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
 263   /* Compute number of pspaces we will print.  */
 264   ALL_PSPACES (pspace)
 265     {
 266       if (requested != -1 && pspace->num != requested)
 267         continue;
 268
 269       ++count;
 270     }
 271
 272   /* There should always be at least one.  */
 273   gdb_assert (count > 0);
 274
 275   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 276   uiout->table_header (1, ui_left, "current", "");
 277   uiout->table_header (4, ui_left, "id", "Id");
 278   uiout->table_header (17, ui_left, "exec", "Executable");
 279   uiout->table_body ();
 280
 281   ALL_PSPACES (pspace)
 282     {
 283       struct inferior *inf;
 284       int printed_header;
 285
 286       if (requested != -1 && requested != pspace->num)
 287         continue;
 288
 289       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 290
 291       if (pspace == current_program_space)
 292         uiout->field_string ("current", "*");
 293       else
 294         uiout->field_skip ("current");
 295
 296       uiout->field_int ("id", pspace->num);
 297
 298       if (pspace->pspace_exec_filename)
 299         uiout->field_string ("exec", pspace->pspace_exec_filename);
 300       else
 301         uiout->field_skip ("exec");
 302
 303       /* Print extra info that doesn't really fit in tabular form.
 304          Currently, we print the list of inferiors bound to a pspace.
 305          There can be more than one inferior bound to the same pspace,
 306          e.g., both parent/child inferiors in a vfork, or, on targets
 307          that share pspaces between inferiors.  */
 308       printed_header = 0;
 309       for (inf = inferior_list; inf; inf = inf->next)
 310         if (inf->pspace == pspace)
 311           {
 312             if (!printed_header)
 313               {
 314                 printed_header = 1;
 315                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 316                                  inf->num,
 317                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 318               }
 319             else
 320               printf_filtered (", ID %d (%s)",
 321                                inf->num,
 322                                target_pid_to_str (pid_to_ptid (inf->pid)));
 323           }
 324
 325       uiout->text ("\n");
 326     }
 327 }
 328
 329 /* Boolean test for an already-known program space id.  */
 330
 331 static int
 332 valid_program_space_id (int num)
 333 {
 334   struct program_space *pspace;
 335
 336   ALL_PSPACES (pspace)
 337     if (pspace->num == num)
 338       return 1;
 339
 340   return 0;
 341 }
 342
 343 /* If ARGS is NULL or empty, print information about all program
 344    spaces.  Otherwise, ARGS is a text representation of a LONG
 345    indicating which the program space to print information about.  */
 346
 347 static void
 348 maintenance_info_program_spaces_command (char *args, int from_tty)
 349 {
 350   int requested = -1;
 351
 352   if (args && *args)
 353     {
 354       requested = parse_and_eval_long (args);
 355       if (!valid_program_space_id (requested))
 356         error (_("program space ID %d not known."), requested);
 357     }
 358
 359   print_program_space (current_uiout, requested);
 360 }
 361
 362 /* Simply returns the count of program spaces.  */
 363
 364 int
 365 number_of_program_spaces (void)
 366 {
 367   struct program_space *pspace;
 368   int count = 0;
 369
 370   ALL_PSPACES (pspace)
 371     count++;
 372
 373   return count;
 374 }
 375
 376 /* Update all program spaces matching to address spaces.  The user may
 377    have created several program spaces, and loaded executables into
 378    them before connecting to the target interface that will create the
 379    inferiors.  All that happens before GDB has a chance to know if the
 380    inferiors will share an address space or not.  Call this after
 381    having connected to the target interface and having fetched the
 382    target description, to fixup the program/address spaces mappings.
 383
 384    It is assumed that there are no bound inferiors yet, otherwise,
 385    they'd be left with stale referenced to released aspaces.  */
 386
 387 void
 388 update_address_spaces (void)
 389 {
 390   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 391   struct program_space *pspace;
 392   struct inferior *inf;
 393
 394   init_address_spaces ();
 395
 396   if (shared_aspace)
 397     {
 398       struct address_space *aspace = new_address_space ();
 399
 400       free_address_space (current_program_space->aspace);
 401       ALL_PSPACES (pspace)
 402         pspace->aspace = aspace;
 403     }
 404   else
 405     ALL_PSPACES (pspace)
 406       {
 407         free_address_space (pspace->aspace);
 408         pspace->aspace = new_address_space ();
 409       }
 410
 411   for (inf = inferior_list; inf; inf = inf->next)
 412     if (gdbarch_has_global_solist (target_gdbarch ()))
 413       inf->aspace = maybe_new_address_space ();
 414     else
 415       inf->aspace = inf->pspace->aspace;
 416 }
 417
 418 \f
 419
 420 /* See progspace.h.  */
 421
 422 void
 423 clear_program_space_solib_cache (struct program_space *pspace)
 424 {
 425   VEC_free (so_list_ptr, pspace->added_solibs);
 426
 427   free_char_ptr_vec (pspace->deleted_solibs);
 428   pspace->deleted_solibs = NULL;
 429 }
 430
 431 \f
 432
 433 void
 434 initialize_progspace (void)
 435 {
 436   add_cmd ("program-spaces", class_maintenance,
 437            maintenance_info_program_spaces_command,
 438            _("Info about currently known program spaces."),
 439            &maintenanceinfolist);
 440
 441   /* There's always one program space.  Note that this function isn't
 442      an automatic _initialize_foo function, since other
 443      _initialize_foo routines may need to install their per-pspace
 444      data keys.  We can only allocate a progspace when all those
 445      modules have done that.  Do this before
 446      initialize_current_architecture, because that accesses exec_bfd,
 447      which in turn dereferences current_program_space.  */
 448   current_program_space = add_program_space (new_address_space ());
 449 }