gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2022 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 static 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   free_all_objfiles ();
 151   /* Defer breakpoint re-set because we don't want to create new
 152      locations for this pspace which we're tearing down.  */
 153   clear_symtab_users (SYMFILE_DEFER_BP_RESET);
 154   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 155     free_address_space (this->aspace);
 156     /* Discard any data modules have associated with the PSPACE.  */
 157   program_space_free_data (this);
 158 }
 159
 160 /* See progspace.h.  */
 161
 162 void
 163 program_space::free_all_objfiles ()
 164 {
 165   /* Any objfile reference would become stale.  */
 166   for (struct so_list *so : current_program_space->solibs ())
 167     gdb_assert (so->objfile == NULL);
 168
 169   while (!objfiles_list.empty ())
 170     objfiles_list.front ()->unlink ();
 171 }
 172
 173 /* See progspace.h.  */
 174
 175 void
 176 program_space::add_objfile (std::shared_ptr<objfile> &&objfile,
 177                             struct objfile *before)
 178 {
 179   if (before == nullptr)
 180     objfiles_list.push_back (std::move (objfile));
 181   else
 182     {
 183       auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 184                                 [=] (const std::shared_ptr<::objfile> &objf)
 185                                 {
 186                                   return objf.get () == before;
 187                                 });
 188       gdb_assert (iter != objfiles_list.end ());
 189       objfiles_list.insert (iter, std::move (objfile));
 190     }
 191 }
 192
 193 /* See progspace.h.  */
 194
 195 void
 196 program_space::remove_objfile (struct objfile *objfile)
 197 {
 198   /* Removing an objfile from the objfile list invalidates any frame
 199      that was built using frame info found in the objfile.  Reinit the
 200      frame cache to get rid of any frame that might otherwise
 201      reference stale info.  */
 202   reinit_frame_cache ();
 203
 204   auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 205                             [=] (const std::shared_ptr<::objfile> &objf)
 206                             {
 207                               return objf.get () == objfile;
 208                             });
 209   gdb_assert (iter != objfiles_list.end ());
 210   objfiles_list.erase (iter);
 211
 212   if (objfile == symfile_object_file)
 213     symfile_object_file = NULL;
 214 }
 215
 216 /* See progspace.h.  */
 217
 218 next_adapter<struct so_list>
 219 program_space::solibs () const
 220 {
 221   return next_adapter<struct so_list> (this->so_list);
 222 }
 223
 224 /* See progspace.h.  */
 225
 226 void
 227 program_space::exec_close ()
 228 {
 229   if (ebfd != nullptr)
 230     {
 231       /* Removing target sections may close the exec_ops target.
 232          Clear ebfd before doing so to prevent recursion.  */
 233       ebfd.reset (nullptr);
 234       ebfd_mtime = 0;
 235
 236       remove_target_sections (&ebfd);
 237
 238       exec_filename.reset (nullptr);
 239     }
 240 }
 241
 242 /* Copies program space SRC to DEST.  Copies the main executable file,
 243    and the main symbol file.  Returns DEST.  */
 244
 245 struct program_space *
 246 clone_program_space (struct program_space *dest, struct program_space *src)
 247 {
 248   scoped_restore_current_program_space restore_pspace;
 249
 250   set_current_program_space (dest);
 251
 252   if (src->exec_filename != NULL)
 253     exec_file_attach (src->exec_filename.get (), 0);
 254
 255   if (src->symfile_object_file != NULL)
 256     symbol_file_add_main (objfile_name (src->symfile_object_file),
 257                           SYMFILE_DEFER_BP_RESET);
 258
 259   return dest;
 260 }
 261
 262 /* Sets PSPACE as the current program space.  It is the caller's
 263    responsibility to make sure that the currently selected
 264    inferior/thread matches the selected program space.  */
 265
 266 void
 267 set_current_program_space (struct program_space *pspace)
 268 {
 269   if (current_program_space == pspace)
 270     return;
 271
 272   gdb_assert (pspace != NULL);
 273
 274   current_program_space = pspace;
 275
 276   /* Different symbols change our view of the frame chain.  */
 277   reinit_frame_cache ();
 278 }
 279
 280 /* Returns true iff there's no inferior bound to PSPACE.  */
 281
 282 bool
 283 program_space::empty ()
 284 {
 285   return find_inferior_for_program_space (this) == nullptr;
 286 }
 287
 288 /* Prints the list of program spaces and their details on UIOUT.  If
 289    REQUESTED is not -1, it's the ID of the pspace that should be
 290    printed.  Otherwise, all spaces are printed.  */
 291
 292 static void
 293 print_program_space (struct ui_out *uiout, int requested)
 294 {
 295   int count = 0;
 296
 297   /* Compute number of pspaces we will print.  */
 298   for (struct program_space *pspace : program_spaces)
 299     {
 300       if (requested != -1 && pspace->num != requested)
 301         continue;
 302
 303       ++count;
 304     }
 305
 306   /* There should always be at least one.  */
 307   gdb_assert (count > 0);
 308
 309   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 310   uiout->table_header (1, ui_left, "current", "");
 311   uiout->table_header (4, ui_left, "id", "Id");
 312   uiout->table_header (17, ui_left, "exec", "Executable");
 313   uiout->table_body ();
 314
 315   for (struct program_space *pspace : program_spaces)
 316     {
 317       int printed_header;
 318
 319       if (requested != -1 && requested != pspace->num)
 320         continue;
 321
 322       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 323
 324       if (pspace == current_program_space)
 325         uiout->field_string ("current", "*");
 326       else
 327         uiout->field_skip ("current");
 328
 329       uiout->field_signed ("id", pspace->num);
 330
 331       if (pspace->exec_filename != nullptr)
 332         uiout->field_string ("exec", pspace->exec_filename.get ());
 333       else
 334         uiout->field_skip ("exec");
 335
 336       /* Print extra info that doesn't really fit in tabular form.
 337          Currently, we print the list of inferiors bound to a pspace.
 338          There can be more than one inferior bound to the same pspace,
 339          e.g., both parent/child inferiors in a vfork, or, on targets
 340          that share pspaces between inferiors.  */
 341       printed_header = 0;
 342
 343       /* We're going to switch inferiors.  */
 344       scoped_restore_current_thread restore_thread;
 345
 346       for (inferior *inf : all_inferiors ())
 347         if (inf->pspace == pspace)
 348           {
 349             /* Switch to inferior in order to call target methods.  */
 350             switch_to_inferior_no_thread (inf);
 351
 352             if (!printed_header)
 353               {
 354                 printed_header = 1;
 355                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 356                                  inf->num,
 357                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 358               }
 359             else
 360               printf_filtered (", ID %d (%s)",
 361                                inf->num,
 362                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 363           }
 364
 365       uiout->text ("\n");
 366     }
 367 }
 368
 369 /* Boolean test for an already-known program space id.  */
 370
 371 static int
 372 valid_program_space_id (int num)
 373 {
 374   for (struct program_space *pspace : program_spaces)
 375     if (pspace->num == num)
 376       return 1;
 377
 378   return 0;
 379 }
 380
 381 /* If ARGS is NULL or empty, print information about all program
 382    spaces.  Otherwise, ARGS is a text representation of a LONG
 383    indicating which the program space to print information about.  */
 384
 385 static void
 386 maintenance_info_program_spaces_command (const char *args, int from_tty)
 387 {
 388   int requested = -1;
 389
 390   if (args && *args)
 391     {
 392       requested = parse_and_eval_long (args);
 393       if (!valid_program_space_id (requested))
 394         error (_("program space ID %d not known."), requested);
 395     }
 396
 397   print_program_space (current_uiout, requested);
 398 }
 399
 400 /* Update all program spaces matching to address spaces.  The user may
 401    have created several program spaces, and loaded executables into
 402    them before connecting to the target interface that will create the
 403    inferiors.  All that happens before GDB has a chance to know if the
 404    inferiors will share an address space or not.  Call this after
 405    having connected to the target interface and having fetched the
 406    target description, to fixup the program/address spaces mappings.
 407
 408    It is assumed that there are no bound inferiors yet, otherwise,
 409    they'd be left with stale referenced to released aspaces.  */
 410
 411 void
 412 update_address_spaces (void)
 413 {
 414   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 415   struct inferior *inf;
 416
 417   init_address_spaces ();
 418
 419   if (shared_aspace)
 420     {
 421       struct address_space *aspace = new_address_space ();
 422
 423       free_address_space (current_program_space->aspace);
 424       for (struct program_space *pspace : program_spaces)
 425         pspace->aspace = aspace;
 426     }
 427   else
 428     for (struct program_space *pspace : program_spaces)
 429       {
 430         free_address_space (pspace->aspace);
 431         pspace->aspace = new_address_space ();
 432       }
 433
 434   for (inf = inferior_list; inf; inf = inf->next)
 435     if (gdbarch_has_global_solist (target_gdbarch ()))
 436       inf->aspace = maybe_new_address_space ();
 437     else
 438       inf->aspace = inf->pspace->aspace;
 439 }
 440
 441 \f
 442
 443 /* See progspace.h.  */
 444
 445 void
 446 program_space::clear_solib_cache ()
 447 {
 448   added_solibs.clear ();
 449   deleted_solibs.clear ();
 450 }
 451
 452 \f
 453
 454 void
 455 initialize_progspace (void)
 456 {
 457   add_cmd ("program-spaces", class_maintenance,
 458            maintenance_info_program_spaces_command,
 459            _("Info about currently known program spaces."),
 460            &maintenanceinfolist);
 461
 462   /* There's always one program space.  Note that this function isn't
 463      an automatic _initialize_foo function, since other
 464      _initialize_foo routines may need to install their per-pspace
 465      data keys.  We can only allocate a progspace when all those
 466      modules have done that.  Do this before
 467      initialize_current_architecture, because that accesses the ebfd
 468      of current_program_space.  */
 469   current_program_space = new program_space (new_address_space ());
 470 }