gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2015 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 "gdbthread.h"
  27
  28 /* The last program space number assigned.  */
  29 int last_program_space_num = 0;
  30
  31 /* The head of the program spaces list.  */
  32 struct program_space *program_spaces;
  33
  34 /* Pointer to the current program space.  */
  35 struct program_space *current_program_space;
  36
  37 /* The last address space number assigned.  */
  38 static int highest_address_space_num;
  39
  40 \f
  41
  42 /* Keep a registry of per-program_space data-pointers required by other GDB
  43    modules.  */
  44
  45 DEFINE_REGISTRY (program_space, REGISTRY_ACCESS_FIELD)
  46
  47 /* An address space.  It is used for comparing if pspaces/inferior/threads
  48    see the same address space and for associating caches to each address
  49    space.  */
  50
  51 struct address_space
  52 {
  53   int num;
  54
  55   /* Per aspace data-pointers required by other GDB modules.  */
  56   REGISTRY_FIELDS;
  57 };
  58
  59 /* Keep a registry of per-address_space data-pointers required by other GDB
  60    modules.  */
  61
  62 DEFINE_REGISTRY (address_space, REGISTRY_ACCESS_FIELD)
  63
  64 \f
  65
  66 /* Create a new address space object, and add it to the list.  */
  67
  68 struct address_space *
  69 new_address_space (void)
  70 {
  71   struct address_space *aspace;
  72
  73   aspace = XCNEW (struct address_space);
  74   aspace->num = ++highest_address_space_num;
  75   address_space_alloc_data (aspace);
  76
  77   return aspace;
  78 }
  79
  80 /* Maybe create a new address space object, and add it to the list, or
  81    return a pointer to an existing address space, in case inferiors
  82    share an address space on this target system.  */
  83
  84 struct address_space *
  85 maybe_new_address_space (void)
  86 {
  87   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
  88
  89   if (shared_aspace)
  90     {
  91       /* Just return the first in the list.  */
  92       return program_spaces->aspace;
  93     }
  94
  95   return new_address_space ();
  96 }
  97
  98 static void
  99 free_address_space (struct address_space *aspace)
 100 {
 101   address_space_free_data (aspace);
 102   xfree (aspace);
 103 }
 104
 105 int
 106 address_space_num (struct address_space *aspace)
 107 {
 108   return aspace->num;
 109 }
 110
 111 /* Start counting over from scratch.  */
 112
 113 static void
 114 init_address_spaces (void)
 115 {
 116   highest_address_space_num = 0;
 117 }
 118
 119 \f
 120
 121 /* Adds a new empty program space to the program space list, and binds
 122    it to ASPACE.  Returns the pointer to the new object.  */
 123
 124 struct program_space *
 125 add_program_space (struct address_space *aspace)
 126 {
 127   struct program_space *pspace;
 128
 129   pspace = XCNEW (struct program_space);
 130
 131   pspace->num = ++last_program_space_num;
 132   pspace->aspace = aspace;
 133
 134   program_space_alloc_data (pspace);
 135
 136   pspace->next = program_spaces;
 137   program_spaces = pspace;
 138
 139   return pspace;
 140 }
 141
 142 /* Releases program space PSPACE, and all its contents (shared
 143    libraries, objfiles, and any other references to the PSPACE in
 144    other modules).  It is an internal error to call this when PSPACE
 145    is the current program space, since there should always be a
 146    program space.  */
 147
 148 static void
 149 release_program_space (struct program_space *pspace)
 150 {
 151   struct cleanup *old_chain = save_current_program_space ();
 152
 153   gdb_assert (pspace != current_program_space);
 154
 155   set_current_program_space (pspace);
 156
 157   breakpoint_program_space_exit (pspace);
 158   no_shared_libraries (NULL, 0);
 159   exec_close ();
 160   free_all_objfiles ();
 161   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 162     free_address_space (pspace->aspace);
 163   clear_section_table (&pspace->target_sections);
 164   clear_program_space_solib_cache (pspace);
 165     /* Discard any data modules have associated with the PSPACE.  */
 166   program_space_free_data (pspace);
 167   xfree (pspace);
 168
 169   do_cleanups (old_chain);
 170 }
 171
 172 /* Copies program space SRC to DEST.  Copies the main executable file,
 173    and the main symbol file.  Returns DEST.  */
 174
 175 struct program_space *
 176 clone_program_space (struct program_space *dest, struct program_space *src)
 177 {
 178   struct cleanup *old_chain;
 179
 180   old_chain = save_current_program_space ();
 181
 182   set_current_program_space (dest);
 183
 184   if (src->pspace_exec_filename != NULL)
 185     exec_file_attach (src->pspace_exec_filename, 0);
 186
 187   if (src->symfile_object_file != NULL)
 188     symbol_file_add_main (objfile_name (src->symfile_object_file), 0);
 189
 190   do_cleanups (old_chain);
 191   return dest;
 192 }
 193
 194 /* Sets PSPACE as the current program space.  It is the caller's
 195    responsibility to make sure that the currently selected
 196    inferior/thread matches the selected program space.  */
 197
 198 void
 199 set_current_program_space (struct program_space *pspace)
 200 {
 201   if (current_program_space == pspace)
 202     return;
 203
 204   gdb_assert (pspace != NULL);
 205
 206   current_program_space = pspace;
 207
 208   /* Different symbols change our view of the frame chain.  */
 209   reinit_frame_cache ();
 210 }
 211
 212 /* A cleanups callback, helper for save_current_program_space
 213    below.  */
 214
 215 static void
 216 restore_program_space (void *arg)
 217 {
 218   struct program_space *saved_pspace = (struct program_space *) arg;
 219
 220   set_current_program_space (saved_pspace);
 221 }
 222
 223 /* Save the current program space so that it may be restored by a later
 224    call to do_cleanups.  Returns the struct cleanup pointer needed for
 225    later doing the cleanup.  */
 226
 227 struct cleanup *
 228 save_current_program_space (void)
 229 {
 230   struct cleanup *old_chain = make_cleanup (restore_program_space,
 231                                             current_program_space);
 232
 233   return old_chain;
 234 }
 235
 236 /* Returns true iff there's no inferior bound to PSPACE.  */
 237
 238 int
 239 program_space_empty_p (struct program_space *pspace)
 240 {
 241   if (find_inferior_for_program_space (pspace) != NULL)
 242       return 0;
 243
 244   return 1;
 245 }
 246
 247 /* Remove a program space from the program spaces list and release it.  It is
 248    an error to call this function while PSPACE is the current program space. */
 249
 250 void
 251 delete_program_space (struct program_space *pspace)
 252 {
 253   struct program_space *ss, **ss_link;
 254   gdb_assert (pspace != NULL);
 255   gdb_assert (pspace != current_program_space);
 256
 257   ss = program_spaces;
 258   ss_link = &program_spaces;
 259   while (ss != NULL)
 260     {
 261       if (ss == pspace)
 262         {
 263           *ss_link = ss->next;
 264           break;
 265         }
 266
 267       ss_link = &ss->next;
 268       ss = *ss_link;
 269     }
 270
 271   release_program_space (pspace);
 272 }
 273
 274 /* Prints the list of program spaces and their details on UIOUT.  If
 275    REQUESTED is not -1, it's the ID of the pspace that should be
 276    printed.  Otherwise, all spaces are printed.  */
 277
 278 static void
 279 print_program_space (struct ui_out *uiout, int requested)
 280 {
 281   struct program_space *pspace;
 282   int count = 0;
 283   struct cleanup *old_chain;
 284
 285   /* Compute number of pspaces we will print.  */
 286   ALL_PSPACES (pspace)
 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   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 3, count, "pspaces");
 298   ui_out_table_header (uiout, 1, ui_left, "current", "");
 299   ui_out_table_header (uiout, 4, ui_left, "id", "Id");
 300   ui_out_table_header (uiout, 17, ui_left, "exec", "Executable");
 301   ui_out_table_body (uiout);
 302
 303   ALL_PSPACES (pspace)
 304     {
 305       struct cleanup *chain2;
 306       struct inferior *inf;
 307       int printed_header;
 308
 309       if (requested != -1 && requested != pspace->num)
 310         continue;
 311
 312       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 313
 314       if (pspace == current_program_space)
 315         ui_out_field_string (uiout, "current", "*");
 316       else
 317         ui_out_field_skip (uiout, "current");
 318
 319       ui_out_field_int (uiout, "id", pspace->num);
 320
 321       if (pspace->pspace_exec_filename)
 322         ui_out_field_string (uiout, "exec", pspace->pspace_exec_filename);
 323       else
 324         ui_out_field_skip (uiout, "exec");
 325
 326       /* Print extra info that doesn't really fit in tabular form.
 327          Currently, we print the list of inferiors bound to a pspace.
 328          There can be more than one inferior bound to the same pspace,
 329          e.g., both parent/child inferiors in a vfork, or, on targets
 330          that share pspaces between inferiors.  */
 331       printed_header = 0;
 332       for (inf = inferior_list; inf; inf = inf->next)
 333         if (inf->pspace == pspace)
 334           {
 335             if (!printed_header)
 336               {
 337                 printed_header = 1;
 338                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 339                                  inf->num,
 340                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 341               }
 342             else
 343               printf_filtered (", ID %d (%s)",
 344                                inf->num,
 345                                target_pid_to_str (pid_to_ptid (inf->pid)));
 346           }
 347
 348       ui_out_text (uiout, "\n");
 349       do_cleanups (chain2);
 350     }
 351
 352   do_cleanups (old_chain);
 353 }
 354
 355 /* Boolean test for an already-known program space id.  */
 356
 357 static int
 358 valid_program_space_id (int num)
 359 {
 360   struct program_space *pspace;
 361
 362   ALL_PSPACES (pspace)
 363     if (pspace->num == num)
 364       return 1;
 365
 366   return 0;
 367 }
 368
 369 /* If ARGS is NULL or empty, print information about all program
 370    spaces.  Otherwise, ARGS is a text representation of a LONG
 371    indicating which the program space to print information about.  */
 372
 373 static void
 374 maintenance_info_program_spaces_command (char *args, int from_tty)
 375 {
 376   int requested = -1;
 377
 378   if (args && *args)
 379     {
 380       requested = parse_and_eval_long (args);
 381       if (!valid_program_space_id (requested))
 382         error (_("program space ID %d not known."), requested);
 383     }
 384
 385   print_program_space (current_uiout, requested);
 386 }
 387
 388 /* Simply returns the count of program spaces.  */
 389
 390 int
 391 number_of_program_spaces (void)
 392 {
 393   struct program_space *pspace;
 394   int count = 0;
 395
 396   ALL_PSPACES (pspace)
 397     count++;
 398
 399   return count;
 400 }
 401
 402 /* Update all program spaces matching to address spaces.  The user may
 403    have created several program spaces, and loaded executables into
 404    them before connecting to the target interface that will create the
 405    inferiors.  All that happens before GDB has a chance to know if the
 406    inferiors will share an address space or not.  Call this after
 407    having connected to the target interface and having fetched the
 408    target description, to fixup the program/address spaces mappings.
 409
 410    It is assumed that there are no bound inferiors yet, otherwise,
 411    they'd be left with stale referenced to released aspaces.  */
 412
 413 void
 414 update_address_spaces (void)
 415 {
 416   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 417   struct program_space *pspace;
 418   struct inferior *inf;
 419
 420   init_address_spaces ();
 421
 422   if (shared_aspace)
 423     {
 424       struct address_space *aspace = new_address_space ();
 425
 426       free_address_space (current_program_space->aspace);
 427       ALL_PSPACES (pspace)
 428         pspace->aspace = aspace;
 429     }
 430   else
 431     ALL_PSPACES (pspace)
 432       {
 433         free_address_space (pspace->aspace);
 434         pspace->aspace = new_address_space ();
 435       }
 436
 437   for (inf = inferior_list; inf; inf = inf->next)
 438     if (gdbarch_has_global_solist (target_gdbarch ()))
 439       inf->aspace = maybe_new_address_space ();
 440     else
 441       inf->aspace = inf->pspace->aspace;
 442 }
 443
 444 /* Save the current program space so that it may be restored by a later
 445    call to do_cleanups.  Returns the struct cleanup pointer needed for
 446    later doing the cleanup.  */
 447
 448 struct cleanup *
 449 save_current_space_and_thread (void)
 450 {
 451   struct cleanup *old_chain;
 452
 453   /* If restoring to null thread, we need to restore the pspace as
 454      well, hence, we need to save the current program space first.  */
 455   old_chain = save_current_program_space ();
 456   /* There's no need to save the current inferior here.
 457      That is handled by make_cleanup_restore_current_thread.  */
 458   make_cleanup_restore_current_thread ();
 459
 460   return old_chain;
 461 }
 462
 463 /* See progspace.h  */
 464
 465 void
 466 switch_to_program_space_and_thread (struct program_space *pspace)
 467 {
 468   struct inferior *inf;
 469
 470   inf = find_inferior_for_program_space (pspace);
 471   if (inf != NULL && inf->pid != 0)
 472     {
 473       struct thread_info *tp;
 474
 475       tp = any_live_thread_of_process (inf->pid);
 476       if (tp != NULL)
 477         {
 478           switch_to_thread (tp->ptid);
 479           /* Switching thread switches pspace implicitly.  We're
 480              done.  */
 481           return;
 482         }
 483     }
 484
 485   switch_to_thread (null_ptid);
 486   set_current_program_space (pspace);
 487 }
 488
 489 \f
 490
 491 /* See progspace.h.  */
 492
 493 void
 494 clear_program_space_solib_cache (struct program_space *pspace)
 495 {
 496   VEC_free (so_list_ptr, pspace->added_solibs);
 497
 498   free_char_ptr_vec (pspace->deleted_solibs);
 499   pspace->deleted_solibs = NULL;
 500 }
 501
 502 \f
 503
 504 void
 505 initialize_progspace (void)
 506 {
 507   add_cmd ("program-spaces", class_maintenance,
 508            maintenance_info_program_spaces_command,
 509            _("Info about currently known program spaces."),
 510            &maintenanceinfolist);
 511
 512   /* There's always one program space.  Note that this function isn't
 513      an automatic _initialize_foo function, since other
 514      _initialize_foo routines may need to install their per-pspace
 515      data keys.  We can only allocate a progspace when all those
 516      modules have done that.  Do this before
 517      initialize_current_architecture, because that accesses exec_bfd,
 518      which in turn dereferences current_program_space.  */
 519   current_program_space = add_program_space (new_address_space ());
 520 }