gold/layout.cc

   1 // layout.cc -- lay out output file sections for gold
   2
   3 // Copyright 2006, 2007 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 <cstring>
  26 #include <algorithm>
  27 #include <iostream>
  28 #include <utility>
  29
  30 #include "parameters.h"
  31 #include "output.h"
  32 #include "symtab.h"
  33 #include "dynobj.h"
  34 #include "ehframe.h"
  35 #include "layout.h"
  36
  37 namespace gold
  38 {
  39
  40 // Layout_task_runner methods.
  41
  42 // Lay out the sections.  This is called after all the input objects
  43 // have been read.
  44
  45 void
  46 Layout_task_runner::run(Workqueue* workqueue)
  47 {
  48   off_t file_size = this->layout_->finalize(this->input_objects_,
  49                                             this->symtab_);
  50
  51   // Now we know the final size of the output file and we know where
  52   // each piece of information goes.
  53   Output_file* of = new Output_file(this->options_,
  54                                     this->input_objects_->target());
  55   of->open(file_size);
  56
  57   // Queue up the final set of tasks.
  58   gold::queue_final_tasks(this->options_, this->input_objects_,
  59                           this->symtab_, this->layout_, workqueue, of);
  60 }
  61
  62 // Layout methods.
  63
  64 Layout::Layout(const General_options& options)
  65   : options_(options), namepool_(), sympool_(), dynpool_(), signatures_(),
  66     section_name_map_(), segment_list_(), section_list_(),
  67     unattached_section_list_(), special_output_list_(),
  68     tls_segment_(NULL), symtab_section_(NULL),
  69     dynsym_section_(NULL), dynamic_section_(NULL), dynamic_data_(NULL),
  70     eh_frame_section_(NULL), output_file_size_(-1),
  71     input_requires_executable_stack_(false),
  72     input_with_gnu_stack_note_(false),
  73     input_without_gnu_stack_note_(false),
  74     have_textrel_(false)
  75 {
  76   // Make space for more than enough segments for a typical file.
  77   // This is just for efficiency--it's OK if we wind up needing more.
  78   this->segment_list_.reserve(12);
  79
  80   // We expect three unattached Output_data objects: the file header,
  81   // the segment headers, and the section headers.
  82   this->special_output_list_.reserve(3);
  83 }
  84
  85 // Hash a key we use to look up an output section mapping.
  86
  87 size_t
  88 Layout::Hash_key::operator()(const Layout::Key& k) const
  89 {
  90  return k.first + k.second.first + k.second.second;
  91 }
  92
  93 // Return whether PREFIX is a prefix of STR.
  94
  95 static inline bool
  96 is_prefix_of(const char* prefix, const char* str)
  97 {
  98   return strncmp(prefix, str, strlen(prefix)) == 0;
  99 }
 100
 101 // Returns whether the given section is in the list of
 102 // debug-sections-used-by-some-version-of-gdb.  Currently,
 103 // we've checked versions of gdb up to and including 6.7.1.
 104
 105 static const char* gdb_sections[] =
 106 { ".debug_abbrev",
 107   // ".debug_aranges",   // not used by gdb as of 6.7.1
 108   ".debug_frame",
 109   ".debug_info",
 110   ".debug_line",
 111   ".debug_loc",
 112   ".debug_macinfo",
 113   // ".debug_pubnames",  // not used by gdb as of 6.7.1
 114   ".debug_ranges",
 115   ".debug_str",
 116 };
 117
 118 static inline bool
 119 is_gdb_debug_section(const char* str)
 120 {
 121   // We can do this faster: binary search or a hashtable.  But why bother?
 122   for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
 123     if (strcmp(str, gdb_sections[i]) == 0)
 124       return true;
 125   return false;
 126 }
 127
 128 // Whether to include this section in the link.
 129
 130 template<int size, bool big_endian>
 131 bool
 132 Layout::include_section(Sized_relobj<size, big_endian>*, const char* name,
 133                         const elfcpp::Shdr<size, big_endian>& shdr)
 134 {
 135   // Some section types are never linked.  Some are only linked when
 136   // doing a relocateable link.
 137   switch (shdr.get_sh_type())
 138     {
 139     case elfcpp::SHT_NULL:
 140     case elfcpp::SHT_SYMTAB:
 141     case elfcpp::SHT_DYNSYM:
 142     case elfcpp::SHT_STRTAB:
 143     case elfcpp::SHT_HASH:
 144     case elfcpp::SHT_DYNAMIC:
 145     case elfcpp::SHT_SYMTAB_SHNDX:
 146       return false;
 147
 148     case elfcpp::SHT_RELA:
 149     case elfcpp::SHT_REL:
 150     case elfcpp::SHT_GROUP:
 151       return parameters->output_is_object();
 152
 153     case elfcpp::SHT_PROGBITS:
 154       if (parameters->strip_debug()
 155           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 156         {
 157           // Debugging sections can only be recognized by name.
 158           if (is_prefix_of(".debug", name)
 159               || is_prefix_of(".gnu.linkonce.wi.", name)
 160               || is_prefix_of(".line", name)
 161               || is_prefix_of(".stab", name))
 162             return false;
 163         }
 164       if (parameters->strip_debug_gdb()
 165           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 166         {
 167           // Debugging sections can only be recognized by name.
 168           if (is_prefix_of(".debug", name)
 169               && !is_gdb_debug_section(name))
 170             return false;
 171         }
 172       return true;
 173
 174     default:
 175       return true;
 176     }
 177 }
 178
 179 // Return an output section named NAME, or NULL if there is none.
 180
 181 Output_section*
 182 Layout::find_output_section(const char* name) const
 183 {
 184   for (Section_name_map::const_iterator p = this->section_name_map_.begin();
 185        p != this->section_name_map_.end();
 186        ++p)
 187     if (strcmp(p->second->name(), name) == 0)
 188       return p->second;
 189   return NULL;
 190 }
 191
 192 // Return an output segment of type TYPE, with segment flags SET set
 193 // and segment flags CLEAR clear.  Return NULL if there is none.
 194
 195 Output_segment*
 196 Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
 197                             elfcpp::Elf_Word clear) const
 198 {
 199   for (Segment_list::const_iterator p = this->segment_list_.begin();
 200        p != this->segment_list_.end();
 201        ++p)
 202     if (static_cast<elfcpp::PT>((*p)->type()) == type
 203         && ((*p)->flags() & set) == set
 204         && ((*p)->flags() & clear) == 0)
 205       return *p;
 206   return NULL;
 207 }
 208
 209 // Return the output section to use for section NAME with type TYPE
 210 // and section flags FLAGS.
 211
 212 Output_section*
 213 Layout::get_output_section(const char* name, Stringpool::Key name_key,
 214                            elfcpp::Elf_Word type, elfcpp::Elf_Xword flags)
 215 {
 216   // We should ignore some flags.
 217   flags &= ~ (elfcpp::SHF_INFO_LINK
 218               | elfcpp::SHF_LINK_ORDER
 219               | elfcpp::SHF_GROUP
 220               | elfcpp::SHF_MERGE
 221               | elfcpp::SHF_STRINGS);
 222
 223   const Key key(name_key, std::make_pair(type, flags));
 224   const std::pair<Key, Output_section*> v(key, NULL);
 225   std::pair<Section_name_map::iterator, bool> ins(
 226     this->section_name_map_.insert(v));
 227
 228   if (!ins.second)
 229     return ins.first->second;
 230   else
 231     {
 232       // This is the first time we've seen this name/type/flags
 233       // combination.
 234       Output_section* os = this->make_output_section(name, type, flags);
 235       ins.first->second = os;
 236       return os;
 237     }
 238 }
 239
 240 // Return the output section to use for input section SHNDX, with name
 241 // NAME, with header HEADER, from object OBJECT.  RELOC_SHNDX is the
 242 // index of a relocation section which applies to this section, or 0
 243 // if none, or -1U if more than one.  RELOC_TYPE is the type of the
 244 // relocation section if there is one.  Set *OFF to the offset of this
 245 // input section without the output section.  Return NULL if the
 246 // section should be discarded.  Set *OFF to -1 if the section
 247 // contents should not be written directly to the output file, but
 248 // will instead receive special handling.
 249
 250 template<int size, bool big_endian>
 251 Output_section*
 252 Layout::layout(Sized_relobj<size, big_endian>* object, unsigned int shndx,
 253                const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
 254                unsigned int reloc_shndx, unsigned int, off_t* off)
 255 {
 256   if (!this->include_section(object, name, shdr))
 257     return NULL;
 258
 259   // If we are not doing a relocateable link, choose the name to use
 260   // for the output section.
 261   size_t len = strlen(name);
 262   if (!parameters->output_is_object())
 263     name = Layout::output_section_name(name, &len);
 264
 265   // FIXME: Handle SHF_OS_NONCONFORMING here.
 266
 267   // Canonicalize the section name.
 268   Stringpool::Key name_key;
 269   name = this->namepool_.add_prefix(name, len, &name_key);
 270
 271   // Find the output section.  The output section is selected based on
 272   // the section name, type, and flags.
 273   Output_section* os = this->get_output_section(name, name_key,
 274                                                 shdr.get_sh_type(),
 275                                                 shdr.get_sh_flags());
 276
 277   // FIXME: Handle SHF_LINK_ORDER somewhere.
 278
 279   *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx);
 280
 281   return os;
 282 }
 283
 284 // Special GNU handling of sections name .eh_frame.  They will
 285 // normally hold exception frame data as defined by the C++ ABI
 286 // (http://codesourcery.com/cxx-abi/).
 287
 288 template<int size, bool big_endian>
 289 Output_section*
 290 Layout::layout_eh_frame(Sized_relobj<size, big_endian>* object,
 291                         const unsigned char* symbols,
 292                         off_t symbols_size,
 293                         const unsigned char* symbol_names,
 294                         off_t symbol_names_size,
 295                         unsigned int shndx,
 296                         const elfcpp::Shdr<size, big_endian>& shdr,
 297                         unsigned int reloc_shndx, unsigned int reloc_type,
 298                         off_t* off)
 299 {
 300   gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS);
 301   gold_assert(shdr.get_sh_flags() == elfcpp::SHF_ALLOC);
 302
 303   Stringpool::Key name_key;
 304   const char* name = this->namepool_.add(".eh_frame", false, &name_key);
 305
 306   Output_section* os = this->get_output_section(name, name_key,
 307                                                 elfcpp::SHT_PROGBITS,
 308                                                 elfcpp::SHF_ALLOC);
 309
 310   if (this->eh_frame_section_ == NULL)
 311     {
 312       this->eh_frame_section_ = os;
 313       this->eh_frame_data_ = new Eh_frame();
 314       os->add_output_section_data(this->eh_frame_data_);
 315
 316       if (this->options_.create_eh_frame_hdr())
 317         {
 318           Stringpool::Key hdr_name_key;
 319           const char* hdr_name = this->namepool_.add(".eh_frame_hdr",
 320                                                      false,
 321                                                      &hdr_name_key);
 322           Output_section* hdr_os =
 323             this->get_output_section(hdr_name, hdr_name_key,
 324                                      elfcpp::SHT_PROGBITS,
 325                                      elfcpp::SHF_ALLOC);
 326
 327           Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os, this->eh_frame_data_);
 328           hdr_os->add_output_section_data(hdr_posd);
 329
 330           hdr_os->set_after_input_sections();
 331
 332           Output_segment* hdr_oseg =
 333             new Output_segment(elfcpp::PT_GNU_EH_FRAME, elfcpp::PF_R);
 334           this->segment_list_.push_back(hdr_oseg);
 335           hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R);
 336
 337           this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
 338         }
 339     }
 340
 341   gold_assert(this->eh_frame_section_ == os);
 342
 343   if (this->eh_frame_data_->add_ehframe_input_section(object,
 344                                                       symbols,
 345                                                       symbols_size,
 346                                                       symbol_names,
 347                                                       symbol_names_size,
 348                                                       shndx,
 349                                                       reloc_shndx,
 350                                                       reloc_type))
 351     *off = -1;
 352   else
 353     {
 354       // We couldn't handle this .eh_frame section for some reason.
 355       // Add it as a normal section.
 356       *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx);
 357     }
 358
 359   return os;
 360 }
 361
 362 // Add POSD to an output section using NAME, TYPE, and FLAGS.
 363
 364 void
 365 Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
 366                                 elfcpp::Elf_Xword flags,
 367                                 Output_section_data* posd)
 368 {
 369   // Canonicalize the name.
 370   Stringpool::Key name_key;
 371   name = this->namepool_.add(name, true, &name_key);
 372
 373   Output_section* os = this->get_output_section(name, name_key, type, flags);
 374   os->add_output_section_data(posd);
 375 }
 376
 377 // Map section flags to segment flags.
 378
 379 elfcpp::Elf_Word
 380 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
 381 {
 382   elfcpp::Elf_Word ret = elfcpp::PF_R;
 383   if ((flags & elfcpp::SHF_WRITE) != 0)
 384     ret |= elfcpp::PF_W;
 385   if ((flags & elfcpp::SHF_EXECINSTR) != 0)
 386     ret |= elfcpp::PF_X;
 387   return ret;
 388 }
 389
 390 // Make a new Output_section, and attach it to segments as
 391 // appropriate.
 392
 393 Output_section*
 394 Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
 395                             elfcpp::Elf_Xword flags)
 396 {
 397   Output_section* os = new Output_section(name, type, flags);
 398   this->section_list_.push_back(os);
 399
 400   if ((flags & elfcpp::SHF_ALLOC) == 0)
 401     this->unattached_section_list_.push_back(os);
 402   else
 403     {
 404       // This output section goes into a PT_LOAD segment.
 405
 406       elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
 407
 408       // The only thing we really care about for PT_LOAD segments is
 409       // whether or not they are writable, so that is how we search
 410       // for them.  People who need segments sorted on some other
 411       // basis will have to wait until we implement a mechanism for
 412       // them to describe the segments they want.
 413
 414       Segment_list::const_iterator p;
 415       for (p = this->segment_list_.begin();
 416            p != this->segment_list_.end();
 417            ++p)
 418         {
 419           if ((*p)->type() == elfcpp::PT_LOAD
 420               && ((*p)->flags() & elfcpp::PF_W) == (seg_flags & elfcpp::PF_W))
 421             {
 422               (*p)->add_output_section(os, seg_flags);
 423               break;
 424             }
 425         }
 426
 427       if (p == this->segment_list_.end())
 428         {
 429           Output_segment* oseg = new Output_segment(elfcpp::PT_LOAD,
 430                                                     seg_flags);
 431           this->segment_list_.push_back(oseg);
 432           oseg->add_output_section(os, seg_flags);
 433         }
 434
 435       // If we see a loadable SHT_NOTE section, we create a PT_NOTE
 436       // segment.
 437       if (type == elfcpp::SHT_NOTE)
 438         {
 439           // See if we already have an equivalent PT_NOTE segment.
 440           for (p = this->segment_list_.begin();
 441                p != segment_list_.end();
 442                ++p)
 443             {
 444               if ((*p)->type() == elfcpp::PT_NOTE
 445                   && (((*p)->flags() & elfcpp::PF_W)
 446                       == (seg_flags & elfcpp::PF_W)))
 447                 {
 448                   (*p)->add_output_section(os, seg_flags);
 449                   break;
 450                 }
 451             }
 452
 453           if (p == this->segment_list_.end())
 454             {
 455               Output_segment* oseg = new Output_segment(elfcpp::PT_NOTE,
 456                                                         seg_flags);
 457               this->segment_list_.push_back(oseg);
 458               oseg->add_output_section(os, seg_flags);
 459             }
 460         }
 461
 462       // If we see a loadable SHF_TLS section, we create a PT_TLS
 463       // segment.  There can only be one such segment.
 464       if ((flags & elfcpp::SHF_TLS) != 0)
 465         {
 466           if (this->tls_segment_ == NULL)
 467             {
 468               this->tls_segment_ = new Output_segment(elfcpp::PT_TLS,
 469                                                       seg_flags);
 470               this->segment_list_.push_back(this->tls_segment_);
 471             }
 472           this->tls_segment_->add_output_section(os, seg_flags);
 473         }
 474     }
 475
 476   return os;
 477 }
 478
 479 // Handle the .note.GNU-stack section at layout time.  SEEN_GNU_STACK
 480 // is whether we saw a .note.GNU-stack section in the object file.
 481 // GNU_STACK_FLAGS is the section flags.  The flags give the
 482 // protection required for stack memory.  We record this in an
 483 // executable as a PT_GNU_STACK segment.  If an object file does not
 484 // have a .note.GNU-stack segment, we must assume that it is an old
 485 // object.  On some targets that will force an executable stack.
 486
 487 void
 488 Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
 489 {
 490   if (!seen_gnu_stack)
 491     this->input_without_gnu_stack_note_ = true;
 492   else
 493     {
 494       this->input_with_gnu_stack_note_ = true;
 495       if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
 496         this->input_requires_executable_stack_ = true;
 497     }
 498 }
 499
 500 // Create the dynamic sections which are needed before we read the
 501 // relocs.
 502
 503 void
 504 Layout::create_initial_dynamic_sections(const Input_objects* input_objects,
 505                                         Symbol_table* symtab)
 506 {
 507   if (parameters->doing_static_link())
 508     return;
 509
 510   const char* dynamic_name = this->namepool_.add(".dynamic", false, NULL);
 511   this->dynamic_section_ = this->make_output_section(dynamic_name,
 512                                                      elfcpp::SHT_DYNAMIC,
 513                                                      (elfcpp::SHF_ALLOC
 514                                                       | elfcpp::SHF_WRITE));
 515
 516   symtab->define_in_output_data(input_objects->target(), "_DYNAMIC", NULL,
 517                                 this->dynamic_section_, 0, 0,
 518                                 elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
 519                                 elfcpp::STV_HIDDEN, 0, false, false);
 520
 521   this->dynamic_data_ =  new Output_data_dynamic(&this->dynpool_);
 522
 523   this->dynamic_section_->add_output_section_data(this->dynamic_data_);
 524 }
 525
 526 // For each output section whose name can be represented as C symbol,
 527 // define __start and __stop symbols for the section.  This is a GNU
 528 // extension.
 529
 530 void
 531 Layout::define_section_symbols(Symbol_table* symtab, const Target* target)
 532 {
 533   for (Section_list::const_iterator p = this->section_list_.begin();
 534        p != this->section_list_.end();
 535        ++p)
 536     {
 537       const char* const name = (*p)->name();
 538       if (name[strspn(name,
 539                       ("0123456789"
 540                        "ABCDEFGHIJKLMNOPWRSTUVWXYZ"
 541                        "abcdefghijklmnopqrstuvwxyz"
 542                        "_"))]
 543           == '\0')
 544         {
 545           const std::string name_string(name);
 546           const std::string start_name("__start_" + name_string);
 547           const std::string stop_name("__stop_" + name_string);
 548
 549           symtab->define_in_output_data(target,
 550                                         start_name.c_str(),
 551                                         NULL, // version
 552                                         *p,
 553                                         0, // value
 554                                         0, // symsize
 555                                         elfcpp::STT_NOTYPE,
 556                                         elfcpp::STB_GLOBAL,
 557                                         elfcpp::STV_DEFAULT,
 558                                         0, // nonvis
 559                                         false, // offset_is_from_end
 560                                         false); // only_if_ref
 561
 562           symtab->define_in_output_data(target,
 563                                         stop_name.c_str(),
 564                                         NULL, // version
 565                                         *p,
 566                                         0, // value
 567                                         0, // symsize
 568                                         elfcpp::STT_NOTYPE,
 569                                         elfcpp::STB_GLOBAL,
 570                                         elfcpp::STV_DEFAULT,
 571                                         0, // nonvis
 572                                         true, // offset_is_from_end
 573                                         false); // only_if_ref
 574         }
 575     }
 576 }
 577
 578 // Find the first read-only PT_LOAD segment, creating one if
 579 // necessary.
 580
 581 Output_segment*
 582 Layout::find_first_load_seg()
 583 {
 584   for (Segment_list::const_iterator p = this->segment_list_.begin();
 585        p != this->segment_list_.end();
 586        ++p)
 587     {
 588       if ((*p)->type() == elfcpp::PT_LOAD
 589           && ((*p)->flags() & elfcpp::PF_R) != 0
 590           && ((*p)->flags() & elfcpp::PF_W) == 0)
 591         return *p;
 592     }
 593
 594   Output_segment* load_seg = new Output_segment(elfcpp::PT_LOAD, elfcpp::PF_R);
 595   this->segment_list_.push_back(load_seg);
 596   return load_seg;
 597 }
 598
 599 // Finalize the layout.  When this is called, we have created all the
 600 // output sections and all the output segments which are based on
 601 // input sections.  We have several things to do, and we have to do
 602 // them in the right order, so that we get the right results correctly
 603 // and efficiently.
 604
 605 // 1) Finalize the list of output segments and create the segment
 606 // table header.
 607
 608 // 2) Finalize the dynamic symbol table and associated sections.
 609
 610 // 3) Determine the final file offset of all the output segments.
 611
 612 // 4) Determine the final file offset of all the SHF_ALLOC output
 613 // sections.
 614
 615 // 5) Create the symbol table sections and the section name table
 616 // section.
 617
 618 // 6) Finalize the symbol table: set symbol values to their final
 619 // value and make a final determination of which symbols are going
 620 // into the output symbol table.
 621
 622 // 7) Create the section table header.
 623
 624 // 8) Determine the final file offset of all the output sections which
 625 // are not SHF_ALLOC, including the section table header.
 626
 627 // 9) Finalize the ELF file header.
 628
 629 // This function returns the size of the output file.
 630
 631 off_t
 632 Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
 633 {
 634   Target* const target = input_objects->target();
 635
 636   target->finalize_sections(this);
 637
 638   this->create_gold_note();
 639   this->create_executable_stack_info(target);
 640
 641   Output_segment* phdr_seg = NULL;
 642   if (!parameters->doing_static_link())
 643     {
 644       // There was a dynamic object in the link.  We need to create
 645       // some information for the dynamic linker.
 646
 647       // Create the PT_PHDR segment which will hold the program
 648       // headers.
 649       phdr_seg = new Output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
 650       this->segment_list_.push_back(phdr_seg);
 651
 652       // Create the dynamic symbol table, including the hash table.
 653       Output_section* dynstr;
 654       std::vector<Symbol*> dynamic_symbols;
 655       unsigned int local_dynamic_count;
 656       Versions versions;
 657       this->create_dynamic_symtab(target, symtab, &dynstr,
 658                                   &local_dynamic_count, &dynamic_symbols,
 659                                   &versions);
 660
 661       // Create the .interp section to hold the name of the
 662       // interpreter, and put it in a PT_INTERP segment.
 663       if (!parameters->output_is_shared())
 664         this->create_interp(target);
 665
 666       // Finish the .dynamic section to hold the dynamic data, and put
 667       // it in a PT_DYNAMIC segment.
 668       this->finish_dynamic_section(input_objects, symtab);
 669
 670       // We should have added everything we need to the dynamic string
 671       // table.
 672       this->dynpool_.set_string_offsets();
 673
 674       // Create the version sections.  We can't do this until the
 675       // dynamic string table is complete.
 676       this->create_version_sections(&versions, symtab, local_dynamic_count,
 677                                     dynamic_symbols, dynstr);
 678     }
 679
 680   // FIXME: Handle PT_GNU_STACK.
 681
 682   Output_segment* load_seg = this->find_first_load_seg();
 683
 684   // Lay out the segment headers.
 685   Output_segment_headers* segment_headers;
 686   segment_headers = new Output_segment_headers(this->segment_list_);
 687   load_seg->add_initial_output_data(segment_headers);
 688   this->special_output_list_.push_back(segment_headers);
 689   if (phdr_seg != NULL)
 690     phdr_seg->add_initial_output_data(segment_headers);
 691
 692   // Lay out the file header.
 693   Output_file_header* file_header;
 694   file_header = new Output_file_header(target, symtab, segment_headers);
 695   load_seg->add_initial_output_data(file_header);
 696   this->special_output_list_.push_back(file_header);
 697
 698   // We set the output section indexes in set_segment_offsets and
 699   // set_section_offsets.
 700   unsigned int shndx = 1;
 701
 702   // Set the file offsets of all the segments, and all the sections
 703   // they contain.
 704   off_t off = this->set_segment_offsets(target, load_seg, &shndx);
 705
 706   // Set the file offsets of all the data sections not associated with
 707   // segments. This makes sure that debug sections have their offsets
 708   // before symbols are finalized.
 709   off = this->set_section_offsets(off, true);
 710
 711   // Create the symbol table sections.
 712   this->create_symtab_sections(input_objects, symtab, &off);
 713
 714   // Create the .shstrtab section.
 715   Output_section* shstrtab_section = this->create_shstrtab();
 716
 717   // Set the file offsets of all the non-data sections not associated with
 718   // segments.
 719   off = this->set_section_offsets(off, false);
 720
 721   // Now that all sections have been created, set the section indexes.
 722   shndx = this->set_section_indexes(shndx);
 723
 724   // Create the section table header.
 725   Output_section_headers* oshdrs = this->create_shdrs(&off);
 726
 727   file_header->set_section_info(oshdrs, shstrtab_section);
 728
 729   // Now we know exactly where everything goes in the output file.
 730   Output_data::layout_complete();
 731
 732   this->output_file_size_ = off;
 733
 734   return off;
 735 }
 736
 737 // Create a .note section for an executable or shared library.  This
 738 // records the version of gold used to create the binary.
 739
 740 void
 741 Layout::create_gold_note()
 742 {
 743   if (parameters->output_is_object())
 744     return;
 745
 746   // Authorities all agree that the values in a .note field should
 747   // be aligned on 4-byte boundaries for 32-bit binaries.  However,
 748   // they differ on what the alignment is for 64-bit binaries.
 749   // The GABI says unambiguously they take 8-byte alignment:
 750   //    http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
 751   // Other documentation says alignment should always be 4 bytes:
 752   //    http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
 753   // GNU ld and GNU readelf both support the latter (at least as of
 754   // version 2.16.91), and glibc always generates the latter for
 755   // .note.ABI-tag (as of version 1.6), so that's the one we go with
 756   // here.
 757 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION   // This is not defined by default.
 758   const int size = parameters->get_size();
 759 #else
 760   const int size = 32;
 761 #endif
 762
 763   // The contents of the .note section.
 764   const char* name = "GNU";
 765   std::string desc(std::string("gold ") + gold::get_version_string());
 766   size_t namesz = strlen(name) + 1;
 767   size_t aligned_namesz = align_address(namesz, size / 8);
 768   size_t descsz = desc.length() + 1;
 769   size_t aligned_descsz = align_address(descsz, size / 8);
 770   const int note_type = 4;
 771
 772   size_t notesz = 3 * (size / 8) + aligned_namesz + aligned_descsz;
 773
 774   unsigned char buffer[128];
 775   gold_assert(sizeof buffer >= notesz);
 776   memset(buffer, 0, notesz);
 777
 778   bool is_big_endian = parameters->is_big_endian();
 779
 780   if (size == 32)
 781     {
 782       if (!is_big_endian)
 783         {
 784           elfcpp::Swap<32, false>::writeval(buffer, namesz);
 785           elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
 786           elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
 787         }
 788       else
 789         {
 790           elfcpp::Swap<32, true>::writeval(buffer, namesz);
 791           elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
 792           elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
 793         }
 794     }
 795   else if (size == 64)
 796     {
 797       if (!is_big_endian)
 798         {
 799           elfcpp::Swap<64, false>::writeval(buffer, namesz);
 800           elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
 801           elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
 802         }
 803       else
 804         {
 805           elfcpp::Swap<64, true>::writeval(buffer, namesz);
 806           elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
 807           elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
 808         }
 809     }
 810   else
 811     gold_unreachable();
 812
 813   memcpy(buffer + 3 * (size / 8), name, namesz);
 814   memcpy(buffer + 3 * (size / 8) + aligned_namesz, desc.data(), descsz);
 815
 816   const char* note_name = this->namepool_.add(".note", false, NULL);
 817   Output_section* os = this->make_output_section(note_name,
 818                                                  elfcpp::SHT_NOTE,
 819                                                  0);
 820   Output_section_data* posd = new Output_data_const(buffer, notesz,
 821                                                     size / 8);
 822   os->add_output_section_data(posd);
 823 }
 824
 825 // Record whether the stack should be executable.  This can be set
 826 // from the command line using the -z execstack or -z noexecstack
 827 // options.  Otherwise, if any input file has a .note.GNU-stack
 828 // section with the SHF_EXECINSTR flag set, the stack should be
 829 // executable.  Otherwise, if at least one input file a
 830 // .note.GNU-stack section, and some input file has no .note.GNU-stack
 831 // section, we use the target default for whether the stack should be
 832 // executable.  Otherwise, we don't generate a stack note.  When
 833 // generating a object file, we create a .note.GNU-stack section with
 834 // the appropriate marking.  When generating an executable or shared
 835 // library, we create a PT_GNU_STACK segment.
 836
 837 void
 838 Layout::create_executable_stack_info(const Target* target)
 839 {
 840   bool is_stack_executable;
 841   if (this->options_.is_execstack_set())
 842     is_stack_executable = this->options_.is_stack_executable();
 843   else if (!this->input_with_gnu_stack_note_)
 844     return;
 845   else
 846     {
 847       if (this->input_requires_executable_stack_)
 848         is_stack_executable = true;
 849       else if (this->input_without_gnu_stack_note_)
 850         is_stack_executable = target->is_default_stack_executable();
 851       else
 852         is_stack_executable = false;
 853     }
 854
 855   if (parameters->output_is_object())
 856     {
 857       const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
 858       elfcpp::Elf_Xword flags = 0;
 859       if (is_stack_executable)
 860         flags |= elfcpp::SHF_EXECINSTR;
 861       this->make_output_section(name, elfcpp::SHT_PROGBITS, flags);
 862     }
 863   else
 864     {
 865       int flags = elfcpp::PF_R | elfcpp::PF_W;
 866       if (is_stack_executable)
 867         flags |= elfcpp::PF_X;
 868       Output_segment* oseg = new Output_segment(elfcpp::PT_GNU_STACK, flags);
 869       this->segment_list_.push_back(oseg);
 870     }
 871 }
 872
 873 // Return whether SEG1 should be before SEG2 in the output file.  This
 874 // is based entirely on the segment type and flags.  When this is
 875 // called the segment addresses has normally not yet been set.
 876
 877 bool
 878 Layout::segment_precedes(const Output_segment* seg1,
 879                          const Output_segment* seg2)
 880 {
 881   elfcpp::Elf_Word type1 = seg1->type();
 882   elfcpp::Elf_Word type2 = seg2->type();
 883
 884   // The single PT_PHDR segment is required to precede any loadable
 885   // segment.  We simply make it always first.
 886   if (type1 == elfcpp::PT_PHDR)
 887     {
 888       gold_assert(type2 != elfcpp::PT_PHDR);
 889       return true;
 890     }
 891   if (type2 == elfcpp::PT_PHDR)
 892     return false;
 893
 894   // The single PT_INTERP segment is required to precede any loadable
 895   // segment.  We simply make it always second.
 896   if (type1 == elfcpp::PT_INTERP)
 897     {
 898       gold_assert(type2 != elfcpp::PT_INTERP);
 899       return true;
 900     }
 901   if (type2 == elfcpp::PT_INTERP)
 902     return false;
 903
 904   // We then put PT_LOAD segments before any other segments.
 905   if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
 906     return true;
 907   if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
 908     return false;
 909
 910   // We put the PT_TLS segment last, because that is where the dynamic
 911   // linker expects to find it (this is just for efficiency; other
 912   // positions would also work correctly).
 913   if (type1 == elfcpp::PT_TLS && type2 != elfcpp::PT_TLS)
 914     return false;
 915   if (type2 == elfcpp::PT_TLS && type1 != elfcpp::PT_TLS)
 916     return true;
 917
 918   const elfcpp::Elf_Word flags1 = seg1->flags();
 919   const elfcpp::Elf_Word flags2 = seg2->flags();
 920
 921   // The order of non-PT_LOAD segments is unimportant.  We simply sort
 922   // by the numeric segment type and flags values.  There should not
 923   // be more than one segment with the same type and flags.
 924   if (type1 != elfcpp::PT_LOAD)
 925     {
 926       if (type1 != type2)
 927         return type1 < type2;
 928       gold_assert(flags1 != flags2);
 929       return flags1 < flags2;
 930     }
 931
 932   // We sort PT_LOAD segments based on the flags.  Readonly segments
 933   // come before writable segments.  Then executable segments come
 934   // before non-executable segments.  Then the unlikely case of a
 935   // non-readable segment comes before the normal case of a readable
 936   // segment.  If there are multiple segments with the same type and
 937   // flags, we require that the address be set, and we sort by
 938   // virtual address and then physical address.
 939   if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
 940     return (flags1 & elfcpp::PF_W) == 0;
 941   if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
 942     return (flags1 & elfcpp::PF_X) != 0;
 943   if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
 944     return (flags1 & elfcpp::PF_R) == 0;
 945
 946   uint64_t vaddr1 = seg1->vaddr();
 947   uint64_t vaddr2 = seg2->vaddr();
 948   if (vaddr1 != vaddr2)
 949     return vaddr1 < vaddr2;
 950
 951   uint64_t paddr1 = seg1->paddr();
 952   uint64_t paddr2 = seg2->paddr();
 953   gold_assert(paddr1 != paddr2);
 954   return paddr1 < paddr2;
 955 }
 956
 957 // Set the file offsets of all the segments, and all the sections they
 958 // contain.  They have all been created.  LOAD_SEG must be be laid out
 959 // first.  Return the offset of the data to follow.
 960
 961 off_t
 962 Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
 963                             unsigned int *pshndx)
 964 {
 965   // Sort them into the final order.
 966   std::sort(this->segment_list_.begin(), this->segment_list_.end(),
 967             Layout::Compare_segments());
 968
 969   // Find the PT_LOAD segments, and set their addresses and offsets
 970   // and their section's addresses and offsets.
 971   uint64_t addr;
 972   if (options_.user_set_text_segment_address())
 973     addr = options_.text_segment_address();
 974   else
 975     addr = target->default_text_segment_address();
 976   off_t off = 0;
 977   bool was_readonly = false;
 978   for (Segment_list::iterator p = this->segment_list_.begin();
 979        p != this->segment_list_.end();
 980        ++p)
 981     {
 982       if ((*p)->type() == elfcpp::PT_LOAD)
 983         {
 984           if (load_seg != NULL && load_seg != *p)
 985             gold_unreachable();
 986           load_seg = NULL;
 987
 988           // If the last segment was readonly, and this one is not,
 989           // then skip the address forward one page, maintaining the
 990           // same position within the page.  This lets us store both
 991           // segments overlapping on a single page in the file, but
 992           // the loader will put them on different pages in memory.
 993
 994           uint64_t orig_addr = addr;
 995           uint64_t orig_off = off;
 996
 997           uint64_t aligned_addr = addr;
 998           uint64_t abi_pagesize = target->abi_pagesize();
 999
1000           // FIXME: This should depend on the -n and -N options.
1001           (*p)->set_minimum_addralign(target->common_pagesize());
1002
1003           if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0)
1004             {
1005               uint64_t align = (*p)->addralign();
1006
1007               addr = align_address(addr, align);
1008               aligned_addr = addr;
1009               if ((addr & (abi_pagesize - 1)) != 0)
1010                 addr = addr + abi_pagesize;
1011             }
1012
1013           unsigned int shndx_hold = *pshndx;
1014           off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
1015           uint64_t new_addr = (*p)->set_section_addresses(addr, &off, pshndx);
1016
1017           // Now that we know the size of this segment, we may be able
1018           // to save a page in memory, at the cost of wasting some
1019           // file space, by instead aligning to the start of a new
1020           // page.  Here we use the real machine page size rather than
1021           // the ABI mandated page size.
1022
1023           if (aligned_addr != addr)
1024             {
1025               uint64_t common_pagesize = target->common_pagesize();
1026               uint64_t first_off = (common_pagesize
1027                                     - (aligned_addr
1028                                        & (common_pagesize - 1)));
1029               uint64_t last_off = new_addr & (common_pagesize - 1);
1030               if (first_off > 0
1031                   && last_off > 0
1032                   && ((aligned_addr & ~ (common_pagesize - 1))
1033                       != (new_addr & ~ (common_pagesize - 1)))
1034                   && first_off + last_off <= common_pagesize)
1035                 {
1036                   *pshndx = shndx_hold;
1037                   addr = align_address(aligned_addr, common_pagesize);
1038                   off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
1039                   new_addr = (*p)->set_section_addresses(addr, &off, pshndx);
1040                 }
1041             }
1042
1043           addr = new_addr;
1044
1045           if (((*p)->flags() & elfcpp::PF_W) == 0)
1046             was_readonly = true;
1047         }
1048     }
1049
1050   // Handle the non-PT_LOAD segments, setting their offsets from their
1051   // section's offsets.
1052   for (Segment_list::iterator p = this->segment_list_.begin();
1053        p != this->segment_list_.end();
1054        ++p)
1055     {
1056       if ((*p)->type() != elfcpp::PT_LOAD)
1057         (*p)->set_offset();
1058     }
1059
1060   return off;
1061 }
1062
1063 // Set the file offset of all the sections not associated with a
1064 // segment.
1065
1066 off_t
1067 Layout::set_section_offsets(off_t off,
1068                             bool do_bits_sections)
1069 {
1070   for (Section_list::iterator p = this->unattached_section_list_.begin();
1071        p != this->unattached_section_list_.end();
1072        ++p)
1073     {
1074       bool is_bits_section = ((*p)->type() == elfcpp::SHT_PROGBITS
1075                               || (*p)->type() == elfcpp::SHT_NOBITS);
1076       if (is_bits_section != do_bits_sections)
1077         continue;
1078       if ((*p)->offset() != -1)
1079         continue;
1080       off = align_address(off, (*p)->addralign());
1081       (*p)->set_address(0, off);
1082       off += (*p)->data_size();
1083     }
1084   return off;
1085 }
1086
1087 // Set the section indexes of all the sections not associated with a
1088 // segment.
1089
1090 unsigned int
1091 Layout::set_section_indexes(unsigned int shndx)
1092 {
1093   for (Section_list::iterator p = this->unattached_section_list_.begin();
1094        p != this->unattached_section_list_.end();
1095        ++p)
1096     {
1097       (*p)->set_out_shndx(shndx);
1098       ++shndx;
1099     }
1100   return shndx;
1101 }
1102
1103 // Create the symbol table sections.  Here we also set the final
1104 // values of the symbols.  At this point all the loadable sections are
1105 // fully laid out.
1106
1107 void
1108 Layout::create_symtab_sections(const Input_objects* input_objects,
1109                                Symbol_table* symtab,
1110                                off_t* poff)
1111 {
1112   int symsize;
1113   unsigned int align;
1114   if (parameters->get_size() == 32)
1115     {
1116       symsize = elfcpp::Elf_sizes<32>::sym_size;
1117       align = 4;
1118     }
1119   else if (parameters->get_size() == 64)
1120     {
1121       symsize = elfcpp::Elf_sizes<64>::sym_size;
1122       align = 8;
1123     }
1124   else
1125     gold_unreachable();
1126
1127   off_t off = *poff;
1128   off = align_address(off, align);
1129   off_t startoff = off;
1130
1131   // Save space for the dummy symbol at the start of the section.  We
1132   // never bother to write this out--it will just be left as zero.
1133   off += symsize;
1134   unsigned int local_symbol_index = 1;
1135
1136   // Add STT_SECTION symbols for each Output section which needs one.
1137   for (Section_list::iterator p = this->section_list_.begin();
1138        p != this->section_list_.end();
1139        ++p)
1140     {
1141       if (!(*p)->needs_symtab_index())
1142         (*p)->set_symtab_index(-1U);
1143       else
1144         {
1145           (*p)->set_symtab_index(local_symbol_index);
1146           ++local_symbol_index;
1147           off += symsize;
1148         }
1149     }
1150
1151   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
1152        p != input_objects->relobj_end();
1153        ++p)
1154     {
1155       Task_lock_obj<Object> tlo(**p);
1156       unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
1157                                                         off,
1158                                                         &this->sympool_);
1159       off += (index - local_symbol_index) * symsize;
1160       local_symbol_index = index;
1161     }
1162
1163   unsigned int local_symcount = local_symbol_index;
1164   gold_assert(local_symcount * symsize == off - startoff);
1165
1166   off_t dynoff;
1167   size_t dyn_global_index;
1168   size_t dyncount;
1169   if (this->dynsym_section_ == NULL)
1170     {
1171       dynoff = 0;
1172       dyn_global_index = 0;
1173       dyncount = 0;
1174     }
1175   else
1176     {
1177       dyn_global_index = this->dynsym_section_->info();
1178       off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
1179       dynoff = this->dynsym_section_->offset() + locsize;
1180       dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
1181       gold_assert(static_cast<off_t>(dyncount * symsize)
1182                   == this->dynsym_section_->data_size() - locsize);
1183     }
1184
1185   off = symtab->finalize(local_symcount, off, dynoff, dyn_global_index,
1186                          dyncount, &this->sympool_);
1187
1188   if (!parameters->strip_all())
1189     {
1190       this->sympool_.set_string_offsets();
1191
1192       const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
1193       Output_section* osymtab = this->make_output_section(symtab_name,
1194                                                           elfcpp::SHT_SYMTAB,
1195                                                           0);
1196       this->symtab_section_ = osymtab;
1197
1198       Output_section_data* pos = new Output_data_space(off - startoff,
1199                                                        align);
1200       osymtab->add_output_section_data(pos);
1201
1202       const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
1203       Output_section* ostrtab = this->make_output_section(strtab_name,
1204                                                           elfcpp::SHT_STRTAB,
1205                                                           0);
1206
1207       Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
1208       ostrtab->add_output_section_data(pstr);
1209
1210       osymtab->set_address(0, startoff);
1211       osymtab->set_link_section(ostrtab);
1212       osymtab->set_info(local_symcount);
1213       osymtab->set_entsize(symsize);
1214
1215       *poff = off;
1216     }
1217 }
1218
1219 // Create the .shstrtab section, which holds the names of the
1220 // sections.  At the time this is called, we have created all the
1221 // output sections except .shstrtab itself.
1222
1223 Output_section*
1224 Layout::create_shstrtab()
1225 {
1226   // FIXME: We don't need to create a .shstrtab section if we are
1227   // stripping everything.
1228
1229   const char* name = this->namepool_.add(".shstrtab", false, NULL);
1230
1231   this->namepool_.set_string_offsets();
1232
1233   Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0);
1234
1235   Output_section_data* posd = new Output_data_strtab(&this->namepool_);
1236   os->add_output_section_data(posd);
1237
1238   return os;
1239 }
1240
1241 // Create the section headers.  SIZE is 32 or 64.  OFF is the file
1242 // offset.
1243
1244 Output_section_headers*
1245 Layout::create_shdrs(off_t* poff)
1246 {
1247   Output_section_headers* oshdrs;
1248   oshdrs = new Output_section_headers(this,
1249                                       &this->segment_list_,
1250                                       &this->unattached_section_list_,
1251                                       &this->namepool_);
1252   off_t off = align_address(*poff, oshdrs->addralign());
1253   oshdrs->set_address(0, off);
1254   off += oshdrs->data_size();
1255   *poff = off;
1256   this->special_output_list_.push_back(oshdrs);
1257   return oshdrs;
1258 }
1259
1260 // Create the dynamic symbol table.
1261
1262 void
1263 Layout::create_dynamic_symtab(const Target* target, Symbol_table* symtab,
1264                               Output_section **pdynstr,
1265                               unsigned int* plocal_dynamic_count,
1266                               std::vector<Symbol*>* pdynamic_symbols,
1267                               Versions* pversions)
1268 {
1269   // Count all the symbols in the dynamic symbol table, and set the
1270   // dynamic symbol indexes.
1271
1272   // Skip symbol 0, which is always all zeroes.
1273   unsigned int index = 1;
1274
1275   // Add STT_SECTION symbols for each Output section which needs one.
1276   for (Section_list::iterator p = this->section_list_.begin();
1277        p != this->section_list_.end();
1278        ++p)
1279     {
1280       if (!(*p)->needs_dynsym_index())
1281         (*p)->set_dynsym_index(-1U);
1282       else
1283         {
1284           (*p)->set_dynsym_index(index);
1285           ++index;
1286         }
1287     }
1288
1289   // FIXME: Some targets apparently require local symbols in the
1290   // dynamic symbol table.  Here is where we will have to count them,
1291   // and set the dynamic symbol indexes, and add the names to
1292   // this->dynpool_.
1293
1294   unsigned int local_symcount = index;
1295   *plocal_dynamic_count = local_symcount;
1296
1297   // FIXME: We have to tell set_dynsym_indexes whether the
1298   // -E/--export-dynamic option was used.
1299   index = symtab->set_dynsym_indexes(target, index, pdynamic_symbols,
1300                                      &this->dynpool_, pversions);
1301
1302   int symsize;
1303   unsigned int align;
1304   const int size = parameters->get_size();
1305   if (size == 32)
1306     {
1307       symsize = elfcpp::Elf_sizes<32>::sym_size;
1308       align = 4;
1309     }
1310   else if (size == 64)
1311     {
1312       symsize = elfcpp::Elf_sizes<64>::sym_size;
1313       align = 8;
1314     }
1315   else
1316     gold_unreachable();
1317
1318   // Create the dynamic symbol table section.
1319
1320   const char* dynsym_name = this->namepool_.add(".dynsym", false, NULL);
1321   Output_section* dynsym = this->make_output_section(dynsym_name,
1322                                                      elfcpp::SHT_DYNSYM,
1323                                                      elfcpp::SHF_ALLOC);
1324
1325   Output_section_data* odata = new Output_data_space(index * symsize,
1326                                                      align);
1327   dynsym->add_output_section_data(odata);
1328
1329   dynsym->set_info(local_symcount);
1330   dynsym->set_entsize(symsize);
1331   dynsym->set_addralign(align);
1332
1333   this->dynsym_section_ = dynsym;
1334
1335   Output_data_dynamic* const odyn = this->dynamic_data_;
1336   odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
1337   odyn->add_constant(elfcpp::DT_SYMENT, symsize);
1338
1339   // Create the dynamic string table section.
1340
1341   const char* dynstr_name = this->namepool_.add(".dynstr", false, NULL);
1342   Output_section* dynstr = this->make_output_section(dynstr_name,
1343                                                      elfcpp::SHT_STRTAB,
1344                                                      elfcpp::SHF_ALLOC);
1345
1346   Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
1347   dynstr->add_output_section_data(strdata);
1348
1349   dynsym->set_link_section(dynstr);
1350   this->dynamic_section_->set_link_section(dynstr);
1351
1352   odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
1353   odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
1354
1355   *pdynstr = dynstr;
1356
1357   // Create the hash tables.
1358
1359   // FIXME: We need an option to create a GNU hash table.
1360
1361   unsigned char* phash;
1362   unsigned int hashlen;
1363   Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
1364                                 &phash, &hashlen);
1365
1366   const char* hash_name = this->namepool_.add(".hash", false, NULL);
1367   Output_section* hashsec = this->make_output_section(hash_name,
1368                                                       elfcpp::SHT_HASH,
1369                                                       elfcpp::SHF_ALLOC);
1370
1371   Output_section_data* hashdata = new Output_data_const_buffer(phash,
1372                                                                hashlen,
1373                                                                align);
1374   hashsec->add_output_section_data(hashdata);
1375
1376   hashsec->set_link_section(dynsym);
1377   hashsec->set_entsize(4);
1378
1379   odyn->add_section_address(elfcpp::DT_HASH, hashsec);
1380 }
1381
1382 // Create the version sections.
1383
1384 void
1385 Layout::create_version_sections(const Versions* versions,
1386                                 const Symbol_table* symtab,
1387                                 unsigned int local_symcount,
1388                                 const std::vector<Symbol*>& dynamic_symbols,
1389                                 const Output_section* dynstr)
1390 {
1391   if (!versions->any_defs() && !versions->any_needs())
1392     return;
1393
1394   if (parameters->get_size() == 32)
1395     {
1396       if (parameters->is_big_endian())
1397         {
1398 #ifdef HAVE_TARGET_32_BIG
1399           this->sized_create_version_sections
1400               SELECT_SIZE_ENDIAN_NAME(32, true)(
1401                   versions, symtab, local_symcount, dynamic_symbols, dynstr
1402                   SELECT_SIZE_ENDIAN(32, true));
1403 #else
1404           gold_unreachable();
1405 #endif
1406         }
1407       else
1408         {
1409 #ifdef HAVE_TARGET_32_LITTLE
1410           this->sized_create_version_sections
1411               SELECT_SIZE_ENDIAN_NAME(32, false)(
1412                   versions, symtab, local_symcount, dynamic_symbols, dynstr
1413                   SELECT_SIZE_ENDIAN(32, false));
1414 #else
1415           gold_unreachable();
1416 #endif
1417         }
1418     }
1419   else if (parameters->get_size() == 64)
1420     {
1421       if (parameters->is_big_endian())
1422         {
1423 #ifdef HAVE_TARGET_64_BIG
1424           this->sized_create_version_sections
1425               SELECT_SIZE_ENDIAN_NAME(64, true)(
1426                   versions, symtab, local_symcount, dynamic_symbols, dynstr
1427                   SELECT_SIZE_ENDIAN(64, true));
1428 #else
1429           gold_unreachable();
1430 #endif
1431         }
1432       else
1433         {
1434 #ifdef HAVE_TARGET_64_LITTLE
1435           this->sized_create_version_sections
1436               SELECT_SIZE_ENDIAN_NAME(64, false)(
1437                   versions, symtab, local_symcount, dynamic_symbols, dynstr
1438                   SELECT_SIZE_ENDIAN(64, false));
1439 #else
1440           gold_unreachable();
1441 #endif
1442         }
1443     }
1444   else
1445     gold_unreachable();
1446 }
1447
1448 // Create the version sections, sized version.
1449
1450 template<int size, bool big_endian>
1451 void
1452 Layout::sized_create_version_sections(
1453     const Versions* versions,
1454     const Symbol_table* symtab,
1455     unsigned int local_symcount,
1456     const std::vector<Symbol*>& dynamic_symbols,
1457     const Output_section* dynstr
1458     ACCEPT_SIZE_ENDIAN)
1459 {
1460   const char* vname = this->namepool_.add(".gnu.version", false, NULL);
1461   Output_section* vsec = this->make_output_section(vname,
1462                                                    elfcpp::SHT_GNU_versym,
1463                                                    elfcpp::SHF_ALLOC);
1464
1465   unsigned char* vbuf;
1466   unsigned int vsize;
1467   versions->symbol_section_contents SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
1468       symtab, &this->dynpool_, local_symcount, dynamic_symbols, &vbuf, &vsize
1469       SELECT_SIZE_ENDIAN(size, big_endian));
1470
1471   Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2);
1472
1473   vsec->add_output_section_data(vdata);
1474   vsec->set_entsize(2);
1475   vsec->set_link_section(this->dynsym_section_);
1476
1477   Output_data_dynamic* const odyn = this->dynamic_data_;
1478   odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
1479
1480   if (versions->any_defs())
1481     {
1482       const char* vdname = this->namepool_.add(".gnu.version_d", false, NULL);
1483       Output_section *vdsec;
1484       vdsec = this->make_output_section(vdname, elfcpp::SHT_GNU_verdef,
1485                                         elfcpp::SHF_ALLOC);
1486
1487       unsigned char* vdbuf;
1488       unsigned int vdsize;
1489       unsigned int vdentries;
1490       versions->def_section_contents SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
1491           &this->dynpool_, &vdbuf, &vdsize, &vdentries
1492           SELECT_SIZE_ENDIAN(size, big_endian));
1493
1494       Output_section_data* vddata = new Output_data_const_buffer(vdbuf,
1495                                                                  vdsize,
1496                                                                  4);
1497
1498       vdsec->add_output_section_data(vddata);
1499       vdsec->set_link_section(dynstr);
1500       vdsec->set_info(vdentries);
1501
1502       odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
1503       odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
1504     }
1505
1506   if (versions->any_needs())
1507     {
1508       const char* vnname = this->namepool_.add(".gnu.version_r", false, NULL);
1509       Output_section* vnsec;
1510       vnsec = this->make_output_section(vnname, elfcpp::SHT_GNU_verneed,
1511                                         elfcpp::SHF_ALLOC);
1512
1513       unsigned char* vnbuf;
1514       unsigned int vnsize;
1515       unsigned int vnentries;
1516       versions->need_section_contents SELECT_SIZE_ENDIAN_NAME(size, big_endian)
1517         (&this->dynpool_, &vnbuf, &vnsize, &vnentries
1518          SELECT_SIZE_ENDIAN(size, big_endian));
1519
1520       Output_section_data* vndata = new Output_data_const_buffer(vnbuf,
1521                                                                  vnsize,
1522                                                                  4);
1523
1524       vnsec->add_output_section_data(vndata);
1525       vnsec->set_link_section(dynstr);
1526       vnsec->set_info(vnentries);
1527
1528       odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
1529       odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
1530     }
1531 }
1532
1533 // Create the .interp section and PT_INTERP segment.
1534
1535 void
1536 Layout::create_interp(const Target* target)
1537 {
1538   const char* interp = this->options_.dynamic_linker();
1539   if (interp == NULL)
1540     {
1541       interp = target->dynamic_linker();
1542       gold_assert(interp != NULL);
1543     }
1544
1545   size_t len = strlen(interp) + 1;
1546
1547   Output_section_data* odata = new Output_data_const(interp, len, 1);
1548
1549   const char* interp_name = this->namepool_.add(".interp", false, NULL);
1550   Output_section* osec = this->make_output_section(interp_name,
1551                                                    elfcpp::SHT_PROGBITS,
1552                                                    elfcpp::SHF_ALLOC);
1553   osec->add_output_section_data(odata);
1554
1555   Output_segment* oseg = new Output_segment(elfcpp::PT_INTERP, elfcpp::PF_R);
1556   this->segment_list_.push_back(oseg);
1557   oseg->add_initial_output_section(osec, elfcpp::PF_R);
1558 }
1559
1560 // Finish the .dynamic section and PT_DYNAMIC segment.
1561
1562 void
1563 Layout::finish_dynamic_section(const Input_objects* input_objects,
1564                                const Symbol_table* symtab)
1565 {
1566   Output_segment* oseg = new Output_segment(elfcpp::PT_DYNAMIC,
1567                                             elfcpp::PF_R | elfcpp::PF_W);
1568   this->segment_list_.push_back(oseg);
1569   oseg->add_initial_output_section(this->dynamic_section_,
1570                                    elfcpp::PF_R | elfcpp::PF_W);
1571
1572   Output_data_dynamic* const odyn = this->dynamic_data_;
1573
1574   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
1575        p != input_objects->dynobj_end();
1576        ++p)
1577     {
1578       // FIXME: Handle --as-needed.
1579       odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
1580     }
1581
1582   // FIXME: Support --init and --fini.
1583   Symbol* sym = symtab->lookup("_init");
1584   if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
1585     odyn->add_symbol(elfcpp::DT_INIT, sym);
1586
1587   sym = symtab->lookup("_fini");
1588   if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
1589     odyn->add_symbol(elfcpp::DT_FINI, sym);
1590
1591   // FIXME: Support DT_INIT_ARRAY and DT_FINI_ARRAY.
1592
1593   // Add a DT_RPATH entry if needed.
1594   const General_options::Dir_list& rpath(this->options_.rpath());
1595   if (!rpath.empty())
1596     {
1597       std::string rpath_val;
1598       for (General_options::Dir_list::const_iterator p = rpath.begin();
1599            p != rpath.end();
1600            ++p)
1601         {
1602           if (rpath_val.empty())
1603             rpath_val = p->name();
1604           else
1605             {
1606               // Eliminate duplicates.
1607               General_options::Dir_list::const_iterator q;
1608               for (q = rpath.begin(); q != p; ++q)
1609                 if (q->name() == p->name())
1610                   break;
1611               if (q == p)
1612                 {
1613                   rpath_val += ':';
1614                   rpath_val += p->name();
1615                 }
1616             }
1617         }
1618
1619       odyn->add_string(elfcpp::DT_RPATH, rpath_val);
1620     }
1621
1622     // Add a DT_FLAGS entry. We add it even if no flags are set so that
1623     // post-link tools can easily modify these flags if desired.
1624     unsigned int flags = 0;
1625     if (this->have_textrel_)
1626       flags |= elfcpp::DF_TEXTREL;
1627     odyn->add_constant(elfcpp::DT_FLAGS, flags);
1628 }
1629
1630 // The mapping of .gnu.linkonce section names to real section names.
1631
1632 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
1633 const Layout::Linkonce_mapping Layout::linkonce_mapping[] =
1634 {
1635   MAPPING_INIT("d.rel.ro", ".data.rel.ro"),     // Must be before "d".
1636   MAPPING_INIT("t", ".text"),
1637   MAPPING_INIT("r", ".rodata"),
1638   MAPPING_INIT("d", ".data"),
1639   MAPPING_INIT("b", ".bss"),
1640   MAPPING_INIT("s", ".sdata"),
1641   MAPPING_INIT("sb", ".sbss"),
1642   MAPPING_INIT("s2", ".sdata2"),
1643   MAPPING_INIT("sb2", ".sbss2"),
1644   MAPPING_INIT("wi", ".debug_info"),
1645   MAPPING_INIT("td", ".tdata"),
1646   MAPPING_INIT("tb", ".tbss"),
1647   MAPPING_INIT("lr", ".lrodata"),
1648   MAPPING_INIT("l", ".ldata"),
1649   MAPPING_INIT("lb", ".lbss"),
1650 };
1651 #undef MAPPING_INIT
1652
1653 const int Layout::linkonce_mapping_count =
1654   sizeof(Layout::linkonce_mapping) / sizeof(Layout::linkonce_mapping[0]);
1655
1656 // Return the name of the output section to use for a .gnu.linkonce
1657 // section.  This is based on the default ELF linker script of the old
1658 // GNU linker.  For example, we map a name like ".gnu.linkonce.t.foo"
1659 // to ".text".  Set *PLEN to the length of the name.  *PLEN is
1660 // initialized to the length of NAME.
1661
1662 const char*
1663 Layout::linkonce_output_name(const char* name, size_t *plen)
1664 {
1665   const char* s = name + sizeof(".gnu.linkonce") - 1;
1666   if (*s != '.')
1667     return name;
1668   ++s;
1669   const Linkonce_mapping* plm = linkonce_mapping;
1670   for (int i = 0; i < linkonce_mapping_count; ++i, ++plm)
1671     {
1672       if (strncmp(s, plm->from, plm->fromlen) == 0 && s[plm->fromlen] == '.')
1673         {
1674           *plen = plm->tolen;
1675           return plm->to;
1676         }
1677     }
1678   return name;
1679 }
1680
1681 // Choose the output section name to use given an input section name.
1682 // Set *PLEN to the length of the name.  *PLEN is initialized to the
1683 // length of NAME.
1684
1685 const char*
1686 Layout::output_section_name(const char* name, size_t* plen)
1687 {
1688   if (Layout::is_linkonce(name))
1689     {
1690       // .gnu.linkonce sections are laid out as though they were named
1691       // for the sections are placed into.
1692       return Layout::linkonce_output_name(name, plen);
1693     }
1694
1695   // gcc 4.3 generates the following sorts of section names when it
1696   // needs a section name specific to a function:
1697   //   .text.FN
1698   //   .rodata.FN
1699   //   .sdata2.FN
1700   //   .data.FN
1701   //   .data.rel.FN
1702   //   .data.rel.local.FN
1703   //   .data.rel.ro.FN
1704   //   .data.rel.ro.local.FN
1705   //   .sdata.FN
1706   //   .bss.FN
1707   //   .sbss.FN
1708   //   .tdata.FN
1709   //   .tbss.FN
1710
1711   // The GNU linker maps all of those to the part before the .FN,
1712   // except that .data.rel.local.FN is mapped to .data, and
1713   // .data.rel.ro.local.FN is mapped to .data.rel.ro.  The sections
1714   // beginning with .data.rel.ro.local are grouped together.
1715
1716   // For an anonymous namespace, the string FN can contain a '.'.
1717
1718   // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
1719   // GNU linker maps to .rodata.
1720
1721   // The .data.rel.ro sections enable a security feature triggered by
1722   // the -z relro option.  Section which need to be relocated at
1723   // program startup time but which may be readonly after startup are
1724   // grouped into .data.rel.ro.  They are then put into a PT_GNU_RELRO
1725   // segment.  The dynamic linker will make that segment writable,
1726   // perform relocations, and then make it read-only.  FIXME: We do
1727   // not yet implement this optimization.
1728
1729   // It is hard to handle this in a principled way.
1730
1731   // These are the rules we follow:
1732
1733   // If the section name has no initial '.', or no dot other than an
1734   // initial '.', we use the name unchanged (i.e., "mysection" and
1735   // ".text" are unchanged).
1736
1737   // If the name starts with ".data.rel.ro" we use ".data.rel.ro".
1738
1739   // Otherwise, we drop the second '.' and everything that comes after
1740   // it (i.e., ".text.XXX" becomes ".text").
1741
1742   const char* s = name;
1743   if (*s != '.')
1744     return name;
1745   ++s;
1746   const char* sdot = strchr(s, '.');
1747   if (sdot == NULL)
1748     return name;
1749
1750   const char* const data_rel_ro = ".data.rel.ro";
1751   if (strncmp(name, data_rel_ro, strlen(data_rel_ro)) == 0)
1752     {
1753       *plen = strlen(data_rel_ro);
1754       return data_rel_ro;
1755     }
1756
1757   *plen = sdot - name;
1758   return name;
1759 }
1760
1761 // Record the signature of a comdat section, and return whether to
1762 // include it in the link.  If GROUP is true, this is a regular
1763 // section group.  If GROUP is false, this is a group signature
1764 // derived from the name of a linkonce section.  We want linkonce
1765 // signatures and group signatures to block each other, but we don't
1766 // want a linkonce signature to block another linkonce signature.
1767
1768 bool
1769 Layout::add_comdat(const char* signature, bool group)
1770 {
1771   std::string sig(signature);
1772   std::pair<Signatures::iterator, bool> ins(
1773     this->signatures_.insert(std::make_pair(sig, group)));
1774
1775   if (ins.second)
1776     {
1777       // This is the first time we've seen this signature.
1778       return true;
1779     }
1780
1781   if (ins.first->second)
1782     {
1783       // We've already seen a real section group with this signature.
1784       return false;
1785     }
1786   else if (group)
1787     {
1788       // This is a real section group, and we've already seen a
1789       // linkonce section with this signature.  Record that we've seen
1790       // a section group, and don't include this section group.
1791       ins.first->second = true;
1792       return false;
1793     }
1794   else
1795     {
1796       // We've already seen a linkonce section and this is a linkonce
1797       // section.  These don't block each other--this may be the same
1798       // symbol name with different section types.
1799       return true;
1800     }
1801 }
1802
1803 // Write out the Output_sections.  Most won't have anything to write,
1804 // since most of the data will come from input sections which are
1805 // handled elsewhere.  But some Output_sections do have Output_data.
1806
1807 void
1808 Layout::write_output_sections(Output_file* of) const
1809 {
1810   for (Section_list::const_iterator p = this->section_list_.begin();
1811        p != this->section_list_.end();
1812        ++p)
1813     {
1814       if (!(*p)->after_input_sections())
1815         (*p)->write(of);
1816     }
1817 }
1818
1819 // Write out data not associated with a section or the symbol table.
1820
1821 void
1822 Layout::write_data(const Symbol_table* symtab, Output_file* of) const
1823 {
1824   if (!parameters->strip_all())
1825     {
1826       const Output_section* symtab_section = this->symtab_section_;
1827       for (Section_list::const_iterator p = this->section_list_.begin();
1828            p != this->section_list_.end();
1829            ++p)
1830         {
1831           if ((*p)->needs_symtab_index())
1832             {
1833               gold_assert(symtab_section != NULL);
1834               unsigned int index = (*p)->symtab_index();
1835               gold_assert(index > 0 && index != -1U);
1836               off_t off = (symtab_section->offset()
1837                            + index * symtab_section->entsize());
1838               symtab->write_section_symbol(*p, of, off);
1839             }
1840         }
1841     }
1842
1843   const Output_section* dynsym_section = this->dynsym_section_;
1844   for (Section_list::const_iterator p = this->section_list_.begin();
1845        p != this->section_list_.end();
1846        ++p)
1847     {
1848       if ((*p)->needs_dynsym_index())
1849         {
1850           gold_assert(dynsym_section != NULL);
1851           unsigned int index = (*p)->dynsym_index();
1852           gold_assert(index > 0 && index != -1U);
1853           off_t off = (dynsym_section->offset()
1854                        + index * dynsym_section->entsize());
1855           symtab->write_section_symbol(*p, of, off);
1856         }
1857     }
1858
1859   // Write out the Output_data which are not in an Output_section.
1860   for (Data_list::const_iterator p = this->special_output_list_.begin();
1861        p != this->special_output_list_.end();
1862        ++p)
1863     (*p)->write(of);
1864 }
1865
1866 // Write out the Output_sections which can only be written after the
1867 // input sections are complete.
1868
1869 void
1870 Layout::write_sections_after_input_sections(Output_file* of) const
1871 {
1872   for (Section_list::const_iterator p = this->section_list_.begin();
1873        p != this->section_list_.end();
1874        ++p)
1875     {
1876       if ((*p)->after_input_sections())
1877         (*p)->write(of);
1878     }
1879 }
1880
1881 // Write_sections_task methods.
1882
1883 // We can always run this task.
1884
1885 Task::Is_runnable_type
1886 Write_sections_task::is_runnable(Workqueue*)
1887 {
1888   return IS_RUNNABLE;
1889 }
1890
1891 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
1892 // when finished.
1893
1894 class Write_sections_task::Write_sections_locker : public Task_locker
1895 {
1896  public:
1897   Write_sections_locker(Task_token& output_sections_blocker,
1898                         Task_token& final_blocker,
1899                         Workqueue* workqueue)
1900     : output_sections_block_(output_sections_blocker, workqueue),
1901       final_block_(final_blocker, workqueue)
1902   { }
1903
1904  private:
1905   Task_block_token output_sections_block_;
1906   Task_block_token final_block_;
1907 };
1908
1909 Task_locker*
1910 Write_sections_task::locks(Workqueue* workqueue)
1911 {
1912   return new Write_sections_locker(*this->output_sections_blocker_,
1913                                    *this->final_blocker_,
1914                                    workqueue);
1915 }
1916
1917 // Run the task--write out the data.
1918
1919 void
1920 Write_sections_task::run(Workqueue*)
1921 {
1922   this->layout_->write_output_sections(this->of_);
1923 }
1924
1925 // Write_data_task methods.
1926
1927 // We can always run this task.
1928
1929 Task::Is_runnable_type
1930 Write_data_task::is_runnable(Workqueue*)
1931 {
1932   return IS_RUNNABLE;
1933 }
1934
1935 // We need to unlock FINAL_BLOCKER when finished.
1936
1937 Task_locker*
1938 Write_data_task::locks(Workqueue* workqueue)
1939 {
1940   return new Task_locker_block(*this->final_blocker_, workqueue);
1941 }
1942
1943 // Run the task--write out the data.
1944
1945 void
1946 Write_data_task::run(Workqueue*)
1947 {
1948   this->layout_->write_data(this->symtab_, this->of_);
1949 }
1950
1951 // Write_symbols_task methods.
1952
1953 // We can always run this task.
1954
1955 Task::Is_runnable_type
1956 Write_symbols_task::is_runnable(Workqueue*)
1957 {
1958   return IS_RUNNABLE;
1959 }
1960
1961 // We need to unlock FINAL_BLOCKER when finished.
1962
1963 Task_locker*
1964 Write_symbols_task::locks(Workqueue* workqueue)
1965 {
1966   return new Task_locker_block(*this->final_blocker_, workqueue);
1967 }
1968
1969 // Run the task--write out the symbols.
1970
1971 void
1972 Write_symbols_task::run(Workqueue*)
1973 {
1974   this->symtab_->write_globals(this->input_objects_, this->sympool_,
1975                                this->dynpool_, this->of_);
1976 }
1977
1978 // Write_after_input_sections_task methods.
1979
1980 // We can only run this task after the input sections have completed.
1981
1982 Task::Is_runnable_type
1983 Write_after_input_sections_task::is_runnable(Workqueue*)
1984 {
1985   if (this->input_sections_blocker_->is_blocked())
1986     return IS_BLOCKED;
1987   return IS_RUNNABLE;
1988 }
1989
1990 // We need to unlock FINAL_BLOCKER when finished.
1991
1992 Task_locker*
1993 Write_after_input_sections_task::locks(Workqueue* workqueue)
1994 {
1995   return new Task_locker_block(*this->final_blocker_, workqueue);
1996 }
1997
1998 // Run the task.
1999
2000 void
2001 Write_after_input_sections_task::run(Workqueue*)
2002 {
2003   this->layout_->write_sections_after_input_sections(this->of_);
2004 }
2005
2006 // Close_task_runner methods.
2007
2008 // Run the task--close the file.
2009
2010 void
2011 Close_task_runner::run(Workqueue*)
2012 {
2013   this->of_->close();
2014 }
2015
2016 // Instantiate the templates we need.  We could use the configure
2017 // script to restrict this to only the ones for implemented targets.
2018
2019 #ifdef HAVE_TARGET_32_LITTLE
2020 template
2021 Output_section*
2022 Layout::layout<32, false>(Sized_relobj<32, false>* object, unsigned int shndx,
2023                           const char* name,
2024                           const elfcpp::Shdr<32, false>& shdr,
2025                           unsigned int, unsigned int, off_t*);
2026 #endif
2027
2028 #ifdef HAVE_TARGET_32_BIG
2029 template
2030 Output_section*
2031 Layout::layout<32, true>(Sized_relobj<32, true>* object, unsigned int shndx,
2032                          const char* name,
2033                          const elfcpp::Shdr<32, true>& shdr,
2034                          unsigned int, unsigned int, off_t*);
2035 #endif
2036
2037 #ifdef HAVE_TARGET_64_LITTLE
2038 template
2039 Output_section*
2040 Layout::layout<64, false>(Sized_relobj<64, false>* object, unsigned int shndx,
2041                           const char* name,
2042                           const elfcpp::Shdr<64, false>& shdr,
2043                           unsigned int, unsigned int, off_t*);
2044 #endif
2045
2046 #ifdef HAVE_TARGET_64_BIG
2047 template
2048 Output_section*
2049 Layout::layout<64, true>(Sized_relobj<64, true>* object, unsigned int shndx,
2050                          const char* name,
2051                          const elfcpp::Shdr<64, true>& shdr,
2052                          unsigned int, unsigned int, off_t*);
2053 #endif
2054
2055 #ifdef HAVE_TARGET_32_LITTLE
2056 template
2057 Output_section*
2058 Layout::layout_eh_frame<32, false>(Sized_relobj<32, false>* object,
2059                                    const unsigned char* symbols,
2060                                    off_t symbols_size,
2061                                    const unsigned char* symbol_names,
2062                                    off_t symbol_names_size,
2063                                    unsigned int shndx,
2064                                    const elfcpp::Shdr<32, false>& shdr,
2065                                    unsigned int reloc_shndx,
2066                                    unsigned int reloc_type,
2067                                    off_t* off);
2068 #endif
2069
2070 #ifdef HAVE_TARGET_32_BIG
2071 template
2072 Output_section*
2073 Layout::layout_eh_frame<32, true>(Sized_relobj<32, true>* object,
2074                                    const unsigned char* symbols,
2075                                    off_t symbols_size,
2076                                   const unsigned char* symbol_names,
2077                                   off_t symbol_names_size,
2078                                   unsigned int shndx,
2079                                   const elfcpp::Shdr<32, true>& shdr,
2080                                   unsigned int reloc_shndx,
2081                                   unsigned int reloc_type,
2082                                   off_t* off);
2083 #endif
2084
2085 #ifdef HAVE_TARGET_64_LITTLE
2086 template
2087 Output_section*
2088 Layout::layout_eh_frame<64, false>(Sized_relobj<64, false>* object,
2089                                    const unsigned char* symbols,
2090                                    off_t symbols_size,
2091                                    const unsigned char* symbol_names,
2092                                    off_t symbol_names_size,
2093                                    unsigned int shndx,
2094                                    const elfcpp::Shdr<64, false>& shdr,
2095                                    unsigned int reloc_shndx,
2096                                    unsigned int reloc_type,
2097                                    off_t* off);
2098 #endif
2099
2100 #ifdef HAVE_TARGET_64_BIG
2101 template
2102 Output_section*
2103 Layout::layout_eh_frame<64, true>(Sized_relobj<64, true>* object,
2104                                    const unsigned char* symbols,
2105                                    off_t symbols_size,
2106                                   const unsigned char* symbol_names,
2107                                   off_t symbol_names_size,
2108                                   unsigned int shndx,
2109                                   const elfcpp::Shdr<64, true>& shdr,
2110                                   unsigned int reloc_shndx,
2111                                   unsigned int reloc_type,
2112                                   off_t* off);
2113 #endif
2114
2115 } // End namespace gold.