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
  33 #include "parameters.h"
  34 #include "object.h"
  35 #include "symtab.h"
  36 #include "reloc.h"
  37 #include "merge.h"
  38 #include "output.h"
  39
  40 namespace gold
  41 {
  42
  43 // Output_data variables.
  44
  45 bool Output_data::sizes_are_fixed;
  46
  47 // Output_data methods.
  48
  49 Output_data::~Output_data()
  50 {
  51 }
  52
  53 // Set the address and offset.
  54
  55 void
  56 Output_data::set_address(uint64_t addr, off_t off)
  57 {
  58   this->address_ = addr;
  59   this->offset_ = off;
  60
  61   // Let the child class know.
  62   this->do_set_address(addr, off);
  63 }
  64
  65 // Return the default alignment for a size--32 or 64.
  66
  67 uint64_t
  68 Output_data::default_alignment(int size)
  69 {
  70   if (size == 32)
  71     return 4;
  72   else if (size == 64)
  73     return 8;
  74   else
  75     gold_unreachable();
  76 }
  77
  78 // Output_section_header methods.  This currently assumes that the
  79 // segment and section lists are complete at construction time.
  80
  81 Output_section_headers::Output_section_headers(
  82     const Layout* layout,
  83     const Layout::Segment_list* segment_list,
  84     const Layout::Section_list* unattached_section_list,
  85     const Stringpool* secnamepool)
  86   : layout_(layout),
  87     segment_list_(segment_list),
  88     unattached_section_list_(unattached_section_list),
  89     secnamepool_(secnamepool)
  90 {
  91   // Count all the sections.  Start with 1 for the null section.
  92   off_t count = 1;
  93   for (Layout::Segment_list::const_iterator p = segment_list->begin();
  94        p != segment_list->end();
  95        ++p)
  96     if ((*p)->type() == elfcpp::PT_LOAD)
  97       count += (*p)->output_section_count();
  98   count += unattached_section_list->size();
  99
 100   const int size = parameters->get_size();
 101   int shdr_size;
 102   if (size == 32)
 103     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
 104   else if (size == 64)
 105     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
 106   else
 107     gold_unreachable();
 108
 109   this->set_data_size(count * shdr_size);
 110 }
 111
 112 // Write out the section headers.
 113
 114 void
 115 Output_section_headers::do_write(Output_file* of)
 116 {
 117   if (parameters->get_size() == 32)
 118     {
 119       if (parameters->is_big_endian())
 120         {
 121 #ifdef HAVE_TARGET_32_BIG
 122           this->do_sized_write<32, true>(of);
 123 #else
 124           gold_unreachable();
 125 #endif
 126         }
 127       else
 128         {
 129 #ifdef HAVE_TARGET_32_LITTLE
 130           this->do_sized_write<32, false>(of);
 131 #else
 132           gold_unreachable();
 133 #endif
 134         }
 135     }
 136   else if (parameters->get_size() == 64)
 137     {
 138       if (parameters->is_big_endian())
 139         {
 140 #ifdef HAVE_TARGET_64_BIG
 141           this->do_sized_write<64, true>(of);
 142 #else
 143           gold_unreachable();
 144 #endif
 145         }
 146       else
 147         {
 148 #ifdef HAVE_TARGET_64_LITTLE
 149           this->do_sized_write<64, false>(of);
 150 #else
 151           gold_unreachable();
 152 #endif
 153         }
 154     }
 155   else
 156     gold_unreachable();
 157 }
 158
 159 template<int size, bool big_endian>
 160 void
 161 Output_section_headers::do_sized_write(Output_file* of)
 162 {
 163   off_t all_shdrs_size = this->data_size();
 164   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
 165
 166   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
 167   unsigned char* v = view;
 168
 169   {
 170     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
 171     oshdr.put_sh_name(0);
 172     oshdr.put_sh_type(elfcpp::SHT_NULL);
 173     oshdr.put_sh_flags(0);
 174     oshdr.put_sh_addr(0);
 175     oshdr.put_sh_offset(0);
 176     oshdr.put_sh_size(0);
 177     oshdr.put_sh_link(0);
 178     oshdr.put_sh_info(0);
 179     oshdr.put_sh_addralign(0);
 180     oshdr.put_sh_entsize(0);
 181   }
 182
 183   v += shdr_size;
 184
 185   unsigned shndx = 1;
 186   for (Layout::Segment_list::const_iterator p = this->segment_list_->begin();
 187        p != this->segment_list_->end();
 188        ++p)
 189     v = (*p)->write_section_headers SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
 190             this->layout_, this->secnamepool_, v, &shndx
 191             SELECT_SIZE_ENDIAN(size, big_endian));
 192   for (Layout::Section_list::const_iterator p =
 193          this->unattached_section_list_->begin();
 194        p != this->unattached_section_list_->end();
 195        ++p)
 196     {
 197       gold_assert(shndx == (*p)->out_shndx());
 198       elfcpp::Shdr_write<size, big_endian> oshdr(v);
 199       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
 200       v += shdr_size;
 201       ++shndx;
 202     }
 203
 204   of->write_output_view(this->offset(), all_shdrs_size, view);
 205 }
 206
 207 // Output_segment_header methods.
 208
 209 Output_segment_headers::Output_segment_headers(
 210     const Layout::Segment_list& segment_list)
 211   : segment_list_(segment_list)
 212 {
 213   const int size = parameters->get_size();
 214   int phdr_size;
 215   if (size == 32)
 216     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
 217   else if (size == 64)
 218     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
 219   else
 220     gold_unreachable();
 221
 222   this->set_data_size(segment_list.size() * phdr_size);
 223 }
 224
 225 void
 226 Output_segment_headers::do_write(Output_file* of)
 227 {
 228   if (parameters->get_size() == 32)
 229     {
 230       if (parameters->is_big_endian())
 231         {
 232 #ifdef HAVE_TARGET_32_BIG
 233           this->do_sized_write<32, true>(of);
 234 #else
 235           gold_unreachable();
 236 #endif
 237         }
 238       else
 239         {
 240 #ifdef HAVE_TARGET_32_LITTLE
 241         this->do_sized_write<32, false>(of);
 242 #else
 243         gold_unreachable();
 244 #endif
 245         }
 246     }
 247   else if (parameters->get_size() == 64)
 248     {
 249       if (parameters->is_big_endian())
 250         {
 251 #ifdef HAVE_TARGET_64_BIG
 252           this->do_sized_write<64, true>(of);
 253 #else
 254           gold_unreachable();
 255 #endif
 256         }
 257       else
 258         {
 259 #ifdef HAVE_TARGET_64_LITTLE
 260           this->do_sized_write<64, false>(of);
 261 #else
 262           gold_unreachable();
 263 #endif
 264         }
 265     }
 266   else
 267     gold_unreachable();
 268 }
 269
 270 template<int size, bool big_endian>
 271 void
 272 Output_segment_headers::do_sized_write(Output_file* of)
 273 {
 274   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
 275   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
 276   unsigned char* view = of->get_output_view(this->offset(),
 277                                             all_phdrs_size);
 278   unsigned char* v = view;
 279   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
 280        p != this->segment_list_.end();
 281        ++p)
 282     {
 283       elfcpp::Phdr_write<size, big_endian> ophdr(v);
 284       (*p)->write_header(&ophdr);
 285       v += phdr_size;
 286     }
 287
 288   of->write_output_view(this->offset(), all_phdrs_size, view);
 289 }
 290
 291 // Output_file_header methods.
 292
 293 Output_file_header::Output_file_header(const Target* target,
 294                                        const Symbol_table* symtab,
 295                                        const Output_segment_headers* osh)
 296   : target_(target),
 297     symtab_(symtab),
 298     segment_header_(osh),
 299     section_header_(NULL),
 300     shstrtab_(NULL)
 301 {
 302   const int size = parameters->get_size();
 303   int ehdr_size;
 304   if (size == 32)
 305     ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size;
 306   else if (size == 64)
 307     ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
 308   else
 309     gold_unreachable();
 310
 311   this->set_data_size(ehdr_size);
 312 }
 313
 314 // Set the section table information for a file header.
 315
 316 void
 317 Output_file_header::set_section_info(const Output_section_headers* shdrs,
 318                                      const Output_section* shstrtab)
 319 {
 320   this->section_header_ = shdrs;
 321   this->shstrtab_ = shstrtab;
 322 }
 323
 324 // Write out the file header.
 325
 326 void
 327 Output_file_header::do_write(Output_file* of)
 328 {
 329   if (parameters->get_size() == 32)
 330     {
 331       if (parameters->is_big_endian())
 332         {
 333 #ifdef HAVE_TARGET_32_BIG
 334           this->do_sized_write<32, true>(of);
 335 #else
 336           gold_unreachable();
 337 #endif
 338         }
 339       else
 340         {
 341 #ifdef HAVE_TARGET_32_LITTLE
 342           this->do_sized_write<32, false>(of);
 343 #else
 344           gold_unreachable();
 345 #endif
 346         }
 347     }
 348   else if (parameters->get_size() == 64)
 349     {
 350       if (parameters->is_big_endian())
 351         {
 352 #ifdef HAVE_TARGET_64_BIG
 353           this->do_sized_write<64, true>(of);
 354 #else
 355           gold_unreachable();
 356 #endif
 357         }
 358       else
 359         {
 360 #ifdef HAVE_TARGET_64_LITTLE
 361           this->do_sized_write<64, false>(of);
 362 #else
 363           gold_unreachable();
 364 #endif
 365         }
 366     }
 367   else
 368     gold_unreachable();
 369 }
 370
 371 // Write out the file header with appropriate size and endianess.
 372
 373 template<int size, bool big_endian>
 374 void
 375 Output_file_header::do_sized_write(Output_file* of)
 376 {
 377   gold_assert(this->offset() == 0);
 378
 379   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
 380   unsigned char* view = of->get_output_view(0, ehdr_size);
 381   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
 382
 383   unsigned char e_ident[elfcpp::EI_NIDENT];
 384   memset(e_ident, 0, elfcpp::EI_NIDENT);
 385   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
 386   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
 387   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
 388   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
 389   if (size == 32)
 390     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
 391   else if (size == 64)
 392     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
 393   else
 394     gold_unreachable();
 395   e_ident[elfcpp::EI_DATA] = (big_endian
 396                               ? elfcpp::ELFDATA2MSB
 397                               : elfcpp::ELFDATA2LSB);
 398   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
 399   // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION.
 400   oehdr.put_e_ident(e_ident);
 401
 402   elfcpp::ET e_type;
 403   // FIXME: ET_DYN.
 404   if (parameters->output_is_object())
 405     e_type = elfcpp::ET_REL;
 406   else
 407     e_type = elfcpp::ET_EXEC;
 408   oehdr.put_e_type(e_type);
 409
 410   oehdr.put_e_machine(this->target_->machine_code());
 411   oehdr.put_e_version(elfcpp::EV_CURRENT);
 412
 413   // FIXME: Need to support -e, and target specific entry symbol.
 414   Symbol* sym = this->symtab_->lookup("_start");
 415   typename Sized_symbol<size>::Value_type v;
 416   if (sym == NULL)
 417     v = 0;
 418   else
 419     {
 420       Sized_symbol<size>* ssym;
 421       ssym = this->symtab_->get_sized_symbol SELECT_SIZE_NAME(size) (
 422         sym SELECT_SIZE(size));
 423       v = ssym->value();
 424     }
 425   oehdr.put_e_entry(v);
 426
 427   oehdr.put_e_phoff(this->segment_header_->offset());
 428   oehdr.put_e_shoff(this->section_header_->offset());
 429
 430   // FIXME: The target needs to set the flags.
 431   oehdr.put_e_flags(0);
 432
 433   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
 434   oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
 435   oehdr.put_e_phnum(this->segment_header_->data_size()
 436                      / elfcpp::Elf_sizes<size>::phdr_size);
 437   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
 438   oehdr.put_e_shnum(this->section_header_->data_size()
 439                      / elfcpp::Elf_sizes<size>::shdr_size);
 440   oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
 441
 442   of->write_output_view(0, ehdr_size, view);
 443 }
 444
 445 // Output_data_const methods.
 446
 447 void
 448 Output_data_const::do_write(Output_file* of)
 449 {
 450   of->write(this->offset(), this->data_.data(), this->data_.size());
 451 }
 452
 453 // Output_data_const_buffer methods.
 454
 455 void
 456 Output_data_const_buffer::do_write(Output_file* of)
 457 {
 458   of->write(this->offset(), this->p_, this->data_size());
 459 }
 460
 461 // Output_section_data methods.
 462
 463 // Record the output section, and set the entry size and such.
 464
 465 void
 466 Output_section_data::set_output_section(Output_section* os)
 467 {
 468   gold_assert(this->output_section_ == NULL);
 469   this->output_section_ = os;
 470   this->do_adjust_output_section(os);
 471 }
 472
 473 // Return the section index of the output section.
 474
 475 unsigned int
 476 Output_section_data::do_out_shndx() const
 477 {
 478   gold_assert(this->output_section_ != NULL);
 479   return this->output_section_->out_shndx();
 480 }
 481
 482 // Output_data_strtab methods.
 483
 484 // Set the address.  We don't actually care about the address, but we
 485 // do set our final size.
 486
 487 void
 488 Output_data_strtab::do_set_address(uint64_t, off_t)
 489 {
 490   this->strtab_->set_string_offsets();
 491   this->set_data_size(this->strtab_->get_strtab_size());
 492 }
 493
 494 // Write out a string table.
 495
 496 void
 497 Output_data_strtab::do_write(Output_file* of)
 498 {
 499   this->strtab_->write(of, this->offset());
 500 }
 501
 502 // Output_reloc methods.
 503
 504 // Get the symbol index of a relocation.
 505
 506 template<bool dynamic, int size, bool big_endian>
 507 unsigned int
 508 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
 509   const
 510 {
 511   unsigned int index;
 512   switch (this->local_sym_index_)
 513     {
 514     case INVALID_CODE:
 515       gold_unreachable();
 516
 517     case GSYM_CODE:
 518       if (this->u1_.gsym == NULL)
 519         index = 0;
 520       else if (dynamic)
 521         index = this->u1_.gsym->dynsym_index();
 522       else
 523         index = this->u1_.gsym->symtab_index();
 524       break;
 525
 526     case SECTION_CODE:
 527       if (dynamic)
 528         index = this->u1_.os->dynsym_index();
 529       else
 530         index = this->u1_.os->symtab_index();
 531       break;
 532
 533     default:
 534       if (dynamic)
 535         {
 536           // FIXME: It seems that some targets may need to generate
 537           // dynamic relocations against local symbols for some
 538           // reasons.  This will have to be addressed at some point.
 539           gold_unreachable();
 540         }
 541       else
 542         index = this->u1_.relobj->symtab_index(this->local_sym_index_);
 543       break;
 544     }
 545   gold_assert(index != -1U);
 546   return index;
 547 }
 548
 549 // Write out the offset and info fields of a Rel or Rela relocation
 550 // entry.
 551
 552 template<bool dynamic, int size, bool big_endian>
 553 template<typename Write_rel>
 554 void
 555 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
 556     Write_rel* wr) const
 557 {
 558   Address address = this->address_;
 559   if (this->shndx_ != INVALID_CODE)
 560     {
 561       off_t off;
 562       Output_section* os = this->u2_.relobj->output_section(this->shndx_,
 563                                                             &off);
 564       gold_assert(os != NULL);
 565       address += os->address() + off;
 566     }
 567   else if (this->u2_.od != NULL)
 568     address += this->u2_.od->address();
 569   wr->put_r_offset(address);
 570   wr->put_r_info(elfcpp::elf_r_info<size>(this->get_symbol_index(),
 571                                           this->type_));
 572 }
 573
 574 // Write out a Rel relocation.
 575
 576 template<bool dynamic, int size, bool big_endian>
 577 void
 578 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
 579     unsigned char* pov) const
 580 {
 581   elfcpp::Rel_write<size, big_endian> orel(pov);
 582   this->write_rel(&orel);
 583 }
 584
 585 // Write out a Rela relocation.
 586
 587 template<bool dynamic, int size, bool big_endian>
 588 void
 589 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
 590     unsigned char* pov) const
 591 {
 592   elfcpp::Rela_write<size, big_endian> orel(pov);
 593   this->rel_.write_rel(&orel);
 594   orel.put_r_addend(this->addend_);
 595 }
 596
 597 // Output_data_reloc_base methods.
 598
 599 // Adjust the output section.
 600
 601 template<int sh_type, bool dynamic, int size, bool big_endian>
 602 void
 603 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
 604     ::do_adjust_output_section(Output_section* os)
 605 {
 606   if (sh_type == elfcpp::SHT_REL)
 607     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
 608   else if (sh_type == elfcpp::SHT_RELA)
 609     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
 610   else
 611     gold_unreachable();
 612   if (dynamic)
 613     os->set_should_link_to_dynsym();
 614   else
 615     os->set_should_link_to_symtab();
 616 }
 617
 618 // Write out relocation data.
 619
 620 template<int sh_type, bool dynamic, int size, bool big_endian>
 621 void
 622 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
 623     Output_file* of)
 624 {
 625   const off_t off = this->offset();
 626   const off_t oview_size = this->data_size();
 627   unsigned char* const oview = of->get_output_view(off, oview_size);
 628
 629   unsigned char* pov = oview;
 630   for (typename Relocs::const_iterator p = this->relocs_.begin();
 631        p != this->relocs_.end();
 632        ++p)
 633     {
 634       p->write(pov);
 635       pov += reloc_size;
 636     }
 637
 638   gold_assert(pov - oview == oview_size);
 639
 640   of->write_output_view(off, oview_size, oview);
 641
 642   // We no longer need the relocation entries.
 643   this->relocs_.clear();
 644 }
 645
 646 // Output_data_got::Got_entry methods.
 647
 648 // Write out the entry.
 649
 650 template<int size, bool big_endian>
 651 void
 652 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
 653 {
 654   Valtype val = 0;
 655
 656   switch (this->local_sym_index_)
 657     {
 658     case GSYM_CODE:
 659       {
 660         Symbol* gsym = this->u_.gsym;
 661
 662         // If the symbol is resolved locally, we need to write out its
 663         // value.  Otherwise we just write zero.  The target code is
 664         // responsible for creating a relocation entry to fill in the
 665         // value at runtime.
 666         if (gsym->final_value_is_known())
 667           {
 668             Sized_symbol<size>* sgsym;
 669             // This cast is a bit ugly.  We don't want to put a
 670             // virtual method in Symbol, because we want Symbol to be
 671             // as small as possible.
 672             sgsym = static_cast<Sized_symbol<size>*>(gsym);
 673             val = sgsym->value();
 674           }
 675       }
 676       break;
 677
 678     case CONSTANT_CODE:
 679       val = this->u_.constant;
 680       break;
 681
 682     default:
 683       val = this->u_.object->local_symbol_value(this->local_sym_index_);
 684       break;
 685     }
 686
 687   elfcpp::Swap<size, big_endian>::writeval(pov, val);
 688 }
 689
 690 // Output_data_got methods.
 691
 692 // Add an entry for a global symbol to the GOT.  This returns true if
 693 // this is a new GOT entry, false if the symbol already had a GOT
 694 // entry.
 695
 696 template<int size, bool big_endian>
 697 bool
 698 Output_data_got<size, big_endian>::add_global(Symbol* gsym)
 699 {
 700   if (gsym->has_got_offset())
 701     return false;
 702
 703   this->entries_.push_back(Got_entry(gsym));
 704   this->set_got_size();
 705   gsym->set_got_offset(this->last_got_offset());
 706   return true;
 707 }
 708
 709 // Add an entry for a local symbol to the GOT.  This returns true if
 710 // this is a new GOT entry, false if the symbol already has a GOT
 711 // entry.
 712
 713 template<int size, bool big_endian>
 714 bool
 715 Output_data_got<size, big_endian>::add_local(
 716     Sized_relobj<size, big_endian>* object,
 717     unsigned int symndx)
 718 {
 719   if (object->local_has_got_offset(symndx))
 720     return false;
 721   this->entries_.push_back(Got_entry(object, symndx));
 722   this->set_got_size();
 723   object->set_local_got_offset(symndx, this->last_got_offset());
 724   return true;
 725 }
 726
 727 // Write out the GOT.
 728
 729 template<int size, bool big_endian>
 730 void
 731 Output_data_got<size, big_endian>::do_write(Output_file* of)
 732 {
 733   const int add = size / 8;
 734
 735   const off_t off = this->offset();
 736   const off_t oview_size = this->data_size();
 737   unsigned char* const oview = of->get_output_view(off, oview_size);
 738
 739   unsigned char* pov = oview;
 740   for (typename Got_entries::const_iterator p = this->entries_.begin();
 741        p != this->entries_.end();
 742        ++p)
 743     {
 744       p->write(pov);
 745       pov += add;
 746     }
 747
 748   gold_assert(pov - oview == oview_size);
 749
 750   of->write_output_view(off, oview_size, oview);
 751
 752   // We no longer need the GOT entries.
 753   this->entries_.clear();
 754 }
 755
 756 // Output_data_dynamic::Dynamic_entry methods.
 757
 758 // Write out the entry.
 759
 760 template<int size, bool big_endian>
 761 void
 762 Output_data_dynamic::Dynamic_entry::write(
 763     unsigned char* pov,
 764     const Stringpool* pool
 765     ACCEPT_SIZE_ENDIAN) const
 766 {
 767   typename elfcpp::Elf_types<size>::Elf_WXword val;
 768   switch (this->classification_)
 769     {
 770     case DYNAMIC_NUMBER:
 771       val = this->u_.val;
 772       break;
 773
 774     case DYNAMIC_SECTION_ADDRESS:
 775       val = this->u_.od->address();
 776       break;
 777
 778     case DYNAMIC_SECTION_SIZE:
 779       val = this->u_.od->data_size();
 780       break;
 781
 782     case DYNAMIC_SYMBOL:
 783       {
 784         const Sized_symbol<size>* s =
 785           static_cast<const Sized_symbol<size>*>(this->u_.sym);
 786         val = s->value();
 787       }
 788       break;
 789
 790     case DYNAMIC_STRING:
 791       val = pool->get_offset(this->u_.str);
 792       break;
 793
 794     default:
 795       gold_unreachable();
 796     }
 797
 798   elfcpp::Dyn_write<size, big_endian> dw(pov);
 799   dw.put_d_tag(this->tag_);
 800   dw.put_d_val(val);
 801 }
 802
 803 // Output_data_dynamic methods.
 804
 805 // Adjust the output section to set the entry size.
 806
 807 void
 808 Output_data_dynamic::do_adjust_output_section(Output_section* os)
 809 {
 810   if (parameters->get_size() == 32)
 811     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
 812   else if (parameters->get_size() == 64)
 813     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
 814   else
 815     gold_unreachable();
 816 }
 817
 818 // Set the final data size.
 819
 820 void
 821 Output_data_dynamic::do_set_address(uint64_t, off_t)
 822 {
 823   // Add the terminating entry.
 824   this->add_constant(elfcpp::DT_NULL, 0);
 825
 826   int dyn_size;
 827   if (parameters->get_size() == 32)
 828     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
 829   else if (parameters->get_size() == 64)
 830     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
 831   else
 832     gold_unreachable();
 833   this->set_data_size(this->entries_.size() * dyn_size);
 834 }
 835
 836 // Write out the dynamic entries.
 837
 838 void
 839 Output_data_dynamic::do_write(Output_file* of)
 840 {
 841   if (parameters->get_size() == 32)
 842     {
 843       if (parameters->is_big_endian())
 844         {
 845 #ifdef HAVE_TARGET_32_BIG
 846           this->sized_write<32, true>(of);
 847 #else
 848           gold_unreachable();
 849 #endif
 850         }
 851       else
 852         {
 853 #ifdef HAVE_TARGET_32_LITTLE
 854           this->sized_write<32, false>(of);
 855 #else
 856           gold_unreachable();
 857 #endif
 858         }
 859     }
 860   else if (parameters->get_size() == 64)
 861     {
 862       if (parameters->is_big_endian())
 863         {
 864 #ifdef HAVE_TARGET_64_BIG
 865           this->sized_write<64, true>(of);
 866 #else
 867           gold_unreachable();
 868 #endif
 869         }
 870       else
 871         {
 872 #ifdef HAVE_TARGET_64_LITTLE
 873           this->sized_write<64, false>(of);
 874 #else
 875           gold_unreachable();
 876 #endif
 877         }
 878     }
 879   else
 880     gold_unreachable();
 881 }
 882
 883 template<int size, bool big_endian>
 884 void
 885 Output_data_dynamic::sized_write(Output_file* of)
 886 {
 887   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
 888
 889   const off_t offset = this->offset();
 890   const off_t oview_size = this->data_size();
 891   unsigned char* const oview = of->get_output_view(offset, oview_size);
 892
 893   unsigned char* pov = oview;
 894   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
 895        p != this->entries_.end();
 896        ++p)
 897     {
 898       p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
 899           pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian));
 900       pov += dyn_size;
 901     }
 902
 903   gold_assert(pov - oview == oview_size);
 904
 905   of->write_output_view(offset, oview_size, oview);
 906
 907   // We no longer need the dynamic entries.
 908   this->entries_.clear();
 909 }
 910
 911 // Output_section::Input_section methods.
 912
 913 // Return the data size.  For an input section we store the size here.
 914 // For an Output_section_data, we have to ask it for the size.
 915
 916 off_t
 917 Output_section::Input_section::data_size() const
 918 {
 919   if (this->is_input_section())
 920     return this->u1_.data_size;
 921   else
 922     return this->u2_.posd->data_size();
 923 }
 924
 925 // Set the address and file offset.
 926
 927 void
 928 Output_section::Input_section::set_address(uint64_t addr, off_t off,
 929                                            off_t secoff)
 930 {
 931   if (this->is_input_section())
 932     this->u2_.object->set_section_offset(this->shndx_, off - secoff);
 933   else
 934     this->u2_.posd->set_address(addr, off);
 935 }
 936
 937 // Try to turn an input address into an output address.
 938
 939 bool
 940 Output_section::Input_section::output_address(const Relobj* object,
 941                                               unsigned int shndx,
 942                                               off_t offset,
 943                                               uint64_t output_section_address,
 944                                               uint64_t *poutput) const
 945 {
 946   if (!this->is_input_section())
 947     return this->u2_.posd->output_address(object, shndx, offset,
 948                                           output_section_address, poutput);
 949   else
 950     {
 951       if (this->shndx_ != shndx
 952           || this->u2_.object != object)
 953         return false;
 954       off_t output_offset;
 955       Output_section* os = object->output_section(shndx, &output_offset);
 956       gold_assert(os != NULL);
 957       *poutput = output_section_address + output_offset + offset;
 958       return true;
 959     }
 960 }
 961
 962 // Write out the data.  We don't have to do anything for an input
 963 // section--they are handled via Object::relocate--but this is where
 964 // we write out the data for an Output_section_data.
 965
 966 void
 967 Output_section::Input_section::write(Output_file* of)
 968 {
 969   if (!this->is_input_section())
 970     this->u2_.posd->write(of);
 971 }
 972
 973 // Output_section methods.
 974
 975 // Construct an Output_section.  NAME will point into a Stringpool.
 976
 977 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
 978                                elfcpp::Elf_Xword flags)
 979   : name_(name),
 980     addralign_(0),
 981     entsize_(0),
 982     link_section_(NULL),
 983     link_(0),
 984     info_section_(NULL),
 985     info_(0),
 986     type_(type),
 987     flags_(flags),
 988     out_shndx_(0),
 989     symtab_index_(0),
 990     dynsym_index_(0),
 991     input_sections_(),
 992     first_input_offset_(0),
 993     fills_(),
 994     needs_symtab_index_(false),
 995     needs_dynsym_index_(false),
 996     should_link_to_symtab_(false),
 997     should_link_to_dynsym_(false)
 998 {
 999 }
1000
1001 Output_section::~Output_section()
1002 {
1003 }
1004
1005 // Set the entry size.
1006
1007 void
1008 Output_section::set_entsize(uint64_t v)
1009 {
1010   if (this->entsize_ == 0)
1011     this->entsize_ = v;
1012   else
1013     gold_assert(this->entsize_ == v);
1014 }
1015
1016 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1017 // OBJECT, to the Output_section.  Return the offset of the input
1018 // section within the output section.  We don't always keep track of
1019 // input sections for an Output_section.  Instead, each Object keeps
1020 // track of the Output_section for each of its input sections.
1021
1022 template<int size, bool big_endian>
1023 off_t
1024 Output_section::add_input_section(Relobj* object, unsigned int shndx,
1025                                   const char* secname,
1026                                   const elfcpp::Shdr<size, big_endian>& shdr)
1027 {
1028   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1029   if ((addralign & (addralign - 1)) != 0)
1030     {
1031       fprintf(stderr, _("%s: %s: invalid alignment %lu for section \"%s\"\n"),
1032               program_name, object->name().c_str(),
1033               static_cast<unsigned long>(addralign), secname);
1034       gold_exit(false);
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   // FIXME: unlink the file if it's a symlink, even a symlink to a dir.
1690   //        Or do we want to follow the symlink and unlink its target?
1691   struct stat s;
1692   if (::stat(this->name_, &s) == 0 && s.st_size != 0 && S_ISREG(s.st_mode))
1693     ::unlink(this->name_);
1694
1695   int mode = parameters->output_is_object() ? 0666 : 0777;
1696   int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
1697   if (o < 0)
1698     {
1699       fprintf(stderr, _("%s: %s: open: %s\n"),
1700               program_name, this->name_, strerror(errno));
1701       gold_exit(false);
1702     }
1703   this->o_ = o;
1704
1705   // Write out one byte to make the file the right size.
1706   if (::lseek(o, file_size - 1, SEEK_SET) < 0)
1707     {
1708       fprintf(stderr, _("%s: %s: lseek: %s\n"),
1709               program_name, this->name_, strerror(errno));
1710       gold_exit(false);
1711     }
1712   char b = 0;
1713   if (::write(o, &b, 1) != 1)
1714     {
1715       fprintf(stderr, _("%s: %s: write: %s\n"),
1716               program_name, this->name_, strerror(errno));
1717       gold_exit(false);
1718     }
1719
1720   // Map the file into memory.
1721   void* base = ::mmap(NULL, file_size, PROT_READ | PROT_WRITE,
1722                       MAP_SHARED, o, 0);
1723   if (base == MAP_FAILED)
1724     {
1725       fprintf(stderr, _("%s: %s: mmap: %s\n"),
1726               program_name, this->name_, strerror(errno));
1727       gold_exit(false);
1728     }
1729   this->base_ = static_cast<unsigned char*>(base);
1730 }
1731
1732 // Close the output file.
1733
1734 void
1735 Output_file::close()
1736 {
1737   if (::munmap(this->base_, this->file_size_) < 0)
1738     {
1739       fprintf(stderr, _("%s: %s: munmap: %s\n"),
1740               program_name, this->name_, strerror(errno));
1741       gold_exit(false);
1742     }
1743   this->base_ = NULL;
1744
1745   if (::close(this->o_) < 0)
1746     {
1747       fprintf(stderr, _("%s: %s: close: %s\n"),
1748               program_name, this->name_, strerror(errno));
1749       gold_exit(false);
1750     }
1751   this->o_ = -1;
1752 }
1753
1754 // Instantiate the templates we need.  We could use the configure
1755 // script to restrict this to only the ones for implemented targets.
1756
1757 #ifdef HAVE_TARGET_32_LITTLE
1758 template
1759 off_t
1760 Output_section::add_input_section<32, false>(
1761     Relobj* object,
1762     unsigned int shndx,
1763     const char* secname,
1764     const elfcpp::Shdr<32, false>& shdr);
1765 #endif
1766
1767 #ifdef HAVE_TARGET_32_BIG
1768 template
1769 off_t
1770 Output_section::add_input_section<32, true>(
1771     Relobj* object,
1772     unsigned int shndx,
1773     const char* secname,
1774     const elfcpp::Shdr<32, true>& shdr);
1775 #endif
1776
1777 #ifdef HAVE_TARGET_64_LITTLE
1778 template
1779 off_t
1780 Output_section::add_input_section<64, false>(
1781     Relobj* object,
1782     unsigned int shndx,
1783     const char* secname,
1784     const elfcpp::Shdr<64, false>& shdr);
1785 #endif
1786
1787 #ifdef HAVE_TARGET_64_BIG
1788 template
1789 off_t
1790 Output_section::add_input_section<64, true>(
1791     Relobj* object,
1792     unsigned int shndx,
1793     const char* secname,
1794     const elfcpp::Shdr<64, true>& shdr);
1795 #endif
1796
1797 #ifdef HAVE_TARGET_32_LITTLE
1798 template
1799 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
1800 #endif
1801
1802 #ifdef HAVE_TARGET_32_BIG
1803 template
1804 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
1805 #endif
1806
1807 #ifdef HAVE_TARGET_64_LITTLE
1808 template
1809 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
1810 #endif
1811
1812 #ifdef HAVE_TARGET_64_BIG
1813 template
1814 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
1815 #endif
1816
1817 #ifdef HAVE_TARGET_32_LITTLE
1818 template
1819 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
1820 #endif
1821
1822 #ifdef HAVE_TARGET_32_BIG
1823 template
1824 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
1825 #endif
1826
1827 #ifdef HAVE_TARGET_64_LITTLE
1828 template
1829 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
1830 #endif
1831
1832 #ifdef HAVE_TARGET_64_BIG
1833 template
1834 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
1835 #endif
1836
1837 #ifdef HAVE_TARGET_32_LITTLE
1838 template
1839 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
1840 #endif
1841
1842 #ifdef HAVE_TARGET_32_BIG
1843 template
1844 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
1845 #endif
1846
1847 #ifdef HAVE_TARGET_64_LITTLE
1848 template
1849 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
1850 #endif
1851
1852 #ifdef HAVE_TARGET_64_BIG
1853 template
1854 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
1855 #endif
1856
1857 #ifdef HAVE_TARGET_32_LITTLE
1858 template
1859 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
1860 #endif
1861
1862 #ifdef HAVE_TARGET_32_BIG
1863 template
1864 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
1865 #endif
1866
1867 #ifdef HAVE_TARGET_64_LITTLE
1868 template
1869 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
1870 #endif
1871
1872 #ifdef HAVE_TARGET_64_BIG
1873 template
1874 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
1875 #endif
1876
1877 #ifdef HAVE_TARGET_32_LITTLE
1878 template
1879 class Output_data_got<32, false>;
1880 #endif
1881
1882 #ifdef HAVE_TARGET_32_BIG
1883 template
1884 class Output_data_got<32, true>;
1885 #endif
1886
1887 #ifdef HAVE_TARGET_64_LITTLE
1888 template
1889 class Output_data_got<64, false>;
1890 #endif
1891
1892 #ifdef HAVE_TARGET_64_BIG
1893 template
1894 class Output_data_got<64, true>;
1895 #endif
1896
1897 } // End namespace gold.