gold/output.cc

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