gold/output.cc

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