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 <sys/stat.h>
  31 #include <algorithm>
  32 #include "libiberty.h"   // for unlink_if_ordinary()
  33
  34 #include "parameters.h"
  35 #include "object.h"
  36 #include "symtab.h"
  37 #include "reloc.h"
  38 #include "merge.h"
  39 #include "output.h"
  40
  41 namespace gold
  42 {
  43
  44 // Output_data variables.
  45
  46 bool Output_data::sizes_are_fixed;
  47
  48 // Output_data methods.
  49
  50 Output_data::~Output_data()
  51 {
  52 }
  53
  54 // Set the address and offset.
  55
  56 void
  57 Output_data::set_address(uint64_t addr, off_t off)
  58 {
  59   this->address_ = addr;
  60   this->offset_ = off;
  61
  62   // Let the child class know.
  63   this->do_set_address(addr, off);
  64 }
  65
  66 // Return the default alignment for a size--32 or 64.
  67
  68 uint64_t
  69 Output_data::default_alignment(int size)
  70 {
  71   if (size == 32)
  72     return 4;
  73   else if (size == 64)
  74     return 8;
  75   else
  76     gold_unreachable();
  77 }
  78
  79 // Output_section_header methods.  This currently assumes that the
  80 // segment and section lists are complete at construction time.
  81
  82 Output_section_headers::Output_section_headers(
  83     const Layout* layout,
  84     const Layout::Segment_list* segment_list,
  85     const Layout::Section_list* unattached_section_list,
  86     const Stringpool* secnamepool)
  87   : layout_(layout),
  88     segment_list_(segment_list),
  89     unattached_section_list_(unattached_section_list),
  90     secnamepool_(secnamepool)
  91 {
  92   // Count all the sections.  Start with 1 for the null section.
  93   off_t count = 1;
  94   for (Layout::Segment_list::const_iterator p = segment_list->begin();
  95        p != segment_list->end();
  96        ++p)
  97     if ((*p)->type() == elfcpp::PT_LOAD)
  98       count += (*p)->output_section_count();
  99   count += unattached_section_list->size();
 100
 101   const int size = parameters->get_size();
 102   int shdr_size;
 103   if (size == 32)
 104     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
 105   else if (size == 64)
 106     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
 107   else
 108     gold_unreachable();
 109
 110   this->set_data_size(count * shdr_size);
 111 }
 112
 113 // Write out the section headers.
 114
 115 void
 116 Output_section_headers::do_write(Output_file* of)
 117 {
 118   if (parameters->get_size() == 32)
 119     {
 120       if (parameters->is_big_endian())
 121         {
 122 #ifdef HAVE_TARGET_32_BIG
 123           this->do_sized_write<32, true>(of);
 124 #else
 125           gold_unreachable();
 126 #endif
 127         }
 128       else
 129         {
 130 #ifdef HAVE_TARGET_32_LITTLE
 131           this->do_sized_write<32, false>(of);
 132 #else
 133           gold_unreachable();
 134 #endif
 135         }
 136     }
 137   else if (parameters->get_size() == 64)
 138     {
 139       if (parameters->is_big_endian())
 140         {
 141 #ifdef HAVE_TARGET_64_BIG
 142           this->do_sized_write<64, true>(of);
 143 #else
 144           gold_unreachable();
 145 #endif
 146         }
 147       else
 148         {
 149 #ifdef HAVE_TARGET_64_LITTLE
 150           this->do_sized_write<64, false>(of);
 151 #else
 152           gold_unreachable();
 153 #endif
 154         }
 155     }
 156   else
 157     gold_unreachable();
 158 }
 159
 160 template<int size, bool big_endian>
 161 void
 162 Output_section_headers::do_sized_write(Output_file* of)
 163 {
 164   off_t all_shdrs_size = this->data_size();
 165   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
 166
 167   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
 168   unsigned char* v = view;
 169
 170   {
 171     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
 172     oshdr.put_sh_name(0);
 173     oshdr.put_sh_type(elfcpp::SHT_NULL);
 174     oshdr.put_sh_flags(0);
 175     oshdr.put_sh_addr(0);
 176     oshdr.put_sh_offset(0);
 177     oshdr.put_sh_size(0);
 178     oshdr.put_sh_link(0);
 179     oshdr.put_sh_info(0);
 180     oshdr.put_sh_addralign(0);
 181     oshdr.put_sh_entsize(0);
 182   }
 183
 184   v += shdr_size;
 185
 186   unsigned shndx = 1;
 187   for (Layout::Segment_list::const_iterator p = this->segment_list_->begin();
 188        p != this->segment_list_->end();
 189        ++p)
 190     v = (*p)->write_section_headers SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
 191             this->layout_, this->secnamepool_, v, &shndx
 192             SELECT_SIZE_ENDIAN(size, big_endian));
 193   for (Layout::Section_list::const_iterator p =
 194          this->unattached_section_list_->begin();
 195        p != this->unattached_section_list_->end();
 196        ++p)
 197     {
 198       gold_assert(shndx == (*p)->out_shndx());
 199       elfcpp::Shdr_write<size, big_endian> oshdr(v);
 200       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
 201       v += shdr_size;
 202       ++shndx;
 203     }
 204
 205   of->write_output_view(this->offset(), all_shdrs_size, view);
 206 }
 207
 208 // Output_segment_header methods.
 209
 210 Output_segment_headers::Output_segment_headers(
 211     const Layout::Segment_list& segment_list)
 212   : segment_list_(segment_list)
 213 {
 214   const int size = parameters->get_size();
 215   int phdr_size;
 216   if (size == 32)
 217     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
 218   else if (size == 64)
 219     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
 220   else
 221     gold_unreachable();
 222
 223   this->set_data_size(segment_list.size() * phdr_size);
 224 }
 225
 226 void
 227 Output_segment_headers::do_write(Output_file* of)
 228 {
 229   if (parameters->get_size() == 32)
 230     {
 231       if (parameters->is_big_endian())
 232         {
 233 #ifdef HAVE_TARGET_32_BIG
 234           this->do_sized_write<32, true>(of);
 235 #else
 236           gold_unreachable();
 237 #endif
 238         }
 239       else
 240         {
 241 #ifdef HAVE_TARGET_32_LITTLE
 242         this->do_sized_write<32, false>(of);
 243 #else
 244         gold_unreachable();
 245 #endif
 246         }
 247     }
 248   else if (parameters->get_size() == 64)
 249     {
 250       if (parameters->is_big_endian())
 251         {
 252 #ifdef HAVE_TARGET_64_BIG
 253           this->do_sized_write<64, true>(of);
 254 #else
 255           gold_unreachable();
 256 #endif
 257         }
 258       else
 259         {
 260 #ifdef HAVE_TARGET_64_LITTLE
 261           this->do_sized_write<64, false>(of);
 262 #else
 263           gold_unreachable();
 264 #endif
 265         }
 266     }
 267   else
 268     gold_unreachable();
 269 }
 270
 271 template<int size, bool big_endian>
 272 void
 273 Output_segment_headers::do_sized_write(Output_file* of)
 274 {
 275   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
 276   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
 277   unsigned char* view = of->get_output_view(this->offset(),
 278                                             all_phdrs_size);
 279   unsigned char* v = view;
 280   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
 281        p != this->segment_list_.end();
 282        ++p)
 283     {
 284       elfcpp::Phdr_write<size, big_endian> ophdr(v);
 285       (*p)->write_header(&ophdr);
 286       v += phdr_size;
 287     }
 288
 289   of->write_output_view(this->offset(), all_phdrs_size, view);
 290 }
 291
 292 // Output_file_header methods.
 293
 294 Output_file_header::Output_file_header(const Target* target,
 295                                        const Symbol_table* symtab,
 296                                        const Output_segment_headers* osh)
 297   : target_(target),
 298     symtab_(symtab),
 299     segment_header_(osh),
 300     section_header_(NULL),
 301     shstrtab_(NULL)
 302 {
 303   const int size = parameters->get_size();
 304   int ehdr_size;
 305   if (size == 32)
 306     ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size;
 307   else if (size == 64)
 308     ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
 309   else
 310     gold_unreachable();
 311
 312   this->set_data_size(ehdr_size);
 313 }
 314
 315 // Set the section table information for a file header.
 316
 317 void
 318 Output_file_header::set_section_info(const Output_section_headers* shdrs,
 319                                      const Output_section* shstrtab)
 320 {
 321   this->section_header_ = shdrs;
 322   this->shstrtab_ = shstrtab;
 323 }
 324
 325 // Write out the file header.
 326
 327 void
 328 Output_file_header::do_write(Output_file* of)
 329 {
 330   if (parameters->get_size() == 32)
 331     {
 332       if (parameters->is_big_endian())
 333         {
 334 #ifdef HAVE_TARGET_32_BIG
 335           this->do_sized_write<32, true>(of);
 336 #else
 337           gold_unreachable();
 338 #endif
 339         }
 340       else
 341         {
 342 #ifdef HAVE_TARGET_32_LITTLE
 343           this->do_sized_write<32, false>(of);
 344 #else
 345           gold_unreachable();
 346 #endif
 347         }
 348     }
 349   else if (parameters->get_size() == 64)
 350     {
 351       if (parameters->is_big_endian())
 352         {
 353 #ifdef HAVE_TARGET_64_BIG
 354           this->do_sized_write<64, true>(of);
 355 #else
 356           gold_unreachable();
 357 #endif
 358         }
 359       else
 360         {
 361 #ifdef HAVE_TARGET_64_LITTLE
 362           this->do_sized_write<64, false>(of);
 363 #else
 364           gold_unreachable();
 365 #endif
 366         }
 367     }
 368   else
 369     gold_unreachable();
 370 }
 371
 372 // Write out the file header with appropriate size and endianess.
 373
 374 template<int size, bool big_endian>
 375 void
 376 Output_file_header::do_sized_write(Output_file* of)
 377 {
 378   gold_assert(this->offset() == 0);
 379
 380   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
 381   unsigned char* view = of->get_output_view(0, ehdr_size);
 382   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
 383
 384   unsigned char e_ident[elfcpp::EI_NIDENT];
 385   memset(e_ident, 0, elfcpp::EI_NIDENT);
 386   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
 387   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
 388   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
 389   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
 390   if (size == 32)
 391     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
 392   else if (size == 64)
 393     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
 394   else
 395     gold_unreachable();
 396   e_ident[elfcpp::EI_DATA] = (big_endian
 397                               ? elfcpp::ELFDATA2MSB
 398                               : elfcpp::ELFDATA2LSB);
 399   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
 400   // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION.
 401   oehdr.put_e_ident(e_ident);
 402
 403   elfcpp::ET e_type;
 404   // FIXME: ET_DYN.
 405   if (parameters->output_is_object())
 406     e_type = elfcpp::ET_REL;
 407   else
 408     e_type = elfcpp::ET_EXEC;
 409   oehdr.put_e_type(e_type);
 410
 411   oehdr.put_e_machine(this->target_->machine_code());
 412   oehdr.put_e_version(elfcpp::EV_CURRENT);
 413
 414   // FIXME: Need to support -e, and target specific entry symbol.
 415   Symbol* sym = this->symtab_->lookup("_start");
 416   typename Sized_symbol<size>::Value_type v;
 417   if (sym == NULL)
 418     v = 0;
 419   else
 420     {
 421       Sized_symbol<size>* ssym;
 422       ssym = this->symtab_->get_sized_symbol SELECT_SIZE_NAME(size) (
 423         sym SELECT_SIZE(size));
 424       v = ssym->value();
 425     }
 426   oehdr.put_e_entry(v);
 427
 428   oehdr.put_e_phoff(this->segment_header_->offset());
 429   oehdr.put_e_shoff(this->section_header_->offset());
 430
 431   // FIXME: The target needs to set the flags.
 432   oehdr.put_e_flags(0);
 433
 434   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
 435   oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
 436   oehdr.put_e_phnum(this->segment_header_->data_size()
 437                      / elfcpp::Elf_sizes<size>::phdr_size);
 438   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
 439   oehdr.put_e_shnum(this->section_header_->data_size()
 440                      / elfcpp::Elf_sizes<size>::shdr_size);
 441   oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
 442
 443   of->write_output_view(0, ehdr_size, view);
 444 }
 445
 446 // Output_data_const methods.
 447
 448 void
 449 Output_data_const::do_write(Output_file* of)
 450 {
 451   of->write(this->offset(), this->data_.data(), this->data_.size());
 452 }
 453
 454 // Output_data_const_buffer methods.
 455
 456 void
 457 Output_data_const_buffer::do_write(Output_file* of)
 458 {
 459   of->write(this->offset(), this->p_, this->data_size());
 460 }
 461
 462 // Output_section_data methods.
 463
 464 // Record the output section, and set the entry size and such.
 465
 466 void
 467 Output_section_data::set_output_section(Output_section* os)
 468 {
 469   gold_assert(this->output_section_ == NULL);
 470   this->output_section_ = os;
 471   this->do_adjust_output_section(os);
 472 }
 473
 474 // Return the section index of the output section.
 475
 476 unsigned int
 477 Output_section_data::do_out_shndx() const
 478 {
 479   gold_assert(this->output_section_ != NULL);
 480   return this->output_section_->out_shndx();
 481 }
 482
 483 // Output_data_strtab methods.
 484
 485 // Set the address.  We don't actually care about the address, but we
 486 // do set our final size.
 487
 488 void
 489 Output_data_strtab::do_set_address(uint64_t, off_t)
 490 {
 491   this->strtab_->set_string_offsets();
 492   this->set_data_size(this->strtab_->get_strtab_size());
 493 }
 494
 495 // Write out a string table.
 496
 497 void
 498 Output_data_strtab::do_write(Output_file* of)
 499 {
 500   this->strtab_->write(of, this->offset());
 501 }
 502
 503 // Output_reloc methods.
 504
 505 // Get the symbol index of a relocation.
 506
 507 template<bool dynamic, int size, bool big_endian>
 508 unsigned int
 509 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
 510   const
 511 {
 512   unsigned int index;
 513   switch (this->local_sym_index_)
 514     {
 515     case INVALID_CODE:
 516       gold_unreachable();
 517
 518     case GSYM_CODE:
 519       if (this->u1_.gsym == NULL)
 520         index = 0;
 521       else if (dynamic)
 522         index = this->u1_.gsym->dynsym_index();
 523       else
 524         index = this->u1_.gsym->symtab_index();
 525       break;
 526
 527     case SECTION_CODE:
 528       if (dynamic)
 529         index = this->u1_.os->dynsym_index();
 530       else
 531         index = this->u1_.os->symtab_index();
 532       break;
 533
 534     default:
 535       if (dynamic)
 536         {
 537           // FIXME: It seems that some targets may need to generate
 538           // dynamic relocations against local symbols for some
 539           // reasons.  This will have to be addressed at some point.
 540           gold_unreachable();
 541         }
 542       else
 543         index = this->u1_.relobj->symtab_index(this->local_sym_index_);
 544       break;
 545     }
 546   gold_assert(index != -1U);
 547   return index;
 548 }
 549
 550 // Write out the offset and info fields of a Rel or Rela relocation
 551 // entry.
 552
 553 template<bool dynamic, int size, bool big_endian>
 554 template<typename Write_rel>
 555 void
 556 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
 557     Write_rel* wr) const
 558 {
 559   Address address = this->address_;
 560   if (this->shndx_ != INVALID_CODE)
 561     {
 562       off_t off;
 563       Output_section* os = this->u2_.relobj->output_section(this->shndx_,
 564                                                             &off);
 565       gold_assert(os != NULL);
 566       address += os->address() + off;
 567     }
 568   else if (this->u2_.od != NULL)
 569     address += this->u2_.od->address();
 570   wr->put_r_offset(address);
 571   wr->put_r_info(elfcpp::elf_r_info<size>(this->get_symbol_index(),
 572                                           this->type_));
 573 }
 574
 575 // Write out a Rel relocation.
 576
 577 template<bool dynamic, int size, bool big_endian>
 578 void
 579 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
 580     unsigned char* pov) const
 581 {
 582   elfcpp::Rel_write<size, big_endian> orel(pov);
 583   this->write_rel(&orel);
 584 }
 585
 586 // Write out a Rela relocation.
 587
 588 template<bool dynamic, int size, bool big_endian>
 589 void
 590 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
 591     unsigned char* pov) const
 592 {
 593   elfcpp::Rela_write<size, big_endian> orel(pov);
 594   this->rel_.write_rel(&orel);
 595   orel.put_r_addend(this->addend_);
 596 }
 597
 598 // Output_data_reloc_base methods.
 599
 600 // Adjust the output section.
 601
 602 template<int sh_type, bool dynamic, int size, bool big_endian>
 603 void
 604 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
 605     ::do_adjust_output_section(Output_section* os)
 606 {
 607   if (sh_type == elfcpp::SHT_REL)
 608     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
 609   else if (sh_type == elfcpp::SHT_RELA)
 610     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
 611   else
 612     gold_unreachable();
 613   if (dynamic)
 614     os->set_should_link_to_dynsym();
 615   else
 616     os->set_should_link_to_symtab();
 617 }
 618
 619 // Write out relocation data.
 620
 621 template<int sh_type, bool dynamic, int size, bool big_endian>
 622 void
 623 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
 624     Output_file* of)
 625 {
 626   const off_t off = this->offset();
 627   const off_t oview_size = this->data_size();
 628   unsigned char* const oview = of->get_output_view(off, oview_size);
 629
 630   unsigned char* pov = oview;
 631   for (typename Relocs::const_iterator p = this->relocs_.begin();
 632        p != this->relocs_.end();
 633        ++p)
 634     {
 635       p->write(pov);
 636       pov += reloc_size;
 637     }
 638
 639   gold_assert(pov - oview == oview_size);
 640
 641   of->write_output_view(off, oview_size, oview);
 642
 643   // We no longer need the relocation entries.
 644   this->relocs_.clear();
 645 }
 646
 647 // Output_data_got::Got_entry methods.
 648
 649 // Write out the entry.
 650
 651 template<int size, bool big_endian>
 652 void
 653 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
 654 {
 655   Valtype val = 0;
 656
 657   switch (this->local_sym_index_)
 658     {
 659     case GSYM_CODE:
 660       {
 661         Symbol* gsym = this->u_.gsym;
 662
 663         // If the symbol is resolved locally, we need to write out its
 664         // value.  Otherwise we just write zero.  The target code is
 665         // responsible for creating a relocation entry to fill in the
 666         // value at runtime.
 667         if (gsym->final_value_is_known())
 668           {
 669             Sized_symbol<size>* sgsym;
 670             // This cast is a bit ugly.  We don't want to put a
 671             // virtual method in Symbol, because we want Symbol to be
 672             // as small as possible.
 673             sgsym = static_cast<Sized_symbol<size>*>(gsym);
 674             val = sgsym->value();
 675           }
 676       }
 677       break;
 678
 679     case CONSTANT_CODE:
 680       val = this->u_.constant;
 681       break;
 682
 683     default:
 684       val = this->u_.object->local_symbol_value(this->local_sym_index_);
 685       break;
 686     }
 687
 688   elfcpp::Swap<size, big_endian>::writeval(pov, val);
 689 }
 690
 691 // Output_data_got methods.
 692
 693 // Add an entry for a global symbol to the GOT.  This returns true if
 694 // this is a new GOT entry, false if the symbol already had a GOT
 695 // entry.
 696
 697 template<int size, bool big_endian>
 698 bool
 699 Output_data_got<size, big_endian>::add_global(Symbol* gsym)
 700 {
 701   if (gsym->has_got_offset())
 702     return false;
 703
 704   this->entries_.push_back(Got_entry(gsym));
 705   this->set_got_size();
 706   gsym->set_got_offset(this->last_got_offset());
 707   return true;
 708 }
 709
 710 // Add an entry for a local symbol to the GOT.  This returns true if
 711 // this is a new GOT entry, false if the symbol already has a GOT
 712 // entry.
 713
 714 template<int size, bool big_endian>
 715 bool
 716 Output_data_got<size, big_endian>::add_local(
 717     Sized_relobj<size, big_endian>* object,
 718     unsigned int symndx)
 719 {
 720   if (object->local_has_got_offset(symndx))
 721     return false;
 722   this->entries_.push_back(Got_entry(object, symndx));
 723   this->set_got_size();
 724   object->set_local_got_offset(symndx, this->last_got_offset());
 725   return true;
 726 }
 727
 728 // Write out the GOT.
 729
 730 template<int size, bool big_endian>
 731 void
 732 Output_data_got<size, big_endian>::do_write(Output_file* of)
 733 {
 734   const int add = size / 8;
 735
 736   const off_t off = this->offset();
 737   const off_t oview_size = this->data_size();
 738   unsigned char* const oview = of->get_output_view(off, oview_size);
 739
 740   unsigned char* pov = oview;
 741   for (typename Got_entries::const_iterator p = this->entries_.begin();
 742        p != this->entries_.end();
 743        ++p)
 744     {
 745       p->write(pov);
 746       pov += add;
 747     }
 748
 749   gold_assert(pov - oview == oview_size);
 750
 751   of->write_output_view(off, oview_size, oview);
 752
 753   // We no longer need the GOT entries.
 754   this->entries_.clear();
 755 }
 756
 757 // Output_data_dynamic::Dynamic_entry methods.
 758
 759 // Write out the entry.
 760
 761 template<int size, bool big_endian>
 762 void
 763 Output_data_dynamic::Dynamic_entry::write(
 764     unsigned char* pov,
 765     const Stringpool* pool
 766     ACCEPT_SIZE_ENDIAN) const
 767 {
 768   typename elfcpp::Elf_types<size>::Elf_WXword val;
 769   switch (this->classification_)
 770     {
 771     case DYNAMIC_NUMBER:
 772       val = this->u_.val;
 773       break;
 774
 775     case DYNAMIC_SECTION_ADDRESS:
 776       val = this->u_.od->address();
 777       break;
 778
 779     case DYNAMIC_SECTION_SIZE:
 780       val = this->u_.od->data_size();
 781       break;
 782
 783     case DYNAMIC_SYMBOL:
 784       {
 785         const Sized_symbol<size>* s =
 786           static_cast<const Sized_symbol<size>*>(this->u_.sym);
 787         val = s->value();
 788       }
 789       break;
 790
 791     case DYNAMIC_STRING:
 792       val = pool->get_offset(this->u_.str);
 793       break;
 794
 795     default:
 796       gold_unreachable();
 797     }
 798
 799   elfcpp::Dyn_write<size, big_endian> dw(pov);
 800   dw.put_d_tag(this->tag_);
 801   dw.put_d_val(val);
 802 }
 803
 804 // Output_data_dynamic methods.
 805
 806 // Adjust the output section to set the entry size.
 807
 808 void
 809 Output_data_dynamic::do_adjust_output_section(Output_section* os)
 810 {
 811   if (parameters->get_size() == 32)
 812     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
 813   else if (parameters->get_size() == 64)
 814     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
 815   else
 816     gold_unreachable();
 817 }
 818
 819 // Set the final data size.
 820
 821 void
 822 Output_data_dynamic::do_set_address(uint64_t, off_t)
 823 {
 824   // Add the terminating entry.
 825   this->add_constant(elfcpp::DT_NULL, 0);
 826
 827   int dyn_size;
 828   if (parameters->get_size() == 32)
 829     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
 830   else if (parameters->get_size() == 64)
 831     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
 832   else
 833     gold_unreachable();
 834   this->set_data_size(this->entries_.size() * dyn_size);
 835 }
 836
 837 // Write out the dynamic entries.
 838
 839 void
 840 Output_data_dynamic::do_write(Output_file* of)
 841 {
 842   if (parameters->get_size() == 32)
 843     {
 844       if (parameters->is_big_endian())
 845         {
 846 #ifdef HAVE_TARGET_32_BIG
 847           this->sized_write<32, true>(of);
 848 #else
 849           gold_unreachable();
 850 #endif
 851         }
 852       else
 853         {
 854 #ifdef HAVE_TARGET_32_LITTLE
 855           this->sized_write<32, false>(of);
 856 #else
 857           gold_unreachable();
 858 #endif
 859         }
 860     }
 861   else if (parameters->get_size() == 64)
 862     {
 863       if (parameters->is_big_endian())
 864         {
 865 #ifdef HAVE_TARGET_64_BIG
 866           this->sized_write<64, true>(of);
 867 #else
 868           gold_unreachable();
 869 #endif
 870         }
 871       else
 872         {
 873 #ifdef HAVE_TARGET_64_LITTLE
 874           this->sized_write<64, false>(of);
 875 #else
 876           gold_unreachable();
 877 #endif
 878         }
 879     }
 880   else
 881     gold_unreachable();
 882 }
 883
 884 template<int size, bool big_endian>
 885 void
 886 Output_data_dynamic::sized_write(Output_file* of)
 887 {
 888   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
 889
 890   const off_t offset = this->offset();
 891   const off_t oview_size = this->data_size();
 892   unsigned char* const oview = of->get_output_view(offset, oview_size);
 893
 894   unsigned char* pov = oview;
 895   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
 896        p != this->entries_.end();
 897        ++p)
 898     {
 899       p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
 900           pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian));
 901       pov += dyn_size;
 902     }
 903
 904   gold_assert(pov - oview == oview_size);
 905
 906   of->write_output_view(offset, oview_size, oview);
 907
 908   // We no longer need the dynamic entries.
 909   this->entries_.clear();
 910 }
 911
 912 // Output_section::Input_section methods.
 913
 914 // Return the data size.  For an input section we store the size here.
 915 // For an Output_section_data, we have to ask it for the size.
 916
 917 off_t
 918 Output_section::Input_section::data_size() const
 919 {
 920   if (this->is_input_section())
 921     return this->u1_.data_size;
 922   else
 923     return this->u2_.posd->data_size();
 924 }
 925
 926 // Set the address and file offset.
 927
 928 void
 929 Output_section::Input_section::set_address(uint64_t addr, off_t off,
 930                                            off_t secoff)
 931 {
 932   if (this->is_input_section())
 933     this->u2_.object->set_section_offset(this->shndx_, off - secoff);
 934   else
 935     this->u2_.posd->set_address(addr, off);
 936 }
 937
 938 // Try to turn an input address into an output address.
 939
 940 bool
 941 Output_section::Input_section::output_address(const Relobj* object,
 942                                               unsigned int shndx,
 943                                               off_t offset,
 944                                               uint64_t output_section_address,
 945                                               uint64_t *poutput) const
 946 {
 947   if (!this->is_input_section())
 948     return this->u2_.posd->output_address(object, shndx, offset,
 949                                           output_section_address, poutput);
 950   else
 951     {
 952       if (this->shndx_ != shndx
 953           || this->u2_.object != object)
 954         return false;
 955       off_t output_offset;
 956       Output_section* os = object->output_section(shndx, &output_offset);
 957       gold_assert(os != NULL);
 958       *poutput = output_section_address + output_offset + offset;
 959       return true;
 960     }
 961 }
 962
 963 // Write out the data.  We don't have to do anything for an input
 964 // section--they are handled via Object::relocate--but this is where
 965 // we write out the data for an Output_section_data.
 966
 967 void
 968 Output_section::Input_section::write(Output_file* of)
 969 {
 970   if (!this->is_input_section())
 971     this->u2_.posd->write(of);
 972 }
 973
 974 // Output_section methods.
 975
 976 // Construct an Output_section.  NAME will point into a Stringpool.
 977
 978 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
 979                                elfcpp::Elf_Xword flags)
 980   : name_(name),
 981     addralign_(0),
 982     entsize_(0),
 983     link_section_(NULL),
 984     link_(0),
 985     info_section_(NULL),
 986     info_(0),
 987     type_(type),
 988     flags_(flags),
 989     out_shndx_(0),
 990     symtab_index_(0),
 991     dynsym_index_(0),
 992     input_sections_(),
 993     first_input_offset_(0),
 994     fills_(),
 995     needs_symtab_index_(false),
 996     needs_dynsym_index_(false),
 997     should_link_to_symtab_(false),
 998     should_link_to_dynsym_(false)
 999 {
1000 }
1001
1002 Output_section::~Output_section()
1003 {
1004 }
1005
1006 // Set the entry size.
1007
1008 void
1009 Output_section::set_entsize(uint64_t v)
1010 {
1011   if (this->entsize_ == 0)
1012     this->entsize_ = v;
1013   else
1014     gold_assert(this->entsize_ == v);
1015 }
1016
1017 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1018 // OBJECT, to the Output_section.  Return the offset of the input
1019 // section within the output section.  We don't always keep track of
1020 // input sections for an Output_section.  Instead, each Object keeps
1021 // track of the Output_section for each of its input sections.
1022
1023 template<int size, bool big_endian>
1024 off_t
1025 Output_section::add_input_section(Relobj* object, unsigned int shndx,
1026                                   const char* secname,
1027                                   const elfcpp::Shdr<size, big_endian>& shdr)
1028 {
1029   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1030   if ((addralign & (addralign - 1)) != 0)
1031     {
1032       object->error(_("invalid alignment %lu for section \"%s\""),
1033                     static_cast<unsigned long>(addralign), secname);
1034       addralign = 1;
1035     }
1036
1037   if (addralign > this->addralign_)
1038     this->addralign_ = addralign;
1039
1040   // If this is a SHF_MERGE section, we pass all the input sections to
1041   // a Output_data_merge.
1042   if ((shdr.get_sh_flags() & elfcpp::SHF_MERGE) != 0)
1043     {
1044       if (this->add_merge_input_section(object, shndx, shdr.get_sh_flags(),
1045                                         shdr.get_sh_entsize(),
1046                                         addralign))
1047         {
1048           // Tell the relocation routines that they need to call the
1049           // output_address method to determine the final address.
1050           return -1;
1051         }
1052     }
1053
1054   off_t offset_in_section = this->data_size();
1055   off_t aligned_offset_in_section = align_address(offset_in_section,
1056                                                   addralign);
1057
1058   if (aligned_offset_in_section > offset_in_section
1059       && (shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0
1060       && object->target()->has_code_fill())
1061     {
1062       // We need to add some fill data.  Using fill_list_ when
1063       // possible is an optimization, since we will often have fill
1064       // sections without input sections.
1065       off_t fill_len = aligned_offset_in_section - offset_in_section;
1066       if (this->input_sections_.empty())
1067         this->fills_.push_back(Fill(offset_in_section, fill_len));
1068       else
1069         {
1070           // FIXME: When relaxing, the size needs to adjust to
1071           // maintain a constant alignment.
1072           std::string fill_data(object->target()->code_fill(fill_len));
1073           Output_data_const* odc = new Output_data_const(fill_data, 1);
1074           this->input_sections_.push_back(Input_section(odc));
1075         }
1076     }
1077
1078   this->set_data_size(aligned_offset_in_section + shdr.get_sh_size());
1079
1080   // We need to keep track of this section if we are already keeping
1081   // track of sections, or if we are relaxing.  FIXME: Add test for
1082   // relaxing.
1083   if (!this->input_sections_.empty())
1084     this->input_sections_.push_back(Input_section(object, shndx,
1085                                                   shdr.get_sh_size(),
1086                                                   addralign));
1087
1088   return aligned_offset_in_section;
1089 }
1090
1091 // Add arbitrary data to an output section.
1092
1093 void
1094 Output_section::add_output_section_data(Output_section_data* posd)
1095 {
1096   Input_section inp(posd);
1097   this->add_output_section_data(&inp);
1098 }
1099
1100 // Add arbitrary data to an output section by Input_section.
1101
1102 void
1103 Output_section::add_output_section_data(Input_section* inp)
1104 {
1105   if (this->input_sections_.empty())
1106     this->first_input_offset_ = this->data_size();
1107
1108   this->input_sections_.push_back(*inp);
1109
1110   uint64_t addralign = inp->addralign();
1111   if (addralign > this->addralign_)
1112     this->addralign_ = addralign;
1113
1114   inp->set_output_section(this);
1115 }
1116
1117 // Add a merge section to an output section.
1118
1119 void
1120 Output_section::add_output_merge_section(Output_section_data* posd,
1121                                          bool is_string, uint64_t entsize)
1122 {
1123   Input_section inp(posd, is_string, entsize);
1124   this->add_output_section_data(&inp);
1125 }
1126
1127 // Add an input section to a SHF_MERGE section.
1128
1129 bool
1130 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
1131                                         uint64_t flags, uint64_t entsize,
1132                                         uint64_t addralign)
1133 {
1134   // We only merge constants if the alignment is not more than the
1135   // entry size.  This could be handled, but it's unusual.
1136   if (addralign > entsize)
1137     return false;
1138
1139   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
1140   Input_section_list::iterator p;
1141   for (p = this->input_sections_.begin();
1142        p != this->input_sections_.end();
1143        ++p)
1144     if (p->is_merge_section(is_string, entsize))
1145       break;
1146
1147   // We handle the actual constant merging in Output_merge_data or
1148   // Output_merge_string_data.
1149   if (p != this->input_sections_.end())
1150     p->add_input_section(object, shndx);
1151   else
1152     {
1153       Output_section_data* posd;
1154       if (!is_string)
1155         posd = new Output_merge_data(entsize);
1156       else if (entsize == 1)
1157         posd = new Output_merge_string<char>();
1158       else if (entsize == 2)
1159         posd = new Output_merge_string<uint16_t>();
1160       else if (entsize == 4)
1161         posd = new Output_merge_string<uint32_t>();
1162       else
1163         return false;
1164
1165       this->add_output_merge_section(posd, is_string, entsize);
1166       posd->add_input_section(object, shndx);
1167     }
1168
1169   return true;
1170 }
1171
1172 // Return the output virtual address of OFFSET relative to the start
1173 // of input section SHNDX in object OBJECT.
1174
1175 uint64_t
1176 Output_section::output_address(const Relobj* object, unsigned int shndx,
1177                                off_t offset) const
1178 {
1179   uint64_t addr = this->address() + this->first_input_offset_;
1180   for (Input_section_list::const_iterator p = this->input_sections_.begin();
1181        p != this->input_sections_.end();
1182        ++p)
1183     {
1184       addr = align_address(addr, p->addralign());
1185       uint64_t output;
1186       if (p->output_address(object, shndx, offset, addr, &output))
1187         return output;
1188       addr += p->data_size();
1189     }
1190
1191   // If we get here, it means that we don't know the mapping for this
1192   // input section.  This might happen in principle if
1193   // add_input_section were called before add_output_section_data.
1194   // But it should never actually happen.
1195
1196   gold_unreachable();
1197 }
1198
1199 // Set the address of an Output_section.  This is where we handle
1200 // setting the addresses of any Output_section_data objects.
1201
1202 void
1203 Output_section::do_set_address(uint64_t address, off_t startoff)
1204 {
1205   if (this->input_sections_.empty())
1206     return;
1207
1208   off_t off = startoff + this->first_input_offset_;
1209   for (Input_section_list::iterator p = this->input_sections_.begin();
1210        p != this->input_sections_.end();
1211        ++p)
1212     {
1213       off = align_address(off, p->addralign());
1214       p->set_address(address + (off - startoff), off, startoff);
1215       off += p->data_size();
1216     }
1217
1218   this->set_data_size(off - startoff);
1219 }
1220
1221 // Write the section header to *OSHDR.
1222
1223 template<int size, bool big_endian>
1224 void
1225 Output_section::write_header(const Layout* layout,
1226                              const Stringpool* secnamepool,
1227                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
1228 {
1229   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
1230   oshdr->put_sh_type(this->type_);
1231   oshdr->put_sh_flags(this->flags_);
1232   oshdr->put_sh_addr(this->address());
1233   oshdr->put_sh_offset(this->offset());
1234   oshdr->put_sh_size(this->data_size());
1235   if (this->link_section_ != NULL)
1236     oshdr->put_sh_link(this->link_section_->out_shndx());
1237   else if (this->should_link_to_symtab_)
1238     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
1239   else if (this->should_link_to_dynsym_)
1240     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
1241   else
1242     oshdr->put_sh_link(this->link_);
1243   if (this->info_section_ != NULL)
1244     oshdr->put_sh_info(this->info_section_->out_shndx());
1245   else
1246     oshdr->put_sh_info(this->info_);
1247   oshdr->put_sh_addralign(this->addralign_);
1248   oshdr->put_sh_entsize(this->entsize_);
1249 }
1250
1251 // Write out the data.  For input sections the data is written out by
1252 // Object::relocate, but we have to handle Output_section_data objects
1253 // here.
1254
1255 void
1256 Output_section::do_write(Output_file* of)
1257 {
1258   off_t output_section_file_offset = this->offset();
1259   for (Fill_list::iterator p = this->fills_.begin();
1260        p != this->fills_.end();
1261        ++p)
1262     {
1263       std::string fill_data(of->target()->code_fill(p->length()));
1264       of->write(output_section_file_offset + p->section_offset(),
1265                 fill_data.data(), fill_data.size());
1266     }
1267
1268   for (Input_section_list::iterator p = this->input_sections_.begin();
1269        p != this->input_sections_.end();
1270        ++p)
1271     p->write(of);
1272 }
1273
1274 // Output segment methods.
1275
1276 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
1277   : output_data_(),
1278     output_bss_(),
1279     vaddr_(0),
1280     paddr_(0),
1281     memsz_(0),
1282     align_(0),
1283     offset_(0),
1284     filesz_(0),
1285     type_(type),
1286     flags_(flags),
1287     is_align_known_(false)
1288 {
1289 }
1290
1291 // Add an Output_section to an Output_segment.
1292
1293 void
1294 Output_segment::add_output_section(Output_section* os,
1295                                    elfcpp::Elf_Word seg_flags,
1296                                    bool front)
1297 {
1298   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1299   gold_assert(!this->is_align_known_);
1300
1301   // Update the segment flags.
1302   this->flags_ |= seg_flags;
1303
1304   Output_segment::Output_data_list* pdl;
1305   if (os->type() == elfcpp::SHT_NOBITS)
1306     pdl = &this->output_bss_;
1307   else
1308     pdl = &this->output_data_;
1309
1310   // So that PT_NOTE segments will work correctly, we need to ensure
1311   // that all SHT_NOTE sections are adjacent.  This will normally
1312   // happen automatically, because all the SHT_NOTE input sections
1313   // will wind up in the same output section.  However, it is possible
1314   // for multiple SHT_NOTE input sections to have different section
1315   // flags, and thus be in different output sections, but for the
1316   // different section flags to map into the same segment flags and
1317   // thus the same output segment.
1318
1319   // Note that while there may be many input sections in an output
1320   // section, there are normally only a few output sections in an
1321   // output segment.  This loop is expected to be fast.
1322
1323   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
1324     {
1325       Output_segment::Output_data_list::iterator p = pdl->end();
1326       do
1327         {
1328           --p;
1329           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
1330             {
1331               // We don't worry about the FRONT parameter.
1332               ++p;
1333               pdl->insert(p, os);
1334               return;
1335             }
1336         }
1337       while (p != pdl->begin());
1338     }
1339
1340   // Similarly, so that PT_TLS segments will work, we need to group
1341   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
1342   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
1343   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
1344   // correctly.
1345   if ((os->flags() & elfcpp::SHF_TLS) != 0 && !this->output_data_.empty())
1346     {
1347       pdl = &this->output_data_;
1348       bool nobits = os->type() == elfcpp::SHT_NOBITS;
1349       bool sawtls = false;
1350       Output_segment::Output_data_list::iterator p = pdl->end();
1351       do
1352         {
1353           --p;
1354           bool insert;
1355           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
1356             {
1357               sawtls = true;
1358               // Put a NOBITS section after the first TLS section.
1359               // But a PROGBITS section after the first TLS/PROGBITS
1360               // section.
1361               insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
1362             }
1363           else
1364             {
1365               // If we've gone past the TLS sections, but we've seen a
1366               // TLS section, then we need to insert this section now.
1367               insert = sawtls;
1368             }
1369
1370           if (insert)
1371             {
1372               // We don't worry about the FRONT parameter.
1373               ++p;
1374               pdl->insert(p, os);
1375               return;
1376             }
1377         }
1378       while (p != pdl->begin());
1379
1380       // There are no TLS sections yet; put this one at the requested
1381       // location in the section list.
1382     }
1383
1384   if (front)
1385     pdl->push_front(os);
1386   else
1387     pdl->push_back(os);
1388 }
1389
1390 // Add an Output_data (which is not an Output_section) to the start of
1391 // a segment.
1392
1393 void
1394 Output_segment::add_initial_output_data(Output_data* od)
1395 {
1396   gold_assert(!this->is_align_known_);
1397   this->output_data_.push_front(od);
1398 }
1399
1400 // Return the maximum alignment of the Output_data in Output_segment.
1401 // Once we compute this, we prohibit new sections from being added.
1402
1403 uint64_t
1404 Output_segment::addralign()
1405 {
1406   if (!this->is_align_known_)
1407     {
1408       uint64_t addralign;
1409
1410       addralign = Output_segment::maximum_alignment(&this->output_data_);
1411       if (addralign > this->align_)
1412         this->align_ = addralign;
1413
1414       addralign = Output_segment::maximum_alignment(&this->output_bss_);
1415       if (addralign > this->align_)
1416         this->align_ = addralign;
1417
1418       this->is_align_known_ = true;
1419     }
1420
1421   return this->align_;
1422 }
1423
1424 // Return the maximum alignment of a list of Output_data.
1425
1426 uint64_t
1427 Output_segment::maximum_alignment(const Output_data_list* pdl)
1428 {
1429   uint64_t ret = 0;
1430   for (Output_data_list::const_iterator p = pdl->begin();
1431        p != pdl->end();
1432        ++p)
1433     {
1434       uint64_t addralign = (*p)->addralign();
1435       if (addralign > ret)
1436         ret = addralign;
1437     }
1438   return ret;
1439 }
1440
1441 // Set the section addresses for an Output_segment.  ADDR is the
1442 // address and *POFF is the file offset.  Set the section indexes
1443 // starting with *PSHNDX.  Return the address of the immediately
1444 // following segment.  Update *POFF and *PSHNDX.
1445
1446 uint64_t
1447 Output_segment::set_section_addresses(uint64_t addr, off_t* poff,
1448                                       unsigned int* pshndx)
1449 {
1450   gold_assert(this->type_ == elfcpp::PT_LOAD);
1451
1452   this->vaddr_ = addr;
1453   this->paddr_ = addr;
1454
1455   off_t orig_off = *poff;
1456   this->offset_ = orig_off;
1457
1458   *poff = align_address(*poff, this->addralign());
1459
1460   addr = this->set_section_list_addresses(&this->output_data_, addr, poff,
1461                                           pshndx);
1462   this->filesz_ = *poff - orig_off;
1463
1464   off_t off = *poff;
1465
1466   uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr,
1467                                                   poff, pshndx);
1468   this->memsz_ = *poff - orig_off;
1469
1470   // Ignore the file offset adjustments made by the BSS Output_data
1471   // objects.
1472   *poff = off;
1473
1474   return ret;
1475 }
1476
1477 // Set the addresses and file offsets in a list of Output_data
1478 // structures.
1479
1480 uint64_t
1481 Output_segment::set_section_list_addresses(Output_data_list* pdl,
1482                                            uint64_t addr, off_t* poff,
1483                                            unsigned int* pshndx)
1484 {
1485   off_t startoff = *poff;
1486
1487   off_t off = startoff;
1488   for (Output_data_list::iterator p = pdl->begin();
1489        p != pdl->end();
1490        ++p)
1491     {
1492       off = align_address(off, (*p)->addralign());
1493       (*p)->set_address(addr + (off - startoff), off);
1494
1495       // Unless this is a PT_TLS segment, we want to ignore the size
1496       // of a SHF_TLS/SHT_NOBITS section.  Such a section does not
1497       // affect the size of a PT_LOAD segment.
1498       if (this->type_ == elfcpp::PT_TLS
1499           || !(*p)->is_section_flag_set(elfcpp::SHF_TLS)
1500           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
1501         off += (*p)->data_size();
1502
1503       if ((*p)->is_section())
1504         {
1505           (*p)->set_out_shndx(*pshndx);
1506           ++*pshndx;
1507         }
1508     }
1509
1510   *poff = off;
1511   return addr + (off - startoff);
1512 }
1513
1514 // For a non-PT_LOAD segment, set the offset from the sections, if
1515 // any.
1516
1517 void
1518 Output_segment::set_offset()
1519 {
1520   gold_assert(this->type_ != elfcpp::PT_LOAD);
1521
1522   if (this->output_data_.empty() && this->output_bss_.empty())
1523     {
1524       this->vaddr_ = 0;
1525       this->paddr_ = 0;
1526       this->memsz_ = 0;
1527       this->align_ = 0;
1528       this->offset_ = 0;
1529       this->filesz_ = 0;
1530       return;
1531     }
1532
1533   const Output_data* first;
1534   if (this->output_data_.empty())
1535     first = this->output_bss_.front();
1536   else
1537     first = this->output_data_.front();
1538   this->vaddr_ = first->address();
1539   this->paddr_ = this->vaddr_;
1540   this->offset_ = first->offset();
1541
1542   if (this->output_data_.empty())
1543     this->filesz_ = 0;
1544   else
1545     {
1546       const Output_data* last_data = this->output_data_.back();
1547       this->filesz_ = (last_data->address()
1548                        + last_data->data_size()
1549                        - this->vaddr_);
1550     }
1551
1552   const Output_data* last;
1553   if (this->output_bss_.empty())
1554     last = this->output_data_.back();
1555   else
1556     last = this->output_bss_.back();
1557   this->memsz_ = (last->address()
1558                   + last->data_size()
1559                   - this->vaddr_);
1560 }
1561
1562 // Return the number of Output_sections in an Output_segment.
1563
1564 unsigned int
1565 Output_segment::output_section_count() const
1566 {
1567   return (this->output_section_count_list(&this->output_data_)
1568           + this->output_section_count_list(&this->output_bss_));
1569 }
1570
1571 // Return the number of Output_sections in an Output_data_list.
1572
1573 unsigned int
1574 Output_segment::output_section_count_list(const Output_data_list* pdl) const
1575 {
1576   unsigned int count = 0;
1577   for (Output_data_list::const_iterator p = pdl->begin();
1578        p != pdl->end();
1579        ++p)
1580     {
1581       if ((*p)->is_section())
1582         ++count;
1583     }
1584   return count;
1585 }
1586
1587 // Write the segment data into *OPHDR.
1588
1589 template<int size, bool big_endian>
1590 void
1591 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
1592 {
1593   ophdr->put_p_type(this->type_);
1594   ophdr->put_p_offset(this->offset_);
1595   ophdr->put_p_vaddr(this->vaddr_);
1596   ophdr->put_p_paddr(this->paddr_);
1597   ophdr->put_p_filesz(this->filesz_);
1598   ophdr->put_p_memsz(this->memsz_);
1599   ophdr->put_p_flags(this->flags_);
1600   ophdr->put_p_align(this->addralign());
1601 }
1602
1603 // Write the section headers into V.
1604
1605 template<int size, bool big_endian>
1606 unsigned char*
1607 Output_segment::write_section_headers(const Layout* layout,
1608                                       const Stringpool* secnamepool,
1609                                       unsigned char* v,
1610                                       unsigned int *pshndx
1611                                       ACCEPT_SIZE_ENDIAN) const
1612 {
1613   // Every section that is attached to a segment must be attached to a
1614   // PT_LOAD segment, so we only write out section headers for PT_LOAD
1615   // segments.
1616   if (this->type_ != elfcpp::PT_LOAD)
1617     return v;
1618
1619   v = this->write_section_headers_list
1620       SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1621           layout, secnamepool, &this->output_data_, v, pshndx
1622           SELECT_SIZE_ENDIAN(size, big_endian));
1623   v = this->write_section_headers_list
1624       SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1625           layout, secnamepool, &this->output_bss_, v, pshndx
1626           SELECT_SIZE_ENDIAN(size, big_endian));
1627   return v;
1628 }
1629
1630 template<int size, bool big_endian>
1631 unsigned char*
1632 Output_segment::write_section_headers_list(const Layout* layout,
1633                                            const Stringpool* secnamepool,
1634                                            const Output_data_list* pdl,
1635                                            unsigned char* v,
1636                                            unsigned int* pshndx
1637                                            ACCEPT_SIZE_ENDIAN) const
1638 {
1639   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
1640   for (Output_data_list::const_iterator p = pdl->begin();
1641        p != pdl->end();
1642        ++p)
1643     {
1644       if ((*p)->is_section())
1645         {
1646           const Output_section* ps = static_cast<const Output_section*>(*p);
1647           gold_assert(*pshndx == ps->out_shndx());
1648           elfcpp::Shdr_write<size, big_endian> oshdr(v);
1649           ps->write_header(layout, secnamepool, &oshdr);
1650           v += shdr_size;
1651           ++*pshndx;
1652         }
1653     }
1654   return v;
1655 }
1656
1657 // Output_file methods.
1658
1659 Output_file::Output_file(const General_options& options, Target* target)
1660   : options_(options),
1661     target_(target),
1662     name_(options.output_file_name()),
1663     o_(-1),
1664     file_size_(0),
1665     base_(NULL)
1666 {
1667 }
1668
1669 // Open the output file.
1670
1671 void
1672 Output_file::open(off_t file_size)
1673 {
1674   this->file_size_ = file_size;
1675
1676   // Unlink the file first; otherwise the open() may fail if the file
1677   // is busy (e.g. it's an executable that's currently being executed).
1678   //
1679   // However, the linker may be part of a system where a zero-length
1680   // file is created for it to write to, with tight permissions (gcc
1681   // 2.95 did something like this).  Unlinking the file would work
1682   // around those permission controls, so we only unlink if the file
1683   // has a non-zero size.  We also unlink only regular files to avoid
1684   // trouble with directories/etc.
1685   //
1686   // If we fail, continue; this command is merely a best-effort attempt
1687   // to improve the odds for open().
1688
1689   struct stat s;
1690   if (::stat(this->name_, &s) == 0 && s.st_size != 0)
1691     unlink_if_ordinary(this->name_);
1692
1693   int mode = parameters->output_is_object() ? 0666 : 0777;
1694   int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
1695   if (o < 0)
1696     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
1697   this->o_ = o;
1698
1699   // Write out one byte to make the file the right size.
1700   if (::lseek(o, file_size - 1, SEEK_SET) < 0)
1701     gold_fatal(_("%s: lseek: %s"), this->name_, strerror(errno));
1702   char b = 0;
1703   if (::write(o, &b, 1) != 1)
1704     gold_fatal(_("%s: write: %s"), this->name_, strerror(errno));
1705
1706   // Map the file into memory.
1707   void* base = ::mmap(NULL, file_size, PROT_READ | PROT_WRITE,
1708                       MAP_SHARED, o, 0);
1709   if (base == MAP_FAILED)
1710     gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
1711   this->base_ = static_cast<unsigned char*>(base);
1712 }
1713
1714 // Close the output file.
1715
1716 void
1717 Output_file::close()
1718 {
1719   if (::munmap(this->base_, this->file_size_) < 0)
1720     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
1721   this->base_ = NULL;
1722
1723   if (::close(this->o_) < 0)
1724     gold_error(_("%s: close: %s"), this->name_, strerror(errno));
1725   this->o_ = -1;
1726 }
1727
1728 // Instantiate the templates we need.  We could use the configure
1729 // script to restrict this to only the ones for implemented targets.
1730
1731 #ifdef HAVE_TARGET_32_LITTLE
1732 template
1733 off_t
1734 Output_section::add_input_section<32, false>(
1735     Relobj* object,
1736     unsigned int shndx,
1737     const char* secname,
1738     const elfcpp::Shdr<32, false>& shdr);
1739 #endif
1740
1741 #ifdef HAVE_TARGET_32_BIG
1742 template
1743 off_t
1744 Output_section::add_input_section<32, true>(
1745     Relobj* object,
1746     unsigned int shndx,
1747     const char* secname,
1748     const elfcpp::Shdr<32, true>& shdr);
1749 #endif
1750
1751 #ifdef HAVE_TARGET_64_LITTLE
1752 template
1753 off_t
1754 Output_section::add_input_section<64, false>(
1755     Relobj* object,
1756     unsigned int shndx,
1757     const char* secname,
1758     const elfcpp::Shdr<64, false>& shdr);
1759 #endif
1760
1761 #ifdef HAVE_TARGET_64_BIG
1762 template
1763 off_t
1764 Output_section::add_input_section<64, true>(
1765     Relobj* object,
1766     unsigned int shndx,
1767     const char* secname,
1768     const elfcpp::Shdr<64, true>& shdr);
1769 #endif
1770
1771 #ifdef HAVE_TARGET_32_LITTLE
1772 template
1773 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
1774 #endif
1775
1776 #ifdef HAVE_TARGET_32_BIG
1777 template
1778 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
1779 #endif
1780
1781 #ifdef HAVE_TARGET_64_LITTLE
1782 template
1783 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
1784 #endif
1785
1786 #ifdef HAVE_TARGET_64_BIG
1787 template
1788 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
1789 #endif
1790
1791 #ifdef HAVE_TARGET_32_LITTLE
1792 template
1793 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
1794 #endif
1795
1796 #ifdef HAVE_TARGET_32_BIG
1797 template
1798 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
1799 #endif
1800
1801 #ifdef HAVE_TARGET_64_LITTLE
1802 template
1803 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
1804 #endif
1805
1806 #ifdef HAVE_TARGET_64_BIG
1807 template
1808 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
1809 #endif
1810
1811 #ifdef HAVE_TARGET_32_LITTLE
1812 template
1813 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
1814 #endif
1815
1816 #ifdef HAVE_TARGET_32_BIG
1817 template
1818 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
1819 #endif
1820
1821 #ifdef HAVE_TARGET_64_LITTLE
1822 template
1823 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
1824 #endif
1825
1826 #ifdef HAVE_TARGET_64_BIG
1827 template
1828 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
1829 #endif
1830
1831 #ifdef HAVE_TARGET_32_LITTLE
1832 template
1833 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
1834 #endif
1835
1836 #ifdef HAVE_TARGET_32_BIG
1837 template
1838 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
1839 #endif
1840
1841 #ifdef HAVE_TARGET_64_LITTLE
1842 template
1843 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
1844 #endif
1845
1846 #ifdef HAVE_TARGET_64_BIG
1847 template
1848 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
1849 #endif
1850
1851 #ifdef HAVE_TARGET_32_LITTLE
1852 template
1853 class Output_data_got<32, false>;
1854 #endif
1855
1856 #ifdef HAVE_TARGET_32_BIG
1857 template
1858 class Output_data_got<32, true>;
1859 #endif
1860
1861 #ifdef HAVE_TARGET_64_LITTLE
1862 template
1863 class Output_data_got<64, false>;
1864 #endif
1865
1866 #ifdef HAVE_TARGET_64_BIG
1867 template
1868 class Output_data_got<64, true>;
1869 #endif
1870
1871 } // End namespace gold.