gold/output.cc

   1 // output.cc -- manage the output file for gold
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstdlib>
  26 #include <cstring>
  27 #include <cerrno>
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30 #include <sys/mman.h>
  31 #include <sys/stat.h>
  32 #include <algorithm>
  33 #include "libiberty.h"
  34
  35 #include "parameters.h"
  36 #include "object.h"
  37 #include "symtab.h"
  38 #include "reloc.h"
  39 #include "merge.h"
  40 #include "descriptors.h"
  41 #include "output.h"
  42
  43 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
  44 #ifndef MAP_ANONYMOUS
  45 # define MAP_ANONYMOUS  MAP_ANON
  46 #endif
  47
  48 #ifndef HAVE_POSIX_FALLOCATE
  49 // A dummy, non general, version of posix_fallocate.  Here we just set
  50 // the file size and hope that there is enough disk space.  FIXME: We
  51 // could allocate disk space by walking block by block and writing a
  52 // zero byte into each block.
  53 static int
  54 posix_fallocate(int o, off_t offset, off_t len)
  55 {
  56   return ftruncate(o, offset + len);
  57 }
  58 #endif // !defined(HAVE_POSIX_FALLOCATE)
  59
  60 namespace gold
  61 {
  62
  63 // Output_data variables.
  64
  65 bool Output_data::allocated_sizes_are_fixed;
  66
  67 // Output_data methods.
  68
  69 Output_data::~Output_data()
  70 {
  71 }
  72
  73 // Return the default alignment for the target size.
  74
  75 uint64_t
  76 Output_data::default_alignment()
  77 {
  78   return Output_data::default_alignment_for_size(
  79       parameters->target().get_size());
  80 }
  81
  82 // Return the default alignment for a size--32 or 64.
  83
  84 uint64_t
  85 Output_data::default_alignment_for_size(int size)
  86 {
  87   if (size == 32)
  88     return 4;
  89   else if (size == 64)
  90     return 8;
  91   else
  92     gold_unreachable();
  93 }
  94
  95 // Output_section_header methods.  This currently assumes that the
  96 // segment and section lists are complete at construction time.
  97
  98 Output_section_headers::Output_section_headers(
  99     const Layout* layout,
 100     const Layout::Segment_list* segment_list,
 101     const Layout::Section_list* section_list,
 102     const Layout::Section_list* unattached_section_list,
 103     const Stringpool* secnamepool,
 104     const Output_section* shstrtab_section)
 105   : layout_(layout),
 106     segment_list_(segment_list),
 107     section_list_(section_list),
 108     unattached_section_list_(unattached_section_list),
 109     secnamepool_(secnamepool),
 110     shstrtab_section_(shstrtab_section)
 111 {
 112 }
 113
 114 // Compute the current data size.
 115
 116 off_t
 117 Output_section_headers::do_size() const
 118 {
 119   // Count all the sections.  Start with 1 for the null section.
 120   off_t count = 1;
 121   if (!parameters->options().relocatable())
 122     {
 123       for (Layout::Segment_list::const_iterator p =
 124              this->segment_list_->begin();
 125            p != this->segment_list_->end();
 126            ++p)
 127         if ((*p)->type() == elfcpp::PT_LOAD)
 128           count += (*p)->output_section_count();
 129     }
 130   else
 131     {
 132       for (Layout::Section_list::const_iterator p =
 133              this->section_list_->begin();
 134            p != this->section_list_->end();
 135            ++p)
 136         if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
 137           ++count;
 138     }
 139   count += this->unattached_section_list_->size();
 140
 141   const int size = parameters->target().get_size();
 142   int shdr_size;
 143   if (size == 32)
 144     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
 145   else if (size == 64)
 146     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
 147   else
 148     gold_unreachable();
 149
 150   return count * shdr_size;
 151 }
 152
 153 // Write out the section headers.
 154
 155 void
 156 Output_section_headers::do_write(Output_file* of)
 157 {
 158   switch (parameters->size_and_endianness())
 159     {
 160 #ifdef HAVE_TARGET_32_LITTLE
 161     case Parameters::TARGET_32_LITTLE:
 162       this->do_sized_write<32, false>(of);
 163       break;
 164 #endif
 165 #ifdef HAVE_TARGET_32_BIG
 166     case Parameters::TARGET_32_BIG:
 167       this->do_sized_write<32, true>(of);
 168       break;
 169 #endif
 170 #ifdef HAVE_TARGET_64_LITTLE
 171     case Parameters::TARGET_64_LITTLE:
 172       this->do_sized_write<64, false>(of);
 173       break;
 174 #endif
 175 #ifdef HAVE_TARGET_64_BIG
 176     case Parameters::TARGET_64_BIG:
 177       this->do_sized_write<64, true>(of);
 178       break;
 179 #endif
 180     default:
 181       gold_unreachable();
 182     }
 183 }
 184
 185 template<int size, bool big_endian>
 186 void
 187 Output_section_headers::do_sized_write(Output_file* of)
 188 {
 189   off_t all_shdrs_size = this->data_size();
 190   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
 191
 192   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
 193   unsigned char* v = view;
 194
 195   {
 196     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
 197     oshdr.put_sh_name(0);
 198     oshdr.put_sh_type(elfcpp::SHT_NULL);
 199     oshdr.put_sh_flags(0);
 200     oshdr.put_sh_addr(0);
 201     oshdr.put_sh_offset(0);
 202
 203     size_t section_count = (this->data_size()
 204                             / elfcpp::Elf_sizes<size>::shdr_size);
 205     if (section_count < elfcpp::SHN_LORESERVE)
 206       oshdr.put_sh_size(0);
 207     else
 208       oshdr.put_sh_size(section_count);
 209
 210     unsigned int shstrndx = this->shstrtab_section_->out_shndx();
 211     if (shstrndx < elfcpp::SHN_LORESERVE)
 212       oshdr.put_sh_link(0);
 213     else
 214       oshdr.put_sh_link(shstrndx);
 215
 216     size_t segment_count = this->segment_list_->size();
 217     oshdr.put_sh_info(segment_count >= elfcpp::PN_XNUM ? segment_count : 0);
 218
 219     oshdr.put_sh_addralign(0);
 220     oshdr.put_sh_entsize(0);
 221   }
 222
 223   v += shdr_size;
 224
 225   unsigned int shndx = 1;
 226   if (!parameters->options().relocatable())
 227     {
 228       for (Layout::Segment_list::const_iterator p =
 229              this->segment_list_->begin();
 230            p != this->segment_list_->end();
 231            ++p)
 232         v = (*p)->write_section_headers<size, big_endian>(this->layout_,
 233                                                           this->secnamepool_,
 234                                                           v,
 235                                                           &shndx);
 236     }
 237   else
 238     {
 239       for (Layout::Section_list::const_iterator p =
 240              this->section_list_->begin();
 241            p != this->section_list_->end();
 242            ++p)
 243         {
 244           // We do unallocated sections below, except that group
 245           // sections have to come first.
 246           if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
 247               && (*p)->type() != elfcpp::SHT_GROUP)
 248             continue;
 249           gold_assert(shndx == (*p)->out_shndx());
 250           elfcpp::Shdr_write<size, big_endian> oshdr(v);
 251           (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
 252           v += shdr_size;
 253           ++shndx;
 254         }
 255     }
 256
 257   for (Layout::Section_list::const_iterator p =
 258          this->unattached_section_list_->begin();
 259        p != this->unattached_section_list_->end();
 260        ++p)
 261     {
 262       // For a relocatable link, we did unallocated group sections
 263       // above, since they have to come first.
 264       if ((*p)->type() == elfcpp::SHT_GROUP
 265           && parameters->options().relocatable())
 266         continue;
 267       gold_assert(shndx == (*p)->out_shndx());
 268       elfcpp::Shdr_write<size, big_endian> oshdr(v);
 269       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
 270       v += shdr_size;
 271       ++shndx;
 272     }
 273
 274   of->write_output_view(this->offset(), all_shdrs_size, view);
 275 }
 276
 277 // Output_segment_header methods.
 278
 279 Output_segment_headers::Output_segment_headers(
 280     const Layout::Segment_list& segment_list)
 281   : segment_list_(segment_list)
 282 {
 283 }
 284
 285 void
 286 Output_segment_headers::do_write(Output_file* of)
 287 {
 288   switch (parameters->size_and_endianness())
 289     {
 290 #ifdef HAVE_TARGET_32_LITTLE
 291     case Parameters::TARGET_32_LITTLE:
 292       this->do_sized_write<32, false>(of);
 293       break;
 294 #endif
 295 #ifdef HAVE_TARGET_32_BIG
 296     case Parameters::TARGET_32_BIG:
 297       this->do_sized_write<32, true>(of);
 298       break;
 299 #endif
 300 #ifdef HAVE_TARGET_64_LITTLE
 301     case Parameters::TARGET_64_LITTLE:
 302       this->do_sized_write<64, false>(of);
 303       break;
 304 #endif
 305 #ifdef HAVE_TARGET_64_BIG
 306     case Parameters::TARGET_64_BIG:
 307       this->do_sized_write<64, true>(of);
 308       break;
 309 #endif
 310     default:
 311       gold_unreachable();
 312     }
 313 }
 314
 315 template<int size, bool big_endian>
 316 void
 317 Output_segment_headers::do_sized_write(Output_file* of)
 318 {
 319   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
 320   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
 321   gold_assert(all_phdrs_size == this->data_size());
 322   unsigned char* view = of->get_output_view(this->offset(),
 323                                             all_phdrs_size);
 324   unsigned char* v = view;
 325   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
 326        p != this->segment_list_.end();
 327        ++p)
 328     {
 329       elfcpp::Phdr_write<size, big_endian> ophdr(v);
 330       (*p)->write_header(&ophdr);
 331       v += phdr_size;
 332     }
 333
 334   gold_assert(v - view == all_phdrs_size);
 335
 336   of->write_output_view(this->offset(), all_phdrs_size, view);
 337 }
 338
 339 off_t
 340 Output_segment_headers::do_size() const
 341 {
 342   const int size = parameters->target().get_size();
 343   int phdr_size;
 344   if (size == 32)
 345     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
 346   else if (size == 64)
 347     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
 348   else
 349     gold_unreachable();
 350
 351   return this->segment_list_.size() * phdr_size;
 352 }
 353
 354 // Output_file_header methods.
 355
 356 Output_file_header::Output_file_header(const Target* target,
 357                                        const Symbol_table* symtab,
 358                                        const Output_segment_headers* osh,
 359                                        const char* entry)
 360   : target_(target),
 361     symtab_(symtab),
 362     segment_header_(osh),
 363     section_header_(NULL),
 364     shstrtab_(NULL),
 365     entry_(entry)
 366 {
 367   this->set_data_size(this->do_size());
 368 }
 369
 370 // Set the section table information for a file header.
 371
 372 void
 373 Output_file_header::set_section_info(const Output_section_headers* shdrs,
 374                                      const Output_section* shstrtab)
 375 {
 376   this->section_header_ = shdrs;
 377   this->shstrtab_ = shstrtab;
 378 }
 379
 380 // Write out the file header.
 381
 382 void
 383 Output_file_header::do_write(Output_file* of)
 384 {
 385   gold_assert(this->offset() == 0);
 386
 387   switch (parameters->size_and_endianness())
 388     {
 389 #ifdef HAVE_TARGET_32_LITTLE
 390     case Parameters::TARGET_32_LITTLE:
 391       this->do_sized_write<32, false>(of);
 392       break;
 393 #endif
 394 #ifdef HAVE_TARGET_32_BIG
 395     case Parameters::TARGET_32_BIG:
 396       this->do_sized_write<32, true>(of);
 397       break;
 398 #endif
 399 #ifdef HAVE_TARGET_64_LITTLE
 400     case Parameters::TARGET_64_LITTLE:
 401       this->do_sized_write<64, false>(of);
 402       break;
 403 #endif
 404 #ifdef HAVE_TARGET_64_BIG
 405     case Parameters::TARGET_64_BIG:
 406       this->do_sized_write<64, true>(of);
 407       break;
 408 #endif
 409     default:
 410       gold_unreachable();
 411     }
 412 }
 413
 414 // Write out the file header with appropriate size and endianess.
 415
 416 template<int size, bool big_endian>
 417 void
 418 Output_file_header::do_sized_write(Output_file* of)
 419 {
 420   gold_assert(this->offset() == 0);
 421
 422   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
 423   unsigned char* view = of->get_output_view(0, ehdr_size);
 424   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
 425
 426   unsigned char e_ident[elfcpp::EI_NIDENT];
 427   memset(e_ident, 0, elfcpp::EI_NIDENT);
 428   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
 429   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
 430   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
 431   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
 432   if (size == 32)
 433     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
 434   else if (size == 64)
 435     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
 436   else
 437     gold_unreachable();
 438   e_ident[elfcpp::EI_DATA] = (big_endian
 439                               ? elfcpp::ELFDATA2MSB
 440                               : elfcpp::ELFDATA2LSB);
 441   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
 442   oehdr.put_e_ident(e_ident);
 443
 444   elfcpp::ET e_type;
 445   if (parameters->options().relocatable())
 446     e_type = elfcpp::ET_REL;
 447   else if (parameters->options().output_is_position_independent())
 448     e_type = elfcpp::ET_DYN;
 449   else
 450     e_type = elfcpp::ET_EXEC;
 451   oehdr.put_e_type(e_type);
 452
 453   oehdr.put_e_machine(this->target_->machine_code());
 454   oehdr.put_e_version(elfcpp::EV_CURRENT);
 455
 456   oehdr.put_e_entry(this->entry<size>());
 457
 458   if (this->segment_header_ == NULL)
 459     oehdr.put_e_phoff(0);
 460   else
 461     oehdr.put_e_phoff(this->segment_header_->offset());
 462
 463   oehdr.put_e_shoff(this->section_header_->offset());
 464   oehdr.put_e_flags(this->target_->processor_specific_flags());
 465   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
 466
 467   if (this->segment_header_ == NULL)
 468     {
 469       oehdr.put_e_phentsize(0);
 470       oehdr.put_e_phnum(0);
 471     }
 472   else
 473     {
 474       oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
 475       size_t phnum = (this->segment_header_->data_size()
 476                       / elfcpp::Elf_sizes<size>::phdr_size);
 477       if (phnum > elfcpp::PN_XNUM)
 478         phnum = elfcpp::PN_XNUM;
 479       oehdr.put_e_phnum(phnum);
 480     }
 481
 482   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
 483   size_t section_count = (this->section_header_->data_size()
 484                           / elfcpp::Elf_sizes<size>::shdr_size);
 485
 486   if (section_count < elfcpp::SHN_LORESERVE)
 487     oehdr.put_e_shnum(this->section_header_->data_size()
 488                       / elfcpp::Elf_sizes<size>::shdr_size);
 489   else
 490     oehdr.put_e_shnum(0);
 491
 492   unsigned int shstrndx = this->shstrtab_->out_shndx();
 493   if (shstrndx < elfcpp::SHN_LORESERVE)
 494     oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
 495   else
 496     oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
 497
 498   // Let the target adjust the ELF header, e.g., to set EI_OSABI in
 499   // the e_ident field.
 500   parameters->target().adjust_elf_header(view, ehdr_size);
 501
 502   of->write_output_view(0, ehdr_size, view);
 503 }
 504
 505 // Return the value to use for the entry address.  THIS->ENTRY_ is the
 506 // symbol specified on the command line, if any.
 507
 508 template<int size>
 509 typename elfcpp::Elf_types<size>::Elf_Addr
 510 Output_file_header::entry()
 511 {
 512   const bool should_issue_warning = (this->entry_ != NULL
 513                                      && !parameters->options().relocatable()
 514                                      && !parameters->options().shared());
 515
 516   // FIXME: Need to support target specific entry symbol.
 517   const char* entry = this->entry_;
 518   if (entry == NULL)
 519     entry = "_start";
 520
 521   Symbol* sym = this->symtab_->lookup(entry);
 522
 523   typename Sized_symbol<size>::Value_type v;
 524   if (sym != NULL)
 525     {
 526       Sized_symbol<size>* ssym;
 527       ssym = this->symtab_->get_sized_symbol<size>(sym);
 528       if (!ssym->is_defined() && should_issue_warning)
 529         gold_warning("entry symbol '%s' exists but is not defined", entry);
 530       v = ssym->value();
 531     }
 532   else
 533     {
 534       // We couldn't find the entry symbol.  See if we can parse it as
 535       // a number.  This supports, e.g., -e 0x1000.
 536       char* endptr;
 537       v = strtoull(entry, &endptr, 0);
 538       if (*endptr != '\0')
 539         {
 540           if (should_issue_warning)
 541             gold_warning("cannot find entry symbol '%s'", entry);
 542           v = 0;
 543         }
 544     }
 545
 546   return v;
 547 }
 548
 549 // Compute the current data size.
 550
 551 off_t
 552 Output_file_header::do_size() const
 553 {
 554   const int size = parameters->target().get_size();
 555   if (size == 32)
 556     return elfcpp::Elf_sizes<32>::ehdr_size;
 557   else if (size == 64)
 558     return elfcpp::Elf_sizes<64>::ehdr_size;
 559   else
 560     gold_unreachable();
 561 }
 562
 563 // Output_data_const methods.
 564
 565 void
 566 Output_data_const::do_write(Output_file* of)
 567 {
 568   of->write(this->offset(), this->data_.data(), this->data_.size());
 569 }
 570
 571 // Output_data_const_buffer methods.
 572
 573 void
 574 Output_data_const_buffer::do_write(Output_file* of)
 575 {
 576   of->write(this->offset(), this->p_, this->data_size());
 577 }
 578
 579 // Output_section_data methods.
 580
 581 // Record the output section, and set the entry size and such.
 582
 583 void
 584 Output_section_data::set_output_section(Output_section* os)
 585 {
 586   gold_assert(this->output_section_ == NULL);
 587   this->output_section_ = os;
 588   this->do_adjust_output_section(os);
 589 }
 590
 591 // Return the section index of the output section.
 592
 593 unsigned int
 594 Output_section_data::do_out_shndx() const
 595 {
 596   gold_assert(this->output_section_ != NULL);
 597   return this->output_section_->out_shndx();
 598 }
 599
 600 // Set the alignment, which means we may need to update the alignment
 601 // of the output section.
 602
 603 void
 604 Output_section_data::set_addralign(uint64_t addralign)
 605 {
 606   this->addralign_ = addralign;
 607   if (this->output_section_ != NULL
 608       && this->output_section_->addralign() < addralign)
 609     this->output_section_->set_addralign(addralign);
 610 }
 611
 612 // Output_data_strtab methods.
 613
 614 // Set the final data size.
 615
 616 void
 617 Output_data_strtab::set_final_data_size()
 618 {
 619   this->strtab_->set_string_offsets();
 620   this->set_data_size(this->strtab_->get_strtab_size());
 621 }
 622
 623 // Write out a string table.
 624
 625 void
 626 Output_data_strtab::do_write(Output_file* of)
 627 {
 628   this->strtab_->write(of, this->offset());
 629 }
 630
 631 // Output_reloc methods.
 632
 633 // A reloc against a global symbol.
 634
 635 template<bool dynamic, int size, bool big_endian>
 636 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 637     Symbol* gsym,
 638     unsigned int type,
 639     Output_data* od,
 640     Address address,
 641     bool is_relative,
 642     bool is_symbolless)
 643   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
 644     is_relative_(is_relative), is_symbolless_(is_symbolless),
 645     is_section_symbol_(false), shndx_(INVALID_CODE)
 646 {
 647   // this->type_ is a bitfield; make sure TYPE fits.
 648   gold_assert(this->type_ == type);
 649   this->u1_.gsym = gsym;
 650   this->u2_.od = od;
 651   if (dynamic)
 652     this->set_needs_dynsym_index();
 653 }
 654
 655 template<bool dynamic, int size, bool big_endian>
 656 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 657     Symbol* gsym,
 658     unsigned int type,
 659     Sized_relobj<size, big_endian>* relobj,
 660     unsigned int shndx,
 661     Address address,
 662     bool is_relative,
 663     bool is_symbolless)
 664   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
 665     is_relative_(is_relative), is_symbolless_(is_symbolless),
 666     is_section_symbol_(false), shndx_(shndx)
 667 {
 668   gold_assert(shndx != INVALID_CODE);
 669   // this->type_ is a bitfield; make sure TYPE fits.
 670   gold_assert(this->type_ == type);
 671   this->u1_.gsym = gsym;
 672   this->u2_.relobj = relobj;
 673   if (dynamic)
 674     this->set_needs_dynsym_index();
 675 }
 676
 677 // A reloc against a local symbol.
 678
 679 template<bool dynamic, int size, bool big_endian>
 680 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 681     Sized_relobj<size, big_endian>* relobj,
 682     unsigned int local_sym_index,
 683     unsigned int type,
 684     Output_data* od,
 685     Address address,
 686     bool is_relative,
 687     bool is_symbolless,
 688     bool is_section_symbol)
 689   : address_(address), local_sym_index_(local_sym_index), type_(type),
 690     is_relative_(is_relative), is_symbolless_(is_symbolless),
 691     is_section_symbol_(is_section_symbol), shndx_(INVALID_CODE)
 692 {
 693   gold_assert(local_sym_index != GSYM_CODE
 694               && local_sym_index != INVALID_CODE);
 695   // this->type_ is a bitfield; make sure TYPE fits.
 696   gold_assert(this->type_ == type);
 697   this->u1_.relobj = relobj;
 698   this->u2_.od = od;
 699   if (dynamic)
 700     this->set_needs_dynsym_index();
 701 }
 702
 703 template<bool dynamic, int size, bool big_endian>
 704 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 705     Sized_relobj<size, big_endian>* relobj,
 706     unsigned int local_sym_index,
 707     unsigned int type,
 708     unsigned int shndx,
 709     Address address,
 710     bool is_relative,
 711     bool is_symbolless,
 712     bool is_section_symbol)
 713   : address_(address), local_sym_index_(local_sym_index), type_(type),
 714     is_relative_(is_relative), is_symbolless_(is_symbolless),
 715     is_section_symbol_(is_section_symbol), shndx_(shndx)
 716 {
 717   gold_assert(local_sym_index != GSYM_CODE
 718               && local_sym_index != INVALID_CODE);
 719   gold_assert(shndx != INVALID_CODE);
 720   // this->type_ is a bitfield; make sure TYPE fits.
 721   gold_assert(this->type_ == type);
 722   this->u1_.relobj = relobj;
 723   this->u2_.relobj = relobj;
 724   if (dynamic)
 725     this->set_needs_dynsym_index();
 726 }
 727
 728 // A reloc against the STT_SECTION symbol of an output section.
 729
 730 template<bool dynamic, int size, bool big_endian>
 731 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 732     Output_section* os,
 733     unsigned int type,
 734     Output_data* od,
 735     Address address)
 736   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
 737     is_relative_(false), is_symbolless_(false),
 738     is_section_symbol_(true), shndx_(INVALID_CODE)
 739 {
 740   // this->type_ is a bitfield; make sure TYPE fits.
 741   gold_assert(this->type_ == type);
 742   this->u1_.os = os;
 743   this->u2_.od = od;
 744   if (dynamic)
 745     this->set_needs_dynsym_index();
 746   else
 747     os->set_needs_symtab_index();
 748 }
 749
 750 template<bool dynamic, int size, bool big_endian>
 751 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 752     Output_section* os,
 753     unsigned int type,
 754     Sized_relobj<size, big_endian>* relobj,
 755     unsigned int shndx,
 756     Address address)
 757   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
 758     is_relative_(false), is_symbolless_(false),
 759     is_section_symbol_(true), shndx_(shndx)
 760 {
 761   gold_assert(shndx != INVALID_CODE);
 762   // this->type_ is a bitfield; make sure TYPE fits.
 763   gold_assert(this->type_ == type);
 764   this->u1_.os = os;
 765   this->u2_.relobj = relobj;
 766   if (dynamic)
 767     this->set_needs_dynsym_index();
 768   else
 769     os->set_needs_symtab_index();
 770 }
 771
 772 // An absolute relocation.
 773
 774 template<bool dynamic, int size, bool big_endian>
 775 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 776     unsigned int type,
 777     Output_data* od,
 778     Address address)
 779   : address_(address), local_sym_index_(0), type_(type),
 780     is_relative_(false), is_symbolless_(false),
 781     is_section_symbol_(false), shndx_(INVALID_CODE)
 782 {
 783   // this->type_ is a bitfield; make sure TYPE fits.
 784   gold_assert(this->type_ == type);
 785   this->u1_.relobj = NULL;
 786   this->u2_.od = od;
 787 }
 788
 789 template<bool dynamic, int size, bool big_endian>
 790 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 791     unsigned int type,
 792     Sized_relobj<size, big_endian>* relobj,
 793     unsigned int shndx,
 794     Address address)
 795   : address_(address), local_sym_index_(0), type_(type),
 796     is_relative_(false), is_symbolless_(false),
 797     is_section_symbol_(false), shndx_(shndx)
 798 {
 799   gold_assert(shndx != INVALID_CODE);
 800   // this->type_ is a bitfield; make sure TYPE fits.
 801   gold_assert(this->type_ == type);
 802   this->u1_.relobj = NULL;
 803   this->u2_.relobj = relobj;
 804 }
 805
 806 // A target specific relocation.
 807
 808 template<bool dynamic, int size, bool big_endian>
 809 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 810     unsigned int type,
 811     void* arg,
 812     Output_data* od,
 813     Address address)
 814   : address_(address), local_sym_index_(TARGET_CODE), type_(type),
 815     is_relative_(false), is_symbolless_(false),
 816     is_section_symbol_(false), shndx_(INVALID_CODE)
 817 {
 818   // this->type_ is a bitfield; make sure TYPE fits.
 819   gold_assert(this->type_ == type);
 820   this->u1_.arg = arg;
 821   this->u2_.od = od;
 822 }
 823
 824 template<bool dynamic, int size, bool big_endian>
 825 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
 826     unsigned int type,
 827     void* arg,
 828     Sized_relobj<size, big_endian>* relobj,
 829     unsigned int shndx,
 830     Address address)
 831   : address_(address), local_sym_index_(TARGET_CODE), type_(type),
 832     is_relative_(false), is_symbolless_(false),
 833     is_section_symbol_(false), shndx_(shndx)
 834 {
 835   gold_assert(shndx != INVALID_CODE);
 836   // this->type_ is a bitfield; make sure TYPE fits.
 837   gold_assert(this->type_ == type);
 838   this->u1_.arg = arg;
 839   this->u2_.relobj = relobj;
 840 }
 841
 842 // Record that we need a dynamic symbol index for this relocation.
 843
 844 template<bool dynamic, int size, bool big_endian>
 845 void
 846 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
 847 set_needs_dynsym_index()
 848 {
 849   if (this->is_symbolless_)
 850     return;
 851   switch (this->local_sym_index_)
 852     {
 853     case INVALID_CODE:
 854       gold_unreachable();
 855
 856     case GSYM_CODE:
 857       this->u1_.gsym->set_needs_dynsym_entry();
 858       break;
 859
 860     case SECTION_CODE:
 861       this->u1_.os->set_needs_dynsym_index();
 862       break;
 863
 864     case TARGET_CODE:
 865       // The target must take care of this if necessary.
 866       break;
 867
 868     case 0:
 869       break;
 870
 871     default:
 872       {
 873         const unsigned int lsi = this->local_sym_index_;
 874         if (!this->is_section_symbol_)
 875           this->u1_.relobj->set_needs_output_dynsym_entry(lsi);
 876         else
 877           this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index();
 878       }
 879       break;
 880     }
 881 }
 882
 883 // Get the symbol index of a relocation.
 884
 885 template<bool dynamic, int size, bool big_endian>
 886 unsigned int
 887 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
 888   const
 889 {
 890   unsigned int index;
 891   if (this->is_symbolless_)
 892     return 0;
 893   switch (this->local_sym_index_)
 894     {
 895     case INVALID_CODE:
 896       gold_unreachable();
 897
 898     case GSYM_CODE:
 899       if (this->u1_.gsym == NULL)
 900         index = 0;
 901       else if (dynamic)
 902         index = this->u1_.gsym->dynsym_index();
 903       else
 904         index = this->u1_.gsym->symtab_index();
 905       break;
 906
 907     case SECTION_CODE:
 908       if (dynamic)
 909         index = this->u1_.os->dynsym_index();
 910       else
 911         index = this->u1_.os->symtab_index();
 912       break;
 913
 914     case TARGET_CODE:
 915       index = parameters->target().reloc_symbol_index(this->u1_.arg,
 916                                                       this->type_);
 917       break;
 918
 919     case 0:
 920       // Relocations without symbols use a symbol index of 0.
 921       index = 0;
 922       break;
 923
 924     default:
 925       {
 926         const unsigned int lsi = this->local_sym_index_;
 927         if (!this->is_section_symbol_)
 928           {
 929             if (dynamic)
 930               index = this->u1_.relobj->dynsym_index(lsi);
 931             else
 932               index = this->u1_.relobj->symtab_index(lsi);
 933           }
 934         else
 935           {
 936             Output_section* os = this->u1_.relobj->output_section(lsi);
 937             gold_assert(os != NULL);
 938             if (dynamic)
 939               index = os->dynsym_index();
 940             else
 941               index = os->symtab_index();
 942           }
 943       }
 944       break;
 945     }
 946   gold_assert(index != -1U);
 947   return index;
 948 }
 949
 950 // For a local section symbol, get the address of the offset ADDEND
 951 // within the input section.
 952
 953 template<bool dynamic, int size, bool big_endian>
 954 typename elfcpp::Elf_types<size>::Elf_Addr
 955 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
 956   local_section_offset(Addend addend) const
 957 {
 958   gold_assert(this->local_sym_index_ != GSYM_CODE
 959               && this->local_sym_index_ != SECTION_CODE
 960               && this->local_sym_index_ != TARGET_CODE
 961               && this->local_sym_index_ != INVALID_CODE
 962               && this->local_sym_index_ != 0
 963               && this->is_section_symbol_);
 964   const unsigned int lsi = this->local_sym_index_;
 965   Output_section* os = this->u1_.relobj->output_section(lsi);
 966   gold_assert(os != NULL);
 967   Address offset = this->u1_.relobj->get_output_section_offset(lsi);
 968   if (offset != invalid_address)
 969     return offset + addend;
 970   // This is a merge section.
 971   offset = os->output_address(this->u1_.relobj, lsi, addend);
 972   gold_assert(offset != invalid_address);
 973   return offset;
 974 }
 975
 976 // Get the output address of a relocation.
 977
 978 template<bool dynamic, int size, bool big_endian>
 979 typename elfcpp::Elf_types<size>::Elf_Addr
 980 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
 981 {
 982   Address address = this->address_;
 983   if (this->shndx_ != INVALID_CODE)
 984     {
 985       Output_section* os = this->u2_.relobj->output_section(this->shndx_);
 986       gold_assert(os != NULL);
 987       Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
 988       if (off != invalid_address)
 989         address += os->address() + off;
 990       else
 991         {
 992           address = os->output_address(this->u2_.relobj, this->shndx_,
 993                                        address);
 994           gold_assert(address != invalid_address);
 995         }
 996     }
 997   else if (this->u2_.od != NULL)
 998     address += this->u2_.od->address();
 999   return address;
1000 }
1001
1002 // Write out the offset and info fields of a Rel or Rela relocation
1003 // entry.
1004
1005 template<bool dynamic, int size, bool big_endian>
1006 template<typename Write_rel>
1007 void
1008 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
1009     Write_rel* wr) const
1010 {
1011   wr->put_r_offset(this->get_address());
1012   unsigned int sym_index = this->get_symbol_index();
1013   wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
1014 }
1015
1016 // Write out a Rel relocation.
1017
1018 template<bool dynamic, int size, bool big_endian>
1019 void
1020 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
1021     unsigned char* pov) const
1022 {
1023   elfcpp::Rel_write<size, big_endian> orel(pov);
1024   this->write_rel(&orel);
1025 }
1026
1027 // Get the value of the symbol referred to by a Rel relocation.
1028
1029 template<bool dynamic, int size, bool big_endian>
1030 typename elfcpp::Elf_types<size>::Elf_Addr
1031 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
1032     Addend addend) const
1033 {
1034   if (this->local_sym_index_ == GSYM_CODE)
1035     {
1036       const Sized_symbol<size>* sym;
1037       sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
1038       return sym->value() + addend;
1039     }
1040   gold_assert(this->local_sym_index_ != SECTION_CODE
1041               && this->local_sym_index_ != TARGET_CODE
1042               && this->local_sym_index_ != INVALID_CODE
1043               && this->local_sym_index_ != 0
1044               && !this->is_section_symbol_);
1045   const unsigned int lsi = this->local_sym_index_;
1046   const Symbol_value<size>* symval = this->u1_.relobj->local_symbol(lsi);
1047   return symval->value(this->u1_.relobj, addend);
1048 }
1049
1050 // Reloc comparison.  This function sorts the dynamic relocs for the
1051 // benefit of the dynamic linker.  First we sort all relative relocs
1052 // to the front.  Among relative relocs, we sort by output address.
1053 // Among non-relative relocs, we sort by symbol index, then by output
1054 // address.
1055
1056 template<bool dynamic, int size, bool big_endian>
1057 int
1058 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
1059   compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
1060     const
1061 {
1062   if (this->is_relative_)
1063     {
1064       if (!r2.is_relative_)
1065         return -1;
1066       // Otherwise sort by reloc address below.
1067     }
1068   else if (r2.is_relative_)
1069     return 1;
1070   else
1071     {
1072       unsigned int sym1 = this->get_symbol_index();
1073       unsigned int sym2 = r2.get_symbol_index();
1074       if (sym1 < sym2)
1075         return -1;
1076       else if (sym1 > sym2)
1077         return 1;
1078       // Otherwise sort by reloc address.
1079     }
1080
1081   section_offset_type addr1 = this->get_address();
1082   section_offset_type addr2 = r2.get_address();
1083   if (addr1 < addr2)
1084     return -1;
1085   else if (addr1 > addr2)
1086     return 1;
1087
1088   // Final tie breaker, in order to generate the same output on any
1089   // host: reloc type.
1090   unsigned int type1 = this->type_;
1091   unsigned int type2 = r2.type_;
1092   if (type1 < type2)
1093     return -1;
1094   else if (type1 > type2)
1095     return 1;
1096
1097   // These relocs appear to be exactly the same.
1098   return 0;
1099 }
1100
1101 // Write out a Rela relocation.
1102
1103 template<bool dynamic, int size, bool big_endian>
1104 void
1105 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
1106     unsigned char* pov) const
1107 {
1108   elfcpp::Rela_write<size, big_endian> orel(pov);
1109   this->rel_.write_rel(&orel);
1110   Addend addend = this->addend_;
1111   if (this->rel_.is_target_specific())
1112     addend = parameters->target().reloc_addend(this->rel_.target_arg(),
1113                                                this->rel_.type(), addend);
1114   else if (this->rel_.is_symbolless())
1115     addend = this->rel_.symbol_value(addend);
1116   else if (this->rel_.is_local_section_symbol())
1117     addend = this->rel_.local_section_offset(addend);
1118   orel.put_r_addend(addend);
1119 }
1120
1121 // Output_data_reloc_base methods.
1122
1123 // Adjust the output section.
1124
1125 template<int sh_type, bool dynamic, int size, bool big_endian>
1126 void
1127 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
1128     ::do_adjust_output_section(Output_section* os)
1129 {
1130   if (sh_type == elfcpp::SHT_REL)
1131     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1132   else if (sh_type == elfcpp::SHT_RELA)
1133     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1134   else
1135     gold_unreachable();
1136
1137   // A STT_GNU_IFUNC symbol may require a IRELATIVE reloc when doing a
1138   // static link.  The backends will generate a dynamic reloc section
1139   // to hold this.  In that case we don't want to link to the dynsym
1140   // section, because there isn't one.
1141   if (!dynamic)
1142     os->set_should_link_to_symtab();
1143   else if (parameters->doing_static_link())
1144     ;
1145   else
1146     os->set_should_link_to_dynsym();
1147 }
1148
1149 // Write out relocation data.
1150
1151 template<int sh_type, bool dynamic, int size, bool big_endian>
1152 void
1153 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1154     Output_file* of)
1155 {
1156   const off_t off = this->offset();
1157   const off_t oview_size = this->data_size();
1158   unsigned char* const oview = of->get_output_view(off, oview_size);
1159
1160   if (this->sort_relocs())
1161     {
1162       gold_assert(dynamic);
1163       std::sort(this->relocs_.begin(), this->relocs_.end(),
1164                 Sort_relocs_comparison());
1165     }
1166
1167   unsigned char* pov = oview;
1168   for (typename Relocs::const_iterator p = this->relocs_.begin();
1169        p != this->relocs_.end();
1170        ++p)
1171     {
1172       p->write(pov);
1173       pov += reloc_size;
1174     }
1175
1176   gold_assert(pov - oview == oview_size);
1177
1178   of->write_output_view(off, oview_size, oview);
1179
1180   // We no longer need the relocation entries.
1181   this->relocs_.clear();
1182 }
1183
1184 // Class Output_relocatable_relocs.
1185
1186 template<int sh_type, int size, bool big_endian>
1187 void
1188 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1189 {
1190   this->set_data_size(this->rr_->output_reloc_count()
1191                       * Reloc_types<sh_type, size, big_endian>::reloc_size);
1192 }
1193
1194 // class Output_data_group.
1195
1196 template<int size, bool big_endian>
1197 Output_data_group<size, big_endian>::Output_data_group(
1198     Sized_relobj<size, big_endian>* relobj,
1199     section_size_type entry_count,
1200     elfcpp::Elf_Word flags,
1201     std::vector<unsigned int>* input_shndxes)
1202   : Output_section_data(entry_count * 4, 4, false),
1203     relobj_(relobj),
1204     flags_(flags)
1205 {
1206   this->input_shndxes_.swap(*input_shndxes);
1207 }
1208
1209 // Write out the section group, which means translating the section
1210 // indexes to apply to the output file.
1211
1212 template<int size, bool big_endian>
1213 void
1214 Output_data_group<size, big_endian>::do_write(Output_file* of)
1215 {
1216   const off_t off = this->offset();
1217   const section_size_type oview_size =
1218     convert_to_section_size_type(this->data_size());
1219   unsigned char* const oview = of->get_output_view(off, oview_size);
1220
1221   elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1222   elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1223   ++contents;
1224
1225   for (std::vector<unsigned int>::const_iterator p =
1226          this->input_shndxes_.begin();
1227        p != this->input_shndxes_.end();
1228        ++p, ++contents)
1229     {
1230       Output_section* os = this->relobj_->output_section(*p);
1231
1232       unsigned int output_shndx;
1233       if (os != NULL)
1234         output_shndx = os->out_shndx();
1235       else
1236         {
1237           this->relobj_->error(_("section group retained but "
1238                                  "group element discarded"));
1239           output_shndx = 0;
1240         }
1241
1242       elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1243     }
1244
1245   size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1246   gold_assert(wrote == oview_size);
1247
1248   of->write_output_view(off, oview_size, oview);
1249
1250   // We no longer need this information.
1251   this->input_shndxes_.clear();
1252 }
1253
1254 // Output_data_got::Got_entry methods.
1255
1256 // Write out the entry.
1257
1258 template<int size, bool big_endian>
1259 void
1260 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1261 {
1262   Valtype val = 0;
1263
1264   switch (this->local_sym_index_)
1265     {
1266     case GSYM_CODE:
1267       {
1268         // If the symbol is resolved locally, we need to write out the
1269         // link-time value, which will be relocated dynamically by a
1270         // RELATIVE relocation.
1271         Symbol* gsym = this->u_.gsym;
1272         if (this->use_plt_offset_ && gsym->has_plt_offset())
1273           val = (parameters->target().plt_section_for_global(gsym)->address()
1274                  + gsym->plt_offset());
1275         else
1276           {
1277             Sized_symbol<size>* sgsym;
1278             // This cast is a bit ugly.  We don't want to put a
1279             // virtual method in Symbol, because we want Symbol to be
1280             // as small as possible.
1281             sgsym = static_cast<Sized_symbol<size>*>(gsym);
1282             val = sgsym->value();
1283           }
1284       }
1285       break;
1286
1287     case CONSTANT_CODE:
1288       val = this->u_.constant;
1289       break;
1290
1291     default:
1292       {
1293         const Sized_relobj<size, big_endian>* object = this->u_.object;
1294         const unsigned int lsi = this->local_sym_index_;
1295         const Symbol_value<size>* symval = object->local_symbol(lsi);
1296         if (!this->use_plt_offset_)
1297           val = symval->value(this->u_.object, 0);
1298         else
1299           {
1300             const Output_data* plt =
1301               parameters->target().plt_section_for_local(object, lsi);
1302             val = plt->address() + object->local_plt_offset(lsi);
1303           }
1304       }
1305       break;
1306     }
1307
1308   elfcpp::Swap<size, big_endian>::writeval(pov, val);
1309 }
1310
1311 // Output_data_got methods.
1312
1313 // Add an entry for a global symbol to the GOT.  This returns true if
1314 // this is a new GOT entry, false if the symbol already had a GOT
1315 // entry.
1316
1317 template<int size, bool big_endian>
1318 bool
1319 Output_data_got<size, big_endian>::add_global(
1320     Symbol* gsym,
1321     unsigned int got_type)
1322 {
1323   if (gsym->has_got_offset(got_type))
1324     return false;
1325
1326   this->entries_.push_back(Got_entry(gsym, false));
1327   this->set_got_size();
1328   gsym->set_got_offset(got_type, this->last_got_offset());
1329   return true;
1330 }
1331
1332 // Like add_global, but use the PLT offset.
1333
1334 template<int size, bool big_endian>
1335 bool
1336 Output_data_got<size, big_endian>::add_global_plt(Symbol* gsym,
1337                                                   unsigned int got_type)
1338 {
1339   if (gsym->has_got_offset(got_type))
1340     return false;
1341
1342   this->entries_.push_back(Got_entry(gsym, true));
1343   this->set_got_size();
1344   gsym->set_got_offset(got_type, this->last_got_offset());
1345   return true;
1346 }
1347
1348 // Add an entry for a global symbol to the GOT, and add a dynamic
1349 // relocation of type R_TYPE for the GOT entry.
1350
1351 template<int size, bool big_endian>
1352 void
1353 Output_data_got<size, big_endian>::add_global_with_rel(
1354     Symbol* gsym,
1355     unsigned int got_type,
1356     Rel_dyn* rel_dyn,
1357     unsigned int r_type)
1358 {
1359   if (gsym->has_got_offset(got_type))
1360     return;
1361
1362   this->entries_.push_back(Got_entry());
1363   this->set_got_size();
1364   unsigned int got_offset = this->last_got_offset();
1365   gsym->set_got_offset(got_type, got_offset);
1366   rel_dyn->add_global(gsym, r_type, this, got_offset);
1367 }
1368
1369 template<int size, bool big_endian>
1370 void
1371 Output_data_got<size, big_endian>::add_global_with_rela(
1372     Symbol* gsym,
1373     unsigned int got_type,
1374     Rela_dyn* rela_dyn,
1375     unsigned int r_type)
1376 {
1377   if (gsym->has_got_offset(got_type))
1378     return;
1379
1380   this->entries_.push_back(Got_entry());
1381   this->set_got_size();
1382   unsigned int got_offset = this->last_got_offset();
1383   gsym->set_got_offset(got_type, got_offset);
1384   rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1385 }
1386
1387 // Add a pair of entries for a global symbol to the GOT, and add
1388 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1389 // If R_TYPE_2 == 0, add the second entry with no relocation.
1390 template<int size, bool big_endian>
1391 void
1392 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1393     Symbol* gsym,
1394     unsigned int got_type,
1395     Rel_dyn* rel_dyn,
1396     unsigned int r_type_1,
1397     unsigned int r_type_2)
1398 {
1399   if (gsym->has_got_offset(got_type))
1400     return;
1401
1402   this->entries_.push_back(Got_entry());
1403   unsigned int got_offset = this->last_got_offset();
1404   gsym->set_got_offset(got_type, got_offset);
1405   rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1406
1407   this->entries_.push_back(Got_entry());
1408   if (r_type_2 != 0)
1409     {
1410       got_offset = this->last_got_offset();
1411       rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1412     }
1413
1414   this->set_got_size();
1415 }
1416
1417 template<int size, bool big_endian>
1418 void
1419 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1420     Symbol* gsym,
1421     unsigned int got_type,
1422     Rela_dyn* rela_dyn,
1423     unsigned int r_type_1,
1424     unsigned int r_type_2)
1425 {
1426   if (gsym->has_got_offset(got_type))
1427     return;
1428
1429   this->entries_.push_back(Got_entry());
1430   unsigned int got_offset = this->last_got_offset();
1431   gsym->set_got_offset(got_type, got_offset);
1432   rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1433
1434   this->entries_.push_back(Got_entry());
1435   if (r_type_2 != 0)
1436     {
1437       got_offset = this->last_got_offset();
1438       rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1439     }
1440
1441   this->set_got_size();
1442 }
1443
1444 // Add an entry for a local symbol to the GOT.  This returns true if
1445 // this is a new GOT entry, false if the symbol already has a GOT
1446 // entry.
1447
1448 template<int size, bool big_endian>
1449 bool
1450 Output_data_got<size, big_endian>::add_local(
1451     Sized_relobj<size, big_endian>* object,
1452     unsigned int symndx,
1453     unsigned int got_type)
1454 {
1455   if (object->local_has_got_offset(symndx, got_type))
1456     return false;
1457
1458   this->entries_.push_back(Got_entry(object, symndx, false));
1459   this->set_got_size();
1460   object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1461   return true;
1462 }
1463
1464 // Like add_local, but use the PLT offset.
1465
1466 template<int size, bool big_endian>
1467 bool
1468 Output_data_got<size, big_endian>::add_local_plt(
1469     Sized_relobj<size, big_endian>* object,
1470     unsigned int symndx,
1471     unsigned int got_type)
1472 {
1473   if (object->local_has_got_offset(symndx, got_type))
1474     return false;
1475
1476   this->entries_.push_back(Got_entry(object, symndx, true));
1477   this->set_got_size();
1478   object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1479   return true;
1480 }
1481
1482 // Add an entry for a local symbol to the GOT, and add a dynamic
1483 // relocation of type R_TYPE for the GOT entry.
1484
1485 template<int size, bool big_endian>
1486 void
1487 Output_data_got<size, big_endian>::add_local_with_rel(
1488     Sized_relobj<size, big_endian>* object,
1489     unsigned int symndx,
1490     unsigned int got_type,
1491     Rel_dyn* rel_dyn,
1492     unsigned int r_type)
1493 {
1494   if (object->local_has_got_offset(symndx, got_type))
1495     return;
1496
1497   this->entries_.push_back(Got_entry());
1498   this->set_got_size();
1499   unsigned int got_offset = this->last_got_offset();
1500   object->set_local_got_offset(symndx, got_type, got_offset);
1501   rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1502 }
1503
1504 template<int size, bool big_endian>
1505 void
1506 Output_data_got<size, big_endian>::add_local_with_rela(
1507     Sized_relobj<size, big_endian>* object,
1508     unsigned int symndx,
1509     unsigned int got_type,
1510     Rela_dyn* rela_dyn,
1511     unsigned int r_type)
1512 {
1513   if (object->local_has_got_offset(symndx, got_type))
1514     return;
1515
1516   this->entries_.push_back(Got_entry());
1517   this->set_got_size();
1518   unsigned int got_offset = this->last_got_offset();
1519   object->set_local_got_offset(symndx, got_type, got_offset);
1520   rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1521 }
1522
1523 // Add a pair of entries for a local symbol to the GOT, and add
1524 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1525 // If R_TYPE_2 == 0, add the second entry with no relocation.
1526 template<int size, bool big_endian>
1527 void
1528 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1529     Sized_relobj<size, big_endian>* object,
1530     unsigned int symndx,
1531     unsigned int shndx,
1532     unsigned int got_type,
1533     Rel_dyn* rel_dyn,
1534     unsigned int r_type_1,
1535     unsigned int r_type_2)
1536 {
1537   if (object->local_has_got_offset(symndx, got_type))
1538     return;
1539
1540   this->entries_.push_back(Got_entry());
1541   unsigned int got_offset = this->last_got_offset();
1542   object->set_local_got_offset(symndx, got_type, got_offset);
1543   Output_section* os = object->output_section(shndx);
1544   rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1545
1546   this->entries_.push_back(Got_entry(object, symndx, false));
1547   if (r_type_2 != 0)
1548     {
1549       got_offset = this->last_got_offset();
1550       rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1551     }
1552
1553   this->set_got_size();
1554 }
1555
1556 template<int size, bool big_endian>
1557 void
1558 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1559     Sized_relobj<size, big_endian>* object,
1560     unsigned int symndx,
1561     unsigned int shndx,
1562     unsigned int got_type,
1563     Rela_dyn* rela_dyn,
1564     unsigned int r_type_1,
1565     unsigned int r_type_2)
1566 {
1567   if (object->local_has_got_offset(symndx, got_type))
1568     return;
1569
1570   this->entries_.push_back(Got_entry());
1571   unsigned int got_offset = this->last_got_offset();
1572   object->set_local_got_offset(symndx, got_type, got_offset);
1573   Output_section* os = object->output_section(shndx);
1574   rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1575
1576   this->entries_.push_back(Got_entry(object, symndx, false));
1577   if (r_type_2 != 0)
1578     {
1579       got_offset = this->last_got_offset();
1580       rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1581     }
1582
1583   this->set_got_size();
1584 }
1585
1586 // Write out the GOT.
1587
1588 template<int size, bool big_endian>
1589 void
1590 Output_data_got<size, big_endian>::do_write(Output_file* of)
1591 {
1592   const int add = size / 8;
1593
1594   const off_t off = this->offset();
1595   const off_t oview_size = this->data_size();
1596   unsigned char* const oview = of->get_output_view(off, oview_size);
1597
1598   unsigned char* pov = oview;
1599   for (typename Got_entries::const_iterator p = this->entries_.begin();
1600        p != this->entries_.end();
1601        ++p)
1602     {
1603       p->write(pov);
1604       pov += add;
1605     }
1606
1607   gold_assert(pov - oview == oview_size);
1608
1609   of->write_output_view(off, oview_size, oview);
1610
1611   // We no longer need the GOT entries.
1612   this->entries_.clear();
1613 }
1614
1615 // Output_data_dynamic::Dynamic_entry methods.
1616
1617 // Write out the entry.
1618
1619 template<int size, bool big_endian>
1620 void
1621 Output_data_dynamic::Dynamic_entry::write(
1622     unsigned char* pov,
1623     const Stringpool* pool) const
1624 {
1625   typename elfcpp::Elf_types<size>::Elf_WXword val;
1626   switch (this->offset_)
1627     {
1628     case DYNAMIC_NUMBER:
1629       val = this->u_.val;
1630       break;
1631
1632     case DYNAMIC_SECTION_SIZE:
1633       val = this->u_.od->data_size();
1634       if (this->od2 != NULL)
1635         val += this->od2->data_size();
1636       break;
1637
1638     case DYNAMIC_SYMBOL:
1639       {
1640         const Sized_symbol<size>* s =
1641           static_cast<const Sized_symbol<size>*>(this->u_.sym);
1642         val = s->value();
1643       }
1644       break;
1645
1646     case DYNAMIC_STRING:
1647       val = pool->get_offset(this->u_.str);
1648       break;
1649
1650     default:
1651       val = this->u_.od->address() + this->offset_;
1652       break;
1653     }
1654
1655   elfcpp::Dyn_write<size, big_endian> dw(pov);
1656   dw.put_d_tag(this->tag_);
1657   dw.put_d_val(val);
1658 }
1659
1660 // Output_data_dynamic methods.
1661
1662 // Adjust the output section to set the entry size.
1663
1664 void
1665 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1666 {
1667   if (parameters->target().get_size() == 32)
1668     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1669   else if (parameters->target().get_size() == 64)
1670     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1671   else
1672     gold_unreachable();
1673 }
1674
1675 // Set the final data size.
1676
1677 void
1678 Output_data_dynamic::set_final_data_size()
1679 {
1680   // Add the terminating entry if it hasn't been added.
1681   // Because of relaxation, we can run this multiple times.
1682   if (this->entries_.empty() || this->entries_.back().tag() != elfcpp::DT_NULL)
1683     {
1684       int extra = parameters->options().spare_dynamic_tags();
1685       for (int i = 0; i < extra; ++i)
1686         this->add_constant(elfcpp::DT_NULL, 0);
1687       this->add_constant(elfcpp::DT_NULL, 0);
1688     }
1689
1690   int dyn_size;
1691   if (parameters->target().get_size() == 32)
1692     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1693   else if (parameters->target().get_size() == 64)
1694     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1695   else
1696     gold_unreachable();
1697   this->set_data_size(this->entries_.size() * dyn_size);
1698 }
1699
1700 // Write out the dynamic entries.
1701
1702 void
1703 Output_data_dynamic::do_write(Output_file* of)
1704 {
1705   switch (parameters->size_and_endianness())
1706     {
1707 #ifdef HAVE_TARGET_32_LITTLE
1708     case Parameters::TARGET_32_LITTLE:
1709       this->sized_write<32, false>(of);
1710       break;
1711 #endif
1712 #ifdef HAVE_TARGET_32_BIG
1713     case Parameters::TARGET_32_BIG:
1714       this->sized_write<32, true>(of);
1715       break;
1716 #endif
1717 #ifdef HAVE_TARGET_64_LITTLE
1718     case Parameters::TARGET_64_LITTLE:
1719       this->sized_write<64, false>(of);
1720       break;
1721 #endif
1722 #ifdef HAVE_TARGET_64_BIG
1723     case Parameters::TARGET_64_BIG:
1724       this->sized_write<64, true>(of);
1725       break;
1726 #endif
1727     default:
1728       gold_unreachable();
1729     }
1730 }
1731
1732 template<int size, bool big_endian>
1733 void
1734 Output_data_dynamic::sized_write(Output_file* of)
1735 {
1736   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1737
1738   const off_t offset = this->offset();
1739   const off_t oview_size = this->data_size();
1740   unsigned char* const oview = of->get_output_view(offset, oview_size);
1741
1742   unsigned char* pov = oview;
1743   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1744        p != this->entries_.end();
1745        ++p)
1746     {
1747       p->write<size, big_endian>(pov, this->pool_);
1748       pov += dyn_size;
1749     }
1750
1751   gold_assert(pov - oview == oview_size);
1752
1753   of->write_output_view(offset, oview_size, oview);
1754
1755   // We no longer need the dynamic entries.
1756   this->entries_.clear();
1757 }
1758
1759 // Class Output_symtab_xindex.
1760
1761 void
1762 Output_symtab_xindex::do_write(Output_file* of)
1763 {
1764   const off_t offset = this->offset();
1765   const off_t oview_size = this->data_size();
1766   unsigned char* const oview = of->get_output_view(offset, oview_size);
1767
1768   memset(oview, 0, oview_size);
1769
1770   if (parameters->target().is_big_endian())
1771     this->endian_do_write<true>(oview);
1772   else
1773     this->endian_do_write<false>(oview);
1774
1775   of->write_output_view(offset, oview_size, oview);
1776
1777   // We no longer need the data.
1778   this->entries_.clear();
1779 }
1780
1781 template<bool big_endian>
1782 void
1783 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1784 {
1785   for (Xindex_entries::const_iterator p = this->entries_.begin();
1786        p != this->entries_.end();
1787        ++p)
1788     {
1789       unsigned int symndx = p->first;
1790       gold_assert(symndx * 4 < this->data_size());
1791       elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1792     }
1793 }
1794
1795 // Output_section::Input_section methods.
1796
1797 // Return the data size.  For an input section we store the size here.
1798 // For an Output_section_data, we have to ask it for the size.
1799
1800 off_t
1801 Output_section::Input_section::data_size() const
1802 {
1803   if (this->is_input_section())
1804     return this->u1_.data_size;
1805   else
1806     return this->u2_.posd->data_size();
1807 }
1808
1809 // Return the object for an input section.
1810
1811 Relobj*
1812 Output_section::Input_section::relobj() const
1813 {
1814   if (this->is_input_section())
1815     return this->u2_.object;
1816   else if (this->is_merge_section())
1817     {
1818       gold_assert(this->u2_.pomb->first_relobj() != NULL);
1819       return this->u2_.pomb->first_relobj();
1820     }
1821   else if (this->is_relaxed_input_section())
1822     return this->u2_.poris->relobj();
1823   else
1824     gold_unreachable();
1825 }
1826
1827 // Return the input section index for an input section.
1828
1829 unsigned int
1830 Output_section::Input_section::shndx() const
1831 {
1832   if (this->is_input_section())
1833     return this->shndx_;
1834   else if (this->is_merge_section())
1835     {
1836       gold_assert(this->u2_.pomb->first_relobj() != NULL);
1837       return this->u2_.pomb->first_shndx();
1838     }
1839   else if (this->is_relaxed_input_section())
1840     return this->u2_.poris->shndx();
1841   else
1842     gold_unreachable();
1843 }
1844
1845 // Set the address and file offset.
1846
1847 void
1848 Output_section::Input_section::set_address_and_file_offset(
1849     uint64_t address,
1850     off_t file_offset,
1851     off_t section_file_offset)
1852 {
1853   if (this->is_input_section())
1854     this->u2_.object->set_section_offset(this->shndx_,
1855                                          file_offset - section_file_offset);
1856   else
1857     this->u2_.posd->set_address_and_file_offset(address, file_offset);
1858 }
1859
1860 // Reset the address and file offset.
1861
1862 void
1863 Output_section::Input_section::reset_address_and_file_offset()
1864 {
1865   if (!this->is_input_section())
1866     this->u2_.posd->reset_address_and_file_offset();
1867 }
1868
1869 // Finalize the data size.
1870
1871 void
1872 Output_section::Input_section::finalize_data_size()
1873 {
1874   if (!this->is_input_section())
1875     this->u2_.posd->finalize_data_size();
1876 }
1877
1878 // Try to turn an input offset into an output offset.  We want to
1879 // return the output offset relative to the start of this
1880 // Input_section in the output section.
1881
1882 inline bool
1883 Output_section::Input_section::output_offset(
1884     const Relobj* object,
1885     unsigned int shndx,
1886     section_offset_type offset,
1887     section_offset_type* poutput) const
1888 {
1889   if (!this->is_input_section())
1890     return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1891   else
1892     {
1893       if (this->shndx_ != shndx || this->u2_.object != object)
1894         return false;
1895       *poutput = offset;
1896       return true;
1897     }
1898 }
1899
1900 // Return whether this is the merge section for the input section
1901 // SHNDX in OBJECT.
1902
1903 inline bool
1904 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1905                                                     unsigned int shndx) const
1906 {
1907   if (this->is_input_section())
1908     return false;
1909   return this->u2_.posd->is_merge_section_for(object, shndx);
1910 }
1911
1912 // Write out the data.  We don't have to do anything for an input
1913 // section--they are handled via Object::relocate--but this is where
1914 // we write out the data for an Output_section_data.
1915
1916 void
1917 Output_section::Input_section::write(Output_file* of)
1918 {
1919   if (!this->is_input_section())
1920     this->u2_.posd->write(of);
1921 }
1922
1923 // Write the data to a buffer.  As for write(), we don't have to do
1924 // anything for an input section.
1925
1926 void
1927 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1928 {
1929   if (!this->is_input_section())
1930     this->u2_.posd->write_to_buffer(buffer);
1931 }
1932
1933 // Print to a map file.
1934
1935 void
1936 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1937 {
1938   switch (this->shndx_)
1939     {
1940     case OUTPUT_SECTION_CODE:
1941     case MERGE_DATA_SECTION_CODE:
1942     case MERGE_STRING_SECTION_CODE:
1943       this->u2_.posd->print_to_mapfile(mapfile);
1944       break;
1945
1946     case RELAXED_INPUT_SECTION_CODE:
1947       {
1948         Output_relaxed_input_section* relaxed_section =
1949           this->relaxed_input_section();
1950         mapfile->print_input_section(relaxed_section->relobj(),
1951                                      relaxed_section->shndx());
1952       }
1953       break;
1954     default:
1955       mapfile->print_input_section(this->u2_.object, this->shndx_);
1956       break;
1957     }
1958 }
1959
1960 // Output_section methods.
1961
1962 // Construct an Output_section.  NAME will point into a Stringpool.
1963
1964 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1965                                elfcpp::Elf_Xword flags)
1966   : name_(name),
1967     addralign_(0),
1968     entsize_(0),
1969     load_address_(0),
1970     link_section_(NULL),
1971     link_(0),
1972     info_section_(NULL),
1973     info_symndx_(NULL),
1974     info_(0),
1975     type_(type),
1976     flags_(flags),
1977     order_(ORDER_INVALID),
1978     out_shndx_(-1U),
1979     symtab_index_(0),
1980     dynsym_index_(0),
1981     input_sections_(),
1982     first_input_offset_(0),
1983     fills_(),
1984     postprocessing_buffer_(NULL),
1985     needs_symtab_index_(false),
1986     needs_dynsym_index_(false),
1987     should_link_to_symtab_(false),
1988     should_link_to_dynsym_(false),
1989     after_input_sections_(false),
1990     requires_postprocessing_(false),
1991     found_in_sections_clause_(false),
1992     has_load_address_(false),
1993     info_uses_section_index_(false),
1994     input_section_order_specified_(false),
1995     may_sort_attached_input_sections_(false),
1996     must_sort_attached_input_sections_(false),
1997     attached_input_sections_are_sorted_(false),
1998     is_relro_(false),
1999     is_small_section_(false),
2000     is_large_section_(false),
2001     generate_code_fills_at_write_(false),
2002     is_entsize_zero_(false),
2003     section_offsets_need_adjustment_(false),
2004     is_noload_(false),
2005     always_keeps_input_sections_(false),
2006     tls_offset_(0),
2007     checkpoint_(NULL),
2008     lookup_maps_(new Output_section_lookup_maps)
2009 {
2010   // An unallocated section has no address.  Forcing this means that
2011   // we don't need special treatment for symbols defined in debug
2012   // sections.
2013   if ((flags & elfcpp::SHF_ALLOC) == 0)
2014     this->set_address(0);
2015 }
2016
2017 Output_section::~Output_section()
2018 {
2019   delete this->checkpoint_;
2020 }
2021
2022 // Set the entry size.
2023
2024 void
2025 Output_section::set_entsize(uint64_t v)
2026 {
2027   if (this->is_entsize_zero_)
2028     ;
2029   else if (this->entsize_ == 0)
2030     this->entsize_ = v;
2031   else if (this->entsize_ != v)
2032     {
2033       this->entsize_ = 0;
2034       this->is_entsize_zero_ = 1;
2035     }
2036 }
2037
2038 // Add the input section SHNDX, with header SHDR, named SECNAME, in
2039 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
2040 // relocation section which applies to this section, or 0 if none, or
2041 // -1U if more than one.  Return the offset of the input section
2042 // within the output section.  Return -1 if the input section will
2043 // receive special handling.  In the normal case we don't always keep
2044 // track of input sections for an Output_section.  Instead, each
2045 // Object keeps track of the Output_section for each of its input
2046 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
2047 // track of input sections here; this is used when SECTIONS appears in
2048 // a linker script.
2049
2050 template<int size, bool big_endian>
2051 off_t
2052 Output_section::add_input_section(Layout* layout,
2053                                   Sized_relobj<size, big_endian>* object,
2054                                   unsigned int shndx,
2055                                   const char* secname,
2056                                   const elfcpp::Shdr<size, big_endian>& shdr,
2057                                   unsigned int reloc_shndx,
2058                                   bool have_sections_script)
2059 {
2060   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
2061   if ((addralign & (addralign - 1)) != 0)
2062     {
2063       object->error(_("invalid alignment %lu for section \"%s\""),
2064                     static_cast<unsigned long>(addralign), secname);
2065       addralign = 1;
2066     }
2067
2068   if (addralign > this->addralign_)
2069     this->addralign_ = addralign;
2070
2071   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
2072   uint64_t entsize = shdr.get_sh_entsize();
2073
2074   // .debug_str is a mergeable string section, but is not always so
2075   // marked by compilers.  Mark manually here so we can optimize.
2076   if (strcmp(secname, ".debug_str") == 0)
2077     {
2078       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
2079       entsize = 1;
2080     }
2081
2082   this->update_flags_for_input_section(sh_flags);
2083   this->set_entsize(entsize);
2084
2085   // If this is a SHF_MERGE section, we pass all the input sections to
2086   // a Output_data_merge.  We don't try to handle relocations for such
2087   // a section.  We don't try to handle empty merge sections--they
2088   // mess up the mappings, and are useless anyhow.
2089   if ((sh_flags & elfcpp::SHF_MERGE) != 0
2090       && reloc_shndx == 0
2091       && shdr.get_sh_size() > 0)
2092     {
2093       // Keep information about merged input sections for rebuilding fast
2094       // lookup maps if we have sections-script or we do relaxation.
2095       bool keeps_input_sections = (this->always_keeps_input_sections_
2096                                    || have_sections_script
2097                                    || parameters->target().may_relax());
2098
2099       if (this->add_merge_input_section(object, shndx, sh_flags, entsize,
2100                                         addralign, keeps_input_sections))
2101         {
2102           // Tell the relocation routines that they need to call the
2103           // output_offset method to determine the final address.
2104           return -1;
2105         }
2106     }
2107
2108   off_t offset_in_section = this->current_data_size_for_child();
2109   off_t aligned_offset_in_section = align_address(offset_in_section,
2110                                                   addralign);
2111
2112   // Determine if we want to delay code-fill generation until the output
2113   // section is written.  When the target is relaxing, we want to delay fill
2114   // generating to avoid adjusting them during relaxation.  Also, if we are
2115   // sorting input sections we must delay fill generation.
2116   if (!this->generate_code_fills_at_write_
2117       && !have_sections_script
2118       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2119       && parameters->target().has_code_fill()
2120       && (parameters->target().may_relax()
2121           || parameters->options().section_ordering_file()))
2122     {
2123       gold_assert(this->fills_.empty());
2124       this->generate_code_fills_at_write_ = true;
2125     }
2126
2127   if (aligned_offset_in_section > offset_in_section
2128       && !this->generate_code_fills_at_write_
2129       && !have_sections_script
2130       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2131       && parameters->target().has_code_fill())
2132     {
2133       // We need to add some fill data.  Using fill_list_ when
2134       // possible is an optimization, since we will often have fill
2135       // sections without input sections.
2136       off_t fill_len = aligned_offset_in_section - offset_in_section;
2137       if (this->input_sections_.empty())
2138         this->fills_.push_back(Fill(offset_in_section, fill_len));
2139       else
2140         {
2141           std::string fill_data(parameters->target().code_fill(fill_len));
2142           Output_data_const* odc = new Output_data_const(fill_data, 1);
2143           this->input_sections_.push_back(Input_section(odc));
2144         }
2145     }
2146
2147   section_size_type input_section_size = shdr.get_sh_size();
2148   section_size_type uncompressed_size;
2149   if (object->section_is_compressed(shndx, &uncompressed_size))
2150     input_section_size = uncompressed_size;
2151
2152   this->set_current_data_size_for_child(aligned_offset_in_section
2153                                         + input_section_size);
2154
2155   // We need to keep track of this section if we are already keeping
2156   // track of sections, or if we are relaxing.  Also, if this is a
2157   // section which requires sorting, or which may require sorting in
2158   // the future, we keep track of the sections.  If the
2159   // --section-ordering-file option is used to specify the order of
2160   // sections, we need to keep track of sections.
2161   if (this->always_keeps_input_sections_
2162       || have_sections_script
2163       || !this->input_sections_.empty()
2164       || this->may_sort_attached_input_sections()
2165       || this->must_sort_attached_input_sections()
2166       || parameters->options().user_set_Map()
2167       || parameters->target().may_relax()
2168       || parameters->options().section_ordering_file())
2169     {
2170       Input_section isecn(object, shndx, input_section_size, addralign);
2171       if (parameters->options().section_ordering_file())
2172         {
2173           unsigned int section_order_index =
2174             layout->find_section_order_index(std::string(secname));
2175           if (section_order_index != 0)
2176             {
2177               isecn.set_section_order_index(section_order_index);
2178               this->set_input_section_order_specified();
2179             }
2180         }
2181       this->input_sections_.push_back(isecn);
2182     }
2183
2184   return aligned_offset_in_section;
2185 }
2186
2187 // Add arbitrary data to an output section.
2188
2189 void
2190 Output_section::add_output_section_data(Output_section_data* posd)
2191 {
2192   Input_section inp(posd);
2193   this->add_output_section_data(&inp);
2194
2195   if (posd->is_data_size_valid())
2196     {
2197       off_t offset_in_section = this->current_data_size_for_child();
2198       off_t aligned_offset_in_section = align_address(offset_in_section,
2199                                                       posd->addralign());
2200       this->set_current_data_size_for_child(aligned_offset_in_section
2201                                             + posd->data_size());
2202     }
2203 }
2204
2205 // Add a relaxed input section.
2206
2207 void
2208 Output_section::add_relaxed_input_section(Layout* layout,
2209                                           Output_relaxed_input_section* poris,
2210                                           const std::string& name)
2211 {
2212   Input_section inp(poris);
2213
2214   // If the --section-ordering-file option is used to specify the order of
2215   // sections, we need to keep track of sections.
2216   if (parameters->options().section_ordering_file())
2217     {
2218       unsigned int section_order_index =
2219         layout->find_section_order_index(name);
2220       if (section_order_index != 0)
2221         {
2222           inp.set_section_order_index(section_order_index);
2223           this->set_input_section_order_specified();
2224         }
2225     }
2226
2227   this->add_output_section_data(&inp);
2228   if (this->lookup_maps_->is_valid())
2229     this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2230                                                   poris->shndx(), poris);
2231
2232   // For a relaxed section, we use the current data size.  Linker scripts
2233   // get all the input sections, including relaxed one from an output
2234   // section and add them back to them same output section to compute the
2235   // output section size.  If we do not account for sizes of relaxed input
2236   // sections,  an output section would be incorrectly sized.
2237   off_t offset_in_section = this->current_data_size_for_child();
2238   off_t aligned_offset_in_section = align_address(offset_in_section,
2239                                                   poris->addralign());
2240   this->set_current_data_size_for_child(aligned_offset_in_section
2241                                         + poris->current_data_size());
2242 }
2243
2244 // Add arbitrary data to an output section by Input_section.
2245
2246 void
2247 Output_section::add_output_section_data(Input_section* inp)
2248 {
2249   if (this->input_sections_.empty())
2250     this->first_input_offset_ = this->current_data_size_for_child();
2251
2252   this->input_sections_.push_back(*inp);
2253
2254   uint64_t addralign = inp->addralign();
2255   if (addralign > this->addralign_)
2256     this->addralign_ = addralign;
2257
2258   inp->set_output_section(this);
2259 }
2260
2261 // Add a merge section to an output section.
2262
2263 void
2264 Output_section::add_output_merge_section(Output_section_data* posd,
2265                                          bool is_string, uint64_t entsize)
2266 {
2267   Input_section inp(posd, is_string, entsize);
2268   this->add_output_section_data(&inp);
2269 }
2270
2271 // Add an input section to a SHF_MERGE section.
2272
2273 bool
2274 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2275                                         uint64_t flags, uint64_t entsize,
2276                                         uint64_t addralign,
2277                                         bool keeps_input_sections)
2278 {
2279   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2280
2281   // We only merge strings if the alignment is not more than the
2282   // character size.  This could be handled, but it's unusual.
2283   if (is_string && addralign > entsize)
2284     return false;
2285
2286   // We cannot restore merged input section states.
2287   gold_assert(this->checkpoint_ == NULL);
2288
2289   // Look up merge sections by required properties.
2290   // Currently, we only invalidate the lookup maps in script processing
2291   // and relaxation.  We should not have done either when we reach here.
2292   // So we assume that the lookup maps are valid to simply code.
2293   gold_assert(this->lookup_maps_->is_valid());
2294   Merge_section_properties msp(is_string, entsize, addralign);
2295   Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp);
2296   bool is_new = false;
2297   if (pomb != NULL)
2298     {
2299       gold_assert(pomb->is_string() == is_string
2300                   && pomb->entsize() == entsize
2301                   && pomb->addralign() == addralign);
2302     }
2303   else
2304     {
2305       // Create a new Output_merge_data or Output_merge_string_data.
2306       if (!is_string)
2307         pomb = new Output_merge_data(entsize, addralign);
2308       else
2309         {
2310           switch (entsize)
2311             {
2312             case 1:
2313               pomb = new Output_merge_string<char>(addralign);
2314               break;
2315             case 2:
2316               pomb = new Output_merge_string<uint16_t>(addralign);
2317               break;
2318             case 4:
2319               pomb = new Output_merge_string<uint32_t>(addralign);
2320               break;
2321             default:
2322               return false;
2323             }
2324         }
2325       // If we need to do script processing or relaxation, we need to keep
2326       // the original input sections to rebuild the fast lookup maps.
2327       if (keeps_input_sections)
2328         pomb->set_keeps_input_sections();
2329       is_new = true;
2330     }
2331
2332   if (pomb->add_input_section(object, shndx))
2333     {
2334       // Add new merge section to this output section and link merge
2335       // section properties to new merge section in map.
2336       if (is_new)
2337         {
2338           this->add_output_merge_section(pomb, is_string, entsize);
2339           this->lookup_maps_->add_merge_section(msp, pomb);
2340         }
2341
2342       // Add input section to new merge section and link input section to new
2343       // merge section in map.
2344       this->lookup_maps_->add_merge_input_section(object, shndx, pomb);
2345       return true;
2346     }
2347   else
2348     {
2349       // If add_input_section failed, delete new merge section to avoid
2350       // exporting empty merge sections in Output_section::get_input_section.
2351       if (is_new)
2352         delete pomb;
2353       return false;
2354     }
2355 }
2356
2357 // Build a relaxation map to speed up relaxation of existing input sections.
2358 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2359
2360 void
2361 Output_section::build_relaxation_map(
2362   const Input_section_list& input_sections,
2363   size_t limit,
2364   Relaxation_map* relaxation_map) const
2365 {
2366   for (size_t i = 0; i < limit; ++i)
2367     {
2368       const Input_section& is(input_sections[i]);
2369       if (is.is_input_section() || is.is_relaxed_input_section())
2370         {
2371           Section_id sid(is.relobj(), is.shndx());
2372           (*relaxation_map)[sid] = i;
2373         }
2374     }
2375 }
2376
2377 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2378 // sections in RELAXED_SECTIONS.  MAP is a prebuilt map from section id
2379 // indices of INPUT_SECTIONS.
2380
2381 void
2382 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2383   const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2384   const Relaxation_map& map,
2385   Input_section_list* input_sections)
2386 {
2387   for (size_t i = 0; i < relaxed_sections.size(); ++i)
2388     {
2389       Output_relaxed_input_section* poris = relaxed_sections[i];
2390       Section_id sid(poris->relobj(), poris->shndx());
2391       Relaxation_map::const_iterator p = map.find(sid);
2392       gold_assert(p != map.end());
2393       gold_assert((*input_sections)[p->second].is_input_section());
2394
2395       // Remember section order index of original input section
2396       // if it is set.  Copy it to the relaxed input section.
2397       unsigned int soi =
2398         (*input_sections)[p->second].section_order_index();
2399       (*input_sections)[p->second] = Input_section(poris);
2400       (*input_sections)[p->second].set_section_order_index(soi);
2401     }
2402 }
2403
2404 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2405 // is a vector of pointers to Output_relaxed_input_section or its derived
2406 // classes.  The relaxed sections must correspond to existing input sections.
2407
2408 void
2409 Output_section::convert_input_sections_to_relaxed_sections(
2410   const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2411 {
2412   gold_assert(parameters->target().may_relax());
2413
2414   // We want to make sure that restore_states does not undo the effect of
2415   // this.  If there is no checkpoint active, just search the current
2416   // input section list and replace the sections there.  If there is
2417   // a checkpoint, also replace the sections there.
2418
2419   // By default, we look at the whole list.
2420   size_t limit = this->input_sections_.size();
2421
2422   if (this->checkpoint_ != NULL)
2423     {
2424       // Replace input sections with relaxed input section in the saved
2425       // copy of the input section list.
2426       if (this->checkpoint_->input_sections_saved())
2427         {
2428           Relaxation_map map;
2429           this->build_relaxation_map(
2430                     *(this->checkpoint_->input_sections()),
2431                     this->checkpoint_->input_sections()->size(),
2432                     &map);
2433           this->convert_input_sections_in_list_to_relaxed_sections(
2434                     relaxed_sections,
2435                     map,
2436                     this->checkpoint_->input_sections());
2437         }
2438       else
2439         {
2440           // We have not copied the input section list yet.  Instead, just
2441           // look at the portion that would be saved.
2442           limit = this->checkpoint_->input_sections_size();
2443         }
2444     }
2445
2446   // Convert input sections in input_section_list.
2447   Relaxation_map map;
2448   this->build_relaxation_map(this->input_sections_, limit, &map);
2449   this->convert_input_sections_in_list_to_relaxed_sections(
2450             relaxed_sections,
2451             map,
2452             &this->input_sections_);
2453
2454   // Update fast look-up map.
2455   if (this->lookup_maps_->is_valid())
2456     for (size_t i = 0; i < relaxed_sections.size(); ++i)
2457       {
2458         Output_relaxed_input_section* poris = relaxed_sections[i];
2459         this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2460                                                       poris->shndx(), poris);
2461       }
2462 }
2463
2464 // Update the output section flags based on input section flags.
2465
2466 void
2467 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2468 {
2469   // If we created the section with SHF_ALLOC clear, we set the
2470   // address.  If we are now setting the SHF_ALLOC flag, we need to
2471   // undo that.
2472   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2473       && (flags & elfcpp::SHF_ALLOC) != 0)
2474     this->mark_address_invalid();
2475
2476   this->flags_ |= (flags
2477                    & (elfcpp::SHF_WRITE
2478                       | elfcpp::SHF_ALLOC
2479                       | elfcpp::SHF_EXECINSTR));
2480
2481   if ((flags & elfcpp::SHF_MERGE) == 0)
2482     this->flags_ &=~ elfcpp::SHF_MERGE;
2483   else
2484     {
2485       if (this->current_data_size_for_child() == 0)
2486         this->flags_ |= elfcpp::SHF_MERGE;
2487     }
2488
2489   if ((flags & elfcpp::SHF_STRINGS) == 0)
2490     this->flags_ &=~ elfcpp::SHF_STRINGS;
2491   else
2492     {
2493       if (this->current_data_size_for_child() == 0)
2494         this->flags_ |= elfcpp::SHF_STRINGS;
2495     }
2496 }
2497
2498 // Find the merge section into which an input section with index SHNDX in
2499 // OBJECT has been added.  Return NULL if none found.
2500
2501 Output_section_data*
2502 Output_section::find_merge_section(const Relobj* object,
2503                                    unsigned int shndx) const
2504 {
2505   if (!this->lookup_maps_->is_valid())
2506     this->build_lookup_maps();
2507   return this->lookup_maps_->find_merge_section(object, shndx);
2508 }
2509
2510 // Build the lookup maps for merge and relaxed sections.  This is needs
2511 // to be declared as a const methods so that it is callable with a const
2512 // Output_section pointer.  The method only updates states of the maps.
2513
2514 void
2515 Output_section::build_lookup_maps() const
2516 {
2517   this->lookup_maps_->clear();
2518   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2519        p != this->input_sections_.end();
2520        ++p)
2521     {
2522       if (p->is_merge_section())
2523         {
2524           Output_merge_base* pomb = p->output_merge_base();
2525           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
2526                                        pomb->addralign());
2527           this->lookup_maps_->add_merge_section(msp, pomb);
2528           for (Output_merge_base::Input_sections::const_iterator is =
2529                  pomb->input_sections_begin();
2530                is != pomb->input_sections_end();
2531                ++is)
2532             {
2533               const Const_section_id& csid = *is;
2534             this->lookup_maps_->add_merge_input_section(csid.first,
2535                                                         csid.second, pomb);
2536             }
2537
2538         }
2539       else if (p->is_relaxed_input_section())
2540         {
2541           Output_relaxed_input_section* poris = p->relaxed_input_section();
2542           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2543                                                         poris->shndx(), poris);
2544         }
2545     }
2546 }
2547
2548 // Find an relaxed input section corresponding to an input section
2549 // in OBJECT with index SHNDX.
2550
2551 const Output_relaxed_input_section*
2552 Output_section::find_relaxed_input_section(const Relobj* object,
2553                                            unsigned int shndx) const
2554 {
2555   if (!this->lookup_maps_->is_valid())
2556     this->build_lookup_maps();
2557   return this->lookup_maps_->find_relaxed_input_section(object, shndx);
2558 }
2559
2560 // Given an address OFFSET relative to the start of input section
2561 // SHNDX in OBJECT, return whether this address is being included in
2562 // the final link.  This should only be called if SHNDX in OBJECT has
2563 // a special mapping.
2564
2565 bool
2566 Output_section::is_input_address_mapped(const Relobj* object,
2567                                         unsigned int shndx,
2568                                         off_t offset) const
2569 {
2570   // Look at the Output_section_data_maps first.
2571   const Output_section_data* posd = this->find_merge_section(object, shndx);
2572   if (posd == NULL)
2573     posd = this->find_relaxed_input_section(object, shndx);
2574
2575   if (posd != NULL)
2576     {
2577       section_offset_type output_offset;
2578       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2579       gold_assert(found);
2580       return output_offset != -1;
2581     }
2582
2583   // Fall back to the slow look-up.
2584   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2585        p != this->input_sections_.end();
2586        ++p)
2587     {
2588       section_offset_type output_offset;
2589       if (p->output_offset(object, shndx, offset, &output_offset))
2590         return output_offset != -1;
2591     }
2592
2593   // By default we assume that the address is mapped.  This should
2594   // only be called after we have passed all sections to Layout.  At
2595   // that point we should know what we are discarding.
2596   return true;
2597 }
2598
2599 // Given an address OFFSET relative to the start of input section
2600 // SHNDX in object OBJECT, return the output offset relative to the
2601 // start of the input section in the output section.  This should only
2602 // be called if SHNDX in OBJECT has a special mapping.
2603
2604 section_offset_type
2605 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2606                               section_offset_type offset) const
2607 {
2608   // This can only be called meaningfully when we know the data size
2609   // of this.
2610   gold_assert(this->is_data_size_valid());
2611
2612   // Look at the Output_section_data_maps first.
2613   const Output_section_data* posd = this->find_merge_section(object, shndx);
2614   if (posd == NULL)
2615     posd = this->find_relaxed_input_section(object, shndx);
2616   if (posd != NULL)
2617     {
2618       section_offset_type output_offset;
2619       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2620       gold_assert(found);
2621       return output_offset;
2622     }
2623
2624   // Fall back to the slow look-up.
2625   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2626        p != this->input_sections_.end();
2627        ++p)
2628     {
2629       section_offset_type output_offset;
2630       if (p->output_offset(object, shndx, offset, &output_offset))
2631         return output_offset;
2632     }
2633   gold_unreachable();
2634 }
2635
2636 // Return the output virtual address of OFFSET relative to the start
2637 // of input section SHNDX in object OBJECT.
2638
2639 uint64_t
2640 Output_section::output_address(const Relobj* object, unsigned int shndx,
2641                                off_t offset) const
2642 {
2643   uint64_t addr = this->address() + this->first_input_offset_;
2644
2645   // Look at the Output_section_data_maps first.
2646   const Output_section_data* posd = this->find_merge_section(object, shndx);
2647   if (posd == NULL)
2648     posd = this->find_relaxed_input_section(object, shndx);
2649   if (posd != NULL && posd->is_address_valid())
2650     {
2651       section_offset_type output_offset;
2652       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2653       gold_assert(found);
2654       return posd->address() + output_offset;
2655     }
2656
2657   // Fall back to the slow look-up.
2658   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2659        p != this->input_sections_.end();
2660        ++p)
2661     {
2662       addr = align_address(addr, p->addralign());
2663       section_offset_type output_offset;
2664       if (p->output_offset(object, shndx, offset, &output_offset))
2665         {
2666           if (output_offset == -1)
2667             return -1ULL;
2668           return addr + output_offset;
2669         }
2670       addr += p->data_size();
2671     }
2672
2673   // If we get here, it means that we don't know the mapping for this
2674   // input section.  This might happen in principle if
2675   // add_input_section were called before add_output_section_data.
2676   // But it should never actually happen.
2677
2678   gold_unreachable();
2679 }
2680
2681 // Find the output address of the start of the merged section for
2682 // input section SHNDX in object OBJECT.
2683
2684 bool
2685 Output_section::find_starting_output_address(const Relobj* object,
2686                                              unsigned int shndx,
2687                                              uint64_t* paddr) const
2688 {
2689   // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2690   // Looking up the merge section map does not always work as we sometimes
2691   // find a merge section without its address set.
2692   uint64_t addr = this->address() + this->first_input_offset_;
2693   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2694        p != this->input_sections_.end();
2695        ++p)
2696     {
2697       addr = align_address(addr, p->addralign());
2698
2699       // It would be nice if we could use the existing output_offset
2700       // method to get the output offset of input offset 0.
2701       // Unfortunately we don't know for sure that input offset 0 is
2702       // mapped at all.
2703       if (p->is_merge_section_for(object, shndx))
2704         {
2705           *paddr = addr;
2706           return true;
2707         }
2708
2709       addr += p->data_size();
2710     }
2711
2712   // We couldn't find a merge output section for this input section.
2713   return false;
2714 }
2715
2716 // Set the data size of an Output_section.  This is where we handle
2717 // setting the addresses of any Output_section_data objects.
2718
2719 void
2720 Output_section::set_final_data_size()
2721 {
2722   if (this->input_sections_.empty())
2723     {
2724       this->set_data_size(this->current_data_size_for_child());
2725       return;
2726     }
2727
2728   if (this->must_sort_attached_input_sections()
2729       || this->input_section_order_specified())
2730     this->sort_attached_input_sections();
2731
2732   uint64_t address = this->address();
2733   off_t startoff = this->offset();
2734   off_t off = startoff + this->first_input_offset_;
2735   for (Input_section_list::iterator p = this->input_sections_.begin();
2736        p != this->input_sections_.end();
2737        ++p)
2738     {
2739       off = align_address(off, p->addralign());
2740       p->set_address_and_file_offset(address + (off - startoff), off,
2741                                      startoff);
2742       off += p->data_size();
2743     }
2744
2745   this->set_data_size(off - startoff);
2746 }
2747
2748 // Reset the address and file offset.
2749
2750 void
2751 Output_section::do_reset_address_and_file_offset()
2752 {
2753   // An unallocated section has no address.  Forcing this means that
2754   // we don't need special treatment for symbols defined in debug
2755   // sections.  We do the same in the constructor.  This does not
2756   // apply to NOLOAD sections though.
2757   if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
2758      this->set_address(0);
2759
2760   for (Input_section_list::iterator p = this->input_sections_.begin();
2761        p != this->input_sections_.end();
2762        ++p)
2763     p->reset_address_and_file_offset();
2764 }
2765
2766 // Return true if address and file offset have the values after reset.
2767
2768 bool
2769 Output_section::do_address_and_file_offset_have_reset_values() const
2770 {
2771   if (this->is_offset_valid())
2772     return false;
2773
2774   // An unallocated section has address 0 after its construction or a reset.
2775   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2776     return this->is_address_valid() && this->address() == 0;
2777   else
2778     return !this->is_address_valid();
2779 }
2780
2781 // Set the TLS offset.  Called only for SHT_TLS sections.
2782
2783 void
2784 Output_section::do_set_tls_offset(uint64_t tls_base)
2785 {
2786   this->tls_offset_ = this->address() - tls_base;
2787 }
2788
2789 // In a few cases we need to sort the input sections attached to an
2790 // output section.  This is used to implement the type of constructor
2791 // priority ordering implemented by the GNU linker, in which the
2792 // priority becomes part of the section name and the sections are
2793 // sorted by name.  We only do this for an output section if we see an
2794 // attached input section matching ".ctor.*", ".dtor.*",
2795 // ".init_array.*" or ".fini_array.*".
2796
2797 class Output_section::Input_section_sort_entry
2798 {
2799  public:
2800   Input_section_sort_entry()
2801     : input_section_(), index_(-1U), section_has_name_(false),
2802       section_name_()
2803   { }
2804
2805   Input_section_sort_entry(const Input_section& input_section,
2806                            unsigned int index,
2807                            bool must_sort_attached_input_sections)
2808     : input_section_(input_section), index_(index),
2809       section_has_name_(input_section.is_input_section()
2810                         || input_section.is_relaxed_input_section())
2811   {
2812     if (this->section_has_name_
2813         && must_sort_attached_input_sections)
2814       {
2815         // This is only called single-threaded from Layout::finalize,
2816         // so it is OK to lock.  Unfortunately we have no way to pass
2817         // in a Task token.
2818         const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2819         Object* obj = (input_section.is_input_section()
2820                        ? input_section.relobj()
2821                        : input_section.relaxed_input_section()->relobj());
2822         Task_lock_obj<Object> tl(dummy_task, obj);
2823
2824         // This is a slow operation, which should be cached in
2825         // Layout::layout if this becomes a speed problem.
2826         this->section_name_ = obj->section_name(input_section.shndx());
2827       }
2828   }
2829
2830   // Return the Input_section.
2831   const Input_section&
2832   input_section() const
2833   {
2834     gold_assert(this->index_ != -1U);
2835     return this->input_section_;
2836   }
2837
2838   // The index of this entry in the original list.  This is used to
2839   // make the sort stable.
2840   unsigned int
2841   index() const
2842   {
2843     gold_assert(this->index_ != -1U);
2844     return this->index_;
2845   }
2846
2847   // Whether there is a section name.
2848   bool
2849   section_has_name() const
2850   { return this->section_has_name_; }
2851
2852   // The section name.
2853   const std::string&
2854   section_name() const
2855   {
2856     gold_assert(this->section_has_name_);
2857     return this->section_name_;
2858   }
2859
2860   // Return true if the section name has a priority.  This is assumed
2861   // to be true if it has a dot after the initial dot.
2862   bool
2863   has_priority() const
2864   {
2865     gold_assert(this->section_has_name_);
2866     return this->section_name_.find('.', 1) != std::string::npos;
2867   }
2868
2869   // Return true if this an input file whose base name matches
2870   // FILE_NAME.  The base name must have an extension of ".o", and
2871   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2872   // This is to match crtbegin.o as well as crtbeginS.o without
2873   // getting confused by other possibilities.  Overall matching the
2874   // file name this way is a dreadful hack, but the GNU linker does it
2875   // in order to better support gcc, and we need to be compatible.
2876   bool
2877   match_file_name(const char* match_file_name) const
2878   {
2879     const std::string& file_name(this->input_section_.relobj()->name());
2880     const char* base_name = lbasename(file_name.c_str());
2881     size_t match_len = strlen(match_file_name);
2882     if (strncmp(base_name, match_file_name, match_len) != 0)
2883       return false;
2884     size_t base_len = strlen(base_name);
2885     if (base_len != match_len + 2 && base_len != match_len + 3)
2886       return false;
2887     return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2888   }
2889
2890   // Returns 1 if THIS should appear before S in section order, -1 if S
2891   // appears before THIS and 0 if they are not comparable.
2892   int
2893   compare_section_ordering(const Input_section_sort_entry& s) const
2894   {
2895     unsigned int this_secn_index = this->input_section_.section_order_index();
2896     unsigned int s_secn_index = s.input_section().section_order_index();
2897     if (this_secn_index > 0 && s_secn_index > 0)
2898       {
2899         if (this_secn_index < s_secn_index)
2900           return 1;
2901         else if (this_secn_index > s_secn_index)
2902           return -1;
2903       }
2904     return 0;
2905   }
2906
2907  private:
2908   // The Input_section we are sorting.
2909   Input_section input_section_;
2910   // The index of this Input_section in the original list.
2911   unsigned int index_;
2912   // Whether this Input_section has a section name--it won't if this
2913   // is some random Output_section_data.
2914   bool section_has_name_;
2915   // The section name if there is one.
2916   std::string section_name_;
2917 };
2918
2919 // Return true if S1 should come before S2 in the output section.
2920
2921 bool
2922 Output_section::Input_section_sort_compare::operator()(
2923     const Output_section::Input_section_sort_entry& s1,
2924     const Output_section::Input_section_sort_entry& s2) const
2925 {
2926   // crtbegin.o must come first.
2927   bool s1_begin = s1.match_file_name("crtbegin");
2928   bool s2_begin = s2.match_file_name("crtbegin");
2929   if (s1_begin || s2_begin)
2930     {
2931       if (!s1_begin)
2932         return false;
2933       if (!s2_begin)
2934         return true;
2935       return s1.index() < s2.index();
2936     }
2937
2938   // crtend.o must come last.
2939   bool s1_end = s1.match_file_name("crtend");
2940   bool s2_end = s2.match_file_name("crtend");
2941   if (s1_end || s2_end)
2942     {
2943       if (!s1_end)
2944         return true;
2945       if (!s2_end)
2946         return false;
2947       return s1.index() < s2.index();
2948     }
2949
2950   // We sort all the sections with no names to the end.
2951   if (!s1.section_has_name() || !s2.section_has_name())
2952     {
2953       if (s1.section_has_name())
2954         return true;
2955       if (s2.section_has_name())
2956         return false;
2957       return s1.index() < s2.index();
2958     }
2959
2960   // A section with a priority follows a section without a priority.
2961   bool s1_has_priority = s1.has_priority();
2962   bool s2_has_priority = s2.has_priority();
2963   if (s1_has_priority && !s2_has_priority)
2964     return false;
2965   if (!s1_has_priority && s2_has_priority)
2966     return true;
2967
2968   // Check if a section order exists for these sections through a section
2969   // ordering file.  If sequence_num is 0, an order does not exist.
2970   int sequence_num = s1.compare_section_ordering(s2);
2971   if (sequence_num != 0)
2972     return sequence_num == 1;
2973
2974   // Otherwise we sort by name.
2975   int compare = s1.section_name().compare(s2.section_name());
2976   if (compare != 0)
2977     return compare < 0;
2978
2979   // Otherwise we keep the input order.
2980   return s1.index() < s2.index();
2981 }
2982
2983 // Return true if S1 should come before S2 in an .init_array or .fini_array
2984 // output section.
2985
2986 bool
2987 Output_section::Input_section_sort_init_fini_compare::operator()(
2988     const Output_section::Input_section_sort_entry& s1,
2989     const Output_section::Input_section_sort_entry& s2) const
2990 {
2991   // We sort all the sections with no names to the end.
2992   if (!s1.section_has_name() || !s2.section_has_name())
2993     {
2994       if (s1.section_has_name())
2995         return true;
2996       if (s2.section_has_name())
2997         return false;
2998       return s1.index() < s2.index();
2999     }
3000
3001   // A section without a priority follows a section with a priority.
3002   // This is the reverse of .ctors and .dtors sections.
3003   bool s1_has_priority = s1.has_priority();
3004   bool s2_has_priority = s2.has_priority();
3005   if (s1_has_priority && !s2_has_priority)
3006     return true;
3007   if (!s1_has_priority && s2_has_priority)
3008     return false;
3009
3010   // Check if a section order exists for these sections through a section
3011   // ordering file.  If sequence_num is 0, an order does not exist.
3012   int sequence_num = s1.compare_section_ordering(s2);
3013   if (sequence_num != 0)
3014     return sequence_num == 1;
3015
3016   // Otherwise we sort by name.
3017   int compare = s1.section_name().compare(s2.section_name());
3018   if (compare != 0)
3019     return compare < 0;
3020
3021   // Otherwise we keep the input order.
3022   return s1.index() < s2.index();
3023 }
3024
3025 // Return true if S1 should come before S2.  Sections that do not match
3026 // any pattern in the section ordering file are placed ahead of the sections
3027 // that match some pattern.
3028
3029 bool
3030 Output_section::Input_section_sort_section_order_index_compare::operator()(
3031     const Output_section::Input_section_sort_entry& s1,
3032     const Output_section::Input_section_sort_entry& s2) const
3033 {
3034   unsigned int s1_secn_index = s1.input_section().section_order_index();
3035   unsigned int s2_secn_index = s2.input_section().section_order_index();
3036
3037   // Keep input order if section ordering cannot determine order.
3038   if (s1_secn_index == s2_secn_index)
3039     return s1.index() < s2.index();
3040
3041   return s1_secn_index < s2_secn_index;
3042 }
3043
3044 // Sort the input sections attached to an output section.
3045
3046 void
3047 Output_section::sort_attached_input_sections()
3048 {
3049   if (this->attached_input_sections_are_sorted_)
3050     return;
3051
3052   if (this->checkpoint_ != NULL
3053       && !this->checkpoint_->input_sections_saved())
3054     this->checkpoint_->save_input_sections();
3055
3056   // The only thing we know about an input section is the object and
3057   // the section index.  We need the section name.  Recomputing this
3058   // is slow but this is an unusual case.  If this becomes a speed
3059   // problem we can cache the names as required in Layout::layout.
3060
3061   // We start by building a larger vector holding a copy of each
3062   // Input_section, plus its current index in the list and its name.
3063   std::vector<Input_section_sort_entry> sort_list;
3064
3065   unsigned int i = 0;
3066   for (Input_section_list::iterator p = this->input_sections_.begin();
3067        p != this->input_sections_.end();
3068        ++p, ++i)
3069       sort_list.push_back(Input_section_sort_entry(*p, i,
3070                             this->must_sort_attached_input_sections()));
3071
3072   // Sort the input sections.
3073   if (this->must_sort_attached_input_sections())
3074     {
3075       if (this->type() == elfcpp::SHT_PREINIT_ARRAY
3076           || this->type() == elfcpp::SHT_INIT_ARRAY
3077           || this->type() == elfcpp::SHT_FINI_ARRAY)
3078         std::sort(sort_list.begin(), sort_list.end(),
3079                   Input_section_sort_init_fini_compare());
3080       else
3081         std::sort(sort_list.begin(), sort_list.end(),
3082                   Input_section_sort_compare());
3083     }
3084   else
3085     {
3086       gold_assert(parameters->options().section_ordering_file());
3087       std::sort(sort_list.begin(), sort_list.end(),
3088                 Input_section_sort_section_order_index_compare());
3089     }
3090
3091   // Copy the sorted input sections back to our list.
3092   this->input_sections_.clear();
3093   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
3094        p != sort_list.end();
3095        ++p)
3096     this->input_sections_.push_back(p->input_section());
3097   sort_list.clear();
3098
3099   // Remember that we sorted the input sections, since we might get
3100   // called again.
3101   this->attached_input_sections_are_sorted_ = true;
3102 }
3103
3104 // Write the section header to *OSHDR.
3105
3106 template<int size, bool big_endian>
3107 void
3108 Output_section::write_header(const Layout* layout,
3109                              const Stringpool* secnamepool,
3110                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
3111 {
3112   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
3113   oshdr->put_sh_type(this->type_);
3114
3115   elfcpp::Elf_Xword flags = this->flags_;
3116   if (this->info_section_ != NULL && this->info_uses_section_index_)
3117     flags |= elfcpp::SHF_INFO_LINK;
3118   oshdr->put_sh_flags(flags);
3119
3120   oshdr->put_sh_addr(this->address());
3121   oshdr->put_sh_offset(this->offset());
3122   oshdr->put_sh_size(this->data_size());
3123   if (this->link_section_ != NULL)
3124     oshdr->put_sh_link(this->link_section_->out_shndx());
3125   else if (this->should_link_to_symtab_)
3126     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
3127   else if (this->should_link_to_dynsym_)
3128     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
3129   else
3130     oshdr->put_sh_link(this->link_);
3131
3132   elfcpp::Elf_Word info;
3133   if (this->info_section_ != NULL)
3134     {
3135       if (this->info_uses_section_index_)
3136         info = this->info_section_->out_shndx();
3137       else
3138         info = this->info_section_->symtab_index();
3139     }
3140   else if (this->info_symndx_ != NULL)
3141     info = this->info_symndx_->symtab_index();
3142   else
3143     info = this->info_;
3144   oshdr->put_sh_info(info);
3145
3146   oshdr->put_sh_addralign(this->addralign_);
3147   oshdr->put_sh_entsize(this->entsize_);
3148 }
3149
3150 // Write out the data.  For input sections the data is written out by
3151 // Object::relocate, but we have to handle Output_section_data objects
3152 // here.
3153
3154 void
3155 Output_section::do_write(Output_file* of)
3156 {
3157   gold_assert(!this->requires_postprocessing());
3158
3159   // If the target performs relaxation, we delay filler generation until now.
3160   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3161
3162   off_t output_section_file_offset = this->offset();
3163   for (Fill_list::iterator p = this->fills_.begin();
3164        p != this->fills_.end();
3165        ++p)
3166     {
3167       std::string fill_data(parameters->target().code_fill(p->length()));
3168       of->write(output_section_file_offset + p->section_offset(),
3169                 fill_data.data(), fill_data.size());
3170     }
3171
3172   off_t off = this->offset() + this->first_input_offset_;
3173   for (Input_section_list::iterator p = this->input_sections_.begin();
3174        p != this->input_sections_.end();
3175        ++p)
3176     {
3177       off_t aligned_off = align_address(off, p->addralign());
3178       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3179         {
3180           size_t fill_len = aligned_off - off;
3181           std::string fill_data(parameters->target().code_fill(fill_len));
3182           of->write(off, fill_data.data(), fill_data.size());
3183         }
3184
3185       p->write(of);
3186       off = aligned_off + p->data_size();
3187     }
3188 }
3189
3190 // If a section requires postprocessing, create the buffer to use.
3191
3192 void
3193 Output_section::create_postprocessing_buffer()
3194 {
3195   gold_assert(this->requires_postprocessing());
3196
3197   if (this->postprocessing_buffer_ != NULL)
3198     return;
3199
3200   if (!this->input_sections_.empty())
3201     {
3202       off_t off = this->first_input_offset_;
3203       for (Input_section_list::iterator p = this->input_sections_.begin();
3204            p != this->input_sections_.end();
3205            ++p)
3206         {
3207           off = align_address(off, p->addralign());
3208           p->finalize_data_size();
3209           off += p->data_size();
3210         }
3211       this->set_current_data_size_for_child(off);
3212     }
3213
3214   off_t buffer_size = this->current_data_size_for_child();
3215   this->postprocessing_buffer_ = new unsigned char[buffer_size];
3216 }
3217
3218 // Write all the data of an Output_section into the postprocessing
3219 // buffer.  This is used for sections which require postprocessing,
3220 // such as compression.  Input sections are handled by
3221 // Object::Relocate.
3222
3223 void
3224 Output_section::write_to_postprocessing_buffer()
3225 {
3226   gold_assert(this->requires_postprocessing());
3227
3228   // If the target performs relaxation, we delay filler generation until now.
3229   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3230
3231   unsigned char* buffer = this->postprocessing_buffer();
3232   for (Fill_list::iterator p = this->fills_.begin();
3233        p != this->fills_.end();
3234        ++p)
3235     {
3236       std::string fill_data(parameters->target().code_fill(p->length()));
3237       memcpy(buffer + p->section_offset(), fill_data.data(),
3238              fill_data.size());
3239     }
3240
3241   off_t off = this->first_input_offset_;
3242   for (Input_section_list::iterator p = this->input_sections_.begin();
3243        p != this->input_sections_.end();
3244        ++p)
3245     {
3246       off_t aligned_off = align_address(off, p->addralign());
3247       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3248         {
3249           size_t fill_len = aligned_off - off;
3250           std::string fill_data(parameters->target().code_fill(fill_len));
3251           memcpy(buffer + off, fill_data.data(), fill_data.size());
3252         }
3253
3254       p->write_to_buffer(buffer + aligned_off);
3255       off = aligned_off + p->data_size();
3256     }
3257 }
3258
3259 // Get the input sections for linker script processing.  We leave
3260 // behind the Output_section_data entries.  Note that this may be
3261 // slightly incorrect for merge sections.  We will leave them behind,
3262 // but it is possible that the script says that they should follow
3263 // some other input sections, as in:
3264 //    .rodata { *(.rodata) *(.rodata.cst*) }
3265 // For that matter, we don't handle this correctly:
3266 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
3267 // With luck this will never matter.
3268
3269 uint64_t
3270 Output_section::get_input_sections(
3271     uint64_t address,
3272     const std::string& fill,
3273     std::list<Input_section>* input_sections)
3274 {
3275   if (this->checkpoint_ != NULL
3276       && !this->checkpoint_->input_sections_saved())
3277     this->checkpoint_->save_input_sections();
3278
3279   // Invalidate fast look-up maps.
3280   this->lookup_maps_->invalidate();
3281
3282   uint64_t orig_address = address;
3283
3284   address = align_address(address, this->addralign());
3285
3286   Input_section_list remaining;
3287   for (Input_section_list::iterator p = this->input_sections_.begin();
3288        p != this->input_sections_.end();
3289        ++p)
3290     {
3291       if (p->is_input_section()
3292           || p->is_relaxed_input_section()
3293           || p->is_merge_section())
3294         input_sections->push_back(*p);
3295       else
3296         {
3297           uint64_t aligned_address = align_address(address, p->addralign());
3298           if (aligned_address != address && !fill.empty())
3299             {
3300               section_size_type length =
3301                 convert_to_section_size_type(aligned_address - address);
3302               std::string this_fill;
3303               this_fill.reserve(length);
3304               while (this_fill.length() + fill.length() <= length)
3305                 this_fill += fill;
3306               if (this_fill.length() < length)
3307                 this_fill.append(fill, 0, length - this_fill.length());
3308
3309               Output_section_data* posd = new Output_data_const(this_fill, 0);
3310               remaining.push_back(Input_section(posd));
3311             }
3312           address = aligned_address;
3313
3314           remaining.push_back(*p);
3315
3316           p->finalize_data_size();
3317           address += p->data_size();
3318         }
3319     }
3320
3321   this->input_sections_.swap(remaining);
3322   this->first_input_offset_ = 0;
3323
3324   uint64_t data_size = address - orig_address;
3325   this->set_current_data_size_for_child(data_size);
3326   return data_size;
3327 }
3328
3329 // Add a script input section.  SIS is an Output_section::Input_section,
3330 // which can be either a plain input section or a special input section like
3331 // a relaxed input section.  For a special input section, its size must be
3332 // finalized.
3333
3334 void
3335 Output_section::add_script_input_section(const Input_section& sis)
3336 {
3337   uint64_t data_size = sis.data_size();
3338   uint64_t addralign = sis.addralign();
3339   if (addralign > this->addralign_)
3340     this->addralign_ = addralign;
3341
3342   off_t offset_in_section = this->current_data_size_for_child();
3343   off_t aligned_offset_in_section = align_address(offset_in_section,
3344                                                   addralign);
3345
3346   this->set_current_data_size_for_child(aligned_offset_in_section
3347                                         + data_size);
3348
3349   this->input_sections_.push_back(sis);
3350
3351   // Update fast lookup maps if necessary.
3352   if (this->lookup_maps_->is_valid())
3353     {
3354       if (sis.is_merge_section())
3355         {
3356           Output_merge_base* pomb = sis.output_merge_base();
3357           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
3358                                        pomb->addralign());
3359           this->lookup_maps_->add_merge_section(msp, pomb);
3360           for (Output_merge_base::Input_sections::const_iterator p =
3361                  pomb->input_sections_begin();
3362                p != pomb->input_sections_end();
3363                ++p)
3364             this->lookup_maps_->add_merge_input_section(p->first, p->second,
3365                                                         pomb);
3366         }
3367       else if (sis.is_relaxed_input_section())
3368         {
3369           Output_relaxed_input_section* poris = sis.relaxed_input_section();
3370           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
3371                                                         poris->shndx(), poris);
3372         }
3373     }
3374 }
3375
3376 // Save states for relaxation.
3377
3378 void
3379 Output_section::save_states()
3380 {
3381   gold_assert(this->checkpoint_ == NULL);
3382   Checkpoint_output_section* checkpoint =
3383     new Checkpoint_output_section(this->addralign_, this->flags_,
3384                                   this->input_sections_,
3385                                   this->first_input_offset_,
3386                                   this->attached_input_sections_are_sorted_);
3387   this->checkpoint_ = checkpoint;
3388   gold_assert(this->fills_.empty());
3389 }
3390
3391 void
3392 Output_section::discard_states()
3393 {
3394   gold_assert(this->checkpoint_ != NULL);
3395   delete this->checkpoint_;
3396   this->checkpoint_ = NULL;
3397   gold_assert(this->fills_.empty());
3398
3399   // Simply invalidate the fast lookup maps since we do not keep
3400   // track of them.
3401   this->lookup_maps_->invalidate();
3402 }
3403
3404 void
3405 Output_section::restore_states()
3406 {
3407   gold_assert(this->checkpoint_ != NULL);
3408   Checkpoint_output_section* checkpoint = this->checkpoint_;
3409
3410   this->addralign_ = checkpoint->addralign();
3411   this->flags_ = checkpoint->flags();
3412   this->first_input_offset_ = checkpoint->first_input_offset();
3413
3414   if (!checkpoint->input_sections_saved())
3415     {
3416       // If we have not copied the input sections, just resize it.
3417       size_t old_size = checkpoint->input_sections_size();
3418       gold_assert(this->input_sections_.size() >= old_size);
3419       this->input_sections_.resize(old_size);
3420     }
3421   else
3422     {
3423       // We need to copy the whole list.  This is not efficient for
3424       // extremely large output with hundreads of thousands of input
3425       // objects.  We may need to re-think how we should pass sections
3426       // to scripts.
3427       this->input_sections_ = *checkpoint->input_sections();
3428     }
3429
3430   this->attached_input_sections_are_sorted_ =
3431     checkpoint->attached_input_sections_are_sorted();
3432
3433   // Simply invalidate the fast lookup maps since we do not keep
3434   // track of them.
3435   this->lookup_maps_->invalidate();
3436 }
3437
3438 // Update the section offsets of input sections in this.  This is required if
3439 // relaxation causes some input sections to change sizes.
3440
3441 void
3442 Output_section::adjust_section_offsets()
3443 {
3444   if (!this->section_offsets_need_adjustment_)
3445     return;
3446
3447   off_t off = 0;
3448   for (Input_section_list::iterator p = this->input_sections_.begin();
3449        p != this->input_sections_.end();
3450        ++p)
3451     {
3452       off = align_address(off, p->addralign());
3453       if (p->is_input_section())
3454         p->relobj()->set_section_offset(p->shndx(), off);
3455       off += p->data_size();
3456     }
3457
3458   this->section_offsets_need_adjustment_ = false;
3459 }
3460
3461 // Print to the map file.
3462
3463 void
3464 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3465 {
3466   mapfile->print_output_section(this);
3467
3468   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3469        p != this->input_sections_.end();
3470        ++p)
3471     p->print_to_mapfile(mapfile);
3472 }
3473
3474 // Print stats for merge sections to stderr.
3475
3476 void
3477 Output_section::print_merge_stats()
3478 {
3479   Input_section_list::iterator p;
3480   for (p = this->input_sections_.begin();
3481        p != this->input_sections_.end();
3482        ++p)
3483     p->print_merge_stats(this->name_);
3484 }
3485
3486 // Output segment methods.
3487
3488 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3489   : vaddr_(0),
3490     paddr_(0),
3491     memsz_(0),
3492     max_align_(0),
3493     min_p_align_(0),
3494     offset_(0),
3495     filesz_(0),
3496     type_(type),
3497     flags_(flags),
3498     is_max_align_known_(false),
3499     are_addresses_set_(false),
3500     is_large_data_segment_(false)
3501 {
3502   // The ELF ABI specifies that a PT_TLS segment always has PF_R as
3503   // the flags.
3504   if (type == elfcpp::PT_TLS)
3505     this->flags_ = elfcpp::PF_R;
3506 }
3507
3508 // Add an Output_section to a PT_LOAD Output_segment.
3509
3510 void
3511 Output_segment::add_output_section_to_load(Layout* layout,
3512                                            Output_section* os,
3513                                            elfcpp::Elf_Word seg_flags)
3514 {
3515   gold_assert(this->type() == elfcpp::PT_LOAD);
3516   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3517   gold_assert(!this->is_max_align_known_);
3518   gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3519
3520   this->update_flags_for_output_section(seg_flags);
3521
3522   // We don't want to change the ordering if we have a linker script
3523   // with a SECTIONS clause.
3524   Output_section_order order = os->order();
3525   if (layout->script_options()->saw_sections_clause())
3526     order = static_cast<Output_section_order>(0);
3527   else
3528     gold_assert(order != ORDER_INVALID);
3529
3530   this->output_lists_[order].push_back(os);
3531 }
3532
3533 // Add an Output_section to a non-PT_LOAD Output_segment.
3534
3535 void
3536 Output_segment::add_output_section_to_nonload(Output_section* os,
3537                                               elfcpp::Elf_Word seg_flags)
3538 {
3539   gold_assert(this->type() != elfcpp::PT_LOAD);
3540   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3541   gold_assert(!this->is_max_align_known_);
3542
3543   this->update_flags_for_output_section(seg_flags);
3544
3545   this->output_lists_[0].push_back(os);
3546 }
3547
3548 // Remove an Output_section from this segment.  It is an error if it
3549 // is not present.
3550
3551 void
3552 Output_segment::remove_output_section(Output_section* os)
3553 {
3554   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3555     {
3556       Output_data_list* pdl = &this->output_lists_[i];
3557       for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p)
3558         {
3559           if (*p == os)
3560             {
3561               pdl->erase(p);
3562               return;
3563             }
3564         }
3565     }
3566   gold_unreachable();
3567 }
3568
3569 // Add an Output_data (which need not be an Output_section) to the
3570 // start of a segment.
3571
3572 void
3573 Output_segment::add_initial_output_data(Output_data* od)
3574 {
3575   gold_assert(!this->is_max_align_known_);
3576   Output_data_list::iterator p = this->output_lists_[0].begin();
3577   this->output_lists_[0].insert(p, od);
3578 }
3579
3580 // Return true if this segment has any sections which hold actual
3581 // data, rather than being a BSS section.
3582
3583 bool
3584 Output_segment::has_any_data_sections() const
3585 {
3586   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3587     {
3588       const Output_data_list* pdl = &this->output_lists_[i];
3589       for (Output_data_list::const_iterator p = pdl->begin();
3590            p != pdl->end();
3591            ++p)
3592         {
3593           if (!(*p)->is_section())
3594             return true;
3595           if ((*p)->output_section()->type() != elfcpp::SHT_NOBITS)
3596             return true;
3597         }
3598     }
3599   return false;
3600 }
3601
3602 // Return whether the first data section (not counting TLS sections)
3603 // is a relro section.
3604
3605 bool
3606 Output_segment::is_first_section_relro() const
3607 {
3608   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3609     {
3610       if (i == static_cast<int>(ORDER_TLS_DATA)
3611           || i == static_cast<int>(ORDER_TLS_BSS))
3612         continue;
3613       const Output_data_list* pdl = &this->output_lists_[i];
3614       if (!pdl->empty())
3615         {
3616           Output_data* p = pdl->front();
3617           return p->is_section() && p->output_section()->is_relro();
3618         }
3619     }
3620   return false;
3621 }
3622
3623 // Return the maximum alignment of the Output_data in Output_segment.
3624
3625 uint64_t
3626 Output_segment::maximum_alignment()
3627 {
3628   if (!this->is_max_align_known_)
3629     {
3630       for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3631         {
3632           const Output_data_list* pdl = &this->output_lists_[i];
3633           uint64_t addralign = Output_segment::maximum_alignment_list(pdl);
3634           if (addralign > this->max_align_)
3635             this->max_align_ = addralign;
3636         }
3637       this->is_max_align_known_ = true;
3638     }
3639
3640   return this->max_align_;
3641 }
3642
3643 // Return the maximum alignment of a list of Output_data.
3644
3645 uint64_t
3646 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3647 {
3648   uint64_t ret = 0;
3649   for (Output_data_list::const_iterator p = pdl->begin();
3650        p != pdl->end();
3651        ++p)
3652     {
3653       uint64_t addralign = (*p)->addralign();
3654       if (addralign > ret)
3655         ret = addralign;
3656     }
3657   return ret;
3658 }
3659
3660 // Return whether this segment has any dynamic relocs.
3661
3662 bool
3663 Output_segment::has_dynamic_reloc() const
3664 {
3665   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3666     if (this->has_dynamic_reloc_list(&this->output_lists_[i]))
3667       return true;
3668   return false;
3669 }
3670
3671 // Return whether this Output_data_list has any dynamic relocs.
3672
3673 bool
3674 Output_segment::has_dynamic_reloc_list(const Output_data_list* pdl) const
3675 {
3676   for (Output_data_list::const_iterator p = pdl->begin();
3677        p != pdl->end();
3678        ++p)
3679     if ((*p)->has_dynamic_reloc())
3680       return true;
3681   return false;
3682 }
3683
3684 // Set the section addresses for an Output_segment.  If RESET is true,
3685 // reset the addresses first.  ADDR is the address and *POFF is the
3686 // file offset.  Set the section indexes starting with *PSHNDX.
3687 // INCREASE_RELRO is the size of the portion of the first non-relro
3688 // section that should be included in the PT_GNU_RELRO segment.
3689 // If this segment has relro sections, and has been aligned for
3690 // that purpose, set *HAS_RELRO to TRUE.  Return the address of
3691 // the immediately following segment.  Update *HAS_RELRO, *POFF,
3692 // and *PSHNDX.
3693
3694 uint64_t
3695 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3696                                       uint64_t addr,
3697                                       unsigned int* increase_relro,
3698                                       bool* has_relro,
3699                                       off_t* poff,
3700                                       unsigned int* pshndx)
3701 {
3702   gold_assert(this->type_ == elfcpp::PT_LOAD);
3703
3704   uint64_t last_relro_pad = 0;
3705   off_t orig_off = *poff;
3706
3707   bool in_tls = false;
3708
3709   // If we have relro sections, we need to pad forward now so that the
3710   // relro sections plus INCREASE_RELRO end on a common page boundary.
3711   if (parameters->options().relro()
3712       && this->is_first_section_relro()
3713       && (!this->are_addresses_set_ || reset))
3714     {
3715       uint64_t relro_size = 0;
3716       off_t off = *poff;
3717       uint64_t max_align = 0;
3718       for (int i = 0; i <= static_cast<int>(ORDER_RELRO_LAST); ++i)
3719         {
3720           Output_data_list* pdl = &this->output_lists_[i];
3721           Output_data_list::iterator p;
3722           for (p = pdl->begin(); p != pdl->end(); ++p)
3723             {
3724               if (!(*p)->is_section())
3725                 break;
3726               uint64_t align = (*p)->addralign();
3727               if (align > max_align)
3728                 max_align = align;
3729               if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3730                 in_tls = true;
3731               else if (in_tls)
3732                 {
3733                   // Align the first non-TLS section to the alignment
3734                   // of the TLS segment.
3735                   align = max_align;
3736                   in_tls = false;
3737                 }
3738               relro_size = align_address(relro_size, align);
3739               // Ignore the size of the .tbss section.
3740               if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)
3741                   && (*p)->is_section_type(elfcpp::SHT_NOBITS))
3742                 continue;
3743               if ((*p)->is_address_valid())
3744                 relro_size += (*p)->data_size();
3745               else
3746                 {
3747                   // FIXME: This could be faster.
3748                   (*p)->set_address_and_file_offset(addr + relro_size,
3749                                                     off + relro_size);
3750                   relro_size += (*p)->data_size();
3751                   (*p)->reset_address_and_file_offset();
3752                 }
3753             }
3754           if (p != pdl->end())
3755             break;
3756         }
3757       relro_size += *increase_relro;
3758       // Pad the total relro size to a multiple of the maximum
3759       // section alignment seen.
3760       uint64_t aligned_size = align_address(relro_size, max_align);
3761       // Note the amount of padding added after the last relro section.
3762       last_relro_pad = aligned_size - relro_size;
3763       *has_relro = true;
3764
3765       uint64_t page_align = parameters->target().common_pagesize();
3766
3767       // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
3768       uint64_t desired_align = page_align - (aligned_size % page_align);
3769       if (desired_align < *poff % page_align)
3770         *poff += page_align - *poff % page_align;
3771       *poff += desired_align - *poff % page_align;
3772       addr += *poff - orig_off;
3773       orig_off = *poff;
3774     }
3775
3776   if (!reset && this->are_addresses_set_)
3777     {
3778       gold_assert(this->paddr_ == addr);
3779       addr = this->vaddr_;
3780     }
3781   else
3782     {
3783       this->vaddr_ = addr;
3784       this->paddr_ = addr;
3785       this->are_addresses_set_ = true;
3786     }
3787
3788   in_tls = false;
3789
3790   this->offset_ = orig_off;
3791
3792   off_t off = 0;
3793   uint64_t ret;
3794   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3795     {
3796       if (i == static_cast<int>(ORDER_RELRO_LAST))
3797         {
3798           *poff += last_relro_pad;
3799           addr += last_relro_pad;
3800           if (this->output_lists_[i].empty())
3801             {
3802               // If there is nothing in the ORDER_RELRO_LAST list,
3803               // the padding will occur at the end of the relro
3804               // segment, and we need to add it to *INCREASE_RELRO.
3805               *increase_relro += last_relro_pad;
3806             }
3807         }
3808       addr = this->set_section_list_addresses(layout, reset,
3809                                               &this->output_lists_[i],
3810                                               addr, poff, pshndx, &in_tls);
3811       if (i < static_cast<int>(ORDER_SMALL_BSS))
3812         {
3813           this->filesz_ = *poff - orig_off;
3814           off = *poff;
3815         }
3816
3817       ret = addr;
3818     }
3819
3820   // If the last section was a TLS section, align upward to the
3821   // alignment of the TLS segment, so that the overall size of the TLS
3822   // segment is aligned.
3823   if (in_tls)
3824     {
3825       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3826       *poff = align_address(*poff, segment_align);
3827     }
3828
3829   this->memsz_ = *poff - orig_off;
3830
3831   // Ignore the file offset adjustments made by the BSS Output_data
3832   // objects.
3833   *poff = off;
3834
3835   return ret;
3836 }
3837
3838 // Set the addresses and file offsets in a list of Output_data
3839 // structures.
3840
3841 uint64_t
3842 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3843                                            Output_data_list* pdl,
3844                                            uint64_t addr, off_t* poff,
3845                                            unsigned int* pshndx,
3846                                            bool* in_tls)
3847 {
3848   off_t startoff = *poff;
3849
3850   off_t off = startoff;
3851   for (Output_data_list::iterator p = pdl->begin();
3852        p != pdl->end();
3853        ++p)
3854     {
3855       if (reset)
3856         (*p)->reset_address_and_file_offset();
3857
3858       // When using a linker script the section will most likely
3859       // already have an address.
3860       if (!(*p)->is_address_valid())
3861         {
3862           uint64_t align = (*p)->addralign();
3863
3864           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3865             {
3866               // Give the first TLS section the alignment of the
3867               // entire TLS segment.  Otherwise the TLS segment as a
3868               // whole may be misaligned.
3869               if (!*in_tls)
3870                 {
3871                   Output_segment* tls_segment = layout->tls_segment();
3872                   gold_assert(tls_segment != NULL);
3873                   uint64_t segment_align = tls_segment->maximum_alignment();
3874                   gold_assert(segment_align >= align);
3875                   align = segment_align;
3876
3877                   *in_tls = true;
3878                 }
3879             }
3880           else
3881             {
3882               // If this is the first section after the TLS segment,
3883               // align it to at least the alignment of the TLS
3884               // segment, so that the size of the overall TLS segment
3885               // is aligned.
3886               if (*in_tls)
3887                 {
3888                   uint64_t segment_align =
3889                       layout->tls_segment()->maximum_alignment();
3890                   if (segment_align > align)
3891                     align = segment_align;
3892
3893                   *in_tls = false;
3894                 }
3895             }
3896
3897           off = align_address(off, align);
3898           (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3899         }
3900       else
3901         {
3902           // The script may have inserted a skip forward, but it
3903           // better not have moved backward.
3904           if ((*p)->address() >= addr + (off - startoff))
3905             off += (*p)->address() - (addr + (off - startoff));
3906           else
3907             {
3908               if (!layout->script_options()->saw_sections_clause())
3909                 gold_unreachable();
3910               else
3911                 {
3912                   Output_section* os = (*p)->output_section();
3913
3914                   // Cast to unsigned long long to avoid format warnings.
3915                   unsigned long long previous_dot =
3916                     static_cast<unsigned long long>(addr + (off - startoff));
3917                   unsigned long long dot =
3918                     static_cast<unsigned long long>((*p)->address());
3919
3920                   if (os == NULL)
3921                     gold_error(_("dot moves backward in linker script "
3922                                  "from 0x%llx to 0x%llx"), previous_dot, dot);
3923                   else
3924                     gold_error(_("address of section '%s' moves backward "
3925                                  "from 0x%llx to 0x%llx"),
3926                                os->name(), previous_dot, dot);
3927                 }
3928             }
3929           (*p)->set_file_offset(off);
3930           (*p)->finalize_data_size();
3931         }
3932
3933       // We want to ignore the size of a SHF_TLS or SHT_NOBITS
3934       // section.  Such a section does not affect the size of a
3935       // PT_LOAD segment.
3936       if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
3937           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
3938         off += (*p)->data_size();
3939
3940       if ((*p)->is_section())
3941         {
3942           (*p)->set_out_shndx(*pshndx);
3943           ++*pshndx;
3944         }
3945     }
3946
3947   *poff = off;
3948   return addr + (off - startoff);
3949 }
3950
3951 // For a non-PT_LOAD segment, set the offset from the sections, if
3952 // any.  Add INCREASE to the file size and the memory size.
3953
3954 void
3955 Output_segment::set_offset(unsigned int increase)
3956 {
3957   gold_assert(this->type_ != elfcpp::PT_LOAD);
3958
3959   gold_assert(!this->are_addresses_set_);
3960
3961   // A non-load section only uses output_lists_[0].
3962
3963   Output_data_list* pdl = &this->output_lists_[0];
3964
3965   if (pdl->empty())
3966     {
3967       gold_assert(increase == 0);
3968       this->vaddr_ = 0;
3969       this->paddr_ = 0;
3970       this->are_addresses_set_ = true;
3971       this->memsz_ = 0;
3972       this->min_p_align_ = 0;
3973       this->offset_ = 0;
3974       this->filesz_ = 0;
3975       return;
3976     }
3977
3978   // Find the first and last section by address.
3979   const Output_data* first = NULL;
3980   const Output_data* last_data = NULL;
3981   const Output_data* last_bss = NULL;
3982   for (Output_data_list::const_iterator p = pdl->begin();
3983        p != pdl->end();
3984        ++p)
3985     {
3986       if (first == NULL
3987           || (*p)->address() < first->address()
3988           || ((*p)->address() == first->address()
3989               && (*p)->data_size() < first->data_size()))
3990         first = *p;
3991       const Output_data** plast;
3992       if ((*p)->is_section()
3993           && (*p)->output_section()->type() == elfcpp::SHT_NOBITS)
3994         plast = &last_bss;
3995       else
3996         plast = &last_data;
3997       if (*plast == NULL
3998           || (*p)->address() > (*plast)->address()
3999           || ((*p)->address() == (*plast)->address()
4000               && (*p)->data_size() > (*plast)->data_size()))
4001         *plast = *p;
4002     }
4003
4004   this->vaddr_ = first->address();
4005   this->paddr_ = (first->has_load_address()
4006                   ? first->load_address()
4007                   : this->vaddr_);
4008   this->are_addresses_set_ = true;
4009   this->offset_ = first->offset();
4010
4011   if (last_data == NULL)
4012     this->filesz_ = 0;
4013   else
4014     this->filesz_ = (last_data->address()
4015                      + last_data->data_size()
4016                      - this->vaddr_);
4017
4018   const Output_data* last = last_bss != NULL ? last_bss : last_data;
4019   this->memsz_ = (last->address()
4020                   + last->data_size()
4021                   - this->vaddr_);
4022
4023   this->filesz_ += increase;
4024   this->memsz_ += increase;
4025
4026   // If this is a RELRO segment, verify that the segment ends at a
4027   // page boundary.
4028   if (this->type_ == elfcpp::PT_GNU_RELRO)
4029     {
4030       uint64_t page_align = parameters->target().common_pagesize();
4031       uint64_t segment_end = this->vaddr_ + this->memsz_;
4032       gold_assert(segment_end == align_address(segment_end, page_align));
4033     }
4034
4035   // If this is a TLS segment, align the memory size.  The code in
4036   // set_section_list ensures that the section after the TLS segment
4037   // is aligned to give us room.
4038   if (this->type_ == elfcpp::PT_TLS)
4039     {
4040       uint64_t segment_align = this->maximum_alignment();
4041       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
4042       this->memsz_ = align_address(this->memsz_, segment_align);
4043     }
4044 }
4045
4046 // Set the TLS offsets of the sections in the PT_TLS segment.
4047
4048 void
4049 Output_segment::set_tls_offsets()
4050 {
4051   gold_assert(this->type_ == elfcpp::PT_TLS);
4052
4053   for (Output_data_list::iterator p = this->output_lists_[0].begin();
4054        p != this->output_lists_[0].end();
4055        ++p)
4056     (*p)->set_tls_offset(this->vaddr_);
4057 }
4058
4059 // Return the load address of the first section.
4060
4061 uint64_t
4062 Output_segment::first_section_load_address() const
4063 {
4064   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4065     {
4066       const Output_data_list* pdl = &this->output_lists_[i];
4067       for (Output_data_list::const_iterator p = pdl->begin();
4068            p != pdl->end();
4069            ++p)
4070         {
4071           if ((*p)->is_section())
4072             return ((*p)->has_load_address()
4073                     ? (*p)->load_address()
4074                     : (*p)->address());
4075         }
4076     }
4077   gold_unreachable();
4078 }
4079
4080 // Return the number of Output_sections in an Output_segment.
4081
4082 unsigned int
4083 Output_segment::output_section_count() const
4084 {
4085   unsigned int ret = 0;
4086   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4087     ret += this->output_section_count_list(&this->output_lists_[i]);
4088   return ret;
4089 }
4090
4091 // Return the number of Output_sections in an Output_data_list.
4092
4093 unsigned int
4094 Output_segment::output_section_count_list(const Output_data_list* pdl) const
4095 {
4096   unsigned int count = 0;
4097   for (Output_data_list::const_iterator p = pdl->begin();
4098        p != pdl->end();
4099        ++p)
4100     {
4101       if ((*p)->is_section())
4102         ++count;
4103     }
4104   return count;
4105 }
4106
4107 // Return the section attached to the list segment with the lowest
4108 // load address.  This is used when handling a PHDRS clause in a
4109 // linker script.
4110
4111 Output_section*
4112 Output_segment::section_with_lowest_load_address() const
4113 {
4114   Output_section* found = NULL;
4115   uint64_t found_lma = 0;
4116   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4117     this->lowest_load_address_in_list(&this->output_lists_[i], &found,
4118                                       &found_lma);
4119   return found;
4120 }
4121
4122 // Look through a list for a section with a lower load address.
4123
4124 void
4125 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
4126                                             Output_section** found,
4127                                             uint64_t* found_lma) const
4128 {
4129   for (Output_data_list::const_iterator p = pdl->begin();
4130        p != pdl->end();
4131        ++p)
4132     {
4133       if (!(*p)->is_section())
4134         continue;
4135       Output_section* os = static_cast<Output_section*>(*p);
4136       uint64_t lma = (os->has_load_address()
4137                       ? os->load_address()
4138                       : os->address());
4139       if (*found == NULL || lma < *found_lma)
4140         {
4141           *found = os;
4142           *found_lma = lma;
4143         }
4144     }
4145 }
4146
4147 // Write the segment data into *OPHDR.
4148
4149 template<int size, bool big_endian>
4150 void
4151 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
4152 {
4153   ophdr->put_p_type(this->type_);
4154   ophdr->put_p_offset(this->offset_);
4155   ophdr->put_p_vaddr(this->vaddr_);
4156   ophdr->put_p_paddr(this->paddr_);
4157   ophdr->put_p_filesz(this->filesz_);
4158   ophdr->put_p_memsz(this->memsz_);
4159   ophdr->put_p_flags(this->flags_);
4160   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
4161 }
4162
4163 // Write the section headers into V.
4164
4165 template<int size, bool big_endian>
4166 unsigned char*
4167 Output_segment::write_section_headers(const Layout* layout,
4168                                       const Stringpool* secnamepool,
4169                                       unsigned char* v,
4170                                       unsigned int* pshndx) const
4171 {
4172   // Every section that is attached to a segment must be attached to a
4173   // PT_LOAD segment, so we only write out section headers for PT_LOAD
4174   // segments.
4175   if (this->type_ != elfcpp::PT_LOAD)
4176     return v;
4177
4178   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4179     {
4180       const Output_data_list* pdl = &this->output_lists_[i];
4181       v = this->write_section_headers_list<size, big_endian>(layout,
4182                                                              secnamepool,
4183                                                              pdl,
4184                                                              v, pshndx);
4185     }
4186
4187   return v;
4188 }
4189
4190 template<int size, bool big_endian>
4191 unsigned char*
4192 Output_segment::write_section_headers_list(const Layout* layout,
4193                                            const Stringpool* secnamepool,
4194                                            const Output_data_list* pdl,
4195                                            unsigned char* v,
4196                                            unsigned int* pshndx) const
4197 {
4198   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
4199   for (Output_data_list::const_iterator p = pdl->begin();
4200        p != pdl->end();
4201        ++p)
4202     {
4203       if ((*p)->is_section())
4204         {
4205           const Output_section* ps = static_cast<const Output_section*>(*p);
4206           gold_assert(*pshndx == ps->out_shndx());
4207           elfcpp::Shdr_write<size, big_endian> oshdr(v);
4208           ps->write_header(layout, secnamepool, &oshdr);
4209           v += shdr_size;
4210           ++*pshndx;
4211         }
4212     }
4213   return v;
4214 }
4215
4216 // Print the output sections to the map file.
4217
4218 void
4219 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
4220 {
4221   if (this->type() != elfcpp::PT_LOAD)
4222     return;
4223   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4224     this->print_section_list_to_mapfile(mapfile, &this->output_lists_[i]);
4225 }
4226
4227 // Print an output section list to the map file.
4228
4229 void
4230 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
4231                                               const Output_data_list* pdl) const
4232 {
4233   for (Output_data_list::const_iterator p = pdl->begin();
4234        p != pdl->end();
4235        ++p)
4236     (*p)->print_to_mapfile(mapfile);
4237 }
4238
4239 // Output_file methods.
4240
4241 Output_file::Output_file(const char* name)
4242   : name_(name),
4243     o_(-1),
4244     file_size_(0),
4245     base_(NULL),
4246     map_is_anonymous_(false),
4247     is_temporary_(false)
4248 {
4249 }
4250
4251 // Try to open an existing file.  Returns false if the file doesn't
4252 // exist, has a size of 0 or can't be mmapped.
4253
4254 bool
4255 Output_file::open_for_modification()
4256 {
4257   // The name "-" means "stdout".
4258   if (strcmp(this->name_, "-") == 0)
4259     return false;
4260
4261   // Don't bother opening files with a size of zero.
4262   struct stat s;
4263   if (::stat(this->name_, &s) != 0 || s.st_size == 0)
4264     return false;
4265
4266   int o = open_descriptor(-1, this->name_, O_RDWR, 0);
4267   if (o < 0)
4268     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4269   this->o_ = o;
4270   this->file_size_ = s.st_size;
4271
4272   // If the file can't be mmapped, copying the content to an anonymous
4273   // map will probably negate the performance benefits of incremental
4274   // linking.  This could be helped by using views and loading only
4275   // the necessary parts, but this is not supported as of now.
4276   if (!this->map_no_anonymous())
4277     {
4278       release_descriptor(o, true);
4279       this->o_ = -1;
4280       this->file_size_ = 0;
4281       return false;
4282     }
4283
4284   return true;
4285 }
4286
4287 // Open the output file.
4288
4289 void
4290 Output_file::open(off_t file_size)
4291 {
4292   this->file_size_ = file_size;
4293
4294   // Unlink the file first; otherwise the open() may fail if the file
4295   // is busy (e.g. it's an executable that's currently being executed).
4296   //
4297   // However, the linker may be part of a system where a zero-length
4298   // file is created for it to write to, with tight permissions (gcc
4299   // 2.95 did something like this).  Unlinking the file would work
4300   // around those permission controls, so we only unlink if the file
4301   // has a non-zero size.  We also unlink only regular files to avoid
4302   // trouble with directories/etc.
4303   //
4304   // If we fail, continue; this command is merely a best-effort attempt
4305   // to improve the odds for open().
4306
4307   // We let the name "-" mean "stdout"
4308   if (!this->is_temporary_)
4309     {
4310       if (strcmp(this->name_, "-") == 0)
4311         this->o_ = STDOUT_FILENO;
4312       else
4313         {
4314           struct stat s;
4315           if (::stat(this->name_, &s) == 0
4316               && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
4317             {
4318               if (s.st_size != 0)
4319                 ::unlink(this->name_);
4320               else if (!parameters->options().relocatable())
4321                 {
4322                   // If we don't unlink the existing file, add execute
4323                   // permission where read permissions already exist
4324                   // and where the umask permits.
4325                   int mask = ::umask(0);
4326                   ::umask(mask);
4327                   s.st_mode |= (s.st_mode & 0444) >> 2;
4328                   ::chmod(this->name_, s.st_mode & ~mask);
4329                 }
4330             }
4331
4332           int mode = parameters->options().relocatable() ? 0666 : 0777;
4333           int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
4334                                   mode);
4335           if (o < 0)
4336             gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4337           this->o_ = o;
4338         }
4339     }
4340
4341   this->map();
4342 }
4343
4344 // Resize the output file.
4345
4346 void
4347 Output_file::resize(off_t file_size)
4348 {
4349   // If the mmap is mapping an anonymous memory buffer, this is easy:
4350   // just mremap to the new size.  If it's mapping to a file, we want
4351   // to unmap to flush to the file, then remap after growing the file.
4352   if (this->map_is_anonymous_)
4353     {
4354       void* base = ::mremap(this->base_, this->file_size_, file_size,
4355                             MREMAP_MAYMOVE);
4356       if (base == MAP_FAILED)
4357         gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
4358       this->base_ = static_cast<unsigned char*>(base);
4359       this->file_size_ = file_size;
4360     }
4361   else
4362     {
4363       this->unmap();
4364       this->file_size_ = file_size;
4365       if (!this->map_no_anonymous())
4366         gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
4367     }
4368 }
4369
4370 // Map an anonymous block of memory which will later be written to the
4371 // file.  Return whether the map succeeded.
4372
4373 bool
4374 Output_file::map_anonymous()
4375 {
4376   void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4377                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
4378   if (base != MAP_FAILED)
4379     {
4380       this->map_is_anonymous_ = true;
4381       this->base_ = static_cast<unsigned char*>(base);
4382       return true;
4383     }
4384   return false;
4385 }
4386
4387 // Map the file into memory.  Return whether the mapping succeeded.
4388
4389 bool
4390 Output_file::map_no_anonymous()
4391 {
4392   const int o = this->o_;
4393
4394   // If the output file is not a regular file, don't try to mmap it;
4395   // instead, we'll mmap a block of memory (an anonymous buffer), and
4396   // then later write the buffer to the file.
4397   void* base;
4398   struct stat statbuf;
4399   if (o == STDOUT_FILENO || o == STDERR_FILENO
4400       || ::fstat(o, &statbuf) != 0
4401       || !S_ISREG(statbuf.st_mode)
4402       || this->is_temporary_)
4403     return false;
4404
4405   // Ensure that we have disk space available for the file.  If we
4406   // don't do this, it is possible that we will call munmap, close,
4407   // and exit with dirty buffers still in the cache with no assigned
4408   // disk blocks.  If the disk is out of space at that point, the
4409   // output file will wind up incomplete, but we will have already
4410   // exited.  The alternative to fallocate would be to use fdatasync,
4411   // but that would be a more significant performance hit.
4412   if (::posix_fallocate(o, 0, this->file_size_) < 0)
4413     gold_fatal(_("%s: %s"), this->name_, strerror(errno));
4414
4415   // Map the file into memory.
4416   base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4417                 MAP_SHARED, o, 0);
4418
4419   // The mmap call might fail because of file system issues: the file
4420   // system might not support mmap at all, or it might not support
4421   // mmap with PROT_WRITE.
4422   if (base == MAP_FAILED)
4423     return false;
4424
4425   this->map_is_anonymous_ = false;
4426   this->base_ = static_cast<unsigned char*>(base);
4427   return true;
4428 }
4429
4430 // Map the file into memory.
4431
4432 void
4433 Output_file::map()
4434 {
4435   if (this->map_no_anonymous())
4436     return;
4437
4438   // The mmap call might fail because of file system issues: the file
4439   // system might not support mmap at all, or it might not support
4440   // mmap with PROT_WRITE.  I'm not sure which errno values we will
4441   // see in all cases, so if the mmap fails for any reason and we
4442   // don't care about file contents, try for an anonymous map.
4443   if (this->map_anonymous())
4444     return;
4445
4446   gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
4447              this->name_, static_cast<unsigned long>(this->file_size_),
4448              strerror(errno));
4449 }
4450
4451 // Unmap the file from memory.
4452
4453 void
4454 Output_file::unmap()
4455 {
4456   if (::munmap(this->base_, this->file_size_) < 0)
4457     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4458   this->base_ = NULL;
4459 }
4460
4461 // Close the output file.
4462
4463 void
4464 Output_file::close()
4465 {
4466   // If the map isn't file-backed, we need to write it now.
4467   if (this->map_is_anonymous_ && !this->is_temporary_)
4468     {
4469       size_t bytes_to_write = this->file_size_;
4470       size_t offset = 0;
4471       while (bytes_to_write > 0)
4472         {
4473           ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4474                                           bytes_to_write);
4475           if (bytes_written == 0)
4476             gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4477           else if (bytes_written < 0)
4478             gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4479           else
4480             {
4481               bytes_to_write -= bytes_written;
4482               offset += bytes_written;
4483             }
4484         }
4485     }
4486   this->unmap();
4487
4488   // We don't close stdout or stderr
4489   if (this->o_ != STDOUT_FILENO
4490       && this->o_ != STDERR_FILENO
4491       && !this->is_temporary_)
4492     if (::close(this->o_) < 0)
4493       gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4494   this->o_ = -1;
4495 }
4496
4497 // Instantiate the templates we need.  We could use the configure
4498 // script to restrict this to only the ones for implemented targets.
4499
4500 #ifdef HAVE_TARGET_32_LITTLE
4501 template
4502 off_t
4503 Output_section::add_input_section<32, false>(
4504     Layout* layout,
4505     Sized_relobj<32, false>* object,
4506     unsigned int shndx,
4507     const char* secname,
4508     const elfcpp::Shdr<32, false>& shdr,
4509     unsigned int reloc_shndx,
4510     bool have_sections_script);
4511 #endif
4512
4513 #ifdef HAVE_TARGET_32_BIG
4514 template
4515 off_t
4516 Output_section::add_input_section<32, true>(
4517     Layout* layout,
4518     Sized_relobj<32, true>* object,
4519     unsigned int shndx,
4520     const char* secname,
4521     const elfcpp::Shdr<32, true>& shdr,
4522     unsigned int reloc_shndx,
4523     bool have_sections_script);
4524 #endif
4525
4526 #ifdef HAVE_TARGET_64_LITTLE
4527 template
4528 off_t
4529 Output_section::add_input_section<64, false>(
4530     Layout* layout,
4531     Sized_relobj<64, false>* object,
4532     unsigned int shndx,
4533     const char* secname,
4534     const elfcpp::Shdr<64, false>& shdr,
4535     unsigned int reloc_shndx,
4536     bool have_sections_script);
4537 #endif
4538
4539 #ifdef HAVE_TARGET_64_BIG
4540 template
4541 off_t
4542 Output_section::add_input_section<64, true>(
4543     Layout* layout,
4544     Sized_relobj<64, true>* object,
4545     unsigned int shndx,
4546     const char* secname,
4547     const elfcpp::Shdr<64, true>& shdr,
4548     unsigned int reloc_shndx,
4549     bool have_sections_script);
4550 #endif
4551
4552 #ifdef HAVE_TARGET_32_LITTLE
4553 template
4554 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4555 #endif
4556
4557 #ifdef HAVE_TARGET_32_BIG
4558 template
4559 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4560 #endif
4561
4562 #ifdef HAVE_TARGET_64_LITTLE
4563 template
4564 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4565 #endif
4566
4567 #ifdef HAVE_TARGET_64_BIG
4568 template
4569 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4570 #endif
4571
4572 #ifdef HAVE_TARGET_32_LITTLE
4573 template
4574 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4575 #endif
4576
4577 #ifdef HAVE_TARGET_32_BIG
4578 template
4579 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4580 #endif
4581
4582 #ifdef HAVE_TARGET_64_LITTLE
4583 template
4584 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4585 #endif
4586
4587 #ifdef HAVE_TARGET_64_BIG
4588 template
4589 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4590 #endif
4591
4592 #ifdef HAVE_TARGET_32_LITTLE
4593 template
4594 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4595 #endif
4596
4597 #ifdef HAVE_TARGET_32_BIG
4598 template
4599 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4600 #endif
4601
4602 #ifdef HAVE_TARGET_64_LITTLE
4603 template
4604 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4605 #endif
4606
4607 #ifdef HAVE_TARGET_64_BIG
4608 template
4609 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4610 #endif
4611
4612 #ifdef HAVE_TARGET_32_LITTLE
4613 template
4614 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4615 #endif
4616
4617 #ifdef HAVE_TARGET_32_BIG
4618 template
4619 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4620 #endif
4621
4622 #ifdef HAVE_TARGET_64_LITTLE
4623 template
4624 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4625 #endif
4626
4627 #ifdef HAVE_TARGET_64_BIG
4628 template
4629 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4630 #endif
4631
4632 #ifdef HAVE_TARGET_32_LITTLE
4633 template
4634 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4635 #endif
4636
4637 #ifdef HAVE_TARGET_32_BIG
4638 template
4639 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4640 #endif
4641
4642 #ifdef HAVE_TARGET_64_LITTLE
4643 template
4644 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4645 #endif
4646
4647 #ifdef HAVE_TARGET_64_BIG
4648 template
4649 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4650 #endif
4651
4652 #ifdef HAVE_TARGET_32_LITTLE
4653 template
4654 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4655 #endif
4656
4657 #ifdef HAVE_TARGET_32_BIG
4658 template
4659 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4660 #endif
4661
4662 #ifdef HAVE_TARGET_64_LITTLE
4663 template
4664 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4665 #endif
4666
4667 #ifdef HAVE_TARGET_64_BIG
4668 template
4669 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4670 #endif
4671
4672 #ifdef HAVE_TARGET_32_LITTLE
4673 template
4674 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4675 #endif
4676
4677 #ifdef HAVE_TARGET_32_BIG
4678 template
4679 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4680 #endif
4681
4682 #ifdef HAVE_TARGET_64_LITTLE
4683 template
4684 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4685 #endif
4686
4687 #ifdef HAVE_TARGET_64_BIG
4688 template
4689 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4690 #endif
4691
4692 #ifdef HAVE_TARGET_32_LITTLE
4693 template
4694 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4695 #endif
4696
4697 #ifdef HAVE_TARGET_32_BIG
4698 template
4699 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4700 #endif
4701
4702 #ifdef HAVE_TARGET_64_LITTLE
4703 template
4704 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4705 #endif
4706
4707 #ifdef HAVE_TARGET_64_BIG
4708 template
4709 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4710 #endif
4711
4712 #ifdef HAVE_TARGET_32_LITTLE
4713 template
4714 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4715 #endif
4716
4717 #ifdef HAVE_TARGET_32_BIG
4718 template
4719 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4720 #endif
4721
4722 #ifdef HAVE_TARGET_64_LITTLE
4723 template
4724 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4725 #endif
4726
4727 #ifdef HAVE_TARGET_64_BIG
4728 template
4729 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4730 #endif
4731
4732 #ifdef HAVE_TARGET_32_LITTLE
4733 template
4734 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4735 #endif
4736
4737 #ifdef HAVE_TARGET_32_BIG
4738 template
4739 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4740 #endif
4741
4742 #ifdef HAVE_TARGET_64_LITTLE
4743 template
4744 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4745 #endif
4746
4747 #ifdef HAVE_TARGET_64_BIG
4748 template
4749 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4750 #endif
4751
4752 #ifdef HAVE_TARGET_32_LITTLE
4753 template
4754 class Output_data_group<32, false>;
4755 #endif
4756
4757 #ifdef HAVE_TARGET_32_BIG
4758 template
4759 class Output_data_group<32, true>;
4760 #endif
4761
4762 #ifdef HAVE_TARGET_64_LITTLE
4763 template
4764 class Output_data_group<64, false>;
4765 #endif
4766
4767 #ifdef HAVE_TARGET_64_BIG
4768 template
4769 class Output_data_group<64, true>;
4770 #endif
4771
4772 #ifdef HAVE_TARGET_32_LITTLE
4773 template
4774 class Output_data_got<32, false>;
4775 #endif
4776
4777 #ifdef HAVE_TARGET_32_BIG
4778 template
4779 class Output_data_got<32, true>;
4780 #endif
4781
4782 #ifdef HAVE_TARGET_64_LITTLE
4783 template
4784 class Output_data_got<64, false>;
4785 #endif
4786
4787 #ifdef HAVE_TARGET_64_BIG
4788 template
4789 class Output_data_got<64, true>;
4790 #endif
4791
4792 } // End namespace gold.