gold/incremental.h

   1 // inremental.h -- incremental linking support for gold   -*- C++ -*-
   2
   3 // Copyright 2009, 2010, 2011 Free Software Foundation, Inc.
   4 // Written by Mikolaj Zalewski <mikolajz@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_INCREMENTAL_H
  24 #define GOLD_INCREMENTAL_H
  25
  26 #include <map>
  27 #include <vector>
  28
  29 #include "elfcpp_file.h"
  30 #include "stringpool.h"
  31 #include "workqueue.h"
  32 #include "fileread.h"
  33 #include "output.h"
  34 #include "archive.h"
  35
  36 namespace gold
  37 {
  38
  39 class Input_argument;
  40 class Incremental_inputs_checker;
  41 class Incremental_script_entry;
  42 class Incremental_object_entry;
  43 class Incremental_dynobj_entry;
  44 class Incremental_archive_entry;
  45 class Incremental_inputs;
  46 class Incremental_binary;
  47 class Incremental_library;
  48 class Object;
  49
  50 // Incremental input type as stored in .gnu_incremental_inputs.
  51
  52 enum Incremental_input_type
  53 {
  54   INCREMENTAL_INPUT_OBJECT = 1,
  55   INCREMENTAL_INPUT_ARCHIVE_MEMBER = 2,
  56   INCREMENTAL_INPUT_ARCHIVE = 3,
  57   INCREMENTAL_INPUT_SHARED_LIBRARY = 4,
  58   INCREMENTAL_INPUT_SCRIPT = 5
  59 };
  60
  61 // Incremental input file flags.
  62 // The input file type is stored in the lower eight bits.
  63
  64 enum Incremental_input_flags
  65 {
  66   INCREMENTAL_INPUT_IN_SYSTEM_DIR = 0x8000,
  67   INCREMENTAL_INPUT_AS_NEEDED = 0x4000
  68 };
  69
  70 // Symbol flags for the incremental symbol table.
  71 // These flags are stored in the top two bits of
  72 // the symbol index field.
  73
  74 enum Incremental_shlib_symbol_flags
  75 {
  76   // Symbol is defined in this library.
  77   INCREMENTAL_SHLIB_SYM_DEF = 2,
  78   // Symbol is defined in this library, with a COPY relocation.
  79   INCREMENTAL_SHLIB_SYM_COPY = 3
  80 };
  81
  82 static const int INCREMENTAL_SHLIB_SYM_FLAGS_SHIFT = 30;
  83
  84 // Return TRUE if a section of type SH_TYPE can be updated in place
  85 // during an incremental update.
  86 bool
  87 can_incremental_update(unsigned int sh_type);
  88
  89 // Create an Incremental_binary object for FILE. Returns NULL is this is not
  90 // possible, e.g. FILE is not an ELF file or has an unsupported target.
  91
  92 Incremental_binary*
  93 open_incremental_binary(Output_file* file);
  94
  95 // Base class for recording each input file.
  96
  97 class Incremental_input_entry
  98 {
  99  public:
 100   Incremental_input_entry(Stringpool::Key filename_key, unsigned int arg_serial,
 101                           Timespec mtime)
 102     : filename_key_(filename_key), file_index_(0), offset_(0), info_offset_(0),
 103       arg_serial_(arg_serial), mtime_(mtime), is_in_system_directory_(false),
 104       as_needed_(false)
 105   { }
 106
 107   virtual
 108   ~Incremental_input_entry()
 109   { }
 110
 111   // Return the type of input file.
 112   Incremental_input_type
 113   type() const
 114   { return this->do_type(); }
 115
 116   // Set the index and section offset of this input file entry.
 117   void
 118   set_offset(unsigned int file_index, unsigned int offset)
 119   {
 120     this->file_index_ = file_index;
 121     this->offset_ = offset;
 122   }
 123
 124   // Set the section offset of the supplemental information for this entry.
 125   void
 126   set_info_offset(unsigned int info_offset)
 127   { this->info_offset_ = info_offset; }
 128
 129   // Get the index of this input file entry.
 130   unsigned int
 131   get_file_index() const
 132   { return this->file_index_; }
 133
 134   // Get the section offset of this input file entry.
 135   unsigned int
 136   get_offset() const
 137   { return this->offset_; }
 138
 139   // Get the section offset of the supplemental information for this entry.
 140   unsigned int
 141   get_info_offset() const
 142   { return this->info_offset_; }
 143
 144   // Get the stringpool key for the input filename.
 145   Stringpool::Key
 146   get_filename_key() const
 147   { return this->filename_key_; }
 148
 149   // Get the serial number of the input file.
 150   unsigned int
 151   arg_serial() const
 152   { return this->arg_serial_; }
 153
 154   // Get the modification time of the input file.
 155   const Timespec&
 156   get_mtime() const
 157   { return this->mtime_; }
 158
 159   // Record that the file was found in a system directory.
 160   void
 161   set_is_in_system_directory()
 162   { this->is_in_system_directory_ = true; }
 163
 164   // Return TRUE if the file was found in a system directory.
 165   bool
 166   is_in_system_directory() const
 167   { return this->is_in_system_directory_; }
 168
 169   // Record that the file was linked with --as-needed.
 170   void
 171   set_as_needed()
 172   { this->as_needed_ = true; }
 173
 174   // Return TRUE if the file was linked with --as-needed.
 175   bool
 176   as_needed() const
 177   { return this->as_needed_; }
 178
 179   // Return a pointer to the derived Incremental_script_entry object.
 180   // Return NULL for input entries that are not script files.
 181   Incremental_script_entry*
 182   script_entry()
 183   { return this->do_script_entry(); }
 184
 185   // Return a pointer to the derived Incremental_object_entry object.
 186   // Return NULL for input entries that are not object files.
 187   Incremental_object_entry*
 188   object_entry()
 189   { return this->do_object_entry(); }
 190
 191   // Return a pointer to the derived Incremental_dynobj_entry object.
 192   // Return NULL for input entries that are not shared object files.
 193   Incremental_dynobj_entry*
 194   dynobj_entry()
 195   { return this->do_dynobj_entry(); }
 196
 197   // Return a pointer to the derived Incremental_archive_entry object.
 198   // Return NULL for input entries that are not archive files.
 199   Incremental_archive_entry*
 200   archive_entry()
 201   { return this->do_archive_entry(); }
 202
 203  protected:
 204   // Return the type of input file.
 205   virtual Incremental_input_type
 206   do_type() const = 0;
 207
 208   // Return a pointer to the derived Incremental_script_entry object.
 209   // Return NULL for input entries that are not script files.
 210   virtual Incremental_script_entry*
 211   do_script_entry()
 212   { return NULL; }
 213
 214   // Return a pointer to the derived Incremental_object_entry object.
 215   // Return NULL for input entries that are not object files.
 216   virtual Incremental_object_entry*
 217   do_object_entry()
 218   { return NULL; }
 219
 220   // Return a pointer to the derived Incremental_dynobj_entry object.
 221   // Return NULL for input entries that are not shared object files.
 222   virtual Incremental_dynobj_entry*
 223   do_dynobj_entry()
 224   { return NULL; }
 225
 226   // Return a pointer to the derived Incremental_archive_entry object.
 227   // Return NULL for input entries that are not archive files.
 228   virtual Incremental_archive_entry*
 229   do_archive_entry()
 230   { return NULL; }
 231
 232  private:
 233   // Key of the filename string in the section stringtable.
 234   Stringpool::Key filename_key_;
 235
 236   // Index of the entry in the output section.
 237   unsigned int file_index_;
 238
 239   // Offset of the entry in the output section.
 240   unsigned int offset_;
 241
 242   // Offset of the extra information in the output section.
 243   unsigned int info_offset_;
 244
 245   // Serial number of the file in the argument list.
 246   unsigned int arg_serial_;
 247
 248   // Last modification time of the file.
 249   Timespec mtime_;
 250
 251   // TRUE if the file was found in a system directory.
 252   bool is_in_system_directory_;
 253
 254   // TRUE if the file was linked with --as-needed.
 255   bool as_needed_;
 256 };
 257
 258 // Information about a script input that will persist during the whole linker
 259 // run.  Needed only during an incremental build to retrieve the input files
 260 // added by this script.
 261
 262 class Script_info
 263 {
 264  public:
 265   Script_info(const std::string& filename)
 266     : filename_(filename), input_file_index_(0),
 267       incremental_script_entry_(NULL)
 268   { }
 269
 270   Script_info(const std::string& filename, unsigned int input_file_index)
 271     : filename_(filename), input_file_index_(input_file_index),
 272       incremental_script_entry_(NULL)
 273   { }
 274
 275   // Store a pointer to the incremental information for this script.
 276   void
 277   set_incremental_info(Incremental_script_entry* entry)
 278   { this->incremental_script_entry_ = entry; }
 279
 280   // Return the filename.
 281   const std::string&
 282   filename() const
 283   { return this->filename_; }
 284
 285   // Return the input file index.
 286   unsigned int
 287   input_file_index() const
 288   { return this->input_file_index_; }
 289
 290   // Return the pointer to the incremental information for this script.
 291   Incremental_script_entry*
 292   incremental_info() const
 293   { return this->incremental_script_entry_; }
 294
 295  private:
 296   const std::string filename_;
 297   unsigned int input_file_index_;
 298   Incremental_script_entry* incremental_script_entry_;
 299 };
 300
 301 // Class for recording input scripts.
 302
 303 class Incremental_script_entry : public Incremental_input_entry
 304 {
 305  public:
 306   Incremental_script_entry(Stringpool::Key filename_key,
 307                            unsigned int arg_serial, Script_info* script,
 308                            Timespec mtime)
 309     : Incremental_input_entry(filename_key, arg_serial, mtime),
 310       script_(script), objects_()
 311   { }
 312
 313   // Add a member object to the archive.
 314   void
 315   add_object(Incremental_input_entry* obj_entry)
 316   {
 317     this->objects_.push_back(obj_entry);
 318   }
 319
 320   // Return the number of objects included by this script.
 321   unsigned int
 322   get_object_count()
 323   { return this->objects_.size(); }
 324
 325   // Return the Nth object.
 326   Incremental_input_entry*
 327   get_object(unsigned int n)
 328   {
 329     gold_assert(n < this->objects_.size());
 330     return this->objects_[n];
 331   }
 332
 333  protected:
 334   virtual Incremental_input_type
 335   do_type() const
 336   { return INCREMENTAL_INPUT_SCRIPT; }
 337
 338   // Return a pointer to the derived Incremental_script_entry object.
 339   virtual Incremental_script_entry*
 340   do_script_entry()
 341   { return this; }
 342
 343  private:
 344   // Information about the script file.
 345   Script_info* script_;
 346   // Objects that have been included by this script.
 347   std::vector<Incremental_input_entry*> objects_;
 348 };
 349
 350 // Class for recording input object files.
 351
 352 class Incremental_object_entry : public Incremental_input_entry
 353 {
 354  public:
 355   Incremental_object_entry(Stringpool::Key filename_key, Object* obj,
 356                            unsigned int arg_serial, Timespec mtime)
 357     : Incremental_input_entry(filename_key, arg_serial, mtime), obj_(obj),
 358       is_member_(false), sections_(), groups_()
 359   { this->sections_.reserve(obj->shnum()); }
 360
 361   // Get the object.
 362   Object*
 363   object() const
 364   { return this->obj_; }
 365
 366   // Record that this object is an archive member.
 367   void
 368   set_is_member()
 369   { this->is_member_ = true; }
 370
 371   // Return true if this object is an archive member.
 372   bool
 373   is_member() const
 374   { return this->is_member_; }
 375
 376   // Add an input section.
 377   void
 378   add_input_section(unsigned int shndx, Stringpool::Key name_key, off_t sh_size)
 379   { this->sections_.push_back(Input_section(shndx, name_key, sh_size)); }
 380
 381   // Return the number of input sections in this object.
 382   unsigned int
 383   get_input_section_count() const
 384   { return this->sections_.size(); }
 385
 386   // Return the input section index for the Nth input section.
 387   Stringpool::Key
 388   get_input_section_index(unsigned int n) const
 389   { return this->sections_[n].shndx_; }
 390
 391   // Return the stringpool key of the Nth input section.
 392   Stringpool::Key
 393   get_input_section_name_key(unsigned int n) const
 394   { return this->sections_[n].name_key_; }
 395
 396   // Return the size of the Nth input section.
 397   off_t
 398   get_input_section_size(unsigned int n) const
 399   { return this->sections_[n].sh_size_; }
 400
 401   // Add a kept COMDAT group.
 402   void
 403   add_comdat_group(Stringpool::Key signature_key)
 404   { this->groups_.push_back(signature_key); }
 405
 406   // Return the number of COMDAT groups.
 407   unsigned int
 408   get_comdat_group_count() const
 409   { return this->groups_.size(); }
 410
 411   // Return the stringpool key for the signature of the Nth comdat group.
 412   Stringpool::Key
 413   get_comdat_signature_key(unsigned int n) const
 414   { return this->groups_[n]; }
 415
 416  protected:
 417   virtual Incremental_input_type
 418   do_type() const
 419   {
 420     return (this->is_member_
 421             ? INCREMENTAL_INPUT_ARCHIVE_MEMBER
 422             : INCREMENTAL_INPUT_OBJECT);
 423   }
 424
 425   // Return a pointer to the derived Incremental_object_entry object.
 426   virtual Incremental_object_entry*
 427   do_object_entry()
 428   { return this; }
 429
 430  private:
 431   // The object file itself.
 432   Object* obj_;
 433
 434   // Whether this object is an archive member.
 435   bool is_member_;
 436
 437   // Input sections.
 438   struct Input_section
 439   {
 440     Input_section(unsigned int shndx, Stringpool::Key name_key, off_t sh_size)
 441       : shndx_(shndx), name_key_(name_key), sh_size_(sh_size)
 442     { }
 443     unsigned int shndx_;
 444     Stringpool::Key name_key_;
 445     off_t sh_size_;
 446   };
 447   std::vector<Input_section> sections_;
 448
 449   // COMDAT groups.
 450   std::vector<Stringpool::Key> groups_;
 451 };
 452
 453 // Class for recording shared library input files.
 454
 455 class Incremental_dynobj_entry : public Incremental_input_entry
 456 {
 457  public:
 458   Incremental_dynobj_entry(Stringpool::Key filename_key,
 459                            Stringpool::Key soname_key, Object* obj,
 460                            unsigned int arg_serial, Timespec mtime)
 461     : Incremental_input_entry(filename_key, arg_serial, mtime),
 462       soname_key_(soname_key), obj_(obj)
 463   { }
 464
 465   // Get the object.
 466   Object*
 467   object() const
 468   { return this->obj_; }
 469
 470   // Get the stringpool key for the soname.
 471   Stringpool::Key
 472   get_soname_key() const
 473   { return this->soname_key_; }
 474
 475  protected:
 476   virtual Incremental_input_type
 477   do_type() const
 478   { return INCREMENTAL_INPUT_SHARED_LIBRARY; }
 479
 480   // Return a pointer to the derived Incremental_dynobj_entry object.
 481   virtual Incremental_dynobj_entry*
 482   do_dynobj_entry()
 483   { return this; }
 484
 485  private:
 486   // Key of the soname string in the section stringtable.
 487   Stringpool::Key soname_key_;
 488
 489   // The object file itself.
 490   Object* obj_;
 491 };
 492
 493 // Class for recording archive library input files.
 494
 495 class Incremental_archive_entry : public Incremental_input_entry
 496 {
 497  public:
 498   Incremental_archive_entry(Stringpool::Key filename_key,
 499                             unsigned int arg_serial, Timespec mtime)
 500     : Incremental_input_entry(filename_key, arg_serial, mtime), members_(),
 501       unused_syms_()
 502   { }
 503
 504   // Add a member object to the archive.
 505   void
 506   add_object(Incremental_object_entry* obj_entry)
 507   {
 508     this->members_.push_back(obj_entry);
 509     obj_entry->set_is_member();
 510   }
 511
 512   // Add an unused global symbol to the archive.
 513   void
 514   add_unused_global_symbol(Stringpool::Key symbol_key)
 515   { this->unused_syms_.push_back(symbol_key); }
 516
 517   // Return the number of member objects included in the link.
 518   unsigned int
 519   get_member_count()
 520   { return this->members_.size(); }
 521
 522   // Return the Nth member object.
 523   Incremental_object_entry*
 524   get_member(unsigned int n)
 525   { return this->members_[n]; }
 526
 527   // Return the number of unused global symbols in this archive.
 528   unsigned int
 529   get_unused_global_symbol_count()
 530   { return this->unused_syms_.size(); }
 531
 532   // Return the Nth unused global symbol.
 533   Stringpool::Key
 534   get_unused_global_symbol(unsigned int n)
 535   { return this->unused_syms_[n]; }
 536
 537  protected:
 538   virtual Incremental_input_type
 539   do_type() const
 540   { return INCREMENTAL_INPUT_ARCHIVE; }
 541
 542   // Return a pointer to the derived Incremental_archive_entry object.
 543   virtual Incremental_archive_entry*
 544   do_archive_entry()
 545   { return this; }
 546
 547  private:
 548   // Members of the archive that have been included in the link.
 549   std::vector<Incremental_object_entry*> members_;
 550
 551   // Unused global symbols from this archive.
 552   std::vector<Stringpool::Key> unused_syms_;
 553 };
 554
 555 // This class contains the information needed during an incremental
 556 // build about the inputs necessary to build the .gnu_incremental_inputs.
 557
 558 class Incremental_inputs
 559 {
 560  public:
 561   typedef std::vector<Incremental_input_entry*> Input_list;
 562
 563   Incremental_inputs()
 564     : inputs_(), command_line_(), command_line_key_(0),
 565       strtab_(new Stringpool()), current_object_(NULL),
 566       current_object_entry_(NULL), inputs_section_(NULL),
 567       symtab_section_(NULL), relocs_section_(NULL),
 568       reloc_count_(0)
 569   { }
 570
 571   ~Incremental_inputs() { delete this->strtab_; }
 572
 573   // Record the command line.
 574   void
 575   report_command_line(int argc, const char* const* argv);
 576
 577   // Record the initial info for archive file ARCHIVE.
 578   void
 579   report_archive_begin(Library_base* arch, unsigned int arg_serial,
 580                        Script_info* script_info);
 581
 582   // Record the final info for archive file ARCHIVE.
 583   void
 584   report_archive_end(Library_base* arch);
 585
 586   // Record the info for object file OBJ.  If ARCH is not NULL,
 587   // attach the object file to the archive.
 588   void
 589   report_object(Object* obj, unsigned int arg_serial, Library_base* arch,
 590                 Script_info* script_info);
 591
 592   // Record an input section belonging to object file OBJ.
 593   void
 594   report_input_section(Object* obj, unsigned int shndx, const char* name,
 595                        off_t sh_size);
 596
 597   // Record a kept COMDAT group belonging to object file OBJ.
 598   void
 599   report_comdat_group(Object* obj, const char* name);
 600
 601   // Record the info for input script SCRIPT.
 602   void
 603   report_script(Script_info* script, unsigned int arg_serial,
 604                 Timespec mtime);
 605
 606   // Return the running count of incremental relocations.
 607   unsigned int
 608   get_reloc_count() const
 609   { return this->reloc_count_; }
 610
 611   // Update the running count of incremental relocations.
 612   void
 613   set_reloc_count(unsigned int count)
 614   { this->reloc_count_ = count; }
 615
 616   // Prepare for layout.  Called from Layout::finalize.
 617   void
 618   finalize();
 619
 620   // Create the .gnu_incremental_inputs and related sections.
 621   void
 622   create_data_sections(Symbol_table* symtab);
 623
 624   // Return the .gnu_incremental_inputs section.
 625   Output_section_data*
 626   inputs_section() const
 627   { return this->inputs_section_; }
 628
 629   // Return the .gnu_incremental_symtab section.
 630   Output_data_space*
 631   symtab_section() const
 632   { return this->symtab_section_; }
 633
 634   // Return the .gnu_incremental_relocs section.
 635   Output_data_space*
 636   relocs_section() const
 637   { return this->relocs_section_; }
 638
 639   // Return the .gnu_incremental_got_plt section.
 640   Output_data_space*
 641   got_plt_section() const
 642   { return this->got_plt_section_; }
 643
 644   // Return the .gnu_incremental_strtab stringpool.
 645   Stringpool*
 646   get_stringpool() const
 647   { return this->strtab_; }
 648
 649   // Return the canonical form of the command line, as will be stored in
 650   // .gnu_incremental_strtab.
 651   const std::string&
 652   command_line() const
 653   { return this->command_line_; }
 654
 655   // Return the stringpool key of the command line.
 656   Stringpool::Key
 657   command_line_key() const
 658   { return this->command_line_key_; }
 659
 660   // Return the number of input files.
 661   int
 662   input_file_count() const
 663   { return this->inputs_.size(); }
 664
 665   // Return the input files.
 666   const Input_list&
 667   input_files() const
 668   { return this->inputs_; }
 669
 670   // Return the sh_entsize value for the .gnu_incremental_relocs section.
 671   unsigned int
 672   relocs_entsize() const;
 673
 674  private:
 675   // The list of input files.
 676   Input_list inputs_;
 677
 678   // Canonical form of the command line, as will be stored in
 679   // .gnu_incremental_strtab.
 680   std::string command_line_;
 681
 682   // The key of the command line string in the string pool.
 683   Stringpool::Key command_line_key_;
 684
 685   // The .gnu_incremental_strtab string pool associated with the
 686   // .gnu_incremental_inputs.
 687   Stringpool* strtab_;
 688
 689   // Keep track of the object currently being processed.
 690   Object* current_object_;
 691   Incremental_object_entry* current_object_entry_;
 692
 693   // The .gnu_incremental_inputs section.
 694   Output_section_data* inputs_section_;
 695
 696   // The .gnu_incremental_symtab section.
 697   Output_data_space* symtab_section_;
 698
 699   // The .gnu_incremental_relocs section.
 700   Output_data_space* relocs_section_;
 701
 702   // The .gnu_incremental_got_plt section.
 703   Output_data_space* got_plt_section_;
 704
 705   // Total count of incremental relocations.  Updated during Scan_relocs
 706   // phase at the completion of each object file.
 707   unsigned int reloc_count_;
 708 };
 709
 710 // Reader class for global symbol info from an object file entry in
 711 // the .gnu_incremental_inputs section.
 712
 713 template<bool big_endian>
 714 class Incremental_global_symbol_reader
 715 {
 716  private:
 717   typedef elfcpp::Swap<32, big_endian> Swap32;
 718
 719  public:
 720   Incremental_global_symbol_reader(const unsigned char* p)
 721     : p_(p)
 722   { }
 723
 724   unsigned int
 725   output_symndx() const
 726   { return Swap32::readval(this->p_); }
 727
 728   unsigned int
 729   shndx() const
 730   { return Swap32::readval(this->p_ + 4); }
 731
 732   unsigned int
 733   next_offset() const
 734   { return Swap32::readval(this->p_ + 8); }
 735
 736   unsigned int
 737   reloc_count() const
 738   { return Swap32::readval(this->p_ + 12); }
 739
 740   unsigned int
 741   reloc_offset() const
 742   { return Swap32::readval(this->p_ + 16); }
 743
 744  private:
 745   // Base address of the symbol entry.
 746   const unsigned char* p_;
 747 };
 748
 749 // Reader class for .gnu_incremental_inputs section.
 750
 751 template<int size, bool big_endian>
 752 class Incremental_inputs_reader
 753 {
 754  private:
 755   typedef elfcpp::Swap<size, big_endian> Swap;
 756   typedef elfcpp::Swap<16, big_endian> Swap16;
 757   typedef elfcpp::Swap<32, big_endian> Swap32;
 758   typedef elfcpp::Swap<64, big_endian> Swap64;
 759
 760  public:
 761   Incremental_inputs_reader()
 762     : p_(NULL), strtab_(NULL, 0), input_file_count_(0)
 763   { }
 764
 765   Incremental_inputs_reader(const unsigned char* p,
 766                             const elfcpp::Elf_strtab& strtab)
 767     : p_(p), strtab_(strtab)
 768   { this->input_file_count_ = Swap32::readval(this->p_ + 4); }
 769
 770   // Return the version number.
 771   unsigned int
 772   version() const
 773   { return Swap32::readval(this->p_); }
 774
 775   // Return the count of input file entries.
 776   unsigned int
 777   input_file_count() const
 778   { return this->input_file_count_; }
 779
 780   // Return the command line.
 781   const char*
 782   command_line() const
 783   {
 784     unsigned int offset = Swap32::readval(this->p_ + 8);
 785     return this->get_string(offset);
 786   }
 787
 788   // Reader class for an input file entry and its supplemental info.
 789   class Incremental_input_entry_reader
 790   {
 791    public:
 792     Incremental_input_entry_reader(const Incremental_inputs_reader* inputs,
 793                                    unsigned int offset)
 794       : inputs_(inputs), offset_(offset)
 795     {
 796       this->info_offset_ = Swap32::readval(inputs->p_ + offset + 4);
 797       this->flags_ = Swap16::readval(this->inputs_->p_ + offset + 20);
 798     }
 799
 800     // Return the filename.
 801     const char*
 802     filename() const
 803     {
 804       unsigned int offset = Swap32::readval(this->inputs_->p_ + this->offset_);
 805       return this->inputs_->get_string(offset);
 806     }
 807
 808     // Return the argument serial number.
 809     unsigned int
 810     arg_serial() const
 811     {
 812       return Swap16::readval(this->inputs_->p_ + this->offset_ + 22);
 813     }
 814
 815     // Return the timestamp.
 816     Timespec
 817     get_mtime() const
 818     {
 819       Timespec t;
 820       const unsigned char* p = this->inputs_->p_ + this->offset_ + 8;
 821       t.seconds = Swap64::readval(p);
 822       t.nanoseconds = Swap32::readval(p+8);
 823       return t;
 824     }
 825
 826     // Return the type of input file.
 827     Incremental_input_type
 828     type() const
 829     { return static_cast<Incremental_input_type>(this->flags_ & 0xff); }
 830
 831     // Return TRUE if the file was found in a system directory.
 832     bool
 833     is_in_system_directory() const
 834     { return (this->flags_ & INCREMENTAL_INPUT_IN_SYSTEM_DIR) != 0; }
 835
 836     // Return TRUE if the file was linked with --as-needed.
 837     bool
 838     as_needed() const
 839     { return (this->flags_ & INCREMENTAL_INPUT_AS_NEEDED) != 0; }
 840
 841     // Return the input section count -- for objects only.
 842     unsigned int
 843     get_input_section_count() const
 844     {
 845       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
 846                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER);
 847       return Swap32::readval(this->inputs_->p_ + this->info_offset_);
 848     }
 849
 850     // Return the soname -- for shared libraries only.
 851     const char*
 852     get_soname() const
 853     {
 854       gold_assert(this->type() == INCREMENTAL_INPUT_SHARED_LIBRARY);
 855       unsigned int offset = Swap32::readval(this->inputs_->p_
 856                                             + this->info_offset_);
 857       return this->inputs_->get_string(offset);
 858     }
 859
 860     // Return the offset of the supplemental info for symbol SYMNDX --
 861     // for objects only.
 862     unsigned int
 863     get_symbol_offset(unsigned int symndx) const
 864     {
 865       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
 866                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER);
 867
 868       unsigned int section_count = this->get_input_section_count();
 869       return (this->info_offset_ + 28
 870               + section_count * input_section_entry_size
 871               + symndx * 20);
 872     }
 873
 874     // Return the global symbol count -- for objects & shared libraries only.
 875     unsigned int
 876     get_global_symbol_count() const
 877     {
 878       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
 879                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER
 880                   || this->type() == INCREMENTAL_INPUT_SHARED_LIBRARY);
 881       return Swap32::readval(this->inputs_->p_ + this->info_offset_ + 4);
 882     }
 883
 884     // Return the offset of the first local symbol -- for objects only.
 885     unsigned int
 886     get_local_symbol_offset() const
 887     {
 888       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
 889                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER);
 890
 891       return Swap32::readval(this->inputs_->p_ + this->info_offset_ + 8);
 892     }
 893
 894     // Return the local symbol count -- for objects only.
 895     unsigned int
 896     get_local_symbol_count() const
 897     {
 898       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
 899                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER);
 900
 901       return Swap32::readval(this->inputs_->p_ + this->info_offset_ + 12);
 902     }
 903
 904     // Return the index of the first dynamic relocation -- for objects only.
 905     unsigned int
 906     get_first_dyn_reloc() const
 907     {
 908       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
 909                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER);
 910
 911       return Swap32::readval(this->inputs_->p_ + this->info_offset_ + 16);
 912     }
 913
 914     // Return the dynamic relocation count -- for objects only.
 915     unsigned int
 916     get_dyn_reloc_count() const
 917     {
 918       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
 919                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER);
 920
 921       return Swap32::readval(this->inputs_->p_ + this->info_offset_ + 20);
 922     }
 923
 924     // Return the COMDAT group count -- for objects only.
 925     unsigned int
 926     get_comdat_group_count() const
 927     {
 928       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
 929                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER);
 930
 931       return Swap32::readval(this->inputs_->p_ + this->info_offset_ + 24);
 932     }
 933
 934     // Return the object count -- for scripts only.
 935     unsigned int
 936     get_object_count() const
 937     {
 938       gold_assert(this->type() == INCREMENTAL_INPUT_SCRIPT);
 939       return Swap32::readval(this->inputs_->p_ + this->info_offset_);
 940     }
 941
 942     // Return the input file offset for object N -- for scripts only.
 943     unsigned int
 944     get_object_offset(unsigned int n) const
 945     {
 946       gold_assert(this->type() == INCREMENTAL_INPUT_SCRIPT);
 947       return Swap32::readval(this->inputs_->p_ + this->info_offset_
 948                              + 4 + n * 4);
 949     }
 950
 951     // Return the member count -- for archives only.
 952     unsigned int
 953     get_member_count() const
 954     {
 955       gold_assert(this->type() == INCREMENTAL_INPUT_ARCHIVE);
 956       return Swap32::readval(this->inputs_->p_ + this->info_offset_);
 957     }
 958
 959     // Return the unused symbol count -- for archives only.
 960     unsigned int
 961     get_unused_symbol_count() const
 962     {
 963       gold_assert(this->type() == INCREMENTAL_INPUT_ARCHIVE);
 964       return Swap32::readval(this->inputs_->p_ + this->info_offset_ + 4);
 965     }
 966
 967     // Return the input file offset for archive member N -- for archives only.
 968     unsigned int
 969     get_member_offset(unsigned int n) const
 970     {
 971       gold_assert(this->type() == INCREMENTAL_INPUT_ARCHIVE);
 972       return Swap32::readval(this->inputs_->p_ + this->info_offset_
 973                              + 8 + n * 4);
 974     }
 975
 976     // Return the Nth unused global symbol -- for archives only.
 977     const char*
 978     get_unused_symbol(unsigned int n) const
 979     {
 980       gold_assert(this->type() == INCREMENTAL_INPUT_ARCHIVE);
 981       unsigned int member_count = this->get_member_count();
 982       unsigned int offset = Swap32::readval(this->inputs_->p_
 983                                             + this->info_offset_ + 8
 984                                             + member_count * 4
 985                                             + n * 4);
 986       return this->inputs_->get_string(offset);
 987     }
 988
 989     // Information about an input section.
 990     struct Input_section_info
 991     {
 992       const char* name;
 993       unsigned int output_shndx;
 994       off_t sh_offset;
 995       off_t sh_size;
 996     };
 997
 998     // Return info about the Nth input section -- for objects only.
 999     Input_section_info
1000     get_input_section(unsigned int n) const
1001     {
1002       Input_section_info info;
1003       const unsigned char* p = (this->inputs_->p_
1004                                 + this->info_offset_ + 28
1005                                 + n * input_section_entry_size);
1006       unsigned int name_offset = Swap32::readval(p);
1007       info.name = this->inputs_->get_string(name_offset);
1008       info.output_shndx = Swap32::readval(p + 4);
1009       info.sh_offset = Swap::readval(p + 8);
1010       info.sh_size = Swap::readval(p + 8 + size / 8);
1011       return info;
1012     }
1013
1014     // Return info about the Nth global symbol -- for objects only.
1015     Incremental_global_symbol_reader<big_endian>
1016     get_global_symbol_reader(unsigned int n) const
1017     {
1018       gold_assert(this->type() == INCREMENTAL_INPUT_OBJECT
1019                   || this->type() == INCREMENTAL_INPUT_ARCHIVE_MEMBER);
1020       unsigned int section_count = this->get_input_section_count();
1021       const unsigned char* p = (this->inputs_->p_
1022                                 + this->info_offset_ + 28
1023                                 + section_count * input_section_entry_size
1024                                 + n * 20);
1025       return Incremental_global_symbol_reader<big_endian>(p);
1026     }
1027
1028     // Return the signature of the Nth comdat group -- for objects only.
1029     const char*
1030     get_comdat_group_signature(unsigned int n) const
1031     {
1032       unsigned int section_count = this->get_input_section_count();
1033       unsigned int symbol_count = this->get_global_symbol_count();
1034       const unsigned char* p = (this->inputs_->p_
1035                                 + this->info_offset_ + 28
1036                                 + section_count * input_section_entry_size
1037                                 + symbol_count * 20
1038                                 + n * 4);
1039       unsigned int name_offset = Swap32::readval(p);
1040       return this->inputs_->get_string(name_offset);
1041     }
1042
1043     // Return the output symbol index for the Nth global symbol -- for shared
1044     // libraries only.  Sets *IS_DEF to TRUE if the symbol is defined in this
1045     // input file.  Sets *IS_COPY to TRUE if the symbol was copied from this
1046     // input file with a COPY relocation.
1047     unsigned int
1048     get_output_symbol_index(unsigned int n, bool* is_def, bool* is_copy)
1049     {
1050       gold_assert(this->type() == INCREMENTAL_INPUT_SHARED_LIBRARY);
1051       const unsigned char* p = (this->inputs_->p_
1052                                 + this->info_offset_ + 8
1053                                 + n * 4);
1054       unsigned int output_symndx = Swap32::readval(p);
1055       unsigned int flags = output_symndx >> INCREMENTAL_SHLIB_SYM_FLAGS_SHIFT;
1056       output_symndx &= ((1U << INCREMENTAL_SHLIB_SYM_FLAGS_SHIFT) - 1);
1057       switch (flags)
1058         {
1059           case INCREMENTAL_SHLIB_SYM_DEF:
1060             *is_def = true;
1061             *is_copy = false;
1062             break;
1063           case INCREMENTAL_SHLIB_SYM_COPY:
1064             *is_def = true;
1065             *is_copy = true;
1066             break;
1067           default:
1068             *is_def = false;
1069             *is_copy = false;
1070         }
1071       return output_symndx;
1072     }
1073
1074    private:
1075     // Size of an input section entry.
1076     static const unsigned int input_section_entry_size = 8 + 2 * size / 8;
1077     // The reader instance for the containing section.
1078     const Incremental_inputs_reader* inputs_;
1079     // The flags, including the type of input file.
1080     unsigned int flags_;
1081     // Section offset to the input file entry.
1082     unsigned int offset_;
1083     // Section offset to the supplemental info for the input file.
1084     unsigned int info_offset_;
1085   };
1086
1087   // Return the offset of an input file entry given its index N.
1088   unsigned int
1089   input_file_offset(unsigned int n) const
1090   {
1091     gold_assert(n < this->input_file_count_);
1092     return 16 + n * 24;
1093   }
1094
1095   // Return the index of an input file entry given its OFFSET.
1096   unsigned int
1097   input_file_index(unsigned int offset) const
1098   {
1099     int n = (offset - 16) / 24;
1100     gold_assert(input_file_offset(n) == offset);
1101     return n;
1102   }
1103
1104   // Return a reader for the Nth input file entry.
1105   Incremental_input_entry_reader
1106   input_file(unsigned int n) const
1107   { return Incremental_input_entry_reader(this, this->input_file_offset(n)); }
1108
1109   // Return a reader for the input file entry at OFFSET.
1110   Incremental_input_entry_reader
1111   input_file_at_offset(unsigned int offset) const
1112   {
1113     gold_assert(offset < 16 + this->input_file_count_ * 24);
1114     return Incremental_input_entry_reader(this, offset);
1115   }
1116
1117   // Return a reader for the global symbol info at OFFSET.
1118   Incremental_global_symbol_reader<big_endian>
1119   global_symbol_reader_at_offset(unsigned int offset) const
1120   {
1121     const unsigned char* p = this->p_ + offset;
1122     return Incremental_global_symbol_reader<big_endian>(p);
1123   }
1124
1125  private:
1126   // Lookup a string in the ELF string table.
1127   const char* get_string(unsigned int offset) const
1128   {
1129     const char* s;
1130     if (this->strtab_.get_c_string(offset, &s))
1131       return s;
1132     return NULL;
1133   }
1134
1135   // Base address of the .gnu_incremental_inputs section.
1136   const unsigned char* p_;
1137   // The associated ELF string table.
1138   elfcpp::Elf_strtab strtab_;
1139   // The number of input file entries in this section.
1140   unsigned int input_file_count_;
1141 };
1142
1143 // Reader class for the .gnu_incremental_symtab section.
1144
1145 template<bool big_endian>
1146 class Incremental_symtab_reader
1147 {
1148  public:
1149   Incremental_symtab_reader()
1150     : p_(NULL), len_(0)
1151   { }
1152
1153   Incremental_symtab_reader(const unsigned char* p, off_t len)
1154     : p_(p), len_(len)
1155   { }
1156
1157   // Return the count of symbols in this section.
1158   unsigned int
1159   symbol_count() const
1160   { return static_cast<unsigned int>(this->len_ / 4); }
1161
1162   // Return the list head for symbol table entry N.
1163   unsigned int
1164   get_list_head(unsigned int n) const
1165   { return elfcpp::Swap<32, big_endian>::readval(this->p_ + 4 * n); }
1166
1167  private:
1168   // Base address of the .gnu_incremental_relocs section.
1169   const unsigned char* p_;
1170   // Size of the section.
1171   off_t len_;
1172 };
1173
1174 // Reader class for the .gnu_incremental_relocs section.
1175
1176 template<int size, bool big_endian>
1177 class Incremental_relocs_reader
1178 {
1179  private:
1180   // Size of each field.
1181   static const unsigned int field_size = size / 8;
1182
1183  public:
1184   typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
1185   typedef typename elfcpp::Elf_types<size>::Elf_Swxword Addend;
1186
1187   // Size of each entry.
1188   static const unsigned int reloc_size = 8 + 2 * field_size;
1189
1190   Incremental_relocs_reader()
1191     : p_(NULL), len_(0)
1192   { }
1193
1194   Incremental_relocs_reader(const unsigned char* p, off_t len)
1195     : p_(p), len_(len)
1196   { }
1197
1198   // Return the count of relocations in this section.
1199   unsigned int
1200   reloc_count() const
1201   { return static_cast<unsigned int>(this->len_ / reloc_size); }
1202
1203   // Return the relocation type for relocation entry at offset OFF.
1204   unsigned int
1205   get_r_type(unsigned int off) const
1206   { return elfcpp::Swap<32, big_endian>::readval(this->p_ + off); }
1207
1208   // Return the output section index for relocation entry at offset OFF.
1209   unsigned int
1210   get_r_shndx(unsigned int off) const
1211   { return elfcpp::Swap<32, big_endian>::readval(this->p_ + off + 4); }
1212
1213   // Return the output section offset for relocation entry at offset OFF.
1214   Address
1215   get_r_offset(unsigned int off) const
1216   { return elfcpp::Swap<size, big_endian>::readval(this->p_ + off + 8); }
1217
1218   // Return the addend for relocation entry at offset OFF.
1219   Addend
1220   get_r_addend(unsigned int off) const
1221   {
1222     return elfcpp::Swap<size, big_endian>::readval(this->p_ + off + 8
1223                                                    + this->field_size);
1224   }
1225
1226   // Return a pointer to the relocation entry at offset OFF.
1227   const unsigned char*
1228   data(unsigned int off) const
1229   { return this->p_ + off; }
1230
1231  private:
1232   // Base address of the .gnu_incremental_relocs section.
1233   const unsigned char* p_;
1234   // Size of the section.
1235   off_t len_;
1236 };
1237
1238 // Reader class for the .gnu_incremental_got_plt section.
1239
1240 template<bool big_endian>
1241 class Incremental_got_plt_reader
1242 {
1243  public:
1244   Incremental_got_plt_reader()
1245     : p_(NULL), got_count_(0), got_desc_p_(NULL), plt_desc_p_(NULL)
1246   { }
1247
1248   Incremental_got_plt_reader(const unsigned char* p) : p_(p)
1249   {
1250     this->got_count_ = elfcpp::Swap<32, big_endian>::readval(p);
1251     this->got_desc_p_ = p + 8 + ((this->got_count_ + 3) & ~3);
1252     this->plt_desc_p_ = this->got_desc_p_ + this->got_count_ * 8;
1253   }
1254
1255   // Return the GOT entry count.
1256   unsigned int
1257   get_got_entry_count() const
1258   {
1259     return this->got_count_;
1260   }
1261
1262   // Return the PLT entry count.
1263   unsigned int
1264   get_plt_entry_count() const
1265   {
1266     return elfcpp::Swap<32, big_endian>::readval(this->p_ + 4);
1267   }
1268
1269   // Return the GOT type for GOT entry N.
1270   unsigned int
1271   get_got_type(unsigned int n)
1272   {
1273     return this->p_[8 + n];
1274   }
1275
1276   // Return the symbol index for GOT entry N.
1277   unsigned int
1278   get_got_symndx(unsigned int n)
1279   {
1280     return elfcpp::Swap<32, big_endian>::readval(this->got_desc_p_ + n * 8);
1281   }
1282
1283   // Return the input file index for GOT entry N.
1284   unsigned int
1285   get_got_input_index(unsigned int n)
1286   {
1287     return elfcpp::Swap<32, big_endian>::readval(this->got_desc_p_ + n * 8 + 4);
1288   }
1289
1290   // Return the PLT descriptor for PLT entry N.
1291   unsigned int
1292   get_plt_desc(unsigned int n)
1293   {
1294     return elfcpp::Swap<32, big_endian>::readval(this->plt_desc_p_ + n * 4);
1295   }
1296
1297  private:
1298   // Base address of the .gnu_incremental_got_plt section.
1299   const unsigned char* p_;
1300   // GOT entry count.
1301   unsigned int got_count_;
1302   // Base address of the GOT descriptor array.
1303   const unsigned char* got_desc_p_;
1304   // Base address of the PLT descriptor array.
1305   const unsigned char* plt_desc_p_;
1306 };
1307
1308 // An object representing the ELF file we edit during an incremental build.
1309 // Similar to Object or Dynobj, but operates on Output_file and contains
1310 // methods to support incremental updating. This is the abstract parent class
1311 // implemented in Sized_incremental_binary<size, big_endian> for a specific
1312 // endianness and size.
1313
1314 class Incremental_binary
1315 {
1316  public:
1317   Incremental_binary(Output_file* output, Target* target)
1318     : input_args_map_(), library_map_(), script_map_(),
1319       output_(output), target_(target)
1320   { }
1321
1322   virtual
1323   ~Incremental_binary()
1324   { }
1325
1326   // Check the .gnu_incremental_inputs section to see whether an incremental
1327   // build is possible.
1328   bool
1329   check_inputs(const Command_line& cmdline,
1330                Incremental_inputs* incremental_inputs)
1331   { return this->do_check_inputs(cmdline, incremental_inputs); }
1332
1333   // Report an error.
1334   void
1335   error(const char* format, ...) const ATTRIBUTE_PRINTF_2;
1336
1337   // Proxy class for a sized Incremental_input_entry_reader.
1338
1339   class Input_reader
1340   {
1341    public:
1342     Input_reader()
1343     { }
1344
1345     virtual
1346     ~Input_reader()
1347     { }
1348
1349     const char*
1350     filename() const
1351     { return this->do_filename(); }
1352
1353     Timespec
1354     get_mtime() const
1355     { return this->do_get_mtime(); }
1356
1357     Incremental_input_type
1358     type() const
1359     { return this->do_type(); }
1360
1361     unsigned int
1362     arg_serial() const
1363     { return this->do_arg_serial(); }
1364
1365     unsigned int
1366     get_unused_symbol_count() const
1367     { return this->do_get_unused_symbol_count(); }
1368
1369     const char*
1370     get_unused_symbol(unsigned int n) const
1371     { return this->do_get_unused_symbol(n); }
1372
1373    protected:
1374     virtual const char*
1375     do_filename() const = 0;
1376
1377     virtual Timespec
1378     do_get_mtime() const = 0;
1379
1380     virtual Incremental_input_type
1381     do_type() const = 0;
1382
1383     virtual unsigned int
1384     do_arg_serial() const = 0;
1385
1386     virtual unsigned int
1387     do_get_unused_symbol_count() const = 0;
1388
1389     virtual const char*
1390     do_get_unused_symbol(unsigned int n) const = 0;
1391   };
1392
1393   // Return the number of input files.
1394   unsigned int
1395   input_file_count() const
1396   { return this->do_input_file_count(); }
1397
1398   // Return an Input_reader for input file N.
1399   const Input_reader*
1400   get_input_reader(unsigned int n) const
1401   { return this->do_get_input_reader(n); }
1402
1403   // Return TRUE if the input file N has changed since the last link.
1404   bool
1405   file_has_changed(unsigned int n) const
1406   { return this->do_file_has_changed(n); }
1407
1408   // Return the Input_argument for input file N.  Returns NULL if
1409   // the Input_argument is not available.
1410   const Input_argument*
1411   get_input_argument(unsigned int n) const
1412   {
1413     const Input_reader* input_file = this->do_get_input_reader(n);
1414     unsigned int arg_serial = input_file->arg_serial();
1415     if (arg_serial == 0 || arg_serial > this->input_args_map_.size())
1416       return NULL;
1417     return this->input_args_map_[arg_serial - 1];
1418   }
1419
1420   // Return an Incremental_library for the given input file.
1421   Incremental_library*
1422   get_library(unsigned int n) const
1423   { return this->library_map_[n]; }
1424
1425   // Return a Script_info for the given input file.
1426   Script_info*
1427   get_script_info(unsigned int n) const
1428   { return this->script_map_[n]; }
1429
1430   // Initialize the layout of the output file based on the existing
1431   // output file.
1432   void
1433   init_layout(Layout* layout)
1434   { this->do_init_layout(layout); }
1435
1436   // Mark regions of the input file that must be kept unchanged.
1437   void
1438   reserve_layout(unsigned int input_file_index)
1439   { this->do_reserve_layout(input_file_index); }
1440
1441   // Process the GOT and PLT entries from the existing output file.
1442   void
1443   process_got_plt(Symbol_table* symtab, Layout* layout)
1444   { this->do_process_got_plt(symtab, layout); }
1445
1446   // Emit COPY relocations from the existing output file.
1447   void
1448   emit_copy_relocs(Symbol_table* symtab)
1449   { this->do_emit_copy_relocs(symtab); }
1450
1451   // Apply incremental relocations for symbols whose values have changed.
1452   void
1453   apply_incremental_relocs(const Symbol_table* symtab, Layout* layout,
1454                            Output_file* of)
1455   { this->do_apply_incremental_relocs(symtab, layout, of); }
1456
1457   // Functions and types for the elfcpp::Elf_file interface.  This
1458   // permit us to use Incremental_binary as the File template parameter for
1459   // elfcpp::Elf_file.
1460
1461   // The View class is returned by view.  It must support a single
1462   // method, data().  This is trivial, because Output_file::get_output_view
1463   // does what we need.
1464   class View
1465   {
1466    public:
1467     View(const unsigned char* p)
1468       : p_(p)
1469     { }
1470
1471     const unsigned char*
1472     data() const
1473     { return this->p_; }
1474
1475    private:
1476     const unsigned char* p_;
1477   };
1478
1479   // Return a View.
1480   View
1481   view(off_t file_offset, section_size_type data_size)
1482   { return View(this->output_->get_input_view(file_offset, data_size)); }
1483
1484   // A location in the file.
1485   struct Location
1486   {
1487     off_t file_offset;
1488     off_t data_size;
1489
1490     Location(off_t fo, section_size_type ds)
1491       : file_offset(fo), data_size(ds)
1492     { }
1493
1494     Location()
1495       : file_offset(0), data_size(0)
1496     { }
1497   };
1498
1499   // Get a View given a Location.
1500   View
1501   view(Location loc)
1502   { return View(this->view(loc.file_offset, loc.data_size)); }
1503
1504   // Return the Output_file.
1505   Output_file*
1506   output_file()
1507   { return this->output_; }
1508
1509  protected:
1510   // Check the .gnu_incremental_inputs section to see whether an incremental
1511   // build is possible.
1512   virtual bool
1513   do_check_inputs(const Command_line& cmdline,
1514                   Incremental_inputs* incremental_inputs) = 0;
1515
1516   // Return TRUE if input file N has changed since the last incremental link.
1517   virtual bool
1518   do_file_has_changed(unsigned int n) const = 0;
1519
1520   // Initialize the layout of the output file based on the existing
1521   // output file.
1522   virtual void
1523   do_init_layout(Layout* layout) = 0;
1524
1525   // Mark regions of the input file that must be kept unchanged.
1526   virtual void
1527   do_reserve_layout(unsigned int input_file_index) = 0;
1528
1529   // Process the GOT and PLT entries from the existing output file.
1530   virtual void
1531   do_process_got_plt(Symbol_table* symtab, Layout* layout) = 0;
1532
1533   // Emit COPY relocations from the existing output file.
1534   virtual void
1535   do_emit_copy_relocs(Symbol_table* symtab) = 0;
1536
1537   // Apply incremental relocations for symbols whose values have changed.
1538   virtual void
1539   do_apply_incremental_relocs(const Symbol_table*, Layout*, Output_file*) = 0;
1540
1541   virtual unsigned int
1542   do_input_file_count() const = 0;
1543
1544   virtual const Input_reader*
1545   do_get_input_reader(unsigned int) const = 0;
1546
1547   // Map from input file index to Input_argument.
1548   std::vector<const Input_argument*> input_args_map_;
1549   // Map from an input file index to an Incremental_library.
1550   std::vector<Incremental_library*> library_map_;
1551   // Map from an input file index to a Script_info.
1552   std::vector<Script_info*> script_map_;
1553
1554  private:
1555   // Edited output file object.
1556   Output_file* output_;
1557   // Target of the output file.
1558   Target* target_;
1559 };
1560
1561 template<int size, bool big_endian>
1562 class Sized_relobj_incr;
1563
1564 template<int size, bool big_endian>
1565 class Sized_incremental_binary : public Incremental_binary
1566 {
1567  public:
1568   Sized_incremental_binary(Output_file* output,
1569                            const elfcpp::Ehdr<size, big_endian>& ehdr,
1570                            Target* target)
1571     : Incremental_binary(output, target), elf_file_(this, ehdr),
1572       input_objects_(), section_map_(), symbol_map_(), copy_relocs_(),
1573       main_symtab_loc_(), main_strtab_loc_(), has_incremental_info_(false),
1574       inputs_reader_(), symtab_reader_(), relocs_reader_(), got_plt_reader_(),
1575       input_entry_readers_()
1576   { this->setup_readers(); }
1577
1578   // Returns TRUE if the file contains incremental info.
1579   bool
1580   has_incremental_info() const
1581   { return this->has_incremental_info_; }
1582
1583   // Record a pointer to the object for input file N.
1584   void
1585   set_input_object(unsigned int n,
1586                    Sized_relobj_incr<size, big_endian>* obj)
1587   { this->input_objects_[n] = obj; }
1588
1589   // Return a pointer to the object for input file N.
1590   Sized_relobj_incr<size, big_endian>*
1591   input_object(unsigned int n) const
1592   {
1593     gold_assert(n < this->input_objects_.size());
1594     return this->input_objects_[n];
1595   }
1596
1597   // Return the Output_section for section index SHNDX.
1598   Output_section*
1599   output_section(unsigned int shndx)
1600   { return this->section_map_[shndx]; }
1601
1602   // Map a symbol table entry from the base file to the output symbol table.
1603   // SYMNDX is relative to the first forced-local or global symbol in the
1604   // input file symbol table.
1605   void
1606   add_global_symbol(unsigned int symndx, Symbol* gsym)
1607   { this->symbol_map_[symndx] = gsym; }
1608
1609   // Map a symbol table entry from the base file to the output symbol table.
1610   // SYMNDX is relative to the first forced-local or global symbol in the
1611   // input file symbol table.
1612   Symbol*
1613   global_symbol(unsigned int symndx) const
1614   { return this->symbol_map_[symndx]; }
1615
1616   // Add a COPY relocation for a global symbol.
1617   void
1618   add_copy_reloc(Symbol* gsym, Output_section* os, off_t offset)
1619   { this->copy_relocs_.push_back(Copy_reloc(gsym, os, offset)); }
1620
1621   // Readers for the incremental info sections.
1622
1623   const Incremental_inputs_reader<size, big_endian>&
1624   inputs_reader() const
1625   { return this->inputs_reader_; }
1626
1627   const Incremental_symtab_reader<big_endian>&
1628   symtab_reader() const
1629   { return this->symtab_reader_; }
1630
1631   const Incremental_relocs_reader<size, big_endian>&
1632   relocs_reader() const
1633   { return this->relocs_reader_; }
1634
1635   const Incremental_got_plt_reader<big_endian>&
1636   got_plt_reader() const
1637   { return this->got_plt_reader_; }
1638
1639   void
1640   get_symtab_view(View* symtab_view, unsigned int* sym_count,
1641                   elfcpp::Elf_strtab* strtab);
1642
1643  protected:
1644   typedef Incremental_inputs_reader<size, big_endian> Inputs_reader;
1645   typedef typename Inputs_reader::Incremental_input_entry_reader
1646       Input_entry_reader;
1647
1648   virtual bool
1649   do_check_inputs(const Command_line& cmdline,
1650                   Incremental_inputs* incremental_inputs);
1651
1652   // Return TRUE if input file N has changed since the last incremental link.
1653   virtual bool
1654   do_file_has_changed(unsigned int n) const;
1655
1656   // Initialize the layout of the output file based on the existing
1657   // output file.
1658   virtual void
1659   do_init_layout(Layout* layout);
1660
1661   // Mark regions of the input file that must be kept unchanged.
1662   virtual void
1663   do_reserve_layout(unsigned int input_file_index);
1664
1665   // Process the GOT and PLT entries from the existing output file.
1666   virtual void
1667   do_process_got_plt(Symbol_table* symtab, Layout* layout);
1668
1669   // Emit COPY relocations from the existing output file.
1670   virtual void
1671   do_emit_copy_relocs(Symbol_table* symtab);
1672
1673   // Apply incremental relocations for symbols whose values have changed.
1674   virtual void
1675   do_apply_incremental_relocs(const Symbol_table* symtab, Layout* layout,
1676                               Output_file* of);
1677
1678   // Proxy class for a sized Incremental_input_entry_reader.
1679
1680   class Sized_input_reader : public Input_reader
1681   {
1682    public:
1683     Sized_input_reader(Input_entry_reader r)
1684       : Input_reader(), reader_(r)
1685     { }
1686
1687     virtual
1688     ~Sized_input_reader()
1689     { }
1690
1691    private:
1692     const char*
1693     do_filename() const
1694     { return this->reader_.filename(); }
1695
1696     Timespec
1697     do_get_mtime() const
1698     { return this->reader_.get_mtime(); }
1699
1700     Incremental_input_type
1701     do_type() const
1702     { return this->reader_.type(); }
1703
1704     unsigned int
1705     do_arg_serial() const
1706     { return this->reader_.arg_serial(); }
1707
1708     unsigned int
1709     do_get_unused_symbol_count() const
1710     { return this->reader_.get_unused_symbol_count(); }
1711
1712     const char*
1713     do_get_unused_symbol(unsigned int n) const
1714     { return this->reader_.get_unused_symbol(n); }
1715
1716     Input_entry_reader reader_;
1717   };
1718
1719   virtual unsigned int
1720   do_input_file_count() const
1721   { return this->inputs_reader_.input_file_count(); }
1722
1723   virtual const Input_reader*
1724   do_get_input_reader(unsigned int n) const
1725   {
1726     gold_assert(n < this->input_entry_readers_.size());
1727     return &this->input_entry_readers_[n];
1728   }
1729
1730  private:
1731   // List of symbols that need COPY relocations.
1732   struct Copy_reloc
1733   {
1734     Copy_reloc(Symbol* sym, Output_section* os, off_t off)
1735       : symbol(sym), output_section(os), offset(off)
1736     { }
1737
1738     // The global symbol to copy.
1739     Symbol* symbol;
1740     // The output section into which the symbol was copied.
1741     Output_section* output_section;
1742     // The offset within that output section.
1743     off_t offset;
1744   };
1745   typedef std::vector<Copy_reloc> Copy_relocs;
1746
1747   bool
1748   find_incremental_inputs_sections(unsigned int* p_inputs_shndx,
1749                                    unsigned int* p_symtab_shndx,
1750                                    unsigned int* p_relocs_shndx,
1751                                    unsigned int* p_got_plt_shndx,
1752                                    unsigned int* p_strtab_shndx);
1753
1754   void
1755   setup_readers();
1756
1757   // Output as an ELF file.
1758   elfcpp::Elf_file<size, big_endian, Incremental_binary> elf_file_;
1759
1760   // Vector of pointers to the input objects for the unchanged files.
1761   // For replaced files, the corresponding pointer is NULL.
1762   std::vector<Sized_relobj_incr<size, big_endian>*> input_objects_;
1763
1764   // Map section index to an Output_section in the updated layout.
1765   std::vector<Output_section*> section_map_;
1766
1767   // Map global symbols from the input file to the symbol table.
1768   std::vector<Symbol*> symbol_map_;
1769
1770   // List of symbols that need COPY relocations.
1771   Copy_relocs copy_relocs_;
1772
1773   // Locations of the main symbol table and symbol string table.
1774   Location main_symtab_loc_;
1775   Location main_strtab_loc_;
1776
1777   // Readers for the incremental info sections.
1778   bool has_incremental_info_;
1779   Incremental_inputs_reader<size, big_endian> inputs_reader_;
1780   Incremental_symtab_reader<big_endian> symtab_reader_;
1781   Incremental_relocs_reader<size, big_endian> relocs_reader_;
1782   Incremental_got_plt_reader<big_endian> got_plt_reader_;
1783   std::vector<Sized_input_reader> input_entry_readers_;
1784 };
1785
1786 // An incremental Relobj.  This class represents a relocatable object
1787 // that has not changed since the last incremental link, and whose contents
1788 // can be used directly from the base file.
1789
1790 template<int size, bool big_endian>
1791 class Sized_relobj_incr : public Sized_relobj<size, big_endian>
1792 {
1793  public:
1794   typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
1795   typedef typename Sized_relobj<size, big_endian>::Symbols Symbols;
1796
1797   Sized_relobj_incr(const std::string& name,
1798                     Sized_incremental_binary<size, big_endian>* ibase,
1799                     unsigned int input_file_index);
1800
1801  private:
1802   // For convenience.
1803   typedef Sized_relobj_incr<size, big_endian> This;
1804   static const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1805
1806   typedef typename Sized_relobj<size, big_endian>::Output_sections
1807       Output_sections;
1808   typedef Incremental_inputs_reader<size, big_endian> Inputs_reader;
1809   typedef typename Inputs_reader::Incremental_input_entry_reader
1810       Input_entry_reader;
1811
1812   // A local symbol.
1813   struct Local_symbol
1814   {
1815     Local_symbol(const char* name_, Address value_, unsigned int size_,
1816                  unsigned int shndx_, unsigned int type_,
1817                  bool needs_dynsym_entry_)
1818       : st_value(value_), name(name_), st_size(size_), st_shndx(shndx_),
1819         st_type(type_), output_dynsym_index(0),
1820         needs_dynsym_entry(needs_dynsym_entry_)
1821     { }
1822     // The symbol value.
1823     Address st_value;
1824     // The symbol name.  This points to the stringpool entry.
1825     const char* name;
1826     // The symbol size.
1827     unsigned int st_size;
1828     // The output section index.
1829     unsigned int st_shndx : 28;
1830     // The symbol type.
1831     unsigned int st_type : 4;
1832     // The index of the symbol in the output dynamic symbol table.
1833     unsigned int output_dynsym_index : 31;
1834     // TRUE if the symbol needs to appear in the dynamic symbol table.
1835     unsigned int needs_dynsym_entry : 1;
1836   };
1837
1838   // Return TRUE if this is an incremental (unchanged) input file.
1839   bool
1840   do_is_incremental() const
1841   { return true; }
1842
1843   // Return the last modified time of the file.
1844   Timespec
1845   do_get_mtime()
1846   { return this->input_reader_.get_mtime(); }
1847
1848   // Read the symbols.
1849   void
1850   do_read_symbols(Read_symbols_data*);
1851
1852   // Lay out the input sections.
1853   void
1854   do_layout(Symbol_table*, Layout*, Read_symbols_data*);
1855
1856   // Layout sections whose layout was deferred while waiting for
1857   // input files from a plugin.
1858   void
1859   do_layout_deferred_sections(Layout*);
1860
1861   // Add the symbols to the symbol table.
1862   void
1863   do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
1864
1865   Archive::Should_include
1866   do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
1867                            std::string* why);
1868
1869   // Iterate over global symbols, calling a visitor class V for each.
1870   void
1871   do_for_all_global_symbols(Read_symbols_data* sd,
1872                             Library_base::Symbol_visitor_base* v);
1873
1874   // Get the size of a section.
1875   uint64_t
1876   do_section_size(unsigned int shndx);
1877
1878   // Get the name of a section.
1879   std::string
1880   do_section_name(unsigned int shndx);
1881
1882   // Return a view of the contents of a section.
1883   Object::Location
1884   do_section_contents(unsigned int shndx);
1885
1886   // Return section flags.
1887   uint64_t
1888   do_section_flags(unsigned int shndx);
1889
1890   // Return section entsize.
1891   uint64_t
1892   do_section_entsize(unsigned int shndx);
1893
1894   // Return section address.
1895   uint64_t
1896   do_section_address(unsigned int shndx);
1897
1898   // Return section type.
1899   unsigned int
1900   do_section_type(unsigned int shndx);
1901
1902   // Return the section link field.
1903   unsigned int
1904   do_section_link(unsigned int shndx);
1905
1906   // Return the section link field.
1907   unsigned int
1908   do_section_info(unsigned int shndx);
1909
1910   // Return the section alignment.
1911   uint64_t
1912   do_section_addralign(unsigned int shndx);
1913
1914   // Return the Xindex structure to use.
1915   Xindex*
1916   do_initialize_xindex();
1917
1918   // Get symbol counts.
1919   void
1920   do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;
1921
1922   // Get global symbols.
1923   const Symbols*
1924   do_get_global_symbols() const
1925   { return &this->symbols_; }
1926
1927   // Return the value of a local symbol.
1928   uint64_t
1929   do_local_symbol_value(unsigned int, uint64_t) const
1930   { gold_unreachable(); }
1931
1932   unsigned int
1933   do_local_plt_offset(unsigned int) const
1934   { gold_unreachable(); }
1935
1936   // Return the number of local symbols.
1937   unsigned int
1938   do_local_symbol_count() const
1939   { return this->local_symbol_count_; }
1940
1941   // Return the number of local symbols in the output symbol table.
1942   unsigned int
1943   do_output_local_symbol_count() const
1944   { return this->local_symbol_count_; }
1945
1946   // Return the file offset for local symbols in the output symbol table.
1947   off_t
1948   do_local_symbol_offset() const
1949   { return this->local_symbol_offset_; }
1950
1951   // Read the relocs.
1952   void
1953   do_read_relocs(Read_relocs_data*);
1954
1955   // Process the relocs to find list of referenced sections. Used only
1956   // during garbage collection.
1957   void
1958   do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1959
1960   // Scan the relocs and adjust the symbol table.
1961   void
1962   do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1963
1964   // Count the local symbols.
1965   void
1966   do_count_local_symbols(Stringpool_template<char>*,
1967                          Stringpool_template<char>*);
1968
1969   // Finalize the local symbols.
1970   unsigned int
1971   do_finalize_local_symbols(unsigned int, off_t, Symbol_table*);
1972
1973   // Set the offset where local dynamic symbol information will be stored.
1974   unsigned int
1975   do_set_local_dynsym_indexes(unsigned int);
1976
1977   // Set the offset where local dynamic symbol information will be stored.
1978   unsigned int
1979   do_set_local_dynsym_offset(off_t);
1980
1981   // Relocate the input sections and write out the local symbols.
1982   void
1983   do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of);
1984
1985   // Set the offset of a section.
1986   void
1987   do_set_section_offset(unsigned int shndx, uint64_t off);
1988
1989   // The Incremental_binary base file.
1990   Sized_incremental_binary<size, big_endian>* ibase_;
1991   // The index of the object in the input file list.
1992   unsigned int input_file_index_;
1993   // The reader for the input file.
1994   Input_entry_reader input_reader_;
1995   // The number of local symbols.
1996   unsigned int local_symbol_count_;
1997   // The number of local symbols which go into the output file's dynamic
1998   // symbol table.
1999   unsigned int output_local_dynsym_count_;
2000   // This starting symbol index in the output symbol table.
2001   unsigned int local_symbol_index_;
2002   // The file offset for local symbols in the output symbol table.
2003   unsigned int local_symbol_offset_;
2004   // The file offset for local symbols in the output symbol table.
2005   unsigned int local_dynsym_offset_;
2006   // The entries in the symbol table for the external symbols.
2007   Symbols symbols_;
2008   // Number of symbols defined in object file itself.
2009   size_t defined_count_;
2010   // The offset of the first incremental relocation for this object.
2011   unsigned int incr_reloc_offset_;
2012   // The number of incremental relocations for this object.
2013   unsigned int incr_reloc_count_;
2014   // The index of the first incremental relocation for this object in the
2015   // updated output file.
2016   unsigned int incr_reloc_output_index_;
2017   // A copy of the incremental relocations from this object.
2018   unsigned char* incr_relocs_;
2019   // The local symbols.
2020   std::vector<Local_symbol> local_symbols_;
2021 };
2022
2023 // An incremental Dynobj.  This class represents a shared object that has
2024 // not changed since the last incremental link, and whose contents can be
2025 // used directly from the base file.
2026
2027 template<int size, bool big_endian>
2028 class Sized_incr_dynobj : public Dynobj
2029 {
2030  public:
2031   typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
2032
2033   static const Address invalid_address = static_cast<Address>(0) - 1;
2034
2035   Sized_incr_dynobj(const std::string& name,
2036                     Sized_incremental_binary<size, big_endian>* ibase,
2037                     unsigned int input_file_index);
2038
2039  private:
2040   typedef Incremental_inputs_reader<size, big_endian> Inputs_reader;
2041   typedef typename Inputs_reader::Incremental_input_entry_reader
2042       Input_entry_reader;
2043
2044   // Return TRUE if this is an incremental (unchanged) input file.
2045   bool
2046   do_is_incremental() const
2047   { return true; }
2048
2049   // Return the last modified time of the file.
2050   Timespec
2051   do_get_mtime()
2052   { return this->input_reader_.get_mtime(); }
2053
2054   // Read the symbols.
2055   void
2056   do_read_symbols(Read_symbols_data*);
2057
2058   // Lay out the input sections.
2059   void
2060   do_layout(Symbol_table*, Layout*, Read_symbols_data*);
2061
2062   // Add the symbols to the symbol table.
2063   void
2064   do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
2065
2066   Archive::Should_include
2067   do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
2068                            std::string* why);
2069
2070   // Iterate over global symbols, calling a visitor class V for each.
2071   void
2072   do_for_all_global_symbols(Read_symbols_data* sd,
2073                             Library_base::Symbol_visitor_base* v);
2074
2075   // Iterate over local symbols, calling a visitor class V for each GOT offset
2076   // associated with a local symbol.
2077   void
2078   do_for_all_local_got_entries(Got_offset_list::Visitor* v) const;
2079
2080   // Get the size of a section.
2081   uint64_t
2082   do_section_size(unsigned int shndx);
2083
2084   // Get the name of a section.
2085   std::string
2086   do_section_name(unsigned int shndx);
2087
2088   // Return a view of the contents of a section.
2089   Object::Location
2090   do_section_contents(unsigned int shndx);
2091
2092   // Return section flags.
2093   uint64_t
2094   do_section_flags(unsigned int shndx);
2095
2096   // Return section entsize.
2097   uint64_t
2098   do_section_entsize(unsigned int shndx);
2099
2100   // Return section address.
2101   uint64_t
2102   do_section_address(unsigned int shndx);
2103
2104   // Return section type.
2105   unsigned int
2106   do_section_type(unsigned int shndx);
2107
2108   // Return the section link field.
2109   unsigned int
2110   do_section_link(unsigned int shndx);
2111
2112   // Return the section link field.
2113   unsigned int
2114   do_section_info(unsigned int shndx);
2115
2116   // Return the section alignment.
2117   uint64_t
2118   do_section_addralign(unsigned int shndx);
2119
2120   // Return the Xindex structure to use.
2121   Xindex*
2122   do_initialize_xindex();
2123
2124   // Get symbol counts.
2125   void
2126   do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;
2127
2128   // Get global symbols.
2129   const Symbols*
2130   do_get_global_symbols() const
2131   { return &this->symbols_; }
2132
2133   // The Incremental_binary base file.
2134   Sized_incremental_binary<size, big_endian>* ibase_;
2135   // The index of the object in the input file list.
2136   unsigned int input_file_index_;
2137   // The reader for the input file.
2138   Input_entry_reader input_reader_;
2139   // The entries in the symbol table for the external symbols.
2140   Symbols symbols_;
2141   // Number of symbols defined in object file itself.
2142   size_t defined_count_;
2143 };
2144
2145 // Allocate an incremental object of the appropriate size and endianness.
2146 extern Object*
2147 make_sized_incremental_object(
2148     Incremental_binary* base,
2149     unsigned int input_file_index,
2150     Incremental_input_type input_type,
2151     const Incremental_binary::Input_reader* input_reader);
2152
2153 // This class represents an Archive library (or --start-lib/--end-lib group)
2154 // that has not changed since the last incremental link.  Its contents come
2155 // from the incremental inputs entry in the base file.
2156
2157 class Incremental_library : public Library_base
2158 {
2159  public:
2160   Incremental_library(const char* filename, unsigned int input_file_index,
2161                       const Incremental_binary::Input_reader* input_reader)
2162     : Library_base(NULL), filename_(filename),
2163       input_file_index_(input_file_index), input_reader_(input_reader),
2164       unused_symbols_(), is_reported_(false)
2165   { }
2166
2167   // Return the input file index.
2168   unsigned int
2169   input_file_index() const
2170   { return this->input_file_index_; }
2171
2172   // Return the serial number of the input file.
2173   unsigned int
2174   arg_serial() const
2175   { return this->input_reader_->arg_serial(); }
2176
2177   // Copy the unused symbols from the incremental input info.
2178   // We need to do this because we may be overwriting the incremental
2179   // input info in the base file before we write the new incremental
2180   // info.
2181   void
2182   copy_unused_symbols();
2183
2184   // Return FALSE on the first call to indicate that the library needs
2185   // to be recorded; return TRUE subsequently.
2186   bool
2187   is_reported()
2188   {
2189     bool was_reported = this->is_reported_;
2190     is_reported_ = true;
2191     return was_reported;
2192   }
2193
2194  private:
2195   typedef std::vector<std::string> Symbol_list;
2196
2197   // The file name.
2198   const std::string&
2199   do_filename() const
2200   { return this->filename_; }
2201
2202   // Return the modification time of the archive file.
2203   Timespec
2204   do_get_mtime()
2205   { return this->input_reader_->get_mtime(); }
2206
2207   // Iterator for unused global symbols in the library.
2208   void
2209   do_for_all_unused_symbols(Symbol_visitor_base* v) const;
2210
2211   // The name of the library.
2212   std::string filename_;
2213   // The input file index of this library.
2214   unsigned int input_file_index_;
2215   // A reader for the incremental input information.
2216   const Incremental_binary::Input_reader* input_reader_;
2217   // List of unused symbols defined in this library.
2218   Symbol_list unused_symbols_;
2219   // TRUE when this library has been reported to the new incremental info.
2220   bool is_reported_;
2221 };
2222
2223 } // End namespace gold.
2224
2225 #endif // !defined(GOLD_INCREMENTAL_H)