gold/output.cc

   1 // output.cc -- manage the output file for gold
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <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
1137   // A STT_GNU_IFUNC symbol may require a IRELATIVE reloc when doing a
1138   // static link.  The backends will generate a dynamic reloc section
1139   // to hold this.  In that case we don't want to link to the dynsym
1140   // section, because there isn't one.
1141   if (!dynamic)
1142     os->set_should_link_to_symtab();
1143   else if (parameters->doing_static_link())
1144     ;
1145   else
1146     os->set_should_link_to_dynsym();
1147 }
1148
1149 // Write out relocation data.
1150
1151 template<int sh_type, bool dynamic, int size, bool big_endian>
1152 void
1153 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1154     Output_file* of)
1155 {
1156   const off_t off = this->offset();
1157   const off_t oview_size = this->data_size();
1158   unsigned char* const oview = of->get_output_view(off, oview_size);
1159
1160   if (this->sort_relocs())
1161     {
1162       gold_assert(dynamic);
1163       std::sort(this->relocs_.begin(), this->relocs_.end(),
1164                 Sort_relocs_comparison());
1165     }
1166
1167   unsigned char* pov = oview;
1168   for (typename Relocs::const_iterator p = this->relocs_.begin();
1169        p != this->relocs_.end();
1170        ++p)
1171     {
1172       p->write(pov);
1173       pov += reloc_size;
1174     }
1175
1176   gold_assert(pov - oview == oview_size);
1177
1178   of->write_output_view(off, oview_size, oview);
1179
1180   // We no longer need the relocation entries.
1181   this->relocs_.clear();
1182 }
1183
1184 // Class Output_relocatable_relocs.
1185
1186 template<int sh_type, int size, bool big_endian>
1187 void
1188 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1189 {
1190   this->set_data_size(this->rr_->output_reloc_count()
1191                       * Reloc_types<sh_type, size, big_endian>::reloc_size);
1192 }
1193
1194 // class Output_data_group.
1195
1196 template<int size, bool big_endian>
1197 Output_data_group<size, big_endian>::Output_data_group(
1198     Sized_relobj<size, big_endian>* relobj,
1199     section_size_type entry_count,
1200     elfcpp::Elf_Word flags,
1201     std::vector<unsigned int>* input_shndxes)
1202   : Output_section_data(entry_count * 4, 4, false),
1203     relobj_(relobj),
1204     flags_(flags)
1205 {
1206   this->input_shndxes_.swap(*input_shndxes);
1207 }
1208
1209 // Write out the section group, which means translating the section
1210 // indexes to apply to the output file.
1211
1212 template<int size, bool big_endian>
1213 void
1214 Output_data_group<size, big_endian>::do_write(Output_file* of)
1215 {
1216   const off_t off = this->offset();
1217   const section_size_type oview_size =
1218     convert_to_section_size_type(this->data_size());
1219   unsigned char* const oview = of->get_output_view(off, oview_size);
1220
1221   elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1222   elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1223   ++contents;
1224
1225   for (std::vector<unsigned int>::const_iterator p =
1226          this->input_shndxes_.begin();
1227        p != this->input_shndxes_.end();
1228        ++p, ++contents)
1229     {
1230       Output_section* os = this->relobj_->output_section(*p);
1231
1232       unsigned int output_shndx;
1233       if (os != NULL)
1234         output_shndx = os->out_shndx();
1235       else
1236         {
1237           this->relobj_->error(_("section group retained but "
1238                                  "group element discarded"));
1239           output_shndx = 0;
1240         }
1241
1242       elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1243     }
1244
1245   size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1246   gold_assert(wrote == oview_size);
1247
1248   of->write_output_view(off, oview_size, oview);
1249
1250   // We no longer need this information.
1251   this->input_shndxes_.clear();
1252 }
1253
1254 // Output_data_got::Got_entry methods.
1255
1256 // Write out the entry.
1257
1258 template<int size, bool big_endian>
1259 void
1260 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1261 {
1262   Valtype val = 0;
1263
1264   switch (this->local_sym_index_)
1265     {
1266     case GSYM_CODE:
1267       {
1268         // If the symbol is resolved locally, we need to write out the
1269         // link-time value, which will be relocated dynamically by a
1270         // RELATIVE relocation.
1271         Symbol* gsym = this->u_.gsym;
1272         if (this->use_plt_offset_ && gsym->has_plt_offset())
1273           val = (parameters->target().plt_section_for_global(gsym)->address()
1274                  + gsym->plt_offset());
1275         else
1276           {
1277             Sized_symbol<size>* sgsym;
1278             // This cast is a bit ugly.  We don't want to put a
1279             // virtual method in Symbol, because we want Symbol to be
1280             // as small as possible.
1281             sgsym = static_cast<Sized_symbol<size>*>(gsym);
1282             val = sgsym->value();
1283           }
1284       }
1285       break;
1286
1287     case CONSTANT_CODE:
1288       val = this->u_.constant;
1289       break;
1290
1291     default:
1292       {
1293         const Sized_relobj<size, big_endian>* object = this->u_.object;
1294         const unsigned int lsi = this->local_sym_index_;
1295         const Symbol_value<size>* symval = object->local_symbol(lsi);
1296         if (!this->use_plt_offset_)
1297           val = symval->value(this->u_.object, 0);
1298         else
1299           {
1300             const Output_data* plt =
1301               parameters->target().plt_section_for_local(object, lsi);
1302             val = plt->address() + object->local_plt_offset(lsi);
1303           }
1304       }
1305       break;
1306     }
1307
1308   elfcpp::Swap<size, big_endian>::writeval(pov, val);
1309 }
1310
1311 // Output_data_got methods.
1312
1313 // Add an entry for a global symbol to the GOT.  This returns true if
1314 // this is a new GOT entry, false if the symbol already had a GOT
1315 // entry.
1316
1317 template<int size, bool big_endian>
1318 bool
1319 Output_data_got<size, big_endian>::add_global(
1320     Symbol* gsym,
1321     unsigned int got_type)
1322 {
1323   if (gsym->has_got_offset(got_type))
1324     return false;
1325
1326   this->entries_.push_back(Got_entry(gsym, false));
1327   this->set_got_size();
1328   gsym->set_got_offset(got_type, this->last_got_offset());
1329   return true;
1330 }
1331
1332 // Like add_global, but use the PLT offset.
1333
1334 template<int size, bool big_endian>
1335 bool
1336 Output_data_got<size, big_endian>::add_global_plt(Symbol* gsym,
1337                                                   unsigned int got_type)
1338 {
1339   if (gsym->has_got_offset(got_type))
1340     return false;
1341
1342   this->entries_.push_back(Got_entry(gsym, true));
1343   this->set_got_size();
1344   gsym->set_got_offset(got_type, this->last_got_offset());
1345   return true;
1346 }
1347
1348 // Add an entry for a global symbol to the GOT, and add a dynamic
1349 // relocation of type R_TYPE for the GOT entry.
1350
1351 template<int size, bool big_endian>
1352 void
1353 Output_data_got<size, big_endian>::add_global_with_rel(
1354     Symbol* gsym,
1355     unsigned int got_type,
1356     Rel_dyn* rel_dyn,
1357     unsigned int r_type)
1358 {
1359   if (gsym->has_got_offset(got_type))
1360     return;
1361
1362   this->entries_.push_back(Got_entry());
1363   this->set_got_size();
1364   unsigned int got_offset = this->last_got_offset();
1365   gsym->set_got_offset(got_type, got_offset);
1366   rel_dyn->add_global(gsym, r_type, this, got_offset);
1367 }
1368
1369 template<int size, bool big_endian>
1370 void
1371 Output_data_got<size, big_endian>::add_global_with_rela(
1372     Symbol* gsym,
1373     unsigned int got_type,
1374     Rela_dyn* rela_dyn,
1375     unsigned int r_type)
1376 {
1377   if (gsym->has_got_offset(got_type))
1378     return;
1379
1380   this->entries_.push_back(Got_entry());
1381   this->set_got_size();
1382   unsigned int got_offset = this->last_got_offset();
1383   gsym->set_got_offset(got_type, got_offset);
1384   rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1385 }
1386
1387 // Add a pair of entries for a global symbol to the GOT, and add
1388 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1389 // If R_TYPE_2 == 0, add the second entry with no relocation.
1390 template<int size, bool big_endian>
1391 void
1392 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1393     Symbol* gsym,
1394     unsigned int got_type,
1395     Rel_dyn* rel_dyn,
1396     unsigned int r_type_1,
1397     unsigned int r_type_2)
1398 {
1399   if (gsym->has_got_offset(got_type))
1400     return;
1401
1402   this->entries_.push_back(Got_entry());
1403   unsigned int got_offset = this->last_got_offset();
1404   gsym->set_got_offset(got_type, got_offset);
1405   rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1406
1407   this->entries_.push_back(Got_entry());
1408   if (r_type_2 != 0)
1409     {
1410       got_offset = this->last_got_offset();
1411       rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1412     }
1413
1414   this->set_got_size();
1415 }
1416
1417 template<int size, bool big_endian>
1418 void
1419 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1420     Symbol* gsym,
1421     unsigned int got_type,
1422     Rela_dyn* rela_dyn,
1423     unsigned int r_type_1,
1424     unsigned int r_type_2)
1425 {
1426   if (gsym->has_got_offset(got_type))
1427     return;
1428
1429   this->entries_.push_back(Got_entry());
1430   unsigned int got_offset = this->last_got_offset();
1431   gsym->set_got_offset(got_type, got_offset);
1432   rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1433
1434   this->entries_.push_back(Got_entry());
1435   if (r_type_2 != 0)
1436     {
1437       got_offset = this->last_got_offset();
1438       rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1439     }
1440
1441   this->set_got_size();
1442 }
1443
1444 // Add an entry for a local symbol to the GOT.  This returns true if
1445 // this is a new GOT entry, false if the symbol already has a GOT
1446 // entry.
1447
1448 template<int size, bool big_endian>
1449 bool
1450 Output_data_got<size, big_endian>::add_local(
1451     Sized_relobj<size, big_endian>* object,
1452     unsigned int symndx,
1453     unsigned int got_type)
1454 {
1455   if (object->local_has_got_offset(symndx, got_type))
1456     return false;
1457
1458   this->entries_.push_back(Got_entry(object, symndx, false));
1459   this->set_got_size();
1460   object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1461   return true;
1462 }
1463
1464 // Like add_local, but use the PLT offset.
1465
1466 template<int size, bool big_endian>
1467 bool
1468 Output_data_got<size, big_endian>::add_local_plt(
1469     Sized_relobj<size, big_endian>* object,
1470     unsigned int symndx,
1471     unsigned int got_type)
1472 {
1473   if (object->local_has_got_offset(symndx, got_type))
1474     return false;
1475
1476   this->entries_.push_back(Got_entry(object, symndx, true));
1477   this->set_got_size();
1478   object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1479   return true;
1480 }
1481
1482 // Add an entry for a local symbol to the GOT, and add a dynamic
1483 // relocation of type R_TYPE for the GOT entry.
1484
1485 template<int size, bool big_endian>
1486 void
1487 Output_data_got<size, big_endian>::add_local_with_rel(
1488     Sized_relobj<size, big_endian>* object,
1489     unsigned int symndx,
1490     unsigned int got_type,
1491     Rel_dyn* rel_dyn,
1492     unsigned int r_type)
1493 {
1494   if (object->local_has_got_offset(symndx, got_type))
1495     return;
1496
1497   this->entries_.push_back(Got_entry());
1498   this->set_got_size();
1499   unsigned int got_offset = this->last_got_offset();
1500   object->set_local_got_offset(symndx, got_type, got_offset);
1501   rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1502 }
1503
1504 template<int size, bool big_endian>
1505 void
1506 Output_data_got<size, big_endian>::add_local_with_rela(
1507     Sized_relobj<size, big_endian>* object,
1508     unsigned int symndx,
1509     unsigned int got_type,
1510     Rela_dyn* rela_dyn,
1511     unsigned int r_type)
1512 {
1513   if (object->local_has_got_offset(symndx, got_type))
1514     return;
1515
1516   this->entries_.push_back(Got_entry());
1517   this->set_got_size();
1518   unsigned int got_offset = this->last_got_offset();
1519   object->set_local_got_offset(symndx, got_type, got_offset);
1520   rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1521 }
1522
1523 // Add a pair of entries for a local symbol to the GOT, and add
1524 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1525 // If R_TYPE_2 == 0, add the second entry with no relocation.
1526 template<int size, bool big_endian>
1527 void
1528 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1529     Sized_relobj<size, big_endian>* object,
1530     unsigned int symndx,
1531     unsigned int shndx,
1532     unsigned int got_type,
1533     Rel_dyn* rel_dyn,
1534     unsigned int r_type_1,
1535     unsigned int r_type_2)
1536 {
1537   if (object->local_has_got_offset(symndx, got_type))
1538     return;
1539
1540   this->entries_.push_back(Got_entry());
1541   unsigned int got_offset = this->last_got_offset();
1542   object->set_local_got_offset(symndx, got_type, got_offset);
1543   Output_section* os = object->output_section(shndx);
1544   rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1545
1546   this->entries_.push_back(Got_entry(object, symndx, false));
1547   if (r_type_2 != 0)
1548     {
1549       got_offset = this->last_got_offset();
1550       rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1551     }
1552
1553   this->set_got_size();
1554 }
1555
1556 template<int size, bool big_endian>
1557 void
1558 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1559     Sized_relobj<size, big_endian>* object,
1560     unsigned int symndx,
1561     unsigned int shndx,
1562     unsigned int got_type,
1563     Rela_dyn* rela_dyn,
1564     unsigned int r_type_1,
1565     unsigned int r_type_2)
1566 {
1567   if (object->local_has_got_offset(symndx, got_type))
1568     return;
1569
1570   this->entries_.push_back(Got_entry());
1571   unsigned int got_offset = this->last_got_offset();
1572   object->set_local_got_offset(symndx, got_type, got_offset);
1573   Output_section* os = object->output_section(shndx);
1574   rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1575
1576   this->entries_.push_back(Got_entry(object, symndx, false));
1577   if (r_type_2 != 0)
1578     {
1579       got_offset = this->last_got_offset();
1580       rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1581     }
1582
1583   this->set_got_size();
1584 }
1585
1586 // Write out the GOT.
1587
1588 template<int size, bool big_endian>
1589 void
1590 Output_data_got<size, big_endian>::do_write(Output_file* of)
1591 {
1592   const int add = size / 8;
1593
1594   const off_t off = this->offset();
1595   const off_t oview_size = this->data_size();
1596   unsigned char* const oview = of->get_output_view(off, oview_size);
1597
1598   unsigned char* pov = oview;
1599   for (typename Got_entries::const_iterator p = this->entries_.begin();
1600        p != this->entries_.end();
1601        ++p)
1602     {
1603       p->write(pov);
1604       pov += add;
1605     }
1606
1607   gold_assert(pov - oview == oview_size);
1608
1609   of->write_output_view(off, oview_size, oview);
1610
1611   // We no longer need the GOT entries.
1612   this->entries_.clear();
1613 }
1614
1615 // Output_data_dynamic::Dynamic_entry methods.
1616
1617 // Write out the entry.
1618
1619 template<int size, bool big_endian>
1620 void
1621 Output_data_dynamic::Dynamic_entry::write(
1622     unsigned char* pov,
1623     const Stringpool* pool) const
1624 {
1625   typename elfcpp::Elf_types<size>::Elf_WXword val;
1626   switch (this->offset_)
1627     {
1628     case DYNAMIC_NUMBER:
1629       val = this->u_.val;
1630       break;
1631
1632     case DYNAMIC_SECTION_SIZE:
1633       val = this->u_.od->data_size();
1634       if (this->od2 != NULL)
1635         val += this->od2->data_size();
1636       break;
1637
1638     case DYNAMIC_SYMBOL:
1639       {
1640         const Sized_symbol<size>* s =
1641           static_cast<const Sized_symbol<size>*>(this->u_.sym);
1642         val = s->value();
1643       }
1644       break;
1645
1646     case DYNAMIC_STRING:
1647       val = pool->get_offset(this->u_.str);
1648       break;
1649
1650     default:
1651       val = this->u_.od->address() + this->offset_;
1652       break;
1653     }
1654
1655   elfcpp::Dyn_write<size, big_endian> dw(pov);
1656   dw.put_d_tag(this->tag_);
1657   dw.put_d_val(val);
1658 }
1659
1660 // Output_data_dynamic methods.
1661
1662 // Adjust the output section to set the entry size.
1663
1664 void
1665 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1666 {
1667   if (parameters->target().get_size() == 32)
1668     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1669   else if (parameters->target().get_size() == 64)
1670     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1671   else
1672     gold_unreachable();
1673 }
1674
1675 // Set the final data size.
1676
1677 void
1678 Output_data_dynamic::set_final_data_size()
1679 {
1680   // Add the terminating entry if it hasn't been added.
1681   // Because of relaxation, we can run this multiple times.
1682   if (this->entries_.empty() || this->entries_.back().tag() != elfcpp::DT_NULL)
1683     {
1684       int extra = parameters->options().spare_dynamic_tags();
1685       for (int i = 0; i < extra; ++i)
1686         this->add_constant(elfcpp::DT_NULL, 0);
1687       this->add_constant(elfcpp::DT_NULL, 0);
1688     }
1689
1690   int dyn_size;
1691   if (parameters->target().get_size() == 32)
1692     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1693   else if (parameters->target().get_size() == 64)
1694     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1695   else
1696     gold_unreachable();
1697   this->set_data_size(this->entries_.size() * dyn_size);
1698 }
1699
1700 // Write out the dynamic entries.
1701
1702 void
1703 Output_data_dynamic::do_write(Output_file* of)
1704 {
1705   switch (parameters->size_and_endianness())
1706     {
1707 #ifdef HAVE_TARGET_32_LITTLE
1708     case Parameters::TARGET_32_LITTLE:
1709       this->sized_write<32, false>(of);
1710       break;
1711 #endif
1712 #ifdef HAVE_TARGET_32_BIG
1713     case Parameters::TARGET_32_BIG:
1714       this->sized_write<32, true>(of);
1715       break;
1716 #endif
1717 #ifdef HAVE_TARGET_64_LITTLE
1718     case Parameters::TARGET_64_LITTLE:
1719       this->sized_write<64, false>(of);
1720       break;
1721 #endif
1722 #ifdef HAVE_TARGET_64_BIG
1723     case Parameters::TARGET_64_BIG:
1724       this->sized_write<64, true>(of);
1725       break;
1726 #endif
1727     default:
1728       gold_unreachable();
1729     }
1730 }
1731
1732 template<int size, bool big_endian>
1733 void
1734 Output_data_dynamic::sized_write(Output_file* of)
1735 {
1736   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1737
1738   const off_t offset = this->offset();
1739   const off_t oview_size = this->data_size();
1740   unsigned char* const oview = of->get_output_view(offset, oview_size);
1741
1742   unsigned char* pov = oview;
1743   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1744        p != this->entries_.end();
1745        ++p)
1746     {
1747       p->write<size, big_endian>(pov, this->pool_);
1748       pov += dyn_size;
1749     }
1750
1751   gold_assert(pov - oview == oview_size);
1752
1753   of->write_output_view(offset, oview_size, oview);
1754
1755   // We no longer need the dynamic entries.
1756   this->entries_.clear();
1757 }
1758
1759 // Class Output_symtab_xindex.
1760
1761 void
1762 Output_symtab_xindex::do_write(Output_file* of)
1763 {
1764   const off_t offset = this->offset();
1765   const off_t oview_size = this->data_size();
1766   unsigned char* const oview = of->get_output_view(offset, oview_size);
1767
1768   memset(oview, 0, oview_size);
1769
1770   if (parameters->target().is_big_endian())
1771     this->endian_do_write<true>(oview);
1772   else
1773     this->endian_do_write<false>(oview);
1774
1775   of->write_output_view(offset, oview_size, oview);
1776
1777   // We no longer need the data.
1778   this->entries_.clear();
1779 }
1780
1781 template<bool big_endian>
1782 void
1783 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1784 {
1785   for (Xindex_entries::const_iterator p = this->entries_.begin();
1786        p != this->entries_.end();
1787        ++p)
1788     {
1789       unsigned int symndx = p->first;
1790       gold_assert(symndx * 4 < this->data_size());
1791       elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1792     }
1793 }
1794
1795 // Output_section::Input_section methods.
1796
1797 // Return the data size.  For an input section we store the size here.
1798 // For an Output_section_data, we have to ask it for the size.
1799
1800 off_t
1801 Output_section::Input_section::data_size() const
1802 {
1803   if (this->is_input_section())
1804     return this->u1_.data_size;
1805   else
1806     return this->u2_.posd->data_size();
1807 }
1808
1809 // Return the object for an input section.
1810
1811 Relobj*
1812 Output_section::Input_section::relobj() const
1813 {
1814   if (this->is_input_section())
1815     return this->u2_.object;
1816   else if (this->is_merge_section())
1817     {
1818       gold_assert(this->u2_.pomb->first_relobj() != NULL);
1819       return this->u2_.pomb->first_relobj();
1820     }
1821   else if (this->is_relaxed_input_section())
1822     return this->u2_.poris->relobj();
1823   else
1824     gold_unreachable();
1825 }
1826
1827 // Return the input section index for an input section.
1828
1829 unsigned int
1830 Output_section::Input_section::shndx() const
1831 {
1832   if (this->is_input_section())
1833     return this->shndx_;
1834   else if (this->is_merge_section())
1835     {
1836       gold_assert(this->u2_.pomb->first_relobj() != NULL);
1837       return this->u2_.pomb->first_shndx();
1838     }
1839   else if (this->is_relaxed_input_section())
1840     return this->u2_.poris->shndx();
1841   else
1842     gold_unreachable();
1843 }
1844
1845 // Set the address and file offset.
1846
1847 void
1848 Output_section::Input_section::set_address_and_file_offset(
1849     uint64_t address,
1850     off_t file_offset,
1851     off_t section_file_offset)
1852 {
1853   if (this->is_input_section())
1854     this->u2_.object->set_section_offset(this->shndx_,
1855                                          file_offset - section_file_offset);
1856   else
1857     this->u2_.posd->set_address_and_file_offset(address, file_offset);
1858 }
1859
1860 // Reset the address and file offset.
1861
1862 void
1863 Output_section::Input_section::reset_address_and_file_offset()
1864 {
1865   if (!this->is_input_section())
1866     this->u2_.posd->reset_address_and_file_offset();
1867 }
1868
1869 // Finalize the data size.
1870
1871 void
1872 Output_section::Input_section::finalize_data_size()
1873 {
1874   if (!this->is_input_section())
1875     this->u2_.posd->finalize_data_size();
1876 }
1877
1878 // Try to turn an input offset into an output offset.  We want to
1879 // return the output offset relative to the start of this
1880 // Input_section in the output section.
1881
1882 inline bool
1883 Output_section::Input_section::output_offset(
1884     const Relobj* object,
1885     unsigned int shndx,
1886     section_offset_type offset,
1887     section_offset_type* poutput) const
1888 {
1889   if (!this->is_input_section())
1890     return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1891   else
1892     {
1893       if (this->shndx_ != shndx || this->u2_.object != object)
1894         return false;
1895       *poutput = offset;
1896       return true;
1897     }
1898 }
1899
1900 // Return whether this is the merge section for the input section
1901 // SHNDX in OBJECT.
1902
1903 inline bool
1904 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1905                                                     unsigned int shndx) const
1906 {
1907   if (this->is_input_section())
1908     return false;
1909   return this->u2_.posd->is_merge_section_for(object, shndx);
1910 }
1911
1912 // Write out the data.  We don't have to do anything for an input
1913 // section--they are handled via Object::relocate--but this is where
1914 // we write out the data for an Output_section_data.
1915
1916 void
1917 Output_section::Input_section::write(Output_file* of)
1918 {
1919   if (!this->is_input_section())
1920     this->u2_.posd->write(of);
1921 }
1922
1923 // Write the data to a buffer.  As for write(), we don't have to do
1924 // anything for an input section.
1925
1926 void
1927 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1928 {
1929   if (!this->is_input_section())
1930     this->u2_.posd->write_to_buffer(buffer);
1931 }
1932
1933 // Print to a map file.
1934
1935 void
1936 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1937 {
1938   switch (this->shndx_)
1939     {
1940     case OUTPUT_SECTION_CODE:
1941     case MERGE_DATA_SECTION_CODE:
1942     case MERGE_STRING_SECTION_CODE:
1943       this->u2_.posd->print_to_mapfile(mapfile);
1944       break;
1945
1946     case RELAXED_INPUT_SECTION_CODE:
1947       {
1948         Output_relaxed_input_section* relaxed_section =
1949           this->relaxed_input_section();
1950         mapfile->print_input_section(relaxed_section->relobj(),
1951                                      relaxed_section->shndx());
1952       }
1953       break;
1954     default:
1955       mapfile->print_input_section(this->u2_.object, this->shndx_);
1956       break;
1957     }
1958 }
1959
1960 // Output_section methods.
1961
1962 // Construct an Output_section.  NAME will point into a Stringpool.
1963
1964 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1965                                elfcpp::Elf_Xword flags)
1966   : name_(name),
1967     addralign_(0),
1968     entsize_(0),
1969     load_address_(0),
1970     link_section_(NULL),
1971     link_(0),
1972     info_section_(NULL),
1973     info_symndx_(NULL),
1974     info_(0),
1975     type_(type),
1976     flags_(flags),
1977     order_(ORDER_INVALID),
1978     out_shndx_(-1U),
1979     symtab_index_(0),
1980     dynsym_index_(0),
1981     input_sections_(),
1982     first_input_offset_(0),
1983     fills_(),
1984     postprocessing_buffer_(NULL),
1985     needs_symtab_index_(false),
1986     needs_dynsym_index_(false),
1987     should_link_to_symtab_(false),
1988     should_link_to_dynsym_(false),
1989     after_input_sections_(false),
1990     requires_postprocessing_(false),
1991     found_in_sections_clause_(false),
1992     has_load_address_(false),
1993     info_uses_section_index_(false),
1994     input_section_order_specified_(false),
1995     may_sort_attached_input_sections_(false),
1996     must_sort_attached_input_sections_(false),
1997     attached_input_sections_are_sorted_(false),
1998     is_relro_(false),
1999     is_small_section_(false),
2000     is_large_section_(false),
2001     generate_code_fills_at_write_(false),
2002     is_entsize_zero_(false),
2003     section_offsets_need_adjustment_(false),
2004     is_noload_(false),
2005     always_keeps_input_sections_(false),
2006     tls_offset_(0),
2007     checkpoint_(NULL),
2008     lookup_maps_(new Output_section_lookup_maps)
2009 {
2010   // An unallocated section has no address.  Forcing this means that
2011   // we don't need special treatment for symbols defined in debug
2012   // sections.
2013   if ((flags & elfcpp::SHF_ALLOC) == 0)
2014     this->set_address(0);
2015 }
2016
2017 Output_section::~Output_section()
2018 {
2019   delete this->checkpoint_;
2020 }
2021
2022 // Set the entry size.
2023
2024 void
2025 Output_section::set_entsize(uint64_t v)
2026 {
2027   if (this->is_entsize_zero_)
2028     ;
2029   else if (this->entsize_ == 0)
2030     this->entsize_ = v;
2031   else if (this->entsize_ != v)
2032     {
2033       this->entsize_ = 0;
2034       this->is_entsize_zero_ = 1;
2035     }
2036 }
2037
2038 // Add the input section SHNDX, with header SHDR, named SECNAME, in
2039 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
2040 // relocation section which applies to this section, or 0 if none, or
2041 // -1U if more than one.  Return the offset of the input section
2042 // within the output section.  Return -1 if the input section will
2043 // receive special handling.  In the normal case we don't always keep
2044 // track of input sections for an Output_section.  Instead, each
2045 // Object keeps track of the Output_section for each of its input
2046 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
2047 // track of input sections here; this is used when SECTIONS appears in
2048 // a linker script.
2049
2050 template<int size, bool big_endian>
2051 off_t
2052 Output_section::add_input_section(Layout* layout,
2053                                   Sized_relobj<size, big_endian>* object,
2054                                   unsigned int shndx,
2055                                   const char* secname,
2056                                   const elfcpp::Shdr<size, big_endian>& shdr,
2057                                   unsigned int reloc_shndx,
2058                                   bool have_sections_script)
2059 {
2060   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
2061   if ((addralign & (addralign - 1)) != 0)
2062     {
2063       object->error(_("invalid alignment %lu for section \"%s\""),
2064                     static_cast<unsigned long>(addralign), secname);
2065       addralign = 1;
2066     }
2067
2068   if (addralign > this->addralign_)
2069     this->addralign_ = addralign;
2070
2071   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
2072   uint64_t entsize = shdr.get_sh_entsize();
2073
2074   // .debug_str is a mergeable string section, but is not always so
2075   // marked by compilers.  Mark manually here so we can optimize.
2076   if (strcmp(secname, ".debug_str") == 0)
2077     {
2078       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
2079       entsize = 1;
2080     }
2081
2082   this->update_flags_for_input_section(sh_flags);
2083   this->set_entsize(entsize);
2084
2085   // If this is a SHF_MERGE section, we pass all the input sections to
2086   // a Output_data_merge.  We don't try to handle relocations for such
2087   // a section.  We don't try to handle empty merge sections--they
2088   // mess up the mappings, and are useless anyhow.
2089   if ((sh_flags & elfcpp::SHF_MERGE) != 0
2090       && reloc_shndx == 0
2091       && shdr.get_sh_size() > 0)
2092     {
2093       // Keep information about merged input sections for rebuilding fast
2094       // lookup maps if we have sections-script or we do relaxation.
2095       bool keeps_input_sections = (this->always_keeps_input_sections_
2096                                    || have_sections_script
2097                                    || parameters->target().may_relax());
2098
2099       if (this->add_merge_input_section(object, shndx, sh_flags, entsize,
2100                                         addralign, keeps_input_sections))
2101         {
2102           // Tell the relocation routines that they need to call the
2103           // output_offset method to determine the final address.
2104           return -1;
2105         }
2106     }
2107
2108   off_t offset_in_section = this->current_data_size_for_child();
2109   off_t aligned_offset_in_section = align_address(offset_in_section,
2110                                                   addralign);
2111
2112   // Determine if we want to delay code-fill generation until the output
2113   // section is written.  When the target is relaxing, we want to delay fill
2114   // generating to avoid adjusting them during relaxation.
2115   if (!this->generate_code_fills_at_write_
2116       && !have_sections_script
2117       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2118       && parameters->target().has_code_fill()
2119       && parameters->target().may_relax())
2120     {
2121       gold_assert(this->fills_.empty());
2122       this->generate_code_fills_at_write_ = true;
2123     }
2124
2125   if (aligned_offset_in_section > offset_in_section
2126       && !this->generate_code_fills_at_write_
2127       && !have_sections_script
2128       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2129       && parameters->target().has_code_fill())
2130     {
2131       // We need to add some fill data.  Using fill_list_ when
2132       // possible is an optimization, since we will often have fill
2133       // sections without input sections.
2134       off_t fill_len = aligned_offset_in_section - offset_in_section;
2135       if (this->input_sections_.empty())
2136         this->fills_.push_back(Fill(offset_in_section, fill_len));
2137       else
2138         {
2139           std::string fill_data(parameters->target().code_fill(fill_len));
2140           Output_data_const* odc = new Output_data_const(fill_data, 1);
2141           this->input_sections_.push_back(Input_section(odc));
2142         }
2143     }
2144
2145   section_size_type input_section_size = shdr.get_sh_size();
2146   section_size_type uncompressed_size;
2147   if (object->section_is_compressed(shndx, &uncompressed_size))
2148     input_section_size = uncompressed_size;
2149
2150   this->set_current_data_size_for_child(aligned_offset_in_section
2151                                         + input_section_size);
2152
2153   // We need to keep track of this section if we are already keeping
2154   // track of sections, or if we are relaxing.  Also, if this is a
2155   // section which requires sorting, or which may require sorting in
2156   // the future, we keep track of the sections.  If the
2157   // --section-ordering-file option is used to specify the order of
2158   // sections, we need to keep track of sections.
2159   if (this->always_keeps_input_sections_
2160       || have_sections_script
2161       || !this->input_sections_.empty()
2162       || this->may_sort_attached_input_sections()
2163       || this->must_sort_attached_input_sections()
2164       || parameters->options().user_set_Map()
2165       || parameters->target().may_relax()
2166       || parameters->options().section_ordering_file())
2167     {
2168       Input_section isecn(object, shndx, shdr.get_sh_size(), addralign);
2169       if (parameters->options().section_ordering_file())
2170         {
2171           unsigned int section_order_index =
2172             layout->find_section_order_index(std::string(secname));
2173           if (section_order_index != 0)
2174             {
2175               isecn.set_section_order_index(section_order_index);
2176               this->set_input_section_order_specified();
2177             }
2178         }
2179       this->input_sections_.push_back(isecn);
2180     }
2181
2182   return aligned_offset_in_section;
2183 }
2184
2185 // Add arbitrary data to an output section.
2186
2187 void
2188 Output_section::add_output_section_data(Output_section_data* posd)
2189 {
2190   Input_section inp(posd);
2191   this->add_output_section_data(&inp);
2192
2193   if (posd->is_data_size_valid())
2194     {
2195       off_t offset_in_section = this->current_data_size_for_child();
2196       off_t aligned_offset_in_section = align_address(offset_in_section,
2197                                                       posd->addralign());
2198       this->set_current_data_size_for_child(aligned_offset_in_section
2199                                             + posd->data_size());
2200     }
2201 }
2202
2203 // Add a relaxed input section.
2204
2205 void
2206 Output_section::add_relaxed_input_section(Output_relaxed_input_section* poris)
2207 {
2208   Input_section inp(poris);
2209   this->add_output_section_data(&inp);
2210   if (this->lookup_maps_->is_valid())
2211     this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2212                                                   poris->shndx(), poris);
2213
2214   // For a relaxed section, we use the current data size.  Linker scripts
2215   // get all the input sections, including relaxed one from an output
2216   // section and add them back to them same output section to compute the
2217   // output section size.  If we do not account for sizes of relaxed input
2218   // sections,  an output section would be incorrectly sized.
2219   off_t offset_in_section = this->current_data_size_for_child();
2220   off_t aligned_offset_in_section = align_address(offset_in_section,
2221                                                   poris->addralign());
2222   this->set_current_data_size_for_child(aligned_offset_in_section
2223                                         + poris->current_data_size());
2224 }
2225
2226 // Add arbitrary data to an output section by Input_section.
2227
2228 void
2229 Output_section::add_output_section_data(Input_section* inp)
2230 {
2231   if (this->input_sections_.empty())
2232     this->first_input_offset_ = this->current_data_size_for_child();
2233
2234   this->input_sections_.push_back(*inp);
2235
2236   uint64_t addralign = inp->addralign();
2237   if (addralign > this->addralign_)
2238     this->addralign_ = addralign;
2239
2240   inp->set_output_section(this);
2241 }
2242
2243 // Add a merge section to an output section.
2244
2245 void
2246 Output_section::add_output_merge_section(Output_section_data* posd,
2247                                          bool is_string, uint64_t entsize)
2248 {
2249   Input_section inp(posd, is_string, entsize);
2250   this->add_output_section_data(&inp);
2251 }
2252
2253 // Add an input section to a SHF_MERGE section.
2254
2255 bool
2256 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2257                                         uint64_t flags, uint64_t entsize,
2258                                         uint64_t addralign,
2259                                         bool keeps_input_sections)
2260 {
2261   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2262
2263   // We only merge strings if the alignment is not more than the
2264   // character size.  This could be handled, but it's unusual.
2265   if (is_string && addralign > entsize)
2266     return false;
2267
2268   // We cannot restore merged input section states.
2269   gold_assert(this->checkpoint_ == NULL);
2270
2271   // Look up merge sections by required properties.
2272   // Currently, we only invalidate the lookup maps in script processing
2273   // and relaxation.  We should not have done either when we reach here.
2274   // So we assume that the lookup maps are valid to simply code.
2275   gold_assert(this->lookup_maps_->is_valid());
2276   Merge_section_properties msp(is_string, entsize, addralign);
2277   Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp);
2278   bool is_new = false;
2279   if (pomb != NULL)
2280     {
2281       gold_assert(pomb->is_string() == is_string
2282                   && pomb->entsize() == entsize
2283                   && pomb->addralign() == addralign);
2284     }
2285   else
2286     {
2287       // Create a new Output_merge_data or Output_merge_string_data.
2288       if (!is_string)
2289         pomb = new Output_merge_data(entsize, addralign);
2290       else
2291         {
2292           switch (entsize)
2293             {
2294             case 1:
2295               pomb = new Output_merge_string<char>(addralign);
2296               break;
2297             case 2:
2298               pomb = new Output_merge_string<uint16_t>(addralign);
2299               break;
2300             case 4:
2301               pomb = new Output_merge_string<uint32_t>(addralign);
2302               break;
2303             default:
2304               return false;
2305             }
2306         }
2307       // If we need to do script processing or relaxation, we need to keep
2308       // the original input sections to rebuild the fast lookup maps.
2309       if (keeps_input_sections)
2310         pomb->set_keeps_input_sections();
2311       is_new = true;
2312     }
2313
2314   if (pomb->add_input_section(object, shndx))
2315     {
2316       // Add new merge section to this output section and link merge
2317       // section properties to new merge section in map.
2318       if (is_new)
2319         {
2320           this->add_output_merge_section(pomb, is_string, entsize);
2321           this->lookup_maps_->add_merge_section(msp, pomb);
2322         }
2323
2324       // Add input section to new merge section and link input section to new
2325       // merge section in map.
2326       this->lookup_maps_->add_merge_input_section(object, shndx, pomb);
2327       return true;
2328     }
2329   else
2330     {
2331       // If add_input_section failed, delete new merge section to avoid
2332       // exporting empty merge sections in Output_section::get_input_section.
2333       if (is_new)
2334         delete pomb;
2335       return false;
2336     }
2337 }
2338
2339 // Build a relaxation map to speed up relaxation of existing input sections.
2340 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2341
2342 void
2343 Output_section::build_relaxation_map(
2344   const Input_section_list& input_sections,
2345   size_t limit,
2346   Relaxation_map* relaxation_map) const
2347 {
2348   for (size_t i = 0; i < limit; ++i)
2349     {
2350       const Input_section& is(input_sections[i]);
2351       if (is.is_input_section() || is.is_relaxed_input_section())
2352         {
2353           Section_id sid(is.relobj(), is.shndx());
2354           (*relaxation_map)[sid] = i;
2355         }
2356     }
2357 }
2358
2359 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2360 // sections in RELAXED_SECTIONS.  MAP is a prebuilt map from section id
2361 // indices of INPUT_SECTIONS.
2362
2363 void
2364 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2365   const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2366   const Relaxation_map& map,
2367   Input_section_list* input_sections)
2368 {
2369   for (size_t i = 0; i < relaxed_sections.size(); ++i)
2370     {
2371       Output_relaxed_input_section* poris = relaxed_sections[i];
2372       Section_id sid(poris->relobj(), poris->shndx());
2373       Relaxation_map::const_iterator p = map.find(sid);
2374       gold_assert(p != map.end());
2375       gold_assert((*input_sections)[p->second].is_input_section());
2376       (*input_sections)[p->second] = Input_section(poris);
2377     }
2378 }
2379
2380 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2381 // is a vector of pointers to Output_relaxed_input_section or its derived
2382 // classes.  The relaxed sections must correspond to existing input sections.
2383
2384 void
2385 Output_section::convert_input_sections_to_relaxed_sections(
2386   const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2387 {
2388   gold_assert(parameters->target().may_relax());
2389
2390   // We want to make sure that restore_states does not undo the effect of
2391   // this.  If there is no checkpoint active, just search the current
2392   // input section list and replace the sections there.  If there is
2393   // a checkpoint, also replace the sections there.
2394
2395   // By default, we look at the whole list.
2396   size_t limit = this->input_sections_.size();
2397
2398   if (this->checkpoint_ != NULL)
2399     {
2400       // Replace input sections with relaxed input section in the saved
2401       // copy of the input section list.
2402       if (this->checkpoint_->input_sections_saved())
2403         {
2404           Relaxation_map map;
2405           this->build_relaxation_map(
2406                     *(this->checkpoint_->input_sections()),
2407                     this->checkpoint_->input_sections()->size(),
2408                     &map);
2409           this->convert_input_sections_in_list_to_relaxed_sections(
2410                     relaxed_sections,
2411                     map,
2412                     this->checkpoint_->input_sections());
2413         }
2414       else
2415         {
2416           // We have not copied the input section list yet.  Instead, just
2417           // look at the portion that would be saved.
2418           limit = this->checkpoint_->input_sections_size();
2419         }
2420     }
2421
2422   // Convert input sections in input_section_list.
2423   Relaxation_map map;
2424   this->build_relaxation_map(this->input_sections_, limit, &map);
2425   this->convert_input_sections_in_list_to_relaxed_sections(
2426             relaxed_sections,
2427             map,
2428             &this->input_sections_);
2429
2430   // Update fast look-up map.
2431   if (this->lookup_maps_->is_valid())
2432     for (size_t i = 0; i < relaxed_sections.size(); ++i)
2433       {
2434         Output_relaxed_input_section* poris = relaxed_sections[i];
2435         this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2436                                                       poris->shndx(), poris);
2437       }
2438 }
2439
2440 // Update the output section flags based on input section flags.
2441
2442 void
2443 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2444 {
2445   // If we created the section with SHF_ALLOC clear, we set the
2446   // address.  If we are now setting the SHF_ALLOC flag, we need to
2447   // undo that.
2448   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2449       && (flags & elfcpp::SHF_ALLOC) != 0)
2450     this->mark_address_invalid();
2451
2452   this->flags_ |= (flags
2453                    & (elfcpp::SHF_WRITE
2454                       | elfcpp::SHF_ALLOC
2455                       | elfcpp::SHF_EXECINSTR));
2456
2457   if ((flags & elfcpp::SHF_MERGE) == 0)
2458     this->flags_ &=~ elfcpp::SHF_MERGE;
2459   else
2460     {
2461       if (this->current_data_size_for_child() == 0)
2462         this->flags_ |= elfcpp::SHF_MERGE;
2463     }
2464
2465   if ((flags & elfcpp::SHF_STRINGS) == 0)
2466     this->flags_ &=~ elfcpp::SHF_STRINGS;
2467   else
2468     {
2469       if (this->current_data_size_for_child() == 0)
2470         this->flags_ |= elfcpp::SHF_STRINGS;
2471     }
2472 }
2473
2474 // Find the merge section into which an input section with index SHNDX in
2475 // OBJECT has been added.  Return NULL if none found.
2476
2477 Output_section_data*
2478 Output_section::find_merge_section(const Relobj* object,
2479                                    unsigned int shndx) const
2480 {
2481   if (!this->lookup_maps_->is_valid())
2482     this->build_lookup_maps();
2483   return this->lookup_maps_->find_merge_section(object, shndx);
2484 }
2485
2486 // Build the lookup maps for merge and relaxed sections.  This is needs
2487 // to be declared as a const methods so that it is callable with a const
2488 // Output_section pointer.  The method only updates states of the maps.
2489
2490 void
2491 Output_section::build_lookup_maps() const
2492 {
2493   this->lookup_maps_->clear();
2494   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2495        p != this->input_sections_.end();
2496        ++p)
2497     {
2498       if (p->is_merge_section())
2499         {
2500           Output_merge_base* pomb = p->output_merge_base();
2501           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
2502                                        pomb->addralign());
2503           this->lookup_maps_->add_merge_section(msp, pomb);
2504           for (Output_merge_base::Input_sections::const_iterator is =
2505                  pomb->input_sections_begin();
2506                is != pomb->input_sections_end();
2507                ++is)
2508             {
2509               const Const_section_id& csid = *is;
2510             this->lookup_maps_->add_merge_input_section(csid.first,
2511                                                         csid.second, pomb);
2512             }
2513
2514         }
2515       else if (p->is_relaxed_input_section())
2516         {
2517           Output_relaxed_input_section* poris = p->relaxed_input_section();
2518           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2519                                                         poris->shndx(), poris);
2520         }
2521     }
2522 }
2523
2524 // Find an relaxed input section corresponding to an input section
2525 // in OBJECT with index SHNDX.
2526
2527 const Output_relaxed_input_section*
2528 Output_section::find_relaxed_input_section(const Relobj* object,
2529                                            unsigned int shndx) const
2530 {
2531   if (!this->lookup_maps_->is_valid())
2532     this->build_lookup_maps();
2533   return this->lookup_maps_->find_relaxed_input_section(object, shndx);
2534 }
2535
2536 // Given an address OFFSET relative to the start of input section
2537 // SHNDX in OBJECT, return whether this address is being included in
2538 // the final link.  This should only be called if SHNDX in OBJECT has
2539 // a special mapping.
2540
2541 bool
2542 Output_section::is_input_address_mapped(const Relobj* object,
2543                                         unsigned int shndx,
2544                                         off_t offset) const
2545 {
2546   // Look at the Output_section_data_maps first.
2547   const Output_section_data* posd = this->find_merge_section(object, shndx);
2548   if (posd == NULL)
2549     posd = this->find_relaxed_input_section(object, shndx);
2550
2551   if (posd != NULL)
2552     {
2553       section_offset_type output_offset;
2554       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2555       gold_assert(found);
2556       return output_offset != -1;
2557     }
2558
2559   // Fall back to the slow look-up.
2560   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2561        p != this->input_sections_.end();
2562        ++p)
2563     {
2564       section_offset_type output_offset;
2565       if (p->output_offset(object, shndx, offset, &output_offset))
2566         return output_offset != -1;
2567     }
2568
2569   // By default we assume that the address is mapped.  This should
2570   // only be called after we have passed all sections to Layout.  At
2571   // that point we should know what we are discarding.
2572   return true;
2573 }
2574
2575 // Given an address OFFSET relative to the start of input section
2576 // SHNDX in object OBJECT, return the output offset relative to the
2577 // start of the input section in the output section.  This should only
2578 // be called if SHNDX in OBJECT has a special mapping.
2579
2580 section_offset_type
2581 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2582                               section_offset_type offset) const
2583 {
2584   // This can only be called meaningfully when we know the data size
2585   // of this.
2586   gold_assert(this->is_data_size_valid());
2587
2588   // Look at the Output_section_data_maps first.
2589   const Output_section_data* posd = this->find_merge_section(object, shndx);
2590   if (posd == NULL)
2591     posd = this->find_relaxed_input_section(object, shndx);
2592   if (posd != NULL)
2593     {
2594       section_offset_type output_offset;
2595       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2596       gold_assert(found);
2597       return output_offset;
2598     }
2599
2600   // Fall back to the slow look-up.
2601   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2602        p != this->input_sections_.end();
2603        ++p)
2604     {
2605       section_offset_type output_offset;
2606       if (p->output_offset(object, shndx, offset, &output_offset))
2607         return output_offset;
2608     }
2609   gold_unreachable();
2610 }
2611
2612 // Return the output virtual address of OFFSET relative to the start
2613 // of input section SHNDX in object OBJECT.
2614
2615 uint64_t
2616 Output_section::output_address(const Relobj* object, unsigned int shndx,
2617                                off_t offset) const
2618 {
2619   uint64_t addr = this->address() + this->first_input_offset_;
2620
2621   // Look at the Output_section_data_maps first.
2622   const Output_section_data* posd = this->find_merge_section(object, shndx);
2623   if (posd == NULL)
2624     posd = this->find_relaxed_input_section(object, shndx);
2625   if (posd != NULL && posd->is_address_valid())
2626     {
2627       section_offset_type output_offset;
2628       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2629       gold_assert(found);
2630       return posd->address() + output_offset;
2631     }
2632
2633   // Fall back to the slow look-up.
2634   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2635        p != this->input_sections_.end();
2636        ++p)
2637     {
2638       addr = align_address(addr, p->addralign());
2639       section_offset_type output_offset;
2640       if (p->output_offset(object, shndx, offset, &output_offset))
2641         {
2642           if (output_offset == -1)
2643             return -1ULL;
2644           return addr + output_offset;
2645         }
2646       addr += p->data_size();
2647     }
2648
2649   // If we get here, it means that we don't know the mapping for this
2650   // input section.  This might happen in principle if
2651   // add_input_section were called before add_output_section_data.
2652   // But it should never actually happen.
2653
2654   gold_unreachable();
2655 }
2656
2657 // Find the output address of the start of the merged section for
2658 // input section SHNDX in object OBJECT.
2659
2660 bool
2661 Output_section::find_starting_output_address(const Relobj* object,
2662                                              unsigned int shndx,
2663                                              uint64_t* paddr) const
2664 {
2665   // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2666   // Looking up the merge section map does not always work as we sometimes
2667   // find a merge section without its address set.
2668   uint64_t addr = this->address() + this->first_input_offset_;
2669   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2670        p != this->input_sections_.end();
2671        ++p)
2672     {
2673       addr = align_address(addr, p->addralign());
2674
2675       // It would be nice if we could use the existing output_offset
2676       // method to get the output offset of input offset 0.
2677       // Unfortunately we don't know for sure that input offset 0 is
2678       // mapped at all.
2679       if (p->is_merge_section_for(object, shndx))
2680         {
2681           *paddr = addr;
2682           return true;
2683         }
2684
2685       addr += p->data_size();
2686     }
2687
2688   // We couldn't find a merge output section for this input section.
2689   return false;
2690 }
2691
2692 // Set the data size of an Output_section.  This is where we handle
2693 // setting the addresses of any Output_section_data objects.
2694
2695 void
2696 Output_section::set_final_data_size()
2697 {
2698   if (this->input_sections_.empty())
2699     {
2700       this->set_data_size(this->current_data_size_for_child());
2701       return;
2702     }
2703
2704   if (this->must_sort_attached_input_sections()
2705       || this->input_section_order_specified())
2706     this->sort_attached_input_sections();
2707
2708   uint64_t address = this->address();
2709   off_t startoff = this->offset();
2710   off_t off = startoff + this->first_input_offset_;
2711   for (Input_section_list::iterator p = this->input_sections_.begin();
2712        p != this->input_sections_.end();
2713        ++p)
2714     {
2715       off = align_address(off, p->addralign());
2716       p->set_address_and_file_offset(address + (off - startoff), off,
2717                                      startoff);
2718       off += p->data_size();
2719     }
2720
2721   this->set_data_size(off - startoff);
2722 }
2723
2724 // Reset the address and file offset.
2725
2726 void
2727 Output_section::do_reset_address_and_file_offset()
2728 {
2729   // An unallocated section has no address.  Forcing this means that
2730   // we don't need special treatment for symbols defined in debug
2731   // sections.  We do the same in the constructor.  This does not
2732   // apply to NOLOAD sections though.
2733   if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
2734      this->set_address(0);
2735
2736   for (Input_section_list::iterator p = this->input_sections_.begin();
2737        p != this->input_sections_.end();
2738        ++p)
2739     p->reset_address_and_file_offset();
2740 }
2741
2742 // Return true if address and file offset have the values after reset.
2743
2744 bool
2745 Output_section::do_address_and_file_offset_have_reset_values() const
2746 {
2747   if (this->is_offset_valid())
2748     return false;
2749
2750   // An unallocated section has address 0 after its construction or a reset.
2751   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2752     return this->is_address_valid() && this->address() == 0;
2753   else
2754     return !this->is_address_valid();
2755 }
2756
2757 // Set the TLS offset.  Called only for SHT_TLS sections.
2758
2759 void
2760 Output_section::do_set_tls_offset(uint64_t tls_base)
2761 {
2762   this->tls_offset_ = this->address() - tls_base;
2763 }
2764
2765 // In a few cases we need to sort the input sections attached to an
2766 // output section.  This is used to implement the type of constructor
2767 // priority ordering implemented by the GNU linker, in which the
2768 // priority becomes part of the section name and the sections are
2769 // sorted by name.  We only do this for an output section if we see an
2770 // attached input section matching ".ctor.*", ".dtor.*",
2771 // ".init_array.*" or ".fini_array.*".
2772
2773 class Output_section::Input_section_sort_entry
2774 {
2775  public:
2776   Input_section_sort_entry()
2777     : input_section_(), index_(-1U), section_has_name_(false),
2778       section_name_()
2779   { }
2780
2781   Input_section_sort_entry(const Input_section& input_section,
2782                            unsigned int index,
2783                            bool must_sort_attached_input_sections)
2784     : input_section_(input_section), index_(index),
2785       section_has_name_(input_section.is_input_section()
2786                         || input_section.is_relaxed_input_section())
2787   {
2788     if (this->section_has_name_
2789         && must_sort_attached_input_sections)
2790       {
2791         // This is only called single-threaded from Layout::finalize,
2792         // so it is OK to lock.  Unfortunately we have no way to pass
2793         // in a Task token.
2794         const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2795         Object* obj = (input_section.is_input_section()
2796                        ? input_section.relobj()
2797                        : input_section.relaxed_input_section()->relobj());
2798         Task_lock_obj<Object> tl(dummy_task, obj);
2799
2800         // This is a slow operation, which should be cached in
2801         // Layout::layout if this becomes a speed problem.
2802         this->section_name_ = obj->section_name(input_section.shndx());
2803       }
2804   }
2805
2806   // Return the Input_section.
2807   const Input_section&
2808   input_section() const
2809   {
2810     gold_assert(this->index_ != -1U);
2811     return this->input_section_;
2812   }
2813
2814   // The index of this entry in the original list.  This is used to
2815   // make the sort stable.
2816   unsigned int
2817   index() const
2818   {
2819     gold_assert(this->index_ != -1U);
2820     return this->index_;
2821   }
2822
2823   // Whether there is a section name.
2824   bool
2825   section_has_name() const
2826   { return this->section_has_name_; }
2827
2828   // The section name.
2829   const std::string&
2830   section_name() const
2831   {
2832     gold_assert(this->section_has_name_);
2833     return this->section_name_;
2834   }
2835
2836   // Return true if the section name has a priority.  This is assumed
2837   // to be true if it has a dot after the initial dot.
2838   bool
2839   has_priority() const
2840   {
2841     gold_assert(this->section_has_name_);
2842     return this->section_name_.find('.', 1) != std::string::npos;
2843   }
2844
2845   // Return true if this an input file whose base name matches
2846   // FILE_NAME.  The base name must have an extension of ".o", and
2847   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2848   // This is to match crtbegin.o as well as crtbeginS.o without
2849   // getting confused by other possibilities.  Overall matching the
2850   // file name this way is a dreadful hack, but the GNU linker does it
2851   // in order to better support gcc, and we need to be compatible.
2852   bool
2853   match_file_name(const char* match_file_name) const
2854   {
2855     const std::string& file_name(this->input_section_.relobj()->name());
2856     const char* base_name = lbasename(file_name.c_str());
2857     size_t match_len = strlen(match_file_name);
2858     if (strncmp(base_name, match_file_name, match_len) != 0)
2859       return false;
2860     size_t base_len = strlen(base_name);
2861     if (base_len != match_len + 2 && base_len != match_len + 3)
2862       return false;
2863     return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2864   }
2865
2866   // Returns 1 if THIS should appear before S in section order, -1 if S
2867   // appears before THIS and 0 if they are not comparable.
2868   int
2869   compare_section_ordering(const Input_section_sort_entry& s) const
2870   {
2871     unsigned int this_secn_index = this->input_section_.section_order_index();
2872     unsigned int s_secn_index = s.input_section().section_order_index();
2873     if (this_secn_index > 0 && s_secn_index > 0)
2874       {
2875         if (this_secn_index < s_secn_index)
2876           return 1;
2877         else if (this_secn_index > s_secn_index)
2878           return -1;
2879       }
2880     return 0;
2881   }
2882
2883  private:
2884   // The Input_section we are sorting.
2885   Input_section input_section_;
2886   // The index of this Input_section in the original list.
2887   unsigned int index_;
2888   // Whether this Input_section has a section name--it won't if this
2889   // is some random Output_section_data.
2890   bool section_has_name_;
2891   // The section name if there is one.
2892   std::string section_name_;
2893 };
2894
2895 // Return true if S1 should come before S2 in the output section.
2896
2897 bool
2898 Output_section::Input_section_sort_compare::operator()(
2899     const Output_section::Input_section_sort_entry& s1,
2900     const Output_section::Input_section_sort_entry& s2) const
2901 {
2902   // crtbegin.o must come first.
2903   bool s1_begin = s1.match_file_name("crtbegin");
2904   bool s2_begin = s2.match_file_name("crtbegin");
2905   if (s1_begin || s2_begin)
2906     {
2907       if (!s1_begin)
2908         return false;
2909       if (!s2_begin)
2910         return true;
2911       return s1.index() < s2.index();
2912     }
2913
2914   // crtend.o must come last.
2915   bool s1_end = s1.match_file_name("crtend");
2916   bool s2_end = s2.match_file_name("crtend");
2917   if (s1_end || s2_end)
2918     {
2919       if (!s1_end)
2920         return true;
2921       if (!s2_end)
2922         return false;
2923       return s1.index() < s2.index();
2924     }
2925
2926   // We sort all the sections with no names to the end.
2927   if (!s1.section_has_name() || !s2.section_has_name())
2928     {
2929       if (s1.section_has_name())
2930         return true;
2931       if (s2.section_has_name())
2932         return false;
2933       return s1.index() < s2.index();
2934     }
2935
2936   // A section with a priority follows a section without a priority.
2937   bool s1_has_priority = s1.has_priority();
2938   bool s2_has_priority = s2.has_priority();
2939   if (s1_has_priority && !s2_has_priority)
2940     return false;
2941   if (!s1_has_priority && s2_has_priority)
2942     return true;
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 sort by name.
2951   int compare = s1.section_name().compare(s2.section_name());
2952   if (compare != 0)
2953     return compare < 0;
2954
2955   // Otherwise we keep the input order.
2956   return s1.index() < s2.index();
2957 }
2958
2959 // Return true if S1 should come before S2 in an .init_array or .fini_array
2960 // output section.
2961
2962 bool
2963 Output_section::Input_section_sort_init_fini_compare::operator()(
2964     const Output_section::Input_section_sort_entry& s1,
2965     const Output_section::Input_section_sort_entry& s2) const
2966 {
2967   // We sort all the sections with no names to the end.
2968   if (!s1.section_has_name() || !s2.section_has_name())
2969     {
2970       if (s1.section_has_name())
2971         return true;
2972       if (s2.section_has_name())
2973         return false;
2974       return s1.index() < s2.index();
2975     }
2976
2977   // A section without a priority follows a section with a priority.
2978   // This is the reverse of .ctors and .dtors sections.
2979   bool s1_has_priority = s1.has_priority();
2980   bool s2_has_priority = s2.has_priority();
2981   if (s1_has_priority && !s2_has_priority)
2982     return true;
2983   if (!s1_has_priority && s2_has_priority)
2984     return false;
2985
2986   // Check if a section order exists for these sections through a section
2987   // ordering file.  If sequence_num is 0, an order does not exist.
2988   int sequence_num = s1.compare_section_ordering(s2);
2989   if (sequence_num != 0)
2990     return sequence_num == 1;
2991
2992   // Otherwise we sort by name.
2993   int compare = s1.section_name().compare(s2.section_name());
2994   if (compare != 0)
2995     return compare < 0;
2996
2997   // Otherwise we keep the input order.
2998   return s1.index() < s2.index();
2999 }
3000
3001 // Return true if S1 should come before S2.  Sections that do not match
3002 // any pattern in the section ordering file are placed ahead of the sections
3003 // that match some pattern.
3004
3005 bool
3006 Output_section::Input_section_sort_section_order_index_compare::operator()(
3007     const Output_section::Input_section_sort_entry& s1,
3008     const Output_section::Input_section_sort_entry& s2) const
3009 {
3010   unsigned int s1_secn_index = s1.input_section().section_order_index();
3011   unsigned int s2_secn_index = s2.input_section().section_order_index();
3012
3013   // Keep input order if section ordering cannot determine order.
3014   if (s1_secn_index == s2_secn_index)
3015     return s1.index() < s2.index();
3016
3017   return s1_secn_index < s2_secn_index;
3018 }
3019
3020 // Sort the input sections attached to an output section.
3021
3022 void
3023 Output_section::sort_attached_input_sections()
3024 {
3025   if (this->attached_input_sections_are_sorted_)
3026     return;
3027
3028   if (this->checkpoint_ != NULL
3029       && !this->checkpoint_->input_sections_saved())
3030     this->checkpoint_->save_input_sections();
3031
3032   // The only thing we know about an input section is the object and
3033   // the section index.  We need the section name.  Recomputing this
3034   // is slow but this is an unusual case.  If this becomes a speed
3035   // problem we can cache the names as required in Layout::layout.
3036
3037   // We start by building a larger vector holding a copy of each
3038   // Input_section, plus its current index in the list and its name.
3039   std::vector<Input_section_sort_entry> sort_list;
3040
3041   unsigned int i = 0;
3042   for (Input_section_list::iterator p = this->input_sections_.begin();
3043        p != this->input_sections_.end();
3044        ++p, ++i)
3045       sort_list.push_back(Input_section_sort_entry(*p, i,
3046                             this->must_sort_attached_input_sections()));
3047
3048   // Sort the input sections.
3049   if (this->must_sort_attached_input_sections())
3050     {
3051       if (this->type() == elfcpp::SHT_PREINIT_ARRAY
3052           || this->type() == elfcpp::SHT_INIT_ARRAY
3053           || this->type() == elfcpp::SHT_FINI_ARRAY)
3054         std::sort(sort_list.begin(), sort_list.end(),
3055                   Input_section_sort_init_fini_compare());
3056       else
3057         std::sort(sort_list.begin(), sort_list.end(),
3058                   Input_section_sort_compare());
3059     }
3060   else
3061     {
3062       gold_assert(parameters->options().section_ordering_file());
3063       std::sort(sort_list.begin(), sort_list.end(),
3064                 Input_section_sort_section_order_index_compare());
3065     }
3066
3067   // Copy the sorted input sections back to our list.
3068   this->input_sections_.clear();
3069   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
3070        p != sort_list.end();
3071        ++p)
3072     this->input_sections_.push_back(p->input_section());
3073   sort_list.clear();
3074
3075   // Remember that we sorted the input sections, since we might get
3076   // called again.
3077   this->attached_input_sections_are_sorted_ = true;
3078 }
3079
3080 // Write the section header to *OSHDR.
3081
3082 template<int size, bool big_endian>
3083 void
3084 Output_section::write_header(const Layout* layout,
3085                              const Stringpool* secnamepool,
3086                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
3087 {
3088   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
3089   oshdr->put_sh_type(this->type_);
3090
3091   elfcpp::Elf_Xword flags = this->flags_;
3092   if (this->info_section_ != NULL && this->info_uses_section_index_)
3093     flags |= elfcpp::SHF_INFO_LINK;
3094   oshdr->put_sh_flags(flags);
3095
3096   oshdr->put_sh_addr(this->address());
3097   oshdr->put_sh_offset(this->offset());
3098   oshdr->put_sh_size(this->data_size());
3099   if (this->link_section_ != NULL)
3100     oshdr->put_sh_link(this->link_section_->out_shndx());
3101   else if (this->should_link_to_symtab_)
3102     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
3103   else if (this->should_link_to_dynsym_)
3104     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
3105   else
3106     oshdr->put_sh_link(this->link_);
3107
3108   elfcpp::Elf_Word info;
3109   if (this->info_section_ != NULL)
3110     {
3111       if (this->info_uses_section_index_)
3112         info = this->info_section_->out_shndx();
3113       else
3114         info = this->info_section_->symtab_index();
3115     }
3116   else if (this->info_symndx_ != NULL)
3117     info = this->info_symndx_->symtab_index();
3118   else
3119     info = this->info_;
3120   oshdr->put_sh_info(info);
3121
3122   oshdr->put_sh_addralign(this->addralign_);
3123   oshdr->put_sh_entsize(this->entsize_);
3124 }
3125
3126 // Write out the data.  For input sections the data is written out by
3127 // Object::relocate, but we have to handle Output_section_data objects
3128 // here.
3129
3130 void
3131 Output_section::do_write(Output_file* of)
3132 {
3133   gold_assert(!this->requires_postprocessing());
3134
3135   // If the target performs relaxation, we delay filler generation until now.
3136   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3137
3138   off_t output_section_file_offset = this->offset();
3139   for (Fill_list::iterator p = this->fills_.begin();
3140        p != this->fills_.end();
3141        ++p)
3142     {
3143       std::string fill_data(parameters->target().code_fill(p->length()));
3144       of->write(output_section_file_offset + p->section_offset(),
3145                 fill_data.data(), fill_data.size());
3146     }
3147
3148   off_t off = this->offset() + this->first_input_offset_;
3149   for (Input_section_list::iterator p = this->input_sections_.begin();
3150        p != this->input_sections_.end();
3151        ++p)
3152     {
3153       off_t aligned_off = align_address(off, p->addralign());
3154       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3155         {
3156           size_t fill_len = aligned_off - off;
3157           std::string fill_data(parameters->target().code_fill(fill_len));
3158           of->write(off, fill_data.data(), fill_data.size());
3159         }
3160
3161       p->write(of);
3162       off = aligned_off + p->data_size();
3163     }
3164 }
3165
3166 // If a section requires postprocessing, create the buffer to use.
3167
3168 void
3169 Output_section::create_postprocessing_buffer()
3170 {
3171   gold_assert(this->requires_postprocessing());
3172
3173   if (this->postprocessing_buffer_ != NULL)
3174     return;
3175
3176   if (!this->input_sections_.empty())
3177     {
3178       off_t off = this->first_input_offset_;
3179       for (Input_section_list::iterator p = this->input_sections_.begin();
3180            p != this->input_sections_.end();
3181            ++p)
3182         {
3183           off = align_address(off, p->addralign());
3184           p->finalize_data_size();
3185           off += p->data_size();
3186         }
3187       this->set_current_data_size_for_child(off);
3188     }
3189
3190   off_t buffer_size = this->current_data_size_for_child();
3191   this->postprocessing_buffer_ = new unsigned char[buffer_size];
3192 }
3193
3194 // Write all the data of an Output_section into the postprocessing
3195 // buffer.  This is used for sections which require postprocessing,
3196 // such as compression.  Input sections are handled by
3197 // Object::Relocate.
3198
3199 void
3200 Output_section::write_to_postprocessing_buffer()
3201 {
3202   gold_assert(this->requires_postprocessing());
3203
3204   // If the target performs relaxation, we delay filler generation until now.
3205   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3206
3207   unsigned char* buffer = this->postprocessing_buffer();
3208   for (Fill_list::iterator p = this->fills_.begin();
3209        p != this->fills_.end();
3210        ++p)
3211     {
3212       std::string fill_data(parameters->target().code_fill(p->length()));
3213       memcpy(buffer + p->section_offset(), fill_data.data(),
3214              fill_data.size());
3215     }
3216
3217   off_t off = this->first_input_offset_;
3218   for (Input_section_list::iterator p = this->input_sections_.begin();
3219        p != this->input_sections_.end();
3220        ++p)
3221     {
3222       off_t aligned_off = align_address(off, p->addralign());
3223       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3224         {
3225           size_t fill_len = aligned_off - off;
3226           std::string fill_data(parameters->target().code_fill(fill_len));
3227           memcpy(buffer + off, fill_data.data(), fill_data.size());
3228         }
3229
3230       p->write_to_buffer(buffer + aligned_off);
3231       off = aligned_off + p->data_size();
3232     }
3233 }
3234
3235 // Get the input sections for linker script processing.  We leave
3236 // behind the Output_section_data entries.  Note that this may be
3237 // slightly incorrect for merge sections.  We will leave them behind,
3238 // but it is possible that the script says that they should follow
3239 // some other input sections, as in:
3240 //    .rodata { *(.rodata) *(.rodata.cst*) }
3241 // For that matter, we don't handle this correctly:
3242 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
3243 // With luck this will never matter.
3244
3245 uint64_t
3246 Output_section::get_input_sections(
3247     uint64_t address,
3248     const std::string& fill,
3249     std::list<Input_section>* input_sections)
3250 {
3251   if (this->checkpoint_ != NULL
3252       && !this->checkpoint_->input_sections_saved())
3253     this->checkpoint_->save_input_sections();
3254
3255   // Invalidate fast look-up maps.
3256   this->lookup_maps_->invalidate();
3257
3258   uint64_t orig_address = address;
3259
3260   address = align_address(address, this->addralign());
3261
3262   Input_section_list remaining;
3263   for (Input_section_list::iterator p = this->input_sections_.begin();
3264        p != this->input_sections_.end();
3265        ++p)
3266     {
3267       if (p->is_input_section()
3268           || p->is_relaxed_input_section()
3269           || p->is_merge_section())
3270         input_sections->push_back(*p);
3271       else
3272         {
3273           uint64_t aligned_address = align_address(address, p->addralign());
3274           if (aligned_address != address && !fill.empty())
3275             {
3276               section_size_type length =
3277                 convert_to_section_size_type(aligned_address - address);
3278               std::string this_fill;
3279               this_fill.reserve(length);
3280               while (this_fill.length() + fill.length() <= length)
3281                 this_fill += fill;
3282               if (this_fill.length() < length)
3283                 this_fill.append(fill, 0, length - this_fill.length());
3284
3285               Output_section_data* posd = new Output_data_const(this_fill, 0);
3286               remaining.push_back(Input_section(posd));
3287             }
3288           address = aligned_address;
3289
3290           remaining.push_back(*p);
3291
3292           p->finalize_data_size();
3293           address += p->data_size();
3294         }
3295     }
3296
3297   this->input_sections_.swap(remaining);
3298   this->first_input_offset_ = 0;
3299
3300   uint64_t data_size = address - orig_address;
3301   this->set_current_data_size_for_child(data_size);
3302   return data_size;
3303 }
3304
3305 // Add a script input section.  SIS is an Output_section::Input_section,
3306 // which can be either a plain input section or a special input section like
3307 // a relaxed input section.  For a special input section, its size must be
3308 // finalized.
3309
3310 void
3311 Output_section::add_script_input_section(const Input_section& sis)
3312 {
3313   uint64_t data_size = sis.data_size();
3314   uint64_t addralign = sis.addralign();
3315   if (addralign > this->addralign_)
3316     this->addralign_ = addralign;
3317
3318   off_t offset_in_section = this->current_data_size_for_child();
3319   off_t aligned_offset_in_section = align_address(offset_in_section,
3320                                                   addralign);
3321
3322   this->set_current_data_size_for_child(aligned_offset_in_section
3323                                         + data_size);
3324
3325   this->input_sections_.push_back(sis);
3326
3327   // Update fast lookup maps if necessary.
3328   if (this->lookup_maps_->is_valid())
3329     {
3330       if (sis.is_merge_section())
3331         {
3332           Output_merge_base* pomb = sis.output_merge_base();
3333           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
3334                                        pomb->addralign());
3335           this->lookup_maps_->add_merge_section(msp, pomb);
3336           for (Output_merge_base::Input_sections::const_iterator p =
3337                  pomb->input_sections_begin();
3338                p != pomb->input_sections_end();
3339                ++p)
3340             this->lookup_maps_->add_merge_input_section(p->first, p->second,
3341                                                         pomb);
3342         }
3343       else if (sis.is_relaxed_input_section())
3344         {
3345           Output_relaxed_input_section* poris = sis.relaxed_input_section();
3346           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
3347                                                         poris->shndx(), poris);
3348         }
3349     }
3350 }
3351
3352 // Save states for relaxation.
3353
3354 void
3355 Output_section::save_states()
3356 {
3357   gold_assert(this->checkpoint_ == NULL);
3358   Checkpoint_output_section* checkpoint =
3359     new Checkpoint_output_section(this->addralign_, this->flags_,
3360                                   this->input_sections_,
3361                                   this->first_input_offset_,
3362                                   this->attached_input_sections_are_sorted_);
3363   this->checkpoint_ = checkpoint;
3364   gold_assert(this->fills_.empty());
3365 }
3366
3367 void
3368 Output_section::discard_states()
3369 {
3370   gold_assert(this->checkpoint_ != NULL);
3371   delete this->checkpoint_;
3372   this->checkpoint_ = NULL;
3373   gold_assert(this->fills_.empty());
3374
3375   // Simply invalidate the fast lookup maps since we do not keep
3376   // track of them.
3377   this->lookup_maps_->invalidate();
3378 }
3379
3380 void
3381 Output_section::restore_states()
3382 {
3383   gold_assert(this->checkpoint_ != NULL);
3384   Checkpoint_output_section* checkpoint = this->checkpoint_;
3385
3386   this->addralign_ = checkpoint->addralign();
3387   this->flags_ = checkpoint->flags();
3388   this->first_input_offset_ = checkpoint->first_input_offset();
3389
3390   if (!checkpoint->input_sections_saved())
3391     {
3392       // If we have not copied the input sections, just resize it.
3393       size_t old_size = checkpoint->input_sections_size();
3394       gold_assert(this->input_sections_.size() >= old_size);
3395       this->input_sections_.resize(old_size);
3396     }
3397   else
3398     {
3399       // We need to copy the whole list.  This is not efficient for
3400       // extremely large output with hundreads of thousands of input
3401       // objects.  We may need to re-think how we should pass sections
3402       // to scripts.
3403       this->input_sections_ = *checkpoint->input_sections();
3404     }
3405
3406   this->attached_input_sections_are_sorted_ =
3407     checkpoint->attached_input_sections_are_sorted();
3408
3409   // Simply invalidate the fast lookup maps since we do not keep
3410   // track of them.
3411   this->lookup_maps_->invalidate();
3412 }
3413
3414 // Update the section offsets of input sections in this.  This is required if
3415 // relaxation causes some input sections to change sizes.
3416
3417 void
3418 Output_section::adjust_section_offsets()
3419 {
3420   if (!this->section_offsets_need_adjustment_)
3421     return;
3422
3423   off_t off = 0;
3424   for (Input_section_list::iterator p = this->input_sections_.begin();
3425        p != this->input_sections_.end();
3426        ++p)
3427     {
3428       off = align_address(off, p->addralign());
3429       if (p->is_input_section())
3430         p->relobj()->set_section_offset(p->shndx(), off);
3431       off += p->data_size();
3432     }
3433
3434   this->section_offsets_need_adjustment_ = false;
3435 }
3436
3437 // Print to the map file.
3438
3439 void
3440 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3441 {
3442   mapfile->print_output_section(this);
3443
3444   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3445        p != this->input_sections_.end();
3446        ++p)
3447     p->print_to_mapfile(mapfile);
3448 }
3449
3450 // Print stats for merge sections to stderr.
3451
3452 void
3453 Output_section::print_merge_stats()
3454 {
3455   Input_section_list::iterator p;
3456   for (p = this->input_sections_.begin();
3457        p != this->input_sections_.end();
3458        ++p)
3459     p->print_merge_stats(this->name_);
3460 }
3461
3462 // Output segment methods.
3463
3464 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3465   : vaddr_(0),
3466     paddr_(0),
3467     memsz_(0),
3468     max_align_(0),
3469     min_p_align_(0),
3470     offset_(0),
3471     filesz_(0),
3472     type_(type),
3473     flags_(flags),
3474     is_max_align_known_(false),
3475     are_addresses_set_(false),
3476     is_large_data_segment_(false)
3477 {
3478   // The ELF ABI specifies that a PT_TLS segment always has PF_R as
3479   // the flags.
3480   if (type == elfcpp::PT_TLS)
3481     this->flags_ = elfcpp::PF_R;
3482 }
3483
3484 // Add an Output_section to a PT_LOAD Output_segment.
3485
3486 void
3487 Output_segment::add_output_section_to_load(Layout* layout,
3488                                            Output_section* os,
3489                                            elfcpp::Elf_Word seg_flags)
3490 {
3491   gold_assert(this->type() == elfcpp::PT_LOAD);
3492   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3493   gold_assert(!this->is_max_align_known_);
3494   gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3495
3496   this->update_flags_for_output_section(seg_flags);
3497
3498   // We don't want to change the ordering if we have a linker script
3499   // with a SECTIONS clause.
3500   Output_section_order order = os->order();
3501   if (layout->script_options()->saw_sections_clause())
3502     order = static_cast<Output_section_order>(0);
3503   else
3504     gold_assert(order != ORDER_INVALID);
3505
3506   this->output_lists_[order].push_back(os);
3507 }
3508
3509 // Add an Output_section to a non-PT_LOAD Output_segment.
3510
3511 void
3512 Output_segment::add_output_section_to_nonload(Output_section* os,
3513                                               elfcpp::Elf_Word seg_flags)
3514 {
3515   gold_assert(this->type() != elfcpp::PT_LOAD);
3516   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3517   gold_assert(!this->is_max_align_known_);
3518
3519   this->update_flags_for_output_section(seg_flags);
3520
3521   this->output_lists_[0].push_back(os);
3522 }
3523
3524 // Remove an Output_section from this segment.  It is an error if it
3525 // is not present.
3526
3527 void
3528 Output_segment::remove_output_section(Output_section* os)
3529 {
3530   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3531     {
3532       Output_data_list* pdl = &this->output_lists_[i];
3533       for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p)
3534         {
3535           if (*p == os)
3536             {
3537               pdl->erase(p);
3538               return;
3539             }
3540         }
3541     }
3542   gold_unreachable();
3543 }
3544
3545 // Add an Output_data (which need not be an Output_section) to the
3546 // start of a segment.
3547
3548 void
3549 Output_segment::add_initial_output_data(Output_data* od)
3550 {
3551   gold_assert(!this->is_max_align_known_);
3552   Output_data_list::iterator p = this->output_lists_[0].begin();
3553   this->output_lists_[0].insert(p, od);
3554 }
3555
3556 // Return true if this segment has any sections which hold actual
3557 // data, rather than being a BSS section.
3558
3559 bool
3560 Output_segment::has_any_data_sections() const
3561 {
3562   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3563     {
3564       const Output_data_list* pdl = &this->output_lists_[i];
3565       for (Output_data_list::const_iterator p = pdl->begin();
3566            p != pdl->end();
3567            ++p)
3568         {
3569           if (!(*p)->is_section())
3570             return true;
3571           if ((*p)->output_section()->type() != elfcpp::SHT_NOBITS)
3572             return true;
3573         }
3574     }
3575   return false;
3576 }
3577
3578 // Return whether the first data section is a relro section.
3579
3580 bool
3581 Output_segment::is_first_section_relro() const
3582 {
3583   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3584     {
3585       const Output_data_list* pdl = &this->output_lists_[i];
3586       if (!pdl->empty())
3587         {
3588           Output_data* p = pdl->front();
3589           return p->is_section() && p->output_section()->is_relro();
3590         }
3591     }
3592   return false;
3593 }
3594
3595 // Return the maximum alignment of the Output_data in Output_segment.
3596
3597 uint64_t
3598 Output_segment::maximum_alignment()
3599 {
3600   if (!this->is_max_align_known_)
3601     {
3602       for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3603         {
3604           const Output_data_list* pdl = &this->output_lists_[i];
3605           uint64_t addralign = Output_segment::maximum_alignment_list(pdl);
3606           if (addralign > this->max_align_)
3607             this->max_align_ = addralign;
3608         }
3609       this->is_max_align_known_ = true;
3610     }
3611
3612   return this->max_align_;
3613 }
3614
3615 // Return the maximum alignment of a list of Output_data.
3616
3617 uint64_t
3618 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3619 {
3620   uint64_t ret = 0;
3621   for (Output_data_list::const_iterator p = pdl->begin();
3622        p != pdl->end();
3623        ++p)
3624     {
3625       uint64_t addralign = (*p)->addralign();
3626       if (addralign > ret)
3627         ret = addralign;
3628     }
3629   return ret;
3630 }
3631
3632 // Return whether this segment has any dynamic relocs.
3633
3634 bool
3635 Output_segment::has_dynamic_reloc() const
3636 {
3637   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3638     if (this->has_dynamic_reloc_list(&this->output_lists_[i]))
3639       return true;
3640   return false;
3641 }
3642
3643 // Return whether this Output_data_list has any dynamic relocs.
3644
3645 bool
3646 Output_segment::has_dynamic_reloc_list(const Output_data_list* pdl) const
3647 {
3648   for (Output_data_list::const_iterator p = pdl->begin();
3649        p != pdl->end();
3650        ++p)
3651     if ((*p)->has_dynamic_reloc())
3652       return true;
3653   return false;
3654 }
3655
3656 // Set the section addresses for an Output_segment.  If RESET is true,
3657 // reset the addresses first.  ADDR is the address and *POFF is the
3658 // file offset.  Set the section indexes starting with *PSHNDX.
3659 // *PINCREASE_RELRO is the size of the portion of the first non-relro
3660 // section that should be included in the PT_GNU_RELRO segment; if
3661 // there is alignment padding between the last relro section and the
3662 // next section, we add that padding to that size and return the
3663 // updated value.  If this segment has relro sections, and has been
3664 // aligned for that purpose, set *HAS_RELRO to TRUE.
3665 // Return the address of the immediately following segment.  Update
3666 // *PINCREASE_RELRO, *HAS_RELRO, *POFF, and *PSHNDX.
3667
3668 uint64_t
3669 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3670                                       uint64_t addr,
3671                                       unsigned int* pincrease_relro,
3672                                       bool* has_relro,
3673                                       off_t* poff,
3674                                       unsigned int* pshndx)
3675 {
3676   gold_assert(this->type_ == elfcpp::PT_LOAD);
3677
3678   uint64_t last_relro_pad = 0;
3679   off_t orig_off = *poff;
3680
3681   // If we have relro sections, we need to pad forward now so that the
3682   // relro sections plus INCREASE_RELRO end on a common page boundary.
3683   if (parameters->options().relro()
3684       && this->is_first_section_relro()
3685       && (!this->are_addresses_set_ || reset))
3686     {
3687       uint64_t relro_size = 0;
3688       off_t off = *poff;
3689       uint64_t max_align = 0;
3690       for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3691         {
3692           Output_data_list* pdl = &this->output_lists_[i];
3693           Output_data_list::iterator p;
3694           for (p = pdl->begin(); p != pdl->end(); ++p)
3695             {
3696               if (!(*p)->is_section())
3697                 break;
3698               Output_section* pos = (*p)->output_section();
3699               if (!pos->is_relro())
3700                 break;
3701               uint64_t align = (*p)->addralign();
3702               if (align > max_align)
3703                 max_align = align;
3704               relro_size = align_address(relro_size, align);
3705               if ((*p)->is_address_valid())
3706                 relro_size += (*p)->data_size();
3707               else
3708                 {
3709                   // FIXME: This could be faster.
3710                   (*p)->set_address_and_file_offset(addr + relro_size,
3711                                                     off + relro_size);
3712                   relro_size += (*p)->data_size();
3713                   (*p)->reset_address_and_file_offset();
3714                 }
3715             }
3716           if (p != pdl->end())
3717             break;
3718         }
3719       relro_size += *pincrease_relro;
3720       // Pad the total relro size to a multiple of the maximum
3721       // section alignment seen.
3722       uint64_t aligned_size = align_address(relro_size, max_align);
3723       // Note the amount of padding added after the last relro section.
3724       last_relro_pad = aligned_size - relro_size;
3725       // Adjust *PINCREASE_RELRO to include the padding.
3726       *pincrease_relro += last_relro_pad;
3727       *has_relro = true;
3728
3729       uint64_t page_align = parameters->target().common_pagesize();
3730
3731       // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
3732       uint64_t desired_align = page_align - (aligned_size % page_align);
3733       if (desired_align < *poff % page_align)
3734         *poff += page_align - *poff % page_align;
3735       *poff += desired_align - *poff % page_align;
3736       addr += *poff - orig_off;
3737       orig_off = *poff;
3738     }
3739
3740   if (!reset && this->are_addresses_set_)
3741     {
3742       gold_assert(this->paddr_ == addr);
3743       addr = this->vaddr_;
3744     }
3745   else
3746     {
3747       this->vaddr_ = addr;
3748       this->paddr_ = addr;
3749       this->are_addresses_set_ = true;
3750     }
3751
3752   bool in_tls = false;
3753
3754   this->offset_ = orig_off;
3755
3756   off_t off = 0;
3757   uint64_t ret;
3758   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3759     {
3760       addr = this->set_section_list_addresses(layout, reset,
3761                                               &this->output_lists_[i],
3762                                               addr, poff, pshndx, &in_tls);
3763       if (i == static_cast<int>(ORDER_RELRO_LAST))
3764         {
3765           *poff += last_relro_pad;
3766           addr += last_relro_pad;
3767         }
3768       if (i < static_cast<int>(ORDER_SMALL_BSS))
3769         {
3770           this->filesz_ = *poff - orig_off;
3771           off = *poff;
3772         }
3773
3774       ret = addr;
3775     }
3776
3777   // If the last section was a TLS section, align upward to the
3778   // alignment of the TLS segment, so that the overall size of the TLS
3779   // segment is aligned.
3780   if (in_tls)
3781     {
3782       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3783       *poff = align_address(*poff, segment_align);
3784     }
3785
3786   this->memsz_ = *poff - orig_off;
3787
3788   // Ignore the file offset adjustments made by the BSS Output_data
3789   // objects.
3790   *poff = off;
3791
3792   return ret;
3793 }
3794
3795 // Set the addresses and file offsets in a list of Output_data
3796 // structures.
3797
3798 uint64_t
3799 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3800                                            Output_data_list* pdl,
3801                                            uint64_t addr, off_t* poff,
3802                                            unsigned int* pshndx,
3803                                            bool* in_tls)
3804 {
3805   off_t startoff = *poff;
3806
3807   off_t off = startoff;
3808   for (Output_data_list::iterator p = pdl->begin();
3809        p != pdl->end();
3810        ++p)
3811     {
3812       if (reset)
3813         (*p)->reset_address_and_file_offset();
3814
3815       // When using a linker script the section will most likely
3816       // already have an address.
3817       if (!(*p)->is_address_valid())
3818         {
3819           uint64_t align = (*p)->addralign();
3820
3821           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3822             {
3823               // Give the first TLS section the alignment of the
3824               // entire TLS segment.  Otherwise the TLS segment as a
3825               // whole may be misaligned.
3826               if (!*in_tls)
3827                 {
3828                   Output_segment* tls_segment = layout->tls_segment();
3829                   gold_assert(tls_segment != NULL);
3830                   uint64_t segment_align = tls_segment->maximum_alignment();
3831                   gold_assert(segment_align >= align);
3832                   align = segment_align;
3833
3834                   *in_tls = true;
3835                 }
3836             }
3837           else
3838             {
3839               // If this is the first section after the TLS segment,
3840               // align it to at least the alignment of the TLS
3841               // segment, so that the size of the overall TLS segment
3842               // is aligned.
3843               if (*in_tls)
3844                 {
3845                   uint64_t segment_align =
3846                       layout->tls_segment()->maximum_alignment();
3847                   if (segment_align > align)
3848                     align = segment_align;
3849
3850                   *in_tls = false;
3851                 }
3852             }
3853
3854           off = align_address(off, align);
3855           (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3856         }
3857       else
3858         {
3859           // The script may have inserted a skip forward, but it
3860           // better not have moved backward.
3861           if ((*p)->address() >= addr + (off - startoff))
3862             off += (*p)->address() - (addr + (off - startoff));
3863           else
3864             {
3865               if (!layout->script_options()->saw_sections_clause())
3866                 gold_unreachable();
3867               else
3868                 {
3869                   Output_section* os = (*p)->output_section();
3870
3871                   // Cast to unsigned long long to avoid format warnings.
3872                   unsigned long long previous_dot =
3873                     static_cast<unsigned long long>(addr + (off - startoff));
3874                   unsigned long long dot =
3875                     static_cast<unsigned long long>((*p)->address());
3876
3877                   if (os == NULL)
3878                     gold_error(_("dot moves backward in linker script "
3879                                  "from 0x%llx to 0x%llx"), previous_dot, dot);
3880                   else
3881                     gold_error(_("address of section '%s' moves backward "
3882                                  "from 0x%llx to 0x%llx"),
3883                                os->name(), previous_dot, dot);
3884                 }
3885             }
3886           (*p)->set_file_offset(off);
3887           (*p)->finalize_data_size();
3888         }
3889
3890       // We want to ignore the size of a SHF_TLS or SHT_NOBITS
3891       // section.  Such a section does not affect the size of a
3892       // PT_LOAD segment.
3893       if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
3894           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
3895         off += (*p)->data_size();
3896
3897       if ((*p)->is_section())
3898         {
3899           (*p)->set_out_shndx(*pshndx);
3900           ++*pshndx;
3901         }
3902     }
3903
3904   *poff = off;
3905   return addr + (off - startoff);
3906 }
3907
3908 // For a non-PT_LOAD segment, set the offset from the sections, if
3909 // any.  Add INCREASE to the file size and the memory size.
3910
3911 void
3912 Output_segment::set_offset(unsigned int increase)
3913 {
3914   gold_assert(this->type_ != elfcpp::PT_LOAD);
3915
3916   gold_assert(!this->are_addresses_set_);
3917
3918   // A non-load section only uses output_lists_[0].
3919
3920   Output_data_list* pdl = &this->output_lists_[0];
3921
3922   if (pdl->empty())
3923     {
3924       gold_assert(increase == 0);
3925       this->vaddr_ = 0;
3926       this->paddr_ = 0;
3927       this->are_addresses_set_ = true;
3928       this->memsz_ = 0;
3929       this->min_p_align_ = 0;
3930       this->offset_ = 0;
3931       this->filesz_ = 0;
3932       return;
3933     }
3934
3935   // Find the first and last section by address.
3936   const Output_data* first = NULL;
3937   const Output_data* last_data = NULL;
3938   const Output_data* last_bss = NULL;
3939   for (Output_data_list::const_iterator p = pdl->begin();
3940        p != pdl->end();
3941        ++p)
3942     {
3943       if (first == NULL
3944           || (*p)->address() < first->address()
3945           || ((*p)->address() == first->address()
3946               && (*p)->data_size() < first->data_size()))
3947         first = *p;
3948       const Output_data** plast;
3949       if ((*p)->is_section()
3950           && (*p)->output_section()->type() == elfcpp::SHT_NOBITS)
3951         plast = &last_bss;
3952       else
3953         plast = &last_data;
3954       if (*plast == NULL
3955           || (*p)->address() > (*plast)->address()
3956           || ((*p)->address() == (*plast)->address()
3957               && (*p)->data_size() > (*plast)->data_size()))
3958         *plast = *p;
3959     }
3960
3961   this->vaddr_ = first->address();
3962   this->paddr_ = (first->has_load_address()
3963                   ? first->load_address()
3964                   : this->vaddr_);
3965   this->are_addresses_set_ = true;
3966   this->offset_ = first->offset();
3967
3968   if (last_data == NULL)
3969     this->filesz_ = 0;
3970   else
3971     this->filesz_ = (last_data->address()
3972                      + last_data->data_size()
3973                      - this->vaddr_);
3974
3975   const Output_data* last = last_bss != NULL ? last_bss : last_data;
3976   this->memsz_ = (last->address()
3977                   + last->data_size()
3978                   - this->vaddr_);
3979
3980   this->filesz_ += increase;
3981   this->memsz_ += increase;
3982
3983   // If this is a TLS segment, align the memory size.  The code in
3984   // set_section_list ensures that the section after the TLS segment
3985   // is aligned to give us room.
3986   if (this->type_ == elfcpp::PT_TLS)
3987     {
3988       uint64_t segment_align = this->maximum_alignment();
3989       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
3990       this->memsz_ = align_address(this->memsz_, segment_align);
3991     }
3992 }
3993
3994 // Set the TLS offsets of the sections in the PT_TLS segment.
3995
3996 void
3997 Output_segment::set_tls_offsets()
3998 {
3999   gold_assert(this->type_ == elfcpp::PT_TLS);
4000
4001   for (Output_data_list::iterator p = this->output_lists_[0].begin();
4002        p != this->output_lists_[0].end();
4003        ++p)
4004     (*p)->set_tls_offset(this->vaddr_);
4005 }
4006
4007 // Return the load address of the first section.
4008
4009 uint64_t
4010 Output_segment::first_section_load_address() const
4011 {
4012   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4013     {
4014       const Output_data_list* pdl = &this->output_lists_[i];
4015       for (Output_data_list::const_iterator p = pdl->begin();
4016            p != pdl->end();
4017            ++p)
4018         {
4019           if ((*p)->is_section())
4020             return ((*p)->has_load_address()
4021                     ? (*p)->load_address()
4022                     : (*p)->address());
4023         }
4024     }
4025   gold_unreachable();
4026 }
4027
4028 // Return the number of Output_sections in an Output_segment.
4029
4030 unsigned int
4031 Output_segment::output_section_count() const
4032 {
4033   unsigned int ret = 0;
4034   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4035     ret += this->output_section_count_list(&this->output_lists_[i]);
4036   return ret;
4037 }
4038
4039 // Return the number of Output_sections in an Output_data_list.
4040
4041 unsigned int
4042 Output_segment::output_section_count_list(const Output_data_list* pdl) const
4043 {
4044   unsigned int count = 0;
4045   for (Output_data_list::const_iterator p = pdl->begin();
4046        p != pdl->end();
4047        ++p)
4048     {
4049       if ((*p)->is_section())
4050         ++count;
4051     }
4052   return count;
4053 }
4054
4055 // Return the section attached to the list segment with the lowest
4056 // load address.  This is used when handling a PHDRS clause in a
4057 // linker script.
4058
4059 Output_section*
4060 Output_segment::section_with_lowest_load_address() const
4061 {
4062   Output_section* found = NULL;
4063   uint64_t found_lma = 0;
4064   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4065     this->lowest_load_address_in_list(&this->output_lists_[i], &found,
4066                                       &found_lma);
4067   return found;
4068 }
4069
4070 // Look through a list for a section with a lower load address.
4071
4072 void
4073 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
4074                                             Output_section** found,
4075                                             uint64_t* found_lma) const
4076 {
4077   for (Output_data_list::const_iterator p = pdl->begin();
4078        p != pdl->end();
4079        ++p)
4080     {
4081       if (!(*p)->is_section())
4082         continue;
4083       Output_section* os = static_cast<Output_section*>(*p);
4084       uint64_t lma = (os->has_load_address()
4085                       ? os->load_address()
4086                       : os->address());
4087       if (*found == NULL || lma < *found_lma)
4088         {
4089           *found = os;
4090           *found_lma = lma;
4091         }
4092     }
4093 }
4094
4095 // Write the segment data into *OPHDR.
4096
4097 template<int size, bool big_endian>
4098 void
4099 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
4100 {
4101   ophdr->put_p_type(this->type_);
4102   ophdr->put_p_offset(this->offset_);
4103   ophdr->put_p_vaddr(this->vaddr_);
4104   ophdr->put_p_paddr(this->paddr_);
4105   ophdr->put_p_filesz(this->filesz_);
4106   ophdr->put_p_memsz(this->memsz_);
4107   ophdr->put_p_flags(this->flags_);
4108   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
4109 }
4110
4111 // Write the section headers into V.
4112
4113 template<int size, bool big_endian>
4114 unsigned char*
4115 Output_segment::write_section_headers(const Layout* layout,
4116                                       const Stringpool* secnamepool,
4117                                       unsigned char* v,
4118                                       unsigned int* pshndx) const
4119 {
4120   // Every section that is attached to a segment must be attached to a
4121   // PT_LOAD segment, so we only write out section headers for PT_LOAD
4122   // segments.
4123   if (this->type_ != elfcpp::PT_LOAD)
4124     return v;
4125
4126   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4127     {
4128       const Output_data_list* pdl = &this->output_lists_[i];
4129       v = this->write_section_headers_list<size, big_endian>(layout,
4130                                                              secnamepool,
4131                                                              pdl,
4132                                                              v, pshndx);
4133     }
4134
4135   return v;
4136 }
4137
4138 template<int size, bool big_endian>
4139 unsigned char*
4140 Output_segment::write_section_headers_list(const Layout* layout,
4141                                            const Stringpool* secnamepool,
4142                                            const Output_data_list* pdl,
4143                                            unsigned char* v,
4144                                            unsigned int* pshndx) const
4145 {
4146   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
4147   for (Output_data_list::const_iterator p = pdl->begin();
4148        p != pdl->end();
4149        ++p)
4150     {
4151       if ((*p)->is_section())
4152         {
4153           const Output_section* ps = static_cast<const Output_section*>(*p);
4154           gold_assert(*pshndx == ps->out_shndx());
4155           elfcpp::Shdr_write<size, big_endian> oshdr(v);
4156           ps->write_header(layout, secnamepool, &oshdr);
4157           v += shdr_size;
4158           ++*pshndx;
4159         }
4160     }
4161   return v;
4162 }
4163
4164 // Print the output sections to the map file.
4165
4166 void
4167 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
4168 {
4169   if (this->type() != elfcpp::PT_LOAD)
4170     return;
4171   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4172     this->print_section_list_to_mapfile(mapfile, &this->output_lists_[i]);
4173 }
4174
4175 // Print an output section list to the map file.
4176
4177 void
4178 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
4179                                               const Output_data_list* pdl) const
4180 {
4181   for (Output_data_list::const_iterator p = pdl->begin();
4182        p != pdl->end();
4183        ++p)
4184     (*p)->print_to_mapfile(mapfile);
4185 }
4186
4187 // Output_file methods.
4188
4189 Output_file::Output_file(const char* name)
4190   : name_(name),
4191     o_(-1),
4192     file_size_(0),
4193     base_(NULL),
4194     map_is_anonymous_(false),
4195     is_temporary_(false)
4196 {
4197 }
4198
4199 // Try to open an existing file.  Returns false if the file doesn't
4200 // exist, has a size of 0 or can't be mmapped.
4201
4202 bool
4203 Output_file::open_for_modification()
4204 {
4205   // The name "-" means "stdout".
4206   if (strcmp(this->name_, "-") == 0)
4207     return false;
4208
4209   // Don't bother opening files with a size of zero.
4210   struct stat s;
4211   if (::stat(this->name_, &s) != 0 || s.st_size == 0)
4212     return false;
4213
4214   int o = open_descriptor(-1, this->name_, O_RDWR, 0);
4215   if (o < 0)
4216     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4217   this->o_ = o;
4218   this->file_size_ = s.st_size;
4219
4220   // If the file can't be mmapped, copying the content to an anonymous
4221   // map will probably negate the performance benefits of incremental
4222   // linking.  This could be helped by using views and loading only
4223   // the necessary parts, but this is not supported as of now.
4224   if (!this->map_no_anonymous())
4225     {
4226       release_descriptor(o, true);
4227       this->o_ = -1;
4228       this->file_size_ = 0;
4229       return false;
4230     }
4231
4232   return true;
4233 }
4234
4235 // Open the output file.
4236
4237 void
4238 Output_file::open(off_t file_size)
4239 {
4240   this->file_size_ = file_size;
4241
4242   // Unlink the file first; otherwise the open() may fail if the file
4243   // is busy (e.g. it's an executable that's currently being executed).
4244   //
4245   // However, the linker may be part of a system where a zero-length
4246   // file is created for it to write to, with tight permissions (gcc
4247   // 2.95 did something like this).  Unlinking the file would work
4248   // around those permission controls, so we only unlink if the file
4249   // has a non-zero size.  We also unlink only regular files to avoid
4250   // trouble with directories/etc.
4251   //
4252   // If we fail, continue; this command is merely a best-effort attempt
4253   // to improve the odds for open().
4254
4255   // We let the name "-" mean "stdout"
4256   if (!this->is_temporary_)
4257     {
4258       if (strcmp(this->name_, "-") == 0)
4259         this->o_ = STDOUT_FILENO;
4260       else
4261         {
4262           struct stat s;
4263           if (::stat(this->name_, &s) == 0
4264               && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
4265             {
4266               if (s.st_size != 0)
4267                 ::unlink(this->name_);
4268               else if (!parameters->options().relocatable())
4269                 {
4270                   // If we don't unlink the existing file, add execute
4271                   // permission where read permissions already exist
4272                   // and where the umask permits.
4273                   int mask = ::umask(0);
4274                   ::umask(mask);
4275                   s.st_mode |= (s.st_mode & 0444) >> 2;
4276                   ::chmod(this->name_, s.st_mode & ~mask);
4277                 }
4278             }
4279
4280           int mode = parameters->options().relocatable() ? 0666 : 0777;
4281           int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
4282                                   mode);
4283           if (o < 0)
4284             gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4285           this->o_ = o;
4286         }
4287     }
4288
4289   this->map();
4290 }
4291
4292 // Resize the output file.
4293
4294 void
4295 Output_file::resize(off_t file_size)
4296 {
4297   // If the mmap is mapping an anonymous memory buffer, this is easy:
4298   // just mremap to the new size.  If it's mapping to a file, we want
4299   // to unmap to flush to the file, then remap after growing the file.
4300   if (this->map_is_anonymous_)
4301     {
4302       void* base = ::mremap(this->base_, this->file_size_, file_size,
4303                             MREMAP_MAYMOVE);
4304       if (base == MAP_FAILED)
4305         gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
4306       this->base_ = static_cast<unsigned char*>(base);
4307       this->file_size_ = file_size;
4308     }
4309   else
4310     {
4311       this->unmap();
4312       this->file_size_ = file_size;
4313       if (!this->map_no_anonymous())
4314         gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
4315     }
4316 }
4317
4318 // Map an anonymous block of memory which will later be written to the
4319 // file.  Return whether the map succeeded.
4320
4321 bool
4322 Output_file::map_anonymous()
4323 {
4324   void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4325                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
4326   if (base != MAP_FAILED)
4327     {
4328       this->map_is_anonymous_ = true;
4329       this->base_ = static_cast<unsigned char*>(base);
4330       return true;
4331     }
4332   return false;
4333 }
4334
4335 // Map the file into memory.  Return whether the mapping succeeded.
4336
4337 bool
4338 Output_file::map_no_anonymous()
4339 {
4340   const int o = this->o_;
4341
4342   // If the output file is not a regular file, don't try to mmap it;
4343   // instead, we'll mmap a block of memory (an anonymous buffer), and
4344   // then later write the buffer to the file.
4345   void* base;
4346   struct stat statbuf;
4347   if (o == STDOUT_FILENO || o == STDERR_FILENO
4348       || ::fstat(o, &statbuf) != 0
4349       || !S_ISREG(statbuf.st_mode)
4350       || this->is_temporary_)
4351     return false;
4352
4353   // Ensure that we have disk space available for the file.  If we
4354   // don't do this, it is possible that we will call munmap, close,
4355   // and exit with dirty buffers still in the cache with no assigned
4356   // disk blocks.  If the disk is out of space at that point, the
4357   // output file will wind up incomplete, but we will have already
4358   // exited.  The alternative to fallocate would be to use fdatasync,
4359   // but that would be a more significant performance hit.
4360   if (::posix_fallocate(o, 0, this->file_size_) < 0)
4361     gold_fatal(_("%s: %s"), this->name_, strerror(errno));
4362
4363   // Map the file into memory.
4364   base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4365                 MAP_SHARED, o, 0);
4366
4367   // The mmap call might fail because of file system issues: the file
4368   // system might not support mmap at all, or it might not support
4369   // mmap with PROT_WRITE.
4370   if (base == MAP_FAILED)
4371     return false;
4372
4373   this->map_is_anonymous_ = false;
4374   this->base_ = static_cast<unsigned char*>(base);
4375   return true;
4376 }
4377
4378 // Map the file into memory.
4379
4380 void
4381 Output_file::map()
4382 {
4383   if (this->map_no_anonymous())
4384     return;
4385
4386   // The mmap call might fail because of file system issues: the file
4387   // system might not support mmap at all, or it might not support
4388   // mmap with PROT_WRITE.  I'm not sure which errno values we will
4389   // see in all cases, so if the mmap fails for any reason and we
4390   // don't care about file contents, try for an anonymous map.
4391   if (this->map_anonymous())
4392     return;
4393
4394   gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
4395              this->name_, static_cast<unsigned long>(this->file_size_),
4396              strerror(errno));
4397 }
4398
4399 // Unmap the file from memory.
4400
4401 void
4402 Output_file::unmap()
4403 {
4404   if (::munmap(this->base_, this->file_size_) < 0)
4405     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4406   this->base_ = NULL;
4407 }
4408
4409 // Close the output file.
4410
4411 void
4412 Output_file::close()
4413 {
4414   // If the map isn't file-backed, we need to write it now.
4415   if (this->map_is_anonymous_ && !this->is_temporary_)
4416     {
4417       size_t bytes_to_write = this->file_size_;
4418       size_t offset = 0;
4419       while (bytes_to_write > 0)
4420         {
4421           ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4422                                           bytes_to_write);
4423           if (bytes_written == 0)
4424             gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4425           else if (bytes_written < 0)
4426             gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4427           else
4428             {
4429               bytes_to_write -= bytes_written;
4430               offset += bytes_written;
4431             }
4432         }
4433     }
4434   this->unmap();
4435
4436   // We don't close stdout or stderr
4437   if (this->o_ != STDOUT_FILENO
4438       && this->o_ != STDERR_FILENO
4439       && !this->is_temporary_)
4440     if (::close(this->o_) < 0)
4441       gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4442   this->o_ = -1;
4443 }
4444
4445 // Instantiate the templates we need.  We could use the configure
4446 // script to restrict this to only the ones for implemented targets.
4447
4448 #ifdef HAVE_TARGET_32_LITTLE
4449 template
4450 off_t
4451 Output_section::add_input_section<32, false>(
4452     Layout* layout,
4453     Sized_relobj<32, false>* object,
4454     unsigned int shndx,
4455     const char* secname,
4456     const elfcpp::Shdr<32, false>& shdr,
4457     unsigned int reloc_shndx,
4458     bool have_sections_script);
4459 #endif
4460
4461 #ifdef HAVE_TARGET_32_BIG
4462 template
4463 off_t
4464 Output_section::add_input_section<32, true>(
4465     Layout* layout,
4466     Sized_relobj<32, true>* object,
4467     unsigned int shndx,
4468     const char* secname,
4469     const elfcpp::Shdr<32, true>& shdr,
4470     unsigned int reloc_shndx,
4471     bool have_sections_script);
4472 #endif
4473
4474 #ifdef HAVE_TARGET_64_LITTLE
4475 template
4476 off_t
4477 Output_section::add_input_section<64, false>(
4478     Layout* layout,
4479     Sized_relobj<64, false>* object,
4480     unsigned int shndx,
4481     const char* secname,
4482     const elfcpp::Shdr<64, false>& shdr,
4483     unsigned int reloc_shndx,
4484     bool have_sections_script);
4485 #endif
4486
4487 #ifdef HAVE_TARGET_64_BIG
4488 template
4489 off_t
4490 Output_section::add_input_section<64, true>(
4491     Layout* layout,
4492     Sized_relobj<64, true>* object,
4493     unsigned int shndx,
4494     const char* secname,
4495     const elfcpp::Shdr<64, true>& shdr,
4496     unsigned int reloc_shndx,
4497     bool have_sections_script);
4498 #endif
4499
4500 #ifdef HAVE_TARGET_32_LITTLE
4501 template
4502 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4503 #endif
4504
4505 #ifdef HAVE_TARGET_32_BIG
4506 template
4507 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4508 #endif
4509
4510 #ifdef HAVE_TARGET_64_LITTLE
4511 template
4512 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4513 #endif
4514
4515 #ifdef HAVE_TARGET_64_BIG
4516 template
4517 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4518 #endif
4519
4520 #ifdef HAVE_TARGET_32_LITTLE
4521 template
4522 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4523 #endif
4524
4525 #ifdef HAVE_TARGET_32_BIG
4526 template
4527 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4528 #endif
4529
4530 #ifdef HAVE_TARGET_64_LITTLE
4531 template
4532 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4533 #endif
4534
4535 #ifdef HAVE_TARGET_64_BIG
4536 template
4537 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4538 #endif
4539
4540 #ifdef HAVE_TARGET_32_LITTLE
4541 template
4542 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4543 #endif
4544
4545 #ifdef HAVE_TARGET_32_BIG
4546 template
4547 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4548 #endif
4549
4550 #ifdef HAVE_TARGET_64_LITTLE
4551 template
4552 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4553 #endif
4554
4555 #ifdef HAVE_TARGET_64_BIG
4556 template
4557 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4558 #endif
4559
4560 #ifdef HAVE_TARGET_32_LITTLE
4561 template
4562 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4563 #endif
4564
4565 #ifdef HAVE_TARGET_32_BIG
4566 template
4567 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4568 #endif
4569
4570 #ifdef HAVE_TARGET_64_LITTLE
4571 template
4572 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4573 #endif
4574
4575 #ifdef HAVE_TARGET_64_BIG
4576 template
4577 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4578 #endif
4579
4580 #ifdef HAVE_TARGET_32_LITTLE
4581 template
4582 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4583 #endif
4584
4585 #ifdef HAVE_TARGET_32_BIG
4586 template
4587 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4588 #endif
4589
4590 #ifdef HAVE_TARGET_64_LITTLE
4591 template
4592 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4593 #endif
4594
4595 #ifdef HAVE_TARGET_64_BIG
4596 template
4597 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4598 #endif
4599
4600 #ifdef HAVE_TARGET_32_LITTLE
4601 template
4602 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4603 #endif
4604
4605 #ifdef HAVE_TARGET_32_BIG
4606 template
4607 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4608 #endif
4609
4610 #ifdef HAVE_TARGET_64_LITTLE
4611 template
4612 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4613 #endif
4614
4615 #ifdef HAVE_TARGET_64_BIG
4616 template
4617 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4618 #endif
4619
4620 #ifdef HAVE_TARGET_32_LITTLE
4621 template
4622 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4623 #endif
4624
4625 #ifdef HAVE_TARGET_32_BIG
4626 template
4627 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4628 #endif
4629
4630 #ifdef HAVE_TARGET_64_LITTLE
4631 template
4632 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4633 #endif
4634
4635 #ifdef HAVE_TARGET_64_BIG
4636 template
4637 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4638 #endif
4639
4640 #ifdef HAVE_TARGET_32_LITTLE
4641 template
4642 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4643 #endif
4644
4645 #ifdef HAVE_TARGET_32_BIG
4646 template
4647 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4648 #endif
4649
4650 #ifdef HAVE_TARGET_64_LITTLE
4651 template
4652 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4653 #endif
4654
4655 #ifdef HAVE_TARGET_64_BIG
4656 template
4657 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4658 #endif
4659
4660 #ifdef HAVE_TARGET_32_LITTLE
4661 template
4662 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4663 #endif
4664
4665 #ifdef HAVE_TARGET_32_BIG
4666 template
4667 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4668 #endif
4669
4670 #ifdef HAVE_TARGET_64_LITTLE
4671 template
4672 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4673 #endif
4674
4675 #ifdef HAVE_TARGET_64_BIG
4676 template
4677 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4678 #endif
4679
4680 #ifdef HAVE_TARGET_32_LITTLE
4681 template
4682 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4683 #endif
4684
4685 #ifdef HAVE_TARGET_32_BIG
4686 template
4687 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4688 #endif
4689
4690 #ifdef HAVE_TARGET_64_LITTLE
4691 template
4692 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4693 #endif
4694
4695 #ifdef HAVE_TARGET_64_BIG
4696 template
4697 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4698 #endif
4699
4700 #ifdef HAVE_TARGET_32_LITTLE
4701 template
4702 class Output_data_group<32, false>;
4703 #endif
4704
4705 #ifdef HAVE_TARGET_32_BIG
4706 template
4707 class Output_data_group<32, true>;
4708 #endif
4709
4710 #ifdef HAVE_TARGET_64_LITTLE
4711 template
4712 class Output_data_group<64, false>;
4713 #endif
4714
4715 #ifdef HAVE_TARGET_64_BIG
4716 template
4717 class Output_data_group<64, true>;
4718 #endif
4719
4720 #ifdef HAVE_TARGET_32_LITTLE
4721 template
4722 class Output_data_got<32, false>;
4723 #endif
4724
4725 #ifdef HAVE_TARGET_32_BIG
4726 template
4727 class Output_data_got<32, true>;
4728 #endif
4729
4730 #ifdef HAVE_TARGET_64_LITTLE
4731 template
4732 class Output_data_got<64, false>;
4733 #endif
4734
4735 #ifdef HAVE_TARGET_64_BIG
4736 template
4737 class Output_data_got<64, true>;
4738 #endif
4739
4740 } // End namespace gold.