gold/layout.h

   1 // layout.h -- lay out output file sections for gold  -*- C++ -*-
   2
   3 // Copyright 2006, 2007, 2008 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 #ifndef GOLD_LAYOUT_H
  24 #define GOLD_LAYOUT_H
  25
  26 #include <list>
  27 #include <string>
  28 #include <utility>
  29 #include <vector>
  30
  31 #include "script.h"
  32 #include "workqueue.h"
  33 #include "object.h"
  34 #include "dynobj.h"
  35 #include "stringpool.h"
  36
  37 namespace gold
  38 {
  39
  40 class General_options;
  41 class Input_objects;
  42 class Symbol_table;
  43 class Output_section_data;
  44 class Output_section;
  45 class Output_section_headers;
  46 class Output_segment;
  47 class Output_data;
  48 class Output_data_dynamic;
  49 class Eh_frame;
  50 class Target;
  51
  52 // This task function handles mapping the input sections to output
  53 // sections and laying them out in memory.
  54
  55 class Layout_task_runner : public Task_function_runner
  56 {
  57  public:
  58   // OPTIONS is the command line options, INPUT_OBJECTS is the list of
  59   // input objects, SYMTAB is the symbol table, LAYOUT is the layout
  60   // object.
  61   Layout_task_runner(const General_options& options,
  62                      const Input_objects* input_objects,
  63                      Symbol_table* symtab,
  64                      Target* target,
  65                      Layout* layout)
  66     : options_(options), input_objects_(input_objects), symtab_(symtab),
  67       target_(target), layout_(layout)
  68   { }
  69
  70   // Run the operation.
  71   void
  72   run(Workqueue*, const Task*);
  73
  74  private:
  75   Layout_task_runner(const Layout_task_runner&);
  76   Layout_task_runner& operator=(const Layout_task_runner&);
  77
  78   const General_options& options_;
  79   const Input_objects* input_objects_;
  80   Symbol_table* symtab_;
  81   Target* target_;
  82   Layout* layout_;
  83 };
  84
  85 // This class handles the details of laying out input sections.
  86
  87 class Layout
  88 {
  89  public:
  90   Layout(const General_options& options, Script_options*);
  91
  92   // Given an input section SHNDX, named NAME, with data in SHDR, from
  93   // the object file OBJECT, return the output section where this
  94   // input section should go.  RELOC_SHNDX is the index of a
  95   // relocation section which applies to this section, or 0 if none,
  96   // or -1U if more than one.  RELOC_TYPE is the type of the
  97   // relocation section if there is one.  Set *OFFSET to the offset
  98   // within the output section.
  99   template<int size, bool big_endian>
 100   Output_section*
 101   layout(Sized_relobj<size, big_endian> *object, unsigned int shndx,
 102          const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
 103          unsigned int reloc_shndx, unsigned int reloc_type, off_t* offset);
 104
 105   // Layout an input reloc section when doing a relocatable link.  The
 106   // section is RELOC_SHNDX in OBJECT, with data in SHDR.
 107   // DATA_SECTION is the reloc section to which it refers.  RR is the
 108   // relocatable information.
 109   template<int size, bool big_endian>
 110   Output_section*
 111   layout_reloc(Sized_relobj<size, big_endian>* object,
 112                unsigned int reloc_shndx,
 113                const elfcpp::Shdr<size, big_endian>& shdr,
 114                Output_section* data_section,
 115                Relocatable_relocs* rr);
 116
 117   // Layout a group section when doing a relocatable link.
 118   template<int size, bool big_endian>
 119   void
 120   layout_group(Symbol_table* symtab,
 121                Sized_relobj<size, big_endian>* object,
 122                unsigned int group_shndx,
 123                const char* group_section_name,
 124                const char* signature,
 125                const elfcpp::Shdr<size, big_endian>& shdr,
 126                const elfcpp::Elf_Word* contents);
 127
 128   // Like layout, only for exception frame sections.  OBJECT is an
 129   // object file.  SYMBOLS is the contents of the symbol table
 130   // section, with size SYMBOLS_SIZE.  SYMBOL_NAMES is the contents of
 131   // the symbol name section, with size SYMBOL_NAMES_SIZE.  SHNDX is a
 132   // .eh_frame section in OBJECT.  SHDR is the section header.
 133   // RELOC_SHNDX is the index of a relocation section which applies to
 134   // this section, or 0 if none, or -1U if more than one.  RELOC_TYPE
 135   // is the type of the relocation section if there is one.  This
 136   // returns the output section, and sets *OFFSET to the offset.
 137   template<int size, bool big_endian>
 138   Output_section*
 139   layout_eh_frame(Sized_relobj<size, big_endian>* object,
 140                   const unsigned char* symbols,
 141                   off_t symbols_size,
 142                   const unsigned char* symbol_names,
 143                   off_t symbol_names_size,
 144                   unsigned int shndx,
 145                   const elfcpp::Shdr<size, big_endian>& shdr,
 146                   unsigned int reloc_shndx, unsigned int reloc_type,
 147                   off_t* offset);
 148
 149   // Handle a GNU stack note.  This is called once per input object
 150   // file.  SEEN_GNU_STACK is true if the object file has a
 151   // .note.GNU-stack section.  GNU_STACK_FLAGS is the section flags
 152   // from that section if there was one.
 153   void
 154   layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags);
 155
 156   // Add an Output_section_data to the layout.  This is used for
 157   // special sections like the GOT section.
 158   void
 159   add_output_section_data(const char* name, elfcpp::Elf_Word type,
 160                           elfcpp::Elf_Xword flags,
 161                           Output_section_data*);
 162
 163   // Create dynamic sections if necessary.
 164   void
 165   create_initial_dynamic_sections(Symbol_table*);
 166
 167   // Define __start and __stop symbols for output sections.
 168   void
 169   define_section_symbols(Symbol_table*);
 170
 171   // Define symbols from any linker script.
 172   void
 173   define_script_symbols(Symbol_table* symtab)
 174   { this->script_options_->add_symbols_to_table(symtab); }
 175
 176   // Define symbols for group signatures.
 177   void
 178   define_group_signatures(Symbol_table*);
 179
 180   // Return the Stringpool used for symbol names.
 181   const Stringpool*
 182   sympool() const
 183   { return &this->sympool_; }
 184
 185   // Return the Stringpool used for dynamic symbol names and dynamic
 186   // tags.
 187   const Stringpool*
 188   dynpool() const
 189   { return &this->dynpool_; }
 190
 191   // Return whether a section is a .gnu.linkonce section, given the
 192   // section name.
 193   static inline bool
 194   is_linkonce(const char* name)
 195   { return strncmp(name, ".gnu.linkonce", sizeof(".gnu.linkonce") - 1) == 0; }
 196
 197   // Record the signature of a comdat section, and return whether to
 198   // include it in the link.  The GROUP parameter is true for a
 199   // section group signature, false for a signature derived from a
 200   // .gnu.linkonce section.
 201   bool
 202   add_comdat(const char*, bool group);
 203
 204   // Finalize the layout after all the input sections have been added.
 205   off_t
 206   finalize(const Input_objects*, Symbol_table*, Target*, const Task*);
 207
 208   // Return whether any sections require postprocessing.
 209   bool
 210   any_postprocessing_sections() const
 211   { return this->any_postprocessing_sections_; }
 212
 213   // Return the size of the output file.
 214   off_t
 215   output_file_size() const
 216   { return this->output_file_size_; }
 217
 218   // Return the TLS segment.  This will return NULL if there isn't
 219   // one.
 220   Output_segment*
 221   tls_segment() const
 222   { return this->tls_segment_; }
 223
 224   // Return the normal symbol table.
 225   Output_section*
 226   symtab_section() const
 227   {
 228     gold_assert(this->symtab_section_ != NULL);
 229     return this->symtab_section_;
 230   }
 231
 232   // Return the dynamic symbol table.
 233   Output_section*
 234   dynsym_section() const
 235   {
 236     gold_assert(this->dynsym_section_ != NULL);
 237     return this->dynsym_section_;
 238   }
 239
 240   // Return the dynamic tags.
 241   Output_data_dynamic*
 242   dynamic_data() const
 243   { return this->dynamic_data_; }
 244
 245   // Write out the output sections.
 246   void
 247   write_output_sections(Output_file* of) const;
 248
 249   // Write out data not associated with an input file or the symbol
 250   // table.
 251   void
 252   write_data(const Symbol_table*, Output_file*) const;
 253
 254   // Write out output sections which can not be written until all the
 255   // input sections are complete.
 256   void
 257   write_sections_after_input_sections(Output_file* of);
 258
 259   // Return an output section named NAME, or NULL if there is none.
 260   Output_section*
 261   find_output_section(const char* name) const;
 262
 263   // Return an output segment of type TYPE, with segment flags SET set
 264   // and segment flags CLEAR clear.  Return NULL if there is none.
 265   Output_segment*
 266   find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
 267                       elfcpp::Elf_Word clear) const;
 268
 269   // Return the number of segments we expect to produce.
 270   size_t
 271   expected_segment_count() const;
 272
 273   // Set a flag to indicate that an object file uses the static TLS model.
 274   void
 275   set_has_static_tls()
 276   { this->has_static_tls_ = true; }
 277
 278   // Return true if any object file uses the static TLS model.
 279   bool
 280   has_static_tls() const
 281   { return this->has_static_tls_; }
 282
 283   // Return the options which may be set by a linker script.
 284   Script_options*
 285   script_options()
 286   { return this->script_options_; }
 287
 288   const Script_options*
 289   script_options() const
 290   { return this->script_options_; }
 291
 292   // Rewrite output file in binary format.
 293   void
 294   write_binary(Output_file* in) const;
 295
 296   // Dump statistical information to stderr.
 297   void
 298   print_stats() const;
 299
 300   // A list of segments.
 301
 302   typedef std::vector<Output_segment*> Segment_list;
 303
 304   // A list of sections.
 305
 306   typedef std::vector<Output_section*> Section_list;
 307
 308   // The list of information to write out which is not attached to
 309   // either a section or a segment.
 310   typedef std::vector<Output_data*> Data_list;
 311
 312   // Store the allocated sections into the section list.  This is used
 313   // by the linker script code.
 314   void
 315   get_allocated_sections(Section_list*) const;
 316
 317   // Make a segment.  This is used by the linker script code.
 318   Output_segment*
 319   make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags);
 320
 321   // Return the number of segments.
 322   size_t
 323   segment_count() const
 324   { return this->segment_list_.size(); }
 325
 326   // Map from section flags to segment flags.
 327   static elfcpp::Elf_Word
 328   section_flags_to_segment(elfcpp::Elf_Xword flags);
 329
 330  private:
 331   Layout(const Layout&);
 332   Layout& operator=(const Layout&);
 333
 334   // Mapping from .gnu.linkonce section names to output section names.
 335   struct Linkonce_mapping
 336   {
 337     const char* from;
 338     int fromlen;
 339     const char* to;
 340     int tolen;
 341   };
 342   static const Linkonce_mapping linkonce_mapping[];
 343   static const int linkonce_mapping_count;
 344
 345   // During a relocatable link, a list of group sections and
 346   // signatures.
 347   struct Group_signature
 348   {
 349     // The group section.
 350     Output_section* section;
 351     // The signature.
 352     const char* signature;
 353
 354     Group_signature()
 355       : section(NULL), signature(NULL)
 356     { }
 357
 358     Group_signature(Output_section* sectiona, const char* signaturea)
 359       : section(sectiona), signature(signaturea)
 360     { }
 361   };
 362   typedef std::vector<Group_signature> Group_signatures;
 363
 364   // Create a .note section for gold.
 365   void
 366   create_gold_note();
 367
 368   // Record whether the stack must be executable.
 369   void
 370   create_executable_stack_info(const Target*);
 371
 372   // Find the first read-only PT_LOAD segment, creating one if
 373   // necessary.
 374   Output_segment*
 375   find_first_load_seg();
 376
 377   // Count the local symbols in the regular symbol table and the dynamic
 378   // symbol table, and build the respective string pools.
 379   void
 380   count_local_symbols(const Task*, const Input_objects*);
 381
 382   // Create the output sections for the symbol table.
 383   void
 384   create_symtab_sections(const Input_objects*, Symbol_table*, off_t*);
 385
 386   // Create the .shstrtab section.
 387   Output_section*
 388   create_shstrtab();
 389
 390   // Create the section header table.
 391   void
 392   create_shdrs(off_t*);
 393
 394   // Create the dynamic symbol table.
 395   void
 396   create_dynamic_symtab(const Input_objects*, Symbol_table*,
 397                         Output_section** pdynstr,
 398                         unsigned int* plocal_dynamic_count,
 399                         std::vector<Symbol*>* pdynamic_symbols,
 400                         Versions* versions);
 401
 402   // Assign offsets to each local portion of the dynamic symbol table.
 403   void
 404   assign_local_dynsym_offsets(const Input_objects*);
 405
 406   // Finish the .dynamic section and PT_DYNAMIC segment.
 407   void
 408   finish_dynamic_section(const Input_objects*, const Symbol_table*);
 409
 410   // Create the .interp section and PT_INTERP segment.
 411   void
 412   create_interp(const Target* target);
 413
 414   // Create the version sections.
 415   void
 416   create_version_sections(const Versions*,
 417                           const Symbol_table*,
 418                           unsigned int local_symcount,
 419                           const std::vector<Symbol*>& dynamic_symbols,
 420                           const Output_section* dynstr);
 421
 422   template<int size, bool big_endian>
 423   void
 424   sized_create_version_sections(const Versions* versions,
 425                                 const Symbol_table*,
 426                                 unsigned int local_symcount,
 427                                 const std::vector<Symbol*>& dynamic_symbols,
 428                                 const Output_section* dynstr
 429                                 ACCEPT_SIZE_ENDIAN);
 430
 431   // Return whether to include this section in the link.
 432   template<int size, bool big_endian>
 433   bool
 434   include_section(Sized_relobj<size, big_endian>* object, const char* name,
 435                   const elfcpp::Shdr<size, big_endian>&);
 436
 437   // Return the output section name to use given an input section
 438   // name.  Set *PLEN to the length of the name.  *PLEN must be
 439   // initialized to the length of NAME.
 440   static const char*
 441   output_section_name(const char* name, size_t* plen);
 442
 443   // Return the output section name to use for a linkonce section
 444   // name.  PLEN is as for output_section_name.
 445   static const char*
 446   linkonce_output_name(const char* name, size_t* plen);
 447
 448   // Return the output section for NAME, TYPE and FLAGS.
 449   Output_section*
 450   get_output_section(const char* name, Stringpool::Key name_key,
 451                      elfcpp::Elf_Word type, elfcpp::Elf_Xword flags);
 452
 453   // Choose the output section for NAME in RELOBJ.
 454   Output_section*
 455   choose_output_section(const Relobj* relobj, const char* name,
 456                         elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
 457                         bool adjust_name);
 458
 459   // Create a new Output_section.
 460   Output_section*
 461   make_output_section(const char* name, elfcpp::Elf_Word type,
 462                       elfcpp::Elf_Xword flags);
 463
 464   // Set the final file offsets of all the segments.
 465   off_t
 466   set_segment_offsets(const Target*, Output_segment*, unsigned int* pshndx);
 467
 468   // Set the file offsets of the sections when doing a relocatable
 469   // link.
 470   off_t
 471   set_relocatable_section_offsets(Output_data*, unsigned int* pshndx);
 472
 473   // Set the final file offsets of all the sections not associated
 474   // with a segment.  We set section offsets in three passes: the
 475   // first handles all allocated sections, the second sections that
 476   // require postprocessing, and the last the late-bound STRTAB
 477   // sections (probably only shstrtab, which is the one we care about
 478   // because it holds section names).
 479   enum Section_offset_pass
 480   {
 481     BEFORE_INPUT_SECTIONS_PASS,
 482     POSTPROCESSING_SECTIONS_PASS,
 483     STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
 484   };
 485   off_t
 486   set_section_offsets(off_t, Section_offset_pass pass);
 487
 488   // Set the final section indexes of all the sections not associated
 489   // with a segment.  Returns the next unused index.
 490   unsigned int
 491   set_section_indexes(unsigned int pshndx);
 492
 493   // Set the section addresses when using a script.
 494   Output_segment*
 495   set_section_addresses_from_script(Symbol_table*);
 496
 497   // Return whether SEG1 comes before SEG2 in the output file.
 498   static bool
 499   segment_precedes(const Output_segment* seg1, const Output_segment* seg2);
 500
 501   // A mapping used for group signatures.
 502   typedef Unordered_map<std::string, bool> Signatures;
 503
 504   // Mapping from input section name/type/flags to output section.  We
 505   // use canonicalized strings here.
 506
 507   typedef std::pair<Stringpool::Key,
 508                     std::pair<elfcpp::Elf_Word, elfcpp::Elf_Xword> > Key;
 509
 510   struct Hash_key
 511   {
 512     size_t
 513     operator()(const Key& k) const;
 514   };
 515
 516   typedef Unordered_map<Key, Output_section*, Hash_key> Section_name_map;
 517
 518   // A comparison class for segments.
 519
 520   struct Compare_segments
 521   {
 522     bool
 523     operator()(const Output_segment* seg1, const Output_segment* seg2)
 524     { return Layout::segment_precedes(seg1, seg2); }
 525   };
 526
 527   // A reference to the options on the command line.
 528   const General_options& options_;
 529   // Information set by scripts or by command line options.
 530   Script_options* script_options_;
 531   // The output section names.
 532   Stringpool namepool_;
 533   // The output symbol names.
 534   Stringpool sympool_;
 535   // The dynamic strings, if needed.
 536   Stringpool dynpool_;
 537   // The list of group sections and linkonce sections which we have seen.
 538   Signatures signatures_;
 539   // The mapping from input section name/type/flags to output sections.
 540   Section_name_map section_name_map_;
 541   // The list of output segments.
 542   Segment_list segment_list_;
 543   // The list of output sections.
 544   Section_list section_list_;
 545   // The list of output sections which are not attached to any output
 546   // segment.
 547   Section_list unattached_section_list_;
 548   // The list of unattached Output_data objects which require special
 549   // handling because they are not Output_sections.
 550   Data_list special_output_list_;
 551   // The section headers.
 552   Output_section_headers* section_headers_;
 553   // A pointer to the PT_TLS segment if there is one.
 554   Output_segment* tls_segment_;
 555   // The SHT_SYMTAB output section.
 556   Output_section* symtab_section_;
 557   // The SHT_DYNSYM output section if there is one.
 558   Output_section* dynsym_section_;
 559   // The SHT_DYNAMIC output section if there is one.
 560   Output_section* dynamic_section_;
 561   // The dynamic data which goes into dynamic_section_.
 562   Output_data_dynamic* dynamic_data_;
 563   // The exception frame output section if there is one.
 564   Output_section* eh_frame_section_;
 565   // The exception frame data for eh_frame_section_.
 566   Eh_frame* eh_frame_data_;
 567   // The exception frame header output section if there is one.
 568   Output_section* eh_frame_hdr_section_;
 569   // A list of group sections and their signatures.
 570   Group_signatures group_signatures_;
 571   // The size of the output file.
 572   off_t output_file_size_;
 573   // Whether we have seen an object file marked to require an
 574   // executable stack.
 575   bool input_requires_executable_stack_;
 576   // Whether we have seen at least one object file with an executable
 577   // stack marker.
 578   bool input_with_gnu_stack_note_;
 579   // Whether we have seen at least one object file without an
 580   // executable stack marker.
 581   bool input_without_gnu_stack_note_;
 582   // Whether we have seen an object file that uses the static TLS model.
 583   bool has_static_tls_;
 584   // Whether any sections require postprocessing.
 585   bool any_postprocessing_sections_;
 586 };
 587
 588 // This task handles writing out data in output sections which is not
 589 // part of an input section, or which requires special handling.  When
 590 // this is done, it unblocks both output_sections_blocker and
 591 // final_blocker.
 592
 593 class Write_sections_task : public Task
 594 {
 595  public:
 596   Write_sections_task(const Layout* layout, Output_file* of,
 597                       Task_token* output_sections_blocker,
 598                       Task_token* final_blocker)
 599     : layout_(layout), of_(of),
 600       output_sections_blocker_(output_sections_blocker),
 601       final_blocker_(final_blocker)
 602   { }
 603
 604   // The standard Task methods.
 605
 606   Task_token*
 607   is_runnable();
 608
 609   void
 610   locks(Task_locker*);
 611
 612   void
 613   run(Workqueue*);
 614
 615   std::string
 616   get_name() const
 617   { return "Write_sections_task"; }
 618
 619  private:
 620   class Write_sections_locker;
 621
 622   const Layout* layout_;
 623   Output_file* of_;
 624   Task_token* output_sections_blocker_;
 625   Task_token* final_blocker_;
 626 };
 627
 628 // This task handles writing out data which is not part of a section
 629 // or segment.
 630
 631 class Write_data_task : public Task
 632 {
 633  public:
 634   Write_data_task(const Layout* layout, const Symbol_table* symtab,
 635                   Output_file* of, Task_token* final_blocker)
 636     : layout_(layout), symtab_(symtab), of_(of), final_blocker_(final_blocker)
 637   { }
 638
 639   // The standard Task methods.
 640
 641   Task_token*
 642   is_runnable();
 643
 644   void
 645   locks(Task_locker*);
 646
 647   void
 648   run(Workqueue*);
 649
 650   std::string
 651   get_name() const
 652   { return "Write_data_task"; }
 653
 654  private:
 655   const Layout* layout_;
 656   const Symbol_table* symtab_;
 657   Output_file* of_;
 658   Task_token* final_blocker_;
 659 };
 660
 661 // This task handles writing out the global symbols.
 662
 663 class Write_symbols_task : public Task
 664 {
 665  public:
 666   Write_symbols_task(const Symbol_table* symtab,
 667                      const Input_objects* input_objects,
 668                      const Stringpool* sympool, const Stringpool* dynpool,
 669                      Output_file* of, Task_token* final_blocker)
 670     : symtab_(symtab), input_objects_(input_objects), sympool_(sympool),
 671       dynpool_(dynpool), of_(of), final_blocker_(final_blocker)
 672   { }
 673
 674   // The standard Task methods.
 675
 676   Task_token*
 677   is_runnable();
 678
 679   void
 680   locks(Task_locker*);
 681
 682   void
 683   run(Workqueue*);
 684
 685   std::string
 686   get_name() const
 687   { return "Write_symbols_task"; }
 688
 689  private:
 690   const Symbol_table* symtab_;
 691   const Input_objects* input_objects_;
 692   const Stringpool* sympool_;
 693   const Stringpool* dynpool_;
 694   Output_file* of_;
 695   Task_token* final_blocker_;
 696 };
 697
 698 // This task handles writing out data in output sections which can't
 699 // be written out until all the input sections have been handled.
 700 // This is for sections whose contents is based on the contents of
 701 // other output sections.
 702
 703 class Write_after_input_sections_task : public Task
 704 {
 705  public:
 706   Write_after_input_sections_task(Layout* layout, Output_file* of,
 707                                   Task_token* input_sections_blocker,
 708                                   Task_token* final_blocker)
 709     : layout_(layout), of_(of),
 710       input_sections_blocker_(input_sections_blocker),
 711       final_blocker_(final_blocker)
 712   { }
 713
 714   // The standard Task methods.
 715
 716   Task_token*
 717   is_runnable();
 718
 719   void
 720   locks(Task_locker*);
 721
 722   void
 723   run(Workqueue*);
 724
 725   std::string
 726   get_name() const
 727   { return "Write_after_input_sections_task"; }
 728
 729  private:
 730   Layout* layout_;
 731   Output_file* of_;
 732   Task_token* input_sections_blocker_;
 733   Task_token* final_blocker_;
 734 };
 735
 736 // This task function handles closing the file.
 737
 738 class Close_task_runner : public Task_function_runner
 739 {
 740  public:
 741   Close_task_runner(const General_options* options, const Layout* layout,
 742                     Output_file* of)
 743     : options_(options), layout_(layout), of_(of)
 744   { }
 745
 746   // Run the operation.
 747   void
 748   run(Workqueue*, const Task*);
 749
 750  private:
 751   const General_options* options_;
 752   const Layout* layout_;
 753   Output_file* of_;
 754 };
 755
 756 // A small helper function to align an address.
 757
 758 inline uint64_t
 759 align_address(uint64_t address, uint64_t addralign)
 760 {
 761   if (addralign != 0)
 762     address = (address + addralign - 1) &~ (addralign - 1);
 763   return address;
 764 }
 765
 766 } // End namespace gold.
 767
 768 #endif // !defined(GOLD_LAYOUT_H)