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->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   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 (int pid)
 234 {
 235   struct inferior *inf = find_inferior_pid (pid);
 236
 237   exit_inferior_1 (inf, 0);
 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 (%s) detached]\n"),
 268                        inf->num,
 269                        target_pid_to_str (pid_to_ptid (pid)));
 270 }
 271
 272 /* See inferior.h.  */
 273
 274 void
 275 detach_inferior (int pid)
 276 {
 277   detach_inferior (find_inferior_pid (pid));
 278 }
 279
 280 void
 281 inferior_appeared (struct inferior *inf, int pid)
 282 {
 283   inf->pid = pid;
 284   inf->has_exit_code = 0;
 285   inf->exit_code = 0;
 286
 287   gdb::observers::inferior_appeared.notify (inf);
 288 }
 289
 290 void
 291 discard_all_inferiors (void)
 292 {
 293   struct inferior *inf;
 294
 295   for (inf = inferior_list; inf; inf = inf->next)
 296     {
 297       if (inf->pid != 0)
 298         exit_inferior_silent (inf->pid);
 299     }
 300 }
 301
 302 struct inferior *
 303 find_inferior_id (int num)
 304 {
 305   struct inferior *inf;
 306
 307   for (inf = inferior_list; inf; inf = inf->next)
 308     if (inf->num == num)
 309       return inf;
 310
 311   return NULL;
 312 }
 313
 314 struct inferior *
 315 find_inferior_pid (int pid)
 316 {
 317   struct inferior *inf;
 318
 319   /* Looking for inferior pid == 0 is always wrong, and indicative of
 320      a bug somewhere else.  There may be more than one with pid == 0,
 321      for instance.  */
 322   gdb_assert (pid != 0);
 323
 324   for (inf = inferior_list; inf; inf = inf->next)
 325     if (inf->pid == pid)
 326       return inf;
 327
 328   return NULL;
 329 }
 330
 331 /* See inferior.h */
 332
 333 struct inferior *
 334 find_inferior_ptid (ptid_t ptid)
 335 {
 336   return find_inferior_pid (ptid_get_pid (ptid));
 337 }
 338
 339 /* See inferior.h.  */
 340
 341 struct inferior *
 342 find_inferior_for_program_space (struct program_space *pspace)
 343 {
 344   struct inferior *inf = current_inferior ();
 345
 346   if (inf->pspace == pspace)
 347     return inf;
 348
 349   for (inf = inferior_list; inf != NULL; inf = inf->next)
 350     {
 351       if (inf->pspace == pspace)
 352         return inf;
 353     }
 354
 355   return NULL;
 356 }
 357
 358 struct inferior *
 359 iterate_over_inferiors (int (*callback) (struct inferior *, void *),
 360                         void *data)
 361 {
 362   struct inferior *inf, *infnext;
 363
 364   for (inf = inferior_list; inf; inf = infnext)
 365     {
 366       infnext = inf->next;
 367       if ((*callback) (inf, data))
 368         return inf;
 369     }
 370
 371   return NULL;
 372 }
 373
 374 int
 375 valid_gdb_inferior_id (int num)
 376 {
 377   struct inferior *inf;
 378
 379   for (inf = inferior_list; inf; inf = inf->next)
 380     if (inf->num == num)
 381       return 1;
 382
 383   return 0;
 384 }
 385
 386 int
 387 pid_to_gdb_inferior_id (int pid)
 388 {
 389   struct inferior *inf;
 390
 391   for (inf = inferior_list; inf; inf = inf->next)
 392     if (inf->pid == pid)
 393       return inf->num;
 394
 395   return 0;
 396 }
 397
 398 int
 399 gdb_inferior_id_to_pid (int num)
 400 {
 401   struct inferior *inferior = find_inferior_id (num);
 402   if (inferior)
 403     return inferior->pid;
 404   else
 405     return -1;
 406 }
 407
 408 int
 409 in_inferior_list (int pid)
 410 {
 411   struct inferior *inf;
 412
 413   for (inf = inferior_list; inf; inf = inf->next)
 414     if (inf->pid == pid)
 415       return 1;
 416
 417   return 0;
 418 }
 419
 420 int
 421 have_inferiors (void)
 422 {
 423   struct inferior *inf;
 424
 425   for (inf = inferior_list; inf; inf = inf->next)
 426     if (inf->pid != 0)
 427       return 1;
 428
 429   return 0;
 430 }
 431
 432 /* Return the number of live inferiors.  We account for the case
 433    where an inferior might have a non-zero pid but no threads, as
 434    in the middle of a 'mourn' operation.  */
 435
 436 int
 437 number_of_live_inferiors (void)
 438 {
 439   struct inferior *inf;
 440   int num_inf = 0;
 441
 442   for (inf = inferior_list; inf; inf = inf->next)
 443     if (inf->pid != 0)
 444       {
 445         struct thread_info *tp;
 446
 447         ALL_NON_EXITED_THREADS (tp)
 448          if (tp && ptid_get_pid (tp->ptid) == inf->pid)
 449            if (target_has_execution_1 (tp->ptid))
 450              {
 451                /* Found a live thread in this inferior, go to the next
 452                   inferior.  */
 453                ++num_inf;
 454                break;
 455              }
 456       }
 457
 458   return num_inf;
 459 }
 460
 461 /* Return true if there is at least one live inferior.  */
 462
 463 int
 464 have_live_inferiors (void)
 465 {
 466   return number_of_live_inferiors () > 0;
 467 }
 468
 469 /* Prune away any unused inferiors, and then prune away no longer used
 470    program spaces.  */
 471
 472 void
 473 prune_inferiors (void)
 474 {
 475   struct inferior *ss, **ss_link;
 476
 477   ss = inferior_list;
 478   ss_link = &inferior_list;
 479   while (ss)
 480     {
 481       if (!ss->deletable ()
 482           || !ss->removable
 483           || ss->pid != 0)
 484         {
 485           ss_link = &ss->next;
 486           ss = *ss_link;
 487           continue;
 488         }
 489
 490       *ss_link = ss->next;
 491       delete_inferior (ss);
 492       ss = *ss_link;
 493     }
 494 }
 495
 496 /* Simply returns the count of inferiors.  */
 497
 498 int
 499 number_of_inferiors (void)
 500 {
 501   struct inferior *inf;
 502   int count = 0;
 503
 504   for (inf = inferior_list; inf != NULL; inf = inf->next)
 505     count++;
 506
 507   return count;
 508 }
 509
 510 /* Converts an inferior process id to a string.  Like
 511    target_pid_to_str, but special cases the null process.  */
 512
 513 static const char *
 514 inferior_pid_to_str (int pid)
 515 {
 516   if (pid != 0)
 517     return target_pid_to_str (pid_to_ptid (pid));
 518   else
 519     return _("<null>");
 520 }
 521
 522 /* See inferior.h.  */
 523
 524 void
 525 print_selected_inferior (struct ui_out *uiout)
 526 {
 527   struct inferior *inf = current_inferior ();
 528   const char *filename = inf->pspace->pspace_exec_filename;
 529
 530   if (filename == NULL)
 531     filename = _("<noexec>");
 532
 533   uiout->message (_("[Switching to inferior %d [%s] (%s)]\n"),
 534                   inf->num, inferior_pid_to_str (inf->pid), filename);
 535 }
 536
 537 /* Prints the list of inferiors and their details on UIOUT.  This is a
 538    version of 'info_inferior_command' suitable for use from MI.
 539
 540    If REQUESTED_INFERIORS is not NULL, it's a list of GDB ids of the
 541    inferiors that should be printed.  Otherwise, all inferiors are
 542    printed.  */
 543
 544 static void
 545 print_inferior (struct ui_out *uiout, const char *requested_inferiors)
 546 {
 547   struct inferior *inf;
 548   int inf_count = 0;
 549
 550   /* Compute number of inferiors we will print.  */
 551   for (inf = inferior_list; inf; inf = inf->next)
 552     {
 553       if (!number_is_in_list (requested_inferiors, inf->num))
 554         continue;
 555
 556       ++inf_count;
 557     }
 558
 559   if (inf_count == 0)
 560     {
 561       uiout->message ("No inferiors.\n");
 562       return;
 563     }
 564
 565   ui_out_emit_table table_emitter (uiout, 4, inf_count, "inferiors");
 566   uiout->table_header (1, ui_left, "current", "");
 567   uiout->table_header (4, ui_left, "number", "Num");
 568   uiout->table_header (17, ui_left, "target-id", "Description");
 569   uiout->table_header (17, ui_left, "exec", "Executable");
 570
 571   uiout->table_body ();
 572   for (inf = inferior_list; inf; inf = inf->next)
 573     {
 574       if (!number_is_in_list (requested_inferiors, inf->num))
 575         continue;
 576
 577       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 578
 579       if (inf == current_inferior ())
 580         uiout->field_string ("current", "*");
 581       else
 582         uiout->field_skip ("current");
 583
 584       uiout->field_int ("number", inf->num);
 585
 586       uiout->field_string ("target-id", inferior_pid_to_str (inf->pid));
 587
 588       if (inf->pspace->pspace_exec_filename != NULL)
 589         uiout->field_string ("exec", inf->pspace->pspace_exec_filename);
 590       else
 591         uiout->field_skip ("exec");
 592
 593       /* Print extra info that isn't really fit to always present in
 594          tabular form.  Currently we print the vfork parent/child
 595          relationships, if any.  */
 596       if (inf->vfork_parent)
 597         {
 598           uiout->text (_("\n\tis vfork child of inferior "));
 599           uiout->field_int ("vfork-parent", inf->vfork_parent->num);
 600         }
 601       if (inf->vfork_child)
 602         {
 603           uiout->text (_("\n\tis vfork parent of inferior "));
 604           uiout->field_int ("vfork-child", inf->vfork_child->num);
 605         }
 606
 607       uiout->text ("\n");
 608     }
 609 }
 610
 611 static void
 612 detach_inferior_command (const char *args, int from_tty)
 613 {
 614   struct thread_info *tp;
 615
 616   if (!args || !*args)
 617     error (_("Requires argument (inferior id(s) to detach)"));
 618
 619   number_or_range_parser parser (args);
 620   while (!parser.finished ())
 621     {
 622       int num = parser.get_number ();
 623
 624       if (!valid_gdb_inferior_id (num))
 625         {
 626           warning (_("Inferior ID %d not known."), num);
 627           continue;
 628         }
 629
 630       int pid = gdb_inferior_id_to_pid (num);
 631       if (pid == 0)
 632         {
 633           warning (_("Inferior ID %d is not running."), num);
 634           continue;
 635         }
 636
 637       tp = any_thread_of_process (pid);
 638       if (!tp)
 639         {
 640           warning (_("Inferior ID %d has no threads."), num);
 641           continue;
 642         }
 643
 644       switch_to_thread (tp->ptid);
 645
 646       detach_command (NULL, from_tty);
 647     }
 648 }
 649
 650 static void
 651 kill_inferior_command (const char *args, int from_tty)
 652 {
 653   struct thread_info *tp;
 654
 655   if (!args || !*args)
 656     error (_("Requires argument (inferior id(s) to kill)"));
 657
 658   number_or_range_parser parser (args);
 659   while (!parser.finished ())
 660     {
 661       int num = parser.get_number ();
 662
 663       if (!valid_gdb_inferior_id (num))
 664         {
 665           warning (_("Inferior ID %d not known."), num);
 666           continue;
 667         }
 668
 669       int pid = gdb_inferior_id_to_pid (num);
 670       if (pid == 0)
 671         {
 672           warning (_("Inferior ID %d is not running."), num);
 673           continue;
 674         }
 675
 676       tp = any_thread_of_process (pid);
 677       if (!tp)
 678         {
 679           warning (_("Inferior ID %d has no threads."), num);
 680           continue;
 681         }
 682
 683       switch_to_thread (tp->ptid);
 684
 685       target_kill ();
 686     }
 687
 688   bfd_cache_close_all ();
 689 }
 690
 691 static void
 692 inferior_command (const char *args, int from_tty)
 693 {
 694   struct inferior *inf;
 695   int num;
 696
 697   num = parse_and_eval_long (args);
 698
 699   inf = find_inferior_id (num);
 700   if (inf == NULL)
 701     error (_("Inferior ID %d not known."), num);
 702
 703   if (inf->pid != 0)
 704     {
 705       if (inf->pid != ptid_get_pid (inferior_ptid))
 706         {
 707           struct thread_info *tp;
 708
 709           tp = any_thread_of_process (inf->pid);
 710           if (!tp)
 711             error (_("Inferior has no threads."));
 712
 713           switch_to_thread (tp->ptid);
 714         }
 715
 716       gdb::observers::user_selected_context_changed.notify
 717         (USER_SELECTED_INFERIOR
 718          | USER_SELECTED_THREAD
 719          | USER_SELECTED_FRAME);
 720     }
 721   else
 722     {
 723       set_current_inferior (inf);
 724       switch_to_thread (null_ptid);
 725       set_current_program_space (inf->pspace);
 726
 727       gdb::observers::user_selected_context_changed.notify
 728         (USER_SELECTED_INFERIOR);
 729     }
 730 }
 731
 732 /* Print information about currently known inferiors.  */
 733
 734 static void
 735 info_inferiors_command (const char *args, int from_tty)
 736 {
 737   print_inferior (current_uiout, args);
 738 }
 739
 740 /* remove-inferior ID */
 741
 742 static void
 743 remove_inferior_command (const char *args, int from_tty)
 744 {
 745   if (args == NULL || *args == '\0')
 746     error (_("Requires an argument (inferior id(s) to remove)"));
 747
 748   number_or_range_parser parser (args);
 749   while (!parser.finished ())
 750     {
 751       int num = parser.get_number ();
 752       struct inferior *inf = find_inferior_id (num);
 753
 754       if (inf == NULL)
 755         {
 756           warning (_("Inferior ID %d not known."), num);
 757           continue;
 758         }
 759
 760       if (!inf->deletable ())
 761         {
 762           warning (_("Can not remove current inferior %d."), num);
 763           continue;
 764         }
 765
 766       if (inf->pid != 0)
 767         {
 768           warning (_("Can not remove active inferior %d."), num);
 769           continue;
 770         }
 771
 772       delete_inferior (inf);
 773     }
 774 }
 775
 776 struct inferior *
 777 add_inferior_with_spaces (void)
 778 {
 779   struct address_space *aspace;
 780   struct program_space *pspace;
 781   struct inferior *inf;
 782   struct gdbarch_info info;
 783
 784   /* If all inferiors share an address space on this system, this
 785      doesn't really return a new address space; otherwise, it
 786      really does.  */
 787   aspace = maybe_new_address_space ();
 788   pspace = new program_space (aspace);
 789   inf = add_inferior (0);
 790   inf->pspace = pspace;
 791   inf->aspace = pspace->aspace;
 792
 793   /* Setup the inferior's initial arch, based on information obtained
 794      from the global "set ..." options.  */
 795   gdbarch_info_init (&info);
 796   inf->gdbarch = gdbarch_find_by_info (info);
 797   /* The "set ..." options reject invalid settings, so we should
 798      always have a valid arch by now.  */
 799   gdb_assert (inf->gdbarch != NULL);
 800
 801   return inf;
 802 }
 803
 804 /* add-inferior [-copies N] [-exec FILENAME]  */
 805
 806 static void
 807 add_inferior_command (const char *args, int from_tty)
 808 {
 809   int i, copies = 1;
 810   gdb::unique_xmalloc_ptr<char> exec;
 811   symfile_add_flags add_flags = 0;
 812
 813   if (from_tty)
 814     add_flags |= SYMFILE_VERBOSE;
 815
 816   if (args)
 817     {
 818       gdb_argv built_argv (args);
 819
 820       for (char **argv = built_argv.get (); *argv != NULL; argv++)
 821         {
 822           if (**argv == '-')
 823             {
 824               if (strcmp (*argv, "-copies") == 0)
 825                 {
 826                   ++argv;
 827                   if (!*argv)
 828                     error (_("No argument to -copies"));
 829                   copies = parse_and_eval_long (*argv);
 830                 }
 831               else if (strcmp (*argv, "-exec") == 0)
 832                 {
 833                   ++argv;
 834                   if (!*argv)
 835                     error (_("No argument to -exec"));
 836                   exec.reset (tilde_expand (*argv));
 837                 }
 838             }
 839           else
 840             error (_("Invalid argument"));
 841         }
 842     }
 843
 844   scoped_restore_current_pspace_and_thread restore_pspace_thread;
 845
 846   for (i = 0; i < copies; ++i)
 847     {
 848       struct inferior *inf = add_inferior_with_spaces ();
 849
 850       printf_filtered (_("Added inferior %d\n"), inf->num);
 851
 852       if (exec != NULL)
 853         {
 854           /* Switch over temporarily, while reading executable and
 855              symbols.q.  */
 856           set_current_program_space (inf->pspace);
 857           set_current_inferior (inf);
 858           switch_to_thread (null_ptid);
 859
 860           exec_file_attach (exec.get (), from_tty);
 861           symbol_file_add_main (exec.get (), add_flags);
 862         }
 863     }
 864 }
 865
 866 /* clone-inferior [-copies N] [ID] */
 867
 868 static void
 869 clone_inferior_command (const char *args, int from_tty)
 870 {
 871   int i, copies = 1;
 872   struct inferior *orginf = NULL;
 873
 874   if (args)
 875     {
 876       gdb_argv built_argv (args);
 877
 878       char **argv = built_argv.get ();
 879       for (; *argv != NULL; argv++)
 880         {
 881           if (**argv == '-')
 882             {
 883               if (strcmp (*argv, "-copies") == 0)
 884                 {
 885                   ++argv;
 886                   if (!*argv)
 887                     error (_("No argument to -copies"));
 888                   copies = parse_and_eval_long (*argv);
 889
 890                   if (copies < 0)
 891                     error (_("Invalid copies number"));
 892                 }
 893             }
 894           else
 895             {
 896               if (orginf == NULL)
 897                 {
 898                   int num;
 899
 900                   /* The first non-option (-) argument specified the
 901                      program space ID.  */
 902                   num = parse_and_eval_long (*argv);
 903                   orginf = find_inferior_id (num);
 904
 905                   if (orginf == NULL)
 906                     error (_("Inferior ID %d not known."), num);
 907                   continue;
 908                 }
 909               else
 910                 error (_("Invalid argument"));
 911             }
 912         }
 913     }
 914
 915   /* If no inferior id was specified, then the user wants to clone the
 916      current inferior.  */
 917   if (orginf == NULL)
 918     orginf = current_inferior ();
 919
 920   scoped_restore_current_pspace_and_thread restore_pspace_thread;
 921
 922   for (i = 0; i < copies; ++i)
 923     {
 924       struct address_space *aspace;
 925       struct program_space *pspace;
 926       struct inferior *inf;
 927
 928       /* If all inferiors share an address space on this system, this
 929          doesn't really return a new address space; otherwise, it
 930          really does.  */
 931       aspace = maybe_new_address_space ();
 932       pspace = new program_space (aspace);
 933       inf = add_inferior (0);
 934       inf->pspace = pspace;
 935       inf->aspace = pspace->aspace;
 936       inf->gdbarch = orginf->gdbarch;
 937
 938       /* If the original inferior had a user specified target
 939          description, make the clone use it too.  */
 940       if (target_desc_info_from_user_p (inf->tdesc_info))
 941         copy_inferior_target_desc_info (inf, orginf);
 942
 943       printf_filtered (_("Added inferior %d.\n"), inf->num);
 944
 945       set_current_inferior (inf);
 946       switch_to_thread (null_ptid);
 947       clone_program_space (pspace, orginf->pspace);
 948     }
 949 }
 950
 951 /* Print notices when new inferiors are created and die.  */
 952 static void
 953 show_print_inferior_events (struct ui_file *file, int from_tty,
 954                            struct cmd_list_element *c, const char *value)
 955 {
 956   fprintf_filtered (file, _("Printing of inferior events is %s.\n"), value);
 957 }
 958
 959 /* Return a new value for the selected inferior's id.  */
 960
 961 static struct value *
 962 inferior_id_make_value (struct gdbarch *gdbarch, struct internalvar *var,
 963                         void *ignore)
 964 {
 965   struct inferior *inf = current_inferior ();
 966
 967   return value_from_longest (builtin_type (gdbarch)->builtin_int, inf->num);
 968 }
 969
 970 /* Implementation of `$_inferior' variable.  */
 971
 972 static const struct internalvar_funcs inferior_funcs =
 973 {
 974   inferior_id_make_value,
 975   NULL,
 976   NULL
 977 };
 978
 979 \f
 980
 981 void
 982 initialize_inferiors (void)
 983 {
 984   struct cmd_list_element *c = NULL;
 985
 986   /* There's always one inferior.  Note that this function isn't an
 987      automatic _initialize_foo function, since other _initialize_foo
 988      routines may need to install their per-inferior data keys.  We
 989      can only allocate an inferior when all those modules have done
 990      that.  Do this after initialize_progspace, due to the
 991      current_program_space reference.  */
 992   current_inferior_ = add_inferior_silent (0);
 993   current_inferior_->incref ();
 994   current_inferior_->pspace = current_program_space;
 995   current_inferior_->aspace = current_program_space->aspace;
 996   /* The architecture will be initialized shortly, by
 997      initialize_current_architecture.  */
 998
 999   add_info ("inferiors", info_inferiors_command,
1000             _("IDs of specified inferiors (all inferiors if no argument)."));
1001
1002   c = add_com ("add-inferior", no_class, add_inferior_command, _("\
1003 Add a new inferior.\n\
1004 Usage: add-inferior [-copies <N>] [-exec <FILENAME>]\n\
1005 N is the optional number of inferiors to add, default is 1.\n\
1006 FILENAME is the file name of the executable to use\n\
1007 as main program."));
1008   set_cmd_completer (c, filename_completer);
1009
1010   add_com ("remove-inferiors", no_class, remove_inferior_command, _("\
1011 Remove inferior ID (or list of IDs).\n\
1012 Usage: remove-inferiors ID..."));
1013
1014   add_com ("clone-inferior", no_class, clone_inferior_command, _("\
1015 Clone inferior ID.\n\
1016 Usage: clone-inferior [-copies <N>] [ID]\n\
1017 Add N copies of inferior ID.  The new inferior has the same\n\
1018 executable loaded as the copied inferior.  If -copies is not specified,\n\
1019 adds 1 copy.  If ID is not specified, it is the current inferior\n\
1020 that is cloned."));
1021
1022   add_cmd ("inferiors", class_run, detach_inferior_command, _("\
1023 Detach from inferior ID (or list of IDS)."),
1024            &detachlist);
1025
1026   add_cmd ("inferiors", class_run, kill_inferior_command, _("\
1027 Kill inferior ID (or list of IDs)."),
1028            &killlist);
1029
1030   add_cmd ("inferior", class_run, inferior_command, _("\
1031 Use this command to switch between inferiors.\n\
1032 The new inferior ID must be currently known."),
1033            &cmdlist);
1034
1035   add_setshow_boolean_cmd ("inferior-events", no_class,
1036          &print_inferior_events, _("\
1037 Set printing of inferior events (e.g., inferior start and exit)."), _("\
1038 Show printing of inferior events (e.g., inferior start and exit)."), NULL,
1039          NULL,
1040          show_print_inferior_events,
1041          &setprintlist, &showprintlist);
1042
1043   create_internalvar_type_lazy ("_inferior", &inferior_funcs, NULL);
1044 }