gold/layout.cc

   1 // layout.cc -- lay out output file sections for gold
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cerrno>
  26 #include <cstring>
  27 #include <algorithm>
  28 #include <iostream>
  29 #include <fstream>
  30 #include <utility>
  31 #include <fcntl.h>
  32 #include <fnmatch.h>
  33 #include <unistd.h>
  34 #include "libiberty.h"
  35 #include "md5.h"
  36 #include "sha1.h"
  37
  38 #include "parameters.h"
  39 #include "options.h"
  40 #include "mapfile.h"
  41 #include "script.h"
  42 #include "script-sections.h"
  43 #include "output.h"
  44 #include "symtab.h"
  45 #include "dynobj.h"
  46 #include "ehframe.h"
  47 #include "compressed_output.h"
  48 #include "reduced_debug_output.h"
  49 #include "reloc.h"
  50 #include "descriptors.h"
  51 #include "plugin.h"
  52 #include "incremental.h"
  53 #include "layout.h"
  54
  55 namespace gold
  56 {
  57
  58 // Layout::Relaxation_debug_check methods.
  59
  60 // Check that sections and special data are in reset states.
  61 // We do not save states for Output_sections and special Output_data.
  62 // So we check that they have not assigned any addresses or offsets.
  63 // clean_up_after_relaxation simply resets their addresses and offsets.
  64 void
  65 Layout::Relaxation_debug_check::check_output_data_for_reset_values(
  66     const Layout::Section_list& sections,
  67     const Layout::Data_list& special_outputs)
  68 {
  69   for(Layout::Section_list::const_iterator p = sections.begin();
  70       p != sections.end();
  71       ++p)
  72     gold_assert((*p)->address_and_file_offset_have_reset_values());
  73
  74   for(Layout::Data_list::const_iterator p = special_outputs.begin();
  75       p != special_outputs.end();
  76       ++p)
  77     gold_assert((*p)->address_and_file_offset_have_reset_values());
  78 }
  79
  80 // Save information of SECTIONS for checking later.
  81
  82 void
  83 Layout::Relaxation_debug_check::read_sections(
  84     const Layout::Section_list& sections)
  85 {
  86   for(Layout::Section_list::const_iterator p = sections.begin();
  87       p != sections.end();
  88       ++p)
  89     {
  90       Output_section* os = *p;
  91       Section_info info;
  92       info.output_section = os;
  93       info.address = os->is_address_valid() ? os->address() : 0;
  94       info.data_size = os->is_data_size_valid() ? os->data_size() : -1;
  95       info.offset = os->is_offset_valid()? os->offset() : -1 ;
  96       this->section_infos_.push_back(info);
  97     }
  98 }
  99
 100 // Verify SECTIONS using previously recorded information.
 101
 102 void
 103 Layout::Relaxation_debug_check::verify_sections(
 104     const Layout::Section_list& sections)
 105 {
 106   size_t i = 0;
 107   for(Layout::Section_list::const_iterator p = sections.begin();
 108       p != sections.end();
 109       ++p, ++i)
 110     {
 111       Output_section* os = *p;
 112       uint64_t address = os->is_address_valid() ? os->address() : 0;
 113       off_t data_size = os->is_data_size_valid() ? os->data_size() : -1;
 114       off_t offset = os->is_offset_valid()? os->offset() : -1 ;
 115
 116       if (i >= this->section_infos_.size())
 117         {
 118           gold_fatal("Section_info of %s missing.\n", os->name());
 119         }
 120       const Section_info& info = this->section_infos_[i];
 121       if (os != info.output_section)
 122         gold_fatal("Section order changed.  Expecting %s but see %s\n",
 123                    info.output_section->name(), os->name());
 124       if (address != info.address
 125           || data_size != info.data_size
 126           || offset != info.offset)
 127         gold_fatal("Section %s changed.\n", os->name());
 128     }
 129 }
 130
 131 // Layout_task_runner methods.
 132
 133 // Lay out the sections.  This is called after all the input objects
 134 // have been read.
 135
 136 void
 137 Layout_task_runner::run(Workqueue* workqueue, const Task* task)
 138 {
 139   off_t file_size = this->layout_->finalize(this->input_objects_,
 140                                             this->symtab_,
 141                                             this->target_,
 142                                             task);
 143
 144   // Now we know the final size of the output file and we know where
 145   // each piece of information goes.
 146
 147   if (this->mapfile_ != NULL)
 148     {
 149       this->mapfile_->print_discarded_sections(this->input_objects_);
 150       this->layout_->print_to_mapfile(this->mapfile_);
 151     }
 152
 153   Output_file* of = new Output_file(parameters->options().output_file_name());
 154   if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
 155     of->set_is_temporary();
 156   of->open(file_size);
 157
 158   // Queue up the final set of tasks.
 159   gold::queue_final_tasks(this->options_, this->input_objects_,
 160                           this->symtab_, this->layout_, workqueue, of);
 161 }
 162
 163 // Layout methods.
 164
 165 Layout::Layout(int number_of_input_files, Script_options* script_options)
 166   : number_of_input_files_(number_of_input_files),
 167     script_options_(script_options),
 168     namepool_(),
 169     sympool_(),
 170     dynpool_(),
 171     signatures_(),
 172     section_name_map_(),
 173     segment_list_(),
 174     section_list_(),
 175     unattached_section_list_(),
 176     special_output_list_(),
 177     section_headers_(NULL),
 178     tls_segment_(NULL),
 179     relro_segment_(NULL),
 180     increase_relro_(0),
 181     symtab_section_(NULL),
 182     symtab_xindex_(NULL),
 183     dynsym_section_(NULL),
 184     dynsym_xindex_(NULL),
 185     dynamic_section_(NULL),
 186     dynamic_symbol_(NULL),
 187     dynamic_data_(NULL),
 188     eh_frame_section_(NULL),
 189     eh_frame_data_(NULL),
 190     added_eh_frame_data_(false),
 191     eh_frame_hdr_section_(NULL),
 192     build_id_note_(NULL),
 193     debug_abbrev_(NULL),
 194     debug_info_(NULL),
 195     group_signatures_(),
 196     output_file_size_(-1),
 197     have_added_input_section_(false),
 198     sections_are_attached_(false),
 199     input_requires_executable_stack_(false),
 200     input_with_gnu_stack_note_(false),
 201     input_without_gnu_stack_note_(false),
 202     has_static_tls_(false),
 203     any_postprocessing_sections_(false),
 204     resized_signatures_(false),
 205     have_stabstr_section_(false),
 206     incremental_inputs_(NULL),
 207     record_output_section_data_from_script_(false),
 208     script_output_section_data_list_(),
 209     segment_states_(NULL),
 210     relaxation_debug_check_(NULL)
 211 {
 212   // Make space for more than enough segments for a typical file.
 213   // This is just for efficiency--it's OK if we wind up needing more.
 214   this->segment_list_.reserve(12);
 215
 216   // We expect two unattached Output_data objects: the file header and
 217   // the segment headers.
 218   this->special_output_list_.reserve(2);
 219
 220   // Initialize structure needed for an incremental build.
 221   if (parameters->options().incremental())
 222     this->incremental_inputs_ = new Incremental_inputs;
 223
 224   // The section name pool is worth optimizing in all cases, because
 225   // it is small, but there are often overlaps due to .rel sections.
 226   this->namepool_.set_optimize();
 227 }
 228
 229 // Hash a key we use to look up an output section mapping.
 230
 231 size_t
 232 Layout::Hash_key::operator()(const Layout::Key& k) const
 233 {
 234  return k.first + k.second.first + k.second.second;
 235 }
 236
 237 // Returns whether the given section is in the list of
 238 // debug-sections-used-by-some-version-of-gdb.  Currently,
 239 // we've checked versions of gdb up to and including 6.7.1.
 240
 241 static const char* gdb_sections[] =
 242 { ".debug_abbrev",
 243   // ".debug_aranges",   // not used by gdb as of 6.7.1
 244   ".debug_frame",
 245   ".debug_info",
 246   ".debug_types",
 247   ".debug_line",
 248   ".debug_loc",
 249   ".debug_macinfo",
 250   // ".debug_pubnames",  // not used by gdb as of 6.7.1
 251   ".debug_ranges",
 252   ".debug_str",
 253 };
 254
 255 static const char* lines_only_debug_sections[] =
 256 { ".debug_abbrev",
 257   // ".debug_aranges",   // not used by gdb as of 6.7.1
 258   // ".debug_frame",
 259   ".debug_info",
 260   // ".debug_types",
 261   ".debug_line",
 262   // ".debug_loc",
 263   // ".debug_macinfo",
 264   // ".debug_pubnames",  // not used by gdb as of 6.7.1
 265   // ".debug_ranges",
 266   ".debug_str",
 267 };
 268
 269 static inline bool
 270 is_gdb_debug_section(const char* str)
 271 {
 272   // We can do this faster: binary search or a hashtable.  But why bother?
 273   for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
 274     if (strcmp(str, gdb_sections[i]) == 0)
 275       return true;
 276   return false;
 277 }
 278
 279 static inline bool
 280 is_lines_only_debug_section(const char* str)
 281 {
 282   // We can do this faster: binary search or a hashtable.  But why bother?
 283   for (size_t i = 0;
 284        i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
 285        ++i)
 286     if (strcmp(str, lines_only_debug_sections[i]) == 0)
 287       return true;
 288   return false;
 289 }
 290
 291 // Whether to include this section in the link.
 292
 293 template<int size, bool big_endian>
 294 bool
 295 Layout::include_section(Sized_relobj<size, big_endian>*, const char* name,
 296                         const elfcpp::Shdr<size, big_endian>& shdr)
 297 {
 298   if (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)
 299     return false;
 300
 301   switch (shdr.get_sh_type())
 302     {
 303     case elfcpp::SHT_NULL:
 304     case elfcpp::SHT_SYMTAB:
 305     case elfcpp::SHT_DYNSYM:
 306     case elfcpp::SHT_HASH:
 307     case elfcpp::SHT_DYNAMIC:
 308     case elfcpp::SHT_SYMTAB_SHNDX:
 309       return false;
 310
 311     case elfcpp::SHT_STRTAB:
 312       // Discard the sections which have special meanings in the ELF
 313       // ABI.  Keep others (e.g., .stabstr).  We could also do this by
 314       // checking the sh_link fields of the appropriate sections.
 315       return (strcmp(name, ".dynstr") != 0
 316               && strcmp(name, ".strtab") != 0
 317               && strcmp(name, ".shstrtab") != 0);
 318
 319     case elfcpp::SHT_RELA:
 320     case elfcpp::SHT_REL:
 321     case elfcpp::SHT_GROUP:
 322       // If we are emitting relocations these should be handled
 323       // elsewhere.
 324       gold_assert(!parameters->options().relocatable()
 325                   && !parameters->options().emit_relocs());
 326       return false;
 327
 328     case elfcpp::SHT_PROGBITS:
 329       if (parameters->options().strip_debug()
 330           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 331         {
 332           if (is_debug_info_section(name))
 333             return false;
 334         }
 335       if (parameters->options().strip_debug_non_line()
 336           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 337         {
 338           // Debugging sections can only be recognized by name.
 339           if (is_prefix_of(".debug", name)
 340               && !is_lines_only_debug_section(name))
 341             return false;
 342         }
 343       if (parameters->options().strip_debug_gdb()
 344           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 345         {
 346           // Debugging sections can only be recognized by name.
 347           if (is_prefix_of(".debug", name)
 348               && !is_gdb_debug_section(name))
 349             return false;
 350         }
 351       if (parameters->options().strip_lto_sections()
 352           && !parameters->options().relocatable()
 353           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 354         {
 355           // Ignore LTO sections containing intermediate code.
 356           if (is_prefix_of(".gnu.lto_", name))
 357             return false;
 358         }
 359       // The GNU linker strips .gnu_debuglink sections, so we do too.
 360       // This is a feature used to keep debugging information in
 361       // separate files.
 362       if (strcmp(name, ".gnu_debuglink") == 0)
 363         return false;
 364       return true;
 365
 366     default:
 367       return true;
 368     }
 369 }
 370
 371 // Return an output section named NAME, or NULL if there is none.
 372
 373 Output_section*
 374 Layout::find_output_section(const char* name) const
 375 {
 376   for (Section_list::const_iterator p = this->section_list_.begin();
 377        p != this->section_list_.end();
 378        ++p)
 379     if (strcmp((*p)->name(), name) == 0)
 380       return *p;
 381   return NULL;
 382 }
 383
 384 // Return an output segment of type TYPE, with segment flags SET set
 385 // and segment flags CLEAR clear.  Return NULL if there is none.
 386
 387 Output_segment*
 388 Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
 389                             elfcpp::Elf_Word clear) const
 390 {
 391   for (Segment_list::const_iterator p = this->segment_list_.begin();
 392        p != this->segment_list_.end();
 393        ++p)
 394     if (static_cast<elfcpp::PT>((*p)->type()) == type
 395         && ((*p)->flags() & set) == set
 396         && ((*p)->flags() & clear) == 0)
 397       return *p;
 398   return NULL;
 399 }
 400
 401 // Return the output section to use for section NAME with type TYPE
 402 // and section flags FLAGS.  NAME must be canonicalized in the string
 403 // pool, and NAME_KEY is the key.  IS_INTERP is true if this is the
 404 // .interp section.  IS_DYNAMIC_LINKER_SECTION is true if this section
 405 // is used by the dynamic linker.  IS_RELRO is true for a relro
 406 // section.  IS_LAST_RELRO is true for the last relro section.
 407 // IS_FIRST_NON_RELRO is true for the first non-relro section.
 408
 409 Output_section*
 410 Layout::get_output_section(const char* name, Stringpool::Key name_key,
 411                            elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
 412                            Output_section_order order, bool is_relro)
 413 {
 414   elfcpp::Elf_Xword lookup_flags = flags;
 415
 416   // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
 417   // read-write with read-only sections.  Some other ELF linkers do
 418   // not do this.  FIXME: Perhaps there should be an option
 419   // controlling this.
 420   lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
 421
 422   const Key key(name_key, std::make_pair(type, lookup_flags));
 423   const std::pair<Key, Output_section*> v(key, NULL);
 424   std::pair<Section_name_map::iterator, bool> ins(
 425     this->section_name_map_.insert(v));
 426
 427   if (!ins.second)
 428     return ins.first->second;
 429   else
 430     {
 431       // This is the first time we've seen this name/type/flags
 432       // combination.  For compatibility with the GNU linker, we
 433       // combine sections with contents and zero flags with sections
 434       // with non-zero flags.  This is a workaround for cases where
 435       // assembler code forgets to set section flags.  FIXME: Perhaps
 436       // there should be an option to control this.
 437       Output_section* os = NULL;
 438
 439       if (type == elfcpp::SHT_PROGBITS)
 440         {
 441           if (flags == 0)
 442             {
 443               Output_section* same_name = this->find_output_section(name);
 444               if (same_name != NULL
 445                   && same_name->type() == elfcpp::SHT_PROGBITS
 446                   && (same_name->flags() & elfcpp::SHF_TLS) == 0)
 447                 os = same_name;
 448             }
 449           else if ((flags & elfcpp::SHF_TLS) == 0)
 450             {
 451               elfcpp::Elf_Xword zero_flags = 0;
 452               const Key zero_key(name_key, std::make_pair(type, zero_flags));
 453               Section_name_map::iterator p =
 454                   this->section_name_map_.find(zero_key);
 455               if (p != this->section_name_map_.end())
 456                 os = p->second;
 457             }
 458         }
 459
 460       if (os == NULL)
 461         os = this->make_output_section(name, type, flags, order, is_relro);
 462
 463       ins.first->second = os;
 464       return os;
 465     }
 466 }
 467
 468 // Pick the output section to use for section NAME, in input file
 469 // RELOBJ, with type TYPE and flags FLAGS.  RELOBJ may be NULL for a
 470 // linker created section.  IS_INPUT_SECTION is true if we are
 471 // choosing an output section for an input section found in a input
 472 // file.  IS_INTERP is true if this is the .interp section.
 473 // IS_DYNAMIC_LINKER_SECTION is true if this section is used by the
 474 // dynamic linker.  IS_RELRO is true for a relro section.
 475 // IS_LAST_RELRO is true for the last relro section.
 476 // IS_FIRST_NON_RELRO is true for the first non-relro section.  This
 477 // will return NULL if the input section should be discarded.
 478
 479 Output_section*
 480 Layout::choose_output_section(const Relobj* relobj, const char* name,
 481                               elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
 482                               bool is_input_section, Output_section_order order,
 483                               bool is_relro)
 484 {
 485   // We should not see any input sections after we have attached
 486   // sections to segments.
 487   gold_assert(!is_input_section || !this->sections_are_attached_);
 488
 489   // Some flags in the input section should not be automatically
 490   // copied to the output section.
 491   flags &= ~ (elfcpp::SHF_INFO_LINK
 492               | elfcpp::SHF_LINK_ORDER
 493               | elfcpp::SHF_GROUP
 494               | elfcpp::SHF_MERGE
 495               | elfcpp::SHF_STRINGS);
 496
 497   if (this->script_options_->saw_sections_clause())
 498     {
 499       // We are using a SECTIONS clause, so the output section is
 500       // chosen based only on the name.
 501
 502       Script_sections* ss = this->script_options_->script_sections();
 503       const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
 504       Output_section** output_section_slot;
 505       Script_sections::Section_type script_section_type;
 506       name = ss->output_section_name(file_name, name, &output_section_slot,
 507                                      &script_section_type);
 508       if (name == NULL)
 509         {
 510           // The SECTIONS clause says to discard this input section.
 511           return NULL;
 512         }
 513
 514       // We can only handle script section types ST_NONE and ST_NOLOAD.
 515       switch (script_section_type)
 516         {
 517         case Script_sections::ST_NONE:
 518           break;
 519         case Script_sections::ST_NOLOAD:
 520           flags &= elfcpp::SHF_ALLOC;
 521           break;
 522         default:
 523           gold_unreachable();
 524         }
 525
 526       // If this is an orphan section--one not mentioned in the linker
 527       // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
 528       // default processing below.
 529
 530       if (output_section_slot != NULL)
 531         {
 532           if (*output_section_slot != NULL)
 533             {
 534               (*output_section_slot)->update_flags_for_input_section(flags);
 535               return *output_section_slot;
 536             }
 537
 538           // We don't put sections found in the linker script into
 539           // SECTION_NAME_MAP_.  That keeps us from getting confused
 540           // if an orphan section is mapped to a section with the same
 541           // name as one in the linker script.
 542
 543           name = this->namepool_.add(name, false, NULL);
 544
 545           Output_section* os = this->make_output_section(name, type, flags,
 546                                                          order, is_relro);
 547
 548           os->set_found_in_sections_clause();
 549
 550           // Special handling for NOLOAD sections.
 551           if (script_section_type == Script_sections::ST_NOLOAD)
 552             {
 553               os->set_is_noload();
 554
 555               // The constructor of Output_section sets addresses of non-ALLOC
 556               // sections to 0 by default.  We don't want that for NOLOAD
 557               // sections even if they have no SHF_ALLOC flag.
 558               if ((os->flags() & elfcpp::SHF_ALLOC) == 0
 559                   && os->is_address_valid())
 560                 {
 561                   gold_assert(os->address() == 0
 562                               && !os->is_offset_valid()
 563                               && !os->is_data_size_valid());
 564                   os->reset_address_and_file_offset();
 565                 }
 566             }
 567
 568           *output_section_slot = os;
 569           return os;
 570         }
 571     }
 572
 573   // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
 574
 575   // Turn NAME from the name of the input section into the name of the
 576   // output section.
 577
 578   size_t len = strlen(name);
 579   if (is_input_section
 580       && !this->script_options_->saw_sections_clause()
 581       && !parameters->options().relocatable())
 582     name = Layout::output_section_name(name, &len);
 583
 584   Stringpool::Key name_key;
 585   name = this->namepool_.add_with_length(name, len, true, &name_key);
 586
 587   // Find or make the output section.  The output section is selected
 588   // based on the section name, type, and flags.
 589   return this->get_output_section(name, name_key, type, flags, order, is_relro);
 590 }
 591
 592 // Return the output section to use for input section SHNDX, with name
 593 // NAME, with header HEADER, from object OBJECT.  RELOC_SHNDX is the
 594 // index of a relocation section which applies to this section, or 0
 595 // if none, or -1U if more than one.  RELOC_TYPE is the type of the
 596 // relocation section if there is one.  Set *OFF to the offset of this
 597 // input section without the output section.  Return NULL if the
 598 // section should be discarded.  Set *OFF to -1 if the section
 599 // contents should not be written directly to the output file, but
 600 // will instead receive special handling.
 601
 602 template<int size, bool big_endian>
 603 Output_section*
 604 Layout::layout(Sized_relobj<size, big_endian>* object, unsigned int shndx,
 605                const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
 606                unsigned int reloc_shndx, unsigned int, off_t* off)
 607 {
 608   *off = 0;
 609
 610   if (!this->include_section(object, name, shdr))
 611     return NULL;
 612
 613   Output_section* os;
 614
 615   // Sometimes .init_array*, .preinit_array* and .fini_array* do not have
 616   // correct section types.  Force them here.
 617   elfcpp::Elf_Word sh_type = shdr.get_sh_type();
 618   if (sh_type == elfcpp::SHT_PROGBITS)
 619     {
 620       static const char init_array_prefix[] = ".init_array";
 621       static const char preinit_array_prefix[] = ".preinit_array";
 622       static const char fini_array_prefix[] = ".fini_array";
 623       static size_t init_array_prefix_size = sizeof(init_array_prefix) - 1;
 624       static size_t preinit_array_prefix_size =
 625         sizeof(preinit_array_prefix) - 1;
 626       static size_t fini_array_prefix_size = sizeof(fini_array_prefix) - 1;
 627
 628       if (strncmp(name, init_array_prefix, init_array_prefix_size) == 0)
 629         sh_type = elfcpp::SHT_INIT_ARRAY;
 630       else if (strncmp(name, preinit_array_prefix, preinit_array_prefix_size)
 631                == 0)
 632         sh_type = elfcpp::SHT_PREINIT_ARRAY;
 633       else if (strncmp(name, fini_array_prefix, fini_array_prefix_size) == 0)
 634         sh_type = elfcpp::SHT_FINI_ARRAY;
 635     }
 636
 637   // In a relocatable link a grouped section must not be combined with
 638   // any other sections.
 639   if (parameters->options().relocatable()
 640       && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
 641     {
 642       name = this->namepool_.add(name, true, NULL);
 643       os = this->make_output_section(name, sh_type, shdr.get_sh_flags(),
 644                                      ORDER_INVALID, false);
 645     }
 646   else
 647     {
 648       os = this->choose_output_section(object, name, sh_type,
 649                                        shdr.get_sh_flags(), true,
 650                                        ORDER_INVALID, false);
 651       if (os == NULL)
 652         return NULL;
 653     }
 654
 655   // By default the GNU linker sorts input sections whose names match
 656   // .ctor.*, .dtor.*, .init_array.*, or .fini_array.*.  The sections
 657   // are sorted by name.  This is used to implement constructor
 658   // priority ordering.  We are compatible.
 659   if (!this->script_options_->saw_sections_clause()
 660       && (is_prefix_of(".ctors.", name)
 661           || is_prefix_of(".dtors.", name)
 662           || is_prefix_of(".init_array.", name)
 663           || is_prefix_of(".fini_array.", name)))
 664     os->set_must_sort_attached_input_sections();
 665
 666   // FIXME: Handle SHF_LINK_ORDER somewhere.
 667
 668   *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
 669                                this->script_options_->saw_sections_clause());
 670   this->have_added_input_section_ = true;
 671
 672   return os;
 673 }
 674
 675 // Handle a relocation section when doing a relocatable link.
 676
 677 template<int size, bool big_endian>
 678 Output_section*
 679 Layout::layout_reloc(Sized_relobj<size, big_endian>* object,
 680                      unsigned int,
 681                      const elfcpp::Shdr<size, big_endian>& shdr,
 682                      Output_section* data_section,
 683                      Relocatable_relocs* rr)
 684 {
 685   gold_assert(parameters->options().relocatable()
 686               || parameters->options().emit_relocs());
 687
 688   int sh_type = shdr.get_sh_type();
 689
 690   std::string name;
 691   if (sh_type == elfcpp::SHT_REL)
 692     name = ".rel";
 693   else if (sh_type == elfcpp::SHT_RELA)
 694     name = ".rela";
 695   else
 696     gold_unreachable();
 697   name += data_section->name();
 698
 699   // In a relocatable link relocs for a grouped section must not be
 700   // combined with other reloc sections.
 701   Output_section* os;
 702   if (!parameters->options().relocatable()
 703       || (data_section->flags() & elfcpp::SHF_GROUP) == 0)
 704     os = this->choose_output_section(object, name.c_str(), sh_type,
 705                                      shdr.get_sh_flags(), false,
 706                                      ORDER_INVALID, false);
 707   else
 708     {
 709       const char* n = this->namepool_.add(name.c_str(), true, NULL);
 710       os = this->make_output_section(n, sh_type, shdr.get_sh_flags(),
 711                                      ORDER_INVALID, false);
 712     }
 713
 714   os->set_should_link_to_symtab();
 715   os->set_info_section(data_section);
 716
 717   Output_section_data* posd;
 718   if (sh_type == elfcpp::SHT_REL)
 719     {
 720       os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
 721       posd = new Output_relocatable_relocs<elfcpp::SHT_REL,
 722                                            size,
 723                                            big_endian>(rr);
 724     }
 725   else if (sh_type == elfcpp::SHT_RELA)
 726     {
 727       os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
 728       posd = new Output_relocatable_relocs<elfcpp::SHT_RELA,
 729                                            size,
 730                                            big_endian>(rr);
 731     }
 732   else
 733     gold_unreachable();
 734
 735   os->add_output_section_data(posd);
 736   rr->set_output_data(posd);
 737
 738   return os;
 739 }
 740
 741 // Handle a group section when doing a relocatable link.
 742
 743 template<int size, bool big_endian>
 744 void
 745 Layout::layout_group(Symbol_table* symtab,
 746                      Sized_relobj<size, big_endian>* object,
 747                      unsigned int,
 748                      const char* group_section_name,
 749                      const char* signature,
 750                      const elfcpp::Shdr<size, big_endian>& shdr,
 751                      elfcpp::Elf_Word flags,
 752                      std::vector<unsigned int>* shndxes)
 753 {
 754   gold_assert(parameters->options().relocatable());
 755   gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
 756   group_section_name = this->namepool_.add(group_section_name, true, NULL);
 757   Output_section* os = this->make_output_section(group_section_name,
 758                                                  elfcpp::SHT_GROUP,
 759                                                  shdr.get_sh_flags(),
 760                                                  ORDER_INVALID, false);
 761
 762   // We need to find a symbol with the signature in the symbol table.
 763   // If we don't find one now, we need to look again later.
 764   Symbol* sym = symtab->lookup(signature, NULL);
 765   if (sym != NULL)
 766     os->set_info_symndx(sym);
 767   else
 768     {
 769       // Reserve some space to minimize reallocations.
 770       if (this->group_signatures_.empty())
 771         this->group_signatures_.reserve(this->number_of_input_files_ * 16);
 772
 773       // We will wind up using a symbol whose name is the signature.
 774       // So just put the signature in the symbol name pool to save it.
 775       signature = symtab->canonicalize_name(signature);
 776       this->group_signatures_.push_back(Group_signature(os, signature));
 777     }
 778
 779   os->set_should_link_to_symtab();
 780   os->set_entsize(4);
 781
 782   section_size_type entry_count =
 783     convert_to_section_size_type(shdr.get_sh_size() / 4);
 784   Output_section_data* posd =
 785     new Output_data_group<size, big_endian>(object, entry_count, flags,
 786                                             shndxes);
 787   os->add_output_section_data(posd);
 788 }
 789
 790 // Special GNU handling of sections name .eh_frame.  They will
 791 // normally hold exception frame data as defined by the C++ ABI
 792 // (http://codesourcery.com/cxx-abi/).
 793
 794 template<int size, bool big_endian>
 795 Output_section*
 796 Layout::layout_eh_frame(Sized_relobj<size, big_endian>* object,
 797                         const unsigned char* symbols,
 798                         off_t symbols_size,
 799                         const unsigned char* symbol_names,
 800                         off_t symbol_names_size,
 801                         unsigned int shndx,
 802                         const elfcpp::Shdr<size, big_endian>& shdr,
 803                         unsigned int reloc_shndx, unsigned int reloc_type,
 804                         off_t* off)
 805 {
 806   gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS);
 807   gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
 808
 809   const char* const name = ".eh_frame";
 810   Output_section* os = this->choose_output_section(object, name,
 811                                                    elfcpp::SHT_PROGBITS,
 812                                                    elfcpp::SHF_ALLOC, false,
 813                                                    ORDER_EHFRAME, false);
 814   if (os == NULL)
 815     return NULL;
 816
 817   if (this->eh_frame_section_ == NULL)
 818     {
 819       this->eh_frame_section_ = os;
 820       this->eh_frame_data_ = new Eh_frame();
 821
 822       if (parameters->options().eh_frame_hdr())
 823         {
 824           Output_section* hdr_os =
 825             this->choose_output_section(NULL, ".eh_frame_hdr",
 826                                         elfcpp::SHT_PROGBITS,
 827                                         elfcpp::SHF_ALLOC, false,
 828                                         ORDER_EHFRAME, false);
 829
 830           if (hdr_os != NULL)
 831             {
 832               Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os,
 833                                                         this->eh_frame_data_);
 834               hdr_os->add_output_section_data(hdr_posd);
 835
 836               hdr_os->set_after_input_sections();
 837
 838               if (!this->script_options_->saw_phdrs_clause())
 839                 {
 840                   Output_segment* hdr_oseg;
 841                   hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
 842                                                        elfcpp::PF_R);
 843                   hdr_oseg->add_output_section_to_nonload(hdr_os,
 844                                                           elfcpp::PF_R);
 845                 }
 846
 847               this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
 848             }
 849         }
 850     }
 851
 852   gold_assert(this->eh_frame_section_ == os);
 853
 854   if (this->eh_frame_data_->add_ehframe_input_section(object,
 855                                                       symbols,
 856                                                       symbols_size,
 857                                                       symbol_names,
 858                                                       symbol_names_size,
 859                                                       shndx,
 860                                                       reloc_shndx,
 861                                                       reloc_type))
 862     {
 863       os->update_flags_for_input_section(shdr.get_sh_flags());
 864
 865       // We found a .eh_frame section we are going to optimize, so now
 866       // we can add the set of optimized sections to the output
 867       // section.  We need to postpone adding this until we've found a
 868       // section we can optimize so that the .eh_frame section in
 869       // crtbegin.o winds up at the start of the output section.
 870       if (!this->added_eh_frame_data_)
 871         {
 872           os->add_output_section_data(this->eh_frame_data_);
 873           this->added_eh_frame_data_ = true;
 874         }
 875       *off = -1;
 876     }
 877   else
 878     {
 879       // We couldn't handle this .eh_frame section for some reason.
 880       // Add it as a normal section.
 881       bool saw_sections_clause = this->script_options_->saw_sections_clause();
 882       *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
 883                                    saw_sections_clause);
 884       this->have_added_input_section_ = true;
 885     }
 886
 887   return os;
 888 }
 889
 890 // Add POSD to an output section using NAME, TYPE, and FLAGS.  Return
 891 // the output section.
 892
 893 Output_section*
 894 Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
 895                                 elfcpp::Elf_Xword flags,
 896                                 Output_section_data* posd,
 897                                 Output_section_order order, bool is_relro)
 898 {
 899   Output_section* os = this->choose_output_section(NULL, name, type, flags,
 900                                                    false, order, is_relro);
 901   if (os != NULL)
 902     os->add_output_section_data(posd);
 903   return os;
 904 }
 905
 906 // Map section flags to segment flags.
 907
 908 elfcpp::Elf_Word
 909 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
 910 {
 911   elfcpp::Elf_Word ret = elfcpp::PF_R;
 912   if ((flags & elfcpp::SHF_WRITE) != 0)
 913     ret |= elfcpp::PF_W;
 914   if ((flags & elfcpp::SHF_EXECINSTR) != 0)
 915     ret |= elfcpp::PF_X;
 916   return ret;
 917 }
 918
 919 // Sometimes we compress sections.  This is typically done for
 920 // sections that are not part of normal program execution (such as
 921 // .debug_* sections), and where the readers of these sections know
 922 // how to deal with compressed sections.  This routine doesn't say for
 923 // certain whether we'll compress -- it depends on commandline options
 924 // as well -- just whether this section is a candidate for compression.
 925 // (The Output_compressed_section class decides whether to compress
 926 // a given section, and picks the name of the compressed section.)
 927
 928 static bool
 929 is_compressible_debug_section(const char* secname)
 930 {
 931   return (is_prefix_of(".debug", secname));
 932 }
 933
 934 // We may see compressed debug sections in input files.  Return TRUE
 935 // if this is the name of a compressed debug section.
 936
 937 bool
 938 is_compressed_debug_section(const char* secname)
 939 {
 940   return (is_prefix_of(".zdebug", secname));
 941 }
 942
 943 // Make a new Output_section, and attach it to segments as
 944 // appropriate.  ORDER is the order in which this section should
 945 // appear in the output segment.  IS_RELRO is true if this is a relro
 946 // (read-only after relocations) section.
 947
 948 Output_section*
 949 Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
 950                             elfcpp::Elf_Xword flags,
 951                             Output_section_order order, bool is_relro)
 952 {
 953   Output_section* os;
 954   if ((flags & elfcpp::SHF_ALLOC) == 0
 955       && strcmp(parameters->options().compress_debug_sections(), "none") != 0
 956       && is_compressible_debug_section(name))
 957     os = new Output_compressed_section(&parameters->options(), name, type,
 958                                        flags);
 959   else if ((flags & elfcpp::SHF_ALLOC) == 0
 960            && parameters->options().strip_debug_non_line()
 961            && strcmp(".debug_abbrev", name) == 0)
 962     {
 963       os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
 964           name, type, flags);
 965       if (this->debug_info_)
 966         this->debug_info_->set_abbreviations(this->debug_abbrev_);
 967     }
 968   else if ((flags & elfcpp::SHF_ALLOC) == 0
 969            && parameters->options().strip_debug_non_line()
 970            && strcmp(".debug_info", name) == 0)
 971     {
 972       os = this->debug_info_ = new Output_reduced_debug_info_section(
 973           name, type, flags);
 974       if (this->debug_abbrev_)
 975         this->debug_info_->set_abbreviations(this->debug_abbrev_);
 976     }
 977   else
 978     {
 979       // FIXME: const_cast is ugly.
 980       Target* target = const_cast<Target*>(&parameters->target());
 981       os = target->make_output_section(name, type, flags);
 982     }
 983
 984   // With -z relro, we have to recognize the special sections by name.
 985   // There is no other way.
 986   bool is_relro_local = false;
 987   if (!this->script_options_->saw_sections_clause()
 988       && parameters->options().relro()
 989       && type == elfcpp::SHT_PROGBITS
 990       && (flags & elfcpp::SHF_ALLOC) != 0
 991       && (flags & elfcpp::SHF_WRITE) != 0)
 992     {
 993       if (strcmp(name, ".data.rel.ro") == 0)
 994         is_relro = true;
 995       else if (strcmp(name, ".data.rel.ro.local") == 0)
 996         {
 997           is_relro = true;
 998           is_relro_local = true;
 999         }
1000       else if (type == elfcpp::SHT_INIT_ARRAY
1001                || type == elfcpp::SHT_FINI_ARRAY
1002                || type == elfcpp::SHT_PREINIT_ARRAY)
1003         is_relro = true;
1004       else if (strcmp(name, ".ctors") == 0
1005                || strcmp(name, ".dtors") == 0
1006                || strcmp(name, ".jcr") == 0)
1007         is_relro = true;
1008     }
1009
1010   if (is_relro)
1011     os->set_is_relro();
1012
1013   if (order == ORDER_INVALID && (flags & elfcpp::SHF_ALLOC) != 0)
1014     order = this->default_section_order(os, is_relro_local);
1015
1016   os->set_order(order);
1017
1018   parameters->target().new_output_section(os);
1019
1020   this->section_list_.push_back(os);
1021
1022   // The GNU linker by default sorts some sections by priority, so we
1023   // do the same.  We need to know that this might happen before we
1024   // attach any input sections.
1025   if (!this->script_options_->saw_sections_clause()
1026       && (strcmp(name, ".ctors") == 0
1027           || strcmp(name, ".dtors") == 0
1028           || strcmp(name, ".init_array") == 0
1029           || strcmp(name, ".fini_array") == 0))
1030     os->set_may_sort_attached_input_sections();
1031
1032   // Check for .stab*str sections, as .stab* sections need to link to
1033   // them.
1034   if (type == elfcpp::SHT_STRTAB
1035       && !this->have_stabstr_section_
1036       && strncmp(name, ".stab", 5) == 0
1037       && strcmp(name + strlen(name) - 3, "str") == 0)
1038     this->have_stabstr_section_ = true;
1039
1040   // If we have already attached the sections to segments, then we
1041   // need to attach this one now.  This happens for sections created
1042   // directly by the linker.
1043   if (this->sections_are_attached_)
1044     this->attach_section_to_segment(os);
1045
1046   return os;
1047 }
1048
1049 // Return the default order in which a section should be placed in an
1050 // output segment.  This function captures a lot of the ideas in
1051 // ld/scripttempl/elf.sc in the GNU linker.  Note that the order of a
1052 // linker created section is normally set when the section is created;
1053 // this function is used for input sections.
1054
1055 Output_section_order
1056 Layout::default_section_order(Output_section* os, bool is_relro_local)
1057 {
1058   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1059   bool is_write = (os->flags() & elfcpp::SHF_WRITE) != 0;
1060   bool is_execinstr = (os->flags() & elfcpp::SHF_EXECINSTR) != 0;
1061   bool is_bss = false;
1062
1063   switch (os->type())
1064     {
1065     default:
1066     case elfcpp::SHT_PROGBITS:
1067       break;
1068     case elfcpp::SHT_NOBITS:
1069       is_bss = true;
1070       break;
1071     case elfcpp::SHT_RELA:
1072     case elfcpp::SHT_REL:
1073       if (!is_write)
1074         return ORDER_DYNAMIC_RELOCS;
1075       break;
1076     case elfcpp::SHT_HASH:
1077     case elfcpp::SHT_DYNAMIC:
1078     case elfcpp::SHT_SHLIB:
1079     case elfcpp::SHT_DYNSYM:
1080     case elfcpp::SHT_GNU_HASH:
1081     case elfcpp::SHT_GNU_verdef:
1082     case elfcpp::SHT_GNU_verneed:
1083     case elfcpp::SHT_GNU_versym:
1084       if (!is_write)
1085         return ORDER_DYNAMIC_LINKER;
1086       break;
1087     case elfcpp::SHT_NOTE:
1088       return is_write ? ORDER_RW_NOTE : ORDER_RO_NOTE;
1089     }
1090
1091   if ((os->flags() & elfcpp::SHF_TLS) != 0)
1092     return is_bss ? ORDER_TLS_BSS : ORDER_TLS_DATA;
1093
1094   if (!is_bss && !is_write)
1095     {
1096       if (is_execinstr)
1097         {
1098           if (strcmp(os->name(), ".init") == 0)
1099             return ORDER_INIT;
1100           else if (strcmp(os->name(), ".fini") == 0)
1101             return ORDER_FINI;
1102         }
1103       return is_execinstr ? ORDER_TEXT : ORDER_READONLY;
1104     }
1105
1106   if (os->is_relro())
1107     return is_relro_local ? ORDER_RELRO_LOCAL : ORDER_RELRO;
1108
1109   if (os->is_small_section())
1110     return is_bss ? ORDER_SMALL_BSS : ORDER_SMALL_DATA;
1111   if (os->is_large_section())
1112     return is_bss ? ORDER_LARGE_BSS : ORDER_LARGE_DATA;
1113
1114   return is_bss ? ORDER_BSS : ORDER_DATA;
1115 }
1116
1117 // Attach output sections to segments.  This is called after we have
1118 // seen all the input sections.
1119
1120 void
1121 Layout::attach_sections_to_segments()
1122 {
1123   for (Section_list::iterator p = this->section_list_.begin();
1124        p != this->section_list_.end();
1125        ++p)
1126     this->attach_section_to_segment(*p);
1127
1128   this->sections_are_attached_ = true;
1129 }
1130
1131 // Attach an output section to a segment.
1132
1133 void
1134 Layout::attach_section_to_segment(Output_section* os)
1135 {
1136   if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
1137     this->unattached_section_list_.push_back(os);
1138   else
1139     this->attach_allocated_section_to_segment(os);
1140 }
1141
1142 // Attach an allocated output section to a segment.
1143
1144 void
1145 Layout::attach_allocated_section_to_segment(Output_section* os)
1146 {
1147   elfcpp::Elf_Xword flags = os->flags();
1148   gold_assert((flags & elfcpp::SHF_ALLOC) != 0);
1149
1150   if (parameters->options().relocatable())
1151     return;
1152
1153   // If we have a SECTIONS clause, we can't handle the attachment to
1154   // segments until after we've seen all the sections.
1155   if (this->script_options_->saw_sections_clause())
1156     return;
1157
1158   gold_assert(!this->script_options_->saw_phdrs_clause());
1159
1160   // This output section goes into a PT_LOAD segment.
1161
1162   elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
1163
1164   // Check for --section-start.
1165   uint64_t addr;
1166   bool is_address_set = parameters->options().section_start(os->name(), &addr);
1167
1168   // In general the only thing we really care about for PT_LOAD
1169   // segments is whether or not they are writable, so that is how we
1170   // search for them.  Large data sections also go into their own
1171   // PT_LOAD segment.  People who need segments sorted on some other
1172   // basis will have to use a linker script.
1173
1174   Segment_list::const_iterator p;
1175   for (p = this->segment_list_.begin();
1176        p != this->segment_list_.end();
1177        ++p)
1178     {
1179       if ((*p)->type() != elfcpp::PT_LOAD)
1180         continue;
1181       if (!parameters->options().omagic()
1182           && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
1183         continue;
1184       // If -Tbss was specified, we need to separate the data and BSS
1185       // segments.
1186       if (parameters->options().user_set_Tbss())
1187         {
1188           if ((os->type() == elfcpp::SHT_NOBITS)
1189               == (*p)->has_any_data_sections())
1190             continue;
1191         }
1192       if (os->is_large_data_section() && !(*p)->is_large_data_segment())
1193         continue;
1194
1195       if (is_address_set)
1196         {
1197           if ((*p)->are_addresses_set())
1198             continue;
1199
1200           (*p)->add_initial_output_data(os);
1201           (*p)->update_flags_for_output_section(seg_flags);
1202           (*p)->set_addresses(addr, addr);
1203           break;
1204         }
1205
1206       (*p)->add_output_section_to_load(this, os, seg_flags);
1207       break;
1208     }
1209
1210   if (p == this->segment_list_.end())
1211     {
1212       Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
1213                                                        seg_flags);
1214       if (os->is_large_data_section())
1215         oseg->set_is_large_data_segment();
1216       oseg->add_output_section_to_load(this, os, seg_flags);
1217       if (is_address_set)
1218         oseg->set_addresses(addr, addr);
1219     }
1220
1221   // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1222   // segment.
1223   if (os->type() == elfcpp::SHT_NOTE)
1224     {
1225       // See if we already have an equivalent PT_NOTE segment.
1226       for (p = this->segment_list_.begin();
1227            p != segment_list_.end();
1228            ++p)
1229         {
1230           if ((*p)->type() == elfcpp::PT_NOTE
1231               && (((*p)->flags() & elfcpp::PF_W)
1232                   == (seg_flags & elfcpp::PF_W)))
1233             {
1234               (*p)->add_output_section_to_nonload(os, seg_flags);
1235               break;
1236             }
1237         }
1238
1239       if (p == this->segment_list_.end())
1240         {
1241           Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
1242                                                            seg_flags);
1243           oseg->add_output_section_to_nonload(os, seg_flags);
1244         }
1245     }
1246
1247   // If we see a loadable SHF_TLS section, we create a PT_TLS
1248   // segment.  There can only be one such segment.
1249   if ((flags & elfcpp::SHF_TLS) != 0)
1250     {
1251       if (this->tls_segment_ == NULL)
1252         this->make_output_segment(elfcpp::PT_TLS, seg_flags);
1253       this->tls_segment_->add_output_section_to_nonload(os, seg_flags);
1254     }
1255
1256   // If -z relro is in effect, and we see a relro section, we create a
1257   // PT_GNU_RELRO segment.  There can only be one such segment.
1258   if (os->is_relro() && parameters->options().relro())
1259     {
1260       gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
1261       if (this->relro_segment_ == NULL)
1262         this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags);
1263       this->relro_segment_->add_output_section_to_nonload(os, seg_flags);
1264     }
1265 }
1266
1267 // Make an output section for a script.
1268
1269 Output_section*
1270 Layout::make_output_section_for_script(
1271     const char* name,
1272     Script_sections::Section_type section_type)
1273 {
1274   name = this->namepool_.add(name, false, NULL);
1275   elfcpp::Elf_Xword sh_flags = elfcpp::SHF_ALLOC;
1276   if (section_type == Script_sections::ST_NOLOAD)
1277     sh_flags = 0;
1278   Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
1279                                                  sh_flags, ORDER_INVALID,
1280                                                  false);
1281   os->set_found_in_sections_clause();
1282   if (section_type == Script_sections::ST_NOLOAD)
1283     os->set_is_noload();
1284   return os;
1285 }
1286
1287 // Return the number of segments we expect to see.
1288
1289 size_t
1290 Layout::expected_segment_count() const
1291 {
1292   size_t ret = this->segment_list_.size();
1293
1294   // If we didn't see a SECTIONS clause in a linker script, we should
1295   // already have the complete list of segments.  Otherwise we ask the
1296   // SECTIONS clause how many segments it expects, and add in the ones
1297   // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1298
1299   if (!this->script_options_->saw_sections_clause())
1300     return ret;
1301   else
1302     {
1303       const Script_sections* ss = this->script_options_->script_sections();
1304       return ret + ss->expected_segment_count(this);
1305     }
1306 }
1307
1308 // Handle the .note.GNU-stack section at layout time.  SEEN_GNU_STACK
1309 // is whether we saw a .note.GNU-stack section in the object file.
1310 // GNU_STACK_FLAGS is the section flags.  The flags give the
1311 // protection required for stack memory.  We record this in an
1312 // executable as a PT_GNU_STACK segment.  If an object file does not
1313 // have a .note.GNU-stack segment, we must assume that it is an old
1314 // object.  On some targets that will force an executable stack.
1315
1316 void
1317 Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
1318 {
1319   if (!seen_gnu_stack)
1320     this->input_without_gnu_stack_note_ = true;
1321   else
1322     {
1323       this->input_with_gnu_stack_note_ = true;
1324       if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
1325         this->input_requires_executable_stack_ = true;
1326     }
1327 }
1328
1329 // Create automatic note sections.
1330
1331 void
1332 Layout::create_notes()
1333 {
1334   this->create_gold_note();
1335   this->create_executable_stack_info();
1336   this->create_build_id();
1337 }
1338
1339 // Create the dynamic sections which are needed before we read the
1340 // relocs.
1341
1342 void
1343 Layout::create_initial_dynamic_sections(Symbol_table* symtab)
1344 {
1345   if (parameters->doing_static_link())
1346     return;
1347
1348   this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic",
1349                                                        elfcpp::SHT_DYNAMIC,
1350                                                        (elfcpp::SHF_ALLOC
1351                                                         | elfcpp::SHF_WRITE),
1352                                                        false, ORDER_RELRO,
1353                                                        true);
1354
1355   this->dynamic_symbol_ =
1356     symtab->define_in_output_data("_DYNAMIC", NULL, Symbol_table::PREDEFINED,
1357                                   this->dynamic_section_, 0, 0,
1358                                   elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
1359                                   elfcpp::STV_HIDDEN, 0, false, false);
1360
1361   this->dynamic_data_ =  new Output_data_dynamic(&this->dynpool_);
1362
1363   this->dynamic_section_->add_output_section_data(this->dynamic_data_);
1364 }
1365
1366 // For each output section whose name can be represented as C symbol,
1367 // define __start and __stop symbols for the section.  This is a GNU
1368 // extension.
1369
1370 void
1371 Layout::define_section_symbols(Symbol_table* symtab)
1372 {
1373   for (Section_list::const_iterator p = this->section_list_.begin();
1374        p != this->section_list_.end();
1375        ++p)
1376     {
1377       const char* const name = (*p)->name();
1378       if (is_cident(name))
1379         {
1380           const std::string name_string(name);
1381           const std::string start_name(cident_section_start_prefix
1382                                        + name_string);
1383           const std::string stop_name(cident_section_stop_prefix
1384                                       + name_string);
1385
1386           symtab->define_in_output_data(start_name.c_str(),
1387                                         NULL, // version
1388                                         Symbol_table::PREDEFINED,
1389                                         *p,
1390                                         0, // value
1391                                         0, // symsize
1392                                         elfcpp::STT_NOTYPE,
1393                                         elfcpp::STB_GLOBAL,
1394                                         elfcpp::STV_DEFAULT,
1395                                         0, // nonvis
1396                                         false, // offset_is_from_end
1397                                         true); // only_if_ref
1398
1399           symtab->define_in_output_data(stop_name.c_str(),
1400                                         NULL, // version
1401                                         Symbol_table::PREDEFINED,
1402                                         *p,
1403                                         0, // value
1404                                         0, // symsize
1405                                         elfcpp::STT_NOTYPE,
1406                                         elfcpp::STB_GLOBAL,
1407                                         elfcpp::STV_DEFAULT,
1408                                         0, // nonvis
1409                                         true, // offset_is_from_end
1410                                         true); // only_if_ref
1411         }
1412     }
1413 }
1414
1415 // Define symbols for group signatures.
1416
1417 void
1418 Layout::define_group_signatures(Symbol_table* symtab)
1419 {
1420   for (Group_signatures::iterator p = this->group_signatures_.begin();
1421        p != this->group_signatures_.end();
1422        ++p)
1423     {
1424       Symbol* sym = symtab->lookup(p->signature, NULL);
1425       if (sym != NULL)
1426         p->section->set_info_symndx(sym);
1427       else
1428         {
1429           // Force the name of the group section to the group
1430           // signature, and use the group's section symbol as the
1431           // signature symbol.
1432           if (strcmp(p->section->name(), p->signature) != 0)
1433             {
1434               const char* name = this->namepool_.add(p->signature,
1435                                                      true, NULL);
1436               p->section->set_name(name);
1437             }
1438           p->section->set_needs_symtab_index();
1439           p->section->set_info_section_symndx(p->section);
1440         }
1441     }
1442
1443   this->group_signatures_.clear();
1444 }
1445
1446 // Find the first read-only PT_LOAD segment, creating one if
1447 // necessary.
1448
1449 Output_segment*
1450 Layout::find_first_load_seg()
1451 {
1452   for (Segment_list::const_iterator p = this->segment_list_.begin();
1453        p != this->segment_list_.end();
1454        ++p)
1455     {
1456       if ((*p)->type() == elfcpp::PT_LOAD
1457           && ((*p)->flags() & elfcpp::PF_R) != 0
1458           && (parameters->options().omagic()
1459               || ((*p)->flags() & elfcpp::PF_W) == 0))
1460         return *p;
1461     }
1462
1463   gold_assert(!this->script_options_->saw_phdrs_clause());
1464
1465   Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD,
1466                                                        elfcpp::PF_R);
1467   return load_seg;
1468 }
1469
1470 // Save states of all current output segments.  Store saved states
1471 // in SEGMENT_STATES.
1472
1473 void
1474 Layout::save_segments(Segment_states* segment_states)
1475 {
1476   for (Segment_list::const_iterator p = this->segment_list_.begin();
1477        p != this->segment_list_.end();
1478        ++p)
1479     {
1480       Output_segment* segment = *p;
1481       // Shallow copy.
1482       Output_segment* copy = new Output_segment(*segment);
1483       (*segment_states)[segment] = copy;
1484     }
1485 }
1486
1487 // Restore states of output segments and delete any segment not found in
1488 // SEGMENT_STATES.
1489
1490 void
1491 Layout::restore_segments(const Segment_states* segment_states)
1492 {
1493   // Go through the segment list and remove any segment added in the
1494   // relaxation loop.
1495   this->tls_segment_ = NULL;
1496   this->relro_segment_ = NULL;
1497   Segment_list::iterator list_iter = this->segment_list_.begin();
1498   while (list_iter != this->segment_list_.end())
1499     {
1500       Output_segment* segment = *list_iter;
1501       Segment_states::const_iterator states_iter =
1502           segment_states->find(segment);
1503       if (states_iter != segment_states->end())
1504         {
1505           const Output_segment* copy = states_iter->second;
1506           // Shallow copy to restore states.
1507           *segment = *copy;
1508
1509           // Also fix up TLS and RELRO segment pointers as appropriate.
1510           if (segment->type() == elfcpp::PT_TLS)
1511             this->tls_segment_ = segment;
1512           else if (segment->type() == elfcpp::PT_GNU_RELRO)
1513             this->relro_segment_ = segment;
1514
1515           ++list_iter;
1516         }
1517       else
1518         {
1519           list_iter = this->segment_list_.erase(list_iter);
1520           // This is a segment created during section layout.  It should be
1521           // safe to remove it since we should have removed all pointers to it.
1522           delete segment;
1523         }
1524     }
1525 }
1526
1527 // Clean up after relaxation so that sections can be laid out again.
1528
1529 void
1530 Layout::clean_up_after_relaxation()
1531 {
1532   // Restore the segments to point state just prior to the relaxation loop.
1533   Script_sections* script_section = this->script_options_->script_sections();
1534   script_section->release_segments();
1535   this->restore_segments(this->segment_states_);
1536
1537   // Reset section addresses and file offsets
1538   for (Section_list::iterator p = this->section_list_.begin();
1539        p != this->section_list_.end();
1540        ++p)
1541     {
1542       (*p)->restore_states();
1543
1544       // If an input section changes size because of relaxation,
1545       // we need to adjust the section offsets of all input sections.
1546       // after such a section.
1547       if ((*p)->section_offsets_need_adjustment())
1548         (*p)->adjust_section_offsets();
1549
1550       (*p)->reset_address_and_file_offset();
1551     }
1552
1553   // Reset special output object address and file offsets.
1554   for (Data_list::iterator p = this->special_output_list_.begin();
1555        p != this->special_output_list_.end();
1556        ++p)
1557     (*p)->reset_address_and_file_offset();
1558
1559   // A linker script may have created some output section data objects.
1560   // They are useless now.
1561   for (Output_section_data_list::const_iterator p =
1562          this->script_output_section_data_list_.begin();
1563        p != this->script_output_section_data_list_.end();
1564        ++p)
1565     delete *p;
1566   this->script_output_section_data_list_.clear();
1567 }
1568
1569 // Prepare for relaxation.
1570
1571 void
1572 Layout::prepare_for_relaxation()
1573 {
1574   // Create an relaxation debug check if in debugging mode.
1575   if (is_debugging_enabled(DEBUG_RELAXATION))
1576     this->relaxation_debug_check_ = new Relaxation_debug_check();
1577
1578   // Save segment states.
1579   this->segment_states_ = new Segment_states();
1580   this->save_segments(this->segment_states_);
1581
1582   for(Section_list::const_iterator p = this->section_list_.begin();
1583       p != this->section_list_.end();
1584       ++p)
1585     (*p)->save_states();
1586
1587   if (is_debugging_enabled(DEBUG_RELAXATION))
1588     this->relaxation_debug_check_->check_output_data_for_reset_values(
1589         this->section_list_, this->special_output_list_);
1590
1591   // Also enable recording of output section data from scripts.
1592   this->record_output_section_data_from_script_ = true;
1593 }
1594
1595 // Relaxation loop body:  If target has no relaxation, this runs only once
1596 // Otherwise, the target relaxation hook is called at the end of
1597 // each iteration.  If the hook returns true, it means re-layout of
1598 // section is required.
1599 //
1600 // The number of segments created by a linking script without a PHDRS
1601 // clause may be affected by section sizes and alignments.  There is
1602 // a remote chance that relaxation causes different number of PT_LOAD
1603 // segments are created and sections are attached to different segments.
1604 // Therefore, we always throw away all segments created during section
1605 // layout.  In order to be able to restart the section layout, we keep
1606 // a copy of the segment list right before the relaxation loop and use
1607 // that to restore the segments.
1608 //
1609 // PASS is the current relaxation pass number.
1610 // SYMTAB is a symbol table.
1611 // PLOAD_SEG is the address of a pointer for the load segment.
1612 // PHDR_SEG is a pointer to the PHDR segment.
1613 // SEGMENT_HEADERS points to the output segment header.
1614 // FILE_HEADER points to the output file header.
1615 // PSHNDX is the address to store the output section index.
1616
1617 off_t inline
1618 Layout::relaxation_loop_body(
1619     int pass,
1620     Target* target,
1621     Symbol_table* symtab,
1622     Output_segment** pload_seg,
1623     Output_segment* phdr_seg,
1624     Output_segment_headers* segment_headers,
1625     Output_file_header* file_header,
1626     unsigned int* pshndx)
1627 {
1628   // If this is not the first iteration, we need to clean up after
1629   // relaxation so that we can lay out the sections again.
1630   if (pass != 0)
1631     this->clean_up_after_relaxation();
1632
1633   // If there is a SECTIONS clause, put all the input sections into
1634   // the required order.
1635   Output_segment* load_seg;
1636   if (this->script_options_->saw_sections_clause())
1637     load_seg = this->set_section_addresses_from_script(symtab);
1638   else if (parameters->options().relocatable())
1639     load_seg = NULL;
1640   else
1641     load_seg = this->find_first_load_seg();
1642
1643   if (parameters->options().oformat_enum()
1644       != General_options::OBJECT_FORMAT_ELF)
1645     load_seg = NULL;
1646
1647   // If the user set the address of the text segment, that may not be
1648   // compatible with putting the segment headers and file headers into
1649   // that segment.
1650   if (parameters->options().user_set_Ttext())
1651     load_seg = NULL;
1652
1653   gold_assert(phdr_seg == NULL
1654               || load_seg != NULL
1655               || this->script_options_->saw_sections_clause());
1656
1657   // If the address of the load segment we found has been set by
1658   // --section-start rather than by a script, then adjust the VMA and
1659   // LMA downward if possible to include the file and section headers.
1660   uint64_t header_gap = 0;
1661   if (load_seg != NULL
1662       && load_seg->are_addresses_set()
1663       && !this->script_options_->saw_sections_clause()
1664       && !parameters->options().relocatable())
1665     {
1666       file_header->finalize_data_size();
1667       segment_headers->finalize_data_size();
1668       size_t sizeof_headers = (file_header->data_size()
1669                                + segment_headers->data_size());
1670       const uint64_t abi_pagesize = target->abi_pagesize();
1671       uint64_t hdr_paddr = load_seg->paddr() - sizeof_headers;
1672       hdr_paddr &= ~(abi_pagesize - 1);
1673       uint64_t subtract = load_seg->paddr() - hdr_paddr;
1674       if (load_seg->paddr() < subtract || load_seg->vaddr() < subtract)
1675         load_seg = NULL;
1676       else
1677         {
1678           load_seg->set_addresses(load_seg->vaddr() - subtract,
1679                                   load_seg->paddr() - subtract);
1680           header_gap = subtract - sizeof_headers;
1681         }
1682     }
1683
1684   // Lay out the segment headers.
1685   if (!parameters->options().relocatable())
1686     {
1687       gold_assert(segment_headers != NULL);
1688       if (header_gap != 0 && load_seg != NULL)
1689         {
1690           Output_data_zero_fill* z = new Output_data_zero_fill(header_gap, 1);
1691           load_seg->add_initial_output_data(z);
1692         }
1693       if (load_seg != NULL)
1694         load_seg->add_initial_output_data(segment_headers);
1695       if (phdr_seg != NULL)
1696         phdr_seg->add_initial_output_data(segment_headers);
1697     }
1698
1699   // Lay out the file header.
1700   if (load_seg != NULL)
1701     load_seg->add_initial_output_data(file_header);
1702
1703   if (this->script_options_->saw_phdrs_clause()
1704       && !parameters->options().relocatable())
1705     {
1706       // Support use of FILEHDRS and PHDRS attachments in a PHDRS
1707       // clause in a linker script.
1708       Script_sections* ss = this->script_options_->script_sections();
1709       ss->put_headers_in_phdrs(file_header, segment_headers);
1710     }
1711
1712   // We set the output section indexes in set_segment_offsets and
1713   // set_section_indexes.
1714   *pshndx = 1;
1715
1716   // Set the file offsets of all the segments, and all the sections
1717   // they contain.
1718   off_t off;
1719   if (!parameters->options().relocatable())
1720     off = this->set_segment_offsets(target, load_seg, pshndx);
1721   else
1722     off = this->set_relocatable_section_offsets(file_header, pshndx);
1723
1724    // Verify that the dummy relaxation does not change anything.
1725   if (is_debugging_enabled(DEBUG_RELAXATION))
1726     {
1727       if (pass == 0)
1728         this->relaxation_debug_check_->read_sections(this->section_list_);
1729       else
1730         this->relaxation_debug_check_->verify_sections(this->section_list_);
1731     }
1732
1733   *pload_seg = load_seg;
1734   return off;
1735 }
1736
1737 // Search the list of patterns and find the postion of the given section
1738 // name in the output section.  If the section name matches a glob
1739 // pattern and a non-glob name, then the non-glob position takes
1740 // precedence.  Return 0 if no match is found.
1741
1742 unsigned int
1743 Layout::find_section_order_index(const std::string& section_name)
1744 {
1745   Unordered_map<std::string, unsigned int>::iterator map_it;
1746   map_it = this->input_section_position_.find(section_name);
1747   if (map_it != this->input_section_position_.end())
1748     return map_it->second;
1749
1750   // Absolute match failed.  Linear search the glob patterns.
1751   std::vector<std::string>::iterator it;
1752   for (it = this->input_section_glob_.begin();
1753        it != this->input_section_glob_.end();
1754        ++it)
1755     {
1756        if (fnmatch((*it).c_str(), section_name.c_str(), FNM_NOESCAPE) == 0)
1757          {
1758            map_it = this->input_section_position_.find(*it);
1759            gold_assert(map_it != this->input_section_position_.end());
1760            return map_it->second;
1761          }
1762     }
1763   return 0;
1764 }
1765
1766 // Read the sequence of input sections from the file specified with
1767 // --section-ordering-file.
1768
1769 void
1770 Layout::read_layout_from_file()
1771 {
1772   const char* filename = parameters->options().section_ordering_file();
1773   std::ifstream in;
1774   std::string line;
1775
1776   in.open(filename);
1777   if (!in)
1778     gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
1779                filename, strerror(errno));
1780
1781   std::getline(in, line);   // this chops off the trailing \n, if any
1782   unsigned int position = 1;
1783
1784   while (in)
1785     {
1786       if (!line.empty() && line[line.length() - 1] == '\r')   // Windows
1787         line.resize(line.length() - 1);
1788       // Ignore comments, beginning with '#'
1789       if (line[0] == '#')
1790         {
1791           std::getline(in, line);
1792           continue;
1793         }
1794       this->input_section_position_[line] = position;
1795       // Store all glob patterns in a vector.
1796       if (is_wildcard_string(line.c_str()))
1797         this->input_section_glob_.push_back(line);
1798       position++;
1799       std::getline(in, line);
1800     }
1801 }
1802
1803 // Finalize the layout.  When this is called, we have created all the
1804 // output sections and all the output segments which are based on
1805 // input sections.  We have several things to do, and we have to do
1806 // them in the right order, so that we get the right results correctly
1807 // and efficiently.
1808
1809 // 1) Finalize the list of output segments and create the segment
1810 // table header.
1811
1812 // 2) Finalize the dynamic symbol table and associated sections.
1813
1814 // 3) Determine the final file offset of all the output segments.
1815
1816 // 4) Determine the final file offset of all the SHF_ALLOC output
1817 // sections.
1818
1819 // 5) Create the symbol table sections and the section name table
1820 // section.
1821
1822 // 6) Finalize the symbol table: set symbol values to their final
1823 // value and make a final determination of which symbols are going
1824 // into the output symbol table.
1825
1826 // 7) Create the section table header.
1827
1828 // 8) Determine the final file offset of all the output sections which
1829 // are not SHF_ALLOC, including the section table header.
1830
1831 // 9) Finalize the ELF file header.
1832
1833 // This function returns the size of the output file.
1834
1835 off_t
1836 Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
1837                  Target* target, const Task* task)
1838 {
1839   target->finalize_sections(this, input_objects, symtab);
1840
1841   this->count_local_symbols(task, input_objects);
1842
1843   this->link_stabs_sections();
1844
1845   Output_segment* phdr_seg = NULL;
1846   if (!parameters->options().relocatable() && !parameters->doing_static_link())
1847     {
1848       // There was a dynamic object in the link.  We need to create
1849       // some information for the dynamic linker.
1850
1851       // Create the PT_PHDR segment which will hold the program
1852       // headers.
1853       if (!this->script_options_->saw_phdrs_clause())
1854         phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
1855
1856       // Create the dynamic symbol table, including the hash table.
1857       Output_section* dynstr;
1858       std::vector<Symbol*> dynamic_symbols;
1859       unsigned int local_dynamic_count;
1860       Versions versions(*this->script_options()->version_script_info(),
1861                         &this->dynpool_);
1862       this->create_dynamic_symtab(input_objects, symtab, &dynstr,
1863                                   &local_dynamic_count, &dynamic_symbols,
1864                                   &versions);
1865
1866       // Create the .interp section to hold the name of the
1867       // interpreter, and put it in a PT_INTERP segment.
1868       if (!parameters->options().shared())
1869         this->create_interp(target);
1870
1871       // Finish the .dynamic section to hold the dynamic data, and put
1872       // it in a PT_DYNAMIC segment.
1873       this->finish_dynamic_section(input_objects, symtab);
1874
1875       // We should have added everything we need to the dynamic string
1876       // table.
1877       this->dynpool_.set_string_offsets();
1878
1879       // Create the version sections.  We can't do this until the
1880       // dynamic string table is complete.
1881       this->create_version_sections(&versions, symtab, local_dynamic_count,
1882                                     dynamic_symbols, dynstr);
1883
1884       // Set the size of the _DYNAMIC symbol.  We can't do this until
1885       // after we call create_version_sections.
1886       this->set_dynamic_symbol_size(symtab);
1887     }
1888
1889   // Create segment headers.
1890   Output_segment_headers* segment_headers =
1891     (parameters->options().relocatable()
1892      ? NULL
1893      : new Output_segment_headers(this->segment_list_));
1894
1895   // Lay out the file header.
1896   Output_file_header* file_header
1897     = new Output_file_header(target, symtab, segment_headers,
1898                              parameters->options().entry());
1899
1900   this->special_output_list_.push_back(file_header);
1901   if (segment_headers != NULL)
1902     this->special_output_list_.push_back(segment_headers);
1903
1904   // Find approriate places for orphan output sections if we are using
1905   // a linker script.
1906   if (this->script_options_->saw_sections_clause())
1907     this->place_orphan_sections_in_script();
1908
1909   Output_segment* load_seg;
1910   off_t off;
1911   unsigned int shndx;
1912   int pass = 0;
1913
1914   // Take a snapshot of the section layout as needed.
1915   if (target->may_relax())
1916     this->prepare_for_relaxation();
1917
1918   // Run the relaxation loop to lay out sections.
1919   do
1920     {
1921       off = this->relaxation_loop_body(pass, target, symtab, &load_seg,
1922                                        phdr_seg, segment_headers, file_header,
1923                                        &shndx);
1924       pass++;
1925     }
1926   while (target->may_relax()
1927          && target->relax(pass, input_objects, symtab, this));
1928
1929   // Set the file offsets of all the non-data sections we've seen so
1930   // far which don't have to wait for the input sections.  We need
1931   // this in order to finalize local symbols in non-allocated
1932   // sections.
1933   off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
1934
1935   // Set the section indexes of all unallocated sections seen so far,
1936   // in case any of them are somehow referenced by a symbol.
1937   shndx = this->set_section_indexes(shndx);
1938
1939   // Create the symbol table sections.
1940   this->create_symtab_sections(input_objects, symtab, shndx, &off);
1941   if (!parameters->doing_static_link())
1942     this->assign_local_dynsym_offsets(input_objects);
1943
1944   // Process any symbol assignments from a linker script.  This must
1945   // be called after the symbol table has been finalized.
1946   this->script_options_->finalize_symbols(symtab, this);
1947
1948   // Create the incremental inputs sections.
1949   if (this->incremental_inputs_)
1950     {
1951       this->incremental_inputs_->finalize();
1952       this->create_incremental_info_sections(symtab);
1953     }
1954
1955   // Create the .shstrtab section.
1956   Output_section* shstrtab_section = this->create_shstrtab();
1957
1958   // Set the file offsets of the rest of the non-data sections which
1959   // don't have to wait for the input sections.
1960   off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
1961
1962   // Now that all sections have been created, set the section indexes
1963   // for any sections which haven't been done yet.
1964   shndx = this->set_section_indexes(shndx);
1965
1966   // Create the section table header.
1967   this->create_shdrs(shstrtab_section, &off);
1968
1969   // If there are no sections which require postprocessing, we can
1970   // handle the section names now, and avoid a resize later.
1971   if (!this->any_postprocessing_sections_)
1972     {
1973       off = this->set_section_offsets(off,
1974                                       POSTPROCESSING_SECTIONS_PASS);
1975       off =
1976           this->set_section_offsets(off,
1977                                     STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
1978     }
1979
1980   file_header->set_section_info(this->section_headers_, shstrtab_section);
1981
1982   // Now we know exactly where everything goes in the output file
1983   // (except for non-allocated sections which require postprocessing).
1984   Output_data::layout_complete();
1985
1986   this->output_file_size_ = off;
1987
1988   return off;
1989 }
1990
1991 // Create a note header following the format defined in the ELF ABI.
1992 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
1993 // of the section to create, DESCSZ is the size of the descriptor.
1994 // ALLOCATE is true if the section should be allocated in memory.
1995 // This returns the new note section.  It sets *TRAILING_PADDING to
1996 // the number of trailing zero bytes required.
1997
1998 Output_section*
1999 Layout::create_note(const char* name, int note_type,
2000                     const char* section_name, size_t descsz,
2001                     bool allocate, size_t* trailing_padding)
2002 {
2003   // Authorities all agree that the values in a .note field should
2004   // be aligned on 4-byte boundaries for 32-bit binaries.  However,
2005   // they differ on what the alignment is for 64-bit binaries.
2006   // The GABI says unambiguously they take 8-byte alignment:
2007   //    http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2008   // Other documentation says alignment should always be 4 bytes:
2009   //    http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2010   // GNU ld and GNU readelf both support the latter (at least as of
2011   // version 2.16.91), and glibc always generates the latter for
2012   // .note.ABI-tag (as of version 1.6), so that's the one we go with
2013   // here.
2014 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION   // This is not defined by default.
2015   const int size = parameters->target().get_size();
2016 #else
2017   const int size = 32;
2018 #endif
2019
2020   // The contents of the .note section.
2021   size_t namesz = strlen(name) + 1;
2022   size_t aligned_namesz = align_address(namesz, size / 8);
2023   size_t aligned_descsz = align_address(descsz, size / 8);
2024
2025   size_t notehdrsz = 3 * (size / 8) + aligned_namesz;
2026
2027   unsigned char* buffer = new unsigned char[notehdrsz];
2028   memset(buffer, 0, notehdrsz);
2029
2030   bool is_big_endian = parameters->target().is_big_endian();
2031
2032   if (size == 32)
2033     {
2034       if (!is_big_endian)
2035         {
2036           elfcpp::Swap<32, false>::writeval(buffer, namesz);
2037           elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
2038           elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
2039         }
2040       else
2041         {
2042           elfcpp::Swap<32, true>::writeval(buffer, namesz);
2043           elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
2044           elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
2045         }
2046     }
2047   else if (size == 64)
2048     {
2049       if (!is_big_endian)
2050         {
2051           elfcpp::Swap<64, false>::writeval(buffer, namesz);
2052           elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
2053           elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
2054         }
2055       else
2056         {
2057           elfcpp::Swap<64, true>::writeval(buffer, namesz);
2058           elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
2059           elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
2060         }
2061     }
2062   else
2063     gold_unreachable();
2064
2065   memcpy(buffer + 3 * (size / 8), name, namesz);
2066
2067   elfcpp::Elf_Xword flags = 0;
2068   Output_section_order order = ORDER_INVALID;
2069   if (allocate)
2070     {
2071       flags = elfcpp::SHF_ALLOC;
2072       order = ORDER_RO_NOTE;
2073     }
2074   Output_section* os = this->choose_output_section(NULL, section_name,
2075                                                    elfcpp::SHT_NOTE,
2076                                                    flags, false, order, false);
2077   if (os == NULL)
2078     return NULL;
2079
2080   Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
2081                                                            size / 8,
2082                                                            "** note header");
2083   os->add_output_section_data(posd);
2084
2085   *trailing_padding = aligned_descsz - descsz;
2086
2087   return os;
2088 }
2089
2090 // For an executable or shared library, create a note to record the
2091 // version of gold used to create the binary.
2092
2093 void
2094 Layout::create_gold_note()
2095 {
2096   if (parameters->options().relocatable())
2097     return;
2098
2099   std::string desc = std::string("gold ") + gold::get_version_string();
2100
2101   size_t trailing_padding;
2102   Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
2103                                          ".note.gnu.gold-version", desc.size(),
2104                                          false, &trailing_padding);
2105   if (os == NULL)
2106     return;
2107
2108   Output_section_data* posd = new Output_data_const(desc, 4);
2109   os->add_output_section_data(posd);
2110
2111   if (trailing_padding > 0)
2112     {
2113       posd = new Output_data_zero_fill(trailing_padding, 0);
2114       os->add_output_section_data(posd);
2115     }
2116 }
2117
2118 // Record whether the stack should be executable.  This can be set
2119 // from the command line using the -z execstack or -z noexecstack
2120 // options.  Otherwise, if any input file has a .note.GNU-stack
2121 // section with the SHF_EXECINSTR flag set, the stack should be
2122 // executable.  Otherwise, if at least one input file a
2123 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2124 // section, we use the target default for whether the stack should be
2125 // executable.  Otherwise, we don't generate a stack note.  When
2126 // generating a object file, we create a .note.GNU-stack section with
2127 // the appropriate marking.  When generating an executable or shared
2128 // library, we create a PT_GNU_STACK segment.
2129
2130 void
2131 Layout::create_executable_stack_info()
2132 {
2133   bool is_stack_executable;
2134   if (parameters->options().is_execstack_set())
2135     is_stack_executable = parameters->options().is_stack_executable();
2136   else if (!this->input_with_gnu_stack_note_)
2137     return;
2138   else
2139     {
2140       if (this->input_requires_executable_stack_)
2141         is_stack_executable = true;
2142       else if (this->input_without_gnu_stack_note_)
2143         is_stack_executable =
2144           parameters->target().is_default_stack_executable();
2145       else
2146         is_stack_executable = false;
2147     }
2148
2149   if (parameters->options().relocatable())
2150     {
2151       const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
2152       elfcpp::Elf_Xword flags = 0;
2153       if (is_stack_executable)
2154         flags |= elfcpp::SHF_EXECINSTR;
2155       this->make_output_section(name, elfcpp::SHT_PROGBITS, flags,
2156                                 ORDER_INVALID, false);
2157     }
2158   else
2159     {
2160       if (this->script_options_->saw_phdrs_clause())
2161         return;
2162       int flags = elfcpp::PF_R | elfcpp::PF_W;
2163       if (is_stack_executable)
2164         flags |= elfcpp::PF_X;
2165       this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
2166     }
2167 }
2168
2169 // If --build-id was used, set up the build ID note.
2170
2171 void
2172 Layout::create_build_id()
2173 {
2174   if (!parameters->options().user_set_build_id())
2175     return;
2176
2177   const char* style = parameters->options().build_id();
2178   if (strcmp(style, "none") == 0)
2179     return;
2180
2181   // Set DESCSZ to the size of the note descriptor.  When possible,
2182   // set DESC to the note descriptor contents.
2183   size_t descsz;
2184   std::string desc;
2185   if (strcmp(style, "md5") == 0)
2186     descsz = 128 / 8;
2187   else if (strcmp(style, "sha1") == 0)
2188     descsz = 160 / 8;
2189   else if (strcmp(style, "uuid") == 0)
2190     {
2191       const size_t uuidsz = 128 / 8;
2192
2193       char buffer[uuidsz];
2194       memset(buffer, 0, uuidsz);
2195
2196       int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY);
2197       if (descriptor < 0)
2198         gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2199                    strerror(errno));
2200       else
2201         {
2202           ssize_t got = ::read(descriptor, buffer, uuidsz);
2203           release_descriptor(descriptor, true);
2204           if (got < 0)
2205             gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
2206           else if (static_cast<size_t>(got) != uuidsz)
2207             gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2208                        uuidsz, got);
2209         }
2210
2211       desc.assign(buffer, uuidsz);
2212       descsz = uuidsz;
2213     }
2214   else if (strncmp(style, "0x", 2) == 0)
2215     {
2216       hex_init();
2217       const char* p = style + 2;
2218       while (*p != '\0')
2219         {
2220           if (hex_p(p[0]) && hex_p(p[1]))
2221             {
2222               char c = (hex_value(p[0]) << 4) | hex_value(p[1]);
2223               desc += c;
2224               p += 2;
2225             }
2226           else if (*p == '-' || *p == ':')
2227             ++p;
2228           else
2229             gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2230                        style);
2231         }
2232       descsz = desc.size();
2233     }
2234   else
2235     gold_fatal(_("unrecognized --build-id argument '%s'"), style);
2236
2237   // Create the note.
2238   size_t trailing_padding;
2239   Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
2240                                          ".note.gnu.build-id", descsz, true,
2241                                          &trailing_padding);
2242   if (os == NULL)
2243     return;
2244
2245   if (!desc.empty())
2246     {
2247       // We know the value already, so we fill it in now.
2248       gold_assert(desc.size() == descsz);
2249
2250       Output_section_data* posd = new Output_data_const(desc, 4);
2251       os->add_output_section_data(posd);
2252
2253       if (trailing_padding != 0)
2254         {
2255           posd = new Output_data_zero_fill(trailing_padding, 0);
2256           os->add_output_section_data(posd);
2257         }
2258     }
2259   else
2260     {
2261       // We need to compute a checksum after we have completed the
2262       // link.
2263       gold_assert(trailing_padding == 0);
2264       this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
2265       os->add_output_section_data(this->build_id_note_);
2266     }
2267 }
2268
2269 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2270 // field of the former should point to the latter.  I'm not sure who
2271 // started this, but the GNU linker does it, and some tools depend
2272 // upon it.
2273
2274 void
2275 Layout::link_stabs_sections()
2276 {
2277   if (!this->have_stabstr_section_)
2278     return;
2279
2280   for (Section_list::iterator p = this->section_list_.begin();
2281        p != this->section_list_.end();
2282        ++p)
2283     {
2284       if ((*p)->type() != elfcpp::SHT_STRTAB)
2285         continue;
2286
2287       const char* name = (*p)->name();
2288       if (strncmp(name, ".stab", 5) != 0)
2289         continue;
2290
2291       size_t len = strlen(name);
2292       if (strcmp(name + len - 3, "str") != 0)
2293         continue;
2294
2295       std::string stab_name(name, len - 3);
2296       Output_section* stab_sec;
2297       stab_sec = this->find_output_section(stab_name.c_str());
2298       if (stab_sec != NULL)
2299         stab_sec->set_link_section(*p);
2300     }
2301 }
2302
2303 // Create .gnu_incremental_inputs and related sections needed
2304 // for the next run of incremental linking to check what has changed.
2305
2306 void
2307 Layout::create_incremental_info_sections(Symbol_table* symtab)
2308 {
2309   Incremental_inputs* incr = this->incremental_inputs_;
2310
2311   gold_assert(incr != NULL);
2312
2313   // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
2314   incr->create_data_sections(symtab);
2315
2316   // Add the .gnu_incremental_inputs section.
2317   const char *incremental_inputs_name =
2318     this->namepool_.add(".gnu_incremental_inputs", false, NULL);
2319   Output_section* incremental_inputs_os =
2320     this->make_output_section(incremental_inputs_name,
2321                               elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0,
2322                               ORDER_INVALID, false);
2323   incremental_inputs_os->add_output_section_data(incr->inputs_section());
2324
2325   // Add the .gnu_incremental_symtab section.
2326   const char *incremental_symtab_name =
2327     this->namepool_.add(".gnu_incremental_symtab", false, NULL);
2328   Output_section* incremental_symtab_os =
2329     this->make_output_section(incremental_symtab_name,
2330                               elfcpp::SHT_GNU_INCREMENTAL_SYMTAB, 0,
2331                               ORDER_INVALID, false);
2332   incremental_symtab_os->add_output_section_data(incr->symtab_section());
2333   incremental_symtab_os->set_entsize(4);
2334
2335   // Add the .gnu_incremental_relocs section.
2336   const char *incremental_relocs_name =
2337     this->namepool_.add(".gnu_incremental_relocs", false, NULL);
2338   Output_section* incremental_relocs_os =
2339     this->make_output_section(incremental_relocs_name,
2340                               elfcpp::SHT_GNU_INCREMENTAL_RELOCS, 0,
2341                               ORDER_INVALID, false);
2342   incremental_relocs_os->add_output_section_data(incr->relocs_section());
2343   incremental_relocs_os->set_entsize(incr->relocs_entsize());
2344
2345   // Add the .gnu_incremental_got_plt section.
2346   const char *incremental_got_plt_name =
2347     this->namepool_.add(".gnu_incremental_got_plt", false, NULL);
2348   Output_section* incremental_got_plt_os =
2349     this->make_output_section(incremental_got_plt_name,
2350                               elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT, 0,
2351                               ORDER_INVALID, false);
2352   incremental_got_plt_os->add_output_section_data(incr->got_plt_section());
2353
2354   // Add the .gnu_incremental_strtab section.
2355   const char *incremental_strtab_name =
2356     this->namepool_.add(".gnu_incremental_strtab", false, NULL);
2357   Output_section* incremental_strtab_os = this->make_output_section(incremental_strtab_name,
2358                                                         elfcpp::SHT_STRTAB, 0,
2359                                                         ORDER_INVALID, false);
2360   Output_data_strtab* strtab_data =
2361       new Output_data_strtab(incr->get_stringpool());
2362   incremental_strtab_os->add_output_section_data(strtab_data);
2363
2364   incremental_inputs_os->set_after_input_sections();
2365   incremental_symtab_os->set_after_input_sections();
2366   incremental_relocs_os->set_after_input_sections();
2367   incremental_got_plt_os->set_after_input_sections();
2368
2369   incremental_inputs_os->set_link_section(incremental_strtab_os);
2370   incremental_symtab_os->set_link_section(incremental_inputs_os);
2371   incremental_relocs_os->set_link_section(incremental_inputs_os);
2372   incremental_got_plt_os->set_link_section(incremental_inputs_os);
2373 }
2374
2375 // Return whether SEG1 should be before SEG2 in the output file.  This
2376 // is based entirely on the segment type and flags.  When this is
2377 // called the segment addresses has normally not yet been set.
2378
2379 bool
2380 Layout::segment_precedes(const Output_segment* seg1,
2381                          const Output_segment* seg2)
2382 {
2383   elfcpp::Elf_Word type1 = seg1->type();
2384   elfcpp::Elf_Word type2 = seg2->type();
2385
2386   // The single PT_PHDR segment is required to precede any loadable
2387   // segment.  We simply make it always first.
2388   if (type1 == elfcpp::PT_PHDR)
2389     {
2390       gold_assert(type2 != elfcpp::PT_PHDR);
2391       return true;
2392     }
2393   if (type2 == elfcpp::PT_PHDR)
2394     return false;
2395
2396   // The single PT_INTERP segment is required to precede any loadable
2397   // segment.  We simply make it always second.
2398   if (type1 == elfcpp::PT_INTERP)
2399     {
2400       gold_assert(type2 != elfcpp::PT_INTERP);
2401       return true;
2402     }
2403   if (type2 == elfcpp::PT_INTERP)
2404     return false;
2405
2406   // We then put PT_LOAD segments before any other segments.
2407   if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
2408     return true;
2409   if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
2410     return false;
2411
2412   // We put the PT_TLS segment last except for the PT_GNU_RELRO
2413   // segment, because that is where the dynamic linker expects to find
2414   // it (this is just for efficiency; other positions would also work
2415   // correctly).
2416   if (type1 == elfcpp::PT_TLS
2417       && type2 != elfcpp::PT_TLS
2418       && type2 != elfcpp::PT_GNU_RELRO)
2419     return false;
2420   if (type2 == elfcpp::PT_TLS
2421       && type1 != elfcpp::PT_TLS
2422       && type1 != elfcpp::PT_GNU_RELRO)
2423     return true;
2424
2425   // We put the PT_GNU_RELRO segment last, because that is where the
2426   // dynamic linker expects to find it (as with PT_TLS, this is just
2427   // for efficiency).
2428   if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
2429     return false;
2430   if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
2431     return true;
2432
2433   const elfcpp::Elf_Word flags1 = seg1->flags();
2434   const elfcpp::Elf_Word flags2 = seg2->flags();
2435
2436   // The order of non-PT_LOAD segments is unimportant.  We simply sort
2437   // by the numeric segment type and flags values.  There should not
2438   // be more than one segment with the same type and flags.
2439   if (type1 != elfcpp::PT_LOAD)
2440     {
2441       if (type1 != type2)
2442         return type1 < type2;
2443       gold_assert(flags1 != flags2);
2444       return flags1 < flags2;
2445     }
2446
2447   // If the addresses are set already, sort by load address.
2448   if (seg1->are_addresses_set())
2449     {
2450       if (!seg2->are_addresses_set())
2451         return true;
2452
2453       unsigned int section_count1 = seg1->output_section_count();
2454       unsigned int section_count2 = seg2->output_section_count();
2455       if (section_count1 == 0 && section_count2 > 0)
2456         return true;
2457       if (section_count1 > 0 && section_count2 == 0)
2458         return false;
2459
2460       uint64_t paddr1 = seg1->first_section_load_address();
2461       uint64_t paddr2 = seg2->first_section_load_address();
2462       if (paddr1 != paddr2)
2463         return paddr1 < paddr2;
2464     }
2465   else if (seg2->are_addresses_set())
2466     return false;
2467
2468   // A segment which holds large data comes after a segment which does
2469   // not hold large data.
2470   if (seg1->is_large_data_segment())
2471     {
2472       if (!seg2->is_large_data_segment())
2473         return false;
2474     }
2475   else if (seg2->is_large_data_segment())
2476     return true;
2477
2478   // Otherwise, we sort PT_LOAD segments based on the flags.  Readonly
2479   // segments come before writable segments.  Then writable segments
2480   // with data come before writable segments without data.  Then
2481   // executable segments come before non-executable segments.  Then
2482   // the unlikely case of a non-readable segment comes before the
2483   // normal case of a readable segment.  If there are multiple
2484   // segments with the same type and flags, we require that the
2485   // address be set, and we sort by virtual address and then physical
2486   // address.
2487   if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
2488     return (flags1 & elfcpp::PF_W) == 0;
2489   if ((flags1 & elfcpp::PF_W) != 0
2490       && seg1->has_any_data_sections() != seg2->has_any_data_sections())
2491     return seg1->has_any_data_sections();
2492   if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
2493     return (flags1 & elfcpp::PF_X) != 0;
2494   if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
2495     return (flags1 & elfcpp::PF_R) == 0;
2496
2497   // We shouldn't get here--we shouldn't create segments which we
2498   // can't distinguish.
2499   gold_unreachable();
2500 }
2501
2502 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
2503
2504 static off_t
2505 align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize)
2506 {
2507   uint64_t unsigned_off = off;
2508   uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
2509                           | (addr & (abi_pagesize - 1)));
2510   if (aligned_off < unsigned_off)
2511     aligned_off += abi_pagesize;
2512   return aligned_off;
2513 }
2514
2515 // Set the file offsets of all the segments, and all the sections they
2516 // contain.  They have all been created.  LOAD_SEG must be be laid out
2517 // first.  Return the offset of the data to follow.
2518
2519 off_t
2520 Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
2521                             unsigned int *pshndx)
2522 {
2523   // Sort them into the final order.
2524   std::sort(this->segment_list_.begin(), this->segment_list_.end(),
2525             Layout::Compare_segments());
2526
2527   // Find the PT_LOAD segments, and set their addresses and offsets
2528   // and their section's addresses and offsets.
2529   uint64_t addr;
2530   if (parameters->options().user_set_Ttext())
2531     addr = parameters->options().Ttext();
2532   else if (parameters->options().output_is_position_independent())
2533     addr = 0;
2534   else
2535     addr = target->default_text_segment_address();
2536   off_t off = 0;
2537
2538   // If LOAD_SEG is NULL, then the file header and segment headers
2539   // will not be loadable.  But they still need to be at offset 0 in
2540   // the file.  Set their offsets now.
2541   if (load_seg == NULL)
2542     {
2543       for (Data_list::iterator p = this->special_output_list_.begin();
2544            p != this->special_output_list_.end();
2545            ++p)
2546         {
2547           off = align_address(off, (*p)->addralign());
2548           (*p)->set_address_and_file_offset(0, off);
2549           off += (*p)->data_size();
2550         }
2551     }
2552
2553   unsigned int increase_relro = this->increase_relro_;
2554   if (this->script_options_->saw_sections_clause())
2555     increase_relro = 0;
2556
2557   const bool check_sections = parameters->options().check_sections();
2558   Output_segment* last_load_segment = NULL;
2559
2560   bool was_readonly = false;
2561   for (Segment_list::iterator p = this->segment_list_.begin();
2562        p != this->segment_list_.end();
2563        ++p)
2564     {
2565       if ((*p)->type() == elfcpp::PT_LOAD)
2566         {
2567           if (load_seg != NULL && load_seg != *p)
2568             gold_unreachable();
2569           load_seg = NULL;
2570
2571           bool are_addresses_set = (*p)->are_addresses_set();
2572           if (are_addresses_set)
2573             {
2574               // When it comes to setting file offsets, we care about
2575               // the physical address.
2576               addr = (*p)->paddr();
2577             }
2578           else if (parameters->options().user_set_Tdata()
2579                    && ((*p)->flags() & elfcpp::PF_W) != 0
2580                    && (!parameters->options().user_set_Tbss()
2581                        || (*p)->has_any_data_sections()))
2582             {
2583               addr = parameters->options().Tdata();
2584               are_addresses_set = true;
2585             }
2586           else if (parameters->options().user_set_Tbss()
2587                    && ((*p)->flags() & elfcpp::PF_W) != 0
2588                    && !(*p)->has_any_data_sections())
2589             {
2590               addr = parameters->options().Tbss();
2591               are_addresses_set = true;
2592             }
2593
2594           uint64_t orig_addr = addr;
2595           uint64_t orig_off = off;
2596
2597           uint64_t aligned_addr = 0;
2598           uint64_t abi_pagesize = target->abi_pagesize();
2599           uint64_t common_pagesize = target->common_pagesize();
2600
2601           if (!parameters->options().nmagic()
2602               && !parameters->options().omagic())
2603             (*p)->set_minimum_p_align(common_pagesize);
2604
2605           if (!are_addresses_set)
2606             {
2607               // If the last segment was readonly, and this one is
2608               // not, then skip the address forward one page,
2609               // maintaining the same position within the page.  This
2610               // lets us store both segments overlapping on a single
2611               // page in the file, but the loader will put them on
2612               // different pages in memory.
2613
2614               addr = align_address(addr, (*p)->maximum_alignment());
2615               aligned_addr = addr;
2616
2617               if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0)
2618                 {
2619                   if ((addr & (abi_pagesize - 1)) != 0)
2620                     addr = addr + abi_pagesize;
2621                 }
2622
2623               off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
2624             }
2625
2626           if (!parameters->options().nmagic()
2627               && !parameters->options().omagic())
2628             off = align_file_offset(off, addr, abi_pagesize);
2629           else if (load_seg == NULL)
2630             {
2631               // This is -N or -n with a section script which prevents
2632               // us from using a load segment.  We need to ensure that
2633               // the file offset is aligned to the alignment of the
2634               // segment.  This is because the linker script
2635               // implicitly assumed a zero offset.  If we don't align
2636               // here, then the alignment of the sections in the
2637               // linker script may not match the alignment of the
2638               // sections in the set_section_addresses call below,
2639               // causing an error about dot moving backward.
2640               off = align_address(off, (*p)->maximum_alignment());
2641             }
2642
2643           unsigned int shndx_hold = *pshndx;
2644           uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
2645                                                           increase_relro,
2646                                                           &off, pshndx);
2647
2648           // Now that we know the size of this segment, we may be able
2649           // to save a page in memory, at the cost of wasting some
2650           // file space, by instead aligning to the start of a new
2651           // page.  Here we use the real machine page size rather than
2652           // the ABI mandated page size.
2653
2654           if (!are_addresses_set && aligned_addr != addr)
2655             {
2656               uint64_t first_off = (common_pagesize
2657                                     - (aligned_addr
2658                                        & (common_pagesize - 1)));
2659               uint64_t last_off = new_addr & (common_pagesize - 1);
2660               if (first_off > 0
2661                   && last_off > 0
2662                   && ((aligned_addr & ~ (common_pagesize - 1))
2663                       != (new_addr & ~ (common_pagesize - 1)))
2664                   && first_off + last_off <= common_pagesize)
2665                 {
2666                   *pshndx = shndx_hold;
2667                   addr = align_address(aligned_addr, common_pagesize);
2668                   addr = align_address(addr, (*p)->maximum_alignment());
2669                   off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
2670                   off = align_file_offset(off, addr, abi_pagesize);
2671                   new_addr = (*p)->set_section_addresses(this, true, addr,
2672                                                          increase_relro,
2673                                                          &off, pshndx);
2674                 }
2675             }
2676
2677           addr = new_addr;
2678
2679           if (((*p)->flags() & elfcpp::PF_W) == 0)
2680             was_readonly = true;
2681
2682           // Implement --check-sections.  We know that the segments
2683           // are sorted by LMA.
2684           if (check_sections && last_load_segment != NULL)
2685             {
2686               gold_assert(last_load_segment->paddr() <= (*p)->paddr());
2687               if (last_load_segment->paddr() + last_load_segment->memsz()
2688                   > (*p)->paddr())
2689                 {
2690                   unsigned long long lb1 = last_load_segment->paddr();
2691                   unsigned long long le1 = lb1 + last_load_segment->memsz();
2692                   unsigned long long lb2 = (*p)->paddr();
2693                   unsigned long long le2 = lb2 + (*p)->memsz();
2694                   gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
2695                                "[0x%llx -> 0x%llx]"),
2696                              lb1, le1, lb2, le2);
2697                 }
2698             }
2699           last_load_segment = *p;
2700         }
2701     }
2702
2703   // Handle the non-PT_LOAD segments, setting their offsets from their
2704   // section's offsets.
2705   for (Segment_list::iterator p = this->segment_list_.begin();
2706        p != this->segment_list_.end();
2707        ++p)
2708     {
2709       if ((*p)->type() != elfcpp::PT_LOAD)
2710         (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO
2711                          ? increase_relro
2712                          : 0);
2713     }
2714
2715   // Set the TLS offsets for each section in the PT_TLS segment.
2716   if (this->tls_segment_ != NULL)
2717     this->tls_segment_->set_tls_offsets();
2718
2719   return off;
2720 }
2721
2722 // Set the offsets of all the allocated sections when doing a
2723 // relocatable link.  This does the same jobs as set_segment_offsets,
2724 // only for a relocatable link.
2725
2726 off_t
2727 Layout::set_relocatable_section_offsets(Output_data* file_header,
2728                                         unsigned int *pshndx)
2729 {
2730   off_t off = 0;
2731
2732   file_header->set_address_and_file_offset(0, 0);
2733   off += file_header->data_size();
2734
2735   for (Section_list::iterator p = this->section_list_.begin();
2736        p != this->section_list_.end();
2737        ++p)
2738     {
2739       // We skip unallocated sections here, except that group sections
2740       // have to come first.
2741       if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
2742           && (*p)->type() != elfcpp::SHT_GROUP)
2743         continue;
2744
2745       off = align_address(off, (*p)->addralign());
2746
2747       // The linker script might have set the address.
2748       if (!(*p)->is_address_valid())
2749         (*p)->set_address(0);
2750       (*p)->set_file_offset(off);
2751       (*p)->finalize_data_size();
2752       off += (*p)->data_size();
2753
2754       (*p)->set_out_shndx(*pshndx);
2755       ++*pshndx;
2756     }
2757
2758   return off;
2759 }
2760
2761 // Set the file offset of all the sections not associated with a
2762 // segment.
2763
2764 off_t
2765 Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
2766 {
2767   for (Section_list::iterator p = this->unattached_section_list_.begin();
2768        p != this->unattached_section_list_.end();
2769        ++p)
2770     {
2771       // The symtab section is handled in create_symtab_sections.
2772       if (*p == this->symtab_section_)
2773         continue;
2774
2775       // If we've already set the data size, don't set it again.
2776       if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
2777         continue;
2778
2779       if (pass == BEFORE_INPUT_SECTIONS_PASS
2780           && (*p)->requires_postprocessing())
2781         {
2782           (*p)->create_postprocessing_buffer();
2783           this->any_postprocessing_sections_ = true;
2784         }
2785
2786       if (pass == BEFORE_INPUT_SECTIONS_PASS
2787           && (*p)->after_input_sections())
2788         continue;
2789       else if (pass == POSTPROCESSING_SECTIONS_PASS
2790                && (!(*p)->after_input_sections()
2791                    || (*p)->type() == elfcpp::SHT_STRTAB))
2792         continue;
2793       else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
2794                && (!(*p)->after_input_sections()
2795                    || (*p)->type() != elfcpp::SHT_STRTAB))
2796         continue;
2797
2798       off = align_address(off, (*p)->addralign());
2799       (*p)->set_file_offset(off);
2800       (*p)->finalize_data_size();
2801       off += (*p)->data_size();
2802
2803       // At this point the name must be set.
2804       if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
2805         this->namepool_.add((*p)->name(), false, NULL);
2806     }
2807   return off;
2808 }
2809
2810 // Set the section indexes of all the sections not associated with a
2811 // segment.
2812
2813 unsigned int
2814 Layout::set_section_indexes(unsigned int shndx)
2815 {
2816   for (Section_list::iterator p = this->unattached_section_list_.begin();
2817        p != this->unattached_section_list_.end();
2818        ++p)
2819     {
2820       if (!(*p)->has_out_shndx())
2821         {
2822           (*p)->set_out_shndx(shndx);
2823           ++shndx;
2824         }
2825     }
2826   return shndx;
2827 }
2828
2829 // Set the section addresses according to the linker script.  This is
2830 // only called when we see a SECTIONS clause.  This returns the
2831 // program segment which should hold the file header and segment
2832 // headers, if any.  It will return NULL if they should not be in a
2833 // segment.
2834
2835 Output_segment*
2836 Layout::set_section_addresses_from_script(Symbol_table* symtab)
2837 {
2838   Script_sections* ss = this->script_options_->script_sections();
2839   gold_assert(ss->saw_sections_clause());
2840   return this->script_options_->set_section_addresses(symtab, this);
2841 }
2842
2843 // Place the orphan sections in the linker script.
2844
2845 void
2846 Layout::place_orphan_sections_in_script()
2847 {
2848   Script_sections* ss = this->script_options_->script_sections();
2849   gold_assert(ss->saw_sections_clause());
2850
2851   // Place each orphaned output section in the script.
2852   for (Section_list::iterator p = this->section_list_.begin();
2853        p != this->section_list_.end();
2854        ++p)
2855     {
2856       if (!(*p)->found_in_sections_clause())
2857         ss->place_orphan(*p);
2858     }
2859 }
2860
2861 // Count the local symbols in the regular symbol table and the dynamic
2862 // symbol table, and build the respective string pools.
2863
2864 void
2865 Layout::count_local_symbols(const Task* task,
2866                             const Input_objects* input_objects)
2867 {
2868   // First, figure out an upper bound on the number of symbols we'll
2869   // be inserting into each pool.  This helps us create the pools with
2870   // the right size, to avoid unnecessary hashtable resizing.
2871   unsigned int symbol_count = 0;
2872   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2873        p != input_objects->relobj_end();
2874        ++p)
2875     symbol_count += (*p)->local_symbol_count();
2876
2877   // Go from "upper bound" to "estimate."  We overcount for two
2878   // reasons: we double-count symbols that occur in more than one
2879   // object file, and we count symbols that are dropped from the
2880   // output.  Add it all together and assume we overcount by 100%.
2881   symbol_count /= 2;
2882
2883   // We assume all symbols will go into both the sympool and dynpool.
2884   this->sympool_.reserve(symbol_count);
2885   this->dynpool_.reserve(symbol_count);
2886
2887   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2888        p != input_objects->relobj_end();
2889        ++p)
2890     {
2891       Task_lock_obj<Object> tlo(task, *p);
2892       (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
2893     }
2894 }
2895
2896 // Create the symbol table sections.  Here we also set the final
2897 // values of the symbols.  At this point all the loadable sections are
2898 // fully laid out.  SHNUM is the number of sections so far.
2899
2900 void
2901 Layout::create_symtab_sections(const Input_objects* input_objects,
2902                                Symbol_table* symtab,
2903                                unsigned int shnum,
2904                                off_t* poff)
2905 {
2906   int symsize;
2907   unsigned int align;
2908   if (parameters->target().get_size() == 32)
2909     {
2910       symsize = elfcpp::Elf_sizes<32>::sym_size;
2911       align = 4;
2912     }
2913   else if (parameters->target().get_size() == 64)
2914     {
2915       symsize = elfcpp::Elf_sizes<64>::sym_size;
2916       align = 8;
2917     }
2918   else
2919     gold_unreachable();
2920
2921   off_t off = *poff;
2922   off = align_address(off, align);
2923   off_t startoff = off;
2924
2925   // Save space for the dummy symbol at the start of the section.  We
2926   // never bother to write this out--it will just be left as zero.
2927   off += symsize;
2928   unsigned int local_symbol_index = 1;
2929
2930   // Add STT_SECTION symbols for each Output section which needs one.
2931   for (Section_list::iterator p = this->section_list_.begin();
2932        p != this->section_list_.end();
2933        ++p)
2934     {
2935       if (!(*p)->needs_symtab_index())
2936         (*p)->set_symtab_index(-1U);
2937       else
2938         {
2939           (*p)->set_symtab_index(local_symbol_index);
2940           ++local_symbol_index;
2941           off += symsize;
2942         }
2943     }
2944
2945   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2946        p != input_objects->relobj_end();
2947        ++p)
2948     {
2949       unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
2950                                                         off, symtab);
2951       off += (index - local_symbol_index) * symsize;
2952       local_symbol_index = index;
2953     }
2954
2955   unsigned int local_symcount = local_symbol_index;
2956   gold_assert(static_cast<off_t>(local_symcount * symsize) == off - startoff);
2957
2958   off_t dynoff;
2959   size_t dyn_global_index;
2960   size_t dyncount;
2961   if (this->dynsym_section_ == NULL)
2962     {
2963       dynoff = 0;
2964       dyn_global_index = 0;
2965       dyncount = 0;
2966     }
2967   else
2968     {
2969       dyn_global_index = this->dynsym_section_->info();
2970       off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
2971       dynoff = this->dynsym_section_->offset() + locsize;
2972       dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
2973       gold_assert(static_cast<off_t>(dyncount * symsize)
2974                   == this->dynsym_section_->data_size() - locsize);
2975     }
2976
2977   off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
2978                          &this->sympool_, &local_symcount);
2979
2980   if (!parameters->options().strip_all())
2981     {
2982       this->sympool_.set_string_offsets();
2983
2984       const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
2985       Output_section* osymtab = this->make_output_section(symtab_name,
2986                                                           elfcpp::SHT_SYMTAB,
2987                                                           0, ORDER_INVALID,
2988                                                           false);
2989       this->symtab_section_ = osymtab;
2990
2991       Output_section_data* pos = new Output_data_fixed_space(off - startoff,
2992                                                              align,
2993                                                              "** symtab");
2994       osymtab->add_output_section_data(pos);
2995
2996       // We generate a .symtab_shndx section if we have more than
2997       // SHN_LORESERVE sections.  Technically it is possible that we
2998       // don't need one, because it is possible that there are no
2999       // symbols in any of sections with indexes larger than
3000       // SHN_LORESERVE.  That is probably unusual, though, and it is
3001       // easier to always create one than to compute section indexes
3002       // twice (once here, once when writing out the symbols).
3003       if (shnum >= elfcpp::SHN_LORESERVE)
3004         {
3005           const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
3006                                                                false, NULL);
3007           Output_section* osymtab_xindex =
3008             this->make_output_section(symtab_xindex_name,
3009                                       elfcpp::SHT_SYMTAB_SHNDX, 0,
3010                                       ORDER_INVALID, false);
3011
3012           size_t symcount = (off - startoff) / symsize;
3013           this->symtab_xindex_ = new Output_symtab_xindex(symcount);
3014
3015           osymtab_xindex->add_output_section_data(this->symtab_xindex_);
3016
3017           osymtab_xindex->set_link_section(osymtab);
3018           osymtab_xindex->set_addralign(4);
3019           osymtab_xindex->set_entsize(4);
3020
3021           osymtab_xindex->set_after_input_sections();
3022
3023           // This tells the driver code to wait until the symbol table
3024           // has written out before writing out the postprocessing
3025           // sections, including the .symtab_shndx section.
3026           this->any_postprocessing_sections_ = true;
3027         }
3028
3029       const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
3030       Output_section* ostrtab = this->make_output_section(strtab_name,
3031                                                           elfcpp::SHT_STRTAB,
3032                                                           0, ORDER_INVALID,
3033                                                           false);
3034
3035       Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
3036       ostrtab->add_output_section_data(pstr);
3037
3038       osymtab->set_file_offset(startoff);
3039       osymtab->finalize_data_size();
3040       osymtab->set_link_section(ostrtab);
3041       osymtab->set_info(local_symcount);
3042       osymtab->set_entsize(symsize);
3043
3044       *poff = off;
3045     }
3046 }
3047
3048 // Create the .shstrtab section, which holds the names of the
3049 // sections.  At the time this is called, we have created all the
3050 // output sections except .shstrtab itself.
3051
3052 Output_section*
3053 Layout::create_shstrtab()
3054 {
3055   // FIXME: We don't need to create a .shstrtab section if we are
3056   // stripping everything.
3057
3058   const char* name = this->namepool_.add(".shstrtab", false, NULL);
3059
3060   Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0,
3061                                                  ORDER_INVALID, false);
3062
3063   if (strcmp(parameters->options().compress_debug_sections(), "none") != 0)
3064     {
3065       // We can't write out this section until we've set all the
3066       // section names, and we don't set the names of compressed
3067       // output sections until relocations are complete.  FIXME: With
3068       // the current names we use, this is unnecessary.
3069       os->set_after_input_sections();
3070     }
3071
3072   Output_section_data* posd = new Output_data_strtab(&this->namepool_);
3073   os->add_output_section_data(posd);
3074
3075   return os;
3076 }
3077
3078 // Create the section headers.  SIZE is 32 or 64.  OFF is the file
3079 // offset.
3080
3081 void
3082 Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
3083 {
3084   Output_section_headers* oshdrs;
3085   oshdrs = new Output_section_headers(this,
3086                                       &this->segment_list_,
3087                                       &this->section_list_,
3088                                       &this->unattached_section_list_,
3089                                       &this->namepool_,
3090                                       shstrtab_section);
3091   off_t off = align_address(*poff, oshdrs->addralign());
3092   oshdrs->set_address_and_file_offset(0, off);
3093   off += oshdrs->data_size();
3094   *poff = off;
3095   this->section_headers_ = oshdrs;
3096 }
3097
3098 // Count the allocated sections.
3099
3100 size_t
3101 Layout::allocated_output_section_count() const
3102 {
3103   size_t section_count = 0;
3104   for (Segment_list::const_iterator p = this->segment_list_.begin();
3105        p != this->segment_list_.end();
3106        ++p)
3107     section_count += (*p)->output_section_count();
3108   return section_count;
3109 }
3110
3111 // Create the dynamic symbol table.
3112
3113 void
3114 Layout::create_dynamic_symtab(const Input_objects* input_objects,
3115                               Symbol_table* symtab,
3116                               Output_section **pdynstr,
3117                               unsigned int* plocal_dynamic_count,
3118                               std::vector<Symbol*>* pdynamic_symbols,
3119                               Versions* pversions)
3120 {
3121   // Count all the symbols in the dynamic symbol table, and set the
3122   // dynamic symbol indexes.
3123
3124   // Skip symbol 0, which is always all zeroes.
3125   unsigned int index = 1;
3126
3127   // Add STT_SECTION symbols for each Output section which needs one.
3128   for (Section_list::iterator p = this->section_list_.begin();
3129        p != this->section_list_.end();
3130        ++p)
3131     {
3132       if (!(*p)->needs_dynsym_index())
3133         (*p)->set_dynsym_index(-1U);
3134       else
3135         {
3136           (*p)->set_dynsym_index(index);
3137           ++index;
3138         }
3139     }
3140
3141   // Count the local symbols that need to go in the dynamic symbol table,
3142   // and set the dynamic symbol indexes.
3143   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3144        p != input_objects->relobj_end();
3145        ++p)
3146     {
3147       unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
3148       index = new_index;
3149     }
3150
3151   unsigned int local_symcount = index;
3152   *plocal_dynamic_count = local_symcount;
3153
3154   index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
3155                                      &this->dynpool_, pversions);
3156
3157   int symsize;
3158   unsigned int align;
3159   const int size = parameters->target().get_size();
3160   if (size == 32)
3161     {
3162       symsize = elfcpp::Elf_sizes<32>::sym_size;
3163       align = 4;
3164     }
3165   else if (size == 64)
3166     {
3167       symsize = elfcpp::Elf_sizes<64>::sym_size;
3168       align = 8;
3169     }
3170   else
3171     gold_unreachable();
3172
3173   // Create the dynamic symbol table section.
3174
3175   Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
3176                                                        elfcpp::SHT_DYNSYM,
3177                                                        elfcpp::SHF_ALLOC,
3178                                                        false,
3179                                                        ORDER_DYNAMIC_LINKER,
3180                                                        false);
3181
3182   Output_section_data* odata = new Output_data_fixed_space(index * symsize,
3183                                                            align,
3184                                                            "** dynsym");
3185   dynsym->add_output_section_data(odata);
3186
3187   dynsym->set_info(local_symcount);
3188   dynsym->set_entsize(symsize);
3189   dynsym->set_addralign(align);
3190
3191   this->dynsym_section_ = dynsym;
3192
3193   Output_data_dynamic* const odyn = this->dynamic_data_;
3194   odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
3195   odyn->add_constant(elfcpp::DT_SYMENT, symsize);
3196
3197   // If there are more than SHN_LORESERVE allocated sections, we
3198   // create a .dynsym_shndx section.  It is possible that we don't
3199   // need one, because it is possible that there are no dynamic
3200   // symbols in any of the sections with indexes larger than
3201   // SHN_LORESERVE.  This is probably unusual, though, and at this
3202   // time we don't know the actual section indexes so it is
3203   // inconvenient to check.
3204   if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
3205     {
3206       Output_section* dynsym_xindex =
3207         this->choose_output_section(NULL, ".dynsym_shndx",
3208                                     elfcpp::SHT_SYMTAB_SHNDX,
3209                                     elfcpp::SHF_ALLOC,
3210                                     false, ORDER_DYNAMIC_LINKER, false);
3211
3212       this->dynsym_xindex_ = new Output_symtab_xindex(index);
3213
3214       dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
3215
3216       dynsym_xindex->set_link_section(dynsym);
3217       dynsym_xindex->set_addralign(4);
3218       dynsym_xindex->set_entsize(4);
3219
3220       dynsym_xindex->set_after_input_sections();
3221
3222       // This tells the driver code to wait until the symbol table has
3223       // written out before writing out the postprocessing sections,
3224       // including the .dynsym_shndx section.
3225       this->any_postprocessing_sections_ = true;
3226     }
3227
3228   // Create the dynamic string table section.
3229
3230   Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
3231                                                        elfcpp::SHT_STRTAB,
3232                                                        elfcpp::SHF_ALLOC,
3233                                                        false,
3234                                                        ORDER_DYNAMIC_LINKER,
3235                                                        false);
3236
3237   Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
3238   dynstr->add_output_section_data(strdata);
3239
3240   dynsym->set_link_section(dynstr);
3241   this->dynamic_section_->set_link_section(dynstr);
3242
3243   odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
3244   odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
3245
3246   *pdynstr = dynstr;
3247
3248   // Create the hash tables.
3249
3250   if (strcmp(parameters->options().hash_style(), "sysv") == 0
3251       || strcmp(parameters->options().hash_style(), "both") == 0)
3252     {
3253       unsigned char* phash;
3254       unsigned int hashlen;
3255       Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
3256                                     &phash, &hashlen);
3257
3258       Output_section* hashsec =
3259         this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH,
3260                                     elfcpp::SHF_ALLOC, false,
3261                                     ORDER_DYNAMIC_LINKER, false);
3262
3263       Output_section_data* hashdata = new Output_data_const_buffer(phash,
3264                                                                    hashlen,
3265                                                                    align,
3266                                                                    "** hash");
3267       hashsec->add_output_section_data(hashdata);
3268
3269       hashsec->set_link_section(dynsym);
3270       hashsec->set_entsize(4);
3271
3272       odyn->add_section_address(elfcpp::DT_HASH, hashsec);
3273     }
3274
3275   if (strcmp(parameters->options().hash_style(), "gnu") == 0
3276       || strcmp(parameters->options().hash_style(), "both") == 0)
3277     {
3278       unsigned char* phash;
3279       unsigned int hashlen;
3280       Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
3281                                     &phash, &hashlen);
3282
3283       Output_section* hashsec =
3284         this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH,
3285                                     elfcpp::SHF_ALLOC, false,
3286                                     ORDER_DYNAMIC_LINKER, false);
3287
3288       Output_section_data* hashdata = new Output_data_const_buffer(phash,
3289                                                                    hashlen,
3290                                                                    align,
3291                                                                    "** hash");
3292       hashsec->add_output_section_data(hashdata);
3293
3294       hashsec->set_link_section(dynsym);
3295
3296       // For a 64-bit target, the entries in .gnu.hash do not have a
3297       // uniform size, so we only set the entry size for a 32-bit
3298       // target.
3299       if (parameters->target().get_size() == 32)
3300         hashsec->set_entsize(4);
3301
3302       odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
3303     }
3304 }
3305
3306 // Assign offsets to each local portion of the dynamic symbol table.
3307
3308 void
3309 Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
3310 {
3311   Output_section* dynsym = this->dynsym_section_;
3312   gold_assert(dynsym != NULL);
3313
3314   off_t off = dynsym->offset();
3315
3316   // Skip the dummy symbol at the start of the section.
3317   off += dynsym->entsize();
3318
3319   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3320        p != input_objects->relobj_end();
3321        ++p)
3322     {
3323       unsigned int count = (*p)->set_local_dynsym_offset(off);
3324       off += count * dynsym->entsize();
3325     }
3326 }
3327
3328 // Create the version sections.
3329
3330 void
3331 Layout::create_version_sections(const Versions* versions,
3332                                 const Symbol_table* symtab,
3333                                 unsigned int local_symcount,
3334                                 const std::vector<Symbol*>& dynamic_symbols,
3335                                 const Output_section* dynstr)
3336 {
3337   if (!versions->any_defs() && !versions->any_needs())
3338     return;
3339
3340   switch (parameters->size_and_endianness())
3341     {
3342 #ifdef HAVE_TARGET_32_LITTLE
3343     case Parameters::TARGET_32_LITTLE:
3344       this->sized_create_version_sections<32, false>(versions, symtab,
3345                                                      local_symcount,
3346                                                      dynamic_symbols, dynstr);
3347       break;
3348 #endif
3349 #ifdef HAVE_TARGET_32_BIG
3350     case Parameters::TARGET_32_BIG:
3351       this->sized_create_version_sections<32, true>(versions, symtab,
3352                                                     local_symcount,
3353                                                     dynamic_symbols, dynstr);
3354       break;
3355 #endif
3356 #ifdef HAVE_TARGET_64_LITTLE
3357     case Parameters::TARGET_64_LITTLE:
3358       this->sized_create_version_sections<64, false>(versions, symtab,
3359                                                      local_symcount,
3360                                                      dynamic_symbols, dynstr);
3361       break;
3362 #endif
3363 #ifdef HAVE_TARGET_64_BIG
3364     case Parameters::TARGET_64_BIG:
3365       this->sized_create_version_sections<64, true>(versions, symtab,
3366                                                     local_symcount,
3367                                                     dynamic_symbols, dynstr);
3368       break;
3369 #endif
3370     default:
3371       gold_unreachable();
3372     }
3373 }
3374
3375 // Create the version sections, sized version.
3376
3377 template<int size, bool big_endian>
3378 void
3379 Layout::sized_create_version_sections(
3380     const Versions* versions,
3381     const Symbol_table* symtab,
3382     unsigned int local_symcount,
3383     const std::vector<Symbol*>& dynamic_symbols,
3384     const Output_section* dynstr)
3385 {
3386   Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
3387                                                      elfcpp::SHT_GNU_versym,
3388                                                      elfcpp::SHF_ALLOC,
3389                                                      false,
3390                                                      ORDER_DYNAMIC_LINKER,
3391                                                      false);
3392
3393   unsigned char* vbuf;
3394   unsigned int vsize;
3395   versions->symbol_section_contents<size, big_endian>(symtab, &this->dynpool_,
3396                                                       local_symcount,
3397                                                       dynamic_symbols,
3398                                                       &vbuf, &vsize);
3399
3400   Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
3401                                                             "** versions");
3402
3403   vsec->add_output_section_data(vdata);
3404   vsec->set_entsize(2);
3405   vsec->set_link_section(this->dynsym_section_);
3406
3407   Output_data_dynamic* const odyn = this->dynamic_data_;
3408   odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
3409
3410   if (versions->any_defs())
3411     {
3412       Output_section* vdsec;
3413       vdsec= this->choose_output_section(NULL, ".gnu.version_d",
3414                                          elfcpp::SHT_GNU_verdef,
3415                                          elfcpp::SHF_ALLOC,
3416                                          false, ORDER_DYNAMIC_LINKER, false);
3417
3418       unsigned char* vdbuf;
3419       unsigned int vdsize;
3420       unsigned int vdentries;
3421       versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
3422                                                        &vdsize, &vdentries);
3423
3424       Output_section_data* vddata =
3425         new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
3426
3427       vdsec->add_output_section_data(vddata);
3428       vdsec->set_link_section(dynstr);
3429       vdsec->set_info(vdentries);
3430
3431       odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
3432       odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
3433     }
3434
3435   if (versions->any_needs())
3436     {
3437       Output_section* vnsec;
3438       vnsec = this->choose_output_section(NULL, ".gnu.version_r",
3439                                           elfcpp::SHT_GNU_verneed,
3440                                           elfcpp::SHF_ALLOC,
3441                                           false, ORDER_DYNAMIC_LINKER, false);
3442
3443       unsigned char* vnbuf;
3444       unsigned int vnsize;
3445       unsigned int vnentries;
3446       versions->need_section_contents<size, big_endian>(&this->dynpool_,
3447                                                         &vnbuf, &vnsize,
3448                                                         &vnentries);
3449
3450       Output_section_data* vndata =
3451         new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
3452
3453       vnsec->add_output_section_data(vndata);
3454       vnsec->set_link_section(dynstr);
3455       vnsec->set_info(vnentries);
3456
3457       odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
3458       odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
3459     }
3460 }
3461
3462 // Create the .interp section and PT_INTERP segment.
3463
3464 void
3465 Layout::create_interp(const Target* target)
3466 {
3467   const char* interp = parameters->options().dynamic_linker();
3468   if (interp == NULL)
3469     {
3470       interp = target->dynamic_linker();
3471       gold_assert(interp != NULL);
3472     }
3473
3474   size_t len = strlen(interp) + 1;
3475
3476   Output_section_data* odata = new Output_data_const(interp, len, 1);
3477
3478   Output_section* osec = this->choose_output_section(NULL, ".interp",
3479                                                      elfcpp::SHT_PROGBITS,
3480                                                      elfcpp::SHF_ALLOC,
3481                                                      false, ORDER_INTERP,
3482                                                      false);
3483   osec->add_output_section_data(odata);
3484
3485   if (!this->script_options_->saw_phdrs_clause())
3486     {
3487       Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
3488                                                        elfcpp::PF_R);
3489       oseg->add_output_section_to_nonload(osec, elfcpp::PF_R);
3490     }
3491 }
3492
3493 // Add dynamic tags for the PLT and the dynamic relocs.  This is
3494 // called by the target-specific code.  This does nothing if not doing
3495 // a dynamic link.
3496
3497 // USE_REL is true for REL relocs rather than RELA relocs.
3498
3499 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
3500
3501 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
3502 // and we also set DT_PLTREL.  We use PLT_REL's output section, since
3503 // some targets have multiple reloc sections in PLT_REL.
3504
3505 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
3506 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT.
3507
3508 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
3509 // executable.
3510
3511 void
3512 Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
3513                                 const Output_data* plt_rel,
3514                                 const Output_data_reloc_generic* dyn_rel,
3515                                 bool add_debug, bool dynrel_includes_plt)
3516 {
3517   Output_data_dynamic* odyn = this->dynamic_data_;
3518   if (odyn == NULL)
3519     return;
3520
3521   if (plt_got != NULL && plt_got->output_section() != NULL)
3522     odyn->add_section_address(elfcpp::DT_PLTGOT, plt_got);
3523
3524   if (plt_rel != NULL && plt_rel->output_section() != NULL)
3525     {
3526       odyn->add_section_size(elfcpp::DT_PLTRELSZ, plt_rel->output_section());
3527       odyn->add_section_address(elfcpp::DT_JMPREL, plt_rel->output_section());
3528       odyn->add_constant(elfcpp::DT_PLTREL,
3529                          use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA);
3530     }
3531
3532   if (dyn_rel != NULL && dyn_rel->output_section() != NULL)
3533     {
3534       odyn->add_section_address(use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA,
3535                                 dyn_rel);
3536       if (plt_rel != NULL && dynrel_includes_plt)
3537         odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
3538                                dyn_rel, plt_rel);
3539       else
3540         odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
3541                                dyn_rel);
3542       const int size = parameters->target().get_size();
3543       elfcpp::DT rel_tag;
3544       int rel_size;
3545       if (use_rel)
3546         {
3547           rel_tag = elfcpp::DT_RELENT;
3548           if (size == 32)
3549             rel_size = Reloc_types<elfcpp::SHT_REL, 32, false>::reloc_size;
3550           else if (size == 64)
3551             rel_size = Reloc_types<elfcpp::SHT_REL, 64, false>::reloc_size;
3552           else
3553             gold_unreachable();
3554         }
3555       else
3556         {
3557           rel_tag = elfcpp::DT_RELAENT;
3558           if (size == 32)
3559             rel_size = Reloc_types<elfcpp::SHT_RELA, 32, false>::reloc_size;
3560           else if (size == 64)
3561             rel_size = Reloc_types<elfcpp::SHT_RELA, 64, false>::reloc_size;
3562           else
3563             gold_unreachable();
3564         }
3565       odyn->add_constant(rel_tag, rel_size);
3566
3567       if (parameters->options().combreloc())
3568         {
3569           size_t c = dyn_rel->relative_reloc_count();
3570           if (c > 0)
3571             odyn->add_constant((use_rel
3572                                 ? elfcpp::DT_RELCOUNT
3573                                 : elfcpp::DT_RELACOUNT),
3574                                c);
3575         }
3576     }
3577
3578   if (add_debug && !parameters->options().shared())
3579     {
3580       // The value of the DT_DEBUG tag is filled in by the dynamic
3581       // linker at run time, and used by the debugger.
3582       odyn->add_constant(elfcpp::DT_DEBUG, 0);
3583     }
3584 }
3585
3586 // Finish the .dynamic section and PT_DYNAMIC segment.
3587
3588 void
3589 Layout::finish_dynamic_section(const Input_objects* input_objects,
3590                                const Symbol_table* symtab)
3591 {
3592   if (!this->script_options_->saw_phdrs_clause())
3593     {
3594       Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
3595                                                        (elfcpp::PF_R
3596                                                         | elfcpp::PF_W));
3597       oseg->add_output_section_to_nonload(this->dynamic_section_,
3598                                           elfcpp::PF_R | elfcpp::PF_W);
3599     }
3600
3601   Output_data_dynamic* const odyn = this->dynamic_data_;
3602
3603   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
3604        p != input_objects->dynobj_end();
3605        ++p)
3606     {
3607       if (!(*p)->is_needed()
3608           && (*p)->input_file()->options().as_needed())
3609         {
3610           // This dynamic object was linked with --as-needed, but it
3611           // is not needed.
3612           continue;
3613         }
3614
3615       odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
3616     }
3617
3618   if (parameters->options().shared())
3619     {
3620       const char* soname = parameters->options().soname();
3621       if (soname != NULL)
3622         odyn->add_string(elfcpp::DT_SONAME, soname);
3623     }
3624
3625   Symbol* sym = symtab->lookup(parameters->options().init());
3626   if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
3627     odyn->add_symbol(elfcpp::DT_INIT, sym);
3628
3629   sym = symtab->lookup(parameters->options().fini());
3630   if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
3631     odyn->add_symbol(elfcpp::DT_FINI, sym);
3632
3633   // Look for .init_array, .preinit_array and .fini_array by checking
3634   // section types.
3635   for(Layout::Section_list::const_iterator p = this->section_list_.begin();
3636       p != this->section_list_.end();
3637       ++p)
3638     switch((*p)->type())
3639       {
3640       case elfcpp::SHT_FINI_ARRAY:
3641         odyn->add_section_address(elfcpp::DT_FINI_ARRAY, *p);
3642         odyn->add_section_size(elfcpp::DT_FINI_ARRAYSZ, *p);
3643         break;
3644       case elfcpp::SHT_INIT_ARRAY:
3645         odyn->add_section_address(elfcpp::DT_INIT_ARRAY, *p);
3646         odyn->add_section_size(elfcpp::DT_INIT_ARRAYSZ, *p);
3647         break;
3648       case elfcpp::SHT_PREINIT_ARRAY:
3649         odyn->add_section_address(elfcpp::DT_PREINIT_ARRAY, *p);
3650         odyn->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ, *p);
3651         break;
3652       default:
3653         break;
3654       }
3655
3656   // Add a DT_RPATH entry if needed.
3657   const General_options::Dir_list& rpath(parameters->options().rpath());
3658   if (!rpath.empty())
3659     {
3660       std::string rpath_val;
3661       for (General_options::Dir_list::const_iterator p = rpath.begin();
3662            p != rpath.end();
3663            ++p)
3664         {
3665           if (rpath_val.empty())
3666             rpath_val = p->name();
3667           else
3668             {
3669               // Eliminate duplicates.
3670               General_options::Dir_list::const_iterator q;
3671               for (q = rpath.begin(); q != p; ++q)
3672                 if (q->name() == p->name())
3673                   break;
3674               if (q == p)
3675                 {
3676                   rpath_val += ':';
3677                   rpath_val += p->name();
3678                 }
3679             }
3680         }
3681
3682       odyn->add_string(elfcpp::DT_RPATH, rpath_val);
3683       if (parameters->options().enable_new_dtags())
3684         odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
3685     }
3686
3687   // Look for text segments that have dynamic relocations.
3688   bool have_textrel = false;
3689   if (!this->script_options_->saw_sections_clause())
3690     {
3691       for (Segment_list::const_iterator p = this->segment_list_.begin();
3692            p != this->segment_list_.end();
3693            ++p)
3694         {
3695           if (((*p)->flags() & elfcpp::PF_W) == 0
3696               && (*p)->has_dynamic_reloc())
3697             {
3698               have_textrel = true;
3699               break;
3700             }
3701         }
3702     }
3703   else
3704     {
3705       // We don't know the section -> segment mapping, so we are
3706       // conservative and just look for readonly sections with
3707       // relocations.  If those sections wind up in writable segments,
3708       // then we have created an unnecessary DT_TEXTREL entry.
3709       for (Section_list::const_iterator p = this->section_list_.begin();
3710            p != this->section_list_.end();
3711            ++p)
3712         {
3713           if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
3714               && ((*p)->flags() & elfcpp::SHF_WRITE) == 0
3715               && ((*p)->has_dynamic_reloc()))
3716             {
3717               have_textrel = true;
3718               break;
3719             }
3720         }
3721     }
3722
3723   // Add a DT_FLAGS entry. We add it even if no flags are set so that
3724   // post-link tools can easily modify these flags if desired.
3725   unsigned int flags = 0;
3726   if (have_textrel)
3727     {
3728       // Add a DT_TEXTREL for compatibility with older loaders.
3729       odyn->add_constant(elfcpp::DT_TEXTREL, 0);
3730       flags |= elfcpp::DF_TEXTREL;
3731
3732       if (parameters->options().text())
3733         gold_error(_("read-only segment has dynamic relocations"));
3734       else if (parameters->options().warn_shared_textrel()
3735                && parameters->options().shared())
3736         gold_warning(_("shared library text segment is not shareable"));
3737     }
3738   if (parameters->options().shared() && this->has_static_tls())
3739     flags |= elfcpp::DF_STATIC_TLS;
3740   if (parameters->options().origin())
3741     flags |= elfcpp::DF_ORIGIN;
3742   if (parameters->options().Bsymbolic())
3743     {
3744       flags |= elfcpp::DF_SYMBOLIC;
3745       // Add DT_SYMBOLIC for compatibility with older loaders.
3746       odyn->add_constant(elfcpp::DT_SYMBOLIC, 0);
3747     }
3748   if (parameters->options().now())
3749     flags |= elfcpp::DF_BIND_NOW;
3750   odyn->add_constant(elfcpp::DT_FLAGS, flags);
3751
3752   flags = 0;
3753   if (parameters->options().initfirst())
3754     flags |= elfcpp::DF_1_INITFIRST;
3755   if (parameters->options().interpose())
3756     flags |= elfcpp::DF_1_INTERPOSE;
3757   if (parameters->options().loadfltr())
3758     flags |= elfcpp::DF_1_LOADFLTR;
3759   if (parameters->options().nodefaultlib())
3760     flags |= elfcpp::DF_1_NODEFLIB;
3761   if (parameters->options().nodelete())
3762     flags |= elfcpp::DF_1_NODELETE;
3763   if (parameters->options().nodlopen())
3764     flags |= elfcpp::DF_1_NOOPEN;
3765   if (parameters->options().nodump())
3766     flags |= elfcpp::DF_1_NODUMP;
3767   if (!parameters->options().shared())
3768     flags &= ~(elfcpp::DF_1_INITFIRST
3769                | elfcpp::DF_1_NODELETE
3770                | elfcpp::DF_1_NOOPEN);
3771   if (parameters->options().origin())
3772     flags |= elfcpp::DF_1_ORIGIN;
3773   if (parameters->options().now())
3774     flags |= elfcpp::DF_1_NOW;
3775   if (flags)
3776     odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
3777 }
3778
3779 // Set the size of the _DYNAMIC symbol table to be the size of the
3780 // dynamic data.
3781
3782 void
3783 Layout::set_dynamic_symbol_size(const Symbol_table* symtab)
3784 {
3785   Output_data_dynamic* const odyn = this->dynamic_data_;
3786   odyn->finalize_data_size();
3787   off_t data_size = odyn->data_size();
3788   const int size = parameters->target().get_size();
3789   if (size == 32)
3790     symtab->get_sized_symbol<32>(this->dynamic_symbol_)->set_symsize(data_size);
3791   else if (size == 64)
3792     symtab->get_sized_symbol<64>(this->dynamic_symbol_)->set_symsize(data_size);
3793   else
3794     gold_unreachable();
3795 }
3796
3797 // The mapping of input section name prefixes to output section names.
3798 // In some cases one prefix is itself a prefix of another prefix; in
3799 // such a case the longer prefix must come first.  These prefixes are
3800 // based on the GNU linker default ELF linker script.
3801
3802 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
3803 const Layout::Section_name_mapping Layout::section_name_mapping[] =
3804 {
3805   MAPPING_INIT(".text.", ".text"),
3806   MAPPING_INIT(".ctors.", ".ctors"),
3807   MAPPING_INIT(".dtors.", ".dtors"),
3808   MAPPING_INIT(".rodata.", ".rodata"),
3809   MAPPING_INIT(".data.rel.ro.local", ".data.rel.ro.local"),
3810   MAPPING_INIT(".data.rel.ro", ".data.rel.ro"),
3811   MAPPING_INIT(".data.", ".data"),
3812   MAPPING_INIT(".bss.", ".bss"),
3813   MAPPING_INIT(".tdata.", ".tdata"),
3814   MAPPING_INIT(".tbss.", ".tbss"),
3815   MAPPING_INIT(".init_array.", ".init_array"),
3816   MAPPING_INIT(".fini_array.", ".fini_array"),
3817   MAPPING_INIT(".sdata.", ".sdata"),
3818   MAPPING_INIT(".sbss.", ".sbss"),
3819   // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
3820   // differently depending on whether it is creating a shared library.
3821   MAPPING_INIT(".sdata2.", ".sdata"),
3822   MAPPING_INIT(".sbss2.", ".sbss"),
3823   MAPPING_INIT(".lrodata.", ".lrodata"),
3824   MAPPING_INIT(".ldata.", ".ldata"),
3825   MAPPING_INIT(".lbss.", ".lbss"),
3826   MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
3827   MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
3828   MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
3829   MAPPING_INIT(".gnu.linkonce.t.", ".text"),
3830   MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
3831   MAPPING_INIT(".gnu.linkonce.d.", ".data"),
3832   MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
3833   MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
3834   MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
3835   MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
3836   MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
3837   MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
3838   MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
3839   MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
3840   MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
3841   MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
3842   MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
3843   MAPPING_INIT(".ARM.extab", ".ARM.extab"),
3844   MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
3845   MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
3846   MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
3847 };
3848 #undef MAPPING_INIT
3849
3850 const int Layout::section_name_mapping_count =
3851   (sizeof(Layout::section_name_mapping)
3852    / sizeof(Layout::section_name_mapping[0]));
3853
3854 // Choose the output section name to use given an input section name.
3855 // Set *PLEN to the length of the name.  *PLEN is initialized to the
3856 // length of NAME.
3857
3858 const char*
3859 Layout::output_section_name(const char* name, size_t* plen)
3860 {
3861   // gcc 4.3 generates the following sorts of section names when it
3862   // needs a section name specific to a function:
3863   //   .text.FN
3864   //   .rodata.FN
3865   //   .sdata2.FN
3866   //   .data.FN
3867   //   .data.rel.FN
3868   //   .data.rel.local.FN
3869   //   .data.rel.ro.FN
3870   //   .data.rel.ro.local.FN
3871   //   .sdata.FN
3872   //   .bss.FN
3873   //   .sbss.FN
3874   //   .tdata.FN
3875   //   .tbss.FN
3876
3877   // The GNU linker maps all of those to the part before the .FN,
3878   // except that .data.rel.local.FN is mapped to .data, and
3879   // .data.rel.ro.local.FN is mapped to .data.rel.ro.  The sections
3880   // beginning with .data.rel.ro.local are grouped together.
3881
3882   // For an anonymous namespace, the string FN can contain a '.'.
3883
3884   // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
3885   // GNU linker maps to .rodata.
3886
3887   // The .data.rel.ro sections are used with -z relro.  The sections
3888   // are recognized by name.  We use the same names that the GNU
3889   // linker does for these sections.
3890
3891   // It is hard to handle this in a principled way, so we don't even
3892   // try.  We use a table of mappings.  If the input section name is
3893   // not found in the table, we simply use it as the output section
3894   // name.
3895
3896   const Section_name_mapping* psnm = section_name_mapping;
3897   for (int i = 0; i < section_name_mapping_count; ++i, ++psnm)
3898     {
3899       if (strncmp(name, psnm->from, psnm->fromlen) == 0)
3900         {
3901           *plen = psnm->tolen;
3902           return psnm->to;
3903         }
3904     }
3905
3906   // Compressed debug sections should be mapped to the corresponding
3907   // uncompressed section.
3908   if (is_compressed_debug_section(name))
3909     {
3910       size_t len = strlen(name);
3911       char *uncompressed_name = new char[len];
3912       uncompressed_name[0] = '.';
3913       gold_assert(name[0] == '.' && name[1] == 'z');
3914       strncpy(&uncompressed_name[1], &name[2], len - 2);
3915       uncompressed_name[len - 1] = '\0';
3916       *plen = len - 1;
3917       return uncompressed_name;
3918     }
3919
3920   return name;
3921 }
3922
3923 // Check if a comdat group or .gnu.linkonce section with the given
3924 // NAME is selected for the link.  If there is already a section,
3925 // *KEPT_SECTION is set to point to the existing section and the
3926 // function returns false.  Otherwise, OBJECT, SHNDX, IS_COMDAT, and
3927 // IS_GROUP_NAME are recorded for this NAME in the layout object,
3928 // *KEPT_SECTION is set to the internal copy and the function returns
3929 // true.
3930
3931 bool
3932 Layout::find_or_add_kept_section(const std::string& name,
3933                                  Relobj* object,
3934                                  unsigned int shndx,
3935                                  bool is_comdat,
3936                                  bool is_group_name,
3937                                  Kept_section** kept_section)
3938 {
3939   // It's normal to see a couple of entries here, for the x86 thunk
3940   // sections.  If we see more than a few, we're linking a C++
3941   // program, and we resize to get more space to minimize rehashing.
3942   if (this->signatures_.size() > 4
3943       && !this->resized_signatures_)
3944     {
3945       reserve_unordered_map(&this->signatures_,
3946                             this->number_of_input_files_ * 64);
3947       this->resized_signatures_ = true;
3948     }
3949
3950   Kept_section candidate;
3951   std::pair<Signatures::iterator, bool> ins =
3952     this->signatures_.insert(std::make_pair(name, candidate));
3953
3954   if (kept_section != NULL)
3955     *kept_section = &ins.first->second;
3956   if (ins.second)
3957     {
3958       // This is the first time we've seen this signature.
3959       ins.first->second.set_object(object);
3960       ins.first->second.set_shndx(shndx);
3961       if (is_comdat)
3962         ins.first->second.set_is_comdat();
3963       if (is_group_name)
3964         ins.first->second.set_is_group_name();
3965       return true;
3966     }
3967
3968   // We have already seen this signature.
3969
3970   if (ins.first->second.is_group_name())
3971     {
3972       // We've already seen a real section group with this signature.
3973       // If the kept group is from a plugin object, and we're in the
3974       // replacement phase, accept the new one as a replacement.
3975       if (ins.first->second.object() == NULL
3976           && parameters->options().plugins()->in_replacement_phase())
3977         {
3978           ins.first->second.set_object(object);
3979           ins.first->second.set_shndx(shndx);
3980           return true;
3981         }
3982       return false;
3983     }
3984   else if (is_group_name)
3985     {
3986       // This is a real section group, and we've already seen a
3987       // linkonce section with this signature.  Record that we've seen
3988       // a section group, and don't include this section group.
3989       ins.first->second.set_is_group_name();
3990       return false;
3991     }
3992   else
3993     {
3994       // We've already seen a linkonce section and this is a linkonce
3995       // section.  These don't block each other--this may be the same
3996       // symbol name with different section types.
3997       return true;
3998     }
3999 }
4000
4001 // Store the allocated sections into the section list.
4002
4003 void
4004 Layout::get_allocated_sections(Section_list* section_list) const
4005 {
4006   for (Section_list::const_iterator p = this->section_list_.begin();
4007        p != this->section_list_.end();
4008        ++p)
4009     if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
4010       section_list->push_back(*p);
4011 }
4012
4013 // Create an output segment.
4014
4015 Output_segment*
4016 Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
4017 {
4018   gold_assert(!parameters->options().relocatable());
4019   Output_segment* oseg = new Output_segment(type, flags);
4020   this->segment_list_.push_back(oseg);
4021
4022   if (type == elfcpp::PT_TLS)
4023     this->tls_segment_ = oseg;
4024   else if (type == elfcpp::PT_GNU_RELRO)
4025     this->relro_segment_ = oseg;
4026
4027   return oseg;
4028 }
4029
4030 // Write out the Output_sections.  Most won't have anything to write,
4031 // since most of the data will come from input sections which are
4032 // handled elsewhere.  But some Output_sections do have Output_data.
4033
4034 void
4035 Layout::write_output_sections(Output_file* of) const
4036 {
4037   for (Section_list::const_iterator p = this->section_list_.begin();
4038        p != this->section_list_.end();
4039        ++p)
4040     {
4041       if (!(*p)->after_input_sections())
4042         (*p)->write(of);
4043     }
4044 }
4045
4046 // Write out data not associated with a section or the symbol table.
4047
4048 void
4049 Layout::write_data(const Symbol_table* symtab, Output_file* of) const
4050 {
4051   if (!parameters->options().strip_all())
4052     {
4053       const Output_section* symtab_section = this->symtab_section_;
4054       for (Section_list::const_iterator p = this->section_list_.begin();
4055            p != this->section_list_.end();
4056            ++p)
4057         {
4058           if ((*p)->needs_symtab_index())
4059             {
4060               gold_assert(symtab_section != NULL);
4061               unsigned int index = (*p)->symtab_index();
4062               gold_assert(index > 0 && index != -1U);
4063               off_t off = (symtab_section->offset()
4064                            + index * symtab_section->entsize());
4065               symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
4066             }
4067         }
4068     }
4069
4070   const Output_section* dynsym_section = this->dynsym_section_;
4071   for (Section_list::const_iterator p = this->section_list_.begin();
4072        p != this->section_list_.end();
4073        ++p)
4074     {
4075       if ((*p)->needs_dynsym_index())
4076         {
4077           gold_assert(dynsym_section != NULL);
4078           unsigned int index = (*p)->dynsym_index();
4079           gold_assert(index > 0 && index != -1U);
4080           off_t off = (dynsym_section->offset()
4081                        + index * dynsym_section->entsize());
4082           symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
4083         }
4084     }
4085
4086   // Write out the Output_data which are not in an Output_section.
4087   for (Data_list::const_iterator p = this->special_output_list_.begin();
4088        p != this->special_output_list_.end();
4089        ++p)
4090     (*p)->write(of);
4091 }
4092
4093 // Write out the Output_sections which can only be written after the
4094 // input sections are complete.
4095
4096 void
4097 Layout::write_sections_after_input_sections(Output_file* of)
4098 {
4099   // Determine the final section offsets, and thus the final output
4100   // file size.  Note we finalize the .shstrab last, to allow the
4101   // after_input_section sections to modify their section-names before
4102   // writing.
4103   if (this->any_postprocessing_sections_)
4104     {
4105       off_t off = this->output_file_size_;
4106       off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
4107
4108       // Now that we've finalized the names, we can finalize the shstrab.
4109       off =
4110         this->set_section_offsets(off,
4111                                   STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
4112
4113       if (off > this->output_file_size_)
4114         {
4115           of->resize(off);
4116           this->output_file_size_ = off;
4117         }
4118     }
4119
4120   for (Section_list::const_iterator p = this->section_list_.begin();
4121        p != this->section_list_.end();
4122        ++p)
4123     {
4124       if ((*p)->after_input_sections())
4125         (*p)->write(of);
4126     }
4127
4128   this->section_headers_->write(of);
4129 }
4130
4131 // If the build ID requires computing a checksum, do so here, and
4132 // write it out.  We compute a checksum over the entire file because
4133 // that is simplest.
4134
4135 void
4136 Layout::write_build_id(Output_file* of) const
4137 {
4138   if (this->build_id_note_ == NULL)
4139     return;
4140
4141   const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
4142
4143   unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
4144                                           this->build_id_note_->data_size());
4145
4146   const char* style = parameters->options().build_id();
4147   if (strcmp(style, "sha1") == 0)
4148     {
4149       sha1_ctx ctx;
4150       sha1_init_ctx(&ctx);
4151       sha1_process_bytes(iv, this->output_file_size_, &ctx);
4152       sha1_finish_ctx(&ctx, ov);
4153     }
4154   else if (strcmp(style, "md5") == 0)
4155     {
4156       md5_ctx ctx;
4157       md5_init_ctx(&ctx);
4158       md5_process_bytes(iv, this->output_file_size_, &ctx);
4159       md5_finish_ctx(&ctx, ov);
4160     }
4161   else
4162     gold_unreachable();
4163
4164   of->write_output_view(this->build_id_note_->offset(),
4165                         this->build_id_note_->data_size(),
4166                         ov);
4167
4168   of->free_input_view(0, this->output_file_size_, iv);
4169 }
4170
4171 // Write out a binary file.  This is called after the link is
4172 // complete.  IN is the temporary output file we used to generate the
4173 // ELF code.  We simply walk through the segments, read them from
4174 // their file offset in IN, and write them to their load address in
4175 // the output file.  FIXME: with a bit more work, we could support
4176 // S-records and/or Intel hex format here.
4177
4178 void
4179 Layout::write_binary(Output_file* in) const
4180 {
4181   gold_assert(parameters->options().oformat_enum()
4182               == General_options::OBJECT_FORMAT_BINARY);
4183
4184   // Get the size of the binary file.
4185   uint64_t max_load_address = 0;
4186   for (Segment_list::const_iterator p = this->segment_list_.begin();
4187        p != this->segment_list_.end();
4188        ++p)
4189     {
4190       if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
4191         {
4192           uint64_t max_paddr = (*p)->paddr() + (*p)->filesz();
4193           if (max_paddr > max_load_address)
4194             max_load_address = max_paddr;
4195         }
4196     }
4197
4198   Output_file out(parameters->options().output_file_name());
4199   out.open(max_load_address);
4200
4201   for (Segment_list::const_iterator p = this->segment_list_.begin();
4202        p != this->segment_list_.end();
4203        ++p)
4204     {
4205       if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
4206         {
4207           const unsigned char* vin = in->get_input_view((*p)->offset(),
4208                                                         (*p)->filesz());
4209           unsigned char* vout = out.get_output_view((*p)->paddr(),
4210                                                     (*p)->filesz());
4211           memcpy(vout, vin, (*p)->filesz());
4212           out.write_output_view((*p)->paddr(), (*p)->filesz(), vout);
4213           in->free_input_view((*p)->offset(), (*p)->filesz(), vin);
4214         }
4215     }
4216
4217   out.close();
4218 }
4219
4220 // Print the output sections to the map file.
4221
4222 void
4223 Layout::print_to_mapfile(Mapfile* mapfile) const
4224 {
4225   for (Segment_list::const_iterator p = this->segment_list_.begin();
4226        p != this->segment_list_.end();
4227        ++p)
4228     (*p)->print_sections_to_mapfile(mapfile);
4229 }
4230
4231 // Print statistical information to stderr.  This is used for --stats.
4232
4233 void
4234 Layout::print_stats() const
4235 {
4236   this->namepool_.print_stats("section name pool");
4237   this->sympool_.print_stats("output symbol name pool");
4238   this->dynpool_.print_stats("dynamic name pool");
4239
4240   for (Section_list::const_iterator p = this->section_list_.begin();
4241        p != this->section_list_.end();
4242        ++p)
4243     (*p)->print_merge_stats();
4244 }
4245
4246 // Write_sections_task methods.
4247
4248 // We can always run this task.
4249
4250 Task_token*
4251 Write_sections_task::is_runnable()
4252 {
4253   return NULL;
4254 }
4255
4256 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
4257 // when finished.
4258
4259 void
4260 Write_sections_task::locks(Task_locker* tl)
4261 {
4262   tl->add(this, this->output_sections_blocker_);
4263   tl->add(this, this->final_blocker_);
4264 }
4265
4266 // Run the task--write out the data.
4267
4268 void
4269 Write_sections_task::run(Workqueue*)
4270 {
4271   this->layout_->write_output_sections(this->of_);
4272 }
4273
4274 // Write_data_task methods.
4275
4276 // We can always run this task.
4277
4278 Task_token*
4279 Write_data_task::is_runnable()
4280 {
4281   return NULL;
4282 }
4283
4284 // We need to unlock FINAL_BLOCKER when finished.
4285
4286 void
4287 Write_data_task::locks(Task_locker* tl)
4288 {
4289   tl->add(this, this->final_blocker_);
4290 }
4291
4292 // Run the task--write out the data.
4293
4294 void
4295 Write_data_task::run(Workqueue*)
4296 {
4297   this->layout_->write_data(this->symtab_, this->of_);
4298 }
4299
4300 // Write_symbols_task methods.
4301
4302 // We can always run this task.
4303
4304 Task_token*
4305 Write_symbols_task::is_runnable()
4306 {
4307   return NULL;
4308 }
4309
4310 // We need to unlock FINAL_BLOCKER when finished.
4311
4312 void
4313 Write_symbols_task::locks(Task_locker* tl)
4314 {
4315   tl->add(this, this->final_blocker_);
4316 }
4317
4318 // Run the task--write out the symbols.
4319
4320 void
4321 Write_symbols_task::run(Workqueue*)
4322 {
4323   this->symtab_->write_globals(this->sympool_, this->dynpool_,
4324                                this->layout_->symtab_xindex(),
4325                                this->layout_->dynsym_xindex(), this->of_);
4326 }
4327
4328 // Write_after_input_sections_task methods.
4329
4330 // We can only run this task after the input sections have completed.
4331
4332 Task_token*
4333 Write_after_input_sections_task::is_runnable()
4334 {
4335   if (this->input_sections_blocker_->is_blocked())
4336     return this->input_sections_blocker_;
4337   return NULL;
4338 }
4339
4340 // We need to unlock FINAL_BLOCKER when finished.
4341
4342 void
4343 Write_after_input_sections_task::locks(Task_locker* tl)
4344 {
4345   tl->add(this, this->final_blocker_);
4346 }
4347
4348 // Run the task.
4349
4350 void
4351 Write_after_input_sections_task::run(Workqueue*)
4352 {
4353   this->layout_->write_sections_after_input_sections(this->of_);
4354 }
4355
4356 // Close_task_runner methods.
4357
4358 // Run the task--close the file.
4359
4360 void
4361 Close_task_runner::run(Workqueue*, const Task*)
4362 {
4363   // If we need to compute a checksum for the BUILD if, we do so here.
4364   this->layout_->write_build_id(this->of_);
4365
4366   // If we've been asked to create a binary file, we do so here.
4367   if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)
4368     this->layout_->write_binary(this->of_);
4369
4370   this->of_->close();
4371 }
4372
4373 // Instantiate the templates we need.  We could use the configure
4374 // script to restrict this to only the ones for implemented targets.
4375
4376 #ifdef HAVE_TARGET_32_LITTLE
4377 template
4378 Output_section*
4379 Layout::layout<32, false>(Sized_relobj<32, false>* object, unsigned int shndx,
4380                           const char* name,
4381                           const elfcpp::Shdr<32, false>& shdr,
4382                           unsigned int, unsigned int, off_t*);
4383 #endif
4384
4385 #ifdef HAVE_TARGET_32_BIG
4386 template
4387 Output_section*
4388 Layout::layout<32, true>(Sized_relobj<32, true>* object, unsigned int shndx,
4389                          const char* name,
4390                          const elfcpp::Shdr<32, true>& shdr,
4391                          unsigned int, unsigned int, off_t*);
4392 #endif
4393
4394 #ifdef HAVE_TARGET_64_LITTLE
4395 template
4396 Output_section*
4397 Layout::layout<64, false>(Sized_relobj<64, false>* object, unsigned int shndx,
4398                           const char* name,
4399                           const elfcpp::Shdr<64, false>& shdr,
4400                           unsigned int, unsigned int, off_t*);
4401 #endif
4402
4403 #ifdef HAVE_TARGET_64_BIG
4404 template
4405 Output_section*
4406 Layout::layout<64, true>(Sized_relobj<64, true>* object, unsigned int shndx,
4407                          const char* name,
4408                          const elfcpp::Shdr<64, true>& shdr,
4409                          unsigned int, unsigned int, off_t*);
4410 #endif
4411
4412 #ifdef HAVE_TARGET_32_LITTLE
4413 template
4414 Output_section*
4415 Layout::layout_reloc<32, false>(Sized_relobj<32, false>* object,
4416                                 unsigned int reloc_shndx,
4417                                 const elfcpp::Shdr<32, false>& shdr,
4418                                 Output_section* data_section,
4419                                 Relocatable_relocs* rr);
4420 #endif
4421
4422 #ifdef HAVE_TARGET_32_BIG
4423 template
4424 Output_section*
4425 Layout::layout_reloc<32, true>(Sized_relobj<32, true>* object,
4426                                unsigned int reloc_shndx,
4427                                const elfcpp::Shdr<32, true>& shdr,
4428                                Output_section* data_section,
4429                                Relocatable_relocs* rr);
4430 #endif
4431
4432 #ifdef HAVE_TARGET_64_LITTLE
4433 template
4434 Output_section*
4435 Layout::layout_reloc<64, false>(Sized_relobj<64, false>* object,
4436                                 unsigned int reloc_shndx,
4437                                 const elfcpp::Shdr<64, false>& shdr,
4438                                 Output_section* data_section,
4439                                 Relocatable_relocs* rr);
4440 #endif
4441
4442 #ifdef HAVE_TARGET_64_BIG
4443 template
4444 Output_section*
4445 Layout::layout_reloc<64, true>(Sized_relobj<64, true>* object,
4446                                unsigned int reloc_shndx,
4447                                const elfcpp::Shdr<64, true>& shdr,
4448                                Output_section* data_section,
4449                                Relocatable_relocs* rr);
4450 #endif
4451
4452 #ifdef HAVE_TARGET_32_LITTLE
4453 template
4454 void
4455 Layout::layout_group<32, false>(Symbol_table* symtab,
4456                                 Sized_relobj<32, false>* object,
4457                                 unsigned int,
4458                                 const char* group_section_name,
4459                                 const char* signature,
4460                                 const elfcpp::Shdr<32, false>& shdr,
4461                                 elfcpp::Elf_Word flags,
4462                                 std::vector<unsigned int>* shndxes);
4463 #endif
4464
4465 #ifdef HAVE_TARGET_32_BIG
4466 template
4467 void
4468 Layout::layout_group<32, true>(Symbol_table* symtab,
4469                                Sized_relobj<32, true>* object,
4470                                unsigned int,
4471                                const char* group_section_name,
4472                                const char* signature,
4473                                const elfcpp::Shdr<32, true>& shdr,
4474                                elfcpp::Elf_Word flags,
4475                                std::vector<unsigned int>* shndxes);
4476 #endif
4477
4478 #ifdef HAVE_TARGET_64_LITTLE
4479 template
4480 void
4481 Layout::layout_group<64, false>(Symbol_table* symtab,
4482                                 Sized_relobj<64, false>* object,
4483                                 unsigned int,
4484                                 const char* group_section_name,
4485                                 const char* signature,
4486                                 const elfcpp::Shdr<64, false>& shdr,
4487                                 elfcpp::Elf_Word flags,
4488                                 std::vector<unsigned int>* shndxes);
4489 #endif
4490
4491 #ifdef HAVE_TARGET_64_BIG
4492 template
4493 void
4494 Layout::layout_group<64, true>(Symbol_table* symtab,
4495                                Sized_relobj<64, true>* object,
4496                                unsigned int,
4497                                const char* group_section_name,
4498                                const char* signature,
4499                                const elfcpp::Shdr<64, true>& shdr,
4500                                elfcpp::Elf_Word flags,
4501                                std::vector<unsigned int>* shndxes);
4502 #endif
4503
4504 #ifdef HAVE_TARGET_32_LITTLE
4505 template
4506 Output_section*
4507 Layout::layout_eh_frame<32, false>(Sized_relobj<32, false>* object,
4508                                    const unsigned char* symbols,
4509                                    off_t symbols_size,
4510                                    const unsigned char* symbol_names,
4511                                    off_t symbol_names_size,
4512                                    unsigned int shndx,
4513                                    const elfcpp::Shdr<32, false>& shdr,
4514                                    unsigned int reloc_shndx,
4515                                    unsigned int reloc_type,
4516                                    off_t* off);
4517 #endif
4518
4519 #ifdef HAVE_TARGET_32_BIG
4520 template
4521 Output_section*
4522 Layout::layout_eh_frame<32, true>(Sized_relobj<32, true>* object,
4523                                    const unsigned char* symbols,
4524                                    off_t symbols_size,
4525                                   const unsigned char* symbol_names,
4526                                   off_t symbol_names_size,
4527                                   unsigned int shndx,
4528                                   const elfcpp::Shdr<32, true>& shdr,
4529                                   unsigned int reloc_shndx,
4530                                   unsigned int reloc_type,
4531                                   off_t* off);
4532 #endif
4533
4534 #ifdef HAVE_TARGET_64_LITTLE
4535 template
4536 Output_section*
4537 Layout::layout_eh_frame<64, false>(Sized_relobj<64, false>* object,
4538                                    const unsigned char* symbols,
4539                                    off_t symbols_size,
4540                                    const unsigned char* symbol_names,
4541                                    off_t symbol_names_size,
4542                                    unsigned int shndx,
4543                                    const elfcpp::Shdr<64, false>& shdr,
4544                                    unsigned int reloc_shndx,
4545                                    unsigned int reloc_type,
4546                                    off_t* off);
4547 #endif
4548
4549 #ifdef HAVE_TARGET_64_BIG
4550 template
4551 Output_section*
4552 Layout::layout_eh_frame<64, true>(Sized_relobj<64, true>* object,
4553                                    const unsigned char* symbols,
4554                                    off_t symbols_size,
4555                                   const unsigned char* symbol_names,
4556                                   off_t symbol_names_size,
4557                                   unsigned int shndx,
4558                                   const elfcpp::Shdr<64, true>& shdr,
4559                                   unsigned int reloc_shndx,
4560                                   unsigned int reloc_type,
4561                                   off_t* off);
4562 #endif
4563
4564 } // End namespace gold.