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   if (parameters->output_is_object())
 405     e_type = elfcpp::ET_REL;
 406   else if (parameters->output_is_shared())
 407     e_type = elfcpp::ET_DYN;
 408   else
 409     e_type = elfcpp::ET_EXEC;
 410   oehdr.put_e_type(e_type);
 411
 412   oehdr.put_e_machine(this->target_->machine_code());
 413   oehdr.put_e_version(elfcpp::EV_CURRENT);
 414
 415   // FIXME: Need to support -e, and target specific entry symbol.
 416   Symbol* sym = this->symtab_->lookup("_start");
 417   typename Sized_symbol<size>::Value_type v;
 418   if (sym == NULL)
 419     v = 0;
 420   else
 421     {
 422       Sized_symbol<size>* ssym;
 423       ssym = this->symtab_->get_sized_symbol SELECT_SIZE_NAME(size) (
 424         sym SELECT_SIZE(size));
 425       v = ssym->value();
 426     }
 427   oehdr.put_e_entry(v);
 428
 429   oehdr.put_e_phoff(this->segment_header_->offset());
 430   oehdr.put_e_shoff(this->section_header_->offset());
 431
 432   // FIXME: The target needs to set the flags.
 433   oehdr.put_e_flags(0);
 434
 435   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
 436   oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
 437   oehdr.put_e_phnum(this->segment_header_->data_size()
 438                      / elfcpp::Elf_sizes<size>::phdr_size);
 439   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
 440   oehdr.put_e_shnum(this->section_header_->data_size()
 441                      / elfcpp::Elf_sizes<size>::shdr_size);
 442   oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
 443
 444   of->write_output_view(0, ehdr_size, view);
 445 }
 446
 447 // Output_data_const methods.
 448
 449 void
 450 Output_data_const::do_write(Output_file* of)
 451 {
 452   of->write(this->offset(), this->data_.data(), this->data_.size());
 453 }
 454
 455 // Output_data_const_buffer methods.
 456
 457 void
 458 Output_data_const_buffer::do_write(Output_file* of)
 459 {
 460   of->write(this->offset(), this->p_, this->data_size());
 461 }
 462
 463 // Output_section_data methods.
 464
 465 // Record the output section, and set the entry size and such.
 466
 467 void
 468 Output_section_data::set_output_section(Output_section* os)
 469 {
 470   gold_assert(this->output_section_ == NULL);
 471   this->output_section_ = os;
 472   this->do_adjust_output_section(os);
 473 }
 474
 475 // Return the section index of the output section.
 476
 477 unsigned int
 478 Output_section_data::do_out_shndx() const
 479 {
 480   gold_assert(this->output_section_ != NULL);
 481   return this->output_section_->out_shndx();
 482 }
 483
 484 // Output_data_strtab methods.
 485
 486 // Set the address.  We don't actually care about the address, but we
 487 // do set our final size.
 488
 489 void
 490 Output_data_strtab::do_set_address(uint64_t, off_t)
 491 {
 492   this->strtab_->set_string_offsets();
 493   this->set_data_size(this->strtab_->get_strtab_size());
 494 }
 495
 496 // Write out a string table.
 497
 498 void
 499 Output_data_strtab::do_write(Output_file* of)
 500 {
 501   this->strtab_->write(of, this->offset());
 502 }
 503
 504 // Output_reloc methods.
 505
 506 // Get the symbol index of a relocation.
 507
 508 template<bool dynamic, int size, bool big_endian>
 509 unsigned int
 510 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
 511   const
 512 {
 513   unsigned int index;
 514   switch (this->local_sym_index_)
 515     {
 516     case INVALID_CODE:
 517       gold_unreachable();
 518
 519     case GSYM_CODE:
 520       if (this->u1_.gsym == NULL)
 521         index = 0;
 522       else if (dynamic)
 523         index = this->u1_.gsym->dynsym_index();
 524       else
 525         index = this->u1_.gsym->symtab_index();
 526       break;
 527
 528     case SECTION_CODE:
 529       if (dynamic)
 530         index = this->u1_.os->dynsym_index();
 531       else
 532         index = this->u1_.os->symtab_index();
 533       break;
 534
 535     case 0:
 536       // Relocations without symbols use a symbol index of 0.
 537       index = 0;
 538       break;
 539
 540     default:
 541       if (dynamic)
 542         {
 543           // FIXME: It seems that some targets may need to generate
 544           // dynamic relocations against local symbols for some
 545           // reasons.  This will have to be addressed at some point.
 546           gold_unreachable();
 547         }
 548       else
 549         index = this->u1_.relobj->symtab_index(this->local_sym_index_);
 550       break;
 551     }
 552   gold_assert(index != -1U);
 553   return index;
 554 }
 555
 556 // Write out the offset and info fields of a Rel or Rela relocation
 557 // entry.
 558
 559 template<bool dynamic, int size, bool big_endian>
 560 template<typename Write_rel>
 561 void
 562 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
 563     Write_rel* wr) const
 564 {
 565   Address address = this->address_;
 566   if (this->shndx_ != INVALID_CODE)
 567     {
 568       off_t off;
 569       Output_section* os = this->u2_.relobj->output_section(this->shndx_,
 570                                                             &off);
 571       gold_assert(os != NULL);
 572       address += os->address() + off;
 573     }
 574   else if (this->u2_.od != NULL)
 575     address += this->u2_.od->address();
 576   wr->put_r_offset(address);
 577   wr->put_r_info(elfcpp::elf_r_info<size>(this->get_symbol_index(),
 578                                           this->type_));
 579 }
 580
 581 // Write out a Rel relocation.
 582
 583 template<bool dynamic, int size, bool big_endian>
 584 void
 585 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
 586     unsigned char* pov) const
 587 {
 588   elfcpp::Rel_write<size, big_endian> orel(pov);
 589   this->write_rel(&orel);
 590 }
 591
 592 // Write out a Rela relocation.
 593
 594 template<bool dynamic, int size, bool big_endian>
 595 void
 596 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
 597     unsigned char* pov) const
 598 {
 599   elfcpp::Rela_write<size, big_endian> orel(pov);
 600   this->rel_.write_rel(&orel);
 601   orel.put_r_addend(this->addend_);
 602 }
 603
 604 // Output_data_reloc_base methods.
 605
 606 // Adjust the output section.
 607
 608 template<int sh_type, bool dynamic, int size, bool big_endian>
 609 void
 610 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
 611     ::do_adjust_output_section(Output_section* os)
 612 {
 613   if (sh_type == elfcpp::SHT_REL)
 614     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
 615   else if (sh_type == elfcpp::SHT_RELA)
 616     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
 617   else
 618     gold_unreachable();
 619   if (dynamic)
 620     os->set_should_link_to_dynsym();
 621   else
 622     os->set_should_link_to_symtab();
 623 }
 624
 625 // Write out relocation data.
 626
 627 template<int sh_type, bool dynamic, int size, bool big_endian>
 628 void
 629 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
 630     Output_file* of)
 631 {
 632   const off_t off = this->offset();
 633   const off_t oview_size = this->data_size();
 634   unsigned char* const oview = of->get_output_view(off, oview_size);
 635
 636   unsigned char* pov = oview;
 637   for (typename Relocs::const_iterator p = this->relocs_.begin();
 638        p != this->relocs_.end();
 639        ++p)
 640     {
 641       p->write(pov);
 642       pov += reloc_size;
 643     }
 644
 645   gold_assert(pov - oview == oview_size);
 646
 647   of->write_output_view(off, oview_size, oview);
 648
 649   // We no longer need the relocation entries.
 650   this->relocs_.clear();
 651 }
 652
 653 // Output_data_got::Got_entry methods.
 654
 655 // Write out the entry.
 656
 657 template<int size, bool big_endian>
 658 void
 659 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
 660 {
 661   Valtype val = 0;
 662
 663   switch (this->local_sym_index_)
 664     {
 665     case GSYM_CODE:
 666       {
 667         Symbol* gsym = this->u_.gsym;
 668
 669         // If the symbol is resolved locally, we need to write out its
 670         // value.  Otherwise we just write zero.  The target code is
 671         // responsible for creating a relocation entry to fill in the
 672         // value at runtime.
 673         if (gsym->final_value_is_known())
 674           {
 675             Sized_symbol<size>* sgsym;
 676             // This cast is a bit ugly.  We don't want to put a
 677             // virtual method in Symbol, because we want Symbol to be
 678             // as small as possible.
 679             sgsym = static_cast<Sized_symbol<size>*>(gsym);
 680             val = sgsym->value();
 681           }
 682       }
 683       break;
 684
 685     case CONSTANT_CODE:
 686       val = this->u_.constant;
 687       break;
 688
 689     default:
 690       val = this->u_.object->local_symbol_value(this->local_sym_index_);
 691       break;
 692     }
 693
 694   elfcpp::Swap<size, big_endian>::writeval(pov, val);
 695 }
 696
 697 // Output_data_got methods.
 698
 699 // Add an entry for a global symbol to the GOT.  This returns true if
 700 // this is a new GOT entry, false if the symbol already had a GOT
 701 // entry.
 702
 703 template<int size, bool big_endian>
 704 bool
 705 Output_data_got<size, big_endian>::add_global(Symbol* gsym)
 706 {
 707   if (gsym->has_got_offset())
 708     return false;
 709
 710   this->entries_.push_back(Got_entry(gsym));
 711   this->set_got_size();
 712   gsym->set_got_offset(this->last_got_offset());
 713   return true;
 714 }
 715
 716 // Add an entry for a local symbol to the GOT.  This returns true if
 717 // this is a new GOT entry, false if the symbol already has a GOT
 718 // entry.
 719
 720 template<int size, bool big_endian>
 721 bool
 722 Output_data_got<size, big_endian>::add_local(
 723     Sized_relobj<size, big_endian>* object,
 724     unsigned int symndx)
 725 {
 726   if (object->local_has_got_offset(symndx))
 727     return false;
 728   this->entries_.push_back(Got_entry(object, symndx));
 729   this->set_got_size();
 730   object->set_local_got_offset(symndx, this->last_got_offset());
 731   return true;
 732 }
 733
 734 // Write out the GOT.
 735
 736 template<int size, bool big_endian>
 737 void
 738 Output_data_got<size, big_endian>::do_write(Output_file* of)
 739 {
 740   const int add = size / 8;
 741
 742   const off_t off = this->offset();
 743   const off_t oview_size = this->data_size();
 744   unsigned char* const oview = of->get_output_view(off, oview_size);
 745
 746   unsigned char* pov = oview;
 747   for (typename Got_entries::const_iterator p = this->entries_.begin();
 748        p != this->entries_.end();
 749        ++p)
 750     {
 751       p->write(pov);
 752       pov += add;
 753     }
 754
 755   gold_assert(pov - oview == oview_size);
 756
 757   of->write_output_view(off, oview_size, oview);
 758
 759   // We no longer need the GOT entries.
 760   this->entries_.clear();
 761 }
 762
 763 // Output_data_dynamic::Dynamic_entry methods.
 764
 765 // Write out the entry.
 766
 767 template<int size, bool big_endian>
 768 void
 769 Output_data_dynamic::Dynamic_entry::write(
 770     unsigned char* pov,
 771     const Stringpool* pool
 772     ACCEPT_SIZE_ENDIAN) const
 773 {
 774   typename elfcpp::Elf_types<size>::Elf_WXword val;
 775   switch (this->classification_)
 776     {
 777     case DYNAMIC_NUMBER:
 778       val = this->u_.val;
 779       break;
 780
 781     case DYNAMIC_SECTION_ADDRESS:
 782       val = this->u_.od->address();
 783       break;
 784
 785     case DYNAMIC_SECTION_SIZE:
 786       val = this->u_.od->data_size();
 787       break;
 788
 789     case DYNAMIC_SYMBOL:
 790       {
 791         const Sized_symbol<size>* s =
 792           static_cast<const Sized_symbol<size>*>(this->u_.sym);
 793         val = s->value();
 794       }
 795       break;
 796
 797     case DYNAMIC_STRING:
 798       val = pool->get_offset(this->u_.str);
 799       break;
 800
 801     default:
 802       gold_unreachable();
 803     }
 804
 805   elfcpp::Dyn_write<size, big_endian> dw(pov);
 806   dw.put_d_tag(this->tag_);
 807   dw.put_d_val(val);
 808 }
 809
 810 // Output_data_dynamic methods.
 811
 812 // Adjust the output section to set the entry size.
 813
 814 void
 815 Output_data_dynamic::do_adjust_output_section(Output_section* os)
 816 {
 817   if (parameters->get_size() == 32)
 818     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
 819   else if (parameters->get_size() == 64)
 820     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
 821   else
 822     gold_unreachable();
 823 }
 824
 825 // Set the final data size.
 826
 827 void
 828 Output_data_dynamic::do_set_address(uint64_t, off_t)
 829 {
 830   // Add the terminating entry.
 831   this->add_constant(elfcpp::DT_NULL, 0);
 832
 833   int dyn_size;
 834   if (parameters->get_size() == 32)
 835     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
 836   else if (parameters->get_size() == 64)
 837     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
 838   else
 839     gold_unreachable();
 840   this->set_data_size(this->entries_.size() * dyn_size);
 841 }
 842
 843 // Write out the dynamic entries.
 844
 845 void
 846 Output_data_dynamic::do_write(Output_file* of)
 847 {
 848   if (parameters->get_size() == 32)
 849     {
 850       if (parameters->is_big_endian())
 851         {
 852 #ifdef HAVE_TARGET_32_BIG
 853           this->sized_write<32, true>(of);
 854 #else
 855           gold_unreachable();
 856 #endif
 857         }
 858       else
 859         {
 860 #ifdef HAVE_TARGET_32_LITTLE
 861           this->sized_write<32, false>(of);
 862 #else
 863           gold_unreachable();
 864 #endif
 865         }
 866     }
 867   else if (parameters->get_size() == 64)
 868     {
 869       if (parameters->is_big_endian())
 870         {
 871 #ifdef HAVE_TARGET_64_BIG
 872           this->sized_write<64, true>(of);
 873 #else
 874           gold_unreachable();
 875 #endif
 876         }
 877       else
 878         {
 879 #ifdef HAVE_TARGET_64_LITTLE
 880           this->sized_write<64, false>(of);
 881 #else
 882           gold_unreachable();
 883 #endif
 884         }
 885     }
 886   else
 887     gold_unreachable();
 888 }
 889
 890 template<int size, bool big_endian>
 891 void
 892 Output_data_dynamic::sized_write(Output_file* of)
 893 {
 894   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
 895
 896   const off_t offset = this->offset();
 897   const off_t oview_size = this->data_size();
 898   unsigned char* const oview = of->get_output_view(offset, oview_size);
 899
 900   unsigned char* pov = oview;
 901   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
 902        p != this->entries_.end();
 903        ++p)
 904     {
 905       p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
 906           pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian));
 907       pov += dyn_size;
 908     }
 909
 910   gold_assert(pov - oview == oview_size);
 911
 912   of->write_output_view(offset, oview_size, oview);
 913
 914   // We no longer need the dynamic entries.
 915   this->entries_.clear();
 916 }
 917
 918 // Output_section::Input_section methods.
 919
 920 // Return the data size.  For an input section we store the size here.
 921 // For an Output_section_data, we have to ask it for the size.
 922
 923 off_t
 924 Output_section::Input_section::data_size() const
 925 {
 926   if (this->is_input_section())
 927     return this->u1_.data_size;
 928   else
 929     return this->u2_.posd->data_size();
 930 }
 931
 932 // Set the address and file offset.
 933
 934 void
 935 Output_section::Input_section::set_address(uint64_t addr, off_t off,
 936                                            off_t secoff)
 937 {
 938   if (this->is_input_section())
 939     this->u2_.object->set_section_offset(this->shndx_, off - secoff);
 940   else
 941     this->u2_.posd->set_address(addr, off);
 942 }
 943
 944 // Try to turn an input address into an output address.
 945
 946 bool
 947 Output_section::Input_section::output_address(const Relobj* object,
 948                                               unsigned int shndx,
 949                                               off_t offset,
 950                                               uint64_t output_section_address,
 951                                               uint64_t *poutput) const
 952 {
 953   if (!this->is_input_section())
 954     return this->u2_.posd->output_address(object, shndx, offset,
 955                                           output_section_address, poutput);
 956   else
 957     {
 958       if (this->shndx_ != shndx
 959           || this->u2_.object != object)
 960         return false;
 961       off_t output_offset;
 962       Output_section* os = object->output_section(shndx, &output_offset);
 963       gold_assert(os != NULL);
 964       *poutput = output_section_address + output_offset + offset;
 965       return true;
 966     }
 967 }
 968
 969 // Write out the data.  We don't have to do anything for an input
 970 // section--they are handled via Object::relocate--but this is where
 971 // we write out the data for an Output_section_data.
 972
 973 void
 974 Output_section::Input_section::write(Output_file* of)
 975 {
 976   if (!this->is_input_section())
 977     this->u2_.posd->write(of);
 978 }
 979
 980 // Output_section methods.
 981
 982 // Construct an Output_section.  NAME will point into a Stringpool.
 983
 984 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
 985                                elfcpp::Elf_Xword flags)
 986   : name_(name),
 987     addralign_(0),
 988     entsize_(0),
 989     link_section_(NULL),
 990     link_(0),
 991     info_section_(NULL),
 992     info_(0),
 993     type_(type),
 994     flags_(flags),
 995     out_shndx_(-1U),
 996     symtab_index_(0),
 997     dynsym_index_(0),
 998     input_sections_(),
 999     first_input_offset_(0),
1000     fills_(),
1001     needs_symtab_index_(false),
1002     needs_dynsym_index_(false),
1003     should_link_to_symtab_(false),
1004     should_link_to_dynsym_(false)
1005 {
1006 }
1007
1008 Output_section::~Output_section()
1009 {
1010 }
1011
1012 // Set the entry size.
1013
1014 void
1015 Output_section::set_entsize(uint64_t v)
1016 {
1017   if (this->entsize_ == 0)
1018     this->entsize_ = v;
1019   else
1020     gold_assert(this->entsize_ == v);
1021 }
1022
1023 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1024 // OBJECT, to the Output_section.  Return the offset of the input
1025 // section within the output section.  We don't always keep track of
1026 // input sections for an Output_section.  Instead, each Object keeps
1027 // track of the Output_section for each of its input sections.
1028
1029 template<int size, bool big_endian>
1030 off_t
1031 Output_section::add_input_section(Relobj* object, unsigned int shndx,
1032                                   const char* secname,
1033                                   const elfcpp::Shdr<size, big_endian>& shdr)
1034 {
1035   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1036   if ((addralign & (addralign - 1)) != 0)
1037     {
1038       object->error(_("invalid alignment %lu for section \"%s\""),
1039                     static_cast<unsigned long>(addralign), secname);
1040       addralign = 1;
1041     }
1042
1043   if (addralign > this->addralign_)
1044     this->addralign_ = addralign;
1045
1046   // If this is a SHF_MERGE section, we pass all the input sections to
1047   // a Output_data_merge.
1048   if ((shdr.get_sh_flags() & elfcpp::SHF_MERGE) != 0)
1049     {
1050       if (this->add_merge_input_section(object, shndx, shdr.get_sh_flags(),
1051                                         shdr.get_sh_entsize(),
1052                                         addralign))
1053         {
1054           // Tell the relocation routines that they need to call the
1055           // output_address method to determine the final address.
1056           return -1;
1057         }
1058     }
1059
1060   off_t offset_in_section = this->data_size();
1061   off_t aligned_offset_in_section = align_address(offset_in_section,
1062                                                   addralign);
1063
1064   if (aligned_offset_in_section > offset_in_section
1065       && (shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0
1066       && object->target()->has_code_fill())
1067     {
1068       // We need to add some fill data.  Using fill_list_ when
1069       // possible is an optimization, since we will often have fill
1070       // sections without input sections.
1071       off_t fill_len = aligned_offset_in_section - offset_in_section;
1072       if (this->input_sections_.empty())
1073         this->fills_.push_back(Fill(offset_in_section, fill_len));
1074       else
1075         {
1076           // FIXME: When relaxing, the size needs to adjust to
1077           // maintain a constant alignment.
1078           std::string fill_data(object->target()->code_fill(fill_len));
1079           Output_data_const* odc = new Output_data_const(fill_data, 1);
1080           this->input_sections_.push_back(Input_section(odc));
1081         }
1082     }
1083
1084   this->set_data_size(aligned_offset_in_section + shdr.get_sh_size());
1085
1086   // We need to keep track of this section if we are already keeping
1087   // track of sections, or if we are relaxing.  FIXME: Add test for
1088   // relaxing.
1089   if (!this->input_sections_.empty())
1090     this->input_sections_.push_back(Input_section(object, shndx,
1091                                                   shdr.get_sh_size(),
1092                                                   addralign));
1093
1094   return aligned_offset_in_section;
1095 }
1096
1097 // Add arbitrary data to an output section.
1098
1099 void
1100 Output_section::add_output_section_data(Output_section_data* posd)
1101 {
1102   Input_section inp(posd);
1103   this->add_output_section_data(&inp);
1104 }
1105
1106 // Add arbitrary data to an output section by Input_section.
1107
1108 void
1109 Output_section::add_output_section_data(Input_section* inp)
1110 {
1111   if (this->input_sections_.empty())
1112     this->first_input_offset_ = this->data_size();
1113
1114   this->input_sections_.push_back(*inp);
1115
1116   uint64_t addralign = inp->addralign();
1117   if (addralign > this->addralign_)
1118     this->addralign_ = addralign;
1119
1120   inp->set_output_section(this);
1121 }
1122
1123 // Add a merge section to an output section.
1124
1125 void
1126 Output_section::add_output_merge_section(Output_section_data* posd,
1127                                          bool is_string, uint64_t entsize)
1128 {
1129   Input_section inp(posd, is_string, entsize);
1130   this->add_output_section_data(&inp);
1131 }
1132
1133 // Add an input section to a SHF_MERGE section.
1134
1135 bool
1136 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
1137                                         uint64_t flags, uint64_t entsize,
1138                                         uint64_t addralign)
1139 {
1140   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
1141
1142   // We only merge strings if the alignment is not more than the
1143   // character size.  This could be handled, but it's unusual.
1144   if (is_string && addralign > entsize)
1145     return false;
1146
1147   Input_section_list::iterator p;
1148   for (p = this->input_sections_.begin();
1149        p != this->input_sections_.end();
1150        ++p)
1151     if (p->is_merge_section(is_string, entsize, addralign))
1152       break;
1153
1154   // We handle the actual constant merging in Output_merge_data or
1155   // Output_merge_string_data.
1156   if (p != this->input_sections_.end())
1157     p->add_input_section(object, shndx);
1158   else
1159     {
1160       Output_section_data* posd;
1161       if (!is_string)
1162         posd = new Output_merge_data(entsize, addralign);
1163       else if (entsize == 1)
1164         posd = new Output_merge_string<char>(addralign);
1165       else if (entsize == 2)
1166         posd = new Output_merge_string<uint16_t>(addralign);
1167       else if (entsize == 4)
1168         posd = new Output_merge_string<uint32_t>(addralign);
1169       else
1170         return false;
1171
1172       this->add_output_merge_section(posd, is_string, entsize);
1173       posd->add_input_section(object, shndx);
1174     }
1175
1176   return true;
1177 }
1178
1179 // Return the output virtual address of OFFSET relative to the start
1180 // of input section SHNDX in object OBJECT.
1181
1182 uint64_t
1183 Output_section::output_address(const Relobj* object, unsigned int shndx,
1184                                off_t offset) const
1185 {
1186   uint64_t addr = this->address() + this->first_input_offset_;
1187   for (Input_section_list::const_iterator p = this->input_sections_.begin();
1188        p != this->input_sections_.end();
1189        ++p)
1190     {
1191       addr = align_address(addr, p->addralign());
1192       uint64_t output;
1193       if (p->output_address(object, shndx, offset, addr, &output))
1194         return output;
1195       addr += p->data_size();
1196     }
1197
1198   // If we get here, it means that we don't know the mapping for this
1199   // input section.  This might happen in principle if
1200   // add_input_section were called before add_output_section_data.
1201   // But it should never actually happen.
1202
1203   gold_unreachable();
1204 }
1205
1206 // Set the address of an Output_section.  This is where we handle
1207 // setting the addresses of any Output_section_data objects.
1208
1209 void
1210 Output_section::do_set_address(uint64_t address, off_t startoff)
1211 {
1212   if (this->input_sections_.empty())
1213     return;
1214
1215   off_t off = startoff + this->first_input_offset_;
1216   for (Input_section_list::iterator p = this->input_sections_.begin();
1217        p != this->input_sections_.end();
1218        ++p)
1219     {
1220       off = align_address(off, p->addralign());
1221       p->set_address(address + (off - startoff), off, startoff);
1222       off += p->data_size();
1223     }
1224
1225   this->set_data_size(off - startoff);
1226 }
1227
1228 // Write the section header to *OSHDR.
1229
1230 template<int size, bool big_endian>
1231 void
1232 Output_section::write_header(const Layout* layout,
1233                              const Stringpool* secnamepool,
1234                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
1235 {
1236   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
1237   oshdr->put_sh_type(this->type_);
1238   oshdr->put_sh_flags(this->flags_);
1239   oshdr->put_sh_addr(this->address());
1240   oshdr->put_sh_offset(this->offset());
1241   oshdr->put_sh_size(this->data_size());
1242   if (this->link_section_ != NULL)
1243     oshdr->put_sh_link(this->link_section_->out_shndx());
1244   else if (this->should_link_to_symtab_)
1245     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
1246   else if (this->should_link_to_dynsym_)
1247     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
1248   else
1249     oshdr->put_sh_link(this->link_);
1250   if (this->info_section_ != NULL)
1251     oshdr->put_sh_info(this->info_section_->out_shndx());
1252   else
1253     oshdr->put_sh_info(this->info_);
1254   oshdr->put_sh_addralign(this->addralign_);
1255   oshdr->put_sh_entsize(this->entsize_);
1256 }
1257
1258 // Write out the data.  For input sections the data is written out by
1259 // Object::relocate, but we have to handle Output_section_data objects
1260 // here.
1261
1262 void
1263 Output_section::do_write(Output_file* of)
1264 {
1265   off_t output_section_file_offset = this->offset();
1266   for (Fill_list::iterator p = this->fills_.begin();
1267        p != this->fills_.end();
1268        ++p)
1269     {
1270       std::string fill_data(of->target()->code_fill(p->length()));
1271       of->write(output_section_file_offset + p->section_offset(),
1272                 fill_data.data(), fill_data.size());
1273     }
1274
1275   for (Input_section_list::iterator p = this->input_sections_.begin();
1276        p != this->input_sections_.end();
1277        ++p)
1278     p->write(of);
1279 }
1280
1281 // Output segment methods.
1282
1283 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
1284   : output_data_(),
1285     output_bss_(),
1286     vaddr_(0),
1287     paddr_(0),
1288     memsz_(0),
1289     align_(0),
1290     offset_(0),
1291     filesz_(0),
1292     type_(type),
1293     flags_(flags),
1294     is_align_known_(false)
1295 {
1296 }
1297
1298 // Add an Output_section to an Output_segment.
1299
1300 void
1301 Output_segment::add_output_section(Output_section* os,
1302                                    elfcpp::Elf_Word seg_flags,
1303                                    bool front)
1304 {
1305   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1306   gold_assert(!this->is_align_known_);
1307
1308   // Update the segment flags.
1309   this->flags_ |= seg_flags;
1310
1311   Output_segment::Output_data_list* pdl;
1312   if (os->type() == elfcpp::SHT_NOBITS)
1313     pdl = &this->output_bss_;
1314   else
1315     pdl = &this->output_data_;
1316
1317   // So that PT_NOTE segments will work correctly, we need to ensure
1318   // that all SHT_NOTE sections are adjacent.  This will normally
1319   // happen automatically, because all the SHT_NOTE input sections
1320   // will wind up in the same output section.  However, it is possible
1321   // for multiple SHT_NOTE input sections to have different section
1322   // flags, and thus be in different output sections, but for the
1323   // different section flags to map into the same segment flags and
1324   // thus the same output segment.
1325
1326   // Note that while there may be many input sections in an output
1327   // section, there are normally only a few output sections in an
1328   // output segment.  This loop is expected to be fast.
1329
1330   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
1331     {
1332       Output_segment::Output_data_list::iterator p = pdl->end();
1333       do
1334         {
1335           --p;
1336           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
1337             {
1338               // We don't worry about the FRONT parameter.
1339               ++p;
1340               pdl->insert(p, os);
1341               return;
1342             }
1343         }
1344       while (p != pdl->begin());
1345     }
1346
1347   // Similarly, so that PT_TLS segments will work, we need to group
1348   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
1349   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
1350   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
1351   // correctly.
1352   if ((os->flags() & elfcpp::SHF_TLS) != 0 && !this->output_data_.empty())
1353     {
1354       pdl = &this->output_data_;
1355       bool nobits = os->type() == elfcpp::SHT_NOBITS;
1356       bool sawtls = false;
1357       Output_segment::Output_data_list::iterator p = pdl->end();
1358       do
1359         {
1360           --p;
1361           bool insert;
1362           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
1363             {
1364               sawtls = true;
1365               // Put a NOBITS section after the first TLS section.
1366               // But a PROGBITS section after the first TLS/PROGBITS
1367               // section.
1368               insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
1369             }
1370           else
1371             {
1372               // If we've gone past the TLS sections, but we've seen a
1373               // TLS section, then we need to insert this section now.
1374               insert = sawtls;
1375             }
1376
1377           if (insert)
1378             {
1379               // We don't worry about the FRONT parameter.
1380               ++p;
1381               pdl->insert(p, os);
1382               return;
1383             }
1384         }
1385       while (p != pdl->begin());
1386
1387       // There are no TLS sections yet; put this one at the requested
1388       // location in the section list.
1389     }
1390
1391   if (front)
1392     pdl->push_front(os);
1393   else
1394     pdl->push_back(os);
1395 }
1396
1397 // Add an Output_data (which is not an Output_section) to the start of
1398 // a segment.
1399
1400 void
1401 Output_segment::add_initial_output_data(Output_data* od)
1402 {
1403   gold_assert(!this->is_align_known_);
1404   this->output_data_.push_front(od);
1405 }
1406
1407 // Return the maximum alignment of the Output_data in Output_segment.
1408 // Once we compute this, we prohibit new sections from being added.
1409
1410 uint64_t
1411 Output_segment::addralign()
1412 {
1413   if (!this->is_align_known_)
1414     {
1415       uint64_t addralign;
1416
1417       addralign = Output_segment::maximum_alignment(&this->output_data_);
1418       if (addralign > this->align_)
1419         this->align_ = addralign;
1420
1421       addralign = Output_segment::maximum_alignment(&this->output_bss_);
1422       if (addralign > this->align_)
1423         this->align_ = addralign;
1424
1425       this->is_align_known_ = true;
1426     }
1427
1428   return this->align_;
1429 }
1430
1431 // Return the maximum alignment of a list of Output_data.
1432
1433 uint64_t
1434 Output_segment::maximum_alignment(const Output_data_list* pdl)
1435 {
1436   uint64_t ret = 0;
1437   for (Output_data_list::const_iterator p = pdl->begin();
1438        p != pdl->end();
1439        ++p)
1440     {
1441       uint64_t addralign = (*p)->addralign();
1442       if (addralign > ret)
1443         ret = addralign;
1444     }
1445   return ret;
1446 }
1447
1448 // Set the section addresses for an Output_segment.  ADDR is the
1449 // address and *POFF is the file offset.  Set the section indexes
1450 // starting with *PSHNDX.  Return the address of the immediately
1451 // following segment.  Update *POFF and *PSHNDX.
1452
1453 uint64_t
1454 Output_segment::set_section_addresses(uint64_t addr, off_t* poff,
1455                                       unsigned int* pshndx)
1456 {
1457   gold_assert(this->type_ == elfcpp::PT_LOAD);
1458
1459   this->vaddr_ = addr;
1460   this->paddr_ = addr;
1461
1462   off_t orig_off = *poff;
1463   this->offset_ = orig_off;
1464
1465   *poff = align_address(*poff, this->addralign());
1466
1467   addr = this->set_section_list_addresses(&this->output_data_, addr, poff,
1468                                           pshndx);
1469   this->filesz_ = *poff - orig_off;
1470
1471   off_t off = *poff;
1472
1473   uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr,
1474                                                   poff, pshndx);
1475   this->memsz_ = *poff - orig_off;
1476
1477   // Ignore the file offset adjustments made by the BSS Output_data
1478   // objects.
1479   *poff = off;
1480
1481   return ret;
1482 }
1483
1484 // Set the addresses and file offsets in a list of Output_data
1485 // structures.
1486
1487 uint64_t
1488 Output_segment::set_section_list_addresses(Output_data_list* pdl,
1489                                            uint64_t addr, off_t* poff,
1490                                            unsigned int* pshndx)
1491 {
1492   off_t startoff = *poff;
1493
1494   off_t off = startoff;
1495   for (Output_data_list::iterator p = pdl->begin();
1496        p != pdl->end();
1497        ++p)
1498     {
1499       off = align_address(off, (*p)->addralign());
1500       (*p)->set_address(addr + (off - startoff), off);
1501
1502       // Unless this is a PT_TLS segment, we want to ignore the size
1503       // of a SHF_TLS/SHT_NOBITS section.  Such a section does not
1504       // affect the size of a PT_LOAD segment.
1505       if (this->type_ == elfcpp::PT_TLS
1506           || !(*p)->is_section_flag_set(elfcpp::SHF_TLS)
1507           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
1508         off += (*p)->data_size();
1509
1510       if ((*p)->is_section())
1511         {
1512           (*p)->set_out_shndx(*pshndx);
1513           ++*pshndx;
1514         }
1515     }
1516
1517   *poff = off;
1518   return addr + (off - startoff);
1519 }
1520
1521 // For a non-PT_LOAD segment, set the offset from the sections, if
1522 // any.
1523
1524 void
1525 Output_segment::set_offset()
1526 {
1527   gold_assert(this->type_ != elfcpp::PT_LOAD);
1528
1529   if (this->output_data_.empty() && this->output_bss_.empty())
1530     {
1531       this->vaddr_ = 0;
1532       this->paddr_ = 0;
1533       this->memsz_ = 0;
1534       this->align_ = 0;
1535       this->offset_ = 0;
1536       this->filesz_ = 0;
1537       return;
1538     }
1539
1540   const Output_data* first;
1541   if (this->output_data_.empty())
1542     first = this->output_bss_.front();
1543   else
1544     first = this->output_data_.front();
1545   this->vaddr_ = first->address();
1546   this->paddr_ = this->vaddr_;
1547   this->offset_ = first->offset();
1548
1549   if (this->output_data_.empty())
1550     this->filesz_ = 0;
1551   else
1552     {
1553       const Output_data* last_data = this->output_data_.back();
1554       this->filesz_ = (last_data->address()
1555                        + last_data->data_size()
1556                        - this->vaddr_);
1557     }
1558
1559   const Output_data* last;
1560   if (this->output_bss_.empty())
1561     last = this->output_data_.back();
1562   else
1563     last = this->output_bss_.back();
1564   this->memsz_ = (last->address()
1565                   + last->data_size()
1566                   - this->vaddr_);
1567 }
1568
1569 // Return the number of Output_sections in an Output_segment.
1570
1571 unsigned int
1572 Output_segment::output_section_count() const
1573 {
1574   return (this->output_section_count_list(&this->output_data_)
1575           + this->output_section_count_list(&this->output_bss_));
1576 }
1577
1578 // Return the number of Output_sections in an Output_data_list.
1579
1580 unsigned int
1581 Output_segment::output_section_count_list(const Output_data_list* pdl) const
1582 {
1583   unsigned int count = 0;
1584   for (Output_data_list::const_iterator p = pdl->begin();
1585        p != pdl->end();
1586        ++p)
1587     {
1588       if ((*p)->is_section())
1589         ++count;
1590     }
1591   return count;
1592 }
1593
1594 // Write the segment data into *OPHDR.
1595
1596 template<int size, bool big_endian>
1597 void
1598 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
1599 {
1600   ophdr->put_p_type(this->type_);
1601   ophdr->put_p_offset(this->offset_);
1602   ophdr->put_p_vaddr(this->vaddr_);
1603   ophdr->put_p_paddr(this->paddr_);
1604   ophdr->put_p_filesz(this->filesz_);
1605   ophdr->put_p_memsz(this->memsz_);
1606   ophdr->put_p_flags(this->flags_);
1607   ophdr->put_p_align(this->addralign());
1608 }
1609
1610 // Write the section headers into V.
1611
1612 template<int size, bool big_endian>
1613 unsigned char*
1614 Output_segment::write_section_headers(const Layout* layout,
1615                                       const Stringpool* secnamepool,
1616                                       unsigned char* v,
1617                                       unsigned int *pshndx
1618                                       ACCEPT_SIZE_ENDIAN) const
1619 {
1620   // Every section that is attached to a segment must be attached to a
1621   // PT_LOAD segment, so we only write out section headers for PT_LOAD
1622   // segments.
1623   if (this->type_ != elfcpp::PT_LOAD)
1624     return v;
1625
1626   v = this->write_section_headers_list
1627       SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1628           layout, secnamepool, &this->output_data_, v, pshndx
1629           SELECT_SIZE_ENDIAN(size, big_endian));
1630   v = this->write_section_headers_list
1631       SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1632           layout, secnamepool, &this->output_bss_, v, pshndx
1633           SELECT_SIZE_ENDIAN(size, big_endian));
1634   return v;
1635 }
1636
1637 template<int size, bool big_endian>
1638 unsigned char*
1639 Output_segment::write_section_headers_list(const Layout* layout,
1640                                            const Stringpool* secnamepool,
1641                                            const Output_data_list* pdl,
1642                                            unsigned char* v,
1643                                            unsigned int* pshndx
1644                                            ACCEPT_SIZE_ENDIAN) const
1645 {
1646   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
1647   for (Output_data_list::const_iterator p = pdl->begin();
1648        p != pdl->end();
1649        ++p)
1650     {
1651       if ((*p)->is_section())
1652         {
1653           const Output_section* ps = static_cast<const Output_section*>(*p);
1654           gold_assert(*pshndx == ps->out_shndx());
1655           elfcpp::Shdr_write<size, big_endian> oshdr(v);
1656           ps->write_header(layout, secnamepool, &oshdr);
1657           v += shdr_size;
1658           ++*pshndx;
1659         }
1660     }
1661   return v;
1662 }
1663
1664 // Output_file methods.
1665
1666 Output_file::Output_file(const General_options& options, Target* target)
1667   : options_(options),
1668     target_(target),
1669     name_(options.output_file_name()),
1670     o_(-1),
1671     file_size_(0),
1672     base_(NULL)
1673 {
1674 }
1675
1676 // Open the output file.
1677
1678 void
1679 Output_file::open(off_t file_size)
1680 {
1681   this->file_size_ = file_size;
1682
1683   // Unlink the file first; otherwise the open() may fail if the file
1684   // is busy (e.g. it's an executable that's currently being executed).
1685   //
1686   // However, the linker may be part of a system where a zero-length
1687   // file is created for it to write to, with tight permissions (gcc
1688   // 2.95 did something like this).  Unlinking the file would work
1689   // around those permission controls, so we only unlink if the file
1690   // has a non-zero size.  We also unlink only regular files to avoid
1691   // trouble with directories/etc.
1692   //
1693   // If we fail, continue; this command is merely a best-effort attempt
1694   // to improve the odds for open().
1695
1696   struct stat s;
1697   if (::stat(this->name_, &s) == 0 && s.st_size != 0)
1698     unlink_if_ordinary(this->name_);
1699
1700   int mode = parameters->output_is_object() ? 0666 : 0777;
1701   int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
1702   if (o < 0)
1703     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
1704   this->o_ = o;
1705
1706   // Write out one byte to make the file the right size.
1707   if (::lseek(o, file_size - 1, SEEK_SET) < 0)
1708     gold_fatal(_("%s: lseek: %s"), this->name_, strerror(errno));
1709   char b = 0;
1710   if (::write(o, &b, 1) != 1)
1711     gold_fatal(_("%s: write: %s"), this->name_, strerror(errno));
1712
1713   // Map the file into memory.
1714   void* base = ::mmap(NULL, file_size, PROT_READ | PROT_WRITE,
1715                       MAP_SHARED, o, 0);
1716   if (base == MAP_FAILED)
1717     gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
1718   this->base_ = static_cast<unsigned char*>(base);
1719 }
1720
1721 // Close the output file.
1722
1723 void
1724 Output_file::close()
1725 {
1726   if (::munmap(this->base_, this->file_size_) < 0)
1727     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
1728   this->base_ = NULL;
1729
1730   if (::close(this->o_) < 0)
1731     gold_error(_("%s: close: %s"), this->name_, strerror(errno));
1732   this->o_ = -1;
1733 }
1734
1735 // Instantiate the templates we need.  We could use the configure
1736 // script to restrict this to only the ones for implemented targets.
1737
1738 #ifdef HAVE_TARGET_32_LITTLE
1739 template
1740 off_t
1741 Output_section::add_input_section<32, false>(
1742     Relobj* object,
1743     unsigned int shndx,
1744     const char* secname,
1745     const elfcpp::Shdr<32, false>& shdr);
1746 #endif
1747
1748 #ifdef HAVE_TARGET_32_BIG
1749 template
1750 off_t
1751 Output_section::add_input_section<32, true>(
1752     Relobj* object,
1753     unsigned int shndx,
1754     const char* secname,
1755     const elfcpp::Shdr<32, true>& shdr);
1756 #endif
1757
1758 #ifdef HAVE_TARGET_64_LITTLE
1759 template
1760 off_t
1761 Output_section::add_input_section<64, false>(
1762     Relobj* object,
1763     unsigned int shndx,
1764     const char* secname,
1765     const elfcpp::Shdr<64, false>& shdr);
1766 #endif
1767
1768 #ifdef HAVE_TARGET_64_BIG
1769 template
1770 off_t
1771 Output_section::add_input_section<64, true>(
1772     Relobj* object,
1773     unsigned int shndx,
1774     const char* secname,
1775     const elfcpp::Shdr<64, true>& shdr);
1776 #endif
1777
1778 #ifdef HAVE_TARGET_32_LITTLE
1779 template
1780 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
1781 #endif
1782
1783 #ifdef HAVE_TARGET_32_BIG
1784 template
1785 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
1786 #endif
1787
1788 #ifdef HAVE_TARGET_64_LITTLE
1789 template
1790 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
1791 #endif
1792
1793 #ifdef HAVE_TARGET_64_BIG
1794 template
1795 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
1796 #endif
1797
1798 #ifdef HAVE_TARGET_32_LITTLE
1799 template
1800 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
1801 #endif
1802
1803 #ifdef HAVE_TARGET_32_BIG
1804 template
1805 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
1806 #endif
1807
1808 #ifdef HAVE_TARGET_64_LITTLE
1809 template
1810 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
1811 #endif
1812
1813 #ifdef HAVE_TARGET_64_BIG
1814 template
1815 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
1816 #endif
1817
1818 #ifdef HAVE_TARGET_32_LITTLE
1819 template
1820 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
1821 #endif
1822
1823 #ifdef HAVE_TARGET_32_BIG
1824 template
1825 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
1826 #endif
1827
1828 #ifdef HAVE_TARGET_64_LITTLE
1829 template
1830 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
1831 #endif
1832
1833 #ifdef HAVE_TARGET_64_BIG
1834 template
1835 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
1836 #endif
1837
1838 #ifdef HAVE_TARGET_32_LITTLE
1839 template
1840 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
1841 #endif
1842
1843 #ifdef HAVE_TARGET_32_BIG
1844 template
1845 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
1846 #endif
1847
1848 #ifdef HAVE_TARGET_64_LITTLE
1849 template
1850 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
1851 #endif
1852
1853 #ifdef HAVE_TARGET_64_BIG
1854 template
1855 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
1856 #endif
1857
1858 #ifdef HAVE_TARGET_32_LITTLE
1859 template
1860 class Output_data_got<32, false>;
1861 #endif
1862
1863 #ifdef HAVE_TARGET_32_BIG
1864 template
1865 class Output_data_got<32, true>;
1866 #endif
1867
1868 #ifdef HAVE_TARGET_64_LITTLE
1869 template
1870 class Output_data_got<64, false>;
1871 #endif
1872
1873 #ifdef HAVE_TARGET_64_BIG
1874 template
1875 class Output_data_got<64, true>;
1876 #endif
1877
1878 } // End namespace gold.