gdb/record.c

   1 /* Process record and replay target for GDB, the GNU debugger.
   2
   3    Copyright (C) 2008-2013 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 "gdbcmd.h"
  22 #include "completer.h"
  23 #include "record.h"
  24 #include "observer.h"
  25 #include "inferior.h"
  26 #include "common/common-utils.h"
  27 #include "cli/cli-utils.h"
  28 #include "disasm.h"
  29
  30 #include <ctype.h>
  31
  32 /* This is the debug switch for process record.  */
  33 unsigned int record_debug = 0;
  34
  35 /* The number of instructions to print in "record instruction-history".  */
  36 static unsigned int record_insn_history_size = 10;
  37
  38 /* The variable registered as control variable in the "record
  39    instruction-history" command.  Necessary for extra input
  40    validation.  */
  41 static unsigned int record_insn_history_size_setshow_var;
  42
  43 /* The number of functions to print in "record function-call-history".  */
  44 static unsigned int record_call_history_size = 10;
  45
  46 /* The variable registered as control variable in the "record
  47    call-history" command.  Necessary for extra input validation.  */
  48 static unsigned int record_call_history_size_setshow_var;
  49
  50 struct cmd_list_element *record_cmdlist = NULL;
  51 struct cmd_list_element *set_record_cmdlist = NULL;
  52 struct cmd_list_element *show_record_cmdlist = NULL;
  53 struct cmd_list_element *info_record_cmdlist = NULL;
  54
  55 #define DEBUG(msg, args...)                                             \
  56   if (record_debug)                                                     \
  57     fprintf_unfiltered (gdb_stdlog, "record: " msg "\n", ##args)
  58
  59 /* Find the record target in the target stack.  */
  60
  61 static struct target_ops *
  62 find_record_target (void)
  63 {
  64   struct target_ops *t;
  65
  66   for (t = current_target.beneath; t != NULL; t = t->beneath)
  67     if (t->to_stratum == record_stratum)
  68       return t;
  69
  70   return NULL;
  71 }
  72
  73 /* Check that recording is active.  Throw an error, if it isn't.  */
  74
  75 static struct target_ops *
  76 require_record_target (void)
  77 {
  78   struct target_ops *t;
  79
  80   t = find_record_target ();
  81   if (t == NULL)
  82     error (_("No record target is currently active.\n"
  83              "Use one of the \"target record-<tab><tab>\" commands first."));
  84
  85   return t;
  86 }
  87
  88 /* See record.h.  */
  89
  90 int
  91 record_read_memory (struct gdbarch *gdbarch,
  92                     CORE_ADDR memaddr, gdb_byte *myaddr,
  93                     ssize_t len)
  94 {
  95   int ret = target_read_memory (memaddr, myaddr, len);
  96
  97   if (ret != 0)
  98     DEBUG ("error reading memory at addr %s len = %ld.\n",
  99            paddress (gdbarch, memaddr), (long) len);
 100
 101   return ret;
 102 }
 103
 104 /* Stop recording.  */
 105
 106 static void
 107 record_stop (struct target_ops *t)
 108 {
 109   DEBUG ("stop %s", t->to_shortname);
 110
 111   if (t->to_stop_recording != NULL)
 112     t->to_stop_recording ();
 113 }
 114
 115 /* Unpush the record target.  */
 116
 117 static void
 118 record_unpush (struct target_ops *t)
 119 {
 120   DEBUG ("unpush %s", t->to_shortname);
 121
 122   unpush_target (t);
 123 }
 124
 125 /* See record.h.  */
 126
 127 void
 128 record_disconnect (struct target_ops *t, char *args, int from_tty)
 129 {
 130   gdb_assert (t->to_stratum == record_stratum);
 131
 132   DEBUG ("disconnect %s", t->to_shortname);
 133
 134   record_stop (t);
 135   record_unpush (t);
 136
 137   target_disconnect (args, from_tty);
 138 }
 139
 140 /* See record.h.  */
 141
 142 void
 143 record_detach (struct target_ops *t, char *args, int from_tty)
 144 {
 145   gdb_assert (t->to_stratum == record_stratum);
 146
 147   DEBUG ("detach %s", t->to_shortname);
 148
 149   record_stop (t);
 150   record_unpush (t);
 151
 152   target_detach (args, from_tty);
 153 }
 154
 155 /* See record.h.  */
 156
 157 void
 158 record_mourn_inferior (struct target_ops *t)
 159 {
 160   gdb_assert (t->to_stratum == record_stratum);
 161
 162   DEBUG ("mourn inferior %s", t->to_shortname);
 163
 164   /* It is safer to not stop recording.  Resources will be freed when
 165      threads are discarded.  */
 166   record_unpush (t);
 167
 168   target_mourn_inferior ();
 169 }
 170
 171 /* See record.h.  */
 172
 173 void
 174 record_kill (struct target_ops *t)
 175 {
 176   gdb_assert (t->to_stratum == record_stratum);
 177
 178   DEBUG ("kill %s", t->to_shortname);
 179
 180   /* It is safer to not stop recording.  Resources will be freed when
 181      threads are discarded.  */
 182   record_unpush (t);
 183
 184   target_kill ();
 185 }
 186
 187 /* Implement "show record debug" command.  */
 188
 189 static void
 190 show_record_debug (struct ui_file *file, int from_tty,
 191                    struct cmd_list_element *c, const char *value)
 192 {
 193   fprintf_filtered (file, _("Debugging of process record target is %s.\n"),
 194                     value);
 195 }
 196
 197 /* Alias for "target record".  */
 198
 199 static void
 200 cmd_record_start (char *args, int from_tty)
 201 {
 202   execute_command ("target record-full", from_tty);
 203 }
 204
 205 /* Truncate the record log from the present point
 206    of replay until the end.  */
 207
 208 static void
 209 cmd_record_delete (char *args, int from_tty)
 210 {
 211   require_record_target ();
 212
 213   if (!target_record_is_replaying ())
 214     {
 215       printf_unfiltered (_("Already at end of record list.\n"));
 216       return;
 217     }
 218
 219   if (!target_supports_delete_record ())
 220     {
 221       printf_unfiltered (_("The current record target does not support "
 222                            "this operation.\n"));
 223       return;
 224     }
 225
 226   if (!from_tty || query (_("Delete the log from this point forward "
 227                             "and begin to record the running message "
 228                             "at current PC?")))
 229     target_delete_record ();
 230 }
 231
 232 /* Implement the "stoprecord" or "record stop" command.  */
 233
 234 static void
 235 cmd_record_stop (char *args, int from_tty)
 236 {
 237   struct target_ops *t;
 238
 239   t = require_record_target ();
 240
 241   record_stop (t);
 242   record_unpush (t);
 243
 244   printf_unfiltered (_("Process record is stopped and all execution "
 245                        "logs are deleted.\n"));
 246
 247   observer_notify_record_changed (current_inferior (), 0);
 248 }
 249
 250 /* The "set record" command.  */
 251
 252 static void
 253 set_record_command (char *args, int from_tty)
 254 {
 255   printf_unfiltered (_("\"set record\" must be followed "
 256                        "by an apporpriate subcommand.\n"));
 257   help_list (set_record_cmdlist, "set record ", all_commands, gdb_stdout);
 258 }
 259
 260 /* The "show record" command.  */
 261
 262 static void
 263 show_record_command (char *args, int from_tty)
 264 {
 265   cmd_show_list (show_record_cmdlist, from_tty, "");
 266 }
 267
 268 /* The "info record" command.  */
 269
 270 static void
 271 info_record_command (char *args, int from_tty)
 272 {
 273   struct target_ops *t;
 274
 275   t = find_record_target ();
 276   if (t == NULL)
 277     {
 278       printf_filtered (_("No record target is currently active.\n"));
 279       return;
 280     }
 281
 282   printf_filtered (_("Active record target: %s\n"), t->to_shortname);
 283   if (t->to_info_record != NULL)
 284     t->to_info_record ();
 285 }
 286
 287 /* The "record save" command.  */
 288
 289 static void
 290 cmd_record_save (char *args, int from_tty)
 291 {
 292   char *recfilename, recfilename_buffer[40];
 293
 294   require_record_target ();
 295
 296   if (args != NULL && *args != 0)
 297     recfilename = args;
 298   else
 299     {
 300       /* Default recfile name is "gdb_record.PID".  */
 301       xsnprintf (recfilename_buffer, sizeof (recfilename_buffer),
 302                 "gdb_record.%d", PIDGET (inferior_ptid));
 303       recfilename = recfilename_buffer;
 304     }
 305
 306   target_save_record (recfilename);
 307 }
 308
 309 /* "record goto" command.  Argument is an instruction number,
 310    as given by "info record".
 311
 312    Rewinds the recording (forward or backward) to the given instruction.  */
 313
 314 void
 315 cmd_record_goto (char *arg, int from_tty)
 316 {
 317   require_record_target ();
 318
 319   if (arg == NULL || *arg == '\0')
 320     error (_("Command requires an argument (insn number to go to)."));
 321
 322   if (strncmp (arg, "start", strlen ("start")) == 0
 323       || strncmp (arg, "begin", strlen ("begin")) == 0)
 324     target_goto_record_begin ();
 325   else if (strncmp (arg, "end", strlen ("end")) == 0)
 326     target_goto_record_end ();
 327   else
 328     {
 329       ULONGEST insn;
 330
 331       insn = parse_and_eval_long (arg);
 332       target_goto_record (insn);
 333     }
 334 }
 335
 336 /* Read an instruction number from an argument string.  */
 337
 338 static ULONGEST
 339 get_insn_number (char **arg)
 340 {
 341   ULONGEST number;
 342   const char *begin, *end, *pos;
 343
 344   begin = *arg;
 345   pos = skip_spaces_const (begin);
 346
 347   if (!isdigit (*pos))
 348     error (_("Expected positive number, got: %s."), pos);
 349
 350   number = strtoulst (pos, &end, 10);
 351
 352   *arg += (end - begin);
 353
 354   return number;
 355 }
 356
 357 /* Read a context size from an argument string.  */
 358
 359 static int
 360 get_context_size (char **arg)
 361 {
 362   char *pos;
 363   int number;
 364
 365   pos = skip_spaces (*arg);
 366
 367   if (!isdigit (*pos))
 368     error (_("Expected positive number, got: %s."), pos);
 369
 370   return strtol (pos, arg, 10);
 371 }
 372
 373 /* Complain about junk at the end of an argument string.  */
 374
 375 static void
 376 no_chunk (char *arg)
 377 {
 378   if (*arg != 0)
 379     error (_("Junk after argument: %s."), arg);
 380 }
 381
 382 /* Read instruction-history modifiers from an argument string.  */
 383
 384 static int
 385 get_insn_history_modifiers (char **arg)
 386 {
 387   int modifiers;
 388   char *args;
 389
 390   modifiers = 0;
 391   args = *arg;
 392
 393   if (args == NULL)
 394     return modifiers;
 395
 396   while (*args == '/')
 397     {
 398       ++args;
 399
 400       if (*args == '\0')
 401         error (_("Missing modifier."));
 402
 403       for (; *args; ++args)
 404         {
 405           if (isspace (*args))
 406             break;
 407
 408           if (*args == '/')
 409             continue;
 410
 411           switch (*args)
 412             {
 413             case 'm':
 414               modifiers |= DISASSEMBLY_SOURCE;
 415               modifiers |= DISASSEMBLY_FILENAME;
 416               break;
 417             case 'r':
 418               modifiers |= DISASSEMBLY_RAW_INSN;
 419               break;
 420             case 'f':
 421               modifiers |= DISASSEMBLY_OMIT_FNAME;
 422               break;
 423             case 'p':
 424               modifiers |= DISASSEMBLY_OMIT_PC;
 425               break;
 426             default:
 427               error (_("Invalid modifier: %c."), *args);
 428             }
 429         }
 430
 431       args = skip_spaces (args);
 432     }
 433
 434   /* Update the argument string.  */
 435   *arg = args;
 436
 437   return modifiers;
 438 }
 439
 440 /* The "set record instruction-history-size / set record
 441    function-call-history-size" commands are unsigned, with UINT_MAX
 442    meaning unlimited.  The target interfaces works with signed int
 443    though, to indicate direction, so map "unlimited" to INT_MAX, which
 444    is about the same as unlimited in practice.  If the user does have
 445    a log that huge, she can fetch it in chunks across several requests,
 446    but she'll likely have other problems first...  */
 447
 448 static int
 449 command_size_to_target_size (unsigned int size)
 450 {
 451   gdb_assert (size <= INT_MAX || size == UINT_MAX);
 452
 453   if (size == UINT_MAX)
 454     return INT_MAX;
 455   else
 456     return size;
 457 }
 458
 459 /* The "record instruction-history" command.  */
 460
 461 static void
 462 cmd_record_insn_history (char *arg, int from_tty)
 463 {
 464   int flags, size;
 465
 466   require_record_target ();
 467
 468   flags = get_insn_history_modifiers (&arg);
 469
 470   size = command_size_to_target_size (record_insn_history_size);
 471
 472   if (arg == NULL || *arg == 0 || strcmp (arg, "+") == 0)
 473     target_insn_history (size, flags);
 474   else if (strcmp (arg, "-") == 0)
 475     target_insn_history (-size, flags);
 476   else
 477     {
 478       ULONGEST begin, end;
 479
 480       begin = get_insn_number (&arg);
 481
 482       if (*arg == ',')
 483         {
 484           arg = skip_spaces (++arg);
 485
 486           if (*arg == '+')
 487             {
 488               arg += 1;
 489               size = get_context_size (&arg);
 490
 491               no_chunk (arg);
 492
 493               target_insn_history_from (begin, size, flags);
 494             }
 495           else if (*arg == '-')
 496             {
 497               arg += 1;
 498               size = get_context_size (&arg);
 499
 500               no_chunk (arg);
 501
 502               target_insn_history_from (begin, -size, flags);
 503             }
 504           else
 505             {
 506               end = get_insn_number (&arg);
 507
 508               no_chunk (arg);
 509
 510               target_insn_history_range (begin, end, flags);
 511             }
 512         }
 513       else
 514         {
 515           no_chunk (arg);
 516
 517           target_insn_history_from (begin, size, flags);
 518         }
 519
 520       dont_repeat ();
 521     }
 522 }
 523
 524 /* Read function-call-history modifiers from an argument string.  */
 525
 526 static int
 527 get_call_history_modifiers (char **arg)
 528 {
 529   int modifiers;
 530   char *args;
 531
 532   modifiers = 0;
 533   args = *arg;
 534
 535   if (args == NULL)
 536     return modifiers;
 537
 538   while (*args == '/')
 539     {
 540       ++args;
 541
 542       if (*args == '\0')
 543         error (_("Missing modifier."));
 544
 545       for (; *args; ++args)
 546         {
 547           if (isspace (*args))
 548             break;
 549
 550           if (*args == '/')
 551             continue;
 552
 553           switch (*args)
 554             {
 555             case 'l':
 556               modifiers |= record_print_src_line;
 557               break;
 558             case 'i':
 559               modifiers |= record_print_insn_range;
 560               break;
 561             default:
 562               error (_("Invalid modifier: %c."), *args);
 563             }
 564         }
 565
 566       args = skip_spaces (args);
 567     }
 568
 569   /* Update the argument string.  */
 570   *arg = args;
 571
 572   return modifiers;
 573 }
 574
 575 /* The "record function-call-history" command.  */
 576
 577 static void
 578 cmd_record_call_history (char *arg, int from_tty)
 579 {
 580   int flags, size;
 581
 582   require_record_target ();
 583
 584   flags = get_call_history_modifiers (&arg);
 585
 586   size = command_size_to_target_size (record_call_history_size);
 587
 588   if (arg == NULL || *arg == 0 || strcmp (arg, "+") == 0)
 589     target_call_history (size, flags);
 590   else if (strcmp (arg, "-") == 0)
 591     target_call_history (-size, flags);
 592   else
 593     {
 594       ULONGEST begin, end;
 595
 596       begin = get_insn_number (&arg);
 597
 598       if (*arg == ',')
 599         {
 600           arg = skip_spaces (++arg);
 601
 602           if (*arg == '+')
 603             {
 604               arg += 1;
 605               size = get_context_size (&arg);
 606
 607               no_chunk (arg);
 608
 609               target_call_history_from (begin, size, flags);
 610             }
 611           else if (*arg == '-')
 612             {
 613               arg += 1;
 614               size = get_context_size (&arg);
 615
 616               no_chunk (arg);
 617
 618               target_call_history_from (begin, -size, flags);
 619             }
 620           else
 621             {
 622               end = get_insn_number (&arg);
 623
 624               no_chunk (arg);
 625
 626               target_call_history_range (begin, end, flags);
 627             }
 628         }
 629       else
 630         {
 631           no_chunk (arg);
 632
 633           target_call_history_from (begin, size, flags);
 634         }
 635
 636       dont_repeat ();
 637     }
 638 }
 639
 640 /* Helper for "set record instruction-history-size" and "set record
 641    function-call-history-size" input validation.  COMMAND_VAR is the
 642    variable registered in the command as control variable.  *SETTING
 643    is the real setting the command allows changing.  */
 644
 645 static void
 646 validate_history_size (unsigned int *command_var, int *setting)
 647 {
 648   if (*command_var != UINT_MAX && *command_var > INT_MAX)
 649     {
 650       unsigned int new_value = *command_var;
 651
 652       /* Restore previous value.  */
 653       *command_var = *setting;
 654       error (_("integer %u out of range"), new_value);
 655     }
 656
 657   /* Commit new value.  */
 658   *setting = *command_var;
 659 }
 660
 661 /* Called by do_setshow_command.  We only want values in the
 662    [0..INT_MAX] range, while the command's machinery accepts
 663    [0..UINT_MAX].  See command_size_to_target_size.  */
 664
 665 static void
 666 set_record_insn_history_size (char *args, int from_tty,
 667                               struct cmd_list_element *c)
 668 {
 669   validate_history_size (&record_insn_history_size_setshow_var,
 670                          &record_insn_history_size);
 671 }
 672
 673 /* Called by do_setshow_command.  We only want values in the
 674    [0..INT_MAX] range, while the command's machinery accepts
 675    [0..UINT_MAX].  See command_size_to_target_size.  */
 676
 677 static void
 678 set_record_call_history_size (char *args, int from_tty,
 679                               struct cmd_list_element *c)
 680 {
 681   validate_history_size (&record_call_history_size_setshow_var,
 682                          &record_call_history_size);
 683 }
 684
 685 /* Provide a prototype to silence -Wmissing-prototypes.  */
 686 extern initialize_file_ftype _initialize_record;
 687
 688 void
 689 _initialize_record (void)
 690 {
 691   struct cmd_list_element *c;
 692
 693   add_setshow_zuinteger_cmd ("record", no_class, &record_debug,
 694                              _("Set debugging of record/replay feature."),
 695                              _("Show debugging of record/replay feature."),
 696                              _("When enabled, debugging output for "
 697                                "record/replay feature is displayed."),
 698                              NULL, show_record_debug, &setdebuglist,
 699                              &showdebuglist);
 700
 701   add_setshow_uinteger_cmd ("instruction-history-size", no_class,
 702                             &record_insn_history_size_setshow_var, _("\
 703 Set number of instructions to print in \"record instruction-history\"."), _("\
 704 Show number of instructions to print in \"record instruction-history\"."), _("\
 705 A size of \"unlimited\" means unlimited instructions.  The default is 10."),
 706                             set_record_insn_history_size, NULL,
 707                             &set_record_cmdlist, &show_record_cmdlist);
 708
 709   add_setshow_uinteger_cmd ("function-call-history-size", no_class,
 710                             &record_call_history_size_setshow_var, _("\
 711 Set number of function to print in \"record function-call-history\"."), _("\
 712 Show number of functions to print in \"record function-call-history\"."), _("\
 713 A size of \"unlimited\" means unlimited lines.  The default is 10."),
 714                             set_record_call_history_size, NULL,
 715                             &set_record_cmdlist, &show_record_cmdlist);
 716
 717   c = add_prefix_cmd ("record", class_obscure, cmd_record_start,
 718                       _("Start recording."),
 719                       &record_cmdlist, "record ", 0, &cmdlist);
 720   set_cmd_completer (c, filename_completer);
 721
 722   add_com_alias ("rec", "record", class_obscure, 1);
 723   add_prefix_cmd ("record", class_support, set_record_command,
 724                   _("Set record options"), &set_record_cmdlist,
 725                   "set record ", 0, &setlist);
 726   add_alias_cmd ("rec", "record", class_obscure, 1, &setlist);
 727   add_prefix_cmd ("record", class_support, show_record_command,
 728                   _("Show record options"), &show_record_cmdlist,
 729                   "show record ", 0, &showlist);
 730   add_alias_cmd ("rec", "record", class_obscure, 1, &showlist);
 731   add_prefix_cmd ("record", class_support, info_record_command,
 732                   _("Info record options"), &info_record_cmdlist,
 733                   "info record ", 0, &infolist);
 734   add_alias_cmd ("rec", "record", class_obscure, 1, &infolist);
 735
 736   c = add_cmd ("save", class_obscure, cmd_record_save,
 737                _("Save the execution log to a file.\n\
 738 Argument is optional filename.\n\
 739 Default filename is 'gdb_record.<process_id>'."),
 740                &record_cmdlist);
 741   set_cmd_completer (c, filename_completer);
 742
 743   add_cmd ("delete", class_obscure, cmd_record_delete,
 744            _("Delete the rest of execution log and start recording it anew."),
 745            &record_cmdlist);
 746   add_alias_cmd ("d", "delete", class_obscure, 1, &record_cmdlist);
 747   add_alias_cmd ("del", "delete", class_obscure, 1, &record_cmdlist);
 748
 749   add_cmd ("stop", class_obscure, cmd_record_stop,
 750            _("Stop the record/replay target."),
 751            &record_cmdlist);
 752   add_alias_cmd ("s", "stop", class_obscure, 1, &record_cmdlist);
 753
 754   add_cmd ("goto", class_obscure, cmd_record_goto, _("\
 755 Restore the program to its state at instruction number N.\n\
 756 Argument is instruction number, as shown by 'info record'."),
 757            &record_cmdlist);
 758
 759   add_cmd ("instruction-history", class_obscure, cmd_record_insn_history, _("\
 760 Print disassembled instructions stored in the execution log.\n\
 761 With a /m modifier, source lines are included (if available).\n\
 762 With a /r modifier, raw instructions in hex are included.\n\
 763 With a /f modifier, function names are omitted.\n\
 764 With a /p modifier, current position markers are omitted.\n\
 765 With no argument, disassembles ten more instructions after the previous \
 766 disassembly.\n\
 767 \"record instruction-history -\" disassembles ten instructions before a \
 768 previous disassembly.\n\
 769 One argument specifies an instruction number as shown by 'info record', and \
 770 ten instructions are disassembled after that instruction.\n\
 771 Two arguments with comma between them specify starting and ending instruction \
 772 numbers to disassemble.\n\
 773 If the second argument is preceded by '+' or '-', it specifies the distance \
 774 from the first argument.\n\
 775 The number of instructions to disassemble can be defined with \"set record \
 776 instruction-history-size\"."),
 777            &record_cmdlist);
 778
 779   add_cmd ("function-call-history", class_obscure, cmd_record_call_history, _("\
 780 Prints the execution history at function granularity.\n\
 781 It prints one line for each sequence of instructions that belong to the same \
 782 function.\n\
 783 Without modifiers, it prints the function name.\n\
 784 With a /l modifier, the source file and line number range is included.\n\
 785 With a /i modifier, the instruction number range is included.\n\
 786 With no argument, prints ten more lines after the previous ten-line print.\n\
 787 \"record function-call-history -\" prints ten lines before a previous ten-line \
 788 print.\n\
 789 One argument specifies a function number as shown by 'info record', and \
 790 ten lines are printed after that function.\n\
 791 Two arguments with comma between them specify a range of functions to print.\n\
 792 If the second argument is preceded by '+' or '-', it specifies the distance \
 793 from the first argument.\n\
 794 The number of functions to print can be defined with \"set record \
 795 function-call-history-size\"."),
 796            &record_cmdlist);
 797
 798   /* Sync command control variables.  */
 799   record_insn_history_size_setshow_var = record_insn_history_size;
 800   record_call_history_size_setshow_var = record_call_history_size;
 801 }