gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2019 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 /* Adds a new empty program space to the program space list, and binds
 113    it to ASPACE.  Returns the pointer to the new object.  */
 114
 115 program_space::program_space (address_space *aspace_)
 116 : num (++last_program_space_num), aspace (aspace_)
 117 {
 118   program_space_alloc_data (this);
 119
 120   if (program_spaces == NULL)
 121     program_spaces = this;
 122   else
 123     {
 124       struct program_space *last;
 125
 126       for (last = program_spaces; last->next != NULL; last = last->next)
 127         ;
 128       last->next = this;
 129     }
 130 }
 131
 132 /* Releases program space PSPACE, and all its contents (shared
 133    libraries, objfiles, and any other references to the PSPACE in
 134    other modules).  It is an internal error to call this when PSPACE
 135    is the current program space, since there should always be a
 136    program space.  */
 137
 138 program_space::~program_space ()
 139 {
 140   gdb_assert (this != current_program_space);
 141
 142   scoped_restore_current_program_space restore_pspace;
 143
 144   set_current_program_space (this);
 145
 146   breakpoint_program_space_exit (this);
 147   no_shared_libraries (NULL, 0);
 148   exec_close ();
 149   free_all_objfiles ();
 150   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 151     free_address_space (this->aspace);
 152   clear_section_table (&this->target_sections);
 153   clear_program_space_solib_cache (this);
 154     /* Discard any data modules have associated with the PSPACE.  */
 155   program_space_free_data (this);
 156 }
 157
 158 /* See progspace.h.  */
 159
 160 void
 161 program_space::free_all_objfiles ()
 162 {
 163   struct so_list *so;
 164
 165   /* Any objfile reference would become stale.  */
 166   for (so = master_so_list (); so; so = so->next)
 167     gdb_assert (so->objfile == NULL);
 168
 169   while (!objfiles_list.empty ())
 170     objfiles_list.front ()->unlink ();
 171
 172   clear_symtab_users (0);
 173 }
 174
 175 /* See progspace.h.  */
 176
 177 void
 178 program_space::add_objfile (std::shared_ptr<objfile> &&objfile,
 179                             struct objfile *before)
 180 {
 181   if (before == nullptr)
 182     objfiles_list.push_back (std::move (objfile));
 183   else
 184     {
 185       auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 186                                 [=] (const std::shared_ptr<::objfile> &objf)
 187                                 {
 188                                   return objf.get () == before;
 189                                 });
 190       gdb_assert (iter != objfiles_list.end ());
 191       objfiles_list.insert (iter, std::move (objfile));
 192     }
 193 }
 194
 195 /* See progspace.h.  */
 196
 197 void
 198 program_space::remove_objfile (struct objfile *objfile)
 199 {
 200   auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 201                             [=] (const std::shared_ptr<::objfile> &objf)
 202                             {
 203                               return objf.get () == objfile;
 204                             });
 205   gdb_assert (iter != objfiles_list.end ());
 206   objfiles_list.erase (iter);
 207
 208   if (objfile == symfile_object_file)
 209     symfile_object_file = NULL;
 210 }
 211
 212 /* Copies program space SRC to DEST.  Copies the main executable file,
 213    and the main symbol file.  Returns DEST.  */
 214
 215 struct program_space *
 216 clone_program_space (struct program_space *dest, struct program_space *src)
 217 {
 218   scoped_restore_current_program_space restore_pspace;
 219
 220   set_current_program_space (dest);
 221
 222   if (src->pspace_exec_filename != NULL)
 223     exec_file_attach (src->pspace_exec_filename, 0);
 224
 225   if (src->symfile_object_file != NULL)
 226     symbol_file_add_main (objfile_name (src->symfile_object_file),
 227                           SYMFILE_DEFER_BP_RESET);
 228
 229   return dest;
 230 }
 231
 232 /* Sets PSPACE as the current program space.  It is the caller's
 233    responsibility to make sure that the currently selected
 234    inferior/thread matches the selected program space.  */
 235
 236 void
 237 set_current_program_space (struct program_space *pspace)
 238 {
 239   if (current_program_space == pspace)
 240     return;
 241
 242   gdb_assert (pspace != NULL);
 243
 244   current_program_space = pspace;
 245
 246   /* Different symbols change our view of the frame chain.  */
 247   reinit_frame_cache ();
 248 }
 249
 250 /* Returns true iff there's no inferior bound to PSPACE.  */
 251
 252 int
 253 program_space_empty_p (struct program_space *pspace)
 254 {
 255   if (find_inferior_for_program_space (pspace) != NULL)
 256       return 0;
 257
 258   return 1;
 259 }
 260
 261 /* Remove a program space from the program spaces list and release it.  It is
 262    an error to call this function while PSPACE is the current program space. */
 263
 264 void
 265 delete_program_space (struct program_space *pspace)
 266 {
 267   struct program_space *ss, **ss_link;
 268   gdb_assert (pspace != NULL);
 269   gdb_assert (pspace != current_program_space);
 270
 271   ss = program_spaces;
 272   ss_link = &program_spaces;
 273   while (ss != NULL)
 274     {
 275       if (ss == pspace)
 276         {
 277           *ss_link = ss->next;
 278           break;
 279         }
 280
 281       ss_link = &ss->next;
 282       ss = *ss_link;
 283     }
 284
 285   delete pspace;
 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   struct program_space *pspace;
 296   int count = 0;
 297
 298   /* Compute number of pspaces we will print.  */
 299   ALL_PSPACES (pspace)
 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   ALL_PSPACES (pspace)
 317     {
 318       struct inferior *inf;
 319       int printed_header;
 320
 321       if (requested != -1 && requested != pspace->num)
 322         continue;
 323
 324       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 325
 326       if (pspace == current_program_space)
 327         uiout->field_string ("current", "*");
 328       else
 329         uiout->field_skip ("current");
 330
 331       uiout->field_signed ("id", pspace->num);
 332
 333       if (pspace->pspace_exec_filename)
 334         uiout->field_string ("exec", pspace->pspace_exec_filename);
 335       else
 336         uiout->field_skip ("exec");
 337
 338       /* Print extra info that doesn't really fit in tabular form.
 339          Currently, we print the list of inferiors bound to a pspace.
 340          There can be more than one inferior bound to the same pspace,
 341          e.g., both parent/child inferiors in a vfork, or, on targets
 342          that share pspaces between inferiors.  */
 343       printed_header = 0;
 344       for (inf = inferior_list; inf; inf = inf->next)
 345         if (inf->pspace == pspace)
 346           {
 347             if (!printed_header)
 348               {
 349                 printed_header = 1;
 350                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 351                                  inf->num,
 352                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 353               }
 354             else
 355               printf_filtered (", ID %d (%s)",
 356                                inf->num,
 357                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 358           }
 359
 360       uiout->text ("\n");
 361     }
 362 }
 363
 364 /* Boolean test for an already-known program space id.  */
 365
 366 static int
 367 valid_program_space_id (int num)
 368 {
 369   struct program_space *pspace;
 370
 371   ALL_PSPACES (pspace)
 372     if (pspace->num == num)
 373       return 1;
 374
 375   return 0;
 376 }
 377
 378 /* If ARGS is NULL or empty, print information about all program
 379    spaces.  Otherwise, ARGS is a text representation of a LONG
 380    indicating which the program space to print information about.  */
 381
 382 static void
 383 maintenance_info_program_spaces_command (const char *args, int from_tty)
 384 {
 385   int requested = -1;
 386
 387   if (args && *args)
 388     {
 389       requested = parse_and_eval_long (args);
 390       if (!valid_program_space_id (requested))
 391         error (_("program space ID %d not known."), requested);
 392     }
 393
 394   print_program_space (current_uiout, requested);
 395 }
 396
 397 /* Simply returns the count of program spaces.  */
 398
 399 int
 400 number_of_program_spaces (void)
 401 {
 402   struct program_space *pspace;
 403   int count = 0;
 404
 405   ALL_PSPACES (pspace)
 406     count++;
 407
 408   return count;
 409 }
 410
 411 /* Update all program spaces matching to address spaces.  The user may
 412    have created several program spaces, and loaded executables into
 413    them before connecting to the target interface that will create the
 414    inferiors.  All that happens before GDB has a chance to know if the
 415    inferiors will share an address space or not.  Call this after
 416    having connected to the target interface and having fetched the
 417    target description, to fixup the program/address spaces mappings.
 418
 419    It is assumed that there are no bound inferiors yet, otherwise,
 420    they'd be left with stale referenced to released aspaces.  */
 421
 422 void
 423 update_address_spaces (void)
 424 {
 425   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 426   struct program_space *pspace;
 427   struct inferior *inf;
 428
 429   init_address_spaces ();
 430
 431   if (shared_aspace)
 432     {
 433       struct address_space *aspace = new_address_space ();
 434
 435       free_address_space (current_program_space->aspace);
 436       ALL_PSPACES (pspace)
 437         pspace->aspace = aspace;
 438     }
 439   else
 440     ALL_PSPACES (pspace)
 441       {
 442         free_address_space (pspace->aspace);
 443         pspace->aspace = new_address_space ();
 444       }
 445
 446   for (inf = inferior_list; inf; inf = inf->next)
 447     if (gdbarch_has_global_solist (target_gdbarch ()))
 448       inf->aspace = maybe_new_address_space ();
 449     else
 450       inf->aspace = inf->pspace->aspace;
 451 }
 452
 453 \f
 454
 455 /* See progspace.h.  */
 456
 457 void
 458 clear_program_space_solib_cache (struct program_space *pspace)
 459 {
 460   pspace->added_solibs.clear ();
 461   pspace->deleted_solibs.clear ();
 462 }
 463
 464 \f
 465
 466 void
 467 initialize_progspace (void)
 468 {
 469   add_cmd ("program-spaces", class_maintenance,
 470            maintenance_info_program_spaces_command,
 471            _("Info about currently known program spaces."),
 472            &maintenanceinfolist);
 473
 474   /* There's always one program space.  Note that this function isn't
 475      an automatic _initialize_foo function, since other
 476      _initialize_foo routines may need to install their per-pspace
 477      data keys.  We can only allocate a progspace when all those
 478      modules have done that.  Do this before
 479      initialize_current_architecture, because that accesses exec_bfd,
 480      which in turn dereferences current_program_space.  */
 481   current_program_space = new program_space (new_address_space ());
 482 }