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 (struct objfile *objfile, struct objfile *before)
 179 {
 180   if (before == nullptr)
 181     objfiles_list.push_back (objfile);
 182   else
 183     {
 184       auto iter = std::find (objfiles_list.begin (), objfiles_list.end (),
 185                              before);
 186       gdb_assert (iter != objfiles_list.end ());
 187       objfiles_list.insert (iter, objfile);
 188     }
 189 }
 190
 191 /* See progspace.h.  */
 192
 193 void
 194 program_space::remove_objfile (struct objfile *objfile)
 195 {
 196   auto iter = std::find (objfiles_list.begin (), objfiles_list.end (),
 197                          objfile);
 198   gdb_assert (iter != objfiles_list.end ());
 199   objfiles_list.erase (iter);
 200
 201   if (objfile == symfile_object_file)
 202     symfile_object_file = NULL;
 203 }
 204
 205 /* Copies program space SRC to DEST.  Copies the main executable file,
 206    and the main symbol file.  Returns DEST.  */
 207
 208 struct program_space *
 209 clone_program_space (struct program_space *dest, struct program_space *src)
 210 {
 211   scoped_restore_current_program_space restore_pspace;
 212
 213   set_current_program_space (dest);
 214
 215   if (src->pspace_exec_filename != NULL)
 216     exec_file_attach (src->pspace_exec_filename, 0);
 217
 218   if (src->symfile_object_file != NULL)
 219     symbol_file_add_main (objfile_name (src->symfile_object_file),
 220                           SYMFILE_DEFER_BP_RESET);
 221
 222   return dest;
 223 }
 224
 225 /* Sets PSPACE as the current program space.  It is the caller's
 226    responsibility to make sure that the currently selected
 227    inferior/thread matches the selected program space.  */
 228
 229 void
 230 set_current_program_space (struct program_space *pspace)
 231 {
 232   if (current_program_space == pspace)
 233     return;
 234
 235   gdb_assert (pspace != NULL);
 236
 237   current_program_space = pspace;
 238
 239   /* Different symbols change our view of the frame chain.  */
 240   reinit_frame_cache ();
 241 }
 242
 243 /* Returns true iff there's no inferior bound to PSPACE.  */
 244
 245 int
 246 program_space_empty_p (struct program_space *pspace)
 247 {
 248   if (find_inferior_for_program_space (pspace) != NULL)
 249       return 0;
 250
 251   return 1;
 252 }
 253
 254 /* Remove a program space from the program spaces list and release it.  It is
 255    an error to call this function while PSPACE is the current program space. */
 256
 257 void
 258 delete_program_space (struct program_space *pspace)
 259 {
 260   struct program_space *ss, **ss_link;
 261   gdb_assert (pspace != NULL);
 262   gdb_assert (pspace != current_program_space);
 263
 264   ss = program_spaces;
 265   ss_link = &program_spaces;
 266   while (ss != NULL)
 267     {
 268       if (ss == pspace)
 269         {
 270           *ss_link = ss->next;
 271           break;
 272         }
 273
 274       ss_link = &ss->next;
 275       ss = *ss_link;
 276     }
 277
 278   delete pspace;
 279 }
 280
 281 /* Prints the list of program spaces and their details on UIOUT.  If
 282    REQUESTED is not -1, it's the ID of the pspace that should be
 283    printed.  Otherwise, all spaces are printed.  */
 284
 285 static void
 286 print_program_space (struct ui_out *uiout, int requested)
 287 {
 288   struct program_space *pspace;
 289   int count = 0;
 290
 291   /* Compute number of pspaces we will print.  */
 292   ALL_PSPACES (pspace)
 293     {
 294       if (requested != -1 && pspace->num != requested)
 295         continue;
 296
 297       ++count;
 298     }
 299
 300   /* There should always be at least one.  */
 301   gdb_assert (count > 0);
 302
 303   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 304   uiout->table_header (1, ui_left, "current", "");
 305   uiout->table_header (4, ui_left, "id", "Id");
 306   uiout->table_header (17, ui_left, "exec", "Executable");
 307   uiout->table_body ();
 308
 309   ALL_PSPACES (pspace)
 310     {
 311       struct inferior *inf;
 312       int printed_header;
 313
 314       if (requested != -1 && requested != pspace->num)
 315         continue;
 316
 317       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 318
 319       if (pspace == current_program_space)
 320         uiout->field_string ("current", "*");
 321       else
 322         uiout->field_skip ("current");
 323
 324       uiout->field_signed ("id", pspace->num);
 325
 326       if (pspace->pspace_exec_filename)
 327         uiout->field_string ("exec", pspace->pspace_exec_filename);
 328       else
 329         uiout->field_skip ("exec");
 330
 331       /* Print extra info that doesn't really fit in tabular form.
 332          Currently, we print the list of inferiors bound to a pspace.
 333          There can be more than one inferior bound to the same pspace,
 334          e.g., both parent/child inferiors in a vfork, or, on targets
 335          that share pspaces between inferiors.  */
 336       printed_header = 0;
 337       for (inf = inferior_list; inf; inf = inf->next)
 338         if (inf->pspace == pspace)
 339           {
 340             if (!printed_header)
 341               {
 342                 printed_header = 1;
 343                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 344                                  inf->num,
 345                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 346               }
 347             else
 348               printf_filtered (", ID %d (%s)",
 349                                inf->num,
 350                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 351           }
 352
 353       uiout->text ("\n");
 354     }
 355 }
 356
 357 /* Boolean test for an already-known program space id.  */
 358
 359 static int
 360 valid_program_space_id (int num)
 361 {
 362   struct program_space *pspace;
 363
 364   ALL_PSPACES (pspace)
 365     if (pspace->num == num)
 366       return 1;
 367
 368   return 0;
 369 }
 370
 371 /* If ARGS is NULL or empty, print information about all program
 372    spaces.  Otherwise, ARGS is a text representation of a LONG
 373    indicating which the program space to print information about.  */
 374
 375 static void
 376 maintenance_info_program_spaces_command (const char *args, int from_tty)
 377 {
 378   int requested = -1;
 379
 380   if (args && *args)
 381     {
 382       requested = parse_and_eval_long (args);
 383       if (!valid_program_space_id (requested))
 384         error (_("program space ID %d not known."), requested);
 385     }
 386
 387   print_program_space (current_uiout, requested);
 388 }
 389
 390 /* Simply returns the count of program spaces.  */
 391
 392 int
 393 number_of_program_spaces (void)
 394 {
 395   struct program_space *pspace;
 396   int count = 0;
 397
 398   ALL_PSPACES (pspace)
 399     count++;
 400
 401   return count;
 402 }
 403
 404 /* Update all program spaces matching to address spaces.  The user may
 405    have created several program spaces, and loaded executables into
 406    them before connecting to the target interface that will create the
 407    inferiors.  All that happens before GDB has a chance to know if the
 408    inferiors will share an address space or not.  Call this after
 409    having connected to the target interface and having fetched the
 410    target description, to fixup the program/address spaces mappings.
 411
 412    It is assumed that there are no bound inferiors yet, otherwise,
 413    they'd be left with stale referenced to released aspaces.  */
 414
 415 void
 416 update_address_spaces (void)
 417 {
 418   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 419   struct program_space *pspace;
 420   struct inferior *inf;
 421
 422   init_address_spaces ();
 423
 424   if (shared_aspace)
 425     {
 426       struct address_space *aspace = new_address_space ();
 427
 428       free_address_space (current_program_space->aspace);
 429       ALL_PSPACES (pspace)
 430         pspace->aspace = aspace;
 431     }
 432   else
 433     ALL_PSPACES (pspace)
 434       {
 435         free_address_space (pspace->aspace);
 436         pspace->aspace = new_address_space ();
 437       }
 438
 439   for (inf = inferior_list; inf; inf = inf->next)
 440     if (gdbarch_has_global_solist (target_gdbarch ()))
 441       inf->aspace = maybe_new_address_space ();
 442     else
 443       inf->aspace = inf->pspace->aspace;
 444 }
 445
 446 \f
 447
 448 /* See progspace.h.  */
 449
 450 void
 451 clear_program_space_solib_cache (struct program_space *pspace)
 452 {
 453   pspace->added_solibs.clear ();
 454   pspace->deleted_solibs.clear ();
 455 }
 456
 457 \f
 458
 459 void
 460 initialize_progspace (void)
 461 {
 462   add_cmd ("program-spaces", class_maintenance,
 463            maintenance_info_program_spaces_command,
 464            _("Info about currently known program spaces."),
 465            &maintenanceinfolist);
 466
 467   /* There's always one program space.  Note that this function isn't
 468      an automatic _initialize_foo function, since other
 469      _initialize_foo routines may need to install their per-pspace
 470      data keys.  We can only allocate a progspace when all those
 471      modules have done that.  Do this before
 472      initialize_current_architecture, because that accesses exec_bfd,
 473      which in turn dereferences current_program_space.  */
 474   current_program_space = new program_space (new_address_space ());
 475 }