gdb/inferior.c

   1 /* Multi-process control for GDB, the GNU debugger.
   2
   3    Copyright (C) 2008-2018 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 /* Keep a registry of per-inferior data-pointers required by other GDB
  41    modules.  */
  42
  43 DEFINE_REGISTRY (inferior, REGISTRY_ACCESS_FIELD)
  44
  45 struct inferior *inferior_list = NULL;
  46 static int highest_inferior_num;
  47
  48 /* Print notices on inferior events (attach, detach, etc.), set with
  49    `set print inferior-events'.  */
  50 static int print_inferior_events = 0;
  51
  52 /* The Current Inferior.  This is a strong reference.  I.e., whenever
  53    an inferior is the current inferior, its refcount is
  54    incremented.  */
  55 static struct inferior *current_inferior_ = NULL;
  56
  57 struct inferior*
  58 current_inferior (void)
  59 {
  60   return current_inferior_;
  61 }
  62
  63 void
  64 set_current_inferior (struct inferior *inf)
  65 {
  66   /* There's always an inferior.  */
  67   gdb_assert (inf != NULL);
  68
  69   inf->incref ();
  70   current_inferior_->decref ();
  71   current_inferior_ = inf;
  72 }
  73
  74 private_inferior::~private_inferior () = default;
  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 }
  86
  87 inferior::inferior (int pid_)
  88   : num (++highest_inferior_num),
  89     pid (pid_),
  90     environment (gdb_environ::from_host_environ ()),
  91     registry_data ()
  92 {
  93   inferior_alloc_data (this);
  94 }
  95
  96 struct inferior *
  97 add_inferior_silent (int pid)
  98 {
  99   inferior *inf = new inferior (pid);
 100
 101   if (inferior_list == NULL)
 102     inferior_list = inf;
 103   else
 104     {
 105       inferior *last;
 106
 107       for (last = inferior_list; last->next != NULL; last = last->next)
 108         ;
 109       last->next = inf;
 110     }
 111
 112   observer_notify_inferior_added (inf);
 113
 114   if (pid != 0)
 115     inferior_appeared (inf, pid);
 116
 117   return inf;
 118 }
 119
 120 struct inferior *
 121 add_inferior (int pid)
 122 {
 123   struct inferior *inf = add_inferior_silent (pid);
 124
 125   if (print_inferior_events)
 126     printf_unfiltered (_("[New inferior %d]\n"), pid);
 127
 128   return inf;
 129 }
 130
 131 struct delete_thread_of_inferior_arg
 132 {
 133   int pid;
 134   int silent;
 135 };
 136
 137 static int
 138 delete_thread_of_inferior (struct thread_info *tp, void *data)
 139 {
 140   struct delete_thread_of_inferior_arg *arg
 141     = (struct delete_thread_of_inferior_arg *) data;
 142
 143   if (ptid_get_pid (tp->ptid) == arg->pid)
 144     {
 145       if (arg->silent)
 146         delete_thread_silent (tp->ptid);
 147       else
 148         delete_thread (tp->ptid);
 149     }
 150
 151   return 0;
 152 }
 153
 154 void
 155 delete_inferior (struct inferior *todel)
 156 {
 157   struct inferior *inf, *infprev;
 158   struct delete_thread_of_inferior_arg arg;
 159
 160   infprev = NULL;
 161
 162   for (inf = inferior_list; inf; infprev = inf, inf = inf->next)
 163     if (inf == todel)
 164       break;
 165
 166   if (!inf)
 167     return;
 168
 169   arg.pid = inf->pid;
 170   arg.silent = 1;
 171
 172   iterate_over_threads (delete_thread_of_inferior, &arg);
 173
 174   if (infprev)
 175     infprev->next = inf->next;
 176   else
 177     inferior_list = inf->next;
 178
 179   observer_notify_inferior_removed (inf);
 180
 181   /* If this program space is rendered useless, remove it. */
 182   if (program_space_empty_p (inf->pspace))
 183     delete_program_space (inf->pspace);
 184
 185   delete inf;
 186 }
 187
 188 /* If SILENT then be quiet -- don't announce a inferior exit, or the
 189    exit of its threads.  */
 190
 191 static void
 192 exit_inferior_1 (struct inferior *inftoex, int silent)
 193 {
 194   struct inferior *inf;
 195   struct delete_thread_of_inferior_arg arg;
 196
 197   for (inf = inferior_list; inf; inf = inf->next)
 198     if (inf == inftoex)
 199       break;
 200
 201   if (!inf)
 202     return;
 203
 204   arg.pid = inf->pid;
 205   arg.silent = silent;
 206
 207   iterate_over_threads (delete_thread_of_inferior, &arg);
 208
 209   observer_notify_inferior_exit (inf);
 210
 211   inf->pid = 0;
 212   inf->fake_pid_p = 0;
 213   inf->priv = NULL;
 214
 215   if (inf->vfork_parent != NULL)
 216     {
 217       inf->vfork_parent->vfork_child = NULL;
 218       inf->vfork_parent = NULL;
 219     }
 220   if (inf->vfork_child != NULL)
 221     {
 222       inf->vfork_child->vfork_parent = NULL;
 223       inf->vfork_child = NULL;
 224     }
 225
 226   inf->pending_detach = 0;
 227 }
 228
 229 void
 230 exit_inferior (int pid)
 231 {
 232   struct inferior *inf = find_inferior_pid (pid);
 233
 234   exit_inferior_1 (inf, 0);
 235
 236   if (print_inferior_events)
 237     printf_unfiltered (_("[Inferior %d exited]\n"), pid);
 238 }
 239
 240 void
 241 exit_inferior_silent (int pid)
 242 {
 243   struct inferior *inf = find_inferior_pid (pid);
 244
 245   exit_inferior_1 (inf, 1);
 246 }
 247
 248 void
 249 exit_inferior_num_silent (int num)
 250 {
 251   struct inferior *inf = find_inferior_id (num);
 252
 253   exit_inferior_1 (inf, 1);
 254 }
 255
 256 /* See inferior.h.  */
 257
 258 void
 259 detach_inferior (inferior *inf)
 260 {
 261   /* Save the pid, since exit_inferior_1 will reset it.  */
 262   int pid = inf->pid;
 263
 264   exit_inferior_1 (inf, 0);
 265
 266   if (print_inferior_events)
 267     printf_unfiltered (_("[Inferior %d detached]\n"), pid);
 268 }
 269
 270 /* See inferior.h.  */
 271
 272 void
 273 detach_inferior (int pid)
 274 {
 275   detach_inferior (find_inferior_pid (pid));
 276 }
 277
 278 void
 279 inferior_appeared (struct inferior *inf, int pid)
 280 {
 281   inf->pid = pid;
 282   inf->has_exit_code = 0;
 283   inf->exit_code = 0;
 284
 285   observer_notify_inferior_appeared (inf);
 286 }
 287
 288 void
 289 discard_all_inferiors (void)
 290 {
 291   struct inferior *inf;
 292
 293   for (inf = inferior_list; inf; inf = inf->next)
 294     {
 295       if (inf->pid != 0)
 296         exit_inferior_silent (inf->pid);
 297     }
 298 }
 299
 300 struct inferior *
 301 find_inferior_id (int num)
 302 {
 303   struct inferior *inf;
 304
 305   for (inf = inferior_list; inf; inf = inf->next)
 306     if (inf->num == num)
 307       return inf;
 308
 309   return NULL;
 310 }
 311
 312 struct inferior *
 313 find_inferior_pid (int pid)
 314 {
 315   struct inferior *inf;
 316
 317   /* Looking for inferior pid == 0 is always wrong, and indicative of
 318      a bug somewhere else.  There may be more than one with pid == 0,
 319      for instance.  */
 320   gdb_assert (pid != 0);
 321
 322   for (inf = inferior_list; inf; inf = inf->next)
 323     if (inf->pid == pid)
 324       return inf;
 325
 326   return NULL;
 327 }
 328
 329 /* See inferior.h */
 330
 331 struct inferior *
 332 find_inferior_ptid (ptid_t ptid)
 333 {
 334   return find_inferior_pid (ptid_get_pid (ptid));
 335 }
 336
 337 /* See inferior.h.  */
 338
 339 struct inferior *
 340 find_inferior_for_program_space (struct program_space *pspace)
 341 {
 342   struct inferior *inf = current_inferior ();
 343
 344   if (inf->pspace == pspace)
 345     return inf;
 346
 347   for (inf = inferior_list; inf != NULL; inf = inf->next)
 348     {
 349       if (inf->pspace == pspace)
 350         return inf;
 351     }
 352
 353   return NULL;
 354 }
 355
 356 struct inferior *
 357 iterate_over_inferiors (int (*callback) (struct inferior *, void *),
 358                         void *data)
 359 {
 360   struct inferior *inf, *infnext;
 361
 362   for (inf = inferior_list; inf; inf = infnext)
 363     {
 364       infnext = inf->next;
 365       if ((*callback) (inf, data))
 366         return inf;
 367     }
 368
 369   return NULL;
 370 }
 371
 372 int
 373 valid_gdb_inferior_id (int num)
 374 {
 375   struct inferior *inf;
 376
 377   for (inf = inferior_list; inf; inf = inf->next)
 378     if (inf->num == num)
 379       return 1;
 380
 381   return 0;
 382 }
 383
 384 int
 385 pid_to_gdb_inferior_id (int pid)
 386 {
 387   struct inferior *inf;
 388
 389   for (inf = inferior_list; inf; inf = inf->next)
 390     if (inf->pid == pid)
 391       return inf->num;
 392
 393   return 0;
 394 }
 395
 396 int
 397 gdb_inferior_id_to_pid (int num)
 398 {
 399   struct inferior *inferior = find_inferior_id (num);
 400   if (inferior)
 401     return inferior->pid;
 402   else
 403     return -1;
 404 }
 405
 406 int
 407 in_inferior_list (int pid)
 408 {
 409   struct inferior *inf;
 410
 411   for (inf = inferior_list; inf; inf = inf->next)
 412     if (inf->pid == pid)
 413       return 1;
 414
 415   return 0;
 416 }
 417
 418 int
 419 have_inferiors (void)
 420 {
 421   struct inferior *inf;
 422
 423   for (inf = inferior_list; inf; inf = inf->next)
 424     if (inf->pid != 0)
 425       return 1;
 426
 427   return 0;
 428 }
 429
 430 /* Return the number of live inferiors.  We account for the case
 431    where an inferior might have a non-zero pid but no threads, as
 432    in the middle of a 'mourn' operation.  */
 433
 434 int
 435 number_of_live_inferiors (void)
 436 {
 437   struct inferior *inf;
 438   int num_inf = 0;
 439
 440   for (inf = inferior_list; inf; inf = inf->next)
 441     if (inf->pid != 0)
 442       {
 443         struct thread_info *tp;
 444
 445         ALL_NON_EXITED_THREADS (tp)
 446          if (tp && ptid_get_pid (tp->ptid) == inf->pid)
 447            if (target_has_execution_1 (tp->ptid))
 448              {
 449                /* Found a live thread in this inferior, go to the next
 450                   inferior.  */
 451                ++num_inf;
 452                break;
 453              }
 454       }
 455
 456   return num_inf;
 457 }
 458
 459 /* Return true if there is at least one live inferior.  */
 460
 461 int
 462 have_live_inferiors (void)
 463 {
 464   return number_of_live_inferiors () > 0;
 465 }
 466
 467 /* Prune away any unused inferiors, and then prune away no longer used
 468    program spaces.  */
 469
 470 void
 471 prune_inferiors (void)
 472 {
 473   struct inferior *ss, **ss_link;
 474
 475   ss = inferior_list;
 476   ss_link = &inferior_list;
 477   while (ss)
 478     {
 479       if (!ss->deletable ()
 480           || !ss->removable
 481           || ss->pid != 0)
 482         {
 483           ss_link = &ss->next;
 484           ss = *ss_link;
 485           continue;
 486         }
 487
 488       *ss_link = ss->next;
 489       delete_inferior (ss);
 490       ss = *ss_link;
 491     }
 492 }
 493
 494 /* Simply returns the count of inferiors.  */
 495
 496 int
 497 number_of_inferiors (void)
 498 {
 499   struct inferior *inf;
 500   int count = 0;
 501
 502   for (inf = inferior_list; inf != NULL; inf = inf->next)
 503     count++;
 504
 505   return count;
 506 }
 507
 508 /* Converts an inferior process id to a string.  Like
 509    target_pid_to_str, but special cases the null process.  */
 510
 511 static const char *
 512 inferior_pid_to_str (int pid)
 513 {
 514   if (pid != 0)
 515     return target_pid_to_str (pid_to_ptid (pid));
 516   else
 517     return _("<null>");
 518 }
 519
 520 /* See inferior.h.  */
 521
 522 void
 523 print_selected_inferior (struct ui_out *uiout)
 524 {
 525   struct inferior *inf = current_inferior ();
 526   const char *filename = inf->pspace->pspace_exec_filename;
 527
 528   if (filename == NULL)
 529     filename = _("<noexec>");
 530
 531   uiout->message (_("[Switching to inferior %d [%s] (%s)]\n"),
 532                   inf->num, inferior_pid_to_str (inf->pid), filename);
 533 }
 534
 535 /* Prints the list of inferiors and their details on UIOUT.  This is a
 536    version of 'info_inferior_command' suitable for use from MI.
 537
 538    If REQUESTED_INFERIORS is not NULL, it's a list of GDB ids of the
 539    inferiors that should be printed.  Otherwise, all inferiors are
 540    printed.  */
 541
 542 static void
 543 print_inferior (struct ui_out *uiout, const char *requested_inferiors)
 544 {
 545   struct inferior *inf;
 546   int inf_count = 0;
 547
 548   /* Compute number of inferiors we will print.  */
 549   for (inf = inferior_list; inf; inf = inf->next)
 550     {
 551       if (!number_is_in_list (requested_inferiors, inf->num))
 552         continue;
 553
 554       ++inf_count;
 555     }
 556
 557   if (inf_count == 0)
 558     {
 559       uiout->message ("No inferiors.\n");
 560       return;
 561     }
 562
 563   ui_out_emit_table table_emitter (uiout, 4, inf_count, "inferiors");
 564   uiout->table_header (1, ui_left, "current", "");
 565   uiout->table_header (4, ui_left, "number", "Num");
 566   uiout->table_header (17, ui_left, "target-id", "Description");
 567   uiout->table_header (17, ui_left, "exec", "Executable");
 568
 569   uiout->table_body ();
 570   for (inf = inferior_list; inf; inf = inf->next)
 571     {
 572       if (!number_is_in_list (requested_inferiors, inf->num))
 573         continue;
 574
 575       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 576
 577       if (inf == current_inferior ())
 578         uiout->field_string ("current", "*");
 579       else
 580         uiout->field_skip ("current");
 581
 582       uiout->field_int ("number", inf->num);
 583
 584       uiout->field_string ("target-id", inferior_pid_to_str (inf->pid));
 585
 586       if (inf->pspace->pspace_exec_filename != NULL)
 587         uiout->field_string ("exec", inf->pspace->pspace_exec_filename);
 588       else
 589         uiout->field_skip ("exec");
 590
 591       /* Print extra info that isn't really fit to always present in
 592          tabular form.  Currently we print the vfork parent/child
 593          relationships, if any.  */
 594       if (inf->vfork_parent)
 595         {
 596           uiout->text (_("\n\tis vfork child of inferior "));
 597           uiout->field_int ("vfork-parent", inf->vfork_parent->num);
 598         }
 599       if (inf->vfork_child)
 600         {
 601           uiout->text (_("\n\tis vfork parent of inferior "));
 602           uiout->field_int ("vfork-child", inf->vfork_child->num);
 603         }
 604
 605       uiout->text ("\n");
 606     }
 607 }
 608
 609 static void
 610 detach_inferior_command (const char *args, int from_tty)
 611 {
 612   struct thread_info *tp;
 613
 614   if (!args || !*args)
 615     error (_("Requires argument (inferior id(s) to detach)"));
 616
 617   number_or_range_parser parser (args);
 618   while (!parser.finished ())
 619     {
 620       int num = parser.get_number ();
 621
 622       if (!valid_gdb_inferior_id (num))
 623         {
 624           warning (_("Inferior ID %d not known."), num);
 625           continue;
 626         }
 627
 628       int pid = gdb_inferior_id_to_pid (num);
 629       if (pid == 0)
 630         {
 631           warning (_("Inferior ID %d is not running."), num);
 632           continue;
 633         }
 634
 635       tp = any_thread_of_process (pid);
 636       if (!tp)
 637         {
 638           warning (_("Inferior ID %d has no threads."), num);
 639           continue;
 640         }
 641
 642       switch_to_thread (tp->ptid);
 643
 644       detach_command (NULL, from_tty);
 645     }
 646 }
 647
 648 static void
 649 kill_inferior_command (const char *args, int from_tty)
 650 {
 651   struct thread_info *tp;
 652
 653   if (!args || !*args)
 654     error (_("Requires argument (inferior id(s) to kill)"));
 655
 656   number_or_range_parser parser (args);
 657   while (!parser.finished ())
 658     {
 659       int num = parser.get_number ();
 660
 661       if (!valid_gdb_inferior_id (num))
 662         {
 663           warning (_("Inferior ID %d not known."), num);
 664           continue;
 665         }
 666
 667       int pid = gdb_inferior_id_to_pid (num);
 668       if (pid == 0)
 669         {
 670           warning (_("Inferior ID %d is not running."), num);
 671           continue;
 672         }
 673
 674       tp = any_thread_of_process (pid);
 675       if (!tp)
 676         {
 677           warning (_("Inferior ID %d has no threads."), num);
 678           continue;
 679         }
 680
 681       switch_to_thread (tp->ptid);
 682
 683       target_kill ();
 684     }
 685
 686   bfd_cache_close_all ();
 687 }
 688
 689 static void
 690 inferior_command (const char *args, int from_tty)
 691 {
 692   struct inferior *inf;
 693   int num;
 694
 695   num = parse_and_eval_long (args);
 696
 697   inf = find_inferior_id (num);
 698   if (inf == NULL)
 699     error (_("Inferior ID %d not known."), num);
 700
 701   if (inf->pid != 0)
 702     {
 703       if (inf->pid != ptid_get_pid (inferior_ptid))
 704         {
 705           struct thread_info *tp;
 706
 707           tp = any_thread_of_process (inf->pid);
 708           if (!tp)
 709             error (_("Inferior has no threads."));
 710
 711           switch_to_thread (tp->ptid);
 712         }
 713
 714       observer_notify_user_selected_context_changed
 715         (USER_SELECTED_INFERIOR
 716          | USER_SELECTED_THREAD
 717          | USER_SELECTED_FRAME);
 718     }
 719   else
 720     {
 721       set_current_inferior (inf);
 722       switch_to_thread (null_ptid);
 723       set_current_program_space (inf->pspace);
 724
 725       observer_notify_user_selected_context_changed (USER_SELECTED_INFERIOR);
 726     }
 727 }
 728
 729 /* Print information about currently known inferiors.  */
 730
 731 static void
 732 info_inferiors_command (const char *args, int from_tty)
 733 {
 734   print_inferior (current_uiout, args);
 735 }
 736
 737 /* remove-inferior ID */
 738
 739 static void
 740 remove_inferior_command (const char *args, int from_tty)
 741 {
 742   if (args == NULL || *args == '\0')
 743     error (_("Requires an argument (inferior id(s) to remove)"));
 744
 745   number_or_range_parser parser (args);
 746   while (!parser.finished ())
 747     {
 748       int num = parser.get_number ();
 749       struct inferior *inf = find_inferior_id (num);
 750
 751       if (inf == NULL)
 752         {
 753           warning (_("Inferior ID %d not known."), num);
 754           continue;
 755         }
 756
 757       if (!inf->deletable ())
 758         {
 759           warning (_("Can not remove current inferior %d."), num);
 760           continue;
 761         }
 762
 763       if (inf->pid != 0)
 764         {
 765           warning (_("Can not remove active inferior %d."), num);
 766           continue;
 767         }
 768
 769       delete_inferior (inf);
 770     }
 771 }
 772
 773 struct inferior *
 774 add_inferior_with_spaces (void)
 775 {
 776   struct address_space *aspace;
 777   struct program_space *pspace;
 778   struct inferior *inf;
 779   struct gdbarch_info info;
 780
 781   /* If all inferiors share an address space on this system, this
 782      doesn't really return a new address space; otherwise, it
 783      really does.  */
 784   aspace = maybe_new_address_space ();
 785   pspace = add_program_space (aspace);
 786   inf = add_inferior (0);
 787   inf->pspace = pspace;
 788   inf->aspace = pspace->aspace;
 789
 790   /* Setup the inferior's initial arch, based on information obtained
 791      from the global "set ..." options.  */
 792   gdbarch_info_init (&info);
 793   inf->gdbarch = gdbarch_find_by_info (info);
 794   /* The "set ..." options reject invalid settings, so we should
 795      always have a valid arch by now.  */
 796   gdb_assert (inf->gdbarch != NULL);
 797
 798   return inf;
 799 }
 800
 801 /* add-inferior [-copies N] [-exec FILENAME]  */
 802
 803 static void
 804 add_inferior_command (const char *args, int from_tty)
 805 {
 806   int i, copies = 1;
 807   gdb::unique_xmalloc_ptr<char> exec;
 808   symfile_add_flags add_flags = 0;
 809
 810   if (from_tty)
 811     add_flags |= SYMFILE_VERBOSE;
 812
 813   if (args)
 814     {
 815       gdb_argv built_argv (args);
 816
 817       for (char **argv = built_argv.get (); *argv != NULL; argv++)
 818         {
 819           if (**argv == '-')
 820             {
 821               if (strcmp (*argv, "-copies") == 0)
 822                 {
 823                   ++argv;
 824                   if (!*argv)
 825                     error (_("No argument to -copies"));
 826                   copies = parse_and_eval_long (*argv);
 827                 }
 828               else if (strcmp (*argv, "-exec") == 0)
 829                 {
 830                   ++argv;
 831                   if (!*argv)
 832                     error (_("No argument to -exec"));
 833                   exec.reset (tilde_expand (*argv));
 834                 }
 835             }
 836           else
 837             error (_("Invalid argument"));
 838         }
 839     }
 840
 841   scoped_restore_current_pspace_and_thread restore_pspace_thread;
 842
 843   for (i = 0; i < copies; ++i)
 844     {
 845       struct inferior *inf = add_inferior_with_spaces ();
 846
 847       printf_filtered (_("Added inferior %d\n"), inf->num);
 848
 849       if (exec != NULL)
 850         {
 851           /* Switch over temporarily, while reading executable and
 852              symbols.q.  */
 853           set_current_program_space (inf->pspace);
 854           set_current_inferior (inf);
 855           switch_to_thread (null_ptid);
 856
 857           exec_file_attach (exec.get (), from_tty);
 858           symbol_file_add_main (exec.get (), add_flags);
 859         }
 860     }
 861 }
 862
 863 /* clone-inferior [-copies N] [ID] */
 864
 865 static void
 866 clone_inferior_command (const char *args, int from_tty)
 867 {
 868   int i, copies = 1;
 869   struct inferior *orginf = NULL;
 870
 871   if (args)
 872     {
 873       gdb_argv built_argv (args);
 874
 875       char **argv = built_argv.get ();
 876       for (; *argv != NULL; argv++)
 877         {
 878           if (**argv == '-')
 879             {
 880               if (strcmp (*argv, "-copies") == 0)
 881                 {
 882                   ++argv;
 883                   if (!*argv)
 884                     error (_("No argument to -copies"));
 885                   copies = parse_and_eval_long (*argv);
 886
 887                   if (copies < 0)
 888                     error (_("Invalid copies number"));
 889                 }
 890             }
 891           else
 892             {
 893               if (orginf == NULL)
 894                 {
 895                   int num;
 896
 897                   /* The first non-option (-) argument specified the
 898                      program space ID.  */
 899                   num = parse_and_eval_long (*argv);
 900                   orginf = find_inferior_id (num);
 901
 902                   if (orginf == NULL)
 903                     error (_("Inferior ID %d not known."), num);
 904                   continue;
 905                 }
 906               else
 907                 error (_("Invalid argument"));
 908             }
 909         }
 910     }
 911
 912   /* If no inferior id was specified, then the user wants to clone the
 913      current inferior.  */
 914   if (orginf == NULL)
 915     orginf = current_inferior ();
 916
 917   scoped_restore_current_pspace_and_thread restore_pspace_thread;
 918
 919   for (i = 0; i < copies; ++i)
 920     {
 921       struct address_space *aspace;
 922       struct program_space *pspace;
 923       struct inferior *inf;
 924
 925       /* If all inferiors share an address space on this system, this
 926          doesn't really return a new address space; otherwise, it
 927          really does.  */
 928       aspace = maybe_new_address_space ();
 929       pspace = add_program_space (aspace);
 930       inf = add_inferior (0);
 931       inf->pspace = pspace;
 932       inf->aspace = pspace->aspace;
 933       inf->gdbarch = orginf->gdbarch;
 934
 935       /* If the original inferior had a user specified target
 936          description, make the clone use it too.  */
 937       if (target_desc_info_from_user_p (inf->tdesc_info))
 938         copy_inferior_target_desc_info (inf, orginf);
 939
 940       printf_filtered (_("Added inferior %d.\n"), inf->num);
 941
 942       set_current_inferior (inf);
 943       switch_to_thread (null_ptid);
 944       clone_program_space (pspace, orginf->pspace);
 945     }
 946 }
 947
 948 /* Print notices when new inferiors are created and die.  */
 949 static void
 950 show_print_inferior_events (struct ui_file *file, int from_tty,
 951                            struct cmd_list_element *c, const char *value)
 952 {
 953   fprintf_filtered (file, _("Printing of inferior events is %s.\n"), value);
 954 }
 955
 956 /* Return a new value for the selected inferior's id.  */
 957
 958 static struct value *
 959 inferior_id_make_value (struct gdbarch *gdbarch, struct internalvar *var,
 960                         void *ignore)
 961 {
 962   struct inferior *inf = current_inferior ();
 963
 964   return value_from_longest (builtin_type (gdbarch)->builtin_int, inf->num);
 965 }
 966
 967 /* Implementation of `$_inferior' variable.  */
 968
 969 static const struct internalvar_funcs inferior_funcs =
 970 {
 971   inferior_id_make_value,
 972   NULL,
 973   NULL
 974 };
 975
 976 \f
 977
 978 void
 979 initialize_inferiors (void)
 980 {
 981   struct cmd_list_element *c = NULL;
 982
 983   /* There's always one inferior.  Note that this function isn't an
 984      automatic _initialize_foo function, since other _initialize_foo
 985      routines may need to install their per-inferior data keys.  We
 986      can only allocate an inferior when all those modules have done
 987      that.  Do this after initialize_progspace, due to the
 988      current_program_space reference.  */
 989   current_inferior_ = add_inferior (0);
 990   current_inferior_->incref ();
 991   current_inferior_->pspace = current_program_space;
 992   current_inferior_->aspace = current_program_space->aspace;
 993   /* The architecture will be initialized shortly, by
 994      initialize_current_architecture.  */
 995
 996   add_info ("inferiors", info_inferiors_command,
 997             _("IDs of specified inferiors (all inferiors if no argument)."));
 998
 999   c = add_com ("add-inferior", no_class, add_inferior_command, _("\
1000 Add a new inferior.\n\
1001 Usage: add-inferior [-copies <N>] [-exec <FILENAME>]\n\
1002 N is the optional number of inferiors to add, default is 1.\n\
1003 FILENAME is the file name of the executable to use\n\
1004 as main program."));
1005   set_cmd_completer (c, filename_completer);
1006
1007   add_com ("remove-inferiors", no_class, remove_inferior_command, _("\
1008 Remove inferior ID (or list of IDs).\n\
1009 Usage: remove-inferiors ID..."));
1010
1011   add_com ("clone-inferior", no_class, clone_inferior_command, _("\
1012 Clone inferior ID.\n\
1013 Usage: clone-inferior [-copies <N>] [ID]\n\
1014 Add N copies of inferior ID.  The new inferior has the same\n\
1015 executable loaded as the copied inferior.  If -copies is not specified,\n\
1016 adds 1 copy.  If ID is not specified, it is the current inferior\n\
1017 that is cloned."));
1018
1019   add_cmd ("inferiors", class_run, detach_inferior_command, _("\
1020 Detach from inferior ID (or list of IDS)."),
1021            &detachlist);
1022
1023   add_cmd ("inferiors", class_run, kill_inferior_command, _("\
1024 Kill inferior ID (or list of IDs)."),
1025            &killlist);
1026
1027   add_cmd ("inferior", class_run, inferior_command, _("\
1028 Use this command to switch between inferiors.\n\
1029 The new inferior ID must be currently known."),
1030            &cmdlist);
1031
1032   add_setshow_boolean_cmd ("inferior-events", no_class,
1033          &print_inferior_events, _("\
1034 Set printing of inferior events (e.g., inferior start and exit)."), _("\
1035 Show printing of inferior events (e.g., inferior start and exit)."), NULL,
1036          NULL,
1037          show_print_inferior_events,
1038          &setprintlist, &showprintlist);
1039
1040   create_internalvar_type_lazy ("_inferior", &inferior_funcs, NULL);
1041 }