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

[Pedro Alves <pedro@codesourcery.com>]

On Monday 27 April 2009 07:00:48, Hui Zhu wrote:
> Hi Pedro,
> 
> Could you please help me review this patch?

Thank you very much.  This version is approved.  Please don't forget
a ChangeLog entry thought; I don't think I saw one.

> 
> 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_ */
> >
> 



-- 
Pedro Alves