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 #include "cli/cli-style.h"
  31
  32 /* The last program space number assigned.  */
  33 static int last_program_space_num = 0;
  34
  35 /* The head of the program spaces list.  */
  36 std::vector<struct program_space *> program_spaces;
  37
  38 /* Pointer to the current program space.  */
  39 struct program_space *current_program_space;
  40
  41 /* The last address space number assigned.  */
  42 static int highest_address_space_num;
  43
  44 \f
  45
  46 /* Keep a registry of per-program_space data-pointers required by other GDB
  47    modules.  */
  48
  49 DEFINE_REGISTRY (program_space, REGISTRY_ACCESS_FIELD)
  50
  51 /* Keep a registry of per-address_space data-pointers required by other GDB
  52    modules.  */
  53
  54 DEFINE_REGISTRY (address_space, REGISTRY_ACCESS_FIELD)
  55
  56 \f
  57
  58 /* Create a new address space object, and add it to the list.  */
  59
  60 struct address_space *
  61 new_address_space (void)
  62 {
  63   struct address_space *aspace;
  64
  65   aspace = XCNEW (struct address_space);
  66   aspace->num = ++highest_address_space_num;
  67   address_space_alloc_data (aspace);
  68
  69   return aspace;
  70 }
  71
  72 /* Maybe create a new address space object, and add it to the list, or
  73    return a pointer to an existing address space, in case inferiors
  74    share an address space on this target system.  */
  75
  76 struct address_space *
  77 maybe_new_address_space (void)
  78 {
  79   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
  80
  81   if (shared_aspace)
  82     {
  83       /* Just return the first in the list.  */
  84       return program_spaces[0]->aspace;
  85     }
  86
  87   return new_address_space ();
  88 }
  89
  90 static void
  91 free_address_space (struct address_space *aspace)
  92 {
  93   address_space_free_data (aspace);
  94   xfree (aspace);
  95 }
  96
  97 int
  98 address_space_num (struct address_space *aspace)
  99 {
 100   return aspace->num;
 101 }
 102
 103 /* Start counting over from scratch.  */
 104
 105 static void
 106 init_address_spaces (void)
 107 {
 108   highest_address_space_num = 0;
 109 }
 110
 111 \f
 112
 113 /* Remove a program space from the program spaces list.  */
 114
 115 static void
 116 remove_program_space (program_space *pspace)
 117 {
 118   gdb_assert (pspace != NULL);
 119
 120   auto iter = std::find (program_spaces.begin (), program_spaces.end (),
 121                          pspace);
 122   gdb_assert (iter != program_spaces.end ());
 123   program_spaces.erase (iter);
 124 }
 125
 126 /* See progspace.h.  */
 127
 128 program_space::program_space (address_space *aspace_)
 129   : num (++last_program_space_num),
 130     aspace (aspace_)
 131 {
 132   program_space_alloc_data (this);
 133
 134   program_spaces.push_back (this);
 135 }
 136
 137 /* See progspace.h.  */
 138
 139 program_space::~program_space ()
 140 {
 141   gdb_assert (this != current_program_space);
 142
 143   remove_program_space (this);
 144
 145   scoped_restore_current_program_space restore_pspace;
 146
 147   set_current_program_space (this);
 148
 149   breakpoint_program_space_exit (this);
 150   no_shared_libraries (NULL, 0);
 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 void
 220 program_space::exec_close ()
 221 {
 222   if (ebfd != nullptr)
 223     {
 224       /* Removing target sections may close the exec_ops target.
 225          Clear ebfd before doing so to prevent recursion.  */
 226       ebfd.reset (nullptr);
 227       ebfd_mtime = 0;
 228
 229       remove_target_sections (&ebfd);
 230
 231       exec_filename.reset (nullptr);
 232     }
 233 }
 234
 235 /* Copies program space SRC to DEST.  Copies the main executable file,
 236    and the main symbol file.  Returns DEST.  */
 237
 238 struct program_space *
 239 clone_program_space (struct program_space *dest, struct program_space *src)
 240 {
 241   scoped_restore_current_program_space restore_pspace;
 242
 243   set_current_program_space (dest);
 244
 245   if (src->exec_filename != NULL)
 246     exec_file_attach (src->exec_filename.get (), 0);
 247
 248   if (src->symfile_object_file != NULL)
 249     symbol_file_add_main (objfile_name (src->symfile_object_file),
 250                           SYMFILE_DEFER_BP_RESET);
 251
 252   return dest;
 253 }
 254
 255 /* Sets PSPACE as the current program space.  It is the caller's
 256    responsibility to make sure that the currently selected
 257    inferior/thread matches the selected program space.  */
 258
 259 void
 260 set_current_program_space (struct program_space *pspace)
 261 {
 262   if (current_program_space == pspace)
 263     return;
 264
 265   gdb_assert (pspace != NULL);
 266
 267   current_program_space = pspace;
 268
 269   /* Different symbols change our view of the frame chain.  */
 270   reinit_frame_cache ();
 271 }
 272
 273 /* Returns true iff there's no inferior bound to PSPACE.  */
 274
 275 bool
 276 program_space::empty ()
 277 {
 278   return find_inferior_for_program_space (this) == nullptr;
 279 }
 280
 281 /* Prints the list of program spaces and their details on UIOUT.  If
 282    REQUESTED is not -1, it's the ID of the pspace that should be
 283    printed.  Otherwise, all spaces are printed.  */
 284
 285 static void
 286 print_program_space (struct ui_out *uiout, int requested)
 287 {
 288   int count = 0;
 289
 290   /* Compute number of pspaces we will print.  */
 291   for (struct program_space *pspace : program_spaces)
 292     {
 293       if (requested != -1 && pspace->num != requested)
 294         continue;
 295
 296       ++count;
 297     }
 298
 299   /* There should always be at least one.  */
 300   gdb_assert (count > 0);
 301
 302   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 303   uiout->table_header (1, ui_left, "current", "");
 304   uiout->table_header (4, ui_left, "id", "Id");
 305   uiout->table_header (17, ui_left, "exec", "Executable");
 306   uiout->table_body ();
 307
 308   for (struct program_space *pspace : program_spaces)
 309     {
 310       int printed_header;
 311
 312       if (requested != -1 && requested != pspace->num)
 313         continue;
 314
 315       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 316
 317       if (pspace == current_program_space)
 318         uiout->field_string ("current", "*");
 319       else
 320         uiout->field_skip ("current");
 321
 322       uiout->field_signed ("id", pspace->num);
 323
 324       if (pspace->exec_filename != nullptr)
 325         uiout->field_string ("exec", pspace->exec_filename.get (),
 326                              file_name_style.style ());
 327       else
 328         uiout->field_skip ("exec");
 329
 330       /* Print extra info that doesn't really fit in tabular form.
 331          Currently, we print the list of inferiors bound to a pspace.
 332          There can be more than one inferior bound to the same pspace,
 333          e.g., both parent/child inferiors in a vfork, or, on targets
 334          that share pspaces between inferiors.  */
 335       printed_header = 0;
 336
 337       /* We're going to switch inferiors.  */
 338       scoped_restore_current_thread restore_thread;
 339
 340       for (inferior *inf : all_inferiors ())
 341         if (inf->pspace == pspace)
 342           {
 343             /* Switch to inferior in order to call target methods.  */
 344             switch_to_inferior_no_thread (inf);
 345
 346             if (!printed_header)
 347               {
 348                 printed_header = 1;
 349                 gdb_printf ("\n\tBound inferiors: ID %d (%s)",
 350                             inf->num,
 351                             target_pid_to_str (ptid_t (inf->pid)).c_str ());
 352               }
 353             else
 354               gdb_printf (", ID %d (%s)",
 355                           inf->num,
 356                           target_pid_to_str (ptid_t (inf->pid)).c_str ());
 357           }
 358
 359       uiout->text ("\n");
 360     }
 361 }
 362
 363 /* Boolean test for an already-known program space id.  */
 364
 365 static int
 366 valid_program_space_id (int num)
 367 {
 368   for (struct program_space *pspace : program_spaces)
 369     if (pspace->num == num)
 370       return 1;
 371
 372   return 0;
 373 }
 374
 375 /* If ARGS is NULL or empty, print information about all program
 376    spaces.  Otherwise, ARGS is a text representation of a LONG
 377    indicating which the program space to print information about.  */
 378
 379 static void
 380 maintenance_info_program_spaces_command (const char *args, int from_tty)
 381 {
 382   int requested = -1;
 383
 384   if (args && *args)
 385     {
 386       requested = parse_and_eval_long (args);
 387       if (!valid_program_space_id (requested))
 388         error (_("program space ID %d not known."), requested);
 389     }
 390
 391   print_program_space (current_uiout, requested);
 392 }
 393
 394 /* Update all program spaces matching to address spaces.  The user may
 395    have created several program spaces, and loaded executables into
 396    them before connecting to the target interface that will create the
 397    inferiors.  All that happens before GDB has a chance to know if the
 398    inferiors will share an address space or not.  Call this after
 399    having connected to the target interface and having fetched the
 400    target description, to fixup the program/address spaces mappings.
 401
 402    It is assumed that there are no bound inferiors yet, otherwise,
 403    they'd be left with stale referenced to released aspaces.  */
 404
 405 void
 406 update_address_spaces (void)
 407 {
 408   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 409
 410   init_address_spaces ();
 411
 412   if (shared_aspace)
 413     {
 414       struct address_space *aspace = new_address_space ();
 415
 416       free_address_space (current_program_space->aspace);
 417       for (struct program_space *pspace : program_spaces)
 418         pspace->aspace = aspace;
 419     }
 420   else
 421     for (struct program_space *pspace : program_spaces)
 422       {
 423         free_address_space (pspace->aspace);
 424         pspace->aspace = new_address_space ();
 425       }
 426
 427   for (inferior *inf : all_inferiors ())
 428     if (gdbarch_has_global_solist (target_gdbarch ()))
 429       inf->aspace = maybe_new_address_space ();
 430     else
 431       inf->aspace = inf->pspace->aspace;
 432 }
 433
 434 \f
 435
 436 /* See progspace.h.  */
 437
 438 void
 439 program_space::clear_solib_cache ()
 440 {
 441   added_solibs.clear ();
 442   deleted_solibs.clear ();
 443 }
 444
 445 \f
 446
 447 void
 448 initialize_progspace (void)
 449 {
 450   add_cmd ("program-spaces", class_maintenance,
 451            maintenance_info_program_spaces_command,
 452            _("Info about currently known program spaces."),
 453            &maintenanceinfolist);
 454
 455   /* There's always one program space.  Note that this function isn't
 456      an automatic _initialize_foo function, since other
 457      _initialize_foo routines may need to install their per-pspace
 458      data keys.  We can only allocate a progspace when all those
 459      modules have done that.  Do this before
 460      initialize_current_architecture, because that accesses the ebfd
 461      of current_program_space.  */
 462   current_program_space = new program_space (new_address_space ());
 463 }