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 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->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 /* Add a program space from the program spaces list.  */
 113
 114 static void
 115 add_program_space (program_space *pspace)
 116 {
 117   if (program_spaces == NULL)
 118     program_spaces = pspace;
 119   else
 120     {
 121       program_space *last;
 122
 123       for (last = program_spaces; last->next != NULL; last = last->next)
 124         ;
 125       last->next = pspace;
 126     }
 127 }
 128
 129 /* Remove a program space from the program spaces list.  */
 130
 131 static void
 132 remove_program_space (program_space *pspace)
 133 {
 134   program_space *ss, **ss_link;
 135   gdb_assert (pspace != NULL);
 136
 137   ss = program_spaces;
 138   ss_link = &program_spaces;
 139   while (ss != NULL)
 140     {
 141       if (ss == pspace)
 142         {
 143           *ss_link = ss->next;
 144           return;
 145         }
 146
 147       ss_link = &ss->next;
 148       ss = *ss_link;
 149     }
 150 }
 151
 152 /* See progspace.h.  */
 153
 154 program_space::program_space (address_space *aspace_)
 155   : num (++last_program_space_num),
 156     aspace (aspace_)
 157 {
 158   program_space_alloc_data (this);
 159
 160   add_program_space (this);
 161 }
 162
 163 /* See progspace.h.  */
 164
 165 program_space::~program_space ()
 166 {
 167   gdb_assert (this != current_program_space);
 168
 169   remove_program_space (this);
 170
 171   scoped_restore_current_program_space restore_pspace;
 172
 173   set_current_program_space (this);
 174
 175   breakpoint_program_space_exit (this);
 176   no_shared_libraries (NULL, 0);
 177   exec_close ();
 178   free_all_objfiles ();
 179   /* Defer breakpoint re-set because we don't want to create new
 180      locations for this pspace which we're tearing down.  */
 181   clear_symtab_users (SYMFILE_DEFER_BP_RESET);
 182   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 183     free_address_space (this->aspace);
 184   clear_section_table (&this->target_sections);
 185   clear_program_space_solib_cache (this);
 186     /* Discard any data modules have associated with the PSPACE.  */
 187   program_space_free_data (this);
 188 }
 189
 190 /* See progspace.h.  */
 191
 192 void
 193 program_space::free_all_objfiles ()
 194 {
 195   struct so_list *so;
 196
 197   /* Any objfile reference would become stale.  */
 198   for (so = master_so_list (); so; so = so->next)
 199     gdb_assert (so->objfile == NULL);
 200
 201   while (!objfiles_list.empty ())
 202     objfiles_list.front ()->unlink ();
 203 }
 204
 205 /* See progspace.h.  */
 206
 207 void
 208 program_space::add_objfile (std::shared_ptr<objfile> &&objfile,
 209                             struct objfile *before)
 210 {
 211   if (before == nullptr)
 212     objfiles_list.push_back (std::move (objfile));
 213   else
 214     {
 215       auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 216                                 [=] (const std::shared_ptr<::objfile> &objf)
 217                                 {
 218                                   return objf.get () == before;
 219                                 });
 220       gdb_assert (iter != objfiles_list.end ());
 221       objfiles_list.insert (iter, std::move (objfile));
 222     }
 223 }
 224
 225 /* See progspace.h.  */
 226
 227 void
 228 program_space::remove_objfile (struct objfile *objfile)
 229 {
 230   auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 231                             [=] (const std::shared_ptr<::objfile> &objf)
 232                             {
 233                               return objf.get () == objfile;
 234                             });
 235   gdb_assert (iter != objfiles_list.end ());
 236   objfiles_list.erase (iter);
 237
 238   if (objfile == symfile_object_file)
 239     symfile_object_file = NULL;
 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->pspace_exec_filename != NULL)
 253     exec_file_attach (src->pspace_exec_filename, 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 int
 283 program_space_empty_p (struct program_space *pspace)
 284 {
 285   if (find_inferior_for_program_space (pspace) != NULL)
 286       return 0;
 287
 288   return 1;
 289 }
 290
 291 /* Prints the list of program spaces and their details on UIOUT.  If
 292    REQUESTED is not -1, it's the ID of the pspace that should be
 293    printed.  Otherwise, all spaces are printed.  */
 294
 295 static void
 296 print_program_space (struct ui_out *uiout, int requested)
 297 {
 298   struct program_space *pspace;
 299   int count = 0;
 300
 301   /* Compute number of pspaces we will print.  */
 302   ALL_PSPACES (pspace)
 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   ALL_PSPACES (pspace)
 320     {
 321       struct inferior *inf;
 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->pspace_exec_filename)
 337         uiout->field_string ("exec", pspace->pspace_exec_filename);
 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       for (inf = inferior_list; inf; inf = inf->next)
 348         if (inf->pspace == pspace)
 349           {
 350             if (!printed_header)
 351               {
 352                 printed_header = 1;
 353                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 354                                  inf->num,
 355                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 356               }
 357             else
 358               printf_filtered (", ID %d (%s)",
 359                                inf->num,
 360                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 361           }
 362
 363       uiout->text ("\n");
 364     }
 365 }
 366
 367 /* Boolean test for an already-known program space id.  */
 368
 369 static int
 370 valid_program_space_id (int num)
 371 {
 372   struct program_space *pspace;
 373
 374   ALL_PSPACES (pspace)
 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 /* Simply returns the count of program spaces.  */
 401
 402 int
 403 number_of_program_spaces (void)
 404 {
 405   struct program_space *pspace;
 406   int count = 0;
 407
 408   ALL_PSPACES (pspace)
 409     count++;
 410
 411   return count;
 412 }
 413
 414 /* Update all program spaces matching to address spaces.  The user may
 415    have created several program spaces, and loaded executables into
 416    them before connecting to the target interface that will create the
 417    inferiors.  All that happens before GDB has a chance to know if the
 418    inferiors will share an address space or not.  Call this after
 419    having connected to the target interface and having fetched the
 420    target description, to fixup the program/address spaces mappings.
 421
 422    It is assumed that there are no bound inferiors yet, otherwise,
 423    they'd be left with stale referenced to released aspaces.  */
 424
 425 void
 426 update_address_spaces (void)
 427 {
 428   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 429   struct program_space *pspace;
 430   struct inferior *inf;
 431
 432   init_address_spaces ();
 433
 434   if (shared_aspace)
 435     {
 436       struct address_space *aspace = new_address_space ();
 437
 438       free_address_space (current_program_space->aspace);
 439       ALL_PSPACES (pspace)
 440         pspace->aspace = aspace;
 441     }
 442   else
 443     ALL_PSPACES (pspace)
 444       {
 445         free_address_space (pspace->aspace);
 446         pspace->aspace = new_address_space ();
 447       }
 448
 449   for (inf = inferior_list; inf; inf = inf->next)
 450     if (gdbarch_has_global_solist (target_gdbarch ()))
 451       inf->aspace = maybe_new_address_space ();
 452     else
 453       inf->aspace = inf->pspace->aspace;
 454 }
 455
 456 \f
 457
 458 /* See progspace.h.  */
 459
 460 void
 461 clear_program_space_solib_cache (struct program_space *pspace)
 462 {
 463   pspace->added_solibs.clear ();
 464   pspace->deleted_solibs.clear ();
 465 }
 466
 467 \f
 468
 469 void
 470 initialize_progspace (void)
 471 {
 472   add_cmd ("program-spaces", class_maintenance,
 473            maintenance_info_program_spaces_command,
 474            _("Info about currently known program spaces."),
 475            &maintenanceinfolist);
 476
 477   /* There's always one program space.  Note that this function isn't
 478      an automatic _initialize_foo function, since other
 479      _initialize_foo routines may need to install their per-pspace
 480      data keys.  We can only allocate a progspace when all those
 481      modules have done that.  Do this before
 482      initialize_current_architecture, because that accesses exec_bfd,
 483      which in turn dereferences current_program_space.  */
 484   current_program_space = new program_space (new_address_space ());
 485 }