aboutsummaryrefslogtreecommitdiff
path: root/gdb/reverse.c
blob: 171c53c230d202f0ecc343d6bbf36d0c34d19e02 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
/* Reverse execution and reverse debugging.

   Copyright (C) 2006-2013 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 "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 (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 = 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"));
}