/* Reverse execution and reverse debugging. Copyright (C) 2006-2014 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 <string.h> #include "target.h" #include "top.h" #include "cli/cli-cmds.h" #include "cli/cli-decode.h" #include "cli/cli-utils.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_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 (int num) { struct bookmark *b1, *b; /* Find bookmark with corresponding number. */ ALL_BOOKMARKS (b) if (b->number == num) break; /* Special case, first item in list. */ if (b == bookmark_chain) bookmark_chain = b->next; /* Find bookmark preceding "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) { int num; struct get_number_or_range_state state; 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; } init_number_or_range (&state, args); while (!state.finished) { num = get_number_or_range (&state); if (!delete_one_bookmark (num)) /* Not found. */ warning (_("No bookmark #%d."), num); } } /* 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 ((gdb_byte *) 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 ((gdb_byte *) args, from_tty); return; } /* General case. Bookmark identified by bookmark number. */ num = get_number (&args); 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); } static int bookmark_1 (int bnum) { struct gdbarch *gdbarch = get_regcache_arch (get_current_regcache ()); struct bookmark *b; int matched = 0; ALL_BOOKMARKS (b) { if (bnum == -1 || bnum == b->number) { printf_filtered (" %d %s '%s'\n", b->number, paddress (gdbarch, b->pc), b->opaque_data); matched++; } } if (bnum > 0 && matched == 0) printf_filtered ("No bookmark #%d\n", bnum); return matched; } /* Implement "info bookmarks" command. */ static void bookmarks_info (char *args, int from_tty) { int bnum = -1; if (!bookmark_chain) printf_filtered (_("No bookmarks.\n")); else if (args == NULL || *args == '\0') bookmark_1 (-1); else { struct get_number_or_range_state state; init_number_or_range (&state, args); while (!state.finished) { bnum = get_number_or_range (&state); bookmark_1 (bnum); } } } /* 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 numbers,\n\ 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")); }