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 cleanup *chain2;
 314       struct inferior *inf;
 315       int printed_header;
 316
 317       if (requested != -1 && requested != pspace->num)
 318         continue;
 319
 320       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 321
 322       if (pspace == current_program_space)
 323         uiout->field_string ("current", "*");
 324       else
 325         uiout->field_skip ("current");
 326
 327       uiout->field_int ("id", pspace->num);
 328
 329       if (pspace->pspace_exec_filename)
 330         uiout->field_string ("exec", pspace->pspace_exec_filename);
 331       else
 332         uiout->field_skip ("exec");
 333
 334       /* Print extra info that doesn't really fit in tabular form.
 335          Currently, we print the list of inferiors bound to a pspace.
 336          There can be more than one inferior bound to the same pspace,
 337          e.g., both parent/child inferiors in a vfork, or, on targets
 338          that share pspaces between inferiors.  */
 339       printed_header = 0;
 340       for (inf = inferior_list; inf; inf = inf->next)
 341         if (inf->pspace == pspace)
 342           {
 343             if (!printed_header)
 344               {
 345                 printed_header = 1;
 346                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 347                                  inf->num,
 348                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 349               }
 350             else
 351               printf_filtered (", ID %d (%s)",
 352                                inf->num,
 353                                target_pid_to_str (pid_to_ptid (inf->pid)));
 354           }
 355
 356       uiout->text ("\n");
 357       do_cleanups (chain2);
 358     }
 359
 360   do_cleanups (old_chain);
 361 }
 362
 363 /* Boolean test for an already-known program space id.  */
 364
 365 static int
 366 valid_program_space_id (int num)
 367 {
 368   struct program_space *pspace;
 369
 370   ALL_PSPACES (pspace)
 371     if (pspace->num == num)
 372       return 1;
 373
 374   return 0;
 375 }
 376
 377 /* If ARGS is NULL or empty, print information about all program
 378    spaces.  Otherwise, ARGS is a text representation of a LONG
 379    indicating which the program space to print information about.  */
 380
 381 static void
 382 maintenance_info_program_spaces_command (char *args, int from_tty)
 383 {
 384   int requested = -1;
 385
 386   if (args && *args)
 387     {
 388       requested = parse_and_eval_long (args);
 389       if (!valid_program_space_id (requested))
 390         error (_("program space ID %d not known."), requested);
 391     }
 392
 393   print_program_space (current_uiout, requested);
 394 }
 395
 396 /* Simply returns the count of program spaces.  */
 397
 398 int
 399 number_of_program_spaces (void)
 400 {
 401   struct program_space *pspace;
 402   int count = 0;
 403
 404   ALL_PSPACES (pspace)
 405     count++;
 406
 407   return count;
 408 }
 409
 410 /* Update all program spaces matching to address spaces.  The user may
 411    have created several program spaces, and loaded executables into
 412    them before connecting to the target interface that will create the
 413    inferiors.  All that happens before GDB has a chance to know if the
 414    inferiors will share an address space or not.  Call this after
 415    having connected to the target interface and having fetched the
 416    target description, to fixup the program/address spaces mappings.
 417
 418    It is assumed that there are no bound inferiors yet, otherwise,
 419    they'd be left with stale referenced to released aspaces.  */
 420
 421 void
 422 update_address_spaces (void)
 423 {
 424   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 425   struct program_space *pspace;
 426   struct inferior *inf;
 427
 428   init_address_spaces ();
 429
 430   if (shared_aspace)
 431     {
 432       struct address_space *aspace = new_address_space ();
 433
 434       free_address_space (current_program_space->aspace);
 435       ALL_PSPACES (pspace)
 436         pspace->aspace = aspace;
 437     }
 438   else
 439     ALL_PSPACES (pspace)
 440       {
 441         free_address_space (pspace->aspace);
 442         pspace->aspace = new_address_space ();
 443       }
 444
 445   for (inf = inferior_list; inf; inf = inf->next)
 446     if (gdbarch_has_global_solist (target_gdbarch ()))
 447       inf->aspace = maybe_new_address_space ();
 448     else
 449       inf->aspace = inf->pspace->aspace;
 450 }
 451
 452 /* Save the current program space so that it may be restored by a later
 453    call to do_cleanups.  Returns the struct cleanup pointer needed for
 454    later doing the cleanup.  */
 455
 456 struct cleanup *
 457 save_current_space_and_thread (void)
 458 {
 459   struct cleanup *old_chain;
 460
 461   /* If restoring to null thread, we need to restore the pspace as
 462      well, hence, we need to save the current program space first.  */
 463   old_chain = save_current_program_space ();
 464   /* There's no need to save the current inferior here.
 465      That is handled by make_cleanup_restore_current_thread.  */
 466   make_cleanup_restore_current_thread ();
 467
 468   return old_chain;
 469 }
 470
 471 /* See progspace.h  */
 472
 473 void
 474 switch_to_program_space_and_thread (struct program_space *pspace)
 475 {
 476   struct inferior *inf;
 477
 478   inf = find_inferior_for_program_space (pspace);
 479   if (inf != NULL && inf->pid != 0)
 480     {
 481       struct thread_info *tp;
 482
 483       tp = any_live_thread_of_process (inf->pid);
 484       if (tp != NULL)
 485         {
 486           switch_to_thread (tp->ptid);
 487           /* Switching thread switches pspace implicitly.  We're
 488              done.  */
 489           return;
 490         }
 491     }
 492
 493   switch_to_thread (null_ptid);
 494   set_current_program_space (pspace);
 495 }
 496
 497 \f
 498
 499 /* See progspace.h.  */
 500
 501 void
 502 clear_program_space_solib_cache (struct program_space *pspace)
 503 {
 504   VEC_free (so_list_ptr, pspace->added_solibs);
 505
 506   free_char_ptr_vec (pspace->deleted_solibs);
 507   pspace->deleted_solibs = NULL;
 508 }
 509
 510 \f
 511
 512 void
 513 initialize_progspace (void)
 514 {
 515   add_cmd ("program-spaces", class_maintenance,
 516            maintenance_info_program_spaces_command,
 517            _("Info about currently known program spaces."),
 518            &maintenanceinfolist);
 519
 520   /* There's always one program space.  Note that this function isn't
 521      an automatic _initialize_foo function, since other
 522      _initialize_foo routines may need to install their per-pspace
 523      data keys.  We can only allocate a progspace when all those
 524      modules have done that.  Do this before
 525      initialize_current_architecture, because that accesses exec_bfd,
 526      which in turn dereferences current_program_space.  */
 527   current_program_space = add_program_space (new_address_space ());
 528 }