gold/output.cc

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