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