gold/output.cc

   1 // output.cc -- manage the output file for gold
   2
   3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstdlib>
  26 #include <cstring>
  27 #include <cerrno>
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30 #include <sys/mman.h>
  31 #include <sys/stat.h>
  32 #include <algorithm>
  33 #include "libiberty.h"
  34
  35 #include "parameters.h"
  36 #include "object.h"
  37 #include "symtab.h"
  38 #include "reloc.h"
  39 #include "merge.h"
  40 #include "descriptors.h"
  41 #include "output.h"
  42
  43 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
  44 #ifndef MAP_ANONYMOUS
  45 # define MAP_ANONYMOUS  MAP_ANON
  46 #endif
  47
  48 #ifndef HAVE_POSIX_FALLOCATE
  49 // A dummy, non general, version of posix_fallocate.  Here we just set
  50 // the file size and hope that there is enough disk space.  FIXME: We
  51 // could allocate disk space by walking block by block and writing a
  52 // zero byte into each block.
  53 static int
  54 posix_fallocate(int o, off_t offset, off_t len)
  55 {
  56   return ftruncate(o, offset + len);
  57 }
  58 #endif // !defined(HAVE_POSIX_FALLOCATE)
  59
  60 namespace gold
  61 {
  62
  63 // Output_data variables.
  64
  65 bool Output_data::allocated_sizes_are_fixed;
  66
  67 // Output_data methods.
  68
  69 Output_data::~Output_data()
  70 {
  71 }
  72
  73 // Return the default alignment for the target size.
  74
  75 uint64_t
  76 Output_data::default_alignment()
  77 {
  78   return Output_data::default_alignment_for_size(
  79       parameters->target().get_size());
  80 }
  81
  82 // Return the default alignment for a size--32 or 64.
  83
  84 uint64_t
  85 Output_data::default_alignment_for_size(int size)
  86 {
  87   if (size == 32)
  88     return 4;
  89   else if (size == 64)
  90     return 8;
  91   else
  92     gold_unreachable();
  93 }
  94
  95 // Output_section_header methods.  This currently assumes that the
  96 // segment and section lists are complete at construction time.
  97
  98 Output_section_headers::Output_section_headers(
  99     const Layout* layout,
 100     const Layout::Segment_list* segment_list,
 101     const Layout::Section_list* section_list,
 102     const Layout::Section_list* unattached_section_list,
 103     const Stringpool* secnamepool,
 104     const Output_section* shstrtab_section)
 105   : layout_(layout),
 106     segment_list_(segment_list),
 107     section_list_(section_list),
 108     unattached_section_list_(unattached_section_list),
 109     secnamepool_(secnamepool),
 110     shstrtab_section_(shstrtab_section)
 111 {
 112 }
 113
 114 // Compute the current data size.
 115
 116 off_t
 117 Output_section_headers::do_size() const
 118 {
 119   // Count all the sections.  Start with 1 for the null section.
 120   off_t count = 1;
 121   if (!parameters->options().relocatable())
 122     {
 123       for (Layout::Segment_list::const_iterator p =
 124              this->segment_list_->begin();
 125            p != this->segment_list_->end();
 126            ++p)
 127         if ((*p)->type() == elfcpp::PT_LOAD)
 128           count += (*p)->output_section_count();
 129     }
 130   else
 131     {
 132       for (Layout::Section_list::const_iterator p =
 133              this->section_list_->begin();
 134            p != this->section_list_->end();
 135            ++p)
 136         if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
 137           ++count;
 138     }
 139   count += this->unattached_section_list_->size();
 140
 141   const int size = parameters->target().get_size();
 142   int shdr_size;
 143   if (size == 32)
 144     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
 145   else if (size == 64)
 146     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
 147   else
 148     gold_unreachable();
 149
 150   return count * shdr_size;
 151 }
 152
 153 // Write out the section headers.
 154
 155 void
 156 Output_section_headers::do_write(Output_file* of)
 157 {
 158   switch (parameters->size_and_endianness())
 159     {
 160 #ifdef HAVE_TARGET_32_LITTLE
 161     case Parameters::TARGET_32_LITTLE:
 162       this->do_sized_write<32, false>(of);
 163       break;
 164 #endif
 165 #ifdef HAVE_TARGET_32_BIG
 166     case Parameters::TARGET_32_BIG:
 167       this->do_sized_write<32, true>(of);
 168       break;
 169 #endif
 170 #ifdef HAVE_TARGET_64_LITTLE
 171     case Parameters::TARGET_64_LITTLE:
 172       this->do_sized_write<64, false>(of);
 173       break;
 174 #endif
 175 #ifdef HAVE_TARGET_64_BIG
 176     case Parameters::TARGET_64_BIG:
 177       this->do_sized_write<64, true>(of);
 178       break;
 179 #endif
 180     default:
 181       gold_unreachable();
 182     }
 183 }
 184
 185 template<int size, bool big_endian>
 186 void
 187 Output_section_headers::do_sized_write(Output_file* of)
 188 {
 189   off_t all_shdrs_size = this->data_size();
 190   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
 191
 192   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
 193   unsigned char* v = view;
 194
 195   {
 196     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
 197     oshdr.put_sh_name(0);
 198     oshdr.put_sh_type(elfcpp::SHT_NULL);
 199     oshdr.put_sh_flags(0);
 200     oshdr.put_sh_addr(0);
 201     oshdr.put_sh_offset(0);
 202
 203     size_t section_count = (this->data_size()
 204                             / elfcpp::Elf_sizes<size>::shdr_size);
 205     if (section_count < elfcpp::SHN_LORESERVE)
 206       oshdr.put_sh_size(0);
 207     else
 208       oshdr.put_sh_size(section_count);
 209
 210     unsigned int shstrndx = this->shstrtab_section_->out_shndx();
 211     if (shstrndx < elfcpp::SHN_LORESERVE)
 212       oshdr.put_sh_link(0);
 213     else
 214       oshdr.put_sh_link(shstrndx);
 215
 216     size_t segment_count = this->segment_list_->size();
 217     oshdr.put_sh_info(segment_count >= elfcpp::PN_XNUM ? segment_count : 0);
 218
 219     oshdr.put_sh_addralign(0);
 220     oshdr.put_sh_entsize(0);
 221   }
 222
 223   v += shdr_size;
 224
 225   unsigned int shndx = 1;
 226   if (!parameters->options().relocatable())
 227     {
 228       for (Layout::Segment_list::const_iterator p =
 229              this->segment_list_->begin();
 230            p != this->segment_list_->end();
 231            ++p)
 232         v = (*p)->write_section_headers<size, big_endian>(this->layout_,
 233                                                           this->secnamepool_,
 234                                                           v,
 235                                                           &shndx);
 236     }
 237   else
 238     {
 239       for (Layout::Section_list::const_iterator p =
 240              this->section_list_->begin();
 241            p != this->section_list_->end();
 242            ++p)
 243         {
 244           // We do unallocated sections below, except that group
 245           // sections have to come first.
 246           if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
 247               && (*p)->type() != elfcpp::SHT_GROUP)
 248             continue;
 249           gold_assert(shndx == (*p)->out_shndx());
 250           elfcpp::Shdr_write<size, big_endian> oshdr(v);
 251           (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
 252           v += shdr_size;
 253           ++shndx;
 254         }
 255     }
 256
 257   for (Layout::Section_list::const_iterator p =
 258          this->unattached_section_list_->begin();
 259        p != this->unattached_section_list_->end();
 260        ++p)
 261     {
 262       // For a relocatable link, we did unallocated group sections
 263       // above, since they have to come first.
 264       if ((*p)->type() == elfcpp::SHT_GROUP
 265           && parameters->options().relocatable())
 266         continue;
 267       gold_assert(shndx == (*p)->out_shndx());
 268       elfcpp::Shdr_write<size, big_endian> oshdr(v);
 269       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
 270       v += shdr_size;
 271       ++shndx;
 272     }
 273
 274   of->write_output_view(this->offset(), all_shdrs_size, view);
 275 }
 276
 277 // Output_segment_header methods.
 278
 279 Output_segment_headers::Output_segment_headers(
 280     const Layout::Segment_list& segment_list)
 281   : segment_list_(segment_list)
 282 {
 283 }
 284
 285 void
 286 Output_segment_headers::do_write(Output_file* of)
 287 {
 288   switch (parameters->size_and_endianness())
 289     {
 290 #ifdef HAVE_TARGET_32_LITTLE
 291     case Parameters::TARGET_32_LITTLE:
 292       this->do_sized_write<32, false>(of);
 293       break;
 294 #endif
 295 #ifdef HAVE_TARGET_32_BIG
 296     case Parameters::TARGET_32_BIG:
 297       this->do_sized_write<32, true>(of);
 298       break;
 299 #endif
 300 #ifdef HAVE_TARGET_64_LITTLE
 301     case Parameters::TARGET_64_LITTLE:
 302       this->do_sized_write<64, false>(of);
 303       break;
 304 #endif
 305 #ifdef HAVE_TARGET_64_BIG
 306     case Parameters::TARGET_64_BIG:
 307       this->do_sized_write<64, true>(of);
 308       break;
 309 #endif
 310     default:
 311       gold_unreachable();
 312     }
 313 }
 314
 315 template<int size, bool big_endian>
 316 void
 317 Output_segment_headers::do_sized_write(Output_file* of)
 318 {
 319   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
 320   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
 321   gold_assert(all_phdrs_size == this->data_size());
 322   unsigned char* view = of->get_output_view(this->offset(),
 323                                             all_phdrs_size);
 324   unsigned char* v = view;
 325   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
 326        p != this->segment_list_.end();
 327        ++p)
 328     {
 329       elfcpp::Phdr_write<size, big_endian> ophdr(v);
 330       (*p)->write_header(&ophdr);
 331       v += phdr_size;
 332     }
 333
 334   gold_assert(v - view == all_phdrs_size);
 335
 336   of->write_output_view(this->offset(), all_phdrs_size, view);
 337 }
 338
 339 off_t
 340 Output_segment_headers::do_size() const
 341 {
 342   const int size = parameters->target().get_size();
 343   int phdr_size;
 344   if (size == 32)
 345     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
 346   else if (size == 64)
 347     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
 348   else
 349     gold_unreachable();
 350
 351   return this->segment_list_.size() * phdr_size;
 352 }
 353
 354 // Output_file_header methods.
 355
 356 Output_file_header::Output_file_header(const Target* target,
 357                                        const Symbol_table* symtab,
 358                                        const Output_segment_headers* osh,
 359                                        const char* entry)
 360   : target_(target),
 361     symtab_(symtab),
 362     segment_header_(osh),
 363     section_header_(NULL),
 364     shstrtab_(NULL),
 365     entry_(entry)
 366 {
 367   this->set_data_size(this->do_size());
 368 }
 369
 370 // Set the section table information for a file header.
 371
 372 void
 373 Output_file_header::set_section_info(const Output_section_headers* shdrs,
 374                                      const Output_section* shstrtab)
 375 {
 376   this->section_header_ = shdrs;
 377   this->shstrtab_ = shstrtab;
 378 }
 379
 380 // Write out the file header.
 381
 382 void
 383 Output_file_header::do_write(Output_file* of)
 384 {
 385   gold_assert(this->offset() == 0);
 386
 387   switch (parameters->size_and_endianness())
 388     {
 389 #ifdef HAVE_TARGET_32_LITTLE
 390     case Parameters::TARGET_32_LITTLE:
 391       this->do_sized_write<32, false>(of);
 392       break;
 393 #endif
 394 #ifdef HAVE_TARGET_32_BIG
 395     case Parameters::TARGET_32_BIG:
 396       this->do_sized_write<32, true>(of);
 397       break;
 398 #endif
 399 #ifdef HAVE_TARGET_64_LITTLE
 400     case Parameters::TARGET_64_LITTLE:
 401       this->do_sized_write<64, false>(of);
 402       break;
 403 #endif
 404 #ifdef HAVE_TARGET_64_BIG
 405     case Parameters::TARGET_64_BIG:
 406       this->do_sized_write<64, true>(of);
 407       break;
 408 #endif
 409     default:
 410       gold_unreachable();
 411     }
 412 }
 413
 414 // Write out the file header with appropriate size and endianess.
 415
 416 template<int size, bool big_endian>
 417 void
 418 Output_file_header::do_sized_write(Output_file* of)
 419 {
 420   gold_assert(this->offset() == 0);
 421
 422   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
 423   unsigned char* view = of->get_output_view(0, ehdr_size);
 424   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
 425
 426   unsigned char e_ident[elfcpp::EI_NIDENT];
 427   memset(e_ident, 0, elfcpp::EI_NIDENT);
 428   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
 429   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
 430   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
 431   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
 432   if (size == 32)
 433     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
 434   else if (size == 64)
 435     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
 436   else
 437     gold_unreachable();
 438   e_ident[elfcpp::EI_DATA] = (big_endian
 439                               ? elfcpp::ELFDATA2MSB
 440                               : elfcpp::ELFDATA2LSB);
 441   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
 442   oehdr.put_e_ident(e_ident);
 443
 444   elfcpp::ET e_type;
 445   if (parameters->options().relocatable())
 446     e_type = elfcpp::ET_REL;
 447   else if (parameters->options().output_is_position_independent())
 448     e_type = elfcpp::ET_DYN;
 449   else
 450     e_type = elfcpp::ET_EXEC;
 451   oehdr.put_e_type(e_type);
 452
 453   oehdr.put_e_machine(this->target_->machine_code());
 454   oehdr.put_e_version(elfcpp::EV_CURRENT);
 455
 456   oehdr.put_e_entry(this->entry<size>());
 457
 458   if (this->segment_header_ == NULL)
 459     oehdr.put_e_phoff(0);
 460   else
 461     oehdr.put_e_phoff(this->segment_header_->offset());
 462
 463   oehdr.put_e_shoff(this->section_header_->offset());
 464   oehdr.put_e_flags(this->target_->processor_specific_flags());
 465   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
 466
 467   if (this->segment_header_ == NULL)
 468     {
 469       oehdr.put_e_phentsize(0);
 470       oehdr.put_e_phnum(0);
 471     }
 472   else
 473     {
 474       oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
 475       size_t phnum = (this->segment_header_->data_size()
 476                       / elfcpp::Elf_sizes<size>::phdr_size);
 477       if (phnum > elfcpp::PN_XNUM)
 478         phnum = elfcpp::PN_XNUM;
 479       oehdr.put_e_phnum(phnum);
 480     }
 481
 482   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
 483   size_t section_count = (this->section_header_->data_size()
 484                           / elfcpp::Elf_sizes<size>::shdr_size);
 485
 486   if (section_count < elfcpp::SHN_LORESERVE)
 487     oehdr.put_e_shnum(this->section_header_->data_size()
 488                       / elfcpp::Elf_sizes<size>::shdr_size);
 489   else
 490     oehdr.put_e_shnum(0);
 491
 492   unsigned int shstrndx = this->shstrtab_->out_shndx();
 493   if (shstrndx < elfcpp::SHN_LORESERVE)
 494     oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
 495   else
 496     oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
 497
 498   // Let the target adjust the ELF header, e.g., to set EI_OSABI in
 499   // the e_ident field.
 500   parameters->target().adjust_elf_header(view, ehdr_size);
 501
 502   of->write_output_view(0, ehdr_size, view);
 503 }
 504
 505 // Return the value to use for the entry address.  THIS->ENTRY_ is the
 506 // symbol specified on the command line, if any.
 507
 508 template<int size>
 509 typename elfcpp::Elf_types<size>::Elf_Addr
 510 Output_file_header::entry()
 511 {
 512   const bool should_issue_warning = (this->entry_ != NULL
 513                                      && !parameters->options().relocatable()
 514                                      && !parameters->options().shared());
 515
 516   // FIXME: Need to support target specific entry symbol.
 517   const char* entry = this->entry_;
 518   if (entry == NULL)
 519     entry = "_start";
 520
 521   Symbol* sym = this->symtab_->lookup(entry);
 522
 523   typename Sized_symbol<size>::Value_type v;
 524   if (sym != NULL)
 525     {
 526       Sized_symbol<size>* ssym;
 527       ssym = this->symtab_->get_sized_symbol<size>(sym);
 528       if (!ssym->is_defined() && should_issue_warning)
 529         gold_warning("entry symbol '%s' exists but is not defined", entry);
 530       v = ssym->value();
 531     }
 532   else
 533     {
 534       // We couldn't find the entry symbol.  See if we can parse it as
 535       // a number.  This supports, e.g., -e 0x1000.
 536       char* endptr;
 537       v = strtoull(entry, &endptr, 0);
 538       if (*endptr != '\0')
 539         {
 540           if (should_issue_warning)
 541             gold_warning("cannot find entry symbol '%s'", entry);
 542           v = 0;
 543         }
 544     }
 545
 546   return v;
 547 }
 548
 549 // Compute the current data size.
 550
 551 off_t
 552 Output_file_header::do_size() const
 553 {
 554   const int size = parameters->target().get_size();
 555   if (size == 32)
 556     return elfcpp::Elf_sizes<32>::ehdr_size;
 557   else if (size == 64)
 558     return elfcpp::Elf_sizes<64>::ehdr_size;
 559   else
 560     gold_unreachable();
 561 }
 562
 563 // Output_data_const methods.
 564
 565 void
 566 Output_data_const::do_write(Output_file* of)
 567 {
 568   of->write(this->offset(), this->data_.data(), this->data_.size());
 569 }
 570
 571 // Output_data_const_buffer methods.
 572
 573 void
 574 Output_data_const_buffer::do_write(Output_file* of)
 575 {
 576   of->write(this->offset(), this->p_, this->data_size());
 577 }
 578
 579 // Output_section_data methods.
 580
 581 // Record the output section, and set the entry size and such.
 582
 583 void
 584 Output_section_data::set_output_section(Output_section* os)
 585 {
 586   gold_assert(this->output_section_ == NULL);
 587   this->output_section_ = os;
 588   this->do_adjust_output_section(os);
 589 }
 590
 591 // Return the section index of the output section.
 592
 593 unsigned int
 594 Output_section_data::do_out_shndx() const
 595 {
 596   gold_assert(this->output_section_ != NULL);
 597   return this->output_section_->out_shndx();
 598 }
 599
 600 // Set the alignment, which means we may need to update the alignment
 601 // of the output section.
 602
 603 void
 604 Output_section_data::set_addralign(uint64_t addralign)
 605 {
 606   this->addralign_ = addralign;
 607   if (this->output_section_ != NULL
 608       && this->output_section_->addralign() < addralign)
 609     this->output_section_->set_addralign(addralign);
 610 }
 611
 612 // Output_data_strtab methods.
 613
 614 // Set the final data size.
 615
 616 void
 617 Output_data_strtab::set_final_data_size()
 618 {
 619   this->strtab_->set_string_offsets();
 620   this->set_data_size(this->strtab_->get_strtab_size());
 621 }
 622
 623 // Write out a string table.
 624
 625 void
 626 Output_data_strtab::do_write(Output_file* of)
 627 {
 628   this->strtab_->write(of, this->offset());
 629 }
 630
 631 // Output_reloc methods.
 632
 633 // A reloc against a global symbol.
 634
 635 template<bool dynamic, int size, bool big_endian>
 636 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 637     Symbol* gsym,
 638     unsigned int type,
 639     Output_data* od,
 640     Address address,
 641     bool is_relative,
 642     bool is_symbolless)
 643   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
 644     is_relative_(is_relative), is_symbolless_(is_symbolless),
 645     is_section_symbol_(false), shndx_(INVALID_CODE)
 646 {
 647   // this->type_ is a bitfield; make sure TYPE fits.
 648   gold_assert(this->type_ == type);
 649   this->u1_.gsym = gsym;
 650   this->u2_.od = od;
 651   if (dynamic)
 652     this->set_needs_dynsym_index();
 653 }
 654
 655 template<bool dynamic, int size, bool big_endian>
 656 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 657     Symbol* gsym,
 658     unsigned int type,
 659     Sized_relobj<size, big_endian>* relobj,
 660     unsigned int shndx,
 661     Address address,
 662     bool is_relative,
 663     bool is_symbolless)
 664   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
 665     is_relative_(is_relative), is_symbolless_(is_symbolless),
 666     is_section_symbol_(false), shndx_(shndx)
 667 {
 668   gold_assert(shndx != INVALID_CODE);
 669   // this->type_ is a bitfield; make sure TYPE fits.
 670   gold_assert(this->type_ == type);
 671   this->u1_.gsym = gsym;
 672   this->u2_.relobj = relobj;
 673   if (dynamic)
 674     this->set_needs_dynsym_index();
 675 }
 676
 677 // A reloc against a local symbol.
 678
 679 template<bool dynamic, int size, bool big_endian>
 680 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 681     Sized_relobj<size, big_endian>* relobj,
 682     unsigned int local_sym_index,
 683     unsigned int type,
 684     Output_data* od,
 685     Address address,
 686     bool is_relative,
 687     bool is_symbolless,
 688     bool is_section_symbol)
 689   : address_(address), local_sym_index_(local_sym_index), type_(type),
 690     is_relative_(is_relative), is_symbolless_(is_symbolless),
 691     is_section_symbol_(is_section_symbol), shndx_(INVALID_CODE)
 692 {
 693   gold_assert(local_sym_index != GSYM_CODE
 694               && local_sym_index != INVALID_CODE);
 695   // this->type_ is a bitfield; make sure TYPE fits.
 696   gold_assert(this->type_ == type);
 697   this->u1_.relobj = relobj;
 698   this->u2_.od = od;
 699   if (dynamic)
 700     this->set_needs_dynsym_index();
 701 }
 702
 703 template<bool dynamic, int size, bool big_endian>
 704 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 705     Sized_relobj<size, big_endian>* relobj,
 706     unsigned int local_sym_index,
 707     unsigned int type,
 708     unsigned int shndx,
 709     Address address,
 710     bool is_relative,
 711     bool is_symbolless,
 712     bool is_section_symbol)
 713   : address_(address), local_sym_index_(local_sym_index), type_(type),
 714     is_relative_(is_relative), is_symbolless_(is_symbolless),
 715     is_section_symbol_(is_section_symbol), shndx_(shndx)
 716 {
 717   gold_assert(local_sym_index != GSYM_CODE
 718               && local_sym_index != INVALID_CODE);
 719   gold_assert(shndx != INVALID_CODE);
 720   // this->type_ is a bitfield; make sure TYPE fits.
 721   gold_assert(this->type_ == type);
 722   this->u1_.relobj = relobj;
 723   this->u2_.relobj = relobj;
 724   if (dynamic)
 725     this->set_needs_dynsym_index();
 726 }
 727
 728 // A reloc against the STT_SECTION symbol of an output section.
 729
 730 template<bool dynamic, int size, bool big_endian>
 731 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 732     Output_section* os,
 733     unsigned int type,
 734     Output_data* od,
 735     Address address)
 736   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
 737     is_relative_(false), is_symbolless_(false),
 738     is_section_symbol_(true), shndx_(INVALID_CODE)
 739 {
 740   // this->type_ is a bitfield; make sure TYPE fits.
 741   gold_assert(this->type_ == type);
 742   this->u1_.os = os;
 743   this->u2_.od = od;
 744   if (dynamic)
 745     this->set_needs_dynsym_index();
 746   else
 747     os->set_needs_symtab_index();
 748 }
 749
 750 template<bool dynamic, int size, bool big_endian>
 751 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 752     Output_section* os,
 753     unsigned int type,
 754     Sized_relobj<size, big_endian>* relobj,
 755     unsigned int shndx,
 756     Address address)
 757   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
 758     is_relative_(false), is_symbolless_(false),
 759     is_section_symbol_(true), shndx_(shndx)
 760 {
 761   gold_assert(shndx != INVALID_CODE);
 762   // this->type_ is a bitfield; make sure TYPE fits.
 763   gold_assert(this->type_ == type);
 764   this->u1_.os = os;
 765   this->u2_.relobj = relobj;
 766   if (dynamic)
 767     this->set_needs_dynsym_index();
 768   else
 769     os->set_needs_symtab_index();
 770 }
 771
 772 // An absolute relocation.
 773
 774 template<bool dynamic, int size, bool big_endian>
 775 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 776     unsigned int type,
 777     Output_data* od,
 778     Address address)
 779   : address_(address), local_sym_index_(0), type_(type),
 780     is_relative_(false), is_symbolless_(false),
 781     is_section_symbol_(false), shndx_(INVALID_CODE)
 782 {
 783   // this->type_ is a bitfield; make sure TYPE fits.
 784   gold_assert(this->type_ == type);
 785   this->u1_.relobj = NULL;
 786   this->u2_.od = od;
 787 }
 788
 789 template<bool dynamic, int size, bool big_endian>
 790 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 791     unsigned int type,
 792     Sized_relobj<size, big_endian>* relobj,
 793     unsigned int shndx,
 794     Address address)
 795   : address_(address), local_sym_index_(0), type_(type),
 796     is_relative_(false), is_symbolless_(false),
 797     is_section_symbol_(false), shndx_(shndx)
 798 {
 799   gold_assert(shndx != INVALID_CODE);
 800   // this->type_ is a bitfield; make sure TYPE fits.
 801   gold_assert(this->type_ == type);
 802   this->u1_.relobj = NULL;
 803   this->u2_.relobj = relobj;
 804 }
 805
 806 // A target specific relocation.
 807
 808 template<bool dynamic, int size, bool big_endian>
 809 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 810     unsigned int type,
 811     void* arg,
 812     Output_data* od,
 813     Address address)
 814   : address_(address), local_sym_index_(TARGET_CODE), type_(type),
 815     is_relative_(false), is_symbolless_(false),
 816     is_section_symbol_(false), shndx_(INVALID_CODE)
 817 {
 818   // this->type_ is a bitfield; make sure TYPE fits.
 819   gold_assert(this->type_ == type);
 820   this->u1_.arg = arg;
 821   this->u2_.od = od;
 822 }
 823
 824 template<bool dynamic, int size, bool big_endian>
 825 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 826     unsigned int type,
 827     void* arg,
 828     Sized_relobj<size, big_endian>* relobj,
 829     unsigned int shndx,
 830     Address address)
 831   : address_(address), local_sym_index_(TARGET_CODE), type_(type),
 832     is_relative_(false), is_symbolless_(false),
 833     is_section_symbol_(false), shndx_(shndx)
 834 {
 835   gold_assert(shndx != INVALID_CODE);
 836   // this->type_ is a bitfield; make sure TYPE fits.
 837   gold_assert(this->type_ == type);
 838   this->u1_.arg = arg;
 839   this->u2_.relobj = relobj;
 840 }
 841
 842 // Record that we need a dynamic symbol index for this relocation.
 843
 844 template<bool dynamic, int size, bool big_endian>
 845 void
 846 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
 847 set_needs_dynsym_index()
 848 {
 849   if (this->is_symbolless_)
 850     return;
 851   switch (this->local_sym_index_)
 852     {
 853     case INVALID_CODE:
 854       gold_unreachable();
 855
 856     case GSYM_CODE:
 857       this->u1_.gsym->set_needs_dynsym_entry();
 858       break;
 859
 860     case SECTION_CODE:
 861       this->u1_.os->set_needs_dynsym_index();
 862       break;
 863
 864     case TARGET_CODE:
 865       // The target must take care of this if necessary.
 866       break;
 867
 868     case 0:
 869       break;
 870
 871     default:
 872       {
 873         const unsigned int lsi = this->local_sym_index_;
 874         if (!this->is_section_symbol_)
 875           this->u1_.relobj->set_needs_output_dynsym_entry(lsi);
 876         else
 877           this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index();
 878       }
 879       break;
 880     }
 881 }
 882
 883 // Get the symbol index of a relocation.
 884
 885 template<bool dynamic, int size, bool big_endian>
 886 unsigned int
 887 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
 888   const
 889 {
 890   unsigned int index;
 891   if (this->is_symbolless_)
 892     return 0;
 893   switch (this->local_sym_index_)
 894     {
 895     case INVALID_CODE:
 896       gold_unreachable();
 897
 898     case GSYM_CODE:
 899       if (this->u1_.gsym == NULL)
 900         index = 0;
 901       else if (dynamic)
 902         index = this->u1_.gsym->dynsym_index();
 903       else
 904         index = this->u1_.gsym->symtab_index();
 905       break;
 906
 907     case SECTION_CODE:
 908       if (dynamic)
 909         index = this->u1_.os->dynsym_index();
 910       else
 911         index = this->u1_.os->symtab_index();
 912       break;
 913
 914     case TARGET_CODE:
 915       index = parameters->target().reloc_symbol_index(this->u1_.arg,
 916                                                       this->type_);
 917       break;
 918
 919     case 0:
 920       // Relocations without symbols use a symbol index of 0.
 921       index = 0;
 922       break;
 923
 924     default:
 925       {
 926         const unsigned int lsi = this->local_sym_index_;
 927         if (!this->is_section_symbol_)
 928           {
 929             if (dynamic)
 930               index = this->u1_.relobj->dynsym_index(lsi);
 931             else
 932               index = this->u1_.relobj->symtab_index(lsi);
 933           }
 934         else
 935           {
 936             Output_section* os = this->u1_.relobj->output_section(lsi);
 937             gold_assert(os != NULL);
 938             if (dynamic)
 939               index = os->dynsym_index();
 940             else
 941               index = os->symtab_index();
 942           }
 943       }
 944       break;
 945     }
 946   gold_assert(index != -1U);
 947   return index;
 948 }
 949
 950 // For a local section symbol, get the address of the offset ADDEND
 951 // within the input section.
 952
 953 template<bool dynamic, int size, bool big_endian>
 954 typename elfcpp::Elf_types<size>::Elf_Addr
 955 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
 956   local_section_offset(Addend addend) const
 957 {
 958   gold_assert(this->local_sym_index_ != GSYM_CODE
 959               && this->local_sym_index_ != SECTION_CODE
 960               && this->local_sym_index_ != TARGET_CODE
 961               && this->local_sym_index_ != INVALID_CODE
 962               && this->local_sym_index_ != 0
 963               && this->is_section_symbol_);
 964   const unsigned int lsi = this->local_sym_index_;
 965   Output_section* os = this->u1_.relobj->output_section(lsi);
 966   gold_assert(os != NULL);
 967   Address offset = this->u1_.relobj->get_output_section_offset(lsi);
 968   if (offset != invalid_address)
 969     return offset + addend;
 970   // This is a merge section.
 971   offset = os->output_address(this->u1_.relobj, lsi, addend);
 972   gold_assert(offset != invalid_address);
 973   return offset;
 974 }
 975
 976 // Get the output address of a relocation.
 977
 978 template<bool dynamic, int size, bool big_endian>
 979 typename elfcpp::Elf_types<size>::Elf_Addr
 980 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
 981 {
 982   Address address = this->address_;
 983   if (this->shndx_ != INVALID_CODE)
 984     {
 985       Output_section* os = this->u2_.relobj->output_section(this->shndx_);
 986       gold_assert(os != NULL);
 987       Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
 988       if (off != invalid_address)
 989         address += os->address() + off;
 990       else
 991         {
 992           address = os->output_address(this->u2_.relobj, this->shndx_,
 993                                        address);
 994           gold_assert(address != invalid_address);
 995         }
 996     }
 997   else if (this->u2_.od != NULL)
 998     address += this->u2_.od->address();
 999   return address;
1000 }
1001
1002 // Write out the offset and info fields of a Rel or Rela relocation
1003 // entry.
1004
1005 template<bool dynamic, int size, bool big_endian>
1006 template<typename Write_rel>
1007 void
1008 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
1009     Write_rel* wr) const
1010 {
1011   wr->put_r_offset(this->get_address());
1012   unsigned int sym_index = this->get_symbol_index();
1013   wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
1014 }
1015
1016 // Write out a Rel relocation.
1017
1018 template<bool dynamic, int size, bool big_endian>
1019 void
1020 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
1021     unsigned char* pov) const
1022 {
1023   elfcpp::Rel_write<size, big_endian> orel(pov);
1024   this->write_rel(&orel);
1025 }
1026
1027 // Get the value of the symbol referred to by a Rel relocation.
1028
1029 template<bool dynamic, int size, bool big_endian>
1030 typename elfcpp::Elf_types<size>::Elf_Addr
1031 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
1032     Addend addend) const
1033 {
1034   if (this->local_sym_index_ == GSYM_CODE)
1035     {
1036       const Sized_symbol<size>* sym;
1037       sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
1038       return sym->value() + addend;
1039     }
1040   gold_assert(this->local_sym_index_ != SECTION_CODE
1041               && this->local_sym_index_ != TARGET_CODE
1042               && this->local_sym_index_ != INVALID_CODE
1043               && this->local_sym_index_ != 0
1044               && !this->is_section_symbol_);
1045   const unsigned int lsi = this->local_sym_index_;
1046   const Symbol_value<size>* symval = this->u1_.relobj->local_symbol(lsi);
1047   return symval->value(this->u1_.relobj, addend);
1048 }
1049
1050 // Reloc comparison.  This function sorts the dynamic relocs for the
1051 // benefit of the dynamic linker.  First we sort all relative relocs
1052 // to the front.  Among relative relocs, we sort by output address.
1053 // Among non-relative relocs, we sort by symbol index, then by output
1054 // address.
1055
1056 template<bool dynamic, int size, bool big_endian>
1057 int
1058 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
1059   compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
1060     const
1061 {
1062   if (this->is_relative_)
1063     {
1064       if (!r2.is_relative_)
1065         return -1;
1066       // Otherwise sort by reloc address below.
1067     }
1068   else if (r2.is_relative_)
1069     return 1;
1070   else
1071     {
1072       unsigned int sym1 = this->get_symbol_index();
1073       unsigned int sym2 = r2.get_symbol_index();
1074       if (sym1 < sym2)
1075         return -1;
1076       else if (sym1 > sym2)
1077         return 1;
1078       // Otherwise sort by reloc address.
1079     }
1080
1081   section_offset_type addr1 = this->get_address();
1082   section_offset_type addr2 = r2.get_address();
1083   if (addr1 < addr2)
1084     return -1;
1085   else if (addr1 > addr2)
1086     return 1;
1087
1088   // Final tie breaker, in order to generate the same output on any
1089   // host: reloc type.
1090   unsigned int type1 = this->type_;
1091   unsigned int type2 = r2.type_;
1092   if (type1 < type2)
1093     return -1;
1094   else if (type1 > type2)
1095     return 1;
1096
1097   // These relocs appear to be exactly the same.
1098   return 0;
1099 }
1100
1101 // Write out a Rela relocation.
1102
1103 template<bool dynamic, int size, bool big_endian>
1104 void
1105 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
1106     unsigned char* pov) const
1107 {
1108   elfcpp::Rela_write<size, big_endian> orel(pov);
1109   this->rel_.write_rel(&orel);
1110   Addend addend = this->addend_;
1111   if (this->rel_.is_target_specific())
1112     addend = parameters->target().reloc_addend(this->rel_.target_arg(),
1113                                                this->rel_.type(), addend);
1114   else if (this->rel_.is_symbolless())
1115     addend = this->rel_.symbol_value(addend);
1116   else if (this->rel_.is_local_section_symbol())
1117     addend = this->rel_.local_section_offset(addend);
1118   orel.put_r_addend(addend);
1119 }
1120
1121 // Output_data_reloc_base methods.
1122
1123 // Adjust the output section.
1124
1125 template<int sh_type, bool dynamic, int size, bool big_endian>
1126 void
1127 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
1128     ::do_adjust_output_section(Output_section* os)
1129 {
1130   if (sh_type == elfcpp::SHT_REL)
1131     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1132   else if (sh_type == elfcpp::SHT_RELA)
1133     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1134   else
1135     gold_unreachable();
1136   if (dynamic)
1137     os->set_should_link_to_dynsym();
1138   else
1139     os->set_should_link_to_symtab();
1140 }
1141
1142 // Write out relocation data.
1143
1144 template<int sh_type, bool dynamic, int size, bool big_endian>
1145 void
1146 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1147     Output_file* of)
1148 {
1149   const off_t off = this->offset();
1150   const off_t oview_size = this->data_size();
1151   unsigned char* const oview = of->get_output_view(off, oview_size);
1152
1153   if (this->sort_relocs())
1154     {
1155       gold_assert(dynamic);
1156       std::sort(this->relocs_.begin(), this->relocs_.end(),
1157                 Sort_relocs_comparison());
1158     }
1159
1160   unsigned char* pov = oview;
1161   for (typename Relocs::const_iterator p = this->relocs_.begin();
1162        p != this->relocs_.end();
1163        ++p)
1164     {
1165       p->write(pov);
1166       pov += reloc_size;
1167     }
1168
1169   gold_assert(pov - oview == oview_size);
1170
1171   of->write_output_view(off, oview_size, oview);
1172
1173   // We no longer need the relocation entries.
1174   this->relocs_.clear();
1175 }
1176
1177 // Class Output_relocatable_relocs.
1178
1179 template<int sh_type, int size, bool big_endian>
1180 void
1181 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1182 {
1183   this->set_data_size(this->rr_->output_reloc_count()
1184                       * Reloc_types<sh_type, size, big_endian>::reloc_size);
1185 }
1186
1187 // class Output_data_group.
1188
1189 template<int size, bool big_endian>
1190 Output_data_group<size, big_endian>::Output_data_group(
1191     Sized_relobj<size, big_endian>* relobj,
1192     section_size_type entry_count,
1193     elfcpp::Elf_Word flags,
1194     std::vector<unsigned int>* input_shndxes)
1195   : Output_section_data(entry_count * 4, 4, false),
1196     relobj_(relobj),
1197     flags_(flags)
1198 {
1199   this->input_shndxes_.swap(*input_shndxes);
1200 }
1201
1202 // Write out the section group, which means translating the section
1203 // indexes to apply to the output file.
1204
1205 template<int size, bool big_endian>
1206 void
1207 Output_data_group<size, big_endian>::do_write(Output_file* of)
1208 {
1209   const off_t off = this->offset();
1210   const section_size_type oview_size =
1211     convert_to_section_size_type(this->data_size());
1212   unsigned char* const oview = of->get_output_view(off, oview_size);
1213
1214   elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1215   elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1216   ++contents;
1217
1218   for (std::vector<unsigned int>::const_iterator p =
1219          this->input_shndxes_.begin();
1220        p != this->input_shndxes_.end();
1221        ++p, ++contents)
1222     {
1223       Output_section* os = this->relobj_->output_section(*p);
1224
1225       unsigned int output_shndx;
1226       if (os != NULL)
1227         output_shndx = os->out_shndx();
1228       else
1229         {
1230           this->relobj_->error(_("section group retained but "
1231                                  "group element discarded"));
1232           output_shndx = 0;
1233         }
1234
1235       elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1236     }
1237
1238   size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1239   gold_assert(wrote == oview_size);
1240
1241   of->write_output_view(off, oview_size, oview);
1242
1243   // We no longer need this information.
1244   this->input_shndxes_.clear();
1245 }
1246
1247 // Output_data_got::Got_entry methods.
1248
1249 // Write out the entry.
1250
1251 template<int size, bool big_endian>
1252 void
1253 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1254 {
1255   Valtype val = 0;
1256
1257   switch (this->local_sym_index_)
1258     {
1259     case GSYM_CODE:
1260       {
1261         // If the symbol is resolved locally, we need to write out the
1262         // link-time value, which will be relocated dynamically by a
1263         // RELATIVE relocation.
1264         Symbol* gsym = this->u_.gsym;
1265         Sized_symbol<size>* sgsym;
1266         // This cast is a bit ugly.  We don't want to put a
1267         // virtual method in Symbol, because we want Symbol to be
1268         // as small as possible.
1269         sgsym = static_cast<Sized_symbol<size>*>(gsym);
1270         val = sgsym->value();
1271       }
1272       break;
1273
1274     case CONSTANT_CODE:
1275       val = this->u_.constant;
1276       break;
1277
1278     default:
1279       {
1280         const unsigned int lsi = this->local_sym_index_;
1281         const Symbol_value<size>* symval = this->u_.object->local_symbol(lsi);
1282         val = symval->value(this->u_.object, 0);
1283       }
1284       break;
1285     }
1286
1287   elfcpp::Swap<size, big_endian>::writeval(pov, val);
1288 }
1289
1290 // Output_data_got methods.
1291
1292 // Add an entry for a global symbol to the GOT.  This returns true if
1293 // this is a new GOT entry, false if the symbol already had a GOT
1294 // entry.
1295
1296 template<int size, bool big_endian>
1297 bool
1298 Output_data_got<size, big_endian>::add_global(
1299     Symbol* gsym,
1300     unsigned int got_type)
1301 {
1302   if (gsym->has_got_offset(got_type))
1303     return false;
1304
1305   this->entries_.push_back(Got_entry(gsym));
1306   this->set_got_size();
1307   gsym->set_got_offset(got_type, this->last_got_offset());
1308   return true;
1309 }
1310
1311 // Add an entry for a global symbol to the GOT, and add a dynamic
1312 // relocation of type R_TYPE for the GOT entry.
1313 template<int size, bool big_endian>
1314 void
1315 Output_data_got<size, big_endian>::add_global_with_rel(
1316     Symbol* gsym,
1317     unsigned int got_type,
1318     Rel_dyn* rel_dyn,
1319     unsigned int r_type)
1320 {
1321   if (gsym->has_got_offset(got_type))
1322     return;
1323
1324   this->entries_.push_back(Got_entry());
1325   this->set_got_size();
1326   unsigned int got_offset = this->last_got_offset();
1327   gsym->set_got_offset(got_type, got_offset);
1328   rel_dyn->add_global(gsym, r_type, this, got_offset);
1329 }
1330
1331 template<int size, bool big_endian>
1332 void
1333 Output_data_got<size, big_endian>::add_global_with_rela(
1334     Symbol* gsym,
1335     unsigned int got_type,
1336     Rela_dyn* rela_dyn,
1337     unsigned int r_type)
1338 {
1339   if (gsym->has_got_offset(got_type))
1340     return;
1341
1342   this->entries_.push_back(Got_entry());
1343   this->set_got_size();
1344   unsigned int got_offset = this->last_got_offset();
1345   gsym->set_got_offset(got_type, got_offset);
1346   rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1347 }
1348
1349 // Add a pair of entries for a global symbol to the GOT, and add
1350 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1351 // If R_TYPE_2 == 0, add the second entry with no relocation.
1352 template<int size, bool big_endian>
1353 void
1354 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1355     Symbol* gsym,
1356     unsigned int got_type,
1357     Rel_dyn* rel_dyn,
1358     unsigned int r_type_1,
1359     unsigned int r_type_2)
1360 {
1361   if (gsym->has_got_offset(got_type))
1362     return;
1363
1364   this->entries_.push_back(Got_entry());
1365   unsigned int got_offset = this->last_got_offset();
1366   gsym->set_got_offset(got_type, got_offset);
1367   rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1368
1369   this->entries_.push_back(Got_entry());
1370   if (r_type_2 != 0)
1371     {
1372       got_offset = this->last_got_offset();
1373       rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1374     }
1375
1376   this->set_got_size();
1377 }
1378
1379 template<int size, bool big_endian>
1380 void
1381 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1382     Symbol* gsym,
1383     unsigned int got_type,
1384     Rela_dyn* rela_dyn,
1385     unsigned int r_type_1,
1386     unsigned int r_type_2)
1387 {
1388   if (gsym->has_got_offset(got_type))
1389     return;
1390
1391   this->entries_.push_back(Got_entry());
1392   unsigned int got_offset = this->last_got_offset();
1393   gsym->set_got_offset(got_type, got_offset);
1394   rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1395
1396   this->entries_.push_back(Got_entry());
1397   if (r_type_2 != 0)
1398     {
1399       got_offset = this->last_got_offset();
1400       rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1401     }
1402
1403   this->set_got_size();
1404 }
1405
1406 // Add an entry for a local symbol to the GOT.  This returns true if
1407 // this is a new GOT entry, false if the symbol already has a GOT
1408 // entry.
1409
1410 template<int size, bool big_endian>
1411 bool
1412 Output_data_got<size, big_endian>::add_local(
1413     Sized_relobj<size, big_endian>* object,
1414     unsigned int symndx,
1415     unsigned int got_type)
1416 {
1417   if (object->local_has_got_offset(symndx, got_type))
1418     return false;
1419
1420   this->entries_.push_back(Got_entry(object, symndx));
1421   this->set_got_size();
1422   object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1423   return true;
1424 }
1425
1426 // Add an entry for a local symbol to the GOT, and add a dynamic
1427 // relocation of type R_TYPE for the GOT entry.
1428 template<int size, bool big_endian>
1429 void
1430 Output_data_got<size, big_endian>::add_local_with_rel(
1431     Sized_relobj<size, big_endian>* object,
1432     unsigned int symndx,
1433     unsigned int got_type,
1434     Rel_dyn* rel_dyn,
1435     unsigned int r_type)
1436 {
1437   if (object->local_has_got_offset(symndx, got_type))
1438     return;
1439
1440   this->entries_.push_back(Got_entry());
1441   this->set_got_size();
1442   unsigned int got_offset = this->last_got_offset();
1443   object->set_local_got_offset(symndx, got_type, got_offset);
1444   rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1445 }
1446
1447 template<int size, bool big_endian>
1448 void
1449 Output_data_got<size, big_endian>::add_local_with_rela(
1450     Sized_relobj<size, big_endian>* object,
1451     unsigned int symndx,
1452     unsigned int got_type,
1453     Rela_dyn* rela_dyn,
1454     unsigned int r_type)
1455 {
1456   if (object->local_has_got_offset(symndx, got_type))
1457     return;
1458
1459   this->entries_.push_back(Got_entry());
1460   this->set_got_size();
1461   unsigned int got_offset = this->last_got_offset();
1462   object->set_local_got_offset(symndx, got_type, got_offset);
1463   rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1464 }
1465
1466 // Add a pair of entries for a local symbol to the GOT, and add
1467 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1468 // If R_TYPE_2 == 0, add the second entry with no relocation.
1469 template<int size, bool big_endian>
1470 void
1471 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1472     Sized_relobj<size, big_endian>* object,
1473     unsigned int symndx,
1474     unsigned int shndx,
1475     unsigned int got_type,
1476     Rel_dyn* rel_dyn,
1477     unsigned int r_type_1,
1478     unsigned int r_type_2)
1479 {
1480   if (object->local_has_got_offset(symndx, got_type))
1481     return;
1482
1483   this->entries_.push_back(Got_entry());
1484   unsigned int got_offset = this->last_got_offset();
1485   object->set_local_got_offset(symndx, got_type, got_offset);
1486   Output_section* os = object->output_section(shndx);
1487   rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1488
1489   this->entries_.push_back(Got_entry(object, symndx));
1490   if (r_type_2 != 0)
1491     {
1492       got_offset = this->last_got_offset();
1493       rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1494     }
1495
1496   this->set_got_size();
1497 }
1498
1499 template<int size, bool big_endian>
1500 void
1501 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1502     Sized_relobj<size, big_endian>* object,
1503     unsigned int symndx,
1504     unsigned int shndx,
1505     unsigned int got_type,
1506     Rela_dyn* rela_dyn,
1507     unsigned int r_type_1,
1508     unsigned int r_type_2)
1509 {
1510   if (object->local_has_got_offset(symndx, got_type))
1511     return;
1512
1513   this->entries_.push_back(Got_entry());
1514   unsigned int got_offset = this->last_got_offset();
1515   object->set_local_got_offset(symndx, got_type, got_offset);
1516   Output_section* os = object->output_section(shndx);
1517   rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1518
1519   this->entries_.push_back(Got_entry(object, symndx));
1520   if (r_type_2 != 0)
1521     {
1522       got_offset = this->last_got_offset();
1523       rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1524     }
1525
1526   this->set_got_size();
1527 }
1528
1529 // Write out the GOT.
1530
1531 template<int size, bool big_endian>
1532 void
1533 Output_data_got<size, big_endian>::do_write(Output_file* of)
1534 {
1535   const int add = size / 8;
1536
1537   const off_t off = this->offset();
1538   const off_t oview_size = this->data_size();
1539   unsigned char* const oview = of->get_output_view(off, oview_size);
1540
1541   unsigned char* pov = oview;
1542   for (typename Got_entries::const_iterator p = this->entries_.begin();
1543        p != this->entries_.end();
1544        ++p)
1545     {
1546       p->write(pov);
1547       pov += add;
1548     }
1549
1550   gold_assert(pov - oview == oview_size);
1551
1552   of->write_output_view(off, oview_size, oview);
1553
1554   // We no longer need the GOT entries.
1555   this->entries_.clear();
1556 }
1557
1558 // Output_data_dynamic::Dynamic_entry methods.
1559
1560 // Write out the entry.
1561
1562 template<int size, bool big_endian>
1563 void
1564 Output_data_dynamic::Dynamic_entry::write(
1565     unsigned char* pov,
1566     const Stringpool* pool) const
1567 {
1568   typename elfcpp::Elf_types<size>::Elf_WXword val;
1569   switch (this->offset_)
1570     {
1571     case DYNAMIC_NUMBER:
1572       val = this->u_.val;
1573       break;
1574
1575     case DYNAMIC_SECTION_SIZE:
1576       val = this->u_.od->data_size();
1577       if (this->od2 != NULL)
1578         val += this->od2->data_size();
1579       break;
1580
1581     case DYNAMIC_SYMBOL:
1582       {
1583         const Sized_symbol<size>* s =
1584           static_cast<const Sized_symbol<size>*>(this->u_.sym);
1585         val = s->value();
1586       }
1587       break;
1588
1589     case DYNAMIC_STRING:
1590       val = pool->get_offset(this->u_.str);
1591       break;
1592
1593     default:
1594       val = this->u_.od->address() + this->offset_;
1595       break;
1596     }
1597
1598   elfcpp::Dyn_write<size, big_endian> dw(pov);
1599   dw.put_d_tag(this->tag_);
1600   dw.put_d_val(val);
1601 }
1602
1603 // Output_data_dynamic methods.
1604
1605 // Adjust the output section to set the entry size.
1606
1607 void
1608 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1609 {
1610   if (parameters->target().get_size() == 32)
1611     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1612   else if (parameters->target().get_size() == 64)
1613     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1614   else
1615     gold_unreachable();
1616 }
1617
1618 // Set the final data size.
1619
1620 void
1621 Output_data_dynamic::set_final_data_size()
1622 {
1623   // Add the terminating entry if it hasn't been added.
1624   // Because of relaxation, we can run this multiple times.
1625   if (this->entries_.empty() || this->entries_.back().tag() != elfcpp::DT_NULL)
1626     {
1627       int extra = parameters->options().spare_dynamic_tags();
1628       for (int i = 0; i < extra; ++i)
1629         this->add_constant(elfcpp::DT_NULL, 0);
1630       this->add_constant(elfcpp::DT_NULL, 0);
1631     }
1632
1633   int dyn_size;
1634   if (parameters->target().get_size() == 32)
1635     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1636   else if (parameters->target().get_size() == 64)
1637     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1638   else
1639     gold_unreachable();
1640   this->set_data_size(this->entries_.size() * dyn_size);
1641 }
1642
1643 // Write out the dynamic entries.
1644
1645 void
1646 Output_data_dynamic::do_write(Output_file* of)
1647 {
1648   switch (parameters->size_and_endianness())
1649     {
1650 #ifdef HAVE_TARGET_32_LITTLE
1651     case Parameters::TARGET_32_LITTLE:
1652       this->sized_write<32, false>(of);
1653       break;
1654 #endif
1655 #ifdef HAVE_TARGET_32_BIG
1656     case Parameters::TARGET_32_BIG:
1657       this->sized_write<32, true>(of);
1658       break;
1659 #endif
1660 #ifdef HAVE_TARGET_64_LITTLE
1661     case Parameters::TARGET_64_LITTLE:
1662       this->sized_write<64, false>(of);
1663       break;
1664 #endif
1665 #ifdef HAVE_TARGET_64_BIG
1666     case Parameters::TARGET_64_BIG:
1667       this->sized_write<64, true>(of);
1668       break;
1669 #endif
1670     default:
1671       gold_unreachable();
1672     }
1673 }
1674
1675 template<int size, bool big_endian>
1676 void
1677 Output_data_dynamic::sized_write(Output_file* of)
1678 {
1679   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1680
1681   const off_t offset = this->offset();
1682   const off_t oview_size = this->data_size();
1683   unsigned char* const oview = of->get_output_view(offset, oview_size);
1684
1685   unsigned char* pov = oview;
1686   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1687        p != this->entries_.end();
1688        ++p)
1689     {
1690       p->write<size, big_endian>(pov, this->pool_);
1691       pov += dyn_size;
1692     }
1693
1694   gold_assert(pov - oview == oview_size);
1695
1696   of->write_output_view(offset, oview_size, oview);
1697
1698   // We no longer need the dynamic entries.
1699   this->entries_.clear();
1700 }
1701
1702 // Class Output_symtab_xindex.
1703
1704 void
1705 Output_symtab_xindex::do_write(Output_file* of)
1706 {
1707   const off_t offset = this->offset();
1708   const off_t oview_size = this->data_size();
1709   unsigned char* const oview = of->get_output_view(offset, oview_size);
1710
1711   memset(oview, 0, oview_size);
1712
1713   if (parameters->target().is_big_endian())
1714     this->endian_do_write<true>(oview);
1715   else
1716     this->endian_do_write<false>(oview);
1717
1718   of->write_output_view(offset, oview_size, oview);
1719
1720   // We no longer need the data.
1721   this->entries_.clear();
1722 }
1723
1724 template<bool big_endian>
1725 void
1726 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1727 {
1728   for (Xindex_entries::const_iterator p = this->entries_.begin();
1729        p != this->entries_.end();
1730        ++p)
1731     {
1732       unsigned int symndx = p->first;
1733       gold_assert(symndx * 4 < this->data_size());
1734       elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1735     }
1736 }
1737
1738 // Output_section::Input_section methods.
1739
1740 // Return the data size.  For an input section we store the size here.
1741 // For an Output_section_data, we have to ask it for the size.
1742
1743 off_t
1744 Output_section::Input_section::data_size() const
1745 {
1746   if (this->is_input_section())
1747     return this->u1_.data_size;
1748   else
1749     return this->u2_.posd->data_size();
1750 }
1751
1752 // Return the object for an input section.
1753
1754 Relobj*
1755 Output_section::Input_section::relobj() const
1756 {
1757   if (this->is_input_section())
1758     return this->u2_.object;
1759   else if (this->is_merge_section())
1760     {
1761       gold_assert(this->u2_.pomb->first_relobj() != NULL);
1762       return this->u2_.pomb->first_relobj();
1763     }
1764   else if (this->is_relaxed_input_section())
1765     return this->u2_.poris->relobj();
1766   else
1767     gold_unreachable();
1768 }
1769
1770 // Return the input section index for an input section.
1771
1772 unsigned int
1773 Output_section::Input_section::shndx() const
1774 {
1775   if (this->is_input_section())
1776     return this->shndx_;
1777   else if (this->is_merge_section())
1778     {
1779       gold_assert(this->u2_.pomb->first_relobj() != NULL);
1780       return this->u2_.pomb->first_shndx();
1781     }
1782   else if (this->is_relaxed_input_section())
1783     return this->u2_.poris->shndx();
1784   else
1785     gold_unreachable();
1786 }
1787
1788 // Set the address and file offset.
1789
1790 void
1791 Output_section::Input_section::set_address_and_file_offset(
1792     uint64_t address,
1793     off_t file_offset,
1794     off_t section_file_offset)
1795 {
1796   if (this->is_input_section())
1797     this->u2_.object->set_section_offset(this->shndx_,
1798                                          file_offset - section_file_offset);
1799   else
1800     this->u2_.posd->set_address_and_file_offset(address, file_offset);
1801 }
1802
1803 // Reset the address and file offset.
1804
1805 void
1806 Output_section::Input_section::reset_address_and_file_offset()
1807 {
1808   if (!this->is_input_section())
1809     this->u2_.posd->reset_address_and_file_offset();
1810 }
1811
1812 // Finalize the data size.
1813
1814 void
1815 Output_section::Input_section::finalize_data_size()
1816 {
1817   if (!this->is_input_section())
1818     this->u2_.posd->finalize_data_size();
1819 }
1820
1821 // Try to turn an input offset into an output offset.  We want to
1822 // return the output offset relative to the start of this
1823 // Input_section in the output section.
1824
1825 inline bool
1826 Output_section::Input_section::output_offset(
1827     const Relobj* object,
1828     unsigned int shndx,
1829     section_offset_type offset,
1830     section_offset_type *poutput) const
1831 {
1832   if (!this->is_input_section())
1833     return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1834   else
1835     {
1836       if (this->shndx_ != shndx || this->u2_.object != object)
1837         return false;
1838       *poutput = offset;
1839       return true;
1840     }
1841 }
1842
1843 // Return whether this is the merge section for the input section
1844 // SHNDX in OBJECT.
1845
1846 inline bool
1847 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1848                                                     unsigned int shndx) const
1849 {
1850   if (this->is_input_section())
1851     return false;
1852   return this->u2_.posd->is_merge_section_for(object, shndx);
1853 }
1854
1855 // Write out the data.  We don't have to do anything for an input
1856 // section--they are handled via Object::relocate--but this is where
1857 // we write out the data for an Output_section_data.
1858
1859 void
1860 Output_section::Input_section::write(Output_file* of)
1861 {
1862   if (!this->is_input_section())
1863     this->u2_.posd->write(of);
1864 }
1865
1866 // Write the data to a buffer.  As for write(), we don't have to do
1867 // anything for an input section.
1868
1869 void
1870 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1871 {
1872   if (!this->is_input_section())
1873     this->u2_.posd->write_to_buffer(buffer);
1874 }
1875
1876 // Print to a map file.
1877
1878 void
1879 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1880 {
1881   switch (this->shndx_)
1882     {
1883     case OUTPUT_SECTION_CODE:
1884     case MERGE_DATA_SECTION_CODE:
1885     case MERGE_STRING_SECTION_CODE:
1886       this->u2_.posd->print_to_mapfile(mapfile);
1887       break;
1888
1889     case RELAXED_INPUT_SECTION_CODE:
1890       {
1891         Output_relaxed_input_section* relaxed_section =
1892           this->relaxed_input_section();
1893         mapfile->print_input_section(relaxed_section->relobj(),
1894                                      relaxed_section->shndx());
1895       }
1896       break;
1897     default:
1898       mapfile->print_input_section(this->u2_.object, this->shndx_);
1899       break;
1900     }
1901 }
1902
1903 // Output_section methods.
1904
1905 // Construct an Output_section.  NAME will point into a Stringpool.
1906
1907 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1908                                elfcpp::Elf_Xword flags)
1909   : name_(name),
1910     addralign_(0),
1911     entsize_(0),
1912     load_address_(0),
1913     link_section_(NULL),
1914     link_(0),
1915     info_section_(NULL),
1916     info_symndx_(NULL),
1917     info_(0),
1918     type_(type),
1919     flags_(flags),
1920     out_shndx_(-1U),
1921     symtab_index_(0),
1922     dynsym_index_(0),
1923     input_sections_(),
1924     first_input_offset_(0),
1925     fills_(),
1926     postprocessing_buffer_(NULL),
1927     needs_symtab_index_(false),
1928     needs_dynsym_index_(false),
1929     should_link_to_symtab_(false),
1930     should_link_to_dynsym_(false),
1931     after_input_sections_(false),
1932     requires_postprocessing_(false),
1933     found_in_sections_clause_(false),
1934     has_load_address_(false),
1935     info_uses_section_index_(false),
1936     input_section_order_specified_(false),
1937     may_sort_attached_input_sections_(false),
1938     must_sort_attached_input_sections_(false),
1939     attached_input_sections_are_sorted_(false),
1940     is_relro_(false),
1941     is_relro_local_(false),
1942     is_last_relro_(false),
1943     is_first_non_relro_(false),
1944     is_small_section_(false),
1945     is_large_section_(false),
1946     is_interp_(false),
1947     is_dynamic_linker_section_(false),
1948     generate_code_fills_at_write_(false),
1949     is_entsize_zero_(false),
1950     section_offsets_need_adjustment_(false),
1951     is_noload_(false),
1952     tls_offset_(0),
1953     checkpoint_(NULL),
1954     lookup_maps_(new Output_section_lookup_maps)
1955 {
1956   // An unallocated section has no address.  Forcing this means that
1957   // we don't need special treatment for symbols defined in debug
1958   // sections.
1959   if ((flags & elfcpp::SHF_ALLOC) == 0)
1960     this->set_address(0);
1961 }
1962
1963 Output_section::~Output_section()
1964 {
1965   delete this->checkpoint_;
1966 }
1967
1968 // Set the entry size.
1969
1970 void
1971 Output_section::set_entsize(uint64_t v)
1972 {
1973   if (this->is_entsize_zero_)
1974     ;
1975   else if (this->entsize_ == 0)
1976     this->entsize_ = v;
1977   else if (this->entsize_ != v)
1978     {
1979       this->entsize_ = 0;
1980       this->is_entsize_zero_ = 1;
1981     }
1982 }
1983
1984 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1985 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
1986 // relocation section which applies to this section, or 0 if none, or
1987 // -1U if more than one.  Return the offset of the input section
1988 // within the output section.  Return -1 if the input section will
1989 // receive special handling.  In the normal case we don't always keep
1990 // track of input sections for an Output_section.  Instead, each
1991 // Object keeps track of the Output_section for each of its input
1992 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
1993 // track of input sections here; this is used when SECTIONS appears in
1994 // a linker script.
1995
1996 template<int size, bool big_endian>
1997 off_t
1998 Output_section::add_input_section(Layout* layout,
1999                                   Sized_relobj<size, big_endian>* object,
2000                                   unsigned int shndx,
2001                                   const char* secname,
2002                                   const elfcpp::Shdr<size, big_endian>& shdr,
2003                                   unsigned int reloc_shndx,
2004                                   bool have_sections_script)
2005 {
2006   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
2007   if ((addralign & (addralign - 1)) != 0)
2008     {
2009       object->error(_("invalid alignment %lu for section \"%s\""),
2010                     static_cast<unsigned long>(addralign), secname);
2011       addralign = 1;
2012     }
2013
2014   if (addralign > this->addralign_)
2015     this->addralign_ = addralign;
2016
2017   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
2018   uint64_t entsize = shdr.get_sh_entsize();
2019
2020   // .debug_str is a mergeable string section, but is not always so
2021   // marked by compilers.  Mark manually here so we can optimize.
2022   if (strcmp(secname, ".debug_str") == 0)
2023     {
2024       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
2025       entsize = 1;
2026     }
2027
2028   this->update_flags_for_input_section(sh_flags);
2029   this->set_entsize(entsize);
2030
2031   // If this is a SHF_MERGE section, we pass all the input sections to
2032   // a Output_data_merge.  We don't try to handle relocations for such
2033   // a section.  We don't try to handle empty merge sections--they
2034   // mess up the mappings, and are useless anyhow.
2035   if ((sh_flags & elfcpp::SHF_MERGE) != 0
2036       && reloc_shndx == 0
2037       && shdr.get_sh_size() > 0)
2038     {
2039       // Keep information about merged input sections for rebuilding fast
2040       // lookup maps if we have sections-script or we do relaxation.
2041       bool keeps_input_sections =
2042         have_sections_script || parameters->target().may_relax();
2043       if (this->add_merge_input_section(object, shndx, sh_flags, entsize,
2044                                         addralign, keeps_input_sections))
2045         {
2046           // Tell the relocation routines that they need to call the
2047           // output_offset method to determine the final address.
2048           return -1;
2049         }
2050     }
2051
2052   off_t offset_in_section = this->current_data_size_for_child();
2053   off_t aligned_offset_in_section = align_address(offset_in_section,
2054                                                   addralign);
2055
2056   // Determine if we want to delay code-fill generation until the output
2057   // section is written.  When the target is relaxing, we want to delay fill
2058   // generating to avoid adjusting them during relaxation.
2059   if (!this->generate_code_fills_at_write_
2060       && !have_sections_script
2061       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2062       && parameters->target().has_code_fill()
2063       && parameters->target().may_relax())
2064     {
2065       gold_assert(this->fills_.empty());
2066       this->generate_code_fills_at_write_ = true;
2067     }
2068
2069   if (aligned_offset_in_section > offset_in_section
2070       && !this->generate_code_fills_at_write_
2071       && !have_sections_script
2072       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2073       && parameters->target().has_code_fill())
2074     {
2075       // We need to add some fill data.  Using fill_list_ when
2076       // possible is an optimization, since we will often have fill
2077       // sections without input sections.
2078       off_t fill_len = aligned_offset_in_section - offset_in_section;
2079       if (this->input_sections_.empty())
2080         this->fills_.push_back(Fill(offset_in_section, fill_len));
2081       else
2082         {
2083           std::string fill_data(parameters->target().code_fill(fill_len));
2084           Output_data_const* odc = new Output_data_const(fill_data, 1);
2085           this->input_sections_.push_back(Input_section(odc));
2086         }
2087     }
2088
2089   this->set_current_data_size_for_child(aligned_offset_in_section
2090                                         + shdr.get_sh_size());
2091
2092   // We need to keep track of this section if we are already keeping
2093   // track of sections, or if we are relaxing.  Also, if this is a
2094   // section which requires sorting, or which may require sorting in
2095   // the future, we keep track of the sections.  If the
2096   // --section-ordering-file option is used to specify the order of
2097   // sections, we need to keep track of sections.
2098   if (have_sections_script
2099       || !this->input_sections_.empty()
2100       || this->may_sort_attached_input_sections()
2101       || this->must_sort_attached_input_sections()
2102       || parameters->options().user_set_Map()
2103       || parameters->target().may_relax()
2104       || parameters->options().section_ordering_file())
2105     {
2106       Input_section isecn(object, shndx, shdr.get_sh_size(), addralign);
2107       if (parameters->options().section_ordering_file())
2108         {
2109           unsigned int section_order_index =
2110             layout->find_section_order_index(std::string(secname));
2111           if (section_order_index != 0)
2112             {
2113               isecn.set_section_order_index(section_order_index);
2114               this->set_input_section_order_specified();
2115             }
2116         }
2117       this->input_sections_.push_back(isecn);
2118     }
2119
2120   return aligned_offset_in_section;
2121 }
2122
2123 // Add arbitrary data to an output section.
2124
2125 void
2126 Output_section::add_output_section_data(Output_section_data* posd)
2127 {
2128   Input_section inp(posd);
2129   this->add_output_section_data(&inp);
2130
2131   if (posd->is_data_size_valid())
2132     {
2133       off_t offset_in_section = this->current_data_size_for_child();
2134       off_t aligned_offset_in_section = align_address(offset_in_section,
2135                                                       posd->addralign());
2136       this->set_current_data_size_for_child(aligned_offset_in_section
2137                                             + posd->data_size());
2138     }
2139 }
2140
2141 // Add a relaxed input section.
2142
2143 void
2144 Output_section::add_relaxed_input_section(Output_relaxed_input_section* poris)
2145 {
2146   Input_section inp(poris);
2147   this->add_output_section_data(&inp);
2148   if (this->lookup_maps_->is_valid())
2149     this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2150                                                   poris->shndx(), poris);
2151
2152   // For a relaxed section, we use the current data size.  Linker scripts
2153   // get all the input sections, including relaxed one from an output
2154   // section and add them back to them same output section to compute the
2155   // output section size.  If we do not account for sizes of relaxed input
2156   // sections,  an output section would be incorrectly sized.
2157   off_t offset_in_section = this->current_data_size_for_child();
2158   off_t aligned_offset_in_section = align_address(offset_in_section,
2159                                                   poris->addralign());
2160   this->set_current_data_size_for_child(aligned_offset_in_section
2161                                         + poris->current_data_size());
2162 }
2163
2164 // Add arbitrary data to an output section by Input_section.
2165
2166 void
2167 Output_section::add_output_section_data(Input_section* inp)
2168 {
2169   if (this->input_sections_.empty())
2170     this->first_input_offset_ = this->current_data_size_for_child();
2171
2172   this->input_sections_.push_back(*inp);
2173
2174   uint64_t addralign = inp->addralign();
2175   if (addralign > this->addralign_)
2176     this->addralign_ = addralign;
2177
2178   inp->set_output_section(this);
2179 }
2180
2181 // Add a merge section to an output section.
2182
2183 void
2184 Output_section::add_output_merge_section(Output_section_data* posd,
2185                                          bool is_string, uint64_t entsize)
2186 {
2187   Input_section inp(posd, is_string, entsize);
2188   this->add_output_section_data(&inp);
2189 }
2190
2191 // Add an input section to a SHF_MERGE section.
2192
2193 bool
2194 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2195                                         uint64_t flags, uint64_t entsize,
2196                                         uint64_t addralign,
2197                                         bool keeps_input_sections)
2198 {
2199   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2200
2201   // We only merge strings if the alignment is not more than the
2202   // character size.  This could be handled, but it's unusual.
2203   if (is_string && addralign > entsize)
2204     return false;
2205
2206   // We cannot restore merged input section states.
2207   gold_assert(this->checkpoint_ == NULL);
2208
2209   // Look up merge sections by required properties.
2210   // Currently, we only invalidate the lookup maps in script processing
2211   // and relaxation.  We should not have done either when we reach here.
2212   // So we assume that the lookup maps are valid to simply code.
2213   gold_assert(this->lookup_maps_->is_valid());
2214   Merge_section_properties msp(is_string, entsize, addralign);
2215   Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp);
2216   bool is_new = false;
2217   if (pomb != NULL)
2218     {
2219       gold_assert(pomb->is_string() == is_string
2220                   && pomb->entsize() == entsize
2221                   && pomb->addralign() == addralign);
2222     }
2223   else
2224     {
2225       // Create a new Output_merge_data or Output_merge_string_data.
2226       if (!is_string)
2227         pomb = new Output_merge_data(entsize, addralign);
2228       else
2229         {
2230           switch (entsize)
2231             {
2232             case 1:
2233               pomb = new Output_merge_string<char>(addralign);
2234               break;
2235             case 2:
2236               pomb = new Output_merge_string<uint16_t>(addralign);
2237               break;
2238             case 4:
2239               pomb = new Output_merge_string<uint32_t>(addralign);
2240               break;
2241             default:
2242               return false;
2243             }
2244         }
2245       // If we need to do script processing or relaxation, we need to keep
2246       // the original input sections to rebuild the fast lookup maps.
2247       if (keeps_input_sections)
2248         pomb->set_keeps_input_sections();
2249       is_new = true;
2250     }
2251
2252   if (pomb->add_input_section(object, shndx))
2253     {
2254       // Add new merge section to this output section and link merge
2255       // section properties to new merge section in map.
2256       if (is_new)
2257         {
2258           this->add_output_merge_section(pomb, is_string, entsize);
2259           this->lookup_maps_->add_merge_section(msp, pomb);
2260         }
2261
2262       // Add input section to new merge section and link input section to new
2263       // merge section in map.
2264       this->lookup_maps_->add_merge_input_section(object, shndx, pomb);
2265       return true;
2266     }
2267   else
2268     {
2269       // If add_input_section failed, delete new merge section to avoid
2270       // exporting empty merge sections in Output_section::get_input_section.
2271       if (is_new)
2272         delete pomb;
2273       return false;
2274     }
2275 }
2276
2277 // Build a relaxation map to speed up relaxation of existing input sections.
2278 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2279
2280 void
2281 Output_section::build_relaxation_map(
2282   const Input_section_list& input_sections,
2283   size_t limit,
2284   Relaxation_map* relaxation_map) const
2285 {
2286   for (size_t i = 0; i < limit; ++i)
2287     {
2288       const Input_section& is(input_sections[i]);
2289       if (is.is_input_section() || is.is_relaxed_input_section())
2290         {
2291           Section_id sid(is.relobj(), is.shndx());
2292           (*relaxation_map)[sid] = i;
2293         }
2294     }
2295 }
2296
2297 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2298 // sections in RELAXED_SECTIONS.  MAP is a prebuilt map from section id
2299 // indices of INPUT_SECTIONS.
2300
2301 void
2302 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2303   const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2304   const Relaxation_map& map,
2305   Input_section_list* input_sections)
2306 {
2307   for (size_t i = 0; i < relaxed_sections.size(); ++i)
2308     {
2309       Output_relaxed_input_section* poris = relaxed_sections[i];
2310       Section_id sid(poris->relobj(), poris->shndx());
2311       Relaxation_map::const_iterator p = map.find(sid);
2312       gold_assert(p != map.end());
2313       gold_assert((*input_sections)[p->second].is_input_section());
2314       (*input_sections)[p->second] = Input_section(poris);
2315     }
2316 }
2317
2318 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2319 // is a vector of pointers to Output_relaxed_input_section or its derived
2320 // classes.  The relaxed sections must correspond to existing input sections.
2321
2322 void
2323 Output_section::convert_input_sections_to_relaxed_sections(
2324   const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2325 {
2326   gold_assert(parameters->target().may_relax());
2327
2328   // We want to make sure that restore_states does not undo the effect of
2329   // this.  If there is no checkpoint active, just search the current
2330   // input section list and replace the sections there.  If there is
2331   // a checkpoint, also replace the sections there.
2332
2333   // By default, we look at the whole list.
2334   size_t limit = this->input_sections_.size();
2335
2336   if (this->checkpoint_ != NULL)
2337     {
2338       // Replace input sections with relaxed input section in the saved
2339       // copy of the input section list.
2340       if (this->checkpoint_->input_sections_saved())
2341         {
2342           Relaxation_map map;
2343           this->build_relaxation_map(
2344                     *(this->checkpoint_->input_sections()),
2345                     this->checkpoint_->input_sections()->size(),
2346                     &map);
2347           this->convert_input_sections_in_list_to_relaxed_sections(
2348                     relaxed_sections,
2349                     map,
2350                     this->checkpoint_->input_sections());
2351         }
2352       else
2353         {
2354           // We have not copied the input section list yet.  Instead, just
2355           // look at the portion that would be saved.
2356           limit = this->checkpoint_->input_sections_size();
2357         }
2358     }
2359
2360   // Convert input sections in input_section_list.
2361   Relaxation_map map;
2362   this->build_relaxation_map(this->input_sections_, limit, &map);
2363   this->convert_input_sections_in_list_to_relaxed_sections(
2364             relaxed_sections,
2365             map,
2366             &this->input_sections_);
2367
2368   // Update fast look-up map.
2369   if (this->lookup_maps_->is_valid())
2370     for (size_t i = 0; i < relaxed_sections.size(); ++i)
2371       {
2372         Output_relaxed_input_section* poris = relaxed_sections[i];
2373         this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2374                                                       poris->shndx(), poris);
2375       }
2376 }
2377
2378 // Update the output section flags based on input section flags.
2379
2380 void
2381 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2382 {
2383   // If we created the section with SHF_ALLOC clear, we set the
2384   // address.  If we are now setting the SHF_ALLOC flag, we need to
2385   // undo that.
2386   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2387       && (flags & elfcpp::SHF_ALLOC) != 0)
2388     this->mark_address_invalid();
2389
2390   this->flags_ |= (flags
2391                    & (elfcpp::SHF_WRITE
2392                       | elfcpp::SHF_ALLOC
2393                       | elfcpp::SHF_EXECINSTR));
2394
2395   if ((flags & elfcpp::SHF_MERGE) == 0)
2396     this->flags_ &=~ elfcpp::SHF_MERGE;
2397   else
2398     {
2399       if (this->current_data_size_for_child() == 0)
2400         this->flags_ |= elfcpp::SHF_MERGE;
2401     }
2402
2403   if ((flags & elfcpp::SHF_STRINGS) == 0)
2404     this->flags_ &=~ elfcpp::SHF_STRINGS;
2405   else
2406     {
2407       if (this->current_data_size_for_child() == 0)
2408         this->flags_ |= elfcpp::SHF_STRINGS;
2409     }
2410 }
2411
2412 // Find the merge section into which an input section with index SHNDX in
2413 // OBJECT has been added.  Return NULL if none found.
2414
2415 Output_section_data*
2416 Output_section::find_merge_section(const Relobj* object,
2417                                    unsigned int shndx) const
2418 {
2419   if (!this->lookup_maps_->is_valid())
2420     this->build_lookup_maps();
2421   return this->lookup_maps_->find_merge_section(object, shndx);
2422 }
2423
2424 // Build the lookup maps for merge and relaxed sections.  This is needs
2425 // to be declared as a const methods so that it is callable with a const
2426 // Output_section pointer.  The method only updates states of the maps.
2427
2428 void
2429 Output_section::build_lookup_maps() const
2430 {
2431   this->lookup_maps_->clear();
2432   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2433        p != this->input_sections_.end();
2434        ++p)
2435     {
2436       if (p->is_merge_section())
2437         {
2438           Output_merge_base* pomb = p->output_merge_base();
2439           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
2440                                        pomb->addralign());
2441           this->lookup_maps_->add_merge_section(msp, pomb);
2442           for (Output_merge_base::Input_sections::const_iterator is =
2443                  pomb->input_sections_begin();
2444                is != pomb->input_sections_end();
2445                ++is)
2446             {
2447               const Const_section_id& csid = *is;
2448             this->lookup_maps_->add_merge_input_section(csid.first,
2449                                                         csid.second, pomb);
2450             }
2451
2452         }
2453       else if (p->is_relaxed_input_section())
2454         {
2455           Output_relaxed_input_section* poris = p->relaxed_input_section();
2456           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2457                                                         poris->shndx(), poris);
2458         }
2459     }
2460 }
2461
2462 // Find an relaxed input section corresponding to an input section
2463 // in OBJECT with index SHNDX.
2464
2465 const Output_relaxed_input_section*
2466 Output_section::find_relaxed_input_section(const Relobj* object,
2467                                            unsigned int shndx) const
2468 {
2469   if (!this->lookup_maps_->is_valid())
2470     this->build_lookup_maps();
2471   return this->lookup_maps_->find_relaxed_input_section(object, shndx);
2472 }
2473
2474 // Given an address OFFSET relative to the start of input section
2475 // SHNDX in OBJECT, return whether this address is being included in
2476 // the final link.  This should only be called if SHNDX in OBJECT has
2477 // a special mapping.
2478
2479 bool
2480 Output_section::is_input_address_mapped(const Relobj* object,
2481                                         unsigned int shndx,
2482                                         off_t offset) const
2483 {
2484   // Look at the Output_section_data_maps first.
2485   const Output_section_data* posd = this->find_merge_section(object, shndx);
2486   if (posd == NULL)
2487     posd = this->find_relaxed_input_section(object, shndx);
2488
2489   if (posd != NULL)
2490     {
2491       section_offset_type output_offset;
2492       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2493       gold_assert(found);
2494       return output_offset != -1;
2495     }
2496
2497   // Fall back to the slow look-up.
2498   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2499        p != this->input_sections_.end();
2500        ++p)
2501     {
2502       section_offset_type output_offset;
2503       if (p->output_offset(object, shndx, offset, &output_offset))
2504         return output_offset != -1;
2505     }
2506
2507   // By default we assume that the address is mapped.  This should
2508   // only be called after we have passed all sections to Layout.  At
2509   // that point we should know what we are discarding.
2510   return true;
2511 }
2512
2513 // Given an address OFFSET relative to the start of input section
2514 // SHNDX in object OBJECT, return the output offset relative to the
2515 // start of the input section in the output section.  This should only
2516 // be called if SHNDX in OBJECT has a special mapping.
2517
2518 section_offset_type
2519 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2520                               section_offset_type offset) const
2521 {
2522   // This can only be called meaningfully when we know the data size
2523   // of this.
2524   gold_assert(this->is_data_size_valid());
2525
2526   // Look at the Output_section_data_maps first.
2527   const Output_section_data* posd = this->find_merge_section(object, shndx);
2528   if (posd == NULL)
2529     posd = this->find_relaxed_input_section(object, shndx);
2530   if (posd != NULL)
2531     {
2532       section_offset_type output_offset;
2533       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2534       gold_assert(found);
2535       return output_offset;
2536     }
2537
2538   // Fall back to the slow look-up.
2539   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2540        p != this->input_sections_.end();
2541        ++p)
2542     {
2543       section_offset_type output_offset;
2544       if (p->output_offset(object, shndx, offset, &output_offset))
2545         return output_offset;
2546     }
2547   gold_unreachable();
2548 }
2549
2550 // Return the output virtual address of OFFSET relative to the start
2551 // of input section SHNDX in object OBJECT.
2552
2553 uint64_t
2554 Output_section::output_address(const Relobj* object, unsigned int shndx,
2555                                off_t offset) const
2556 {
2557   uint64_t addr = this->address() + this->first_input_offset_;
2558
2559   // Look at the Output_section_data_maps first.
2560   const Output_section_data* posd = this->find_merge_section(object, shndx);
2561   if (posd == NULL)
2562     posd = this->find_relaxed_input_section(object, shndx);
2563   if (posd != NULL && posd->is_address_valid())
2564     {
2565       section_offset_type output_offset;
2566       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2567       gold_assert(found);
2568       return posd->address() + output_offset;
2569     }
2570
2571   // Fall back to the slow look-up.
2572   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2573        p != this->input_sections_.end();
2574        ++p)
2575     {
2576       addr = align_address(addr, p->addralign());
2577       section_offset_type output_offset;
2578       if (p->output_offset(object, shndx, offset, &output_offset))
2579         {
2580           if (output_offset == -1)
2581             return -1ULL;
2582           return addr + output_offset;
2583         }
2584       addr += p->data_size();
2585     }
2586
2587   // If we get here, it means that we don't know the mapping for this
2588   // input section.  This might happen in principle if
2589   // add_input_section were called before add_output_section_data.
2590   // But it should never actually happen.
2591
2592   gold_unreachable();
2593 }
2594
2595 // Find the output address of the start of the merged section for
2596 // input section SHNDX in object OBJECT.
2597
2598 bool
2599 Output_section::find_starting_output_address(const Relobj* object,
2600                                              unsigned int shndx,
2601                                              uint64_t* paddr) const
2602 {
2603   // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2604   // Looking up the merge section map does not always work as we sometimes
2605   // find a merge section without its address set.
2606   uint64_t addr = this->address() + this->first_input_offset_;
2607   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2608        p != this->input_sections_.end();
2609        ++p)
2610     {
2611       addr = align_address(addr, p->addralign());
2612
2613       // It would be nice if we could use the existing output_offset
2614       // method to get the output offset of input offset 0.
2615       // Unfortunately we don't know for sure that input offset 0 is
2616       // mapped at all.
2617       if (p->is_merge_section_for(object, shndx))
2618         {
2619           *paddr = addr;
2620           return true;
2621         }
2622
2623       addr += p->data_size();
2624     }
2625
2626   // We couldn't find a merge output section for this input section.
2627   return false;
2628 }
2629
2630 // Set the data size of an Output_section.  This is where we handle
2631 // setting the addresses of any Output_section_data objects.
2632
2633 void
2634 Output_section::set_final_data_size()
2635 {
2636   if (this->input_sections_.empty())
2637     {
2638       this->set_data_size(this->current_data_size_for_child());
2639       return;
2640     }
2641
2642   if (this->must_sort_attached_input_sections()
2643       || this->input_section_order_specified())
2644     this->sort_attached_input_sections();
2645
2646   uint64_t address = this->address();
2647   off_t startoff = this->offset();
2648   off_t off = startoff + this->first_input_offset_;
2649   for (Input_section_list::iterator p = this->input_sections_.begin();
2650        p != this->input_sections_.end();
2651        ++p)
2652     {
2653       off = align_address(off, p->addralign());
2654       p->set_address_and_file_offset(address + (off - startoff), off,
2655                                      startoff);
2656       off += p->data_size();
2657     }
2658
2659   this->set_data_size(off - startoff);
2660 }
2661
2662 // Reset the address and file offset.
2663
2664 void
2665 Output_section::do_reset_address_and_file_offset()
2666 {
2667   // An unallocated section has no address.  Forcing this means that
2668   // we don't need special treatment for symbols defined in debug
2669   // sections.  We do the same in the constructor.  This does not
2670   // apply to NOLOAD sections though.
2671   if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
2672      this->set_address(0);
2673
2674   for (Input_section_list::iterator p = this->input_sections_.begin();
2675        p != this->input_sections_.end();
2676        ++p)
2677     p->reset_address_and_file_offset();
2678 }
2679
2680 // Return true if address and file offset have the values after reset.
2681
2682 bool
2683 Output_section::do_address_and_file_offset_have_reset_values() const
2684 {
2685   if (this->is_offset_valid())
2686     return false;
2687
2688   // An unallocated section has address 0 after its construction or a reset.
2689   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2690     return this->is_address_valid() && this->address() == 0;
2691   else
2692     return !this->is_address_valid();
2693 }
2694
2695 // Set the TLS offset.  Called only for SHT_TLS sections.
2696
2697 void
2698 Output_section::do_set_tls_offset(uint64_t tls_base)
2699 {
2700   this->tls_offset_ = this->address() - tls_base;
2701 }
2702
2703 // In a few cases we need to sort the input sections attached to an
2704 // output section.  This is used to implement the type of constructor
2705 // priority ordering implemented by the GNU linker, in which the
2706 // priority becomes part of the section name and the sections are
2707 // sorted by name.  We only do this for an output section if we see an
2708 // attached input section matching ".ctor.*", ".dtor.*",
2709 // ".init_array.*" or ".fini_array.*".
2710
2711 class Output_section::Input_section_sort_entry
2712 {
2713  public:
2714   Input_section_sort_entry()
2715     : input_section_(), index_(-1U), section_has_name_(false),
2716       section_name_()
2717   { }
2718
2719   Input_section_sort_entry(const Input_section& input_section,
2720                            unsigned int index,
2721                            bool must_sort_attached_input_sections)
2722     : input_section_(input_section), index_(index),
2723       section_has_name_(input_section.is_input_section()
2724                         || input_section.is_relaxed_input_section())
2725   {
2726     if (this->section_has_name_
2727         && must_sort_attached_input_sections)
2728       {
2729         // This is only called single-threaded from Layout::finalize,
2730         // so it is OK to lock.  Unfortunately we have no way to pass
2731         // in a Task token.
2732         const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2733         Object* obj = (input_section.is_input_section()
2734                        ? input_section.relobj()
2735                        : input_section.relaxed_input_section()->relobj());
2736         Task_lock_obj<Object> tl(dummy_task, obj);
2737
2738         // This is a slow operation, which should be cached in
2739         // Layout::layout if this becomes a speed problem.
2740         this->section_name_ = obj->section_name(input_section.shndx());
2741       }
2742   }
2743
2744   // Return the Input_section.
2745   const Input_section&
2746   input_section() const
2747   {
2748     gold_assert(this->index_ != -1U);
2749     return this->input_section_;
2750   }
2751
2752   // The index of this entry in the original list.  This is used to
2753   // make the sort stable.
2754   unsigned int
2755   index() const
2756   {
2757     gold_assert(this->index_ != -1U);
2758     return this->index_;
2759   }
2760
2761   // Whether there is a section name.
2762   bool
2763   section_has_name() const
2764   { return this->section_has_name_; }
2765
2766   // The section name.
2767   const std::string&
2768   section_name() const
2769   {
2770     gold_assert(this->section_has_name_);
2771     return this->section_name_;
2772   }
2773
2774   // Return true if the section name has a priority.  This is assumed
2775   // to be true if it has a dot after the initial dot.
2776   bool
2777   has_priority() const
2778   {
2779     gold_assert(this->section_has_name_);
2780     return this->section_name_.find('.', 1) != std::string::npos;
2781   }
2782
2783   // Return true if this an input file whose base name matches
2784   // FILE_NAME.  The base name must have an extension of ".o", and
2785   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2786   // This is to match crtbegin.o as well as crtbeginS.o without
2787   // getting confused by other possibilities.  Overall matching the
2788   // file name this way is a dreadful hack, but the GNU linker does it
2789   // in order to better support gcc, and we need to be compatible.
2790   bool
2791   match_file_name(const char* match_file_name) const
2792   {
2793     const std::string& file_name(this->input_section_.relobj()->name());
2794     const char* base_name = lbasename(file_name.c_str());
2795     size_t match_len = strlen(match_file_name);
2796     if (strncmp(base_name, match_file_name, match_len) != 0)
2797       return false;
2798     size_t base_len = strlen(base_name);
2799     if (base_len != match_len + 2 && base_len != match_len + 3)
2800       return false;
2801     return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2802   }
2803
2804   // Returns 1 if THIS should appear before S in section order, -1 if S
2805   // appears before THIS and 0 if they are not comparable.
2806   int
2807   compare_section_ordering(const Input_section_sort_entry& s) const
2808   {
2809     unsigned int this_secn_index = this->input_section_.section_order_index();
2810     unsigned int s_secn_index = s.input_section().section_order_index();
2811     if (this_secn_index > 0 && s_secn_index > 0)
2812       {
2813         if (this_secn_index < s_secn_index)
2814           return 1;
2815         else if (this_secn_index > s_secn_index)
2816           return -1;
2817       }
2818     return 0;
2819   }
2820
2821  private:
2822   // The Input_section we are sorting.
2823   Input_section input_section_;
2824   // The index of this Input_section in the original list.
2825   unsigned int index_;
2826   // Whether this Input_section has a section name--it won't if this
2827   // is some random Output_section_data.
2828   bool section_has_name_;
2829   // The section name if there is one.
2830   std::string section_name_;
2831 };
2832
2833 // Return true if S1 should come before S2 in the output section.
2834
2835 bool
2836 Output_section::Input_section_sort_compare::operator()(
2837     const Output_section::Input_section_sort_entry& s1,
2838     const Output_section::Input_section_sort_entry& s2) const
2839 {
2840   // crtbegin.o must come first.
2841   bool s1_begin = s1.match_file_name("crtbegin");
2842   bool s2_begin = s2.match_file_name("crtbegin");
2843   if (s1_begin || s2_begin)
2844     {
2845       if (!s1_begin)
2846         return false;
2847       if (!s2_begin)
2848         return true;
2849       return s1.index() < s2.index();
2850     }
2851
2852   // crtend.o must come last.
2853   bool s1_end = s1.match_file_name("crtend");
2854   bool s2_end = s2.match_file_name("crtend");
2855   if (s1_end || s2_end)
2856     {
2857       if (!s1_end)
2858         return true;
2859       if (!s2_end)
2860         return false;
2861       return s1.index() < s2.index();
2862     }
2863
2864   // We sort all the sections with no names to the end.
2865   if (!s1.section_has_name() || !s2.section_has_name())
2866     {
2867       if (s1.section_has_name())
2868         return true;
2869       if (s2.section_has_name())
2870         return false;
2871       return s1.index() < s2.index();
2872     }
2873
2874   // A section with a priority follows a section without a priority.
2875   bool s1_has_priority = s1.has_priority();
2876   bool s2_has_priority = s2.has_priority();
2877   if (s1_has_priority && !s2_has_priority)
2878     return false;
2879   if (!s1_has_priority && s2_has_priority)
2880     return true;
2881
2882   // Check if a section order exists for these sections through a section
2883   // ordering file.  If sequence_num is 0, an order does not exist.
2884   int sequence_num = s1.compare_section_ordering(s2);
2885   if (sequence_num != 0)
2886     return sequence_num == 1;
2887
2888   // Otherwise we sort by name.
2889   int compare = s1.section_name().compare(s2.section_name());
2890   if (compare != 0)
2891     return compare < 0;
2892
2893   // Otherwise we keep the input order.
2894   return s1.index() < s2.index();
2895 }
2896
2897 // Return true if S1 should come before S2 in an .init_array or .fini_array
2898 // output section.
2899
2900 bool
2901 Output_section::Input_section_sort_init_fini_compare::operator()(
2902     const Output_section::Input_section_sort_entry& s1,
2903     const Output_section::Input_section_sort_entry& s2) const
2904 {
2905   // We sort all the sections with no names to the end.
2906   if (!s1.section_has_name() || !s2.section_has_name())
2907     {
2908       if (s1.section_has_name())
2909         return true;
2910       if (s2.section_has_name())
2911         return false;
2912       return s1.index() < s2.index();
2913     }
2914
2915   // A section without a priority follows a section with a priority.
2916   // This is the reverse of .ctors and .dtors sections.
2917   bool s1_has_priority = s1.has_priority();
2918   bool s2_has_priority = s2.has_priority();
2919   if (s1_has_priority && !s2_has_priority)
2920     return true;
2921   if (!s1_has_priority && s2_has_priority)
2922     return false;
2923
2924   // Check if a section order exists for these sections through a section
2925   // ordering file.  If sequence_num is 0, an order does not exist.
2926   int sequence_num = s1.compare_section_ordering(s2);
2927   if (sequence_num != 0)
2928     return sequence_num == 1;
2929
2930   // Otherwise we sort by name.
2931   int compare = s1.section_name().compare(s2.section_name());
2932   if (compare != 0)
2933     return compare < 0;
2934
2935   // Otherwise we keep the input order.
2936   return s1.index() < s2.index();
2937 }
2938
2939 // Return true if S1 should come before S2.  Sections that do not match
2940 // any pattern in the section ordering file are placed ahead of the sections
2941 // that match some pattern.
2942
2943 bool
2944 Output_section::Input_section_sort_section_order_index_compare::operator()(
2945     const Output_section::Input_section_sort_entry& s1,
2946     const Output_section::Input_section_sort_entry& s2) const
2947 {
2948   unsigned int s1_secn_index = s1.input_section().section_order_index();
2949   unsigned int s2_secn_index = s2.input_section().section_order_index();
2950
2951   // Keep input order if section ordering cannot determine order.
2952   if (s1_secn_index == s2_secn_index)
2953     return s1.index() < s2.index();
2954
2955   return s1_secn_index < s2_secn_index;
2956 }
2957
2958 // Sort the input sections attached to an output section.
2959
2960 void
2961 Output_section::sort_attached_input_sections()
2962 {
2963   if (this->attached_input_sections_are_sorted_)
2964     return;
2965
2966   if (this->checkpoint_ != NULL
2967       && !this->checkpoint_->input_sections_saved())
2968     this->checkpoint_->save_input_sections();
2969
2970   // The only thing we know about an input section is the object and
2971   // the section index.  We need the section name.  Recomputing this
2972   // is slow but this is an unusual case.  If this becomes a speed
2973   // problem we can cache the names as required in Layout::layout.
2974
2975   // We start by building a larger vector holding a copy of each
2976   // Input_section, plus its current index in the list and its name.
2977   std::vector<Input_section_sort_entry> sort_list;
2978
2979   unsigned int i = 0;
2980   for (Input_section_list::iterator p = this->input_sections_.begin();
2981        p != this->input_sections_.end();
2982        ++p, ++i)
2983       sort_list.push_back(Input_section_sort_entry(*p, i,
2984                             this->must_sort_attached_input_sections()));
2985
2986   // Sort the input sections.
2987   if (this->must_sort_attached_input_sections())
2988     {
2989       if (this->type() == elfcpp::SHT_PREINIT_ARRAY
2990           || this->type() == elfcpp::SHT_INIT_ARRAY
2991           || this->type() == elfcpp::SHT_FINI_ARRAY)
2992         std::sort(sort_list.begin(), sort_list.end(),
2993                   Input_section_sort_init_fini_compare());
2994       else
2995         std::sort(sort_list.begin(), sort_list.end(),
2996                   Input_section_sort_compare());
2997     }
2998   else
2999     {
3000       gold_assert(parameters->options().section_ordering_file());
3001       std::sort(sort_list.begin(), sort_list.end(),
3002                 Input_section_sort_section_order_index_compare());
3003     }
3004
3005   // Copy the sorted input sections back to our list.
3006   this->input_sections_.clear();
3007   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
3008        p != sort_list.end();
3009        ++p)
3010     this->input_sections_.push_back(p->input_section());
3011   sort_list.clear();
3012
3013   // Remember that we sorted the input sections, since we might get
3014   // called again.
3015   this->attached_input_sections_are_sorted_ = true;
3016 }
3017
3018 // Write the section header to *OSHDR.
3019
3020 template<int size, bool big_endian>
3021 void
3022 Output_section::write_header(const Layout* layout,
3023                              const Stringpool* secnamepool,
3024                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
3025 {
3026   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
3027   oshdr->put_sh_type(this->type_);
3028
3029   elfcpp::Elf_Xword flags = this->flags_;
3030   if (this->info_section_ != NULL && this->info_uses_section_index_)
3031     flags |= elfcpp::SHF_INFO_LINK;
3032   oshdr->put_sh_flags(flags);
3033
3034   oshdr->put_sh_addr(this->address());
3035   oshdr->put_sh_offset(this->offset());
3036   oshdr->put_sh_size(this->data_size());
3037   if (this->link_section_ != NULL)
3038     oshdr->put_sh_link(this->link_section_->out_shndx());
3039   else if (this->should_link_to_symtab_)
3040     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
3041   else if (this->should_link_to_dynsym_)
3042     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
3043   else
3044     oshdr->put_sh_link(this->link_);
3045
3046   elfcpp::Elf_Word info;
3047   if (this->info_section_ != NULL)
3048     {
3049       if (this->info_uses_section_index_)
3050         info = this->info_section_->out_shndx();
3051       else
3052         info = this->info_section_->symtab_index();
3053     }
3054   else if (this->info_symndx_ != NULL)
3055     info = this->info_symndx_->symtab_index();
3056   else
3057     info = this->info_;
3058   oshdr->put_sh_info(info);
3059
3060   oshdr->put_sh_addralign(this->addralign_);
3061   oshdr->put_sh_entsize(this->entsize_);
3062 }
3063
3064 // Write out the data.  For input sections the data is written out by
3065 // Object::relocate, but we have to handle Output_section_data objects
3066 // here.
3067
3068 void
3069 Output_section::do_write(Output_file* of)
3070 {
3071   gold_assert(!this->requires_postprocessing());
3072
3073   // If the target performs relaxation, we delay filler generation until now.
3074   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3075
3076   off_t output_section_file_offset = this->offset();
3077   for (Fill_list::iterator p = this->fills_.begin();
3078        p != this->fills_.end();
3079        ++p)
3080     {
3081       std::string fill_data(parameters->target().code_fill(p->length()));
3082       of->write(output_section_file_offset + p->section_offset(),
3083                 fill_data.data(), fill_data.size());
3084     }
3085
3086   off_t off = this->offset() + this->first_input_offset_;
3087   for (Input_section_list::iterator p = this->input_sections_.begin();
3088        p != this->input_sections_.end();
3089        ++p)
3090     {
3091       off_t aligned_off = align_address(off, p->addralign());
3092       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3093         {
3094           size_t fill_len = aligned_off - off;
3095           std::string fill_data(parameters->target().code_fill(fill_len));
3096           of->write(off, fill_data.data(), fill_data.size());
3097         }
3098
3099       p->write(of);
3100       off = aligned_off + p->data_size();
3101     }
3102 }
3103
3104 // If a section requires postprocessing, create the buffer to use.
3105
3106 void
3107 Output_section::create_postprocessing_buffer()
3108 {
3109   gold_assert(this->requires_postprocessing());
3110
3111   if (this->postprocessing_buffer_ != NULL)
3112     return;
3113
3114   if (!this->input_sections_.empty())
3115     {
3116       off_t off = this->first_input_offset_;
3117       for (Input_section_list::iterator p = this->input_sections_.begin();
3118            p != this->input_sections_.end();
3119            ++p)
3120         {
3121           off = align_address(off, p->addralign());
3122           p->finalize_data_size();
3123           off += p->data_size();
3124         }
3125       this->set_current_data_size_for_child(off);
3126     }
3127
3128   off_t buffer_size = this->current_data_size_for_child();
3129   this->postprocessing_buffer_ = new unsigned char[buffer_size];
3130 }
3131
3132 // Write all the data of an Output_section into the postprocessing
3133 // buffer.  This is used for sections which require postprocessing,
3134 // such as compression.  Input sections are handled by
3135 // Object::Relocate.
3136
3137 void
3138 Output_section::write_to_postprocessing_buffer()
3139 {
3140   gold_assert(this->requires_postprocessing());
3141
3142   // If the target performs relaxation, we delay filler generation until now.
3143   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3144
3145   unsigned char* buffer = this->postprocessing_buffer();
3146   for (Fill_list::iterator p = this->fills_.begin();
3147        p != this->fills_.end();
3148        ++p)
3149     {
3150       std::string fill_data(parameters->target().code_fill(p->length()));
3151       memcpy(buffer + p->section_offset(), fill_data.data(),
3152              fill_data.size());
3153     }
3154
3155   off_t off = this->first_input_offset_;
3156   for (Input_section_list::iterator p = this->input_sections_.begin();
3157        p != this->input_sections_.end();
3158        ++p)
3159     {
3160       off_t aligned_off = align_address(off, p->addralign());
3161       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3162         {
3163           size_t fill_len = aligned_off - off;
3164           std::string fill_data(parameters->target().code_fill(fill_len));
3165           memcpy(buffer + off, fill_data.data(), fill_data.size());
3166         }
3167
3168       p->write_to_buffer(buffer + aligned_off);
3169       off = aligned_off + p->data_size();
3170     }
3171 }
3172
3173 // Get the input sections for linker script processing.  We leave
3174 // behind the Output_section_data entries.  Note that this may be
3175 // slightly incorrect for merge sections.  We will leave them behind,
3176 // but it is possible that the script says that they should follow
3177 // some other input sections, as in:
3178 //    .rodata { *(.rodata) *(.rodata.cst*) }
3179 // For that matter, we don't handle this correctly:
3180 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
3181 // With luck this will never matter.
3182
3183 uint64_t
3184 Output_section::get_input_sections(
3185     uint64_t address,
3186     const std::string& fill,
3187     std::list<Input_section>* input_sections)
3188 {
3189   if (this->checkpoint_ != NULL
3190       && !this->checkpoint_->input_sections_saved())
3191     this->checkpoint_->save_input_sections();
3192
3193   // Invalidate fast look-up maps.
3194   this->lookup_maps_->invalidate();
3195
3196   uint64_t orig_address = address;
3197
3198   address = align_address(address, this->addralign());
3199
3200   Input_section_list remaining;
3201   for (Input_section_list::iterator p = this->input_sections_.begin();
3202        p != this->input_sections_.end();
3203        ++p)
3204     {
3205       if (p->is_input_section()
3206           || p->is_relaxed_input_section()
3207           || p->is_merge_section())
3208         input_sections->push_back(*p);
3209       else
3210         {
3211           uint64_t aligned_address = align_address(address, p->addralign());
3212           if (aligned_address != address && !fill.empty())
3213             {
3214               section_size_type length =
3215                 convert_to_section_size_type(aligned_address - address);
3216               std::string this_fill;
3217               this_fill.reserve(length);
3218               while (this_fill.length() + fill.length() <= length)
3219                 this_fill += fill;
3220               if (this_fill.length() < length)
3221                 this_fill.append(fill, 0, length - this_fill.length());
3222
3223               Output_section_data* posd = new Output_data_const(this_fill, 0);
3224               remaining.push_back(Input_section(posd));
3225             }
3226           address = aligned_address;
3227
3228           remaining.push_back(*p);
3229
3230           p->finalize_data_size();
3231           address += p->data_size();
3232         }
3233     }
3234
3235   this->input_sections_.swap(remaining);
3236   this->first_input_offset_ = 0;
3237
3238   uint64_t data_size = address - orig_address;
3239   this->set_current_data_size_for_child(data_size);
3240   return data_size;
3241 }
3242
3243 // Add a script input section.  SIS is an Output_section::Input_section,
3244 // which can be either a plain input section or a special input section like
3245 // a relaxed input section.  For a special input section, its size must be
3246 // finalized.
3247
3248 void
3249 Output_section::add_script_input_section(const Input_section& sis)
3250 {
3251   uint64_t data_size = sis.data_size();
3252   uint64_t addralign = sis.addralign();
3253   if (addralign > this->addralign_)
3254     this->addralign_ = addralign;
3255
3256   off_t offset_in_section = this->current_data_size_for_child();
3257   off_t aligned_offset_in_section = align_address(offset_in_section,
3258                                                   addralign);
3259
3260   this->set_current_data_size_for_child(aligned_offset_in_section
3261                                         + data_size);
3262
3263   this->input_sections_.push_back(sis);
3264
3265   // Update fast lookup maps if necessary.
3266   if (this->lookup_maps_->is_valid())
3267     {
3268       if (sis.is_merge_section())
3269         {
3270           Output_merge_base* pomb = sis.output_merge_base();
3271           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
3272                                        pomb->addralign());
3273           this->lookup_maps_->add_merge_section(msp, pomb);
3274           for (Output_merge_base::Input_sections::const_iterator p =
3275                  pomb->input_sections_begin();
3276                p != pomb->input_sections_end();
3277                ++p)
3278             this->lookup_maps_->add_merge_input_section(p->first, p->second,
3279                                                         pomb);
3280         }
3281       else if (sis.is_relaxed_input_section())
3282         {
3283           Output_relaxed_input_section* poris = sis.relaxed_input_section();
3284           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
3285                                                         poris->shndx(), poris);
3286         }
3287     }
3288 }
3289
3290 // Save states for relaxation.
3291
3292 void
3293 Output_section::save_states()
3294 {
3295   gold_assert(this->checkpoint_ == NULL);
3296   Checkpoint_output_section* checkpoint =
3297     new Checkpoint_output_section(this->addralign_, this->flags_,
3298                                   this->input_sections_,
3299                                   this->first_input_offset_,
3300                                   this->attached_input_sections_are_sorted_);
3301   this->checkpoint_ = checkpoint;
3302   gold_assert(this->fills_.empty());
3303 }
3304
3305 void
3306 Output_section::discard_states()
3307 {
3308   gold_assert(this->checkpoint_ != NULL);
3309   delete this->checkpoint_;
3310   this->checkpoint_ = NULL;
3311   gold_assert(this->fills_.empty());
3312
3313   // Simply invalidate the fast lookup maps since we do not keep
3314   // track of them.
3315   this->lookup_maps_->invalidate();
3316 }
3317
3318 void
3319 Output_section::restore_states()
3320 {
3321   gold_assert(this->checkpoint_ != NULL);
3322   Checkpoint_output_section* checkpoint = this->checkpoint_;
3323
3324   this->addralign_ = checkpoint->addralign();
3325   this->flags_ = checkpoint->flags();
3326   this->first_input_offset_ = checkpoint->first_input_offset();
3327
3328   if (!checkpoint->input_sections_saved())
3329     {
3330       // If we have not copied the input sections, just resize it.
3331       size_t old_size = checkpoint->input_sections_size();
3332       gold_assert(this->input_sections_.size() >= old_size);
3333       this->input_sections_.resize(old_size);
3334     }
3335   else
3336     {
3337       // We need to copy the whole list.  This is not efficient for
3338       // extremely large output with hundreads of thousands of input
3339       // objects.  We may need to re-think how we should pass sections
3340       // to scripts.
3341       this->input_sections_ = *checkpoint->input_sections();
3342     }
3343
3344   this->attached_input_sections_are_sorted_ =
3345     checkpoint->attached_input_sections_are_sorted();
3346
3347   // Simply invalidate the fast lookup maps since we do not keep
3348   // track of them.
3349   this->lookup_maps_->invalidate();
3350 }
3351
3352 // Update the section offsets of input sections in this.  This is required if
3353 // relaxation causes some input sections to change sizes.
3354
3355 void
3356 Output_section::adjust_section_offsets()
3357 {
3358   if (!this->section_offsets_need_adjustment_)
3359     return;
3360
3361   off_t off = 0;
3362   for (Input_section_list::iterator p = this->input_sections_.begin();
3363        p != this->input_sections_.end();
3364        ++p)
3365     {
3366       off = align_address(off, p->addralign());
3367       if (p->is_input_section())
3368         p->relobj()->set_section_offset(p->shndx(), off);
3369       off += p->data_size();
3370     }
3371
3372   this->section_offsets_need_adjustment_ = false;
3373 }
3374
3375 // Print to the map file.
3376
3377 void
3378 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3379 {
3380   mapfile->print_output_section(this);
3381
3382   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3383        p != this->input_sections_.end();
3384        ++p)
3385     p->print_to_mapfile(mapfile);
3386 }
3387
3388 // Print stats for merge sections to stderr.
3389
3390 void
3391 Output_section::print_merge_stats()
3392 {
3393   Input_section_list::iterator p;
3394   for (p = this->input_sections_.begin();
3395        p != this->input_sections_.end();
3396        ++p)
3397     p->print_merge_stats(this->name_);
3398 }
3399
3400 // Output segment methods.
3401
3402 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3403   : output_data_(),
3404     output_bss_(),
3405     vaddr_(0),
3406     paddr_(0),
3407     memsz_(0),
3408     max_align_(0),
3409     min_p_align_(0),
3410     offset_(0),
3411     filesz_(0),
3412     type_(type),
3413     flags_(flags),
3414     is_max_align_known_(false),
3415     are_addresses_set_(false),
3416     is_large_data_segment_(false)
3417 {
3418   // The ELF ABI specifies that a PT_TLS segment always has PF_R as
3419   // the flags.
3420   if (type == elfcpp::PT_TLS)
3421     this->flags_ = elfcpp::PF_R;
3422 }
3423
3424 // Add an Output_section to an Output_segment.
3425
3426 void
3427 Output_segment::add_output_section(Output_section* os,
3428                                    elfcpp::Elf_Word seg_flags,
3429                                    bool do_sort)
3430 {
3431   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3432   gold_assert(!this->is_max_align_known_);
3433   gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3434   gold_assert(this->type() == elfcpp::PT_LOAD || !do_sort);
3435
3436   this->update_flags_for_output_section(seg_flags);
3437
3438   Output_segment::Output_data_list* pdl;
3439   if (os->type() == elfcpp::SHT_NOBITS)
3440     pdl = &this->output_bss_;
3441   else
3442     pdl = &this->output_data_;
3443
3444   // Note that while there may be many input sections in an output
3445   // section, there are normally only a few output sections in an
3446   // output segment.  The loops below are expected to be fast.
3447
3448   // So that PT_NOTE segments will work correctly, we need to ensure
3449   // that all SHT_NOTE sections are adjacent.
3450   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
3451     {
3452       Output_segment::Output_data_list::iterator p = pdl->end();
3453       do
3454         {
3455           --p;
3456           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
3457             {
3458               ++p;
3459               pdl->insert(p, os);
3460               return;
3461             }
3462         }
3463       while (p != pdl->begin());
3464     }
3465
3466   // Similarly, so that PT_TLS segments will work, we need to group
3467   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
3468   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
3469   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
3470   // correctly.  SHF_TLS sections get added to both a PT_LOAD segment
3471   // and the PT_TLS segment; we do this grouping only for the PT_LOAD
3472   // segment.
3473   if (this->type_ != elfcpp::PT_TLS
3474       && (os->flags() & elfcpp::SHF_TLS) != 0)
3475     {
3476       pdl = &this->output_data_;
3477       if (!pdl->empty())
3478         {
3479           bool nobits = os->type() == elfcpp::SHT_NOBITS;
3480           bool sawtls = false;
3481           Output_segment::Output_data_list::iterator p = pdl->end();
3482           gold_assert(p != pdl->begin());
3483           do
3484             {
3485               --p;
3486               bool insert;
3487               if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3488                 {
3489                   sawtls = true;
3490                   // Put a NOBITS section after the first TLS section.
3491                   // Put a PROGBITS section after the first
3492                   // TLS/PROGBITS section.
3493                   insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
3494                 }
3495               else
3496                 {
3497                   // If we've gone past the TLS sections, but we've
3498                   // seen a TLS section, then we need to insert this
3499                   // section now.
3500                   insert = sawtls;
3501                 }
3502
3503               if (insert)
3504                 {
3505                   ++p;
3506                   pdl->insert(p, os);
3507                   return;
3508                 }
3509             }
3510           while (p != pdl->begin());
3511         }
3512
3513       // There are no TLS sections yet; put this one at the requested
3514       // location in the section list.
3515     }
3516
3517   if (do_sort)
3518     {
3519       // For the PT_GNU_RELRO segment, we need to group relro
3520       // sections, and we need to put them before any non-relro
3521       // sections.  Any relro local sections go before relro non-local
3522       // sections.  One section may be marked as the last relro
3523       // section.
3524       if (os->is_relro())
3525         {
3526           gold_assert(pdl == &this->output_data_);
3527           Output_segment::Output_data_list::iterator p;
3528           for (p = pdl->begin(); p != pdl->end(); ++p)
3529             {
3530               if (!(*p)->is_section())
3531                 break;
3532
3533               Output_section* pos = (*p)->output_section();
3534               if (!pos->is_relro()
3535                   || (os->is_relro_local() && !pos->is_relro_local())
3536                   || (!os->is_last_relro() && pos->is_last_relro()))
3537                 break;
3538             }
3539
3540           pdl->insert(p, os);
3541           return;
3542         }
3543
3544       // One section may be marked as the first section which follows
3545       // the relro sections.
3546       if (os->is_first_non_relro())
3547         {
3548           gold_assert(pdl == &this->output_data_);
3549           Output_segment::Output_data_list::iterator p;
3550           for (p = pdl->begin(); p != pdl->end(); ++p)
3551             {
3552               if (!(*p)->is_section())
3553                 break;
3554
3555               Output_section* pos = (*p)->output_section();
3556               if (!pos->is_relro())
3557                 break;
3558             }
3559
3560           pdl->insert(p, os);
3561           return;
3562         }
3563     }
3564
3565   // Small data sections go at the end of the list of data sections.
3566   // If OS is not small, and there are small sections, we have to
3567   // insert it before the first small section.
3568   if (os->type() != elfcpp::SHT_NOBITS
3569       && !os->is_small_section()
3570       && !pdl->empty()
3571       && pdl->back()->is_section()
3572       && pdl->back()->output_section()->is_small_section())
3573     {
3574       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3575            p != pdl->end();
3576            ++p)
3577         {
3578           if ((*p)->is_section()
3579               && (*p)->output_section()->is_small_section())
3580             {
3581               pdl->insert(p, os);
3582               return;
3583             }
3584         }
3585       gold_unreachable();
3586     }
3587
3588   // A small BSS section goes at the start of the BSS sections, after
3589   // other small BSS sections.
3590   if (os->type() == elfcpp::SHT_NOBITS && os->is_small_section())
3591     {
3592       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3593            p != pdl->end();
3594            ++p)
3595         {
3596           if (!(*p)->is_section()
3597               || !(*p)->output_section()->is_small_section())
3598             {
3599               pdl->insert(p, os);
3600               return;
3601             }
3602         }
3603     }
3604
3605   // A large BSS section goes at the end of the BSS sections, which
3606   // means that one that is not large must come before the first large
3607   // one.
3608   if (os->type() == elfcpp::SHT_NOBITS
3609       && !os->is_large_section()
3610       && !pdl->empty()
3611       && pdl->back()->is_section()
3612       && pdl->back()->output_section()->is_large_section())
3613     {
3614       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3615            p != pdl->end();
3616            ++p)
3617         {
3618           if ((*p)->is_section()
3619               && (*p)->output_section()->is_large_section())
3620             {
3621               pdl->insert(p, os);
3622               return;
3623             }
3624         }
3625       gold_unreachable();
3626     }
3627
3628   // We do some further output section sorting in order to make the
3629   // generated program run more efficiently.  We should only do this
3630   // when not using a linker script, so it is controled by the DO_SORT
3631   // parameter.
3632   if (do_sort)
3633     {
3634       // FreeBSD requires the .interp section to be in the first page
3635       // of the executable.  That is a more efficient location anyhow
3636       // for any OS, since it means that the kernel will have the data
3637       // handy after it reads the program headers.
3638       if (os->is_interp() && !pdl->empty())
3639         {
3640           pdl->insert(pdl->begin(), os);
3641           return;
3642         }
3643
3644       // Put loadable non-writable notes immediately after the .interp
3645       // sections, so that the PT_NOTE segment is on the first page of
3646       // the executable.
3647       if (os->type() == elfcpp::SHT_NOTE
3648           && (os->flags() & elfcpp::SHF_WRITE) == 0
3649           && !pdl->empty())
3650         {
3651           Output_segment::Output_data_list::iterator p = pdl->begin();
3652           if ((*p)->is_section() && (*p)->output_section()->is_interp())
3653             ++p;
3654           pdl->insert(p, os);
3655           return;
3656         }
3657
3658       // If this section is used by the dynamic linker, and it is not
3659       // writable, then put it first, after the .interp section and
3660       // any loadable notes.  This makes it more likely that the
3661       // dynamic linker will have to read less data from the disk.
3662       if (os->is_dynamic_linker_section()
3663           && !pdl->empty()
3664           && (os->flags() & elfcpp::SHF_WRITE) == 0)
3665         {
3666           bool is_reloc = (os->type() == elfcpp::SHT_REL
3667                            || os->type() == elfcpp::SHT_RELA);
3668           Output_segment::Output_data_list::iterator p = pdl->begin();
3669           while (p != pdl->end()
3670                  && (*p)->is_section()
3671                  && ((*p)->output_section()->is_dynamic_linker_section()
3672                      || (*p)->output_section()->type() == elfcpp::SHT_NOTE))
3673             {
3674               // Put reloc sections after the other ones.  Putting the
3675               // dynamic reloc sections first confuses BFD, notably
3676               // objcopy and strip.
3677               if (!is_reloc
3678                   && ((*p)->output_section()->type() == elfcpp::SHT_REL
3679                       || (*p)->output_section()->type() == elfcpp::SHT_RELA))
3680                 break;
3681               ++p;
3682             }
3683           pdl->insert(p, os);
3684           return;
3685         }
3686     }
3687
3688   // If there were no constraints on the output section, just add it
3689   // to the end of the list.
3690   pdl->push_back(os);
3691 }
3692
3693 // Remove an Output_section from this segment.  It is an error if it
3694 // is not present.
3695
3696 void
3697 Output_segment::remove_output_section(Output_section* os)
3698 {
3699   // We only need this for SHT_PROGBITS.
3700   gold_assert(os->type() == elfcpp::SHT_PROGBITS);
3701   for (Output_data_list::iterator p = this->output_data_.begin();
3702        p != this->output_data_.end();
3703        ++p)
3704    {
3705      if (*p == os)
3706        {
3707          this->output_data_.erase(p);
3708          return;
3709        }
3710    }
3711   gold_unreachable();
3712 }
3713
3714 // Add an Output_data (which need not be an Output_section) to the
3715 // start of a segment.
3716
3717 void
3718 Output_segment::add_initial_output_data(Output_data* od)
3719 {
3720   gold_assert(!this->is_max_align_known_);
3721   this->output_data_.push_front(od);
3722 }
3723
3724 // Return whether the first data section is a relro section.
3725
3726 bool
3727 Output_segment::is_first_section_relro() const
3728 {
3729   return (!this->output_data_.empty()
3730           && this->output_data_.front()->is_section()
3731           && this->output_data_.front()->output_section()->is_relro());
3732 }
3733
3734 // Return the maximum alignment of the Output_data in Output_segment.
3735
3736 uint64_t
3737 Output_segment::maximum_alignment()
3738 {
3739   if (!this->is_max_align_known_)
3740     {
3741       uint64_t addralign;
3742
3743       addralign = Output_segment::maximum_alignment_list(&this->output_data_);
3744       if (addralign > this->max_align_)
3745         this->max_align_ = addralign;
3746
3747       addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
3748       if (addralign > this->max_align_)
3749         this->max_align_ = addralign;
3750
3751       this->is_max_align_known_ = true;
3752     }
3753
3754   return this->max_align_;
3755 }
3756
3757 // Return the maximum alignment of a list of Output_data.
3758
3759 uint64_t
3760 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3761 {
3762   uint64_t ret = 0;
3763   for (Output_data_list::const_iterator p = pdl->begin();
3764        p != pdl->end();
3765        ++p)
3766     {
3767       uint64_t addralign = (*p)->addralign();
3768       if (addralign > ret)
3769         ret = addralign;
3770     }
3771   return ret;
3772 }
3773
3774 // Return the number of dynamic relocs applied to this segment.
3775
3776 unsigned int
3777 Output_segment::dynamic_reloc_count() const
3778 {
3779   return (this->dynamic_reloc_count_list(&this->output_data_)
3780           + this->dynamic_reloc_count_list(&this->output_bss_));
3781 }
3782
3783 // Return the number of dynamic relocs applied to an Output_data_list.
3784
3785 unsigned int
3786 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
3787 {
3788   unsigned int count = 0;
3789   for (Output_data_list::const_iterator p = pdl->begin();
3790        p != pdl->end();
3791        ++p)
3792     count += (*p)->dynamic_reloc_count();
3793   return count;
3794 }
3795
3796 // Set the section addresses for an Output_segment.  If RESET is true,
3797 // reset the addresses first.  ADDR is the address and *POFF is the
3798 // file offset.  Set the section indexes starting with *PSHNDX.
3799 // Return the address of the immediately following segment.  Update
3800 // *POFF and *PSHNDX.
3801
3802 uint64_t
3803 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3804                                       uint64_t addr,
3805                                       unsigned int increase_relro,
3806                                       off_t* poff,
3807                                       unsigned int* pshndx)
3808 {
3809   gold_assert(this->type_ == elfcpp::PT_LOAD);
3810
3811   off_t orig_off = *poff;
3812
3813   // If we have relro sections, we need to pad forward now so that the
3814   // relro sections plus INCREASE_RELRO end on a common page boundary.
3815   if (parameters->options().relro()
3816       && this->is_first_section_relro()
3817       && (!this->are_addresses_set_ || reset))
3818     {
3819       uint64_t relro_size = 0;
3820       off_t off = *poff;
3821       for (Output_data_list::iterator p = this->output_data_.begin();
3822            p != this->output_data_.end();
3823            ++p)
3824         {
3825           if (!(*p)->is_section())
3826             break;
3827           Output_section* pos = (*p)->output_section();
3828           if (!pos->is_relro())
3829             break;
3830           gold_assert(!(*p)->is_section_flag_set(elfcpp::SHF_TLS));
3831           if ((*p)->is_address_valid())
3832             relro_size += (*p)->data_size();
3833           else
3834             {
3835               // FIXME: This could be faster.
3836               (*p)->set_address_and_file_offset(addr + relro_size,
3837                                                 off + relro_size);
3838               relro_size += (*p)->data_size();
3839               (*p)->reset_address_and_file_offset();
3840             }
3841         }
3842       relro_size += increase_relro;
3843
3844       uint64_t page_align = parameters->target().common_pagesize();
3845
3846       // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
3847       uint64_t desired_align = page_align - (relro_size % page_align);
3848       if (desired_align < *poff % page_align)
3849         *poff += page_align - *poff % page_align;
3850       *poff += desired_align - *poff % page_align;
3851       addr += *poff - orig_off;
3852       orig_off = *poff;
3853     }
3854
3855   if (!reset && this->are_addresses_set_)
3856     {
3857       gold_assert(this->paddr_ == addr);
3858       addr = this->vaddr_;
3859     }
3860   else
3861     {
3862       this->vaddr_ = addr;
3863       this->paddr_ = addr;
3864       this->are_addresses_set_ = true;
3865     }
3866
3867   bool in_tls = false;
3868
3869   this->offset_ = orig_off;
3870
3871   addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
3872                                           addr, poff, pshndx, &in_tls);
3873   this->filesz_ = *poff - orig_off;
3874
3875   off_t off = *poff;
3876
3877   uint64_t ret = this->set_section_list_addresses(layout, reset,
3878                                                   &this->output_bss_,
3879                                                   addr, poff, pshndx,
3880                                                   &in_tls);
3881
3882   // If the last section was a TLS section, align upward to the
3883   // alignment of the TLS segment, so that the overall size of the TLS
3884   // segment is aligned.
3885   if (in_tls)
3886     {
3887       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3888       *poff = align_address(*poff, segment_align);
3889     }
3890
3891   this->memsz_ = *poff - orig_off;
3892
3893   // Ignore the file offset adjustments made by the BSS Output_data
3894   // objects.
3895   *poff = off;
3896
3897   return ret;
3898 }
3899
3900 // Set the addresses and file offsets in a list of Output_data
3901 // structures.
3902
3903 uint64_t
3904 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3905                                            Output_data_list* pdl,
3906                                            uint64_t addr, off_t* poff,
3907                                            unsigned int* pshndx,
3908                                            bool* in_tls)
3909 {
3910   off_t startoff = *poff;
3911
3912   off_t off = startoff;
3913   for (Output_data_list::iterator p = pdl->begin();
3914        p != pdl->end();
3915        ++p)
3916     {
3917       if (reset)
3918         (*p)->reset_address_and_file_offset();
3919
3920       // When using a linker script the section will most likely
3921       // already have an address.
3922       if (!(*p)->is_address_valid())
3923         {
3924           uint64_t align = (*p)->addralign();
3925
3926           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3927             {
3928               // Give the first TLS section the alignment of the
3929               // entire TLS segment.  Otherwise the TLS segment as a
3930               // whole may be misaligned.
3931               if (!*in_tls)
3932                 {
3933                   Output_segment* tls_segment = layout->tls_segment();
3934                   gold_assert(tls_segment != NULL);
3935                   uint64_t segment_align = tls_segment->maximum_alignment();
3936                   gold_assert(segment_align >= align);
3937                   align = segment_align;
3938
3939                   *in_tls = true;
3940                 }
3941             }
3942           else
3943             {
3944               // If this is the first section after the TLS segment,
3945               // align it to at least the alignment of the TLS
3946               // segment, so that the size of the overall TLS segment
3947               // is aligned.
3948               if (*in_tls)
3949                 {
3950                   uint64_t segment_align =
3951                       layout->tls_segment()->maximum_alignment();
3952                   if (segment_align > align)
3953                     align = segment_align;
3954
3955                   *in_tls = false;
3956                 }
3957             }
3958
3959           off = align_address(off, align);
3960           (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3961         }
3962       else
3963         {
3964           // The script may have inserted a skip forward, but it
3965           // better not have moved backward.
3966           if ((*p)->address() >= addr + (off - startoff))
3967             off += (*p)->address() - (addr + (off - startoff));
3968           else
3969             {
3970               if (!layout->script_options()->saw_sections_clause())
3971                 gold_unreachable();
3972               else
3973                 {
3974                   Output_section* os = (*p)->output_section();
3975
3976                   // Cast to unsigned long long to avoid format warnings.
3977                   unsigned long long previous_dot =
3978                     static_cast<unsigned long long>(addr + (off - startoff));
3979                   unsigned long long dot =
3980                     static_cast<unsigned long long>((*p)->address());
3981
3982                   if (os == NULL)
3983                     gold_error(_("dot moves backward in linker script "
3984                                  "from 0x%llx to 0x%llx"), previous_dot, dot);
3985                   else
3986                     gold_error(_("address of section '%s' moves backward "
3987                                  "from 0x%llx to 0x%llx"),
3988                                os->name(), previous_dot, dot);
3989                 }
3990             }
3991           (*p)->set_file_offset(off);
3992           (*p)->finalize_data_size();
3993         }
3994
3995       // We want to ignore the size of a SHF_TLS or SHT_NOBITS
3996       // section.  Such a section does not affect the size of a
3997       // PT_LOAD segment.
3998       if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
3999           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
4000         off += (*p)->data_size();
4001
4002       if ((*p)->is_section())
4003         {
4004           (*p)->set_out_shndx(*pshndx);
4005           ++*pshndx;
4006         }
4007     }
4008
4009   *poff = off;
4010   return addr + (off - startoff);
4011 }
4012
4013 // For a non-PT_LOAD segment, set the offset from the sections, if
4014 // any.  Add INCREASE to the file size and the memory size.
4015
4016 void
4017 Output_segment::set_offset(unsigned int increase)
4018 {
4019   gold_assert(this->type_ != elfcpp::PT_LOAD);
4020
4021   gold_assert(!this->are_addresses_set_);
4022
4023   if (this->output_data_.empty() && this->output_bss_.empty())
4024     {
4025       gold_assert(increase == 0);
4026       this->vaddr_ = 0;
4027       this->paddr_ = 0;
4028       this->are_addresses_set_ = true;
4029       this->memsz_ = 0;
4030       this->min_p_align_ = 0;
4031       this->offset_ = 0;
4032       this->filesz_ = 0;
4033       return;
4034     }
4035
4036   const Output_data* first;
4037   if (this->output_data_.empty())
4038     first = this->output_bss_.front();
4039   else
4040     first = this->output_data_.front();
4041   this->vaddr_ = first->address();
4042   this->paddr_ = (first->has_load_address()
4043                   ? first->load_address()
4044                   : this->vaddr_);
4045   this->are_addresses_set_ = true;
4046   this->offset_ = first->offset();
4047
4048   if (this->output_data_.empty())
4049     this->filesz_ = 0;
4050   else
4051     {
4052       const Output_data* last_data = this->output_data_.back();
4053       this->filesz_ = (last_data->address()
4054                        + last_data->data_size()
4055                        - this->vaddr_);
4056     }
4057
4058   const Output_data* last;
4059   if (this->output_bss_.empty())
4060     last = this->output_data_.back();
4061   else
4062     last = this->output_bss_.back();
4063   this->memsz_ = (last->address()
4064                   + last->data_size()
4065                   - this->vaddr_);
4066
4067   this->filesz_ += increase;
4068   this->memsz_ += increase;
4069
4070   // If this is a TLS segment, align the memory size.  The code in
4071   // set_section_list ensures that the section after the TLS segment
4072   // is aligned to give us room.
4073   if (this->type_ == elfcpp::PT_TLS)
4074     {
4075       uint64_t segment_align = this->maximum_alignment();
4076       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
4077       this->memsz_ = align_address(this->memsz_, segment_align);
4078     }
4079 }
4080
4081 // Set the TLS offsets of the sections in the PT_TLS segment.
4082
4083 void
4084 Output_segment::set_tls_offsets()
4085 {
4086   gold_assert(this->type_ == elfcpp::PT_TLS);
4087
4088   for (Output_data_list::iterator p = this->output_data_.begin();
4089        p != this->output_data_.end();
4090        ++p)
4091     (*p)->set_tls_offset(this->vaddr_);
4092
4093   for (Output_data_list::iterator p = this->output_bss_.begin();
4094        p != this->output_bss_.end();
4095        ++p)
4096     (*p)->set_tls_offset(this->vaddr_);
4097 }
4098
4099 // Return the address of the first section.
4100
4101 uint64_t
4102 Output_segment::first_section_load_address() const
4103 {
4104   for (Output_data_list::const_iterator p = this->output_data_.begin();
4105        p != this->output_data_.end();
4106        ++p)
4107     if ((*p)->is_section())
4108       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
4109
4110   for (Output_data_list::const_iterator p = this->output_bss_.begin();
4111        p != this->output_bss_.end();
4112        ++p)
4113     if ((*p)->is_section())
4114       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
4115
4116   gold_unreachable();
4117 }
4118
4119 // Return the number of Output_sections in an Output_segment.
4120
4121 unsigned int
4122 Output_segment::output_section_count() const
4123 {
4124   return (this->output_section_count_list(&this->output_data_)
4125           + this->output_section_count_list(&this->output_bss_));
4126 }
4127
4128 // Return the number of Output_sections in an Output_data_list.
4129
4130 unsigned int
4131 Output_segment::output_section_count_list(const Output_data_list* pdl) const
4132 {
4133   unsigned int count = 0;
4134   for (Output_data_list::const_iterator p = pdl->begin();
4135        p != pdl->end();
4136        ++p)
4137     {
4138       if ((*p)->is_section())
4139         ++count;
4140     }
4141   return count;
4142 }
4143
4144 // Return the section attached to the list segment with the lowest
4145 // load address.  This is used when handling a PHDRS clause in a
4146 // linker script.
4147
4148 Output_section*
4149 Output_segment::section_with_lowest_load_address() const
4150 {
4151   Output_section* found = NULL;
4152   uint64_t found_lma = 0;
4153   this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma);
4154
4155   Output_section* found_data = found;
4156   this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma);
4157   if (found != found_data && found_data != NULL)
4158     {
4159       gold_error(_("nobits section %s may not precede progbits section %s "
4160                    "in same segment"),
4161                  found->name(), found_data->name());
4162       return NULL;
4163     }
4164
4165   return found;
4166 }
4167
4168 // Look through a list for a section with a lower load address.
4169
4170 void
4171 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
4172                                             Output_section** found,
4173                                             uint64_t* found_lma) const
4174 {
4175   for (Output_data_list::const_iterator p = pdl->begin();
4176        p != pdl->end();
4177        ++p)
4178     {
4179       if (!(*p)->is_section())
4180         continue;
4181       Output_section* os = static_cast<Output_section*>(*p);
4182       uint64_t lma = (os->has_load_address()
4183                       ? os->load_address()
4184                       : os->address());
4185       if (*found == NULL || lma < *found_lma)
4186         {
4187           *found = os;
4188           *found_lma = lma;
4189         }
4190     }
4191 }
4192
4193 // Write the segment data into *OPHDR.
4194
4195 template<int size, bool big_endian>
4196 void
4197 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
4198 {
4199   ophdr->put_p_type(this->type_);
4200   ophdr->put_p_offset(this->offset_);
4201   ophdr->put_p_vaddr(this->vaddr_);
4202   ophdr->put_p_paddr(this->paddr_);
4203   ophdr->put_p_filesz(this->filesz_);
4204   ophdr->put_p_memsz(this->memsz_);
4205   ophdr->put_p_flags(this->flags_);
4206   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
4207 }
4208
4209 // Write the section headers into V.
4210
4211 template<int size, bool big_endian>
4212 unsigned char*
4213 Output_segment::write_section_headers(const Layout* layout,
4214                                       const Stringpool* secnamepool,
4215                                       unsigned char* v,
4216                                       unsigned int *pshndx) const
4217 {
4218   // Every section that is attached to a segment must be attached to a
4219   // PT_LOAD segment, so we only write out section headers for PT_LOAD
4220   // segments.
4221   if (this->type_ != elfcpp::PT_LOAD)
4222     return v;
4223
4224   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
4225                                                          &this->output_data_,
4226                                                          v, pshndx);
4227   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
4228                                                          &this->output_bss_,
4229                                                          v, pshndx);
4230   return v;
4231 }
4232
4233 template<int size, bool big_endian>
4234 unsigned char*
4235 Output_segment::write_section_headers_list(const Layout* layout,
4236                                            const Stringpool* secnamepool,
4237                                            const Output_data_list* pdl,
4238                                            unsigned char* v,
4239                                            unsigned int* pshndx) const
4240 {
4241   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
4242   for (Output_data_list::const_iterator p = pdl->begin();
4243        p != pdl->end();
4244        ++p)
4245     {
4246       if ((*p)->is_section())
4247         {
4248           const Output_section* ps = static_cast<const Output_section*>(*p);
4249           gold_assert(*pshndx == ps->out_shndx());
4250           elfcpp::Shdr_write<size, big_endian> oshdr(v);
4251           ps->write_header(layout, secnamepool, &oshdr);
4252           v += shdr_size;
4253           ++*pshndx;
4254         }
4255     }
4256   return v;
4257 }
4258
4259 // Print the output sections to the map file.
4260
4261 void
4262 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
4263 {
4264   if (this->type() != elfcpp::PT_LOAD)
4265     return;
4266   this->print_section_list_to_mapfile(mapfile, &this->output_data_);
4267   this->print_section_list_to_mapfile(mapfile, &this->output_bss_);
4268 }
4269
4270 // Print an output section list to the map file.
4271
4272 void
4273 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
4274                                               const Output_data_list* pdl) const
4275 {
4276   for (Output_data_list::const_iterator p = pdl->begin();
4277        p != pdl->end();
4278        ++p)
4279     (*p)->print_to_mapfile(mapfile);
4280 }
4281
4282 // Output_file methods.
4283
4284 Output_file::Output_file(const char* name)
4285   : name_(name),
4286     o_(-1),
4287     file_size_(0),
4288     base_(NULL),
4289     map_is_anonymous_(false),
4290     is_temporary_(false)
4291 {
4292 }
4293
4294 // Try to open an existing file.  Returns false if the file doesn't
4295 // exist, has a size of 0 or can't be mmapped.
4296
4297 bool
4298 Output_file::open_for_modification()
4299 {
4300   // The name "-" means "stdout".
4301   if (strcmp(this->name_, "-") == 0)
4302     return false;
4303
4304   // Don't bother opening files with a size of zero.
4305   struct stat s;
4306   if (::stat(this->name_, &s) != 0 || s.st_size == 0)
4307     return false;
4308
4309   int o = open_descriptor(-1, this->name_, O_RDWR, 0);
4310   if (o < 0)
4311     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4312   this->o_ = o;
4313   this->file_size_ = s.st_size;
4314
4315   // If the file can't be mmapped, copying the content to an anonymous
4316   // map will probably negate the performance benefits of incremental
4317   // linking.  This could be helped by using views and loading only
4318   // the necessary parts, but this is not supported as of now.
4319   if (!this->map_no_anonymous())
4320     {
4321       release_descriptor(o, true);
4322       this->o_ = -1;
4323       this->file_size_ = 0;
4324       return false;
4325     }
4326
4327   return true;
4328 }
4329
4330 // Open the output file.
4331
4332 void
4333 Output_file::open(off_t file_size)
4334 {
4335   this->file_size_ = file_size;
4336
4337   // Unlink the file first; otherwise the open() may fail if the file
4338   // is busy (e.g. it's an executable that's currently being executed).
4339   //
4340   // However, the linker may be part of a system where a zero-length
4341   // file is created for it to write to, with tight permissions (gcc
4342   // 2.95 did something like this).  Unlinking the file would work
4343   // around those permission controls, so we only unlink if the file
4344   // has a non-zero size.  We also unlink only regular files to avoid
4345   // trouble with directories/etc.
4346   //
4347   // If we fail, continue; this command is merely a best-effort attempt
4348   // to improve the odds for open().
4349
4350   // We let the name "-" mean "stdout"
4351   if (!this->is_temporary_)
4352     {
4353       if (strcmp(this->name_, "-") == 0)
4354         this->o_ = STDOUT_FILENO;
4355       else
4356         {
4357           struct stat s;
4358           if (::stat(this->name_, &s) == 0
4359               && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
4360             {
4361               if (s.st_size != 0)
4362                 ::unlink(this->name_);
4363               else if (!parameters->options().relocatable())
4364                 {
4365                   // If we don't unlink the existing file, add execute
4366                   // permission where read permissions already exist
4367                   // and where the umask permits.
4368                   int mask = ::umask(0);
4369                   ::umask(mask);
4370                   s.st_mode |= (s.st_mode & 0444) >> 2;
4371                   ::chmod(this->name_, s.st_mode & ~mask);
4372                 }
4373             }
4374
4375           int mode = parameters->options().relocatable() ? 0666 : 0777;
4376           int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
4377                                   mode);
4378           if (o < 0)
4379             gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4380           this->o_ = o;
4381         }
4382     }
4383
4384   this->map();
4385 }
4386
4387 // Resize the output file.
4388
4389 void
4390 Output_file::resize(off_t file_size)
4391 {
4392   // If the mmap is mapping an anonymous memory buffer, this is easy:
4393   // just mremap to the new size.  If it's mapping to a file, we want
4394   // to unmap to flush to the file, then remap after growing the file.
4395   if (this->map_is_anonymous_)
4396     {
4397       void* base = ::mremap(this->base_, this->file_size_, file_size,
4398                             MREMAP_MAYMOVE);
4399       if (base == MAP_FAILED)
4400         gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
4401       this->base_ = static_cast<unsigned char*>(base);
4402       this->file_size_ = file_size;
4403     }
4404   else
4405     {
4406       this->unmap();
4407       this->file_size_ = file_size;
4408       if (!this->map_no_anonymous())
4409         gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
4410     }
4411 }
4412
4413 // Map an anonymous block of memory which will later be written to the
4414 // file.  Return whether the map succeeded.
4415
4416 bool
4417 Output_file::map_anonymous()
4418 {
4419   void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4420                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
4421   if (base != MAP_FAILED)
4422     {
4423       this->map_is_anonymous_ = true;
4424       this->base_ = static_cast<unsigned char*>(base);
4425       return true;
4426     }
4427   return false;
4428 }
4429
4430 // Map the file into memory.  Return whether the mapping succeeded.
4431
4432 bool
4433 Output_file::map_no_anonymous()
4434 {
4435   const int o = this->o_;
4436
4437   // If the output file is not a regular file, don't try to mmap it;
4438   // instead, we'll mmap a block of memory (an anonymous buffer), and
4439   // then later write the buffer to the file.
4440   void* base;
4441   struct stat statbuf;
4442   if (o == STDOUT_FILENO || o == STDERR_FILENO
4443       || ::fstat(o, &statbuf) != 0
4444       || !S_ISREG(statbuf.st_mode)
4445       || this->is_temporary_)
4446     return false;
4447
4448   // Ensure that we have disk space available for the file.  If we
4449   // don't do this, it is possible that we will call munmap, close,
4450   // and exit with dirty buffers still in the cache with no assigned
4451   // disk blocks.  If the disk is out of space at that point, the
4452   // output file will wind up incomplete, but we will have already
4453   // exited.  The alternative to fallocate would be to use fdatasync,
4454   // but that would be a more significant performance hit.
4455   if (::posix_fallocate(o, 0, this->file_size_) < 0)
4456     gold_fatal(_("%s: %s"), this->name_, strerror(errno));
4457
4458   // Map the file into memory.
4459   base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4460                 MAP_SHARED, o, 0);
4461
4462   // The mmap call might fail because of file system issues: the file
4463   // system might not support mmap at all, or it might not support
4464   // mmap with PROT_WRITE.
4465   if (base == MAP_FAILED)
4466     return false;
4467
4468   this->map_is_anonymous_ = false;
4469   this->base_ = static_cast<unsigned char*>(base);
4470   return true;
4471 }
4472
4473 // Map the file into memory.
4474
4475 void
4476 Output_file::map()
4477 {
4478   if (this->map_no_anonymous())
4479     return;
4480
4481   // The mmap call might fail because of file system issues: the file
4482   // system might not support mmap at all, or it might not support
4483   // mmap with PROT_WRITE.  I'm not sure which errno values we will
4484   // see in all cases, so if the mmap fails for any reason and we
4485   // don't care about file contents, try for an anonymous map.
4486   if (this->map_anonymous())
4487     return;
4488
4489   gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
4490              this->name_, static_cast<unsigned long>(this->file_size_),
4491              strerror(errno));
4492 }
4493
4494 // Unmap the file from memory.
4495
4496 void
4497 Output_file::unmap()
4498 {
4499   if (::munmap(this->base_, this->file_size_) < 0)
4500     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4501   this->base_ = NULL;
4502 }
4503
4504 // Close the output file.
4505
4506 void
4507 Output_file::close()
4508 {
4509   // If the map isn't file-backed, we need to write it now.
4510   if (this->map_is_anonymous_ && !this->is_temporary_)
4511     {
4512       size_t bytes_to_write = this->file_size_;
4513       size_t offset = 0;
4514       while (bytes_to_write > 0)
4515         {
4516           ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4517                                           bytes_to_write);
4518           if (bytes_written == 0)
4519             gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4520           else if (bytes_written < 0)
4521             gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4522           else
4523             {
4524               bytes_to_write -= bytes_written;
4525               offset += bytes_written;
4526             }
4527         }
4528     }
4529   this->unmap();
4530
4531   // We don't close stdout or stderr
4532   if (this->o_ != STDOUT_FILENO
4533       && this->o_ != STDERR_FILENO
4534       && !this->is_temporary_)
4535     if (::close(this->o_) < 0)
4536       gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4537   this->o_ = -1;
4538 }
4539
4540 // Instantiate the templates we need.  We could use the configure
4541 // script to restrict this to only the ones for implemented targets.
4542
4543 #ifdef HAVE_TARGET_32_LITTLE
4544 template
4545 off_t
4546 Output_section::add_input_section<32, false>(
4547     Layout* layout,
4548     Sized_relobj<32, false>* object,
4549     unsigned int shndx,
4550     const char* secname,
4551     const elfcpp::Shdr<32, false>& shdr,
4552     unsigned int reloc_shndx,
4553     bool have_sections_script);
4554 #endif
4555
4556 #ifdef HAVE_TARGET_32_BIG
4557 template
4558 off_t
4559 Output_section::add_input_section<32, true>(
4560     Layout* layout,
4561     Sized_relobj<32, true>* object,
4562     unsigned int shndx,
4563     const char* secname,
4564     const elfcpp::Shdr<32, true>& shdr,
4565     unsigned int reloc_shndx,
4566     bool have_sections_script);
4567 #endif
4568
4569 #ifdef HAVE_TARGET_64_LITTLE
4570 template
4571 off_t
4572 Output_section::add_input_section<64, false>(
4573     Layout* layout,
4574     Sized_relobj<64, false>* object,
4575     unsigned int shndx,
4576     const char* secname,
4577     const elfcpp::Shdr<64, false>& shdr,
4578     unsigned int reloc_shndx,
4579     bool have_sections_script);
4580 #endif
4581
4582 #ifdef HAVE_TARGET_64_BIG
4583 template
4584 off_t
4585 Output_section::add_input_section<64, true>(
4586     Layout* layout,
4587     Sized_relobj<64, true>* object,
4588     unsigned int shndx,
4589     const char* secname,
4590     const elfcpp::Shdr<64, true>& shdr,
4591     unsigned int reloc_shndx,
4592     bool have_sections_script);
4593 #endif
4594
4595 #ifdef HAVE_TARGET_32_LITTLE
4596 template
4597 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4598 #endif
4599
4600 #ifdef HAVE_TARGET_32_BIG
4601 template
4602 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4603 #endif
4604
4605 #ifdef HAVE_TARGET_64_LITTLE
4606 template
4607 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4608 #endif
4609
4610 #ifdef HAVE_TARGET_64_BIG
4611 template
4612 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4613 #endif
4614
4615 #ifdef HAVE_TARGET_32_LITTLE
4616 template
4617 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4618 #endif
4619
4620 #ifdef HAVE_TARGET_32_BIG
4621 template
4622 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4623 #endif
4624
4625 #ifdef HAVE_TARGET_64_LITTLE
4626 template
4627 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4628 #endif
4629
4630 #ifdef HAVE_TARGET_64_BIG
4631 template
4632 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4633 #endif
4634
4635 #ifdef HAVE_TARGET_32_LITTLE
4636 template
4637 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4638 #endif
4639
4640 #ifdef HAVE_TARGET_32_BIG
4641 template
4642 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4643 #endif
4644
4645 #ifdef HAVE_TARGET_64_LITTLE
4646 template
4647 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4648 #endif
4649
4650 #ifdef HAVE_TARGET_64_BIG
4651 template
4652 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4653 #endif
4654
4655 #ifdef HAVE_TARGET_32_LITTLE
4656 template
4657 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4658 #endif
4659
4660 #ifdef HAVE_TARGET_32_BIG
4661 template
4662 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4663 #endif
4664
4665 #ifdef HAVE_TARGET_64_LITTLE
4666 template
4667 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4668 #endif
4669
4670 #ifdef HAVE_TARGET_64_BIG
4671 template
4672 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4673 #endif
4674
4675 #ifdef HAVE_TARGET_32_LITTLE
4676 template
4677 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4678 #endif
4679
4680 #ifdef HAVE_TARGET_32_BIG
4681 template
4682 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4683 #endif
4684
4685 #ifdef HAVE_TARGET_64_LITTLE
4686 template
4687 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4688 #endif
4689
4690 #ifdef HAVE_TARGET_64_BIG
4691 template
4692 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4693 #endif
4694
4695 #ifdef HAVE_TARGET_32_LITTLE
4696 template
4697 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4698 #endif
4699
4700 #ifdef HAVE_TARGET_32_BIG
4701 template
4702 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4703 #endif
4704
4705 #ifdef HAVE_TARGET_64_LITTLE
4706 template
4707 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4708 #endif
4709
4710 #ifdef HAVE_TARGET_64_BIG
4711 template
4712 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4713 #endif
4714
4715 #ifdef HAVE_TARGET_32_LITTLE
4716 template
4717 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4718 #endif
4719
4720 #ifdef HAVE_TARGET_32_BIG
4721 template
4722 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4723 #endif
4724
4725 #ifdef HAVE_TARGET_64_LITTLE
4726 template
4727 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4728 #endif
4729
4730 #ifdef HAVE_TARGET_64_BIG
4731 template
4732 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4733 #endif
4734
4735 #ifdef HAVE_TARGET_32_LITTLE
4736 template
4737 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4738 #endif
4739
4740 #ifdef HAVE_TARGET_32_BIG
4741 template
4742 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4743 #endif
4744
4745 #ifdef HAVE_TARGET_64_LITTLE
4746 template
4747 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4748 #endif
4749
4750 #ifdef HAVE_TARGET_64_BIG
4751 template
4752 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4753 #endif
4754
4755 #ifdef HAVE_TARGET_32_LITTLE
4756 template
4757 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4758 #endif
4759
4760 #ifdef HAVE_TARGET_32_BIG
4761 template
4762 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4763 #endif
4764
4765 #ifdef HAVE_TARGET_64_LITTLE
4766 template
4767 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4768 #endif
4769
4770 #ifdef HAVE_TARGET_64_BIG
4771 template
4772 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4773 #endif
4774
4775 #ifdef HAVE_TARGET_32_LITTLE
4776 template
4777 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4778 #endif
4779
4780 #ifdef HAVE_TARGET_32_BIG
4781 template
4782 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4783 #endif
4784
4785 #ifdef HAVE_TARGET_64_LITTLE
4786 template
4787 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4788 #endif
4789
4790 #ifdef HAVE_TARGET_64_BIG
4791 template
4792 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4793 #endif
4794
4795 #ifdef HAVE_TARGET_32_LITTLE
4796 template
4797 class Output_data_group<32, false>;
4798 #endif
4799
4800 #ifdef HAVE_TARGET_32_BIG
4801 template
4802 class Output_data_group<32, true>;
4803 #endif
4804
4805 #ifdef HAVE_TARGET_64_LITTLE
4806 template
4807 class Output_data_group<64, false>;
4808 #endif
4809
4810 #ifdef HAVE_TARGET_64_BIG
4811 template
4812 class Output_data_group<64, true>;
4813 #endif
4814
4815 #ifdef HAVE_TARGET_32_LITTLE
4816 template
4817 class Output_data_got<32, false>;
4818 #endif
4819
4820 #ifdef HAVE_TARGET_32_BIG
4821 template
4822 class Output_data_got<32, true>;
4823 #endif
4824
4825 #ifdef HAVE_TARGET_64_LITTLE
4826 template
4827 class Output_data_got<64, false>;
4828 #endif
4829
4830 #ifdef HAVE_TARGET_64_BIG
4831 template
4832 class Output_data_got<64, true>;
4833 #endif
4834
4835 } // End namespace gold.