contrib/binutils-2.21/gold/gold.cc

   1 // gold.cc -- main linker functions
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstdlib>
  26 #include <cstdio>
  27 #include <cstring>
  28 #include <unistd.h>
  29 #include <algorithm>
  30 #include "libiberty.h"
  31
  32 #include "options.h"
  33 #include "debug.h"
  34 #include "workqueue.h"
  35 #include "dirsearch.h"
  36 #include "readsyms.h"
  37 #include "symtab.h"
  38 #include "common.h"
  39 #include "object.h"
  40 #include "layout.h"
  41 #include "reloc.h"
  42 #include "defstd.h"
  43 #include "plugin.h"
  44 #include "gc.h"
  45 #include "icf.h"
  46 #include "incremental.h"
  47
  48 namespace gold
  49 {
  50
  51 const char* program_name;
  52
  53 void
  54 gold_exit(bool status)
  55 {
  56   if (parameters != NULL
  57       && parameters->options_valid()
  58       && parameters->options().has_plugins())
  59     parameters->options().plugins()->cleanup();
  60   if (!status && parameters != NULL && parameters->options_valid())
  61     unlink_if_ordinary(parameters->options().output_file_name());
  62   exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
  63 }
  64
  65 void
  66 gold_nomem()
  67 {
  68   // We are out of memory, so try hard to print a reasonable message.
  69   // Note that we don't try to translate this message, since the
  70   // translation process itself will require memory.
  71
  72   // LEN only exists to avoid a pointless warning when write is
  73   // declared with warn_use_result, as when compiling with
  74   // -D_USE_FORTIFY on GNU/Linux.  Casting to void does not appear to
  75   // work, at least not with gcc 4.3.0.
  76
  77   ssize_t len = write(2, program_name, strlen(program_name));
  78   if (len >= 0)
  79     {
  80       const char* const s = ": out of memory\n";
  81       len = write(2, s, strlen(s));
  82     }
  83   gold_exit(false);
  84 }
  85
  86 // Handle an unreachable case.
  87
  88 void
  89 do_gold_unreachable(const char* filename, int lineno, const char* function)
  90 {
  91   fprintf(stderr, _("%s: internal error in %s, at %s:%d\n"),
  92           program_name, function, filename, lineno);
  93   gold_exit(false);
  94 }
  95
  96 // This class arranges to run the functions done in the middle of the
  97 // link.  It is just a closure.
  98
  99 class Middle_runner : public Task_function_runner
 100 {
 101  public:
 102   Middle_runner(const General_options& options,
 103                 const Input_objects* input_objects,
 104                 Symbol_table* symtab,
 105                 Layout* layout, Mapfile* mapfile)
 106     : options_(options), input_objects_(input_objects), symtab_(symtab),
 107       layout_(layout), mapfile_(mapfile)
 108   { }
 109
 110   void
 111   run(Workqueue*, const Task*);
 112
 113  private:
 114   const General_options& options_;
 115   const Input_objects* input_objects_;
 116   Symbol_table* symtab_;
 117   Layout* layout_;
 118   Mapfile* mapfile_;
 119 };
 120
 121 void
 122 Middle_runner::run(Workqueue* workqueue, const Task* task)
 123 {
 124   queue_middle_tasks(this->options_, task, this->input_objects_, this->symtab_,
 125                      this->layout_, workqueue, this->mapfile_);
 126 }
 127
 128 // This class arranges the tasks to process the relocs for garbage collection.
 129
 130 class Gc_runner : public Task_function_runner
 131 {
 132   public:
 133    Gc_runner(const General_options& options,
 134              const Input_objects* input_objects,
 135              Symbol_table* symtab,
 136              Layout* layout, Mapfile* mapfile)
 137     : options_(options), input_objects_(input_objects), symtab_(symtab),
 138       layout_(layout), mapfile_(mapfile)
 139    { }
 140
 141   void
 142   run(Workqueue*, const Task*);
 143
 144  private:
 145   const General_options& options_;
 146   const Input_objects* input_objects_;
 147   Symbol_table* symtab_;
 148   Layout* layout_;
 149   Mapfile* mapfile_;
 150 };
 151
 152 void
 153 Gc_runner::run(Workqueue* workqueue, const Task* task)
 154 {
 155   queue_middle_gc_tasks(this->options_, task, this->input_objects_,
 156                         this->symtab_, this->layout_, workqueue,
 157                         this->mapfile_);
 158 }
 159
 160 // Queue up the initial set of tasks for this link job.
 161
 162 void
 163 queue_initial_tasks(const General_options& options,
 164                     Dirsearch& search_path,
 165                     const Command_line& cmdline,
 166                     Workqueue* workqueue, Input_objects* input_objects,
 167                     Symbol_table* symtab, Layout* layout, Mapfile* mapfile)
 168 {
 169   if (cmdline.begin() == cmdline.end())
 170     {
 171       if (options.printed_version())
 172         gold_exit(true);
 173       gold_fatal(_("no input files"));
 174     }
 175
 176   int thread_count = options.thread_count_initial();
 177   if (thread_count == 0)
 178     thread_count = cmdline.number_of_input_files();
 179   workqueue->set_thread_count(thread_count);
 180
 181   if (parameters->incremental())
 182     {
 183       Incremental_checker incremental_checker(
 184           parameters->options().output_file_name(),
 185           layout->incremental_inputs());
 186       if (incremental_checker.can_incrementally_link_output_file())
 187         {
 188           // TODO: remove when incremental linking implemented.
 189           printf("Incremental linking might be possible "
 190               "(not implemented yet)\n");
 191         }
 192       // TODO: If we decide on an incremental build, fewer tasks
 193       // should be scheduled.
 194     }
 195
 196   // Read the input files.  We have to add the symbols to the symbol
 197   // table in order.  We do this by creating a separate blocker for
 198   // each input file.  We associate the blocker with the following
 199   // input file, to give us a convenient place to delete it.
 200   Task_token* this_blocker = NULL;
 201   for (Command_line::const_iterator p = cmdline.begin();
 202        p != cmdline.end();
 203        ++p)
 204     {
 205       Task_token* next_blocker = new Task_token(true);
 206       next_blocker->add_blocker();
 207       workqueue->queue(new Read_symbols(input_objects, symtab, layout,
 208                                         &search_path, 0, mapfile, &*p, NULL,
 209                                         NULL, this_blocker, next_blocker));
 210       this_blocker = next_blocker;
 211     }
 212
 213   if (options.has_plugins())
 214     {
 215       Task_token* next_blocker = new Task_token(true);
 216       next_blocker->add_blocker();
 217       workqueue->queue(new Plugin_hook(options, input_objects, symtab, layout,
 218                                        &search_path, mapfile, this_blocker,
 219                                        next_blocker));
 220       this_blocker = next_blocker;
 221     }
 222
 223   if (parameters->options().relocatable()
 224       && (parameters->options().gc_sections()
 225           || parameters->options().icf_enabled()))
 226     gold_error(_("cannot mix -r with --gc-sections or --icf"));
 227
 228   if (parameters->options().gc_sections()
 229       || parameters->options().icf_enabled())
 230     {
 231       workqueue->queue(new Task_function(new Gc_runner(options,
 232                                                        input_objects,
 233                                                        symtab,
 234                                                        layout,
 235                                                        mapfile),
 236                                          this_blocker,
 237                                          "Task_function Gc_runner"));
 238     }
 239   else
 240     {
 241       workqueue->queue(new Task_function(new Middle_runner(options,
 242                                                            input_objects,
 243                                                            symtab,
 244                                                            layout,
 245                                                            mapfile),
 246                                          this_blocker,
 247                                          "Task_function Middle_runner"));
 248     }
 249 }
 250
 251 // Queue up a set of tasks to be done before queueing the middle set
 252 // of tasks.  This is only necessary when garbage collection
 253 // (--gc-sections) of unused sections is desired.  The relocs are read
 254 // and processed here early to determine the garbage sections before the
 255 // relocs can be scanned in later tasks.
 256
 257 void
 258 queue_middle_gc_tasks(const General_options& options,
 259                       const Task* ,
 260                       const Input_objects* input_objects,
 261                       Symbol_table* symtab,
 262                       Layout* layout,
 263                       Workqueue* workqueue,
 264                       Mapfile* mapfile)
 265 {
 266   // Read_relocs for all the objects must be done and processed to find
 267   // unused sections before any scanning of the relocs can take place.
 268   Task_token* this_blocker = NULL;
 269   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
 270        p != input_objects->relobj_end();
 271        ++p)
 272     {
 273       Task_token* next_blocker = new Task_token(true);
 274       next_blocker->add_blocker();
 275       workqueue->queue(new Read_relocs(symtab, layout, *p, this_blocker,
 276                                        next_blocker));
 277       this_blocker = next_blocker;
 278     }
 279
 280   // If we are given only archives in input, we have no regular
 281   // objects and THIS_BLOCKER is NULL here.  Create a dummy
 282   // blocker here so that we can run the middle tasks immediately.
 283   if (this_blocker == NULL)
 284     {
 285       gold_assert(input_objects->number_of_relobjs() == 0);
 286       this_blocker = new Task_token(true);
 287     }
 288
 289   workqueue->queue(new Task_function(new Middle_runner(options,
 290                                                        input_objects,
 291                                                        symtab,
 292                                                        layout,
 293                                                        mapfile),
 294                                      this_blocker,
 295                                      "Task_function Middle_runner"));
 296 }
 297
 298 // Queue up the middle set of tasks.  These are the tasks which run
 299 // after all the input objects have been found and all the symbols
 300 // have been read, but before we lay out the output file.
 301
 302 void
 303 queue_middle_tasks(const General_options& options,
 304                    const Task* task,
 305                    const Input_objects* input_objects,
 306                    Symbol_table* symtab,
 307                    Layout* layout,
 308                    Workqueue* workqueue,
 309                    Mapfile* mapfile)
 310 {
 311   // Add any symbols named with -u options to the symbol table.
 312   symtab->add_undefined_symbols_from_command_line(layout);
 313
 314   // If garbage collection was chosen, relocs have been read and processed
 315   // at this point by pre_middle_tasks.  Layout can then be done for all
 316   // objects.
 317   if (parameters->options().gc_sections())
 318     {
 319       // Find the start symbol if any.
 320       Symbol* start_sym;
 321       if (parameters->options().entry())
 322         start_sym = symtab->lookup(parameters->options().entry());
 323       else
 324         start_sym = symtab->lookup("_start");
 325       if (start_sym != NULL)
 326         {
 327           bool is_ordinary;
 328           unsigned int shndx = start_sym->shndx(&is_ordinary);
 329           if (is_ordinary)
 330             {
 331               symtab->gc()->worklist().push(
 332                 Section_id(start_sym->object(), shndx));
 333             }
 334         }
 335       // Symbols named with -u should not be considered garbage.
 336       symtab->gc_mark_undef_symbols(layout);
 337       gold_assert(symtab->gc() != NULL);
 338       // Do a transitive closure on all references to determine the worklist.
 339       symtab->gc()->do_transitive_closure();
 340     }
 341
 342   // If identical code folding (--icf) is chosen it makes sense to do it
 343   // only after garbage collection (--gc-sections) as we do not want to
 344   // be folding sections that will be garbage.
 345   if (parameters->options().icf_enabled())
 346     {
 347       symtab->icf()->find_identical_sections(input_objects, symtab);
 348     }
 349
 350   // Call Object::layout for the second time to determine the
 351   // output_sections for all referenced input sections.  When
 352   // --gc-sections or --icf is turned on, Object::layout is
 353   // called twice.  It is called the first time when the
 354   // symbols are added.
 355   if (parameters->options().gc_sections()
 356       || parameters->options().icf_enabled())
 357     {
 358       for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
 359            p != input_objects->relobj_end();
 360            ++p)
 361         {
 362           Task_lock_obj<Object> tlo(task, *p);
 363           (*p)->layout(symtab, layout, NULL);
 364         }
 365     }
 366
 367   // Layout deferred objects due to plugins.
 368   if (parameters->options().has_plugins())
 369     {
 370       Plugin_manager* plugins = parameters->options().plugins();
 371       gold_assert(plugins != NULL);
 372       plugins->layout_deferred_objects();
 373     }
 374
 375   if (parameters->options().gc_sections()
 376       || parameters->options().icf_enabled())
 377     {
 378       for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
 379            p != input_objects->relobj_end();
 380            ++p)
 381         {
 382           // Update the value of output_section stored in rd.
 383           Read_relocs_data* rd = (*p)->get_relocs_data();
 384           for (Read_relocs_data::Relocs_list::iterator q = rd->relocs.begin();
 385                q != rd->relocs.end();
 386                ++q)
 387             {
 388               q->output_section = (*p)->output_section(q->data_shndx);
 389               q->needs_special_offset_handling =
 390                       (*p)->is_output_section_offset_invalid(q->data_shndx);
 391             }
 392         }
 393     }
 394
 395   // We have to support the case of not seeing any input objects, and
 396   // generate an empty file.  Existing builds depend on being able to
 397   // pass an empty archive to the linker and get an empty object file
 398   // out.  In order to do this we need to use a default target.
 399   if (input_objects->number_of_input_objects() == 0)
 400     parameters_force_valid_target();
 401
 402   int thread_count = options.thread_count_middle();
 403   if (thread_count == 0)
 404     thread_count = std::max(2, input_objects->number_of_input_objects());
 405   workqueue->set_thread_count(thread_count);
 406
 407   // Now we have seen all the input files.
 408   const bool doing_static_link =
 409     (!input_objects->any_dynamic()
 410      && !parameters->options().output_is_position_independent());
 411   set_parameters_doing_static_link(doing_static_link);
 412   if (!doing_static_link && options.is_static())
 413     {
 414       // We print out just the first .so we see; there may be others.
 415       gold_assert(input_objects->dynobj_begin() != input_objects->dynobj_end());
 416       gold_error(_("cannot mix -static with dynamic object %s"),
 417                  (*input_objects->dynobj_begin())->name().c_str());
 418     }
 419   if (!doing_static_link && parameters->options().relocatable())
 420     gold_fatal(_("cannot mix -r with dynamic object %s"),
 421                (*input_objects->dynobj_begin())->name().c_str());
 422   if (!doing_static_link
 423       && options.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
 424     gold_fatal(_("cannot use non-ELF output format with dynamic object %s"),
 425                (*input_objects->dynobj_begin())->name().c_str());
 426
 427   if (parameters->options().relocatable())
 428     {
 429       Input_objects::Relobj_iterator p = input_objects->relobj_begin();
 430       if (p != input_objects->relobj_end())
 431         {
 432           bool uses_split_stack = (*p)->uses_split_stack();
 433           for (++p; p != input_objects->relobj_end(); ++p)
 434             {
 435               if ((*p)->uses_split_stack() != uses_split_stack)
 436                 gold_fatal(_("cannot mix split-stack '%s' and "
 437                              "non-split-stack '%s' when using -r"),
 438                            (*input_objects->relobj_begin())->name().c_str(),
 439                            (*p)->name().c_str());
 440             }
 441         }
 442     }
 443
 444   if (is_debugging_enabled(DEBUG_SCRIPT))
 445     layout->script_options()->print(stderr);
 446
 447   // For each dynamic object, record whether we've seen all the
 448   // dynamic objects that it depends upon.
 449   input_objects->check_dynamic_dependencies();
 450
 451   // See if any of the input definitions violate the One Definition Rule.
 452   // TODO: if this is too slow, do this as a task, rather than inline.
 453   symtab->detect_odr_violations(task, options.output_file_name());
 454
 455   // Do the --no-undefined-version check.
 456   if (!parameters->options().undefined_version())
 457     {
 458       Script_options* so = layout->script_options();
 459       so->version_script_info()->check_unmatched_names(symtab);
 460     }
 461
 462   // Create any automatic note sections.
 463   layout->create_notes();
 464
 465   // Create any output sections required by any linker script.
 466   layout->create_script_sections();
 467
 468   // Define some sections and symbols needed for a dynamic link.  This
 469   // handles some cases we want to see before we read the relocs.
 470   layout->create_initial_dynamic_sections(symtab);
 471
 472   // Define symbols from any linker scripts.
 473   layout->define_script_symbols(symtab);
 474
 475   // Attach sections to segments.
 476   layout->attach_sections_to_segments();
 477
 478   if (!parameters->options().relocatable())
 479     {
 480       // Predefine standard symbols.
 481       define_standard_symbols(symtab, layout);
 482
 483       // Define __start and __stop symbols for output sections where
 484       // appropriate.
 485       layout->define_section_symbols(symtab);
 486     }
 487
 488   // Make sure we have symbols for any required group signatures.
 489   layout->define_group_signatures(symtab);
 490
 491   Task_token* this_blocker = NULL;
 492
 493   // Allocate common symbols.  We use a blocker to run this before the
 494   // Scan_relocs tasks, because it writes to the symbol table just as
 495   // they do.
 496   if (parameters->options().define_common())
 497     {
 498       this_blocker = new Task_token(true);
 499       this_blocker->add_blocker();
 500       workqueue->queue(new Allocate_commons_task(symtab, layout, mapfile,
 501                                                  this_blocker));
 502     }
 503
 504   // If doing garbage collection, the relocations have already been read.
 505   // Otherwise, read and scan the relocations.
 506   if (parameters->options().gc_sections()
 507       || parameters->options().icf_enabled())
 508     {
 509       for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
 510            p != input_objects->relobj_end();
 511            ++p)
 512         {
 513           Task_token* next_blocker = new Task_token(true);
 514           next_blocker->add_blocker();
 515           workqueue->queue(new Scan_relocs(symtab, layout, *p,
 516                                            (*p)->get_relocs_data(),
 517                                            this_blocker, next_blocker));
 518           this_blocker = next_blocker;
 519         }
 520     }
 521   else
 522     {
 523       // Read the relocations of the input files.  We do this to find
 524       // which symbols are used by relocations which require a GOT and/or
 525       // a PLT entry, or a COPY reloc.  When we implement garbage
 526       // collection we will do it here by reading the relocations in a
 527       // breadth first search by references.
 528       //
 529       // We could also read the relocations during the first pass, and
 530       // mark symbols at that time.  That is how the old GNU linker works.
 531       // Doing that is more complex, since we may later decide to discard
 532       // some of the sections, and thus change our minds about the types
 533       // of references made to the symbols.
 534       for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
 535            p != input_objects->relobj_end();
 536            ++p)
 537         {
 538           Task_token* next_blocker = new Task_token(true);
 539           next_blocker->add_blocker();
 540           workqueue->queue(new Read_relocs(symtab, layout, *p, this_blocker,
 541                                            next_blocker));
 542           this_blocker = next_blocker;
 543         }
 544     }
 545
 546   if (this_blocker == NULL)
 547     {
 548       if (input_objects->number_of_relobjs() == 0)
 549         {
 550           // If we are given only archives in input, we have no regular
 551           // objects and THIS_BLOCKER is NULL here.  Create a dummy
 552           // blocker here so that we can run the layout task immediately.
 553           this_blocker = new Task_token(true);
 554         }
 555       else
 556         {
 557           // If we failed to open any input files, it's possible for
 558           // THIS_BLOCKER to be NULL here.  There's no real point in
 559           // continuing if that happens.
 560           gold_assert(parameters->errors()->error_count() > 0);
 561           gold_exit(false);
 562         }
 563     }
 564
 565   // When all those tasks are complete, we can start laying out the
 566   // output file.
 567   // TODO(csilvers): figure out a more principled way to get the target
 568   Target* target = const_cast<Target*>(&parameters->target());
 569   workqueue->queue(new Task_function(new Layout_task_runner(options,
 570                                                             input_objects,
 571                                                             symtab,
 572                                                             target,
 573                                                             layout,
 574                                                             mapfile),
 575                                      this_blocker,
 576                                      "Task_function Layout_task_runner"));
 577 }
 578
 579 // Queue up the final set of tasks.  This is called at the end of
 580 // Layout_task.
 581
 582 void
 583 queue_final_tasks(const General_options& options,
 584                   const Input_objects* input_objects,
 585                   const Symbol_table* symtab,
 586                   Layout* layout,
 587                   Workqueue* workqueue,
 588                   Output_file* of)
 589 {
 590   int thread_count = options.thread_count_final();
 591   if (thread_count == 0)
 592     thread_count = std::max(2, input_objects->number_of_input_objects());
 593   workqueue->set_thread_count(thread_count);
 594
 595   bool any_postprocessing_sections = layout->any_postprocessing_sections();
 596
 597   // Use a blocker to wait until all the input sections have been
 598   // written out.
 599   Task_token* input_sections_blocker = NULL;
 600   if (!any_postprocessing_sections)
 601     {
 602       input_sections_blocker = new Task_token(true);
 603       input_sections_blocker->add_blockers(input_objects->number_of_relobjs());
 604     }
 605
 606   // Use a blocker to block any objects which have to wait for the
 607   // output sections to complete before they can apply relocations.
 608   Task_token* output_sections_blocker = new Task_token(true);
 609   output_sections_blocker->add_blocker();
 610
 611   // Use a blocker to block the final cleanup task.
 612   Task_token* final_blocker = new Task_token(true);
 613   // Write_symbols_task, Write_sections_task, Write_data_task,
 614   // Relocate_tasks.
 615   final_blocker->add_blockers(3);
 616   final_blocker->add_blockers(input_objects->number_of_relobjs());
 617   if (!any_postprocessing_sections)
 618     final_blocker->add_blocker();
 619
 620   // Queue a task to write out the symbol table.
 621   workqueue->queue(new Write_symbols_task(layout,
 622                                           symtab,
 623                                           input_objects,
 624                                           layout->sympool(),
 625                                           layout->dynpool(),
 626                                           of,
 627                                           final_blocker));
 628
 629   // Queue a task to write out the output sections.
 630   workqueue->queue(new Write_sections_task(layout, of, output_sections_blocker,
 631                                            final_blocker));
 632
 633   // Queue a task to write out everything else.
 634   workqueue->queue(new Write_data_task(layout, symtab, of, final_blocker));
 635
 636   // Queue a task for each input object to relocate the sections and
 637   // write out the local symbols.
 638   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
 639        p != input_objects->relobj_end();
 640        ++p)
 641     workqueue->queue(new Relocate_task(symtab, layout, *p, of,
 642                                        input_sections_blocker,
 643                                        output_sections_blocker,
 644                                        final_blocker));
 645
 646   // Queue a task to write out the output sections which depend on
 647   // input sections.  If there are any sections which require
 648   // postprocessing, then we need to do this last, since it may resize
 649   // the output file.
 650   if (!any_postprocessing_sections)
 651     {
 652       Task* t = new Write_after_input_sections_task(layout, of,
 653                                                     input_sections_blocker,
 654                                                     final_blocker);
 655       workqueue->queue(t);
 656     }
 657   else
 658     {
 659       Task_token* new_final_blocker = new Task_token(true);
 660       new_final_blocker->add_blocker();
 661       Task* t = new Write_after_input_sections_task(layout, of,
 662                                                     final_blocker,
 663                                                     new_final_blocker);
 664       workqueue->queue(t);
 665       final_blocker = new_final_blocker;
 666     }
 667
 668   // Queue a task to close the output file.  This will be blocked by
 669   // FINAL_BLOCKER.
 670   workqueue->queue(new Task_function(new Close_task_runner(&options, layout,
 671                                                            of),
 672                                      final_blocker,
 673                                      "Task_function Close_task_runner"));
 674 }
 675
 676 } // End namespace gold.