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 = 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   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   clear_section_table (&pspace->target_sections);
 164   clear_program_space_solib_cache (pspace);
 165     /* Discard any data modules have associated with the PSPACE.  */
 166   program_space_free_data (pspace);
 167   xfree (pspace);
 168
 169   do_cleanups (old_chain);
 170 }
 171
 172 /* Copies program space SRC to DEST.  Copies the main executable file,
 173    and the main symbol file.  Returns DEST.  */
 174
 175 struct program_space *
 176 clone_program_space (struct program_space *dest, struct program_space *src)
 177 {
 178   struct cleanup *old_chain;
 179
 180   old_chain = save_current_program_space ();
 181
 182   set_current_program_space (dest);
 183
 184   if (src->pspace_exec_filename != NULL)
 185     exec_file_attach (src->pspace_exec_filename, 0);
 186
 187   if (src->symfile_object_file != NULL)
 188     symbol_file_add_main (objfile_name (src->symfile_object_file), 0);
 189
 190   do_cleanups (old_chain);
 191   return dest;
 192 }
 193
 194 /* Sets PSPACE as the current program space.  It is the caller's
 195    responsibility to make sure that the currently selected
 196    inferior/thread matches the selected program space.  */
 197
 198 void
 199 set_current_program_space (struct program_space *pspace)
 200 {
 201   if (current_program_space == pspace)
 202     return;
 203
 204   gdb_assert (pspace != NULL);
 205
 206   current_program_space = pspace;
 207
 208   /* Different symbols change our view of the frame chain.  */
 209   reinit_frame_cache ();
 210 }
 211
 212 /* A cleanups callback, helper for save_current_program_space
 213    below.  */
 214
 215 static void
 216 restore_program_space (void *arg)
 217 {
 218   struct program_space *saved_pspace = arg;
 219
 220   set_current_program_space (saved_pspace);
 221 }
 222
 223 /* Save the current program space so that it may be restored by a later
 224    call to do_cleanups.  Returns the struct cleanup pointer needed for
 225    later doing the cleanup.  */
 226
 227 struct cleanup *
 228 save_current_program_space (void)
 229 {
 230   struct cleanup *old_chain = make_cleanup (restore_program_space,
 231                                             current_program_space);
 232
 233   return old_chain;
 234 }
 235
 236 /* Returns true iff there's no inferior bound to PSPACE.  */
 237
 238 static int
 239 pspace_empty_p (struct program_space *pspace)
 240 {
 241   if (find_inferior_for_program_space (pspace) != NULL)
 242       return 0;
 243
 244   return 1;
 245 }
 246
 247 /* Prune away automatically added program spaces that aren't required
 248    anymore.  */
 249
 250 void
 251 prune_program_spaces (void)
 252 {
 253   struct program_space *ss, **ss_link;
 254   struct program_space *current = current_program_space;
 255
 256   ss = program_spaces;
 257   ss_link = &program_spaces;
 258   while (ss)
 259     {
 260       if (ss == current || !pspace_empty_p (ss))
 261         {
 262           ss_link = &ss->next;
 263           ss = *ss_link;
 264           continue;
 265         }
 266
 267       *ss_link = ss->next;
 268       release_program_space (ss);
 269       ss = *ss_link;
 270     }
 271 }
 272
 273 /* Prints the list of program spaces and their details on UIOUT.  If
 274    REQUESTED is not -1, it's the ID of the pspace that should be
 275    printed.  Otherwise, all spaces are printed.  */
 276
 277 static void
 278 print_program_space (struct ui_out *uiout, int requested)
 279 {
 280   struct program_space *pspace;
 281   int count = 0;
 282   struct cleanup *old_chain;
 283
 284   /* Might as well prune away unneeded ones, so the user doesn't even
 285      seem them.  */
 286   prune_program_spaces ();
 287
 288   /* Compute number of pspaces we will print.  */
 289   ALL_PSPACES (pspace)
 290     {
 291       if (requested != -1 && pspace->num != requested)
 292         continue;
 293
 294       ++count;
 295     }
 296
 297   /* There should always be at least one.  */
 298   gdb_assert (count > 0);
 299
 300   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 3, count, "pspaces");
 301   ui_out_table_header (uiout, 1, ui_left, "current", "");
 302   ui_out_table_header (uiout, 4, ui_left, "id", "Id");
 303   ui_out_table_header (uiout, 17, ui_left, "exec", "Executable");
 304   ui_out_table_body (uiout);
 305
 306   ALL_PSPACES (pspace)
 307     {
 308       struct cleanup *chain2;
 309       struct inferior *inf;
 310       int printed_header;
 311
 312       if (requested != -1 && requested != pspace->num)
 313         continue;
 314
 315       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 316
 317       if (pspace == current_program_space)
 318         ui_out_field_string (uiout, "current", "*");
 319       else
 320         ui_out_field_skip (uiout, "current");
 321
 322       ui_out_field_int (uiout, "id", pspace->num);
 323
 324       if (pspace->pspace_exec_filename)
 325         ui_out_field_string (uiout, "exec", pspace->pspace_exec_filename);
 326       else
 327         ui_out_field_skip (uiout, "exec");
 328
 329       /* Print extra info that doesn't really fit in tabular form.
 330          Currently, we print the list of inferiors bound to a pspace.
 331          There can be more than one inferior bound to the same pspace,
 332          e.g., both parent/child inferiors in a vfork, or, on targets
 333          that share pspaces between inferiors.  */
 334       printed_header = 0;
 335       for (inf = inferior_list; inf; inf = inf->next)
 336         if (inf->pspace == pspace)
 337           {
 338             if (!printed_header)
 339               {
 340                 printed_header = 1;
 341                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 342                                  inf->num,
 343                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 344               }
 345             else
 346               printf_filtered (", ID %d (%s)",
 347                                inf->num,
 348                                target_pid_to_str (pid_to_ptid (inf->pid)));
 349           }
 350
 351       ui_out_text (uiout, "\n");
 352       do_cleanups (chain2);
 353     }
 354
 355   do_cleanups (old_chain);
 356 }
 357
 358 /* Boolean test for an already-known program space id.  */
 359
 360 static int
 361 valid_program_space_id (int num)
 362 {
 363   struct program_space *pspace;
 364
 365   ALL_PSPACES (pspace)
 366     if (pspace->num == num)
 367       return 1;
 368
 369   return 0;
 370 }
 371
 372 /* If ARGS is NULL or empty, print information about all program
 373    spaces.  Otherwise, ARGS is a text representation of a LONG
 374    indicating which the program space to print information about.  */
 375
 376 static void
 377 maintenance_info_program_spaces_command (char *args, int from_tty)
 378 {
 379   int requested = -1;
 380
 381   if (args && *args)
 382     {
 383       requested = parse_and_eval_long (args);
 384       if (!valid_program_space_id (requested))
 385         error (_("program space ID %d not known."), requested);
 386     }
 387
 388   print_program_space (current_uiout, requested);
 389 }
 390
 391 /* Simply returns the count of program spaces.  */
 392
 393 int
 394 number_of_program_spaces (void)
 395 {
 396   struct program_space *pspace;
 397   int count = 0;
 398
 399   ALL_PSPACES (pspace)
 400     count++;
 401
 402   return count;
 403 }
 404
 405 /* Update all program spaces matching to address spaces.  The user may
 406    have created several program spaces, and loaded executables into
 407    them before connecting to the target interface that will create the
 408    inferiors.  All that happens before GDB has a chance to know if the
 409    inferiors will share an address space or not.  Call this after
 410    having connected to the target interface and having fetched the
 411    target description, to fixup the program/address spaces mappings.
 412
 413    It is assumed that there are no bound inferiors yet, otherwise,
 414    they'd be left with stale referenced to released aspaces.  */
 415
 416 void
 417 update_address_spaces (void)
 418 {
 419   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 420   struct program_space *pspace;
 421   struct inferior *inf;
 422
 423   init_address_spaces ();
 424
 425   if (shared_aspace)
 426     {
 427       struct address_space *aspace = new_address_space ();
 428
 429       free_address_space (current_program_space->aspace);
 430       ALL_PSPACES (pspace)
 431         pspace->aspace = aspace;
 432     }
 433   else
 434     ALL_PSPACES (pspace)
 435       {
 436         free_address_space (pspace->aspace);
 437         pspace->aspace = new_address_space ();
 438       }
 439
 440   for (inf = inferior_list; inf; inf = inf->next)
 441     if (gdbarch_has_global_solist (target_gdbarch ()))
 442       inf->aspace = maybe_new_address_space ();
 443     else
 444       inf->aspace = inf->pspace->aspace;
 445 }
 446
 447 /* Save the current program space so that it may be restored by a later
 448    call to do_cleanups.  Returns the struct cleanup pointer needed for
 449    later doing the cleanup.  */
 450
 451 struct cleanup *
 452 save_current_space_and_thread (void)
 453 {
 454   struct cleanup *old_chain;
 455
 456   /* If restoring to null thread, we need to restore the pspace as
 457      well, hence, we need to save the current program space first.  */
 458   old_chain = save_current_program_space ();
 459   /* There's no need to save the current inferior here.
 460      That is handled by make_cleanup_restore_current_thread.  */
 461   make_cleanup_restore_current_thread ();
 462
 463   return old_chain;
 464 }
 465
 466 /* Switches full context to program space PSPACE.  Switches to the
 467    first thread found bound to PSPACE.  */
 468
 469 void
 470 switch_to_program_space_and_thread (struct program_space *pspace)
 471 {
 472   struct inferior *inf;
 473
 474   inf = find_inferior_for_program_space (pspace);
 475   if (inf != NULL)
 476     {
 477       struct thread_info *tp;
 478
 479       tp = any_live_thread_of_process (inf->pid);
 480       if (tp != NULL)
 481         {
 482           switch_to_thread (tp->ptid);
 483           /* Switching thread switches pspace implicitly.  We're
 484              done.  */
 485           return;
 486         }
 487     }
 488
 489   switch_to_thread (null_ptid);
 490   set_current_program_space (pspace);
 491 }
 492
 493 \f
 494
 495 /* See progspace.h.  */
 496
 497 void
 498 clear_program_space_solib_cache (struct program_space *pspace)
 499 {
 500   VEC_free (so_list_ptr, pspace->added_solibs);
 501
 502   free_char_ptr_vec (pspace->deleted_solibs);
 503   pspace->deleted_solibs = NULL;
 504 }
 505
 506 \f
 507
 508 void
 509 initialize_progspace (void)
 510 {
 511   add_cmd ("program-spaces", class_maintenance,
 512            maintenance_info_program_spaces_command,
 513            _("Info about currently known program spaces."),
 514            &maintenanceinfolist);
 515
 516   /* There's always one program space.  Note that this function isn't
 517      an automatic _initialize_foo function, since other
 518      _initialize_foo routines may need to install their per-pspace
 519      data keys.  We can only allocate a progspace when all those
 520      modules have done that.  Do this before
 521      initialize_current_architecture, because that accesses exec_bfd,
 522      which in turn dereferences current_program_space.  */
 523   current_program_space = add_program_space (new_address_space ());
 524 }