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 the target size.
  67
  68 uint64_t
  69 Output_data::default_alignment()
  70 {
  71   return Output_data::default_alignment_for_size(parameters->get_size());
  72 }
  73
  74 // Return the default alignment for a size--32 or 64.
  75
  76 uint64_t
  77 Output_data::default_alignment_for_size(int size)
  78 {
  79   if (size == 32)
  80     return 4;
  81   else if (size == 64)
  82     return 8;
  83   else
  84     gold_unreachable();
  85 }
  86
  87 // Output_section_header methods.  This currently assumes that the
  88 // segment and section lists are complete at construction time.
  89
  90 Output_section_headers::Output_section_headers(
  91     const Layout* layout,
  92     const Layout::Segment_list* segment_list,
  93     const Layout::Section_list* unattached_section_list,
  94     const Stringpool* secnamepool)
  95   : layout_(layout),
  96     segment_list_(segment_list),
  97     unattached_section_list_(unattached_section_list),
  98     secnamepool_(secnamepool)
  99 {
 100   // Count all the sections.  Start with 1 for the null section.
 101   off_t count = 1;
 102   for (Layout::Segment_list::const_iterator p = segment_list->begin();
 103        p != segment_list->end();
 104        ++p)
 105     if ((*p)->type() == elfcpp::PT_LOAD)
 106       count += (*p)->output_section_count();
 107   count += unattached_section_list->size();
 108
 109   const int size = parameters->get_size();
 110   int shdr_size;
 111   if (size == 32)
 112     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
 113   else if (size == 64)
 114     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
 115   else
 116     gold_unreachable();
 117
 118   this->set_data_size(count * shdr_size);
 119 }
 120
 121 // Write out the section headers.
 122
 123 void
 124 Output_section_headers::do_write(Output_file* of)
 125 {
 126   if (parameters->get_size() == 32)
 127     {
 128       if (parameters->is_big_endian())
 129         {
 130 #ifdef HAVE_TARGET_32_BIG
 131           this->do_sized_write<32, true>(of);
 132 #else
 133           gold_unreachable();
 134 #endif
 135         }
 136       else
 137         {
 138 #ifdef HAVE_TARGET_32_LITTLE
 139           this->do_sized_write<32, false>(of);
 140 #else
 141           gold_unreachable();
 142 #endif
 143         }
 144     }
 145   else if (parameters->get_size() == 64)
 146     {
 147       if (parameters->is_big_endian())
 148         {
 149 #ifdef HAVE_TARGET_64_BIG
 150           this->do_sized_write<64, true>(of);
 151 #else
 152           gold_unreachable();
 153 #endif
 154         }
 155       else
 156         {
 157 #ifdef HAVE_TARGET_64_LITTLE
 158           this->do_sized_write<64, false>(of);
 159 #else
 160           gold_unreachable();
 161 #endif
 162         }
 163     }
 164   else
 165     gold_unreachable();
 166 }
 167
 168 template<int size, bool big_endian>
 169 void
 170 Output_section_headers::do_sized_write(Output_file* of)
 171 {
 172   off_t all_shdrs_size = this->data_size();
 173   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
 174
 175   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
 176   unsigned char* v = view;
 177
 178   {
 179     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
 180     oshdr.put_sh_name(0);
 181     oshdr.put_sh_type(elfcpp::SHT_NULL);
 182     oshdr.put_sh_flags(0);
 183     oshdr.put_sh_addr(0);
 184     oshdr.put_sh_offset(0);
 185     oshdr.put_sh_size(0);
 186     oshdr.put_sh_link(0);
 187     oshdr.put_sh_info(0);
 188     oshdr.put_sh_addralign(0);
 189     oshdr.put_sh_entsize(0);
 190   }
 191
 192   v += shdr_size;
 193
 194   unsigned shndx = 1;
 195   for (Layout::Segment_list::const_iterator p = this->segment_list_->begin();
 196        p != this->segment_list_->end();
 197        ++p)
 198     v = (*p)->write_section_headers SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
 199             this->layout_, this->secnamepool_, v, &shndx
 200             SELECT_SIZE_ENDIAN(size, big_endian));
 201   for (Layout::Section_list::const_iterator p =
 202          this->unattached_section_list_->begin();
 203        p != this->unattached_section_list_->end();
 204        ++p)
 205     {
 206       gold_assert(shndx == (*p)->out_shndx());
 207       elfcpp::Shdr_write<size, big_endian> oshdr(v);
 208       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
 209       v += shdr_size;
 210       ++shndx;
 211     }
 212
 213   of->write_output_view(this->offset(), all_shdrs_size, view);
 214 }
 215
 216 // Output_segment_header methods.
 217
 218 Output_segment_headers::Output_segment_headers(
 219     const Layout::Segment_list& segment_list)
 220   : segment_list_(segment_list)
 221 {
 222   const int size = parameters->get_size();
 223   int phdr_size;
 224   if (size == 32)
 225     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
 226   else if (size == 64)
 227     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
 228   else
 229     gold_unreachable();
 230
 231   this->set_data_size(segment_list.size() * phdr_size);
 232 }
 233
 234 void
 235 Output_segment_headers::do_write(Output_file* of)
 236 {
 237   if (parameters->get_size() == 32)
 238     {
 239       if (parameters->is_big_endian())
 240         {
 241 #ifdef HAVE_TARGET_32_BIG
 242           this->do_sized_write<32, true>(of);
 243 #else
 244           gold_unreachable();
 245 #endif
 246         }
 247       else
 248         {
 249 #ifdef HAVE_TARGET_32_LITTLE
 250         this->do_sized_write<32, false>(of);
 251 #else
 252         gold_unreachable();
 253 #endif
 254         }
 255     }
 256   else if (parameters->get_size() == 64)
 257     {
 258       if (parameters->is_big_endian())
 259         {
 260 #ifdef HAVE_TARGET_64_BIG
 261           this->do_sized_write<64, true>(of);
 262 #else
 263           gold_unreachable();
 264 #endif
 265         }
 266       else
 267         {
 268 #ifdef HAVE_TARGET_64_LITTLE
 269           this->do_sized_write<64, false>(of);
 270 #else
 271           gold_unreachable();
 272 #endif
 273         }
 274     }
 275   else
 276     gold_unreachable();
 277 }
 278
 279 template<int size, bool big_endian>
 280 void
 281 Output_segment_headers::do_sized_write(Output_file* of)
 282 {
 283   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
 284   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
 285   unsigned char* view = of->get_output_view(this->offset(),
 286                                             all_phdrs_size);
 287   unsigned char* v = view;
 288   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
 289        p != this->segment_list_.end();
 290        ++p)
 291     {
 292       elfcpp::Phdr_write<size, big_endian> ophdr(v);
 293       (*p)->write_header(&ophdr);
 294       v += phdr_size;
 295     }
 296
 297   of->write_output_view(this->offset(), all_phdrs_size, view);
 298 }
 299
 300 // Output_file_header methods.
 301
 302 Output_file_header::Output_file_header(const Target* target,
 303                                        const Symbol_table* symtab,
 304                                        const Output_segment_headers* osh)
 305   : target_(target),
 306     symtab_(symtab),
 307     segment_header_(osh),
 308     section_header_(NULL),
 309     shstrtab_(NULL)
 310 {
 311   const int size = parameters->get_size();
 312   int ehdr_size;
 313   if (size == 32)
 314     ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size;
 315   else if (size == 64)
 316     ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
 317   else
 318     gold_unreachable();
 319
 320   this->set_data_size(ehdr_size);
 321 }
 322
 323 // Set the section table information for a file header.
 324
 325 void
 326 Output_file_header::set_section_info(const Output_section_headers* shdrs,
 327                                      const Output_section* shstrtab)
 328 {
 329   this->section_header_ = shdrs;
 330   this->shstrtab_ = shstrtab;
 331 }
 332
 333 // Write out the file header.
 334
 335 void
 336 Output_file_header::do_write(Output_file* of)
 337 {
 338   if (parameters->get_size() == 32)
 339     {
 340       if (parameters->is_big_endian())
 341         {
 342 #ifdef HAVE_TARGET_32_BIG
 343           this->do_sized_write<32, true>(of);
 344 #else
 345           gold_unreachable();
 346 #endif
 347         }
 348       else
 349         {
 350 #ifdef HAVE_TARGET_32_LITTLE
 351           this->do_sized_write<32, false>(of);
 352 #else
 353           gold_unreachable();
 354 #endif
 355         }
 356     }
 357   else if (parameters->get_size() == 64)
 358     {
 359       if (parameters->is_big_endian())
 360         {
 361 #ifdef HAVE_TARGET_64_BIG
 362           this->do_sized_write<64, true>(of);
 363 #else
 364           gold_unreachable();
 365 #endif
 366         }
 367       else
 368         {
 369 #ifdef HAVE_TARGET_64_LITTLE
 370           this->do_sized_write<64, false>(of);
 371 #else
 372           gold_unreachable();
 373 #endif
 374         }
 375     }
 376   else
 377     gold_unreachable();
 378 }
 379
 380 // Write out the file header with appropriate size and endianess.
 381
 382 template<int size, bool big_endian>
 383 void
 384 Output_file_header::do_sized_write(Output_file* of)
 385 {
 386   gold_assert(this->offset() == 0);
 387
 388   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
 389   unsigned char* view = of->get_output_view(0, ehdr_size);
 390   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
 391
 392   unsigned char e_ident[elfcpp::EI_NIDENT];
 393   memset(e_ident, 0, elfcpp::EI_NIDENT);
 394   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
 395   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
 396   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
 397   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
 398   if (size == 32)
 399     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
 400   else if (size == 64)
 401     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
 402   else
 403     gold_unreachable();
 404   e_ident[elfcpp::EI_DATA] = (big_endian
 405                               ? elfcpp::ELFDATA2MSB
 406                               : elfcpp::ELFDATA2LSB);
 407   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
 408   // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION.
 409   oehdr.put_e_ident(e_ident);
 410
 411   elfcpp::ET e_type;
 412   if (parameters->output_is_object())
 413     e_type = elfcpp::ET_REL;
 414   else if (parameters->output_is_shared())
 415     e_type = elfcpp::ET_DYN;
 416   else
 417     e_type = elfcpp::ET_EXEC;
 418   oehdr.put_e_type(e_type);
 419
 420   oehdr.put_e_machine(this->target_->machine_code());
 421   oehdr.put_e_version(elfcpp::EV_CURRENT);
 422
 423   // FIXME: Need to support -e, and target specific entry symbol.
 424   Symbol* sym = this->symtab_->lookup("_start");
 425   typename Sized_symbol<size>::Value_type v;
 426   if (sym == NULL)
 427     v = 0;
 428   else
 429     {
 430       Sized_symbol<size>* ssym;
 431       ssym = this->symtab_->get_sized_symbol SELECT_SIZE_NAME(size) (
 432         sym SELECT_SIZE(size));
 433       v = ssym->value();
 434     }
 435   oehdr.put_e_entry(v);
 436
 437   oehdr.put_e_phoff(this->segment_header_->offset());
 438   oehdr.put_e_shoff(this->section_header_->offset());
 439
 440   // FIXME: The target needs to set the flags.
 441   oehdr.put_e_flags(0);
 442
 443   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
 444   oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
 445   oehdr.put_e_phnum(this->segment_header_->data_size()
 446                      / elfcpp::Elf_sizes<size>::phdr_size);
 447   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
 448   oehdr.put_e_shnum(this->section_header_->data_size()
 449                      / elfcpp::Elf_sizes<size>::shdr_size);
 450   oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
 451
 452   of->write_output_view(0, ehdr_size, view);
 453 }
 454
 455 // Output_data_const methods.
 456
 457 void
 458 Output_data_const::do_write(Output_file* of)
 459 {
 460   of->write(this->offset(), this->data_.data(), this->data_.size());
 461 }
 462
 463 // Output_data_const_buffer methods.
 464
 465 void
 466 Output_data_const_buffer::do_write(Output_file* of)
 467 {
 468   of->write(this->offset(), this->p_, this->data_size());
 469 }
 470
 471 // Output_section_data methods.
 472
 473 // Record the output section, and set the entry size and such.
 474
 475 void
 476 Output_section_data::set_output_section(Output_section* os)
 477 {
 478   gold_assert(this->output_section_ == NULL);
 479   this->output_section_ = os;
 480   this->do_adjust_output_section(os);
 481 }
 482
 483 // Return the section index of the output section.
 484
 485 unsigned int
 486 Output_section_data::do_out_shndx() const
 487 {
 488   gold_assert(this->output_section_ != NULL);
 489   return this->output_section_->out_shndx();
 490 }
 491
 492 // Output_data_strtab methods.
 493
 494 // Set the address.  We don't actually care about the address, but we
 495 // do set our final size.
 496
 497 void
 498 Output_data_strtab::do_set_address(uint64_t, off_t)
 499 {
 500   this->strtab_->set_string_offsets();
 501   this->set_data_size(this->strtab_->get_strtab_size());
 502 }
 503
 504 // Write out a string table.
 505
 506 void
 507 Output_data_strtab::do_write(Output_file* of)
 508 {
 509   this->strtab_->write(of, this->offset());
 510 }
 511
 512 // Output_reloc methods.
 513
 514 // Get the symbol index of a relocation.
 515
 516 template<bool dynamic, int size, bool big_endian>
 517 unsigned int
 518 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
 519   const
 520 {
 521   unsigned int index;
 522   switch (this->local_sym_index_)
 523     {
 524     case INVALID_CODE:
 525       gold_unreachable();
 526
 527     case GSYM_CODE:
 528       if (this->u1_.gsym == NULL)
 529         index = 0;
 530       else if (dynamic)
 531         index = this->u1_.gsym->dynsym_index();
 532       else
 533         index = this->u1_.gsym->symtab_index();
 534       break;
 535
 536     case SECTION_CODE:
 537       if (dynamic)
 538         index = this->u1_.os->dynsym_index();
 539       else
 540         index = this->u1_.os->symtab_index();
 541       break;
 542
 543     case 0:
 544       // Relocations without symbols use a symbol index of 0.
 545       index = 0;
 546       break;
 547
 548     default:
 549       if (dynamic)
 550         {
 551           // FIXME: It seems that some targets may need to generate
 552           // dynamic relocations against local symbols for some
 553           // reasons.  This will have to be addressed at some point.
 554           gold_unreachable();
 555         }
 556       else
 557         index = this->u1_.relobj->symtab_index(this->local_sym_index_);
 558       break;
 559     }
 560   gold_assert(index != -1U);
 561   return index;
 562 }
 563
 564 // Write out the offset and info fields of a Rel or Rela relocation
 565 // entry.
 566
 567 template<bool dynamic, int size, bool big_endian>
 568 template<typename Write_rel>
 569 void
 570 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
 571     Write_rel* wr) const
 572 {
 573   Address address = this->address_;
 574   if (this->shndx_ != INVALID_CODE)
 575     {
 576       off_t off;
 577       Output_section* os = this->u2_.relobj->output_section(this->shndx_,
 578                                                             &off);
 579       gold_assert(os != NULL);
 580       if (off != -1)
 581         address += os->address() + off;
 582       else
 583         {
 584           address = os->output_address(this->u2_.relobj, this->shndx_,
 585                                        address);
 586           gold_assert(address != -1U);
 587         }
 588     }
 589   else if (this->u2_.od != NULL)
 590     address += this->u2_.od->address();
 591   wr->put_r_offset(address);
 592   wr->put_r_info(elfcpp::elf_r_info<size>(this->get_symbol_index(),
 593                                           this->type_));
 594 }
 595
 596 // Write out a Rel relocation.
 597
 598 template<bool dynamic, int size, bool big_endian>
 599 void
 600 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
 601     unsigned char* pov) const
 602 {
 603   elfcpp::Rel_write<size, big_endian> orel(pov);
 604   this->write_rel(&orel);
 605 }
 606
 607 // Write out a Rela relocation.
 608
 609 template<bool dynamic, int size, bool big_endian>
 610 void
 611 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
 612     unsigned char* pov) const
 613 {
 614   elfcpp::Rela_write<size, big_endian> orel(pov);
 615   this->rel_.write_rel(&orel);
 616   orel.put_r_addend(this->addend_);
 617 }
 618
 619 // Output_data_reloc_base methods.
 620
 621 // Adjust the output section.
 622
 623 template<int sh_type, bool dynamic, int size, bool big_endian>
 624 void
 625 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
 626     ::do_adjust_output_section(Output_section* os)
 627 {
 628   if (sh_type == elfcpp::SHT_REL)
 629     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
 630   else if (sh_type == elfcpp::SHT_RELA)
 631     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
 632   else
 633     gold_unreachable();
 634   if (dynamic)
 635     os->set_should_link_to_dynsym();
 636   else
 637     os->set_should_link_to_symtab();
 638 }
 639
 640 // Write out relocation data.
 641
 642 template<int sh_type, bool dynamic, int size, bool big_endian>
 643 void
 644 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
 645     Output_file* of)
 646 {
 647   const off_t off = this->offset();
 648   const off_t oview_size = this->data_size();
 649   unsigned char* const oview = of->get_output_view(off, oview_size);
 650
 651   unsigned char* pov = oview;
 652   for (typename Relocs::const_iterator p = this->relocs_.begin();
 653        p != this->relocs_.end();
 654        ++p)
 655     {
 656       p->write(pov);
 657       pov += reloc_size;
 658     }
 659
 660   gold_assert(pov - oview == oview_size);
 661
 662   of->write_output_view(off, oview_size, oview);
 663
 664   // We no longer need the relocation entries.
 665   this->relocs_.clear();
 666 }
 667
 668 // Output_data_got::Got_entry methods.
 669
 670 // Write out the entry.
 671
 672 template<int size, bool big_endian>
 673 void
 674 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
 675 {
 676   Valtype val = 0;
 677
 678   switch (this->local_sym_index_)
 679     {
 680     case GSYM_CODE:
 681       {
 682         Symbol* gsym = this->u_.gsym;
 683
 684         // If the symbol is resolved locally, we need to write out its
 685         // value.  Otherwise we just write zero.  The target code is
 686         // responsible for creating a relocation entry to fill in the
 687         // value at runtime. For non-preemptible symbols in a shared
 688         // library, the target will need to record whether or not the
 689         // value should be written (e.g., it may use a RELATIVE
 690         // relocation type).
 691         if (gsym->final_value_is_known() || gsym->needs_value_in_got())
 692           {
 693             Sized_symbol<size>* sgsym;
 694             // This cast is a bit ugly.  We don't want to put a
 695             // virtual method in Symbol, because we want Symbol to be
 696             // as small as possible.
 697             sgsym = static_cast<Sized_symbol<size>*>(gsym);
 698             val = sgsym->value();
 699           }
 700       }
 701       break;
 702
 703     case CONSTANT_CODE:
 704       val = this->u_.constant;
 705       break;
 706
 707     default:
 708       val = this->u_.object->local_symbol_value(this->local_sym_index_);
 709       break;
 710     }
 711
 712   elfcpp::Swap<size, big_endian>::writeval(pov, val);
 713 }
 714
 715 // Output_data_got methods.
 716
 717 // Add an entry for a global symbol to the GOT.  This returns true if
 718 // this is a new GOT entry, false if the symbol already had a GOT
 719 // entry.
 720
 721 template<int size, bool big_endian>
 722 bool
 723 Output_data_got<size, big_endian>::add_global(Symbol* gsym)
 724 {
 725   if (gsym->has_got_offset())
 726     return false;
 727
 728   this->entries_.push_back(Got_entry(gsym));
 729   this->set_got_size();
 730   gsym->set_got_offset(this->last_got_offset());
 731   return true;
 732 }
 733
 734 // Add an entry for a local symbol to the GOT.  This returns true if
 735 // this is a new GOT entry, false if the symbol already has a GOT
 736 // entry.
 737
 738 template<int size, bool big_endian>
 739 bool
 740 Output_data_got<size, big_endian>::add_local(
 741     Sized_relobj<size, big_endian>* object,
 742     unsigned int symndx)
 743 {
 744   if (object->local_has_got_offset(symndx))
 745     return false;
 746   this->entries_.push_back(Got_entry(object, symndx));
 747   this->set_got_size();
 748   object->set_local_got_offset(symndx, this->last_got_offset());
 749   return true;
 750 }
 751
 752 // Write out the GOT.
 753
 754 template<int size, bool big_endian>
 755 void
 756 Output_data_got<size, big_endian>::do_write(Output_file* of)
 757 {
 758   const int add = size / 8;
 759
 760   const off_t off = this->offset();
 761   const off_t oview_size = this->data_size();
 762   unsigned char* const oview = of->get_output_view(off, oview_size);
 763
 764   unsigned char* pov = oview;
 765   for (typename Got_entries::const_iterator p = this->entries_.begin();
 766        p != this->entries_.end();
 767        ++p)
 768     {
 769       p->write(pov);
 770       pov += add;
 771     }
 772
 773   gold_assert(pov - oview == oview_size);
 774
 775   of->write_output_view(off, oview_size, oview);
 776
 777   // We no longer need the GOT entries.
 778   this->entries_.clear();
 779 }
 780
 781 // Output_data_dynamic::Dynamic_entry methods.
 782
 783 // Write out the entry.
 784
 785 template<int size, bool big_endian>
 786 void
 787 Output_data_dynamic::Dynamic_entry::write(
 788     unsigned char* pov,
 789     const Stringpool* pool
 790     ACCEPT_SIZE_ENDIAN) const
 791 {
 792   typename elfcpp::Elf_types<size>::Elf_WXword val;
 793   switch (this->classification_)
 794     {
 795     case DYNAMIC_NUMBER:
 796       val = this->u_.val;
 797       break;
 798
 799     case DYNAMIC_SECTION_ADDRESS:
 800       val = this->u_.od->address();
 801       break;
 802
 803     case DYNAMIC_SECTION_SIZE:
 804       val = this->u_.od->data_size();
 805       break;
 806
 807     case DYNAMIC_SYMBOL:
 808       {
 809         const Sized_symbol<size>* s =
 810           static_cast<const Sized_symbol<size>*>(this->u_.sym);
 811         val = s->value();
 812       }
 813       break;
 814
 815     case DYNAMIC_STRING:
 816       val = pool->get_offset(this->u_.str);
 817       break;
 818
 819     default:
 820       gold_unreachable();
 821     }
 822
 823   elfcpp::Dyn_write<size, big_endian> dw(pov);
 824   dw.put_d_tag(this->tag_);
 825   dw.put_d_val(val);
 826 }
 827
 828 // Output_data_dynamic methods.
 829
 830 // Adjust the output section to set the entry size.
 831
 832 void
 833 Output_data_dynamic::do_adjust_output_section(Output_section* os)
 834 {
 835   if (parameters->get_size() == 32)
 836     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
 837   else if (parameters->get_size() == 64)
 838     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
 839   else
 840     gold_unreachable();
 841 }
 842
 843 // Set the final data size.
 844
 845 void
 846 Output_data_dynamic::do_set_address(uint64_t, off_t)
 847 {
 848   // Add the terminating entry.
 849   this->add_constant(elfcpp::DT_NULL, 0);
 850
 851   int dyn_size;
 852   if (parameters->get_size() == 32)
 853     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
 854   else if (parameters->get_size() == 64)
 855     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
 856   else
 857     gold_unreachable();
 858   this->set_data_size(this->entries_.size() * dyn_size);
 859 }
 860
 861 // Write out the dynamic entries.
 862
 863 void
 864 Output_data_dynamic::do_write(Output_file* of)
 865 {
 866   if (parameters->get_size() == 32)
 867     {
 868       if (parameters->is_big_endian())
 869         {
 870 #ifdef HAVE_TARGET_32_BIG
 871           this->sized_write<32, true>(of);
 872 #else
 873           gold_unreachable();
 874 #endif
 875         }
 876       else
 877         {
 878 #ifdef HAVE_TARGET_32_LITTLE
 879           this->sized_write<32, false>(of);
 880 #else
 881           gold_unreachable();
 882 #endif
 883         }
 884     }
 885   else if (parameters->get_size() == 64)
 886     {
 887       if (parameters->is_big_endian())
 888         {
 889 #ifdef HAVE_TARGET_64_BIG
 890           this->sized_write<64, true>(of);
 891 #else
 892           gold_unreachable();
 893 #endif
 894         }
 895       else
 896         {
 897 #ifdef HAVE_TARGET_64_LITTLE
 898           this->sized_write<64, false>(of);
 899 #else
 900           gold_unreachable();
 901 #endif
 902         }
 903     }
 904   else
 905     gold_unreachable();
 906 }
 907
 908 template<int size, bool big_endian>
 909 void
 910 Output_data_dynamic::sized_write(Output_file* of)
 911 {
 912   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
 913
 914   const off_t offset = this->offset();
 915   const off_t oview_size = this->data_size();
 916   unsigned char* const oview = of->get_output_view(offset, oview_size);
 917
 918   unsigned char* pov = oview;
 919   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
 920        p != this->entries_.end();
 921        ++p)
 922     {
 923       p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
 924           pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian));
 925       pov += dyn_size;
 926     }
 927
 928   gold_assert(pov - oview == oview_size);
 929
 930   of->write_output_view(offset, oview_size, oview);
 931
 932   // We no longer need the dynamic entries.
 933   this->entries_.clear();
 934 }
 935
 936 // Output_section::Input_section methods.
 937
 938 // Return the data size.  For an input section we store the size here.
 939 // For an Output_section_data, we have to ask it for the size.
 940
 941 off_t
 942 Output_section::Input_section::data_size() const
 943 {
 944   if (this->is_input_section())
 945     return this->u1_.data_size;
 946   else
 947     return this->u2_.posd->data_size();
 948 }
 949
 950 // Set the address and file offset.
 951
 952 void
 953 Output_section::Input_section::set_address(uint64_t addr, off_t off,
 954                                            off_t secoff)
 955 {
 956   if (this->is_input_section())
 957     this->u2_.object->set_section_offset(this->shndx_, off - secoff);
 958   else
 959     this->u2_.posd->set_address(addr, off);
 960 }
 961
 962 // Try to turn an input offset into an output offset.
 963
 964 bool
 965 Output_section::Input_section::output_offset(const Relobj* object,
 966                                              unsigned int shndx,
 967                                              off_t offset,
 968                                              off_t *poutput) const
 969 {
 970   if (!this->is_input_section())
 971     return this->u2_.posd->output_offset(object, shndx, offset, poutput);
 972   else
 973     {
 974       if (this->shndx_ != shndx || this->u2_.object != object)
 975         return false;
 976       off_t output_offset;
 977       Output_section* os = object->output_section(shndx, &output_offset);
 978       gold_assert(os != NULL);
 979       gold_assert(output_offset != -1);
 980       *poutput = output_offset + offset;
 981       return true;
 982     }
 983 }
 984
 985 // Write out the data.  We don't have to do anything for an input
 986 // section--they are handled via Object::relocate--but this is where
 987 // we write out the data for an Output_section_data.
 988
 989 void
 990 Output_section::Input_section::write(Output_file* of)
 991 {
 992   if (!this->is_input_section())
 993     this->u2_.posd->write(of);
 994 }
 995
 996 // Output_section methods.
 997
 998 // Construct an Output_section.  NAME will point into a Stringpool.
 999
1000 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1001                                elfcpp::Elf_Xword flags)
1002   : name_(name),
1003     addralign_(0),
1004     entsize_(0),
1005     link_section_(NULL),
1006     link_(0),
1007     info_section_(NULL),
1008     info_(0),
1009     type_(type),
1010     flags_(flags),
1011     out_shndx_(-1U),
1012     symtab_index_(0),
1013     dynsym_index_(0),
1014     input_sections_(),
1015     first_input_offset_(0),
1016     fills_(),
1017     needs_symtab_index_(false),
1018     needs_dynsym_index_(false),
1019     should_link_to_symtab_(false),
1020     should_link_to_dynsym_(false),
1021     after_input_sections_(false)
1022 {
1023 }
1024
1025 Output_section::~Output_section()
1026 {
1027 }
1028
1029 // Set the entry size.
1030
1031 void
1032 Output_section::set_entsize(uint64_t v)
1033 {
1034   if (this->entsize_ == 0)
1035     this->entsize_ = v;
1036   else
1037     gold_assert(this->entsize_ == v);
1038 }
1039
1040 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1041 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
1042 // relocation section which applies to this section, or 0 if none, or
1043 // -1U if more than one.  Return the offset of the input section
1044 // within the output section.  Return -1 if the input section will
1045 // receive special handling.  In the normal case we don't always keep
1046 // track of input sections for an Output_section.  Instead, each
1047 // Object keeps track of the Output_section for each of its input
1048 // sections.
1049
1050 template<int size, bool big_endian>
1051 off_t
1052 Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
1053                                   unsigned int shndx,
1054                                   const char* secname,
1055                                   const elfcpp::Shdr<size, big_endian>& shdr,
1056                                   unsigned int reloc_shndx)
1057 {
1058   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1059   if ((addralign & (addralign - 1)) != 0)
1060     {
1061       object->error(_("invalid alignment %lu for section \"%s\""),
1062                     static_cast<unsigned long>(addralign), secname);
1063       addralign = 1;
1064     }
1065
1066   if (addralign > this->addralign_)
1067     this->addralign_ = addralign;
1068
1069   // If this is a SHF_MERGE section, we pass all the input sections to
1070   // a Output_data_merge.  We don't try to handle relocations for such
1071   // a section.
1072   if ((shdr.get_sh_flags() & elfcpp::SHF_MERGE) != 0
1073       && reloc_shndx == 0)
1074     {
1075       if (this->add_merge_input_section(object, shndx, shdr.get_sh_flags(),
1076                                         shdr.get_sh_entsize(),
1077                                         addralign))
1078         {
1079           // Tell the relocation routines that they need to call the
1080           // output_offset method to determine the final address.
1081           return -1;
1082         }
1083     }
1084
1085   off_t offset_in_section = this->data_size();
1086   off_t aligned_offset_in_section = align_address(offset_in_section,
1087                                                   addralign);
1088
1089   if (aligned_offset_in_section > offset_in_section
1090       && (shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0
1091       && object->target()->has_code_fill())
1092     {
1093       // We need to add some fill data.  Using fill_list_ when
1094       // possible is an optimization, since we will often have fill
1095       // sections without input sections.
1096       off_t fill_len = aligned_offset_in_section - offset_in_section;
1097       if (this->input_sections_.empty())
1098         this->fills_.push_back(Fill(offset_in_section, fill_len));
1099       else
1100         {
1101           // FIXME: When relaxing, the size needs to adjust to
1102           // maintain a constant alignment.
1103           std::string fill_data(object->target()->code_fill(fill_len));
1104           Output_data_const* odc = new Output_data_const(fill_data, 1);
1105           this->input_sections_.push_back(Input_section(odc));
1106         }
1107     }
1108
1109   this->set_data_size(aligned_offset_in_section + shdr.get_sh_size());
1110
1111   // We need to keep track of this section if we are already keeping
1112   // track of sections, or if we are relaxing.  FIXME: Add test for
1113   // relaxing.
1114   if (!this->input_sections_.empty())
1115     this->input_sections_.push_back(Input_section(object, shndx,
1116                                                   shdr.get_sh_size(),
1117                                                   addralign));
1118
1119   return aligned_offset_in_section;
1120 }
1121
1122 // Add arbitrary data to an output section.
1123
1124 void
1125 Output_section::add_output_section_data(Output_section_data* posd)
1126 {
1127   Input_section inp(posd);
1128   this->add_output_section_data(&inp);
1129 }
1130
1131 // Add arbitrary data to an output section by Input_section.
1132
1133 void
1134 Output_section::add_output_section_data(Input_section* inp)
1135 {
1136   if (this->input_sections_.empty())
1137     this->first_input_offset_ = this->data_size();
1138
1139   this->input_sections_.push_back(*inp);
1140
1141   uint64_t addralign = inp->addralign();
1142   if (addralign > this->addralign_)
1143     this->addralign_ = addralign;
1144
1145   inp->set_output_section(this);
1146 }
1147
1148 // Add a merge section to an output section.
1149
1150 void
1151 Output_section::add_output_merge_section(Output_section_data* posd,
1152                                          bool is_string, uint64_t entsize)
1153 {
1154   Input_section inp(posd, is_string, entsize);
1155   this->add_output_section_data(&inp);
1156 }
1157
1158 // Add an input section to a SHF_MERGE section.
1159
1160 bool
1161 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
1162                                         uint64_t flags, uint64_t entsize,
1163                                         uint64_t addralign)
1164 {
1165   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
1166
1167   // We only merge strings if the alignment is not more than the
1168   // character size.  This could be handled, but it's unusual.
1169   if (is_string && addralign > entsize)
1170     return false;
1171
1172   Input_section_list::iterator p;
1173   for (p = this->input_sections_.begin();
1174        p != this->input_sections_.end();
1175        ++p)
1176     if (p->is_merge_section(is_string, entsize, addralign))
1177       break;
1178
1179   // We handle the actual constant merging in Output_merge_data or
1180   // Output_merge_string_data.
1181   if (p != this->input_sections_.end())
1182     p->add_input_section(object, shndx);
1183   else
1184     {
1185       Output_section_data* posd;
1186       if (!is_string)
1187         posd = new Output_merge_data(entsize, addralign);
1188       else if (entsize == 1)
1189         posd = new Output_merge_string<char>(addralign);
1190       else if (entsize == 2)
1191         posd = new Output_merge_string<uint16_t>(addralign);
1192       else if (entsize == 4)
1193         posd = new Output_merge_string<uint32_t>(addralign);
1194       else
1195         return false;
1196
1197       this->add_output_merge_section(posd, is_string, entsize);
1198       posd->add_input_section(object, shndx);
1199     }
1200
1201   return true;
1202 }
1203
1204 // Given an address OFFSET relative to the start of input section
1205 // SHNDX in OBJECT, return whether this address is being included in
1206 // the final link.  This should only be called if SHNDX in OBJECT has
1207 // a special mapping.
1208
1209 bool
1210 Output_section::is_input_address_mapped(const Relobj* object,
1211                                         unsigned int shndx,
1212                                         off_t offset) const
1213 {
1214   gold_assert(object->is_section_specially_mapped(shndx));
1215
1216   for (Input_section_list::const_iterator p = this->input_sections_.begin();
1217        p != this->input_sections_.end();
1218        ++p)
1219     {
1220       off_t output_offset;
1221       if (p->output_offset(object, shndx, offset, &output_offset))
1222         return output_offset != -1;
1223     }
1224
1225   // By default we assume that the address is mapped.  This should
1226   // only be called after we have passed all sections to Layout.  At
1227   // that point we should know what we are discarding.
1228   return true;
1229 }
1230
1231 // Given an address OFFSET relative to the start of input section
1232 // SHNDX in object OBJECT, return the output offset relative to the
1233 // start of the section.  This should only be called if SHNDX in
1234 // OBJECT has a special mapping.
1235
1236 off_t
1237 Output_section::output_offset(const Relobj* object, unsigned int shndx,
1238                               off_t offset) const
1239 {
1240   gold_assert(object->is_section_specially_mapped(shndx));
1241   // This can only be called meaningfully when layout is complete.
1242   gold_assert(Output_data::is_layout_complete());
1243
1244   for (Input_section_list::const_iterator p = this->input_sections_.begin();
1245        p != this->input_sections_.end();
1246        ++p)
1247     {
1248       off_t output_offset;
1249       if (p->output_offset(object, shndx, offset, &output_offset))
1250         return output_offset;
1251     }
1252   gold_unreachable();
1253 }
1254
1255 // Return the output virtual address of OFFSET relative to the start
1256 // of input section SHNDX in object OBJECT.
1257
1258 uint64_t
1259 Output_section::output_address(const Relobj* object, unsigned int shndx,
1260                                off_t offset) const
1261 {
1262   gold_assert(object->is_section_specially_mapped(shndx));
1263   // This can only be called meaningfully when layout is complete.
1264   gold_assert(Output_data::is_layout_complete());
1265
1266   uint64_t addr = this->address() + this->first_input_offset_;
1267   for (Input_section_list::const_iterator p = this->input_sections_.begin();
1268        p != this->input_sections_.end();
1269        ++p)
1270     {
1271       addr = align_address(addr, p->addralign());
1272       off_t output_offset;
1273       if (p->output_offset(object, shndx, offset, &output_offset))
1274         {
1275           if (output_offset == -1)
1276             return -1U;
1277           return addr + output_offset;
1278         }
1279       addr += p->data_size();
1280     }
1281
1282   // If we get here, it means that we don't know the mapping for this
1283   // input section.  This might happen in principle if
1284   // add_input_section were called before add_output_section_data.
1285   // But it should never actually happen.
1286
1287   gold_unreachable();
1288 }
1289
1290 // Set the address of an Output_section.  This is where we handle
1291 // setting the addresses of any Output_section_data objects.
1292
1293 void
1294 Output_section::do_set_address(uint64_t address, off_t startoff)
1295 {
1296   if (this->input_sections_.empty())
1297     return;
1298
1299   off_t off = startoff + this->first_input_offset_;
1300   for (Input_section_list::iterator p = this->input_sections_.begin();
1301        p != this->input_sections_.end();
1302        ++p)
1303     {
1304       off = align_address(off, p->addralign());
1305       p->set_address(address + (off - startoff), off, startoff);
1306       off += p->data_size();
1307     }
1308
1309   this->set_data_size(off - startoff);
1310 }
1311
1312 // Write the section header to *OSHDR.
1313
1314 template<int size, bool big_endian>
1315 void
1316 Output_section::write_header(const Layout* layout,
1317                              const Stringpool* secnamepool,
1318                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
1319 {
1320   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
1321   oshdr->put_sh_type(this->type_);
1322   oshdr->put_sh_flags(this->flags_);
1323   oshdr->put_sh_addr(this->address());
1324   oshdr->put_sh_offset(this->offset());
1325   oshdr->put_sh_size(this->data_size());
1326   if (this->link_section_ != NULL)
1327     oshdr->put_sh_link(this->link_section_->out_shndx());
1328   else if (this->should_link_to_symtab_)
1329     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
1330   else if (this->should_link_to_dynsym_)
1331     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
1332   else
1333     oshdr->put_sh_link(this->link_);
1334   if (this->info_section_ != NULL)
1335     oshdr->put_sh_info(this->info_section_->out_shndx());
1336   else
1337     oshdr->put_sh_info(this->info_);
1338   oshdr->put_sh_addralign(this->addralign_);
1339   oshdr->put_sh_entsize(this->entsize_);
1340 }
1341
1342 // Write out the data.  For input sections the data is written out by
1343 // Object::relocate, but we have to handle Output_section_data objects
1344 // here.
1345
1346 void
1347 Output_section::do_write(Output_file* of)
1348 {
1349   off_t output_section_file_offset = this->offset();
1350   for (Fill_list::iterator p = this->fills_.begin();
1351        p != this->fills_.end();
1352        ++p)
1353     {
1354       std::string fill_data(of->target()->code_fill(p->length()));
1355       of->write(output_section_file_offset + p->section_offset(),
1356                 fill_data.data(), fill_data.size());
1357     }
1358
1359   for (Input_section_list::iterator p = this->input_sections_.begin();
1360        p != this->input_sections_.end();
1361        ++p)
1362     p->write(of);
1363 }
1364
1365 // Output segment methods.
1366
1367 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
1368   : output_data_(),
1369     output_bss_(),
1370     vaddr_(0),
1371     paddr_(0),
1372     memsz_(0),
1373     align_(0),
1374     offset_(0),
1375     filesz_(0),
1376     type_(type),
1377     flags_(flags),
1378     is_align_known_(false)
1379 {
1380 }
1381
1382 // Add an Output_section to an Output_segment.
1383
1384 void
1385 Output_segment::add_output_section(Output_section* os,
1386                                    elfcpp::Elf_Word seg_flags,
1387                                    bool front)
1388 {
1389   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1390   gold_assert(!this->is_align_known_);
1391
1392   // Update the segment flags.
1393   this->flags_ |= seg_flags;
1394
1395   Output_segment::Output_data_list* pdl;
1396   if (os->type() == elfcpp::SHT_NOBITS)
1397     pdl = &this->output_bss_;
1398   else
1399     pdl = &this->output_data_;
1400
1401   // So that PT_NOTE segments will work correctly, we need to ensure
1402   // that all SHT_NOTE sections are adjacent.  This will normally
1403   // happen automatically, because all the SHT_NOTE input sections
1404   // will wind up in the same output section.  However, it is possible
1405   // for multiple SHT_NOTE input sections to have different section
1406   // flags, and thus be in different output sections, but for the
1407   // different section flags to map into the same segment flags and
1408   // thus the same output segment.
1409
1410   // Note that while there may be many input sections in an output
1411   // section, there are normally only a few output sections in an
1412   // output segment.  This loop is expected to be fast.
1413
1414   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
1415     {
1416       Output_segment::Output_data_list::iterator p = pdl->end();
1417       do
1418         {
1419           --p;
1420           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
1421             {
1422               // We don't worry about the FRONT parameter.
1423               ++p;
1424               pdl->insert(p, os);
1425               return;
1426             }
1427         }
1428       while (p != pdl->begin());
1429     }
1430
1431   // Similarly, so that PT_TLS segments will work, we need to group
1432   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
1433   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
1434   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
1435   // correctly.
1436   if ((os->flags() & elfcpp::SHF_TLS) != 0 && !this->output_data_.empty())
1437     {
1438       pdl = &this->output_data_;
1439       bool nobits = os->type() == elfcpp::SHT_NOBITS;
1440       bool sawtls = false;
1441       Output_segment::Output_data_list::iterator p = pdl->end();
1442       do
1443         {
1444           --p;
1445           bool insert;
1446           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
1447             {
1448               sawtls = true;
1449               // Put a NOBITS section after the first TLS section.
1450               // But a PROGBITS section after the first TLS/PROGBITS
1451               // section.
1452               insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
1453             }
1454           else
1455             {
1456               // If we've gone past the TLS sections, but we've seen a
1457               // TLS section, then we need to insert this section now.
1458               insert = sawtls;
1459             }
1460
1461           if (insert)
1462             {
1463               // We don't worry about the FRONT parameter.
1464               ++p;
1465               pdl->insert(p, os);
1466               return;
1467             }
1468         }
1469       while (p != pdl->begin());
1470
1471       // There are no TLS sections yet; put this one at the requested
1472       // location in the section list.
1473     }
1474
1475   if (front)
1476     pdl->push_front(os);
1477   else
1478     pdl->push_back(os);
1479 }
1480
1481 // Add an Output_data (which is not an Output_section) to the start of
1482 // a segment.
1483
1484 void
1485 Output_segment::add_initial_output_data(Output_data* od)
1486 {
1487   gold_assert(!this->is_align_known_);
1488   this->output_data_.push_front(od);
1489 }
1490
1491 // Return the maximum alignment of the Output_data in Output_segment.
1492 // Once we compute this, we prohibit new sections from being added.
1493
1494 uint64_t
1495 Output_segment::addralign()
1496 {
1497   if (!this->is_align_known_)
1498     {
1499       uint64_t addralign;
1500
1501       addralign = Output_segment::maximum_alignment(&this->output_data_);
1502       if (addralign > this->align_)
1503         this->align_ = addralign;
1504
1505       addralign = Output_segment::maximum_alignment(&this->output_bss_);
1506       if (addralign > this->align_)
1507         this->align_ = addralign;
1508
1509       this->is_align_known_ = true;
1510     }
1511
1512   return this->align_;
1513 }
1514
1515 // Return the maximum alignment of a list of Output_data.
1516
1517 uint64_t
1518 Output_segment::maximum_alignment(const Output_data_list* pdl)
1519 {
1520   uint64_t ret = 0;
1521   for (Output_data_list::const_iterator p = pdl->begin();
1522        p != pdl->end();
1523        ++p)
1524     {
1525       uint64_t addralign = (*p)->addralign();
1526       if (addralign > ret)
1527         ret = addralign;
1528     }
1529   return ret;
1530 }
1531
1532 // Set the section addresses for an Output_segment.  ADDR is the
1533 // address and *POFF is the file offset.  Set the section indexes
1534 // starting with *PSHNDX.  Return the address of the immediately
1535 // following segment.  Update *POFF and *PSHNDX.
1536
1537 uint64_t
1538 Output_segment::set_section_addresses(uint64_t addr, off_t* poff,
1539                                       unsigned int* pshndx)
1540 {
1541   gold_assert(this->type_ == elfcpp::PT_LOAD);
1542
1543   this->vaddr_ = addr;
1544   this->paddr_ = addr;
1545
1546   off_t orig_off = *poff;
1547   this->offset_ = orig_off;
1548
1549   *poff = align_address(*poff, this->addralign());
1550
1551   addr = this->set_section_list_addresses(&this->output_data_, addr, poff,
1552                                           pshndx);
1553   this->filesz_ = *poff - orig_off;
1554
1555   off_t off = *poff;
1556
1557   uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr,
1558                                                   poff, pshndx);
1559   this->memsz_ = *poff - orig_off;
1560
1561   // Ignore the file offset adjustments made by the BSS Output_data
1562   // objects.
1563   *poff = off;
1564
1565   return ret;
1566 }
1567
1568 // Set the addresses and file offsets in a list of Output_data
1569 // structures.
1570
1571 uint64_t
1572 Output_segment::set_section_list_addresses(Output_data_list* pdl,
1573                                            uint64_t addr, off_t* poff,
1574                                            unsigned int* pshndx)
1575 {
1576   off_t startoff = *poff;
1577
1578   off_t off = startoff;
1579   for (Output_data_list::iterator p = pdl->begin();
1580        p != pdl->end();
1581        ++p)
1582     {
1583       off = align_address(off, (*p)->addralign());
1584       (*p)->set_address(addr + (off - startoff), off);
1585
1586       // Unless this is a PT_TLS segment, we want to ignore the size
1587       // of a SHF_TLS/SHT_NOBITS section.  Such a section does not
1588       // affect the size of a PT_LOAD segment.
1589       if (this->type_ == elfcpp::PT_TLS
1590           || !(*p)->is_section_flag_set(elfcpp::SHF_TLS)
1591           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
1592         off += (*p)->data_size();
1593
1594       if ((*p)->is_section())
1595         {
1596           (*p)->set_out_shndx(*pshndx);
1597           ++*pshndx;
1598         }
1599     }
1600
1601   *poff = off;
1602   return addr + (off - startoff);
1603 }
1604
1605 // For a non-PT_LOAD segment, set the offset from the sections, if
1606 // any.
1607
1608 void
1609 Output_segment::set_offset()
1610 {
1611   gold_assert(this->type_ != elfcpp::PT_LOAD);
1612
1613   if (this->output_data_.empty() && this->output_bss_.empty())
1614     {
1615       this->vaddr_ = 0;
1616       this->paddr_ = 0;
1617       this->memsz_ = 0;
1618       this->align_ = 0;
1619       this->offset_ = 0;
1620       this->filesz_ = 0;
1621       return;
1622     }
1623
1624   const Output_data* first;
1625   if (this->output_data_.empty())
1626     first = this->output_bss_.front();
1627   else
1628     first = this->output_data_.front();
1629   this->vaddr_ = first->address();
1630   this->paddr_ = this->vaddr_;
1631   this->offset_ = first->offset();
1632
1633   if (this->output_data_.empty())
1634     this->filesz_ = 0;
1635   else
1636     {
1637       const Output_data* last_data = this->output_data_.back();
1638       this->filesz_ = (last_data->address()
1639                        + last_data->data_size()
1640                        - this->vaddr_);
1641     }
1642
1643   const Output_data* last;
1644   if (this->output_bss_.empty())
1645     last = this->output_data_.back();
1646   else
1647     last = this->output_bss_.back();
1648   this->memsz_ = (last->address()
1649                   + last->data_size()
1650                   - this->vaddr_);
1651 }
1652
1653 // Return the number of Output_sections in an Output_segment.
1654
1655 unsigned int
1656 Output_segment::output_section_count() const
1657 {
1658   return (this->output_section_count_list(&this->output_data_)
1659           + this->output_section_count_list(&this->output_bss_));
1660 }
1661
1662 // Return the number of Output_sections in an Output_data_list.
1663
1664 unsigned int
1665 Output_segment::output_section_count_list(const Output_data_list* pdl) const
1666 {
1667   unsigned int count = 0;
1668   for (Output_data_list::const_iterator p = pdl->begin();
1669        p != pdl->end();
1670        ++p)
1671     {
1672       if ((*p)->is_section())
1673         ++count;
1674     }
1675   return count;
1676 }
1677
1678 // Write the segment data into *OPHDR.
1679
1680 template<int size, bool big_endian>
1681 void
1682 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
1683 {
1684   ophdr->put_p_type(this->type_);
1685   ophdr->put_p_offset(this->offset_);
1686   ophdr->put_p_vaddr(this->vaddr_);
1687   ophdr->put_p_paddr(this->paddr_);
1688   ophdr->put_p_filesz(this->filesz_);
1689   ophdr->put_p_memsz(this->memsz_);
1690   ophdr->put_p_flags(this->flags_);
1691   ophdr->put_p_align(this->addralign());
1692 }
1693
1694 // Write the section headers into V.
1695
1696 template<int size, bool big_endian>
1697 unsigned char*
1698 Output_segment::write_section_headers(const Layout* layout,
1699                                       const Stringpool* secnamepool,
1700                                       unsigned char* v,
1701                                       unsigned int *pshndx
1702                                       ACCEPT_SIZE_ENDIAN) const
1703 {
1704   // Every section that is attached to a segment must be attached to a
1705   // PT_LOAD segment, so we only write out section headers for PT_LOAD
1706   // segments.
1707   if (this->type_ != elfcpp::PT_LOAD)
1708     return v;
1709
1710   v = this->write_section_headers_list
1711       SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1712           layout, secnamepool, &this->output_data_, v, pshndx
1713           SELECT_SIZE_ENDIAN(size, big_endian));
1714   v = this->write_section_headers_list
1715       SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1716           layout, secnamepool, &this->output_bss_, v, pshndx
1717           SELECT_SIZE_ENDIAN(size, big_endian));
1718   return v;
1719 }
1720
1721 template<int size, bool big_endian>
1722 unsigned char*
1723 Output_segment::write_section_headers_list(const Layout* layout,
1724                                            const Stringpool* secnamepool,
1725                                            const Output_data_list* pdl,
1726                                            unsigned char* v,
1727                                            unsigned int* pshndx
1728                                            ACCEPT_SIZE_ENDIAN) const
1729 {
1730   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
1731   for (Output_data_list::const_iterator p = pdl->begin();
1732        p != pdl->end();
1733        ++p)
1734     {
1735       if ((*p)->is_section())
1736         {
1737           const Output_section* ps = static_cast<const Output_section*>(*p);
1738           gold_assert(*pshndx == ps->out_shndx());
1739           elfcpp::Shdr_write<size, big_endian> oshdr(v);
1740           ps->write_header(layout, secnamepool, &oshdr);
1741           v += shdr_size;
1742           ++*pshndx;
1743         }
1744     }
1745   return v;
1746 }
1747
1748 // Output_file methods.
1749
1750 Output_file::Output_file(const General_options& options, Target* target)
1751   : options_(options),
1752     target_(target),
1753     name_(options.output_file_name()),
1754     o_(-1),
1755     file_size_(0),
1756     base_(NULL)
1757 {
1758 }
1759
1760 // Open the output file.
1761
1762 void
1763 Output_file::open(off_t file_size)
1764 {
1765   this->file_size_ = file_size;
1766
1767   // Unlink the file first; otherwise the open() may fail if the file
1768   // is busy (e.g. it's an executable that's currently being executed).
1769   //
1770   // However, the linker may be part of a system where a zero-length
1771   // file is created for it to write to, with tight permissions (gcc
1772   // 2.95 did something like this).  Unlinking the file would work
1773   // around those permission controls, so we only unlink if the file
1774   // has a non-zero size.  We also unlink only regular files to avoid
1775   // trouble with directories/etc.
1776   //
1777   // If we fail, continue; this command is merely a best-effort attempt
1778   // to improve the odds for open().
1779
1780   struct stat s;
1781   if (::stat(this->name_, &s) == 0 && s.st_size != 0)
1782     unlink_if_ordinary(this->name_);
1783
1784   int mode = parameters->output_is_object() ? 0666 : 0777;
1785   int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
1786   if (o < 0)
1787     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
1788   this->o_ = o;
1789
1790   // Write out one byte to make the file the right size.
1791   if (::lseek(o, file_size - 1, SEEK_SET) < 0)
1792     gold_fatal(_("%s: lseek: %s"), this->name_, strerror(errno));
1793   char b = 0;
1794   if (::write(o, &b, 1) != 1)
1795     gold_fatal(_("%s: write: %s"), this->name_, strerror(errno));
1796
1797   // Map the file into memory.
1798   void* base = ::mmap(NULL, file_size, PROT_READ | PROT_WRITE,
1799                       MAP_SHARED, o, 0);
1800   if (base == MAP_FAILED)
1801     gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
1802   this->base_ = static_cast<unsigned char*>(base);
1803 }
1804
1805 // Close the output file.
1806
1807 void
1808 Output_file::close()
1809 {
1810   if (::munmap(this->base_, this->file_size_) < 0)
1811     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
1812   this->base_ = NULL;
1813
1814   if (::close(this->o_) < 0)
1815     gold_error(_("%s: close: %s"), this->name_, strerror(errno));
1816   this->o_ = -1;
1817 }
1818
1819 // Instantiate the templates we need.  We could use the configure
1820 // script to restrict this to only the ones for implemented targets.
1821
1822 #ifdef HAVE_TARGET_32_LITTLE
1823 template
1824 off_t
1825 Output_section::add_input_section<32, false>(
1826     Sized_relobj<32, false>* object,
1827     unsigned int shndx,
1828     const char* secname,
1829     const elfcpp::Shdr<32, false>& shdr,
1830     unsigned int reloc_shndx);
1831 #endif
1832
1833 #ifdef HAVE_TARGET_32_BIG
1834 template
1835 off_t
1836 Output_section::add_input_section<32, true>(
1837     Sized_relobj<32, true>* object,
1838     unsigned int shndx,
1839     const char* secname,
1840     const elfcpp::Shdr<32, true>& shdr,
1841     unsigned int reloc_shndx);
1842 #endif
1843
1844 #ifdef HAVE_TARGET_64_LITTLE
1845 template
1846 off_t
1847 Output_section::add_input_section<64, false>(
1848     Sized_relobj<64, false>* object,
1849     unsigned int shndx,
1850     const char* secname,
1851     const elfcpp::Shdr<64, false>& shdr,
1852     unsigned int reloc_shndx);
1853 #endif
1854
1855 #ifdef HAVE_TARGET_64_BIG
1856 template
1857 off_t
1858 Output_section::add_input_section<64, true>(
1859     Sized_relobj<64, true>* object,
1860     unsigned int shndx,
1861     const char* secname,
1862     const elfcpp::Shdr<64, true>& shdr,
1863     unsigned int reloc_shndx);
1864 #endif
1865
1866 #ifdef HAVE_TARGET_32_LITTLE
1867 template
1868 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
1869 #endif
1870
1871 #ifdef HAVE_TARGET_32_BIG
1872 template
1873 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
1874 #endif
1875
1876 #ifdef HAVE_TARGET_64_LITTLE
1877 template
1878 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
1879 #endif
1880
1881 #ifdef HAVE_TARGET_64_BIG
1882 template
1883 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
1884 #endif
1885
1886 #ifdef HAVE_TARGET_32_LITTLE
1887 template
1888 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
1889 #endif
1890
1891 #ifdef HAVE_TARGET_32_BIG
1892 template
1893 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
1894 #endif
1895
1896 #ifdef HAVE_TARGET_64_LITTLE
1897 template
1898 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
1899 #endif
1900
1901 #ifdef HAVE_TARGET_64_BIG
1902 template
1903 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
1904 #endif
1905
1906 #ifdef HAVE_TARGET_32_LITTLE
1907 template
1908 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
1909 #endif
1910
1911 #ifdef HAVE_TARGET_32_BIG
1912 template
1913 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
1914 #endif
1915
1916 #ifdef HAVE_TARGET_64_LITTLE
1917 template
1918 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
1919 #endif
1920
1921 #ifdef HAVE_TARGET_64_BIG
1922 template
1923 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
1924 #endif
1925
1926 #ifdef HAVE_TARGET_32_LITTLE
1927 template
1928 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
1929 #endif
1930
1931 #ifdef HAVE_TARGET_32_BIG
1932 template
1933 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
1934 #endif
1935
1936 #ifdef HAVE_TARGET_64_LITTLE
1937 template
1938 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
1939 #endif
1940
1941 #ifdef HAVE_TARGET_64_BIG
1942 template
1943 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
1944 #endif
1945
1946 #ifdef HAVE_TARGET_32_LITTLE
1947 template
1948 class Output_data_got<32, false>;
1949 #endif
1950
1951 #ifdef HAVE_TARGET_32_BIG
1952 template
1953 class Output_data_got<32, true>;
1954 #endif
1955
1956 #ifdef HAVE_TARGET_64_LITTLE
1957 template
1958 class Output_data_got<64, false>;
1959 #endif
1960
1961 #ifdef HAVE_TARGET_64_BIG
1962 template
1963 class Output_data_got<64, true>;
1964 #endif
1965
1966 } // End namespace gold.