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   /* Removing an objfile from the objfile list invalidates any frame
 202      that was built using frame info found in the objfile.  Reinit the
 203      frame cache to get rid of any frame that might otherwise
 204      reference stale info.  */
 205   reinit_frame_cache ();
 206
 207   auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 208                             [=] (const std::shared_ptr<::objfile> &objf)
 209                             {
 210                               return objf.get () == objfile;
 211                             });
 212   gdb_assert (iter != objfiles_list.end ());
 213   objfiles_list.erase (iter);
 214
 215   if (objfile == symfile_object_file)
 216     symfile_object_file = NULL;
 217 }
 218
 219 /* See progspace.h.  */
 220
 221 next_adapter<struct so_list>
 222 program_space::solibs () const
 223 {
 224   return next_adapter<struct so_list> (this->so_list);
 225 }
 226
 227 /* Copies program space SRC to DEST.  Copies the main executable file,
 228    and the main symbol file.  Returns DEST.  */
 229
 230 struct program_space *
 231 clone_program_space (struct program_space *dest, struct program_space *src)
 232 {
 233   scoped_restore_current_program_space restore_pspace;
 234
 235   set_current_program_space (dest);
 236
 237   if (src->pspace_exec_filename != NULL)
 238     exec_file_attach (src->pspace_exec_filename, 0);
 239
 240   if (src->symfile_object_file != NULL)
 241     symbol_file_add_main (objfile_name (src->symfile_object_file),
 242                           SYMFILE_DEFER_BP_RESET);
 243
 244   return dest;
 245 }
 246
 247 /* Sets PSPACE as the current program space.  It is the caller's
 248    responsibility to make sure that the currently selected
 249    inferior/thread matches the selected program space.  */
 250
 251 void
 252 set_current_program_space (struct program_space *pspace)
 253 {
 254   if (current_program_space == pspace)
 255     return;
 256
 257   gdb_assert (pspace != NULL);
 258
 259   current_program_space = pspace;
 260
 261   /* Different symbols change our view of the frame chain.  */
 262   reinit_frame_cache ();
 263 }
 264
 265 /* Returns true iff there's no inferior bound to PSPACE.  */
 266
 267 int
 268 program_space_empty_p (struct program_space *pspace)
 269 {
 270   if (find_inferior_for_program_space (pspace) != NULL)
 271       return 0;
 272
 273   return 1;
 274 }
 275
 276 /* Prints the list of program spaces and their details on UIOUT.  If
 277    REQUESTED is not -1, it's the ID of the pspace that should be
 278    printed.  Otherwise, all spaces are printed.  */
 279
 280 static void
 281 print_program_space (struct ui_out *uiout, int requested)
 282 {
 283   int count = 0;
 284
 285   /* Compute number of pspaces we will print.  */
 286   for (struct program_space *pspace : program_spaces)
 287     {
 288       if (requested != -1 && pspace->num != requested)
 289         continue;
 290
 291       ++count;
 292     }
 293
 294   /* There should always be at least one.  */
 295   gdb_assert (count > 0);
 296
 297   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 298   uiout->table_header (1, ui_left, "current", "");
 299   uiout->table_header (4, ui_left, "id", "Id");
 300   uiout->table_header (17, ui_left, "exec", "Executable");
 301   uiout->table_body ();
 302
 303   for (struct program_space *pspace : program_spaces)
 304     {
 305       struct inferior *inf;
 306       int printed_header;
 307
 308       if (requested != -1 && requested != pspace->num)
 309         continue;
 310
 311       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 312
 313       if (pspace == current_program_space)
 314         uiout->field_string ("current", "*");
 315       else
 316         uiout->field_skip ("current");
 317
 318       uiout->field_signed ("id", pspace->num);
 319
 320       if (pspace->pspace_exec_filename)
 321         uiout->field_string ("exec", pspace->pspace_exec_filename);
 322       else
 323         uiout->field_skip ("exec");
 324
 325       /* Print extra info that doesn't really fit in tabular form.
 326          Currently, we print the list of inferiors bound to a pspace.
 327          There can be more than one inferior bound to the same pspace,
 328          e.g., both parent/child inferiors in a vfork, or, on targets
 329          that share pspaces between inferiors.  */
 330       printed_header = 0;
 331       for (inf = inferior_list; inf; inf = inf->next)
 332         if (inf->pspace == pspace)
 333           {
 334             if (!printed_header)
 335               {
 336                 printed_header = 1;
 337                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 338                                  inf->num,
 339                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 340               }
 341             else
 342               printf_filtered (", ID %d (%s)",
 343                                inf->num,
 344                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 345           }
 346
 347       uiout->text ("\n");
 348     }
 349 }
 350
 351 /* Boolean test for an already-known program space id.  */
 352
 353 static int
 354 valid_program_space_id (int num)
 355 {
 356   for (struct program_space *pspace : program_spaces)
 357     if (pspace->num == num)
 358       return 1;
 359
 360   return 0;
 361 }
 362
 363 /* If ARGS is NULL or empty, print information about all program
 364    spaces.  Otherwise, ARGS is a text representation of a LONG
 365    indicating which the program space to print information about.  */
 366
 367 static void
 368 maintenance_info_program_spaces_command (const char *args, int from_tty)
 369 {
 370   int requested = -1;
 371
 372   if (args && *args)
 373     {
 374       requested = parse_and_eval_long (args);
 375       if (!valid_program_space_id (requested))
 376         error (_("program space ID %d not known."), requested);
 377     }
 378
 379   print_program_space (current_uiout, requested);
 380 }
 381
 382 /* Update all program spaces matching to address spaces.  The user may
 383    have created several program spaces, and loaded executables into
 384    them before connecting to the target interface that will create the
 385    inferiors.  All that happens before GDB has a chance to know if the
 386    inferiors will share an address space or not.  Call this after
 387    having connected to the target interface and having fetched the
 388    target description, to fixup the program/address spaces mappings.
 389
 390    It is assumed that there are no bound inferiors yet, otherwise,
 391    they'd be left with stale referenced to released aspaces.  */
 392
 393 void
 394 update_address_spaces (void)
 395 {
 396   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 397   struct inferior *inf;
 398
 399   init_address_spaces ();
 400
 401   if (shared_aspace)
 402     {
 403       struct address_space *aspace = new_address_space ();
 404
 405       free_address_space (current_program_space->aspace);
 406       for (struct program_space *pspace : program_spaces)
 407         pspace->aspace = aspace;
 408     }
 409   else
 410     for (struct program_space *pspace : program_spaces)
 411       {
 412         free_address_space (pspace->aspace);
 413         pspace->aspace = new_address_space ();
 414       }
 415
 416   for (inf = inferior_list; inf; inf = inf->next)
 417     if (gdbarch_has_global_solist (target_gdbarch ()))
 418       inf->aspace = maybe_new_address_space ();
 419     else
 420       inf->aspace = inf->pspace->aspace;
 421 }
 422
 423 \f
 424
 425 /* See progspace.h.  */
 426
 427 void
 428 clear_program_space_solib_cache (struct program_space *pspace)
 429 {
 430   pspace->added_solibs.clear ();
 431   pspace->deleted_solibs.clear ();
 432 }
 433
 434 \f
 435
 436 void
 437 initialize_progspace (void)
 438 {
 439   add_cmd ("program-spaces", class_maintenance,
 440            maintenance_info_program_spaces_command,
 441            _("Info about currently known program spaces."),
 442            &maintenanceinfolist);
 443
 444   /* There's always one program space.  Note that this function isn't
 445      an automatic _initialize_foo function, since other
 446      _initialize_foo routines may need to install their per-pspace
 447      data keys.  We can only allocate a progspace when all those
 448      modules have done that.  Do this before
 449      initialize_current_architecture, because that accesses exec_bfd,
 450      which in turn dereferences current_program_space.  */
 451   current_program_space = new program_space (new_address_space ());
 452 }