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     is_noload_(false),
1915     tls_offset_(0),
1916     checkpoint_(NULL),
1917     merge_section_map_(),
1918     merge_section_by_properties_map_(),
1919     relaxed_input_section_map_(),
1920     is_relaxed_input_section_map_valid_(true)
1921 {
1922   // An unallocated section has no address.  Forcing this means that
1923   // we don't need special treatment for symbols defined in debug
1924   // sections.
1925   if ((flags & elfcpp::SHF_ALLOC) == 0)
1926     this->set_address(0);
1927 }
1928
1929 Output_section::~Output_section()
1930 {
1931   delete this->checkpoint_;
1932 }
1933
1934 // Set the entry size.
1935
1936 void
1937 Output_section::set_entsize(uint64_t v)
1938 {
1939   if (this->is_entsize_zero_)
1940     ;
1941   else if (this->entsize_ == 0)
1942     this->entsize_ = v;
1943   else if (this->entsize_ != v)
1944     {
1945       this->entsize_ = 0;
1946       this->is_entsize_zero_ = 1;
1947     }
1948 }
1949
1950 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1951 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
1952 // relocation section which applies to this section, or 0 if none, or
1953 // -1U if more than one.  Return the offset of the input section
1954 // within the output section.  Return -1 if the input section will
1955 // receive special handling.  In the normal case we don't always keep
1956 // track of input sections for an Output_section.  Instead, each
1957 // Object keeps track of the Output_section for each of its input
1958 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
1959 // track of input sections here; this is used when SECTIONS appears in
1960 // a linker script.
1961
1962 template<int size, bool big_endian>
1963 off_t
1964 Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
1965                                   unsigned int shndx,
1966                                   const char* secname,
1967                                   const elfcpp::Shdr<size, big_endian>& shdr,
1968                                   unsigned int reloc_shndx,
1969                                   bool have_sections_script)
1970 {
1971   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1972   if ((addralign & (addralign - 1)) != 0)
1973     {
1974       object->error(_("invalid alignment %lu for section \"%s\""),
1975                     static_cast<unsigned long>(addralign), secname);
1976       addralign = 1;
1977     }
1978
1979   if (addralign > this->addralign_)
1980     this->addralign_ = addralign;
1981
1982   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
1983   uint64_t entsize = shdr.get_sh_entsize();
1984
1985   // .debug_str is a mergeable string section, but is not always so
1986   // marked by compilers.  Mark manually here so we can optimize.
1987   if (strcmp(secname, ".debug_str") == 0)
1988     {
1989       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
1990       entsize = 1;
1991     }
1992
1993   this->update_flags_for_input_section(sh_flags);
1994   this->set_entsize(entsize);
1995
1996   // If this is a SHF_MERGE section, we pass all the input sections to
1997   // a Output_data_merge.  We don't try to handle relocations for such
1998   // a section.  We don't try to handle empty merge sections--they
1999   // mess up the mappings, and are useless anyhow.
2000   if ((sh_flags & elfcpp::SHF_MERGE) != 0
2001       && reloc_shndx == 0
2002       && shdr.get_sh_size() > 0)
2003     {
2004       if (this->add_merge_input_section(object, shndx, sh_flags,
2005                                         entsize, addralign))
2006         {
2007           // Tell the relocation routines that they need to call the
2008           // output_offset method to determine the final address.
2009           return -1;
2010         }
2011     }
2012
2013   off_t offset_in_section = this->current_data_size_for_child();
2014   off_t aligned_offset_in_section = align_address(offset_in_section,
2015                                                   addralign);
2016
2017   // Determine if we want to delay code-fill generation until the output
2018   // section is written.  When the target is relaxing, we want to delay fill
2019   // generating to avoid adjusting them during relaxation.
2020   if (!this->generate_code_fills_at_write_
2021       && !have_sections_script
2022       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2023       && parameters->target().has_code_fill()
2024       && parameters->target().may_relax())
2025     {
2026       gold_assert(this->fills_.empty());
2027       this->generate_code_fills_at_write_ = true;
2028     }
2029
2030   if (aligned_offset_in_section > offset_in_section
2031       && !this->generate_code_fills_at_write_
2032       && !have_sections_script
2033       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2034       && parameters->target().has_code_fill())
2035     {
2036       // We need to add some fill data.  Using fill_list_ when
2037       // possible is an optimization, since we will often have fill
2038       // sections without input sections.
2039       off_t fill_len = aligned_offset_in_section - offset_in_section;
2040       if (this->input_sections_.empty())
2041         this->fills_.push_back(Fill(offset_in_section, fill_len));
2042       else
2043         {
2044           std::string fill_data(parameters->target().code_fill(fill_len));
2045           Output_data_const* odc = new Output_data_const(fill_data, 1);
2046           this->input_sections_.push_back(Input_section(odc));
2047         }
2048     }
2049
2050   this->set_current_data_size_for_child(aligned_offset_in_section
2051                                         + shdr.get_sh_size());
2052
2053   // We need to keep track of this section if we are already keeping
2054   // track of sections, or if we are relaxing.  Also, if this is a
2055   // section which requires sorting, or which may require sorting in
2056   // the future, we keep track of the sections.
2057   if (have_sections_script
2058       || !this->input_sections_.empty()
2059       || this->may_sort_attached_input_sections()
2060       || this->must_sort_attached_input_sections()
2061       || parameters->options().user_set_Map()
2062       || parameters->target().may_relax())
2063     this->input_sections_.push_back(Input_section(object, shndx,
2064                                                   shdr.get_sh_size(),
2065                                                   addralign));
2066
2067   return aligned_offset_in_section;
2068 }
2069
2070 // Add arbitrary data to an output section.
2071
2072 void
2073 Output_section::add_output_section_data(Output_section_data* posd)
2074 {
2075   Input_section inp(posd);
2076   this->add_output_section_data(&inp);
2077
2078   if (posd->is_data_size_valid())
2079     {
2080       off_t offset_in_section = this->current_data_size_for_child();
2081       off_t aligned_offset_in_section = align_address(offset_in_section,
2082                                                       posd->addralign());
2083       this->set_current_data_size_for_child(aligned_offset_in_section
2084                                             + posd->data_size());
2085     }
2086 }
2087
2088 // Add a relaxed input section.
2089
2090 void
2091 Output_section::add_relaxed_input_section(Output_relaxed_input_section* poris)
2092 {
2093   Input_section inp(poris);
2094   this->add_output_section_data(&inp);
2095   if (this->is_relaxed_input_section_map_valid_)
2096     {
2097       Const_section_id csid(poris->relobj(), poris->shndx());
2098       this->relaxed_input_section_map_[csid] = poris;
2099     }
2100
2101   // For a relaxed section, we use the current data size.  Linker scripts
2102   // get all the input sections, including relaxed one from an output
2103   // section and add them back to them same output section to compute the
2104   // output section size.  If we do not account for sizes of relaxed input
2105   // sections,  an output section would be incorrectly sized.
2106   off_t offset_in_section = this->current_data_size_for_child();
2107   off_t aligned_offset_in_section = align_address(offset_in_section,
2108                                                   poris->addralign());
2109   this->set_current_data_size_for_child(aligned_offset_in_section
2110                                         + poris->current_data_size());
2111 }
2112
2113 // Add arbitrary data to an output section by Input_section.
2114
2115 void
2116 Output_section::add_output_section_data(Input_section* inp)
2117 {
2118   if (this->input_sections_.empty())
2119     this->first_input_offset_ = this->current_data_size_for_child();
2120
2121   this->input_sections_.push_back(*inp);
2122
2123   uint64_t addralign = inp->addralign();
2124   if (addralign > this->addralign_)
2125     this->addralign_ = addralign;
2126
2127   inp->set_output_section(this);
2128 }
2129
2130 // Add a merge section to an output section.
2131
2132 void
2133 Output_section::add_output_merge_section(Output_section_data* posd,
2134                                          bool is_string, uint64_t entsize)
2135 {
2136   Input_section inp(posd, is_string, entsize);
2137   this->add_output_section_data(&inp);
2138 }
2139
2140 // Add an input section to a SHF_MERGE section.
2141
2142 bool
2143 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2144                                         uint64_t flags, uint64_t entsize,
2145                                         uint64_t addralign)
2146 {
2147   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2148
2149   // We only merge strings if the alignment is not more than the
2150   // character size.  This could be handled, but it's unusual.
2151   if (is_string && addralign > entsize)
2152     return false;
2153
2154   // We cannot restore merged input section states.
2155   gold_assert(this->checkpoint_ == NULL);
2156
2157   // Look up merge sections by required properties.
2158   Output_merge_base* pomb;
2159   Merge_section_properties msp(is_string, entsize, addralign);
2160   Merge_section_by_properties_map::const_iterator p =
2161     this->merge_section_by_properties_map_.find(msp);
2162   if (p != this->merge_section_by_properties_map_.end())
2163     {
2164       pomb = p->second;
2165       gold_assert(pomb->is_string() == is_string
2166                   && pomb->entsize() == entsize
2167                   && pomb->addralign() == addralign);
2168     }
2169   else
2170     {
2171       // Create a new Output_merge_data or Output_merge_string_data.
2172       if (!is_string)
2173         pomb = new Output_merge_data(entsize, addralign);
2174       else
2175         {
2176           switch (entsize)
2177             {
2178             case 1:
2179               pomb = new Output_merge_string<char>(addralign);
2180               break;
2181             case 2:
2182               pomb = new Output_merge_string<uint16_t>(addralign);
2183               break;
2184             case 4:
2185               pomb = new Output_merge_string<uint32_t>(addralign);
2186               break;
2187             default:
2188               return false;
2189             }
2190         }
2191       // Add new merge section to this output section and link merge
2192       // section properties to new merge section in map.
2193       this->add_output_merge_section(pomb, is_string, entsize);
2194       this->merge_section_by_properties_map_[msp] = pomb;
2195     }
2196
2197   if (pomb->add_input_section(object, shndx))
2198     {
2199       // Add input section to new merge section and link input section to new
2200       // merge section in map.
2201       Const_section_id csid(object, shndx);
2202       this->merge_section_map_[csid] = pomb;
2203       return true;
2204     }
2205   else
2206     return false;
2207 }
2208
2209 // Build a relaxation map to speed up relaxation of existing input sections.
2210 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2211
2212 void
2213 Output_section::build_relaxation_map(
2214   const Input_section_list& input_sections,
2215   size_t limit,
2216   Relaxation_map* relaxation_map) const
2217 {
2218   for (size_t i = 0; i < limit; ++i)
2219     {
2220       const Input_section& is(input_sections[i]);
2221       if (is.is_input_section() || is.is_relaxed_input_section())
2222         {
2223           Section_id sid(is.relobj(), is.shndx());
2224           (*relaxation_map)[sid] = i;
2225         }
2226     }
2227 }
2228
2229 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2230 // sections in RELAXED_SECTIONS.  MAP is a prebuilt map from section id
2231 // indices of INPUT_SECTIONS.
2232
2233 void
2234 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2235   const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2236   const Relaxation_map& map,
2237   Input_section_list* input_sections)
2238 {
2239   for (size_t i = 0; i < relaxed_sections.size(); ++i)
2240     {
2241       Output_relaxed_input_section* poris = relaxed_sections[i];
2242       Section_id sid(poris->relobj(), poris->shndx());
2243       Relaxation_map::const_iterator p = map.find(sid);
2244       gold_assert(p != map.end());
2245       gold_assert((*input_sections)[p->second].is_input_section());
2246       (*input_sections)[p->second] = Input_section(poris);
2247     }
2248 }
2249
2250 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2251 // is a vector of pointers to Output_relaxed_input_section or its derived
2252 // classes.  The relaxed sections must correspond to existing input sections.
2253
2254 void
2255 Output_section::convert_input_sections_to_relaxed_sections(
2256   const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2257 {
2258   gold_assert(parameters->target().may_relax());
2259
2260   // We want to make sure that restore_states does not undo the effect of
2261   // this.  If there is no checkpoint active, just search the current
2262   // input section list and replace the sections there.  If there is
2263   // a checkpoint, also replace the sections there.
2264
2265   // By default, we look at the whole list.
2266   size_t limit = this->input_sections_.size();
2267
2268   if (this->checkpoint_ != NULL)
2269     {
2270       // Replace input sections with relaxed input section in the saved
2271       // copy of the input section list.
2272       if (this->checkpoint_->input_sections_saved())
2273         {
2274           Relaxation_map map;
2275           this->build_relaxation_map(
2276                     *(this->checkpoint_->input_sections()),
2277                     this->checkpoint_->input_sections()->size(),
2278                     &map);
2279           this->convert_input_sections_in_list_to_relaxed_sections(
2280                     relaxed_sections,
2281                     map,
2282                     this->checkpoint_->input_sections());
2283         }
2284       else
2285         {
2286           // We have not copied the input section list yet.  Instead, just
2287           // look at the portion that would be saved.
2288           limit = this->checkpoint_->input_sections_size();
2289         }
2290     }
2291
2292   // Convert input sections in input_section_list.
2293   Relaxation_map map;
2294   this->build_relaxation_map(this->input_sections_, limit, &map);
2295   this->convert_input_sections_in_list_to_relaxed_sections(
2296             relaxed_sections,
2297             map,
2298             &this->input_sections_);
2299
2300   // Update fast look-up map.
2301   if (this->is_relaxed_input_section_map_valid_)
2302     for (size_t i = 0; i < relaxed_sections.size(); ++i)
2303       {
2304         Output_relaxed_input_section* poris = relaxed_sections[i];
2305         Const_section_id csid(poris->relobj(), poris->shndx());
2306         this->relaxed_input_section_map_[csid] = poris;
2307       }
2308 }
2309
2310 // Update the output section flags based on input section flags.
2311
2312 void
2313 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2314 {
2315   // If we created the section with SHF_ALLOC clear, we set the
2316   // address.  If we are now setting the SHF_ALLOC flag, we need to
2317   // undo that.
2318   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2319       && (flags & elfcpp::SHF_ALLOC) != 0)
2320     this->mark_address_invalid();
2321
2322   this->flags_ |= (flags
2323                    & (elfcpp::SHF_WRITE
2324                       | elfcpp::SHF_ALLOC
2325                       | elfcpp::SHF_EXECINSTR));
2326
2327   if ((flags & elfcpp::SHF_MERGE) == 0)
2328     this->flags_ &=~ elfcpp::SHF_MERGE;
2329   else
2330     {
2331       if (this->current_data_size_for_child() == 0)
2332         this->flags_ |= elfcpp::SHF_MERGE;
2333     }
2334
2335   if ((flags & elfcpp::SHF_STRINGS) == 0)
2336     this->flags_ &=~ elfcpp::SHF_STRINGS;
2337   else
2338     {
2339       if (this->current_data_size_for_child() == 0)
2340         this->flags_ |= elfcpp::SHF_STRINGS;
2341     }
2342 }
2343
2344 // Find the merge section into which an input section with index SHNDX in
2345 // OBJECT has been added.  Return NULL if none found.
2346
2347 Output_section_data*
2348 Output_section::find_merge_section(const Relobj* object,
2349                                    unsigned int shndx) const
2350 {
2351   Const_section_id csid(object, shndx);
2352   Output_section_data_by_input_section_map::const_iterator p =
2353     this->merge_section_map_.find(csid);
2354   if (p != this->merge_section_map_.end())
2355     {
2356       Output_section_data* posd = p->second;
2357       gold_assert(posd->is_merge_section_for(object, shndx));
2358       return posd;
2359     }
2360   else
2361     return NULL;
2362 }
2363
2364 // Find an relaxed input section corresponding to an input section
2365 // in OBJECT with index SHNDX.
2366
2367 const Output_relaxed_input_section*
2368 Output_section::find_relaxed_input_section(const Relobj* object,
2369                                            unsigned int shndx) const
2370 {
2371   // Be careful that the map may not be valid due to input section export
2372   // to scripts or a check-point restore.
2373   if (!this->is_relaxed_input_section_map_valid_)
2374     {
2375       // Rebuild the map as needed.
2376       this->relaxed_input_section_map_.clear();
2377       for (Input_section_list::const_iterator p = this->input_sections_.begin();
2378            p != this->input_sections_.end();
2379            ++p)
2380         if (p->is_relaxed_input_section())
2381           {
2382             Const_section_id csid(p->relobj(), p->shndx());
2383             this->relaxed_input_section_map_[csid] =
2384               p->relaxed_input_section();
2385           }
2386       this->is_relaxed_input_section_map_valid_ = true;
2387     }
2388
2389   Const_section_id csid(object, shndx);
2390   Output_relaxed_input_section_by_input_section_map::const_iterator p =
2391     this->relaxed_input_section_map_.find(csid);
2392   if (p != this->relaxed_input_section_map_.end())
2393     return p->second;
2394   else
2395     return NULL;
2396 }
2397
2398 // Given an address OFFSET relative to the start of input section
2399 // SHNDX in OBJECT, return whether this address is being included in
2400 // the final link.  This should only be called if SHNDX in OBJECT has
2401 // a special mapping.
2402
2403 bool
2404 Output_section::is_input_address_mapped(const Relobj* object,
2405                                         unsigned int shndx,
2406                                         off_t offset) const
2407 {
2408   // Look at the Output_section_data_maps first.
2409   const Output_section_data* posd = this->find_merge_section(object, shndx);
2410   if (posd == NULL)
2411     posd = this->find_relaxed_input_section(object, shndx);
2412
2413   if (posd != NULL)
2414     {
2415       section_offset_type output_offset;
2416       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2417       gold_assert(found);
2418       return output_offset != -1;
2419     }
2420
2421   // Fall back to the slow look-up.
2422   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2423        p != this->input_sections_.end();
2424        ++p)
2425     {
2426       section_offset_type output_offset;
2427       if (p->output_offset(object, shndx, offset, &output_offset))
2428         return output_offset != -1;
2429     }
2430
2431   // By default we assume that the address is mapped.  This should
2432   // only be called after we have passed all sections to Layout.  At
2433   // that point we should know what we are discarding.
2434   return true;
2435 }
2436
2437 // Given an address OFFSET relative to the start of input section
2438 // SHNDX in object OBJECT, return the output offset relative to the
2439 // start of the input section in the output section.  This should only
2440 // be called if SHNDX in OBJECT has a special mapping.
2441
2442 section_offset_type
2443 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2444                               section_offset_type offset) const
2445 {
2446   // This can only be called meaningfully when we know the data size
2447   // of this.
2448   gold_assert(this->is_data_size_valid());
2449
2450   // Look at the Output_section_data_maps first.
2451   const Output_section_data* posd = this->find_merge_section(object, shndx);
2452   if (posd == NULL)
2453     posd = this->find_relaxed_input_section(object, shndx);
2454   if (posd != NULL)
2455     {
2456       section_offset_type output_offset;
2457       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2458       gold_assert(found);
2459       return output_offset;
2460     }
2461
2462   // Fall back to the slow look-up.
2463   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2464        p != this->input_sections_.end();
2465        ++p)
2466     {
2467       section_offset_type output_offset;
2468       if (p->output_offset(object, shndx, offset, &output_offset))
2469         return output_offset;
2470     }
2471   gold_unreachable();
2472 }
2473
2474 // Return the output virtual address of OFFSET relative to the start
2475 // of input section SHNDX in object OBJECT.
2476
2477 uint64_t
2478 Output_section::output_address(const Relobj* object, unsigned int shndx,
2479                                off_t offset) const
2480 {
2481   uint64_t addr = this->address() + this->first_input_offset_;
2482
2483   // Look at the Output_section_data_maps first.
2484   const Output_section_data* posd = this->find_merge_section(object, shndx);
2485   if (posd == NULL)
2486     posd = this->find_relaxed_input_section(object, shndx);
2487   if (posd != NULL && posd->is_address_valid())
2488     {
2489       section_offset_type output_offset;
2490       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2491       gold_assert(found);
2492       return posd->address() + output_offset;
2493     }
2494
2495   // Fall back to the slow look-up.
2496   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2497        p != this->input_sections_.end();
2498        ++p)
2499     {
2500       addr = align_address(addr, p->addralign());
2501       section_offset_type output_offset;
2502       if (p->output_offset(object, shndx, offset, &output_offset))
2503         {
2504           if (output_offset == -1)
2505             return -1ULL;
2506           return addr + output_offset;
2507         }
2508       addr += p->data_size();
2509     }
2510
2511   // If we get here, it means that we don't know the mapping for this
2512   // input section.  This might happen in principle if
2513   // add_input_section were called before add_output_section_data.
2514   // But it should never actually happen.
2515
2516   gold_unreachable();
2517 }
2518
2519 // Find the output address of the start of the merged section for
2520 // input section SHNDX in object OBJECT.
2521
2522 bool
2523 Output_section::find_starting_output_address(const Relobj* object,
2524                                              unsigned int shndx,
2525                                              uint64_t* paddr) const
2526 {
2527   // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2528   // Looking up the merge section map does not always work as we sometimes
2529   // find a merge section without its address set.
2530   uint64_t addr = this->address() + this->first_input_offset_;
2531   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2532        p != this->input_sections_.end();
2533        ++p)
2534     {
2535       addr = align_address(addr, p->addralign());
2536
2537       // It would be nice if we could use the existing output_offset
2538       // method to get the output offset of input offset 0.
2539       // Unfortunately we don't know for sure that input offset 0 is
2540       // mapped at all.
2541       if (p->is_merge_section_for(object, shndx))
2542         {
2543           *paddr = addr;
2544           return true;
2545         }
2546
2547       addr += p->data_size();
2548     }
2549
2550   // We couldn't find a merge output section for this input section.
2551   return false;
2552 }
2553
2554 // Set the data size of an Output_section.  This is where we handle
2555 // setting the addresses of any Output_section_data objects.
2556
2557 void
2558 Output_section::set_final_data_size()
2559 {
2560   if (this->input_sections_.empty())
2561     {
2562       this->set_data_size(this->current_data_size_for_child());
2563       return;
2564     }
2565
2566   if (this->must_sort_attached_input_sections())
2567     this->sort_attached_input_sections();
2568
2569   uint64_t address = this->address();
2570   off_t startoff = this->offset();
2571   off_t off = startoff + this->first_input_offset_;
2572   for (Input_section_list::iterator p = this->input_sections_.begin();
2573        p != this->input_sections_.end();
2574        ++p)
2575     {
2576       off = align_address(off, p->addralign());
2577       p->set_address_and_file_offset(address + (off - startoff), off,
2578                                      startoff);
2579       off += p->data_size();
2580     }
2581
2582   this->set_data_size(off - startoff);
2583 }
2584
2585 // Reset the address and file offset.
2586
2587 void
2588 Output_section::do_reset_address_and_file_offset()
2589 {
2590   // An unallocated section has no address.  Forcing this means that
2591   // we don't need special treatment for symbols defined in debug
2592   // sections.  We do the same in the constructor.  This does not
2593   // apply to NOLOAD sections though.
2594   if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
2595      this->set_address(0);
2596
2597   for (Input_section_list::iterator p = this->input_sections_.begin();
2598        p != this->input_sections_.end();
2599        ++p)
2600     p->reset_address_and_file_offset();
2601 }
2602
2603 // Return true if address and file offset have the values after reset.
2604
2605 bool
2606 Output_section::do_address_and_file_offset_have_reset_values() const
2607 {
2608   if (this->is_offset_valid())
2609     return false;
2610
2611   // An unallocated section has address 0 after its construction or a reset.
2612   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2613     return this->is_address_valid() && this->address() == 0;
2614   else
2615     return !this->is_address_valid();
2616 }
2617
2618 // Set the TLS offset.  Called only for SHT_TLS sections.
2619
2620 void
2621 Output_section::do_set_tls_offset(uint64_t tls_base)
2622 {
2623   this->tls_offset_ = this->address() - tls_base;
2624 }
2625
2626 // In a few cases we need to sort the input sections attached to an
2627 // output section.  This is used to implement the type of constructor
2628 // priority ordering implemented by the GNU linker, in which the
2629 // priority becomes part of the section name and the sections are
2630 // sorted by name.  We only do this for an output section if we see an
2631 // attached input section matching ".ctor.*", ".dtor.*",
2632 // ".init_array.*" or ".fini_array.*".
2633
2634 class Output_section::Input_section_sort_entry
2635 {
2636  public:
2637   Input_section_sort_entry()
2638     : input_section_(), index_(-1U), section_has_name_(false),
2639       section_name_()
2640   { }
2641
2642   Input_section_sort_entry(const Input_section& input_section,
2643                            unsigned int index)
2644     : input_section_(input_section), index_(index),
2645       section_has_name_(input_section.is_input_section()
2646                         || input_section.is_relaxed_input_section())
2647   {
2648     if (this->section_has_name_)
2649       {
2650         // This is only called single-threaded from Layout::finalize,
2651         // so it is OK to lock.  Unfortunately we have no way to pass
2652         // in a Task token.
2653         const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2654         Object* obj = (input_section.is_input_section()
2655                        ? input_section.relobj()
2656                        : input_section.relaxed_input_section()->relobj());
2657         Task_lock_obj<Object> tl(dummy_task, obj);
2658
2659         // This is a slow operation, which should be cached in
2660         // Layout::layout if this becomes a speed problem.
2661         this->section_name_ = obj->section_name(input_section.shndx());
2662       }
2663   }
2664
2665   // Return the Input_section.
2666   const Input_section&
2667   input_section() const
2668   {
2669     gold_assert(this->index_ != -1U);
2670     return this->input_section_;
2671   }
2672
2673   // The index of this entry in the original list.  This is used to
2674   // make the sort stable.
2675   unsigned int
2676   index() const
2677   {
2678     gold_assert(this->index_ != -1U);
2679     return this->index_;
2680   }
2681
2682   // Whether there is a section name.
2683   bool
2684   section_has_name() const
2685   { return this->section_has_name_; }
2686
2687   // The section name.
2688   const std::string&
2689   section_name() const
2690   {
2691     gold_assert(this->section_has_name_);
2692     return this->section_name_;
2693   }
2694
2695   // Return true if the section name has a priority.  This is assumed
2696   // to be true if it has a dot after the initial dot.
2697   bool
2698   has_priority() const
2699   {
2700     gold_assert(this->section_has_name_);
2701     return this->section_name_.find('.', 1) != std::string::npos;
2702   }
2703
2704   // Return true if this an input file whose base name matches
2705   // FILE_NAME.  The base name must have an extension of ".o", and
2706   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2707   // This is to match crtbegin.o as well as crtbeginS.o without
2708   // getting confused by other possibilities.  Overall matching the
2709   // file name this way is a dreadful hack, but the GNU linker does it
2710   // in order to better support gcc, and we need to be compatible.
2711   bool
2712   match_file_name(const char* match_file_name) const
2713   {
2714     const std::string& file_name(this->input_section_.relobj()->name());
2715     const char* base_name = lbasename(file_name.c_str());
2716     size_t match_len = strlen(match_file_name);
2717     if (strncmp(base_name, match_file_name, match_len) != 0)
2718       return false;
2719     size_t base_len = strlen(base_name);
2720     if (base_len != match_len + 2 && base_len != match_len + 3)
2721       return false;
2722     return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2723   }
2724
2725  private:
2726   // The Input_section we are sorting.
2727   Input_section input_section_;
2728   // The index of this Input_section in the original list.
2729   unsigned int index_;
2730   // Whether this Input_section has a section name--it won't if this
2731   // is some random Output_section_data.
2732   bool section_has_name_;
2733   // The section name if there is one.
2734   std::string section_name_;
2735 };
2736
2737 // Return true if S1 should come before S2 in the output section.
2738
2739 bool
2740 Output_section::Input_section_sort_compare::operator()(
2741     const Output_section::Input_section_sort_entry& s1,
2742     const Output_section::Input_section_sort_entry& s2) const
2743 {
2744   // crtbegin.o must come first.
2745   bool s1_begin = s1.match_file_name("crtbegin");
2746   bool s2_begin = s2.match_file_name("crtbegin");
2747   if (s1_begin || s2_begin)
2748     {
2749       if (!s1_begin)
2750         return false;
2751       if (!s2_begin)
2752         return true;
2753       return s1.index() < s2.index();
2754     }
2755
2756   // crtend.o must come last.
2757   bool s1_end = s1.match_file_name("crtend");
2758   bool s2_end = s2.match_file_name("crtend");
2759   if (s1_end || s2_end)
2760     {
2761       if (!s1_end)
2762         return true;
2763       if (!s2_end)
2764         return false;
2765       return s1.index() < s2.index();
2766     }
2767
2768   // We sort all the sections with no names to the end.
2769   if (!s1.section_has_name() || !s2.section_has_name())
2770     {
2771       if (s1.section_has_name())
2772         return true;
2773       if (s2.section_has_name())
2774         return false;
2775       return s1.index() < s2.index();
2776     }
2777
2778   // A section with a priority follows a section without a priority.
2779   bool s1_has_priority = s1.has_priority();
2780   bool s2_has_priority = s2.has_priority();
2781   if (s1_has_priority && !s2_has_priority)
2782     return false;
2783   if (!s1_has_priority && s2_has_priority)
2784     return true;
2785
2786   // Otherwise we sort by name.
2787   int compare = s1.section_name().compare(s2.section_name());
2788   if (compare != 0)
2789     return compare < 0;
2790
2791   // Otherwise we keep the input order.
2792   return s1.index() < s2.index();
2793 }
2794
2795 // Return true if S1 should come before S2 in an .init_array or .fini_array
2796 // output section.
2797
2798 bool
2799 Output_section::Input_section_sort_init_fini_compare::operator()(
2800     const Output_section::Input_section_sort_entry& s1,
2801     const Output_section::Input_section_sort_entry& s2) const
2802 {
2803   // We sort all the sections with no names to the end.
2804   if (!s1.section_has_name() || !s2.section_has_name())
2805     {
2806       if (s1.section_has_name())
2807         return true;
2808       if (s2.section_has_name())
2809         return false;
2810       return s1.index() < s2.index();
2811     }
2812
2813   // A section without a priority follows a section with a priority.
2814   // This is the reverse of .ctors and .dtors sections.
2815   bool s1_has_priority = s1.has_priority();
2816   bool s2_has_priority = s2.has_priority();
2817   if (s1_has_priority && !s2_has_priority)
2818     return true;
2819   if (!s1_has_priority && s2_has_priority)
2820     return false;
2821
2822   // Otherwise we sort by name.
2823   int compare = s1.section_name().compare(s2.section_name());
2824   if (compare != 0)
2825     return compare < 0;
2826
2827   // Otherwise we keep the input order.
2828   return s1.index() < s2.index();
2829 }
2830
2831 // Sort the input sections attached to an output section.
2832
2833 void
2834 Output_section::sort_attached_input_sections()
2835 {
2836   if (this->attached_input_sections_are_sorted_)
2837     return;
2838
2839   if (this->checkpoint_ != NULL
2840       && !this->checkpoint_->input_sections_saved())
2841     this->checkpoint_->save_input_sections();
2842
2843   // The only thing we know about an input section is the object and
2844   // the section index.  We need the section name.  Recomputing this
2845   // is slow but this is an unusual case.  If this becomes a speed
2846   // problem we can cache the names as required in Layout::layout.
2847
2848   // We start by building a larger vector holding a copy of each
2849   // Input_section, plus its current index in the list and its name.
2850   std::vector<Input_section_sort_entry> sort_list;
2851
2852   unsigned int i = 0;
2853   for (Input_section_list::iterator p = this->input_sections_.begin();
2854        p != this->input_sections_.end();
2855        ++p, ++i)
2856     sort_list.push_back(Input_section_sort_entry(*p, i));
2857
2858   // Sort the input sections.
2859   if (this->type() == elfcpp::SHT_PREINIT_ARRAY
2860       || this->type() == elfcpp::SHT_INIT_ARRAY
2861       || this->type() == elfcpp::SHT_FINI_ARRAY)
2862     std::sort(sort_list.begin(), sort_list.end(),
2863               Input_section_sort_init_fini_compare());
2864   else
2865     std::sort(sort_list.begin(), sort_list.end(),
2866               Input_section_sort_compare());
2867
2868   // Copy the sorted input sections back to our list.
2869   this->input_sections_.clear();
2870   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
2871        p != sort_list.end();
2872        ++p)
2873     this->input_sections_.push_back(p->input_section());
2874
2875   // Remember that we sorted the input sections, since we might get
2876   // called again.
2877   this->attached_input_sections_are_sorted_ = true;
2878 }
2879
2880 // Write the section header to *OSHDR.
2881
2882 template<int size, bool big_endian>
2883 void
2884 Output_section::write_header(const Layout* layout,
2885                              const Stringpool* secnamepool,
2886                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
2887 {
2888   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
2889   oshdr->put_sh_type(this->type_);
2890
2891   elfcpp::Elf_Xword flags = this->flags_;
2892   if (this->info_section_ != NULL && this->info_uses_section_index_)
2893     flags |= elfcpp::SHF_INFO_LINK;
2894   oshdr->put_sh_flags(flags);
2895
2896   oshdr->put_sh_addr(this->address());
2897   oshdr->put_sh_offset(this->offset());
2898   oshdr->put_sh_size(this->data_size());
2899   if (this->link_section_ != NULL)
2900     oshdr->put_sh_link(this->link_section_->out_shndx());
2901   else if (this->should_link_to_symtab_)
2902     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
2903   else if (this->should_link_to_dynsym_)
2904     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
2905   else
2906     oshdr->put_sh_link(this->link_);
2907
2908   elfcpp::Elf_Word info;
2909   if (this->info_section_ != NULL)
2910     {
2911       if (this->info_uses_section_index_)
2912         info = this->info_section_->out_shndx();
2913       else
2914         info = this->info_section_->symtab_index();
2915     }
2916   else if (this->info_symndx_ != NULL)
2917     info = this->info_symndx_->symtab_index();
2918   else
2919     info = this->info_;
2920   oshdr->put_sh_info(info);
2921
2922   oshdr->put_sh_addralign(this->addralign_);
2923   oshdr->put_sh_entsize(this->entsize_);
2924 }
2925
2926 // Write out the data.  For input sections the data is written out by
2927 // Object::relocate, but we have to handle Output_section_data objects
2928 // here.
2929
2930 void
2931 Output_section::do_write(Output_file* of)
2932 {
2933   gold_assert(!this->requires_postprocessing());
2934
2935   // If the target performs relaxation, we delay filler generation until now.
2936   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
2937
2938   off_t output_section_file_offset = this->offset();
2939   for (Fill_list::iterator p = this->fills_.begin();
2940        p != this->fills_.end();
2941        ++p)
2942     {
2943       std::string fill_data(parameters->target().code_fill(p->length()));
2944       of->write(output_section_file_offset + p->section_offset(),
2945                 fill_data.data(), fill_data.size());
2946     }
2947
2948   off_t off = this->offset() + this->first_input_offset_;
2949   for (Input_section_list::iterator p = this->input_sections_.begin();
2950        p != this->input_sections_.end();
2951        ++p)
2952     {
2953       off_t aligned_off = align_address(off, p->addralign());
2954       if (this->generate_code_fills_at_write_ && (off != aligned_off))
2955         {
2956           size_t fill_len = aligned_off - off;
2957           std::string fill_data(parameters->target().code_fill(fill_len));
2958           of->write(off, fill_data.data(), fill_data.size());
2959         }
2960
2961       p->write(of);
2962       off = aligned_off + p->data_size();
2963     }
2964 }
2965
2966 // If a section requires postprocessing, create the buffer to use.
2967
2968 void
2969 Output_section::create_postprocessing_buffer()
2970 {
2971   gold_assert(this->requires_postprocessing());
2972
2973   if (this->postprocessing_buffer_ != NULL)
2974     return;
2975
2976   if (!this->input_sections_.empty())
2977     {
2978       off_t off = this->first_input_offset_;
2979       for (Input_section_list::iterator p = this->input_sections_.begin();
2980            p != this->input_sections_.end();
2981            ++p)
2982         {
2983           off = align_address(off, p->addralign());
2984           p->finalize_data_size();
2985           off += p->data_size();
2986         }
2987       this->set_current_data_size_for_child(off);
2988     }
2989
2990   off_t buffer_size = this->current_data_size_for_child();
2991   this->postprocessing_buffer_ = new unsigned char[buffer_size];
2992 }
2993
2994 // Write all the data of an Output_section into the postprocessing
2995 // buffer.  This is used for sections which require postprocessing,
2996 // such as compression.  Input sections are handled by
2997 // Object::Relocate.
2998
2999 void
3000 Output_section::write_to_postprocessing_buffer()
3001 {
3002   gold_assert(this->requires_postprocessing());
3003
3004   // If the target performs relaxation, we delay filler generation until now.
3005   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3006
3007   unsigned char* buffer = this->postprocessing_buffer();
3008   for (Fill_list::iterator p = this->fills_.begin();
3009        p != this->fills_.end();
3010        ++p)
3011     {
3012       std::string fill_data(parameters->target().code_fill(p->length()));
3013       memcpy(buffer + p->section_offset(), fill_data.data(),
3014              fill_data.size());
3015     }
3016
3017   off_t off = this->first_input_offset_;
3018   for (Input_section_list::iterator p = this->input_sections_.begin();
3019        p != this->input_sections_.end();
3020        ++p)
3021     {
3022       off_t aligned_off = align_address(off, p->addralign());
3023       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3024         {
3025           size_t fill_len = aligned_off - off;
3026           std::string fill_data(parameters->target().code_fill(fill_len));
3027           memcpy(buffer + off, fill_data.data(), fill_data.size());
3028         }
3029
3030       p->write_to_buffer(buffer + aligned_off);
3031       off = aligned_off + p->data_size();
3032     }
3033 }
3034
3035 // Get the input sections for linker script processing.  We leave
3036 // behind the Output_section_data entries.  Note that this may be
3037 // slightly incorrect for merge sections.  We will leave them behind,
3038 // but it is possible that the script says that they should follow
3039 // some other input sections, as in:
3040 //    .rodata { *(.rodata) *(.rodata.cst*) }
3041 // For that matter, we don't handle this correctly:
3042 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
3043 // With luck this will never matter.
3044
3045 uint64_t
3046 Output_section::get_input_sections(
3047     uint64_t address,
3048     const std::string& fill,
3049     std::list<Simple_input_section>* input_sections)
3050 {
3051   if (this->checkpoint_ != NULL
3052       && !this->checkpoint_->input_sections_saved())
3053     this->checkpoint_->save_input_sections();
3054
3055   // Invalidate the relaxed input section map.
3056   this->is_relaxed_input_section_map_valid_ = false;
3057
3058   uint64_t orig_address = address;
3059
3060   address = align_address(address, this->addralign());
3061
3062   Input_section_list remaining;
3063   for (Input_section_list::iterator p = this->input_sections_.begin();
3064        p != this->input_sections_.end();
3065        ++p)
3066     {
3067       if (p->is_input_section())
3068         input_sections->push_back(Simple_input_section(p->relobj(),
3069                                                        p->shndx()));
3070       else if (p->is_relaxed_input_section())
3071         input_sections->push_back(
3072             Simple_input_section(p->relaxed_input_section()));
3073       else
3074         {
3075           uint64_t aligned_address = align_address(address, p->addralign());
3076           if (aligned_address != address && !fill.empty())
3077             {
3078               section_size_type length =
3079                 convert_to_section_size_type(aligned_address - address);
3080               std::string this_fill;
3081               this_fill.reserve(length);
3082               while (this_fill.length() + fill.length() <= length)
3083                 this_fill += fill;
3084               if (this_fill.length() < length)
3085                 this_fill.append(fill, 0, length - this_fill.length());
3086
3087               Output_section_data* posd = new Output_data_const(this_fill, 0);
3088               remaining.push_back(Input_section(posd));
3089             }
3090           address = aligned_address;
3091
3092           remaining.push_back(*p);
3093
3094           p->finalize_data_size();
3095           address += p->data_size();
3096         }
3097     }
3098
3099   this->input_sections_.swap(remaining);
3100   this->first_input_offset_ = 0;
3101
3102   uint64_t data_size = address - orig_address;
3103   this->set_current_data_size_for_child(data_size);
3104   return data_size;
3105 }
3106
3107 // Add an simple input section.
3108
3109 void
3110 Output_section::add_simple_input_section(const Simple_input_section& sis,
3111                                          off_t data_size,
3112                                          uint64_t addralign)
3113 {
3114   if (addralign > this->addralign_)
3115     this->addralign_ = addralign;
3116
3117   off_t offset_in_section = this->current_data_size_for_child();
3118   off_t aligned_offset_in_section = align_address(offset_in_section,
3119                                                   addralign);
3120
3121   this->set_current_data_size_for_child(aligned_offset_in_section
3122                                         + data_size);
3123
3124   Input_section is =
3125     (sis.is_relaxed_input_section()
3126      ? Input_section(sis.relaxed_input_section())
3127      : Input_section(sis.relobj(), sis.shndx(), data_size, addralign));
3128   this->input_sections_.push_back(is);
3129 }
3130
3131 // Save states for relaxation.
3132
3133 void
3134 Output_section::save_states()
3135 {
3136   gold_assert(this->checkpoint_ == NULL);
3137   Checkpoint_output_section* checkpoint =
3138     new Checkpoint_output_section(this->addralign_, this->flags_,
3139                                   this->input_sections_,
3140                                   this->first_input_offset_,
3141                                   this->attached_input_sections_are_sorted_);
3142   this->checkpoint_ = checkpoint;
3143   gold_assert(this->fills_.empty());
3144 }
3145
3146 void
3147 Output_section::discard_states()
3148 {
3149   gold_assert(this->checkpoint_ != NULL);
3150   delete this->checkpoint_;
3151   this->checkpoint_ = NULL;
3152   gold_assert(this->fills_.empty());
3153
3154   // Simply invalidate the relaxed input section map since we do not keep
3155   // track of it.
3156   this->is_relaxed_input_section_map_valid_ = false;
3157 }
3158
3159 void
3160 Output_section::restore_states()
3161 {
3162   gold_assert(this->checkpoint_ != NULL);
3163   Checkpoint_output_section* checkpoint = this->checkpoint_;
3164
3165   this->addralign_ = checkpoint->addralign();
3166   this->flags_ = checkpoint->flags();
3167   this->first_input_offset_ = checkpoint->first_input_offset();
3168
3169   if (!checkpoint->input_sections_saved())
3170     {
3171       // If we have not copied the input sections, just resize it.
3172       size_t old_size = checkpoint->input_sections_size();
3173       gold_assert(this->input_sections_.size() >= old_size);
3174       this->input_sections_.resize(old_size);
3175     }
3176   else
3177     {
3178       // We need to copy the whole list.  This is not efficient for
3179       // extremely large output with hundreads of thousands of input
3180       // objects.  We may need to re-think how we should pass sections
3181       // to scripts.
3182       this->input_sections_ = *checkpoint->input_sections();
3183     }
3184
3185   this->attached_input_sections_are_sorted_ =
3186     checkpoint->attached_input_sections_are_sorted();
3187
3188   // Simply invalidate the relaxed input section map since we do not keep
3189   // track of it.
3190   this->is_relaxed_input_section_map_valid_ = false;
3191 }
3192
3193 // Update the section offsets of input sections in this.  This is required if
3194 // relaxation causes some input sections to change sizes.
3195
3196 void
3197 Output_section::adjust_section_offsets()
3198 {
3199   if (!this->section_offsets_need_adjustment_)
3200     return;
3201
3202   off_t off = 0;
3203   for (Input_section_list::iterator p = this->input_sections_.begin();
3204        p != this->input_sections_.end();
3205        ++p)
3206     {
3207       off = align_address(off, p->addralign());
3208       if (p->is_input_section())
3209         p->relobj()->set_section_offset(p->shndx(), off);
3210       off += p->data_size();
3211     }
3212
3213   this->section_offsets_need_adjustment_ = false;
3214 }
3215
3216 // Print to the map file.
3217
3218 void
3219 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3220 {
3221   mapfile->print_output_section(this);
3222
3223   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3224        p != this->input_sections_.end();
3225        ++p)
3226     p->print_to_mapfile(mapfile);
3227 }
3228
3229 // Print stats for merge sections to stderr.
3230
3231 void
3232 Output_section::print_merge_stats()
3233 {
3234   Input_section_list::iterator p;
3235   for (p = this->input_sections_.begin();
3236        p != this->input_sections_.end();
3237        ++p)
3238     p->print_merge_stats(this->name_);
3239 }
3240
3241 // Output segment methods.
3242
3243 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3244   : output_data_(),
3245     output_bss_(),
3246     vaddr_(0),
3247     paddr_(0),
3248     memsz_(0),
3249     max_align_(0),
3250     min_p_align_(0),
3251     offset_(0),
3252     filesz_(0),
3253     type_(type),
3254     flags_(flags),
3255     is_max_align_known_(false),
3256     are_addresses_set_(false),
3257     is_large_data_segment_(false)
3258 {
3259   // The ELF ABI specifies that a PT_TLS segment always has PF_R as
3260   // the flags.
3261   if (type == elfcpp::PT_TLS)
3262     this->flags_ = elfcpp::PF_R;
3263 }
3264
3265 // Add an Output_section to an Output_segment.
3266
3267 void
3268 Output_segment::add_output_section(Output_section* os,
3269                                    elfcpp::Elf_Word seg_flags,
3270                                    bool do_sort)
3271 {
3272   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3273   gold_assert(!this->is_max_align_known_);
3274   gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3275   gold_assert(this->type() == elfcpp::PT_LOAD || !do_sort);
3276
3277   this->update_flags_for_output_section(seg_flags);
3278
3279   Output_segment::Output_data_list* pdl;
3280   if (os->type() == elfcpp::SHT_NOBITS)
3281     pdl = &this->output_bss_;
3282   else
3283     pdl = &this->output_data_;
3284
3285   // Note that while there may be many input sections in an output
3286   // section, there are normally only a few output sections in an
3287   // output segment.  The loops below are expected to be fast.
3288
3289   // So that PT_NOTE segments will work correctly, we need to ensure
3290   // that all SHT_NOTE sections are adjacent.
3291   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
3292     {
3293       Output_segment::Output_data_list::iterator p = pdl->end();
3294       do
3295         {
3296           --p;
3297           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
3298             {
3299               ++p;
3300               pdl->insert(p, os);
3301               return;
3302             }
3303         }
3304       while (p != pdl->begin());
3305     }
3306
3307   // Similarly, so that PT_TLS segments will work, we need to group
3308   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
3309   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
3310   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
3311   // correctly.  SHF_TLS sections get added to both a PT_LOAD segment
3312   // and the PT_TLS segment; we do this grouping only for the PT_LOAD
3313   // segment.
3314   if (this->type_ != elfcpp::PT_TLS
3315       && (os->flags() & elfcpp::SHF_TLS) != 0)
3316     {
3317       pdl = &this->output_data_;
3318       if (!pdl->empty())
3319         {
3320           bool nobits = os->type() == elfcpp::SHT_NOBITS;
3321           bool sawtls = false;
3322           Output_segment::Output_data_list::iterator p = pdl->end();
3323           gold_assert(p != pdl->begin());
3324           do
3325             {
3326               --p;
3327               bool insert;
3328               if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3329                 {
3330                   sawtls = true;
3331                   // Put a NOBITS section after the first TLS section.
3332                   // Put a PROGBITS section after the first
3333                   // TLS/PROGBITS section.
3334                   insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
3335                 }
3336               else
3337                 {
3338                   // If we've gone past the TLS sections, but we've
3339                   // seen a TLS section, then we need to insert this
3340                   // section now.
3341                   insert = sawtls;
3342                 }
3343
3344               if (insert)
3345                 {
3346                   ++p;
3347                   pdl->insert(p, os);
3348                   return;
3349                 }
3350             }
3351           while (p != pdl->begin());
3352         }
3353
3354       // There are no TLS sections yet; put this one at the requested
3355       // location in the section list.
3356     }
3357
3358   if (do_sort)
3359     {
3360       // For the PT_GNU_RELRO segment, we need to group relro
3361       // sections, and we need to put them before any non-relro
3362       // sections.  Any relro local sections go before relro non-local
3363       // sections.  One section may be marked as the last relro
3364       // section.
3365       if (os->is_relro())
3366         {
3367           gold_assert(pdl == &this->output_data_);
3368           Output_segment::Output_data_list::iterator p;
3369           for (p = pdl->begin(); p != pdl->end(); ++p)
3370             {
3371               if (!(*p)->is_section())
3372                 break;
3373
3374               Output_section* pos = (*p)->output_section();
3375               if (!pos->is_relro()
3376                   || (os->is_relro_local() && !pos->is_relro_local())
3377                   || (!os->is_last_relro() && pos->is_last_relro()))
3378                 break;
3379             }
3380
3381           pdl->insert(p, os);
3382           return;
3383         }
3384
3385       // One section may be marked as the first section which follows
3386       // the relro sections.
3387       if (os->is_first_non_relro())
3388         {
3389           gold_assert(pdl == &this->output_data_);
3390           Output_segment::Output_data_list::iterator p;
3391           for (p = pdl->begin(); p != pdl->end(); ++p)
3392             {
3393               if (!(*p)->is_section())
3394                 break;
3395
3396               Output_section* pos = (*p)->output_section();
3397               if (!pos->is_relro())
3398                 break;
3399             }
3400
3401           pdl->insert(p, os);
3402           return;
3403         }
3404     }
3405
3406   // Small data sections go at the end of the list of data sections.
3407   // If OS is not small, and there are small sections, we have to
3408   // insert it before the first small section.
3409   if (os->type() != elfcpp::SHT_NOBITS
3410       && !os->is_small_section()
3411       && !pdl->empty()
3412       && pdl->back()->is_section()
3413       && pdl->back()->output_section()->is_small_section())
3414     {
3415       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3416            p != pdl->end();
3417            ++p)
3418         {
3419           if ((*p)->is_section()
3420               && (*p)->output_section()->is_small_section())
3421             {
3422               pdl->insert(p, os);
3423               return;
3424             }
3425         }
3426       gold_unreachable();
3427     }
3428
3429   // A small BSS section goes at the start of the BSS sections, after
3430   // other small BSS sections.
3431   if (os->type() == elfcpp::SHT_NOBITS && os->is_small_section())
3432     {
3433       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3434            p != pdl->end();
3435            ++p)
3436         {
3437           if (!(*p)->is_section()
3438               || !(*p)->output_section()->is_small_section())
3439             {
3440               pdl->insert(p, os);
3441               return;
3442             }
3443         }
3444     }
3445
3446   // A large BSS section goes at the end of the BSS sections, which
3447   // means that one that is not large must come before the first large
3448   // one.
3449   if (os->type() == elfcpp::SHT_NOBITS
3450       && !os->is_large_section()
3451       && !pdl->empty()
3452       && pdl->back()->is_section()
3453       && pdl->back()->output_section()->is_large_section())
3454     {
3455       for (Output_segment::Output_data_list::iterator p = pdl->begin();
3456            p != pdl->end();
3457            ++p)
3458         {
3459           if ((*p)->is_section()
3460               && (*p)->output_section()->is_large_section())
3461             {
3462               pdl->insert(p, os);
3463               return;
3464             }
3465         }
3466       gold_unreachable();
3467     }
3468
3469   // We do some further output section sorting in order to make the
3470   // generated program run more efficiently.  We should only do this
3471   // when not using a linker script, so it is controled by the DO_SORT
3472   // parameter.
3473   if (do_sort)
3474     {
3475       // FreeBSD requires the .interp section to be in the first page
3476       // of the executable.  That is a more efficient location anyhow
3477       // for any OS, since it means that the kernel will have the data
3478       // handy after it reads the program headers.
3479       if (os->is_interp() && !pdl->empty())
3480         {
3481           pdl->insert(pdl->begin(), os);
3482           return;
3483         }
3484
3485       // Put loadable non-writable notes immediately after the .interp
3486       // sections, so that the PT_NOTE segment is on the first page of
3487       // the executable.
3488       if (os->type() == elfcpp::SHT_NOTE
3489           && (os->flags() & elfcpp::SHF_WRITE) == 0
3490           && !pdl->empty())
3491         {
3492           Output_segment::Output_data_list::iterator p = pdl->begin();
3493           if ((*p)->is_section() && (*p)->output_section()->is_interp())
3494             ++p;
3495           pdl->insert(p, os);
3496           return;
3497         }
3498
3499       // If this section is used by the dynamic linker, and it is not
3500       // writable, then put it first, after the .interp section and
3501       // any loadable notes.  This makes it more likely that the
3502       // dynamic linker will have to read less data from the disk.
3503       if (os->is_dynamic_linker_section()
3504           && !pdl->empty()
3505           && (os->flags() & elfcpp::SHF_WRITE) == 0)
3506         {
3507           bool is_reloc = (os->type() == elfcpp::SHT_REL
3508                            || os->type() == elfcpp::SHT_RELA);
3509           Output_segment::Output_data_list::iterator p = pdl->begin();
3510           while (p != pdl->end()
3511                  && (*p)->is_section()
3512                  && ((*p)->output_section()->is_dynamic_linker_section()
3513                      || (*p)->output_section()->type() == elfcpp::SHT_NOTE))
3514             {
3515               // Put reloc sections after the other ones.  Putting the
3516               // dynamic reloc sections first confuses BFD, notably
3517               // objcopy and strip.
3518               if (!is_reloc
3519                   && ((*p)->output_section()->type() == elfcpp::SHT_REL
3520                       || (*p)->output_section()->type() == elfcpp::SHT_RELA))
3521                 break;
3522               ++p;
3523             }
3524           pdl->insert(p, os);
3525           return;
3526         }
3527     }
3528
3529   // If there were no constraints on the output section, just add it
3530   // to the end of the list.
3531   pdl->push_back(os);
3532 }
3533
3534 // Remove an Output_section from this segment.  It is an error if it
3535 // is not present.
3536
3537 void
3538 Output_segment::remove_output_section(Output_section* os)
3539 {
3540   // We only need this for SHT_PROGBITS.
3541   gold_assert(os->type() == elfcpp::SHT_PROGBITS);
3542   for (Output_data_list::iterator p = this->output_data_.begin();
3543        p != this->output_data_.end();
3544        ++p)
3545    {
3546      if (*p == os)
3547        {
3548          this->output_data_.erase(p);
3549          return;
3550        }
3551    }
3552   gold_unreachable();
3553 }
3554
3555 // Add an Output_data (which need not be an Output_section) to the
3556 // start of a segment.
3557
3558 void
3559 Output_segment::add_initial_output_data(Output_data* od)
3560 {
3561   gold_assert(!this->is_max_align_known_);
3562   this->output_data_.push_front(od);
3563 }
3564
3565 // Return whether the first data section is a relro section.
3566
3567 bool
3568 Output_segment::is_first_section_relro() const
3569 {
3570   return (!this->output_data_.empty()
3571           && this->output_data_.front()->is_section()
3572           && this->output_data_.front()->output_section()->is_relro());
3573 }
3574
3575 // Return the maximum alignment of the Output_data in Output_segment.
3576
3577 uint64_t
3578 Output_segment::maximum_alignment()
3579 {
3580   if (!this->is_max_align_known_)
3581     {
3582       uint64_t addralign;
3583
3584       addralign = Output_segment::maximum_alignment_list(&this->output_data_);
3585       if (addralign > this->max_align_)
3586         this->max_align_ = addralign;
3587
3588       addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
3589       if (addralign > this->max_align_)
3590         this->max_align_ = addralign;
3591
3592       this->is_max_align_known_ = true;
3593     }
3594
3595   return this->max_align_;
3596 }
3597
3598 // Return the maximum alignment of a list of Output_data.
3599
3600 uint64_t
3601 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3602 {
3603   uint64_t ret = 0;
3604   for (Output_data_list::const_iterator p = pdl->begin();
3605        p != pdl->end();
3606        ++p)
3607     {
3608       uint64_t addralign = (*p)->addralign();
3609       if (addralign > ret)
3610         ret = addralign;
3611     }
3612   return ret;
3613 }
3614
3615 // Return the number of dynamic relocs applied to this segment.
3616
3617 unsigned int
3618 Output_segment::dynamic_reloc_count() const
3619 {
3620   return (this->dynamic_reloc_count_list(&this->output_data_)
3621           + this->dynamic_reloc_count_list(&this->output_bss_));
3622 }
3623
3624 // Return the number of dynamic relocs applied to an Output_data_list.
3625
3626 unsigned int
3627 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
3628 {
3629   unsigned int count = 0;
3630   for (Output_data_list::const_iterator p = pdl->begin();
3631        p != pdl->end();
3632        ++p)
3633     count += (*p)->dynamic_reloc_count();
3634   return count;
3635 }
3636
3637 // Set the section addresses for an Output_segment.  If RESET is true,
3638 // reset the addresses first.  ADDR is the address and *POFF is the
3639 // file offset.  Set the section indexes starting with *PSHNDX.
3640 // Return the address of the immediately following segment.  Update
3641 // *POFF and *PSHNDX.
3642
3643 uint64_t
3644 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3645                                       uint64_t addr,
3646                                       unsigned int increase_relro,
3647                                       off_t* poff,
3648                                       unsigned int* pshndx)
3649 {
3650   gold_assert(this->type_ == elfcpp::PT_LOAD);
3651
3652   off_t orig_off = *poff;
3653
3654   // If we have relro sections, we need to pad forward now so that the
3655   // relro sections plus INCREASE_RELRO end on a common page boundary.
3656   if (parameters->options().relro()
3657       && this->is_first_section_relro()
3658       && (!this->are_addresses_set_ || reset))
3659     {
3660       uint64_t relro_size = 0;
3661       off_t off = *poff;
3662       for (Output_data_list::iterator p = this->output_data_.begin();
3663            p != this->output_data_.end();
3664            ++p)
3665         {
3666           if (!(*p)->is_section())
3667             break;
3668           Output_section* pos = (*p)->output_section();
3669           if (!pos->is_relro())
3670             break;
3671           gold_assert(!(*p)->is_section_flag_set(elfcpp::SHF_TLS));
3672           if ((*p)->is_address_valid())
3673             relro_size += (*p)->data_size();
3674           else
3675             {
3676               // FIXME: This could be faster.
3677               (*p)->set_address_and_file_offset(addr + relro_size,
3678                                                 off + relro_size);
3679               relro_size += (*p)->data_size();
3680               (*p)->reset_address_and_file_offset();
3681             }
3682         }
3683       relro_size += increase_relro;
3684
3685       uint64_t page_align = parameters->target().common_pagesize();
3686
3687       // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
3688       uint64_t desired_align = page_align - (relro_size % page_align);
3689       if (desired_align < *poff % page_align)
3690         *poff += page_align - *poff % page_align;
3691       *poff += desired_align - *poff % page_align;
3692       addr += *poff - orig_off;
3693       orig_off = *poff;
3694     }
3695
3696   if (!reset && this->are_addresses_set_)
3697     {
3698       gold_assert(this->paddr_ == addr);
3699       addr = this->vaddr_;
3700     }
3701   else
3702     {
3703       this->vaddr_ = addr;
3704       this->paddr_ = addr;
3705       this->are_addresses_set_ = true;
3706     }
3707
3708   bool in_tls = false;
3709
3710   this->offset_ = orig_off;
3711
3712   addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
3713                                           addr, poff, pshndx, &in_tls);
3714   this->filesz_ = *poff - orig_off;
3715
3716   off_t off = *poff;
3717
3718   uint64_t ret = this->set_section_list_addresses(layout, reset,
3719                                                   &this->output_bss_,
3720                                                   addr, poff, pshndx,
3721                                                   &in_tls);
3722
3723   // If the last section was a TLS section, align upward to the
3724   // alignment of the TLS segment, so that the overall size of the TLS
3725   // segment is aligned.
3726   if (in_tls)
3727     {
3728       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3729       *poff = align_address(*poff, segment_align);
3730     }
3731
3732   this->memsz_ = *poff - orig_off;
3733
3734   // Ignore the file offset adjustments made by the BSS Output_data
3735   // objects.
3736   *poff = off;
3737
3738   return ret;
3739 }
3740
3741 // Set the addresses and file offsets in a list of Output_data
3742 // structures.
3743
3744 uint64_t
3745 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3746                                            Output_data_list* pdl,
3747                                            uint64_t addr, off_t* poff,
3748                                            unsigned int* pshndx,
3749                                            bool* in_tls)
3750 {
3751   off_t startoff = *poff;
3752
3753   off_t off = startoff;
3754   for (Output_data_list::iterator p = pdl->begin();
3755        p != pdl->end();
3756        ++p)
3757     {
3758       if (reset)
3759         (*p)->reset_address_and_file_offset();
3760
3761       // When using a linker script the section will most likely
3762       // already have an address.
3763       if (!(*p)->is_address_valid())
3764         {
3765           uint64_t align = (*p)->addralign();
3766
3767           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3768             {
3769               // Give the first TLS section the alignment of the
3770               // entire TLS segment.  Otherwise the TLS segment as a
3771               // whole may be misaligned.
3772               if (!*in_tls)
3773                 {
3774                   Output_segment* tls_segment = layout->tls_segment();
3775                   gold_assert(tls_segment != NULL);
3776                   uint64_t segment_align = tls_segment->maximum_alignment();
3777                   gold_assert(segment_align >= align);
3778                   align = segment_align;
3779
3780                   *in_tls = true;
3781                 }
3782             }
3783           else
3784             {
3785               // If this is the first section after the TLS segment,
3786               // align it to at least the alignment of the TLS
3787               // segment, so that the size of the overall TLS segment
3788               // is aligned.
3789               if (*in_tls)
3790                 {
3791                   uint64_t segment_align =
3792                       layout->tls_segment()->maximum_alignment();
3793                   if (segment_align > align)
3794                     align = segment_align;
3795
3796                   *in_tls = false;
3797                 }
3798             }
3799
3800           off = align_address(off, align);
3801           (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3802         }
3803       else
3804         {
3805           // The script may have inserted a skip forward, but it
3806           // better not have moved backward.
3807           if ((*p)->address() >= addr + (off - startoff))
3808             off += (*p)->address() - (addr + (off - startoff));
3809           else
3810             {
3811               if (!layout->script_options()->saw_sections_clause())
3812                 gold_unreachable();
3813               else
3814                 {
3815                   Output_section* os = (*p)->output_section();
3816
3817                   // Cast to unsigned long long to avoid format warnings.
3818                   unsigned long long previous_dot =
3819                     static_cast<unsigned long long>(addr + (off - startoff));
3820                   unsigned long long dot =
3821                     static_cast<unsigned long long>((*p)->address());
3822
3823                   if (os == NULL)
3824                     gold_error(_("dot moves backward in linker script "
3825                                  "from 0x%llx to 0x%llx"), previous_dot, dot);
3826                   else
3827                     gold_error(_("address of section '%s' moves backward "
3828                                  "from 0x%llx to 0x%llx"),
3829                                os->name(), previous_dot, dot);
3830                 }
3831             }
3832           (*p)->set_file_offset(off);
3833           (*p)->finalize_data_size();
3834         }
3835
3836       // We want to ignore the size of a SHF_TLS or SHT_NOBITS
3837       // section.  Such a section does not affect the size of a
3838       // PT_LOAD segment.
3839       if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
3840           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
3841         off += (*p)->data_size();
3842
3843       if ((*p)->is_section())
3844         {
3845           (*p)->set_out_shndx(*pshndx);
3846           ++*pshndx;
3847         }
3848     }
3849
3850   *poff = off;
3851   return addr + (off - startoff);
3852 }
3853
3854 // For a non-PT_LOAD segment, set the offset from the sections, if
3855 // any.  Add INCREASE to the file size and the memory size.
3856
3857 void
3858 Output_segment::set_offset(unsigned int increase)
3859 {
3860   gold_assert(this->type_ != elfcpp::PT_LOAD);
3861
3862   gold_assert(!this->are_addresses_set_);
3863
3864   if (this->output_data_.empty() && this->output_bss_.empty())
3865     {
3866       gold_assert(increase == 0);
3867       this->vaddr_ = 0;
3868       this->paddr_ = 0;
3869       this->are_addresses_set_ = true;
3870       this->memsz_ = 0;
3871       this->min_p_align_ = 0;
3872       this->offset_ = 0;
3873       this->filesz_ = 0;
3874       return;
3875     }
3876
3877   const Output_data* first;
3878   if (this->output_data_.empty())
3879     first = this->output_bss_.front();
3880   else
3881     first = this->output_data_.front();
3882   this->vaddr_ = first->address();
3883   this->paddr_ = (first->has_load_address()
3884                   ? first->load_address()
3885                   : this->vaddr_);
3886   this->are_addresses_set_ = true;
3887   this->offset_ = first->offset();
3888
3889   if (this->output_data_.empty())
3890     this->filesz_ = 0;
3891   else
3892     {
3893       const Output_data* last_data = this->output_data_.back();
3894       this->filesz_ = (last_data->address()
3895                        + last_data->data_size()
3896                        - this->vaddr_);
3897     }
3898
3899   const Output_data* last;
3900   if (this->output_bss_.empty())
3901     last = this->output_data_.back();
3902   else
3903     last = this->output_bss_.back();
3904   this->memsz_ = (last->address()
3905                   + last->data_size()
3906                   - this->vaddr_);
3907
3908   this->filesz_ += increase;
3909   this->memsz_ += increase;
3910
3911   // If this is a TLS segment, align the memory size.  The code in
3912   // set_section_list ensures that the section after the TLS segment
3913   // is aligned to give us room.
3914   if (this->type_ == elfcpp::PT_TLS)
3915     {
3916       uint64_t segment_align = this->maximum_alignment();
3917       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
3918       this->memsz_ = align_address(this->memsz_, segment_align);
3919     }
3920 }
3921
3922 // Set the TLS offsets of the sections in the PT_TLS segment.
3923
3924 void
3925 Output_segment::set_tls_offsets()
3926 {
3927   gold_assert(this->type_ == elfcpp::PT_TLS);
3928
3929   for (Output_data_list::iterator p = this->output_data_.begin();
3930        p != this->output_data_.end();
3931        ++p)
3932     (*p)->set_tls_offset(this->vaddr_);
3933
3934   for (Output_data_list::iterator p = this->output_bss_.begin();
3935        p != this->output_bss_.end();
3936        ++p)
3937     (*p)->set_tls_offset(this->vaddr_);
3938 }
3939
3940 // Return the address of the first section.
3941
3942 uint64_t
3943 Output_segment::first_section_load_address() const
3944 {
3945   for (Output_data_list::const_iterator p = this->output_data_.begin();
3946        p != this->output_data_.end();
3947        ++p)
3948     if ((*p)->is_section())
3949       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3950
3951   for (Output_data_list::const_iterator p = this->output_bss_.begin();
3952        p != this->output_bss_.end();
3953        ++p)
3954     if ((*p)->is_section())
3955       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3956
3957   gold_unreachable();
3958 }
3959
3960 // Return the number of Output_sections in an Output_segment.
3961
3962 unsigned int
3963 Output_segment::output_section_count() const
3964 {
3965   return (this->output_section_count_list(&this->output_data_)
3966           + this->output_section_count_list(&this->output_bss_));
3967 }
3968
3969 // Return the number of Output_sections in an Output_data_list.
3970
3971 unsigned int
3972 Output_segment::output_section_count_list(const Output_data_list* pdl) const
3973 {
3974   unsigned int count = 0;
3975   for (Output_data_list::const_iterator p = pdl->begin();
3976        p != pdl->end();
3977        ++p)
3978     {
3979       if ((*p)->is_section())
3980         ++count;
3981     }
3982   return count;
3983 }
3984
3985 // Return the section attached to the list segment with the lowest
3986 // load address.  This is used when handling a PHDRS clause in a
3987 // linker script.
3988
3989 Output_section*
3990 Output_segment::section_with_lowest_load_address() const
3991 {
3992   Output_section* found = NULL;
3993   uint64_t found_lma = 0;
3994   this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma);
3995
3996   Output_section* found_data = found;
3997   this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma);
3998   if (found != found_data && found_data != NULL)
3999     {
4000       gold_error(_("nobits section %s may not precede progbits section %s "
4001                    "in same segment"),
4002                  found->name(), found_data->name());
4003       return NULL;
4004     }
4005
4006   return found;
4007 }
4008
4009 // Look through a list for a section with a lower load address.
4010
4011 void
4012 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
4013                                             Output_section** found,
4014                                             uint64_t* found_lma) const
4015 {
4016   for (Output_data_list::const_iterator p = pdl->begin();
4017        p != pdl->end();
4018        ++p)
4019     {
4020       if (!(*p)->is_section())
4021         continue;
4022       Output_section* os = static_cast<Output_section*>(*p);
4023       uint64_t lma = (os->has_load_address()
4024                       ? os->load_address()
4025                       : os->address());
4026       if (*found == NULL || lma < *found_lma)
4027         {
4028           *found = os;
4029           *found_lma = lma;
4030         }
4031     }
4032 }
4033
4034 // Write the segment data into *OPHDR.
4035
4036 template<int size, bool big_endian>
4037 void
4038 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
4039 {
4040   ophdr->put_p_type(this->type_);
4041   ophdr->put_p_offset(this->offset_);
4042   ophdr->put_p_vaddr(this->vaddr_);
4043   ophdr->put_p_paddr(this->paddr_);
4044   ophdr->put_p_filesz(this->filesz_);
4045   ophdr->put_p_memsz(this->memsz_);
4046   ophdr->put_p_flags(this->flags_);
4047   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
4048 }
4049
4050 // Write the section headers into V.
4051
4052 template<int size, bool big_endian>
4053 unsigned char*
4054 Output_segment::write_section_headers(const Layout* layout,
4055                                       const Stringpool* secnamepool,
4056                                       unsigned char* v,
4057                                       unsigned int *pshndx) const
4058 {
4059   // Every section that is attached to a segment must be attached to a
4060   // PT_LOAD segment, so we only write out section headers for PT_LOAD
4061   // segments.
4062   if (this->type_ != elfcpp::PT_LOAD)
4063     return v;
4064
4065   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
4066                                                          &this->output_data_,
4067                                                          v, pshndx);
4068   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
4069                                                          &this->output_bss_,
4070                                                          v, pshndx);
4071   return v;
4072 }
4073
4074 template<int size, bool big_endian>
4075 unsigned char*
4076 Output_segment::write_section_headers_list(const Layout* layout,
4077                                            const Stringpool* secnamepool,
4078                                            const Output_data_list* pdl,
4079                                            unsigned char* v,
4080                                            unsigned int* pshndx) const
4081 {
4082   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
4083   for (Output_data_list::const_iterator p = pdl->begin();
4084        p != pdl->end();
4085        ++p)
4086     {
4087       if ((*p)->is_section())
4088         {
4089           const Output_section* ps = static_cast<const Output_section*>(*p);
4090           gold_assert(*pshndx == ps->out_shndx());
4091           elfcpp::Shdr_write<size, big_endian> oshdr(v);
4092           ps->write_header(layout, secnamepool, &oshdr);
4093           v += shdr_size;
4094           ++*pshndx;
4095         }
4096     }
4097   return v;
4098 }
4099
4100 // Print the output sections to the map file.
4101
4102 void
4103 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
4104 {
4105   if (this->type() != elfcpp::PT_LOAD)
4106     return;
4107   this->print_section_list_to_mapfile(mapfile, &this->output_data_);
4108   this->print_section_list_to_mapfile(mapfile, &this->output_bss_);
4109 }
4110
4111 // Print an output section list to the map file.
4112
4113 void
4114 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
4115                                               const Output_data_list* pdl) const
4116 {
4117   for (Output_data_list::const_iterator p = pdl->begin();
4118        p != pdl->end();
4119        ++p)
4120     (*p)->print_to_mapfile(mapfile);
4121 }
4122
4123 // Output_file methods.
4124
4125 Output_file::Output_file(const char* name)
4126   : name_(name),
4127     o_(-1),
4128     file_size_(0),
4129     base_(NULL),
4130     map_is_anonymous_(false),
4131     is_temporary_(false)
4132 {
4133 }
4134
4135 // Try to open an existing file.  Returns false if the file doesn't
4136 // exist, has a size of 0 or can't be mmapped.
4137
4138 bool
4139 Output_file::open_for_modification()
4140 {
4141   // The name "-" means "stdout".
4142   if (strcmp(this->name_, "-") == 0)
4143     return false;
4144
4145   // Don't bother opening files with a size of zero.
4146   struct stat s;
4147   if (::stat(this->name_, &s) != 0 || s.st_size == 0)
4148     return false;
4149
4150   int o = open_descriptor(-1, this->name_, O_RDWR, 0);
4151   if (o < 0)
4152     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4153   this->o_ = o;
4154   this->file_size_ = s.st_size;
4155
4156   // If the file can't be mmapped, copying the content to an anonymous
4157   // map will probably negate the performance benefits of incremental
4158   // linking.  This could be helped by using views and loading only
4159   // the necessary parts, but this is not supported as of now.
4160   if (!this->map_no_anonymous())
4161     {
4162       release_descriptor(o, true);
4163       this->o_ = -1;
4164       this->file_size_ = 0;
4165       return false;
4166     }
4167
4168   return true;
4169 }
4170
4171 // Open the output file.
4172
4173 void
4174 Output_file::open(off_t file_size)
4175 {
4176   this->file_size_ = file_size;
4177
4178   // Unlink the file first; otherwise the open() may fail if the file
4179   // is busy (e.g. it's an executable that's currently being executed).
4180   //
4181   // However, the linker may be part of a system where a zero-length
4182   // file is created for it to write to, with tight permissions (gcc
4183   // 2.95 did something like this).  Unlinking the file would work
4184   // around those permission controls, so we only unlink if the file
4185   // has a non-zero size.  We also unlink only regular files to avoid
4186   // trouble with directories/etc.
4187   //
4188   // If we fail, continue; this command is merely a best-effort attempt
4189   // to improve the odds for open().
4190
4191   // We let the name "-" mean "stdout"
4192   if (!this->is_temporary_)
4193     {
4194       if (strcmp(this->name_, "-") == 0)
4195         this->o_ = STDOUT_FILENO;
4196       else
4197         {
4198           struct stat s;
4199           if (::stat(this->name_, &s) == 0
4200               && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
4201             {
4202               if (s.st_size != 0)
4203                 ::unlink(this->name_);
4204               else if (!parameters->options().relocatable())
4205                 {
4206                   // If we don't unlink the existing file, add execute
4207                   // permission where read permissions already exist
4208                   // and where the umask permits.
4209                   int mask = ::umask(0);
4210                   ::umask(mask);
4211                   s.st_mode |= (s.st_mode & 0444) >> 2;
4212                   ::chmod(this->name_, s.st_mode & ~mask);
4213                 }
4214             }
4215
4216           int mode = parameters->options().relocatable() ? 0666 : 0777;
4217           int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
4218                                   mode);
4219           if (o < 0)
4220             gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4221           this->o_ = o;
4222         }
4223     }
4224
4225   this->map();
4226 }
4227
4228 // Resize the output file.
4229
4230 void
4231 Output_file::resize(off_t file_size)
4232 {
4233   // If the mmap is mapping an anonymous memory buffer, this is easy:
4234   // just mremap to the new size.  If it's mapping to a file, we want
4235   // to unmap to flush to the file, then remap after growing the file.
4236   if (this->map_is_anonymous_)
4237     {
4238       void* base = ::mremap(this->base_, this->file_size_, file_size,
4239                             MREMAP_MAYMOVE);
4240       if (base == MAP_FAILED)
4241         gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
4242       this->base_ = static_cast<unsigned char*>(base);
4243       this->file_size_ = file_size;
4244     }
4245   else
4246     {
4247       this->unmap();
4248       this->file_size_ = file_size;
4249       if (!this->map_no_anonymous())
4250         gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
4251     }
4252 }
4253
4254 // Map an anonymous block of memory which will later be written to the
4255 // file.  Return whether the map succeeded.
4256
4257 bool
4258 Output_file::map_anonymous()
4259 {
4260   void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4261                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
4262   if (base != MAP_FAILED)
4263     {
4264       this->map_is_anonymous_ = true;
4265       this->base_ = static_cast<unsigned char*>(base);
4266       return true;
4267     }
4268   return false;
4269 }
4270
4271 // Map the file into memory.  Return whether the mapping succeeded.
4272
4273 bool
4274 Output_file::map_no_anonymous()
4275 {
4276   const int o = this->o_;
4277
4278   // If the output file is not a regular file, don't try to mmap it;
4279   // instead, we'll mmap a block of memory (an anonymous buffer), and
4280   // then later write the buffer to the file.
4281   void* base;
4282   struct stat statbuf;
4283   if (o == STDOUT_FILENO || o == STDERR_FILENO
4284       || ::fstat(o, &statbuf) != 0
4285       || !S_ISREG(statbuf.st_mode)
4286       || this->is_temporary_)
4287     return false;
4288
4289   // Ensure that we have disk space available for the file.  If we
4290   // don't do this, it is possible that we will call munmap, close,
4291   // and exit with dirty buffers still in the cache with no assigned
4292   // disk blocks.  If the disk is out of space at that point, the
4293   // output file will wind up incomplete, but we will have already
4294   // exited.  The alternative to fallocate would be to use fdatasync,
4295   // but that would be a more significant performance hit.
4296   if (::posix_fallocate(o, 0, this->file_size_) < 0)
4297     gold_fatal(_("%s: %s"), this->name_, strerror(errno));
4298
4299   // Map the file into memory.
4300   base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4301                 MAP_SHARED, o, 0);
4302
4303   // The mmap call might fail because of file system issues: the file
4304   // system might not support mmap at all, or it might not support
4305   // mmap with PROT_WRITE.
4306   if (base == MAP_FAILED)
4307     return false;
4308
4309   this->map_is_anonymous_ = false;
4310   this->base_ = static_cast<unsigned char*>(base);
4311   return true;
4312 }
4313
4314 // Map the file into memory.
4315
4316 void
4317 Output_file::map()
4318 {
4319   if (this->map_no_anonymous())
4320     return;
4321
4322   // The mmap call might fail because of file system issues: the file
4323   // system might not support mmap at all, or it might not support
4324   // mmap with PROT_WRITE.  I'm not sure which errno values we will
4325   // see in all cases, so if the mmap fails for any reason and we
4326   // don't care about file contents, try for an anonymous map.
4327   if (this->map_anonymous())
4328     return;
4329
4330   gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
4331              this->name_, static_cast<unsigned long>(this->file_size_),
4332              strerror(errno));
4333 }
4334
4335 // Unmap the file from memory.
4336
4337 void
4338 Output_file::unmap()
4339 {
4340   if (::munmap(this->base_, this->file_size_) < 0)
4341     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4342   this->base_ = NULL;
4343 }
4344
4345 // Close the output file.
4346
4347 void
4348 Output_file::close()
4349 {
4350   // If the map isn't file-backed, we need to write it now.
4351   if (this->map_is_anonymous_ && !this->is_temporary_)
4352     {
4353       size_t bytes_to_write = this->file_size_;
4354       size_t offset = 0;
4355       while (bytes_to_write > 0)
4356         {
4357           ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4358                                           bytes_to_write);
4359           if (bytes_written == 0)
4360             gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4361           else if (bytes_written < 0)
4362             gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4363           else
4364             {
4365               bytes_to_write -= bytes_written;
4366               offset += bytes_written;
4367             }
4368         }
4369     }
4370   this->unmap();
4371
4372   // We don't close stdout or stderr
4373   if (this->o_ != STDOUT_FILENO
4374       && this->o_ != STDERR_FILENO
4375       && !this->is_temporary_)
4376     if (::close(this->o_) < 0)
4377       gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4378   this->o_ = -1;
4379 }
4380
4381 // Instantiate the templates we need.  We could use the configure
4382 // script to restrict this to only the ones for implemented targets.
4383
4384 #ifdef HAVE_TARGET_32_LITTLE
4385 template
4386 off_t
4387 Output_section::add_input_section<32, false>(
4388     Sized_relobj<32, false>* object,
4389     unsigned int shndx,
4390     const char* secname,
4391     const elfcpp::Shdr<32, false>& shdr,
4392     unsigned int reloc_shndx,
4393     bool have_sections_script);
4394 #endif
4395
4396 #ifdef HAVE_TARGET_32_BIG
4397 template
4398 off_t
4399 Output_section::add_input_section<32, true>(
4400     Sized_relobj<32, true>* object,
4401     unsigned int shndx,
4402     const char* secname,
4403     const elfcpp::Shdr<32, true>& shdr,
4404     unsigned int reloc_shndx,
4405     bool have_sections_script);
4406 #endif
4407
4408 #ifdef HAVE_TARGET_64_LITTLE
4409 template
4410 off_t
4411 Output_section::add_input_section<64, false>(
4412     Sized_relobj<64, false>* object,
4413     unsigned int shndx,
4414     const char* secname,
4415     const elfcpp::Shdr<64, false>& shdr,
4416     unsigned int reloc_shndx,
4417     bool have_sections_script);
4418 #endif
4419
4420 #ifdef HAVE_TARGET_64_BIG
4421 template
4422 off_t
4423 Output_section::add_input_section<64, true>(
4424     Sized_relobj<64, true>* object,
4425     unsigned int shndx,
4426     const char* secname,
4427     const elfcpp::Shdr<64, true>& shdr,
4428     unsigned int reloc_shndx,
4429     bool have_sections_script);
4430 #endif
4431
4432 #ifdef HAVE_TARGET_32_LITTLE
4433 template
4434 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4435 #endif
4436
4437 #ifdef HAVE_TARGET_32_BIG
4438 template
4439 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4440 #endif
4441
4442 #ifdef HAVE_TARGET_64_LITTLE
4443 template
4444 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4445 #endif
4446
4447 #ifdef HAVE_TARGET_64_BIG
4448 template
4449 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4450 #endif
4451
4452 #ifdef HAVE_TARGET_32_LITTLE
4453 template
4454 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4455 #endif
4456
4457 #ifdef HAVE_TARGET_32_BIG
4458 template
4459 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4460 #endif
4461
4462 #ifdef HAVE_TARGET_64_LITTLE
4463 template
4464 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4465 #endif
4466
4467 #ifdef HAVE_TARGET_64_BIG
4468 template
4469 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4470 #endif
4471
4472 #ifdef HAVE_TARGET_32_LITTLE
4473 template
4474 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4475 #endif
4476
4477 #ifdef HAVE_TARGET_32_BIG
4478 template
4479 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4480 #endif
4481
4482 #ifdef HAVE_TARGET_64_LITTLE
4483 template
4484 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4485 #endif
4486
4487 #ifdef HAVE_TARGET_64_BIG
4488 template
4489 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4490 #endif
4491
4492 #ifdef HAVE_TARGET_32_LITTLE
4493 template
4494 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4495 #endif
4496
4497 #ifdef HAVE_TARGET_32_BIG
4498 template
4499 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4500 #endif
4501
4502 #ifdef HAVE_TARGET_64_LITTLE
4503 template
4504 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4505 #endif
4506
4507 #ifdef HAVE_TARGET_64_BIG
4508 template
4509 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4510 #endif
4511
4512 #ifdef HAVE_TARGET_32_LITTLE
4513 template
4514 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4515 #endif
4516
4517 #ifdef HAVE_TARGET_32_BIG
4518 template
4519 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4520 #endif
4521
4522 #ifdef HAVE_TARGET_64_LITTLE
4523 template
4524 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4525 #endif
4526
4527 #ifdef HAVE_TARGET_64_BIG
4528 template
4529 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4530 #endif
4531
4532 #ifdef HAVE_TARGET_32_LITTLE
4533 template
4534 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4535 #endif
4536
4537 #ifdef HAVE_TARGET_32_BIG
4538 template
4539 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4540 #endif
4541
4542 #ifdef HAVE_TARGET_64_LITTLE
4543 template
4544 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4545 #endif
4546
4547 #ifdef HAVE_TARGET_64_BIG
4548 template
4549 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4550 #endif
4551
4552 #ifdef HAVE_TARGET_32_LITTLE
4553 template
4554 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4555 #endif
4556
4557 #ifdef HAVE_TARGET_32_BIG
4558 template
4559 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4560 #endif
4561
4562 #ifdef HAVE_TARGET_64_LITTLE
4563 template
4564 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4565 #endif
4566
4567 #ifdef HAVE_TARGET_64_BIG
4568 template
4569 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4570 #endif
4571
4572 #ifdef HAVE_TARGET_32_LITTLE
4573 template
4574 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4575 #endif
4576
4577 #ifdef HAVE_TARGET_32_BIG
4578 template
4579 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4580 #endif
4581
4582 #ifdef HAVE_TARGET_64_LITTLE
4583 template
4584 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4585 #endif
4586
4587 #ifdef HAVE_TARGET_64_BIG
4588 template
4589 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4590 #endif
4591
4592 #ifdef HAVE_TARGET_32_LITTLE
4593 template
4594 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4595 #endif
4596
4597 #ifdef HAVE_TARGET_32_BIG
4598 template
4599 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4600 #endif
4601
4602 #ifdef HAVE_TARGET_64_LITTLE
4603 template
4604 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4605 #endif
4606
4607 #ifdef HAVE_TARGET_64_BIG
4608 template
4609 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4610 #endif
4611
4612 #ifdef HAVE_TARGET_32_LITTLE
4613 template
4614 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4615 #endif
4616
4617 #ifdef HAVE_TARGET_32_BIG
4618 template
4619 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4620 #endif
4621
4622 #ifdef HAVE_TARGET_64_LITTLE
4623 template
4624 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4625 #endif
4626
4627 #ifdef HAVE_TARGET_64_BIG
4628 template
4629 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4630 #endif
4631
4632 #ifdef HAVE_TARGET_32_LITTLE
4633 template
4634 class Output_data_group<32, false>;
4635 #endif
4636
4637 #ifdef HAVE_TARGET_32_BIG
4638 template
4639 class Output_data_group<32, true>;
4640 #endif
4641
4642 #ifdef HAVE_TARGET_64_LITTLE
4643 template
4644 class Output_data_group<64, false>;
4645 #endif
4646
4647 #ifdef HAVE_TARGET_64_BIG
4648 template
4649 class Output_data_group<64, true>;
4650 #endif
4651
4652 #ifdef HAVE_TARGET_32_LITTLE
4653 template
4654 class Output_data_got<32, false>;
4655 #endif
4656
4657 #ifdef HAVE_TARGET_32_BIG
4658 template
4659 class Output_data_got<32, true>;
4660 #endif
4661
4662 #ifdef HAVE_TARGET_64_LITTLE
4663 template
4664 class Output_data_got<64, false>;
4665 #endif
4666
4667 #ifdef HAVE_TARGET_64_BIG
4668 template
4669 class Output_data_got<64, true>;
4670 #endif
4671
4672 } // End namespace gold.