gdb/reverse.c

   1 /* Reverse execution and reverse debugging.
   2
   3    Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "gdb_string.h"
  24 #include "target.h"
  25 #include "top.h"
  26 #include "cli/cli-cmds.h"
  27 #include "cli/cli-decode.h"
  28 #include "inferior.h"
  29
  30 /* User interface:
  31    reverse-step, reverse-next etc.  */
  32
  33 static void exec_direction_default (void *notused)
  34 {
  35   /* Return execution direction to default state.  */
  36   execution_direction = EXEC_FORWARD;
  37 }
  38
  39 /* exec_reverse_once -- accepts an arbitrary gdb command (string),
  40    and executes it with exec-direction set to 'reverse'.
  41
  42    Used to implement reverse-next etc. commands.  */
  43
  44 static void
  45 exec_reverse_once (char *cmd, char *args, int from_tty)
  46 {
  47   char *reverse_command;
  48   enum exec_direction_kind dir = execution_direction;
  49   struct cleanup *old_chain;
  50
  51   if (dir == EXEC_ERROR)
  52     error (_("Target %s does not support this command."), target_shortname);
  53
  54   if (dir == EXEC_REVERSE)
  55     error (_("Already in reverse mode.  Use '%s' or 'set exec-dir forward'."),
  56            cmd);
  57
  58   if (!target_can_execute_reverse)
  59     error (_("Target %s does not support this command."), target_shortname);
  60
  61   reverse_command = xstrprintf ("%s %s", cmd, args ? args : "");
  62   old_chain = make_cleanup (exec_direction_default, NULL);
  63   make_cleanup (xfree, reverse_command);
  64   execution_direction = EXEC_REVERSE;
  65   execute_command (reverse_command, from_tty);
  66   do_cleanups (old_chain);
  67 }
  68
  69 static void
  70 reverse_step (char *args, int from_tty)
  71 {
  72   exec_reverse_once ("step", args, from_tty);
  73 }
  74
  75 static void
  76 reverse_stepi (char *args, int from_tty)
  77 {
  78   exec_reverse_once ("stepi", args, from_tty);
  79 }
  80
  81 static void
  82 reverse_next (char *args, int from_tty)
  83 {
  84   exec_reverse_once ("next", args, from_tty);
  85 }
  86
  87 static void
  88 reverse_nexti (char *args, int from_tty)
  89 {
  90   exec_reverse_once ("nexti", args, from_tty);
  91 }
  92
  93 static void
  94 reverse_continue (char *args, int from_tty)
  95 {
  96   exec_reverse_once ("continue", args, from_tty);
  97 }
  98
  99 static void
 100 reverse_finish (char *args, int from_tty)
 101 {
 102   exec_reverse_once ("finish", args, from_tty);
 103 }
 104
 105 void
 106 _initialize_reverse (void)
 107 {
 108   add_com ("reverse-step", class_run, reverse_step, _("\
 109 Step program backward until it reaches the beginning of another source line.\n\
 110 Argument N means do this N times (or till program stops for another reason).")
 111            );
 112   add_com_alias ("rs", "reverse-step", class_alias, 1);
 113
 114   add_com ("reverse-next", class_run, reverse_next, _("\
 115 Step program backward, proceeding through subroutine calls.\n\
 116 Like the \"reverse-step\" command as long as subroutine calls do not happen;\n\
 117 when they do, the call is treated as one instruction.\n\
 118 Argument N means do this N times (or till program stops for another reason).")
 119            );
 120   add_com_alias ("rn", "reverse-next", class_alias, 1);
 121
 122   add_com ("reverse-stepi", class_run, reverse_stepi, _("\
 123 Step backward exactly one instruction.\n\
 124 Argument N means do this N times (or till program stops for another reason).")
 125            );
 126   add_com_alias ("rsi", "reverse-stepi", class_alias, 0);
 127
 128   add_com ("reverse-nexti", class_run, reverse_nexti, _("\
 129 Step backward one instruction, but proceed through called subroutines.\n\
 130 Argument N means do this N times (or till program stops for another reason).")
 131            );
 132   add_com_alias ("rni", "reverse-nexti", class_alias, 0);
 133
 134   add_com ("reverse-continue", class_run, reverse_continue, _("\
 135 Continue program being debugged but run it in reverse.\n\
 136 If proceeding from breakpoint, a number N may be used as an argument,\n\
 137 which means to set the ignore count of that breakpoint to N - 1 (so that\n\
 138 the breakpoint won't break until the Nth time it is reached)."));
 139   add_com_alias ("rc", "reverse-continue", class_alias, 0);
 140
 141   add_com ("reverse-finish", class_run, reverse_finish, _("\
 142 Execute backward until just before selected stack frame is called."));
 143 }