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     always_keeps_input_sections_(false),
1953     tls_offset_(0),
1954     checkpoint_(NULL),
1955     lookup_maps_(new Output_section_lookup_maps)
1956 {
1957   // An unallocated section has no address.  Forcing this means that
1958   // we don't need special treatment for symbols defined in debug
1959   // sections.
1960   if ((flags & elfcpp::SHF_ALLOC) == 0)
1961     this->set_address(0);
1962 }
1963
1964 Output_section::~Output_section()
1965 {
1966   delete this->checkpoint_;
1967 }
1968
1969 // Set the entry size.
1970
1971 void
1972 Output_section::set_entsize(uint64_t v)
1973 {
1974   if (this->is_entsize_zero_)
1975     ;
1976   else if (this->entsize_ == 0)
1977     this->entsize_ = v;
1978   else if (this->entsize_ != v)
1979     {
1980       this->entsize_ = 0;
1981       this->is_entsize_zero_ = 1;
1982     }
1983 }
1984
1985 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1986 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
1987 // relocation section which applies to this section, or 0 if none, or
1988 // -1U if more than one.  Return the offset of the input section
1989 // within the output section.  Return -1 if the input section will
1990 // receive special handling.  In the normal case we don't always keep
1991 // track of input sections for an Output_section.  Instead, each
1992 // Object keeps track of the Output_section for each of its input
1993 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
1994 // track of input sections here; this is used when SECTIONS appears in
1995 // a linker script.
1996
1997 template<int size, bool big_endian>
1998 off_t
1999 Output_section::add_input_section(Layout* layout,
2000                                   Sized_relobj<size, big_endian>* object,
2001                                   unsigned int shndx,
2002                                   const char* secname,
2003                                   const elfcpp::Shdr<size, big_endian>& shdr,
2004                                   unsigned int reloc_shndx,
2005                                   bool have_sections_script)
2006 {
2007   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
2008   if ((addralign & (addralign - 1)) != 0)
2009     {
2010       object->error(_("invalid alignment %lu for section \"%s\""),
2011                     static_cast<unsigned long>(addralign), secname);
2012       addralign = 1;
2013     }
2014
2015   if (addralign > this->addralign_)
2016     this->addralign_ = addralign;
2017
2018   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
2019   uint64_t entsize = shdr.get_sh_entsize();
2020
2021   // .debug_str is a mergeable string section, but is not always so
2022   // marked by compilers.  Mark manually here so we can optimize.
2023   if (strcmp(secname, ".debug_str") == 0)
2024     {
2025       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
2026       entsize = 1;
2027     }
2028
2029   this->update_flags_for_input_section(sh_flags);
2030   this->set_entsize(entsize);
2031
2032   // If this is a SHF_MERGE section, we pass all the input sections to
2033   // a Output_data_merge.  We don't try to handle relocations for such
2034   // a section.  We don't try to handle empty merge sections--they
2035   // mess up the mappings, and are useless anyhow.
2036   if ((sh_flags & elfcpp::SHF_MERGE) != 0
2037       && reloc_shndx == 0
2038       && shdr.get_sh_size() > 0)
2039     {
2040       // Keep information about merged input sections for rebuilding fast
2041       // lookup maps if we have sections-script or we do relaxation.
2042       bool keeps_input_sections = (this->always_keeps_input_sections_
2043                                    || have_sections_script
2044                                    || parameters->target().may_relax());
2045
2046       if (this->add_merge_input_section(object, shndx, sh_flags, entsize,
2047                                         addralign, keeps_input_sections))
2048         {
2049           // Tell the relocation routines that they need to call the
2050           // output_offset method to determine the final address.
2051           return -1;
2052         }
2053     }
2054
2055   off_t offset_in_section = this->current_data_size_for_child();
2056   off_t aligned_offset_in_section = align_address(offset_in_section,
2057                                                   addralign);
2058
2059   // Determine if we want to delay code-fill generation until the output
2060   // section is written.  When the target is relaxing, we want to delay fill
2061   // generating to avoid adjusting them during relaxation.
2062   if (!this->generate_code_fills_at_write_
2063       && !have_sections_script
2064       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2065       && parameters->target().has_code_fill()
2066       && parameters->target().may_relax())
2067     {
2068       gold_assert(this->fills_.empty());
2069       this->generate_code_fills_at_write_ = true;
2070     }
2071
2072   if (aligned_offset_in_section > offset_in_section
2073       && !this->generate_code_fills_at_write_
2074       && !have_sections_script
2075       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2076       && parameters->target().has_code_fill())
2077     {
2078       // We need to add some fill data.  Using fill_list_ when
2079       // possible is an optimization, since we will often have fill
2080       // sections without input sections.
2081       off_t fill_len = aligned_offset_in_section - offset_in_section;
2082       if (this->input_sections_.empty())
2083         this->fills_.push_back(Fill(offset_in_section, fill_len));
2084       else
2085         {
2086           std::string fill_data(parameters->target().code_fill(fill_len));
2087           Output_data_const* odc = new Output_data_const(fill_data, 1);
2088           this->input_sections_.push_back(Input_section(odc));
2089         }
2090     }
2091
2092   section_size_type input_section_size = shdr.get_sh_size();
2093   section_size_type uncompressed_size;
2094   if (object->section_is_compressed(shndx, &uncompressed_size))
2095     input_section_size = uncompressed_size;
2096
2097   this->set_current_data_size_for_child(aligned_offset_in_section
2098                                         + input_section_size);
2099
2100   // We need to keep track of this section if we are already keeping
2101   // track of sections, or if we are relaxing.  Also, if this is a
2102   // section which requires sorting, or which may require sorting in
2103   // the future, we keep track of the sections.  If the
2104   // --section-ordering-file option is used to specify the order of
2105   // sections, we need to keep track of sections.
2106   if (this->always_keeps_input_sections_
2107       || have_sections_script
2108       || !this->input_sections_.empty()
2109       || this->may_sort_attached_input_sections()
2110       || this->must_sort_attached_input_sections()
2111       || parameters->options().user_set_Map()
2112       || parameters->target().may_relax()
2113       || parameters->options().section_ordering_file())
2114     {
2115       Input_section isecn(object, shndx, shdr.get_sh_size(), addralign);
2116       if (parameters->options().section_ordering_file())
2117         {
2118           unsigned int section_order_index =
2119             layout->find_section_order_index(std::string(secname));
2120           if (section_order_index != 0)
2121             {
2122               isecn.set_section_order_index(section_order_index);
2123               this->set_input_section_order_specified();
2124             }
2125         }
2126       this->input_sections_.push_back(isecn);
2127     }
2128
2129   return aligned_offset_in_section;
2130 }
2131
2132 // Add arbitrary data to an output section.
2133
2134 void
2135 Output_section::add_output_section_data(Output_section_data* posd)
2136 {
2137   Input_section inp(posd);
2138   this->add_output_section_data(&inp);
2139
2140   if (posd->is_data_size_valid())
2141     {
2142       off_t offset_in_section = this->current_data_size_for_child();
2143       off_t aligned_offset_in_section = align_address(offset_in_section,
2144                                                       posd->addralign());
2145       this->set_current_data_size_for_child(aligned_offset_in_section
2146                                             + posd->data_size());
2147     }
2148 }
2149
2150 // Add a relaxed input section.
2151
2152 void
2153 Output_section::add_relaxed_input_section(Output_relaxed_input_section* poris)
2154 {
2155   Input_section inp(poris);
2156   this->add_output_section_data(&inp);
2157   if (this->lookup_maps_->is_valid())
2158     this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2159                                                   poris->shndx(), poris);
2160
2161   // For a relaxed section, we use the current data size.  Linker scripts
2162   // get all the input sections, including relaxed one from an output
2163   // section and add them back to them same output section to compute the
2164   // output section size.  If we do not account for sizes of relaxed input
2165   // sections,  an output section would be incorrectly sized.
2166   off_t offset_in_section = this->current_data_size_for_child();
2167   off_t aligned_offset_in_section = align_address(offset_in_section,
2168                                                   poris->addralign());
2169   this->set_current_data_size_for_child(aligned_offset_in_section
2170                                         + poris->current_data_size());
2171 }
2172
2173 // Add arbitrary data to an output section by Input_section.
2174
2175 void
2176 Output_section::add_output_section_data(Input_section* inp)
2177 {
2178   if (this->input_sections_.empty())
2179     this->first_input_offset_ = this->current_data_size_for_child();
2180
2181   this->input_sections_.push_back(*inp);
2182
2183   uint64_t addralign = inp->addralign();
2184   if (addralign > this->addralign_)
2185     this->addralign_ = addralign;
2186
2187   inp->set_output_section(this);
2188 }
2189
2190 // Add a merge section to an output section.
2191
2192 void
2193 Output_section::add_output_merge_section(Output_section_data* posd,
2194                                          bool is_string, uint64_t entsize)
2195 {
2196   Input_section inp(posd, is_string, entsize);
2197   this->add_output_section_data(&inp);
2198 }
2199
2200 // Add an input section to a SHF_MERGE section.
2201
2202 bool
2203 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2204                                         uint64_t flags, uint64_t entsize,
2205                                         uint64_t addralign,
2206                                         bool keeps_input_sections)
2207 {
2208   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2209
2210   // We only merge strings if the alignment is not more than the
2211   // character size.  This could be handled, but it's unusual.
2212   if (is_string && addralign > entsize)
2213     return false;
2214
2215   // We cannot restore merged input section states.
2216   gold_assert(this->checkpoint_ == NULL);
2217
2218   // Look up merge sections by required properties.
2219   // Currently, we only invalidate the lookup maps in script processing
2220   // and relaxation.  We should not have done either when we reach here.
2221   // So we assume that the lookup maps are valid to simply code.
2222   gold_assert(this->lookup_maps_->is_valid());
2223   Merge_section_properties msp(is_string, entsize, addralign);
2224   Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp);
2225   bool is_new = false;
2226   if (pomb != NULL)
2227     {
2228       gold_assert(pomb->is_string() == is_string
2229                   && pomb->entsize() == entsize
2230                   && pomb->addralign() == addralign);
2231     }
2232   else
2233     {
2234       // Create a new Output_merge_data or Output_merge_string_data.
2235       if (!is_string)
2236         pomb = new Output_merge_data(entsize, addralign);
2237       else
2238         {
2239           switch (entsize)
2240             {
2241             case 1:
2242               pomb = new Output_merge_string<char>(addralign);
2243               break;
2244             case 2:
2245               pomb = new Output_merge_string<uint16_t>(addralign);
2246               break;
2247             case 4:
2248               pomb = new Output_merge_string<uint32_t>(addralign);
2249               break;
2250             default:
2251               return false;
2252             }
2253         }
2254       // If we need to do script processing or relaxation, we need to keep
2255       // the original input sections to rebuild the fast lookup maps.
2256       if (keeps_input_sections)
2257         pomb->set_keeps_input_sections();
2258       is_new = true;
2259     }
2260
2261   if (pomb->add_input_section(object, shndx))
2262     {
2263       // Add new merge section to this output section and link merge
2264       // section properties to new merge section in map.
2265       if (is_new)
2266         {
2267           this->add_output_merge_section(pomb, is_string, entsize);
2268           this->lookup_maps_->add_merge_section(msp, pomb);
2269         }
2270
2271       // Add input section to new merge section and link input section to new
2272       // merge section in map.
2273       this->lookup_maps_->add_merge_input_section(object, shndx, pomb);
2274       return true;
2275     }
2276   else
2277     {
2278       // If add_input_section failed, delete new merge section to avoid
2279       // exporting empty merge sections in Output_section::get_input_section.
2280       if (is_new)
2281         delete pomb;
2282       return false;
2283     }
2284 }
2285
2286 // Build a relaxation map to speed up relaxation of existing input sections.
2287 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2288
2289 void
2290 Output_section::build_relaxation_map(
2291   const Input_section_list& input_sections,
2292   size_t limit,
2293   Relaxation_map* relaxation_map) const
2294 {
2295   for (size_t i = 0; i < limit; ++i)
2296     {
2297       const Input_section& is(input_sections[i]);
2298       if (is.is_input_section() || is.is_relaxed_input_section())
2299         {
2300           Section_id sid(is.relobj(), is.shndx());
2301           (*relaxation_map)[sid] = i;
2302         }
2303     }
2304 }
2305
2306 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2307 // sections in RELAXED_SECTIONS.  MAP is a prebuilt map from section id
2308 // indices of INPUT_SECTIONS.
2309
2310 void
2311 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2312   const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2313   const Relaxation_map& map,
2314   Input_section_list* input_sections)
2315 {
2316   for (size_t i = 0; i < relaxed_sections.size(); ++i)
2317     {
2318       Output_relaxed_input_section* poris = relaxed_sections[i];
2319       Section_id sid(poris->relobj(), poris->shndx());
2320       Relaxation_map::const_iterator p = map.find(sid);
2321       gold_assert(p != map.end());
2322       gold_assert((*input_sections)[p->second].is_input_section());
2323       (*input_sections)[p->second] = Input_section(poris);
2324     }
2325 }
2326
2327 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2328 // is a vector of pointers to Output_relaxed_input_section or its derived
2329 // classes.  The relaxed sections must correspond to existing input sections.
2330
2331 void
2332 Output_section::convert_input_sections_to_relaxed_sections(
2333   const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2334 {
2335   gold_assert(parameters->target().may_relax());
2336
2337   // We want to make sure that restore_states does not undo the effect of
2338   // this.  If there is no checkpoint active, just search the current
2339   // input section list and replace the sections there.  If there is
2340   // a checkpoint, also replace the sections there.
2341
2342   // By default, we look at the whole list.
2343   size_t limit = this->input_sections_.size();
2344
2345   if (this->checkpoint_ != NULL)
2346     {
2347       // Replace input sections with relaxed input section in the saved
2348       // copy of the input section list.
2349       if (this->checkpoint_->input_sections_saved())
2350         {
2351           Relaxation_map map;
2352           this->build_relaxation_map(
2353                     *(this->checkpoint_->input_sections()),
2354                     this->checkpoint_->input_sections()->size(),
2355                     &map);
2356           this->convert_input_sections_in_list_to_relaxed_sections(
2357                     relaxed_sections,
2358                     map,
2359                     this->checkpoint_->input_sections());
2360         }
2361       else
2362         {
2363           // We have not copied the input section list yet.  Instead, just
2364           // look at the portion that would be saved.
2365           limit = this->checkpoint_->input_sections_size();
2366         }
2367     }
2368
2369   // Convert input sections in input_section_list.
2370   Relaxation_map map;
2371   this->build_relaxation_map(this->input_sections_, limit, &map);
2372   this->convert_input_sections_in_list_to_relaxed_sections(
2373             relaxed_sections,
2374             map,
2375             &this->input_sections_);
2376
2377   // Update fast look-up map.
2378   if (this->lookup_maps_->is_valid())
2379     for (size_t i = 0; i < relaxed_sections.size(); ++i)
2380       {
2381         Output_relaxed_input_section* poris = relaxed_sections[i];
2382         this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2383                                                       poris->shndx(), poris);
2384       }
2385 }
2386
2387 // Update the output section flags based on input section flags.
2388
2389 void
2390 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2391 {
2392   // If we created the section with SHF_ALLOC clear, we set the
2393   // address.  If we are now setting the SHF_ALLOC flag, we need to
2394   // undo that.
2395   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2396       && (flags & elfcpp::SHF_ALLOC) != 0)
2397     this->mark_address_invalid();
2398
2399   this->flags_ |= (flags
2400                    & (elfcpp::SHF_WRITE
2401                       | elfcpp::SHF_ALLOC
2402                       | elfcpp::SHF_EXECINSTR));
2403
2404   if ((flags & elfcpp::SHF_MERGE) == 0)
2405     this->flags_ &=~ elfcpp::SHF_MERGE;
2406   else
2407     {
2408       if (this->current_data_size_for_child() == 0)
2409         this->flags_ |= elfcpp::SHF_MERGE;
2410     }
2411
2412   if ((flags & elfcpp::SHF_STRINGS) == 0)
2413     this->flags_ &=~ elfcpp::SHF_STRINGS;
2414   else
2415     {
2416       if (this->current_data_size_for_child() == 0)
2417         this->flags_ |= elfcpp::SHF_STRINGS;
2418     }
2419 }
2420
2421 // Find the merge section into which an input section with index SHNDX in
2422 // OBJECT has been added.  Return NULL if none found.
2423
2424 Output_section_data*
2425 Output_section::find_merge_section(const Relobj* object,
2426                                    unsigned int shndx) const
2427 {
2428   if (!this->lookup_maps_->is_valid())
2429     this->build_lookup_maps();
2430   return this->lookup_maps_->find_merge_section(object, shndx);
2431 }
2432
2433 // Build the lookup maps for merge and relaxed sections.  This is needs
2434 // to be declared as a const methods so that it is callable with a const
2435 // Output_section pointer.  The method only updates states of the maps.
2436
2437 void
2438 Output_section::build_lookup_maps() const
2439 {
2440   this->lookup_maps_->clear();
2441   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2442        p != this->input_sections_.end();
2443        ++p)
2444     {
2445       if (p->is_merge_section())
2446         {
2447           Output_merge_base* pomb = p->output_merge_base();
2448           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
2449                                        pomb->addralign());
2450           this->lookup_maps_->add_merge_section(msp, pomb);
2451           for (Output_merge_base::Input_sections::const_iterator is =
2452                  pomb->input_sections_begin();
2453                is != pomb->input_sections_end();
2454                ++is)
2455             {
2456               const Const_section_id& csid = *is;
2457             this->lookup_maps_->add_merge_input_section(csid.first,
2458                                                         csid.second, pomb);
2459             }
2460
2461         }
2462       else if (p->is_relaxed_input_section())
2463         {
2464           Output_relaxed_input_section* poris = p->relaxed_input_section();
2465           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2466                                                         poris->shndx(), poris);
2467         }
2468     }
2469 }
2470
2471 // Find an relaxed input section corresponding to an input section
2472 // in OBJECT with index SHNDX.
2473
2474 const Output_relaxed_input_section*
2475 Output_section::find_relaxed_input_section(const Relobj* object,
2476                                            unsigned int shndx) const
2477 {
2478   if (!this->lookup_maps_->is_valid())
2479     this->build_lookup_maps();
2480   return this->lookup_maps_->find_relaxed_input_section(object, shndx);
2481 }
2482
2483 // Given an address OFFSET relative to the start of input section
2484 // SHNDX in OBJECT, return whether this address is being included in
2485 // the final link.  This should only be called if SHNDX in OBJECT has
2486 // a special mapping.
2487
2488 bool
2489 Output_section::is_input_address_mapped(const Relobj* object,
2490                                         unsigned int shndx,
2491                                         off_t offset) const
2492 {
2493   // Look at the Output_section_data_maps first.
2494   const Output_section_data* posd = this->find_merge_section(object, shndx);
2495   if (posd == NULL)
2496     posd = this->find_relaxed_input_section(object, shndx);
2497
2498   if (posd != NULL)
2499     {
2500       section_offset_type output_offset;
2501       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2502       gold_assert(found);
2503       return output_offset != -1;
2504     }
2505
2506   // Fall back to the slow look-up.
2507   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2508        p != this->input_sections_.end();
2509        ++p)
2510     {
2511       section_offset_type output_offset;
2512       if (p->output_offset(object, shndx, offset, &output_offset))
2513         return output_offset != -1;
2514     }
2515
2516   // By default we assume that the address is mapped.  This should
2517   // only be called after we have passed all sections to Layout.  At
2518   // that point we should know what we are discarding.
2519   return true;
2520 }
2521
2522 // Given an address OFFSET relative to the start of input section
2523 // SHNDX in object OBJECT, return the output offset relative to the
2524 // start of the input section in the output section.  This should only
2525 // be called if SHNDX in OBJECT has a special mapping.
2526
2527 section_offset_type
2528 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2529                               section_offset_type offset) const
2530 {
2531   // This can only be called meaningfully when we know the data size
2532   // of this.
2533   gold_assert(this->is_data_size_valid());
2534
2535   // Look at the Output_section_data_maps first.
2536   const Output_section_data* posd = this->find_merge_section(object, shndx);
2537   if (posd == NULL)
2538     posd = this->find_relaxed_input_section(object, shndx);
2539   if (posd != NULL)
2540     {
2541       section_offset_type output_offset;
2542       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2543       gold_assert(found);
2544       return output_offset;
2545     }
2546
2547   // Fall back to the slow look-up.
2548   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2549        p != this->input_sections_.end();
2550        ++p)
2551     {
2552       section_offset_type output_offset;
2553       if (p->output_offset(object, shndx, offset, &output_offset))
2554         return output_offset;
2555     }
2556   gold_unreachable();
2557 }
2558
2559 // Return the output virtual address of OFFSET relative to the start
2560 // of input section SHNDX in object OBJECT.
2561
2562 uint64_t
2563 Output_section::output_address(const Relobj* object, unsigned int shndx,
2564                                off_t offset) const
2565 {
2566   uint64_t addr = this->address() + this->first_input_offset_;
2567
2568   // Look at the Output_section_data_maps first.
2569   const Output_section_data* posd = this->find_merge_section(object, shndx);
2570   if (posd == NULL)
2571     posd = this->find_relaxed_input_section(object, shndx);
2572   if (posd != NULL && posd->is_address_valid())
2573     {
2574       section_offset_type output_offset;
2575       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2576       gold_assert(found);
2577       return posd->address() + output_offset;
2578     }
2579
2580   // Fall back to the slow look-up.
2581   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2582        p != this->input_sections_.end();
2583        ++p)
2584     {
2585       addr = align_address(addr, p->addralign());
2586       section_offset_type output_offset;
2587       if (p->output_offset(object, shndx, offset, &output_offset))
2588         {
2589           if (output_offset == -1)
2590             return -1ULL;
2591           return addr + output_offset;
2592         }
2593       addr += p->data_size();
2594     }
2595
2596   // If we get here, it means that we don't know the mapping for this
2597   // input section.  This might happen in principle if
2598   // add_input_section were called before add_output_section_data.
2599   // But it should never actually happen.
2600
2601   gold_unreachable();
2602 }
2603
2604 // Find the output address of the start of the merged section for
2605 // input section SHNDX in object OBJECT.
2606
2607 bool
2608 Output_section::find_starting_output_address(const Relobj* object,
2609                                              unsigned int shndx,
2610                                              uint64_t* paddr) const
2611 {
2612   // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2613   // Looking up the merge section map does not always work as we sometimes
2614   // find a merge section without its address set.
2615   uint64_t addr = this->address() + this->first_input_offset_;
2616   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2617        p != this->input_sections_.end();
2618        ++p)
2619     {
2620       addr = align_address(addr, p->addralign());
2621
2622       // It would be nice if we could use the existing output_offset
2623       // method to get the output offset of input offset 0.
2624       // Unfortunately we don't know for sure that input offset 0 is
2625       // mapped at all.
2626       if (p->is_merge_section_for(object, shndx))
2627         {
2628           *paddr = addr;
2629           return true;
2630         }
2631
2632       addr += p->data_size();
2633     }
2634
2635   // We couldn't find a merge output section for this input section.
2636   return false;
2637 }
2638
2639 // Set the data size of an Output_section.  This is where we handle
2640 // setting the addresses of any Output_section_data objects.
2641
2642 void
2643 Output_section::set_final_data_size()
2644 {
2645   if (this->input_sections_.empty())
2646     {
2647       this->set_data_size(this->current_data_size_for_child());
2648       return;
2649     }
2650
2651   if (this->must_sort_attached_input_sections()
2652       || this->input_section_order_specified())
2653     this->sort_attached_input_sections();
2654
2655   uint64_t address = this->address();
2656   off_t startoff = this->offset();
2657   off_t off = startoff + this->first_input_offset_;
2658   for (Input_section_list::iterator p = this->input_sections_.begin();
2659        p != this->input_sections_.end();
2660        ++p)
2661     {
2662       off = align_address(off, p->addralign());
2663       p->set_address_and_file_offset(address + (off - startoff), off,
2664                                      startoff);
2665       off += p->data_size();
2666     }
2667
2668   this->set_data_size(off - startoff);
2669 }
2670
2671 // Reset the address and file offset.
2672
2673 void
2674 Output_section::do_reset_address_and_file_offset()
2675 {
2676   // An unallocated section has no address.  Forcing this means that
2677   // we don't need special treatment for symbols defined in debug
2678   // sections.  We do the same in the constructor.  This does not
2679   // apply to NOLOAD sections though.
2680   if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
2681      this->set_address(0);
2682
2683   for (Input_section_list::iterator p = this->input_sections_.begin();
2684        p != this->input_sections_.end();
2685        ++p)
2686     p->reset_address_and_file_offset();
2687 }
2688
2689 // Return true if address and file offset have the values after reset.
2690
2691 bool
2692 Output_section::do_address_and_file_offset_have_reset_values() const
2693 {
2694   if (this->is_offset_valid())
2695     return false;
2696
2697   // An unallocated section has address 0 after its construction or a reset.
2698   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2699     return this->is_address_valid() && this->address() == 0;
2700   else
2701     return !this->is_address_valid();
2702 }
2703
2704 // Set the TLS offset.  Called only for SHT_TLS sections.
2705
2706 void
2707 Output_section::do_set_tls_offset(uint64_t tls_base)
2708 {
2709   this->tls_offset_ = this->address() - tls_base;
2710 }
2711
2712 // In a few cases we need to sort the input sections attached to an
2713 // output section.  This is used to implement the type of constructor
2714 // priority ordering implemented by the GNU linker, in which the
2715 // priority becomes part of the section name and the sections are
2716 // sorted by name.  We only do this for an output section if we see an
2717 // attached input section matching ".ctor.*", ".dtor.*",
2718 // ".init_array.*" or ".fini_array.*".
2719
2720 class Output_section::Input_section_sort_entry
2721 {
2722  public:
2723   Input_section_sort_entry()
2724     : input_section_(), index_(-1U), section_has_name_(false),
2725       section_name_()
2726   { }
2727
2728   Input_section_sort_entry(const Input_section& input_section,
2729                            unsigned int index,
2730                            bool must_sort_attached_input_sections)
2731     : input_section_(input_section), index_(index),
2732       section_has_name_(input_section.is_input_section()
2733                         || input_section.is_relaxed_input_section())
2734   {
2735     if (this->section_has_name_
2736         && must_sort_attached_input_sections)
2737       {
2738         // This is only called single-threaded from Layout::finalize,
2739         // so it is OK to lock.  Unfortunately we have no way to pass
2740         // in a Task token.
2741         const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2742         Object* obj = (input_section.is_input_section()
2743                        ? input_section.relobj()
2744                        : input_section.relaxed_input_section()->relobj());
2745         Task_lock_obj<Object> tl(dummy_task, obj);
2746
2747         // This is a slow operation, which should be cached in
2748         // Layout::layout if this becomes a speed problem.
2749         this->section_name_ = obj->section_name(input_section.shndx());
2750       }
2751   }
2752
2753   // Return the Input_section.
2754   const Input_section&
2755   input_section() const
2756   {
2757     gold_assert(this->index_ != -1U);
2758     return this->input_section_;
2759   }
2760
2761   // The index of this entry in the original list.  This is used to
2762   // make the sort stable.
2763   unsigned int
2764   index() const
2765   {
2766     gold_assert(this->index_ != -1U);
2767     return this->index_;
2768   }
2769
2770   // Whether there is a section name.
2771   bool
2772   section_has_name() const
2773   { return this->section_has_name_; }
2774
2775   // The section name.
2776   const std::string&
2777   section_name() const
2778   {
2779     gold_assert(this->section_has_name_);
2780     return this->section_name_;
2781   }
2782
2783   // Return true if the section name has a priority.  This is assumed
2784   // to be true if it has a dot after the initial dot.
2785   bool
2786   has_priority() const
2787   {
2788     gold_assert(this->section_has_name_);
2789     return this->section_name_.find('.', 1) != std::string::npos;
2790   }
2791
2792   // Return true if this an input file whose base name matches
2793   // FILE_NAME.  The base name must have an extension of ".o", and
2794   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2795   // This is to match crtbegin.o as well as crtbeginS.o without
2796   // getting confused by other possibilities.  Overall matching the
2797   // file name this way is a dreadful hack, but the GNU linker does it
2798   // in order to better support gcc, and we need to be compatible.
2799   bool
2800   match_file_name(const char* match_file_name) const
2801   {
2802     const std::string& file_name(this->input_section_.relobj()->name());
2803     const char* base_name = lbasename(file_name.c_str());
2804     size_t match_len = strlen(match_file_name);
2805     if (strncmp(base_name, match_file_name, match_len) != 0)
2806       return false;
2807     size_t base_len = strlen(base_name);
2808     if (base_len != match_len + 2 && base_len != match_len + 3)
2809       return false;
2810     return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2811   }
2812
2813   // Returns 1 if THIS should appear before S in section order, -1 if S
2814   // appears before THIS and 0 if they are not comparable.
2815   int
2816   compare_section_ordering(const Input_section_sort_entry& s) const
2817   {
2818     unsigned int this_secn_index = this->input_section_.section_order_index();
2819     unsigned int s_secn_index = s.input_section().section_order_index();
2820     if (this_secn_index > 0 && s_secn_index > 0)
2821       {
2822         if (this_secn_index < s_secn_index)
2823           return 1;
2824         else if (this_secn_index > s_secn_index)
2825           return -1;
2826       }
2827     return 0;
2828   }
2829
2830  private:
2831   // The Input_section we are sorting.
2832   Input_section input_section_;
2833   // The index of this Input_section in the original list.
2834   unsigned int index_;
2835   // Whether this Input_section has a section name--it won't if this
2836   // is some random Output_section_data.
2837   bool section_has_name_;
2838   // The section name if there is one.
2839   std::string section_name_;
2840 };
2841
2842 // Return true if S1 should come before S2 in the output section.
2843
2844 bool
2845 Output_section::Input_section_sort_compare::operator()(
2846     const Output_section::Input_section_sort_entry& s1,
2847     const Output_section::Input_section_sort_entry& s2) const
2848 {
2849   // crtbegin.o must come first.
2850   bool s1_begin = s1.match_file_name("crtbegin");
2851   bool s2_begin = s2.match_file_name("crtbegin");
2852   if (s1_begin || s2_begin)
2853     {
2854       if (!s1_begin)
2855         return false;
2856       if (!s2_begin)
2857         return true;
2858       return s1.index() < s2.index();
2859     }
2860
2861   // crtend.o must come last.
2862   bool s1_end = s1.match_file_name("crtend");
2863   bool s2_end = s2.match_file_name("crtend");
2864   if (s1_end || s2_end)
2865     {
2866       if (!s1_end)
2867         return true;
2868       if (!s2_end)
2869         return false;
2870       return s1.index() < s2.index();
2871     }
2872
2873   // We sort all the sections with no names to the end.
2874   if (!s1.section_has_name() || !s2.section_has_name())
2875     {
2876       if (s1.section_has_name())
2877         return true;
2878       if (s2.section_has_name())
2879         return false;
2880       return s1.index() < s2.index();
2881     }
2882
2883   // A section with a priority follows a section without a priority.
2884   bool s1_has_priority = s1.has_priority();
2885   bool s2_has_priority = s2.has_priority();
2886   if (s1_has_priority && !s2_has_priority)
2887     return false;
2888   if (!s1_has_priority && s2_has_priority)
2889     return true;
2890
2891   // Check if a section order exists for these sections through a section
2892   // ordering file.  If sequence_num is 0, an order does not exist.
2893   int sequence_num = s1.compare_section_ordering(s2);
2894   if (sequence_num != 0)
2895     return sequence_num == 1;
2896
2897   // Otherwise we sort by name.
2898   int compare = s1.section_name().compare(s2.section_name());
2899   if (compare != 0)
2900     return compare < 0;
2901
2902   // Otherwise we keep the input order.
2903   return s1.index() < s2.index();
2904 }
2905
2906 // Return true if S1 should come before S2 in an .init_array or .fini_array
2907 // output section.
2908
2909 bool
2910 Output_section::Input_section_sort_init_fini_compare::operator()(
2911     const Output_section::Input_section_sort_entry& s1,
2912     const Output_section::Input_section_sort_entry& s2) const
2913 {
2914   // We sort all the sections with no names to the end.
2915   if (!s1.section_has_name() || !s2.section_has_name())
2916     {
2917       if (s1.section_has_name())
2918         return true;
2919       if (s2.section_has_name())
2920         return false;
2921       return s1.index() < s2.index();
2922     }
2923
2924   // A section without a priority follows a section with a priority.
2925   // This is the reverse of .ctors and .dtors sections.
2926   bool s1_has_priority = s1.has_priority();
2927   bool s2_has_priority = s2.has_priority();
2928   if (s1_has_priority && !s2_has_priority)
2929     return true;
2930   if (!s1_has_priority && s2_has_priority)
2931     return false;
2932
2933   // Check if a section order exists for these sections through a section
2934   // ordering file.  If sequence_num is 0, an order does not exist.
2935   int sequence_num = s1.compare_section_ordering(s2);
2936   if (sequence_num != 0)
2937     return sequence_num == 1;
2938
2939   // Otherwise we sort by name.
2940   int compare = s1.section_name().compare(s2.section_name());
2941   if (compare != 0)
2942     return compare < 0;
2943
2944   // Otherwise we keep the input order.
2945   return s1.index() < s2.index();
2946 }
2947
2948 // Return true if S1 should come before S2.  Sections that do not match
2949 // any pattern in the section ordering file are placed ahead of the sections
2950 // that match some pattern.
2951
2952 bool
2953 Output_section::Input_section_sort_section_order_index_compare::operator()(
2954     const Output_section::Input_section_sort_entry& s1,
2955     const Output_section::Input_section_sort_entry& s2) const
2956 {
2957   unsigned int s1_secn_index = s1.input_section().section_order_index();
2958   unsigned int s2_secn_index = s2.input_section().section_order_index();
2959
2960   // Keep input order if section ordering cannot determine order.
2961   if (s1_secn_index == s2_secn_index)
2962     return s1.index() < s2.index();
2963
2964   return s1_secn_index < s2_secn_index;
2965 }
2966
2967 // Sort the input sections attached to an output section.
2968
2969 void
2970 Output_section::sort_attached_input_sections()
2971 {
2972   if (this->attached_input_sections_are_sorted_)
2973     return;
2974
2975   if (this->checkpoint_ != NULL
2976       && !this->checkpoint_->input_sections_saved())
2977     this->checkpoint_->save_input_sections();
2978
2979   // The only thing we know about an input section is the object and
2980   // the section index.  We need the section name.  Recomputing this
2981   // is slow but this is an unusual case.  If this becomes a speed
2982   // problem we can cache the names as required in Layout::layout.
2983
2984   // We start by building a larger vector holding a copy of each
2985   // Input_section, plus its current index in the list and its name.
2986   std::vector<Input_section_sort_entry> sort_list;
2987
2988   unsigned int i = 0;
2989   for (Input_section_list::iterator p = this->input_sections_.begin();
2990        p != this->input_sections_.end();
2991        ++p, ++i)
2992       sort_list.push_back(Input_section_sort_entry(*p, i,
2993                             this->must_sort_attached_input_sections()));
2994
2995   // Sort the input sections.
2996   if (this->must_sort_attached_input_sections())
2997     {
2998       if (this->type() == elfcpp::SHT_PREINIT_ARRAY
2999           || this->type() == elfcpp::SHT_INIT_ARRAY
3000           || this->type() == elfcpp::SHT_FINI_ARRAY)
3001         std::sort(sort_list.begin(), sort_list.end(),
3002                   Input_section_sort_init_fini_compare());
3003       else
3004         std::sort(sort_list.begin(), sort_list.end(),
3005                   Input_section_sort_compare());
3006     }
3007   else
3008     {
3009       gold_assert(parameters->options().section_ordering_file());
3010       std::sort(sort_list.begin(), sort_list.end(),
3011                 Input_section_sort_section_order_index_compare());
3012     }
3013
3014   // Copy the sorted input sections back to our list.
3015   this->input_sections_.clear();
3016   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
3017        p != sort_list.end();
3018        ++p)
3019     this->input_sections_.push_back(p->input_section());
3020   sort_list.clear();
3021
3022   // Remember that we sorted the input sections, since we might get
3023   // called again.
3024   this->attached_input_sections_are_sorted_ = true;
3025 }
3026
3027 // Write the section header to *OSHDR.
3028
3029 template<int size, bool big_endian>
3030 void
3031 Output_section::write_header(const Layout* layout,
3032                              const Stringpool* secnamepool,
3033                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
3034 {
3035   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
3036   oshdr->put_sh_type(this->type_);
3037
3038   elfcpp::Elf_Xword flags = this->flags_;
3039   if (this->info_section_ != NULL && this->info_uses_section_index_)
3040     flags |= elfcpp::SHF_INFO_LINK;
3041   oshdr->put_sh_flags(flags);
3042
3043   oshdr->put_sh_addr(this->address());
3044   oshdr->put_sh_offset(this->offset());
3045   oshdr->put_sh_size(this->data_size());
3046   if (this->link_section_ != NULL)
3047     oshdr->put_sh_link(this->link_section_->out_shndx());
3048   else if (this->should_link_to_symtab_)
3049     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
3050   else if (this->should_link_to_dynsym_)
3051     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
3052   else
3053     oshdr->put_sh_link(this->link_);
3054
3055   elfcpp::Elf_Word info;
3056   if (this->info_section_ != NULL)
3057     {
3058       if (this->info_uses_section_index_)
3059         info = this->info_section_->out_shndx();
3060       else
3061         info = this->info_section_->symtab_index();
3062     }
3063   else if (this->info_symndx_ != NULL)
3064     info = this->info_symndx_->symtab_index();
3065   else
3066     info = this->info_;
3067   oshdr->put_sh_info(info);
3068
3069   oshdr->put_sh_addralign(this->addralign_);
3070   oshdr->put_sh_entsize(this->entsize_);
3071 }
3072
3073 // Write out the data.  For input sections the data is written out by
3074 // Object::relocate, but we have to handle Output_section_data objects
3075 // here.
3076
3077 void
3078 Output_section::do_write(Output_file* of)
3079 {
3080   gold_assert(!this->requires_postprocessing());
3081
3082   // If the target performs relaxation, we delay filler generation until now.
3083   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3084
3085   off_t output_section_file_offset = this->offset();
3086   for (Fill_list::iterator p = this->fills_.begin();
3087        p != this->fills_.end();
3088        ++p)
3089     {
3090       std::string fill_data(parameters->target().code_fill(p->length()));
3091       of->write(output_section_file_offset + p->section_offset(),
3092                 fill_data.data(), fill_data.size());
3093     }
3094
3095   off_t off = this->offset() + this->first_input_offset_;
3096   for (Input_section_list::iterator p = this->input_sections_.begin();
3097        p != this->input_sections_.end();
3098        ++p)
3099     {
3100       off_t aligned_off = align_address(off, p->addralign());
3101       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3102         {
3103           size_t fill_len = aligned_off - off;
3104           std::string fill_data(parameters->target().code_fill(fill_len));
3105           of->write(off, fill_data.data(), fill_data.size());
3106         }
3107
3108       p->write(of);
3109       off = aligned_off + p->data_size();
3110     }
3111 }
3112
3113 // If a section requires postprocessing, create the buffer to use.
3114
3115 void
3116 Output_section::create_postprocessing_buffer()
3117 {
3118   gold_assert(this->requires_postprocessing());
3119
3120   if (this->postprocessing_buffer_ != NULL)
3121     return;
3122
3123   if (!this->input_sections_.empty())
3124     {
3125       off_t off = this->first_input_offset_;
3126       for (Input_section_list::iterator p = this->input_sections_.begin();
3127            p != this->input_sections_.end();
3128            ++p)
3129         {
3130           off = align_address(off, p->addralign());
3131           p->finalize_data_size();
3132           off += p->data_size();
3133         }
3134       this->set_current_data_size_for_child(off);
3135     }
3136
3137   off_t buffer_size = this->current_data_size_for_child();
3138   this->postprocessing_buffer_ = new unsigned char[buffer_size];
3139 }
3140
3141 // Write all the data of an Output_section into the postprocessing
3142 // buffer.  This is used for sections which require postprocessing,
3143 // such as compression.  Input sections are handled by
3144 // Object::Relocate.
3145
3146 void
3147 Output_section::write_to_postprocessing_buffer()
3148 {
3149   gold_assert(this->requires_postprocessing());
3150
3151   // If the target performs relaxation, we delay filler generation until now.
3152   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3153
3154   unsigned char* buffer = this->postprocessing_buffer();
3155   for (Fill_list::iterator p = this->fills_.begin();
3156        p != this->fills_.end();
3157        ++p)
3158     {
3159       std::string fill_data(parameters->target().code_fill(p->length()));
3160       memcpy(buffer + p->section_offset(), fill_data.data(),
3161              fill_data.size());
3162     }
3163
3164   off_t off = this->first_input_offset_;
3165   for (Input_section_list::iterator p = this->input_sections_.begin();
3166        p != this->input_sections_.end();
3167        ++p)
3168     {
3169       off_t aligned_off = align_address(off, p->addralign());
3170       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3171         {
3172           size_t fill_len = aligned_off - off;
3173           std::string fill_data(parameters->target().code_fill(fill_len));
3174           memcpy(buffer + off, fill_data.data(), fill_data.size());
3175         }
3176
3177       p->write_to_buffer(buffer + aligned_off);
3178       off = aligned_off + p->data_size();
3179     }
3180 }
3181
3182 // Get the input sections for linker script processing.  We leave
3183 // behind the Output_section_data entries.  Note that this may be
3184 // slightly incorrect for merge sections.  We will leave them behind,
3185 // but it is possible that the script says that they should follow
3186 // some other input sections, as in:
3187 //    .rodata { *(.rodata) *(.rodata.cst*) }
3188 // For that matter, we don't handle this correctly:
3189 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
3190 // With luck this will never matter.
3191
3192 uint64_t
3193 Output_section::get_input_sections(
3194     uint64_t address,
3195     const std::string& fill,
3196     std::list<Input_section>* input_sections)
3197 {
3198   if (this->checkpoint_ != NULL
3199       && !this->checkpoint_->input_sections_saved())
3200     this->checkpoint_->save_input_sections();
3201
3202   // Invalidate fast look-up maps.
3203   this->lookup_maps_->invalidate();
3204
3205   uint64_t orig_address = address;
3206
3207   address = align_address(address, this->addralign());
3208
3209   Input_section_list remaining;
3210   for (Input_section_list::iterator p = this->input_sections_.begin();
3211        p != this->input_sections_.end();
3212        ++p)
3213     {
3214       if (p->is_input_section()
3215           || p->is_relaxed_input_section()
3216           || p->is_merge_section())
3217         input_sections->push_back(*p);
3218       else
3219         {
3220           uint64_t aligned_address = align_address(address, p->addralign());
3221           if (aligned_address != address && !fill.empty())
3222             {
3223               section_size_type length =
3224                 convert_to_section_size_type(aligned_address - address);
3225               std::string this_fill;
3226               this_fill.reserve(length);
3227               while (this_fill.length() + fill.length() <= length)
3228                 this_fill += fill;
3229               if (this_fill.length() < length)
3230                 this_fill.append(fill, 0, length - this_fill.length());
3231
3232               Output_section_data* posd = new Output_data_const(this_fill, 0);
3233               remaining.push_back(Input_section(posd));
3234             }
3235           address = aligned_address;
3236
3237           remaining.push_back(*p);
3238
3239           p->finalize_data_size();
3240           address += p->data_size();
3241         }
3242     }
3243
3244   this->input_sections_.swap(remaining);
3245   this->first_input_offset_ = 0;
3246
3247   uint64_t data_size = address - orig_address;
3248   this->set_current_data_size_for_child(data_size);
3249   return data_size;
3250 }
3251
3252 // Add a script input section.  SIS is an Output_section::Input_section,
3253 // which can be either a plain input section or a special input section like
3254 // a relaxed input section.  For a special input section, its size must be
3255 // finalized.
3256
3257 void
3258 Output_section::add_script_input_section(const Input_section& sis)
3259 {
3260   uint64_t data_size = sis.data_size();
3261   uint64_t addralign = sis.addralign();
3262   if (addralign > this->addralign_)
3263     this->addralign_ = addralign;
3264
3265   off_t offset_in_section = this->current_data_size_for_child();
3266   off_t aligned_offset_in_section = align_address(offset_in_section,
3267                                                   addralign);
3268
3269   this->set_current_data_size_for_child(aligned_offset_in_section
3270                                         + data_size);
3271
3272   this->input_sections_.push_back(sis);
3273
3274   // Update fast lookup maps if necessary.
3275   if (this->lookup_maps_->is_valid())
3276     {
3277       if (sis.is_merge_section())
3278         {
3279           Output_merge_base* pomb = sis.output_merge_base();
3280           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
3281                                        pomb->addralign());
3282           this->lookup_maps_->add_merge_section(msp, pomb);
3283           for (Output_merge_base::Input_sections::const_iterator p =
3284                  pomb->input_sections_begin();
3285                p != pomb->input_sections_end();
3286                ++p)
3287             this->lookup_maps_->add_merge_input_section(p->first, p->second,
3288                                                         pomb);
3289         }
3290       else if (sis.is_relaxed_input_section())
3291         {
3292           Output_relaxed_input_section* poris = sis.relaxed_input_section();
3293           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
3294                                                         poris->shndx(), poris);
3295         }
3296     }
3297 }
3298
3299 // Save states for relaxation.
3300
3301 void
3302 Output_section::save_states()
3303 {
3304   gold_assert(this->checkpoint_ == NULL);
3305   Checkpoint_output_section* checkpoint =
3306     new Checkpoint_output_section(this->addralign_, this->flags_,
3307                                   this->input_sections_,
3308                                   this->first_input_offset_,
3309                                   this->attached_input_sections_are_sorted_);
3310   this->checkpoint_ = checkpoint;
3311   gold_assert(this->fills_.empty());
3312 }
3313
3314 void
3315 Output_section::discard_states()
3316 {
3317   gold_assert(this->checkpoint_ != NULL);
3318   delete this->checkpoint_;
3319   this->checkpoint_ = NULL;
3320   gold_assert(this->fills_.empty());
3321
3322   // Simply invalidate the fast lookup maps since we do not keep
3323   // track of them.
3324   this->lookup_maps_->invalidate();
3325 }
3326
3327 void
3328 Output_section::restore_states()
3329 {
3330   gold_assert(this->checkpoint_ != NULL);
3331   Checkpoint_output_section* checkpoint = this->checkpoint_;
3332
3333   this->addralign_ = checkpoint->addralign();
3334   this->flags_ = checkpoint->flags();
3335   this->first_input_offset_ = checkpoint->first_input_offset();
3336
3337   if (!checkpoint->input_sections_saved())
3338     {
3339       // If we have not copied the input sections, just resize it.
3340       size_t old_size = checkpoint->input_sections_size();
3341       gold_assert(this->input_sections_.size() >= old_size);
3342       this->input_sections_.resize(old_size);
3343     }
3344   else
3345     {
3346       // We need to copy the whole list.  This is not efficient for
3347       // extremely large output with hundreads of thousands of input
3348       // objects.  We may need to re-think how we should pass sections
3349       // to scripts.
3350       this->input_sections_ = *checkpoint->input_sections();
3351     }
3352
3353   this->attached_input_sections_are_sorted_ =
3354     checkpoint->attached_input_sections_are_sorted();
3355
3356   // Simply invalidate the fast lookup maps since we do not keep
3357   // track of them.
3358   this->lookup_maps_->invalidate();
3359 }
3360
3361 // Update the section offsets of input sections in this.  This is required if
3362 // relaxation causes some input sections to change sizes.
3363
3364 void
3365 Output_section::adjust_section_offsets()
3366 {
3367   if (!this->section_offsets_need_adjustment_)
3368     return;
3369
3370   off_t off = 0;
3371   for (Input_section_list::iterator p = this->input_sections_.begin();
3372        p != this->input_sections_.end();
3373        ++p)
3374     {
3375       off = align_address(off, p->addralign());
3376       if (p->is_input_section())
3377         p->relobj()->set_section_offset(p->shndx(), off);
3378       off += p->data_size();
3379     }
3380
3381   this->section_offsets_need_adjustment_ = false;
3382 }
3383
3384 // Print to the map file.
3385
3386 void
3387 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3388 {
3389   mapfile->print_output_section(this);
3390
3391   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3392        p != this->input_sections_.end();
3393        ++p)
3394     p->print_to_mapfile(mapfile);
3395 }
3396
3397 // Print stats for merge sections to stderr.
3398
3399 void
3400 Output_section::print_merge_stats()
3401 {
3402   Input_section_list::iterator p;
3403   for (p = this->input_sections_.begin();
3404        p != this->input_sections_.end();
3405        ++p)
3406     p->print_merge_stats(this->name_);
3407 }
3408
3409 // Output segment methods.
3410
3411 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3412   : output_data_(),
3413     output_bss_(),
3414     vaddr_(0),
3415     paddr_(0),
3416     memsz_(0),
3417     max_align_(0),
3418     min_p_align_(0),
3419     offset_(0),
3420     filesz_(0),
3421     type_(type),
3422     flags_(flags),
3423     is_max_align_known_(false),
3424     are_addresses_set_(false),
3425     is_large_data_segment_(false)
3426 {
3427   // The ELF ABI specifies that a PT_TLS segment always has PF_R as
3428   // the flags.
3429   if (type == elfcpp::PT_TLS)
3430     this->flags_ = elfcpp::PF_R;
3431 }
3432
3433 // Add an Output_section to an Output_segment.
3434
3435 void
3436 Output_segment::add_output_section(Output_section* os,
3437                                    elfcpp::Elf_Word seg_flags,
3438                                    bool do_sort)
3439 {
3440   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3441   gold_assert(!this->is_max_align_known_);
3442   gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3443   gold_assert(this->type() == elfcpp::PT_LOAD || !do_sort);
3444
3445   this->update_flags_for_output_section(seg_flags);
3446
3447   Output_segment::Output_data_list* pdl;
3448   if (os->type() == elfcpp::SHT_NOBITS)
3449     pdl = &this->output_bss_;
3450   else
3451     pdl = &this->output_data_;
3452
3453   // Note that while there may be many input sections in an output
3454   // section, there are normally only a few output sections in an
3455   // output segment.  The loops below are expected to be fast.
3456
3457   // So that PT_NOTE segments will work correctly, we need to ensure
3458   // that all SHT_NOTE sections are adjacent.
3459   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
3460     {
3461       Output_segment::Output_data_list::iterator p = pdl->end();
3462       do
3463         {
3464           --p;
3465           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
3466             {
3467               ++p;
3468               pdl->insert(p, os);
3469               return;
3470             }
3471         }
3472       while (p != pdl->begin());
3473     }
3474
3475   // Similarly, so that PT_TLS segments will work, we need to group
3476   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
3477   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
3478   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
3479   // correctly.  SHF_TLS sections get added to both a PT_LOAD segment
3480   // and the PT_TLS segment; we do this grouping only for the PT_LOAD
3481   // segment.
3482   if (this->type_ != elfcpp::PT_TLS
3483       && (os->flags() & elfcpp::SHF_TLS) != 0)
3484     {
3485       pdl = &this->output_data_;
3486       if (!pdl->empty())
3487         {
3488           bool nobits = os->type() == elfcpp::SHT_NOBITS;
3489           bool sawtls = false;
3490           Output_segment::Output_data_list::iterator p = pdl->end();
3491           gold_assert(p != pdl->begin());
3492           do
3493             {
3494               --p;
3495               bool insert;
3496               if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3497                 {
3498                   sawtls = true;
3499                   // Put a NOBITS section after the first TLS section.
3500                   // Put a PROGBITS section after the first
3501                   // TLS/PROGBITS section.
3502                   insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
3503                 }
3504               else
3505                 {
3506                   // If we've gone past the TLS sections, but we've
3507                   // seen a TLS section, then we need to insert this
3508                   // section now.
3509                   insert = sawtls;
3510                 }
3511
3512               if (insert)
3513                 {
3514                   ++p;
3515                   pdl->insert(p, os);
3516                   return;
3517                 }
3518             }
3519           while (p != pdl->begin());
3520         }
3521
3522       // There are no TLS sections yet; put this one at the requested
3523       // location in the section list.
3524     }
3525
3526   if (do_sort)
3527     {
3528       // For the PT_GNU_RELRO segment, we need to group relro
3529       // sections, and we need to put them before any non-relro
3530       // sections.  Any relro local sections go before relro non-local
3531       // sections.  One section may be marked as the last relro
3532       // section.
3533       if (os->is_relro())
3534         {
3535           gold_assert(pdl == &this->output_data_);
3536           Output_segment::Output_data_list::iterator p;
3537           for (p = pdl->begin(); p != pdl->end(); ++p)
3538             {
3539               if (!(*p)->is_section())
3540                 break;
3541
3542               Output_section* pos = (*p)->output_section();
3543               if (!pos->is_relro()
3544                   || (os->is_relro_local() && !pos->is_relro_local())
3545                   || (!os->is_last_relro() && pos->is_last_relro()))
3546                 break;
3547             }
3548
3549           pdl->insert(p, os);
3550           return;
3551         }
3552
3553       // One section may be marked as the first section which follows
3554       // the relro sections.
3555       if (os->is_first_non_relro())
3556         {
3557           gold_assert(pdl == &this->output_data_);
3558           Output_segment::Output_data_list::iterator p;
3559           for (p = pdl->begin(); p != pdl->end(); ++p)
3560             {
3561               if (!(*p)->is_section())
3562                 break;
3563
3564               Output_section* pos = (*p)->output_section();
3565               if (!pos->is_relro())
3566                 break;
3567             }
3568
3569           pdl->insert(p, os);
3570           return;
3571         }
3572     }
3573
3574   // Small data sections go at the end of the list of data sections.
3575   // If OS is not small, and there are small sections, we have to
3576   // insert it before the first small section.
3577   if (os->type() != elfcpp::SHT_NOBITS
3578       && !os->is_small_section()
3579       && !pdl->empty()
3580       && pdl->back()->is_section()
3581       && pdl->back()->output_section()->is_small_section())
3582     {
3583       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3584            p != pdl->end();
3585            ++p)
3586         {
3587           if ((*p)->is_section()
3588               && (*p)->output_section()->is_small_section())
3589             {
3590               pdl->insert(p, os);
3591               return;
3592             }
3593         }
3594       gold_unreachable();
3595     }
3596
3597   // A small BSS section goes at the start of the BSS sections, after
3598   // other small BSS sections.
3599   if (os->type() == elfcpp::SHT_NOBITS && os->is_small_section())
3600     {
3601       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3602            p != pdl->end();
3603            ++p)
3604         {
3605           if (!(*p)->is_section()
3606               || !(*p)->output_section()->is_small_section())
3607             {
3608               pdl->insert(p, os);
3609               return;
3610             }
3611         }
3612     }
3613
3614   // A large BSS section goes at the end of the BSS sections, which
3615   // means that one that is not large must come before the first large
3616   // one.
3617   if (os->type() == elfcpp::SHT_NOBITS
3618       && !os->is_large_section()
3619       && !pdl->empty()
3620       && pdl->back()->is_section()
3621       && pdl->back()->output_section()->is_large_section())
3622     {
3623       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3624            p != pdl->end();
3625            ++p)
3626         {
3627           if ((*p)->is_section()
3628               && (*p)->output_section()->is_large_section())
3629             {
3630               pdl->insert(p, os);
3631               return;
3632             }
3633         }
3634       gold_unreachable();
3635     }
3636
3637   // We do some further output section sorting in order to make the
3638   // generated program run more efficiently.  We should only do this
3639   // when not using a linker script, so it is controled by the DO_SORT
3640   // parameter.
3641   if (do_sort)
3642     {
3643       // FreeBSD requires the .interp section to be in the first page
3644       // of the executable.  That is a more efficient location anyhow
3645       // for any OS, since it means that the kernel will have the data
3646       // handy after it reads the program headers.
3647       if (os->is_interp() && !pdl->empty())
3648         {
3649           pdl->insert(pdl->begin(), os);
3650           return;
3651         }
3652
3653       // Put loadable non-writable notes immediately after the .interp
3654       // sections, so that the PT_NOTE segment is on the first page of
3655       // the executable.
3656       if (os->type() == elfcpp::SHT_NOTE
3657           && (os->flags() & elfcpp::SHF_WRITE) == 0
3658           && !pdl->empty())
3659         {
3660           Output_segment::Output_data_list::iterator p = pdl->begin();
3661           if ((*p)->is_section() && (*p)->output_section()->is_interp())
3662             ++p;
3663           pdl->insert(p, os);
3664           return;
3665         }
3666
3667       // If this section is used by the dynamic linker, and it is not
3668       // writable, then put it first, after the .interp section and
3669       // any loadable notes.  This makes it more likely that the
3670       // dynamic linker will have to read less data from the disk.
3671       if (os->is_dynamic_linker_section()
3672           && !pdl->empty()
3673           && (os->flags() & elfcpp::SHF_WRITE) == 0)
3674         {
3675           bool is_reloc = (os->type() == elfcpp::SHT_REL
3676                            || os->type() == elfcpp::SHT_RELA);
3677           Output_segment::Output_data_list::iterator p = pdl->begin();
3678           while (p != pdl->end()
3679                  && (*p)->is_section()
3680                  && ((*p)->output_section()->is_dynamic_linker_section()
3681                      || (*p)->output_section()->type() == elfcpp::SHT_NOTE))
3682             {
3683               // Put reloc sections after the other ones.  Putting the
3684               // dynamic reloc sections first confuses BFD, notably
3685               // objcopy and strip.
3686               if (!is_reloc
3687                   && ((*p)->output_section()->type() == elfcpp::SHT_REL
3688                       || (*p)->output_section()->type() == elfcpp::SHT_RELA))
3689                 break;
3690               ++p;
3691             }
3692           pdl->insert(p, os);
3693           return;
3694         }
3695     }
3696
3697   // If there were no constraints on the output section, just add it
3698   // to the end of the list.
3699   pdl->push_back(os);
3700 }
3701
3702 // Remove an Output_section from this segment.  It is an error if it
3703 // is not present.
3704
3705 void
3706 Output_segment::remove_output_section(Output_section* os)
3707 {
3708   // We only need this for SHT_PROGBITS.
3709   gold_assert(os->type() == elfcpp::SHT_PROGBITS);
3710   for (Output_data_list::iterator p = this->output_data_.begin();
3711        p != this->output_data_.end();
3712        ++p)
3713    {
3714      if (*p == os)
3715        {
3716          this->output_data_.erase(p);
3717          return;
3718        }
3719    }
3720   gold_unreachable();
3721 }
3722
3723 // Add an Output_data (which need not be an Output_section) to the
3724 // start of a segment.
3725
3726 void
3727 Output_segment::add_initial_output_data(Output_data* od)
3728 {
3729   gold_assert(!this->is_max_align_known_);
3730   this->output_data_.push_front(od);
3731 }
3732
3733 // Return whether the first data section is a relro section.
3734
3735 bool
3736 Output_segment::is_first_section_relro() const
3737 {
3738   return (!this->output_data_.empty()
3739           && this->output_data_.front()->is_section()
3740           && this->output_data_.front()->output_section()->is_relro());
3741 }
3742
3743 // Return the maximum alignment of the Output_data in Output_segment.
3744
3745 uint64_t
3746 Output_segment::maximum_alignment()
3747 {
3748   if (!this->is_max_align_known_)
3749     {
3750       uint64_t addralign;
3751
3752       addralign = Output_segment::maximum_alignment_list(&this->output_data_);
3753       if (addralign > this->max_align_)
3754         this->max_align_ = addralign;
3755
3756       addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
3757       if (addralign > this->max_align_)
3758         this->max_align_ = addralign;
3759
3760       this->is_max_align_known_ = true;
3761     }
3762
3763   return this->max_align_;
3764 }
3765
3766 // Return the maximum alignment of a list of Output_data.
3767
3768 uint64_t
3769 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3770 {
3771   uint64_t ret = 0;
3772   for (Output_data_list::const_iterator p = pdl->begin();
3773        p != pdl->end();
3774        ++p)
3775     {
3776       uint64_t addralign = (*p)->addralign();
3777       if (addralign > ret)
3778         ret = addralign;
3779     }
3780   return ret;
3781 }
3782
3783 // Return the number of dynamic relocs applied to this segment.
3784
3785 unsigned int
3786 Output_segment::dynamic_reloc_count() const
3787 {
3788   return (this->dynamic_reloc_count_list(&this->output_data_)
3789           + this->dynamic_reloc_count_list(&this->output_bss_));
3790 }
3791
3792 // Return the number of dynamic relocs applied to an Output_data_list.
3793
3794 unsigned int
3795 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
3796 {
3797   unsigned int count = 0;
3798   for (Output_data_list::const_iterator p = pdl->begin();
3799        p != pdl->end();
3800        ++p)
3801     count += (*p)->dynamic_reloc_count();
3802   return count;
3803 }
3804
3805 // Set the section addresses for an Output_segment.  If RESET is true,
3806 // reset the addresses first.  ADDR is the address and *POFF is the
3807 // file offset.  Set the section indexes starting with *PSHNDX.
3808 // Return the address of the immediately following segment.  Update
3809 // *POFF and *PSHNDX.
3810
3811 uint64_t
3812 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3813                                       uint64_t addr,
3814                                       unsigned int increase_relro,
3815                                       off_t* poff,
3816                                       unsigned int* pshndx)
3817 {
3818   gold_assert(this->type_ == elfcpp::PT_LOAD);
3819
3820   off_t orig_off = *poff;
3821
3822   // If we have relro sections, we need to pad forward now so that the
3823   // relro sections plus INCREASE_RELRO end on a common page boundary.
3824   if (parameters->options().relro()
3825       && this->is_first_section_relro()
3826       && (!this->are_addresses_set_ || reset))
3827     {
3828       uint64_t relro_size = 0;
3829       off_t off = *poff;
3830       for (Output_data_list::iterator p = this->output_data_.begin();
3831            p != this->output_data_.end();
3832            ++p)
3833         {
3834           if (!(*p)->is_section())
3835             break;
3836           Output_section* pos = (*p)->output_section();
3837           if (!pos->is_relro())
3838             break;
3839           gold_assert(!(*p)->is_section_flag_set(elfcpp::SHF_TLS));
3840           if ((*p)->is_address_valid())
3841             relro_size += (*p)->data_size();
3842           else
3843             {
3844               // FIXME: This could be faster.
3845               (*p)->set_address_and_file_offset(addr + relro_size,
3846                                                 off + relro_size);
3847               relro_size += (*p)->data_size();
3848               (*p)->reset_address_and_file_offset();
3849             }
3850         }
3851       relro_size += increase_relro;
3852
3853       uint64_t page_align = parameters->target().common_pagesize();
3854
3855       // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
3856       uint64_t desired_align = page_align - (relro_size % page_align);
3857       if (desired_align < *poff % page_align)
3858         *poff += page_align - *poff % page_align;
3859       *poff += desired_align - *poff % page_align;
3860       addr += *poff - orig_off;
3861       orig_off = *poff;
3862     }
3863
3864   if (!reset && this->are_addresses_set_)
3865     {
3866       gold_assert(this->paddr_ == addr);
3867       addr = this->vaddr_;
3868     }
3869   else
3870     {
3871       this->vaddr_ = addr;
3872       this->paddr_ = addr;
3873       this->are_addresses_set_ = true;
3874     }
3875
3876   bool in_tls = false;
3877
3878   this->offset_ = orig_off;
3879
3880   addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
3881                                           addr, poff, pshndx, &in_tls);
3882   this->filesz_ = *poff - orig_off;
3883
3884   off_t off = *poff;
3885
3886   uint64_t ret = this->set_section_list_addresses(layout, reset,
3887                                                   &this->output_bss_,
3888                                                   addr, poff, pshndx,
3889                                                   &in_tls);
3890
3891   // If the last section was a TLS section, align upward to the
3892   // alignment of the TLS segment, so that the overall size of the TLS
3893   // segment is aligned.
3894   if (in_tls)
3895     {
3896       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3897       *poff = align_address(*poff, segment_align);
3898     }
3899
3900   this->memsz_ = *poff - orig_off;
3901
3902   // Ignore the file offset adjustments made by the BSS Output_data
3903   // objects.
3904   *poff = off;
3905
3906   return ret;
3907 }
3908
3909 // Set the addresses and file offsets in a list of Output_data
3910 // structures.
3911
3912 uint64_t
3913 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3914                                            Output_data_list* pdl,
3915                                            uint64_t addr, off_t* poff,
3916                                            unsigned int* pshndx,
3917                                            bool* in_tls)
3918 {
3919   off_t startoff = *poff;
3920
3921   off_t off = startoff;
3922   for (Output_data_list::iterator p = pdl->begin();
3923        p != pdl->end();
3924        ++p)
3925     {
3926       if (reset)
3927         (*p)->reset_address_and_file_offset();
3928
3929       // When using a linker script the section will most likely
3930       // already have an address.
3931       if (!(*p)->is_address_valid())
3932         {
3933           uint64_t align = (*p)->addralign();
3934
3935           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3936             {
3937               // Give the first TLS section the alignment of the
3938               // entire TLS segment.  Otherwise the TLS segment as a
3939               // whole may be misaligned.
3940               if (!*in_tls)
3941                 {
3942                   Output_segment* tls_segment = layout->tls_segment();
3943                   gold_assert(tls_segment != NULL);
3944                   uint64_t segment_align = tls_segment->maximum_alignment();
3945                   gold_assert(segment_align >= align);
3946                   align = segment_align;
3947
3948                   *in_tls = true;
3949                 }
3950             }
3951           else
3952             {
3953               // If this is the first section after the TLS segment,
3954               // align it to at least the alignment of the TLS
3955               // segment, so that the size of the overall TLS segment
3956               // is aligned.
3957               if (*in_tls)
3958                 {
3959                   uint64_t segment_align =
3960                       layout->tls_segment()->maximum_alignment();
3961                   if (segment_align > align)
3962                     align = segment_align;
3963
3964                   *in_tls = false;
3965                 }
3966             }
3967
3968           off = align_address(off, align);
3969           (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3970         }
3971       else
3972         {
3973           // The script may have inserted a skip forward, but it
3974           // better not have moved backward.
3975           if ((*p)->address() >= addr + (off - startoff))
3976             off += (*p)->address() - (addr + (off - startoff));
3977           else
3978             {
3979               if (!layout->script_options()->saw_sections_clause())
3980                 gold_unreachable();
3981               else
3982                 {
3983                   Output_section* os = (*p)->output_section();
3984
3985                   // Cast to unsigned long long to avoid format warnings.
3986                   unsigned long long previous_dot =
3987                     static_cast<unsigned long long>(addr + (off - startoff));
3988                   unsigned long long dot =
3989                     static_cast<unsigned long long>((*p)->address());
3990
3991                   if (os == NULL)
3992                     gold_error(_("dot moves backward in linker script "
3993                                  "from 0x%llx to 0x%llx"), previous_dot, dot);
3994                   else
3995                     gold_error(_("address of section '%s' moves backward "
3996                                  "from 0x%llx to 0x%llx"),
3997                                os->name(), previous_dot, dot);
3998                 }
3999             }
4000           (*p)->set_file_offset(off);
4001           (*p)->finalize_data_size();
4002         }
4003
4004       // We want to ignore the size of a SHF_TLS or SHT_NOBITS
4005       // section.  Such a section does not affect the size of a
4006       // PT_LOAD segment.
4007       if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
4008           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
4009         off += (*p)->data_size();
4010
4011       if ((*p)->is_section())
4012         {
4013           (*p)->set_out_shndx(*pshndx);
4014           ++*pshndx;
4015         }
4016     }
4017
4018   *poff = off;
4019   return addr + (off - startoff);
4020 }
4021
4022 // For a non-PT_LOAD segment, set the offset from the sections, if
4023 // any.  Add INCREASE to the file size and the memory size.
4024
4025 void
4026 Output_segment::set_offset(unsigned int increase)
4027 {
4028   gold_assert(this->type_ != elfcpp::PT_LOAD);
4029
4030   gold_assert(!this->are_addresses_set_);
4031
4032   if (this->output_data_.empty() && this->output_bss_.empty())
4033     {
4034       gold_assert(increase == 0);
4035       this->vaddr_ = 0;
4036       this->paddr_ = 0;
4037       this->are_addresses_set_ = true;
4038       this->memsz_ = 0;
4039       this->min_p_align_ = 0;
4040       this->offset_ = 0;
4041       this->filesz_ = 0;
4042       return;
4043     }
4044
4045   // Find the first and last section by address.  The sections may
4046   // have been sorted for the PT_LOAD segment.
4047   const Output_data* first = NULL;
4048   const Output_data* last_data = NULL;
4049   const Output_data* last_bss = NULL;
4050   this->find_first_and_last_list(&this->output_data_, &first, &last_data);
4051   this->find_first_and_last_list(&this->output_bss_, &first, &last_bss);
4052
4053   this->vaddr_ = first->address();
4054   this->paddr_ = (first->has_load_address()
4055                   ? first->load_address()
4056                   : this->vaddr_);
4057   this->are_addresses_set_ = true;
4058   this->offset_ = first->offset();
4059
4060   if (this->output_data_.empty())
4061     this->filesz_ = 0;
4062   else
4063     this->filesz_ = (last_data->address()
4064                      + last_data->data_size()
4065                      - this->vaddr_);
4066
4067   const Output_data* last = last_bss != NULL ? last_bss : last_data;
4068   this->memsz_ = (last->address()
4069                   + last->data_size()
4070                   - this->vaddr_);
4071
4072   this->filesz_ += increase;
4073   this->memsz_ += increase;
4074
4075   // If this is a TLS segment, align the memory size.  The code in
4076   // set_section_list ensures that the section after the TLS segment
4077   // is aligned to give us room.
4078   if (this->type_ == elfcpp::PT_TLS)
4079     {
4080       uint64_t segment_align = this->maximum_alignment();
4081       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
4082       this->memsz_ = align_address(this->memsz_, segment_align);
4083     }
4084 }
4085
4086 // Look through a list of Output_data objects and find the first and
4087 // last by address.
4088
4089 void
4090 Output_segment::find_first_and_last_list(const Output_data_list* pdl,
4091                                          const Output_data** pfirst,
4092                                          const Output_data** plast) const
4093 {
4094   const Output_data* first = *pfirst;
4095   const Output_data* last = *plast;
4096   for (Output_data_list::const_iterator p = pdl->begin(); p != pdl->end(); ++p)
4097     {
4098       if (first == NULL
4099           || (*p)->address() < first->address()
4100           || ((*p)->address() == first->address()
4101               && (*p)->data_size() < first->data_size()))
4102         {
4103           first = *p;
4104           *pfirst = first;
4105         }
4106       if (last == NULL
4107           || (*p)->address() > last->address()
4108           || ((*p)->address() == last->address()
4109               && (*p)->data_size() > last->data_size()))
4110         {
4111           last = *p;
4112           *plast = last;
4113         }
4114     }
4115 }
4116
4117 // Set the TLS offsets of the sections in the PT_TLS segment.
4118
4119 void
4120 Output_segment::set_tls_offsets()
4121 {
4122   gold_assert(this->type_ == elfcpp::PT_TLS);
4123
4124   for (Output_data_list::iterator p = this->output_data_.begin();
4125        p != this->output_data_.end();
4126        ++p)
4127     (*p)->set_tls_offset(this->vaddr_);
4128
4129   for (Output_data_list::iterator p = this->output_bss_.begin();
4130        p != this->output_bss_.end();
4131        ++p)
4132     (*p)->set_tls_offset(this->vaddr_);
4133 }
4134
4135 // Return the address of the first section.
4136
4137 uint64_t
4138 Output_segment::first_section_load_address() const
4139 {
4140   for (Output_data_list::const_iterator p = this->output_data_.begin();
4141        p != this->output_data_.end();
4142        ++p)
4143     if ((*p)->is_section())
4144       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
4145
4146   for (Output_data_list::const_iterator p = this->output_bss_.begin();
4147        p != this->output_bss_.end();
4148        ++p)
4149     if ((*p)->is_section())
4150       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
4151
4152   gold_unreachable();
4153 }
4154
4155 // Return the number of Output_sections in an Output_segment.
4156
4157 unsigned int
4158 Output_segment::output_section_count() const
4159 {
4160   return (this->output_section_count_list(&this->output_data_)
4161           + this->output_section_count_list(&this->output_bss_));
4162 }
4163
4164 // Return the number of Output_sections in an Output_data_list.
4165
4166 unsigned int
4167 Output_segment::output_section_count_list(const Output_data_list* pdl) const
4168 {
4169   unsigned int count = 0;
4170   for (Output_data_list::const_iterator p = pdl->begin();
4171        p != pdl->end();
4172        ++p)
4173     {
4174       if ((*p)->is_section())
4175         ++count;
4176     }
4177   return count;
4178 }
4179
4180 // Return the section attached to the list segment with the lowest
4181 // load address.  This is used when handling a PHDRS clause in a
4182 // linker script.
4183
4184 Output_section*
4185 Output_segment::section_with_lowest_load_address() const
4186 {
4187   Output_section* found = NULL;
4188   uint64_t found_lma = 0;
4189   this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma);
4190
4191   Output_section* found_data = found;
4192   this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma);
4193   if (found != found_data && found_data != NULL)
4194     {
4195       gold_error(_("nobits section %s may not precede progbits section %s "
4196                    "in same segment"),
4197                  found->name(), found_data->name());
4198       return NULL;
4199     }
4200
4201   return found;
4202 }
4203
4204 // Look through a list for a section with a lower load address.
4205
4206 void
4207 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
4208                                             Output_section** found,
4209                                             uint64_t* found_lma) const
4210 {
4211   for (Output_data_list::const_iterator p = pdl->begin();
4212        p != pdl->end();
4213        ++p)
4214     {
4215       if (!(*p)->is_section())
4216         continue;
4217       Output_section* os = static_cast<Output_section*>(*p);
4218       uint64_t lma = (os->has_load_address()
4219                       ? os->load_address()
4220                       : os->address());
4221       if (*found == NULL || lma < *found_lma)
4222         {
4223           *found = os;
4224           *found_lma = lma;
4225         }
4226     }
4227 }
4228
4229 // Write the segment data into *OPHDR.
4230
4231 template<int size, bool big_endian>
4232 void
4233 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
4234 {
4235   ophdr->put_p_type(this->type_);
4236   ophdr->put_p_offset(this->offset_);
4237   ophdr->put_p_vaddr(this->vaddr_);
4238   ophdr->put_p_paddr(this->paddr_);
4239   ophdr->put_p_filesz(this->filesz_);
4240   ophdr->put_p_memsz(this->memsz_);
4241   ophdr->put_p_flags(this->flags_);
4242   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
4243 }
4244
4245 // Write the section headers into V.
4246
4247 template<int size, bool big_endian>
4248 unsigned char*
4249 Output_segment::write_section_headers(const Layout* layout,
4250                                       const Stringpool* secnamepool,
4251                                       unsigned char* v,
4252                                       unsigned int *pshndx) const
4253 {
4254   // Every section that is attached to a segment must be attached to a
4255   // PT_LOAD segment, so we only write out section headers for PT_LOAD
4256   // segments.
4257   if (this->type_ != elfcpp::PT_LOAD)
4258     return v;
4259
4260   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
4261                                                          &this->output_data_,
4262                                                          v, pshndx);
4263   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
4264                                                          &this->output_bss_,
4265                                                          v, pshndx);
4266   return v;
4267 }
4268
4269 template<int size, bool big_endian>
4270 unsigned char*
4271 Output_segment::write_section_headers_list(const Layout* layout,
4272                                            const Stringpool* secnamepool,
4273                                            const Output_data_list* pdl,
4274                                            unsigned char* v,
4275                                            unsigned int* pshndx) const
4276 {
4277   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
4278   for (Output_data_list::const_iterator p = pdl->begin();
4279        p != pdl->end();
4280        ++p)
4281     {
4282       if ((*p)->is_section())
4283         {
4284           const Output_section* ps = static_cast<const Output_section*>(*p);
4285           gold_assert(*pshndx == ps->out_shndx());
4286           elfcpp::Shdr_write<size, big_endian> oshdr(v);
4287           ps->write_header(layout, secnamepool, &oshdr);
4288           v += shdr_size;
4289           ++*pshndx;
4290         }
4291     }
4292   return v;
4293 }
4294
4295 // Print the output sections to the map file.
4296
4297 void
4298 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
4299 {
4300   if (this->type() != elfcpp::PT_LOAD)
4301     return;
4302   this->print_section_list_to_mapfile(mapfile, &this->output_data_);
4303   this->print_section_list_to_mapfile(mapfile, &this->output_bss_);
4304 }
4305
4306 // Print an output section list to the map file.
4307
4308 void
4309 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
4310                                               const Output_data_list* pdl) const
4311 {
4312   for (Output_data_list::const_iterator p = pdl->begin();
4313        p != pdl->end();
4314        ++p)
4315     (*p)->print_to_mapfile(mapfile);
4316 }
4317
4318 // Output_file methods.
4319
4320 Output_file::Output_file(const char* name)
4321   : name_(name),
4322     o_(-1),
4323     file_size_(0),
4324     base_(NULL),
4325     map_is_anonymous_(false),
4326     is_temporary_(false)
4327 {
4328 }
4329
4330 // Try to open an existing file.  Returns false if the file doesn't
4331 // exist, has a size of 0 or can't be mmapped.
4332
4333 bool
4334 Output_file::open_for_modification()
4335 {
4336   // The name "-" means "stdout".
4337   if (strcmp(this->name_, "-") == 0)
4338     return false;
4339
4340   // Don't bother opening files with a size of zero.
4341   struct stat s;
4342   if (::stat(this->name_, &s) != 0 || s.st_size == 0)
4343     return false;
4344
4345   int o = open_descriptor(-1, this->name_, O_RDWR, 0);
4346   if (o < 0)
4347     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4348   this->o_ = o;
4349   this->file_size_ = s.st_size;
4350
4351   // If the file can't be mmapped, copying the content to an anonymous
4352   // map will probably negate the performance benefits of incremental
4353   // linking.  This could be helped by using views and loading only
4354   // the necessary parts, but this is not supported as of now.
4355   if (!this->map_no_anonymous())
4356     {
4357       release_descriptor(o, true);
4358       this->o_ = -1;
4359       this->file_size_ = 0;
4360       return false;
4361     }
4362
4363   return true;
4364 }
4365
4366 // Open the output file.
4367
4368 void
4369 Output_file::open(off_t file_size)
4370 {
4371   this->file_size_ = file_size;
4372
4373   // Unlink the file first; otherwise the open() may fail if the file
4374   // is busy (e.g. it's an executable that's currently being executed).
4375   //
4376   // However, the linker may be part of a system where a zero-length
4377   // file is created for it to write to, with tight permissions (gcc
4378   // 2.95 did something like this).  Unlinking the file would work
4379   // around those permission controls, so we only unlink if the file
4380   // has a non-zero size.  We also unlink only regular files to avoid
4381   // trouble with directories/etc.
4382   //
4383   // If we fail, continue; this command is merely a best-effort attempt
4384   // to improve the odds for open().
4385
4386   // We let the name "-" mean "stdout"
4387   if (!this->is_temporary_)
4388     {
4389       if (strcmp(this->name_, "-") == 0)
4390         this->o_ = STDOUT_FILENO;
4391       else
4392         {
4393           struct stat s;
4394           if (::stat(this->name_, &s) == 0
4395               && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
4396             {
4397               if (s.st_size != 0)
4398                 ::unlink(this->name_);
4399               else if (!parameters->options().relocatable())
4400                 {
4401                   // If we don't unlink the existing file, add execute
4402                   // permission where read permissions already exist
4403                   // and where the umask permits.
4404                   int mask = ::umask(0);
4405                   ::umask(mask);
4406                   s.st_mode |= (s.st_mode & 0444) >> 2;
4407                   ::chmod(this->name_, s.st_mode & ~mask);
4408                 }
4409             }
4410
4411           int mode = parameters->options().relocatable() ? 0666 : 0777;
4412           int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
4413                                   mode);
4414           if (o < 0)
4415             gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4416           this->o_ = o;
4417         }
4418     }
4419
4420   this->map();
4421 }
4422
4423 // Resize the output file.
4424
4425 void
4426 Output_file::resize(off_t file_size)
4427 {
4428   // If the mmap is mapping an anonymous memory buffer, this is easy:
4429   // just mremap to the new size.  If it's mapping to a file, we want
4430   // to unmap to flush to the file, then remap after growing the file.
4431   if (this->map_is_anonymous_)
4432     {
4433       void* base = ::mremap(this->base_, this->file_size_, file_size,
4434                             MREMAP_MAYMOVE);
4435       if (base == MAP_FAILED)
4436         gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
4437       this->base_ = static_cast<unsigned char*>(base);
4438       this->file_size_ = file_size;
4439     }
4440   else
4441     {
4442       this->unmap();
4443       this->file_size_ = file_size;
4444       if (!this->map_no_anonymous())
4445         gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
4446     }
4447 }
4448
4449 // Map an anonymous block of memory which will later be written to the
4450 // file.  Return whether the map succeeded.
4451
4452 bool
4453 Output_file::map_anonymous()
4454 {
4455   void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4456                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
4457   if (base != MAP_FAILED)
4458     {
4459       this->map_is_anonymous_ = true;
4460       this->base_ = static_cast<unsigned char*>(base);
4461       return true;
4462     }
4463   return false;
4464 }
4465
4466 // Map the file into memory.  Return whether the mapping succeeded.
4467
4468 bool
4469 Output_file::map_no_anonymous()
4470 {
4471   const int o = this->o_;
4472
4473   // If the output file is not a regular file, don't try to mmap it;
4474   // instead, we'll mmap a block of memory (an anonymous buffer), and
4475   // then later write the buffer to the file.
4476   void* base;
4477   struct stat statbuf;
4478   if (o == STDOUT_FILENO || o == STDERR_FILENO
4479       || ::fstat(o, &statbuf) != 0
4480       || !S_ISREG(statbuf.st_mode)
4481       || this->is_temporary_)
4482     return false;
4483
4484   // Ensure that we have disk space available for the file.  If we
4485   // don't do this, it is possible that we will call munmap, close,
4486   // and exit with dirty buffers still in the cache with no assigned
4487   // disk blocks.  If the disk is out of space at that point, the
4488   // output file will wind up incomplete, but we will have already
4489   // exited.  The alternative to fallocate would be to use fdatasync,
4490   // but that would be a more significant performance hit.
4491   if (::posix_fallocate(o, 0, this->file_size_) < 0)
4492     gold_fatal(_("%s: %s"), this->name_, strerror(errno));
4493
4494   // Map the file into memory.
4495   base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4496                 MAP_SHARED, o, 0);
4497
4498   // The mmap call might fail because of file system issues: the file
4499   // system might not support mmap at all, or it might not support
4500   // mmap with PROT_WRITE.
4501   if (base == MAP_FAILED)
4502     return false;
4503
4504   this->map_is_anonymous_ = false;
4505   this->base_ = static_cast<unsigned char*>(base);
4506   return true;
4507 }
4508
4509 // Map the file into memory.
4510
4511 void
4512 Output_file::map()
4513 {
4514   if (this->map_no_anonymous())
4515     return;
4516
4517   // The mmap call might fail because of file system issues: the file
4518   // system might not support mmap at all, or it might not support
4519   // mmap with PROT_WRITE.  I'm not sure which errno values we will
4520   // see in all cases, so if the mmap fails for any reason and we
4521   // don't care about file contents, try for an anonymous map.
4522   if (this->map_anonymous())
4523     return;
4524
4525   gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
4526              this->name_, static_cast<unsigned long>(this->file_size_),
4527              strerror(errno));
4528 }
4529
4530 // Unmap the file from memory.
4531
4532 void
4533 Output_file::unmap()
4534 {
4535   if (::munmap(this->base_, this->file_size_) < 0)
4536     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4537   this->base_ = NULL;
4538 }
4539
4540 // Close the output file.
4541
4542 void
4543 Output_file::close()
4544 {
4545   // If the map isn't file-backed, we need to write it now.
4546   if (this->map_is_anonymous_ && !this->is_temporary_)
4547     {
4548       size_t bytes_to_write = this->file_size_;
4549       size_t offset = 0;
4550       while (bytes_to_write > 0)
4551         {
4552           ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4553                                           bytes_to_write);
4554           if (bytes_written == 0)
4555             gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4556           else if (bytes_written < 0)
4557             gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4558           else
4559             {
4560               bytes_to_write -= bytes_written;
4561               offset += bytes_written;
4562             }
4563         }
4564     }
4565   this->unmap();
4566
4567   // We don't close stdout or stderr
4568   if (this->o_ != STDOUT_FILENO
4569       && this->o_ != STDERR_FILENO
4570       && !this->is_temporary_)
4571     if (::close(this->o_) < 0)
4572       gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4573   this->o_ = -1;
4574 }
4575
4576 // Instantiate the templates we need.  We could use the configure
4577 // script to restrict this to only the ones for implemented targets.
4578
4579 #ifdef HAVE_TARGET_32_LITTLE
4580 template
4581 off_t
4582 Output_section::add_input_section<32, false>(
4583     Layout* layout,
4584     Sized_relobj<32, false>* object,
4585     unsigned int shndx,
4586     const char* secname,
4587     const elfcpp::Shdr<32, false>& shdr,
4588     unsigned int reloc_shndx,
4589     bool have_sections_script);
4590 #endif
4591
4592 #ifdef HAVE_TARGET_32_BIG
4593 template
4594 off_t
4595 Output_section::add_input_section<32, true>(
4596     Layout* layout,
4597     Sized_relobj<32, true>* object,
4598     unsigned int shndx,
4599     const char* secname,
4600     const elfcpp::Shdr<32, true>& shdr,
4601     unsigned int reloc_shndx,
4602     bool have_sections_script);
4603 #endif
4604
4605 #ifdef HAVE_TARGET_64_LITTLE
4606 template
4607 off_t
4608 Output_section::add_input_section<64, false>(
4609     Layout* layout,
4610     Sized_relobj<64, false>* object,
4611     unsigned int shndx,
4612     const char* secname,
4613     const elfcpp::Shdr<64, false>& shdr,
4614     unsigned int reloc_shndx,
4615     bool have_sections_script);
4616 #endif
4617
4618 #ifdef HAVE_TARGET_64_BIG
4619 template
4620 off_t
4621 Output_section::add_input_section<64, true>(
4622     Layout* layout,
4623     Sized_relobj<64, true>* object,
4624     unsigned int shndx,
4625     const char* secname,
4626     const elfcpp::Shdr<64, true>& shdr,
4627     unsigned int reloc_shndx,
4628     bool have_sections_script);
4629 #endif
4630
4631 #ifdef HAVE_TARGET_32_LITTLE
4632 template
4633 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4634 #endif
4635
4636 #ifdef HAVE_TARGET_32_BIG
4637 template
4638 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4639 #endif
4640
4641 #ifdef HAVE_TARGET_64_LITTLE
4642 template
4643 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4644 #endif
4645
4646 #ifdef HAVE_TARGET_64_BIG
4647 template
4648 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4649 #endif
4650
4651 #ifdef HAVE_TARGET_32_LITTLE
4652 template
4653 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4654 #endif
4655
4656 #ifdef HAVE_TARGET_32_BIG
4657 template
4658 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4659 #endif
4660
4661 #ifdef HAVE_TARGET_64_LITTLE
4662 template
4663 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4664 #endif
4665
4666 #ifdef HAVE_TARGET_64_BIG
4667 template
4668 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4669 #endif
4670
4671 #ifdef HAVE_TARGET_32_LITTLE
4672 template
4673 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4674 #endif
4675
4676 #ifdef HAVE_TARGET_32_BIG
4677 template
4678 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4679 #endif
4680
4681 #ifdef HAVE_TARGET_64_LITTLE
4682 template
4683 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4684 #endif
4685
4686 #ifdef HAVE_TARGET_64_BIG
4687 template
4688 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4689 #endif
4690
4691 #ifdef HAVE_TARGET_32_LITTLE
4692 template
4693 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4694 #endif
4695
4696 #ifdef HAVE_TARGET_32_BIG
4697 template
4698 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4699 #endif
4700
4701 #ifdef HAVE_TARGET_64_LITTLE
4702 template
4703 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4704 #endif
4705
4706 #ifdef HAVE_TARGET_64_BIG
4707 template
4708 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4709 #endif
4710
4711 #ifdef HAVE_TARGET_32_LITTLE
4712 template
4713 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4714 #endif
4715
4716 #ifdef HAVE_TARGET_32_BIG
4717 template
4718 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4719 #endif
4720
4721 #ifdef HAVE_TARGET_64_LITTLE
4722 template
4723 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4724 #endif
4725
4726 #ifdef HAVE_TARGET_64_BIG
4727 template
4728 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4729 #endif
4730
4731 #ifdef HAVE_TARGET_32_LITTLE
4732 template
4733 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4734 #endif
4735
4736 #ifdef HAVE_TARGET_32_BIG
4737 template
4738 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4739 #endif
4740
4741 #ifdef HAVE_TARGET_64_LITTLE
4742 template
4743 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4744 #endif
4745
4746 #ifdef HAVE_TARGET_64_BIG
4747 template
4748 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4749 #endif
4750
4751 #ifdef HAVE_TARGET_32_LITTLE
4752 template
4753 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4754 #endif
4755
4756 #ifdef HAVE_TARGET_32_BIG
4757 template
4758 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4759 #endif
4760
4761 #ifdef HAVE_TARGET_64_LITTLE
4762 template
4763 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4764 #endif
4765
4766 #ifdef HAVE_TARGET_64_BIG
4767 template
4768 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4769 #endif
4770
4771 #ifdef HAVE_TARGET_32_LITTLE
4772 template
4773 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4774 #endif
4775
4776 #ifdef HAVE_TARGET_32_BIG
4777 template
4778 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4779 #endif
4780
4781 #ifdef HAVE_TARGET_64_LITTLE
4782 template
4783 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4784 #endif
4785
4786 #ifdef HAVE_TARGET_64_BIG
4787 template
4788 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4789 #endif
4790
4791 #ifdef HAVE_TARGET_32_LITTLE
4792 template
4793 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4794 #endif
4795
4796 #ifdef HAVE_TARGET_32_BIG
4797 template
4798 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4799 #endif
4800
4801 #ifdef HAVE_TARGET_64_LITTLE
4802 template
4803 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4804 #endif
4805
4806 #ifdef HAVE_TARGET_64_BIG
4807 template
4808 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4809 #endif
4810
4811 #ifdef HAVE_TARGET_32_LITTLE
4812 template
4813 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4814 #endif
4815
4816 #ifdef HAVE_TARGET_32_BIG
4817 template
4818 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4819 #endif
4820
4821 #ifdef HAVE_TARGET_64_LITTLE
4822 template
4823 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4824 #endif
4825
4826 #ifdef HAVE_TARGET_64_BIG
4827 template
4828 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4829 #endif
4830
4831 #ifdef HAVE_TARGET_32_LITTLE
4832 template
4833 class Output_data_group<32, false>;
4834 #endif
4835
4836 #ifdef HAVE_TARGET_32_BIG
4837 template
4838 class Output_data_group<32, true>;
4839 #endif
4840
4841 #ifdef HAVE_TARGET_64_LITTLE
4842 template
4843 class Output_data_group<64, false>;
4844 #endif
4845
4846 #ifdef HAVE_TARGET_64_BIG
4847 template
4848 class Output_data_group<64, true>;
4849 #endif
4850
4851 #ifdef HAVE_TARGET_32_LITTLE
4852 template
4853 class Output_data_got<32, false>;
4854 #endif
4855
4856 #ifdef HAVE_TARGET_32_BIG
4857 template
4858 class Output_data_got<32, true>;
4859 #endif
4860
4861 #ifdef HAVE_TARGET_64_LITTLE
4862 template
4863 class Output_data_got<64, false>;
4864 #endif
4865
4866 #ifdef HAVE_TARGET_64_BIG
4867 template
4868 class Output_data_got<64, true>;
4869 #endif
4870
4871 } // End namespace gold.