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 bool
 284 program_space::empty ()
 285 {
 286   return find_inferior_for_program_space (this) == nullptr;
 287 }
 288
 289 /* Prints the list of program spaces and their details on UIOUT.  If
 290    REQUESTED is not -1, it's the ID of the pspace that should be
 291    printed.  Otherwise, all spaces are printed.  */
 292
 293 static void
 294 print_program_space (struct ui_out *uiout, int requested)
 295 {
 296   int count = 0;
 297
 298   /* Compute number of pspaces we will print.  */
 299   for (struct program_space *pspace : program_spaces)
 300     {
 301       if (requested != -1 && pspace->num != requested)
 302         continue;
 303
 304       ++count;
 305     }
 306
 307   /* There should always be at least one.  */
 308   gdb_assert (count > 0);
 309
 310   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 311   uiout->table_header (1, ui_left, "current", "");
 312   uiout->table_header (4, ui_left, "id", "Id");
 313   uiout->table_header (17, ui_left, "exec", "Executable");
 314   uiout->table_body ();
 315
 316   for (struct program_space *pspace : program_spaces)
 317     {
 318       int printed_header;
 319
 320       if (requested != -1 && requested != pspace->num)
 321         continue;
 322
 323       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 324
 325       if (pspace == current_program_space)
 326         uiout->field_string ("current", "*");
 327       else
 328         uiout->field_skip ("current");
 329
 330       uiout->field_signed ("id", pspace->num);
 331
 332       if (pspace->exec_filename != nullptr)
 333         uiout->field_string ("exec", pspace->exec_filename.get ());
 334       else
 335         uiout->field_skip ("exec");
 336
 337       /* Print extra info that doesn't really fit in tabular form.
 338          Currently, we print the list of inferiors bound to a pspace.
 339          There can be more than one inferior bound to the same pspace,
 340          e.g., both parent/child inferiors in a vfork, or, on targets
 341          that share pspaces between inferiors.  */
 342       printed_header = 0;
 343
 344       /* We're going to switch inferiors.  */
 345       scoped_restore_current_thread restore_thread;
 346
 347       for (inferior *inf : all_inferiors ())
 348         if (inf->pspace == pspace)
 349           {
 350             /* Switch to inferior in order to call target methods.  */
 351             switch_to_inferior_no_thread (inf);
 352
 353             if (!printed_header)
 354               {
 355                 printed_header = 1;
 356                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 357                                  inf->num,
 358                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 359               }
 360             else
 361               printf_filtered (", ID %d (%s)",
 362                                inf->num,
 363                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 364           }
 365
 366       uiout->text ("\n");
 367     }
 368 }
 369
 370 /* Boolean test for an already-known program space id.  */
 371
 372 static int
 373 valid_program_space_id (int num)
 374 {
 375   for (struct program_space *pspace : program_spaces)
 376     if (pspace->num == num)
 377       return 1;
 378
 379   return 0;
 380 }
 381
 382 /* If ARGS is NULL or empty, print information about all program
 383    spaces.  Otherwise, ARGS is a text representation of a LONG
 384    indicating which the program space to print information about.  */
 385
 386 static void
 387 maintenance_info_program_spaces_command (const char *args, int from_tty)
 388 {
 389   int requested = -1;
 390
 391   if (args && *args)
 392     {
 393       requested = parse_and_eval_long (args);
 394       if (!valid_program_space_id (requested))
 395         error (_("program space ID %d not known."), requested);
 396     }
 397
 398   print_program_space (current_uiout, requested);
 399 }
 400
 401 /* Update all program spaces matching to address spaces.  The user may
 402    have created several program spaces, and loaded executables into
 403    them before connecting to the target interface that will create the
 404    inferiors.  All that happens before GDB has a chance to know if the
 405    inferiors will share an address space or not.  Call this after
 406    having connected to the target interface and having fetched the
 407    target description, to fixup the program/address spaces mappings.
 408
 409    It is assumed that there are no bound inferiors yet, otherwise,
 410    they'd be left with stale referenced to released aspaces.  */
 411
 412 void
 413 update_address_spaces (void)
 414 {
 415   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 416   struct inferior *inf;
 417
 418   init_address_spaces ();
 419
 420   if (shared_aspace)
 421     {
 422       struct address_space *aspace = new_address_space ();
 423
 424       free_address_space (current_program_space->aspace);
 425       for (struct program_space *pspace : program_spaces)
 426         pspace->aspace = aspace;
 427     }
 428   else
 429     for (struct program_space *pspace : program_spaces)
 430       {
 431         free_address_space (pspace->aspace);
 432         pspace->aspace = new_address_space ();
 433       }
 434
 435   for (inf = inferior_list; inf; inf = inf->next)
 436     if (gdbarch_has_global_solist (target_gdbarch ()))
 437       inf->aspace = maybe_new_address_space ();
 438     else
 439       inf->aspace = inf->pspace->aspace;
 440 }
 441
 442 \f
 443
 444 /* See progspace.h.  */
 445
 446 void
 447 program_space::clear_solib_cache ()
 448 {
 449   added_solibs.clear ();
 450   deleted_solibs.clear ();
 451 }
 452
 453 \f
 454
 455 void
 456 initialize_progspace (void)
 457 {
 458   add_cmd ("program-spaces", class_maintenance,
 459            maintenance_info_program_spaces_command,
 460            _("Info about currently known program spaces."),
 461            &maintenanceinfolist);
 462
 463   /* There's always one program space.  Note that this function isn't
 464      an automatic _initialize_foo function, since other
 465      _initialize_foo routines may need to install their per-pspace
 466      data keys.  We can only allocate a progspace when all those
 467      modules have done that.  Do this before
 468      initialize_current_architecture, because that accesses the ebfd
 469      of current_program_space.  */
 470   current_program_space = new program_space (new_address_space ());
 471 }