gold/output.cc

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