
|
||
struct value *arg_value;
|
||
|
||
/* If we set the longjmp breakpoint via a SystemTap probe,
|
||
then use it to extract the arguments. The destination PC
|
||
is the third argument to the probe. */
|
||
arg_value = probe_safe_evaluate_at_pc (frame, 2);
|
||
if (arg_value)
|
||
jmp_buf_pc = value_as_address (arg_value);
|
||
else if (!gdbarch_get_longjmp_target_p (gdbarch)
|
||
|| !gdbarch_get_longjmp_target (gdbarch,
|
||
frame, &jmp_buf_pc))
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
|
||
"(!gdbarch_get_longjmp_target)\n");
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
/* Insert a breakpoint at resume address. */
|
||
insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
|
||
}
|
||
else
|
||
check_exception_resume (ecs, frame);
|
||
keep_going (ecs);
|
||
return;
|
||
|
||
case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
|
||
{
|
||
struct frame_info *init_frame;
|
||
|
||
/* There are several cases to consider.
|
||
|
||
1. The initiating frame no longer exists. In this case we
|
||
must stop, because the exception or longjmp has gone too
|
||
far.
|
||
|
||
2. The initiating frame exists, and is the same as the
|
||
current frame. We stop, because the exception or longjmp
|
||
has been caught.
|
||
|
||
3. The initiating frame exists and is different from the
|
||
current frame. This means the exception or longjmp has
|
||
been caught beneath the initiating frame, so keep going.
|
||
|
||
4. longjmp breakpoint has been placed just to protect
|
||
against stale dummy frames and user is not interested in
|
||
stopping around longjmps. */
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
|
||
|
||
gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
|
||
!= NULL);
|
||
delete_exception_resume_breakpoint (ecs->event_thread);
|
||
|
||
if (what.is_longjmp)
|
||
{
|
||
check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
|
||
|
||
if (!frame_id_p (ecs->event_thread->initiating_frame))
|
||
{
|
||
/* Case 4. */
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
|
||
|
||
if (init_frame)
|
||
{
|
||
struct frame_id current_id
|
||
= get_frame_id (get_current_frame ());
|
||
if (frame_id_eq (current_id,
|
||
ecs->event_thread->initiating_frame))
|
||
{
|
||
/* Case 2. Fall through. */
|
||
}
|
||
else
|
||
{
|
||
/* Case 3. */
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* For Cases 1 and 2, remove the step-resume breakpoint, if it
|
||
exists. */
|
||
delete_step_resume_breakpoint (ecs->event_thread);
|
||
|
||
end_stepping_range (ecs);
|
||
}
|
||
return;
|
||
|
||
case BPSTAT_WHAT_SINGLE:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
|
||
ecs->event_thread->stepping_over_breakpoint = 1;
|
||
/* Still need to check other stuff, at least the case where we
|
||
are stepping and step out of the right range. */
|
||
break;
|
||
|
||
case BPSTAT_WHAT_STEP_RESUME:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
|
||
|
||
delete_step_resume_breakpoint (ecs->event_thread);
|
||
if (ecs->event_thread->control.proceed_to_finish
|
||
&& execution_direction == EXEC_REVERSE)
|
||
{
|
||
struct thread_info *tp = ecs->event_thread;
|
||
|
||
/* We are finishing a function in reverse, and just hit the
|
||
step-resume breakpoint at the start address of the
|
||
function, and we're almost there -- just need to back up
|
||
by one more single-step, which should take us back to the
|
||
function call. */
|
||
tp->control.step_range_start = tp->control.step_range_end = 1;
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
fill_in_stop_func (gdbarch, ecs);
|
||
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_STOP_NOISY:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
|
||
stop_print_frame = 1;
|
||
|
||
/* Assume the thread stopped for a breapoint. We'll still check
|
||
whether a/the breakpoint is there when the thread is next
|
||
resumed. */
|
||
ecs->event_thread->stepping_over_breakpoint = 1;
|
||
|
||
stop_waiting (ecs);
|
||
return;
|
||
|
||
case BPSTAT_WHAT_STOP_SILENT:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
|
||
stop_print_frame = 0;
|
||
|
||
/* Assume the thread stopped for a breapoint. We'll still check
|
||
whether a/the breakpoint is there when the thread is next
|
||
resumed. */
|
||
ecs->event_thread->stepping_over_breakpoint = 1;
|
||
stop_waiting (ecs);
|
||
return;
|
||
|
||
case BPSTAT_WHAT_HP_STEP_RESUME:
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
|
||
|
||
delete_step_resume_breakpoint (ecs->event_thread);
|
||
if (ecs->event_thread->step_after_step_resume_breakpoint)
|
||
{
|
||
/* Back when the step-resume breakpoint was inserted, we
|
||
were trying to single-step off a breakpoint. Go back to
|
||
doing that. */
|
||
ecs->event_thread->step_after_step_resume_breakpoint = 0;
|
||
ecs->event_thread->stepping_over_breakpoint = 1;
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
break;
|
||
|
||
case BPSTAT_WHAT_KEEP_CHECKING:
|
||
break;
|
||
}
|
||
|
||
/* We come here if we hit a breakpoint but should not stop for it.
|
||
Possibly we also were stepping and should stop for that. So fall
|
||
through and 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 (switch_back_to_stepped_thread (ecs))
|
||
return;
|
||
|
||
if (ecs->event_thread->control.step_resume_breakpoint)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: step-resume breakpoint is inserted\n");
|
||
|
||
/* Having a step-resume breakpoint overrides anything
|
||
else having to do with stepping commands until
|
||
that breakpoint is reached. */
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
if (ecs->event_thread->control.step_range_end == 0)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
|
||
/* Likewise if we aren't even stepping. */
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
/* Re-fetch current thread's frame in case the code above caused
|
||
the frame cache to be re-initialized, making our FRAME variable
|
||
a dangling pointer. */
|
||
frame = get_current_frame ();
|
||
gdbarch = get_frame_arch (frame);
|
||
fill_in_stop_func (gdbarch, ecs);
|
||
|
||
/* If stepping through a line, keep going if still within it.
|
||
|
||
Note that step_range_end is the address of the first instruction
|
||
beyond the step range, and NOT the address of the last instruction
|
||
within it!
|
||
|
||
Note also that during reverse execution, we may be stepping
|
||
through a function epilogue and therefore must detect when
|
||
the current-frame changes in the middle of a line. */
|
||
|
||
if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
|
||
&& (execution_direction != EXEC_REVERSE
|
||
|| frame_id_eq (get_frame_id (frame),
|
||
ecs->event_thread->control.step_frame_id)))
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered
|
||
(gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
|
||
paddress (gdbarch, ecs->event_thread->control.step_range_start),
|
||
paddress (gdbarch, ecs->event_thread->control.step_range_end));
|
||
|
||
/* Tentatively re-enable range stepping; `resume' disables it if
|
||
necessary (e.g., if we're stepping over a breakpoint or we
|
||
have software watchpoints). */
|
||
ecs->event_thread->control.may_range_step = 1;
|
||
|
||
/* 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->control.step_range_start
|
||
&& stop_pc != ecs->stop_func_start
|
||
&& execution_direction == EXEC_REVERSE)
|
||
end_stepping_range (ecs);
|
||
else
|
||
keep_going (ecs);
|
||
|
||
return;
|
||
}
|
||
|
||
/* We stepped out of the stepping range. */
|
||
|
||
/* If we are stepping at the source level and entered the runtime
|
||
loader dynamic symbol resolution code...
|
||
|
||
EXEC_FORWARD: we keep on single stepping until we exit the run
|
||
time loader code and reach the callee's address.
|
||
|
||
EXEC_REVERSE: we've already executed the callee (backward), and
|
||
the runtime loader code is handled just like any other
|
||
undebuggable function call. Now we need only keep stepping
|
||
backward through the trampoline code, and that's handled further
|
||
down, so there is nothing for us to do here. */
|
||
|
||
if (execution_direction != EXEC_REVERSE
|
||
&& ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
|
||
&& in_solib_dynsym_resolve_code (stop_pc))
|
||
{
|
||
CORE_ADDR pc_after_resolver =
|
||
gdbarch_skip_solib_resolver (gdbarch, stop_pc);
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stepped into dynsym resolve code\n");
|
||
|
||
if (pc_after_resolver)
|
||
{
|
||
/* Set up a step-resume breakpoint at the address
|
||
indicated by SKIP_SOLIB_RESOLVER. */
|
||
struct symtab_and_line sr_sal;
|
||
|
||
init_sal (&sr_sal);
|
||
sr_sal.pc = pc_after_resolver;
|
||
sr_sal.pspace = get_frame_program_space (frame);
|
||
|
||
insert_step_resume_breakpoint_at_sal (gdbarch,
|
||
sr_sal, null_frame_id);
|
||
}
|
||
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
if (ecs->event_thread->control.step_range_end != 1
|
||
&& (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
|
||
|| ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
|
||
&& get_frame_type (frame) == SIGTRAMP_FRAME)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stepped into signal trampoline\n");
|
||
/* The inferior, while doing a "step" or "next", has ended up in
|
||
a signal trampoline (either by a signal being delivered or by
|
||
the signal handler returning). Just single-step until the
|
||
inferior leaves the trampoline (either by calling the handler
|
||
or returning). */
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
/* If we're in the return path from a shared library trampoline,
|
||
we want to proceed through the trampoline when stepping. */
|
||
/* macro/2012-04-25: This needs to come before the subroutine
|
||
call check below as on some targets return trampolines look
|
||
like subroutine calls (MIPS16 return thunks). */
|
||
if (gdbarch_in_solib_return_trampoline (gdbarch,
|
||
stop_pc, ecs->stop_func_name)
|
||
&& ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
|
||
{
|
||
/* Determine where this trampoline returns. */
|
||
CORE_ADDR real_stop_pc;
|
||
|
||
real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stepped into solib return tramp\n");
|
||
|
||
/* Only proceed through if we know where it's going. */
|
||
if (real_stop_pc)
|
||
{
|
||
/* And put the step-breakpoint there and go until there. */
|
||
struct symtab_and_line sr_sal;
|
||
|
||
init_sal (&sr_sal); /* initialize to zeroes */
|
||
sr_sal.pc = real_stop_pc;
|
||
sr_sal.section = find_pc_overlay (sr_sal.pc);
|
||
sr_sal.pspace = get_frame_program_space (frame);
|
||
|
||
/* Do not specify what the fp should be when we stop since
|
||
on some machines the prologue is where the new fp value
|
||
is established. */
|
||
insert_step_resume_breakpoint_at_sal (gdbarch,
|
||
sr_sal, null_frame_id);
|
||
|
||
/* Restart without fiddling with the step ranges or
|
||
other state. */
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* Check for subroutine calls. The check for the current frame
|
||
equalling the step ID is not necessary - the check of the
|
||
previous frame's ID is sufficient - but it is a common case and
|
||
cheaper than checking the previous frame's ID.
|
||
|
||
NOTE: frame_id_eq will never report two invalid frame IDs as
|
||
being equal, so to get into this block, both the current and
|
||
previous frame must have valid frame IDs. */
|
||
/* The outer_frame_id check is a heuristic to detect stepping
|
||
through startup code. If we step over an instruction which
|
||
sets the stack pointer from an invalid value to a valid value,
|
||
we may detect that as a subroutine call from the mythical
|
||
"outermost" function. This could be fixed by marking
|
||
outermost frames as !stack_p,code_p,special_p. Then the
|
||
initial outermost frame, before sp was valid, would
|
||
have code_addr == &_start. See the comment in frame_id_eq
|
||
for more. */
|
||
if (!frame_id_eq (get_stack_frame_id (frame),
|
||
ecs->event_thread->control.step_stack_frame_id)
|
||
&& (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
|
||
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))))
|
||
{
|
||
CORE_ADDR real_stop_pc;
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
|
||
|
||
if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
|
||
|| ((ecs->event_thread->control.step_range_end == 1)
|
||
&& in_prologue (gdbarch, ecs->event_thread->prev_pc,
|
||
ecs->stop_func_start)))
|
||
{
|
||
/* I presume that step_over_calls is only 0 when we're
|
||
supposed to be stepping at the assembly language level
|
||
("stepi"). Just stop. */
|
||
/* Also, maybe we just did a "nexti" inside a prolog, so we
|
||
thought it was a subroutine call but it was not. Stop as
|
||
well. FENN */
|
||
/* And this works the same backward as frontward. MVS */
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
|
||
/* Reverse stepping through solib trampolines. */
|
||
|
||
if (execution_direction == EXEC_REVERSE
|
||
&& ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
|
||
&& (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
|
||
|| (ecs->stop_func_start == 0
|
||
&& in_solib_dynsym_resolve_code (stop_pc))))
|
||
{
|
||
/* Any solib trampoline code can be handled in reverse
|
||
by simply continuing to single-step. We have already
|
||
executed the solib function (backwards), and a few
|
||
steps will take us back through the trampoline to the
|
||
caller. */
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
|
||
{
|
||
/* 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)
|
||
{
|
||
/* If we're already at the start of the function, we've either
|
||
just stepped backward into a single instruction function,
|
||
or stepped back out of a signal handler to the first instruction
|
||
of the function. Just keep going, which will single-step back
|
||
to the caller. */
|
||
if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
|
||
{
|
||
struct symtab_and_line sr_sal;
|
||
|
||
/* Normal function call return (static or dynamic). */
|
||
init_sal (&sr_sal);
|
||
sr_sal.pc = ecs->stop_func_start;
|
||
sr_sal.pspace = get_frame_program_space (frame);
|
||
insert_step_resume_breakpoint_at_sal (gdbarch,
|
||
sr_sal, null_frame_id);
|
||
}
|
||
}
|
||
else
|
||
insert_step_resume_breakpoint_at_caller (frame);
|
||
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
/* If we are in a function call trampoline (a stub between the
|
||
calling routine and the real function), locate the real
|
||
function. That's what tells us (a) whether we want to step
|
||
into it at all, and (b) what prologue we want to run to the
|
||
end of, if we do step into it. */
|
||
real_stop_pc = skip_language_trampoline (frame, stop_pc);
|
||
if (real_stop_pc == 0)
|
||
real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
|
||
if (real_stop_pc != 0)
|
||
ecs->stop_func_start = real_stop_pc;
|
||
|
||
if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
|
||
{
|
||
struct symtab_and_line sr_sal;
|
||
|
||
init_sal (&sr_sal);
|
||
sr_sal.pc = ecs->stop_func_start;
|
||
sr_sal.pspace = get_frame_program_space (frame);
|
||
|
||
insert_step_resume_breakpoint_at_sal (gdbarch,
|
||
sr_sal, null_frame_id);
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
/* If we have line number information for the function we are
|
||
thinking of stepping into and the function isn't on the skip
|
||
list, step into it.
|
||
|
||
If there are several symtabs at that PC (e.g. with include
|
||
files), just want to know whether *any* of them have line
|
||
numbers. find_pc_line handles this. */
|
||
{
|
||
struct symtab_and_line tmp_sal;
|
||
|
||
tmp_sal = find_pc_line (ecs->stop_func_start, 0);
|
||
if (tmp_sal.line != 0
|
||
&& !function_name_is_marked_for_skip (ecs->stop_func_name,
|
||
&tmp_sal))
|
||
{
|
||
if (execution_direction == EXEC_REVERSE)
|
||
handle_step_into_function_backward (gdbarch, ecs);
|
||
else
|
||
handle_step_into_function (gdbarch, ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* If we have no line number and the step-stop-if-no-debug is
|
||
set, we stop the step so that the user has a chance to switch
|
||
in assembly mode. */
|
||
if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
|
||
&& step_stop_if_no_debug)
|
||
{
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
|
||
if (execution_direction == EXEC_REVERSE)
|
||
{
|
||
/* If we're already at the start of the function, we've either just
|
||
stepped backward into a single instruction function without line
|
||
number info, or stepped back out of a signal handler to the first
|
||
instruction of the function without line number info. Just keep
|
||
going, which will single-step back to the caller. */
|
||
if (ecs->stop_func_start != stop_pc)
|
||
{
|
||
/* 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;
|
||
sr_sal.pspace = get_frame_program_space (frame);
|
||
insert_step_resume_breakpoint_at_sal (gdbarch,
|
||
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 (frame);
|
||
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
/* Reverse stepping through solib trampolines. */
|
||
|
||
if (execution_direction == EXEC_REVERSE
|
||
&& ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
|
||
{
|
||
if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
|
||
|| (ecs->stop_func_start == 0
|
||
&& in_solib_dynsym_resolve_code (stop_pc)))
|
||
{
|
||
/* Any solib trampoline code can be handled in reverse
|
||
by simply continuing to single-step. We have already
|
||
executed the solib function (backwards), and a few
|
||
steps will take us back through the trampoline to the
|
||
caller. */
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
else if (in_solib_dynsym_resolve_code (stop_pc))
|
||
{
|
||
/* Stepped backward into the solib dynsym resolver.
|
||
Set a breakpoint at its start and continue, then
|
||
one more step will take us out. */
|
||
struct symtab_and_line sr_sal;
|
||
|
||
init_sal (&sr_sal);
|
||
sr_sal.pc = ecs->stop_func_start;
|
||
sr_sal.pspace = get_frame_program_space (frame);
|
||
insert_step_resume_breakpoint_at_sal (gdbarch,
|
||
sr_sal, null_frame_id);
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
stop_pc_sal = find_pc_line (stop_pc, 0);
|
||
|
||
/* NOTE: tausq/2004-05-24: This if block used to be done before all
|
||
the trampoline processing logic, however, there are some trampolines
|
||
that have no names, so we should do trampoline handling first. */
|
||
if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
|
||
&& ecs->stop_func_name == NULL
|
||
&& stop_pc_sal.line == 0)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stepped into undebuggable function\n");
|
||
|
||
/* The inferior just stepped into, or returned to, an
|
||
undebuggable function (where there is no debugging information
|
||
and no line number corresponding to the address where the
|
||
inferior stopped). Since we want to skip this kind of code,
|
||
we keep going until the inferior returns from this
|
||
function - unless the user has asked us not to (via
|
||
set step-mode) or we no longer know how to get back
|
||
to the call site. */
|
||
if (step_stop_if_no_debug
|
||
|| !frame_id_p (frame_unwind_caller_id (frame)))
|
||
{
|
||
/* If we have no line number and the step-stop-if-no-debug
|
||
is set, we stop the step so that the user has a chance to
|
||
switch in assembly mode. */
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
else
|
||
{
|
||
/* Set a breakpoint at callee's return address (the address
|
||
at which the caller will resume). */
|
||
insert_step_resume_breakpoint_at_caller (frame);
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
if (ecs->event_thread->control.step_range_end == 1)
|
||
{
|
||
/* It is stepi or nexti. We always want to stop stepping after
|
||
one instruction. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
|
||
if (stop_pc_sal.line == 0)
|
||
{
|
||
/* We have no line number information. That means to stop
|
||
stepping (does this always happen right after one instruction,
|
||
when we do "s" in a function with no line numbers,
|
||
or can this happen as a result of a return or longjmp?). */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
|
||
/* Look for "calls" to inlined functions, part one. If the inline
|
||
frame machinery detected some skipped call sites, we have entered
|
||
a new inline function. */
|
||
|
||
if (frame_id_eq (get_frame_id (get_current_frame ()),
|
||
ecs->event_thread->control.step_frame_id)
|
||
&& inline_skipped_frames (ecs->ptid))
|
||
{
|
||
struct symtab_and_line call_sal;
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stepped into inlined function\n");
|
||
|
||
find_frame_sal (get_current_frame (), &call_sal);
|
||
|
||
if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
|
||
{
|
||
/* For "step", we're going to stop. But if the call site
|
||
for this inlined function is on the same source line as
|
||
we were previously stepping, go down into the function
|
||
first. Otherwise stop at the call site. */
|
||
|
||
if (call_sal.line == ecs->event_thread->current_line
|
||
&& call_sal.symtab == ecs->event_thread->current_symtab)
|
||
step_into_inline_frame (ecs->ptid);
|
||
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
else
|
||
{
|
||
/* For "next", we should stop at the call site if it is on a
|
||
different source line. Otherwise continue through the
|
||
inlined function. */
|
||
if (call_sal.line == ecs->event_thread->current_line
|
||
&& call_sal.symtab == ecs->event_thread->current_symtab)
|
||
keep_going (ecs);
|
||
else
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* Look for "calls" to inlined functions, part two. If we are still
|
||
in the same real function we were stepping through, but we have
|
||
to go further up to find the exact frame ID, we are stepping
|
||
through a more inlined call beyond its call site. */
|
||
|
||
if (get_frame_type (get_current_frame ()) == INLINE_FRAME
|
||
&& !frame_id_eq (get_frame_id (get_current_frame ()),
|
||
ecs->event_thread->control.step_frame_id)
|
||
&& stepped_in_from (get_current_frame (),
|
||
ecs->event_thread->control.step_frame_id))
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stepping through inlined function\n");
|
||
|
||
if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
|
||
keep_going (ecs);
|
||
else
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
|
||
if ((stop_pc == stop_pc_sal.pc)
|
||
&& (ecs->event_thread->current_line != stop_pc_sal.line
|
||
|| ecs->event_thread->current_symtab != stop_pc_sal.symtab))
|
||
{
|
||
/* We are at the start of a different line. So stop. Note that
|
||
we don't stop if we step into the middle of a different line.
|
||
That is said to make things like for (;;) statements work
|
||
better. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stepped to a different line\n");
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
|
||
/* We aren't done stepping.
|
||
|
||
Optimize by setting the stepping range to the line.
|
||
(We might not be in the original line, but if we entered a
|
||
new line in mid-statement, we continue stepping. This makes
|
||
things like for(;;) statements work better.) */
|
||
|
||
ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
|
||
ecs->event_thread->control.step_range_end = stop_pc_sal.end;
|
||
ecs->event_thread->control.may_range_step = 1;
|
||
set_step_info (frame, stop_pc_sal);
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
|
||
keep_going (ecs);
|
||
}
|
||
|
||
/* In all-stop mode, if we're currently stepping but have stopped in
|
||
some other thread, we may need to switch back to the stepped
|
||
thread. Returns true we set the inferior running, false if we left
|
||
it stopped (and the event needs further processing). */
|
||
|
||
static int
|
||
switch_back_to_stepped_thread (struct execution_control_state *ecs)
|
||
{
|
||
if (!non_stop)
|
||
{
|
||
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
|
||
again, do that first. */
|
||
|
||
/* However, if we see an event for the stepping thread, then we
|
||
know all other threads have been moved past their breakpoints
|
||
already. Let the caller check whether the step is finished,
|
||
etc., before deciding to move it past a breakpoint. */
|
||
if (ecs->event_thread->control.step_range_end != 0)
|
||
return 0;
|
||
|
||
/* Check if the current thread is blocked on an incomplete
|
||
step-over, interrupted by a random signal. */
|
||
if (ecs->event_thread->control.trap_expected
|
||
&& ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
|
||
{
|
||
if (debug_infrun)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: need to finish step-over of [%s]\n",
|
||
target_pid_to_str (ecs->event_thread->ptid));
|
||
}
|
||
keep_going (ecs);
|
||
return 1;
|
||
}
|
||
|
||
/* Check if the current thread is blocked by a single-step
|
||
breakpoint of another thread. */
|
||
if (ecs->hit_singlestep_breakpoint)
|
||
{
|
||
if (debug_infrun)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: need to step [%s] over single-step "
|
||
"breakpoint\n",
|
||
target_pid_to_str (ecs->ptid));
|
||
}
|
||
keep_going (ecs);
|
||
return 1;
|
||
}
|
||
|
||
/* 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. */
|
||
ecs->event_thread->control.trap_expected = 0;
|
||
|
||
/* Likewise, clear the signal if it should not be passed. */
|
||
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
|
||
step/next/etc. */
|
||
stepping_thread = NULL;
|
||
step_over = NULL;
|
||
ALL_NON_EXITED_THREADS (tp)
|
||
{
|
||
/* Ignore threads of processes we're not resuming. */
|
||
if (!sched_multi
|
||
&& ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_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);
|
||
|
||
/* Did we find the stepping thread? */
|
||
if (tp->control.step_range_end)
|
||
{
|
||
/* Yep. There should only one though. */
|
||
gdb_assert (stepping_thread == NULL);
|
||
|
||
/* The event thread is handled at the top, before we
|
||
enter this loop. */
|
||
gdb_assert (tp != ecs->event_thread);
|
||
|
||
/* If some thread other than the event thread is
|
||
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 (1));
|
||
|
||
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)
|
||
{
|
||
tp = step_over;
|
||
if (debug_infrun)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: need to step-over [%s]\n",
|
||
target_pid_to_str (tp->ptid));
|
||
}
|
||
|
||
/* Only the stepping thread should have this set. */
|
||
gdb_assert (tp->control.step_range_end == 0);
|
||
|
||
ecs->ptid = tp->ptid;
|
||
ecs->event_thread = tp;
|
||
switch_to_thread (ecs->ptid);
|
||
keep_going (ecs);
|
||
return 1;
|
||
}
|
||
|
||
if (stepping_thread != NULL)
|
||
{
|
||
struct frame_info *frame;
|
||
struct gdbarch *gdbarch;
|
||
|
||
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");
|
||
|
||
delete_thread (tp->ptid);
|
||
keep_going (ecs);
|
||
return 1;
|
||
}
|
||
|
||
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);
|
||
|
||
stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
|
||
frame = get_current_frame ();
|
||
gdbarch = get_frame_arch (frame);
|
||
|
||
/* 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 (gdbarch_software_single_step_p (gdbarch)
|
||
&& stop_pc != tp->prev_pc)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: expected thread advanced also\n");
|
||
|
||
insert_single_step_breakpoint (get_frame_arch (frame),
|
||
get_frame_address_space (frame),
|
||
stop_pc);
|
||
singlestep_breakpoints_inserted_p = 1;
|
||
ecs->event_thread->control.trap_expected = 1;
|
||
singlestep_ptid = inferior_ptid;
|
||
singlestep_pc = stop_pc;
|
||
|
||
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);
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* Is thread TP in the middle of single-stepping? */
|
||
|
||
static int
|
||
currently_stepping (struct thread_info *tp)
|
||
{
|
||
return ((tp->control.step_range_end
|
||
&& tp->control.step_resume_breakpoint == NULL)
|
||
|| tp->control.trap_expected
|
||
|| bpstat_should_step ());
|
||
}
|
||
|
||
/* 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
|
||
handle_step_into_function (struct gdbarch *gdbarch,
|
||
struct execution_control_state *ecs)
|
||
{
|
||
struct symtab *s;
|
||
struct symtab_and_line stop_func_sal, sr_sal;
|
||
|
||
fill_in_stop_func (gdbarch, ecs);
|
||
|
||
s = find_pc_symtab (stop_pc);
|
||
if (s && s->language != language_asm)
|
||
ecs->stop_func_start = gdbarch_skip_prologue (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,
|
||
even if that involves jumps (as it seems to on the vax under
|
||
4.2). */
|
||
/* If the prologue ends in the middle of a source line, continue to
|
||
the end of that source line (if it is still within the function).
|
||
Otherwise, just go to end of prologue. */
|
||
if (stop_func_sal.end
|
||
&& stop_func_sal.pc != ecs->stop_func_start
|
||
&& stop_func_sal.end < ecs->stop_func_end)
|
||
ecs->stop_func_start = stop_func_sal.end;
|
||
|
||
/* Architectures which require breakpoint adjustment might not be able
|
||
to place a breakpoint at the computed address. If so, the test
|
||
``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
|
||
ecs->stop_func_start to an address at which a breakpoint may be
|
||
legitimately placed.
|
||
|
||
Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
|
||
made, GDB will enter an infinite loop when stepping through
|
||
optimized code consisting of VLIW instructions which contain
|
||
subinstructions corresponding to different source lines. On
|
||
FR-V, it's not permitted to place a breakpoint on any but the
|
||
first subinstruction of a VLIW instruction. When a breakpoint is
|
||
set, GDB will adjust the breakpoint address to the beginning of
|
||
the VLIW instruction. Thus, we need to make the corresponding
|
||
adjustment here when computing the stop address. */
|
||
|
||
if (gdbarch_adjust_breakpoint_address_p (gdbarch))
|
||
{
|
||
ecs->stop_func_start
|
||
= gdbarch_adjust_breakpoint_address (gdbarch,
|
||
ecs->stop_func_start);
|
||
}
|
||
|
||
if (ecs->stop_func_start == stop_pc)
|
||
{
|
||
/* We are already there: stop now. */
|
||
end_stepping_range (ecs);
|
||
return;
|
||
}
|
||
else
|
||
{
|
||
/* Put the step-breakpoint there and go until there. */
|
||
init_sal (&sr_sal); /* initialize to zeroes */
|
||
sr_sal.pc = ecs->stop_func_start;
|
||
sr_sal.section = find_pc_overlay (ecs->stop_func_start);
|
||
sr_sal.pspace = get_frame_program_space (get_current_frame ());
|
||
|
||
/* Do not specify what the fp should be when we stop since on
|
||
some machines the prologue is where the new fp value is
|
||
established. */
|
||
insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
|
||
|
||
/* And make sure stepping stops right away then. */
|
||
ecs->event_thread->control.step_range_end
|
||
= ecs->event_thread->control.step_range_start;
|
||
}
|
||
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 gdbarch *gdbarch,
|
||
struct execution_control_state *ecs)
|
||
{
|
||
struct symtab *s;
|
||
struct symtab_and_line stop_func_sal;
|
||
|
||
fill_in_stop_func (gdbarch, ecs);
|
||
|
||
s = find_pc_symtab (stop_pc);
|
||
if (s && s->language != language_asm)
|
||
ecs->stop_func_start = gdbarch_skip_prologue (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. */
|
||
end_stepping_range (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->control.step_range_start = stop_func_sal.pc;
|
||
ecs->event_thread->control.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. */
|
||
|
||
static void
|
||
insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
|
||
struct symtab_and_line sr_sal,
|
||
struct frame_id sr_id,
|
||
enum bptype sr_type)
|
||
{
|
||
/* There should never be more than one step-resume or longjmp-resume
|
||
breakpoint per thread, so we should never be setting a new
|
||
step_resume_breakpoint when one is already active. */
|
||
gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
|
||
gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: inserting step-resume breakpoint at %s\n",
|
||
paddress (gdbarch, sr_sal.pc));
|
||
|
||
inferior_thread ()->control.step_resume_breakpoint
|
||
= set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
|
||
}
|
||
|
||
void
|
||
insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
|
||
struct symtab_and_line sr_sal,
|
||
struct frame_id sr_id)
|
||
{
|
||
insert_step_resume_breakpoint_at_sal_1 (gdbarch,
|
||
sr_sal, sr_id,
|
||
bp_step_resume);
|
||
}
|
||
|
||
/* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
|
||
This is used to skip a potential signal handler.
|
||
|
||
This is called with the interrupted function's frame. The signal
|
||
handler, when it returns, will resume the interrupted function at
|
||
RETURN_FRAME.pc. */
|
||
|
||
static void
|
||
insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
|
||
{
|
||
struct symtab_and_line sr_sal;
|
||
struct gdbarch *gdbarch;
|
||
|
||
gdb_assert (return_frame != NULL);
|
||
init_sal (&sr_sal); /* initialize to zeros */
|
||
|
||
gdbarch = get_frame_arch (return_frame);
|
||
sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
|
||
sr_sal.section = find_pc_overlay (sr_sal.pc);
|
||
sr_sal.pspace = get_frame_program_space (return_frame);
|
||
|
||
insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
|
||
get_stack_frame_id (return_frame),
|
||
bp_hp_step_resume);
|
||
}
|
||
|
||
/* Insert a "step-resume breakpoint" at the previous frame's PC. This
|
||
is used to skip a function after stepping into it (for "next" or if
|
||
the called function has no debugging information).
|
||
|
||
The current function has almost always been reached by single
|
||
stepping a call or return instruction. NEXT_FRAME belongs to the
|
||
current function, and the breakpoint will be set at the caller's
|
||
resume address.
|
||
|
||
This is a separate function rather than reusing
|
||
insert_hp_step_resume_breakpoint_at_frame in order to avoid
|
||
get_prev_frame, which may stop prematurely (see the implementation
|
||
of frame_unwind_caller_id for an example). */
|
||
|
||
static void
|
||
insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
|
||
{
|
||
struct symtab_and_line sr_sal;
|
||
struct gdbarch *gdbarch;
|
||
|
||
/* We shouldn't have gotten here if we don't know where the call site
|
||
is. */
|
||
gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
|
||
|
||
init_sal (&sr_sal); /* initialize to zeros */
|
||
|
||
gdbarch = frame_unwind_caller_arch (next_frame);
|
||
sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
|
||
frame_unwind_caller_pc (next_frame));
|
||
sr_sal.section = find_pc_overlay (sr_sal.pc);
|
||
sr_sal.pspace = frame_unwind_program_space (next_frame);
|
||
|
||
insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
|
||
frame_unwind_caller_id (next_frame));
|
||
}
|
||
|
||
/* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
|
||
new breakpoint at the target of a jmp_buf. The handling of
|
||
longjmp-resume uses the same mechanisms used for handling
|
||
"step-resume" breakpoints. */
|
||
|
||
static void
|
||
insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
|
||
{
|
||
/* There should never be more than one longjmp-resume breakpoint per
|
||
thread, so we should never be setting a new
|
||
longjmp_resume_breakpoint when one is already active. */
|
||
gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: inserting longjmp-resume breakpoint at %s\n",
|
||
paddress (gdbarch, pc));
|
||
|
||
inferior_thread ()->control.exception_resume_breakpoint =
|
||
set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
|
||
}
|
||
|
||
/* Insert an exception resume breakpoint. TP is the thread throwing
|
||
the exception. The block B is the block of the unwinder debug hook
|
||
function. FRAME is the frame corresponding to the call to this
|
||
function. SYM is the symbol of the function argument holding the
|
||
target PC of the exception. */
|
||
|
||
static void
|
||
insert_exception_resume_breakpoint (struct thread_info *tp,
|
||
const struct block *b,
|
||
struct frame_info *frame,
|
||
struct symbol *sym)
|
||
{
|
||
volatile struct gdb_exception e;
|
||
|
||
/* We want to ignore errors here. */
|
||
TRY_CATCH (e, RETURN_MASK_ERROR)
|
||
{
|
||
struct symbol *vsym;
|
||
struct value *value;
|
||
CORE_ADDR handler;
|
||
struct breakpoint *bp;
|
||
|
||
vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
|
||
value = read_var_value (vsym, frame);
|
||
/* If the value was optimized out, revert to the old behavior. */
|
||
if (! value_optimized_out (value))
|
||
{
|
||
handler = value_as_address (value);
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: exception resume at %lx\n",
|
||
(unsigned long) handler);
|
||
|
||
bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
|
||
handler, bp_exception_resume);
|
||
|
||
/* set_momentary_breakpoint_at_pc invalidates FRAME. */
|
||
frame = NULL;
|
||
|
||
bp->thread = tp->num;
|
||
inferior_thread ()->control.exception_resume_breakpoint = bp;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* A helper for check_exception_resume that sets an
|
||
exception-breakpoint based on a SystemTap probe. */
|
||
|
||
static void
|
||
insert_exception_resume_from_probe (struct thread_info *tp,
|
||
const struct bound_probe *probe,
|
||
struct frame_info *frame)
|
||
{
|
||
struct value *arg_value;
|
||
CORE_ADDR handler;
|
||
struct breakpoint *bp;
|
||
|
||
arg_value = probe_safe_evaluate_at_pc (frame, 1);
|
||
if (!arg_value)
|
||
return;
|
||
|
||
handler = value_as_address (arg_value);
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: exception resume at %s\n",
|
||
paddress (get_objfile_arch (probe->objfile),
|
||
handler));
|
||
|
||
bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
|
||
handler, bp_exception_resume);
|
||
bp->thread = tp->num;
|
||
inferior_thread ()->control.exception_resume_breakpoint = bp;
|
||
}
|
||
|
||
/* This is called when an exception has been intercepted. Check to
|
||
see whether the exception's destination is of interest, and if so,
|
||
set an exception resume breakpoint there. */
|
||
|
||
static void
|
||
check_exception_resume (struct execution_control_state *ecs,
|
||
struct frame_info *frame)
|
||
{
|
||
volatile struct gdb_exception e;
|
||
struct bound_probe probe;
|
||
struct symbol *func;
|
||
|
||
/* First see if this exception unwinding breakpoint was set via a
|
||
SystemTap probe point. If so, the probe has two arguments: the
|
||
CFA and the HANDLER. We ignore the CFA, extract the handler, and
|
||
set a breakpoint there. */
|
||
probe = find_probe_by_pc (get_frame_pc (frame));
|
||
if (probe.probe)
|
||
{
|
||
insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
|
||
return;
|
||
}
|
||
|
||
func = get_frame_function (frame);
|
||
if (!func)
|
||
return;
|
||
|
||
TRY_CATCH (e, RETURN_MASK_ERROR)
|
||
{
|
||
const struct block *b;
|
||
struct block_iterator iter;
|
||
struct symbol *sym;
|
||
int argno = 0;
|
||
|
||
/* The exception breakpoint is a thread-specific breakpoint on
|
||
the unwinder's debug hook, declared as:
|
||
|
||
void _Unwind_DebugHook (void *cfa, void *handler);
|
||
|
||
The CFA argument indicates the frame to which control is
|
||
about to be transferred. HANDLER is the destination PC.
|
||
|
||
We ignore the CFA and set a temporary breakpoint at HANDLER.
|
||
This is not extremely efficient but it avoids issues in gdb
|
||
with computing the DWARF CFA, and it also works even in weird
|
||
cases such as throwing an exception from inside a signal
|
||
handler. */
|
||
|
||
b = SYMBOL_BLOCK_VALUE (func);
|
||
ALL_BLOCK_SYMBOLS (b, iter, sym)
|
||
{
|
||
if (!SYMBOL_IS_ARGUMENT (sym))
|
||
continue;
|
||
|
||
if (argno == 0)
|
||
++argno;
|
||
else
|
||
{
|
||
insert_exception_resume_breakpoint (ecs->event_thread,
|
||
b, frame, sym);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
static void
|
||
stop_waiting (struct execution_control_state *ecs)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
|
||
|
||
clear_step_over_info ();
|
||
|
||
/* Let callers know we don't want to wait for the inferior anymore. */
|
||
ecs->wait_some_more = 0;
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
/* Make sure normal_stop is called if we get a QUIT handled before
|
||
reaching resume. */
|
||
struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
|
||
|
||
/* 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)
|
||
{
|
||
/* 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);
|
||
}
|
||
else
|
||
{
|
||
volatile struct gdb_exception e;
|
||
struct regcache *regcache = get_current_regcache ();
|
||
|
||
/* Either the trap was not expected, but we are continuing
|
||
anyway (if we got a signal, the user asked it be passed to
|
||
the child)
|
||
-- or --
|
||
We got our expected trap, but decided we should resume from
|
||
it.
|
||
|
||
We're going to run this baby now!
|
||
|
||
Note that insert_breakpoints won't try to re-insert
|
||
already inserted breakpoints. Therefore, we don't
|
||
care if breakpoints were already inserted, or not. */
|
||
|
||
/* 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 ((ecs->hit_singlestep_breakpoint
|
||
|| thread_still_needs_step_over (ecs->event_thread))
|
||
&& !use_displaced_stepping (get_regcache_arch (regcache)))
|
||
{
|
||
set_step_over_info (get_regcache_aspace (regcache),
|
||
regcache_read_pc (regcache));
|
||
}
|
||
else
|
||
clear_step_over_info ();
|
||
|
||
/* Stop stepping if inserting breakpoints fails. */
|
||
TRY_CATCH (e, RETURN_MASK_ERROR)
|
||
{
|
||
insert_breakpoints ();
|
||
}
|
||
if (e.reason < 0)
|
||
{
|
||
exception_print (gdb_stderr, e);
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
|
||
ecs->event_thread->control.trap_expected
|
||
= (ecs->event_thread->stepping_over_breakpoint
|
||
|| ecs->hit_singlestep_breakpoint);
|
||
|
||
/* 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);
|
||
}
|
||
|
||
prepare_to_wait (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. */
|
||
|
||
static void
|
||
prepare_to_wait (struct execution_control_state *ecs)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
|
||
|
||
/* This is the old end of the while loop. Let everybody know we
|
||
want to wait for the inferior some more and get called again
|
||
soon. */
|
||
ecs->wait_some_more = 1;
|
||
}
|
||
|
||
/* We are done with the step range of a step/next/si/ni command.
|
||
Called once for each n of a "step n" operation. Notify observers
|
||
if not in the middle of doing a "step N" operation for N > 1. */
|
||
|
||
static void
|
||
end_stepping_range (struct execution_control_state *ecs)
|
||
{
|
||
ecs->event_thread->control.stop_step = 1;
|
||
if (!ecs->event_thread->step_multi)
|
||
observer_notify_end_stepping_range ();
|
||
stop_waiting (ecs);
|
||
}
|
||
|
||
/* Several print_*_reason functions to print why the inferior has stopped.
|
||
We always print something when the inferior exits, or receives a signal.
|
||
The rest of the cases are dealt with later on in normal_stop and
|
||
print_it_typical. Ideally there should be a call to one of these
|
||
print_*_reason functions functions from handle_inferior_event each time
|
||
stop_waiting is called.
|
||
|
||
Note that we don't call these directly, instead we delegate that to
|
||
the interpreters, through observers. Interpreters then call these
|
||
with whatever uiout is right. */
|
||
|
||
void
|
||
print_end_stepping_range_reason (struct ui_out *uiout)
|
||
{
|
||
/* For CLI-like interpreters, print nothing. */
|
||
|
||
if (ui_out_is_mi_like_p (uiout))
|
||
{
|
||
ui_out_field_string (uiout, "reason",
|
||
async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
|
||
}
|
||
}
|
||
|
||
void
|
||
print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
|
||
{
|
||
annotate_signalled ();
|
||
if (ui_out_is_mi_like_p (uiout))
|
||
ui_out_field_string
|
||
(uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
|
||
ui_out_text (uiout, "\nProgram terminated with signal ");
|
||
annotate_signal_name ();
|
||
ui_out_field_string (uiout, "signal-name",
|
||
gdb_signal_to_name (siggnal));
|
||
annotate_signal_name_end ();
|
||
ui_out_text (uiout, ", ");
|
||
annotate_signal_string ();
|
||
ui_out_field_string (uiout, "signal-meaning",
|
||
gdb_signal_to_string (siggnal));
|
||
annotate_signal_string_end ();
|
||
ui_out_text (uiout, ".\n");
|
||
ui_out_text (uiout, "The program no longer exists.\n");
|
||
}
|
||
|
||
void
|
||
print_exited_reason (struct ui_out *uiout, int exitstatus)
|
||
{
|
||
struct inferior *inf = current_inferior ();
|
||
const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
|
||
|
||
annotate_exited (exitstatus);
|
||
if (exitstatus)
|
||
{
|
||
if (ui_out_is_mi_like_p (uiout))
|
||
ui_out_field_string (uiout, "reason",
|
||
async_reason_lookup (EXEC_ASYNC_EXITED));
|
||
ui_out_text (uiout, "[Inferior ");
|
||
ui_out_text (uiout, plongest (inf->num));
|
||
ui_out_text (uiout, " (");
|
||
ui_out_text (uiout, pidstr);
|
||
ui_out_text (uiout, ") exited with code ");
|
||
ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
|
||
ui_out_text (uiout, "]\n");
|
||
}
|
||
else
|
||
{
|
||
if (ui_out_is_mi_like_p (uiout))
|
||
ui_out_field_string
|
||
(uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
|
||
ui_out_text (uiout, "[Inferior ");
|
||
ui_out_text (uiout, plongest (inf->num));
|
||
ui_out_text (uiout, " (");
|
||
ui_out_text (uiout, pidstr);
|
||
ui_out_text (uiout, ") exited normally]\n");
|
||
}
|
||
}
|
||
|
||
void
|
||
print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
|
||
{
|
||
annotate_signal ();
|
||
|
||
if (siggnal == GDB_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",
|
||
gdb_signal_to_name (siggnal));
|
||
annotate_signal_name_end ();
|
||
ui_out_text (uiout, ", ");
|
||
annotate_signal_string ();
|
||
ui_out_field_string (uiout, "signal-meaning",
|
||
gdb_signal_to_string (siggnal));
|
||
annotate_signal_string_end ();
|
||
}
|
||
ui_out_text (uiout, ".\n");
|
||
}
|
||
|
||
void
|
||
print_no_history_reason (struct ui_out *uiout)
|
||
{
|
||
ui_out_text (uiout, "\nNo more reverse-execution history.\n");
|
||
}
|
||
|
||
/* Print current location without a level number, if we have changed
|
||
functions or hit a breakpoint. Print source line if we have one.
|
||
bpstat_print contains the logic deciding in detail what to print,
|
||
based on the event(s) that just occurred. */
|
||
|
||
void
|
||
print_stop_event (struct target_waitstatus *ws)
|
||
{
|
||
int bpstat_ret;
|
||
int source_flag;
|
||
int do_frame_printing = 1;
|
||
struct thread_info *tp = inferior_thread ();
|
||
|
||
bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
|
||
switch (bpstat_ret)
|
||
{
|
||
case PRINT_UNKNOWN:
|
||
/* FIXME: cagney/2002-12-01: Given that a frame ID does (or
|
||
should) carry around the function and does (or should) use
|
||
that when doing a frame comparison. */
|
||
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))
|
||
{
|
||
/* Finished step, just print source line. */
|
||
source_flag = SRC_LINE;
|
||
}
|
||
else
|
||
{
|
||
/* Print location and source line. */
|
||
source_flag = SRC_AND_LOC;
|
||
}
|
||
break;
|
||
case PRINT_SRC_AND_LOC:
|
||
/* Print location and source line. */
|
||
source_flag = SRC_AND_LOC;
|
||
break;
|
||
case PRINT_SRC_ONLY:
|
||
source_flag = SRC_LINE;
|
||
break;
|
||
case PRINT_NOTHING:
|
||
/* Something bogus. */
|
||
source_flag = SRC_LINE;
|
||
do_frame_printing = 0;
|
||
break;
|
||
default:
|
||
internal_error (__FILE__, __LINE__, _("Unknown value."));
|
||
}
|
||
|
||
/* The behavior of this routine with respect to the source
|
||
flag is:
|
||
SRC_LINE: Print only source line
|
||
LOCATION: Print only location
|
||
SRC_AND_LOC: Print location and source line. */
|
||
if (do_frame_printing)
|
||
print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
|
||
|
||
/* Display the auto-display expressions. */
|
||
do_displays ();
|
||
}
|
||
|
||
/* Here to return control to GDB when the inferior stops for real.
|
||
Print appropriate messages, remove breakpoints, give terminal our modes.
|
||
|
||
STOP_PRINT_FRAME nonzero means print the executing frame
|
||
(pc, function, args, file, line number and line text).
|
||
BREAKPOINTS_FAILED nonzero means stop was due to error
|
||
attempting to insert breakpoints. */
|
||
|
||
void
|
||
normal_stop (void)
|
||
{
|
||
struct target_waitstatus last;
|
||
ptid_t last_ptid;
|
||
struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
|
||
|
||
get_last_target_status (&last_ptid, &last);
|
||
|
||
/* 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. A QUIT is an easy exception to see
|
||
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)
|
||
make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
|
||
|
||
/* As with the notification of thread events, we want to delay
|
||
notifying the user that we've switched thread context until
|
||
the inferior actually stops.
|
||
|
||
There's no point in saying anything if the inferior has exited.
|
||
Note that SIGNALLED here means "exited with a signal", not
|
||
"received a signal".
|
||
|
||
Also skip saying anything in non-stop mode. In that mode, as we
|
||
don't want GDB to switch threads behind the user's back, to avoid
|
||
races where the user is typing a command to apply to thread x,
|
||
but GDB switches to thread y before the user finishes entering
|
||
the command, fetch_inferior_event installs a cleanup to restore
|
||
the current thread back to the thread the user had selected right
|
||
after this event is handled, so we're not really switching, only
|
||
informing of a stop. */
|
||
if (!non_stop
|
||
&& !ptid_equal (previous_inferior_ptid, inferior_ptid)
|
||
&& target_has_execution
|
||
&& last.kind != TARGET_WAITKIND_SIGNALLED
|
||
&& last.kind != TARGET_WAITKIND_EXITED
|
||
&& last.kind != TARGET_WAITKIND_NO_RESUMED)
|
||
{
|
||
target_terminal_ours_for_output ();
|
||
printf_filtered (_("[Switching to %s]\n"),
|
||
target_pid_to_str (inferior_ptid));
|
||
annotate_thread_changed ();
|
||
previous_inferior_ptid = inferior_ptid;
|
||
}
|
||
|
||
if (last.kind == TARGET_WAITKIND_NO_RESUMED)
|
||
{
|
||
gdb_assert (sync_execution || !target_can_async_p ());
|
||
|
||
target_terminal_ours_for_output ();
|
||
printf_filtered (_("No unwaited-for children left.\n"));
|
||
}
|
||
|
||
if (!breakpoints_always_inserted_mode () && target_has_execution)
|
||
{
|
||
if (remove_breakpoints ())
|
||
{
|
||
target_terminal_ours_for_output ();
|
||
printf_filtered (_("Cannot remove breakpoints because "
|
||
"program is no longer writable.\nFurther "
|
||
"execution is probably impossible.\n"));
|
||
}
|
||
}
|
||
|
||
/* If an auto-display called a function and that got a signal,
|
||
delete that auto-display to avoid an infinite recursion. */
|
||
|
||
if (stopped_by_random_signal)
|
||
disable_current_display ();
|
||
|
||
/* Don't print a message if in the middle of doing a "step n"
|
||
operation for n > 1 */
|
||
if (target_has_execution
|
||
&& last.kind != TARGET_WAITKIND_SIGNALLED
|
||
&& last.kind != TARGET_WAITKIND_EXITED
|
||
&& inferior_thread ()->step_multi
|
||
&& inferior_thread ()->control.stop_step)
|
||
goto done;
|
||
|
||
target_terminal_ours ();
|
||
async_enable_stdin ();
|
||
|
||
/* Set the current source location. This will also happen if we
|
||
display the frame below, but the current SAL will be incorrect
|
||
during a user hook-stop function. */
|
||
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)
|
||
discard_cleanups (old_chain);
|
||
else
|
||
do_cleanups (old_chain);
|
||
|
||
/* Look up the hook_stop and run it (CLI internally handles problem
|
||
of stop_command's pre-hook not existing). */
|
||
if (stop_command)
|
||
catch_errors (hook_stop_stub, stop_command,
|
||
"Error while running hook_stop:\n", RETURN_MASK_ALL);
|
||
|
||
if (!has_stack_frames ())
|
||
goto done;
|
||
|
||
if (last.kind == TARGET_WAITKIND_SIGNALLED
|
||
|| last.kind == TARGET_WAITKIND_EXITED)
|
||
goto done;
|
||
|
||
/* Select innermost stack frame - i.e., current frame is frame 0,
|
||
and current location is based on that.
|
||
Don't do this on return from a stack dummy routine,
|
||
or if the program has exited. */
|
||
|
||
if (!stop_stack_dummy)
|
||
{
|
||
select_frame (get_current_frame ());
|
||
|
||
/* If --batch-silent is enabled then there's no need to print the current
|
||
source location, and to try risks causing an error message about
|
||
missing source files. */
|
||
if (stop_print_frame && !batch_silent)
|
||
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.
|
||
This also restores inferior state prior to the call
|
||
(struct infcall_suspend_state). */
|
||
struct frame_info *frame = get_current_frame ();
|
||
|
||
gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
|
||
frame_pop (frame);
|
||
/* frame_pop() calls reinit_frame_cache as the last thing it
|
||
does which means there's currently no selected frame. We
|
||
don't need to re-establish a selected frame if the dummy call
|
||
returns normally, that will be done by
|
||
restore_infcall_control_state. However, we do have to handle
|
||
the case where the dummy call is returning after being
|
||
stopped (e.g. the dummy call previously hit a breakpoint).
|
||
We can't know which case we have so just always re-establish
|
||
a selected frame here. */
|
||
select_frame (get_current_frame ());
|
||
}
|
||
|
||
done:
|
||
annotate_stopped ();
|
||
|
||
/* Suppress the stop observer if we're in the middle of:
|
||
|
||
- a step n (n > 1), as there still more steps to be done.
|
||
|
||
- a "finish" command, as the observer will be called in
|
||
finish_command_continuation, so it can include the inferior
|
||
function's return value.
|
||
|
||
- calling an inferior function, as we pretend we inferior didn't
|
||
run at all. The return value of the call is handled by the
|
||
expression evaluator, through call_function_by_hand. */
|
||
|
||
if (!target_has_execution
|
||
|| last.kind == TARGET_WAITKIND_SIGNALLED
|
||
|| last.kind == TARGET_WAITKIND_EXITED
|
||
|| last.kind == TARGET_WAITKIND_NO_RESUMED
|
||
|| (!(inferior_thread ()->step_multi
|
||
&& inferior_thread ()->control.stop_step)
|
||
&& !(inferior_thread ()->control.stop_bpstat
|
||
&& inferior_thread ()->control.proceed_to_finish)
|
||
&& !inferior_thread ()->control.in_infcall))
|
||
{
|
||
if (!ptid_equal (inferior_ptid, null_ptid))
|
||
observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
|
||
stop_print_frame);
|
||
else
|
||
observer_notify_normal_stop (NULL, stop_print_frame);
|
||
}
|
||
|
||
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 ()->control.stop_bpstat);
|
||
}
|
||
|
||
/* Try to get rid of automatically added inferiors that are no
|
||
longer needed. Keeping those around slows down things linearly.
|
||
Note that this never removes the current inferior. */
|
||
prune_inferiors ();
|
||
}
|
||
|
||
static int
|
||
hook_stop_stub (void *cmd)
|
||
{
|
||
execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
|
||
return (0);
|
||
}
|
||
|
||
int
|
||
signal_stop_state (int signo)
|
||
{
|
||
return signal_stop[signo];
|
||
}
|
||
|
||
int
|
||
signal_print_state (int signo)
|
||
{
|
||
return signal_print[signo];
|
||
}
|
||
|
||
int
|
||
signal_pass_state (int signo)
|
||
{
|
||
return signal_program[signo];
|
||
}
|
||
|
||
static void
|
||
signal_cache_update (int signo)
|
||
{
|
||
if (signo == -1)
|
||
{
|
||
for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
|
||
signal_cache_update (signo);
|
||
|
||
return;
|
||
}
|
||
|
||
signal_pass[signo] = (signal_stop[signo] == 0
|
||
&& signal_print[signo] == 0
|
||
&& signal_program[signo] == 1
|
||
&& signal_catch[signo] == 0);
|
||
}
|
||
|
||
int
|
||
signal_stop_update (int signo, int state)
|
||
{
|
||
int ret = signal_stop[signo];
|
||
|
||
signal_stop[signo] = state;
|
||
signal_cache_update (signo);
|
||
return ret;
|
||
}
|
||
|
||
int
|
||
signal_print_update (int signo, int state)
|
||
{
|
||
int ret = signal_print[signo];
|
||
|
||
signal_print[signo] = state;
|
||
signal_cache_update (signo);
|
||
return ret;
|
||
}
|
||
|
||
int
|
||
signal_pass_update (int signo, int state)
|
||
{
|
||
int ret = signal_program[signo];
|
||
|
||
signal_program[signo] = state;
|
||
signal_cache_update (signo);
|
||
return ret;
|
||
}
|
||
|
||
/* Update the global 'signal_catch' from INFO and notify the
|
||
target. */
|
||
|
||
void
|
||
signal_catch_update (const unsigned int *info)
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < GDB_SIGNAL_LAST; ++i)
|
||
signal_catch[i] = info[i] > 0;
|
||
signal_cache_update (-1);
|
||
target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
|
||
}
|
||
|
||
static void
|
||
sig_print_header (void)
|
||
{
|
||
printf_filtered (_("Signal Stop\tPrint\tPass "
|
||
"to program\tDescription\n"));
|
||
}
|
||
|
||
static void
|
||
sig_print_info (enum gdb_signal oursig)
|
||
{
|
||
const char *name = gdb_signal_to_name (oursig);
|
||
int name_padding = 13 - strlen (name);
|
||
|
||
if (name_padding <= 0)
|
||
name_padding = 0;
|
||
|
||
printf_filtered ("%s", name);
|
||
printf_filtered ("%*.*s ", name_padding, name_padding, " ");
|
||
printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
|
||
printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
|
||
printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
|
||
printf_filtered ("%s\n", gdb_signal_to_string (oursig));
|
||
}
|
||
|
||
/* Specify how various signals in the inferior should be handled. */
|
||
|
||
static void
|
||
handle_command (char *args, int from_tty)
|
||
{
|
||
char **argv;
|
||
int digits, wordlen;
|
||
int sigfirst, signum, siglast;
|
||
enum gdb_signal oursig;
|
||
int allsigs;
|
||
int nsigs;
|
||
unsigned char *sigs;
|
||
struct cleanup *old_chain;
|
||
|
||
if (args == NULL)
|
||
{
|
||
error_no_arg (_("signal to handle"));
|
||
}
|
||
|
||
/* Allocate and zero an array of flags for which signals to handle. */
|
||
|
||
nsigs = (int) GDB_SIGNAL_LAST;
|
||
sigs = (unsigned char *) alloca (nsigs);
|
||
memset (sigs, 0, nsigs);
|
||
|
||
/* Break the command line up into args. */
|
||
|
||
argv = gdb_buildargv (args);
|
||
old_chain = make_cleanup_freeargv (argv);
|
||
|
||
/* Walk through the args, looking for signal oursigs, signal names, and
|
||
actions. Signal numbers and signal names may be interspersed with
|
||
actions, with the actions being performed for all signals cumulatively
|
||
specified. Signal ranges can be specified as <LOW>-<HIGH>. */
|
||
|
||
while (*argv != NULL)
|
||
{
|
||
wordlen = strlen (*argv);
|
||
for (digits = 0; isdigit ((*argv)[digits]); digits++)
|
||
{;
|
||
}
|
||
allsigs = 0;
|
||
sigfirst = siglast = -1;
|
||
|
||
if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
|
||
{
|
||
/* Apply action to all signals except those used by the
|
||
debugger. Silently skip those. */
|
||
allsigs = 1;
|
||
sigfirst = 0;
|
||
siglast = nsigs - 1;
|
||
}
|
||
else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
|
||
{
|
||
SET_SIGS (nsigs, sigs, signal_stop);
|
||
SET_SIGS (nsigs, sigs, signal_print);
|
||
}
|
||
else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
|
||
{
|
||
UNSET_SIGS (nsigs, sigs, signal_program);
|
||
}
|
||
else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
|
||
{
|
||
SET_SIGS (nsigs, sigs, signal_print);
|
||
}
|
||
else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
|
||
{
|
||
SET_SIGS (nsigs, sigs, signal_program);
|
||
}
|
||
else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
|
||
{
|
||
UNSET_SIGS (nsigs, sigs, signal_stop);
|
||
}
|
||
else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
|
||
{
|
||
SET_SIGS (nsigs, sigs, signal_program);
|
||
}
|
||
else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
|
||
{
|
||
UNSET_SIGS (nsigs, sigs, signal_print);
|
||
UNSET_SIGS (nsigs, sigs, signal_stop);
|
||
}
|
||
else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
|
||
{
|
||
UNSET_SIGS (nsigs, sigs, signal_program);
|
||
}
|
||
else if (digits > 0)
|
||
{
|
||
/* It is numeric. The numeric signal refers to our own
|
||
internal signal numbering from target.h, not to host/target
|
||
signal number. This is a feature; users really should be
|
||
using symbolic names anyway, and the common ones like
|
||
SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
|
||
|
||
sigfirst = siglast = (int)
|
||
gdb_signal_from_command (atoi (*argv));
|
||
if ((*argv)[digits] == '-')
|
||
{
|
||
siglast = (int)
|
||
gdb_signal_from_command (atoi ((*argv) + digits + 1));
|
||
}
|
||
if (sigfirst > siglast)
|
||
{
|
||
/* Bet he didn't figure we'd think of this case... */
|
||
signum = sigfirst;
|
||
sigfirst = siglast;
|
||
siglast = signum;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
oursig = gdb_signal_from_name (*argv);
|
||
if (oursig != GDB_SIGNAL_UNKNOWN)
|
||
{
|
||
sigfirst = siglast = (int) oursig;
|
||
}
|
||
else
|
||
{
|
||
/* Not a number and not a recognized flag word => complain. */
|
||
error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
|
||
}
|
||
}
|
||
|
||
/* If any signal numbers or symbol names were found, set flags for
|
||
which signals to apply actions to. */
|
||
|
||
for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
|
||
{
|
||
switch ((enum gdb_signal) signum)
|
||
{
|
||
case GDB_SIGNAL_TRAP:
|
||
case GDB_SIGNAL_INT:
|
||
if (!allsigs && !sigs[signum])
|
||
{
|
||
if (query (_("%s is used by the debugger.\n\
|
||
Are you sure you want to change it? "),
|
||
gdb_signal_to_name ((enum gdb_signal) signum)))
|
||
{
|
||
sigs[signum] = 1;
|
||
}
|
||
else
|
||
{
|
||
printf_unfiltered (_("Not confirmed, unchanged.\n"));
|
||
gdb_flush (gdb_stdout);
|
||
}
|
||
}
|
||
break;
|
||
case GDB_SIGNAL_0:
|
||
case GDB_SIGNAL_DEFAULT:
|
||
case GDB_SIGNAL_UNKNOWN:
|
||
/* Make sure that "all" doesn't print these. */
|
||
break;
|
||
default:
|
||
sigs[signum] = 1;
|
||
break;
|
||
}
|
||
}
|
||
|
||
argv++;
|
||
}
|
||
|
||
for (signum = 0; signum < nsigs; signum++)
|
||
if (sigs[signum])
|
||
{
|
||
signal_cache_update (-1);
|
||
target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
|
||
target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
|
||
|
||
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);
|
||
}
|
||
|
||
/* Complete the "handle" command. */
|
||
|
||
static VEC (char_ptr) *
|
||
handle_completer (struct cmd_list_element *ignore,
|
||
const char *text, const char *word)
|
||
{
|
||
VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
|
||
static const char * const keywords[] =
|
||
{
|
||
"all",
|
||
"stop",
|
||
"ignore",
|
||
"print",
|
||
"pass",
|
||
"nostop",
|
||
"noignore",
|
||
"noprint",
|
||
"nopass",
|
||
NULL,
|
||
};
|
||
|
||
vec_signals = signal_completer (ignore, text, word);
|
||
vec_keywords = complete_on_enum (keywords, word, word);
|
||
|
||
return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
|
||
VEC_free (char_ptr, vec_signals);
|
||
VEC_free (char_ptr, vec_keywords);
|
||
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)
|
||
{
|
||
if (num >= 1 && num <= 15)
|
||
return (enum gdb_signal) num;
|
||
error (_("Only signals 1-15 are valid as numeric signals.\n\
|
||
Use \"info signals\" for a list of symbolic signals."));
|
||
}
|
||
|
||
/* Print current contents of the tables set by the handle command.
|
||
It is possible we should just be printing signals actually used
|
||
by the current target (but for things to work right when switching
|
||
targets, all signals should be in the signal tables). */
|
||
|
||
static void
|
||
signals_info (char *signum_exp, int from_tty)
|
||
{
|
||
enum gdb_signal oursig;
|
||
|
||
sig_print_header ();
|
||
|
||
if (signum_exp)
|
||
{
|
||
/* First see if this is a symbol name. */
|
||
oursig = gdb_signal_from_name (signum_exp);
|
||
if (oursig == GDB_SIGNAL_UNKNOWN)
|
||
{
|
||
/* No, try numeric. */
|
||
oursig =
|
||
gdb_signal_from_command (parse_and_eval_long (signum_exp));
|
||
}
|
||
sig_print_info (oursig);
|
||
return;
|
||
}
|
||
|
||
printf_filtered ("\n");
|
||
/* These ugly casts brought to you by the native VAX compiler. */
|
||
for (oursig = GDB_SIGNAL_FIRST;
|
||
(int) oursig < (int) GDB_SIGNAL_LAST;
|
||
oursig = (enum gdb_signal) ((int) oursig + 1))
|
||
{
|
||
QUIT;
|
||
|
||
if (oursig != GDB_SIGNAL_UNKNOWN
|
||
&& oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
|
||
sig_print_info (oursig);
|
||
}
|
||
|
||
printf_filtered (_("\nUse the \"handle\" command "
|
||
"to change these tables.\n"));
|
||
}
|
||
|
||
/* Check if it makes sense to read $_siginfo from the current thread
|
||
at this point. If not, throw an error. */
|
||
|
||
static void
|
||
validate_siginfo_access (void)
|
||
{
|
||
/* No current inferior, no siginfo. */
|
||
if (ptid_equal (inferior_ptid, null_ptid))
|
||
error (_("No thread selected."));
|
||
|
||
/* Don't try to read from a dead thread. */
|
||
if (is_exited (inferior_ptid))
|
||
error (_("The current thread has terminated"));
|
||
|
||
/* ... or from a spinning thread. */
|
||
if (is_running (inferior_ptid))
|
||
error (_("Selected thread is running."));
|
||
}
|
||
|
||
/* The $_siginfo convenience variable is a bit special. We don't know
|
||
for sure the type of the value until we actually have a chance to
|
||
fetch the data. The type can change depending on gdbarch, so it is
|
||
also dependent on which thread you have selected.
|
||
|
||
1. making $_siginfo be an internalvar that creates a new value on
|
||
access.
|
||
|
||
2. making the value of $_siginfo be an lval_computed value. */
|
||
|
||
/* This function implements the lval_computed support for reading a
|
||
$_siginfo value. */
|
||
|
||
static void
|
||
siginfo_value_read (struct value *v)
|
||
{
|
||
LONGEST transferred;
|
||
|
||
validate_siginfo_access ();
|
||
|
||
transferred =
|
||
target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
|
||
NULL,
|
||
value_contents_all_raw (v),
|
||
value_offset (v),
|
||
TYPE_LENGTH (value_type (v)));
|
||
|
||
if (transferred != TYPE_LENGTH (value_type (v)))
|
||
error (_("Unable to read siginfo"));
|
||
}
|
||
|
||
/* This function implements the lval_computed support for writing a
|
||
$_siginfo value. */
|
||
|
||
static void
|
||
siginfo_value_write (struct value *v, struct value *fromval)
|
||
{
|
||
LONGEST transferred;
|
||
|
||
validate_siginfo_access ();
|
||
|
||
transferred = target_write (¤t_target,
|
||
TARGET_OBJECT_SIGNAL_INFO,
|
||
NULL,
|
||
value_contents_all_raw (fromval),
|
||
value_offset (v),
|
||
TYPE_LENGTH (value_type (fromval)));
|
||
|
||
if (transferred != TYPE_LENGTH (value_type (fromval)))
|
||
error (_("Unable to write siginfo"));
|
||
}
|
||
|
||
static const struct lval_funcs siginfo_value_funcs =
|
||
{
|
||
siginfo_value_read,
|
||
siginfo_value_write
|
||
};
|
||
|
||
/* Return a new value with the correct type for the siginfo object of
|
||
the current thread using architecture GDBARCH. Return a void value
|
||
if there's no object available. */
|
||
|
||
static struct value *
|
||
siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
|
||
void *ignore)
|
||
{
|
||
if (target_has_stack
|
||
&& !ptid_equal (inferior_ptid, null_ptid)
|
||
&& gdbarch_get_siginfo_type_p (gdbarch))
|
||
{
|
||
struct type *type = gdbarch_get_siginfo_type (gdbarch);
|
||
|
||
return allocate_computed_value (type, &siginfo_value_funcs, NULL);
|
||
}
|
||
|
||
return allocate_value (builtin_type (gdbarch)->builtin_void);
|
||
}
|
||
|
||
|
||
/* infcall_suspend_state contains state about the program itself like its
|
||
registers and any signal it received when it last stopped.
|
||
This state must be restored regardless of how the inferior function call
|
||
ends (either successfully, or after it hits a breakpoint or signal)
|
||
if the program is to properly continue where it left off. */
|
||
|
||
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 regcache *registers;
|
||
|
||
/* Format of SIGINFO_DATA or NULL if it is not present. */
|
||
struct gdbarch *siginfo_gdbarch;
|
||
|
||
/* The inferior format depends on SIGINFO_GDBARCH and it has a length of
|
||
TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
|
||
content would be invalid. */
|
||
gdb_byte *siginfo_data;
|
||
};
|
||
|
||
struct infcall_suspend_state *
|
||
save_infcall_suspend_state (void)
|
||
{
|
||
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;
|
||
|
||
if (gdbarch_get_siginfo_type_p (gdbarch))
|
||
{
|
||
struct type *type = gdbarch_get_siginfo_type (gdbarch);
|
||
size_t len = TYPE_LENGTH (type);
|
||
struct cleanup *back_to;
|
||
|
||
siginfo_data = xmalloc (len);
|
||
back_to = make_cleanup (xfree, siginfo_data);
|
||
|
||
if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
|
||
siginfo_data, 0, len) == len)
|
||
discard_cleanups (back_to);
|
||
else
|
||
{
|
||
/* Errors ignored. */
|
||
do_cleanups (back_to);
|
||
siginfo_data = NULL;
|
||
}
|
||
}
|
||
|
||
inf_state = XCNEW (struct infcall_suspend_state);
|
||
|
||
if (siginfo_data)
|
||
{
|
||
inf_state->siginfo_gdbarch = gdbarch;
|
||
inf_state->siginfo_data = siginfo_data;
|
||
}
|
||
|
||
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. */
|
||
tp->suspend.stop_signal = GDB_SIGNAL_0;
|
||
|
||
inf_state->stop_pc = stop_pc;
|
||
|
||
inf_state->registers = regcache_dup (regcache);
|
||
|
||
return inf_state;
|
||
}
|
||
|
||
/* Restore inferior session state to INF_STATE. */
|
||
|
||
void
|
||
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;
|
||
|
||
if (inf_state->siginfo_gdbarch == gdbarch)
|
||
{
|
||
struct type *type = gdbarch_get_siginfo_type (gdbarch);
|
||
|
||
/* Errors ignored. */
|
||
target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
|
||
inf_state->siginfo_data, 0, TYPE_LENGTH (type));
|
||
}
|
||
|
||
/* The inferior can be gone if the user types "print exit(0)"
|
||
(and perhaps other times). */
|
||
if (target_has_execution)
|
||
/* NB: The register write goes through to the target. */
|
||
regcache_cpy (regcache, inf_state->registers);
|
||
|
||
discard_infcall_suspend_state (inf_state);
|
||
}
|
||
|
||
static void
|
||
do_restore_infcall_suspend_state_cleanup (void *state)
|
||
{
|
||
restore_infcall_suspend_state (state);
|
||
}
|
||
|
||
struct cleanup *
|
||
make_cleanup_restore_infcall_suspend_state
|
||
(struct infcall_suspend_state *inf_state)
|
||
{
|
||
return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
|
||
}
|
||
|
||
void
|
||
discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
|
||
{
|
||
regcache_xfree (inf_state->registers);
|
||
xfree (inf_state->siginfo_data);
|
||
xfree (inf_state);
|
||
}
|
||
|
||
struct regcache *
|
||
get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
|
||
{
|
||
return inf_state->registers;
|
||
}
|
||
|
||
/* infcall_control_state contains state regarding gdb's control of the
|
||
inferior itself like stepping control. It also contains session state like
|
||
the user's currently selected frame. */
|
||
|
||
struct infcall_control_state
|
||
{
|
||
struct thread_control_state thread_control;
|
||
struct inferior_control_state inferior_control;
|
||
|
||
/* Other fields: */
|
||
enum stop_stack_kind stop_stack_dummy;
|
||
int stopped_by_random_signal;
|
||
int stop_after_trap;
|
||
|
||
/* ID if the selected frame when the inferior function call was made. */
|
||
struct frame_id selected_frame_id;
|
||
};
|
||
|
||
/* Save all of the information associated with the inferior<==>gdb
|
||
connection. */
|
||
|
||
struct infcall_control_state *
|
||
save_infcall_control_state (void)
|
||
{
|
||
struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
|
||
struct thread_info *tp = inferior_thread ();
|
||
struct inferior *inf = current_inferior ();
|
||
|
||
inf_status->thread_control = tp->control;
|
||
inf_status->inferior_control = inf->control;
|
||
|
||
tp->control.step_resume_breakpoint = NULL;
|
||
tp->control.exception_resume_breakpoint = NULL;
|
||
|
||
/* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
|
||
chain. If caller's caller is walking the chain, they'll be happier if we
|
||
hand them back the original chain when restore_infcall_control_state is
|
||
called. */
|
||
tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
|
||
|
||
/* Other fields: */
|
||
inf_status->stop_stack_dummy = stop_stack_dummy;
|
||
inf_status->stopped_by_random_signal = stopped_by_random_signal;
|
||
inf_status->stop_after_trap = stop_after_trap;
|
||
|
||
inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
|
||
|
||
return inf_status;
|
||
}
|
||
|
||
static int
|
||
restore_selected_frame (void *args)
|
||
{
|
||
struct frame_id *fid = (struct frame_id *) args;
|
||
struct frame_info *frame;
|
||
|
||
frame = frame_find_by_id (*fid);
|
||
|
||
/* If inf_status->selected_frame_id is NULL, there was no previously
|
||
selected frame. */
|
||
if (frame == NULL)
|
||
{
|
||
warning (_("Unable to restore previously selected frame."));
|
||
return 0;
|
||
}
|
||
|
||
select_frame (frame);
|
||
|
||
return (1);
|
||
}
|
||
|
||
/* Restore inferior session state to INF_STATUS. */
|
||
|
||
void
|
||
restore_infcall_control_state (struct infcall_control_state *inf_status)
|
||
{
|
||
struct thread_info *tp = inferior_thread ();
|
||
struct inferior *inf = current_inferior ();
|
||
|
||
if (tp->control.step_resume_breakpoint)
|
||
tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
|
||
|
||
if (tp->control.exception_resume_breakpoint)
|
||
tp->control.exception_resume_breakpoint->disposition
|
||
= disp_del_at_next_stop;
|
||
|
||
/* Handle the bpstat_copy of the chain. */
|
||
bpstat_clear (&tp->control.stop_bpstat);
|
||
|
||
tp->control = inf_status->thread_control;
|
||
inf->control = inf_status->inferior_control;
|
||
|
||
/* Other fields: */
|
||
stop_stack_dummy = inf_status->stop_stack_dummy;
|
||
stopped_by_random_signal = inf_status->stopped_by_random_signal;
|
||
stop_after_trap = inf_status->stop_after_trap;
|
||
|
||
if (target_has_stack)
|
||
{
|
||
/* The point of catch_errors is that if the stack is clobbered,
|
||
walking the stack might encounter a garbage pointer and
|
||
error() trying to dereference it. */
|
||
if (catch_errors
|
||
(restore_selected_frame, &inf_status->selected_frame_id,
|
||
"Unable to restore previously selected frame:\n",
|
||
RETURN_MASK_ERROR) == 0)
|
||
/* Error in restoring the selected frame. Select the innermost
|
||
frame. */
|
||
select_frame (get_current_frame ());
|
||
}
|
||
|
||
xfree (inf_status);
|
||
}
|
||
|
||
static void
|
||
do_restore_infcall_control_state_cleanup (void *sts)
|
||
{
|
||
restore_infcall_control_state (sts);
|
||
}
|
||
|
||
struct cleanup *
|
||
make_cleanup_restore_infcall_control_state
|
||
(struct infcall_control_state *inf_status)
|
||
{
|
||
return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
|
||
}
|
||
|
||
void
|
||
discard_infcall_control_state (struct infcall_control_state *inf_status)
|
||
{
|
||
if (inf_status->thread_control.step_resume_breakpoint)
|
||
inf_status->thread_control.step_resume_breakpoint->disposition
|
||
= disp_del_at_next_stop;
|
||
|
||
if (inf_status->thread_control.exception_resume_breakpoint)
|
||
inf_status->thread_control.exception_resume_breakpoint->disposition
|
||
= disp_del_at_next_stop;
|
||
|
||
/* See save_infcall_control_state for info on stop_bpstat. */
|
||
bpstat_clear (&inf_status->thread_control.stop_bpstat);
|
||
|
||
xfree (inf_status);
|
||
}
|
||
|
||
/* restore_inferior_ptid() will be used by the cleanup machinery
|
||
to restore the inferior_ptid value saved in a call to
|
||
save_inferior_ptid(). */
|
||
|
||
static void
|
||
restore_inferior_ptid (void *arg)
|
||
{
|
||
ptid_t *saved_ptid_ptr = arg;
|
||
|
||
inferior_ptid = *saved_ptid_ptr;
|
||
xfree (arg);
|
||
}
|
||
|
||
/* Save the value of inferior_ptid so that it may be restored by a
|
||
later call to do_cleanups(). Returns the struct cleanup pointer
|
||
needed for later doing the cleanup. */
|
||
|
||
struct cleanup *
|
||
save_inferior_ptid (void)
|
||
{
|
||
ptid_t *saved_ptid_ptr;
|
||
|
||
saved_ptid_ptr = xmalloc (sizeof (ptid_t));
|
||
*saved_ptid_ptr = inferior_ptid;
|
||
return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
|
||
}
|
||
|
||
/* See inferior.h. */
|
||
|
||
void
|
||
clear_exit_convenience_vars (void)
|
||
{
|
||
clear_internalvar (lookup_internalvar ("_exitsignal"));
|
||
clear_internalvar (lookup_internalvar ("_exitcode"));
|
||
}
|
||
|
||
|
||
/* User interface for reverse debugging:
|
||
Set exec-direction / show exec-direction commands
|
||
(returns error unless target implements to_set_exec_direction method). */
|
||
|
||
int 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 *const 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;
|
||
}
|
||
else
|
||
{
|
||
exec_direction = exec_forward;
|
||
error (_("Target does not support this operation."));
|
||
}
|
||
}
|
||
|
||
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;
|
||
default:
|
||
internal_error (__FILE__, __LINE__,
|
||
_("bogus execution_direction value: %d"),
|
||
(int) execution_direction);
|
||
}
|
||
}
|
||
|
||
static void
|
||
show_schedule_multiple (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Resuming the execution of threads "
|
||
"of all processes is %s.\n"), value);
|
||
}
|
||
|
||
/* Implementation of `siginfo' variable. */
|
||
|
||
static const struct internalvar_funcs siginfo_funcs =
|
||
{
|
||
siginfo_make_value,
|
||
NULL,
|
||
NULL
|
||
};
|
||
|
||
void
|
||
_initialize_infrun (void)
|
||
{
|
||
int i;
|
||
int numsigs;
|
||
struct cmd_list_element *c;
|
||
|
||
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."));
|
||
add_info_alias ("handle", "signals", 0);
|
||
|
||
c = add_com ("handle", class_run, handle_command, _("\
|
||
Specify how to handle signals.\n\
|
||
Usage: handle SIGNAL [ACTIONS]\n\
|
||
Args are signals and actions to apply to those signals.\n\
|
||
If no actions are specified, the current settings for the specified signals\n\
|
||
will be displayed instead.\n\
|
||
\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\
|
||
\n\
|
||
Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
|
||
\"pass\", \"nopass\", \"ignore\", or \"noignore\".\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.\n\
|
||
\n\
|
||
Multiple signals may be specified. Signal numbers and signal names\n\
|
||
may be interspersed with actions, with the actions being performed for\n\
|
||
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, _("\
|
||
There is no `stop' command, but you can set a hook on `stop'.\n\
|
||
This allows you to set a list of commands to be run each time execution\n\
|
||
of the program stops."), &cmdlist);
|
||
|
||
add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
|
||
Set inferior debugging."), _("\
|
||
Show inferior debugging."), _("\
|
||
When non-zero, inferior specific debugging is enabled."),
|
||
NULL,
|
||
show_debug_infrun,
|
||
&setdebuglist, &showdebuglist);
|
||
|
||
add_setshow_boolean_cmd ("displaced", class_maintenance,
|
||
&debug_displaced, _("\
|
||
Set displaced stepping debugging."), _("\
|
||
Show displaced stepping debugging."), _("\
|
||
When non-zero, displaced stepping specific debugging is enabled."),
|
||
NULL,
|
||
show_debug_displaced,
|
||
&setdebuglist, &showdebuglist);
|
||
|
||
add_setshow_boolean_cmd ("non-stop", no_class,
|
||
&non_stop_1, _("\
|
||
Set whether gdb controls the inferior in non-stop mode."), _("\
|
||
Show whether gdb controls the inferior in non-stop mode."), _("\
|
||
When debugging a multi-threaded program and this setting is\n\
|
||
off (the default, also called all-stop mode), when one thread stops\n\
|
||
(for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
|
||
all other threads in the program while you interact with the thread of\n\
|
||
interest. When you continue or step a thread, you can allow the other\n\
|
||
threads to run, or have them remain stopped, but while you inspect any\n\
|
||
thread's state, all threads stop.\n\
|
||
\n\
|
||
In non-stop mode, when one thread stops, other threads can continue\n\
|
||
to run freely. You'll be able to step each thread independently,\n\
|
||
leave it stopped or free to run as needed."),
|
||
set_non_stop,
|
||
show_non_stop,
|
||
&setlist,
|
||
&showlist);
|
||
|
||
numsigs = (int) GDB_SIGNAL_LAST;
|
||
signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
|
||
signal_print = (unsigned char *)
|
||
xmalloc (sizeof (signal_print[0]) * numsigs);
|
||
signal_program = (unsigned char *)
|
||
xmalloc (sizeof (signal_program[0]) * numsigs);
|
||
signal_catch = (unsigned char *)
|
||
xmalloc (sizeof (signal_catch[0]) * numsigs);
|
||
signal_pass = (unsigned char *)
|
||
xmalloc (sizeof (signal_pass[0]) * numsigs);
|
||
for (i = 0; i < numsigs; i++)
|
||
{
|
||
signal_stop[i] = 1;
|
||
signal_print[i] = 1;
|
||
signal_program[i] = 1;
|
||
signal_catch[i] = 0;
|
||
}
|
||
|
||
/* Signals caused by debugger's own actions
|
||
should not be given to the program afterwards. */
|
||
signal_program[GDB_SIGNAL_TRAP] = 0;
|
||
signal_program[GDB_SIGNAL_INT] = 0;
|
||
|
||
/* Signals that are not errors should not normally enter the debugger. */
|
||
signal_stop[GDB_SIGNAL_ALRM] = 0;
|
||
signal_print[GDB_SIGNAL_ALRM] = 0;
|
||
signal_stop[GDB_SIGNAL_VTALRM] = 0;
|
||
signal_print[GDB_SIGNAL_VTALRM] = 0;
|
||
signal_stop[GDB_SIGNAL_PROF] = 0;
|
||
signal_print[GDB_SIGNAL_PROF] = 0;
|
||
signal_stop[GDB_SIGNAL_CHLD] = 0;
|
||
signal_print[GDB_SIGNAL_CHLD] = 0;
|
||
signal_stop[GDB_SIGNAL_IO] = 0;
|
||
signal_print[GDB_SIGNAL_IO] = 0;
|
||
signal_stop[GDB_SIGNAL_POLL] = 0;
|
||
signal_print[GDB_SIGNAL_POLL] = 0;
|
||
signal_stop[GDB_SIGNAL_URG] = 0;
|
||
signal_print[GDB_SIGNAL_URG] = 0;
|
||
signal_stop[GDB_SIGNAL_WINCH] = 0;
|
||
signal_print[GDB_SIGNAL_WINCH] = 0;
|
||
signal_stop[GDB_SIGNAL_PRIO] = 0;
|
||
signal_print[GDB_SIGNAL_PRIO] = 0;
|
||
|
||
/* These signals are used internally by user-level thread
|
||
implementations. (See signal(5) on Solaris.) Like the above
|
||
signals, a healthy program receives and handles them as part of
|
||
its normal operation. */
|
||
signal_stop[GDB_SIGNAL_LWP] = 0;
|
||
signal_print[GDB_SIGNAL_LWP] = 0;
|
||
signal_stop[GDB_SIGNAL_WAITING] = 0;
|
||
signal_print[GDB_SIGNAL_WAITING] = 0;
|
||
signal_stop[GDB_SIGNAL_CANCEL] = 0;
|
||
signal_print[GDB_SIGNAL_CANCEL] = 0;
|
||
|
||
/* Update cached state. */
|
||
signal_cache_update (-1);
|
||
|
||
add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
|
||
&stop_on_solib_events, _("\
|
||
Set stopping for shared library events."), _("\
|
||
Show stopping for shared library events."), _("\
|
||
If nonzero, gdb will give control to the user when the dynamic linker\n\
|
||
notifies gdb of shared library events. The most common event of interest\n\
|
||
to the user would be loading/unloading of a new library."),
|
||
set_stop_on_solib_events,
|
||
show_stop_on_solib_events,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_enum_cmd ("follow-fork-mode", class_run,
|
||
follow_fork_mode_kind_names,
|
||
&follow_fork_mode_string, _("\
|
||
Set debugger response to a program call of fork or vfork."), _("\
|
||
Show debugger response to a program call of fork or vfork."), _("\
|
||
A fork or vfork creates a new process. follow-fork-mode can be:\n\
|
||
parent - the original process is debugged after a fork\n\
|
||
child - the new process is debugged after a fork\n\
|
||
The unfollowed process will continue to run.\n\
|
||
By default, the debugger will follow the parent process."),
|
||
NULL,
|
||
show_follow_fork_mode_string,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_enum_cmd ("follow-exec-mode", class_run,
|
||
follow_exec_mode_names,
|
||
&follow_exec_mode_string, _("\
|
||
Set debugger response to a program call of exec."), _("\
|
||
Show debugger response to a program call of exec."), _("\
|
||
An exec call replaces the program image of a process.\n\
|
||
\n\
|
||
follow-exec-mode can be:\n\
|
||
\n\
|
||
new - the debugger creates a new inferior and rebinds the process\n\
|
||
to this new inferior. The program the process was running before\n\
|
||
the exec call can be restarted afterwards by restarting the original\n\
|
||
inferior.\n\
|
||
\n\
|
||
same - the debugger keeps the process bound to the same inferior.\n\
|
||
The new executable image replaces the previous executable loaded in\n\
|
||
the inferior. Restarting the inferior after the exec call restarts\n\
|
||
the executable the process was running after the exec call.\n\
|
||
\n\
|
||
By default, the debugger will use the same inferior."),
|
||
NULL,
|
||
show_follow_exec_mode_string,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_enum_cmd ("scheduler-locking", class_run,
|
||
scheduler_enums, &scheduler_mode, _("\
|
||
Set mode for locking scheduler during execution."), _("\
|
||
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')."),
|
||
set_schedlock_func, /* traps on target vector */
|
||
show_scheduler_mode,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
|
||
Set mode for resuming threads of all processes."), _("\
|
||
Show mode for resuming threads of all processes."), _("\
|
||
When on, execution commands (such as 'continue' or 'next') resume all\n\
|
||
threads of all processes. When off (which is the default), execution\n\
|
||
commands only resume the threads of the current process. The set of\n\
|
||
threads that are resumed is further refined by the scheduler-locking\n\
|
||
mode (see help set scheduler-locking)."),
|
||
NULL,
|
||
show_schedule_multiple,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
|
||
Set mode of the step operation."), _("\
|
||
Show mode of the step operation."), _("\
|
||
When set, doing a step over a function without debug line information\n\
|
||
will stop at the first instruction of that function. Otherwise, the\n\
|
||
function is skipped and the step command stops at a different source line."),
|
||
NULL,
|
||
show_step_stop_if_no_debug,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
|
||
&can_use_displaced_stepping, _("\
|
||
Set debugger's willingness to use displaced stepping."), _("\
|
||
Show debugger's willingness to use displaced stepping."), _("\
|
||
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);
|
||
|
||
/* Set/show detach-on-fork: user-settable mode. */
|
||
|
||
add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
|
||
Set whether gdb will detach the child of a fork."), _("\
|
||
Show whether gdb will detach the child of a fork."), _("\
|
||
Tells gdb whether to detach the child of a fork."),
|
||
NULL, NULL, &setlist, &showlist);
|
||
|
||
/* Set/show disable address space randomization mode. */
|
||
|
||
add_setshow_boolean_cmd ("disable-randomization", class_support,
|
||
&disable_randomization, _("\
|
||
Set disabling of debuggee's virtual address space randomization."), _("\
|
||
Show disabling of debuggee's virtual address space randomization."), _("\
|
||
When this mode is on (which is the default), randomization of the virtual\n\
|
||
address space is disabled. Standalone programs run with the randomization\n\
|
||
enabled by default on some platforms."),
|
||
&set_disable_randomization,
|
||
&show_disable_randomization,
|
||
&setlist, &showlist);
|
||
|
||
/* ptid initializations */
|
||
inferior_ptid = null_ptid;
|
||
target_last_wait_ptid = minus_one_ptid;
|
||
|
||
observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
|
||
observer_attach_thread_stop_requested (infrun_thread_stop_requested);
|
||
observer_attach_thread_exit (infrun_thread_thread_exit);
|
||
observer_attach_inferior_exit (infrun_inferior_exit);
|
||
|
||
/* Explicitly create without lookup, since that tries to create a
|
||
value with a void typed value, and when we get here, gdbarch
|
||
isn't initialized yet. At this point, we're quite sure there
|
||
isn't another convenience variable of the same name. */
|
||
create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
|
||
|
||
add_setshow_boolean_cmd ("observer", no_class,
|
||
&observer_mode_1, _("\
|
||
Set whether gdb controls the inferior in observer mode."), _("\
|
||
Show whether gdb controls the inferior in observer mode."), _("\
|
||
In observer mode, GDB can get data from the inferior, but not\n\
|
||
affect its execution. Registers and memory may not be changed,\n\
|
||
breakpoints may not be set, and the program cannot be interrupted\n\
|
||
or signalled."),
|
||
set_observer_mode,
|
||
show_observer_mode,
|
||
&setlist,
|
||
&showlist);
|
||
}
|