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 "gdbthread.h"
  27 #include "inferior.h"
  28
  29 /* The last program space number assigned.  */
  30 int last_program_space_num = 0;
  31
  32 /* The head of the program spaces list.  */
  33 struct program_space *program_spaces;
  34
  35 /* Pointer to the current program space.  */
  36 struct program_space *current_program_space;
  37
  38 /* The last address space number assigned.  */
  39 static int highest_address_space_num;
  40
  41 \f
  42
  43 /* Keep a registry of per-program_space data-pointers required by other GDB
  44    modules.  */
  45
  46 DEFINE_REGISTRY (program_space, REGISTRY_ACCESS_FIELD)
  47
  48 /* Keep a registry of per-address_space data-pointers required by other GDB
  49    modules.  */
  50
  51 DEFINE_REGISTRY (address_space, REGISTRY_ACCESS_FIELD)
  52
  53 \f
  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 = XCNEW (struct address_space);
  63   aspace->num = ++highest_address_space_num;
  64   address_space_alloc_data (aspace);
  65
  66   return aspace;
  67 }
  68
  69 /* Maybe create a new address space object, and add it to the list, or
  70    return a pointer to an existing address space, in case inferiors
  71    share an address space on this target system.  */
  72
  73 struct address_space *
  74 maybe_new_address_space (void)
  75 {
  76   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
  77
  78   if (shared_aspace)
  79     {
  80       /* Just return the first in the list.  */
  81       return program_spaces->aspace;
  82     }
  83
  84   return new_address_space ();
  85 }
  86
  87 static void
  88 free_address_space (struct address_space *aspace)
  89 {
  90   address_space_free_data (aspace);
  91   xfree (aspace);
  92 }
  93
  94 int
  95 address_space_num (struct address_space *aspace)
  96 {
  97   return aspace->num;
  98 }
  99
 100 /* Start counting over from scratch.  */
 101
 102 static void
 103 init_address_spaces (void)
 104 {
 105   highest_address_space_num = 0;
 106 }
 107
 108 \f
 109
 110 /* Adds a new empty program space to the program space list, and binds
 111    it to ASPACE.  Returns the pointer to the new object.  */
 112
 113 program_space::program_space (address_space *aspace_)
 114 : num (++last_program_space_num), aspace (aspace_)
 115 {
 116   program_space_alloc_data (this);
 117
 118   if (program_spaces == NULL)
 119     program_spaces = this;
 120   else
 121     {
 122       struct program_space *last;
 123
 124       for (last = program_spaces; last->next != NULL; last = last->next)
 125         ;
 126       last->next = this;
 127     }
 128 }
 129
 130 /* Releases program space PSPACE, and all its contents (shared
 131    libraries, objfiles, and any other references to the PSPACE in
 132    other modules).  It is an internal error to call this when PSPACE
 133    is the current program space, since there should always be a
 134    program space.  */
 135
 136 program_space::~program_space ()
 137 {
 138   gdb_assert (this != current_program_space);
 139
 140   scoped_restore_current_program_space restore_pspace;
 141
 142   set_current_program_space (this);
 143
 144   breakpoint_program_space_exit (this);
 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 (this->aspace);
 150   clear_section_table (&this->target_sections);
 151   clear_program_space_solib_cache (this);
 152     /* Discard any data modules have associated with the PSPACE.  */
 153   program_space_free_data (this);
 154 }
 155
 156 /* See progspace.h.  */
 157
 158 void
 159 program_space::add_objfile (struct objfile *objfile, struct objfile *before)
 160 {
 161   for (struct objfile **objp = &objfiles_head;
 162        *objp != NULL;
 163        objp = &((*objp)->next))
 164     {
 165       if (*objp == before)
 166         {
 167           objfile->next = *objp;
 168           *objp = objfile;
 169           return;
 170         }
 171     }
 172
 173   internal_error (__FILE__, __LINE__,
 174                   _("put_objfile_before: before objfile not in list"));
 175
 176 }
 177
 178 /* See progspace.h.  */
 179
 180 void
 181 program_space::remove_objfile (struct objfile *objfile)
 182 {
 183   struct objfile **objpp;
 184
 185   for (objpp = &object_files; *objpp != NULL; objpp = &((*objpp)->next))
 186     {
 187       if (*objpp == objfile)
 188         {
 189           *objpp = (*objpp)->next;
 190           objfile->next = NULL;
 191
 192           if (objfile == symfile_object_file)
 193             symfile_object_file = NULL;
 194
 195           return;
 196         }
 197     }
 198
 199   internal_error (__FILE__, __LINE__,
 200                   _("remove_objfile: objfile already unlinked"));
 201 }
 202
 203 /* See progspace.h.  */
 204
 205 bool
 206 program_space::multi_objfile_p () const
 207 {
 208   return objfiles_head != nullptr && objfiles_head->next != nullptr;
 209 }
 210
 211 /* Copies program space SRC to DEST.  Copies the main executable file,
 212    and the main symbol file.  Returns DEST.  */
 213
 214 struct program_space *
 215 clone_program_space (struct program_space *dest, struct program_space *src)
 216 {
 217   scoped_restore_current_program_space restore_pspace;
 218
 219   set_current_program_space (dest);
 220
 221   if (src->pspace_exec_filename != NULL)
 222     exec_file_attach (src->pspace_exec_filename, 0);
 223
 224   if (src->symfile_object_file != NULL)
 225     symbol_file_add_main (objfile_name (src->symfile_object_file),
 226                           SYMFILE_DEFER_BP_RESET);
 227
 228   return dest;
 229 }
 230
 231 /* Sets PSPACE as the current program space.  It is the caller's
 232    responsibility to make sure that the currently selected
 233    inferior/thread matches the selected program space.  */
 234
 235 void
 236 set_current_program_space (struct program_space *pspace)
 237 {
 238   if (current_program_space == pspace)
 239     return;
 240
 241   gdb_assert (pspace != NULL);
 242
 243   current_program_space = pspace;
 244
 245   /* Different symbols change our view of the frame chain.  */
 246   reinit_frame_cache ();
 247 }
 248
 249 /* Returns true iff there's no inferior bound to PSPACE.  */
 250
 251 int
 252 program_space_empty_p (struct program_space *pspace)
 253 {
 254   if (find_inferior_for_program_space (pspace) != NULL)
 255       return 0;
 256
 257   return 1;
 258 }
 259
 260 /* Remove a program space from the program spaces list and release it.  It is
 261    an error to call this function while PSPACE is the current program space. */
 262
 263 void
 264 delete_program_space (struct program_space *pspace)
 265 {
 266   struct program_space *ss, **ss_link;
 267   gdb_assert (pspace != NULL);
 268   gdb_assert (pspace != current_program_space);
 269
 270   ss = program_spaces;
 271   ss_link = &program_spaces;
 272   while (ss != NULL)
 273     {
 274       if (ss == pspace)
 275         {
 276           *ss_link = ss->next;
 277           break;
 278         }
 279
 280       ss_link = &ss->next;
 281       ss = *ss_link;
 282     }
 283
 284   delete pspace;
 285 }
 286
 287 /* Prints the list of program spaces and their details on UIOUT.  If
 288    REQUESTED is not -1, it's the ID of the pspace that should be
 289    printed.  Otherwise, all spaces are printed.  */
 290
 291 static void
 292 print_program_space (struct ui_out *uiout, int requested)
 293 {
 294   struct program_space *pspace;
 295   int count = 0;
 296
 297   /* Compute number of pspaces we will print.  */
 298   ALL_PSPACES (pspace)
 299     {
 300       if (requested != -1 && pspace->num != requested)
 301         continue;
 302
 303       ++count;
 304     }
 305
 306   /* There should always be at least one.  */
 307   gdb_assert (count > 0);
 308
 309   ui_out_emit_table table_emitter (uiout, 3, count, "pspaces");
 310   uiout->table_header (1, ui_left, "current", "");
 311   uiout->table_header (4, ui_left, "id", "Id");
 312   uiout->table_header (17, ui_left, "exec", "Executable");
 313   uiout->table_body ();
 314
 315   ALL_PSPACES (pspace)
 316     {
 317       struct inferior *inf;
 318       int printed_header;
 319
 320       if (requested != -1 && requested != pspace->num)
 321         continue;
 322
 323       ui_out_emit_tuple tuple_emitter (uiout, NULL);
 324
 325       if (pspace == current_program_space)
 326         uiout->field_string ("current", "*");
 327       else
 328         uiout->field_skip ("current");
 329
 330       uiout->field_signed ("id", pspace->num);
 331
 332       if (pspace->pspace_exec_filename)
 333         uiout->field_string ("exec", pspace->pspace_exec_filename);
 334       else
 335         uiout->field_skip ("exec");
 336
 337       /* Print extra info that doesn't really fit in tabular form.
 338          Currently, we print the list of inferiors bound to a pspace.
 339          There can be more than one inferior bound to the same pspace,
 340          e.g., both parent/child inferiors in a vfork, or, on targets
 341          that share pspaces between inferiors.  */
 342       printed_header = 0;
 343       for (inf = inferior_list; inf; inf = inf->next)
 344         if (inf->pspace == pspace)
 345           {
 346             if (!printed_header)
 347               {
 348                 printed_header = 1;
 349                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 350                                  inf->num,
 351                                  target_pid_to_str (ptid_t (inf->pid)).c_str ());
 352               }
 353             else
 354               printf_filtered (", ID %d (%s)",
 355                                inf->num,
 356                                target_pid_to_str (ptid_t (inf->pid)).c_str ());
 357           }
 358
 359       uiout->text ("\n");
 360     }
 361 }
 362
 363 /* Boolean test for an already-known program space id.  */
 364
 365 static int
 366 valid_program_space_id (int num)
 367 {
 368   struct program_space *pspace;
 369
 370   ALL_PSPACES (pspace)
 371     if (pspace->num == num)
 372       return 1;
 373
 374   return 0;
 375 }
 376
 377 /* If ARGS is NULL or empty, print information about all program
 378    spaces.  Otherwise, ARGS is a text representation of a LONG
 379    indicating which the program space to print information about.  */
 380
 381 static void
 382 maintenance_info_program_spaces_command (const char *args, int from_tty)
 383 {
 384   int requested = -1;
 385
 386   if (args && *args)
 387     {
 388       requested = parse_and_eval_long (args);
 389       if (!valid_program_space_id (requested))
 390         error (_("program space ID %d not known."), requested);
 391     }
 392
 393   print_program_space (current_uiout, requested);
 394 }
 395
 396 /* Simply returns the count of program spaces.  */
 397
 398 int
 399 number_of_program_spaces (void)
 400 {
 401   struct program_space *pspace;
 402   int count = 0;
 403
 404   ALL_PSPACES (pspace)
 405     count++;
 406
 407   return count;
 408 }
 409
 410 /* Update all program spaces matching to address spaces.  The user may
 411    have created several program spaces, and loaded executables into
 412    them before connecting to the target interface that will create the
 413    inferiors.  All that happens before GDB has a chance to know if the
 414    inferiors will share an address space or not.  Call this after
 415    having connected to the target interface and having fetched the
 416    target description, to fixup the program/address spaces mappings.
 417
 418    It is assumed that there are no bound inferiors yet, otherwise,
 419    they'd be left with stale referenced to released aspaces.  */
 420
 421 void
 422 update_address_spaces (void)
 423 {
 424   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 425   struct program_space *pspace;
 426   struct inferior *inf;
 427
 428   init_address_spaces ();
 429
 430   if (shared_aspace)
 431     {
 432       struct address_space *aspace = new_address_space ();
 433
 434       free_address_space (current_program_space->aspace);
 435       ALL_PSPACES (pspace)
 436         pspace->aspace = aspace;
 437     }
 438   else
 439     ALL_PSPACES (pspace)
 440       {
 441         free_address_space (pspace->aspace);
 442         pspace->aspace = new_address_space ();
 443       }
 444
 445   for (inf = inferior_list; inf; inf = inf->next)
 446     if (gdbarch_has_global_solist (target_gdbarch ()))
 447       inf->aspace = maybe_new_address_space ();
 448     else
 449       inf->aspace = inf->pspace->aspace;
 450 }
 451
 452 \f
 453
 454 /* See progspace.h.  */
 455
 456 void
 457 clear_program_space_solib_cache (struct program_space *pspace)
 458 {
 459   pspace->added_solibs.clear ();
 460   pspace->deleted_solibs.clear ();
 461 }
 462
 463 \f
 464
 465 void
 466 initialize_progspace (void)
 467 {
 468   add_cmd ("program-spaces", class_maintenance,
 469            maintenance_info_program_spaces_command,
 470            _("Info about currently known program spaces."),
 471            &maintenanceinfolist);
 472
 473   /* There's always one program space.  Note that this function isn't
 474      an automatic _initialize_foo function, since other
 475      _initialize_foo routines may need to install their per-pspace
 476      data keys.  We can only allocate a progspace when all those
 477      modules have done that.  Do this before
 478      initialize_current_architecture, because that accesses exec_bfd,
 479      which in turn dereferences current_program_space.  */
 480   current_program_space = new program_space (new_address_space ());
 481 }