gdb/mi/mi-cmd-var.c

   1 /* MI Command Set - varobj commands.
   2    Copyright (C) 2000-2023 Free Software Foundation, Inc.
   3
   4    Contributed by Cygnus Solutions (a Red Hat company).
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "mi-cmds.h"
  23 #include "mi-main.h"
  24 #include "ui-out.h"
  25 #include "mi-out.h"
  26 #include "varobj.h"
  27 #include "language.h"
  28 #include "value.h"
  29 #include <ctype.h>
  30 #include "mi-getopt.h"
  31 #include "gdbthread.h"
  32 #include "mi-parse.h"
  33 #include "gdbsupport/gdb_optional.h"
  34 #include "inferior.h"
  35
  36 static void varobj_update_one (struct varobj *var,
  37                                enum print_values print_values,
  38                                bool is_explicit);
  39
  40 static int mi_print_value_p (struct varobj *var,
  41                              enum print_values print_values);
  42
  43 /* Print variable object VAR.  The PRINT_VALUES parameter controls
  44    if the value should be printed.  The PRINT_EXPRESSION parameter
  45    controls if the expression should be printed.  */
  46
  47 static void
  48 print_varobj (struct varobj *var, enum print_values print_values,
  49               int print_expression)
  50 {
  51   struct ui_out *uiout = current_uiout;
  52   int thread_id;
  53
  54   uiout->field_string ("name", varobj_get_objname (var));
  55   if (print_expression)
  56     {
  57       std::string exp = varobj_get_expression (var);
  58
  59       uiout->field_string ("exp", exp);
  60     }
  61   uiout->field_signed ("numchild", varobj_get_num_children (var));
  62
  63   if (mi_print_value_p (var, print_values))
  64     {
  65       std::string val = varobj_get_value (var);
  66
  67       uiout->field_string ("value", val);
  68     }
  69
  70   std::string type = varobj_get_type (var);
  71   if (!type.empty ())
  72     uiout->field_string ("type", type);
  73
  74   thread_id = varobj_get_thread_id (var);
  75   if (thread_id > 0)
  76     uiout->field_signed ("thread-id", thread_id);
  77
  78   if (varobj_get_frozen (var))
  79     uiout->field_signed ("frozen", 1);
  80
  81   gdb::unique_xmalloc_ptr<char> display_hint = varobj_get_display_hint (var);
  82   if (display_hint)
  83     uiout->field_string ("displayhint", display_hint.get ());
  84
  85   if (varobj_is_dynamic_p (var))
  86     uiout->field_signed ("dynamic", 1);
  87 }
  88
  89 /* VAROBJ operations */
  90
  91 void
  92 mi_cmd_var_create (const char *command, const char *const *argv, int argc)
  93 {
  94   struct ui_out *uiout = current_uiout;
  95   CORE_ADDR frameaddr = 0;
  96   struct varobj *var;
  97   const char *frame;
  98   const char *expr;
  99   enum varobj_type var_type;
 100
 101   if (argc != 3)
 102     error (_("-var-create: Usage: NAME FRAME EXPRESSION."));
 103
 104   frame = argv[1];
 105   expr = argv[2];
 106
 107   const char *name = argv[0];
 108   std::string gen_name;
 109   if (strcmp (name, "-") == 0)
 110     {
 111       gen_name = varobj_gen_name ();
 112       name = gen_name.c_str ();
 113     }
 114   else if (!isalpha (name[0]))
 115     error (_("-var-create: name of object must begin with a letter"));
 116
 117   if (strcmp (frame, "*") == 0)
 118     var_type = USE_CURRENT_FRAME;
 119   else if (strcmp (frame, "@") == 0)
 120     var_type = USE_SELECTED_FRAME;
 121   else
 122     {
 123       var_type = USE_SPECIFIED_FRAME;
 124       frameaddr = string_to_core_addr (frame);
 125     }
 126
 127   if (varobjdebug)
 128     gdb_printf (gdb_stdlog,
 129                 "Name=\"%s\", Frame=\"%s\" (%s), Expression=\"%s\"\n",
 130                 name, frame, hex_string (frameaddr), expr);
 131
 132   var = varobj_create (name, expr, frameaddr, var_type);
 133
 134   if (var == NULL)
 135     error (_("-var-create: unable to create variable object"));
 136
 137   print_varobj (var, PRINT_ALL_VALUES, 0 /* don't print expression */);
 138
 139   uiout->field_signed ("has_more", varobj_has_more (var, 0));
 140 }
 141
 142 void
 143 mi_cmd_var_delete (const char *command, const char *const *argv, int argc)
 144 {
 145   const char *name;
 146   struct varobj *var;
 147   int numdel;
 148   int children_only_p = 0;
 149   struct ui_out *uiout = current_uiout;
 150
 151   if (argc < 1 || argc > 2)
 152     error (_("-var-delete: Usage: [-c] EXPRESSION."));
 153
 154   name = argv[0];
 155
 156   /* If we have one single argument it cannot be '-c' or any string
 157      starting with '-'.  */
 158   if (argc == 1)
 159     {
 160       if (strcmp (name, "-c") == 0)
 161         error (_("-var-delete: Missing required "
 162                  "argument after '-c': variable object name"));
 163       if (*name == '-')
 164         error (_("-var-delete: Illegal variable object name"));
 165     }
 166
 167   /* If we have 2 arguments they must be '-c' followed by a string
 168      which would be the variable name.  */
 169   if (argc == 2)
 170     {
 171       if (strcmp (name, "-c") != 0)
 172         error (_("-var-delete: Invalid option."));
 173       children_only_p = 1;
 174       name = argv[1];
 175     }
 176
 177   /* If we didn't error out, now NAME contains the name of the
 178      variable.  */
 179
 180   var = varobj_get_handle (name);
 181
 182   numdel = varobj_delete (var, children_only_p);
 183
 184   uiout->field_signed ("ndeleted", numdel);
 185 }
 186
 187 /* Parse a string argument into a format value.  */
 188
 189 static enum varobj_display_formats
 190 mi_parse_format (const char *arg)
 191 {
 192   if (arg != NULL)
 193     {
 194       int len;
 195
 196       len = strlen (arg);
 197
 198       if (strncmp (arg, "natural", len) == 0)
 199         return FORMAT_NATURAL;
 200       else if (strncmp (arg, "binary", len) == 0)
 201         return FORMAT_BINARY;
 202       else if (strncmp (arg, "decimal", len) == 0)
 203         return FORMAT_DECIMAL;
 204       else if (strncmp (arg, "hexadecimal", len) == 0)
 205         return FORMAT_HEXADECIMAL;
 206       else if (strncmp (arg, "octal", len) == 0)
 207         return FORMAT_OCTAL;
 208       else if (strncmp (arg, "zero-hexadecimal", len) == 0)
 209         return FORMAT_ZHEXADECIMAL;
 210     }
 211
 212   error (_("Must specify the format as: \"natural\", "
 213            "\"binary\", \"decimal\", \"hexadecimal\", \"octal\" or \"zero-hexadecimal\""));
 214 }
 215
 216 void
 217 mi_cmd_var_set_format (const char *command, const char *const *argv, int argc)
 218 {
 219   enum varobj_display_formats format;
 220   struct varobj *var;
 221   struct ui_out *uiout = current_uiout;
 222
 223   if (argc != 2)
 224     error (_("-var-set-format: Usage: NAME FORMAT."));
 225
 226   /* Get varobj handle, if a valid var obj name was specified.  */
 227   var = varobj_get_handle (argv[0]);
 228
 229   format = mi_parse_format (argv[1]);
 230
 231   /* Set the format of VAR to the given format.  */
 232   varobj_set_display_format (var, format);
 233
 234   /* Report the new current format.  */
 235   uiout->field_string ("format", varobj_format_string[(int) format]);
 236
 237   /* Report the value in the new format.  */
 238   std::string val = varobj_get_value (var);
 239   uiout->field_string ("value", val);
 240 }
 241
 242 void
 243 mi_cmd_var_set_visualizer (const char *command, const char *const *argv,
 244                            int argc)
 245 {
 246   struct varobj *var;
 247
 248   if (argc != 2)
 249     error (_("Usage: NAME VISUALIZER_FUNCTION."));
 250
 251   var = varobj_get_handle (argv[0]);
 252
 253   if (var == NULL)
 254     error (_("Variable object not found"));
 255
 256   varobj_set_visualizer (var, argv[1]);
 257 }
 258
 259 void
 260 mi_cmd_var_set_frozen (const char *command, const char *const *argv, int argc)
 261 {
 262   struct varobj *var;
 263   bool frozen;
 264
 265   if (argc != 2)
 266     error (_("-var-set-format: Usage: NAME FROZEN_FLAG."));
 267
 268   var = varobj_get_handle (argv[0]);
 269
 270   if (strcmp (argv[1], "0") == 0)
 271     frozen = false;
 272   else if (strcmp (argv[1], "1") == 0)
 273     frozen = true;
 274   else
 275     error (_("Invalid flag value"));
 276
 277   varobj_set_frozen (var, frozen);
 278
 279   /* We don't automatically return the new value, or what varobjs got
 280      new values during unfreezing.  If this information is required,
 281      client should call -var-update explicitly.  */
 282 }
 283
 284 void
 285 mi_cmd_var_show_format (const char *command, const char *const *argv, int argc)
 286 {
 287   struct ui_out *uiout = current_uiout;
 288   enum varobj_display_formats format;
 289   struct varobj *var;
 290
 291   if (argc != 1)
 292     error (_("-var-show-format: Usage: NAME."));
 293
 294   /* Get varobj handle, if a valid var obj name was specified.  */
 295   var = varobj_get_handle (argv[0]);
 296
 297   format = varobj_get_display_format (var);
 298
 299   /* Report the current format.  */
 300   uiout->field_string ("format", varobj_format_string[(int) format]);
 301 }
 302
 303 void
 304 mi_cmd_var_info_num_children (const char *command, const char *const *argv,
 305                               int argc)
 306 {
 307   struct ui_out *uiout = current_uiout;
 308   struct varobj *var;
 309
 310   if (argc != 1)
 311     error (_("-var-info-num-children: Usage: NAME."));
 312
 313   /* Get varobj handle, if a valid var obj name was specified.  */
 314   var = varobj_get_handle (argv[0]);
 315
 316   uiout->field_signed ("numchild", varobj_get_num_children (var));
 317 }
 318
 319 /* Return 1 if given the argument PRINT_VALUES we should display
 320    the varobj VAR.  */
 321
 322 static int
 323 mi_print_value_p (struct varobj *var, enum print_values print_values)
 324 {
 325   struct type *type;
 326
 327   if (print_values == PRINT_NO_VALUES)
 328     return 0;
 329
 330   if (print_values == PRINT_ALL_VALUES)
 331     return 1;
 332
 333   if (varobj_is_dynamic_p (var))
 334     return 1;
 335
 336   type = varobj_get_gdb_type (var);
 337   if (type == NULL)
 338     return 1;
 339   else
 340     return mi_simple_type_p (type);
 341 }
 342
 343 /* See mi-cmds.h.  */
 344
 345 bool
 346 mi_simple_type_p (struct type *type)
 347 {
 348   type = check_typedef (type);
 349
 350   if (TYPE_IS_REFERENCE (type))
 351     type = check_typedef (type->target_type ());
 352
 353   switch (type->code ())
 354     {
 355     case TYPE_CODE_ARRAY:
 356     case TYPE_CODE_STRUCT:
 357     case TYPE_CODE_UNION:
 358       return false;
 359     default:
 360       return true;
 361     }
 362 }
 363
 364 void
 365 mi_cmd_var_list_children (const char *command, const char *const *argv,
 366                           int argc)
 367 {
 368   struct ui_out *uiout = current_uiout;
 369   struct varobj *var;
 370   enum print_values print_values;
 371   int from, to;
 372
 373   if (argc < 1 || argc > 4)
 374     error (_("-var-list-children: Usage: "
 375              "[PRINT_VALUES] NAME [FROM TO]"));
 376
 377   /* Get varobj handle, if a valid var obj name was specified.  */
 378   if (argc == 1 || argc == 3)
 379     var = varobj_get_handle (argv[0]);
 380   else
 381     var = varobj_get_handle (argv[1]);
 382
 383   if (argc > 2)
 384     {
 385       from = atoi (argv[argc - 2]);
 386       to = atoi (argv[argc - 1]);
 387     }
 388   else
 389     {
 390       from = -1;
 391       to = -1;
 392     }
 393
 394   const std::vector<varobj *> &children
 395     = varobj_list_children (var, &from, &to);
 396
 397   uiout->field_signed ("numchild", to - from);
 398   if (argc == 2 || argc == 4)
 399     print_values = mi_parse_print_values (argv[0]);
 400   else
 401     print_values = PRINT_NO_VALUES;
 402
 403   gdb::unique_xmalloc_ptr<char> display_hint = varobj_get_display_hint (var);
 404   if (display_hint)
 405     uiout->field_string ("displayhint", display_hint.get ());
 406
 407   if (from < to)
 408     {
 409       ui_out_emit_list list_emitter (uiout, "children");
 410       for (int ix = from; ix < to && ix < children.size (); ix++)
 411         {
 412           ui_out_emit_tuple child_emitter (uiout, "child");
 413
 414           print_varobj (children[ix], print_values, 1 /* print expression */);
 415         }
 416     }
 417
 418   uiout->field_signed ("has_more", varobj_has_more (var, to));
 419 }
 420
 421 void
 422 mi_cmd_var_info_type (const char *command, const char *const *argv, int argc)
 423 {
 424   struct ui_out *uiout = current_uiout;
 425   struct varobj *var;
 426
 427   if (argc != 1)
 428     error (_("-var-info-type: Usage: NAME."));
 429
 430   /* Get varobj handle, if a valid var obj name was specified.  */
 431   var = varobj_get_handle (argv[0]);
 432
 433   std::string type_name = varobj_get_type (var);
 434   uiout->field_string ("type", type_name);
 435 }
 436
 437 void
 438 mi_cmd_var_info_path_expression (const char *command, const char *const *argv,
 439                                  int argc)
 440 {
 441   struct ui_out *uiout = current_uiout;
 442   struct varobj *var;
 443
 444   if (argc != 1)
 445     error (_("Usage: NAME."));
 446
 447   /* Get varobj handle, if a valid var obj name was specified.  */
 448   var = varobj_get_handle (argv[0]);
 449
 450   const char *path_expr = varobj_get_path_expr (var);
 451
 452   uiout->field_string ("path_expr", path_expr);
 453 }
 454
 455 void
 456 mi_cmd_var_info_expression (const char *command, const char *const *argv,
 457                             int argc)
 458 {
 459   struct ui_out *uiout = current_uiout;
 460   const struct language_defn *lang;
 461   struct varobj *var;
 462
 463   if (argc != 1)
 464     error (_("-var-info-expression: Usage: NAME."));
 465
 466   /* Get varobj handle, if a valid var obj name was specified.  */
 467   var = varobj_get_handle (argv[0]);
 468
 469   lang = varobj_get_language (var);
 470
 471   uiout->field_string ("lang", lang->natural_name ());
 472
 473   std::string exp = varobj_get_expression (var);
 474   uiout->field_string ("exp", exp);
 475 }
 476
 477 void
 478 mi_cmd_var_show_attributes (const char *command, const char *const *argv,
 479                             int argc)
 480 {
 481   struct ui_out *uiout = current_uiout;
 482   int attr;
 483   const char *attstr;
 484   struct varobj *var;
 485
 486   if (argc != 1)
 487     error (_("-var-show-attributes: Usage: NAME."));
 488
 489   /* Get varobj handle, if a valid var obj name was specified */
 490   var = varobj_get_handle (argv[0]);
 491
 492   attr = varobj_get_attributes (var);
 493   /* FIXME: define masks for attributes */
 494   if (attr & 0x00000001)
 495     attstr = "editable";
 496   else
 497     attstr = "noneditable";
 498
 499   uiout->field_string ("attr", attstr);
 500 }
 501
 502 void
 503 mi_cmd_var_evaluate_expression (const char *command, const char *const *argv,
 504                                 int argc)
 505 {
 506   struct ui_out *uiout = current_uiout;
 507   struct varobj *var;
 508
 509   enum varobj_display_formats format;
 510   int formatFound;
 511   int oind;
 512   const char *oarg;
 513
 514   enum opt
 515   {
 516     OP_FORMAT
 517   };
 518   static const struct mi_opt opts[] =
 519     {
 520       {"f", OP_FORMAT, 1},
 521       { 0, 0, 0 }
 522     };
 523
 524   /* Parse arguments.  */
 525   format = FORMAT_NATURAL;
 526   formatFound = 0;
 527   oind = 0;
 528   while (1)
 529     {
 530       int opt = mi_getopt ("-var-evaluate-expression", argc, argv,
 531                            opts, &oind, &oarg);
 532
 533       if (opt < 0)
 534         break;
 535       switch ((enum opt) opt)
 536         {
 537         case OP_FORMAT:
 538           if (formatFound)
 539             error (_("Cannot specify format more than once"));
 540
 541           format = mi_parse_format (oarg);
 542           formatFound = 1;
 543           break;
 544         }
 545     }
 546
 547   if (oind >= argc)
 548     error (_("Usage: [-f FORMAT] NAME"));
 549
 550   if (oind < argc - 1)
 551     error (_("Garbage at end of command"));
 552
 553   /* Get varobj handle, if a valid var obj name was specified.  */
 554   var = varobj_get_handle (argv[oind]);
 555
 556   if (formatFound)
 557     {
 558       std::string val = varobj_get_formatted_value (var, format);
 559
 560       uiout->field_string ("value", val);
 561     }
 562   else
 563     {
 564       std::string val = varobj_get_value (var);
 565
 566       uiout->field_string ("value", val);
 567     }
 568 }
 569
 570 void
 571 mi_cmd_var_assign (const char *command, const char *const *argv, int argc)
 572 {
 573   struct ui_out *uiout = current_uiout;
 574   struct varobj *var;
 575
 576   if (argc != 2)
 577     error (_("-var-assign: Usage: NAME EXPRESSION."));
 578
 579   /* Get varobj handle, if a valid var obj name was specified.  */
 580   var = varobj_get_handle (argv[0]);
 581
 582   if (!varobj_editable_p (var))
 583     error (_("-var-assign: Variable object is not editable"));
 584
 585   const char *expression = argv[1];
 586
 587   /* MI command '-var-assign' may write memory, so suppress memory
 588      changed notification if it does.  */
 589   scoped_restore save_suppress
 590     = make_scoped_restore (&mi_suppress_notification.memory, 1);
 591
 592   if (!varobj_set_value (var, expression))
 593     error (_("-var-assign: Could not assign "
 594              "expression to variable object"));
 595
 596   std::string val = varobj_get_value (var);
 597   uiout->field_string ("value", val);
 598 }
 599
 600 /* Helper for mi_cmd_var_update - update each VAR.  */
 601
 602 static void
 603 mi_cmd_var_update_iter (struct varobj *var, bool only_floating,
 604                         enum print_values print_values)
 605 {
 606   bool thread_stopped;
 607
 608   int thread_id = varobj_get_thread_id (var);
 609
 610   if (thread_id == -1)
 611     {
 612       thread_stopped = (inferior_ptid == null_ptid
 613                         || inferior_thread ()->state == THREAD_STOPPED);
 614     }
 615   else
 616     {
 617       thread_info *tp = find_thread_global_id (thread_id);
 618
 619       thread_stopped = (tp == NULL
 620                         || tp->state == THREAD_STOPPED);
 621     }
 622
 623   if (thread_stopped
 624       && (!only_floating || varobj_floating_p (var)))
 625     varobj_update_one (var, print_values, false /* implicit */);
 626 }
 627
 628 void
 629 mi_cmd_var_update (const char *command, const char *const *argv, int argc)
 630 {
 631   struct ui_out *uiout = current_uiout;
 632   const char *name;
 633   enum print_values print_values;
 634
 635   if (argc != 1 && argc != 2)
 636     error (_("-var-update: Usage: [PRINT_VALUES] NAME."));
 637
 638   if (argc == 1)
 639     name = argv[0];
 640   else
 641     name = argv[1];
 642
 643   if (argc == 2)
 644     print_values = mi_parse_print_values (argv[0]);
 645   else
 646     print_values = PRINT_NO_VALUES;
 647
 648   ui_out_emit_list list_emitter (uiout, "changelist");
 649
 650   /* Check if the parameter is a "*", which means that we want to
 651      update all variables.  */
 652
 653   if ((*name == '*' || *name == '@') && (*(name + 1) == '\0'))
 654     {
 655       /* varobj_update_one automatically updates all the children of
 656          VAROBJ.  Therefore update each VAROBJ only once by iterating
 657          only the root VAROBJs.  */
 658
 659       all_root_varobjs ([=] (varobj *var)
 660         { mi_cmd_var_update_iter (var, *name == '0', print_values); });
 661     }
 662   else
 663     {
 664       /* Get varobj handle, if a valid var obj name was specified.  */
 665       struct varobj *var = varobj_get_handle (name);
 666
 667       varobj_update_one (var, print_values, true /* explicit */);
 668     }
 669 }
 670
 671 /* Helper for mi_cmd_var_update().  */
 672
 673 static void
 674 varobj_update_one (struct varobj *var, enum print_values print_values,
 675                    bool is_explicit)
 676 {
 677   struct ui_out *uiout = current_uiout;
 678
 679   std::vector<varobj_update_result> changes = varobj_update (&var, is_explicit);
 680
 681   for (const varobj_update_result &r : changes)
 682     {
 683       int from, to;
 684
 685       ui_out_emit_tuple tuple_emitter (uiout, nullptr);
 686       uiout->field_string ("name", varobj_get_objname (r.varobj));
 687
 688       switch (r.status)
 689         {
 690         case VAROBJ_IN_SCOPE:
 691           if (mi_print_value_p (r.varobj, print_values))
 692             {
 693               std::string val = varobj_get_value (r.varobj);
 694
 695               uiout->field_string ("value", val);
 696             }
 697           uiout->field_string ("in_scope", "true");
 698           break;
 699         case VAROBJ_NOT_IN_SCOPE:
 700           uiout->field_string ("in_scope", "false");
 701           break;
 702         case VAROBJ_INVALID:
 703           uiout->field_string ("in_scope", "invalid");
 704           break;
 705         }
 706
 707       if (r.status != VAROBJ_INVALID)
 708         {
 709           if (r.type_changed)
 710             uiout->field_string ("type_changed", "true");
 711           else
 712             uiout->field_string ("type_changed", "false");
 713         }
 714
 715       if (r.type_changed)
 716         {
 717           std::string type_name = varobj_get_type (r.varobj);
 718
 719           uiout->field_string ("new_type", type_name);
 720         }
 721
 722       if (r.type_changed || r.children_changed)
 723         uiout->field_signed ("new_num_children",
 724                              varobj_get_num_children (r.varobj));
 725
 726       gdb::unique_xmalloc_ptr<char> display_hint
 727         = varobj_get_display_hint (r.varobj);
 728       if (display_hint)
 729         uiout->field_string ("displayhint", display_hint.get ());
 730
 731       if (varobj_is_dynamic_p (r.varobj))
 732         uiout->field_signed ("dynamic", 1);
 733
 734       varobj_get_child_range (r.varobj, &from, &to);
 735       uiout->field_signed ("has_more", varobj_has_more (r.varobj, to));
 736
 737       if (!r.newobj.empty ())
 738         {
 739           ui_out_emit_list list_emitter (uiout, "new_children");
 740
 741           for (varobj *child : r.newobj)
 742             {
 743               ui_out_emit_tuple inner_tuple_emitter (uiout, NULL);
 744               print_varobj (child, print_values, 1 /* print_expression */);
 745             }
 746         }
 747     }
 748 }
 749
 750 void
 751 mi_cmd_enable_pretty_printing (const char *command, const char *const *argv,
 752                                int argc)
 753 {
 754   if (argc != 0)
 755     error (_("-enable-pretty-printing: no arguments allowed"));
 756
 757   varobj_enable_pretty_printing ();
 758 }
 759
 760 void
 761 mi_cmd_var_set_update_range (const char *command, const char *const *argv,
 762                              int argc)
 763 {
 764   struct varobj *var;
 765   int from, to;
 766
 767   if (argc != 3)
 768     error (_("-var-set-update-range: Usage: VAROBJ FROM TO"));
 769
 770   var = varobj_get_handle (argv[0]);
 771   from = atoi (argv[1]);
 772   to = atoi (argv[2]);
 773
 774   varobj_set_child_range (var, from, to);
 775 }