gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2017 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   if (program_spaces == NULL)
 137     program_spaces = pspace;
 138   else
 139     {
 140       struct program_space *last;
 141
 142       for (last = program_spaces; last->next != NULL; last = last->next)
 143         ;
 144       last->next = pspace;
 145     }
 146
 147   return pspace;
 148 }
 149
 150 /* Releases program space PSPACE, and all its contents (shared
 151    libraries, objfiles, and any other references to the PSPACE in
 152    other modules).  It is an internal error to call this when PSPACE
 153    is the current program space, since there should always be a
 154    program space.  */
 155
 156 static void
 157 release_program_space (struct program_space *pspace)
 158 {
 159   gdb_assert (pspace != current_program_space);
 160
 161   scoped_restore_current_program_space restore_pspace;
 162
 163   set_current_program_space (pspace);
 164
 165   breakpoint_program_space_exit (pspace);
 166   no_shared_libraries (NULL, 0);
 167   exec_close ();
 168   free_all_objfiles ();
 169   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 170     free_address_space (pspace->aspace);
 171   clear_section_table (&pspace->target_sections);
 172   clear_program_space_solib_cache (pspace);
 173     /* Discard any data modules have associated with the PSPACE.  */
 174   program_space_free_data (pspace);
 175   xfree (pspace);
 176 }
 177
 178 /* Copies program space SRC to DEST.  Copies the main executable file,
 179    and the main symbol file.  Returns DEST.  */
 180
 181 struct program_space *
 182 clone_program_space (struct program_space *dest, struct program_space *src)
 183 {
 184   scoped_restore_current_program_space restore_pspace;
 185
 186   set_current_program_space (dest);
 187
 188   if (src->pspace_exec_filename != NULL)
 189     exec_file_attach (src->pspace_exec_filename, 0);
 190
 191   if (src->symfile_object_file != NULL)
 192     symbol_file_add_main (objfile_name (src->symfile_object_file), 0);
 193
 194   return dest;
 195 }
 196
 197 /* Sets PSPACE as the current program space.  It is the caller's
 198    responsibility to make sure that the currently selected
 199    inferior/thread matches the selected program space.  */
 200
 201 void
 202 set_current_program_space (struct program_space *pspace)
 203 {
 204   if (current_program_space == pspace)
 205     return;
 206
 207   gdb_assert (pspace != NULL);
 208
 209   current_program_space = pspace;
 210
 211   /* Different symbols change our view of the frame chain.  */
 212   reinit_frame_cache ();
 213 }
 214
 215 /* Returns true iff there's no inferior bound to PSPACE.  */
 216
 217 int
 218 program_space_empty_p (struct program_space *pspace)
 219 {
 220   if (find_inferior_for_program_space (pspace) != NULL)
 221       return 0;
 222
 223   return 1;
 224 }
 225
 226 /* Remove a program space from the program spaces list and release it.  It is
 227    an error to call this function while PSPACE is the current program space. */
 228
 229 void
 230 delete_program_space (struct program_space *pspace)
 231 {
 232   struct program_space *ss, **ss_link;
 233   gdb_assert (pspace != NULL);
 234   gdb_assert (pspace != current_program_space);
 235
 236   ss = program_spaces;
 237   ss_link = &program_spaces;
 238   while (ss != NULL)
 239     {
 240       if (ss == pspace)
 241         {
 242           *ss_link = ss->next;
 243           break;
 244         }
 245
 246       ss_link = &ss->next;
 247       ss = *ss_link;
 248     }
 249
 250   release_program_space (pspace);
 251 }
 252
 253 /* Prints the list of program spaces and their details on UIOUT.  If
 254    REQUESTED is not -1, it's the ID of the pspace that should be
 255    printed.  Otherwise, all spaces are printed.  */
 256
 257 static void
 258 print_program_space (struct ui_out *uiout, int requested)
 259 {
 260   struct program_space *pspace;
 261   int count = 0;
 262   struct cleanup *old_chain;
 263
 264   /* Compute number of pspaces we will print.  */
 265   ALL_PSPACES (pspace)
 266     {
 267       if (requested != -1 && pspace->num != requested)
 268         continue;
 269
 270       ++count;
 271     }
 272
 273   /* There should always be at least one.  */
 274   gdb_assert (count > 0);
 275
 276   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 3, count, "pspaces");
 277   uiout->table_header (1, ui_left, "current", "");
 278   uiout->table_header (4, ui_left, "id", "Id");
 279   uiout->table_header (17, ui_left, "exec", "Executable");
 280   uiout->table_body ();
 281
 282   ALL_PSPACES (pspace)
 283     {
 284       struct inferior *inf;
 285       int printed_header;
 286
 287       if (requested != -1 && requested != pspace->num)
 288         continue;
 289
 290       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 291
 292       if (pspace == current_program_space)
 293         uiout->field_string ("current", "*");
 294       else
 295         uiout->field_skip ("current");
 296
 297       uiout->field_int ("id", pspace->num);
 298
 299       if (pspace->pspace_exec_filename)
 300         uiout->field_string ("exec", pspace->pspace_exec_filename);
 301       else
 302         uiout->field_skip ("exec");
 303
 304       /* Print extra info that doesn't really fit in tabular form.
 305          Currently, we print the list of inferiors bound to a pspace.
 306          There can be more than one inferior bound to the same pspace,
 307          e.g., both parent/child inferiors in a vfork, or, on targets
 308          that share pspaces between inferiors.  */
 309       printed_header = 0;
 310       for (inf = inferior_list; inf; inf = inf->next)
 311         if (inf->pspace == pspace)
 312           {
 313             if (!printed_header)
 314               {
 315                 printed_header = 1;
 316                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 317                                  inf->num,
 318                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 319               }
 320             else
 321               printf_filtered (", ID %d (%s)",
 322                                inf->num,
 323                                target_pid_to_str (pid_to_ptid (inf->pid)));
 324           }
 325
 326       uiout->text ("\n");
 327     }
 328
 329   do_cleanups (old_chain);
 330 }
 331
 332 /* Boolean test for an already-known program space id.  */
 333
 334 static int
 335 valid_program_space_id (int num)
 336 {
 337   struct program_space *pspace;
 338
 339   ALL_PSPACES (pspace)
 340     if (pspace->num == num)
 341       return 1;
 342
 343   return 0;
 344 }
 345
 346 /* If ARGS is NULL or empty, print information about all program
 347    spaces.  Otherwise, ARGS is a text representation of a LONG
 348    indicating which the program space to print information about.  */
 349
 350 static void
 351 maintenance_info_program_spaces_command (char *args, int from_tty)
 352 {
 353   int requested = -1;
 354
 355   if (args && *args)
 356     {
 357       requested = parse_and_eval_long (args);
 358       if (!valid_program_space_id (requested))
 359         error (_("program space ID %d not known."), requested);
 360     }
 361
 362   print_program_space (current_uiout, requested);
 363 }
 364
 365 /* Simply returns the count of program spaces.  */
 366
 367 int
 368 number_of_program_spaces (void)
 369 {
 370   struct program_space *pspace;
 371   int count = 0;
 372
 373   ALL_PSPACES (pspace)
 374     count++;
 375
 376   return count;
 377 }
 378
 379 /* Update all program spaces matching to address spaces.  The user may
 380    have created several program spaces, and loaded executables into
 381    them before connecting to the target interface that will create the
 382    inferiors.  All that happens before GDB has a chance to know if the
 383    inferiors will share an address space or not.  Call this after
 384    having connected to the target interface and having fetched the
 385    target description, to fixup the program/address spaces mappings.
 386
 387    It is assumed that there are no bound inferiors yet, otherwise,
 388    they'd be left with stale referenced to released aspaces.  */
 389
 390 void
 391 update_address_spaces (void)
 392 {
 393   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 394   struct program_space *pspace;
 395   struct inferior *inf;
 396
 397   init_address_spaces ();
 398
 399   if (shared_aspace)
 400     {
 401       struct address_space *aspace = new_address_space ();
 402
 403       free_address_space (current_program_space->aspace);
 404       ALL_PSPACES (pspace)
 405         pspace->aspace = aspace;
 406     }
 407   else
 408     ALL_PSPACES (pspace)
 409       {
 410         free_address_space (pspace->aspace);
 411         pspace->aspace = new_address_space ();
 412       }
 413
 414   for (inf = inferior_list; inf; inf = inf->next)
 415     if (gdbarch_has_global_solist (target_gdbarch ()))
 416       inf->aspace = maybe_new_address_space ();
 417     else
 418       inf->aspace = inf->pspace->aspace;
 419 }
 420
 421 \f
 422
 423 /* See progspace.h.  */
 424
 425 void
 426 clear_program_space_solib_cache (struct program_space *pspace)
 427 {
 428   VEC_free (so_list_ptr, pspace->added_solibs);
 429
 430   free_char_ptr_vec (pspace->deleted_solibs);
 431   pspace->deleted_solibs = NULL;
 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 = add_program_space (new_address_space ());
 452 }