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/* Reverse execution and reverse debugging.
Copyright (C) 2006-2024 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "target.h"
#include "top.h"
#include "cli/cli-cmds.h"
#include "cli/cli-decode.h"
#include "cli/cli-utils.h"
#include "inferior.h"
#include "infrun.h"
#include "regcache.h"
/* User interface:
reverse-step, reverse-next etc. */
/* exec_reverse_once -- accepts an arbitrary gdb command (string),
and executes it with exec-direction set to 'reverse'.
Used to implement reverse-next etc. commands. */
static void
exec_reverse_once (const char *cmd, const char *args, int from_tty)
{
enum exec_direction_kind dir = execution_direction;
if (dir == EXEC_REVERSE)
error (_("Already in reverse mode. Use '%s' or 'set exec-dir forward'."),
cmd);
if (!target_can_execute_reverse ())
error (_("Target %s does not support this command."), target_shortname ());
std::string reverse_command = string_printf ("%s %s", cmd, args ? args : "");
scoped_restore restore_exec_dir
= make_scoped_restore (&execution_direction, EXEC_REVERSE);
execute_command (reverse_command.c_str (), from_tty);
}
static void
reverse_step (const char *args, int from_tty)
{
exec_reverse_once ("step", args, from_tty);
}
static void
reverse_stepi (const char *args, int from_tty)
{
exec_reverse_once ("stepi", args, from_tty);
}
static void
reverse_next (const char *args, int from_tty)
{
exec_reverse_once ("next", args, from_tty);
}
static void
reverse_nexti (const char *args, int from_tty)
{
exec_reverse_once ("nexti", args, from_tty);
}
static void
reverse_continue (const char *args, int from_tty)
{
exec_reverse_once ("continue", args, from_tty);
}
static void
reverse_finish (const char *args, int from_tty)
{
exec_reverse_once ("finish", args, from_tty);
}
/* Data structures for a bookmark list. */
struct bookmark {
int number = 0;
CORE_ADDR pc = 0;
struct symtab_and_line sal;
gdb::unique_xmalloc_ptr<gdb_byte> opaque_data;
};
static std::vector<struct bookmark> all_bookmarks;
static int bookmark_count;
/* save_bookmark_command -- implement "bookmark" command.
Call target method to get a bookmark identifier.
Insert bookmark identifier into list.
Identifier will be a malloc string (gdb_byte *).
Up to us to free it as required. */
static void
save_bookmark_command (const char *args, int from_tty)
{
/* Get target's idea of a bookmark. */
gdb_byte *bookmark_id = target_get_bookmark (args, from_tty);
regcache *regcache = get_thread_regcache (inferior_thread ());
gdbarch *gdbarch = regcache->arch ();
/* CR should not cause another identical bookmark. */
dont_repeat ();
if (bookmark_id == NULL)
error (_("target_get_bookmark failed."));
/* Set up a bookmark struct. */
bookmark &b = all_bookmarks.emplace_back ();
b.number = ++bookmark_count;
b.pc = regcache_read_pc (regcache);
b.sal = find_pc_line (b.pc, 0);
b.sal.pspace = get_frame_program_space (get_current_frame ());
b.opaque_data.reset (bookmark_id);
gdb_printf (_("Saved bookmark %d at %s\n"), b.number,
paddress (gdbarch, b.sal.pc));
}
/* Implement "delete bookmark" command. */
static bool
delete_one_bookmark (int num)
{
/* Find bookmark with corresponding number. */
for (auto iter = all_bookmarks.begin ();
iter != all_bookmarks.end ();
++iter)
{
if (iter->number == num)
{
all_bookmarks.erase (iter);
return true;
}
}
return false;
}
static void
delete_all_bookmarks ()
{
all_bookmarks.clear ();
}
static void
delete_bookmark_command (const char *args, int from_tty)
{
if (all_bookmarks.empty ())
{
warning (_("No bookmarks."));
return;
}
if (args == NULL || args[0] == '\0')
{
if (from_tty && !query (_("Delete all bookmarks? ")))
return;
delete_all_bookmarks ();
return;
}
number_or_range_parser parser (args);
while (!parser.finished ())
{
int num = parser.get_number ();
if (!delete_one_bookmark (num))
/* Not found. */
warning (_("No bookmark #%d."), num);
}
}
/* Implement "goto-bookmark" command. */
static void
goto_bookmark_command (const char *args, int from_tty)
{
unsigned long num;
const char *p = args;
if (args == NULL || args[0] == '\0')
error (_("Command requires an argument."));
if (startswith (args, "start")
|| startswith (args, "begin")
|| startswith (args, "end"))
{
/* Special case. Give target opportunity to handle. */
target_goto_bookmark ((gdb_byte *) args, from_tty);
return;
}
if (args[0] == '\'' || args[0] == '\"')
{
/* Special case -- quoted string. Pass on to target. */
if (args[strlen (args) - 1] != args[0])
error (_("Unbalanced quotes: %s"), args);
target_goto_bookmark ((gdb_byte *) args, from_tty);
return;
}
/* General case. Bookmark identified by bookmark number. */
num = get_number (&args);
if (num == 0)
error (_("goto-bookmark: invalid bookmark number '%s'."), p);
for (const bookmark &iter : all_bookmarks)
{
if (iter.number == num)
{
/* Found. Send to target method. */
target_goto_bookmark (iter.opaque_data.get (), from_tty);
return;
}
}
/* Not found. */
error (_("goto-bookmark: no bookmark found for '%s'."), p);
}
static int
bookmark_1 (int bnum)
{
gdbarch *gdbarch = get_thread_regcache (inferior_thread ())->arch ();
int matched = 0;
for (const bookmark &iter : all_bookmarks)
{
if (bnum == -1 || bnum == iter.number)
{
gdb_printf (" %d %s '%s'\n",
iter.number,
paddress (gdbarch, iter.pc),
iter.opaque_data.get ());
matched++;
}
}
if (bnum > 0 && matched == 0)
gdb_printf ("No bookmark #%d\n", bnum);
return matched;
}
/* Implement "info bookmarks" command. */
static void
info_bookmarks_command (const char *args, int from_tty)
{
if (all_bookmarks.empty ())
gdb_printf (_("No bookmarks.\n"));
else if (args == NULL || *args == '\0')
bookmark_1 (-1);
else
{
number_or_range_parser parser (args);
while (!parser.finished ())
{
int bnum = parser.get_number ();
bookmark_1 (bnum);
}
}
}
void _initialize_reverse ();
void
_initialize_reverse ()
{
cmd_list_element *reverse_step_cmd
= add_com ("reverse-step", class_run, reverse_step, _("\
Step program backward until it reaches the beginning of another source line.\n\
Argument N means do this N times (or till program stops for another reason)."));
add_com_alias ("rs", reverse_step_cmd, class_run, 1);
cmd_list_element *reverse_next_cmd
= add_com ("reverse-next", class_run, reverse_next, _("\
Step program backward, proceeding through subroutine calls.\n\
Like the \"reverse-step\" command as long as subroutine calls do not happen;\n\
when they do, the call is treated as one instruction.\n\
Argument N means do this N times (or till program stops for another reason)."));
add_com_alias ("rn", reverse_next_cmd, class_run, 1);
cmd_list_element *reverse_stepi_cmd
= add_com ("reverse-stepi", class_run, reverse_stepi, _("\
Step backward exactly one instruction.\n\
Argument N means do this N times (or till program stops for another reason)."));
add_com_alias ("rsi", reverse_stepi_cmd, class_run, 0);
cmd_list_element *reverse_nexti_cmd
= add_com ("reverse-nexti", class_run, reverse_nexti, _("\
Step backward one instruction, but proceed through called subroutines.\n\
Argument N means do this N times (or till program stops for another reason)."));
add_com_alias ("rni", reverse_nexti_cmd, class_run, 0);
cmd_list_element *reverse_continue_cmd
= add_com ("reverse-continue", class_run, reverse_continue, _("\
Continue program being debugged but run it in reverse.\n\
If proceeding from breakpoint, a number N may be used as an argument,\n\
which means to set the ignore count of that breakpoint to N - 1 (so that\n\
the breakpoint won't break until the Nth time it is reached)."));
add_com_alias ("rc", reverse_continue_cmd, class_run, 0);
add_com ("reverse-finish", class_run, reverse_finish, _("\
Execute backward until just before selected stack frame is called."));
add_com ("bookmark", class_bookmark, save_bookmark_command, _("\
Set a bookmark in the program's execution history.\n\
A bookmark represents a point in the execution history\n\
that can be returned to at a later point in the debug session."));
add_info ("bookmarks", info_bookmarks_command, _("\
Status of user-settable bookmarks.\n\
Bookmarks are user-settable markers representing a point in the\n\
execution history that can be returned to later in the same debug\n\
session."));
add_cmd ("bookmark", class_bookmark, delete_bookmark_command, _("\
Delete a bookmark from the bookmark list.\n\
Argument is a bookmark number or numbers,\n\
or no argument to delete all bookmarks."),
&deletelist);
add_com ("goto-bookmark", class_bookmark, goto_bookmark_command, _("\
Go to an earlier-bookmarked point in the program's execution history.\n\
Argument is the bookmark number of a bookmark saved earlier by using\n\
the 'bookmark' command, or the special arguments:\n\
start (beginning of recording)\n\
end (end of recording)"));
}