gold/output.cc

   1 // output.cc -- manage the output file for gold
   2
   3 // Copyright 2006, 2007 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 <cerrno>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29 #include <sys/mman.h>
  30 #include <algorithm>
  31
  32 #include "parameters.h"
  33 #include "object.h"
  34 #include "symtab.h"
  35 #include "reloc.h"
  36 #include "merge.h"
  37 #include "output.h"
  38
  39 namespace gold
  40 {
  41
  42 // Output_data variables.
  43
  44 bool Output_data::sizes_are_fixed;
  45
  46 // Output_data methods.
  47
  48 Output_data::~Output_data()
  49 {
  50 }
  51
  52 // Set the address and offset.
  53
  54 void
  55 Output_data::set_address(uint64_t addr, off_t off)
  56 {
  57   this->address_ = addr;
  58   this->offset_ = off;
  59
  60   // Let the child class know.
  61   this->do_set_address(addr, off);
  62 }
  63
  64 // Return the default alignment for a size--32 or 64.
  65
  66 uint64_t
  67 Output_data::default_alignment(int size)
  68 {
  69   if (size == 32)
  70     return 4;
  71   else if (size == 64)
  72     return 8;
  73   else
  74     gold_unreachable();
  75 }
  76
  77 // Output_section_header methods.  This currently assumes that the
  78 // segment and section lists are complete at construction time.
  79
  80 Output_section_headers::Output_section_headers(
  81     const Layout* layout,
  82     const Layout::Segment_list* segment_list,
  83     const Layout::Section_list* unattached_section_list,
  84     const Stringpool* secnamepool)
  85   : layout_(layout),
  86     segment_list_(segment_list),
  87     unattached_section_list_(unattached_section_list),
  88     secnamepool_(secnamepool)
  89 {
  90   // Count all the sections.  Start with 1 for the null section.
  91   off_t count = 1;
  92   for (Layout::Segment_list::const_iterator p = segment_list->begin();
  93        p != segment_list->end();
  94        ++p)
  95     if ((*p)->type() == elfcpp::PT_LOAD)
  96       count += (*p)->output_section_count();
  97   count += unattached_section_list->size();
  98
  99   const int size = parameters->get_size();
 100   int shdr_size;
 101   if (size == 32)
 102     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
 103   else if (size == 64)
 104     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
 105   else
 106     gold_unreachable();
 107
 108   this->set_data_size(count * shdr_size);
 109 }
 110
 111 // Write out the section headers.
 112
 113 void
 114 Output_section_headers::do_write(Output_file* of)
 115 {
 116   if (parameters->get_size() == 32)
 117     {
 118       if (parameters->is_big_endian())
 119         {
 120 #ifdef HAVE_TARGET_32_BIG
 121           this->do_sized_write<32, true>(of);
 122 #else
 123           gold_unreachable();
 124 #endif
 125         }
 126       else
 127         {
 128 #ifdef HAVE_TARGET_32_LITTLE
 129           this->do_sized_write<32, false>(of);
 130 #else
 131           gold_unreachable();
 132 #endif
 133         }
 134     }
 135   else if (parameters->get_size() == 64)
 136     {
 137       if (parameters->is_big_endian())
 138         {
 139 #ifdef HAVE_TARGET_64_BIG
 140           this->do_sized_write<64, true>(of);
 141 #else
 142           gold_unreachable();
 143 #endif
 144         }
 145       else
 146         {
 147 #ifdef HAVE_TARGET_64_LITTLE
 148           this->do_sized_write<64, false>(of);
 149 #else
 150           gold_unreachable();
 151 #endif
 152         }
 153     }
 154   else
 155     gold_unreachable();
 156 }
 157
 158 template<int size, bool big_endian>
 159 void
 160 Output_section_headers::do_sized_write(Output_file* of)
 161 {
 162   off_t all_shdrs_size = this->data_size();
 163   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
 164
 165   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
 166   unsigned char* v = view;
 167
 168   {
 169     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
 170     oshdr.put_sh_name(0);
 171     oshdr.put_sh_type(elfcpp::SHT_NULL);
 172     oshdr.put_sh_flags(0);
 173     oshdr.put_sh_addr(0);
 174     oshdr.put_sh_offset(0);
 175     oshdr.put_sh_size(0);
 176     oshdr.put_sh_link(0);
 177     oshdr.put_sh_info(0);
 178     oshdr.put_sh_addralign(0);
 179     oshdr.put_sh_entsize(0);
 180   }
 181
 182   v += shdr_size;
 183
 184   unsigned shndx = 1;
 185   for (Layout::Segment_list::const_iterator p = this->segment_list_->begin();
 186        p != this->segment_list_->end();
 187        ++p)
 188     v = (*p)->write_section_headers SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
 189             this->layout_, this->secnamepool_, v, &shndx
 190             SELECT_SIZE_ENDIAN(size, big_endian));
 191   for (Layout::Section_list::const_iterator p =
 192          this->unattached_section_list_->begin();
 193        p != this->unattached_section_list_->end();
 194        ++p)
 195     {
 196       gold_assert(shndx == (*p)->out_shndx());
 197       elfcpp::Shdr_write<size, big_endian> oshdr(v);
 198       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
 199       v += shdr_size;
 200       ++shndx;
 201     }
 202
 203   of->write_output_view(this->offset(), all_shdrs_size, view);
 204 }
 205
 206 // Output_segment_header methods.
 207
 208 Output_segment_headers::Output_segment_headers(
 209     const Layout::Segment_list& segment_list)
 210   : segment_list_(segment_list)
 211 {
 212   const int size = parameters->get_size();
 213   int phdr_size;
 214   if (size == 32)
 215     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
 216   else if (size == 64)
 217     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
 218   else
 219     gold_unreachable();
 220
 221   this->set_data_size(segment_list.size() * phdr_size);
 222 }
 223
 224 void
 225 Output_segment_headers::do_write(Output_file* of)
 226 {
 227   if (parameters->get_size() == 32)
 228     {
 229       if (parameters->is_big_endian())
 230         {
 231 #ifdef HAVE_TARGET_32_BIG
 232           this->do_sized_write<32, true>(of);
 233 #else
 234           gold_unreachable();
 235 #endif
 236         }
 237       else
 238         {
 239 #ifdef HAVE_TARGET_32_LITTLE
 240         this->do_sized_write<32, false>(of);
 241 #else
 242         gold_unreachable();
 243 #endif
 244         }
 245     }
 246   else if (parameters->get_size() == 64)
 247     {
 248       if (parameters->is_big_endian())
 249         {
 250 #ifdef HAVE_TARGET_64_BIG
 251           this->do_sized_write<64, true>(of);
 252 #else
 253           gold_unreachable();
 254 #endif
 255         }
 256       else
 257         {
 258 #ifdef HAVE_TARGET_64_LITTLE
 259           this->do_sized_write<64, false>(of);
 260 #else
 261           gold_unreachable();
 262 #endif
 263         }
 264     }
 265   else
 266     gold_unreachable();
 267 }
 268
 269 template<int size, bool big_endian>
 270 void
 271 Output_segment_headers::do_sized_write(Output_file* of)
 272 {
 273   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
 274   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
 275   unsigned char* view = of->get_output_view(this->offset(),
 276                                             all_phdrs_size);
 277   unsigned char* v = view;
 278   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
 279        p != this->segment_list_.end();
 280        ++p)
 281     {
 282       elfcpp::Phdr_write<size, big_endian> ophdr(v);
 283       (*p)->write_header(&ophdr);
 284       v += phdr_size;
 285     }
 286
 287   of->write_output_view(this->offset(), all_phdrs_size, view);
 288 }
 289
 290 // Output_file_header methods.
 291
 292 Output_file_header::Output_file_header(const Target* target,
 293                                        const Symbol_table* symtab,
 294                                        const Output_segment_headers* osh)
 295   : target_(target),
 296     symtab_(symtab),
 297     segment_header_(osh),
 298     section_header_(NULL),
 299     shstrtab_(NULL)
 300 {
 301   const int size = parameters->get_size();
 302   int ehdr_size;
 303   if (size == 32)
 304     ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size;
 305   else if (size == 64)
 306     ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
 307   else
 308     gold_unreachable();
 309
 310   this->set_data_size(ehdr_size);
 311 }
 312
 313 // Set the section table information for a file header.
 314
 315 void
 316 Output_file_header::set_section_info(const Output_section_headers* shdrs,
 317                                      const Output_section* shstrtab)
 318 {
 319   this->section_header_ = shdrs;
 320   this->shstrtab_ = shstrtab;
 321 }
 322
 323 // Write out the file header.
 324
 325 void
 326 Output_file_header::do_write(Output_file* of)
 327 {
 328   if (parameters->get_size() == 32)
 329     {
 330       if (parameters->is_big_endian())
 331         {
 332 #ifdef HAVE_TARGET_32_BIG
 333           this->do_sized_write<32, true>(of);
 334 #else
 335           gold_unreachable();
 336 #endif
 337         }
 338       else
 339         {
 340 #ifdef HAVE_TARGET_32_LITTLE
 341           this->do_sized_write<32, false>(of);
 342 #else
 343           gold_unreachable();
 344 #endif
 345         }
 346     }
 347   else if (parameters->get_size() == 64)
 348     {
 349       if (parameters->is_big_endian())
 350         {
 351 #ifdef HAVE_TARGET_64_BIG
 352           this->do_sized_write<64, true>(of);
 353 #else
 354           gold_unreachable();
 355 #endif
 356         }
 357       else
 358         {
 359 #ifdef HAVE_TARGET_64_LITTLE
 360           this->do_sized_write<64, false>(of);
 361 #else
 362           gold_unreachable();
 363 #endif
 364         }
 365     }
 366   else
 367     gold_unreachable();
 368 }
 369
 370 // Write out the file header with appropriate size and endianess.
 371
 372 template<int size, bool big_endian>
 373 void
 374 Output_file_header::do_sized_write(Output_file* of)
 375 {
 376   gold_assert(this->offset() == 0);
 377
 378   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
 379   unsigned char* view = of->get_output_view(0, ehdr_size);
 380   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
 381
 382   unsigned char e_ident[elfcpp::EI_NIDENT];
 383   memset(e_ident, 0, elfcpp::EI_NIDENT);
 384   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
 385   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
 386   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
 387   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
 388   if (size == 32)
 389     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
 390   else if (size == 64)
 391     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
 392   else
 393     gold_unreachable();
 394   e_ident[elfcpp::EI_DATA] = (big_endian
 395                               ? elfcpp::ELFDATA2MSB
 396                               : elfcpp::ELFDATA2LSB);
 397   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
 398   // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION.
 399   oehdr.put_e_ident(e_ident);
 400
 401   elfcpp::ET e_type;
 402   // FIXME: ET_DYN.
 403   if (parameters->output_is_object())
 404     e_type = elfcpp::ET_REL;
 405   else
 406     e_type = elfcpp::ET_EXEC;
 407   oehdr.put_e_type(e_type);
 408
 409   oehdr.put_e_machine(this->target_->machine_code());
 410   oehdr.put_e_version(elfcpp::EV_CURRENT);
 411
 412   // FIXME: Need to support -e, and target specific entry symbol.
 413   Symbol* sym = this->symtab_->lookup("_start");
 414   typename Sized_symbol<size>::Value_type v;
 415   if (sym == NULL)
 416     v = 0;
 417   else
 418     {
 419       Sized_symbol<size>* ssym;
 420       ssym = this->symtab_->get_sized_symbol SELECT_SIZE_NAME(size) (
 421         sym SELECT_SIZE(size));
 422       v = ssym->value();
 423     }
 424   oehdr.put_e_entry(v);
 425
 426   oehdr.put_e_phoff(this->segment_header_->offset());
 427   oehdr.put_e_shoff(this->section_header_->offset());
 428
 429   // FIXME: The target needs to set the flags.
 430   oehdr.put_e_flags(0);
 431
 432   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
 433   oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
 434   oehdr.put_e_phnum(this->segment_header_->data_size()
 435                      / elfcpp::Elf_sizes<size>::phdr_size);
 436   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
 437   oehdr.put_e_shnum(this->section_header_->data_size()
 438                      / elfcpp::Elf_sizes<size>::shdr_size);
 439   oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
 440
 441   of->write_output_view(0, ehdr_size, view);
 442 }
 443
 444 // Output_data_const methods.
 445
 446 void
 447 Output_data_const::do_write(Output_file* of)
 448 {
 449   of->write(this->offset(), this->data_.data(), this->data_.size());
 450 }
 451
 452 // Output_data_const_buffer methods.
 453
 454 void
 455 Output_data_const_buffer::do_write(Output_file* of)
 456 {
 457   of->write(this->offset(), this->p_, this->data_size());
 458 }
 459
 460 // Output_section_data methods.
 461
 462 // Record the output section, and set the entry size and such.
 463
 464 void
 465 Output_section_data::set_output_section(Output_section* os)
 466 {
 467   gold_assert(this->output_section_ == NULL);
 468   this->output_section_ = os;
 469   this->do_adjust_output_section(os);
 470 }
 471
 472 // Return the section index of the output section.
 473
 474 unsigned int
 475 Output_section_data::do_out_shndx() const
 476 {
 477   gold_assert(this->output_section_ != NULL);
 478   return this->output_section_->out_shndx();
 479 }
 480
 481 // Output_data_strtab methods.
 482
 483 // Set the address.  We don't actually care about the address, but we
 484 // do set our final size.
 485
 486 void
 487 Output_data_strtab::do_set_address(uint64_t, off_t)
 488 {
 489   this->strtab_->set_string_offsets();
 490   this->set_data_size(this->strtab_->get_strtab_size());
 491 }
 492
 493 // Write out a string table.
 494
 495 void
 496 Output_data_strtab::do_write(Output_file* of)
 497 {
 498   this->strtab_->write(of, this->offset());
 499 }
 500
 501 // Output_reloc methods.
 502
 503 // Get the symbol index of a relocation.
 504
 505 template<bool dynamic, int size, bool big_endian>
 506 unsigned int
 507 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
 508   const
 509 {
 510   unsigned int index;
 511   switch (this->local_sym_index_)
 512     {
 513     case INVALID_CODE:
 514       gold_unreachable();
 515
 516     case GSYM_CODE:
 517       if (this->u1_.gsym == NULL)
 518         index = 0;
 519       else if (dynamic)
 520         index = this->u1_.gsym->dynsym_index();
 521       else
 522         index = this->u1_.gsym->symtab_index();
 523       break;
 524
 525     case SECTION_CODE:
 526       if (dynamic)
 527         index = this->u1_.os->dynsym_index();
 528       else
 529         index = this->u1_.os->symtab_index();
 530       break;
 531
 532     default:
 533       if (dynamic)
 534         {
 535           // FIXME: It seems that some targets may need to generate
 536           // dynamic relocations against local symbols for some
 537           // reasons.  This will have to be addressed at some point.
 538           gold_unreachable();
 539         }
 540       else
 541         index = this->u1_.relobj->symtab_index(this->local_sym_index_);
 542       break;
 543     }
 544   gold_assert(index != -1U);
 545   return index;
 546 }
 547
 548 // Write out the offset and info fields of a Rel or Rela relocation
 549 // entry.
 550
 551 template<bool dynamic, int size, bool big_endian>
 552 template<typename Write_rel>
 553 void
 554 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
 555     Write_rel* wr) const
 556 {
 557   Address address = this->address_;
 558   if (this->shndx_ != INVALID_CODE)
 559     {
 560       off_t off;
 561       Output_section* os = this->u2_.relobj->output_section(this->shndx_,
 562                                                             &off);
 563       gold_assert(os != NULL);
 564       address += os->address() + off;
 565     }
 566   else if (this->u2_.od != NULL)
 567     address += this->u2_.od->address();
 568   wr->put_r_offset(address);
 569   wr->put_r_info(elfcpp::elf_r_info<size>(this->get_symbol_index(),
 570                                           this->type_));
 571 }
 572
 573 // Write out a Rel relocation.
 574
 575 template<bool dynamic, int size, bool big_endian>
 576 void
 577 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
 578     unsigned char* pov) const
 579 {
 580   elfcpp::Rel_write<size, big_endian> orel(pov);
 581   this->write_rel(&orel);
 582 }
 583
 584 // Write out a Rela relocation.
 585
 586 template<bool dynamic, int size, bool big_endian>
 587 void
 588 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
 589     unsigned char* pov) const
 590 {
 591   elfcpp::Rela_write<size, big_endian> orel(pov);
 592   this->rel_.write_rel(&orel);
 593   orel.put_r_addend(this->addend_);
 594 }
 595
 596 // Output_data_reloc_base methods.
 597
 598 // Adjust the output section.
 599
 600 template<int sh_type, bool dynamic, int size, bool big_endian>
 601 void
 602 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
 603     ::do_adjust_output_section(Output_section* os)
 604 {
 605   if (sh_type == elfcpp::SHT_REL)
 606     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
 607   else if (sh_type == elfcpp::SHT_RELA)
 608     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
 609   else
 610     gold_unreachable();
 611   if (dynamic)
 612     os->set_should_link_to_dynsym();
 613   else
 614     os->set_should_link_to_symtab();
 615 }
 616
 617 // Write out relocation data.
 618
 619 template<int sh_type, bool dynamic, int size, bool big_endian>
 620 void
 621 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
 622     Output_file* of)
 623 {
 624   const off_t off = this->offset();
 625   const off_t oview_size = this->data_size();
 626   unsigned char* const oview = of->get_output_view(off, oview_size);
 627
 628   unsigned char* pov = oview;
 629   for (typename Relocs::const_iterator p = this->relocs_.begin();
 630        p != this->relocs_.end();
 631        ++p)
 632     {
 633       p->write(pov);
 634       pov += reloc_size;
 635     }
 636
 637   gold_assert(pov - oview == oview_size);
 638
 639   of->write_output_view(off, oview_size, oview);
 640
 641   // We no longer need the relocation entries.
 642   this->relocs_.clear();
 643 }
 644
 645 // Output_data_got::Got_entry methods.
 646
 647 // Write out the entry.
 648
 649 template<int size, bool big_endian>
 650 void
 651 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
 652 {
 653   Valtype val = 0;
 654
 655   switch (this->local_sym_index_)
 656     {
 657     case GSYM_CODE:
 658       {
 659         Symbol* gsym = this->u_.gsym;
 660
 661         // If the symbol is resolved locally, we need to write out its
 662         // value.  Otherwise we just write zero.  The target code is
 663         // responsible for creating a relocation entry to fill in the
 664         // value at runtime.
 665         if (gsym->final_value_is_known())
 666           {
 667             Sized_symbol<size>* sgsym;
 668             // This cast is a bit ugly.  We don't want to put a
 669             // virtual method in Symbol, because we want Symbol to be
 670             // as small as possible.
 671             sgsym = static_cast<Sized_symbol<size>*>(gsym);
 672             val = sgsym->value();
 673           }
 674       }
 675       break;
 676
 677     case CONSTANT_CODE:
 678       val = this->u_.constant;
 679       break;
 680
 681     default:
 682       gold_unreachable();
 683     }
 684
 685   elfcpp::Swap<size, big_endian>::writeval(pov, val);
 686 }
 687
 688 // Output_data_got methods.
 689
 690 // Add an entry for a global symbol to the GOT.  This returns true if
 691 // this is a new GOT entry, false if the symbol already had a GOT
 692 // entry.
 693
 694 template<int size, bool big_endian>
 695 bool
 696 Output_data_got<size, big_endian>::add_global(Symbol* gsym)
 697 {
 698   if (gsym->has_got_offset())
 699     return false;
 700
 701   this->entries_.push_back(Got_entry(gsym));
 702   this->set_got_size();
 703   gsym->set_got_offset(this->last_got_offset());
 704   return true;
 705 }
 706
 707 // Write out the GOT.
 708
 709 template<int size, bool big_endian>
 710 void
 711 Output_data_got<size, big_endian>::do_write(Output_file* of)
 712 {
 713   const int add = size / 8;
 714
 715   const off_t off = this->offset();
 716   const off_t oview_size = this->data_size();
 717   unsigned char* const oview = of->get_output_view(off, oview_size);
 718
 719   unsigned char* pov = oview;
 720   for (typename Got_entries::const_iterator p = this->entries_.begin();
 721        p != this->entries_.end();
 722        ++p)
 723     {
 724       p->write(pov);
 725       pov += add;
 726     }
 727
 728   gold_assert(pov - oview == oview_size);
 729
 730   of->write_output_view(off, oview_size, oview);
 731
 732   // We no longer need the GOT entries.
 733   this->entries_.clear();
 734 }
 735
 736 // Output_data_dynamic::Dynamic_entry methods.
 737
 738 // Write out the entry.
 739
 740 template<int size, bool big_endian>
 741 void
 742 Output_data_dynamic::Dynamic_entry::write(
 743     unsigned char* pov,
 744     const Stringpool* pool
 745     ACCEPT_SIZE_ENDIAN) const
 746 {
 747   typename elfcpp::Elf_types<size>::Elf_WXword val;
 748   switch (this->classification_)
 749     {
 750     case DYNAMIC_NUMBER:
 751       val = this->u_.val;
 752       break;
 753
 754     case DYNAMIC_SECTION_ADDRESS:
 755       val = this->u_.od->address();
 756       break;
 757
 758     case DYNAMIC_SECTION_SIZE:
 759       val = this->u_.od->data_size();
 760       break;
 761
 762     case DYNAMIC_SYMBOL:
 763       {
 764         const Sized_symbol<size>* s =
 765           static_cast<const Sized_symbol<size>*>(this->u_.sym);
 766         val = s->value();
 767       }
 768       break;
 769
 770     case DYNAMIC_STRING:
 771       val = pool->get_offset(this->u_.str);
 772       break;
 773
 774     default:
 775       gold_unreachable();
 776     }
 777
 778   elfcpp::Dyn_write<size, big_endian> dw(pov);
 779   dw.put_d_tag(this->tag_);
 780   dw.put_d_val(val);
 781 }
 782
 783 // Output_data_dynamic methods.
 784
 785 // Adjust the output section to set the entry size.
 786
 787 void
 788 Output_data_dynamic::do_adjust_output_section(Output_section* os)
 789 {
 790   if (parameters->get_size() == 32)
 791     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
 792   else if (parameters->get_size() == 64)
 793     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
 794   else
 795     gold_unreachable();
 796 }
 797
 798 // Set the final data size.
 799
 800 void
 801 Output_data_dynamic::do_set_address(uint64_t, off_t)
 802 {
 803   // Add the terminating entry.
 804   this->add_constant(elfcpp::DT_NULL, 0);
 805
 806   int dyn_size;
 807   if (parameters->get_size() == 32)
 808     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
 809   else if (parameters->get_size() == 64)
 810     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
 811   else
 812     gold_unreachable();
 813   this->set_data_size(this->entries_.size() * dyn_size);
 814 }
 815
 816 // Write out the dynamic entries.
 817
 818 void
 819 Output_data_dynamic::do_write(Output_file* of)
 820 {
 821   if (parameters->get_size() == 32)
 822     {
 823       if (parameters->is_big_endian())
 824         {
 825 #ifdef HAVE_TARGET_32_BIG
 826           this->sized_write<32, true>(of);
 827 #else
 828           gold_unreachable();
 829 #endif
 830         }
 831       else
 832         {
 833 #ifdef HAVE_TARGET_32_LITTLE
 834           this->sized_write<32, false>(of);
 835 #else
 836           gold_unreachable();
 837 #endif
 838         }
 839     }
 840   else if (parameters->get_size() == 64)
 841     {
 842       if (parameters->is_big_endian())
 843         {
 844 #ifdef HAVE_TARGET_64_BIG
 845           this->sized_write<64, true>(of);
 846 #else
 847           gold_unreachable();
 848 #endif
 849         }
 850       else
 851         {
 852 #ifdef HAVE_TARGET_64_LITTLE
 853           this->sized_write<64, false>(of);
 854 #else
 855           gold_unreachable();
 856 #endif
 857         }
 858     }
 859   else
 860     gold_unreachable();
 861 }
 862
 863 template<int size, bool big_endian>
 864 void
 865 Output_data_dynamic::sized_write(Output_file* of)
 866 {
 867   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
 868
 869   const off_t offset = this->offset();
 870   const off_t oview_size = this->data_size();
 871   unsigned char* const oview = of->get_output_view(offset, oview_size);
 872
 873   unsigned char* pov = oview;
 874   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
 875        p != this->entries_.end();
 876        ++p)
 877     {
 878       p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
 879           pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian));
 880       pov += dyn_size;
 881     }
 882
 883   gold_assert(pov - oview == oview_size);
 884
 885   of->write_output_view(offset, oview_size, oview);
 886
 887   // We no longer need the dynamic entries.
 888   this->entries_.clear();
 889 }
 890
 891 // Output_section::Input_section methods.
 892
 893 // Return the data size.  For an input section we store the size here.
 894 // For an Output_section_data, we have to ask it for the size.
 895
 896 off_t
 897 Output_section::Input_section::data_size() const
 898 {
 899   if (this->is_input_section())
 900     return this->u1_.data_size;
 901   else
 902     return this->u2_.posd->data_size();
 903 }
 904
 905 // Set the address and file offset.
 906
 907 void
 908 Output_section::Input_section::set_address(uint64_t addr, off_t off,
 909                                            off_t secoff)
 910 {
 911   if (this->is_input_section())
 912     this->u2_.object->set_section_offset(this->shndx_, off - secoff);
 913   else
 914     this->u2_.posd->set_address(addr, off);
 915 }
 916
 917 // Try to turn an input address into an output address.
 918
 919 bool
 920 Output_section::Input_section::output_address(const Relobj* object,
 921                                               unsigned int shndx,
 922                                               off_t offset,
 923                                               uint64_t output_section_address,
 924                                               uint64_t *poutput) const
 925 {
 926   if (!this->is_input_section())
 927     return this->u2_.posd->output_address(object, shndx, offset,
 928                                           output_section_address, poutput);
 929   else
 930     {
 931       if (this->shndx_ != shndx
 932           || this->u2_.object != object)
 933         return false;
 934       off_t output_offset;
 935       Output_section* os = object->output_section(shndx, &output_offset);
 936       gold_assert(os != NULL);
 937       *poutput = output_section_address + output_offset + offset;
 938       return true;
 939     }
 940 }
 941
 942 // Write out the data.  We don't have to do anything for an input
 943 // section--they are handled via Object::relocate--but this is where
 944 // we write out the data for an Output_section_data.
 945
 946 void
 947 Output_section::Input_section::write(Output_file* of)
 948 {
 949   if (!this->is_input_section())
 950     this->u2_.posd->write(of);
 951 }
 952
 953 // Output_section methods.
 954
 955 // Construct an Output_section.  NAME will point into a Stringpool.
 956
 957 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
 958                                elfcpp::Elf_Xword flags)
 959   : name_(name),
 960     addralign_(0),
 961     entsize_(0),
 962     link_section_(NULL),
 963     link_(0),
 964     info_section_(NULL),
 965     info_(0),
 966     type_(type),
 967     flags_(flags),
 968     out_shndx_(0),
 969     symtab_index_(0),
 970     dynsym_index_(0),
 971     input_sections_(),
 972     first_input_offset_(0),
 973     fills_(),
 974     needs_symtab_index_(false),
 975     needs_dynsym_index_(false),
 976     should_link_to_symtab_(false),
 977     should_link_to_dynsym_(false)
 978 {
 979 }
 980
 981 Output_section::~Output_section()
 982 {
 983 }
 984
 985 // Set the entry size.
 986
 987 void
 988 Output_section::set_entsize(uint64_t v)
 989 {
 990   if (this->entsize_ == 0)
 991     this->entsize_ = v;
 992   else
 993     gold_assert(this->entsize_ == v);
 994 }
 995
 996 // Add the input section SHNDX, with header SHDR, named SECNAME, in
 997 // OBJECT, to the Output_section.  Return the offset of the input
 998 // section within the output section.  We don't always keep track of
 999 // input sections for an Output_section.  Instead, each Object keeps
1000 // track of the Output_section for each of its input sections.
1001
1002 template<int size, bool big_endian>
1003 off_t
1004 Output_section::add_input_section(Relobj* object, unsigned int shndx,
1005                                   const char* secname,
1006                                   const elfcpp::Shdr<size, big_endian>& shdr)
1007 {
1008   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1009   if ((addralign & (addralign - 1)) != 0)
1010     {
1011       fprintf(stderr, _("%s: %s: invalid alignment %lu for section \"%s\"\n"),
1012               program_name, object->name().c_str(),
1013               static_cast<unsigned long>(addralign), secname);
1014       gold_exit(false);
1015     }
1016
1017   if (addralign > this->addralign_)
1018     this->addralign_ = addralign;
1019
1020   // If this is a SHF_MERGE section, we pass all the input sections to
1021   // a Output_data_merge.
1022   if ((shdr.get_sh_flags() & elfcpp::SHF_MERGE) != 0)
1023     {
1024       if (this->add_merge_input_section(object, shndx, shdr.get_sh_flags(),
1025                                         shdr.get_sh_entsize(),
1026                                         addralign))
1027         {
1028           // Tell the relocation routines that they need to call the
1029           // output_address method to determine the final address.
1030           return -1;
1031         }
1032     }
1033
1034   off_t offset_in_section = this->data_size();
1035   off_t aligned_offset_in_section = align_address(offset_in_section,
1036                                                   addralign);
1037
1038   if (aligned_offset_in_section > offset_in_section
1039       && (shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0
1040       && object->target()->has_code_fill())
1041     {
1042       // We need to add some fill data.  Using fill_list_ when
1043       // possible is an optimization, since we will often have fill
1044       // sections without input sections.
1045       off_t fill_len = aligned_offset_in_section - offset_in_section;
1046       if (this->input_sections_.empty())
1047         this->fills_.push_back(Fill(offset_in_section, fill_len));
1048       else
1049         {
1050           // FIXME: When relaxing, the size needs to adjust to
1051           // maintain a constant alignment.
1052           std::string fill_data(object->target()->code_fill(fill_len));
1053           Output_data_const* odc = new Output_data_const(fill_data, 1);
1054           this->input_sections_.push_back(Input_section(odc));
1055         }
1056     }
1057
1058   this->set_data_size(aligned_offset_in_section + shdr.get_sh_size());
1059
1060   // We need to keep track of this section if we are already keeping
1061   // track of sections, or if we are relaxing.  FIXME: Add test for
1062   // relaxing.
1063   if (!this->input_sections_.empty())
1064     this->input_sections_.push_back(Input_section(object, shndx,
1065                                                   shdr.get_sh_size(),
1066                                                   addralign));
1067
1068   return aligned_offset_in_section;
1069 }
1070
1071 // Add arbitrary data to an output section.
1072
1073 void
1074 Output_section::add_output_section_data(Output_section_data* posd)
1075 {
1076   Input_section inp(posd);
1077   this->add_output_section_data(&inp);
1078 }
1079
1080 // Add arbitrary data to an output section by Input_section.
1081
1082 void
1083 Output_section::add_output_section_data(Input_section* inp)
1084 {
1085   if (this->input_sections_.empty())
1086     this->first_input_offset_ = this->data_size();
1087
1088   this->input_sections_.push_back(*inp);
1089
1090   uint64_t addralign = inp->addralign();
1091   if (addralign > this->addralign_)
1092     this->addralign_ = addralign;
1093
1094   inp->set_output_section(this);
1095 }
1096
1097 // Add a merge section to an output section.
1098
1099 void
1100 Output_section::add_output_merge_section(Output_section_data* posd,
1101                                          bool is_string, uint64_t entsize)
1102 {
1103   Input_section inp(posd, is_string, entsize);
1104   this->add_output_section_data(&inp);
1105 }
1106
1107 // Add an input section to a SHF_MERGE section.
1108
1109 bool
1110 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
1111                                         uint64_t flags, uint64_t entsize,
1112                                         uint64_t addralign)
1113 {
1114   // We only merge constants if the alignment is not more than the
1115   // entry size.  This could be handled, but it's unusual.
1116   if (addralign > entsize)
1117     return false;
1118
1119   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
1120   Input_section_list::iterator p;
1121   for (p = this->input_sections_.begin();
1122        p != this->input_sections_.end();
1123        ++p)
1124     if (p->is_merge_section(is_string, entsize))
1125       break;
1126
1127   // We handle the actual constant merging in Output_merge_data or
1128   // Output_merge_string_data.
1129   if (p != this->input_sections_.end())
1130     p->add_input_section(object, shndx);
1131   else
1132     {
1133       Output_section_data* posd;
1134       if (!is_string)
1135         posd = new Output_merge_data(entsize);
1136       else if (entsize == 1)
1137         posd = new Output_merge_string<char>();
1138       else if (entsize == 2)
1139         posd = new Output_merge_string<uint16_t>();
1140       else if (entsize == 4)
1141         posd = new Output_merge_string<uint32_t>();
1142       else
1143         return false;
1144
1145       this->add_output_merge_section(posd, is_string, entsize);
1146       posd->add_input_section(object, shndx);
1147     }
1148
1149   return true;
1150 }
1151
1152 // Return the output virtual address of OFFSET relative to the start
1153 // of input section SHNDX in object OBJECT.
1154
1155 uint64_t
1156 Output_section::output_address(const Relobj* object, unsigned int shndx,
1157                                off_t offset) const
1158 {
1159   uint64_t addr = this->address() + this->first_input_offset_;
1160   for (Input_section_list::const_iterator p = this->input_sections_.begin();
1161        p != this->input_sections_.end();
1162        ++p)
1163     {
1164       addr = align_address(addr, p->addralign());
1165       uint64_t output;
1166       if (p->output_address(object, shndx, offset, addr, &output))
1167         return output;
1168       addr += p->data_size();
1169     }
1170
1171   // If we get here, it means that we don't know the mapping for this
1172   // input section.  This might happen in principle if
1173   // add_input_section were called before add_output_section_data.
1174   // But it should never actually happen.
1175
1176   gold_unreachable();
1177 }
1178
1179 // Set the address of an Output_section.  This is where we handle
1180 // setting the addresses of any Output_section_data objects.
1181
1182 void
1183 Output_section::do_set_address(uint64_t address, off_t startoff)
1184 {
1185   if (this->input_sections_.empty())
1186     return;
1187
1188   off_t off = startoff + this->first_input_offset_;
1189   for (Input_section_list::iterator p = this->input_sections_.begin();
1190        p != this->input_sections_.end();
1191        ++p)
1192     {
1193       off = align_address(off, p->addralign());
1194       p->set_address(address + (off - startoff), off, startoff);
1195       off += p->data_size();
1196     }
1197
1198   this->set_data_size(off - startoff);
1199 }
1200
1201 // Write the section header to *OSHDR.
1202
1203 template<int size, bool big_endian>
1204 void
1205 Output_section::write_header(const Layout* layout,
1206                              const Stringpool* secnamepool,
1207                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
1208 {
1209   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
1210   oshdr->put_sh_type(this->type_);
1211   oshdr->put_sh_flags(this->flags_);
1212   oshdr->put_sh_addr(this->address());
1213   oshdr->put_sh_offset(this->offset());
1214   oshdr->put_sh_size(this->data_size());
1215   if (this->link_section_ != NULL)
1216     oshdr->put_sh_link(this->link_section_->out_shndx());
1217   else if (this->should_link_to_symtab_)
1218     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
1219   else if (this->should_link_to_dynsym_)
1220     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
1221   else
1222     oshdr->put_sh_link(this->link_);
1223   if (this->info_section_ != NULL)
1224     oshdr->put_sh_info(this->info_section_->out_shndx());
1225   else
1226     oshdr->put_sh_info(this->info_);
1227   oshdr->put_sh_addralign(this->addralign_);
1228   oshdr->put_sh_entsize(this->entsize_);
1229 }
1230
1231 // Write out the data.  For input sections the data is written out by
1232 // Object::relocate, but we have to handle Output_section_data objects
1233 // here.
1234
1235 void
1236 Output_section::do_write(Output_file* of)
1237 {
1238   off_t output_section_file_offset = this->offset();
1239   for (Fill_list::iterator p = this->fills_.begin();
1240        p != this->fills_.end();
1241        ++p)
1242     {
1243       std::string fill_data(of->target()->code_fill(p->length()));
1244       of->write(output_section_file_offset + p->section_offset(),
1245                 fill_data.data(), fill_data.size());
1246     }
1247
1248   for (Input_section_list::iterator p = this->input_sections_.begin();
1249        p != this->input_sections_.end();
1250        ++p)
1251     p->write(of);
1252 }
1253
1254 // Output segment methods.
1255
1256 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
1257   : output_data_(),
1258     output_bss_(),
1259     vaddr_(0),
1260     paddr_(0),
1261     memsz_(0),
1262     align_(0),
1263     offset_(0),
1264     filesz_(0),
1265     type_(type),
1266     flags_(flags),
1267     is_align_known_(false)
1268 {
1269 }
1270
1271 // Add an Output_section to an Output_segment.
1272
1273 void
1274 Output_segment::add_output_section(Output_section* os,
1275                                    elfcpp::Elf_Word seg_flags,
1276                                    bool front)
1277 {
1278   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1279   gold_assert(!this->is_align_known_);
1280
1281   // Update the segment flags.
1282   this->flags_ |= seg_flags;
1283
1284   Output_segment::Output_data_list* pdl;
1285   if (os->type() == elfcpp::SHT_NOBITS)
1286     pdl = &this->output_bss_;
1287   else
1288     pdl = &this->output_data_;
1289
1290   // So that PT_NOTE segments will work correctly, we need to ensure
1291   // that all SHT_NOTE sections are adjacent.  This will normally
1292   // happen automatically, because all the SHT_NOTE input sections
1293   // will wind up in the same output section.  However, it is possible
1294   // for multiple SHT_NOTE input sections to have different section
1295   // flags, and thus be in different output sections, but for the
1296   // different section flags to map into the same segment flags and
1297   // thus the same output segment.
1298
1299   // Note that while there may be many input sections in an output
1300   // section, there are normally only a few output sections in an
1301   // output segment.  This loop is expected to be fast.
1302
1303   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
1304     {
1305       Output_segment::Output_data_list::iterator p = pdl->end();
1306       do
1307         {
1308           --p;
1309           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
1310             {
1311               // We don't worry about the FRONT parameter.
1312               ++p;
1313               pdl->insert(p, os);
1314               return;
1315             }
1316         }
1317       while (p != pdl->begin());
1318     }
1319
1320   // Similarly, so that PT_TLS segments will work, we need to group
1321   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
1322   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
1323   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
1324   // correctly.
1325   if ((os->flags() & elfcpp::SHF_TLS) != 0 && !this->output_data_.empty())
1326     {
1327       pdl = &this->output_data_;
1328       bool nobits = os->type() == elfcpp::SHT_NOBITS;
1329       bool sawtls = false;
1330       Output_segment::Output_data_list::iterator p = pdl->end();
1331       do
1332         {
1333           --p;
1334           bool insert;
1335           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
1336             {
1337               sawtls = true;
1338               // Put a NOBITS section after the first TLS section.
1339               // But a PROGBITS section after the first TLS/PROGBITS
1340               // section.
1341               insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
1342             }
1343           else
1344             {
1345               // If we've gone past the TLS sections, but we've seen a
1346               // TLS section, then we need to insert this section now.
1347               insert = sawtls;
1348             }
1349
1350           if (insert)
1351             {
1352               // We don't worry about the FRONT parameter.
1353               ++p;
1354               pdl->insert(p, os);
1355               return;
1356             }
1357         }
1358       while (p != pdl->begin());
1359
1360       // There are no TLS sections yet; put this one at the requested
1361       // location in the section list.
1362     }
1363
1364   if (front)
1365     pdl->push_front(os);
1366   else
1367     pdl->push_back(os);
1368 }
1369
1370 // Add an Output_data (which is not an Output_section) to the start of
1371 // a segment.
1372
1373 void
1374 Output_segment::add_initial_output_data(Output_data* od)
1375 {
1376   gold_assert(!this->is_align_known_);
1377   this->output_data_.push_front(od);
1378 }
1379
1380 // Return the maximum alignment of the Output_data in Output_segment.
1381 // Once we compute this, we prohibit new sections from being added.
1382
1383 uint64_t
1384 Output_segment::addralign()
1385 {
1386   if (!this->is_align_known_)
1387     {
1388       uint64_t addralign;
1389
1390       addralign = Output_segment::maximum_alignment(&this->output_data_);
1391       if (addralign > this->align_)
1392         this->align_ = addralign;
1393
1394       addralign = Output_segment::maximum_alignment(&this->output_bss_);
1395       if (addralign > this->align_)
1396         this->align_ = addralign;
1397
1398       this->is_align_known_ = true;
1399     }
1400
1401   return this->align_;
1402 }
1403
1404 // Return the maximum alignment of a list of Output_data.
1405
1406 uint64_t
1407 Output_segment::maximum_alignment(const Output_data_list* pdl)
1408 {
1409   uint64_t ret = 0;
1410   for (Output_data_list::const_iterator p = pdl->begin();
1411        p != pdl->end();
1412        ++p)
1413     {
1414       uint64_t addralign = (*p)->addralign();
1415       if (addralign > ret)
1416         ret = addralign;
1417     }
1418   return ret;
1419 }
1420
1421 // Set the section addresses for an Output_segment.  ADDR is the
1422 // address and *POFF is the file offset.  Set the section indexes
1423 // starting with *PSHNDX.  Return the address of the immediately
1424 // following segment.  Update *POFF and *PSHNDX.
1425
1426 uint64_t
1427 Output_segment::set_section_addresses(uint64_t addr, off_t* poff,
1428                                       unsigned int* pshndx)
1429 {
1430   gold_assert(this->type_ == elfcpp::PT_LOAD);
1431
1432   this->vaddr_ = addr;
1433   this->paddr_ = addr;
1434
1435   off_t orig_off = *poff;
1436   this->offset_ = orig_off;
1437
1438   *poff = align_address(*poff, this->addralign());
1439
1440   addr = this->set_section_list_addresses(&this->output_data_, addr, poff,
1441                                           pshndx);
1442   this->filesz_ = *poff - orig_off;
1443
1444   off_t off = *poff;
1445
1446   uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr,
1447                                                   poff, pshndx);
1448   this->memsz_ = *poff - orig_off;
1449
1450   // Ignore the file offset adjustments made by the BSS Output_data
1451   // objects.
1452   *poff = off;
1453
1454   return ret;
1455 }
1456
1457 // Set the addresses and file offsets in a list of Output_data
1458 // structures.
1459
1460 uint64_t
1461 Output_segment::set_section_list_addresses(Output_data_list* pdl,
1462                                            uint64_t addr, off_t* poff,
1463                                            unsigned int* pshndx)
1464 {
1465   off_t startoff = *poff;
1466
1467   off_t off = startoff;
1468   for (Output_data_list::iterator p = pdl->begin();
1469        p != pdl->end();
1470        ++p)
1471     {
1472       off = align_address(off, (*p)->addralign());
1473       (*p)->set_address(addr + (off - startoff), off);
1474
1475       // Unless this is a PT_TLS segment, we want to ignore the size
1476       // of a SHF_TLS/SHT_NOBITS section.  Such a section does not
1477       // affect the size of a PT_LOAD segment.
1478       if (this->type_ == elfcpp::PT_TLS
1479           || !(*p)->is_section_flag_set(elfcpp::SHF_TLS)
1480           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
1481         off += (*p)->data_size();
1482
1483       if ((*p)->is_section())
1484         {
1485           (*p)->set_out_shndx(*pshndx);
1486           ++*pshndx;
1487         }
1488     }
1489
1490   *poff = off;
1491   return addr + (off - startoff);
1492 }
1493
1494 // For a non-PT_LOAD segment, set the offset from the sections, if
1495 // any.
1496
1497 void
1498 Output_segment::set_offset()
1499 {
1500   gold_assert(this->type_ != elfcpp::PT_LOAD);
1501
1502   if (this->output_data_.empty() && this->output_bss_.empty())
1503     {
1504       this->vaddr_ = 0;
1505       this->paddr_ = 0;
1506       this->memsz_ = 0;
1507       this->align_ = 0;
1508       this->offset_ = 0;
1509       this->filesz_ = 0;
1510       return;
1511     }
1512
1513   const Output_data* first;
1514   if (this->output_data_.empty())
1515     first = this->output_bss_.front();
1516   else
1517     first = this->output_data_.front();
1518   this->vaddr_ = first->address();
1519   this->paddr_ = this->vaddr_;
1520   this->offset_ = first->offset();
1521
1522   if (this->output_data_.empty())
1523     this->filesz_ = 0;
1524   else
1525     {
1526       const Output_data* last_data = this->output_data_.back();
1527       this->filesz_ = (last_data->address()
1528                        + last_data->data_size()
1529                        - this->vaddr_);
1530     }
1531
1532   const Output_data* last;
1533   if (this->output_bss_.empty())
1534     last = this->output_data_.back();
1535   else
1536     last = this->output_bss_.back();
1537   this->memsz_ = (last->address()
1538                   + last->data_size()
1539                   - this->vaddr_);
1540 }
1541
1542 // Return the number of Output_sections in an Output_segment.
1543
1544 unsigned int
1545 Output_segment::output_section_count() const
1546 {
1547   return (this->output_section_count_list(&this->output_data_)
1548           + this->output_section_count_list(&this->output_bss_));
1549 }
1550
1551 // Return the number of Output_sections in an Output_data_list.
1552
1553 unsigned int
1554 Output_segment::output_section_count_list(const Output_data_list* pdl) const
1555 {
1556   unsigned int count = 0;
1557   for (Output_data_list::const_iterator p = pdl->begin();
1558        p != pdl->end();
1559        ++p)
1560     {
1561       if ((*p)->is_section())
1562         ++count;
1563     }
1564   return count;
1565 }
1566
1567 // Write the segment data into *OPHDR.
1568
1569 template<int size, bool big_endian>
1570 void
1571 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
1572 {
1573   ophdr->put_p_type(this->type_);
1574   ophdr->put_p_offset(this->offset_);
1575   ophdr->put_p_vaddr(this->vaddr_);
1576   ophdr->put_p_paddr(this->paddr_);
1577   ophdr->put_p_filesz(this->filesz_);
1578   ophdr->put_p_memsz(this->memsz_);
1579   ophdr->put_p_flags(this->flags_);
1580   ophdr->put_p_align(this->addralign());
1581 }
1582
1583 // Write the section headers into V.
1584
1585 template<int size, bool big_endian>
1586 unsigned char*
1587 Output_segment::write_section_headers(const Layout* layout,
1588                                       const Stringpool* secnamepool,
1589                                       unsigned char* v,
1590                                       unsigned int *pshndx
1591                                       ACCEPT_SIZE_ENDIAN) const
1592 {
1593   // Every section that is attached to a segment must be attached to a
1594   // PT_LOAD segment, so we only write out section headers for PT_LOAD
1595   // segments.
1596   if (this->type_ != elfcpp::PT_LOAD)
1597     return v;
1598
1599   v = this->write_section_headers_list
1600       SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1601           layout, secnamepool, &this->output_data_, v, pshndx
1602           SELECT_SIZE_ENDIAN(size, big_endian));
1603   v = this->write_section_headers_list
1604       SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1605           layout, secnamepool, &this->output_bss_, v, pshndx
1606           SELECT_SIZE_ENDIAN(size, big_endian));
1607   return v;
1608 }
1609
1610 template<int size, bool big_endian>
1611 unsigned char*
1612 Output_segment::write_section_headers_list(const Layout* layout,
1613                                            const Stringpool* secnamepool,
1614                                            const Output_data_list* pdl,
1615                                            unsigned char* v,
1616                                            unsigned int* pshndx
1617                                            ACCEPT_SIZE_ENDIAN) const
1618 {
1619   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
1620   for (Output_data_list::const_iterator p = pdl->begin();
1621        p != pdl->end();
1622        ++p)
1623     {
1624       if ((*p)->is_section())
1625         {
1626           const Output_section* ps = static_cast<const Output_section*>(*p);
1627           gold_assert(*pshndx == ps->out_shndx());
1628           elfcpp::Shdr_write<size, big_endian> oshdr(v);
1629           ps->write_header(layout, secnamepool, &oshdr);
1630           v += shdr_size;
1631           ++*pshndx;
1632         }
1633     }
1634   return v;
1635 }
1636
1637 // Output_file methods.
1638
1639 Output_file::Output_file(const General_options& options, Target* target)
1640   : options_(options),
1641     target_(target),
1642     name_(options.output_file_name()),
1643     o_(-1),
1644     file_size_(0),
1645     base_(NULL)
1646 {
1647 }
1648
1649 // Open the output file.
1650
1651 void
1652 Output_file::open(off_t file_size)
1653 {
1654   this->file_size_ = file_size;
1655
1656   int mode = parameters->output_is_object() ? 0666 : 0777;
1657   int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
1658   if (o < 0)
1659     {
1660       fprintf(stderr, _("%s: %s: open: %s\n"),
1661               program_name, this->name_, strerror(errno));
1662       gold_exit(false);
1663     }
1664   this->o_ = o;
1665
1666   // Write out one byte to make the file the right size.
1667   if (::lseek(o, file_size - 1, SEEK_SET) < 0)
1668     {
1669       fprintf(stderr, _("%s: %s: lseek: %s\n"),
1670               program_name, this->name_, strerror(errno));
1671       gold_exit(false);
1672     }
1673   char b = 0;
1674   if (::write(o, &b, 1) != 1)
1675     {
1676       fprintf(stderr, _("%s: %s: write: %s\n"),
1677               program_name, this->name_, strerror(errno));
1678       gold_exit(false);
1679     }
1680
1681   // Map the file into memory.
1682   void* base = ::mmap(NULL, file_size, PROT_READ | PROT_WRITE,
1683                       MAP_SHARED, o, 0);
1684   if (base == MAP_FAILED)
1685     {
1686       fprintf(stderr, _("%s: %s: mmap: %s\n"),
1687               program_name, this->name_, strerror(errno));
1688       gold_exit(false);
1689     }
1690   this->base_ = static_cast<unsigned char*>(base);
1691 }
1692
1693 // Close the output file.
1694
1695 void
1696 Output_file::close()
1697 {
1698   if (::munmap(this->base_, this->file_size_) < 0)
1699     {
1700       fprintf(stderr, _("%s: %s: munmap: %s\n"),
1701               program_name, this->name_, strerror(errno));
1702       gold_exit(false);
1703     }
1704   this->base_ = NULL;
1705
1706   if (::close(this->o_) < 0)
1707     {
1708       fprintf(stderr, _("%s: %s: close: %s\n"),
1709               program_name, this->name_, strerror(errno));
1710       gold_exit(false);
1711     }
1712   this->o_ = -1;
1713 }
1714
1715 // Instantiate the templates we need.  We could use the configure
1716 // script to restrict this to only the ones for implemented targets.
1717
1718 #ifdef HAVE_TARGET_32_LITTLE
1719 template
1720 off_t
1721 Output_section::add_input_section<32, false>(
1722     Relobj* object,
1723     unsigned int shndx,
1724     const char* secname,
1725     const elfcpp::Shdr<32, false>& shdr);
1726 #endif
1727
1728 #ifdef HAVE_TARGET_32_BIG
1729 template
1730 off_t
1731 Output_section::add_input_section<32, true>(
1732     Relobj* object,
1733     unsigned int shndx,
1734     const char* secname,
1735     const elfcpp::Shdr<32, true>& shdr);
1736 #endif
1737
1738 #ifdef HAVE_TARGET_64_LITTLE
1739 template
1740 off_t
1741 Output_section::add_input_section<64, false>(
1742     Relobj* object,
1743     unsigned int shndx,
1744     const char* secname,
1745     const elfcpp::Shdr<64, false>& shdr);
1746 #endif
1747
1748 #ifdef HAVE_TARGET_64_BIG
1749 template
1750 off_t
1751 Output_section::add_input_section<64, true>(
1752     Relobj* object,
1753     unsigned int shndx,
1754     const char* secname,
1755     const elfcpp::Shdr<64, true>& shdr);
1756 #endif
1757
1758 #ifdef HAVE_TARGET_32_LITTLE
1759 template
1760 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
1761 #endif
1762
1763 #ifdef HAVE_TARGET_32_BIG
1764 template
1765 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
1766 #endif
1767
1768 #ifdef HAVE_TARGET_64_LITTLE
1769 template
1770 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
1771 #endif
1772
1773 #ifdef HAVE_TARGET_64_BIG
1774 template
1775 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
1776 #endif
1777
1778 #ifdef HAVE_TARGET_32_LITTLE
1779 template
1780 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
1781 #endif
1782
1783 #ifdef HAVE_TARGET_32_BIG
1784 template
1785 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
1786 #endif
1787
1788 #ifdef HAVE_TARGET_64_LITTLE
1789 template
1790 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
1791 #endif
1792
1793 #ifdef HAVE_TARGET_64_BIG
1794 template
1795 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
1796 #endif
1797
1798 #ifdef HAVE_TARGET_32_LITTLE
1799 template
1800 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
1801 #endif
1802
1803 #ifdef HAVE_TARGET_32_BIG
1804 template
1805 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
1806 #endif
1807
1808 #ifdef HAVE_TARGET_64_LITTLE
1809 template
1810 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
1811 #endif
1812
1813 #ifdef HAVE_TARGET_64_BIG
1814 template
1815 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
1816 #endif
1817
1818 #ifdef HAVE_TARGET_32_LITTLE
1819 template
1820 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
1821 #endif
1822
1823 #ifdef HAVE_TARGET_32_BIG
1824 template
1825 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
1826 #endif
1827
1828 #ifdef HAVE_TARGET_64_LITTLE
1829 template
1830 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
1831 #endif
1832
1833 #ifdef HAVE_TARGET_64_BIG
1834 template
1835 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
1836 #endif
1837
1838 #ifdef HAVE_TARGET_32_LITTLE
1839 template
1840 class Output_data_got<32, false>;
1841 #endif
1842
1843 #ifdef HAVE_TARGET_32_BIG
1844 template
1845 class Output_data_got<32, true>;
1846 #endif
1847
1848 #ifdef HAVE_TARGET_64_LITTLE
1849 template
1850 class Output_data_got<64, false>;
1851 #endif
1852
1853 #ifdef HAVE_TARGET_64_BIG
1854 template
1855 class Output_data_got<64, true>;
1856 #endif
1857
1858 } // End namespace gold.