gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2021 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 static 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   free_all_objfiles ();
 151   /* Defer breakpoint re-set because we don't want to create new
 152      locations for this pspace which we're tearing down.  */
 153   clear_symtab_users (SYMFILE_DEFER_BP_RESET);
 154   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 155     free_address_space (this->aspace);
 156     /* Discard any data modules have associated with the PSPACE.  */
 157   program_space_free_data (this);
 158 }
 159
 160 /* See progspace.h.  */
 161
 162 void
 163 program_space::free_all_objfiles ()
 164 {
 165   /* Any objfile reference would become stale.  */
 166   for (struct so_list *so : current_program_space->solibs ())
 167     gdb_assert (so->objfile == NULL);
 168
 169   while (!objfiles_list.empty ())
 170     objfiles_list.front ()->unlink ();
 171 }
 172
 173 /* See progspace.h.  */
 174
 175 void
 176 program_space::add_objfile (std::shared_ptr<objfile> &&objfile,
 177                             struct objfile *before)
 178 {
 179   if (before == nullptr)
 180     objfiles_list.push_back (std::move (objfile));
 181   else
 182     {
 183       auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 184                                 [=] (const std::shared_ptr<::objfile> &objf)
 185                                 {
 186                                   return objf.get () == before;
 187                                 });
 188       gdb_assert (iter != objfiles_list.end ());
 189       objfiles_list.insert (iter, std::move (objfile));
 190     }
 191 }
 192
 193 /* See progspace.h.  */
 194
 195 void
 196 program_space::remove_objfile (struct objfile *objfile)
 197 {
 198   /* Removing an objfile from the objfile list invalidates any frame
 199      that was built using frame info found in the objfile.  Reinit the
 200      frame cache to get rid of any frame that might otherwise
 201      reference stale info.  */
 202   reinit_frame_cache ();
 203
 204   auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 205                             [=] (const std::shared_ptr<::objfile> &objf)
 206                             {
 207                               return objf.get () == objfile;
 208                             });
 209   gdb_assert (iter != objfiles_list.end ());
 210   objfiles_list.erase (iter);
 211
 212   if (objfile == symfile_object_file)
 213     symfile_object_file = NULL;
 214 }
 215
 216 /* See progspace.h.  */
 217
 218 void
 219 program_space::exec_close ()
 220 {
 221   if (ebfd != nullptr)
 222     {
 223       /* Removing target sections may close the exec_ops target.
 224          Clear ebfd before doing so to prevent recursion.  */
 225       ebfd.reset (nullptr);
 226       ebfd_mtime = 0;
 227
 228       remove_target_sections (&ebfd);
 229
 230       exec_filename.reset (nullptr);
 231     }
 232 }
 233
 234 /* Copies program space SRC to DEST.  Copies the main executable file,
 235    and the main symbol file.  Returns DEST.  */
 236
 237 struct program_space *
 238 clone_program_space (struct program_space *dest, struct program_space *src)
 239 {
 240   scoped_restore_current_program_space restore_pspace;
 241
 242   set_current_program_space (dest);
 243
 244   if (src->exec_filename != NULL)
 245     exec_file_attach (src->exec_filename.get (), 0);
 246
 247   if (src->symfile_object_file != NULL)
 248     symbol_file_add_main (objfile_name (src->symfile_object_file),
 249                           SYMFILE_DEFER_BP_RESET);
 250
 251   return dest;
 252 }
 253
 254 /* Sets PSPACE as the current program space.  It is the caller's
 255    responsibility to make sure that the currently selected
 256    inferior/thread matches the selected program space.  */
 257
 258 void
 259 set_current_program_space (struct program_space *pspace)
 260 {
 261   if (current_program_space == pspace)
 262     return;
 263
 264   gdb_assert (pspace != NULL);
 265
 266   current_program_space = pspace;
 267
 268   /* Different symbols change our view of the frame chain.  */
 269   reinit_frame_cache ();
 270 }
 271
 272 /* Returns true iff there's no inferior bound to PSPACE.  */
 273
 274 bool
 275 program_space::empty ()
 276 {
 277   return find_inferior_for_program_space (this) == nullptr;
 278 }
 279
 280 /* Prints the list of program spaces and their details on UIOUT.  If
 281    REQUESTED is not -1, it's the ID of the pspace that should be
 282    printed.  Otherwise, all spaces are printed.  */
 283
 284 static void
 285 print_program_space (struct ui_out *uiout, int requested)
 286 {
 287   int count = 0;
 288
 289   /* Compute number of pspaces we will print.  */
 290   for (struct program_space *pspace : program_spaces)
 291     {
 292       if (requested != -1 && pspace->num != requested)
 293         continue;
 294
 295       ++count;
 296     }
 297
 298   /* There should always be at least one.  */
 299   gdb_assert (count > 0);
 300
 301   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 302   uiout->table_header (1, ui_left, "current", "");
 303   uiout->table_header (4, ui_left, "id", "Id");
 304   uiout->table_header (17, ui_left, "exec", "Executable");
 305   uiout->table_body ();
 306
 307   for (struct program_space *pspace : program_spaces)
 308     {
 309       int printed_header;
 310
 311       if (requested != -1 && requested != pspace->num)
 312         continue;
 313
 314       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 315
 316       if (pspace == current_program_space)
 317         uiout->field_string ("current", "*");
 318       else
 319         uiout->field_skip ("current");
 320
 321       uiout->field_signed ("id", pspace->num);
 322
 323       if (pspace->exec_filename != nullptr)
 324         uiout->field_string ("exec", pspace->exec_filename.get ());
 325       else
 326         uiout->field_skip ("exec");
 327
 328       /* Print extra info that doesn't really fit in tabular form.
 329          Currently, we print the list of inferiors bound to a pspace.
 330          There can be more than one inferior bound to the same pspace,
 331          e.g., both parent/child inferiors in a vfork, or, on targets
 332          that share pspaces between inferiors.  */
 333       printed_header = 0;
 334
 335       /* We're going to switch inferiors.  */
 336       scoped_restore_current_thread restore_thread;
 337
 338       for (inferior *inf : all_inferiors ())
 339         if (inf->pspace == pspace)
 340           {
 341             /* Switch to inferior in order to call target methods.  */
 342             switch_to_inferior_no_thread (inf);
 343
 344             if (!printed_header)
 345               {
 346                 printed_header = 1;
 347                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 348                                  inf->num,
 349                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 350               }
 351             else
 352               printf_filtered (", ID %d (%s)",
 353                                inf->num,
 354                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 355           }
 356
 357       uiout->text ("\n");
 358     }
 359 }
 360
 361 /* Boolean test for an already-known program space id.  */
 362
 363 static int
 364 valid_program_space_id (int num)
 365 {
 366   for (struct program_space *pspace : program_spaces)
 367     if (pspace->num == num)
 368       return 1;
 369
 370   return 0;
 371 }
 372
 373 /* If ARGS is NULL or empty, print information about all program
 374    spaces.  Otherwise, ARGS is a text representation of a LONG
 375    indicating which the program space to print information about.  */
 376
 377 static void
 378 maintenance_info_program_spaces_command (const char *args, int from_tty)
 379 {
 380   int requested = -1;
 381
 382   if (args && *args)
 383     {
 384       requested = parse_and_eval_long (args);
 385       if (!valid_program_space_id (requested))
 386         error (_("program space ID %d not known."), requested);
 387     }
 388
 389   print_program_space (current_uiout, requested);
 390 }
 391
 392 /* Update all program spaces matching to address spaces.  The user may
 393    have created several program spaces, and loaded executables into
 394    them before connecting to the target interface that will create the
 395    inferiors.  All that happens before GDB has a chance to know if the
 396    inferiors will share an address space or not.  Call this after
 397    having connected to the target interface and having fetched the
 398    target description, to fixup the program/address spaces mappings.
 399
 400    It is assumed that there are no bound inferiors yet, otherwise,
 401    they'd be left with stale referenced to released aspaces.  */
 402
 403 void
 404 update_address_spaces (void)
 405 {
 406   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 407   struct inferior *inf;
 408
 409   init_address_spaces ();
 410
 411   if (shared_aspace)
 412     {
 413       struct address_space *aspace = new_address_space ();
 414
 415       free_address_space (current_program_space->aspace);
 416       for (struct program_space *pspace : program_spaces)
 417         pspace->aspace = aspace;
 418     }
 419   else
 420     for (struct program_space *pspace : program_spaces)
 421       {
 422         free_address_space (pspace->aspace);
 423         pspace->aspace = new_address_space ();
 424       }
 425
 426   for (inf = inferior_list; inf; inf = inf->next)
 427     if (gdbarch_has_global_solist (target_gdbarch ()))
 428       inf->aspace = maybe_new_address_space ();
 429     else
 430       inf->aspace = inf->pspace->aspace;
 431 }
 432
 433 \f
 434
 435 /* See progspace.h.  */
 436
 437 void
 438 program_space::clear_solib_cache ()
 439 {
 440   added_solibs.clear ();
 441   deleted_solibs.clear ();
 442 }
 443
 444 \f
 445
 446 void
 447 initialize_progspace (void)
 448 {
 449   add_cmd ("program-spaces", class_maintenance,
 450            maintenance_info_program_spaces_command,
 451            _("Info about currently known program spaces."),
 452            &maintenanceinfolist);
 453
 454   /* There's always one program space.  Note that this function isn't
 455      an automatic _initialize_foo function, since other
 456      _initialize_foo routines may need to install their per-pspace
 457      data keys.  We can only allocate a progspace when all those
 458      modules have done that.  Do this before
 459      initialize_current_architecture, because that accesses the ebfd
 460      of current_program_space.  */
 461   current_program_space = new program_space (new_address_space ());
 462 }