Re: [RFA] Submit process record and replay fourth time, 3/8

[Hui Zhu <teawater@gmail.com>]

Hi Pedro,

Could you please help me review this patch?

Thanks,
Hui

On Wed, Apr 22, 2009 at 17:05, Hui Zhu <teawater@gmail.com> wrote:
> I fix the error in "record_gdb_operation_disable_set" in this version.
>
> ---
>  Makefile.in |    5
>  record.c    | 1289 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  record.h    |   32 +
>  3 files changed, 1324 insertions(+), 2 deletions(-)
>
> --- a/Makefile.in
> +++ b/Makefile.in
> @@ -664,7 +664,8 @@ SFILES = ada-exp.y ada-lang.c ada-typepr
>        valarith.c valops.c valprint.c value.c varobj.c vec.c \
>        wrapper.c \
>        xml-tdesc.c xml-support.c \
> -       inferior.c gdb_usleep.c
> +       inferior.c gdb_usleep.c \
> +       record.c
>
>  LINTFILES = $(SFILES) $(YYFILES) $(CONFIG_SRCS) init.c
>
> @@ -816,7 +817,7 @@ COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $
>        solib.o solib-null.o \
>        prologue-value.o memory-map.o xml-support.o \
>        target-descriptions.o target-memory.o xml-tdesc.o xml-builtin.o \
> -       inferior.o osdata.o gdb_usleep.o
> +       inferior.o osdata.o gdb_usleep.o record.o
>
>  TSOBS = inflow.o
>
> --- /dev/null
> +++ b/record.c
> @@ -0,0 +1,1289 @@
> +/* Process record and replay target for GDB, the GNU debugger.
> +
> +   Copyright (C) 2008, 2009 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 "regcache.h"
> +#include "gdbthread.h"
> +#include "event-top.h"
> +#include "exceptions.h"
> +#include "record.h"
> +
> +#include <signal.h>
> +
> +#define DEFAULT_RECORD_INSN_MAX_NUM    200000
> +
> +#define RECORD_IS_REPLAY \
> +     (record_list->next || execution_direction == EXEC_REVERSE)
> +
> +/* These are the core struct of record function.
> +
> +   An record_entry is a record of the value change of a register
> +   ("record_reg") or a part of memory ("record_mem").  And each
> +   instruction must has a struct record_entry ("record_end") that
> points out this
> +   is the last struct record_entry of this instruction.
> +
> +   Each struct record_entry is linked to "record_list" by "prev" and "next". */
> +
> +struct record_reg_entry
> +{
> +  int num;
> +  gdb_byte *val;
> +};
> +
> +struct record_mem_entry
> +{
> +  CORE_ADDR addr;
> +  int len;
> +  gdb_byte *val;
> +};
> +
> +enum record_type
> +{
> +  record_end = 0,
> +  record_reg,
> +  record_mem
> +};
> +
> +struct record_entry
> +{
> +  struct record_entry *prev;
> +  struct record_entry *next;
> +  enum record_type type;
> +  union
> +  {
> +    /* reg */
> +    struct record_reg_entry reg;
> +    /* mem */
> +    struct record_mem_entry mem;
> +  } u;
> +};
> +
> +/* This is the debug switch for process record.  */
> +int record_debug = 0;
> +
> +/* These list is for execution log.  */
> +static struct record_entry record_first;
> +static struct record_entry *record_list = &record_first;
> +static struct record_entry *record_arch_list_head = NULL;
> +static struct record_entry *record_arch_list_tail = NULL;
> +
> +/* 1 ask user. 0 auto delete the last struct record_entry.  */
> +static int record_stop_at_limit = 1;
> +static int record_insn_max_num = DEFAULT_RECORD_INSN_MAX_NUM;
> +static int record_insn_num = 0;
> +
> +/* The target_ops of process record.  */
> +static struct target_ops record_ops;
> +
> +/* The beneath function pointers.  */
> +static struct target_ops *record_beneath_to_resume_ops;
> +static void (*record_beneath_to_resume) (struct target_ops *, ptid_t, int,
> +                                         enum target_signal);
> +static struct target_ops *record_beneath_to_wait_ops;
> +static ptid_t (*record_beneath_to_wait) (struct target_ops *, ptid_t,
> +                                        struct target_waitstatus *);
> +static struct target_ops *record_beneath_to_store_registers_ops;
> +static void (*record_beneath_to_store_registers) (struct target_ops *,
> +                                                  struct regcache *,
> +                                                 int regno);
> +static struct target_ops *record_beneath_to_xfer_partial_ops;
> +static LONGEST (*record_beneath_to_xfer_partial) (struct target_ops *ops,
> +                                                 enum target_object object,
> +                                                 const char *annex,
> +                                                 gdb_byte *readbuf,
> +                                                 const gdb_byte *writebuf,
> +                                                 ULONGEST offset,
> +                                                 LONGEST len);
> +static int (*record_beneath_to_insert_breakpoint) (struct bp_target_info *);
> +static int (*record_beneath_to_remove_breakpoint) (struct bp_target_info *);
> +
> +static void
> +record_list_release (struct record_entry *rec)
> +{
> +  struct record_entry *tmp;
> +
> +  if (!rec)
> +    return;
> +
> +  while (rec->next)
> +    {
> +      rec = rec->next;
> +    }
> +
> +  while (rec->prev)
> +    {
> +      tmp = rec;
> +      rec = rec->prev;
> +      if (tmp->type == record_reg)
> +       xfree (tmp->u.reg.val);
> +      else if (tmp->type == record_mem)
> +       xfree (tmp->u.mem.val);
> +      xfree (tmp);
> +    }
> +
> +  if (rec != &record_first)
> +    xfree (rec);
> +}
> +
> +static void
> +record_list_release_next (void)
> +{
> +  struct record_entry *rec = record_list;
> +  struct record_entry *tmp = rec->next;
> +  rec->next = NULL;
> +  while (tmp)
> +    {
> +      rec = tmp->next;
> +      if (tmp->type == record_reg)
> +       record_insn_num--;
> +      else if (tmp->type == record_reg)
> +       xfree (tmp->u.reg.val);
> +      else if (tmp->type == record_mem)
> +       xfree (tmp->u.mem.val);
> +      xfree (tmp);
> +      tmp = rec;
> +    }
> +}
> +
> +static void
> +record_list_release_first (void)
> +{
> +  struct record_entry *tmp = NULL;
> +  enum record_type type;
> +
> +  if (!record_first.next)
> +    return;
> +
> +  while (1)
> +    {
> +      type = record_first.next->type;
> +
> +      if (type == record_reg)
> +       xfree (record_first.next->u.reg.val);
> +      else if (type == record_mem)
> +       xfree (record_first.next->u.mem.val);
> +      tmp = record_first.next;
> +      record_first.next = tmp->next;
> +      xfree (tmp);
> +
> +      if (!record_first.next)
> +       {
> +         gdb_assert (record_insn_num == 1);
> +         break;
> +       }
> +
> +      record_first.next->prev = &record_first;
> +
> +      if (type == record_end)
> +       break;
> +    }
> +
> +  record_insn_num--;
> +}
> +
> +/* Add a struct record_entry to record_arch_list.  */
> +
> +static void
> +record_arch_list_add (struct record_entry *rec)
> +{
> +  if (record_debug > 1)
> +    fprintf_unfiltered (gdb_stdlog,
> +                       "Process record: record_arch_list_add %s.\n",
> +                       host_address_to_string (rec));
> +
> +  if (record_arch_list_tail)
> +    {
> +      record_arch_list_tail->next = rec;
> +      rec->prev = record_arch_list_tail;
> +      record_arch_list_tail = rec;
> +    }
> +  else
> +    {
> +      record_arch_list_head = rec;
> +      record_arch_list_tail = rec;
> +    }
> +}
> +
> +/* Record the value of a register NUM to record_arch_list.  */
> +
> +int
> +record_arch_list_add_reg (struct regcache *regcache, int num)
> +{
> +  struct record_entry *rec;
> +
> +  if (record_debug > 1)
> +    fprintf_unfiltered (gdb_stdlog,
> +                       "Process record: add register num = %d to "
> +                       "record list.\n",
> +                       num);
> +
> +  rec = (struct record_entry *) xmalloc (sizeof (struct record_entry));
> +  rec->u.reg.val = (gdb_byte *) xmalloc (MAX_REGISTER_SIZE);
> +  rec->prev = NULL;
> +  rec->next = NULL;
> +  rec->type = record_reg;
> +  rec->u.reg.num = num;
> +
> +  regcache_raw_read (regcache, num, rec->u.reg.val);
> +
> +  record_arch_list_add (rec);
> +
> +  return 0;
> +}
> +
> +/* Record the value of a region of memory whose address is ADDR and
> +   length is LEN to record_arch_list.  */
> +
> +int
> +record_arch_list_add_mem (CORE_ADDR addr, int len)
> +{
> +  struct record_entry *rec;
> +
> +  if (record_debug > 1)
> +    fprintf_unfiltered (gdb_stdlog,
> +                       "Process record: add mem addr = 0x%s len = %d to "
> +                       "record list.\n",
> +                       paddr_nz (addr), len);
> +
> +  if (!addr)
> +    return 0;
> +
> +  rec = (struct record_entry *) xmalloc (sizeof (struct record_entry));
> +  rec->u.mem.val = (gdb_byte *) xmalloc (len);
> +  rec->prev = NULL;
> +  rec->next = NULL;
> +  rec->type = record_mem;
> +  rec->u.mem.addr = addr;
> +  rec->u.mem.len = len;
> +
> +  if (target_read_memory (addr, rec->u.mem.val, len))
> +    {
> +      if (record_debug)
> +       fprintf_unfiltered (gdb_stdlog,
> +                           "Process record: error reading memory at "
> +                           "addr = 0x%s len = %d.\n",
> +                           paddr_nz (addr), len);
> +      xfree (rec->u.mem.val);
> +      xfree (rec);
> +      return -1;
> +    }
> +
> +  record_arch_list_add (rec);
> +
> +  return 0;
> +}
> +
> +/* Add a record_end type struct record_entry to record_arch_list.  */
> +
> +int
> +record_arch_list_add_end (void)
> +{
> +  struct record_entry *rec;
> +
> +  if (record_debug > 1)
> +    fprintf_unfiltered (gdb_stdlog,
> +                       "Process record: add end to arch list.\n");
> +
> +  rec = (struct record_entry *) xmalloc (sizeof (struct record_entry));
> +  rec->prev = NULL;
> +  rec->next = NULL;
> +  rec->type = record_end;
> +
> +  record_arch_list_add (rec);
> +
> +  return 0;
> +}
> +
> +static void
> +record_check_insn_num (int set_terminal)
> +{
> +  if (record_insn_max_num)
> +    {
> +      gdb_assert (record_insn_num <= record_insn_max_num);
> +      if (record_insn_num == record_insn_max_num)
> +       {
> +         /* Ask user what to do.  */
> +         if (record_stop_at_limit)
> +           {
> +             int q;
> +             if (set_terminal)
> +               target_terminal_ours ();
> +             q = yquery (_("Do you want to auto delete previous execution "
> +                           "log entries when record/replay buffer becomes "
> +                           "full (record stop-at-limit)?"));
> +             if (set_terminal)
> +               target_terminal_inferior ();
> +             if (q)
> +               record_stop_at_limit = 0;
> +             else
> +               error (_("Process record: inferior program stopped."));
> +           }
> +       }
> +    }
> +}
> +
> +/* Before inferior step (when GDB record the running message, inferior
> +   only can step), GDB will call this function to record the values to
> +   record_list.  This function will call gdbarch_process_record to
> +   record the running message of inferior and set them to
> +   record_arch_list, and add it to record_list.  */
> +
> +static void
> +record_message_cleanups (void *ignore)
> +{
> +  record_list_release (record_arch_list_tail);
> +}
> +
> +static int
> +record_message (void *args)
> +{
> +  int ret;
> +  struct regcache *regcache = args;
> +  struct cleanup *old_cleanups = make_cleanup (record_message_cleanups, 0);
> +
> +  record_arch_list_head = NULL;
> +  record_arch_list_tail = NULL;
> +
> +  /* Check record_insn_num.  */
> +  record_check_insn_num (1);
> +
> +  ret = gdbarch_process_record (get_regcache_arch (regcache),
> +                               regcache,
> +                               regcache_read_pc (regcache));
> +  if (ret > 0)
> +    error (_("Process record: inferior program stopped."));
> +  if (ret < 0)
> +    error (_("Process record: failed to record execution log."));
> +
> +  discard_cleanups (old_cleanups);
> +
> +  record_list->next = record_arch_list_head;
> +  record_arch_list_head->prev = record_list;
> +  record_list = record_arch_list_tail;
> +
> +  if (record_insn_num == record_insn_max_num && record_insn_max_num)
> +    record_list_release_first ();
> +  else
> +    record_insn_num++;
> +
> +  return 1;
> +}
> +
> +static int
> +do_record_message (struct regcache *regcache)
> +{
> +  return catch_errors (record_message, regcache, NULL, RETURN_MASK_ALL);
> +}
> +
> +/* Set to 1 if record_store_registers and record_xfer_partial
> +   doesn't need record.  */
> +
> +static int record_gdb_operation_disable = 0;
> +
> +struct cleanup *
> +record_gdb_operation_disable_set (void)
> +{
> +  struct cleanup *old_cleanups = NULL;
> +
> +  old_cleanups =
> +    make_cleanup_restore_integer (&record_gdb_operation_disable);
> +  record_gdb_operation_disable = 1;
> +
> +  return old_cleanups;
> +}
> +
> +static void
> +record_open (char *name, int from_tty)
> +{
> +  struct target_ops *t;
> +
> +  if (record_debug)
> +    fprintf_unfiltered (gdb_stdlog, "Process record: record_open\n");
> +
> +  /* check exec */
> +  if (!target_has_execution)
> +    error (_("Process record: the program is not being run."));
> +  if (non_stop)
> +    error (_("Process record target can't debug inferior in non-stop mode "
> +            "(non-stop)."));
> +  if (target_async_permitted)
> +    error (_("Process record target can't debug inferior in asynchronous "
> +            "mode (target-async)."));
> +
> +  if (!gdbarch_process_record_p (current_gdbarch))
> +    error (_("Process record: the current architecture doesn't support "
> +            "record function."));
> +
> +  /* Check if record target is already running.  */
> +  if (current_target.to_stratum == record_stratum)
> +    {
> +      if (!nquery
> +         (_("Process record target already running, do you want to delete "
> +            "the old record log?")))
> +       return;
> +    }
> +
> +  /*Reset the beneath function pointers.  */
> +  record_beneath_to_resume = NULL;
> +  record_beneath_to_wait = NULL;
> +  record_beneath_to_store_registers = NULL;
> +  record_beneath_to_xfer_partial = NULL;
> +  record_beneath_to_insert_breakpoint = NULL;
> +  record_beneath_to_remove_breakpoint = NULL;
> +
> +  /* Set the beneath function pointers.  */
> +  for (t = current_target.beneath; t != NULL; t = t->beneath)
> +    {
> +      if (!record_beneath_to_resume)
> +        {
> +         record_beneath_to_resume = t->to_resume;
> +         record_beneath_to_resume_ops = t;
> +        }
> +      if (!record_beneath_to_wait)
> +        {
> +         record_beneath_to_wait = t->to_wait;
> +         record_beneath_to_wait_ops = t;
> +        }
> +      if (!record_beneath_to_store_registers)
> +        {
> +         record_beneath_to_store_registers = t->to_store_registers;
> +         record_beneath_to_store_registers_ops = t;
> +        }
> +      if (!record_beneath_to_xfer_partial)
> +        {
> +         record_beneath_to_xfer_partial = t->to_xfer_partial;
> +         record_beneath_to_xfer_partial_ops = t;
> +        }
> +      if (!record_beneath_to_insert_breakpoint)
> +       record_beneath_to_insert_breakpoint = t->to_insert_breakpoint;
> +      if (!record_beneath_to_remove_breakpoint)
> +       record_beneath_to_remove_breakpoint = t->to_remove_breakpoint;
> +    }
> +  if (!record_beneath_to_resume)
> +    error (_("Process record can't get to_resume."));
> +  if (!record_beneath_to_wait)
> +    error (_("Process record can't get to_wait."));
> +  if (!record_beneath_to_store_registers)
> +    error (_("Process record can't get to_store_registers."));
> +  if (!record_beneath_to_xfer_partial)
> +    error (_("Process record can't get to_xfer_partial."));
> +  if (!record_beneath_to_insert_breakpoint)
> +    error (_("Process record can't get to_insert_breakpoint."));
> +  if (!record_beneath_to_remove_breakpoint)
> +    error (_("Process record can't get to_remove_breakpoint."));
> +
> +  push_target (&record_ops);
> +
> +  /* Reset */
> +  record_insn_num = 0;
> +  record_list = &record_first;
> +  record_list->next = NULL;
> +}
> +
> +static void
> +record_close (int quitting)
> +{
> +  if (record_debug)
> +    fprintf_unfiltered (gdb_stdlog, "Process record: record_close\n");
> +
> +  record_list_release (record_list);
> +}
> +
> +static int record_resume_step = 0;
> +static enum target_signal record_resume_siggnal;
> +static int record_resume_error;
> +
> +static void
> +record_resume (struct target_ops *ops, ptid_t ptid, int step,
> +               enum target_signal siggnal)
> +{
> +  record_resume_step = step;
> +  record_resume_siggnal = siggnal;
> +
> +  if (!RECORD_IS_REPLAY)
> +    {
> +      if (do_record_message (get_current_regcache ()))
> +        {
> +          record_resume_error = 0;
> +        }
> +      else
> +        {
> +          record_resume_error = 1;
> +          return;
> +        }
> +      record_beneath_to_resume (record_beneath_to_resume_ops, ptid, 1,
> +                                siggnal);
> +    }
> +}
> +
> +static int record_get_sig = 0;
> +
> +static void
> +record_sig_handler (int signo)
> +{
> +  if (record_debug)
> +    fprintf_unfiltered (gdb_stdlog, "Process record: get a signal\n");
> +
> +  /* It will break the running inferior in replay mode.  */
> +  record_resume_step = 1;
> +
> +  /* It will let record_wait set inferior status to get the signal
> +     SIGINT.  */
> +  record_get_sig = 1;
> +}
> +
> +static void
> +record_wait_cleanups (void *ignore)
> +{
> +  if (execution_direction == EXEC_REVERSE)
> +    {
> +      if (record_list->next)
> +       record_list = record_list->next;
> +    }
> +  else
> +    record_list = record_list->prev;
> +}
> +
> +/* In replay mode, this function examines the recorded log and
> +   determines where to stop.  */
> +
> +static ptid_t
> +record_wait (struct target_ops *ops,
> +              ptid_t ptid, struct target_waitstatus *status)
> +{
> +  struct cleanup *set_cleanups = record_gdb_operation_disable_set ();
> +
> +  if (record_debug)
> +    fprintf_unfiltered (gdb_stdlog,
> +                       "Process record: record_wait "
> +                       "record_resume_step = %d\n",
> +                       record_resume_step);
> +
> +  if (!RECORD_IS_REPLAY)
> +    {
> +      if (record_resume_error)
> +       {
> +         /* If record_resume get error, return directly.  */
> +         status->kind = TARGET_WAITKIND_STOPPED;
> +         status->value.sig = TARGET_SIGNAL_TRAP;
> +         return inferior_ptid;
> +       }
> +
> +      if (record_resume_step)
> +       {
> +         /* This is a single step.  */
> +         return record_beneath_to_wait (record_beneath_to_wait_ops,
> +                                                      ptid, status);
> +       }
> +      else
> +       {
> +         /* This is not a single step.  */
> +         ptid_t ret;
> +         CORE_ADDR tmp_pc;
> +
> +         while (1)
> +           {
> +             ret = record_beneath_to_wait (record_beneath_to_wait_ops,
> +                                           ptid, status);
> +
> +             if (status->kind == TARGET_WAITKIND_STOPPED
> +                 && status->value.sig == TARGET_SIGNAL_TRAP)
> +               {
> +                 /* Check if there is a breakpoint.  */
> +                 registers_changed ();
> +                 tmp_pc = read_pc ();
> +                 if (breakpoint_inserted_here_p (tmp_pc))
> +                   {
> +                     /* There is a breakpoint.  */
> +                     CORE_ADDR decr_pc_after_break =
> +                       gdbarch_decr_pc_after_break
> +                       (get_regcache_arch (get_current_regcache ()));
> +                     if (decr_pc_after_break)
> +                       {
> +                         regcache_write_pc (get_thread_regcache (ret),
> +                                            tmp_pc + decr_pc_after_break);
> +                       }
> +                   }
> +                 else
> +                   {
> +                     /* There is not a breakpoint.  */
> +                     if (!do_record_message (get_current_regcache ()))
> +                       {
> +                          break;
> +                       }
> +                     record_beneath_to_resume (record_beneath_to_resume_ops,
> +                                               ptid, 1,
> +                                               record_resume_siggnal);
> +                     continue;
> +                   }
> +               }
> +
> +             /* The inferior is broken by a breakpoint or a signal.  */
> +             break;
> +           }
> +
> +         return ret;
> +       }
> +    }
> +  else
> +    {
> +      struct regcache *regcache = get_current_regcache ();
> +      int continue_flag = 1;
> +      int first_record_end = 1;
> +      struct cleanup *old_cleanups = make_cleanup (record_wait_cleanups, 0);
> +      CORE_ADDR tmp_pc;
> +
> +      status->kind = TARGET_WAITKIND_STOPPED;
> +
> +      /* Check breakpoint when forward execute.  */
> +      if (execution_direction == EXEC_FORWARD)
> +       {
> +         tmp_pc = regcache_read_pc (regcache);
> +         if (breakpoint_inserted_here_p (tmp_pc))
> +           {
> +             if (record_debug)
> +               fprintf_unfiltered (gdb_stdlog,
> +                                   "Process record: break at 0x%s.\n",
> +                                   paddr_nz (tmp_pc));
> +             if (gdbarch_decr_pc_after_break (get_regcache_arch (regcache))
> +                 && !record_resume_step)
> +               regcache_write_pc (regcache,
> +                                  tmp_pc +
> +                                  gdbarch_decr_pc_after_break
> +                                  (get_regcache_arch (regcache)));
> +             goto replay_out;
> +           }
> +       }
> +
> +      record_get_sig = 0;
> +      signal (SIGINT, record_sig_handler);
> +      /* If GDB is in terminal_inferior mode, it will not get the signal.
> +         And in GDB replay mode, GDB doesn't need to be in terminal_inferior
> +         mode, because inferior will not executed.
> +         Then set it to terminal_ours to make GDB get the signal.  */
> +      target_terminal_ours ();
> +
> +      /* In EXEC_FORWARD mode, record_list points to the tail of prev
> +         instruction.  */
> +      if (execution_direction == EXEC_FORWARD && record_list->next)
> +       record_list = record_list->next;
> +
> +      /* Loop over the record_list, looking for the next place to
> +        stop.  */
> +      do
> +       {
> +         /* Check for beginning and end of log.  */
> +         if (execution_direction == EXEC_REVERSE
> +             && record_list == &record_first)
> +           {
> +             /* Hit beginning of record log in reverse.  */
> +             status->kind = TARGET_WAITKIND_NO_HISTORY;
> +             break;
> +           }
> +         if (execution_direction != EXEC_REVERSE && !record_list->next)
> +           {
> +             /* Hit end of record log going forward.  */
> +             status->kind = TARGET_WAITKIND_NO_HISTORY;
> +             break;
> +           }
> +
> +         /* Set ptid, register and memory according to record_list.  */
> +         if (record_list->type == record_reg)
> +           {
> +             /* reg */
> +             gdb_byte reg[MAX_REGISTER_SIZE];
> +             if (record_debug > 1)
> +               fprintf_unfiltered (gdb_stdlog,
> +                                   "Process record: record_reg %s to "
> +                                   "inferior num = %d.\n",
> +                                   host_address_to_string (record_list),
> +                                   record_list->u.reg.num);
> +             regcache_cooked_read (regcache, record_list->u.reg.num, reg);
> +             regcache_cooked_write (regcache, record_list->u.reg.num,
> +                                    record_list->u.reg.val);
> +             memcpy (record_list->u.reg.val, reg, MAX_REGISTER_SIZE);
> +           }
> +         else if (record_list->type == record_mem)
> +           {
> +             /* mem */
> +             gdb_byte *mem = alloca (record_list->u.mem.len);
> +             if (record_debug > 1)
> +               fprintf_unfiltered (gdb_stdlog,
> +                                   "Process record: record_mem %s to "
> +                                   "inferior addr = 0x%s len = %d.\n",
> +                                   host_address_to_string (record_list),
> +                                   paddr_nz (record_list->u.mem.addr),
> +                                   record_list->u.mem.len);
> +
> +             if (target_read_memory
> +                 (record_list->u.mem.addr, mem, record_list->u.mem.len))
> +               error (_("Process record: error reading memory at "
> +                        "addr = 0x%s len = %d."),
> +                      paddr_nz (record_list->u.mem.addr),
> +                      record_list->u.mem.len);
> +
> +             if (target_write_memory
> +                 (record_list->u.mem.addr, record_list->u.mem.val,
> +                  record_list->u.mem.len))
> +               error (_
> +                      ("Process record: error writing memory at "
> +                       "addr = 0x%s len = %d."),
> +                      paddr_nz (record_list->u.mem.addr),
> +                      record_list->u.mem.len);
> +
> +             memcpy (record_list->u.mem.val, mem, record_list->u.mem.len);
> +           }
> +         else
> +           {
> +             if (record_debug > 1)
> +               fprintf_unfiltered (gdb_stdlog,
> +                                   "Process record: record_end %s to "
> +                                   "inferior.\n",
> +                                   host_address_to_string (record_list));
> +
> +             if (first_record_end && execution_direction == EXEC_REVERSE)
> +               {
> +                 /* When reverse excute, the first record_end is the part of
> +                    current instruction.  */
> +                 first_record_end = 0;
> +               }
> +             else
> +               {
> +                 /* In EXEC_REVERSE mode, this is the record_end of prev
> +                    instruction.
> +                    In EXEC_FORWARD mode, this is the record_end of current
> +                    instruction.  */
> +                 /* step */
> +                 if (record_resume_step)
> +                   {
> +                     if (record_debug > 1)
> +                       fprintf_unfiltered (gdb_stdlog,
> +                                           "Process record: step.\n");
> +                     continue_flag = 0;
> +                   }
> +
> +                 /* check breakpoint */
> +                 tmp_pc = regcache_read_pc (regcache);
> +                 if (breakpoint_inserted_here_p (tmp_pc))
> +                   {
> +                     if (record_debug)
> +                       fprintf_unfiltered (gdb_stdlog,
> +                                           "Process record: break "
> +                                           "at 0x%s.\n",
> +                                           paddr_nz (tmp_pc));
> +                     if (gdbarch_decr_pc_after_break (get_regcache_arch (regcache))
> +                         && execution_direction == EXEC_FORWARD
> +                         && !record_resume_step)
> +                       regcache_write_pc (regcache,
> +                                          tmp_pc +
> +                                          gdbarch_decr_pc_after_break
> +                                          (get_regcache_arch (regcache)));
> +                     continue_flag = 0;
> +                   }
> +               }
> +           }
> +
> +         if (continue_flag)
> +           {
> +             if (execution_direction == EXEC_REVERSE)
> +               {
> +                 if (record_list->prev)
> +                   record_list = record_list->prev;
> +               }
> +             else
> +               {
> +                 if (record_list->next)
> +                   record_list = record_list->next;
> +               }
> +           }
> +       }
> +      while (continue_flag);
> +
> +      signal (SIGINT, handle_sigint);
> +
> +replay_out:
> +      if (record_get_sig)
> +       status->value.sig = TARGET_SIGNAL_INT;
> +      else
> +       status->value.sig = TARGET_SIGNAL_TRAP;
> +
> +      discard_cleanups (old_cleanups);
> +    }
> +
> +  do_cleanups (set_cleanups);
> +  return inferior_ptid;
> +}
> +
> +static void
> +record_disconnect (struct target_ops *target, char *args, int from_tty)
> +{
> +  if (record_debug)
> +    fprintf_unfiltered (gdb_stdlog, "Process record: record_disconnect\n");
> +
> +  unpush_target (&record_ops);
> +  target_disconnect (args, from_tty);
> +}
> +
> +static void
> +record_detach (struct target_ops *ops, char *args, int from_tty)
> +{
> +  if (record_debug)
> +    fprintf_unfiltered (gdb_stdlog, "Process record: record_detach\n");
> +
> +  unpush_target (&record_ops);
> +  target_detach (args, from_tty);
> +}
> +
> +static void
> +record_mourn_inferior (struct target_ops *ops)
> +{
> +  if (record_debug)
> +    fprintf_unfiltered (gdb_stdlog, "Process record: "
> +                                   "record_mourn_inferior\n");
> +
> +  unpush_target (&record_ops);
> +  target_mourn_inferior ();
> +}
> +
> +/* Close process record target before killing the inferior process.  */
> +
> +static void
> +record_kill (struct target_ops *ops)
> +{
> +  if (record_debug)
> +    fprintf_unfiltered (gdb_stdlog, "Process record: record_kill\n");
> +
> +  unpush_target (&record_ops);
> +  target_kill ();
> +}
> +
> +/* Record registers change (by user or by GDB) to list as an instruction.  */
> +
> +static void
> +record_registers_change (struct regcache *regcache, int regnum)
> +{
> +  /* Check record_insn_num.  */
> +  record_check_insn_num (0);
> +
> +  record_arch_list_head = NULL;
> +  record_arch_list_tail = NULL;
> +
> +  if (regnum < 0)
> +    {
> +      int i;
> +      for (i = 0; i < gdbarch_num_regs (get_regcache_arch (regcache)); i++)
> +       {
> +         if (record_arch_list_add_reg (regcache, i))
> +           {
> +             record_list_release (record_arch_list_tail);
> +             error (_("Process record: failed to record execution log."));
> +           }
> +       }
> +    }
> +  else
> +    {
> +      if (record_arch_list_add_reg (regcache, regnum))
> +       {
> +         record_list_release (record_arch_list_tail);
> +         error (_("Process record: failed to record execution log."));
> +       }
> +    }
> +  if (record_arch_list_add_end ())
> +    {
> +      record_list_release (record_arch_list_tail);
> +      error (_("Process record: failed to record execution log."));
> +    }
> +  record_list->next = record_arch_list_head;
> +  record_arch_list_head->prev = record_list;
> +  record_list = record_arch_list_tail;
> +
> +  if (record_insn_num == record_insn_max_num && record_insn_max_num)
> +    record_list_release_first ();
> +  else
> +    record_insn_num++;
> +}
> +
> +static void
> +record_store_registers (struct target_ops *ops, struct regcache *regcache,
> +                        int regno)
> +{
> +  if (!record_gdb_operation_disable)
> +    {
> +      if (RECORD_IS_REPLAY)
> +       {
> +         int n;
> +         struct cleanup *old_cleanups;
> +
> +         /* Let user choose if he wants to write register or not.  */
> +         if (regno < 0)
> +           n =
> +             nquery (_("Because GDB is in replay mode, changing the "
> +                       "value of a register will make the execution "
> +                       "log unusable from this point onward.  "
> +                       "Change all registers?"));
> +         else
> +           n =
> +             nquery (_("Because GDB is in replay mode, changing the value "
> +                       "of a register will make the execution log unusable "
> +                       "from this point onward.  Change register %s?"),
> +                     gdbarch_register_name (get_regcache_arch (regcache),
> +                                              regno));
> +
> +         if (!n)
> +           {
> +             /* Invalidate the value of regcache that was set in function
> +                "regcache_raw_write".  */
> +             if (regno < 0)
> +               {
> +                 int i;
> +                 for (i = 0;
> +                      i < gdbarch_num_regs (get_regcache_arch (regcache));
> +                      i++)
> +                   regcache_invalidate (regcache, i);
> +               }
> +             else
> +               regcache_invalidate (regcache, regno);
> +
> +             error (_("Process record canceled the operation."));
> +           }
> +
> +         /* Destroy the record from here forward.  */
> +         record_list_release_next ();
> +       }
> +
> +      record_registers_change (regcache, regno);
> +    }
> +  record_beneath_to_store_registers (record_beneath_to_store_registers_ops,
> +                                     regcache, regno);
> +}
> +
> +/* Behavior is conditional on RECORD_IS_REPLAY.
> +   In replay mode, we cannot write memory unles we are willing to
> +   invalidate the record/replay log from this point forward.  */
> +
> +static LONGEST
> +record_xfer_partial (struct target_ops *ops, enum target_object object,
> +                    const char *annex, gdb_byte *readbuf,
> +                    const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
> +{
> +  if (!record_gdb_operation_disable
> +      && (object == TARGET_OBJECT_MEMORY
> +         || object == TARGET_OBJECT_RAW_MEMORY) && writebuf)
> +    {
> +      if (RECORD_IS_REPLAY)
> +       {
> +         /* Let user choose if he wants to write memory or not.  */
> +         if (!nquery (_("Because GDB is in replay mode, writing to memory "
> +                        "will make the execution log unusable from this "
> +                        "point onward.  Write memory at address 0x%s?"),
> +                      paddr_nz (offset)))
> +           return -1;
> +
> +         /* Destroy the record from here forward.  */
> +         record_list_release_next ();
> +       }
> +
> +      /* Check record_insn_num */
> +      record_check_insn_num (0);
> +
> +      /* Record registers change to list as an instruction.  */
> +      record_arch_list_head = NULL;
> +      record_arch_list_tail = NULL;
> +      if (record_arch_list_add_mem (offset, len))
> +       {
> +         record_list_release (record_arch_list_tail);
> +         if (record_debug)
> +           fprintf_unfiltered (gdb_stdlog,
> +                               _("Process record: failed to record "
> +                                 "execution log."));
> +         return -1;
> +       }
> +      if (record_arch_list_add_end ())
> +       {
> +         record_list_release (record_arch_list_tail);
> +         if (record_debug)
> +           fprintf_unfiltered (gdb_stdlog,
> +                               _("Process record: failed to record "
> +                                 "execution log."));
> +         return -1;
> +       }
> +      record_list->next = record_arch_list_head;
> +      record_arch_list_head->prev = record_list;
> +      record_list = record_arch_list_tail;
> +
> +      if (record_insn_num == record_insn_max_num && record_insn_max_num)
> +       record_list_release_first ();
> +      else
> +       record_insn_num++;
> +    }
> +
> +  return record_beneath_to_xfer_partial (record_beneath_to_xfer_partial_ops,
> +                                         object, annex, readbuf, writebuf,
> +                                         offset, len);
> +}
> +
> +/* Behavior is conditional on RECORD_IS_REPLAY.
> +   We will not actually insert or remove breakpoints when replaying,
> +   nor when recording.  */
> +
> +static int
> +record_insert_breakpoint (struct bp_target_info *bp_tgt)
> +{
> +  if (!RECORD_IS_REPLAY)
> +    {
> +      struct cleanup *old_cleanups = record_gdb_operation_disable_set ();
> +      int ret = record_beneath_to_insert_breakpoint (bp_tgt);
> +
> +      do_cleanups (old_cleanups);
> +
> +      return ret;
> +    }
> +
> +  return 0;
> +}
> +
> +static int
> +record_remove_breakpoint (struct bp_target_info *bp_tgt)
> +{
> +  if (!RECORD_IS_REPLAY)
> +    {
> +      struct cleanup *old_cleanups = record_gdb_operation_disable_set ();
> +      int ret = record_beneath_to_remove_breakpoint (bp_tgt);
> +
> +      do_cleanups (old_cleanups);
> +
> +      return ret;
> +    }
> +
> +  return 0;
> +}
> +
> +static int
> +record_can_execute_reverse (void)
> +{
> +  return 1;
> +}
> +
> +static void
> +init_record_ops (void)
> +{
> +  record_ops.to_shortname = "record";
> +  record_ops.to_longname = "Process record and replay target";
> +  record_ops.to_doc =
> +    "Log program while executing and replay execution from log.";
> +  record_ops.to_open = record_open;
> +  record_ops.to_close = record_close;
> +  record_ops.to_resume = record_resume;
> +  record_ops.to_wait = record_wait;
> +  record_ops.to_disconnect = record_disconnect;
> +  record_ops.to_detach = record_detach;
> +  record_ops.to_mourn_inferior = record_mourn_inferior;
> +  record_ops.to_kill = record_kill;
> +  record_ops.to_create_inferior = find_default_create_inferior;
> +  record_ops.to_store_registers = record_store_registers;
> +  record_ops.to_xfer_partial = record_xfer_partial;
> +  record_ops.to_insert_breakpoint = record_insert_breakpoint;
> +  record_ops.to_remove_breakpoint = record_remove_breakpoint;
> +  record_ops.to_can_execute_reverse = record_can_execute_reverse;
> +  record_ops.to_stratum = record_stratum;
> +  record_ops.to_magic = OPS_MAGIC;
> +}
> +
> +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 ("target record", 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)
> +{
> +  if (current_target.to_stratum == record_stratum)
> +    {
> +      if (RECORD_IS_REPLAY)
> +       {
> +         if (!from_tty || query (_("Delete the log from this point forward "
> +                                   "and begin to record the running message "
> +                                   "at current PC?")))
> +           record_list_release_next ();
> +       }
> +      else
> +         printf_unfiltered (_("Already at end of record list.\n"));
> +
> +    }
> +  else
> +    printf_unfiltered (_("Process record is not started.\n"));
> +}
> +
> +/* Implement the "stoprecord" command.  */
> +
> +static void
> +cmd_record_stop (char *args, int from_tty)
> +{
> +  if (current_target.to_stratum == record_stratum)
> +    {
> +      if (!record_list || !from_tty || query (_("Delete recorded log and "
> +                                               "stop recording?")))
> +       unpush_target (&record_ops);
> +    }
> +  else
> +    printf_unfiltered (_("Process record is not started.\n"));
> +}
> +
> +/* Set upper limit of record log size.  */
> +
> +static void
> +set_record_insn_max_num (char *args, int from_tty, struct cmd_list_element *c)
> +{
> +  if (record_insn_num > record_insn_max_num && record_insn_max_num)
> +    {
> +      printf_unfiltered (_("Record instructions number is bigger than "
> +                          "record instructions max number.  Auto delete "
> +                          "the first ones?\n"));
> +
> +      while (record_insn_num > record_insn_max_num)
> +       record_list_release_first ();
> +    }
> +}
> +
> +/* Print the current index into the record log (number of insns recorded
> +   so far).  */
> +
> +static void
> +show_record_insn_number (char *ignore, int from_tty)
> +{
> +  printf_unfiltered (_("Record instruction number is %d.\n"),
> +                    record_insn_num);
> +}
> +
> +static struct cmd_list_element *record_cmdlist, *set_record_cmdlist,
> +                              *show_record_cmdlist, *info_record_cmdlist;
> +
> +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);
> +}
> +
> +static void
> +show_record_command (char *args, int from_tty)
> +{
> +  cmd_show_list (show_record_cmdlist, from_tty, "");
> +}
> +
> +static void
> +info_record_command (char *args, int from_tty)
> +{
> +  cmd_show_list (info_record_cmdlist, from_tty, "");
> +}
> +
> +void
> +_initialize_record (void)
> +{
> +  /* Init record_first.  */
> +  record_first.prev = NULL;
> +  record_first.next = NULL;
> +  record_first.type = record_end;
> +
> +  init_record_ops ();
> +  add_target (&record_ops);
> +
> +  add_setshow_zinteger_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_prefix_cmd ("record", class_obscure, cmd_record_start,
> +                 _("Abbreviated form of \"target record\" command."),
> +                 &record_cmdlist, "record ", 0, &cmdlist);
> +  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);
> +
> +
> +  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);
> +
> +  /* Record instructions number limit command.  */
> +  add_setshow_boolean_cmd ("stop-at-limit", no_class,
> +                           &record_stop_at_limit,
> +                           _("Set whether record/replay stop when "
> +                             "record/replay buffer becomes full."),
> +                           _("Show whether record/replay stop when "
> +                             "record/replay buffer becomes full."),
> +                           _("Enable is default value.\n"
> +                             "When enabled, if the record/replay buffer "
> +                             "becomes full,\n"
> +                              "ask user what to do.\n"
> +                              "When disabled, if the record/replay buffer "
> +                             "becomes full,\n"
> +                              "delete it and start new recording."),
> +                           NULL, NULL,
> +                            &set_record_cmdlist, &show_record_cmdlist);
> +  add_setshow_zinteger_cmd ("insn-number-max", no_class,
> +                           &record_insn_max_num,
> +                           _("Set record/replay buffer limit."),
> +                           _("Show record/replay buffer limit."),
> +                           _("Set the maximum number of instructions to be "
> +                              "stored in the\n"
> +                              "record/replay buffer.  "
> +                              "Zero means unlimited (default 200000)."),
> +                           set_record_insn_max_num,
> +                           NULL, &set_record_cmdlist, &show_record_cmdlist);
> +  add_cmd ("insn-number", class_obscure, show_record_insn_number,
> +           _("Show the current number of instructions in the "
> +             "record/replay buffer."), &info_record_cmdlist);
> +}
> --- /dev/null
> +++ b/record.h
> @@ -0,0 +1,32 @@
> +/* Process record and replay target for GDB, the GNU debugger.
> +
> +   Copyright (C) 2008, 2009 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/>.  */
> +
> +#ifndef _RECORD_H_
> +#define _RECORD_H_
> +
> +#define RECORD_IS_USED (current_target.to_stratum == record_stratum)
> +
> +extern int record_debug;
> +
> +extern int record_arch_list_add_reg (struct regcache *regcache, int num);
> +extern int record_arch_list_add_mem (CORE_ADDR addr, int len);
> +extern int record_arch_list_add_end (void);
> +extern struct cleanup *record_gdb_operation_disable_set (void);
> +
> +#endif /* _RECORD_H_ */
>