gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2020 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 "solist.h"
  27 #include "gdbthread.h"
  28 #include "inferior.h"
  29 #include <algorithm>
  30
  31 /* The last program space number assigned.  */
  32 int last_program_space_num = 0;
  33
  34 /* The head of the program spaces list.  */
  35 std::vector<struct program_space *> program_spaces;
  36
  37 /* Pointer to the current program space.  */
  38 struct program_space *current_program_space;
  39
  40 /* The last address space number assigned.  */
  41 static int highest_address_space_num;
  42
  43 \f
  44
  45 /* Keep a registry of per-program_space data-pointers required by other GDB
  46    modules.  */
  47
  48 DEFINE_REGISTRY (program_space, REGISTRY_ACCESS_FIELD)
  49
  50 /* Keep a registry of per-address_space data-pointers required by other GDB
  51    modules.  */
  52
  53 DEFINE_REGISTRY (address_space, REGISTRY_ACCESS_FIELD)
  54
  55 \f
  56
  57 /* Create a new address space object, and add it to the list.  */
  58
  59 struct address_space *
  60 new_address_space (void)
  61 {
  62   struct address_space *aspace;
  63
  64   aspace = XCNEW (struct address_space);
  65   aspace->num = ++highest_address_space_num;
  66   address_space_alloc_data (aspace);
  67
  68   return aspace;
  69 }
  70
  71 /* Maybe create a new address space object, and add it to the list, or
  72    return a pointer to an existing address space, in case inferiors
  73    share an address space on this target system.  */
  74
  75 struct address_space *
  76 maybe_new_address_space (void)
  77 {
  78   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
  79
  80   if (shared_aspace)
  81     {
  82       /* Just return the first in the list.  */
  83       return program_spaces[0]->aspace;
  84     }
  85
  86   return new_address_space ();
  87 }
  88
  89 static void
  90 free_address_space (struct address_space *aspace)
  91 {
  92   address_space_free_data (aspace);
  93   xfree (aspace);
  94 }
  95
  96 int
  97 address_space_num (struct address_space *aspace)
  98 {
  99   return aspace->num;
 100 }
 101
 102 /* Start counting over from scratch.  */
 103
 104 static void
 105 init_address_spaces (void)
 106 {
 107   highest_address_space_num = 0;
 108 }
 109
 110 \f
 111
 112 /* Remove a program space from the program spaces list.  */
 113
 114 static void
 115 remove_program_space (program_space *pspace)
 116 {
 117   gdb_assert (pspace != NULL);
 118
 119   auto iter = std::find (program_spaces.begin (), program_spaces.end (),
 120                          pspace);
 121   gdb_assert (iter != program_spaces.end ());
 122   program_spaces.erase (iter);
 123 }
 124
 125 /* See progspace.h.  */
 126
 127 program_space::program_space (address_space *aspace_)
 128   : num (++last_program_space_num),
 129     aspace (aspace_)
 130 {
 131   program_space_alloc_data (this);
 132
 133   program_spaces.push_back (this);
 134 }
 135
 136 /* See progspace.h.  */
 137
 138 program_space::~program_space ()
 139 {
 140   gdb_assert (this != current_program_space);
 141
 142   remove_program_space (this);
 143
 144   scoped_restore_current_program_space restore_pspace;
 145
 146   set_current_program_space (this);
 147
 148   breakpoint_program_space_exit (this);
 149   no_shared_libraries (NULL, 0);
 150   exec_close ();
 151   free_all_objfiles ();
 152   /* Defer breakpoint re-set because we don't want to create new
 153      locations for this pspace which we're tearing down.  */
 154   clear_symtab_users (SYMFILE_DEFER_BP_RESET);
 155   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 156     free_address_space (this->aspace);
 157   clear_program_space_solib_cache (this);
 158     /* Discard any data modules have associated with the PSPACE.  */
 159   program_space_free_data (this);
 160 }
 161
 162 /* See progspace.h.  */
 163
 164 void
 165 program_space::free_all_objfiles ()
 166 {
 167   /* Any objfile reference would become stale.  */
 168   for (struct so_list *so : current_program_space->solibs ())
 169     gdb_assert (so->objfile == NULL);
 170
 171   while (!objfiles_list.empty ())
 172     objfiles_list.front ()->unlink ();
 173 }
 174
 175 /* See progspace.h.  */
 176
 177 void
 178 program_space::add_objfile (std::shared_ptr<objfile> &&objfile,
 179                             struct objfile *before)
 180 {
 181   if (before == nullptr)
 182     objfiles_list.push_back (std::move (objfile));
 183   else
 184     {
 185       auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 186                                 [=] (const std::shared_ptr<::objfile> &objf)
 187                                 {
 188                                   return objf.get () == before;
 189                                 });
 190       gdb_assert (iter != objfiles_list.end ());
 191       objfiles_list.insert (iter, std::move (objfile));
 192     }
 193 }
 194
 195 /* See progspace.h.  */
 196
 197 void
 198 program_space::remove_objfile (struct objfile *objfile)
 199 {
 200   /* Removing an objfile from the objfile list invalidates any frame
 201      that was built using frame info found in the objfile.  Reinit the
 202      frame cache to get rid of any frame that might otherwise
 203      reference stale info.  */
 204   reinit_frame_cache ();
 205
 206   auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 207                             [=] (const std::shared_ptr<::objfile> &objf)
 208                             {
 209                               return objf.get () == objfile;
 210                             });
 211   gdb_assert (iter != objfiles_list.end ());
 212   objfiles_list.erase (iter);
 213
 214   if (objfile == symfile_object_file)
 215     symfile_object_file = NULL;
 216 }
 217
 218 /* See progspace.h.  */
 219
 220 next_adapter<struct so_list>
 221 program_space::solibs () const
 222 {
 223   return next_adapter<struct so_list> (this->so_list);
 224 }
 225
 226 /* See progspace.h.  */
 227
 228 void
 229 program_space::exec_close ()
 230 {
 231   if (ebfd != nullptr)
 232     {
 233       /* Removing target sections may close the exec_ops target.
 234          Clear ebfd before doing so to prevent recursion.  */
 235       ebfd.reset (nullptr);
 236       ebfd_mtime = 0;
 237
 238       remove_target_sections (&ebfd);
 239
 240       exec_filename.reset (nullptr);
 241     }
 242 }
 243
 244 /* Copies program space SRC to DEST.  Copies the main executable file,
 245    and the main symbol file.  Returns DEST.  */
 246
 247 struct program_space *
 248 clone_program_space (struct program_space *dest, struct program_space *src)
 249 {
 250   scoped_restore_current_program_space restore_pspace;
 251
 252   set_current_program_space (dest);
 253
 254   if (src->exec_filename != NULL)
 255     exec_file_attach (src->exec_filename.get (), 0);
 256
 257   if (src->symfile_object_file != NULL)
 258     symbol_file_add_main (objfile_name (src->symfile_object_file),
 259                           SYMFILE_DEFER_BP_RESET);
 260
 261   return dest;
 262 }
 263
 264 /* Sets PSPACE as the current program space.  It is the caller's
 265    responsibility to make sure that the currently selected
 266    inferior/thread matches the selected program space.  */
 267
 268 void
 269 set_current_program_space (struct program_space *pspace)
 270 {
 271   if (current_program_space == pspace)
 272     return;
 273
 274   gdb_assert (pspace != NULL);
 275
 276   current_program_space = pspace;
 277
 278   /* Different symbols change our view of the frame chain.  */
 279   reinit_frame_cache ();
 280 }
 281
 282 /* Returns true iff there's no inferior bound to PSPACE.  */
 283
 284 int
 285 program_space_empty_p (struct program_space *pspace)
 286 {
 287   if (find_inferior_for_program_space (pspace) != NULL)
 288       return 0;
 289
 290   return 1;
 291 }
 292
 293 /* Prints the list of program spaces and their details on UIOUT.  If
 294    REQUESTED is not -1, it's the ID of the pspace that should be
 295    printed.  Otherwise, all spaces are printed.  */
 296
 297 static void
 298 print_program_space (struct ui_out *uiout, int requested)
 299 {
 300   int count = 0;
 301
 302   /* Compute number of pspaces we will print.  */
 303   for (struct program_space *pspace : program_spaces)
 304     {
 305       if (requested != -1 && pspace->num != requested)
 306         continue;
 307
 308       ++count;
 309     }
 310
 311   /* There should always be at least one.  */
 312   gdb_assert (count > 0);
 313
 314   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 315   uiout->table_header (1, ui_left, "current", "");
 316   uiout->table_header (4, ui_left, "id", "Id");
 317   uiout->table_header (17, ui_left, "exec", "Executable");
 318   uiout->table_body ();
 319
 320   for (struct program_space *pspace : program_spaces)
 321     {
 322       int printed_header;
 323
 324       if (requested != -1 && requested != pspace->num)
 325         continue;
 326
 327       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 328
 329       if (pspace == current_program_space)
 330         uiout->field_string ("current", "*");
 331       else
 332         uiout->field_skip ("current");
 333
 334       uiout->field_signed ("id", pspace->num);
 335
 336       if (pspace->exec_filename != nullptr)
 337         uiout->field_string ("exec", pspace->exec_filename.get ());
 338       else
 339         uiout->field_skip ("exec");
 340
 341       /* Print extra info that doesn't really fit in tabular form.
 342          Currently, we print the list of inferiors bound to a pspace.
 343          There can be more than one inferior bound to the same pspace,
 344          e.g., both parent/child inferiors in a vfork, or, on targets
 345          that share pspaces between inferiors.  */
 346       printed_header = 0;
 347
 348       /* We're going to switch inferiors.  */
 349       scoped_restore_current_thread restore_thread;
 350
 351       for (inferior *inf : all_inferiors ())
 352         if (inf->pspace == pspace)
 353           {
 354             /* Switch to inferior in order to call target methods.  */
 355             switch_to_inferior_no_thread (inf);
 356
 357             if (!printed_header)
 358               {
 359                 printed_header = 1;
 360                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 361                                  inf->num,
 362                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 363               }
 364             else
 365               printf_filtered (", ID %d (%s)",
 366                                inf->num,
 367                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 368           }
 369
 370       uiout->text ("\n");
 371     }
 372 }
 373
 374 /* Boolean test for an already-known program space id.  */
 375
 376 static int
 377 valid_program_space_id (int num)
 378 {
 379   for (struct program_space *pspace : program_spaces)
 380     if (pspace->num == num)
 381       return 1;
 382
 383   return 0;
 384 }
 385
 386 /* If ARGS is NULL or empty, print information about all program
 387    spaces.  Otherwise, ARGS is a text representation of a LONG
 388    indicating which the program space to print information about.  */
 389
 390 static void
 391 maintenance_info_program_spaces_command (const char *args, int from_tty)
 392 {
 393   int requested = -1;
 394
 395   if (args && *args)
 396     {
 397       requested = parse_and_eval_long (args);
 398       if (!valid_program_space_id (requested))
 399         error (_("program space ID %d not known."), requested);
 400     }
 401
 402   print_program_space (current_uiout, requested);
 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 inferior *inf;
 421
 422   init_address_spaces ();
 423
 424   if (shared_aspace)
 425     {
 426       struct address_space *aspace = new_address_space ();
 427
 428       free_address_space (current_program_space->aspace);
 429       for (struct program_space *pspace : program_spaces)
 430         pspace->aspace = aspace;
 431     }
 432   else
 433     for (struct program_space *pspace : program_spaces)
 434       {
 435         free_address_space (pspace->aspace);
 436         pspace->aspace = new_address_space ();
 437       }
 438
 439   for (inf = inferior_list; inf; inf = inf->next)
 440     if (gdbarch_has_global_solist (target_gdbarch ()))
 441       inf->aspace = maybe_new_address_space ();
 442     else
 443       inf->aspace = inf->pspace->aspace;
 444 }
 445
 446 \f
 447
 448 /* See progspace.h.  */
 449
 450 void
 451 clear_program_space_solib_cache (struct program_space *pspace)
 452 {
 453   pspace->added_solibs.clear ();
 454   pspace->deleted_solibs.clear ();
 455 }
 456
 457 \f
 458
 459 void
 460 initialize_progspace (void)
 461 {
 462   add_cmd ("program-spaces", class_maintenance,
 463            maintenance_info_program_spaces_command,
 464            _("Info about currently known program spaces."),
 465            &maintenanceinfolist);
 466
 467   /* There's always one program space.  Note that this function isn't
 468      an automatic _initialize_foo function, since other
 469      _initialize_foo routines may need to install their per-pspace
 470      data keys.  We can only allocate a progspace when all those
 471      modules have done that.  Do this before
 472      initialize_current_architecture, because that accesses the ebfd
 473      of current_program_space.  */
 474   current_program_space = new program_space (new_address_space ());
 475 }