gdb/inferior.c

   1 /* Multi-process control for GDB, the GNU debugger.
   2
   3    Copyright (C) 2008-2016 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
  39 void _initialize_inferiors (void);
  40
  41 /* Keep a registry of per-inferior data-pointers required by other GDB
  42    modules.  */
  43
  44 DEFINE_REGISTRY (inferior, REGISTRY_ACCESS_FIELD)
  45
  46 struct inferior *inferior_list = NULL;
  47 static int highest_inferior_num;
  48
  49 /* Print notices on inferior events (attach, detach, etc.), set with
  50    `set print inferior-events'.  */
  51 static int print_inferior_events = 0;
  52
  53 /* The Current Inferior.  */
  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   current_inferior_ = inf;
  69 }
  70
  71 /* A cleanups callback, helper for save_current_program_space
  72    below.  */
  73
  74 static void
  75 restore_inferior (void *arg)
  76 {
  77   struct inferior *saved_inferior = (struct inferior *) arg;
  78
  79   set_current_inferior (saved_inferior);
  80 }
  81
  82 /* Save the current program space so that it may be restored by a later
  83    call to do_cleanups.  Returns the struct cleanup pointer needed for
  84    later doing the cleanup.  */
  85
  86 struct cleanup *
  87 save_current_inferior (void)
  88 {
  89   struct cleanup *old_chain = make_cleanup (restore_inferior,
  90                                             current_inferior_);
  91
  92   return old_chain;
  93 }
  94
  95 static void
  96 free_inferior (struct inferior *inf)
  97 {
  98   discard_all_inferior_continuations (inf);
  99   inferior_free_data (inf);
 100   xfree (inf->args);
 101   xfree (inf->terminal);
 102   free_environ (inf->environment);
 103   target_desc_info_free (inf->tdesc_info);
 104   xfree (inf->priv);
 105   xfree (inf);
 106 }
 107
 108 void
 109 init_inferior_list (void)
 110 {
 111   struct inferior *inf, *infnext;
 112
 113   highest_inferior_num = 0;
 114   if (!inferior_list)
 115     return;
 116
 117   for (inf = inferior_list; inf; inf = infnext)
 118     {
 119       infnext = inf->next;
 120       free_inferior (inf);
 121     }
 122
 123   inferior_list = NULL;
 124 }
 125
 126 struct inferior *
 127 add_inferior_silent (int pid)
 128 {
 129   struct inferior *inf;
 130
 131   inf = XNEW (struct inferior);
 132   memset (inf, 0, sizeof (*inf));
 133   inf->pid = pid;
 134
 135   inf->control.stop_soon = NO_STOP_QUIETLY;
 136
 137   inf->num = ++highest_inferior_num;
 138
 139   if (inferior_list == NULL)
 140     inferior_list = inf;
 141   else
 142     {
 143       struct inferior *last;
 144
 145       for (last = inferior_list; last->next != NULL; last = last->next)
 146         ;
 147       last->next = inf;
 148     }
 149
 150   inf->environment = make_environ ();
 151   init_environ (inf->environment);
 152
 153   inferior_alloc_data (inf);
 154
 155   observer_notify_inferior_added (inf);
 156
 157   if (pid != 0)
 158     inferior_appeared (inf, pid);
 159
 160   return inf;
 161 }
 162
 163 struct inferior *
 164 add_inferior (int pid)
 165 {
 166   struct inferior *inf = add_inferior_silent (pid);
 167
 168   if (print_inferior_events)
 169     printf_unfiltered (_("[New inferior %d]\n"), pid);
 170
 171   return inf;
 172 }
 173
 174 struct delete_thread_of_inferior_arg
 175 {
 176   int pid;
 177   int silent;
 178 };
 179
 180 static int
 181 delete_thread_of_inferior (struct thread_info *tp, void *data)
 182 {
 183   struct delete_thread_of_inferior_arg *arg
 184     = (struct delete_thread_of_inferior_arg *) data;
 185
 186   if (ptid_get_pid (tp->ptid) == arg->pid)
 187     {
 188       if (arg->silent)
 189         delete_thread_silent (tp->ptid);
 190       else
 191         delete_thread (tp->ptid);
 192     }
 193
 194   return 0;
 195 }
 196
 197 void
 198 delete_inferior (struct inferior *todel)
 199 {
 200   struct inferior *inf, *infprev;
 201   struct delete_thread_of_inferior_arg arg;
 202
 203   infprev = NULL;
 204
 205   for (inf = inferior_list; inf; infprev = inf, inf = inf->next)
 206     if (inf == todel)
 207       break;
 208
 209   if (!inf)
 210     return;
 211
 212   arg.pid = inf->pid;
 213   arg.silent = 1;
 214
 215   iterate_over_threads (delete_thread_of_inferior, &arg);
 216
 217   if (infprev)
 218     infprev->next = inf->next;
 219   else
 220     inferior_list = inf->next;
 221
 222   observer_notify_inferior_removed (inf);
 223
 224   /* If this program space is rendered useless, remove it. */
 225   if (program_space_empty_p (inf->pspace))
 226     delete_program_space (inf->pspace);
 227
 228   free_inferior (inf);
 229 }
 230
 231 /* If SILENT then be quiet -- don't announce a inferior exit, or the
 232    exit of its threads.  */
 233
 234 static void
 235 exit_inferior_1 (struct inferior *inftoex, int silent)
 236 {
 237   struct inferior *inf;
 238   struct delete_thread_of_inferior_arg arg;
 239
 240   for (inf = inferior_list; inf; inf = inf->next)
 241     if (inf == inftoex)
 242       break;
 243
 244   if (!inf)
 245     return;
 246
 247   arg.pid = inf->pid;
 248   arg.silent = silent;
 249
 250   iterate_over_threads (delete_thread_of_inferior, &arg);
 251
 252   observer_notify_inferior_exit (inf);
 253
 254   inf->pid = 0;
 255   inf->fake_pid_p = 0;
 256   xfree (inf->priv);
 257   inf->priv = NULL;
 258
 259   if (inf->vfork_parent != NULL)
 260     {
 261       inf->vfork_parent->vfork_child = NULL;
 262       inf->vfork_parent = NULL;
 263     }
 264   if (inf->vfork_child != NULL)
 265     {
 266       inf->vfork_child->vfork_parent = NULL;
 267       inf->vfork_child = NULL;
 268     }
 269
 270   inf->pending_detach = 0;
 271 }
 272
 273 void
 274 exit_inferior (int pid)
 275 {
 276   struct inferior *inf = find_inferior_pid (pid);
 277
 278   exit_inferior_1 (inf, 0);
 279
 280   if (print_inferior_events)
 281     printf_unfiltered (_("[Inferior %d exited]\n"), pid);
 282 }
 283
 284 void
 285 exit_inferior_silent (int pid)
 286 {
 287   struct inferior *inf = find_inferior_pid (pid);
 288
 289   exit_inferior_1 (inf, 1);
 290 }
 291
 292 void
 293 exit_inferior_num_silent (int num)
 294 {
 295   struct inferior *inf = find_inferior_id (num);
 296
 297   exit_inferior_1 (inf, 1);
 298 }
 299
 300 void
 301 detach_inferior (int pid)
 302 {
 303   struct inferior *inf = find_inferior_pid (pid);
 304
 305   exit_inferior_1 (inf, 0);
 306
 307   if (print_inferior_events)
 308     printf_unfiltered (_("[Inferior %d detached]\n"), pid);
 309 }
 310
 311 void
 312 inferior_appeared (struct inferior *inf, int pid)
 313 {
 314   inf->pid = pid;
 315   inf->has_exit_code = 0;
 316   inf->exit_code = 0;
 317
 318   observer_notify_inferior_appeared (inf);
 319 }
 320
 321 void
 322 discard_all_inferiors (void)
 323 {
 324   struct inferior *inf;
 325
 326   for (inf = inferior_list; inf; inf = inf->next)
 327     {
 328       if (inf->pid != 0)
 329         exit_inferior_silent (inf->pid);
 330     }
 331 }
 332
 333 struct inferior *
 334 find_inferior_id (int num)
 335 {
 336   struct inferior *inf;
 337
 338   for (inf = inferior_list; inf; inf = inf->next)
 339     if (inf->num == num)
 340       return inf;
 341
 342   return NULL;
 343 }
 344
 345 struct inferior *
 346 find_inferior_pid (int pid)
 347 {
 348   struct inferior *inf;
 349
 350   /* Looking for inferior pid == 0 is always wrong, and indicative of
 351      a bug somewhere else.  There may be more than one with pid == 0,
 352      for instance.  */
 353   gdb_assert (pid != 0);
 354
 355   for (inf = inferior_list; inf; inf = inf->next)
 356     if (inf->pid == pid)
 357       return inf;
 358
 359   return NULL;
 360 }
 361
 362 /* See inferior.h */
 363
 364 struct inferior *
 365 find_inferior_ptid (ptid_t ptid)
 366 {
 367   return find_inferior_pid (ptid_get_pid (ptid));
 368 }
 369
 370 /* See inferior.h.  */
 371
 372 struct inferior *
 373 find_inferior_for_program_space (struct program_space *pspace)
 374 {
 375   struct inferior *inf = current_inferior ();
 376
 377   if (inf->pspace == pspace)
 378     return inf;
 379
 380   for (inf = inferior_list; inf != NULL; inf = inf->next)
 381     {
 382       if (inf->pspace == pspace)
 383         return inf;
 384     }
 385
 386   return NULL;
 387 }
 388
 389 struct inferior *
 390 iterate_over_inferiors (int (*callback) (struct inferior *, void *),
 391                         void *data)
 392 {
 393   struct inferior *inf, *infnext;
 394
 395   for (inf = inferior_list; inf; inf = infnext)
 396     {
 397       infnext = inf->next;
 398       if ((*callback) (inf, data))
 399         return inf;
 400     }
 401
 402   return NULL;
 403 }
 404
 405 int
 406 valid_gdb_inferior_id (int num)
 407 {
 408   struct inferior *inf;
 409
 410   for (inf = inferior_list; inf; inf = inf->next)
 411     if (inf->num == num)
 412       return 1;
 413
 414   return 0;
 415 }
 416
 417 int
 418 pid_to_gdb_inferior_id (int pid)
 419 {
 420   struct inferior *inf;
 421
 422   for (inf = inferior_list; inf; inf = inf->next)
 423     if (inf->pid == pid)
 424       return inf->num;
 425
 426   return 0;
 427 }
 428
 429 int
 430 gdb_inferior_id_to_pid (int num)
 431 {
 432   struct inferior *inferior = find_inferior_id (num);
 433   if (inferior)
 434     return inferior->pid;
 435   else
 436     return -1;
 437 }
 438
 439 int
 440 in_inferior_list (int pid)
 441 {
 442   struct inferior *inf;
 443
 444   for (inf = inferior_list; inf; inf = inf->next)
 445     if (inf->pid == pid)
 446       return 1;
 447
 448   return 0;
 449 }
 450
 451 int
 452 have_inferiors (void)
 453 {
 454   struct inferior *inf;
 455
 456   for (inf = inferior_list; inf; inf = inf->next)
 457     if (inf->pid != 0)
 458       return 1;
 459
 460   return 0;
 461 }
 462
 463 /* Return the number of live inferiors.  We account for the case
 464    where an inferior might have a non-zero pid but no threads, as
 465    in the middle of a 'mourn' operation.  */
 466
 467 int
 468 number_of_live_inferiors (void)
 469 {
 470   struct inferior *inf;
 471   int num_inf = 0;
 472
 473   for (inf = inferior_list; inf; inf = inf->next)
 474     if (inf->pid != 0)
 475       {
 476         struct thread_info *tp;
 477
 478         ALL_NON_EXITED_THREADS (tp)
 479          if (tp && ptid_get_pid (tp->ptid) == inf->pid)
 480            if (target_has_execution_1 (tp->ptid))
 481              {
 482                /* Found a live thread in this inferior, go to the next
 483                   inferior.  */
 484                ++num_inf;
 485                break;
 486              }
 487       }
 488
 489   return num_inf;
 490 }
 491
 492 /* Return true if there is at least one live inferior.  */
 493
 494 int
 495 have_live_inferiors (void)
 496 {
 497   return number_of_live_inferiors () > 0;
 498 }
 499
 500 /* Prune away any unused inferiors, and then prune away no longer used
 501    program spaces.  */
 502
 503 void
 504 prune_inferiors (void)
 505 {
 506   struct inferior *ss, **ss_link;
 507   struct inferior *current = current_inferior ();
 508
 509   ss = inferior_list;
 510   ss_link = &inferior_list;
 511   while (ss)
 512     {
 513       if (ss == current
 514           || !ss->removable
 515           || ss->pid != 0)
 516         {
 517           ss_link = &ss->next;
 518           ss = *ss_link;
 519           continue;
 520         }
 521
 522       *ss_link = ss->next;
 523       delete_inferior (ss);
 524       ss = *ss_link;
 525     }
 526 }
 527
 528 /* Simply returns the count of inferiors.  */
 529
 530 int
 531 number_of_inferiors (void)
 532 {
 533   struct inferior *inf;
 534   int count = 0;
 535
 536   for (inf = inferior_list; inf != NULL; inf = inf->next)
 537     count++;
 538
 539   return count;
 540 }
 541
 542 /* Converts an inferior process id to a string.  Like
 543    target_pid_to_str, but special cases the null process.  */
 544
 545 static char *
 546 inferior_pid_to_str (int pid)
 547 {
 548   if (pid != 0)
 549     return target_pid_to_str (pid_to_ptid (pid));
 550   else
 551     return _("<null>");
 552 }
 553
 554 /* See inferior.h.  */
 555
 556 void
 557 print_selected_inferior (struct ui_out *uiout)
 558 {
 559   struct inferior *inf = current_inferior ();
 560   const char *filename = inf->pspace->pspace_exec_filename;
 561
 562   if (filename == NULL)
 563     filename = _("<noexec>");
 564
 565   uiout->message (_("[Switching to inferior %d [%s] (%s)]\n"),
 566                   inf->num, inferior_pid_to_str (inf->pid), filename);
 567 }
 568
 569 /* Prints the list of inferiors and their details on UIOUT.  This is a
 570    version of 'info_inferior_command' suitable for use from MI.
 571
 572    If REQUESTED_INFERIORS is not NULL, it's a list of GDB ids of the
 573    inferiors that should be printed.  Otherwise, all inferiors are
 574    printed.  */
 575
 576 static void
 577 print_inferior (struct ui_out *uiout, char *requested_inferiors)
 578 {
 579   struct inferior *inf;
 580   struct cleanup *old_chain;
 581   int inf_count = 0;
 582
 583   /* Compute number of inferiors we will print.  */
 584   for (inf = inferior_list; inf; inf = inf->next)
 585     {
 586       if (!number_is_in_list (requested_inferiors, inf->num))
 587         continue;
 588
 589       ++inf_count;
 590     }
 591
 592   if (inf_count == 0)
 593     {
 594       uiout->message ("No inferiors.\n");
 595       return;
 596     }
 597
 598   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 4, inf_count,
 599                                                    "inferiors");
 600   uiout->table_header (1, ui_left, "current", "");
 601   uiout->table_header (4, ui_left, "number", "Num");
 602   uiout->table_header (17, ui_left, "target-id", "Description");
 603   uiout->table_header (17, ui_left, "exec", "Executable");
 604
 605   uiout->table_body ();
 606   for (inf = inferior_list; inf; inf = inf->next)
 607     {
 608       struct cleanup *chain2;
 609
 610       if (!number_is_in_list (requested_inferiors, inf->num))
 611         continue;
 612
 613       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 614
 615       if (inf == current_inferior ())
 616         uiout->field_string ("current", "*");
 617       else
 618         uiout->field_skip ("current");
 619
 620       uiout->field_int ("number", inf->num);
 621
 622       uiout->field_string ("target-id", inferior_pid_to_str (inf->pid));
 623
 624       if (inf->pspace->pspace_exec_filename != NULL)
 625         uiout->field_string ("exec", inf->pspace->pspace_exec_filename);
 626       else
 627         uiout->field_skip ("exec");
 628
 629       /* Print extra info that isn't really fit to always present in
 630          tabular form.  Currently we print the vfork parent/child
 631          relationships, if any.  */
 632       if (inf->vfork_parent)
 633         {
 634           uiout->text (_("\n\tis vfork child of inferior "));
 635           uiout->field_int ("vfork-parent", inf->vfork_parent->num);
 636         }
 637       if (inf->vfork_child)
 638         {
 639           uiout->text (_("\n\tis vfork parent of inferior "));
 640           uiout->field_int ("vfork-child", inf->vfork_child->num);
 641         }
 642
 643       uiout->text ("\n");
 644       do_cleanups (chain2);
 645     }
 646
 647   do_cleanups (old_chain);
 648 }
 649
 650 static void
 651 detach_inferior_command (char *args, int from_tty)
 652 {
 653   struct thread_info *tp;
 654
 655   if (!args || !*args)
 656     error (_("Requires argument (inferior id(s) to detach)"));
 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       detach_command (NULL, from_tty);
 686     }
 687 }
 688
 689 static void
 690 kill_inferior_command (char *args, int from_tty)
 691 {
 692   struct thread_info *tp;
 693
 694   if (!args || !*args)
 695     error (_("Requires argument (inferior id(s) to kill)"));
 696
 697   number_or_range_parser parser (args);
 698   while (!parser.finished ())
 699     {
 700       int num = parser.get_number ();
 701
 702       if (!valid_gdb_inferior_id (num))
 703         {
 704           warning (_("Inferior ID %d not known."), num);
 705           continue;
 706         }
 707
 708       int pid = gdb_inferior_id_to_pid (num);
 709       if (pid == 0)
 710         {
 711           warning (_("Inferior ID %d is not running."), num);
 712           continue;
 713         }
 714
 715       tp = any_thread_of_process (pid);
 716       if (!tp)
 717         {
 718           warning (_("Inferior ID %d has no threads."), num);
 719           continue;
 720         }
 721
 722       switch_to_thread (tp->ptid);
 723
 724       target_kill ();
 725     }
 726
 727   bfd_cache_close_all ();
 728 }
 729
 730 static void
 731 inferior_command (char *args, int from_tty)
 732 {
 733   struct inferior *inf;
 734   int num;
 735
 736   num = parse_and_eval_long (args);
 737
 738   inf = find_inferior_id (num);
 739   if (inf == NULL)
 740     error (_("Inferior ID %d not known."), num);
 741
 742   if (inf->pid != 0)
 743     {
 744       if (inf->pid != ptid_get_pid (inferior_ptid))
 745         {
 746           struct thread_info *tp;
 747
 748           tp = any_thread_of_process (inf->pid);
 749           if (!tp)
 750             error (_("Inferior has no threads."));
 751
 752           switch_to_thread (tp->ptid);
 753         }
 754
 755       observer_notify_user_selected_context_changed
 756         (USER_SELECTED_INFERIOR
 757          | USER_SELECTED_THREAD
 758          | USER_SELECTED_FRAME);
 759     }
 760   else
 761     {
 762       set_current_inferior (inf);
 763       switch_to_thread (null_ptid);
 764       set_current_program_space (inf->pspace);
 765
 766       observer_notify_user_selected_context_changed (USER_SELECTED_INFERIOR);
 767     }
 768 }
 769
 770 /* Print information about currently known inferiors.  */
 771
 772 static void
 773 info_inferiors_command (char *args, int from_tty)
 774 {
 775   print_inferior (current_uiout, args);
 776 }
 777
 778 /* remove-inferior ID */
 779
 780 static void
 781 remove_inferior_command (char *args, int from_tty)
 782 {
 783   if (args == NULL || *args == '\0')
 784     error (_("Requires an argument (inferior id(s) to remove)"));
 785
 786   number_or_range_parser parser (args);
 787   while (!parser.finished ())
 788     {
 789       int num = parser.get_number ();
 790       struct inferior *inf = find_inferior_id (num);
 791
 792       if (inf == NULL)
 793         {
 794           warning (_("Inferior ID %d not known."), num);
 795           continue;
 796         }
 797
 798       if (inf == current_inferior ())
 799         {
 800           warning (_("Can not remove current inferior %d."), num);
 801           continue;
 802         }
 803
 804       if (inf->pid != 0)
 805         {
 806           warning (_("Can not remove active inferior %d."), num);
 807           continue;
 808         }
 809
 810       delete_inferior (inf);
 811     }
 812 }
 813
 814 struct inferior *
 815 add_inferior_with_spaces (void)
 816 {
 817   struct address_space *aspace;
 818   struct program_space *pspace;
 819   struct inferior *inf;
 820   struct gdbarch_info info;
 821
 822   /* If all inferiors share an address space on this system, this
 823      doesn't really return a new address space; otherwise, it
 824      really does.  */
 825   aspace = maybe_new_address_space ();
 826   pspace = add_program_space (aspace);
 827   inf = add_inferior (0);
 828   inf->pspace = pspace;
 829   inf->aspace = pspace->aspace;
 830
 831   /* Setup the inferior's initial arch, based on information obtained
 832      from the global "set ..." options.  */
 833   gdbarch_info_init (&info);
 834   inf->gdbarch = gdbarch_find_by_info (info);
 835   /* The "set ..." options reject invalid settings, so we should
 836      always have a valid arch by now.  */
 837   gdb_assert (inf->gdbarch != NULL);
 838
 839   return inf;
 840 }
 841
 842 /* add-inferior [-copies N] [-exec FILENAME]  */
 843
 844 static void
 845 add_inferior_command (char *args, int from_tty)
 846 {
 847   int i, copies = 1;
 848   char *exec = NULL;
 849   char **argv;
 850   symfile_add_flags add_flags = 0;
 851   struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
 852
 853   if (from_tty)
 854     add_flags |= SYMFILE_VERBOSE;
 855
 856   if (args)
 857     {
 858       argv = gdb_buildargv (args);
 859       make_cleanup_freeargv (argv);
 860
 861       for (; *argv != NULL; argv++)
 862         {
 863           if (**argv == '-')
 864             {
 865               if (strcmp (*argv, "-copies") == 0)
 866                 {
 867                   ++argv;
 868                   if (!*argv)
 869                     error (_("No argument to -copies"));
 870                   copies = parse_and_eval_long (*argv);
 871                 }
 872               else if (strcmp (*argv, "-exec") == 0)
 873                 {
 874                   ++argv;
 875                   if (!*argv)
 876                     error (_("No argument to -exec"));
 877                   exec = tilde_expand (*argv);
 878                   make_cleanup (xfree, exec);
 879                 }
 880             }
 881           else
 882             error (_("Invalid argument"));
 883         }
 884     }
 885
 886   save_current_space_and_thread ();
 887
 888   for (i = 0; i < copies; ++i)
 889     {
 890       struct inferior *inf = add_inferior_with_spaces ();
 891
 892       printf_filtered (_("Added inferior %d\n"), inf->num);
 893
 894       if (exec != NULL)
 895         {
 896           /* Switch over temporarily, while reading executable and
 897              symbols.q.  */
 898           set_current_program_space (inf->pspace);
 899           set_current_inferior (inf);
 900           switch_to_thread (null_ptid);
 901
 902           exec_file_attach (exec, from_tty);
 903           symbol_file_add_main (exec, add_flags);
 904         }
 905     }
 906
 907   do_cleanups (old_chain);
 908 }
 909
 910 /* clone-inferior [-copies N] [ID] */
 911
 912 static void
 913 clone_inferior_command (char *args, int from_tty)
 914 {
 915   int i, copies = 1;
 916   char **argv;
 917   struct inferior *orginf = NULL;
 918   struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
 919
 920   if (args)
 921     {
 922       argv = gdb_buildargv (args);
 923       make_cleanup_freeargv (argv);
 924
 925       for (; *argv != NULL; argv++)
 926         {
 927           if (**argv == '-')
 928             {
 929               if (strcmp (*argv, "-copies") == 0)
 930                 {
 931                   ++argv;
 932                   if (!*argv)
 933                     error (_("No argument to -copies"));
 934                   copies = parse_and_eval_long (*argv);
 935
 936                   if (copies < 0)
 937                     error (_("Invalid copies number"));
 938                 }
 939             }
 940           else
 941             {
 942               if (orginf == NULL)
 943                 {
 944                   int num;
 945
 946                   /* The first non-option (-) argument specified the
 947                      program space ID.  */
 948                   num = parse_and_eval_long (*argv);
 949                   orginf = find_inferior_id (num);
 950
 951                   if (orginf == NULL)
 952                     error (_("Inferior ID %d not known."), num);
 953                   continue;
 954                 }
 955               else
 956                 error (_("Invalid argument"));
 957             }
 958         }
 959     }
 960
 961   /* If no inferior id was specified, then the user wants to clone the
 962      current inferior.  */
 963   if (orginf == NULL)
 964     orginf = current_inferior ();
 965
 966   save_current_space_and_thread ();
 967
 968   for (i = 0; i < copies; ++i)
 969     {
 970       struct address_space *aspace;
 971       struct program_space *pspace;
 972       struct inferior *inf;
 973
 974       /* If all inferiors share an address space on this system, this
 975          doesn't really return a new address space; otherwise, it
 976          really does.  */
 977       aspace = maybe_new_address_space ();
 978       pspace = add_program_space (aspace);
 979       inf = add_inferior (0);
 980       inf->pspace = pspace;
 981       inf->aspace = pspace->aspace;
 982       inf->gdbarch = orginf->gdbarch;
 983
 984       /* If the original inferior had a user specified target
 985          description, make the clone use it too.  */
 986       if (target_desc_info_from_user_p (inf->tdesc_info))
 987         copy_inferior_target_desc_info (inf, orginf);
 988
 989       printf_filtered (_("Added inferior %d.\n"), inf->num);
 990
 991       set_current_inferior (inf);
 992       switch_to_thread (null_ptid);
 993       clone_program_space (pspace, orginf->pspace);
 994     }
 995
 996   do_cleanups (old_chain);
 997 }
 998
 999 /* Print notices when new inferiors are created and die.  */
1000 static void
1001 show_print_inferior_events (struct ui_file *file, int from_tty,
1002                            struct cmd_list_element *c, const char *value)
1003 {
1004   fprintf_filtered (file, _("Printing of inferior events is %s.\n"), value);
1005 }
1006
1007 /* Return a new value for the selected inferior's id.  */
1008
1009 static struct value *
1010 inferior_id_make_value (struct gdbarch *gdbarch, struct internalvar *var,
1011                         void *ignore)
1012 {
1013   struct inferior *inf = current_inferior ();
1014
1015   return value_from_longest (builtin_type (gdbarch)->builtin_int, inf->num);
1016 }
1017
1018 /* Implementation of `$_inferior' variable.  */
1019
1020 static const struct internalvar_funcs inferior_funcs =
1021 {
1022   inferior_id_make_value,
1023   NULL,
1024   NULL
1025 };
1026
1027 \f
1028
1029 void
1030 initialize_inferiors (void)
1031 {
1032   struct cmd_list_element *c = NULL;
1033
1034   /* There's always one inferior.  Note that this function isn't an
1035      automatic _initialize_foo function, since other _initialize_foo
1036      routines may need to install their per-inferior data keys.  We
1037      can only allocate an inferior when all those modules have done
1038      that.  Do this after initialize_progspace, due to the
1039      current_program_space reference.  */
1040   current_inferior_ = add_inferior (0);
1041   current_inferior_->pspace = current_program_space;
1042   current_inferior_->aspace = current_program_space->aspace;
1043   /* The architecture will be initialized shortly, by
1044      initialize_current_architecture.  */
1045
1046   add_info ("inferiors", info_inferiors_command,
1047             _("IDs of specified inferiors (all inferiors if no argument)."));
1048
1049   c = add_com ("add-inferior", no_class, add_inferior_command, _("\
1050 Add a new inferior.\n\
1051 Usage: add-inferior [-copies <N>] [-exec <FILENAME>]\n\
1052 N is the optional number of inferiors to add, default is 1.\n\
1053 FILENAME is the file name of the executable to use\n\
1054 as main program."));
1055   set_cmd_completer (c, filename_completer);
1056
1057   add_com ("remove-inferiors", no_class, remove_inferior_command, _("\
1058 Remove inferior ID (or list of IDs).\n\
1059 Usage: remove-inferiors ID..."));
1060
1061   add_com ("clone-inferior", no_class, clone_inferior_command, _("\
1062 Clone inferior ID.\n\
1063 Usage: clone-inferior [-copies <N>] [ID]\n\
1064 Add N copies of inferior ID.  The new inferior has the same\n\
1065 executable loaded as the copied inferior.  If -copies is not specified,\n\
1066 adds 1 copy.  If ID is not specified, it is the current inferior\n\
1067 that is cloned."));
1068
1069   add_cmd ("inferiors", class_run, detach_inferior_command, _("\
1070 Detach from inferior ID (or list of IDS)."),
1071            &detachlist);
1072
1073   add_cmd ("inferiors", class_run, kill_inferior_command, _("\
1074 Kill inferior ID (or list of IDs)."),
1075            &killlist);
1076
1077   add_cmd ("inferior", class_run, inferior_command, _("\
1078 Use this command to switch between inferiors.\n\
1079 The new inferior ID must be currently known."),
1080            &cmdlist);
1081
1082   add_setshow_boolean_cmd ("inferior-events", no_class,
1083          &print_inferior_events, _("\
1084 Set printing of inferior events (e.g., inferior start and exit)."), _("\
1085 Show printing of inferior events (e.g., inferior start and exit)."), NULL,
1086          NULL,
1087          show_print_inferior_events,
1088          &setprintlist, &showprintlist);
1089
1090   create_internalvar_type_lazy ("_inferior", &inferior_funcs, NULL);
1091 }