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     /* Discard any data modules have associated with the PSPACE.  */
 158   program_space_free_data (this);
 159 }
 160
 161 /* See progspace.h.  */
 162
 163 void
 164 program_space::free_all_objfiles ()
 165 {
 166   /* Any objfile reference would become stale.  */
 167   for (struct so_list *so : current_program_space->solibs ())
 168     gdb_assert (so->objfile == NULL);
 169
 170   while (!objfiles_list.empty ())
 171     objfiles_list.front ()->unlink ();
 172 }
 173
 174 /* See progspace.h.  */
 175
 176 void
 177 program_space::add_objfile (std::shared_ptr<objfile> &&objfile,
 178                             struct objfile *before)
 179 {
 180   if (before == nullptr)
 181     objfiles_list.push_back (std::move (objfile));
 182   else
 183     {
 184       auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 185                                 [=] (const std::shared_ptr<::objfile> &objf)
 186                                 {
 187                                   return objf.get () == before;
 188                                 });
 189       gdb_assert (iter != objfiles_list.end ());
 190       objfiles_list.insert (iter, std::move (objfile));
 191     }
 192 }
 193
 194 /* See progspace.h.  */
 195
 196 void
 197 program_space::remove_objfile (struct objfile *objfile)
 198 {
 199   /* Removing an objfile from the objfile list invalidates any frame
 200      that was built using frame info found in the objfile.  Reinit the
 201      frame cache to get rid of any frame that might otherwise
 202      reference stale info.  */
 203   reinit_frame_cache ();
 204
 205   auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 206                             [=] (const std::shared_ptr<::objfile> &objf)
 207                             {
 208                               return objf.get () == objfile;
 209                             });
 210   gdb_assert (iter != objfiles_list.end ());
 211   objfiles_list.erase (iter);
 212
 213   if (objfile == symfile_object_file)
 214     symfile_object_file = NULL;
 215 }
 216
 217 /* See progspace.h.  */
 218
 219 next_adapter<struct so_list>
 220 program_space::solibs () const
 221 {
 222   return next_adapter<struct so_list> (this->so_list);
 223 }
 224
 225 /* See progspace.h.  */
 226
 227 void
 228 program_space::exec_close ()
 229 {
 230   if (ebfd != nullptr)
 231     {
 232       /* Removing target sections may close the exec_ops target.
 233          Clear ebfd before doing so to prevent recursion.  */
 234       ebfd.reset (nullptr);
 235       ebfd_mtime = 0;
 236
 237       remove_target_sections (&ebfd);
 238
 239       exec_filename.reset (nullptr);
 240     }
 241 }
 242
 243 /* Copies program space SRC to DEST.  Copies the main executable file,
 244    and the main symbol file.  Returns DEST.  */
 245
 246 struct program_space *
 247 clone_program_space (struct program_space *dest, struct program_space *src)
 248 {
 249   scoped_restore_current_program_space restore_pspace;
 250
 251   set_current_program_space (dest);
 252
 253   if (src->exec_filename != NULL)
 254     exec_file_attach (src->exec_filename.get (), 0);
 255
 256   if (src->symfile_object_file != NULL)
 257     symbol_file_add_main (objfile_name (src->symfile_object_file),
 258                           SYMFILE_DEFER_BP_RESET);
 259
 260   return dest;
 261 }
 262
 263 /* Sets PSPACE as the current program space.  It is the caller's
 264    responsibility to make sure that the currently selected
 265    inferior/thread matches the selected program space.  */
 266
 267 void
 268 set_current_program_space (struct program_space *pspace)
 269 {
 270   if (current_program_space == pspace)
 271     return;
 272
 273   gdb_assert (pspace != NULL);
 274
 275   current_program_space = pspace;
 276
 277   /* Different symbols change our view of the frame chain.  */
 278   reinit_frame_cache ();
 279 }
 280
 281 /* Returns true iff there's no inferior bound to PSPACE.  */
 282
 283 int
 284 program_space_empty_p (struct program_space *pspace)
 285 {
 286   if (find_inferior_for_program_space (pspace) != NULL)
 287       return 0;
 288
 289   return 1;
 290 }
 291
 292 /* Prints the list of program spaces and their details on UIOUT.  If
 293    REQUESTED is not -1, it's the ID of the pspace that should be
 294    printed.  Otherwise, all spaces are printed.  */
 295
 296 static void
 297 print_program_space (struct ui_out *uiout, int requested)
 298 {
 299   int count = 0;
 300
 301   /* Compute number of pspaces we will print.  */
 302   for (struct program_space *pspace : program_spaces)
 303     {
 304       if (requested != -1 && pspace->num != requested)
 305         continue;
 306
 307       ++count;
 308     }
 309
 310   /* There should always be at least one.  */
 311   gdb_assert (count > 0);
 312
 313   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 314   uiout->table_header (1, ui_left, "current", "");
 315   uiout->table_header (4, ui_left, "id", "Id");
 316   uiout->table_header (17, ui_left, "exec", "Executable");
 317   uiout->table_body ();
 318
 319   for (struct program_space *pspace : program_spaces)
 320     {
 321       int printed_header;
 322
 323       if (requested != -1 && requested != pspace->num)
 324         continue;
 325
 326       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 327
 328       if (pspace == current_program_space)
 329         uiout->field_string ("current", "*");
 330       else
 331         uiout->field_skip ("current");
 332
 333       uiout->field_signed ("id", pspace->num);
 334
 335       if (pspace->exec_filename != nullptr)
 336         uiout->field_string ("exec", pspace->exec_filename.get ());
 337       else
 338         uiout->field_skip ("exec");
 339
 340       /* Print extra info that doesn't really fit in tabular form.
 341          Currently, we print the list of inferiors bound to a pspace.
 342          There can be more than one inferior bound to the same pspace,
 343          e.g., both parent/child inferiors in a vfork, or, on targets
 344          that share pspaces between inferiors.  */
 345       printed_header = 0;
 346
 347       /* We're going to switch inferiors.  */
 348       scoped_restore_current_thread restore_thread;
 349
 350       for (inferior *inf : all_inferiors ())
 351         if (inf->pspace == pspace)
 352           {
 353             /* Switch to inferior in order to call target methods.  */
 354             switch_to_inferior_no_thread (inf);
 355
 356             if (!printed_header)
 357               {
 358                 printed_header = 1;
 359                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 360                                  inf->num,
 361                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 362               }
 363             else
 364               printf_filtered (", ID %d (%s)",
 365                                inf->num,
 366                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 367           }
 368
 369       uiout->text ("\n");
 370     }
 371 }
 372
 373 /* Boolean test for an already-known program space id.  */
 374
 375 static int
 376 valid_program_space_id (int num)
 377 {
 378   for (struct program_space *pspace : program_spaces)
 379     if (pspace->num == num)
 380       return 1;
 381
 382   return 0;
 383 }
 384
 385 /* If ARGS is NULL or empty, print information about all program
 386    spaces.  Otherwise, ARGS is a text representation of a LONG
 387    indicating which the program space to print information about.  */
 388
 389 static void
 390 maintenance_info_program_spaces_command (const char *args, int from_tty)
 391 {
 392   int requested = -1;
 393
 394   if (args && *args)
 395     {
 396       requested = parse_and_eval_long (args);
 397       if (!valid_program_space_id (requested))
 398         error (_("program space ID %d not known."), requested);
 399     }
 400
 401   print_program_space (current_uiout, requested);
 402 }
 403
 404 /* Update all program spaces matching to address spaces.  The user may
 405    have created several program spaces, and loaded executables into
 406    them before connecting to the target interface that will create the
 407    inferiors.  All that happens before GDB has a chance to know if the
 408    inferiors will share an address space or not.  Call this after
 409    having connected to the target interface and having fetched the
 410    target description, to fixup the program/address spaces mappings.
 411
 412    It is assumed that there are no bound inferiors yet, otherwise,
 413    they'd be left with stale referenced to released aspaces.  */
 414
 415 void
 416 update_address_spaces (void)
 417 {
 418   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 419   struct inferior *inf;
 420
 421   init_address_spaces ();
 422
 423   if (shared_aspace)
 424     {
 425       struct address_space *aspace = new_address_space ();
 426
 427       free_address_space (current_program_space->aspace);
 428       for (struct program_space *pspace : program_spaces)
 429         pspace->aspace = aspace;
 430     }
 431   else
 432     for (struct program_space *pspace : program_spaces)
 433       {
 434         free_address_space (pspace->aspace);
 435         pspace->aspace = new_address_space ();
 436       }
 437
 438   for (inf = inferior_list; inf; inf = inf->next)
 439     if (gdbarch_has_global_solist (target_gdbarch ()))
 440       inf->aspace = maybe_new_address_space ();
 441     else
 442       inf->aspace = inf->pspace->aspace;
 443 }
 444
 445 \f
 446
 447 /* See progspace.h.  */
 448
 449 void
 450 program_space::clear_solib_cache ()
 451 {
 452   added_solibs.clear ();
 453   deleted_solibs.clear ();
 454 }
 455
 456 \f
 457
 458 void
 459 initialize_progspace (void)
 460 {
 461   add_cmd ("program-spaces", class_maintenance,
 462            maintenance_info_program_spaces_command,
 463            _("Info about currently known program spaces."),
 464            &maintenanceinfolist);
 465
 466   /* There's always one program space.  Note that this function isn't
 467      an automatic _initialize_foo function, since other
 468      _initialize_foo routines may need to install their per-pspace
 469      data keys.  We can only allocate a progspace when all those
 470      modules have done that.  Do this before
 471      initialize_current_architecture, because that accesses the ebfd
 472      of current_program_space.  */
 473   current_program_space = new program_space (new_address_space ());
 474 }