gdb/symfile-debug.c

   1 /* Debug logging for the symbol file functions for the GNU debugger, GDB.
   2
   3    Copyright (C) 2013-2019 Free Software Foundation, Inc.
   4
   5    Contributed by Cygnus Support, using pieces from other GDB modules.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 /* Note: Be careful with functions that can throw errors.
  23    We want to see a logging message regardless of whether an error was thrown.
  24    This typically means printing a message before calling the real function
  25    and then if the function returns a result printing a message after it
  26    returns.  */
  27
  28 #include "defs.h"
  29 #include "gdbcmd.h"
  30 #include "objfiles.h"
  31 #include "observable.h"
  32 #include "source.h"
  33 #include "symtab.h"
  34 #include "symfile.h"
  35
  36 /* We need to save a pointer to the real symbol functions.
  37    Plus, the debug versions are malloc'd because we have to NULL out the
  38    ones that are NULL in the real copy.  */
  39
  40 struct debug_sym_fns_data
  41 {
  42   const struct sym_fns *real_sf = nullptr;
  43   struct sym_fns debug_sf {};
  44 };
  45
  46 /* We need to record a pointer to the real set of functions for each
  47    objfile.  */
  48 static const struct objfile_key<debug_sym_fns_data>
  49   symfile_debug_objfile_data_key;
  50
  51 /* If true all calls to the symfile functions are logged.  */
  52 static bool debug_symfile = false;
  53
  54 /* Return non-zero if symfile debug logging is installed.  */
  55
  56 static int
  57 symfile_debug_installed (struct objfile *objfile)
  58 {
  59   return (objfile->sf != NULL
  60           && symfile_debug_objfile_data_key.get (objfile) != NULL);
  61 }
  62
  63 /* Utility return the name to print for SYMTAB.  */
  64
  65 static const char *
  66 debug_symtab_name (struct symtab *symtab)
  67 {
  68   return symtab_to_filename_for_display (symtab);
  69 }
  70 \f
  71 /* Debugging version of struct quick_symbol_functions.  */
  72
  73 static int
  74 debug_qf_has_symbols (struct objfile *objfile)
  75 {
  76   const struct debug_sym_fns_data *debug_data
  77     = symfile_debug_objfile_data_key.get (objfile);
  78   int retval;
  79
  80   retval = debug_data->real_sf->qf->has_symbols (objfile);
  81
  82   fprintf_filtered (gdb_stdlog, "qf->has_symbols (%s) = %d\n",
  83                     objfile_debug_name (objfile), retval);
  84
  85   return retval;
  86 }
  87
  88 static struct symtab *
  89 debug_qf_find_last_source_symtab (struct objfile *objfile)
  90 {
  91   const struct debug_sym_fns_data *debug_data
  92     = symfile_debug_objfile_data_key.get (objfile);
  93   struct symtab *retval;
  94
  95   fprintf_filtered (gdb_stdlog, "qf->find_last_source_symtab (%s)\n",
  96                     objfile_debug_name (objfile));
  97
  98   retval = debug_data->real_sf->qf->find_last_source_symtab (objfile);
  99
 100   fprintf_filtered (gdb_stdlog, "qf->find_last_source_symtab (...) = %s\n",
 101                     retval ? debug_symtab_name (retval) : "NULL");
 102
 103   return retval;
 104 }
 105
 106 static void
 107 debug_qf_forget_cached_source_info (struct objfile *objfile)
 108 {
 109   const struct debug_sym_fns_data *debug_data
 110     = symfile_debug_objfile_data_key.get (objfile);
 111
 112   fprintf_filtered (gdb_stdlog, "qf->forget_cached_source_info (%s)\n",
 113                     objfile_debug_name (objfile));
 114
 115   debug_data->real_sf->qf->forget_cached_source_info (objfile);
 116 }
 117
 118 static bool
 119 debug_qf_map_symtabs_matching_filename
 120   (struct objfile *objfile, const char *name, const char *real_path,
 121    gdb::function_view<bool (symtab *)> callback)
 122 {
 123   const struct debug_sym_fns_data *debug_data
 124     = symfile_debug_objfile_data_key.get (objfile);
 125
 126   fprintf_filtered (gdb_stdlog,
 127                     "qf->map_symtabs_matching_filename (%s, \"%s\", \"%s\", %s)\n",
 128                     objfile_debug_name (objfile), name,
 129                     real_path ? real_path : NULL,
 130                     host_address_to_string (&callback));
 131
 132   bool retval = (debug_data->real_sf->qf->map_symtabs_matching_filename
 133                  (objfile, name, real_path, callback));
 134
 135   fprintf_filtered (gdb_stdlog,
 136                     "qf->map_symtabs_matching_filename (...) = %d\n",
 137                     retval);
 138
 139   return retval;
 140 }
 141
 142 static struct compunit_symtab *
 143 debug_qf_lookup_symbol (struct objfile *objfile, block_enum kind,
 144                         const char *name, domain_enum domain)
 145 {
 146   const struct debug_sym_fns_data *debug_data
 147     = symfile_debug_objfile_data_key.get (objfile);
 148   struct compunit_symtab *retval;
 149
 150   fprintf_filtered (gdb_stdlog,
 151                     "qf->lookup_symbol (%s, %d, \"%s\", %s)\n",
 152                     objfile_debug_name (objfile), kind, name,
 153                     domain_name (domain));
 154
 155   retval = debug_data->real_sf->qf->lookup_symbol (objfile, kind, name,
 156                                                    domain);
 157
 158   fprintf_filtered (gdb_stdlog, "qf->lookup_symbol (...) = %s\n",
 159                     retval
 160                     ? debug_symtab_name (compunit_primary_filetab (retval))
 161                     : "NULL");
 162
 163   return retval;
 164 }
 165
 166 static void
 167 debug_qf_print_stats (struct objfile *objfile)
 168 {
 169   const struct debug_sym_fns_data *debug_data
 170     = symfile_debug_objfile_data_key.get (objfile);
 171
 172   fprintf_filtered (gdb_stdlog, "qf->print_stats (%s)\n",
 173                     objfile_debug_name (objfile));
 174
 175   debug_data->real_sf->qf->print_stats (objfile);
 176 }
 177
 178 static void
 179 debug_qf_dump (struct objfile *objfile)
 180 {
 181   const struct debug_sym_fns_data *debug_data
 182     = symfile_debug_objfile_data_key.get (objfile);
 183
 184   fprintf_filtered (gdb_stdlog, "qf->dump (%s)\n",
 185                     objfile_debug_name (objfile));
 186
 187   debug_data->real_sf->qf->dump (objfile);
 188 }
 189
 190 static void
 191 debug_qf_expand_symtabs_for_function (struct objfile *objfile,
 192                                       const char *func_name)
 193 {
 194   const struct debug_sym_fns_data *debug_data
 195     = symfile_debug_objfile_data_key.get (objfile);
 196
 197   fprintf_filtered (gdb_stdlog,
 198                     "qf->expand_symtabs_for_function (%s, \"%s\")\n",
 199                     objfile_debug_name (objfile), func_name);
 200
 201   debug_data->real_sf->qf->expand_symtabs_for_function (objfile, func_name);
 202 }
 203
 204 static void
 205 debug_qf_expand_all_symtabs (struct objfile *objfile)
 206 {
 207   const struct debug_sym_fns_data *debug_data
 208     = symfile_debug_objfile_data_key.get (objfile);
 209
 210   fprintf_filtered (gdb_stdlog, "qf->expand_all_symtabs (%s)\n",
 211                     objfile_debug_name (objfile));
 212
 213   debug_data->real_sf->qf->expand_all_symtabs (objfile);
 214 }
 215
 216 static void
 217 debug_qf_expand_symtabs_with_fullname (struct objfile *objfile,
 218                                        const char *fullname)
 219 {
 220   const struct debug_sym_fns_data *debug_data
 221     = symfile_debug_objfile_data_key.get (objfile);
 222
 223   fprintf_filtered (gdb_stdlog,
 224                     "qf->expand_symtabs_with_fullname (%s, \"%s\")\n",
 225                     objfile_debug_name (objfile), fullname);
 226
 227   debug_data->real_sf->qf->expand_symtabs_with_fullname (objfile, fullname);
 228 }
 229
 230 static void
 231 debug_qf_map_matching_symbols
 232   (struct objfile *objfile,
 233    const lookup_name_info &name, domain_enum domain,
 234    int global,
 235    gdb::function_view<symbol_found_callback_ftype> callback,
 236    symbol_compare_ftype *ordered_compare)
 237 {
 238   const struct debug_sym_fns_data *debug_data
 239     = symfile_debug_objfile_data_key.get (objfile);
 240
 241   fprintf_filtered (gdb_stdlog,
 242                     "qf->map_matching_symbols (%s, %s, %d, %s)\n",
 243                     objfile_debug_name (objfile),
 244                     domain_name (domain), global,
 245                     host_address_to_string (ordered_compare));
 246
 247   debug_data->real_sf->qf->map_matching_symbols (objfile, name,
 248                                                  domain, global,
 249                                                  callback,
 250                                                  ordered_compare);
 251 }
 252
 253 static void
 254 debug_qf_expand_symtabs_matching
 255   (struct objfile *objfile,
 256    gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher,
 257    const lookup_name_info &lookup_name,
 258    gdb::function_view<expand_symtabs_symbol_matcher_ftype> symbol_matcher,
 259    gdb::function_view<expand_symtabs_exp_notify_ftype> expansion_notify,
 260    enum search_domain kind)
 261 {
 262   const struct debug_sym_fns_data *debug_data
 263     = symfile_debug_objfile_data_key.get (objfile);
 264
 265   fprintf_filtered (gdb_stdlog,
 266                     "qf->expand_symtabs_matching (%s, %s, %s, %s, %s)\n",
 267                     objfile_debug_name (objfile),
 268                     host_address_to_string (&file_matcher),
 269                     host_address_to_string (&symbol_matcher),
 270                     host_address_to_string (&expansion_notify),
 271                     search_domain_name (kind));
 272
 273   debug_data->real_sf->qf->expand_symtabs_matching (objfile,
 274                                                     file_matcher,
 275                                                     lookup_name,
 276                                                     symbol_matcher,
 277                                                     expansion_notify,
 278                                                     kind);
 279 }
 280
 281 static struct compunit_symtab *
 282 debug_qf_find_pc_sect_compunit_symtab (struct objfile *objfile,
 283                                        struct bound_minimal_symbol msymbol,
 284                                        CORE_ADDR pc,
 285                                        struct obj_section *section,
 286                                        int warn_if_readin)
 287 {
 288   const struct debug_sym_fns_data *debug_data
 289     = symfile_debug_objfile_data_key.get (objfile);
 290   struct compunit_symtab *retval;
 291
 292   fprintf_filtered (gdb_stdlog,
 293                     "qf->find_pc_sect_compunit_symtab (%s, %s, %s, %s, %d)\n",
 294                     objfile_debug_name (objfile),
 295                     host_address_to_string (msymbol.minsym),
 296                     hex_string (pc),
 297                     host_address_to_string (section),
 298                     warn_if_readin);
 299
 300   retval
 301     = debug_data->real_sf->qf->find_pc_sect_compunit_symtab (objfile, msymbol,
 302                                                              pc, section,
 303                                                              warn_if_readin);
 304
 305   fprintf_filtered (gdb_stdlog,
 306                     "qf->find_pc_sect_compunit_symtab (...) = %s\n",
 307                     retval
 308                     ? debug_symtab_name (compunit_primary_filetab (retval))
 309                     : "NULL");
 310
 311   return retval;
 312 }
 313
 314 static void
 315 debug_qf_map_symbol_filenames (struct objfile *objfile,
 316                                symbol_filename_ftype *fun, void *data,
 317                                int need_fullname)
 318 {
 319   const struct debug_sym_fns_data *debug_data
 320     = symfile_debug_objfile_data_key.get (objfile);
 321   fprintf_filtered (gdb_stdlog,
 322                     "qf->map_symbol_filenames (%s, %s, %s, %d)\n",
 323                     objfile_debug_name (objfile),
 324                     host_address_to_string (fun),
 325                     host_address_to_string (data),
 326                     need_fullname);
 327
 328   debug_data->real_sf->qf->map_symbol_filenames (objfile, fun, data,
 329                                                  need_fullname);
 330 }
 331
 332 static struct compunit_symtab *
 333 debug_qf_find_compunit_symtab_by_address (struct objfile *objfile,
 334                                           CORE_ADDR address)
 335 {
 336   const struct debug_sym_fns_data *debug_data
 337     = symfile_debug_objfile_data_key.get (objfile);
 338   fprintf_filtered (gdb_stdlog,
 339                     "qf->find_compunit_symtab_by_address (%s, %s)\n",
 340                     objfile_debug_name (objfile),
 341                     hex_string (address));
 342
 343   struct compunit_symtab *result = NULL;
 344   if (debug_data->real_sf->qf->map_symbol_filenames != NULL)
 345     result
 346       = debug_data->real_sf->qf->find_compunit_symtab_by_address (objfile,
 347                                                                   address);
 348
 349   fprintf_filtered (gdb_stdlog,
 350                     "qf->find_compunit_symtab_by_address (...) = %s\n",
 351                     result
 352                     ? debug_symtab_name (compunit_primary_filetab (result))
 353                     : "NULL");
 354
 355   return result;
 356 }
 357
 358 static const struct quick_symbol_functions debug_sym_quick_functions =
 359 {
 360   debug_qf_has_symbols,
 361   debug_qf_find_last_source_symtab,
 362   debug_qf_forget_cached_source_info,
 363   debug_qf_map_symtabs_matching_filename,
 364   debug_qf_lookup_symbol,
 365   debug_qf_print_stats,
 366   debug_qf_dump,
 367   debug_qf_expand_symtabs_for_function,
 368   debug_qf_expand_all_symtabs,
 369   debug_qf_expand_symtabs_with_fullname,
 370   debug_qf_map_matching_symbols,
 371   debug_qf_expand_symtabs_matching,
 372   debug_qf_find_pc_sect_compunit_symtab,
 373   debug_qf_find_compunit_symtab_by_address,
 374   debug_qf_map_symbol_filenames
 375 };
 376 \f
 377 /* Debugging version of struct sym_probe_fns.  */
 378
 379 static const std::vector<std::unique_ptr<probe>> &
 380 debug_sym_get_probes (struct objfile *objfile)
 381 {
 382   const struct debug_sym_fns_data *debug_data
 383     = symfile_debug_objfile_data_key.get (objfile);
 384
 385   const std::vector<std::unique_ptr<probe>> &retval
 386     = debug_data->real_sf->sym_probe_fns->sym_get_probes (objfile);
 387
 388   fprintf_filtered (gdb_stdlog,
 389                     "probes->sym_get_probes (%s) = %s\n",
 390                     objfile_debug_name (objfile),
 391                     host_address_to_string (retval.data ()));
 392
 393   return retval;
 394 }
 395
 396 static const struct sym_probe_fns debug_sym_probe_fns =
 397 {
 398   debug_sym_get_probes,
 399 };
 400 \f
 401 /* Debugging version of struct sym_fns.  */
 402
 403 static void
 404 debug_sym_new_init (struct objfile *objfile)
 405 {
 406   const struct debug_sym_fns_data *debug_data
 407     = symfile_debug_objfile_data_key.get (objfile);
 408
 409   fprintf_filtered (gdb_stdlog, "sf->sym_new_init (%s)\n",
 410                     objfile_debug_name (objfile));
 411
 412   debug_data->real_sf->sym_new_init (objfile);
 413 }
 414
 415 static void
 416 debug_sym_init (struct objfile *objfile)
 417 {
 418   const struct debug_sym_fns_data *debug_data
 419     = symfile_debug_objfile_data_key.get (objfile);
 420
 421   fprintf_filtered (gdb_stdlog, "sf->sym_init (%s)\n",
 422                     objfile_debug_name (objfile));
 423
 424   debug_data->real_sf->sym_init (objfile);
 425 }
 426
 427 static void
 428 debug_sym_read (struct objfile *objfile, symfile_add_flags symfile_flags)
 429 {
 430   const struct debug_sym_fns_data *debug_data
 431     = symfile_debug_objfile_data_key.get (objfile);
 432
 433   fprintf_filtered (gdb_stdlog, "sf->sym_read (%s, 0x%x)\n",
 434                     objfile_debug_name (objfile), (unsigned) symfile_flags);
 435
 436   debug_data->real_sf->sym_read (objfile, symfile_flags);
 437 }
 438
 439 static void
 440 debug_sym_read_psymbols (struct objfile *objfile)
 441 {
 442   const struct debug_sym_fns_data *debug_data
 443     = symfile_debug_objfile_data_key.get (objfile);
 444
 445   fprintf_filtered (gdb_stdlog, "sf->sym_read_psymbols (%s)\n",
 446                     objfile_debug_name (objfile));
 447
 448   debug_data->real_sf->sym_read_psymbols (objfile);
 449 }
 450
 451 static void
 452 debug_sym_finish (struct objfile *objfile)
 453 {
 454   const struct debug_sym_fns_data *debug_data
 455     = symfile_debug_objfile_data_key.get (objfile);
 456
 457   fprintf_filtered (gdb_stdlog, "sf->sym_finish (%s)\n",
 458                     objfile_debug_name (objfile));
 459
 460   debug_data->real_sf->sym_finish (objfile);
 461 }
 462
 463 static void
 464 debug_sym_offsets (struct objfile *objfile,
 465                    const section_addr_info &info)
 466 {
 467   const struct debug_sym_fns_data *debug_data
 468     = symfile_debug_objfile_data_key.get (objfile);
 469
 470   fprintf_filtered (gdb_stdlog, "sf->sym_offsets (%s, %s)\n",
 471                     objfile_debug_name (objfile),
 472                     host_address_to_string (&info));
 473
 474   debug_data->real_sf->sym_offsets (objfile, info);
 475 }
 476
 477 static struct symfile_segment_data *
 478 debug_sym_segments (bfd *abfd)
 479 {
 480   /* This API function is annoying, it doesn't take a "this" pointer.
 481      Fortunately it is only used in one place where we (re-)lookup the
 482      sym_fns table to use.  Thus we will never be called.  */
 483   gdb_assert_not_reached ("debug_sym_segments called");
 484 }
 485
 486 static void
 487 debug_sym_read_linetable (struct objfile *objfile)
 488 {
 489   const struct debug_sym_fns_data *debug_data
 490     = symfile_debug_objfile_data_key.get (objfile);
 491
 492   fprintf_filtered (gdb_stdlog, "sf->sym_read_linetable (%s)\n",
 493                     objfile_debug_name (objfile));
 494
 495   debug_data->real_sf->sym_read_linetable (objfile);
 496 }
 497
 498 static bfd_byte *
 499 debug_sym_relocate (struct objfile *objfile, asection *sectp, bfd_byte *buf)
 500 {
 501   const struct debug_sym_fns_data *debug_data
 502     = symfile_debug_objfile_data_key.get (objfile);
 503   bfd_byte *retval;
 504
 505   retval = debug_data->real_sf->sym_relocate (objfile, sectp, buf);
 506
 507   fprintf_filtered (gdb_stdlog,
 508                     "sf->sym_relocate (%s, %s, %s) = %s\n",
 509                     objfile_debug_name (objfile),
 510                     host_address_to_string (sectp),
 511                     host_address_to_string (buf),
 512                     host_address_to_string (retval));
 513
 514   return retval;
 515 }
 516
 517 /* Template of debugging version of struct sym_fns.
 518    A copy is made, with sym_flavour updated, and a pointer to the real table
 519    installed in real_sf, and then a pointer to the copy is installed in the
 520    objfile.  */
 521
 522 static const struct sym_fns debug_sym_fns =
 523 {
 524   debug_sym_new_init,
 525   debug_sym_init,
 526   debug_sym_read,
 527   debug_sym_read_psymbols,
 528   debug_sym_finish,
 529   debug_sym_offsets,
 530   debug_sym_segments,
 531   debug_sym_read_linetable,
 532   debug_sym_relocate,
 533   &debug_sym_probe_fns,
 534   &debug_sym_quick_functions
 535 };
 536 \f
 537 /* Install the debugging versions of the symfile functions for OBJFILE.
 538    Do not call this if the debug versions are already installed.  */
 539
 540 static void
 541 install_symfile_debug_logging (struct objfile *objfile)
 542 {
 543   const struct sym_fns *real_sf;
 544   struct debug_sym_fns_data *debug_data;
 545
 546   /* The debug versions should not already be installed.  */
 547   gdb_assert (!symfile_debug_installed (objfile));
 548
 549   real_sf = objfile->sf;
 550
 551   /* Alas we have to preserve NULL entries in REAL_SF.  */
 552   debug_data = new struct debug_sym_fns_data;
 553
 554 #define COPY_SF_PTR(from, to, name, func)       \
 555   do {                                          \
 556     if ((from)->name)                           \
 557       (to)->debug_sf.name = func;               \
 558   } while (0)
 559
 560   COPY_SF_PTR (real_sf, debug_data, sym_new_init, debug_sym_new_init);
 561   COPY_SF_PTR (real_sf, debug_data, sym_init, debug_sym_init);
 562   COPY_SF_PTR (real_sf, debug_data, sym_read, debug_sym_read);
 563   COPY_SF_PTR (real_sf, debug_data, sym_read_psymbols,
 564                debug_sym_read_psymbols);
 565   COPY_SF_PTR (real_sf, debug_data, sym_finish, debug_sym_finish);
 566   COPY_SF_PTR (real_sf, debug_data, sym_offsets, debug_sym_offsets);
 567   COPY_SF_PTR (real_sf, debug_data, sym_segments, debug_sym_segments);
 568   COPY_SF_PTR (real_sf, debug_data, sym_read_linetable,
 569                debug_sym_read_linetable);
 570   COPY_SF_PTR (real_sf, debug_data, sym_relocate, debug_sym_relocate);
 571   if (real_sf->sym_probe_fns)
 572     debug_data->debug_sf.sym_probe_fns = &debug_sym_probe_fns;
 573   debug_data->debug_sf.qf = &debug_sym_quick_functions;
 574
 575 #undef COPY_SF_PTR
 576
 577   debug_data->real_sf = real_sf;
 578   symfile_debug_objfile_data_key.set (objfile, debug_data);
 579   objfile->sf = &debug_data->debug_sf;
 580 }
 581
 582 /* Uninstall the debugging versions of the symfile functions for OBJFILE.
 583    Do not call this if the debug versions are not installed.  */
 584
 585 static void
 586 uninstall_symfile_debug_logging (struct objfile *objfile)
 587 {
 588   struct debug_sym_fns_data *debug_data;
 589
 590   /* The debug versions should be currently installed.  */
 591   gdb_assert (symfile_debug_installed (objfile));
 592
 593   debug_data = symfile_debug_objfile_data_key.get (objfile);
 594
 595   objfile->sf = debug_data->real_sf;
 596   symfile_debug_objfile_data_key.clear (objfile);
 597 }
 598
 599 /* Call this function to set OBJFILE->SF.
 600    Do not set OBJFILE->SF directly.  */
 601
 602 void
 603 objfile_set_sym_fns (struct objfile *objfile, const struct sym_fns *sf)
 604 {
 605   if (symfile_debug_installed (objfile))
 606     {
 607       gdb_assert (debug_symfile);
 608       /* Remove the current one, and reinstall a new one later.  */
 609       uninstall_symfile_debug_logging (objfile);
 610     }
 611
 612   /* Assume debug logging is disabled.  */
 613   objfile->sf = sf;
 614
 615   /* Turn debug logging on if enabled.  */
 616   if (debug_symfile)
 617     install_symfile_debug_logging (objfile);
 618 }
 619
 620 static void
 621 set_debug_symfile (const char *args, int from_tty, struct cmd_list_element *c)
 622 {
 623   struct program_space *pspace;
 624
 625   ALL_PSPACES (pspace)
 626     for (objfile *objfile : pspace->objfiles ())
 627       {
 628         if (debug_symfile)
 629           {
 630             if (!symfile_debug_installed (objfile))
 631               install_symfile_debug_logging (objfile);
 632           }
 633         else
 634           {
 635             if (symfile_debug_installed (objfile))
 636               uninstall_symfile_debug_logging (objfile);
 637           }
 638       }
 639 }
 640
 641 static void
 642 show_debug_symfile (struct ui_file *file, int from_tty,
 643                         struct cmd_list_element *c, const char *value)
 644 {
 645   fprintf_filtered (file, _("Symfile debugging is %s.\n"), value);
 646 }
 647
 648 void
 649 _initialize_symfile_debug (void)
 650 {
 651   add_setshow_boolean_cmd ("symfile", no_class, &debug_symfile, _("\
 652 Set debugging of the symfile functions."), _("\
 653 Show debugging of the symfile functions."), _("\
 654 When enabled, all calls to the symfile functions are logged."),
 655                            set_debug_symfile, show_debug_symfile,
 656                            &setdebuglist, &showdebuglist);
 657
 658   /* Note: We don't need a new-objfile observer because debug logging
 659      will be installed when objfile init'n calls objfile_set_sym_fns.  */
 660 }