gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2012 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 /* Prototypes for local functions */
  41
  42 static void program_space_alloc_data (struct program_space *);
  43 static void program_space_free_data (struct program_space *);
  44 \f
  45
  46 /* An address space.  Currently this is not used for much other than
  47    for comparing if pspaces/inferior/threads see the same address
  48    space.  */
  49
  50 struct address_space
  51 {
  52   int num;
  53 };
  54
  55 /* Create a new address space object, and add it to the list.  */
  56
  57 struct address_space *
  58 new_address_space (void)
  59 {
  60   struct address_space *aspace;
  61
  62   aspace = XZALLOC (struct address_space);
  63   aspace->num = ++highest_address_space_num;
  64
  65   return aspace;
  66 }
  67
  68 /* Maybe create a new address space object, and add it to the list, or
  69    return a pointer to an existing address space, in case inferiors
  70    share an address space on this target system.  */
  71
  72 struct address_space *
  73 maybe_new_address_space (void)
  74 {
  75   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch);
  76
  77   if (shared_aspace)
  78     {
  79       /* Just return the first in the list.  */
  80       return program_spaces->aspace;
  81     }
  82
  83   return new_address_space ();
  84 }
  85
  86 static void
  87 free_address_space (struct address_space *aspace)
  88 {
  89   xfree (aspace);
  90 }
  91
  92 int
  93 address_space_num (struct address_space *aspace)
  94 {
  95   return aspace->num;
  96 }
  97
  98 /* Start counting over from scratch.  */
  99
 100 static void
 101 init_address_spaces (void)
 102 {
 103   highest_address_space_num = 0;
 104 }
 105
 106 \f
 107
 108 /* Adds a new empty program space to the program space list, and binds
 109    it to ASPACE.  Returns the pointer to the new object.  */
 110
 111 struct program_space *
 112 add_program_space (struct address_space *aspace)
 113 {
 114   struct program_space *pspace;
 115
 116   pspace = XZALLOC (struct program_space);
 117
 118   pspace->num = ++last_program_space_num;
 119   pspace->aspace = aspace;
 120
 121   program_space_alloc_data (pspace);
 122
 123   pspace->next = program_spaces;
 124   program_spaces = pspace;
 125
 126   return pspace;
 127 }
 128
 129 /* Releases program space PSPACE, and all its contents (shared
 130    libraries, objfiles, and any other references to the PSPACE in
 131    other modules).  It is an internal error to call this when PSPACE
 132    is the current program space, since there should always be a
 133    program space.  */
 134
 135 static void
 136 release_program_space (struct program_space *pspace)
 137 {
 138   struct cleanup *old_chain = save_current_program_space ();
 139
 140   gdb_assert (pspace != current_program_space);
 141
 142   set_current_program_space (pspace);
 143
 144   breakpoint_program_space_exit (pspace);
 145   no_shared_libraries (NULL, 0);
 146   exec_close ();
 147   free_all_objfiles ();
 148   if (!gdbarch_has_shared_address_space (target_gdbarch))
 149     free_address_space (pspace->aspace);
 150   resize_section_table (&pspace->target_sections,
 151                         -resize_section_table (&pspace->target_sections, 0));
 152   clear_program_space_solib_cache (pspace);
 153     /* Discard any data modules have associated with the PSPACE.  */
 154   program_space_free_data (pspace);
 155   xfree (pspace);
 156
 157   do_cleanups (old_chain);
 158 }
 159
 160 /* Unlinks PSPACE from the pspace list, and releases it.  */
 161
 162 void
 163 remove_program_space (struct program_space *pspace)
 164 {
 165   struct program_space *ss, **ss_link;
 166
 167   ss = program_spaces;
 168   ss_link = &program_spaces;
 169   while (ss)
 170     {
 171       if (ss != pspace)
 172         {
 173           ss_link = &ss->next;
 174           ss = *ss_link;
 175           continue;
 176         }
 177
 178       *ss_link = ss->next;
 179       release_program_space (ss);
 180       ss = *ss_link;
 181     }
 182 }
 183
 184 /* Copies program space SRC to DEST.  Copies the main executable file,
 185    and the main symbol file.  Returns DEST.  */
 186
 187 struct program_space *
 188 clone_program_space (struct program_space *dest, struct program_space *src)
 189 {
 190   struct cleanup *old_chain;
 191
 192   old_chain = save_current_program_space ();
 193
 194   set_current_program_space (dest);
 195
 196   if (src->ebfd != NULL)
 197     exec_file_attach (bfd_get_filename (src->ebfd), 0);
 198
 199   if (src->symfile_object_file != NULL)
 200     symbol_file_add_main (src->symfile_object_file->name, 0);
 201
 202   do_cleanups (old_chain);
 203   return dest;
 204 }
 205
 206 /* Sets PSPACE as the current program space.  It is the caller's
 207    responsibility to make sure that the currently selected
 208    inferior/thread matches the selected program space.  */
 209
 210 void
 211 set_current_program_space (struct program_space *pspace)
 212 {
 213   if (current_program_space == pspace)
 214     return;
 215
 216   gdb_assert (pspace != NULL);
 217
 218   current_program_space = pspace;
 219
 220   /* Different symbols change our view of the frame chain.  */
 221   reinit_frame_cache ();
 222 }
 223
 224 /* A cleanups callback, helper for save_current_program_space
 225    below.  */
 226
 227 static void
 228 restore_program_space (void *arg)
 229 {
 230   struct program_space *saved_pspace = arg;
 231
 232   set_current_program_space (saved_pspace);
 233 }
 234
 235 /* Save the current program space so that it may be restored by a later
 236    call to do_cleanups.  Returns the struct cleanup pointer needed for
 237    later doing the cleanup.  */
 238
 239 struct cleanup *
 240 save_current_program_space (void)
 241 {
 242   struct cleanup *old_chain = make_cleanup (restore_program_space,
 243                                             current_program_space);
 244
 245   return old_chain;
 246 }
 247
 248 /* Returns true iff there's no inferior bound to PSPACE.  */
 249
 250 static int
 251 pspace_empty_p (struct program_space *pspace)
 252 {
 253   if (find_inferior_for_program_space (pspace) != NULL)
 254       return 0;
 255
 256   return 1;
 257 }
 258
 259 /* Prune away automatically added program spaces that aren't required
 260    anymore.  */
 261
 262 void
 263 prune_program_spaces (void)
 264 {
 265   struct program_space *ss, **ss_link;
 266   struct program_space *current = current_program_space;
 267
 268   ss = program_spaces;
 269   ss_link = &program_spaces;
 270   while (ss)
 271     {
 272       if (ss == current || !pspace_empty_p (ss))
 273         {
 274           ss_link = &ss->next;
 275           ss = *ss_link;
 276           continue;
 277         }
 278
 279       *ss_link = ss->next;
 280       release_program_space (ss);
 281       ss = *ss_link;
 282     }
 283 }
 284
 285 /* Prints the list of program spaces and their details on UIOUT.  If
 286    REQUESTED is not -1, it's the ID of the pspace that should be
 287    printed.  Otherwise, all spaces are printed.  */
 288
 289 static void
 290 print_program_space (struct ui_out *uiout, int requested)
 291 {
 292   struct program_space *pspace;
 293   int count = 0;
 294   struct cleanup *old_chain;
 295
 296   /* Might as well prune away unneeded ones, so the user doesn't even
 297      seem them.  */
 298   prune_program_spaces ();
 299
 300   /* Compute number of pspaces we will print.  */
 301   ALL_PSPACES (pspace)
 302     {
 303       if (requested != -1 && pspace->num != requested)
 304         continue;
 305
 306       ++count;
 307     }
 308
 309   /* There should always be at least one.  */
 310   gdb_assert (count > 0);
 311
 312   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 3, count, "pspaces");
 313   ui_out_table_header (uiout, 1, ui_left, "current", "");
 314   ui_out_table_header (uiout, 4, ui_left, "id", "Id");
 315   ui_out_table_header (uiout, 17, ui_left, "exec", "Executable");
 316   ui_out_table_body (uiout);
 317
 318   ALL_PSPACES (pspace)
 319     {
 320       struct cleanup *chain2;
 321       struct inferior *inf;
 322       int printed_header;
 323
 324       if (requested != -1 && requested != pspace->num)
 325         continue;
 326
 327       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 328
 329       if (pspace == current_program_space)
 330         ui_out_field_string (uiout, "current", "*");
 331       else
 332         ui_out_field_skip (uiout, "current");
 333
 334       ui_out_field_int (uiout, "id", pspace->num);
 335
 336       if (pspace->ebfd)
 337         ui_out_field_string (uiout, "exec",
 338                              bfd_get_filename (pspace->ebfd));
 339       else
 340         ui_out_field_skip (uiout, "exec");
 341
 342       /* Print extra info that doesn't really fit in tabular form.
 343          Currently, we print the list of inferiors bound to a pspace.
 344          There can be more than one inferior bound to the same pspace,
 345          e.g., both parent/child inferiors in a vfork, or, on targets
 346          that share pspaces between inferiors.  */
 347       printed_header = 0;
 348       for (inf = inferior_list; inf; inf = inf->next)
 349         if (inf->pspace == pspace)
 350           {
 351             if (!printed_header)
 352               {
 353                 printed_header = 1;
 354                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 355                                  inf->num,
 356                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 357               }
 358             else
 359               printf_filtered (", ID %d (%s)",
 360                                inf->num,
 361                                target_pid_to_str (pid_to_ptid (inf->pid)));
 362           }
 363
 364       ui_out_text (uiout, "\n");
 365       do_cleanups (chain2);
 366     }
 367
 368   do_cleanups (old_chain);
 369 }
 370
 371 /* Boolean test for an already-known program space id.  */
 372
 373 static int
 374 valid_program_space_id (int num)
 375 {
 376   struct program_space *pspace;
 377
 378   ALL_PSPACES (pspace)
 379     if (pspace->num == num)
 380       return 1;
 381
 382   return 0;
 383 }
 384
 385 /* If ARGS is NULL or empty, print information about all program
 386    spaces.  Otherwise, ARGS is a text representation of a LONG
 387    indicating which the program space to print information about.  */
 388
 389 static void
 390 maintenance_info_program_spaces_command (char *args, int from_tty)
 391 {
 392   int requested = -1;
 393
 394   if (args && *args)
 395     {
 396       requested = parse_and_eval_long (args);
 397       if (!valid_program_space_id (requested))
 398         error (_("program space ID %d not known."), requested);
 399     }
 400
 401   print_program_space (current_uiout, requested);
 402 }
 403
 404 /* Simply returns the count of program spaces.  */
 405
 406 int
 407 number_of_program_spaces (void)
 408 {
 409   struct program_space *pspace;
 410   int count = 0;
 411
 412   ALL_PSPACES (pspace)
 413     count++;
 414
 415   return count;
 416 }
 417
 418 /* Update all program spaces matching to address spaces.  The user may
 419    have created several program spaces, and loaded executables into
 420    them before connecting to the target interface that will create the
 421    inferiors.  All that happens before GDB has a chance to know if the
 422    inferiors will share an address space or not.  Call this after
 423    having connected to the target interface and having fetched the
 424    target description, to fixup the program/address spaces mappings.
 425
 426    It is assumed that there are no bound inferiors yet, otherwise,
 427    they'd be left with stale referenced to released aspaces.  */
 428
 429 void
 430 update_address_spaces (void)
 431 {
 432   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch);
 433   struct program_space *pspace;
 434   struct inferior *inf;
 435
 436   init_address_spaces ();
 437
 438   if (shared_aspace)
 439     {
 440       struct address_space *aspace = new_address_space ();
 441
 442       free_address_space (current_program_space->aspace);
 443       ALL_PSPACES (pspace)
 444         pspace->aspace = aspace;
 445     }
 446   else
 447     ALL_PSPACES (pspace)
 448       {
 449         free_address_space (pspace->aspace);
 450         pspace->aspace = new_address_space ();
 451       }
 452
 453   for (inf = inferior_list; inf; inf = inf->next)
 454     if (gdbarch_has_global_solist (target_gdbarch))
 455       inf->aspace = maybe_new_address_space ();
 456     else
 457       inf->aspace = inf->pspace->aspace;
 458 }
 459
 460 /* Save the current program space so that it may be restored by a later
 461    call to do_cleanups.  Returns the struct cleanup pointer needed for
 462    later doing the cleanup.  */
 463
 464 struct cleanup *
 465 save_current_space_and_thread (void)
 466 {
 467   struct cleanup *old_chain;
 468
 469   /* If restoring to null thread, we need to restore the pspace as
 470      well, hence, we need to save the current program space first.  */
 471   old_chain = save_current_program_space ();
 472   save_current_inferior ();
 473   make_cleanup_restore_current_thread ();
 474
 475   return old_chain;
 476 }
 477
 478 /* Switches full context to program space PSPACE.  Switches to the
 479    first thread found bound to PSPACE.  */
 480
 481 void
 482 switch_to_program_space_and_thread (struct program_space *pspace)
 483 {
 484   struct inferior *inf;
 485
 486   inf = find_inferior_for_program_space (pspace);
 487   if (inf != NULL)
 488     {
 489       struct thread_info *tp;
 490
 491       tp = any_live_thread_of_process (inf->pid);
 492       if (tp != NULL)
 493         {
 494           switch_to_thread (tp->ptid);
 495           /* Switching thread switches pspace implicitly.  We're
 496              done.  */
 497           return;
 498         }
 499     }
 500
 501   switch_to_thread (null_ptid);
 502   set_current_program_space (pspace);
 503 }
 504
 505 \f
 506
 507 /* See progspace.h.  */
 508
 509 void
 510 clear_program_space_solib_cache (struct program_space *pspace)
 511 {
 512   VEC_free (so_list_ptr, pspace->added_solibs);
 513
 514   free_char_ptr_vec (pspace->deleted_solibs);
 515   pspace->deleted_solibs = NULL;
 516 }
 517
 518 \f
 519
 520 /* Keep a registry of per-program_space data-pointers required by other GDB
 521    modules.  */
 522
 523 struct program_space_data
 524 {
 525   unsigned index;
 526   void (*cleanup) (struct program_space *, void *);
 527 };
 528
 529 struct program_space_data_registration
 530 {
 531   struct program_space_data *data;
 532   struct program_space_data_registration *next;
 533 };
 534
 535 struct program_space_data_registry
 536 {
 537   struct program_space_data_registration *registrations;
 538   unsigned num_registrations;
 539 };
 540
 541 static struct program_space_data_registry program_space_data_registry
 542   = { NULL, 0 };
 543
 544 const struct program_space_data *
 545 register_program_space_data_with_cleanup
 546   (void (*cleanup) (struct program_space *, void *))
 547 {
 548   struct program_space_data_registration **curr;
 549
 550   /* Append new registration.  */
 551   for (curr = &program_space_data_registry.registrations;
 552        *curr != NULL; curr = &(*curr)->next);
 553
 554   *curr = XMALLOC (struct program_space_data_registration);
 555   (*curr)->next = NULL;
 556   (*curr)->data = XMALLOC (struct program_space_data);
 557   (*curr)->data->index = program_space_data_registry.num_registrations++;
 558   (*curr)->data->cleanup = cleanup;
 559
 560   return (*curr)->data;
 561 }
 562
 563 const struct program_space_data *
 564 register_program_space_data (void)
 565 {
 566   return register_program_space_data_with_cleanup (NULL);
 567 }
 568
 569 static void
 570 program_space_alloc_data (struct program_space *pspace)
 571 {
 572   gdb_assert (pspace->data == NULL);
 573   pspace->num_data = program_space_data_registry.num_registrations;
 574   pspace->data = XCALLOC (pspace->num_data, void *);
 575 }
 576
 577 static void
 578 program_space_free_data (struct program_space *pspace)
 579 {
 580   gdb_assert (pspace->data != NULL);
 581   clear_program_space_data (pspace);
 582   xfree (pspace->data);
 583   pspace->data = NULL;
 584 }
 585
 586 void
 587 clear_program_space_data (struct program_space *pspace)
 588 {
 589   struct program_space_data_registration *registration;
 590   int i;
 591
 592   gdb_assert (pspace->data != NULL);
 593
 594   for (registration = program_space_data_registry.registrations, i = 0;
 595        i < pspace->num_data;
 596        registration = registration->next, i++)
 597     if (pspace->data[i] != NULL && registration->data->cleanup)
 598       registration->data->cleanup (pspace, pspace->data[i]);
 599
 600   memset (pspace->data, 0, pspace->num_data * sizeof (void *));
 601 }
 602
 603 void
 604 set_program_space_data (struct program_space *pspace,
 605                        const struct program_space_data *data,
 606                        void *value)
 607 {
 608   gdb_assert (data->index < pspace->num_data);
 609   pspace->data[data->index] = value;
 610 }
 611
 612 void *
 613 program_space_data (struct program_space *pspace,
 614                     const struct program_space_data *data)
 615 {
 616   gdb_assert (data->index < pspace->num_data);
 617   return pspace->data[data->index];
 618 }
 619
 620 \f
 621
 622 void
 623 initialize_progspace (void)
 624 {
 625   add_cmd ("program-spaces", class_maintenance,
 626            maintenance_info_program_spaces_command,
 627            _("Info about currently known program spaces."),
 628            &maintenanceinfolist);
 629
 630   /* There's always one program space.  Note that this function isn't
 631      an automatic _initialize_foo function, since other
 632      _initialize_foo routines may need to install their per-pspace
 633      data keys.  We can only allocate a progspace when all those
 634      modules have done that.  Do this before
 635      initialize_current_architecture, because that accesses exec_bfd,
 636      which in turn dereferences current_program_space.  */
 637   current_program_space = add_program_space (new_address_space ());
 638 }