gdb/thread.c

   1 /* Multi-process/thread control for GDB, the GNU debugger.
   2    Copyright 1986, 1987, 1988, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   3    2000, 2001
   4    Free Software Foundation, Inc.
   5    Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.
   6
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 59 Temple Place - Suite 330,
  23    Boston, MA 02111-1307, USA.  */
  24
  25 #include "defs.h"
  26 #include "symtab.h"
  27 #include "frame.h"
  28 #include "inferior.h"
  29 #include "environ.h"
  30 #include "value.h"
  31 #include "target.h"
  32 #include "gdbthread.h"
  33 #include "command.h"
  34 #include "gdbcmd.h"
  35 #include "regcache.h"
  36 #include "gdb.h"
  37
  38 #include <ctype.h>
  39 #include <sys/types.h>
  40 #include <signal.h>
  41 #ifdef UI_OUT
  42 #include "ui-out.h"
  43 #endif
  44
  45 /*#include "lynxos-core.h" */
  46
  47 /* Definition of struct thread_info exported to gdbthread.h */
  48
  49 /* Prototypes for exported functions. */
  50
  51 void _initialize_thread (void);
  52
  53 /* Prototypes for local functions. */
  54
  55 static struct thread_info *thread_list = NULL;
  56 static int highest_thread_num;
  57
  58 static struct thread_info *find_thread_id (int num);
  59
  60 static void thread_command (char *tidstr, int from_tty);
  61 static void thread_apply_all_command (char *, int);
  62 static int thread_alive (struct thread_info *);
  63 static void info_threads_command (char *, int);
  64 static void thread_apply_command (char *, int);
  65 static void restore_current_thread (ptid_t);
  66 static void switch_to_thread (ptid_t ptid);
  67 static void prune_threads (void);
  68
  69 void
  70 delete_step_resume_breakpoint (void *arg)
  71 {
  72   struct breakpoint **breakpointp = (struct breakpoint **) arg;
  73   struct thread_info *tp;
  74
  75   if (*breakpointp != NULL)
  76     {
  77       delete_breakpoint (*breakpointp);
  78       for (tp = thread_list; tp; tp = tp->next)
  79         if (tp->step_resume_breakpoint == *breakpointp)
  80           tp->step_resume_breakpoint = NULL;
  81
  82       *breakpointp = NULL;
  83     }
  84 }
  85
  86 static void
  87 free_thread (struct thread_info *tp)
  88 {
  89   /* NOTE: this will take care of any left-over step_resume breakpoints,
  90      but not any user-specified thread-specific breakpoints. */
  91   if (tp->step_resume_breakpoint)
  92     delete_breakpoint (tp->step_resume_breakpoint);
  93
  94   /* FIXME: do I ever need to call the back-end to give it a
  95      chance at this private data before deleting the thread?  */
  96   if (tp->private)
  97     xfree (tp->private);
  98
  99   xfree (tp);
 100 }
 101
 102 void
 103 init_thread_list (void)
 104 {
 105   struct thread_info *tp, *tpnext;
 106
 107   highest_thread_num = 0;
 108   if (!thread_list)
 109     return;
 110
 111   for (tp = thread_list; tp; tp = tpnext)
 112     {
 113       tpnext = tp->next;
 114       free_thread (tp);
 115     }
 116
 117   thread_list = NULL;
 118 }
 119
 120 /* add_thread now returns a pointer to the new thread_info,
 121    so that back_ends can initialize their private data.  */
 122
 123 struct thread_info *
 124 add_thread (ptid_t ptid)
 125 {
 126   struct thread_info *tp;
 127
 128   tp = (struct thread_info *) xmalloc (sizeof (*tp));
 129   memset (tp, 0, sizeof (*tp));
 130   tp->ptid = ptid;
 131   tp->num = ++highest_thread_num;
 132   tp->next = thread_list;
 133   thread_list = tp;
 134   return tp;
 135 }
 136
 137 void
 138 delete_thread (ptid_t ptid)
 139 {
 140   struct thread_info *tp, *tpprev;
 141
 142   tpprev = NULL;
 143
 144   for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
 145     if (ptid_equal (tp->ptid, ptid))
 146       break;
 147
 148   if (!tp)
 149     return;
 150
 151   if (tpprev)
 152     tpprev->next = tp->next;
 153   else
 154     thread_list = tp->next;
 155
 156   free_thread (tp);
 157 }
 158
 159 static struct thread_info *
 160 find_thread_id (int num)
 161 {
 162   struct thread_info *tp;
 163
 164   for (tp = thread_list; tp; tp = tp->next)
 165     if (tp->num == num)
 166       return tp;
 167
 168   return NULL;
 169 }
 170
 171 /* Find a thread_info by matching PTID.  */
 172 struct thread_info *
 173 find_thread_pid (ptid_t ptid)
 174 {
 175   struct thread_info *tp;
 176
 177   for (tp = thread_list; tp; tp = tp->next)
 178     if (ptid_equal (tp->ptid, ptid))
 179       return tp;
 180
 181   return NULL;
 182 }
 183
 184 /*
 185  * Thread iterator function.
 186  *
 187  * Calls a callback function once for each thread, so long as
 188  * the callback function returns false.  If the callback function
 189  * returns true, the iteration will end and the current thread
 190  * will be returned.  This can be useful for implementing a
 191  * search for a thread with arbitrary attributes, or for applying
 192  * some operation to every thread.
 193  *
 194  * FIXME: some of the existing functionality, such as
 195  * "Thread apply all", might be rewritten using this functionality.
 196  */
 197
 198 struct thread_info *
 199 iterate_over_threads (int (*callback) (struct thread_info *, void *),
 200                       void *data)
 201 {
 202   struct thread_info *tp;
 203
 204   for (tp = thread_list; tp; tp = tp->next)
 205     if ((*callback) (tp, data))
 206       return tp;
 207
 208   return NULL;
 209 }
 210
 211 int
 212 valid_thread_id (int num)
 213 {
 214   struct thread_info *tp;
 215
 216   for (tp = thread_list; tp; tp = tp->next)
 217     if (tp->num == num)
 218       return 1;
 219
 220   return 0;
 221 }
 222
 223 int
 224 pid_to_thread_id (ptid_t ptid)
 225 {
 226   struct thread_info *tp;
 227
 228   for (tp = thread_list; tp; tp = tp->next)
 229     if (ptid_equal (tp->ptid, ptid))
 230       return tp->num;
 231
 232   return 0;
 233 }
 234
 235 ptid_t
 236 thread_id_to_pid (int num)
 237 {
 238   struct thread_info *thread = find_thread_id (num);
 239   if (thread)
 240     return thread->ptid;
 241   else
 242     return pid_to_ptid (-1);
 243 }
 244
 245 int
 246 in_thread_list (ptid_t ptid)
 247 {
 248   struct thread_info *tp;
 249
 250   for (tp = thread_list; tp; tp = tp->next)
 251     if (ptid_equal (tp->ptid, ptid))
 252       return 1;
 253
 254   return 0;                     /* Never heard of 'im */
 255 }
 256 #ifdef UI_OUT
 257 /* Print a list of thread ids currently known, and the total number of
 258    threads. To be used from within catch_errors. */
 259 static int
 260 do_captured_list_thread_ids (void *arg)
 261 {
 262   struct thread_info *tp;
 263   int num = 0;
 264
 265   ui_out_tuple_begin (uiout, "thread-ids");
 266
 267   for (tp = thread_list; tp; tp = tp->next)
 268     {
 269       num++;
 270       ui_out_field_int (uiout, "thread-id", tp->num);
 271     }
 272
 273   ui_out_tuple_end (uiout);
 274   ui_out_field_int (uiout, "number-of-threads", num);
 275   return GDB_RC_OK;
 276 }
 277
 278 /* Official gdblib interface function to get a list of thread ids and
 279    the total number. */
 280 enum gdb_rc
 281 gdb_list_thread_ids (/* output object */)
 282 {
 283   return catch_errors (do_captured_list_thread_ids, NULL,
 284                        NULL, RETURN_MASK_ALL);
 285 }
 286 #endif
 287
 288 /* Load infrun state for the thread PID.  */
 289
 290 void
 291 load_infrun_state (ptid_t ptid,
 292                    CORE_ADDR *prev_pc,
 293                    CORE_ADDR *prev_func_start,
 294                    char **prev_func_name,
 295                    int *trap_expected,
 296                    struct breakpoint **step_resume_breakpoint,
 297                    struct breakpoint **through_sigtramp_breakpoint,
 298                    CORE_ADDR *step_range_start,
 299                    CORE_ADDR *step_range_end,
 300                    CORE_ADDR *step_frame_address,
 301                    int *handling_longjmp,
 302                    int *another_trap,
 303                    int *stepping_through_solib_after_catch,
 304                    bpstat *stepping_through_solib_catchpoints,
 305                    int *stepping_through_sigtramp,
 306                    int *current_line,
 307                    struct symtab **current_symtab,
 308                    CORE_ADDR *step_sp)
 309 {
 310   struct thread_info *tp;
 311
 312   /* If we can't find the thread, then we're debugging a single threaded
 313      process.  No need to do anything in that case.  */
 314   tp = find_thread_id (pid_to_thread_id (ptid));
 315   if (tp == NULL)
 316     return;
 317
 318   *prev_pc = tp->prev_pc;
 319   *prev_func_start = tp->prev_func_start;
 320   *prev_func_name = tp->prev_func_name;
 321   *trap_expected = tp->trap_expected;
 322   *step_resume_breakpoint = tp->step_resume_breakpoint;
 323   *through_sigtramp_breakpoint = tp->through_sigtramp_breakpoint;
 324   *step_range_start = tp->step_range_start;
 325   *step_range_end = tp->step_range_end;
 326   *step_frame_address = tp->step_frame_address;
 327   *handling_longjmp = tp->handling_longjmp;
 328   *another_trap = tp->another_trap;
 329   *stepping_through_solib_after_catch = tp->stepping_through_solib_after_catch;
 330   *stepping_through_solib_catchpoints = tp->stepping_through_solib_catchpoints;
 331   *stepping_through_sigtramp = tp->stepping_through_sigtramp;
 332   *current_line = tp->current_line;
 333   *current_symtab = tp->current_symtab;
 334   *step_sp = tp->step_sp;
 335 }
 336
 337 /* Save infrun state for the thread PID.  */
 338
 339 void
 340 save_infrun_state (ptid_t ptid,
 341                    CORE_ADDR prev_pc,
 342                    CORE_ADDR prev_func_start,
 343                    char *prev_func_name,
 344                    int trap_expected,
 345                    struct breakpoint *step_resume_breakpoint,
 346                    struct breakpoint *through_sigtramp_breakpoint,
 347                    CORE_ADDR step_range_start,
 348                    CORE_ADDR step_range_end,
 349                    CORE_ADDR step_frame_address,
 350                    int handling_longjmp,
 351                    int another_trap,
 352                    int stepping_through_solib_after_catch,
 353                    bpstat stepping_through_solib_catchpoints,
 354                    int stepping_through_sigtramp,
 355                    int current_line,
 356                    struct symtab *current_symtab,
 357                    CORE_ADDR step_sp)
 358 {
 359   struct thread_info *tp;
 360
 361   /* If we can't find the thread, then we're debugging a single-threaded
 362      process.  Nothing to do in that case.  */
 363   tp = find_thread_id (pid_to_thread_id (ptid));
 364   if (tp == NULL)
 365     return;
 366
 367   tp->prev_pc = prev_pc;
 368   tp->prev_func_start = prev_func_start;
 369   tp->prev_func_name = prev_func_name;
 370   tp->trap_expected = trap_expected;
 371   tp->step_resume_breakpoint = step_resume_breakpoint;
 372   tp->through_sigtramp_breakpoint = through_sigtramp_breakpoint;
 373   tp->step_range_start = step_range_start;
 374   tp->step_range_end = step_range_end;
 375   tp->step_frame_address = step_frame_address;
 376   tp->handling_longjmp = handling_longjmp;
 377   tp->another_trap = another_trap;
 378   tp->stepping_through_solib_after_catch = stepping_through_solib_after_catch;
 379   tp->stepping_through_solib_catchpoints = stepping_through_solib_catchpoints;
 380   tp->stepping_through_sigtramp = stepping_through_sigtramp;
 381   tp->current_line = current_line;
 382   tp->current_symtab = current_symtab;
 383   tp->step_sp = step_sp;
 384 }
 385
 386 /* Return true if TP is an active thread. */
 387 static int
 388 thread_alive (struct thread_info *tp)
 389 {
 390   if (PIDGET (tp->ptid) == -1)
 391     return 0;
 392   if (!target_thread_alive (tp->ptid))
 393     {
 394       tp->ptid = pid_to_ptid (-1);      /* Mark it as dead */
 395       return 0;
 396     }
 397   return 1;
 398 }
 399
 400 static void
 401 prune_threads (void)
 402 {
 403   struct thread_info *tp, *next;
 404
 405   for (tp = thread_list; tp; tp = next)
 406     {
 407       next = tp->next;
 408       if (!thread_alive (tp))
 409         delete_thread (tp->ptid);
 410     }
 411 }
 412
 413 /* Print information about currently known threads
 414
 415  * Note: this has the drawback that it _really_ switches
 416  *       threads, which frees the frame cache.  A no-side
 417  *       effects info-threads command would be nicer.
 418  */
 419
 420 static void
 421 info_threads_command (char *arg, int from_tty)
 422 {
 423   struct thread_info *tp;
 424   ptid_t current_ptid;
 425   struct frame_info *cur_frame;
 426   int saved_frame_level = selected_frame_level;
 427   int counter;
 428   char *extra_info;
 429
 430   /* Avoid coredumps which would happen if we tried to access a NULL
 431      selected_frame.  */
 432   if (!target_has_stack)
 433     error ("No stack.");
 434
 435   prune_threads ();
 436   target_find_new_threads ();
 437   current_ptid = inferior_ptid;
 438   for (tp = thread_list; tp; tp = tp->next)
 439     {
 440       if (ptid_equal (tp->ptid, current_ptid))
 441         printf_filtered ("* ");
 442       else
 443         printf_filtered ("  ");
 444
 445 #ifdef HPUXHPPA
 446       printf_filtered ("%d %s", tp->num, target_tid_to_str (tp->ptid));
 447 #else
 448       printf_filtered ("%d %s", tp->num, target_pid_to_str (tp->ptid));
 449 #endif
 450
 451       extra_info = target_extra_thread_info (tp);
 452       if (extra_info)
 453         printf_filtered (" (%s)", extra_info);
 454       puts_filtered ("  ");
 455
 456       switch_to_thread (tp->ptid);
 457       if (selected_frame)
 458         print_only_stack_frame (selected_frame, -1, 0);
 459       else
 460         printf_filtered ("[No stack.]\n");
 461     }
 462
 463   switch_to_thread (current_ptid);
 464
 465   /* Code below copied from "up_silently_base" in "stack.c".
 466    * It restores the frame set by the user before the "info threads"
 467    * command.  We have finished the info-threads display by switching
 468    * back to the current thread.  That switch has put us at the top
 469    * of the stack (leaf frame).
 470    */
 471   counter = saved_frame_level;
 472   cur_frame = find_relative_frame (selected_frame, &counter);
 473   if (counter != 0)
 474     {
 475       /* Ooops, can't restore, tell user where we are. */
 476       warning ("Couldn't restore frame in current thread, at frame 0");
 477       print_stack_frame (selected_frame, -1, 0);
 478     }
 479   else
 480     {
 481       select_frame (cur_frame, saved_frame_level);
 482     }
 483
 484   /* re-show current frame. */
 485   show_stack_frame (cur_frame);
 486 }
 487
 488 /* Switch from one thread to another. */
 489
 490 static void
 491 switch_to_thread (ptid_t ptid)
 492 {
 493   if (ptid_equal (ptid, inferior_ptid))
 494     return;
 495
 496   inferior_ptid = ptid;
 497   flush_cached_frames ();
 498   registers_changed ();
 499   stop_pc = read_pc ();
 500   select_frame (get_current_frame (), 0);
 501 }
 502
 503 static void
 504 restore_current_thread (ptid_t ptid)
 505 {
 506   if (! ptid_equal (ptid, inferior_ptid))
 507     {
 508       switch_to_thread (ptid);
 509       print_stack_frame (get_current_frame (), 0, -1);
 510     }
 511 }
 512
 513 struct current_thread_cleanup
 514 {
 515   ptid_t inferior_ptid;
 516 };
 517
 518 static void
 519 do_restore_current_thread_cleanup (void *arg)
 520 {
 521   struct current_thread_cleanup *old = arg;
 522   restore_current_thread (old->inferior_ptid);
 523   xfree (old);
 524 }
 525
 526 static struct cleanup *
 527 make_cleanup_restore_current_thread (ptid_t inferior_ptid)
 528 {
 529   struct current_thread_cleanup *old
 530     = xmalloc (sizeof (struct current_thread_cleanup));
 531   old->inferior_ptid = inferior_ptid;
 532   return make_cleanup (do_restore_current_thread_cleanup, old);
 533 }
 534
 535 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
 536    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
 537    of two numbers seperated by a hyphen.  Examples:
 538
 539    thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
 540    thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
 541    thread apply all p x/i $pc   Apply x/i $pc cmd to all threads
 542  */
 543
 544 static void
 545 thread_apply_all_command (char *cmd, int from_tty)
 546 {
 547   struct thread_info *tp;
 548   struct cleanup *old_chain;
 549   struct cleanup *saved_cmd_cleanup_chain;
 550   char *saved_cmd;
 551
 552   if (cmd == NULL || *cmd == '\000')
 553     error ("Please specify a command following the thread ID list");
 554
 555   old_chain = make_cleanup_restore_current_thread (inferior_ptid);
 556
 557   /* It is safe to update the thread list now, before
 558      traversing it for "thread apply all".  MVS */
 559   target_find_new_threads ();
 560
 561   /* Save a copy of the command in case it is clobbered by
 562      execute_command */
 563   saved_cmd = xstrdup (cmd);
 564   saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
 565   for (tp = thread_list; tp; tp = tp->next)
 566     if (thread_alive (tp))
 567       {
 568         switch_to_thread (tp->ptid);
 569 #ifdef HPUXHPPA
 570         printf_filtered ("\nThread %d (%s):\n",
 571                          tp->num,
 572                          target_tid_to_str (inferior_ptid));
 573 #else
 574         printf_filtered ("\nThread %d (%s):\n", tp->num,
 575                          target_pid_to_str (inferior_ptid));
 576 #endif
 577         execute_command (cmd, from_tty);
 578         strcpy (cmd, saved_cmd); /* Restore exact command used previously */
 579       }
 580
 581   do_cleanups (saved_cmd_cleanup_chain);
 582   do_cleanups (old_chain);
 583 }
 584
 585 static void
 586 thread_apply_command (char *tidlist, int from_tty)
 587 {
 588   char *cmd;
 589   char *p;
 590   struct cleanup *old_chain;
 591   struct cleanup *saved_cmd_cleanup_chain;
 592   char *saved_cmd;
 593
 594   if (tidlist == NULL || *tidlist == '\000')
 595     error ("Please specify a thread ID list");
 596
 597   for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);
 598
 599   if (*cmd == '\000')
 600     error ("Please specify a command following the thread ID list");
 601
 602   old_chain = make_cleanup_restore_current_thread (inferior_ptid);
 603
 604   /* Save a copy of the command in case it is clobbered by
 605      execute_command */
 606   saved_cmd = xstrdup (cmd);
 607   saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
 608   while (tidlist < cmd)
 609     {
 610       struct thread_info *tp;
 611       int start, end;
 612
 613       start = strtol (tidlist, &p, 10);
 614       if (p == tidlist)
 615         error ("Error parsing %s", tidlist);
 616       tidlist = p;
 617
 618       while (*tidlist == ' ' || *tidlist == '\t')
 619         tidlist++;
 620
 621       if (*tidlist == '-')      /* Got a range of IDs? */
 622         {
 623           tidlist++;            /* Skip the - */
 624           end = strtol (tidlist, &p, 10);
 625           if (p == tidlist)
 626             error ("Error parsing %s", tidlist);
 627           tidlist = p;
 628
 629           while (*tidlist == ' ' || *tidlist == '\t')
 630             tidlist++;
 631         }
 632       else
 633         end = start;
 634
 635       for (; start <= end; start++)
 636         {
 637           tp = find_thread_id (start);
 638
 639           if (!tp)
 640             warning ("Unknown thread %d.", start);
 641           else if (!thread_alive (tp))
 642             warning ("Thread %d has terminated.", start);
 643           else
 644             {
 645               switch_to_thread (tp->ptid);
 646 #ifdef HPUXHPPA
 647               printf_filtered ("\nThread %d (%s):\n", tp->num,
 648                                target_tid_to_str (inferior_ptid));
 649 #else
 650               printf_filtered ("\nThread %d (%s):\n", tp->num,
 651                                target_pid_to_str (inferior_ptid));
 652 #endif
 653               execute_command (cmd, from_tty);
 654               strcpy (cmd, saved_cmd);  /* Restore exact command used previously */
 655             }
 656         }
 657     }
 658
 659   do_cleanups (saved_cmd_cleanup_chain);
 660   do_cleanups (old_chain);
 661 }
 662
 663 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
 664    if prefix of arg is `apply'.  */
 665
 666 static void
 667 thread_command (char *tidstr, int from_tty)
 668 {
 669   if (!tidstr)
 670     {
 671       /* Don't generate an error, just say which thread is current. */
 672       if (target_has_stack)
 673         printf_filtered ("[Current thread is %d (%s)]\n",
 674                          pid_to_thread_id (inferior_ptid),
 675 #if defined(HPUXHPPA)
 676                          target_tid_to_str (inferior_ptid)
 677 #else
 678                          target_pid_to_str (inferior_ptid)
 679 #endif
 680           );
 681       else
 682         error ("No stack.");
 683       return;
 684     }
 685
 686   gdb_thread_select (tidstr);
 687 }
 688
 689 static int
 690 do_captured_thread_select (void *tidstr)
 691 {
 692   int num;
 693   struct thread_info *tp;
 694
 695   num = value_as_long (parse_and_eval (tidstr));
 696
 697   tp = find_thread_id (num);
 698
 699 #ifdef UI_OUT
 700   if (!tp)
 701     error ("Thread ID %d not known.", num);
 702 #else
 703   if (!tp)
 704     error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
 705 see the IDs of currently known threads.", num);
 706 #endif
 707
 708   if (!thread_alive (tp))
 709     error ("Thread ID %d has terminated.\n", num);
 710
 711   switch_to_thread (tp->ptid);
 712
 713 #ifdef UI_OUT
 714   ui_out_text (uiout, "[Switching to thread ");
 715   ui_out_field_int (uiout, "new-thread-id", pid_to_thread_id (inferior_ptid));
 716   ui_out_text (uiout, " (");
 717 #if defined(HPUXHPPA)
 718   ui_out_text (uiout, target_tid_to_str (inferior_ptid));
 719 #else
 720   ui_out_text (uiout, target_pid_to_str (inferior_ptid));
 721 #endif
 722   ui_out_text (uiout, ")]");
 723 #else /* UI_OUT */
 724   printf_filtered ("[Switching to thread %d (%s)]\n",
 725                    pid_to_thread_id (inferior_ptid),
 726 #if defined(HPUXHPPA)
 727                    target_tid_to_str (inferior_ptid)
 728 #else
 729                    target_pid_to_str (inferior_ptid)
 730 #endif
 731     );
 732 #endif /* UI_OUT */
 733
 734   print_stack_frame (selected_frame, selected_frame_level, 1);
 735   return GDB_RC_OK;
 736 }
 737
 738 enum gdb_rc
 739 gdb_thread_select (char *tidstr)
 740 {
 741   return catch_errors (do_captured_thread_select, tidstr,
 742                        NULL, RETURN_MASK_ALL);
 743 }
 744
 745 /* Commands with a prefix of `thread'.  */
 746 struct cmd_list_element *thread_cmd_list = NULL;
 747
 748 void
 749 _initialize_thread (void)
 750 {
 751   static struct cmd_list_element *thread_apply_list = NULL;
 752
 753   add_info ("threads", info_threads_command,
 754             "IDs of currently known threads.");
 755
 756   add_prefix_cmd ("thread", class_run, thread_command,
 757                   "Use this command to switch between threads.\n\
 758 The new thread ID must be currently known.", &thread_cmd_list, "thread ", 1,
 759                   &cmdlist);
 760
 761   add_prefix_cmd ("apply", class_run, thread_apply_command,
 762                   "Apply a command to a list of threads.",
 763                   &thread_apply_list, "apply ", 1, &thread_cmd_list);
 764
 765   add_cmd ("all", class_run, thread_apply_all_command,
 766            "Apply a command to all threads.",
 767            &thread_apply_list);
 768
 769   if (!xdb_commands)
 770     add_com_alias ("t", "thread", class_run, 1);
 771 }