gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2014 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 "gdbcmd.h"
  22 #include "objfiles.h"
  23 #include "arch-utils.h"
  24 #include "gdbcore.h"
  25 #include "solib.h"
  26 #include "gdbthread.h"
  27
  28 /* The last program space number assigned.  */
  29 int last_program_space_num = 0;
  30
  31 /* The head of the program spaces list.  */
  32 struct program_space *program_spaces;
  33
  34 /* Pointer to the current program space.  */
  35 struct program_space *current_program_space;
  36
  37 /* The last address space number assigned.  */
  38 static int highest_address_space_num;
  39
  40 \f
  41
  42 /* Keep a registry of per-program_space data-pointers required by other GDB
  43    modules.  */
  44
  45 DEFINE_REGISTRY (program_space, REGISTRY_ACCESS_FIELD)
  46
  47 /* An address space.  It is used for comparing if pspaces/inferior/threads
  48    see the same address space and for associating caches to each address
  49    space.  */
  50
  51 struct address_space
  52 {
  53   int num;
  54
  55   /* Per aspace data-pointers required by other GDB modules.  */
  56   REGISTRY_FIELDS;
  57 };
  58
  59 /* Keep a registry of per-address_space data-pointers required by other GDB
  60    modules.  */
  61
  62 DEFINE_REGISTRY (address_space, REGISTRY_ACCESS_FIELD)
  63
  64 \f
  65
  66 /* Create a new address space object, and add it to the list.  */
  67
  68 struct address_space *
  69 new_address_space (void)
  70 {
  71   struct address_space *aspace;
  72
  73   aspace = XZALLOC (struct address_space);
  74   aspace->num = ++highest_address_space_num;
  75   address_space_alloc_data (aspace);
  76
  77   return aspace;
  78 }
  79
  80 /* Maybe create a new address space object, and add it to the list, or
  81    return a pointer to an existing address space, in case inferiors
  82    share an address space on this target system.  */
  83
  84 struct address_space *
  85 maybe_new_address_space (void)
  86 {
  87   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
  88
  89   if (shared_aspace)
  90     {
  91       /* Just return the first in the list.  */
  92       return program_spaces->aspace;
  93     }
  94
  95   return new_address_space ();
  96 }
  97
  98 static void
  99 free_address_space (struct address_space *aspace)
 100 {
 101   address_space_free_data (aspace);
 102   xfree (aspace);
 103 }
 104
 105 int
 106 address_space_num (struct address_space *aspace)
 107 {
 108   return aspace->num;
 109 }
 110
 111 /* Start counting over from scratch.  */
 112
 113 static void
 114 init_address_spaces (void)
 115 {
 116   highest_address_space_num = 0;
 117 }
 118
 119 \f
 120
 121 /* Adds a new empty program space to the program space list, and binds
 122    it to ASPACE.  Returns the pointer to the new object.  */
 123
 124 struct program_space *
 125 add_program_space (struct address_space *aspace)
 126 {
 127   struct program_space *pspace;
 128
 129   pspace = XZALLOC (struct program_space);
 130
 131   pspace->num = ++last_program_space_num;
 132   pspace->aspace = aspace;
 133
 134   program_space_alloc_data (pspace);
 135
 136   pspace->next = program_spaces;
 137   program_spaces = pspace;
 138
 139   return pspace;
 140 }
 141
 142 /* Releases program space PSPACE, and all its contents (shared
 143    libraries, objfiles, and any other references to the PSPACE in
 144    other modules).  It is an internal error to call this when PSPACE
 145    is the current program space, since there should always be a
 146    program space.  */
 147
 148 static void
 149 release_program_space (struct program_space *pspace)
 150 {
 151   struct cleanup *old_chain = save_current_program_space ();
 152
 153   gdb_assert (pspace != current_program_space);
 154
 155   set_current_program_space (pspace);
 156
 157   breakpoint_program_space_exit (pspace);
 158   no_shared_libraries (NULL, 0);
 159   exec_close ();
 160   free_all_objfiles ();
 161   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 162     free_address_space (pspace->aspace);
 163   resize_section_table (&pspace->target_sections,
 164                         -resize_section_table (&pspace->target_sections, 0));
 165   clear_program_space_solib_cache (pspace);
 166     /* Discard any data modules have associated with the PSPACE.  */
 167   program_space_free_data (pspace);
 168   xfree (pspace);
 169
 170   do_cleanups (old_chain);
 171 }
 172
 173 /* Unlinks PSPACE from the pspace list, and releases it.  */
 174
 175 void
 176 remove_program_space (struct program_space *pspace)
 177 {
 178   struct program_space *ss, **ss_link;
 179
 180   ss = program_spaces;
 181   ss_link = &program_spaces;
 182   while (ss)
 183     {
 184       if (ss != pspace)
 185         {
 186           ss_link = &ss->next;
 187           ss = *ss_link;
 188           continue;
 189         }
 190
 191       *ss_link = ss->next;
 192       release_program_space (ss);
 193       ss = *ss_link;
 194     }
 195 }
 196
 197 /* Copies program space SRC to DEST.  Copies the main executable file,
 198    and the main symbol file.  Returns DEST.  */
 199
 200 struct program_space *
 201 clone_program_space (struct program_space *dest, struct program_space *src)
 202 {
 203   struct cleanup *old_chain;
 204
 205   old_chain = save_current_program_space ();
 206
 207   set_current_program_space (dest);
 208
 209   if (src->pspace_exec_filename != NULL)
 210     exec_file_attach (src->pspace_exec_filename, 0);
 211
 212   if (src->symfile_object_file != NULL)
 213     symbol_file_add_main (objfile_name (src->symfile_object_file), 0);
 214
 215   do_cleanups (old_chain);
 216   return dest;
 217 }
 218
 219 /* Sets PSPACE as the current program space.  It is the caller's
 220    responsibility to make sure that the currently selected
 221    inferior/thread matches the selected program space.  */
 222
 223 void
 224 set_current_program_space (struct program_space *pspace)
 225 {
 226   if (current_program_space == pspace)
 227     return;
 228
 229   gdb_assert (pspace != NULL);
 230
 231   current_program_space = pspace;
 232
 233   /* Different symbols change our view of the frame chain.  */
 234   reinit_frame_cache ();
 235 }
 236
 237 /* A cleanups callback, helper for save_current_program_space
 238    below.  */
 239
 240 static void
 241 restore_program_space (void *arg)
 242 {
 243   struct program_space *saved_pspace = arg;
 244
 245   set_current_program_space (saved_pspace);
 246 }
 247
 248 /* Save the current program space so that it may be restored by a later
 249    call to do_cleanups.  Returns the struct cleanup pointer needed for
 250    later doing the cleanup.  */
 251
 252 struct cleanup *
 253 save_current_program_space (void)
 254 {
 255   struct cleanup *old_chain = make_cleanup (restore_program_space,
 256                                             current_program_space);
 257
 258   return old_chain;
 259 }
 260
 261 /* Returns true iff there's no inferior bound to PSPACE.  */
 262
 263 static int
 264 pspace_empty_p (struct program_space *pspace)
 265 {
 266   if (find_inferior_for_program_space (pspace) != NULL)
 267       return 0;
 268
 269   return 1;
 270 }
 271
 272 /* Prune away automatically added program spaces that aren't required
 273    anymore.  */
 274
 275 void
 276 prune_program_spaces (void)
 277 {
 278   struct program_space *ss, **ss_link;
 279   struct program_space *current = current_program_space;
 280
 281   ss = program_spaces;
 282   ss_link = &program_spaces;
 283   while (ss)
 284     {
 285       if (ss == current || !pspace_empty_p (ss))
 286         {
 287           ss_link = &ss->next;
 288           ss = *ss_link;
 289           continue;
 290         }
 291
 292       *ss_link = ss->next;
 293       release_program_space (ss);
 294       ss = *ss_link;
 295     }
 296 }
 297
 298 /* Prints the list of program spaces and their details on UIOUT.  If
 299    REQUESTED is not -1, it's the ID of the pspace that should be
 300    printed.  Otherwise, all spaces are printed.  */
 301
 302 static void
 303 print_program_space (struct ui_out *uiout, int requested)
 304 {
 305   struct program_space *pspace;
 306   int count = 0;
 307   struct cleanup *old_chain;
 308
 309   /* Might as well prune away unneeded ones, so the user doesn't even
 310      seem them.  */
 311   prune_program_spaces ();
 312
 313   /* Compute number of pspaces we will print.  */
 314   ALL_PSPACES (pspace)
 315     {
 316       if (requested != -1 && pspace->num != requested)
 317         continue;
 318
 319       ++count;
 320     }
 321
 322   /* There should always be at least one.  */
 323   gdb_assert (count > 0);
 324
 325   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 3, count, "pspaces");
 326   ui_out_table_header (uiout, 1, ui_left, "current", "");
 327   ui_out_table_header (uiout, 4, ui_left, "id", "Id");
 328   ui_out_table_header (uiout, 17, ui_left, "exec", "Executable");
 329   ui_out_table_body (uiout);
 330
 331   ALL_PSPACES (pspace)
 332     {
 333       struct cleanup *chain2;
 334       struct inferior *inf;
 335       int printed_header;
 336
 337       if (requested != -1 && requested != pspace->num)
 338         continue;
 339
 340       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 341
 342       if (pspace == current_program_space)
 343         ui_out_field_string (uiout, "current", "*");
 344       else
 345         ui_out_field_skip (uiout, "current");
 346
 347       ui_out_field_int (uiout, "id", pspace->num);
 348
 349       if (pspace->pspace_exec_filename)
 350         ui_out_field_string (uiout, "exec", pspace->pspace_exec_filename);
 351       else
 352         ui_out_field_skip (uiout, "exec");
 353
 354       /* Print extra info that doesn't really fit in tabular form.
 355          Currently, we print the list of inferiors bound to a pspace.
 356          There can be more than one inferior bound to the same pspace,
 357          e.g., both parent/child inferiors in a vfork, or, on targets
 358          that share pspaces between inferiors.  */
 359       printed_header = 0;
 360       for (inf = inferior_list; inf; inf = inf->next)
 361         if (inf->pspace == pspace)
 362           {
 363             if (!printed_header)
 364               {
 365                 printed_header = 1;
 366                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 367                                  inf->num,
 368                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 369               }
 370             else
 371               printf_filtered (", ID %d (%s)",
 372                                inf->num,
 373                                target_pid_to_str (pid_to_ptid (inf->pid)));
 374           }
 375
 376       ui_out_text (uiout, "\n");
 377       do_cleanups (chain2);
 378     }
 379
 380   do_cleanups (old_chain);
 381 }
 382
 383 /* Boolean test for an already-known program space id.  */
 384
 385 static int
 386 valid_program_space_id (int num)
 387 {
 388   struct program_space *pspace;
 389
 390   ALL_PSPACES (pspace)
 391     if (pspace->num == num)
 392       return 1;
 393
 394   return 0;
 395 }
 396
 397 /* If ARGS is NULL or empty, print information about all program
 398    spaces.  Otherwise, ARGS is a text representation of a LONG
 399    indicating which the program space to print information about.  */
 400
 401 static void
 402 maintenance_info_program_spaces_command (char *args, int from_tty)
 403 {
 404   int requested = -1;
 405
 406   if (args && *args)
 407     {
 408       requested = parse_and_eval_long (args);
 409       if (!valid_program_space_id (requested))
 410         error (_("program space ID %d not known."), requested);
 411     }
 412
 413   print_program_space (current_uiout, requested);
 414 }
 415
 416 /* Simply returns the count of program spaces.  */
 417
 418 int
 419 number_of_program_spaces (void)
 420 {
 421   struct program_space *pspace;
 422   int count = 0;
 423
 424   ALL_PSPACES (pspace)
 425     count++;
 426
 427   return count;
 428 }
 429
 430 /* Update all program spaces matching to address spaces.  The user may
 431    have created several program spaces, and loaded executables into
 432    them before connecting to the target interface that will create the
 433    inferiors.  All that happens before GDB has a chance to know if the
 434    inferiors will share an address space or not.  Call this after
 435    having connected to the target interface and having fetched the
 436    target description, to fixup the program/address spaces mappings.
 437
 438    It is assumed that there are no bound inferiors yet, otherwise,
 439    they'd be left with stale referenced to released aspaces.  */
 440
 441 void
 442 update_address_spaces (void)
 443 {
 444   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 445   struct program_space *pspace;
 446   struct inferior *inf;
 447
 448   init_address_spaces ();
 449
 450   if (shared_aspace)
 451     {
 452       struct address_space *aspace = new_address_space ();
 453
 454       free_address_space (current_program_space->aspace);
 455       ALL_PSPACES (pspace)
 456         pspace->aspace = aspace;
 457     }
 458   else
 459     ALL_PSPACES (pspace)
 460       {
 461         free_address_space (pspace->aspace);
 462         pspace->aspace = new_address_space ();
 463       }
 464
 465   for (inf = inferior_list; inf; inf = inf->next)
 466     if (gdbarch_has_global_solist (target_gdbarch ()))
 467       inf->aspace = maybe_new_address_space ();
 468     else
 469       inf->aspace = inf->pspace->aspace;
 470 }
 471
 472 /* Save the current program space so that it may be restored by a later
 473    call to do_cleanups.  Returns the struct cleanup pointer needed for
 474    later doing the cleanup.  */
 475
 476 struct cleanup *
 477 save_current_space_and_thread (void)
 478 {
 479   struct cleanup *old_chain;
 480
 481   /* If restoring to null thread, we need to restore the pspace as
 482      well, hence, we need to save the current program space first.  */
 483   old_chain = save_current_program_space ();
 484   /* There's no need to save the current inferior here.
 485      That is handled by make_cleanup_restore_current_thread.  */
 486   make_cleanup_restore_current_thread ();
 487
 488   return old_chain;
 489 }
 490
 491 /* Switches full context to program space PSPACE.  Switches to the
 492    first thread found bound to PSPACE.  */
 493
 494 void
 495 switch_to_program_space_and_thread (struct program_space *pspace)
 496 {
 497   struct inferior *inf;
 498
 499   inf = find_inferior_for_program_space (pspace);
 500   if (inf != NULL)
 501     {
 502       struct thread_info *tp;
 503
 504       tp = any_live_thread_of_process (inf->pid);
 505       if (tp != NULL)
 506         {
 507           switch_to_thread (tp->ptid);
 508           /* Switching thread switches pspace implicitly.  We're
 509              done.  */
 510           return;
 511         }
 512     }
 513
 514   switch_to_thread (null_ptid);
 515   set_current_program_space (pspace);
 516 }
 517
 518 \f
 519
 520 /* See progspace.h.  */
 521
 522 void
 523 clear_program_space_solib_cache (struct program_space *pspace)
 524 {
 525   VEC_free (so_list_ptr, pspace->added_solibs);
 526
 527   free_char_ptr_vec (pspace->deleted_solibs);
 528   pspace->deleted_solibs = NULL;
 529 }
 530
 531 \f
 532
 533 void
 534 initialize_progspace (void)
 535 {
 536   add_cmd ("program-spaces", class_maintenance,
 537            maintenance_info_program_spaces_command,
 538            _("Info about currently known program spaces."),
 539            &maintenanceinfolist);
 540
 541   /* There's always one program space.  Note that this function isn't
 542      an automatic _initialize_foo function, since other
 543      _initialize_foo routines may need to install their per-pspace
 544      data keys.  We can only allocate a progspace when all those
 545      modules have done that.  Do this before
 546      initialize_current_architecture, because that accesses exec_bfd,
 547      which in turn dereferences current_program_space.  */
 548   current_program_space = add_program_space (new_address_space ());
 549 }