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