gold/output.cc

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