Subversion Repositories openrisc_2011-10-31

/* Reverse execution and reverse debugging.

   Copyright (C) 2006, 2007, 2008, 2009, 2010 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 "gdb_string.h"

#include "target.h"

#include "top.h"

#include "cli/cli-cmds.h"

#include "cli/cli-decode.h"

#include "inferior.h"

#include "regcache.h"

/* User interface:

   reverse-step, reverse-next etc.  */

static void

exec_direction_default (void *notused)

{

  /* Return execution direction to default state.  */

  execution_direction = EXEC_FORWARD;

}

/* exec_reverse_once -- accepts an arbitrary gdb command (string),

   and executes it with exec-direction set to 'reverse'.

   Used to implement reverse-next etc. commands.  */

static void

exec_reverse_once (char *cmd, char *args, int from_tty)

{

  char *reverse_command;

  enum exec_direction_kind dir = execution_direction;

  struct cleanup *old_chain;

  if (dir == EXEC_ERROR)

    error (_("Target %s does not support this command."), target_shortname);

  if (dir == EXEC_REVERSE)

    error (_("Already in reverse mode.  Use '%s' or 'set exec-dir forward'."),

           cmd);

  if (!target_can_execute_reverse)

    error (_("Target %s does not support this command."), target_shortname);

  reverse_command = xstrprintf ("%s %s", cmd, args ? args : "");

  old_chain = make_cleanup (exec_direction_default, NULL);

  make_cleanup (xfree, reverse_command);

  execution_direction = EXEC_REVERSE;

  execute_command (reverse_command, from_tty);

  do_cleanups (old_chain);

}

static void

reverse_step (char *args, int from_tty)

{

  exec_reverse_once ("step", args, from_tty);

}

static void

reverse_stepi (char *args, int from_tty)

{

  exec_reverse_once ("stepi", args, from_tty);

}

static void

reverse_next (char *args, int from_tty)

{

  exec_reverse_once ("next", args, from_tty);

}

static void

reverse_nexti (char *args, int from_tty)

{

  exec_reverse_once ("nexti", args, from_tty);

}

static void

reverse_continue (char *args, int from_tty)

{

  exec_reverse_once ("continue", args, from_tty);

}

static void

reverse_finish (char *args, int from_tty)

{

  exec_reverse_once ("finish", args, from_tty);

}

/* Data structures for a bookmark list.  */

struct bookmark {

  struct bookmark *next;

  int number;

  CORE_ADDR pc;

  struct symtab_and_line sal;

  gdb_byte *opaque_data;

};

static struct bookmark *bookmark_chain;

static int bookmark_count;

#define ALL_BOOKMARKS(B) for ((B) = bookmark_chain; (B); (B) = (B)->next)

#define ALL_BOOKMARKS_SAFE(B,TMP)           \

     for ((B) = bookmark_chain;             \

          (B) ? ((TMP) = (B)->next, 1) : 0; \

          (B) = (TMP))

/* save_bookmark_command -- implement "bookmark" command.

   Call target method to get a bookmark identifier.

   Insert bookmark identifier into list.

   Identifier will be a malloc string (gdb_byte *).

   Up to us to free it as required.  */

static void

save_bookmark_command (char *args, int from_tty)

{

  /* Get target's idea of a bookmark.  */

  gdb_byte *bookmark_id = target_get_bookmark (args, from_tty);

  struct bookmark *b, *b1;

  struct gdbarch *gdbarch = get_regcache_arch (get_current_regcache ());

  /* CR should not cause another identical bookmark.  */

  dont_repeat ();

  if (bookmark_id == NULL)

    error (_("target_get_bookmark failed."));

  /* Set up a bookmark struct.  */

  b = xcalloc (1, sizeof (struct bookmark));

  b->number = ++bookmark_count;

  init_sal (&b->sal);

  b->pc = regcache_read_pc (get_current_regcache ());

  b->sal = find_pc_line (b->pc, 0);

  b->sal.pspace = get_frame_program_space (get_current_frame ());

  b->opaque_data = bookmark_id;

  b->next = NULL;

  /* Add this bookmark to the end of the chain, so that a list

     of bookmarks will come out in order of increasing numbers.  */

  b1 = bookmark_chain;

  if (b1 == 0)

    bookmark_chain = b;

  else

    {

      while (b1->next)

        b1 = b1->next;

      b1->next = b;

    }

  printf_filtered (_("Saved bookmark %d at %s\n"), b->number,

                     paddress (gdbarch, b->sal.pc));

}

/* Implement "delete bookmark" command.  */

static int

delete_one_bookmark (struct bookmark *b)

{

  struct bookmark *b1;

  /* Special case, first item in list.  */

  if (b == bookmark_chain)

    bookmark_chain = b->next;

  /* Find bookmark preceeding "marked" one, so we can unlink.  */

  if (b)

    {

      ALL_BOOKMARKS (b1)

        if (b1->next == b)

          {

            /* Found designated bookmark.  Unlink and delete.  */

            b1->next = b->next;

            break;

          }

      xfree (b->opaque_data);

      xfree (b);

      return 1;         /* success */

    }

  return 0;              /* failure */

}

static void

delete_all_bookmarks (void)

{

  struct bookmark *b, *b1;

  ALL_BOOKMARKS_SAFE (b, b1)

    {

      xfree (b->opaque_data);

      xfree (b);

    }

  bookmark_chain = NULL;

}

static void

delete_bookmark_command (char *args, int from_tty)

{

  struct bookmark *b, *b1;

  unsigned long num;

  if (bookmark_chain == NULL)

    {

      warning (_("No bookmarks."));

      return;

    }

  if (args == NULL || args[0] == '\0')

    {

      if (from_tty && !query (_("Delete all bookmarks? ")))

        return;

      delete_all_bookmarks ();

      return;

    }

  num = strtoul (args, NULL, 0);

  /* Find bookmark with corresponding number.  */

  ALL_BOOKMARKS (b)

    if (b->number == num)

      break;

  if (!delete_one_bookmark (b))

    /* Not found.  */

    error (_("delete bookmark: no bookmark found for '%s'."), args);

}

/* Implement "goto-bookmark" command.  */

static void

goto_bookmark_command (char *args, int from_tty)

{

  struct bookmark *b;

  unsigned long num;

  if (args == NULL || args[0] == '\0')

    error (_("Command requires an argument."));

  if (strncmp (args, "start", strlen ("start")) == 0

      || strncmp (args, "begin", strlen ("begin")) == 0

      || strncmp (args, "end",   strlen ("end")) == 0)

    {

      /* Special case.  Give target opportunity to handle.  */

      target_goto_bookmark (args, from_tty);

      return;

    }

  if (args[0] == '\'' || args[0] == '\"')

    {

      /* Special case -- quoted string.  Pass on to target.  */

      if (args[strlen (args) - 1] != args[0])

        error (_("Unbalanced quotes: %s"), args);

      target_goto_bookmark (args, from_tty);

      return;

    }

  /* General case.  Bookmark identified by bookmark number.  */

  num = strtoul (args, NULL, 0);

  ALL_BOOKMARKS (b)

    if (b->number == num)

      break;

  if (b)

    {

      /* Found.  Send to target method.  */

      target_goto_bookmark (b->opaque_data, from_tty);

      return;

    }

  /* Not found.  */

  error (_("goto-bookmark: no bookmark found for '%s'."), args);

}

/* Implement "info bookmarks" command.  */

static void

bookmarks_info (char *args, int from_tty)

{

  struct bookmark *b;

  int bnum = -1;

  struct gdbarch *gdbarch;

  if (args)

    bnum = parse_and_eval_long (args);

  if (!bookmark_chain)

    {

      printf_filtered (_("No bookmarks.\n"));

      return;

    }

  gdbarch = get_regcache_arch (get_current_regcache ());

  printf_filtered (_("Bookmark    Address     Opaque\n"));

  printf_filtered (_("   ID                    Data \n"));

  ALL_BOOKMARKS (b)

    printf_filtered ("   %d       %s    '%s'\n",

                     b->number,

                     paddress (gdbarch, b->pc),

                     b->opaque_data);

}

/* Provide a prototype to silence -Wmissing-prototypes.  */

extern initialize_file_ftype _initialize_reverse;

void

_initialize_reverse (void)

{

  add_com ("reverse-step", class_run, reverse_step, _("\

Step program backward until it reaches the beginning of another source line.\n\

Argument N means do this N times (or till program stops for another reason).")

           );

  add_com_alias ("rs", "reverse-step", class_alias, 1);

  add_com ("reverse-next", class_run, reverse_next, _("\

Step program backward, proceeding through subroutine calls.\n\

Like the \"reverse-step\" command as long as subroutine calls do not happen;\n\

when they do, the call is treated as one instruction.\n\

Argument N means do this N times (or till program stops for another reason).")

           );

  add_com_alias ("rn", "reverse-next", class_alias, 1);

  add_com ("reverse-stepi", class_run, reverse_stepi, _("\

Step backward exactly one instruction.\n\

Argument N means do this N times (or till program stops for another reason).")

           );

  add_com_alias ("rsi", "reverse-stepi", class_alias, 0);

  add_com ("reverse-nexti", class_run, reverse_nexti, _("\

Step backward one instruction, but proceed through called subroutines.\n\

Argument N means do this N times (or till program stops for another reason).")

           );

  add_com_alias ("rni", "reverse-nexti", class_alias, 0);

  add_com ("reverse-continue", class_run, reverse_continue, _("\

Continue program being debugged but run it in reverse.\n\

If proceeding from breakpoint, a number N may be used as an argument,\n\

which means to set the ignore count of that breakpoint to N - 1 (so that\n\

the breakpoint won't break until the Nth time it is reached)."));

  add_com_alias ("rc", "reverse-continue", class_alias, 0);

  add_com ("reverse-finish", class_run, reverse_finish, _("\

Execute backward until just before selected stack frame is called."));

  add_com ("bookmark", class_bookmark, save_bookmark_command, _("\

Set a bookmark in the program's execution history.\n\

A bookmark represents a point in the execution history \n\

that can be returned to at a later point in the debug session."));

  add_info ("bookmarks", bookmarks_info, _("\

Status of user-settable bookmarks.\n\

Bookmarks are user-settable markers representing a point in the \n\

execution history that can be returned to later in the same debug \n\

session."));

  add_cmd ("bookmark", class_bookmark, delete_bookmark_command, _("\

Delete a bookmark from the bookmark list.\n\

Argument is a bookmark number, or no argument to delete all bookmarks.\n"),

           &deletelist);

  add_com ("goto-bookmark", class_bookmark, goto_bookmark_command, _("\

Go to an earlier-bookmarked point in the program's execution history.\n\

Argument is the bookmark number of a bookmark saved earlier by using \n\

the 'bookmark' command, or the special arguments:\n\

  start (beginning of recording)\n\

  end   (end of recording)\n"));

}