gdb/inferior.c

   1 /* Multi-process control for GDB, the GNU debugger.
   2
   3    Copyright (C) 2008, 2009, 2010, 2011 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 "gdbcmd.h"
  26 #include "gdbthread.h"
  27 #include "ui-out.h"
  28 #include "observer.h"
  29 #include "gdbthread.h"
  30 #include "gdbcore.h"
  31 #include "symfile.h"
  32 #include "environ.h"
  33 #include "cli/cli-utils.h"
  34
  35 void _initialize_inferiors (void);
  36
  37 static void inferior_alloc_data (struct inferior *inf);
  38 static void inferior_free_data (struct inferior *inf);
  39
  40 struct inferior *inferior_list = NULL;
  41 static int highest_inferior_num;
  42
  43 /* Print notices on inferior events (attach, detach, etc.), set with
  44    `set print inferior-events'.  */
  45 static int print_inferior_events = 0;
  46
  47 /* The Current Inferior.  */
  48 static struct inferior *current_inferior_ = NULL;
  49
  50 struct inferior*
  51 current_inferior (void)
  52 {
  53   return current_inferior_;
  54 }
  55
  56 void
  57 set_current_inferior (struct inferior *inf)
  58 {
  59   /* There's always an inferior.  */
  60   gdb_assert (inf != NULL);
  61
  62   current_inferior_ = inf;
  63 }
  64
  65 /* A cleanups callback, helper for save_current_program_space
  66    below.  */
  67
  68 static void
  69 restore_inferior (void *arg)
  70 {
  71   struct inferior *saved_inferior = arg;
  72
  73   set_current_inferior (saved_inferior);
  74 }
  75
  76 /* Save the current program space so that it may be restored by a later
  77    call to do_cleanups.  Returns the struct cleanup pointer needed for
  78    later doing the cleanup.  */
  79
  80 struct cleanup *
  81 save_current_inferior (void)
  82 {
  83   struct cleanup *old_chain = make_cleanup (restore_inferior,
  84                                             current_inferior_);
  85
  86   return old_chain;
  87 }
  88
  89 static void
  90 free_inferior (struct inferior *inf)
  91 {
  92   discard_all_inferior_continuations (inf);
  93   inferior_free_data (inf);
  94   xfree (inf->args);
  95   xfree (inf->terminal);
  96   free_environ (inf->environment);
  97   xfree (inf->private);
  98   xfree (inf);
  99 }
 100
 101 void
 102 init_inferior_list (void)
 103 {
 104   struct inferior *inf, *infnext;
 105
 106   highest_inferior_num = 0;
 107   if (!inferior_list)
 108     return;
 109
 110   for (inf = inferior_list; inf; inf = infnext)
 111     {
 112       infnext = inf->next;
 113       free_inferior (inf);
 114     }
 115
 116   inferior_list = NULL;
 117 }
 118
 119 struct inferior *
 120 add_inferior_silent (int pid)
 121 {
 122   struct inferior *inf;
 123
 124   inf = xmalloc (sizeof (*inf));
 125   memset (inf, 0, sizeof (*inf));
 126   inf->pid = pid;
 127
 128   inf->control.stop_soon = NO_STOP_QUIETLY;
 129
 130   inf->num = ++highest_inferior_num;
 131   inf->next = inferior_list;
 132   inferior_list = inf;
 133
 134   inf->environment = make_environ ();
 135   init_environ (inf->environment);
 136
 137   inferior_alloc_data (inf);
 138
 139   observer_notify_inferior_added (inf);
 140
 141   if (pid != 0)
 142     inferior_appeared (inf, pid);
 143
 144   return inf;
 145 }
 146
 147 struct inferior *
 148 add_inferior (int pid)
 149 {
 150   struct inferior *inf = add_inferior_silent (pid);
 151
 152   if (print_inferior_events)
 153     printf_unfiltered (_("[New inferior %d]\n"), pid);
 154
 155   return inf;
 156 }
 157
 158 struct delete_thread_of_inferior_arg
 159 {
 160   int pid;
 161   int silent;
 162 };
 163
 164 static int
 165 delete_thread_of_inferior (struct thread_info *tp, void *data)
 166 {
 167   struct delete_thread_of_inferior_arg *arg = data;
 168
 169   if (ptid_get_pid (tp->ptid) == arg->pid)
 170     {
 171       if (arg->silent)
 172         delete_thread_silent (tp->ptid);
 173       else
 174         delete_thread (tp->ptid);
 175     }
 176
 177   return 0;
 178 }
 179
 180 void
 181 delete_threads_of_inferior (int pid)
 182 {
 183   struct inferior *inf;
 184   struct delete_thread_of_inferior_arg arg;
 185
 186   for (inf = inferior_list; inf; inf = inf->next)
 187     if (inf->pid == pid)
 188       break;
 189
 190   if (!inf)
 191     return;
 192
 193   arg.pid = pid;
 194   arg.silent = 1;
 195
 196   iterate_over_threads (delete_thread_of_inferior, &arg);
 197 }
 198
 199 /* If SILENT then be quiet -- don't announce a inferior death, or the
 200    exit of its threads.  */
 201
 202 void
 203 delete_inferior_1 (struct inferior *todel, int silent)
 204 {
 205   struct inferior *inf, *infprev;
 206   struct delete_thread_of_inferior_arg arg;
 207
 208   infprev = NULL;
 209
 210   for (inf = inferior_list; inf; infprev = inf, inf = inf->next)
 211     if (inf == todel)
 212       break;
 213
 214   if (!inf)
 215     return;
 216
 217   arg.pid = inf->pid;
 218   arg.silent = silent;
 219
 220   iterate_over_threads (delete_thread_of_inferior, &arg);
 221
 222   if (infprev)
 223     infprev->next = inf->next;
 224   else
 225     inferior_list = inf->next;
 226
 227   observer_notify_inferior_removed (inf);
 228
 229   free_inferior (inf);
 230 }
 231
 232 void
 233 delete_inferior (int pid)
 234 {
 235   struct inferior *inf = find_inferior_pid (pid);
 236
 237   delete_inferior_1 (inf, 0);
 238
 239   if (print_inferior_events)
 240     printf_unfiltered (_("[Inferior %d exited]\n"), pid);
 241 }
 242
 243 void
 244 delete_inferior_silent (int pid)
 245 {
 246   struct inferior *inf = find_inferior_pid (pid);
 247
 248   delete_inferior_1 (inf, 1);
 249 }
 250
 251
 252 /* If SILENT then be quiet -- don't announce a inferior exit, or the
 253    exit of its threads.  */
 254
 255 static void
 256 exit_inferior_1 (struct inferior *inftoex, int silent)
 257 {
 258   struct inferior *inf;
 259   struct delete_thread_of_inferior_arg arg;
 260
 261   for (inf = inferior_list; inf; inf = inf->next)
 262     if (inf == inftoex)
 263       break;
 264
 265   if (!inf)
 266     return;
 267
 268   arg.pid = inf->pid;
 269   arg.silent = silent;
 270
 271   iterate_over_threads (delete_thread_of_inferior, &arg);
 272
 273   /* Notify the observers before removing the inferior from the list,
 274      so that the observers have a chance to look it up.  */
 275   observer_notify_inferior_exit (inf);
 276
 277   inf->pid = 0;
 278   if (inf->vfork_parent != NULL)
 279     {
 280       inf->vfork_parent->vfork_child = NULL;
 281       inf->vfork_parent = NULL;
 282     }
 283 }
 284
 285 void
 286 exit_inferior (int pid)
 287 {
 288   struct inferior *inf = find_inferior_pid (pid);
 289
 290   exit_inferior_1 (inf, 0);
 291
 292   if (print_inferior_events)
 293     printf_unfiltered (_("[Inferior %d exited]\n"), pid);
 294 }
 295
 296 void
 297 exit_inferior_silent (int pid)
 298 {
 299   struct inferior *inf = find_inferior_pid (pid);
 300
 301   exit_inferior_1 (inf, 1);
 302 }
 303
 304 void
 305 exit_inferior_num_silent (int num)
 306 {
 307   struct inferior *inf = find_inferior_id (num);
 308
 309   exit_inferior_1 (inf, 1);
 310 }
 311
 312 void
 313 detach_inferior (int pid)
 314 {
 315   struct inferior *inf = find_inferior_pid (pid);
 316
 317   exit_inferior_1 (inf, 1);
 318
 319   if (print_inferior_events)
 320     printf_unfiltered (_("[Inferior %d detached]\n"), pid);
 321 }
 322
 323 void
 324 inferior_appeared (struct inferior *inf, int pid)
 325 {
 326   inf->pid = pid;
 327
 328   observer_notify_inferior_appeared (inf);
 329 }
 330
 331 void
 332 discard_all_inferiors (void)
 333 {
 334   struct inferior *inf;
 335
 336   for (inf = inferior_list; inf; inf = inf->next)
 337     {
 338       if (inf->pid != 0)
 339         exit_inferior_silent (inf->pid);
 340     }
 341 }
 342
 343 struct inferior *
 344 find_inferior_id (int num)
 345 {
 346   struct inferior *inf;
 347
 348   for (inf = inferior_list; inf; inf = inf->next)
 349     if (inf->num == num)
 350       return inf;
 351
 352   return NULL;
 353 }
 354
 355 struct inferior *
 356 find_inferior_pid (int pid)
 357 {
 358   struct inferior *inf;
 359
 360   /* Looking for inferior pid == 0 is always wrong, and indicative of
 361      a bug somewhere else.  There may be more than one with pid == 0,
 362      for instance.  */
 363   gdb_assert (pid != 0);
 364
 365   for (inf = inferior_list; inf; inf = inf->next)
 366     if (inf->pid == pid)
 367       return inf;
 368
 369   return NULL;
 370 }
 371
 372 /* Find an inferior bound to PSPACE.  */
 373
 374 struct inferior *
 375 find_inferior_for_program_space (struct program_space *pspace)
 376 {
 377   struct inferior *inf;
 378
 379   for (inf = inferior_list; inf != NULL; inf = inf->next)
 380     {
 381       if (inf->pspace == pspace)
 382         return inf;
 383     }
 384
 385   return NULL;
 386 }
 387
 388 struct inferior *
 389 iterate_over_inferiors (int (*callback) (struct inferior *, void *),
 390                         void *data)
 391 {
 392   struct inferior *inf, *infnext;
 393
 394   for (inf = inferior_list; inf; inf = infnext)
 395     {
 396       infnext = inf->next;
 397       if ((*callback) (inf, data))
 398         return inf;
 399     }
 400
 401   return NULL;
 402 }
 403
 404 int
 405 valid_gdb_inferior_id (int num)
 406 {
 407   struct inferior *inf;
 408
 409   for (inf = inferior_list; inf; inf = inf->next)
 410     if (inf->num == num)
 411       return 1;
 412
 413   return 0;
 414 }
 415
 416 int
 417 pid_to_gdb_inferior_id (int pid)
 418 {
 419   struct inferior *inf;
 420
 421   for (inf = inferior_list; inf; inf = inf->next)
 422     if (inf->pid == pid)
 423       return inf->num;
 424
 425   return 0;
 426 }
 427
 428 int
 429 gdb_inferior_id_to_pid (int num)
 430 {
 431   struct inferior *inferior = find_inferior_id (num);
 432   if (inferior)
 433     return inferior->pid;
 434   else
 435     return -1;
 436 }
 437
 438 int
 439 in_inferior_list (int pid)
 440 {
 441   struct inferior *inf;
 442
 443   for (inf = inferior_list; inf; inf = inf->next)
 444     if (inf->pid == pid)
 445       return 1;
 446
 447   return 0;
 448 }
 449
 450 int
 451 have_inferiors (void)
 452 {
 453   struct inferior *inf;
 454
 455   for (inf = inferior_list; inf; inf = inf->next)
 456     if (inf->pid != 0)
 457       return 1;
 458
 459   return 0;
 460 }
 461
 462 int
 463 have_live_inferiors (void)
 464 {
 465   struct cleanup *old_chain;
 466   struct inferior *inf;
 467
 468   old_chain = make_cleanup_restore_current_thread ();
 469
 470   for (inf = inferior_list; inf; inf = inf->next)
 471     if (inf->pid != 0)
 472       {
 473         struct thread_info *tp;
 474
 475         tp = any_thread_of_process (inf->pid);
 476         if (tp)
 477           {
 478             switch_to_thread (tp->ptid);
 479
 480             if (target_has_execution)
 481               break;
 482           }
 483       }
 484
 485   do_cleanups (old_chain);
 486
 487   return inf != NULL;
 488 }
 489
 490 /* Prune away automatically added program spaces that aren't required
 491    anymore.  */
 492
 493 void
 494 prune_inferiors (void)
 495 {
 496   struct inferior *ss, **ss_link;
 497   struct inferior *current = current_inferior ();
 498
 499   ss = inferior_list;
 500   ss_link = &inferior_list;
 501   while (ss)
 502     {
 503       if (ss == current
 504           || !ss->removable
 505           || ss->pid != 0)
 506         {
 507           ss_link = &ss->next;
 508           ss = *ss_link;
 509           continue;
 510         }
 511
 512       *ss_link = ss->next;
 513       delete_inferior_1 (ss, 1);
 514       ss = *ss_link;
 515     }
 516
 517   prune_program_spaces ();
 518 }
 519
 520 /* Simply returns the count of inferiors.  */
 521
 522 int
 523 number_of_inferiors (void)
 524 {
 525   struct inferior *inf;
 526   int count = 0;
 527
 528   for (inf = inferior_list; inf != NULL; inf = inf->next)
 529     count++;
 530
 531   return count;
 532 }
 533
 534 /* Prints the list of inferiors and their details on UIOUT.  This is a
 535    version of 'info_inferior_command' suitable for use from MI.
 536
 537    If REQUESTED_INFERIORS is not NULL, it's a list of GDB ids of the
 538    inferiors that should be printed.  Otherwise, all inferiors are
 539    printed.  */
 540
 541 static void
 542 print_inferior (struct ui_out *uiout, char *requested_inferiors)
 543 {
 544   struct inferior *inf;
 545   struct cleanup *old_chain;
 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       ui_out_message (uiout, 0, "No inferiors.\n");
 560       return;
 561     }
 562
 563   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 4, inf_count,
 564                                                    "inferiors");
 565   ui_out_table_header (uiout, 1, ui_left, "current", "");
 566   ui_out_table_header (uiout, 4, ui_left, "number", "Num");
 567   ui_out_table_header (uiout, 17, ui_left, "target-id", "Description");
 568   ui_out_table_header (uiout, 17, ui_left, "exec", "Executable");
 569
 570   ui_out_table_body (uiout);
 571   for (inf = inferior_list; inf; inf = inf->next)
 572     {
 573       struct cleanup *chain2;
 574
 575       if (!number_is_in_list (requested_inferiors, inf->num))
 576         continue;
 577
 578       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 579
 580       if (inf == current_inferior ())
 581         ui_out_field_string (uiout, "current", "*");
 582       else
 583         ui_out_field_skip (uiout, "current");
 584
 585       ui_out_field_int (uiout, "number", inf->num);
 586
 587       if (inf->pid)
 588         ui_out_field_string (uiout, "target-id",
 589                              target_pid_to_str (pid_to_ptid (inf->pid)));
 590       else
 591         ui_out_field_string (uiout, "target-id", "<null>");
 592
 593       if (inf->pspace->ebfd)
 594         ui_out_field_string (uiout, "exec",
 595                              bfd_get_filename (inf->pspace->ebfd));
 596       else
 597         ui_out_field_skip (uiout, "exec");
 598
 599       /* Print extra info that isn't really fit to always present in
 600          tabular form.  Currently we print the vfork parent/child
 601          relationships, if any.  */
 602       if (inf->vfork_parent)
 603         {
 604           ui_out_text (uiout, _("\n\tis vfork child of inferior "));
 605           ui_out_field_int (uiout, "vfork-parent", inf->vfork_parent->num);
 606         }
 607       if (inf->vfork_child)
 608         {
 609           ui_out_text (uiout, _("\n\tis vfork parent of inferior "));
 610           ui_out_field_int (uiout, "vfork-child", inf->vfork_child->num);
 611         }
 612
 613       ui_out_text (uiout, "\n");
 614       do_cleanups (chain2);
 615     }
 616
 617   do_cleanups (old_chain);
 618 }
 619
 620 static void
 621 detach_inferior_command (char *args, int from_tty)
 622 {
 623   int num, pid;
 624   struct thread_info *tp;
 625
 626   if (!args || !*args)
 627     error (_("Requires argument (inferior id(s) to detach)"));
 628
 629   while (*args != '\0')
 630     {
 631       num = get_number_or_range (&args);
 632
 633       if (!valid_gdb_inferior_id (num))
 634         {
 635           warning (_("Inferior ID %d not known."), num);
 636           continue;
 637         }
 638
 639       pid = gdb_inferior_id_to_pid (num);
 640
 641       tp = any_thread_of_process (pid);
 642       if (!tp)
 643         {
 644           warning (_("Inferior ID %d has no threads."), num);
 645           continue;
 646         }
 647
 648       switch_to_thread (tp->ptid);
 649
 650       detach_command (NULL, from_tty);
 651     }
 652 }
 653
 654 static void
 655 kill_inferior_command (char *args, int from_tty)
 656 {
 657   int num, pid;
 658   struct thread_info *tp;
 659
 660   if (!args || !*args)
 661     error (_("Requires argument (inferior id(s) to kill)"));
 662
 663   while (*args != '\0')
 664     {
 665       num = get_number_or_range (&args);
 666
 667       if (!valid_gdb_inferior_id (num))
 668         {
 669           warning (_("Inferior ID %d not known."), num);
 670           continue;
 671         }
 672
 673       pid = gdb_inferior_id_to_pid (num);
 674
 675       tp = any_thread_of_process (pid);
 676       if (!tp)
 677         {
 678           warning (_("Inferior ID %d has no threads."), num);
 679           continue;
 680         }
 681
 682       switch_to_thread (tp->ptid);
 683
 684       target_kill ();
 685     }
 686
 687   bfd_cache_close_all ();
 688 }
 689
 690 static void
 691 inferior_command (char *args, int from_tty)
 692 {
 693   struct inferior *inf;
 694   int num;
 695
 696   num = parse_and_eval_long (args);
 697
 698   inf = find_inferior_id (num);
 699   if (inf == NULL)
 700     error (_("Inferior ID %d not known."), num);
 701
 702   printf_filtered (_("[Switching to inferior %d [%s] (%s)]\n"),
 703                    inf->num,
 704                    target_pid_to_str (pid_to_ptid (inf->pid)),
 705                    (inf->pspace->ebfd
 706                     ? bfd_get_filename (inf->pspace->ebfd)
 707                     : _("<noexec>")));
 708
 709   if (inf->pid != 0)
 710     {
 711       if (inf->pid != ptid_get_pid (inferior_ptid))
 712         {
 713           struct thread_info *tp;
 714
 715           tp = any_thread_of_process (inf->pid);
 716           if (!tp)
 717             error (_("Inferior has no threads."));
 718
 719           switch_to_thread (tp->ptid);
 720         }
 721
 722       printf_filtered (_("[Switching to thread %d (%s)] "),
 723                        pid_to_thread_id (inferior_ptid),
 724                        target_pid_to_str (inferior_ptid));
 725     }
 726   else
 727     {
 728       struct inferior *inf;
 729
 730       inf = find_inferior_id (num);
 731       set_current_inferior (inf);
 732       switch_to_thread (null_ptid);
 733       set_current_program_space (inf->pspace);
 734     }
 735
 736   if (inf->pid != 0 && is_running (inferior_ptid))
 737     ui_out_text (uiout, "(running)\n");
 738   else if (inf->pid != 0)
 739     {
 740       ui_out_text (uiout, "\n");
 741       print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
 742     }
 743 }
 744
 745 /* Print information about currently known inferiors.  */
 746
 747 static void
 748 info_inferiors_command (char *args, int from_tty)
 749 {
 750   print_inferior (uiout, args);
 751 }
 752
 753 /* remove-inferior ID */
 754
 755 void
 756 remove_inferior_command (char *args, int from_tty)
 757 {
 758   int num;
 759   struct inferior *inf;
 760
 761   if (args == NULL || *args == '\0')
 762     error (_("Requires an argument (inferior id(s) to remove)"));
 763
 764   while (*args != '\0')
 765     {
 766       num = get_number_or_range (&args);
 767       inf = find_inferior_id (num);
 768
 769       if (inf == NULL)
 770         {
 771           warning (_("Inferior ID %d not known."), num);
 772           continue;
 773         }
 774
 775       if (inf == current_inferior ())
 776         {
 777           warning (_("Can not remove current symbol inferior %d."), num);
 778           continue;
 779         }
 780
 781       if (inf->pid != 0)
 782         {
 783           warning (_("Can not remove active inferior %d."), num);
 784           continue;
 785         }
 786
 787       delete_inferior_1 (inf, 1);
 788     }
 789 }
 790
 791 struct inferior *
 792 add_inferior_with_spaces (void)
 793 {
 794   struct address_space *aspace;
 795   struct program_space *pspace;
 796   struct inferior *inf;
 797
 798   /* If all inferiors share an address space on this system, this
 799      doesn't really return a new address space; otherwise, it
 800      really does.  */
 801   aspace = maybe_new_address_space ();
 802   pspace = add_program_space (aspace);
 803   inf = add_inferior (0);
 804   inf->pspace = pspace;
 805   inf->aspace = pspace->aspace;
 806
 807   return inf;
 808 }
 809
 810 /* add-inferior [-copies N] [-exec FILENAME]  */
 811
 812 void
 813 add_inferior_command (char *args, int from_tty)
 814 {
 815   int i, copies = 1;
 816   char *exec = NULL;
 817   char **argv;
 818   struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
 819
 820   if (args)
 821     {
 822       argv = gdb_buildargv (args);
 823       make_cleanup_freeargv (argv);
 824
 825       for (; *argv != NULL; argv++)
 826         {
 827           if (**argv == '-')
 828             {
 829               if (strcmp (*argv, "-copies") == 0)
 830                 {
 831                   ++argv;
 832                   if (!*argv)
 833                     error (_("No argument to -copies"));
 834                   copies = parse_and_eval_long (*argv);
 835                 }
 836               else if (strcmp (*argv, "-exec") == 0)
 837                 {
 838                   ++argv;
 839                   if (!*argv)
 840                     error (_("No argument to -exec"));
 841                   exec = *argv;
 842                 }
 843             }
 844           else
 845             error (_("Invalid argument"));
 846         }
 847     }
 848
 849   save_current_space_and_thread ();
 850
 851   for (i = 0; i < copies; ++i)
 852     {
 853       struct inferior *inf = add_inferior_with_spaces ();
 854
 855       printf_filtered (_("Added inferior %d\n"), inf->num);
 856
 857       if (exec != NULL)
 858         {
 859           /* Switch over temporarily, while reading executable and
 860              symbols.q.  */
 861           set_current_program_space (inf->pspace);
 862           set_current_inferior (inf);
 863           switch_to_thread (null_ptid);
 864
 865           exec_file_attach (exec, from_tty);
 866           symbol_file_add_main (exec, from_tty);
 867         }
 868     }
 869
 870   do_cleanups (old_chain);
 871 }
 872
 873 /* clone-inferior [-copies N] [ID] */
 874
 875 void
 876 clone_inferior_command (char *args, int from_tty)
 877 {
 878   int i, copies = 1;
 879   char **argv;
 880   struct inferior *orginf = NULL;
 881   struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
 882
 883   if (args)
 884     {
 885       argv = gdb_buildargv (args);
 886       make_cleanup_freeargv (argv);
 887
 888       for (; *argv != NULL; argv++)
 889         {
 890           if (**argv == '-')
 891             {
 892               if (strcmp (*argv, "-copies") == 0)
 893                 {
 894                   ++argv;
 895                   if (!*argv)
 896                     error (_("No argument to -copies"));
 897                   copies = parse_and_eval_long (*argv);
 898
 899                   if (copies < 0)
 900                     error (_("Invalid copies number"));
 901                 }
 902             }
 903           else
 904             {
 905               if (orginf == NULL)
 906                 {
 907                   int num;
 908
 909                   /* The first non-option (-) argument specified the
 910                      program space ID.  */
 911                   num = parse_and_eval_long (*argv);
 912                   orginf = find_inferior_id (num);
 913
 914                   if (orginf == NULL)
 915                     error (_("Inferior ID %d not known."), num);
 916                   continue;
 917                 }
 918               else
 919                 error (_("Invalid argument"));
 920             }
 921         }
 922     }
 923
 924   /* If no inferior id was specified, then the user wants to clone the
 925      current inferior.  */
 926   if (orginf == NULL)
 927     orginf = current_inferior ();
 928
 929   save_current_space_and_thread ();
 930
 931   for (i = 0; i < copies; ++i)
 932     {
 933       struct address_space *aspace;
 934       struct program_space *pspace;
 935       struct inferior *inf;
 936
 937       /* If all inferiors share an address space on this system, this
 938          doesn't really return a new address space; otherwise, it
 939          really does.  */
 940       aspace = maybe_new_address_space ();
 941       pspace = add_program_space (aspace);
 942       inf = add_inferior (0);
 943       inf->pspace = pspace;
 944       inf->aspace = pspace->aspace;
 945
 946       printf_filtered (_("Added inferior %d.\n"), inf->num);
 947
 948       set_current_inferior (inf);
 949       switch_to_thread (null_ptid);
 950       clone_program_space (pspace, orginf->pspace);
 951     }
 952
 953   do_cleanups (old_chain);
 954 }
 955
 956 /* Print notices when new inferiors are created and die.  */
 957 static void
 958 show_print_inferior_events (struct ui_file *file, int from_tty,
 959                            struct cmd_list_element *c, const char *value)
 960 {
 961   fprintf_filtered (file, _("Printing of inferior events is %s.\n"), value);
 962 }
 963
 964 \f
 965
 966 /* Keep a registry of per-inferior data-pointers required by other GDB
 967    modules.  */
 968
 969 struct inferior_data
 970 {
 971   unsigned index;
 972   void (*cleanup) (struct inferior *, void *);
 973 };
 974
 975 struct inferior_data_registration
 976 {
 977   struct inferior_data *data;
 978   struct inferior_data_registration *next;
 979 };
 980
 981 struct inferior_data_registry
 982 {
 983   struct inferior_data_registration *registrations;
 984   unsigned num_registrations;
 985 };
 986
 987 static struct inferior_data_registry inferior_data_registry
 988   = { NULL, 0 };
 989
 990 const struct inferior_data *
 991 register_inferior_data_with_cleanup
 992   (void (*cleanup) (struct inferior *, void *))
 993 {
 994   struct inferior_data_registration **curr;
 995
 996   /* Append new registration.  */
 997   for (curr = &inferior_data_registry.registrations;
 998        *curr != NULL; curr = &(*curr)->next);
 999
1000   *curr = XMALLOC (struct inferior_data_registration);
1001   (*curr)->next = NULL;
1002   (*curr)->data = XMALLOC (struct inferior_data);
1003   (*curr)->data->index = inferior_data_registry.num_registrations++;
1004   (*curr)->data->cleanup = cleanup;
1005
1006   return (*curr)->data;
1007 }
1008
1009 const struct inferior_data *
1010 register_inferior_data (void)
1011 {
1012   return register_inferior_data_with_cleanup (NULL);
1013 }
1014
1015 static void
1016 inferior_alloc_data (struct inferior *inf)
1017 {
1018   gdb_assert (inf->data == NULL);
1019   inf->num_data = inferior_data_registry.num_registrations;
1020   inf->data = XCALLOC (inf->num_data, void *);
1021 }
1022
1023 static void
1024 inferior_free_data (struct inferior *inf)
1025 {
1026   gdb_assert (inf->data != NULL);
1027   clear_inferior_data (inf);
1028   xfree (inf->data);
1029   inf->data = NULL;
1030 }
1031
1032 void
1033 clear_inferior_data (struct inferior *inf)
1034 {
1035   struct inferior_data_registration *registration;
1036   int i;
1037
1038   gdb_assert (inf->data != NULL);
1039
1040   for (registration = inferior_data_registry.registrations, i = 0;
1041        i < inf->num_data;
1042        registration = registration->next, i++)
1043     if (inf->data[i] != NULL && registration->data->cleanup)
1044       registration->data->cleanup (inf, inf->data[i]);
1045
1046   memset (inf->data, 0, inf->num_data * sizeof (void *));
1047 }
1048
1049 void
1050 set_inferior_data (struct inferior *inf,
1051                        const struct inferior_data *data,
1052                        void *value)
1053 {
1054   gdb_assert (data->index < inf->num_data);
1055   inf->data[data->index] = value;
1056 }
1057
1058 void *
1059 inferior_data (struct inferior *inf, const struct inferior_data *data)
1060 {
1061   gdb_assert (data->index < inf->num_data);
1062   return inf->data[data->index];
1063 }
1064
1065 void
1066 initialize_inferiors (void)
1067 {
1068   /* There's always one inferior.  Note that this function isn't an
1069      automatic _initialize_foo function, since other _initialize_foo
1070      routines may need to install their per-inferior data keys.  We
1071      can only allocate an inferior when all those modules have done
1072      that.  Do this after initialize_progspace, due to the
1073      current_program_space reference.  */
1074   current_inferior_ = add_inferior (0);
1075   current_inferior_->pspace = current_program_space;
1076   current_inferior_->aspace = current_program_space->aspace;
1077
1078   add_info ("inferiors", info_inferiors_command,
1079             _("IDs of specified inferiors (all inferiors if no argument)."));
1080
1081   add_com ("add-inferior", no_class, add_inferior_command, _("\
1082 Add a new inferior.\n\
1083 Usage: add-inferior [-copies <N>] [-exec <FILENAME>]\n\
1084 N is the optional number of inferiors to add, default is 1.\n\
1085 FILENAME is the file name of the executable to use\n\
1086 as main program."));
1087
1088   add_com ("remove-inferiors", no_class, remove_inferior_command, _("\
1089 Remove inferior ID (or list of IDs).\n\
1090 Usage: remove-inferiors ID..."));
1091
1092   add_com ("clone-inferior", no_class, clone_inferior_command, _("\
1093 Clone inferior ID.\n\
1094 Usage: clone-inferior [-copies <N>] [ID]\n\
1095 Add N copies of inferior ID.  The new inferior has the same\n\
1096 executable loaded as the copied inferior.  If -copies is not specified,\n\
1097 adds 1 copy.  If ID is not specified, it is the current inferior\n\
1098 that is cloned."));
1099
1100   add_cmd ("inferiors", class_run, detach_inferior_command, _("\
1101 Detach from inferior ID (or list of IDS)."),
1102            &detachlist);
1103
1104   add_cmd ("inferiors", class_run, kill_inferior_command, _("\
1105 Kill inferior ID (or list of IDs)."),
1106            &killlist);
1107
1108   add_cmd ("inferior", class_run, inferior_command, _("\
1109 Use this command to switch between inferiors.\n\
1110 The new inferior ID must be currently known."),
1111            &cmdlist);
1112
1113   add_setshow_boolean_cmd ("inferior-events", no_class,
1114          &print_inferior_events, _("\
1115 Set printing of inferior events (e.g., inferior start and exit)."), _("\
1116 Show printing of inferior events (e.g., inferior start and exit)."), NULL,
1117          NULL,
1118          show_print_inferior_events,
1119          &setprintlist, &showprintlist);
1120
1121 }