28bf096c62
Refs: https://sourceware.org/ml/gdb/2015-03/msg00024.html https://sourceware.org/ml/gdb/2015-06/msg00005.html On GNU/Linux, if an infcall spawns a thread, that thread ends up with stuck running state. This happens because: - when linux-nat.c detects a new thread, it marks them as running, and does not report anything to the core. - we skip finish_thread_state when the thread that is running the infcall stops. As result, that new thread ends up with stuck "running" state, even though it really is stopped. On Windows, _all_ threads end up stuck in running state, not just the one that was spawned. That happens because when a new thread is detected, unlike linux-nat.c, windows-nat.c reports TARGET_WAITKIND_SPURIOUS to infrun. It's the fact that that event does not cause a user-visible stop that triggers the problem. When the target is re-resumed, we call set_running with a wildcard ptid, which marks all thread as running. That set_running is not suppressed because the (leader) thread being resumed does not have in_infcall set. Later, when the infcall finally finishes successfully, nothing marks all threads back to stopped. We can trigger the same problem on all targets by having a thread other than the one that is running the infcall report a breakpoint hit to infrun, and then have that breakpoint not cause a stop. That's what the included test does. The fix is to stop GDB from suppressing the set_running calls while doing an infcall, and then set the threads back to stopped when the call finishes, iff they were originally stopped before the infcall started. (Note the MI *running/*stopped event suppression isn't affected.) Tested on x86_64 GNU/Linux. gdb/ChangeLog: 2015-06-29 Pedro Alves <palves@redhat.com> PR threads/18127 * infcall.c (run_inferior_call): On infcall success, if the thread was marked stopped before, reset it back to stopped. * infrun.c (resume): Don't suppress the set_running calls when doing an infcall. (normal_stop): Only discard the finish_thread_state cleanup if the infcall succeeded. gdb/testsuite/ChangeLog: 2015-06-29 Pedro Alves <palves@redhat.com> PR threads/18127 * gdb.threads/hand-call-new-thread.c: New file. * gdb.threads/hand-call-new-thread.c: New file.
7917 lines
257 KiB
C
7917 lines
257 KiB
C
/* Target-struct-independent code to start (run) and stop an inferior
|
||
process.
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||
Copyright (C) 1986-2015 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 3 of the License, or
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||
(at your option) any later version.
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||
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||
This program is distributed in the hope that it will be useful,
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||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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||
GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "infrun.h"
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#include <ctype.h>
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#include "symtab.h"
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#include "frame.h"
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#include "inferior.h"
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#include "breakpoint.h"
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#include "gdb_wait.h"
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#include "gdbcore.h"
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#include "gdbcmd.h"
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#include "cli/cli-script.h"
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#include "target.h"
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#include "gdbthread.h"
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#include "annotate.h"
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#include "symfile.h"
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#include "top.h"
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#include <signal.h>
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#include "inf-loop.h"
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#include "regcache.h"
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#include "value.h"
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#include "observer.h"
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#include "language.h"
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#include "solib.h"
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#include "main.h"
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#include "dictionary.h"
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#include "block.h"
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#include "mi/mi-common.h"
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#include "event-top.h"
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#include "record.h"
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#include "record-full.h"
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#include "inline-frame.h"
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#include "jit.h"
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#include "tracepoint.h"
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#include "continuations.h"
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#include "interps.h"
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#include "skip.h"
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#include "probe.h"
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#include "objfiles.h"
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#include "completer.h"
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#include "target-descriptions.h"
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#include "target-dcache.h"
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#include "terminal.h"
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#include "solist.h"
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/* Prototypes for local functions */
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static void signals_info (char *, int);
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static void handle_command (char *, int);
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static void sig_print_info (enum gdb_signal);
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static void sig_print_header (void);
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static void resume_cleanups (void *);
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static int hook_stop_stub (void *);
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static int restore_selected_frame (void *);
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static int follow_fork (void);
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static int follow_fork_inferior (int follow_child, int detach_fork);
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static void follow_inferior_reset_breakpoints (void);
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static void set_schedlock_func (char *args, int from_tty,
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struct cmd_list_element *c);
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static int currently_stepping (struct thread_info *tp);
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void _initialize_infrun (void);
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void nullify_last_target_wait_ptid (void);
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static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
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static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
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static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
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static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
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/* When set, stop the 'step' command if we enter a function which has
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no line number information. The normal behavior is that we step
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over such function. */
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int step_stop_if_no_debug = 0;
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static void
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show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
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}
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/* In asynchronous mode, but simulating synchronous execution. */
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int sync_execution = 0;
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/* proceed and normal_stop use this to notify the user when the
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inferior stopped in a different thread than it had been running
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in. */
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static ptid_t previous_inferior_ptid;
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/* If set (default for legacy reasons), when following a fork, GDB
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will detach from one of the fork branches, child or parent.
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Exactly which branch is detached depends on 'set follow-fork-mode'
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setting. */
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static int detach_fork = 1;
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int debug_displaced = 0;
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static void
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show_debug_displaced (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
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}
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unsigned int debug_infrun = 0;
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static void
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show_debug_infrun (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
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}
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/* Support for disabling address space randomization. */
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int disable_randomization = 1;
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static void
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show_disable_randomization (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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if (target_supports_disable_randomization ())
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fprintf_filtered (file,
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_("Disabling randomization of debuggee's "
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"virtual address space is %s.\n"),
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value);
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else
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fputs_filtered (_("Disabling randomization of debuggee's "
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"virtual address space is unsupported on\n"
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"this platform.\n"), file);
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}
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static void
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set_disable_randomization (char *args, int from_tty,
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struct cmd_list_element *c)
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{
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if (!target_supports_disable_randomization ())
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error (_("Disabling randomization of debuggee's "
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"virtual address space is unsupported on\n"
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"this platform."));
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}
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/* User interface for non-stop mode. */
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int non_stop = 0;
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static int non_stop_1 = 0;
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static void
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set_non_stop (char *args, int from_tty,
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struct cmd_list_element *c)
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{
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if (target_has_execution)
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{
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non_stop_1 = non_stop;
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error (_("Cannot change this setting while the inferior is running."));
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}
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non_stop = non_stop_1;
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}
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static void
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show_non_stop (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file,
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_("Controlling the inferior in non-stop mode is %s.\n"),
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value);
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}
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/* "Observer mode" is somewhat like a more extreme version of
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non-stop, in which all GDB operations that might affect the
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target's execution have been disabled. */
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int observer_mode = 0;
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static int observer_mode_1 = 0;
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static void
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set_observer_mode (char *args, int from_tty,
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struct cmd_list_element *c)
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{
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if (target_has_execution)
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{
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observer_mode_1 = observer_mode;
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error (_("Cannot change this setting while the inferior is running."));
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}
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observer_mode = observer_mode_1;
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may_write_registers = !observer_mode;
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may_write_memory = !observer_mode;
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may_insert_breakpoints = !observer_mode;
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may_insert_tracepoints = !observer_mode;
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/* We can insert fast tracepoints in or out of observer mode,
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but enable them if we're going into this mode. */
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if (observer_mode)
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may_insert_fast_tracepoints = 1;
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may_stop = !observer_mode;
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update_target_permissions ();
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/* Going *into* observer mode we must force non-stop, then
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going out we leave it that way. */
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if (observer_mode)
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{
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pagination_enabled = 0;
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non_stop = non_stop_1 = 1;
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}
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if (from_tty)
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printf_filtered (_("Observer mode is now %s.\n"),
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(observer_mode ? "on" : "off"));
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}
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static void
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show_observer_mode (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Observer mode is %s.\n"), value);
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}
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/* This updates the value of observer mode based on changes in
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permissions. Note that we are deliberately ignoring the values of
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may-write-registers and may-write-memory, since the user may have
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reason to enable these during a session, for instance to turn on a
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debugging-related global. */
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void
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update_observer_mode (void)
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{
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int newval;
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newval = (!may_insert_breakpoints
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&& !may_insert_tracepoints
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&& may_insert_fast_tracepoints
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&& !may_stop
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&& non_stop);
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/* Let the user know if things change. */
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if (newval != observer_mode)
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printf_filtered (_("Observer mode is now %s.\n"),
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(newval ? "on" : "off"));
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observer_mode = observer_mode_1 = newval;
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}
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/* Tables of how to react to signals; the user sets them. */
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static unsigned char *signal_stop;
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static unsigned char *signal_print;
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static unsigned char *signal_program;
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/* Table of signals that are registered with "catch signal". A
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non-zero entry indicates that the signal is caught by some "catch
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signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
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signals. */
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static unsigned char *signal_catch;
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/* Table of signals that the target may silently handle.
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This is automatically determined from the flags above,
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and simply cached here. */
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static unsigned char *signal_pass;
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#define SET_SIGS(nsigs,sigs,flags) \
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do { \
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int signum = (nsigs); \
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while (signum-- > 0) \
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if ((sigs)[signum]) \
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(flags)[signum] = 1; \
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} while (0)
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#define UNSET_SIGS(nsigs,sigs,flags) \
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do { \
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int signum = (nsigs); \
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while (signum-- > 0) \
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if ((sigs)[signum]) \
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(flags)[signum] = 0; \
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} while (0)
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/* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
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this function is to avoid exporting `signal_program'. */
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void
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update_signals_program_target (void)
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{
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target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
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}
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/* Value to pass to target_resume() to cause all threads to resume. */
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#define RESUME_ALL minus_one_ptid
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/* Command list pointer for the "stop" placeholder. */
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static struct cmd_list_element *stop_command;
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/* Nonzero if we want to give control to the user when we're notified
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of shared library events by the dynamic linker. */
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int stop_on_solib_events;
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/* Enable or disable optional shared library event breakpoints
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as appropriate when the above flag is changed. */
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static void
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set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
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{
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update_solib_breakpoints ();
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}
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static void
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show_stop_on_solib_events (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
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value);
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}
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/* Nonzero means expecting a trace trap
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and should stop the inferior and return silently when it happens. */
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int stop_after_trap;
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/* Nonzero after stop if current stack frame should be printed. */
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static int stop_print_frame;
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/* This is a cached copy of the pid/waitstatus of the last event
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returned by target_wait()/deprecated_target_wait_hook(). This
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information is returned by get_last_target_status(). */
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static ptid_t target_last_wait_ptid;
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static struct target_waitstatus target_last_waitstatus;
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static void context_switch (ptid_t ptid);
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void init_thread_stepping_state (struct thread_info *tss);
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static const char follow_fork_mode_child[] = "child";
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static const char follow_fork_mode_parent[] = "parent";
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static const char *const follow_fork_mode_kind_names[] = {
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follow_fork_mode_child,
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follow_fork_mode_parent,
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NULL
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};
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static const char *follow_fork_mode_string = follow_fork_mode_parent;
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static void
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show_follow_fork_mode_string (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file,
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_("Debugger response to a program "
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"call of fork or vfork is \"%s\".\n"),
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value);
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}
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/* Handle changes to the inferior list based on the type of fork,
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which process is being followed, and whether the other process
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should be detached. On entry inferior_ptid must be the ptid of
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the fork parent. At return inferior_ptid is the ptid of the
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followed inferior. */
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static int
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follow_fork_inferior (int follow_child, int detach_fork)
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{
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int has_vforked;
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ptid_t parent_ptid, child_ptid;
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has_vforked = (inferior_thread ()->pending_follow.kind
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== TARGET_WAITKIND_VFORKED);
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parent_ptid = inferior_ptid;
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child_ptid = inferior_thread ()->pending_follow.value.related_pid;
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if (has_vforked
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&& !non_stop /* Non-stop always resumes both branches. */
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&& (!target_is_async_p () || sync_execution)
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&& !(follow_child || detach_fork || sched_multi))
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{
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/* The parent stays blocked inside the vfork syscall until the
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child execs or exits. If we don't let the child run, then
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the parent stays blocked. If we're telling the parent to run
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in the foreground, the user will not be able to ctrl-c to get
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back the terminal, effectively hanging the debug session. */
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fprintf_filtered (gdb_stderr, _("\
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Can not resume the parent process over vfork in the foreground while\n\
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holding the child stopped. Try \"set detach-on-fork\" or \
|
||
\"set schedule-multiple\".\n"));
|
||
/* FIXME output string > 80 columns. */
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||
return 1;
|
||
}
|
||
|
||
if (!follow_child)
|
||
{
|
||
/* Detach new forked process? */
|
||
if (detach_fork)
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||
{
|
||
struct cleanup *old_chain;
|
||
|
||
/* Before detaching from the child, remove all breakpoints
|
||
from it. If we forked, then this has already been taken
|
||
care of by infrun.c. If we vforked however, any
|
||
breakpoint inserted in the parent is visible in the
|
||
child, even those added while stopped in a vfork
|
||
catchpoint. This will remove the breakpoints from the
|
||
parent also, but they'll be reinserted below. */
|
||
if (has_vforked)
|
||
{
|
||
/* Keep breakpoints list in sync. */
|
||
remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
|
||
}
|
||
|
||
if (info_verbose || debug_infrun)
|
||
{
|
||
/* Ensure that we have a process ptid. */
|
||
ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
|
||
|
||
target_terminal_ours_for_output ();
|
||
fprintf_filtered (gdb_stdlog,
|
||
_("Detaching after %s from child %s.\n"),
|
||
has_vforked ? "vfork" : "fork",
|
||
target_pid_to_str (process_ptid));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
struct inferior *parent_inf, *child_inf;
|
||
struct cleanup *old_chain;
|
||
|
||
/* Add process to GDB's tables. */
|
||
child_inf = add_inferior (ptid_get_pid (child_ptid));
|
||
|
||
parent_inf = current_inferior ();
|
||
child_inf->attach_flag = parent_inf->attach_flag;
|
||
copy_terminal_info (child_inf, parent_inf);
|
||
child_inf->gdbarch = parent_inf->gdbarch;
|
||
copy_inferior_target_desc_info (child_inf, parent_inf);
|
||
|
||
old_chain = save_inferior_ptid ();
|
||
save_current_program_space ();
|
||
|
||
inferior_ptid = child_ptid;
|
||
add_thread (inferior_ptid);
|
||
child_inf->symfile_flags = SYMFILE_NO_READ;
|
||
|
||
/* If this is a vfork child, then the address-space is
|
||
shared with the parent. */
|
||
if (has_vforked)
|
||
{
|
||
child_inf->pspace = parent_inf->pspace;
|
||
child_inf->aspace = parent_inf->aspace;
|
||
|
||
/* The parent will be frozen until the child is done
|
||
with the shared region. Keep track of the
|
||
parent. */
|
||
child_inf->vfork_parent = parent_inf;
|
||
child_inf->pending_detach = 0;
|
||
parent_inf->vfork_child = child_inf;
|
||
parent_inf->pending_detach = 0;
|
||
}
|
||
else
|
||
{
|
||
child_inf->aspace = new_address_space ();
|
||
child_inf->pspace = add_program_space (child_inf->aspace);
|
||
child_inf->removable = 1;
|
||
set_current_program_space (child_inf->pspace);
|
||
clone_program_space (child_inf->pspace, parent_inf->pspace);
|
||
|
||
/* Let the shared library layer (e.g., solib-svr4) learn
|
||
about this new process, relocate the cloned exec, pull
|
||
in shared libraries, and install the solib event
|
||
breakpoint. If a "cloned-VM" event was propagated
|
||
better throughout the core, this wouldn't be
|
||
required. */
|
||
solib_create_inferior_hook (0);
|
||
}
|
||
|
||
do_cleanups (old_chain);
|
||
}
|
||
|
||
if (has_vforked)
|
||
{
|
||
struct inferior *parent_inf;
|
||
|
||
parent_inf = current_inferior ();
|
||
|
||
/* If we detached from the child, then we have to be careful
|
||
to not insert breakpoints in the parent until the child
|
||
is done with the shared memory region. However, if we're
|
||
staying attached to the child, then we can and should
|
||
insert breakpoints, so that we can debug it. A
|
||
subsequent child exec or exit is enough to know when does
|
||
the child stops using the parent's address space. */
|
||
parent_inf->waiting_for_vfork_done = detach_fork;
|
||
parent_inf->pspace->breakpoints_not_allowed = detach_fork;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Follow the child. */
|
||
struct inferior *parent_inf, *child_inf;
|
||
struct program_space *parent_pspace;
|
||
|
||
if (info_verbose || debug_infrun)
|
||
{
|
||
target_terminal_ours_for_output ();
|
||
fprintf_filtered (gdb_stdlog,
|
||
_("Attaching after %s %s to child %s.\n"),
|
||
target_pid_to_str (parent_ptid),
|
||
has_vforked ? "vfork" : "fork",
|
||
target_pid_to_str (child_ptid));
|
||
}
|
||
|
||
/* Add the new inferior first, so that the target_detach below
|
||
doesn't unpush the target. */
|
||
|
||
child_inf = add_inferior (ptid_get_pid (child_ptid));
|
||
|
||
parent_inf = current_inferior ();
|
||
child_inf->attach_flag = parent_inf->attach_flag;
|
||
copy_terminal_info (child_inf, parent_inf);
|
||
child_inf->gdbarch = parent_inf->gdbarch;
|
||
copy_inferior_target_desc_info (child_inf, parent_inf);
|
||
|
||
parent_pspace = parent_inf->pspace;
|
||
|
||
/* If we're vforking, we want to hold on to the parent until the
|
||
child exits or execs. At child exec or exit time we can
|
||
remove the old breakpoints from the parent and detach or
|
||
resume debugging it. Otherwise, detach the parent now; we'll
|
||
want to reuse it's program/address spaces, but we can't set
|
||
them to the child before removing breakpoints from the
|
||
parent, otherwise, the breakpoints module could decide to
|
||
remove breakpoints from the wrong process (since they'd be
|
||
assigned to the same address space). */
|
||
|
||
if (has_vforked)
|
||
{
|
||
gdb_assert (child_inf->vfork_parent == NULL);
|
||
gdb_assert (parent_inf->vfork_child == NULL);
|
||
child_inf->vfork_parent = parent_inf;
|
||
child_inf->pending_detach = 0;
|
||
parent_inf->vfork_child = child_inf;
|
||
parent_inf->pending_detach = detach_fork;
|
||
parent_inf->waiting_for_vfork_done = 0;
|
||
}
|
||
else if (detach_fork)
|
||
{
|
||
if (info_verbose || debug_infrun)
|
||
{
|
||
/* Ensure that we have a process ptid. */
|
||
ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
|
||
|
||
target_terminal_ours_for_output ();
|
||
fprintf_filtered (gdb_stdlog,
|
||
_("Detaching after fork from "
|
||
"child %s.\n"),
|
||
target_pid_to_str (process_ptid));
|
||
}
|
||
|
||
target_detach (NULL, 0);
|
||
}
|
||
|
||
/* Note that the detach above makes PARENT_INF dangling. */
|
||
|
||
/* Add the child thread to the appropriate lists, and switch to
|
||
this new thread, before cloning the program space, and
|
||
informing the solib layer about this new process. */
|
||
|
||
inferior_ptid = child_ptid;
|
||
add_thread (inferior_ptid);
|
||
|
||
/* If this is a vfork child, then the address-space is shared
|
||
with the parent. If we detached from the parent, then we can
|
||
reuse the parent's program/address spaces. */
|
||
if (has_vforked || detach_fork)
|
||
{
|
||
child_inf->pspace = parent_pspace;
|
||
child_inf->aspace = child_inf->pspace->aspace;
|
||
}
|
||
else
|
||
{
|
||
child_inf->aspace = new_address_space ();
|
||
child_inf->pspace = add_program_space (child_inf->aspace);
|
||
child_inf->removable = 1;
|
||
child_inf->symfile_flags = SYMFILE_NO_READ;
|
||
set_current_program_space (child_inf->pspace);
|
||
clone_program_space (child_inf->pspace, parent_pspace);
|
||
|
||
/* Let the shared library layer (e.g., solib-svr4) learn
|
||
about this new process, relocate the cloned exec, pull in
|
||
shared libraries, and install the solib event breakpoint.
|
||
If a "cloned-VM" event was propagated better throughout
|
||
the core, this wouldn't be required. */
|
||
solib_create_inferior_hook (0);
|
||
}
|
||
}
|
||
|
||
return target_follow_fork (follow_child, detach_fork);
|
||
}
|
||
|
||
/* 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;
|
||
|
||
/* Set up inferior(s) as specified by the caller, and tell the
|
||
target to do whatever is necessary to follow either parent
|
||
or child. */
|
||
if (follow_fork_inferior (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;
|
||
}
|
||
|
||
static 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);
|
||
}
|
||
|
||
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_for_output ();
|
||
|
||
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 ptid, char *execd_pathname)
|
||
{
|
||
struct thread_info *th, *tmp;
|
||
struct inferior *inf = current_inferior ();
|
||
int pid = ptid_get_pid (ptid);
|
||
|
||
/* 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 ();
|
||
|
||
/* 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
|
||
stopped or already gone. We may still have non-leader threads of
|
||
the process on our list. E.g., on targets that don't have thread
|
||
exit events (like remote); or on native Linux in non-stop mode if
|
||
there were only two threads in the inferior and the non-leader
|
||
one is the one that execs (and nothing forces an update of the
|
||
thread list up to here). When debugging remotely, it's best to
|
||
avoid extra traffic, when possible, so avoid syncing the thread
|
||
list with the target, and instead go ahead and delete all threads
|
||
of the process but one that reported the event. Note this must
|
||
be done before calling update_breakpoints_after_exec, as
|
||
otherwise clearing the threads' resources would reference stale
|
||
thread breakpoints -- it may have been one of these threads that
|
||
stepped across the exec. We could just clear their stepping
|
||
states, but as long as we're iterating, might as well delete
|
||
them. Deleting them now rather than at the next user-visible
|
||
stop provides a nicer sequence of events for user and MI
|
||
notifications. */
|
||
ALL_THREADS_SAFE (th, tmp)
|
||
if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
|
||
delete_thread (th->ptid);
|
||
|
||
/* We also need to clear any left over stale state for the
|
||
leader/event thread. E.g., if there was any step-resume
|
||
breakpoint or similar, it's gone now. We cannot truly
|
||
step-to-next statement through an exec(). */
|
||
th = inferior_thread ();
|
||
th->control.step_resume_breakpoint = NULL;
|
||
th->control.exception_resume_breakpoint = NULL;
|
||
th->control.single_step_breakpoints = NULL;
|
||
th->control.step_range_start = 0;
|
||
th->control.step_range_end = 0;
|
||
|
||
/* The user may have had the main thread held stopped in the
|
||
previous image (e.g., schedlock on, or non-stop). Release
|
||
it now. */
|
||
th->stop_requested = 0;
|
||
|
||
update_breakpoints_after_exec ();
|
||
|
||
/* 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 != '\0')
|
||
{
|
||
char *name = exec_file_find (execd_pathname, NULL);
|
||
|
||
execd_pathname = alloca (strlen (name) + 1);
|
||
strcpy (execd_pathname, name);
|
||
xfree (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.). */
|
||
}
|
||
|
||
/* Info about an instruction that is being stepped over. */
|
||
|
||
struct step_over_info
|
||
{
|
||
/* If we're stepping past a breakpoint, this is the address space
|
||
and address of the instruction the breakpoint is set at. We'll
|
||
skip inserting all breakpoints here. Valid iff ASPACE is
|
||
non-NULL. */
|
||
struct address_space *aspace;
|
||
CORE_ADDR address;
|
||
|
||
/* The instruction being stepped over triggers a nonsteppable
|
||
watchpoint. If true, we'll skip inserting watchpoints. */
|
||
int nonsteppable_watchpoint_p;
|
||
};
|
||
|
||
/* 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,
|
||
int nonsteppable_watchpoint_p)
|
||
{
|
||
step_over_info.aspace = aspace;
|
||
step_over_info.address = address;
|
||
step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
|
||
}
|
||
|
||
/* 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;
|
||
step_over_info.nonsteppable_watchpoint_p = 0;
|
||
}
|
||
|
||
/* See infrun.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));
|
||
}
|
||
|
||
/* See infrun.h. */
|
||
|
||
int
|
||
stepping_past_nonsteppable_watchpoint (void)
|
||
{
|
||
return step_over_info.nonsteppable_watchpoint_p;
|
||
}
|
||
|
||
/* Returns true if step-over info is valid. */
|
||
|
||
static int
|
||
step_over_info_valid_p (void)
|
||
{
|
||
return (step_over_info.aspace != NULL
|
||
|| stepping_past_nonsteppable_watchpoint ());
|
||
}
|
||
|
||
|
||
/* 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;
|
||
}
|
||
|
||
/* Return true if process PID has a thread doing a displaced step. */
|
||
|
||
static int
|
||
displaced_step_in_progress (int pid)
|
||
{
|
||
struct displaced_step_inferior_state *displaced;
|
||
|
||
displaced = get_displaced_stepping_state (pid);
|
||
if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Add a new displaced stepping state for process PID to the displaced
|
||
stepping state list, or return a pointer to an already existing
|
||
entry, if it already exists. Never returns NULL. */
|
||
|
||
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);
|
||
|
||
/* Fixup may need to read memory/registers. Switch to the thread
|
||
that we're fixing up. Also, target_stopped_by_watchpoint checks
|
||
the current thread. */
|
||
switch_to_thread (event_ptid);
|
||
|
||
/* Did the instruction complete successfully? */
|
||
if (signal == GDB_SIGNAL_TRAP
|
||
&& !(target_stopped_by_watchpoint ()
|
||
&& (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
|
||
|| target_have_steppable_watchpoint)))
|
||
{
|
||
/* 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);
|
||
gdbarch = get_regcache_arch (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);
|
||
|
||
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 (step)
|
||
step = maybe_software_singlestep (gdbarch, actual_pc);
|
||
|
||
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;
|
||
|
||
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)
|
||
{
|
||
if (!ptid_equal (inferior_ptid, null_ptid))
|
||
delete_single_step_breakpoints (inferior_thread ());
|
||
|
||
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;
|
||
}
|
||
return hw_step;
|
||
}
|
||
|
||
/* See infrun.h. */
|
||
|
||
ptid_t
|
||
user_visible_resume_ptid (int step)
|
||
{
|
||
ptid_t resume_ptid;
|
||
|
||
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))
|
||
{
|
||
/* User-settable 'scheduler' mode requires solo thread
|
||
resume. */
|
||
resume_ptid = inferior_ptid;
|
||
}
|
||
else if (!sched_multi && target_supports_multi_process ())
|
||
{
|
||
/* Resume all threads of the current process (and none of other
|
||
processes). */
|
||
resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
|
||
}
|
||
else
|
||
{
|
||
/* Resume all threads of all processes. */
|
||
resume_ptid = RESUME_ALL;
|
||
}
|
||
|
||
return resume_ptid;
|
||
}
|
||
|
||
/* Wrapper for target_resume, that handles infrun-specific
|
||
bookkeeping. */
|
||
|
||
static void
|
||
do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
|
||
{
|
||
struct thread_info *tp = inferior_thread ();
|
||
|
||
/* Install inferior's terminal modes. */
|
||
target_terminal_inferior ();
|
||
|
||
/* Avoid confusing the next resume, if the next stop/resume
|
||
happens to apply to another thread. */
|
||
tp->suspend.stop_signal = GDB_SIGNAL_0;
|
||
|
||
/* Advise target which signals may be handled silently.
|
||
|
||
If we have removed breakpoints because we are stepping over one
|
||
in-line (in any thread), we need to receive all signals to avoid
|
||
accidentally skipping a breakpoint during execution of a signal
|
||
handler.
|
||
|
||
Likewise if we're displaced stepping, otherwise a trap for a
|
||
breakpoint in a signal handler might be confused with the
|
||
displaced step finishing. We don't make the displaced_step_fixup
|
||
step distinguish the cases instead, because:
|
||
|
||
- a backtrace while stopped in the signal handler would show the
|
||
scratch pad as frame older than the signal handler, instead of
|
||
the real mainline code.
|
||
|
||
- when the thread is later resumed, the signal handler would
|
||
return to the scratch pad area, which would no longer be
|
||
valid. */
|
||
if (step_over_info_valid_p ()
|
||
|| displaced_step_in_progress (ptid_get_pid (tp->ptid)))
|
||
target_pass_signals (0, NULL);
|
||
else
|
||
target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
|
||
|
||
target_resume (resume_ptid, step, sig);
|
||
}
|
||
|
||
/* Resume the inferior, but allow a QUIT. This is useful if the user
|
||
wants to interrupt some lengthy single-stepping operation
|
||
(for child processes, the SIGINT goes to the inferior, and so
|
||
we get a SIGINT random_signal, but for remote debugging and perhaps
|
||
other targets, that's not true).
|
||
|
||
SIG is the signal to give the inferior (zero for none). */
|
||
void
|
||
resume (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;
|
||
/* This represents the user's step vs continue request. When
|
||
deciding whether "set scheduler-locking step" applies, it's the
|
||
user's intention that counts. */
|
||
const int user_step = tp->control.stepping_command;
|
||
/* This represents what we'll actually request the target to do.
|
||
This can decay from a step to a continue, if e.g., we need to
|
||
implement single-stepping with breakpoints (software
|
||
single-step). */
|
||
int step;
|
||
|
||
tp->stepped_breakpoint = 0;
|
||
|
||
QUIT;
|
||
|
||
/* Depends on stepped_breakpoint. */
|
||
step = currently_stepping (tp);
|
||
|
||
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 (sig != GDB_SIGNAL_0)
|
||
{
|
||
/* We have a signal to pass to the inferior. The resume
|
||
may, or may not take us to the signal handler. If this
|
||
is a step, we'll need to stop in the signal handler, if
|
||
there's one, (if the target supports stepping into
|
||
handlers), or in the next mainline instruction, if
|
||
there's no handler. If this is a continue, we need to be
|
||
sure to run the handler with all breakpoints inserted.
|
||
In all cases, set a breakpoint at the current address
|
||
(where the handler returns to), and once that breakpoint
|
||
is hit, resume skipping the permanent breakpoint. If
|
||
that breakpoint isn't hit, then we've stepped into the
|
||
signal handler (or hit some other event). We'll delete
|
||
the step-resume breakpoint then. */
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: resume: skipping permanent breakpoint, "
|
||
"deliver signal first\n");
|
||
|
||
clear_step_over_info ();
|
||
tp->control.trap_expected = 0;
|
||
|
||
if (tp->control.step_resume_breakpoint == NULL)
|
||
{
|
||
/* Set a "high-priority" step-resume, as we don't want
|
||
user breakpoints at PC to trigger (again) when this
|
||
hits. */
|
||
insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
|
||
gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
|
||
|
||
tp->step_after_step_resume_breakpoint = step;
|
||
}
|
||
|
||
insert_breakpoints ();
|
||
}
|
||
else
|
||
{
|
||
/* There's no signal to pass, we can go ahead and skip the
|
||
permanent breakpoint manually. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: resume: skipping permanent breakpoint\n");
|
||
gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
|
||
/* Update pc to reflect the new address from which we will
|
||
execute instructions. */
|
||
pc = regcache_read_pc (regcache);
|
||
|
||
if (step)
|
||
{
|
||
/* We've already advanced the PC, so the stepping part
|
||
is done. Now we need to arrange for a trap to be
|
||
reported to handle_inferior_event. Set a breakpoint
|
||
at the current PC, and run to it. Don't update
|
||
prev_pc, because if we end in
|
||
switch_back_to_stepped_thread, we want the "expected
|
||
thread advanced also" branch to be taken. IOW, we
|
||
don't want this thread to step further from PC
|
||
(overstep). */
|
||
gdb_assert (!step_over_info_valid_p ());
|
||
insert_single_step_breakpoint (gdbarch, aspace, pc);
|
||
insert_breakpoints ();
|
||
|
||
resume_ptid = user_visible_resume_ptid (user_step);
|
||
do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
|
||
discard_cleanups (old_cleanups);
|
||
return;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* 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_over_info_valid_p ()
|
||
&& 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. */
|
||
set_running (user_visible_resume_ptid (user_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 (thread_has_single_step_breakpoints_set (tp)
|
||
&& sig != GDB_SIGNAL_0
|
||
&& step_over_info_valid_p ())
|
||
{
|
||
/* 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;
|
||
}
|
||
|
||
delete_single_step_breakpoints (tp);
|
||
|
||
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 (!(thread_has_single_step_breakpoints_set (tp) && step));
|
||
|
||
/* Decide the set of threads to ask the target to resume. Start
|
||
by assuming everything will be resumed, than narrow the set
|
||
by applying increasingly restricting conditions. */
|
||
resume_ptid = user_visible_resume_ptid (user_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. */
|
||
set_running (resume_ptid, 1);
|
||
|
||
/* Maybe resume a single thread after all. */
|
||
if ((step || thread_has_single_step_breakpoints_set (tp))
|
||
&& 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 (execution_direction != EXEC_REVERSE
|
||
&& step && breakpoint_inserted_here_p (aspace, pc))
|
||
{
|
||
/* The only case we currently need to step a breakpoint
|
||
instruction is when we have a signal to deliver. See
|
||
handle_signal_stop where we handle random signals that could
|
||
take out us out of the stepping range. Normally, in that
|
||
case we end up continuing (instead of stepping) over the
|
||
signal handler with a breakpoint at PC, but there are cases
|
||
where we should _always_ single-step, even if we have a
|
||
step-resume breakpoint, like when a software watchpoint is
|
||
set. Assuming single-stepping and delivering a signal at the
|
||
same time would takes us to the signal handler, then we could
|
||
have removed the breakpoint at PC to step over it. However,
|
||
some hardware step targets (like e.g., Mac OS) can't step
|
||
into signal handlers, and for those, we need to leave the
|
||
breakpoint at PC inserted, as otherwise if the handler
|
||
recurses and executes PC again, it'll miss the breakpoint.
|
||
So we leave the breakpoint inserted anyway, but we need to
|
||
record that we tried to step a breakpoint instruction, so
|
||
that adjust_pc_after_break doesn't end up confused. */
|
||
gdb_assert (sig != GDB_SIGNAL_0);
|
||
|
||
tp->stepped_breakpoint = 1;
|
||
|
||
/* 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 (gdbarch_cannot_step_breakpoint (gdbarch))
|
||
step = 0;
|
||
}
|
||
|
||
if (debug_displaced
|
||
&& use_displaced_stepping (gdbarch)
|
||
&& tp->control.trap_expected
|
||
&& !step_over_info_valid_p ())
|
||
{
|
||
struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
|
||
struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
|
||
CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
|
||
gdb_byte buf[4];
|
||
|
||
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));
|
||
}
|
||
|
||
do_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->control.step_start_function = NULL;
|
||
tp->stop_requested = 0;
|
||
|
||
tp->control.stop_step = 0;
|
||
|
||
tp->control.proceed_to_finish = 0;
|
||
|
||
tp->control.command_interp = NULL;
|
||
tp->control.stepping_command = 0;
|
||
|
||
/* Discard any remaining commands or status from previous stop. */
|
||
bpstat_clear (&tp->control.stop_bpstat);
|
||
}
|
||
|
||
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 ();
|
||
}
|
||
|
||
/* 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))
|
||
== ordinary_breakpoint_here)
|
||
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 (struct thread_info *tp)
|
||
{
|
||
return (scheduler_mode == schedlock_on
|
||
|| (scheduler_mode == schedlock_step
|
||
&& tp->control.stepping_command));
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
static struct thread_info *
|
||
find_thread_needs_step_over (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 (except))
|
||
{
|
||
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)
|
||
{
|
||
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 ();
|
||
|
||
/* 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) == ordinary_breakpoint_here
|
||
&& 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)\n",
|
||
paddress (gdbarch, addr),
|
||
gdb_signal_to_symbol_string (siggnal));
|
||
|
||
if (non_stop)
|
||
/* In non-stop, each thread is handled individually. The context
|
||
must already be set to the right thread here. */
|
||
;
|
||
else
|
||
{
|
||
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 (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_stepped_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), 0);
|
||
}
|
||
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 ());
|
||
|
||
/* Resume inferior. */
|
||
resume (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;
|
||
|
||
/* Discard any skipped inlined frames. */
|
||
clear_inline_frame_state (minus_one_ptid);
|
||
}
|
||
|
||
|
||
/* Data to be passed around while handling an event. This data is
|
||
discarded between events. */
|
||
struct execution_control_state
|
||
{
|
||
ptid_t ptid;
|
||
/* The thread that got the event, if this was a thread event; NULL
|
||
otherwise. */
|
||
struct thread_info *event_thread;
|
||
|
||
struct target_waitstatus ws;
|
||
int stop_func_filled_in;
|
||
CORE_ADDR stop_func_start;
|
||
CORE_ADDR stop_func_end;
|
||
const char *stop_func_name;
|
||
int wait_some_more;
|
||
|
||
/* True if the event thread hit the single-step breakpoint of
|
||
another thread. Thus the event doesn't cause a stop, the thread
|
||
needs to be single-stepped past the single-step breakpoint before
|
||
we can switch back to the original stepping thread. */
|
||
int hit_singlestep_breakpoint;
|
||
};
|
||
|
||
static void handle_inferior_event (struct execution_control_state *ecs);
|
||
|
||
static void 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 ();
|
||
}
|
||
|
||
/* Delete the step resume, single-step and longjmp/exception resume
|
||
breakpoints of TP. */
|
||
|
||
static void
|
||
delete_thread_infrun_breakpoints (struct thread_info *tp)
|
||
{
|
||
delete_step_resume_breakpoint (tp);
|
||
delete_exception_resume_breakpoint (tp);
|
||
delete_single_step_breakpoints (tp);
|
||
}
|
||
|
||
/* If the target still has execution, call FUNC for each thread that
|
||
just stopped. In all-stop, that's all the non-exited threads; in
|
||
non-stop, that's the current thread, only. */
|
||
|
||
typedef void (*for_each_just_stopped_thread_callback_func)
|
||
(struct thread_info *tp);
|
||
|
||
static void
|
||
for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
|
||
{
|
||
if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
|
||
return;
|
||
|
||
if (non_stop)
|
||
{
|
||
/* If in non-stop mode, only the current thread stopped. */
|
||
func (inferior_thread ());
|
||
}
|
||
else
|
||
{
|
||
struct thread_info *tp;
|
||
|
||
/* In all-stop mode, all threads have stopped. */
|
||
ALL_NON_EXITED_THREADS (tp)
|
||
{
|
||
func (tp);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Delete the step resume and longjmp/exception resume breakpoints of
|
||
the threads that just stopped. */
|
||
|
||
static void
|
||
delete_just_stopped_threads_infrun_breakpoints (void)
|
||
{
|
||
for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
|
||
}
|
||
|
||
/* Delete the single-step breakpoints of the threads that just
|
||
stopped. */
|
||
|
||
static void
|
||
delete_just_stopped_threads_single_step_breakpoints (void)
|
||
{
|
||
for_each_just_stopped_thread (delete_single_step_breakpoints);
|
||
}
|
||
|
||
/* A cleanup wrapper. */
|
||
|
||
static void
|
||
delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
|
||
{
|
||
delete_just_stopped_threads_infrun_breakpoints ();
|
||
}
|
||
|
||
/* 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.%ld.%ld",
|
||
ptid_get_pid (waiton_ptid),
|
||
ptid_get_lwp (waiton_ptid),
|
||
ptid_get_tid (waiton_ptid));
|
||
if (ptid_get_pid (waiton_ptid) != -1)
|
||
fprintf_unfiltered (tmp_stream,
|
||
" [%s]", target_pid_to_str (waiton_ptid));
|
||
fprintf_unfiltered (tmp_stream, ", status) =\n");
|
||
fprintf_unfiltered (tmp_stream,
|
||
"infrun: %d.%ld.%ld [%s],\n",
|
||
ptid_get_pid (result_ptid),
|
||
ptid_get_lwp (result_ptid),
|
||
ptid_get_tid (result_ptid),
|
||
target_pid_to_str (result_ptid));
|
||
fprintf_unfiltered (tmp_stream,
|
||
"infrun: %s\n",
|
||
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;
|
||
struct cleanup *thread_state_chain;
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered
|
||
(gdb_stdlog, "infrun: wait_for_inferior ()\n");
|
||
|
||
old_cleanups
|
||
= make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
|
||
NULL);
|
||
|
||
/* If an error happens while handling the event, propagate GDB's
|
||
knowledge of the executing state to the frontend/user running
|
||
state. */
|
||
thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
|
||
|
||
while (1)
|
||
{
|
||
struct execution_control_state ecss;
|
||
struct execution_control_state *ecs = &ecss;
|
||
ptid_t waiton_ptid = minus_one_ptid;
|
||
|
||
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);
|
||
|
||
/* Now figure out what to do with the result of the result. */
|
||
handle_inferior_event (ecs);
|
||
|
||
if (!ecs->wait_some_more)
|
||
break;
|
||
}
|
||
|
||
/* No error, don't finish the state yet. */
|
||
discard_cleanups (thread_state_chain);
|
||
|
||
do_cleanups (old_cleanups);
|
||
}
|
||
|
||
/* Cleanup that reinstalls the readline callback handler, if the
|
||
target is running in the background. If while handling the target
|
||
event something triggered a secondary prompt, like e.g., a
|
||
pagination prompt, we'll have removed the callback handler (see
|
||
gdb_readline_wrapper_line). Need to do this as we go back to the
|
||
event loop, ready to process further input. Note this has no
|
||
effect if the handler hasn't actually been removed, because calling
|
||
rl_callback_handler_install resets the line buffer, thus losing
|
||
input. */
|
||
|
||
static void
|
||
reinstall_readline_callback_handler_cleanup (void *arg)
|
||
{
|
||
if (!interpreter_async)
|
||
{
|
||
/* We're not going back to the top level event loop yet. Don't
|
||
install the readline callback, as it'd prep the terminal,
|
||
readline-style (raw, noecho) (e.g., --batch). We'll install
|
||
it the next time the prompt is displayed, when we're ready
|
||
for input. */
|
||
return;
|
||
}
|
||
|
||
if (async_command_editing_p && !sync_execution)
|
||
gdb_rl_callback_handler_reinstall ();
|
||
}
|
||
|
||
/* 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;
|
||
ptid_t waiton_ptid = minus_one_ptid;
|
||
|
||
memset (ecs, 0, sizeof (*ecs));
|
||
|
||
/* End up with readline processing input, if necessary. */
|
||
make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
|
||
|
||
/* 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 ();
|
||
|
||
make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
|
||
|
||
/* 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_ptid (ecs->ptid);
|
||
|
||
delete_just_stopped_threads_infrun_breakpoints ();
|
||
|
||
/* 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->stepped_breakpoint = 0;
|
||
tss->stepping_over_breakpoint = 0;
|
||
tss->stepping_over_watchpoint = 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 the target can tell whether the thread hit a SW breakpoint,
|
||
trust it. Targets that can tell also adjust the PC
|
||
themselves. */
|
||
if (target_supports_stopped_by_sw_breakpoint ())
|
||
return;
|
||
|
||
/* Note that relying on whether a breakpoint is planted in memory to
|
||
determine this can fail. E.g,. the breakpoint could have been
|
||
removed since. Or the thread could have been told to step an
|
||
instruction the size of a breakpoint instruction, and only
|
||
_after_ was a breakpoint inserted at its address. */
|
||
|
||
/* If this target does not decrement the PC after breakpoints, then
|
||
we have nothing to do. */
|
||
regcache = get_thread_regcache (ecs->ptid);
|
||
gdbarch = get_regcache_arch (regcache);
|
||
|
||
decr_pc = gdbarch_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;
|
||
|
||
/* If the target can't tell whether a software breakpoint triggered,
|
||
fallback to figuring it out based on breakpoints we think were
|
||
inserted in the target, and on whether the thread was stepped or
|
||
continued. */
|
||
|
||
/* Check whether there actually is a software breakpoint inserted at
|
||
that location.
|
||
|
||
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. Note
|
||
this is an heuristic and can thus get confused. The real fix is
|
||
to get the "stopped by SW BP and needs adjustment" info out of
|
||
the target/kernel (and thus never reach here; see above). */
|
||
if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
|
||
|| (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
|
||
{
|
||
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
|
||
- 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 (thread_has_single_step_breakpoints_set (ecs->event_thread)
|
||
|| !currently_stepping (ecs->event_thread)
|
||
|| (ecs->event_thread->stepped_breakpoint
|
||
&& ecs->event_thread->prev_pc == breakpoint_pc))
|
||
regcache_write_pc (regcache, breakpoint_pc);
|
||
|
||
do_cleanups (old_cleanups);
|
||
}
|
||
}
|
||
|
||
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_ptid (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_1 (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 (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)
|
||
insert_breakpoints ();
|
||
resume (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 (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_ptid (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 ();
|
||
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_ptid (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);
|
||
}
|
||
|
||
delete_just_stopped_threads_single_step_breakpoints ();
|
||
|
||
/* 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);
|
||
|
||
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. */
|
||
|
||
delete_just_stopped_threads_single_step_breakpoints ();
|
||
stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
|
||
observer_notify_no_history ();
|
||
stop_waiting (ecs);
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* A wrapper around handle_inferior_event_1, which also makes sure
|
||
that all temporary struct value objects that were created during
|
||
the handling of the event get deleted at the end. */
|
||
|
||
static void
|
||
handle_inferior_event (struct execution_control_state *ecs)
|
||
{
|
||
struct value *mark = value_mark ();
|
||
|
||
handle_inferior_event_1 (ecs);
|
||
/* Purge all temporary values created during the event handling,
|
||
as it could be a long time before we return to the command level
|
||
where such values would otherwise be purged. */
|
||
value_free_to_mark (mark);
|
||
}
|
||
|
||
/* 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 (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);
|
||
|
||
/* However, before doing so, if this single-step breakpoint was
|
||
actually for another thread, set this thread up for moving
|
||
past it. */
|
||
if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
|
||
aspace, pc))
|
||
{
|
||
if (single_step_breakpoint_inserted_here_p (aspace, pc))
|
||
{
|
||
if (debug_infrun)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: [%s] hit another thread's "
|
||
"single-step breakpoint\n",
|
||
target_pid_to_str (ecs->ptid));
|
||
}
|
||
ecs->hit_singlestep_breakpoint = 1;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (debug_infrun)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: [%s] hit its "
|
||
"single-step breakpoint\n",
|
||
target_pid_to_str (ecs->ptid));
|
||
}
|
||
}
|
||
}
|
||
delete_just_stopped_threads_single_step_breakpoints ();
|
||
|
||
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
|
||
&& ecs->event_thread->control.trap_expected
|
||
&& ecs->event_thread->stepping_over_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 step 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.
|
||
|
||
Any breakpoint at PC must also be stepped over -- if there's
|
||
one, it will have already triggered before the watchpoint
|
||
triggered, and we either already reported it to the user, or
|
||
it didn't cause a stop and we called keep_going. In either
|
||
case, if there was a breakpoint at PC, we must be trying to
|
||
step past it. */
|
||
ecs->event_thread->stepping_over_watchpoint = 1;
|
||
keep_going (ecs);
|
||
return;
|
||
}
|
||
|
||
ecs->event_thread->stepping_over_breakpoint = 0;
|
||
ecs->event_thread->stepping_over_watchpoint = 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);
|
||
|
||
/* Maybe this was a trap for a software breakpoint that has since
|
||
been removed. */
|
||
if (random_signal && target_stopped_by_sw_breakpoint ())
|
||
{
|
||
if (program_breakpoint_here_p (gdbarch, stop_pc))
|
||
{
|
||
struct regcache *regcache;
|
||
int decr_pc;
|
||
|
||
/* Re-adjust PC to what the program would see if GDB was not
|
||
debugging it. */
|
||
regcache = get_thread_regcache (ecs->event_thread->ptid);
|
||
decr_pc = gdbarch_decr_pc_after_break (gdbarch);
|
||
if (decr_pc != 0)
|
||
{
|
||
struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
|
||
|
||
if (record_full_is_used ())
|
||
record_full_gdb_operation_disable_set ();
|
||
|
||
regcache_write_pc (regcache, stop_pc + decr_pc);
|
||
|
||
do_cleanups (old_cleanups);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* A delayed software breakpoint event. Ignore the trap. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: delayed software breakpoint "
|
||
"trap, ignoring\n");
|
||
random_signal = 0;
|
||
}
|
||
}
|
||
|
||
/* Maybe this was a trap for a hardware breakpoint/watchpoint that
|
||
has since been removed. */
|
||
if (random_signal && target_stopped_by_hw_breakpoint ())
|
||
{
|
||
/* A delayed hardware breakpoint event. Ignore the trap. */
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: delayed hardware breakpoint/watchpoint "
|
||
"trap, ignoring\n");
|
||
random_signal = 0;
|
||
}
|
||
|
||
/* If not, perhaps stepping/nexting can. */
|
||
if (random_signal)
|
||
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. */
|
||
struct inferior *inf = find_inferior_ptid (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;
|
||
|
||
/* 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;
|
||
}
|
||
|
||
/* Notify observers the signal has "handle print" set. Note we
|
||
returned early above if stopping; normal_stop handles the
|
||
printing in that case. */
|
||
if (signal_print[ecs->event_thread->suspend.stop_signal])
|
||
{
|
||
/* The signal table tells us to print about this signal. */
|
||
target_terminal_ours_for_output ();
|
||
observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
|
||
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->suspend.stop_signal != GDB_SIGNAL_0
|
||
&& (pc_in_thread_step_range (stop_pc, ecs->event_thread)
|
||
|| ecs->event_thread->control.step_range_end == 1)
|
||
&& 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);
|
||
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;
|
||
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);
|
||
jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
|
||
}
|
||
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;
|
||
}
|
||
|
||
/* If we stepped a permanent breakpoint and we had a high priority
|
||
step-resume breakpoint for the address we stepped, but we didn't
|
||
hit it, then we must have stepped into the signal handler. The
|
||
step-resume was only necessary to catch the case of _not_
|
||
stepping into the handler, so delete it, and fall through to
|
||
checking whether the step finished. */
|
||
if (ecs->event_thread->stepped_breakpoint)
|
||
{
|
||
struct breakpoint *sr_bp
|
||
= ecs->event_thread->control.step_resume_breakpoint;
|
||
|
||
if (sr_bp != NULL
|
||
&& sr_bp->loc->permanent
|
||
&& sr_bp->type == bp_hp_step_resume
|
||
&& sr_bp->loc->address == ecs->event_thread->prev_pc)
|
||
{
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: stepped permanent breakpoint, stopped in "
|
||
"handler\n");
|
||
delete_step_resume_breakpoint (ecs->event_thread);
|
||
ecs->event_thread->step_after_step_resume_breakpoint = 0;
|
||
}
|
||
}
|
||
|
||
/* 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)
|
||
|| (ecs->event_thread->control.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)
|
||
{
|
||
/* I presume that step_over_calls is only 0 when we're
|
||
supposed to be stepping at the assembly language level
|
||
("stepi"). Just stop. */
|
||
/* 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 (ecs->event_thread))
|
||
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 (tp));
|
||
|
||
stepping_thread = tp;
|
||
}
|
||
else if (thread_still_needs_step_over (tp))
|
||
{
|
||
step_over = tp;
|
||
|
||
/* At the top we've returned early if the event thread
|
||
is stepping. If some other thread not the event
|
||
thread is stepping, then scheduler locking can't be
|
||
in effect, and we can resume this thread. No need to
|
||
keep looking for the stepping thread then. */
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (step_over != NULL)
|
||
{
|
||
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 (stop_pc != tp->prev_pc)
|
||
{
|
||
ptid_t resume_ptid;
|
||
|
||
if (debug_infrun)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"infrun: expected thread advanced also\n");
|
||
|
||
/* Clear the info of the previous step-over, as it's no
|
||
longer valid. It's what keep_going would do too, if
|
||
we called it. Must do this before trying to insert
|
||
the sss breakpoint, otherwise if we were previously
|
||
trying to step over this exact address in another
|
||
thread, the breakpoint ends up not installed. */
|
||
clear_step_over_info ();
|
||
|
||
insert_single_step_breakpoint (get_frame_arch (frame),
|
||
get_frame_address_space (frame),
|
||
stop_pc);
|
||
|
||
resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
|
||
do_target_resume (resume_ptid,
|
||
currently_stepping (tp), 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
|
||
|| tp->stepped_breakpoint
|
||
|| 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 compunit_symtab *cust;
|
||
struct symtab_and_line stop_func_sal, sr_sal;
|
||
|
||
fill_in_stop_func (gdbarch, ecs);
|
||
|
||
cust = find_pc_compunit_symtab (stop_pc);
|
||
if (cust != NULL && compunit_language (cust) != 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 compunit_symtab *cust;
|
||
struct symtab_and_line stop_func_sal;
|
||
|
||
fill_in_stop_func (gdbarch, ecs);
|
||
|
||
cust = find_pc_compunit_symtab (stop_pc);
|
||
if (cust != NULL && compunit_language (cust) != 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)
|
||
{
|
||
TRY
|
||
{
|
||
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;
|
||
}
|
||
}
|
||
CATCH (e, RETURN_MASK_ERROR)
|
||
{
|
||
/* We want to ignore errors here. */
|
||
}
|
||
END_CATCH
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
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
|
||
{
|
||
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;
|
||
}
|
||
}
|
||
}
|
||
CATCH (e, RETURN_MASK_ERROR)
|
||
{
|
||
}
|
||
END_CATCH
|
||
}
|
||
|
||
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 (ecs->event_thread->suspend.stop_signal);
|
||
}
|
||
else
|
||
{
|
||
struct regcache *regcache = get_current_regcache ();
|
||
int remove_bp;
|
||
int remove_wps;
|
||
|
||
/* 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. */
|
||
|
||
remove_bp = (ecs->hit_singlestep_breakpoint
|
||
|| thread_still_needs_step_over (ecs->event_thread));
|
||
remove_wps = (ecs->event_thread->stepping_over_watchpoint
|
||
&& !target_have_steppable_watchpoint);
|
||
|
||
/* We can't use displaced stepping if we need to step past a
|
||
watchpoint. The instruction copied to the scratch pad would
|
||
still trigger the watchpoint. */
|
||
if (remove_bp
|
||
&& (remove_wps
|
||
|| !use_displaced_stepping (get_regcache_arch (regcache))))
|
||
{
|
||
set_step_over_info (get_regcache_aspace (regcache),
|
||
regcache_read_pc (regcache), remove_wps);
|
||
}
|
||
else if (remove_wps)
|
||
set_step_over_info (NULL, 0, remove_wps);
|
||
else
|
||
clear_step_over_info ();
|
||
|
||
/* Stop stepping if inserting breakpoints fails. */
|
||
TRY
|
||
{
|
||
insert_breakpoints ();
|
||
}
|
||
CATCH (e, RETURN_MASK_ERROR)
|
||
{
|
||
exception_print (gdb_stderr, e);
|
||
stop_waiting (ecs);
|
||
discard_cleanups (old_cleanups);
|
||
return;
|
||
}
|
||
END_CATCH
|
||
|
||
ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
|
||
|
||
/* Do not deliver GDB_SIGNAL_TRAP (except when the user
|
||
explicitly specifies that such a signal should be delivered
|
||
to the target program). Typically, that would occur when a
|
||
user is debugging a target monitor on a simulator: the target
|
||
monitor sets a breakpoint; the simulator encounters this
|
||
breakpoint and halts the simulation handing control to GDB;
|
||
GDB, noting that the stop address doesn't map to any known
|
||
breakpoint, returns control back to the simulator; the
|
||
simulator then delivers the hardware equivalent of a
|
||
GDB_SIGNAL_TRAP to the program being debugged. */
|
||
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
|
||
&& !signal_program[ecs->event_thread->suspend.stop_signal])
|
||
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
|
||
|
||
discard_cleanups (old_cleanups);
|
||
resume (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. */
|
||
|
||
static void
|
||
end_stepping_range (struct execution_control_state *ecs)
|
||
{
|
||
ecs->event_thread->control.stop_step = 1;
|
||
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 ()))
|
||
&& tp->control.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 we're presenting a stop, and potentially removing breakpoints,
|
||
update the thread list so we can tell whether there are threads
|
||
running on the target. With target remote, for example, we can
|
||
only learn about new threads when we explicitly update the thread
|
||
list. Do this before notifying the interpreters about signal
|
||
stops, end of stepping ranges, etc., so that the "new thread"
|
||
output is emitted before e.g., "Program received signal FOO",
|
||
instead of after. */
|
||
update_thread_list ();
|
||
|
||
if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
|
||
observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
|
||
|
||
/* 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"));
|
||
}
|
||
|
||
/* Note: this depends on the update_thread_list call above. */
|
||
if (!breakpoints_should_be_inserted_now () && 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 ();
|
||
|
||
/* Notify observers if we finished a "step"-like command, etc. */
|
||
if (target_has_execution
|
||
&& last.kind != TARGET_WAITKIND_SIGNALLED
|
||
&& last.kind != TARGET_WAITKIND_EXITED
|
||
&& inferior_thread ()->control.stop_step)
|
||
{
|
||
/* But not if in the middle of doing a "step n" operation for
|
||
n > 1 */
|
||
if (inferior_thread ()->step_multi)
|
||
goto done;
|
||
|
||
observer_notify_end_stepping_range ();
|
||
}
|
||
|
||
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 defer to
|
||
call_function_by_hand if the thread finished an infcall
|
||
successfully. We may be e.g., evaluating a breakpoint condition.
|
||
In that case, the thread had state THREAD_RUNNING before the
|
||
infcall, and shall remain marked running, all without informing
|
||
the user/frontend about state transition changes. */
|
||
if (target_has_execution
|
||
&& inferior_thread ()->control.in_infcall
|
||
&& stop_stack_dummy == STOP_STACK_DUMMY)
|
||
discard_cleanups (old_chain);
|
||
else
|
||
do_cleanups (old_chain);
|
||
|
||
/* 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);
|
||
}
|
||
|
||
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;
|
||
}
|
||
|
||
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;
|
||
|
||
/* 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 ();
|
||
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;
|
||
|
||
/* 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 ();
|
||
struct regcache *regcache = get_current_regcache ();
|
||
struct gdbarch *gdbarch = get_regcache_arch (regcache);
|
||
|
||
tp->suspend = inf_state->thread_suspend;
|
||
|
||
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 infrun.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 (!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 stepping commands (step, next, stepi, nexti).\n\
|
||
In this mode, other threads may run during other commands."),
|
||
set_schedlock_func, /* traps on target vector */
|
||
show_scheduler_mode,
|
||
&setlist, &showlist);
|
||
|
||
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);
|
||
}
|