gdb/reverse.c

   1 /* Reverse execution and reverse debugging.
   2
   3    Copyright (C) 2006, 2007, 2008, 2009 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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "gdb_string.h"
  22 #include "target.h"
  23 #include "top.h"
  24 #include "cli/cli-cmds.h"
  25 #include "cli/cli-decode.h"
  26 #include "inferior.h"
  27
  28 /* User interface:
  29    reverse-step, reverse-next etc.  */
  30
  31 static void
  32 exec_direction_default (void *notused)
  33 {
  34   /* Return execution direction to default state.  */
  35   execution_direction = EXEC_FORWARD;
  36 }
  37
  38 /* exec_reverse_once -- accepts an arbitrary gdb command (string),
  39    and executes it with exec-direction set to 'reverse'.
  40
  41    Used to implement reverse-next etc. commands.  */
  42
  43 static void
  44 exec_reverse_once (char *cmd, char *args, int from_tty)
  45 {
  46   char *reverse_command;
  47   enum exec_direction_kind dir = execution_direction;
  48   struct cleanup *old_chain;
  49
  50   if (dir == EXEC_ERROR)
  51     error (_("Target %s does not support this command."), target_shortname);
  52
  53   if (dir == EXEC_REVERSE)
  54     error (_("Already in reverse mode.  Use '%s' or 'set exec-dir forward'."),
  55            cmd);
  56
  57   if (!target_can_execute_reverse)
  58     error (_("Target %s does not support this command."), target_shortname);
  59
  60   reverse_command = xstrprintf ("%s %s", cmd, args ? args : "");
  61   old_chain = make_cleanup (exec_direction_default, NULL);
  62   make_cleanup (xfree, reverse_command);
  63   execution_direction = EXEC_REVERSE;
  64   execute_command (reverse_command, from_tty);
  65   do_cleanups (old_chain);
  66 }
  67
  68 static void
  69 reverse_step (char *args, int from_tty)
  70 {
  71   exec_reverse_once ("step", args, from_tty);
  72 }
  73
  74 static void
  75 reverse_stepi (char *args, int from_tty)
  76 {
  77   exec_reverse_once ("stepi", args, from_tty);
  78 }
  79
  80 static void
  81 reverse_next (char *args, int from_tty)
  82 {
  83   exec_reverse_once ("next", args, from_tty);
  84 }
  85
  86 static void
  87 reverse_nexti (char *args, int from_tty)
  88 {
  89   exec_reverse_once ("nexti", args, from_tty);
  90 }
  91
  92 static void
  93 reverse_continue (char *args, int from_tty)
  94 {
  95   exec_reverse_once ("continue", args, from_tty);
  96 }
  97
  98 static void
  99 reverse_finish (char *args, int from_tty)
 100 {
 101   exec_reverse_once ("finish", args, from_tty);
 102 }
 103
 104 /* Provide a prototype to silence -Wmissing-prototypes.  */
 105 extern initialize_file_ftype _initialize_reverse;
 106
 107 void
 108 _initialize_reverse (void)
 109 {
 110   add_com ("reverse-step", class_run, reverse_step, _("\
 111 Step program backward until it reaches the beginning of another source line.\n\
 112 Argument N means do this N times (or till program stops for another reason).")
 113            );
 114   add_com_alias ("rs", "reverse-step", class_alias, 1);
 115
 116   add_com ("reverse-next", class_run, reverse_next, _("\
 117 Step program backward, proceeding through subroutine calls.\n\
 118 Like the \"reverse-step\" command as long as subroutine calls do not happen;\n\
 119 when they do, the call is treated as one instruction.\n\
 120 Argument N means do this N times (or till program stops for another reason).")
 121            );
 122   add_com_alias ("rn", "reverse-next", class_alias, 1);
 123
 124   add_com ("reverse-stepi", class_run, reverse_stepi, _("\
 125 Step backward exactly one instruction.\n\
 126 Argument N means do this N times (or till program stops for another reason).")
 127            );
 128   add_com_alias ("rsi", "reverse-stepi", class_alias, 0);
 129
 130   add_com ("reverse-nexti", class_run, reverse_nexti, _("\
 131 Step backward one instruction, but proceed through called subroutines.\n\
 132 Argument N means do this N times (or till program stops for another reason).")
 133            );
 134   add_com_alias ("rni", "reverse-nexti", class_alias, 0);
 135
 136   add_com ("reverse-continue", class_run, reverse_continue, _("\
 137 Continue program being debugged but run it in reverse.\n\
 138 If proceeding from breakpoint, a number N may be used as an argument,\n\
 139 which means to set the ignore count of that breakpoint to N - 1 (so that\n\
 140 the breakpoint won't break until the Nth time it is reached)."));
 141   add_com_alias ("rc", "reverse-continue", class_alias, 0);
 142
 143   add_com ("reverse-finish", class_run, reverse_finish, _("\
 144 Execute backward until just before selected stack frame is called."));
 145 }