gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2017 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 = XCNEW (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 = XCNEW (struct program_space);
 130
 131   pspace->num = ++last_program_space_num;
 132   pspace->aspace = aspace;
 133
 134   program_space_alloc_data (pspace);
 135
 136   if (program_spaces == NULL)
 137     program_spaces = pspace;
 138   else
 139     {
 140       struct program_space *last;
 141
 142       for (last = program_spaces; last->next != NULL; last = last->next)
 143         ;
 144       last->next = pspace;
 145     }
 146
 147   return pspace;
 148 }
 149
 150 /* Releases program space PSPACE, and all its contents (shared
 151    libraries, objfiles, and any other references to the PSPACE in
 152    other modules).  It is an internal error to call this when PSPACE
 153    is the current program space, since there should always be a
 154    program space.  */
 155
 156 static void
 157 release_program_space (struct program_space *pspace)
 158 {
 159   struct cleanup *old_chain = save_current_program_space ();
 160
 161   gdb_assert (pspace != current_program_space);
 162
 163   set_current_program_space (pspace);
 164
 165   breakpoint_program_space_exit (pspace);
 166   no_shared_libraries (NULL, 0);
 167   exec_close ();
 168   free_all_objfiles ();
 169   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 170     free_address_space (pspace->aspace);
 171   clear_section_table (&pspace->target_sections);
 172   clear_program_space_solib_cache (pspace);
 173     /* Discard any data modules have associated with the PSPACE.  */
 174   program_space_free_data (pspace);
 175   xfree (pspace);
 176
 177   do_cleanups (old_chain);
 178 }
 179
 180 /* Copies program space SRC to DEST.  Copies the main executable file,
 181    and the main symbol file.  Returns DEST.  */
 182
 183 struct program_space *
 184 clone_program_space (struct program_space *dest, struct program_space *src)
 185 {
 186   struct cleanup *old_chain;
 187
 188   old_chain = save_current_program_space ();
 189
 190   set_current_program_space (dest);
 191
 192   if (src->pspace_exec_filename != NULL)
 193     exec_file_attach (src->pspace_exec_filename, 0);
 194
 195   if (src->symfile_object_file != NULL)
 196     symbol_file_add_main (objfile_name (src->symfile_object_file), 0);
 197
 198   do_cleanups (old_chain);
 199   return dest;
 200 }
 201
 202 /* Sets PSPACE as the current program space.  It is the caller's
 203    responsibility to make sure that the currently selected
 204    inferior/thread matches the selected program space.  */
 205
 206 void
 207 set_current_program_space (struct program_space *pspace)
 208 {
 209   if (current_program_space == pspace)
 210     return;
 211
 212   gdb_assert (pspace != NULL);
 213
 214   current_program_space = pspace;
 215
 216   /* Different symbols change our view of the frame chain.  */
 217   reinit_frame_cache ();
 218 }
 219
 220 /* A cleanups callback, helper for save_current_program_space
 221    below.  */
 222
 223 static void
 224 restore_program_space (void *arg)
 225 {
 226   struct program_space *saved_pspace = (struct program_space *) arg;
 227
 228   set_current_program_space (saved_pspace);
 229 }
 230
 231 /* Save the current program space so that it may be restored by a later
 232    call to do_cleanups.  Returns the struct cleanup pointer needed for
 233    later doing the cleanup.  */
 234
 235 struct cleanup *
 236 save_current_program_space (void)
 237 {
 238   struct cleanup *old_chain = make_cleanup (restore_program_space,
 239                                             current_program_space);
 240
 241   return old_chain;
 242 }
 243
 244 /* Returns true iff there's no inferior bound to PSPACE.  */
 245
 246 int
 247 program_space_empty_p (struct program_space *pspace)
 248 {
 249   if (find_inferior_for_program_space (pspace) != NULL)
 250       return 0;
 251
 252   return 1;
 253 }
 254
 255 /* Remove a program space from the program spaces list and release it.  It is
 256    an error to call this function while PSPACE is the current program space. */
 257
 258 void
 259 delete_program_space (struct program_space *pspace)
 260 {
 261   struct program_space *ss, **ss_link;
 262   gdb_assert (pspace != NULL);
 263   gdb_assert (pspace != current_program_space);
 264
 265   ss = program_spaces;
 266   ss_link = &program_spaces;
 267   while (ss != NULL)
 268     {
 269       if (ss == pspace)
 270         {
 271           *ss_link = ss->next;
 272           break;
 273         }
 274
 275       ss_link = &ss->next;
 276       ss = *ss_link;
 277     }
 278
 279   release_program_space (pspace);
 280 }
 281
 282 /* Prints the list of program spaces and their details on UIOUT.  If
 283    REQUESTED is not -1, it's the ID of the pspace that should be
 284    printed.  Otherwise, all spaces are printed.  */
 285
 286 static void
 287 print_program_space (struct ui_out *uiout, int requested)
 288 {
 289   struct program_space *pspace;
 290   int count = 0;
 291   struct cleanup *old_chain;
 292
 293   /* Compute number of pspaces we will print.  */
 294   ALL_PSPACES (pspace)
 295     {
 296       if (requested != -1 && pspace->num != requested)
 297         continue;
 298
 299       ++count;
 300     }
 301
 302   /* There should always be at least one.  */
 303   gdb_assert (count > 0);
 304
 305   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 3, count, "pspaces");
 306   uiout->table_header (1, ui_left, "current", "");
 307   uiout->table_header (4, ui_left, "id", "Id");
 308   uiout->table_header (17, ui_left, "exec", "Executable");
 309   uiout->table_body ();
 310
 311   ALL_PSPACES (pspace)
 312     {
 313       struct inferior *inf;
 314       int printed_header;
 315
 316       if (requested != -1 && requested != pspace->num)
 317         continue;
 318
 319       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 320
 321       if (pspace == current_program_space)
 322         uiout->field_string ("current", "*");
 323       else
 324         uiout->field_skip ("current");
 325
 326       uiout->field_int ("id", pspace->num);
 327
 328       if (pspace->pspace_exec_filename)
 329         uiout->field_string ("exec", pspace->pspace_exec_filename);
 330       else
 331         uiout->field_skip ("exec");
 332
 333       /* Print extra info that doesn't really fit in tabular form.
 334          Currently, we print the list of inferiors bound to a pspace.
 335          There can be more than one inferior bound to the same pspace,
 336          e.g., both parent/child inferiors in a vfork, or, on targets
 337          that share pspaces between inferiors.  */
 338       printed_header = 0;
 339       for (inf = inferior_list; inf; inf = inf->next)
 340         if (inf->pspace == pspace)
 341           {
 342             if (!printed_header)
 343               {
 344                 printed_header = 1;
 345                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 346                                  inf->num,
 347                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 348               }
 349             else
 350               printf_filtered (", ID %d (%s)",
 351                                inf->num,
 352                                target_pid_to_str (pid_to_ptid (inf->pid)));
 353           }
 354
 355       uiout->text ("\n");
 356     }
 357
 358   do_cleanups (old_chain);
 359 }
 360
 361 /* Boolean test for an already-known program space id.  */
 362
 363 static int
 364 valid_program_space_id (int num)
 365 {
 366   struct program_space *pspace;
 367
 368   ALL_PSPACES (pspace)
 369     if (pspace->num == num)
 370       return 1;
 371
 372   return 0;
 373 }
 374
 375 /* If ARGS is NULL or empty, print information about all program
 376    spaces.  Otherwise, ARGS is a text representation of a LONG
 377    indicating which the program space to print information about.  */
 378
 379 static void
 380 maintenance_info_program_spaces_command (char *args, int from_tty)
 381 {
 382   int requested = -1;
 383
 384   if (args && *args)
 385     {
 386       requested = parse_and_eval_long (args);
 387       if (!valid_program_space_id (requested))
 388         error (_("program space ID %d not known."), requested);
 389     }
 390
 391   print_program_space (current_uiout, requested);
 392 }
 393
 394 /* Simply returns the count of program spaces.  */
 395
 396 int
 397 number_of_program_spaces (void)
 398 {
 399   struct program_space *pspace;
 400   int count = 0;
 401
 402   ALL_PSPACES (pspace)
 403     count++;
 404
 405   return count;
 406 }
 407
 408 /* Update all program spaces matching to address spaces.  The user may
 409    have created several program spaces, and loaded executables into
 410    them before connecting to the target interface that will create the
 411    inferiors.  All that happens before GDB has a chance to know if the
 412    inferiors will share an address space or not.  Call this after
 413    having connected to the target interface and having fetched the
 414    target description, to fixup the program/address spaces mappings.
 415
 416    It is assumed that there are no bound inferiors yet, otherwise,
 417    they'd be left with stale referenced to released aspaces.  */
 418
 419 void
 420 update_address_spaces (void)
 421 {
 422   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 423   struct program_space *pspace;
 424   struct inferior *inf;
 425
 426   init_address_spaces ();
 427
 428   if (shared_aspace)
 429     {
 430       struct address_space *aspace = new_address_space ();
 431
 432       free_address_space (current_program_space->aspace);
 433       ALL_PSPACES (pspace)
 434         pspace->aspace = aspace;
 435     }
 436   else
 437     ALL_PSPACES (pspace)
 438       {
 439         free_address_space (pspace->aspace);
 440         pspace->aspace = new_address_space ();
 441       }
 442
 443   for (inf = inferior_list; inf; inf = inf->next)
 444     if (gdbarch_has_global_solist (target_gdbarch ()))
 445       inf->aspace = maybe_new_address_space ();
 446     else
 447       inf->aspace = inf->pspace->aspace;
 448 }
 449
 450 /* Save the current program space so that it may be restored by a later
 451    call to do_cleanups.  Returns the struct cleanup pointer needed for
 452    later doing the cleanup.  */
 453
 454 struct cleanup *
 455 save_current_space_and_thread (void)
 456 {
 457   struct cleanup *old_chain;
 458
 459   /* If restoring to null thread, we need to restore the pspace as
 460      well, hence, we need to save the current program space first.  */
 461   old_chain = save_current_program_space ();
 462   /* There's no need to save the current inferior here.
 463      That is handled by make_cleanup_restore_current_thread.  */
 464   make_cleanup_restore_current_thread ();
 465
 466   return old_chain;
 467 }
 468
 469 /* See progspace.h  */
 470
 471 void
 472 switch_to_program_space_and_thread (struct program_space *pspace)
 473 {
 474   struct inferior *inf;
 475
 476   inf = find_inferior_for_program_space (pspace);
 477   if (inf != NULL && inf->pid != 0)
 478     {
 479       struct thread_info *tp;
 480
 481       tp = any_live_thread_of_process (inf->pid);
 482       if (tp != NULL)
 483         {
 484           switch_to_thread (tp->ptid);
 485           /* Switching thread switches pspace implicitly.  We're
 486              done.  */
 487           return;
 488         }
 489     }
 490
 491   switch_to_thread (null_ptid);
 492   set_current_program_space (pspace);
 493 }
 494
 495 \f
 496
 497 /* See progspace.h.  */
 498
 499 void
 500 clear_program_space_solib_cache (struct program_space *pspace)
 501 {
 502   VEC_free (so_list_ptr, pspace->added_solibs);
 503
 504   free_char_ptr_vec (pspace->deleted_solibs);
 505   pspace->deleted_solibs = NULL;
 506 }
 507
 508 \f
 509
 510 void
 511 initialize_progspace (void)
 512 {
 513   add_cmd ("program-spaces", class_maintenance,
 514            maintenance_info_program_spaces_command,
 515            _("Info about currently known program spaces."),
 516            &maintenanceinfolist);
 517
 518   /* There's always one program space.  Note that this function isn't
 519      an automatic _initialize_foo function, since other
 520      _initialize_foo routines may need to install their per-pspace
 521      data keys.  We can only allocate a progspace when all those
 522      modules have done that.  Do this before
 523      initialize_current_architecture, because that accesses exec_bfd,
 524      which in turn dereferences current_program_space.  */
 525   current_program_space = add_program_space (new_address_space ());
 526 }