binutils-gdb/gdb/record.c

905 lines
22 KiB
C

/* Process record and replay target for GDB, the GNU debugger.
Copyright (C) 2008-2017 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "gdbcmd.h"
#include "completer.h"
#include "record.h"
#include "observer.h"
#include "inferior.h"
#include "common/common-utils.h"
#include "cli/cli-utils.h"
#include "disasm.h"
#include <ctype.h>
/* This is the debug switch for process record. */
unsigned int record_debug = 0;
/* The number of instructions to print in "record instruction-history". */
static unsigned int record_insn_history_size = 10;
/* The variable registered as control variable in the "record
instruction-history" command. Necessary for extra input
validation. */
static unsigned int record_insn_history_size_setshow_var;
/* The number of functions to print in "record function-call-history". */
static unsigned int record_call_history_size = 10;
/* The variable registered as control variable in the "record
call-history" command. Necessary for extra input validation. */
static unsigned int record_call_history_size_setshow_var;
struct cmd_list_element *record_cmdlist = NULL;
struct cmd_list_element *record_goto_cmdlist = NULL;
struct cmd_list_element *set_record_cmdlist = NULL;
struct cmd_list_element *show_record_cmdlist = NULL;
struct cmd_list_element *info_record_cmdlist = NULL;
#define DEBUG(msg, args...) \
if (record_debug) \
fprintf_unfiltered (gdb_stdlog, "record: " msg "\n", ##args)
/* See record.h. */
struct target_ops *
find_record_target (void)
{
return find_target_at (record_stratum);
}
/* Check that recording is active. Throw an error, if it isn't. */
static struct target_ops *
require_record_target (void)
{
struct target_ops *t;
t = find_record_target ();
if (t == NULL)
error (_("No record target is currently active.\n"
"Use one of the \"target record-<tab><tab>\" commands first."));
return t;
}
/* See record.h. */
void
record_preopen (void)
{
/* Check if a record target is already running. */
if (find_record_target () != NULL)
error (_("The process is already being recorded. Use \"record stop\" to "
"stop recording first."));
}
/* See record.h. */
void
record_start (const char *method, const char *format, int from_tty)
{
if (method == NULL)
{
if (format == NULL)
execute_command_to_string ((char *) "record", from_tty);
else
error (_("Invalid format."));
}
else if (strcmp (method, "full") == 0)
{
if (format == NULL)
execute_command_to_string ((char *) "record full", from_tty);
else
error (_("Invalid format."));
}
else if (strcmp (method, "btrace") == 0)
{
if (format == NULL)
execute_command_to_string ((char *) "record btrace", from_tty);
else if (strcmp (format, "bts") == 0)
execute_command_to_string ((char *) "record btrace bts", from_tty);
else if (strcmp (format, "pt") == 0)
execute_command_to_string ((char *) "record btrace pt", from_tty);
else
error (_("Invalid format."));
}
else
error (_("Invalid method."));
}
/* See record.h. */
void
record_stop (int from_tty)
{
execute_command_to_string ((char *) "record stop", from_tty);
}
/* See record.h. */
int
record_read_memory (struct gdbarch *gdbarch,
CORE_ADDR memaddr, gdb_byte *myaddr,
ssize_t len)
{
int ret = target_read_memory (memaddr, myaddr, len);
if (ret != 0)
DEBUG ("error reading memory at addr %s len = %ld.\n",
paddress (gdbarch, memaddr), (long) len);
return ret;
}
/* Stop recording. */
static void
record_stop (struct target_ops *t)
{
DEBUG ("stop %s", t->to_shortname);
t->to_stop_recording (t);
}
/* Unpush the record target. */
static void
record_unpush (struct target_ops *t)
{
DEBUG ("unpush %s", t->to_shortname);
unpush_target (t);
}
/* See record.h. */
void
record_disconnect (struct target_ops *t, const char *args, int from_tty)
{
gdb_assert (t->to_stratum == record_stratum);
DEBUG ("disconnect %s", t->to_shortname);
record_stop (t);
record_unpush (t);
target_disconnect (args, from_tty);
}
/* See record.h. */
void
record_detach (struct target_ops *t, const char *args, int from_tty)
{
gdb_assert (t->to_stratum == record_stratum);
DEBUG ("detach %s", t->to_shortname);
record_stop (t);
record_unpush (t);
target_detach (args, from_tty);
}
/* See record.h. */
void
record_mourn_inferior (struct target_ops *t)
{
gdb_assert (t->to_stratum == record_stratum);
DEBUG ("mourn inferior %s", t->to_shortname);
/* It is safer to not stop recording. Resources will be freed when
threads are discarded. */
record_unpush (t);
target_mourn_inferior (inferior_ptid);
}
/* See record.h. */
void
record_kill (struct target_ops *t)
{
gdb_assert (t->to_stratum == record_stratum);
DEBUG ("kill %s", t->to_shortname);
/* It is safer to not stop recording. Resources will be freed when
threads are discarded. */
record_unpush (t);
target_kill ();
}
/* See record.h. */
int
record_check_stopped_by_breakpoint (struct address_space *aspace, CORE_ADDR pc,
enum target_stop_reason *reason)
{
if (breakpoint_inserted_here_p (aspace, pc))
{
if (hardware_breakpoint_inserted_here_p (aspace, pc))
*reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
else
*reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
return 1;
}
*reason = TARGET_STOPPED_BY_NO_REASON;
return 0;
}
/* Implement "show record debug" command. */
static void
show_record_debug (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
fprintf_filtered (file, _("Debugging of process record target is %s.\n"),
value);
}
/* Alias for "target record". */
static void
cmd_record_start (char *args, int from_tty)
{
execute_command ((char *) "target record-full", from_tty);
}
/* Truncate the record log from the present point
of replay until the end. */
static void
cmd_record_delete (char *args, int from_tty)
{
require_record_target ();
if (!target_record_is_replaying (inferior_ptid))
{
printf_unfiltered (_("Already at end of record list.\n"));
return;
}
if (!target_supports_delete_record ())
{
printf_unfiltered (_("The current record target does not support "
"this operation.\n"));
return;
}
if (!from_tty || query (_("Delete the log from this point forward "
"and begin to record the running message "
"at current PC?")))
target_delete_record ();
}
/* Implement the "stoprecord" or "record stop" command. */
static void
cmd_record_stop (char *args, int from_tty)
{
struct target_ops *t;
t = require_record_target ();
record_stop (t);
record_unpush (t);
printf_unfiltered (_("Process record is stopped and all execution "
"logs are deleted.\n"));
observer_notify_record_changed (current_inferior (), 0, NULL, NULL);
}
/* The "set record" command. */
static void
set_record_command (char *args, int from_tty)
{
printf_unfiltered (_("\"set record\" must be followed "
"by an apporpriate subcommand.\n"));
help_list (set_record_cmdlist, "set record ", all_commands, gdb_stdout);
}
/* The "show record" command. */
static void
show_record_command (char *args, int from_tty)
{
cmd_show_list (show_record_cmdlist, from_tty, "");
}
/* The "info record" command. */
static void
info_record_command (char *args, int from_tty)
{
struct target_ops *t;
t = find_record_target ();
if (t == NULL)
{
printf_filtered (_("No record target is currently active.\n"));
return;
}
printf_filtered (_("Active record target: %s\n"), t->to_shortname);
t->to_info_record (t);
}
/* The "record save" command. */
static void
cmd_record_save (char *args, int from_tty)
{
char *recfilename, recfilename_buffer[40];
require_record_target ();
if (args != NULL && *args != 0)
recfilename = args;
else
{
/* Default recfile name is "gdb_record.PID". */
xsnprintf (recfilename_buffer, sizeof (recfilename_buffer),
"gdb_record.%d", ptid_get_pid (inferior_ptid));
recfilename = recfilename_buffer;
}
target_save_record (recfilename);
}
/* See record.h. */
void
record_goto (const char *arg)
{
ULONGEST insn;
if (arg == NULL || *arg == '\0')
error (_("Command requires an argument (insn number to go to)."));
insn = parse_and_eval_long (arg);
require_record_target ();
target_goto_record (insn);
}
/* "record goto" command. Argument is an instruction number,
as given by "info record".
Rewinds the recording (forward or backward) to the given instruction. */
static void
cmd_record_goto (char *arg, int from_tty)
{
record_goto (arg);
}
/* The "record goto begin" command. */
static void
cmd_record_goto_begin (char *arg, int from_tty)
{
if (arg != NULL && *arg != '\0')
error (_("Junk after argument: %s."), arg);
require_record_target ();
target_goto_record_begin ();
}
/* The "record goto end" command. */
static void
cmd_record_goto_end (char *arg, int from_tty)
{
if (arg != NULL && *arg != '\0')
error (_("Junk after argument: %s."), arg);
require_record_target ();
target_goto_record_end ();
}
/* Read an instruction number from an argument string. */
static ULONGEST
get_insn_number (char **arg)
{
ULONGEST number;
const char *begin, *end, *pos;
begin = *arg;
pos = skip_spaces_const (begin);
if (!isdigit (*pos))
error (_("Expected positive number, got: %s."), pos);
number = strtoulst (pos, &end, 10);
*arg += (end - begin);
return number;
}
/* Read a context size from an argument string. */
static int
get_context_size (char **arg)
{
char *pos;
int number;
pos = skip_spaces (*arg);
if (!isdigit (*pos))
error (_("Expected positive number, got: %s."), pos);
return strtol (pos, arg, 10);
}
/* Complain about junk at the end of an argument string. */
static void
no_chunk (char *arg)
{
if (*arg != 0)
error (_("Junk after argument: %s."), arg);
}
/* Read instruction-history modifiers from an argument string. */
static int
get_insn_history_modifiers (char **arg)
{
int modifiers;
char *args;
modifiers = 0;
args = *arg;
if (args == NULL)
return modifiers;
while (*args == '/')
{
++args;
if (*args == '\0')
error (_("Missing modifier."));
for (; *args; ++args)
{
if (isspace (*args))
break;
if (*args == '/')
continue;
switch (*args)
{
case 'm':
case 's':
modifiers |= DISASSEMBLY_SOURCE;
modifiers |= DISASSEMBLY_FILENAME;
break;
case 'r':
modifiers |= DISASSEMBLY_RAW_INSN;
break;
case 'f':
modifiers |= DISASSEMBLY_OMIT_FNAME;
break;
case 'p':
modifiers |= DISASSEMBLY_OMIT_PC;
break;
default:
error (_("Invalid modifier: %c."), *args);
}
}
args = skip_spaces (args);
}
/* Update the argument string. */
*arg = args;
return modifiers;
}
/* The "set record instruction-history-size / set record
function-call-history-size" commands are unsigned, with UINT_MAX
meaning unlimited. The target interfaces works with signed int
though, to indicate direction, so map "unlimited" to INT_MAX, which
is about the same as unlimited in practice. If the user does have
a log that huge, she can fetch it in chunks across several requests,
but she'll likely have other problems first... */
static int
command_size_to_target_size (unsigned int size)
{
gdb_assert (size <= INT_MAX || size == UINT_MAX);
if (size == UINT_MAX)
return INT_MAX;
else
return size;
}
/* The "record instruction-history" command. */
static void
cmd_record_insn_history (char *arg, int from_tty)
{
int flags, size;
require_record_target ();
flags = get_insn_history_modifiers (&arg);
size = command_size_to_target_size (record_insn_history_size);
if (arg == NULL || *arg == 0 || strcmp (arg, "+") == 0)
target_insn_history (size, flags);
else if (strcmp (arg, "-") == 0)
target_insn_history (-size, flags);
else
{
ULONGEST begin, end;
begin = get_insn_number (&arg);
if (*arg == ',')
{
arg = skip_spaces (++arg);
if (*arg == '+')
{
arg += 1;
size = get_context_size (&arg);
no_chunk (arg);
target_insn_history_from (begin, size, flags);
}
else if (*arg == '-')
{
arg += 1;
size = get_context_size (&arg);
no_chunk (arg);
target_insn_history_from (begin, -size, flags);
}
else
{
end = get_insn_number (&arg);
no_chunk (arg);
target_insn_history_range (begin, end, flags);
}
}
else
{
no_chunk (arg);
target_insn_history_from (begin, size, flags);
}
dont_repeat ();
}
}
/* Read function-call-history modifiers from an argument string. */
static int
get_call_history_modifiers (char **arg)
{
int modifiers;
char *args;
modifiers = 0;
args = *arg;
if (args == NULL)
return modifiers;
while (*args == '/')
{
++args;
if (*args == '\0')
error (_("Missing modifier."));
for (; *args; ++args)
{
if (isspace (*args))
break;
if (*args == '/')
continue;
switch (*args)
{
case 'l':
modifiers |= RECORD_PRINT_SRC_LINE;
break;
case 'i':
modifiers |= RECORD_PRINT_INSN_RANGE;
break;
case 'c':
modifiers |= RECORD_PRINT_INDENT_CALLS;
break;
default:
error (_("Invalid modifier: %c."), *args);
}
}
args = skip_spaces (args);
}
/* Update the argument string. */
*arg = args;
return modifiers;
}
/* The "record function-call-history" command. */
static void
cmd_record_call_history (char *arg, int from_tty)
{
int flags, size;
require_record_target ();
flags = get_call_history_modifiers (&arg);
size = command_size_to_target_size (record_call_history_size);
if (arg == NULL || *arg == 0 || strcmp (arg, "+") == 0)
target_call_history (size, flags);
else if (strcmp (arg, "-") == 0)
target_call_history (-size, flags);
else
{
ULONGEST begin, end;
begin = get_insn_number (&arg);
if (*arg == ',')
{
arg = skip_spaces (++arg);
if (*arg == '+')
{
arg += 1;
size = get_context_size (&arg);
no_chunk (arg);
target_call_history_from (begin, size, flags);
}
else if (*arg == '-')
{
arg += 1;
size = get_context_size (&arg);
no_chunk (arg);
target_call_history_from (begin, -size, flags);
}
else
{
end = get_insn_number (&arg);
no_chunk (arg);
target_call_history_range (begin, end, flags);
}
}
else
{
no_chunk (arg);
target_call_history_from (begin, size, flags);
}
dont_repeat ();
}
}
/* Helper for "set record instruction-history-size" and "set record
function-call-history-size" input validation. COMMAND_VAR is the
variable registered in the command as control variable. *SETTING
is the real setting the command allows changing. */
static void
validate_history_size (unsigned int *command_var, unsigned int *setting)
{
if (*command_var != UINT_MAX && *command_var > INT_MAX)
{
unsigned int new_value = *command_var;
/* Restore previous value. */
*command_var = *setting;
error (_("integer %u out of range"), new_value);
}
/* Commit new value. */
*setting = *command_var;
}
/* Called by do_setshow_command. We only want values in the
[0..INT_MAX] range, while the command's machinery accepts
[0..UINT_MAX]. See command_size_to_target_size. */
static void
set_record_insn_history_size (char *args, int from_tty,
struct cmd_list_element *c)
{
validate_history_size (&record_insn_history_size_setshow_var,
&record_insn_history_size);
}
/* Called by do_setshow_command. We only want values in the
[0..INT_MAX] range, while the command's machinery accepts
[0..UINT_MAX]. See command_size_to_target_size. */
static void
set_record_call_history_size (char *args, int from_tty,
struct cmd_list_element *c)
{
validate_history_size (&record_call_history_size_setshow_var,
&record_call_history_size);
}
/* Provide a prototype to silence -Wmissing-prototypes. */
extern initialize_file_ftype _initialize_record;
void
_initialize_record (void)
{
struct cmd_list_element *c;
add_setshow_zuinteger_cmd ("record", no_class, &record_debug,
_("Set debugging of record/replay feature."),
_("Show debugging of record/replay feature."),
_("When enabled, debugging output for "
"record/replay feature is displayed."),
NULL, show_record_debug, &setdebuglist,
&showdebuglist);
add_setshow_uinteger_cmd ("instruction-history-size", no_class,
&record_insn_history_size_setshow_var, _("\
Set number of instructions to print in \"record instruction-history\"."), _("\
Show number of instructions to print in \"record instruction-history\"."), _("\
A size of \"unlimited\" means unlimited instructions. The default is 10."),
set_record_insn_history_size, NULL,
&set_record_cmdlist, &show_record_cmdlist);
add_setshow_uinteger_cmd ("function-call-history-size", no_class,
&record_call_history_size_setshow_var, _("\
Set number of function to print in \"record function-call-history\"."), _("\
Show number of functions to print in \"record function-call-history\"."), _("\
A size of \"unlimited\" means unlimited lines. The default is 10."),
set_record_call_history_size, NULL,
&set_record_cmdlist, &show_record_cmdlist);
c = add_prefix_cmd ("record", class_obscure, cmd_record_start,
_("Start recording."),
&record_cmdlist, "record ", 0, &cmdlist);
set_cmd_completer (c, filename_completer);
add_com_alias ("rec", "record", class_obscure, 1);
add_prefix_cmd ("record", class_support, set_record_command,
_("Set record options"), &set_record_cmdlist,
"set record ", 0, &setlist);
add_alias_cmd ("rec", "record", class_obscure, 1, &setlist);
add_prefix_cmd ("record", class_support, show_record_command,
_("Show record options"), &show_record_cmdlist,
"show record ", 0, &showlist);
add_alias_cmd ("rec", "record", class_obscure, 1, &showlist);
add_prefix_cmd ("record", class_support, info_record_command,
_("Info record options"), &info_record_cmdlist,
"info record ", 0, &infolist);
add_alias_cmd ("rec", "record", class_obscure, 1, &infolist);
c = add_cmd ("save", class_obscure, cmd_record_save,
_("Save the execution log to a file.\n\
Argument is optional filename.\n\
Default filename is 'gdb_record.<process_id>'."),
&record_cmdlist);
set_cmd_completer (c, filename_completer);
add_cmd ("delete", class_obscure, cmd_record_delete,
_("Delete the rest of execution log and start recording it anew."),
&record_cmdlist);
add_alias_cmd ("d", "delete", class_obscure, 1, &record_cmdlist);
add_alias_cmd ("del", "delete", class_obscure, 1, &record_cmdlist);
add_cmd ("stop", class_obscure, cmd_record_stop,
_("Stop the record/replay target."),
&record_cmdlist);
add_alias_cmd ("s", "stop", class_obscure, 1, &record_cmdlist);
add_prefix_cmd ("goto", class_obscure, cmd_record_goto, _("\
Restore the program to its state at instruction number N.\n\
Argument is instruction number, as shown by 'info record'."),
&record_goto_cmdlist, "record goto ", 1, &record_cmdlist);
add_cmd ("begin", class_obscure, cmd_record_goto_begin,
_("Go to the beginning of the execution log."),
&record_goto_cmdlist);
add_alias_cmd ("start", "begin", class_obscure, 1, &record_goto_cmdlist);
add_cmd ("end", class_obscure, cmd_record_goto_end,
_("Go to the end of the execution log."),
&record_goto_cmdlist);
add_cmd ("instruction-history", class_obscure, cmd_record_insn_history, _("\
Print disassembled instructions stored in the execution log.\n\
With a /m or /s modifier, source lines are included (if available).\n\
With a /r modifier, raw instructions in hex are included.\n\
With a /f modifier, function names are omitted.\n\
With a /p modifier, current position markers are omitted.\n\
With no argument, disassembles ten more instructions after the previous \
disassembly.\n\
\"record instruction-history -\" disassembles ten instructions before a \
previous disassembly.\n\
One argument specifies an instruction number as shown by 'info record', and \
ten instructions are disassembled after that instruction.\n\
Two arguments with comma between them specify starting and ending instruction \
numbers to disassemble.\n\
If the second argument is preceded by '+' or '-', it specifies the distance \
from the first argument.\n\
The number of instructions to disassemble can be defined with \"set record \
instruction-history-size\"."),
&record_cmdlist);
add_cmd ("function-call-history", class_obscure, cmd_record_call_history, _("\
Prints the execution history at function granularity.\n\
It prints one line for each sequence of instructions that belong to the same \
function.\n\
Without modifiers, it prints the function name.\n\
With a /l modifier, the source file and line number range is included.\n\
With a /i modifier, the instruction number range is included.\n\
With a /c modifier, the output is indented based on the call stack depth.\n\
With no argument, prints ten more lines after the previous ten-line print.\n\
\"record function-call-history -\" prints ten lines before a previous ten-line \
print.\n\
One argument specifies a function number as shown by 'info record', and \
ten lines are printed after that function.\n\
Two arguments with comma between them specify a range of functions to print.\n\
If the second argument is preceded by '+' or '-', it specifies the distance \
from the first argument.\n\
The number of functions to print can be defined with \"set record \
function-call-history-size\"."),
&record_cmdlist);
/* Sync command control variables. */
record_insn_history_size_setshow_var = record_insn_history_size;
record_call_history_size_setshow_var = record_call_history_size;
}