gdb/inferior.c

   1 /* Multi-process control for GDB, the GNU debugger.
   2
   3    Copyright (C) 2008-2017 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 "exec.h"
  22 #include "inferior.h"
  23 #include "target.h"
  24 #include "command.h"
  25 #include "completer.h"
  26 #include "gdbcmd.h"
  27 #include "gdbthread.h"
  28 #include "ui-out.h"
  29 #include "observer.h"
  30 #include "gdbcore.h"
  31 #include "symfile.h"
  32 #include "environ.h"
  33 #include "cli/cli-utils.h"
  34 #include "continuations.h"
  35 #include "arch-utils.h"
  36 #include "target-descriptions.h"
  37 #include "readline/tilde.h"
  38 #include "progspace-and-thread.h"
  39
  40 void _initialize_inferiors (void);
  41
  42 /* Keep a registry of per-inferior data-pointers required by other GDB
  43    modules.  */
  44
  45 DEFINE_REGISTRY (inferior, REGISTRY_ACCESS_FIELD)
  46
  47 struct inferior *inferior_list = NULL;
  48 static int highest_inferior_num;
  49
  50 /* Print notices on inferior events (attach, detach, etc.), set with
  51    `set print inferior-events'.  */
  52 static int print_inferior_events = 0;
  53
  54 /* The Current Inferior.  This is a strong reference.  I.e., whenever
  55    an inferior is the current inferior, its refcount is
  56    incremented.  */
  57 static struct inferior *current_inferior_ = NULL;
  58
  59 struct inferior*
  60 current_inferior (void)
  61 {
  62   return current_inferior_;
  63 }
  64
  65 void
  66 set_current_inferior (struct inferior *inf)
  67 {
  68   /* There's always an inferior.  */
  69   gdb_assert (inf != NULL);
  70
  71   inf->incref ();
  72   current_inferior_->decref ();
  73   current_inferior_ = inf;
  74 }
  75
  76 inferior::~inferior ()
  77 {
  78   inferior *inf = this;
  79
  80   discard_all_inferior_continuations (inf);
  81   inferior_free_data (inf);
  82   xfree (inf->args);
  83   xfree (inf->terminal);
  84   target_desc_info_free (inf->tdesc_info);
  85   xfree (inf->priv);
  86 }
  87
  88 inferior::inferior (int pid_)
  89   : num (++highest_inferior_num),
  90     pid (pid_),
  91     environment (gdb_environ::from_host_environ ()),
  92     registry_data ()
  93 {
  94   inferior_alloc_data (this);
  95 }
  96
  97 struct inferior *
  98 add_inferior_silent (int pid)
  99 {
 100   inferior *inf = new inferior (pid);
 101
 102   if (inferior_list == NULL)
 103     inferior_list = inf;
 104   else
 105     {
 106       inferior *last;
 107
 108       for (last = inferior_list; last->next != NULL; last = last->next)
 109         ;
 110       last->next = inf;
 111     }
 112
 113   observer_notify_inferior_added (inf);
 114
 115   if (pid != 0)
 116     inferior_appeared (inf, pid);
 117
 118   return inf;
 119 }
 120
 121 struct inferior *
 122 add_inferior (int pid)
 123 {
 124   struct inferior *inf = add_inferior_silent (pid);
 125
 126   if (print_inferior_events)
 127     printf_unfiltered (_("[New inferior %d]\n"), pid);
 128
 129   return inf;
 130 }
 131
 132 struct delete_thread_of_inferior_arg
 133 {
 134   int pid;
 135   int silent;
 136 };
 137
 138 static int
 139 delete_thread_of_inferior (struct thread_info *tp, void *data)
 140 {
 141   struct delete_thread_of_inferior_arg *arg
 142     = (struct delete_thread_of_inferior_arg *) data;
 143
 144   if (ptid_get_pid (tp->ptid) == arg->pid)
 145     {
 146       if (arg->silent)
 147         delete_thread_silent (tp->ptid);
 148       else
 149         delete_thread (tp->ptid);
 150     }
 151
 152   return 0;
 153 }
 154
 155 void
 156 delete_inferior (struct inferior *todel)
 157 {
 158   struct inferior *inf, *infprev;
 159   struct delete_thread_of_inferior_arg arg;
 160
 161   infprev = NULL;
 162
 163   for (inf = inferior_list; inf; infprev = inf, inf = inf->next)
 164     if (inf == todel)
 165       break;
 166
 167   if (!inf)
 168     return;
 169
 170   arg.pid = inf->pid;
 171   arg.silent = 1;
 172
 173   iterate_over_threads (delete_thread_of_inferior, &arg);
 174
 175   if (infprev)
 176     infprev->next = inf->next;
 177   else
 178     inferior_list = inf->next;
 179
 180   observer_notify_inferior_removed (inf);
 181
 182   /* If this program space is rendered useless, remove it. */
 183   if (program_space_empty_p (inf->pspace))
 184     delete_program_space (inf->pspace);
 185
 186   delete inf;
 187 }
 188
 189 /* If SILENT then be quiet -- don't announce a inferior exit, or the
 190    exit of its threads.  */
 191
 192 static void
 193 exit_inferior_1 (struct inferior *inftoex, int silent)
 194 {
 195   struct inferior *inf;
 196   struct delete_thread_of_inferior_arg arg;
 197
 198   for (inf = inferior_list; inf; inf = inf->next)
 199     if (inf == inftoex)
 200       break;
 201
 202   if (!inf)
 203     return;
 204
 205   arg.pid = inf->pid;
 206   arg.silent = silent;
 207
 208   iterate_over_threads (delete_thread_of_inferior, &arg);
 209
 210   observer_notify_inferior_exit (inf);
 211
 212   inf->pid = 0;
 213   inf->fake_pid_p = 0;
 214   xfree (inf->priv);
 215   inf->priv = NULL;
 216
 217   if (inf->vfork_parent != NULL)
 218     {
 219       inf->vfork_parent->vfork_child = NULL;
 220       inf->vfork_parent = NULL;
 221     }
 222   if (inf->vfork_child != NULL)
 223     {
 224       inf->vfork_child->vfork_parent = NULL;
 225       inf->vfork_child = NULL;
 226     }
 227
 228   inf->pending_detach = 0;
 229 }
 230
 231 void
 232 exit_inferior (int pid)
 233 {
 234   struct inferior *inf = find_inferior_pid (pid);
 235
 236   exit_inferior_1 (inf, 0);
 237
 238   if (print_inferior_events)
 239     printf_unfiltered (_("[Inferior %d exited]\n"), pid);
 240 }
 241
 242 void
 243 exit_inferior_silent (int pid)
 244 {
 245   struct inferior *inf = find_inferior_pid (pid);
 246
 247   exit_inferior_1 (inf, 1);
 248 }
 249
 250 void
 251 exit_inferior_num_silent (int num)
 252 {
 253   struct inferior *inf = find_inferior_id (num);
 254
 255   exit_inferior_1 (inf, 1);
 256 }
 257
 258 void
 259 detach_inferior (int pid)
 260 {
 261   struct inferior *inf = find_inferior_pid (pid);
 262
 263   exit_inferior_1 (inf, 0);
 264
 265   if (print_inferior_events)
 266     printf_unfiltered (_("[Inferior %d detached]\n"), pid);
 267 }
 268
 269 void
 270 inferior_appeared (struct inferior *inf, int pid)
 271 {
 272   inf->pid = pid;
 273   inf->has_exit_code = 0;
 274   inf->exit_code = 0;
 275
 276   observer_notify_inferior_appeared (inf);
 277 }
 278
 279 void
 280 discard_all_inferiors (void)
 281 {
 282   struct inferior *inf;
 283
 284   for (inf = inferior_list; inf; inf = inf->next)
 285     {
 286       if (inf->pid != 0)
 287         exit_inferior_silent (inf->pid);
 288     }
 289 }
 290
 291 struct inferior *
 292 find_inferior_id (int num)
 293 {
 294   struct inferior *inf;
 295
 296   for (inf = inferior_list; inf; inf = inf->next)
 297     if (inf->num == num)
 298       return inf;
 299
 300   return NULL;
 301 }
 302
 303 struct inferior *
 304 find_inferior_pid (int pid)
 305 {
 306   struct inferior *inf;
 307
 308   /* Looking for inferior pid == 0 is always wrong, and indicative of
 309      a bug somewhere else.  There may be more than one with pid == 0,
 310      for instance.  */
 311   gdb_assert (pid != 0);
 312
 313   for (inf = inferior_list; inf; inf = inf->next)
 314     if (inf->pid == pid)
 315       return inf;
 316
 317   return NULL;
 318 }
 319
 320 /* See inferior.h */
 321
 322 struct inferior *
 323 find_inferior_ptid (ptid_t ptid)
 324 {
 325   return find_inferior_pid (ptid_get_pid (ptid));
 326 }
 327
 328 /* See inferior.h.  */
 329
 330 struct inferior *
 331 find_inferior_for_program_space (struct program_space *pspace)
 332 {
 333   struct inferior *inf = current_inferior ();
 334
 335   if (inf->pspace == pspace)
 336     return inf;
 337
 338   for (inf = inferior_list; inf != NULL; inf = inf->next)
 339     {
 340       if (inf->pspace == pspace)
 341         return inf;
 342     }
 343
 344   return NULL;
 345 }
 346
 347 struct inferior *
 348 iterate_over_inferiors (int (*callback) (struct inferior *, void *),
 349                         void *data)
 350 {
 351   struct inferior *inf, *infnext;
 352
 353   for (inf = inferior_list; inf; inf = infnext)
 354     {
 355       infnext = inf->next;
 356       if ((*callback) (inf, data))
 357         return inf;
 358     }
 359
 360   return NULL;
 361 }
 362
 363 int
 364 valid_gdb_inferior_id (int num)
 365 {
 366   struct inferior *inf;
 367
 368   for (inf = inferior_list; inf; inf = inf->next)
 369     if (inf->num == num)
 370       return 1;
 371
 372   return 0;
 373 }
 374
 375 int
 376 pid_to_gdb_inferior_id (int pid)
 377 {
 378   struct inferior *inf;
 379
 380   for (inf = inferior_list; inf; inf = inf->next)
 381     if (inf->pid == pid)
 382       return inf->num;
 383
 384   return 0;
 385 }
 386
 387 int
 388 gdb_inferior_id_to_pid (int num)
 389 {
 390   struct inferior *inferior = find_inferior_id (num);
 391   if (inferior)
 392     return inferior->pid;
 393   else
 394     return -1;
 395 }
 396
 397 int
 398 in_inferior_list (int pid)
 399 {
 400   struct inferior *inf;
 401
 402   for (inf = inferior_list; inf; inf = inf->next)
 403     if (inf->pid == pid)
 404       return 1;
 405
 406   return 0;
 407 }
 408
 409 int
 410 have_inferiors (void)
 411 {
 412   struct inferior *inf;
 413
 414   for (inf = inferior_list; inf; inf = inf->next)
 415     if (inf->pid != 0)
 416       return 1;
 417
 418   return 0;
 419 }
 420
 421 /* Return the number of live inferiors.  We account for the case
 422    where an inferior might have a non-zero pid but no threads, as
 423    in the middle of a 'mourn' operation.  */
 424
 425 int
 426 number_of_live_inferiors (void)
 427 {
 428   struct inferior *inf;
 429   int num_inf = 0;
 430
 431   for (inf = inferior_list; inf; inf = inf->next)
 432     if (inf->pid != 0)
 433       {
 434         struct thread_info *tp;
 435
 436         ALL_NON_EXITED_THREADS (tp)
 437          if (tp && ptid_get_pid (tp->ptid) == inf->pid)
 438            if (target_has_execution_1 (tp->ptid))
 439              {
 440                /* Found a live thread in this inferior, go to the next
 441                   inferior.  */
 442                ++num_inf;
 443                break;
 444              }
 445       }
 446
 447   return num_inf;
 448 }
 449
 450 /* Return true if there is at least one live inferior.  */
 451
 452 int
 453 have_live_inferiors (void)
 454 {
 455   return number_of_live_inferiors () > 0;
 456 }
 457
 458 /* Prune away any unused inferiors, and then prune away no longer used
 459    program spaces.  */
 460
 461 void
 462 prune_inferiors (void)
 463 {
 464   struct inferior *ss, **ss_link;
 465
 466   ss = inferior_list;
 467   ss_link = &inferior_list;
 468   while (ss)
 469     {
 470       if (!ss->deletable ()
 471           || !ss->removable
 472           || ss->pid != 0)
 473         {
 474           ss_link = &ss->next;
 475           ss = *ss_link;
 476           continue;
 477         }
 478
 479       *ss_link = ss->next;
 480       delete_inferior (ss);
 481       ss = *ss_link;
 482     }
 483 }
 484
 485 /* Simply returns the count of inferiors.  */
 486
 487 int
 488 number_of_inferiors (void)
 489 {
 490   struct inferior *inf;
 491   int count = 0;
 492
 493   for (inf = inferior_list; inf != NULL; inf = inf->next)
 494     count++;
 495
 496   return count;
 497 }
 498
 499 /* Converts an inferior process id to a string.  Like
 500    target_pid_to_str, but special cases the null process.  */
 501
 502 static const char *
 503 inferior_pid_to_str (int pid)
 504 {
 505   if (pid != 0)
 506     return target_pid_to_str (pid_to_ptid (pid));
 507   else
 508     return _("<null>");
 509 }
 510
 511 /* See inferior.h.  */
 512
 513 void
 514 print_selected_inferior (struct ui_out *uiout)
 515 {
 516   struct inferior *inf = current_inferior ();
 517   const char *filename = inf->pspace->pspace_exec_filename;
 518
 519   if (filename == NULL)
 520     filename = _("<noexec>");
 521
 522   uiout->message (_("[Switching to inferior %d [%s] (%s)]\n"),
 523                   inf->num, inferior_pid_to_str (inf->pid), filename);
 524 }
 525
 526 /* Prints the list of inferiors and their details on UIOUT.  This is a
 527    version of 'info_inferior_command' suitable for use from MI.
 528
 529    If REQUESTED_INFERIORS is not NULL, it's a list of GDB ids of the
 530    inferiors that should be printed.  Otherwise, all inferiors are
 531    printed.  */
 532
 533 static void
 534 print_inferior (struct ui_out *uiout, char *requested_inferiors)
 535 {
 536   struct inferior *inf;
 537   int inf_count = 0;
 538
 539   /* Compute number of inferiors we will print.  */
 540   for (inf = inferior_list; inf; inf = inf->next)
 541     {
 542       if (!number_is_in_list (requested_inferiors, inf->num))
 543         continue;
 544
 545       ++inf_count;
 546     }
 547
 548   if (inf_count == 0)
 549     {
 550       uiout->message ("No inferiors.\n");
 551       return;
 552     }
 553
 554   ui_out_emit_table table_emitter (uiout, 4, inf_count, "inferiors");
 555   uiout->table_header (1, ui_left, "current", "");
 556   uiout->table_header (4, ui_left, "number", "Num");
 557   uiout->table_header (17, ui_left, "target-id", "Description");
 558   uiout->table_header (17, ui_left, "exec", "Executable");
 559
 560   uiout->table_body ();
 561   for (inf = inferior_list; inf; inf = inf->next)
 562     {
 563       if (!number_is_in_list (requested_inferiors, inf->num))
 564         continue;
 565
 566       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 567
 568       if (inf == current_inferior ())
 569         uiout->field_string ("current", "*");
 570       else
 571         uiout->field_skip ("current");
 572
 573       uiout->field_int ("number", inf->num);
 574
 575       uiout->field_string ("target-id", inferior_pid_to_str (inf->pid));
 576
 577       if (inf->pspace->pspace_exec_filename != NULL)
 578         uiout->field_string ("exec", inf->pspace->pspace_exec_filename);
 579       else
 580         uiout->field_skip ("exec");
 581
 582       /* Print extra info that isn't really fit to always present in
 583          tabular form.  Currently we print the vfork parent/child
 584          relationships, if any.  */
 585       if (inf->vfork_parent)
 586         {
 587           uiout->text (_("\n\tis vfork child of inferior "));
 588           uiout->field_int ("vfork-parent", inf->vfork_parent->num);
 589         }
 590       if (inf->vfork_child)
 591         {
 592           uiout->text (_("\n\tis vfork parent of inferior "));
 593           uiout->field_int ("vfork-child", inf->vfork_child->num);
 594         }
 595
 596       uiout->text ("\n");
 597     }
 598 }
 599
 600 static void
 601 detach_inferior_command (char *args, int from_tty)
 602 {
 603   struct thread_info *tp;
 604
 605   if (!args || !*args)
 606     error (_("Requires argument (inferior id(s) to detach)"));
 607
 608   number_or_range_parser parser (args);
 609   while (!parser.finished ())
 610     {
 611       int num = parser.get_number ();
 612
 613       if (!valid_gdb_inferior_id (num))
 614         {
 615           warning (_("Inferior ID %d not known."), num);
 616           continue;
 617         }
 618
 619       int pid = gdb_inferior_id_to_pid (num);
 620       if (pid == 0)
 621         {
 622           warning (_("Inferior ID %d is not running."), num);
 623           continue;
 624         }
 625
 626       tp = any_thread_of_process (pid);
 627       if (!tp)
 628         {
 629           warning (_("Inferior ID %d has no threads."), num);
 630           continue;
 631         }
 632
 633       switch_to_thread (tp->ptid);
 634
 635       detach_command (NULL, from_tty);
 636     }
 637 }
 638
 639 static void
 640 kill_inferior_command (char *args, int from_tty)
 641 {
 642   struct thread_info *tp;
 643
 644   if (!args || !*args)
 645     error (_("Requires argument (inferior id(s) to kill)"));
 646
 647   number_or_range_parser parser (args);
 648   while (!parser.finished ())
 649     {
 650       int num = parser.get_number ();
 651
 652       if (!valid_gdb_inferior_id (num))
 653         {
 654           warning (_("Inferior ID %d not known."), num);
 655           continue;
 656         }
 657
 658       int pid = gdb_inferior_id_to_pid (num);
 659       if (pid == 0)
 660         {
 661           warning (_("Inferior ID %d is not running."), num);
 662           continue;
 663         }
 664
 665       tp = any_thread_of_process (pid);
 666       if (!tp)
 667         {
 668           warning (_("Inferior ID %d has no threads."), num);
 669           continue;
 670         }
 671
 672       switch_to_thread (tp->ptid);
 673
 674       target_kill ();
 675     }
 676
 677   bfd_cache_close_all ();
 678 }
 679
 680 static void
 681 inferior_command (char *args, int from_tty)
 682 {
 683   struct inferior *inf;
 684   int num;
 685
 686   num = parse_and_eval_long (args);
 687
 688   inf = find_inferior_id (num);
 689   if (inf == NULL)
 690     error (_("Inferior ID %d not known."), num);
 691
 692   if (inf->pid != 0)
 693     {
 694       if (inf->pid != ptid_get_pid (inferior_ptid))
 695         {
 696           struct thread_info *tp;
 697
 698           tp = any_thread_of_process (inf->pid);
 699           if (!tp)
 700             error (_("Inferior has no threads."));
 701
 702           switch_to_thread (tp->ptid);
 703         }
 704
 705       observer_notify_user_selected_context_changed
 706         (USER_SELECTED_INFERIOR
 707          | USER_SELECTED_THREAD
 708          | USER_SELECTED_FRAME);
 709     }
 710   else
 711     {
 712       set_current_inferior (inf);
 713       switch_to_thread (null_ptid);
 714       set_current_program_space (inf->pspace);
 715
 716       observer_notify_user_selected_context_changed (USER_SELECTED_INFERIOR);
 717     }
 718 }
 719
 720 /* Print information about currently known inferiors.  */
 721
 722 static void
 723 info_inferiors_command (char *args, int from_tty)
 724 {
 725   print_inferior (current_uiout, args);
 726 }
 727
 728 /* remove-inferior ID */
 729
 730 static void
 731 remove_inferior_command (char *args, int from_tty)
 732 {
 733   if (args == NULL || *args == '\0')
 734     error (_("Requires an argument (inferior id(s) to remove)"));
 735
 736   number_or_range_parser parser (args);
 737   while (!parser.finished ())
 738     {
 739       int num = parser.get_number ();
 740       struct inferior *inf = find_inferior_id (num);
 741
 742       if (inf == NULL)
 743         {
 744           warning (_("Inferior ID %d not known."), num);
 745           continue;
 746         }
 747
 748       if (!inf->deletable ())
 749         {
 750           warning (_("Can not remove current inferior %d."), num);
 751           continue;
 752         }
 753
 754       if (inf->pid != 0)
 755         {
 756           warning (_("Can not remove active inferior %d."), num);
 757           continue;
 758         }
 759
 760       delete_inferior (inf);
 761     }
 762 }
 763
 764 struct inferior *
 765 add_inferior_with_spaces (void)
 766 {
 767   struct address_space *aspace;
 768   struct program_space *pspace;
 769   struct inferior *inf;
 770   struct gdbarch_info info;
 771
 772   /* If all inferiors share an address space on this system, this
 773      doesn't really return a new address space; otherwise, it
 774      really does.  */
 775   aspace = maybe_new_address_space ();
 776   pspace = add_program_space (aspace);
 777   inf = add_inferior (0);
 778   inf->pspace = pspace;
 779   inf->aspace = pspace->aspace;
 780
 781   /* Setup the inferior's initial arch, based on information obtained
 782      from the global "set ..." options.  */
 783   gdbarch_info_init (&info);
 784   inf->gdbarch = gdbarch_find_by_info (info);
 785   /* The "set ..." options reject invalid settings, so we should
 786      always have a valid arch by now.  */
 787   gdb_assert (inf->gdbarch != NULL);
 788
 789   return inf;
 790 }
 791
 792 /* add-inferior [-copies N] [-exec FILENAME]  */
 793
 794 static void
 795 add_inferior_command (char *args, int from_tty)
 796 {
 797   int i, copies = 1;
 798   gdb::unique_xmalloc_ptr<char> exec;
 799   symfile_add_flags add_flags = 0;
 800
 801   if (from_tty)
 802     add_flags |= SYMFILE_VERBOSE;
 803
 804   if (args)
 805     {
 806       gdb_argv built_argv (args);
 807
 808       for (char **argv = built_argv.get (); *argv != NULL; argv++)
 809         {
 810           if (**argv == '-')
 811             {
 812               if (strcmp (*argv, "-copies") == 0)
 813                 {
 814                   ++argv;
 815                   if (!*argv)
 816                     error (_("No argument to -copies"));
 817                   copies = parse_and_eval_long (*argv);
 818                 }
 819               else if (strcmp (*argv, "-exec") == 0)
 820                 {
 821                   ++argv;
 822                   if (!*argv)
 823                     error (_("No argument to -exec"));
 824                   exec.reset (tilde_expand (*argv));
 825                 }
 826             }
 827           else
 828             error (_("Invalid argument"));
 829         }
 830     }
 831
 832   scoped_restore_current_pspace_and_thread restore_pspace_thread;
 833
 834   for (i = 0; i < copies; ++i)
 835     {
 836       struct inferior *inf = add_inferior_with_spaces ();
 837
 838       printf_filtered (_("Added inferior %d\n"), inf->num);
 839
 840       if (exec != NULL)
 841         {
 842           /* Switch over temporarily, while reading executable and
 843              symbols.q.  */
 844           set_current_program_space (inf->pspace);
 845           set_current_inferior (inf);
 846           switch_to_thread (null_ptid);
 847
 848           exec_file_attach (exec.get (), from_tty);
 849           symbol_file_add_main (exec.get (), add_flags);
 850         }
 851     }
 852 }
 853
 854 /* clone-inferior [-copies N] [ID] */
 855
 856 static void
 857 clone_inferior_command (char *args, int from_tty)
 858 {
 859   int i, copies = 1;
 860   struct inferior *orginf = NULL;
 861
 862   if (args)
 863     {
 864       gdb_argv built_argv (args);
 865
 866       char **argv = built_argv.get ();
 867       for (; *argv != NULL; argv++)
 868         {
 869           if (**argv == '-')
 870             {
 871               if (strcmp (*argv, "-copies") == 0)
 872                 {
 873                   ++argv;
 874                   if (!*argv)
 875                     error (_("No argument to -copies"));
 876                   copies = parse_and_eval_long (*argv);
 877
 878                   if (copies < 0)
 879                     error (_("Invalid copies number"));
 880                 }
 881             }
 882           else
 883             {
 884               if (orginf == NULL)
 885                 {
 886                   int num;
 887
 888                   /* The first non-option (-) argument specified the
 889                      program space ID.  */
 890                   num = parse_and_eval_long (*argv);
 891                   orginf = find_inferior_id (num);
 892
 893                   if (orginf == NULL)
 894                     error (_("Inferior ID %d not known."), num);
 895                   continue;
 896                 }
 897               else
 898                 error (_("Invalid argument"));
 899             }
 900         }
 901     }
 902
 903   /* If no inferior id was specified, then the user wants to clone the
 904      current inferior.  */
 905   if (orginf == NULL)
 906     orginf = current_inferior ();
 907
 908   scoped_restore_current_pspace_and_thread restore_pspace_thread;
 909
 910   for (i = 0; i < copies; ++i)
 911     {
 912       struct address_space *aspace;
 913       struct program_space *pspace;
 914       struct inferior *inf;
 915
 916       /* If all inferiors share an address space on this system, this
 917          doesn't really return a new address space; otherwise, it
 918          really does.  */
 919       aspace = maybe_new_address_space ();
 920       pspace = add_program_space (aspace);
 921       inf = add_inferior (0);
 922       inf->pspace = pspace;
 923       inf->aspace = pspace->aspace;
 924       inf->gdbarch = orginf->gdbarch;
 925
 926       /* If the original inferior had a user specified target
 927          description, make the clone use it too.  */
 928       if (target_desc_info_from_user_p (inf->tdesc_info))
 929         copy_inferior_target_desc_info (inf, orginf);
 930
 931       printf_filtered (_("Added inferior %d.\n"), inf->num);
 932
 933       set_current_inferior (inf);
 934       switch_to_thread (null_ptid);
 935       clone_program_space (pspace, orginf->pspace);
 936     }
 937 }
 938
 939 /* Print notices when new inferiors are created and die.  */
 940 static void
 941 show_print_inferior_events (struct ui_file *file, int from_tty,
 942                            struct cmd_list_element *c, const char *value)
 943 {
 944   fprintf_filtered (file, _("Printing of inferior events is %s.\n"), value);
 945 }
 946
 947 /* Return a new value for the selected inferior's id.  */
 948
 949 static struct value *
 950 inferior_id_make_value (struct gdbarch *gdbarch, struct internalvar *var,
 951                         void *ignore)
 952 {
 953   struct inferior *inf = current_inferior ();
 954
 955   return value_from_longest (builtin_type (gdbarch)->builtin_int, inf->num);
 956 }
 957
 958 /* Implementation of `$_inferior' variable.  */
 959
 960 static const struct internalvar_funcs inferior_funcs =
 961 {
 962   inferior_id_make_value,
 963   NULL,
 964   NULL
 965 };
 966
 967 \f
 968
 969 void
 970 initialize_inferiors (void)
 971 {
 972   struct cmd_list_element *c = NULL;
 973
 974   /* There's always one inferior.  Note that this function isn't an
 975      automatic _initialize_foo function, since other _initialize_foo
 976      routines may need to install their per-inferior data keys.  We
 977      can only allocate an inferior when all those modules have done
 978      that.  Do this after initialize_progspace, due to the
 979      current_program_space reference.  */
 980   current_inferior_ = add_inferior (0);
 981   current_inferior_->incref ();
 982   current_inferior_->pspace = current_program_space;
 983   current_inferior_->aspace = current_program_space->aspace;
 984   /* The architecture will be initialized shortly, by
 985      initialize_current_architecture.  */
 986
 987   add_info ("inferiors", info_inferiors_command,
 988             _("IDs of specified inferiors (all inferiors if no argument)."));
 989
 990   c = add_com ("add-inferior", no_class, add_inferior_command, _("\
 991 Add a new inferior.\n\
 992 Usage: add-inferior [-copies <N>] [-exec <FILENAME>]\n\
 993 N is the optional number of inferiors to add, default is 1.\n\
 994 FILENAME is the file name of the executable to use\n\
 995 as main program."));
 996   set_cmd_completer (c, filename_completer);
 997
 998   add_com ("remove-inferiors", no_class, remove_inferior_command, _("\
 999 Remove inferior ID (or list of IDs).\n\
1000 Usage: remove-inferiors ID..."));
1001
1002   add_com ("clone-inferior", no_class, clone_inferior_command, _("\
1003 Clone inferior ID.\n\
1004 Usage: clone-inferior [-copies <N>] [ID]\n\
1005 Add N copies of inferior ID.  The new inferior has the same\n\
1006 executable loaded as the copied inferior.  If -copies is not specified,\n\
1007 adds 1 copy.  If ID is not specified, it is the current inferior\n\
1008 that is cloned."));
1009
1010   add_cmd ("inferiors", class_run, detach_inferior_command, _("\
1011 Detach from inferior ID (or list of IDS)."),
1012            &detachlist);
1013
1014   add_cmd ("inferiors", class_run, kill_inferior_command, _("\
1015 Kill inferior ID (or list of IDs)."),
1016            &killlist);
1017
1018   add_cmd ("inferior", class_run, inferior_command, _("\
1019 Use this command to switch between inferiors.\n\
1020 The new inferior ID must be currently known."),
1021            &cmdlist);
1022
1023   add_setshow_boolean_cmd ("inferior-events", no_class,
1024          &print_inferior_events, _("\
1025 Set printing of inferior events (e.g., inferior start and exit)."), _("\
1026 Show printing of inferior events (e.g., inferior start and exit)."), NULL,
1027          NULL,
1028          show_print_inferior_events,
1029          &setprintlist, &showprintlist);
1030
1031   create_internalvar_type_lazy ("_inferior", &inferior_funcs, NULL);
1032 }