gold/reloc.cc

   1 // reloc.cc -- relocate input files for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009 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 <algorithm>
  26
  27 #include "workqueue.h"
  28 #include "symtab.h"
  29 #include "output.h"
  30 #include "merge.h"
  31 #include "object.h"
  32 #include "target-reloc.h"
  33 #include "reloc.h"
  34 #include "icf.h"
  35
  36 namespace gold
  37 {
  38
  39 // Read_relocs methods.
  40
  41 // These tasks just read the relocation information from the file.
  42 // After reading it, the start another task to process the
  43 // information.  These tasks requires access to the file.
  44
  45 Task_token*
  46 Read_relocs::is_runnable()
  47 {
  48   return this->object_->is_locked() ? this->object_->token() : NULL;
  49 }
  50
  51 // Lock the file.
  52
  53 void
  54 Read_relocs::locks(Task_locker* tl)
  55 {
  56   tl->add(this, this->object_->token());
  57 }
  58
  59 // Read the relocations and then start a Scan_relocs_task.
  60
  61 void
  62 Read_relocs::run(Workqueue* workqueue)
  63 {
  64   Read_relocs_data *rd = new Read_relocs_data;
  65   this->object_->read_relocs(rd);
  66   this->object_->set_relocs_data(rd);
  67   this->object_->release();
  68
  69   // If garbage collection or identical comdat folding is desired, we
  70   // process the relocs first before scanning them.  Scanning of relocs is
  71   // done only after garbage or identical sections is identified.
  72   if (parameters->options().gc_sections()
  73       || parameters->options().icf_enabled())
  74     {
  75       workqueue->queue_next(new Gc_process_relocs(this->symtab_,
  76                                                   this->layout_,
  77                                                   this->object_, rd,
  78                                                   this->symtab_lock_,
  79                                                   this->blocker_));
  80     }
  81   else
  82     {
  83       workqueue->queue_next(new Scan_relocs(this->symtab_, this->layout_,
  84                                             this->object_, rd,
  85                                             this->symtab_lock_,
  86                                             this->blocker_));
  87     }
  88 }
  89
  90 // Return a debugging name for the task.
  91
  92 std::string
  93 Read_relocs::get_name() const
  94 {
  95   return "Read_relocs " + this->object_->name();
  96 }
  97
  98 // Gc_process_relocs methods.
  99
 100 // These tasks process the relocations read by Read_relocs and
 101 // determine which sections are referenced and which are garbage.
 102 // This task is done only when --gc-sections is used.
 103
 104 Task_token*
 105 Gc_process_relocs::is_runnable()
 106 {
 107   if (this->object_->is_locked())
 108     return this->object_->token();
 109   return NULL;
 110 }
 111
 112 void
 113 Gc_process_relocs::locks(Task_locker* tl)
 114 {
 115   tl->add(this, this->object_->token());
 116   tl->add(this, this->blocker_);
 117 }
 118
 119 void
 120 Gc_process_relocs::run(Workqueue*)
 121 {
 122   this->object_->gc_process_relocs(this->symtab_, this->layout_, this->rd_);
 123   this->object_->release();
 124 }
 125
 126 // Return a debugging name for the task.
 127
 128 std::string
 129 Gc_process_relocs::get_name() const
 130 {
 131   return "Gc_process_relocs " + this->object_->name();
 132 }
 133
 134 // Scan_relocs methods.
 135
 136 // These tasks scan the relocations read by Read_relocs and mark up
 137 // the symbol table to indicate which relocations are required.  We
 138 // use a lock on the symbol table to keep them from interfering with
 139 // each other.
 140
 141 Task_token*
 142 Scan_relocs::is_runnable()
 143 {
 144   if (!this->symtab_lock_->is_writable())
 145     return this->symtab_lock_;
 146   if (this->object_->is_locked())
 147     return this->object_->token();
 148   return NULL;
 149 }
 150
 151 // Return the locks we hold: one on the file, one on the symbol table
 152 // and one blocker.
 153
 154 void
 155 Scan_relocs::locks(Task_locker* tl)
 156 {
 157   tl->add(this, this->object_->token());
 158   tl->add(this, this->symtab_lock_);
 159   tl->add(this, this->blocker_);
 160 }
 161
 162 // Scan the relocs.
 163
 164 void
 165 Scan_relocs::run(Workqueue*)
 166 {
 167   this->object_->scan_relocs(this->symtab_, this->layout_, this->rd_);
 168   this->object_->release();
 169   delete this->rd_;
 170   this->rd_ = NULL;
 171 }
 172
 173 // Return a debugging name for the task.
 174
 175 std::string
 176 Scan_relocs::get_name() const
 177 {
 178   return "Scan_relocs " + this->object_->name();
 179 }
 180
 181 // Relocate_task methods.
 182
 183 // We may have to wait for the output sections to be written.
 184
 185 Task_token*
 186 Relocate_task::is_runnable()
 187 {
 188   if (this->object_->relocs_must_follow_section_writes()
 189       && this->output_sections_blocker_->is_blocked())
 190     return this->output_sections_blocker_;
 191
 192   if (this->object_->is_locked())
 193     return this->object_->token();
 194
 195   return NULL;
 196 }
 197
 198 // We want to lock the file while we run.  We want to unblock
 199 // INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done.
 200 // INPUT_SECTIONS_BLOCKER may be NULL.
 201
 202 void
 203 Relocate_task::locks(Task_locker* tl)
 204 {
 205   if (this->input_sections_blocker_ != NULL)
 206     tl->add(this, this->input_sections_blocker_);
 207   tl->add(this, this->final_blocker_);
 208   tl->add(this, this->object_->token());
 209 }
 210
 211 // Run the task.
 212
 213 void
 214 Relocate_task::run(Workqueue*)
 215 {
 216   this->object_->relocate(this->symtab_, this->layout_, this->of_);
 217
 218   // This is normally the last thing we will do with an object, so
 219   // uncache all views.
 220   this->object_->clear_view_cache_marks();
 221
 222   this->object_->release();
 223 }
 224
 225 // Return a debugging name for the task.
 226
 227 std::string
 228 Relocate_task::get_name() const
 229 {
 230   return "Relocate_task " + this->object_->name();
 231 }
 232
 233 // Read the relocs and local symbols from the object file and store
 234 // the information in RD.
 235
 236 template<int size, bool big_endian>
 237 void
 238 Sized_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd)
 239 {
 240   rd->relocs.clear();
 241
 242   unsigned int sec_shnum = this->shnum();
 243   if (sec_shnum == 0)
 244     return;
 245
 246   rd->relocs.reserve(sec_shnum / 2);
 247
 248   const Output_sections& out_sections(this->output_sections());
 249   const std::vector<Address>& out_offsets(this->section_offsets_);
 250
 251   const unsigned char *pshdrs = this->get_view(this->elf_file_.shoff(),
 252                                                sec_shnum * This::shdr_size,
 253                                                true, true);
 254   // Skip the first, dummy, section.
 255   const unsigned char *ps = pshdrs + This::shdr_size;
 256   for (unsigned int i = 1; i < sec_shnum; ++i, ps += This::shdr_size)
 257     {
 258       typename This::Shdr shdr(ps);
 259
 260       unsigned int sh_type = shdr.get_sh_type();
 261       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 262         continue;
 263
 264       unsigned int shndx = this->adjust_shndx(shdr.get_sh_info());
 265       if (shndx >= sec_shnum)
 266         {
 267           this->error(_("relocation section %u has bad info %u"),
 268                       i, shndx);
 269           continue;
 270         }
 271
 272       Output_section* os = out_sections[shndx];
 273       if (os == NULL)
 274         continue;
 275
 276       // We are scanning relocations in order to fill out the GOT and
 277       // PLT sections.  Relocations for sections which are not
 278       // allocated (typically debugging sections) should not add new
 279       // GOT and PLT entries.  So we skip them unless this is a
 280       // relocatable link or we need to emit relocations.  FIXME: What
 281       // should we do if a linker script maps a section with SHF_ALLOC
 282       // clear to a section with SHF_ALLOC set?
 283       typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
 284       bool is_section_allocated = ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC)
 285                                    != 0);
 286       if (!is_section_allocated
 287           && !parameters->options().relocatable()
 288           && !parameters->options().emit_relocs())
 289         continue;
 290
 291       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 292         {
 293           this->error(_("relocation section %u uses unexpected "
 294                         "symbol table %u"),
 295                       i, this->adjust_shndx(shdr.get_sh_link()));
 296           continue;
 297         }
 298
 299       off_t sh_size = shdr.get_sh_size();
 300
 301       unsigned int reloc_size;
 302       if (sh_type == elfcpp::SHT_REL)
 303         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 304       else
 305         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 306       if (reloc_size != shdr.get_sh_entsize())
 307         {
 308           this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
 309                       i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 310                       reloc_size);
 311           continue;
 312         }
 313
 314       size_t reloc_count = sh_size / reloc_size;
 315       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 316         {
 317           this->error(_("reloc section %u size %lu uneven"),
 318                       i, static_cast<unsigned long>(sh_size));
 319           continue;
 320         }
 321
 322       rd->relocs.push_back(Section_relocs());
 323       Section_relocs& sr(rd->relocs.back());
 324       sr.reloc_shndx = i;
 325       sr.data_shndx = shndx;
 326       sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
 327                                            true, true);
 328       sr.sh_type = sh_type;
 329       sr.reloc_count = reloc_count;
 330       sr.output_section = os;
 331       sr.needs_special_offset_handling = out_offsets[shndx] == invalid_address;
 332       sr.is_data_section_allocated = is_section_allocated;
 333     }
 334
 335   // Read the local symbols.
 336   gold_assert(this->symtab_shndx_ != -1U);
 337   if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
 338     rd->local_symbols = NULL;
 339   else
 340     {
 341       typename This::Shdr symtabshdr(pshdrs
 342                                      + this->symtab_shndx_ * This::shdr_size);
 343       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 344       const int symsize = This::sym_size;
 345       const unsigned int loccount = this->local_symbol_count_;
 346       gold_assert(loccount == symtabshdr.get_sh_info());
 347       off_t locsize = loccount * symsize;
 348       rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
 349                                                  locsize, true, true);
 350     }
 351 }
 352
 353 // Process the relocs to generate mappings from source sections to referenced
 354 // sections.  This is used during garbage colletion to determine garbage
 355 // sections.
 356
 357 template<int size, bool big_endian>
 358 void
 359 Sized_relobj<size, big_endian>::do_gc_process_relocs(Symbol_table* symtab,
 360                                                      Layout* alayout,
 361                                                      Read_relocs_data* rd)
 362 {
 363   Sized_target<size, big_endian>* target =
 364     parameters->sized_target<size, big_endian>();
 365
 366   const unsigned char* local_symbols;
 367   if (rd->local_symbols == NULL)
 368     local_symbols = NULL;
 369   else
 370     local_symbols = rd->local_symbols->data();
 371
 372   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 373        p != rd->relocs.end();
 374        ++p)
 375     {
 376       if (!parameters->options().relocatable())
 377           {
 378             // As noted above, when not generating an object file, we
 379             // only scan allocated sections.  We may see a non-allocated
 380             // section here if we are emitting relocs.
 381             if (p->is_data_section_allocated)
 382               target->gc_process_relocs(symtab, alayout, this,
 383                                         p->data_shndx, p->sh_type,
 384                                         p->contents->data(), p->reloc_count,
 385                                         p->output_section,
 386                                         p->needs_special_offset_handling,
 387                                         this->local_symbol_count_,
 388                                         local_symbols);
 389         }
 390     }
 391 }
 392
 393
 394 // Scan the relocs and adjust the symbol table.  This looks for
 395 // relocations which require GOT/PLT/COPY relocations.
 396
 397 template<int size, bool big_endian>
 398 void
 399 Sized_relobj<size, big_endian>::do_scan_relocs(Symbol_table* symtab,
 400                                                Layout* alayout,
 401                                                Read_relocs_data* rd)
 402 {
 403   Sized_target<size, big_endian>* target =
 404     parameters->sized_target<size, big_endian>();
 405
 406   const unsigned char* local_symbols;
 407   if (rd->local_symbols == NULL)
 408     local_symbols = NULL;
 409   else
 410     local_symbols = rd->local_symbols->data();
 411
 412   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 413        p != rd->relocs.end();
 414        ++p)
 415     {
 416       // When garbage collection is on, unreferenced sections are not included
 417       // in the link that would have been included normally. This is known only
 418       // after Read_relocs hence this check has to be done again.
 419       if (parameters->options().gc_sections()
 420           || parameters->options().icf_enabled())
 421         {
 422           if (p->output_section == NULL)
 423             continue;
 424         }
 425       if (!parameters->options().relocatable())
 426         {
 427           // As noted above, when not generating an object file, we
 428           // only scan allocated sections.  We may see a non-allocated
 429           // section here if we are emitting relocs.
 430           if (p->is_data_section_allocated)
 431             target->scan_relocs(symtab, alayout, this, p->data_shndx,
 432                                 p->sh_type, p->contents->data(),
 433                                 p->reloc_count, p->output_section,
 434                                 p->needs_special_offset_handling,
 435                                 this->local_symbol_count_,
 436                                 local_symbols);
 437           if (parameters->options().emit_relocs())
 438             this->emit_relocs_scan(symtab, alayout, local_symbols, p);
 439         }
 440       else
 441         {
 442           Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 443           gold_assert(rr != NULL);
 444           rr->set_reloc_count(p->reloc_count);
 445           target->scan_relocatable_relocs(symtab, alayout, this,
 446                                           p->data_shndx, p->sh_type,
 447                                           p->contents->data(),
 448                                           p->reloc_count,
 449                                           p->output_section,
 450                                           p->needs_special_offset_handling,
 451                                           this->local_symbol_count_,
 452                                           local_symbols,
 453                                           rr);
 454         }
 455
 456       delete p->contents;
 457       p->contents = NULL;
 458     }
 459
 460   if (rd->local_symbols != NULL)
 461     {
 462       delete rd->local_symbols;
 463       rd->local_symbols = NULL;
 464     }
 465 }
 466
 467 // This is a strategy class we use when scanning for --emit-relocs.
 468
 469 template<int sh_type>
 470 class Emit_relocs_strategy
 471 {
 472  public:
 473   // A local non-section symbol.
 474   inline Relocatable_relocs::Reloc_strategy
 475   local_non_section_strategy(unsigned int, Relobj*, unsigned int)
 476   { return Relocatable_relocs::RELOC_COPY; }
 477
 478   // A local section symbol.
 479   inline Relocatable_relocs::Reloc_strategy
 480   local_section_strategy(unsigned int, Relobj*)
 481   {
 482     if (sh_type == elfcpp::SHT_RELA)
 483       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
 484     else
 485       {
 486         // The addend is stored in the section contents.  Since this
 487         // is not a relocatable link, we are going to apply the
 488         // relocation contents to the section as usual.  This means
 489         // that we have no way to record the original addend.  If the
 490         // original addend is not zero, there is basically no way for
 491         // the user to handle this correctly.  Caveat emptor.
 492         return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
 493       }
 494   }
 495
 496   // A global symbol.
 497   inline Relocatable_relocs::Reloc_strategy
 498   global_strategy(unsigned int, Relobj*, unsigned int)
 499   { return Relocatable_relocs::RELOC_COPY; }
 500 };
 501
 502 // Scan the input relocations for --emit-relocs.
 503
 504 template<int size, bool big_endian>
 505 void
 506 Sized_relobj<size, big_endian>::emit_relocs_scan(
 507     Symbol_table* symtab,
 508     Layout* alayout,
 509     const unsigned char* plocal_syms,
 510     const Read_relocs_data::Relocs_list::iterator& p)
 511 {
 512   Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 513   gold_assert(rr != NULL);
 514   rr->set_reloc_count(p->reloc_count);
 515
 516   if (p->sh_type == elfcpp::SHT_REL)
 517     this->emit_relocs_scan_reltype<elfcpp::SHT_REL>(symtab, alayout,
 518                                                     plocal_syms, p, rr);
 519   else
 520     {
 521       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 522       this->emit_relocs_scan_reltype<elfcpp::SHT_RELA>(symtab, alayout,
 523                                                        plocal_syms, p, rr);
 524     }
 525 }
 526
 527 // Scan the input relocation for --emit-relocs, templatized on the
 528 // type of the relocation section.
 529
 530 template<int size, bool big_endian>
 531 template<int sh_type>
 532 void
 533 Sized_relobj<size, big_endian>::emit_relocs_scan_reltype(
 534     Symbol_table* symtab,
 535     Layout* alayout,
 536     const unsigned char* plocal_syms,
 537     const Read_relocs_data::Relocs_list::iterator& p,
 538     Relocatable_relocs* rr)
 539 {
 540   scan_relocatable_relocs<size, big_endian, sh_type,
 541                           Emit_relocs_strategy<sh_type> >(
 542     symtab,
 543     alayout,
 544     this,
 545     p->data_shndx,
 546     p->contents->data(),
 547     p->reloc_count,
 548     p->output_section,
 549     p->needs_special_offset_handling,
 550     this->local_symbol_count_,
 551     plocal_syms,
 552     rr);
 553 }
 554
 555 // Relocate the input sections and write out the local symbols.
 556
 557 template<int size, bool big_endian>
 558 void
 559 Sized_relobj<size, big_endian>::do_relocate(const Symbol_table* symtab,
 560                                             const Layout* alayout,
 561                                             Output_file* of)
 562 {
 563   unsigned int sec_shnum = this->shnum();
 564
 565   // Read the section headers.
 566   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 567                                                sec_shnum * This::shdr_size,
 568                                                true, true);
 569
 570   Views views;
 571   views.resize(sec_shnum);
 572
 573   // Make two passes over the sections.  The first one copies the
 574   // section data to the output file.  The second one applies
 575   // relocations.
 576
 577   this->write_sections(pshdrs, of, &views);
 578
 579   // To speed up relocations, we set up hash tables for fast lookup of
 580   // input offsets to output addresses.
 581   this->initialize_input_to_output_maps();
 582
 583   // Apply relocations.
 584
 585   this->relocate_sections(symtab, alayout, pshdrs, &views);
 586
 587   // After we've done the relocations, we release the hash tables,
 588   // since we no longer need them.
 589   this->free_input_to_output_maps();
 590
 591   // Write out the accumulated views.
 592   for (unsigned int i = 1; i < sec_shnum; ++i)
 593     {
 594       if (views[i].view != NULL)
 595         {
 596           if (!views[i].is_postprocessing_view)
 597             {
 598               if (views[i].is_input_output_view)
 599                 of->write_input_output_view(views[i].offset,
 600                                             views[i].view_size,
 601                                             views[i].view);
 602               else
 603                 of->write_output_view(views[i].offset, views[i].view_size,
 604                                       views[i].view);
 605             }
 606         }
 607     }
 608
 609   // Write out the local symbols.
 610   this->write_local_symbols(of, alayout->sympool(), alayout->dynpool(),
 611                             alayout->symtab_xindex(), alayout->dynsym_xindex());
 612
 613   // We should no longer need the local symbol values.
 614   this->clear_local_symbols();
 615 }
 616
 617 // Sort a Read_multiple vector by file offset.
 618 struct Read_multiple_compare
 619 {
 620   inline bool
 621   operator()(const File_read::Read_multiple_entry& rme1,
 622              const File_read::Read_multiple_entry& rme2) const
 623   { return rme1.file_offset < rme2.file_offset; }
 624 };
 625
 626 // Write section data to the output file.  PSHDRS points to the
 627 // section headers.  Record the views in *PVIEWS for use when
 628 // relocating.
 629
 630 template<int size, bool big_endian>
 631 void
 632 Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
 633                                                Output_file* of,
 634                                                Views* pviews)
 635 {
 636   unsigned int sec_shnum = this->shnum();
 637   const Output_sections& out_sections(this->output_sections());
 638   const std::vector<Address>& out_offsets(this->section_offsets_);
 639
 640   File_read::Read_multiple rm;
 641   bool is_sorted = true;
 642
 643   const unsigned char* p = pshdrs + This::shdr_size;
 644   for (unsigned int i = 1; i < sec_shnum; ++i, p += This::shdr_size)
 645     {
 646       View_size* pvs = &(*pviews)[i];
 647
 648       pvs->view = NULL;
 649
 650       const Output_section* os = out_sections[i];
 651       if (os == NULL)
 652         continue;
 653       Address output_offset = out_offsets[i];
 654
 655       typename This::Shdr shdr(p);
 656
 657       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 658         continue;
 659
 660       if ((parameters->options().relocatable()
 661            || parameters->options().emit_relocs())
 662           && (shdr.get_sh_type() == elfcpp::SHT_REL
 663               || shdr.get_sh_type() == elfcpp::SHT_RELA)
 664           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 665         {
 666           // This is a reloc section in a relocatable link or when
 667           // emitting relocs.  We don't need to read the input file.
 668           // The size and file offset are stored in the
 669           // Relocatable_relocs structure.
 670           Relocatable_relocs* rr = this->relocatable_relocs(i);
 671           gold_assert(rr != NULL);
 672           Output_data* posd = rr->output_data();
 673           gold_assert(posd != NULL);
 674
 675           pvs->offset = posd->offset();
 676           pvs->view_size = posd->data_size();
 677           pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
 678           pvs->address = posd->address();
 679           pvs->is_input_output_view = false;
 680           pvs->is_postprocessing_view = false;
 681
 682           continue;
 683         }
 684
 685       // In the normal case, this input section is simply mapped to
 686       // the output section at offset OUTPUT_OFFSET.
 687
 688       // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is
 689       // handled specially--e.g., a .eh_frame section.  The relocation
 690       // routines need to check for each reloc where it should be
 691       // applied.  For this case, we need an input/output view for the
 692       // entire contents of the section in the output file.  We don't
 693       // want to copy the contents of the input section to the output
 694       // section; the output section contents were already written,
 695       // and we waited for them in Relocate_task::is_runnable because
 696       // relocs_must_follow_section_writes is set for the object.
 697
 698       // Regardless of which of the above cases is true, we have to
 699       // check requires_postprocessing of the output section.  If that
 700       // is false, then we work with views of the output file
 701       // directly.  If it is true, then we work with a separate
 702       // buffer, and the output section is responsible for writing the
 703       // final data to the output file.
 704
 705       off_t out_section_offset;
 706       Address output_section_size;
 707       if (!os->requires_postprocessing())
 708         {
 709           out_section_offset = os->offset();
 710           output_section_size = convert_types<Address, off_t>(os->data_size());
 711         }
 712       else
 713         {
 714           out_section_offset = 0;
 715           output_section_size =
 716               convert_types<Address, off_t>(os->postprocessing_buffer_size());
 717         }
 718
 719       off_t view_start;
 720       section_size_type view_size;
 721       if (output_offset != invalid_address)
 722         {
 723           view_start = out_section_offset + output_offset;
 724           view_size = convert_to_section_size_type(shdr.get_sh_size());
 725         }
 726       else
 727         {
 728           view_start = out_section_offset;
 729           view_size = convert_to_section_size_type(output_section_size);
 730         }
 731
 732       if (view_size == 0)
 733         continue;
 734
 735       gold_assert(output_offset == invalid_address
 736                   || output_offset + view_size <= output_section_size);
 737
 738       unsigned char* aview;
 739       if (os->requires_postprocessing())
 740         {
 741           unsigned char* buffer = os->postprocessing_buffer();
 742           aview = buffer + view_start;
 743           if (output_offset != invalid_address)
 744             {
 745               off_t sh_offset = shdr.get_sh_offset();
 746               if (!rm.empty() && rm.back().file_offset > sh_offset)
 747                 is_sorted = false;
 748               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 749                                                           view_size, aview));
 750             }
 751         }
 752       else
 753         {
 754           if (output_offset == invalid_address)
 755             aview = of->get_input_output_view(view_start, view_size);
 756           else
 757             {
 758               aview = of->get_output_view(view_start, view_size);
 759               off_t sh_offset = shdr.get_sh_offset();
 760               if (!rm.empty() && rm.back().file_offset > sh_offset)
 761                 is_sorted = false;
 762               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 763                                                           view_size, aview));
 764             }
 765         }
 766
 767       pvs->view = aview;
 768       pvs->address = os->address();
 769       if (output_offset != invalid_address)
 770         pvs->address += output_offset;
 771       pvs->offset = view_start;
 772       pvs->view_size = view_size;
 773       pvs->is_input_output_view = output_offset == invalid_address;
 774       pvs->is_postprocessing_view = os->requires_postprocessing();
 775     }
 776
 777   // Actually read the data.
 778   if (!rm.empty())
 779     {
 780       if (!is_sorted)
 781         std::sort(rm.begin(), rm.end(), Read_multiple_compare());
 782       this->read_multiple(rm);
 783     }
 784 }
 785
 786 // Relocate section data.  VIEWS points to the section data as views
 787 // in the output file.
 788
 789 template<int size, bool big_endian>
 790 void
 791 Sized_relobj<size, big_endian>::do_relocate_sections(
 792     const Symbol_table* symtab,
 793     const Layout* alayout,
 794     const unsigned char* pshdrs,
 795     Views* pviews)
 796 {
 797   unsigned int sec_shnum = this->shnum();
 798   Sized_target<size, big_endian>* target =
 799     parameters->sized_target<size, big_endian>();
 800
 801   const Output_sections& out_sections(this->output_sections());
 802   const std::vector<Address>& out_offsets(this->section_offsets_);
 803
 804   Relocate_info<size, big_endian> relinfo;
 805   relinfo.symtab = symtab;
 806   relinfo.layout = alayout;
 807   relinfo.object = this;
 808
 809   const unsigned char* p = pshdrs + This::shdr_size;
 810   for (unsigned int i = 1; i < sec_shnum; ++i, p += This::shdr_size)
 811     {
 812       typename This::Shdr shdr(p);
 813
 814       unsigned int sh_type = shdr.get_sh_type();
 815       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 816         continue;
 817
 818       off_t sh_size = shdr.get_sh_size();
 819       if (sh_size == 0)
 820         continue;
 821
 822       unsigned int index = this->adjust_shndx(shdr.get_sh_info());
 823       if (index >= this->shnum())
 824         {
 825           this->error(_("relocation section %u has bad info %u"),
 826                       i, index);
 827           continue;
 828         }
 829
 830       Output_section* os = out_sections[index];
 831       if (os == NULL)
 832         {
 833           // This relocation section is against a section which we
 834           // discarded.
 835           continue;
 836         }
 837       Address output_offset = out_offsets[index];
 838
 839       gold_assert((*pviews)[index].view != NULL);
 840       if (parameters->options().relocatable())
 841         gold_assert((*pviews)[i].view != NULL);
 842
 843       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 844         {
 845           gold_error(_("relocation section %u uses unexpected "
 846                        "symbol table %u"),
 847                      i, this->adjust_shndx(shdr.get_sh_link()));
 848           continue;
 849         }
 850
 851       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 852                                                     sh_size, true, false);
 853
 854       unsigned int reloc_size;
 855       if (sh_type == elfcpp::SHT_REL)
 856         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 857       else
 858         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 859
 860       if (reloc_size != shdr.get_sh_entsize())
 861         {
 862           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 863                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 864                      reloc_size);
 865           continue;
 866         }
 867
 868       size_t reloc_count = sh_size / reloc_size;
 869       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 870         {
 871           gold_error(_("reloc section %u size %lu uneven"),
 872                      i, static_cast<unsigned long>(sh_size));
 873           continue;
 874         }
 875
 876       gold_assert(output_offset != invalid_address
 877                   || this->relocs_must_follow_section_writes());
 878
 879       relinfo.reloc_shndx = i;
 880       relinfo.reloc_shdr = p;
 881       relinfo.data_shndx = index;
 882       relinfo.data_shdr = pshdrs + index * This::shdr_size;
 883       unsigned char* aview = (*pviews)[index].view;
 884       Address address = (*pviews)[index].address;
 885       section_size_type view_size = (*pviews)[index].view_size;
 886
 887       Reloc_symbol_changes* reloc_map = NULL;
 888       if (this->uses_split_stack() && output_offset != invalid_address)
 889         {
 890           typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
 891           if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
 892             this->split_stack_adjust(symtab, pshdrs, sh_type, index,
 893                                      prelocs, reloc_count, aview, view_size,
 894                                      &reloc_map);
 895         }
 896
 897       if (!parameters->options().relocatable())
 898         {
 899           target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
 900                                    output_offset == invalid_address,
 901                                    aview, address, view_size, reloc_map);
 902           if (parameters->options().emit_relocs())
 903             this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count,
 904                               os, output_offset, aview, address, view_size,
 905                               (*pviews)[i].view, (*pviews)[i].view_size);
 906         }
 907       else
 908         {
 909           Relocatable_relocs* rr = this->relocatable_relocs(i);
 910           target->relocate_for_relocatable(&relinfo, sh_type, prelocs,
 911                                            reloc_count, os, output_offset, rr,
 912                                            aview, address, view_size,
 913                                            (*pviews)[i].view,
 914                                            (*pviews)[i].view_size);
 915         }
 916     }
 917 }
 918
 919 // Emit the relocs for --emit-relocs.
 920
 921 template<int size, bool big_endian>
 922 void
 923 Sized_relobj<size, big_endian>::emit_relocs(
 924     const Relocate_info<size, big_endian>* relinfo,
 925     unsigned int i,
 926     unsigned int sh_type,
 927     const unsigned char* prelocs,
 928     size_t reloc_count,
 929     Output_section* aoutput_section,
 930     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
 931     unsigned char* aview,
 932     typename elfcpp::Elf_types<size>::Elf_Addr address,
 933     section_size_type view_size,
 934     unsigned char* reloc_view,
 935     section_size_type reloc_view_size)
 936 {
 937   if (sh_type == elfcpp::SHT_REL)
 938     this->emit_relocs_reltype<elfcpp::SHT_REL>(relinfo, i, prelocs,
 939                                                reloc_count, aoutput_section,
 940                                                offset_in_output_section,
 941                                                aview, address, view_size,
 942                                                reloc_view, reloc_view_size);
 943   else
 944     {
 945       gold_assert(sh_type == elfcpp::SHT_RELA);
 946       this->emit_relocs_reltype<elfcpp::SHT_RELA>(relinfo, i, prelocs,
 947                                                   reloc_count, aoutput_section,
 948                                                   offset_in_output_section,
 949                                                   aview, address, view_size,
 950                                                   reloc_view, reloc_view_size);
 951     }
 952 }
 953
 954 // Emit the relocs for --emit-relocs, templatized on the type of the
 955 // relocation section.
 956
 957 template<int size, bool big_endian>
 958 template<int sh_type>
 959 void
 960 Sized_relobj<size, big_endian>::emit_relocs_reltype(
 961     const Relocate_info<size, big_endian>* relinfo,
 962     unsigned int i,
 963     const unsigned char* prelocs,
 964     size_t reloc_count,
 965     Output_section* aoutput_section,
 966     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
 967     unsigned char* aview,
 968     typename elfcpp::Elf_types<size>::Elf_Addr address,
 969     section_size_type view_size,
 970     unsigned char* reloc_view,
 971     section_size_type reloc_view_size)
 972 {
 973   const Relocatable_relocs* rr = this->relocatable_relocs(i);
 974   relocate_for_relocatable<size, big_endian, sh_type>(
 975     relinfo,
 976     prelocs,
 977     reloc_count,
 978     aoutput_section,
 979     offset_in_output_section,
 980     rr,
 981     aview,
 982     address,
 983     view_size,
 984     reloc_view,
 985     reloc_view_size);
 986 }
 987
 988 // Create merge hash tables for the local symbols.  These are used to
 989 // speed up relocations.
 990
 991 template<int size, bool big_endian>
 992 void
 993 Sized_relobj<size, big_endian>::initialize_input_to_output_maps()
 994 {
 995   const unsigned int loccount = this->local_symbol_count_;
 996   for (unsigned int i = 1; i < loccount; ++i)
 997     {
 998       Symbol_value<size>& lv(this->local_values_[i]);
 999       lv.initialize_input_to_output_map(this);
1000     }
1001 }
1002
1003 // Free merge hash tables for the local symbols.
1004
1005 template<int size, bool big_endian>
1006 void
1007 Sized_relobj<size, big_endian>::free_input_to_output_maps()
1008 {
1009   const unsigned int loccount = this->local_symbol_count_;
1010   for (unsigned int i = 1; i < loccount; ++i)
1011     {
1012       Symbol_value<size>& lv(this->local_values_[i]);
1013       lv.free_input_to_output_map();
1014     }
1015 }
1016
1017 // If an object was compiled with -fsplit-stack, this is called to
1018 // check whether any relocations refer to functions defined in objects
1019 // which were not compiled with -fsplit-stack.  If they were, then we
1020 // need to apply some target-specific adjustments to request
1021 // additional stack space.
1022
1023 template<int size, bool big_endian>
1024 void
1025 Sized_relobj<size, big_endian>::split_stack_adjust(
1026     const Symbol_table* symtab,
1027     const unsigned char* pshdrs,
1028     unsigned int sh_type,
1029     unsigned int shndx,
1030     const unsigned char* prelocs,
1031     size_t reloc_count,
1032     unsigned char* aview,
1033     section_size_type view_size,
1034     Reloc_symbol_changes** reloc_map)
1035 {
1036   if (sh_type == elfcpp::SHT_REL)
1037     this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
1038                                                       prelocs, reloc_count,
1039                                                       aview, view_size,
1040                                                       reloc_map);
1041   else
1042     {
1043       gold_assert(sh_type == elfcpp::SHT_RELA);
1044       this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
1045                                                          prelocs, reloc_count,
1046                                                          aview, view_size,
1047                                                          reloc_map);
1048     }
1049 }
1050
1051 // Adjust for -fsplit-stack, templatized on the type of the relocation
1052 // section.
1053
1054 template<int size, bool big_endian>
1055 template<int sh_type>
1056 void
1057 Sized_relobj<size, big_endian>::split_stack_adjust_reltype(
1058     const Symbol_table* symtab,
1059     const unsigned char* pshdrs,
1060     unsigned int shndx,
1061     const unsigned char* prelocs,
1062     size_t reloc_count,
1063     unsigned char* aview,
1064     section_size_type view_size,
1065     Reloc_symbol_changes** reloc_map)
1066 {
1067   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
1068   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
1069
1070   size_t local_count = this->local_symbol_count();
1071
1072   std::vector<section_offset_type> non_split_refs;
1073
1074   const unsigned char* pr = prelocs;
1075   for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1076     {
1077       Reltype reloc(pr);
1078
1079       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1080       unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1081       if (r_sym < local_count)
1082         continue;
1083
1084       const Symbol* gsym = this->global_symbol(r_sym);
1085       gold_assert(gsym != NULL);
1086       if (gsym->is_forwarder())
1087         gsym = symtab->resolve_forwards(gsym);
1088
1089       // See if this relocation refers to a function defined in an
1090       // object compiled without -fsplit-stack.  Note that we don't
1091       // care about the type of relocation--this means that in some
1092       // cases we will ask for a large stack unnecessarily, but this
1093       // is not fatal.  FIXME: Some targets have symbols which are
1094       // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
1095       if (gsym->type() == elfcpp::STT_FUNC
1096           && !gsym->is_undefined()
1097           && gsym->source() == Symbol::FROM_OBJECT
1098           && !gsym->object()->uses_split_stack())
1099         {
1100           section_offset_type off =
1101             convert_to_section_size_type(reloc.get_r_offset());
1102           non_split_refs.push_back(off);
1103         }
1104     }
1105
1106   if (non_split_refs.empty())
1107     return;
1108
1109   // At this point, every entry in NON_SPLIT_REFS indicates a
1110   // relocation which refers to a function in an object compiled
1111   // without -fsplit-stack.  We now have to convert that list into a
1112   // set of offsets to functions.  First, we find all the functions.
1113
1114   Function_offsets function_offsets;
1115   this->find_functions(pshdrs, shndx, &function_offsets);
1116   if (function_offsets.empty())
1117     return;
1118
1119   // Now get a list of the function with references to non split-stack
1120   // code.
1121
1122   Function_offsets calls_non_split;
1123   for (std::vector<section_offset_type>::const_iterator p
1124          = non_split_refs.begin();
1125        p != non_split_refs.end();
1126        ++p)
1127     {
1128       Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
1129       if (low == function_offsets.end())
1130         --low;
1131       else if (low->first == *p)
1132         ;
1133       else if (low == function_offsets.begin())
1134         continue;
1135       else
1136         --low;
1137
1138       calls_non_split.insert(*low);
1139     }
1140   if (calls_non_split.empty())
1141     return;
1142
1143   // Now we have a set of functions to adjust.  The adjustments are
1144   // target specific.  Besides changing the output section view
1145   // however, it likes, the target may request a relocation change
1146   // from one global symbol name to another.
1147
1148   for (Function_offsets::const_iterator p = calls_non_split.begin();
1149        p != calls_non_split.end();
1150        ++p)
1151     {
1152       std::string from;
1153       std::string to;
1154       parameters->target().calls_non_split(this, shndx, p->first, p->second,
1155                                            aview, view_size, &from, &to);
1156       if (!from.empty())
1157         {
1158           gold_assert(!to.empty());
1159           Symbol* tosym = NULL;
1160
1161           // Find relocations in the relevant function which are for
1162           // FROM.
1163           pr = prelocs;
1164           for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1165             {
1166               Reltype reloc(pr);
1167
1168               typename elfcpp::Elf_types<size>::Elf_WXword r_info =
1169                 reloc.get_r_info();
1170               unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1171               if (r_sym < local_count)
1172                 continue;
1173
1174               section_offset_type off =
1175                 convert_to_section_size_type(reloc.get_r_offset());
1176               if (off < p->first
1177                   || (off
1178                       >= (p->first
1179                           + static_cast<section_offset_type>(p->second))))
1180                 continue;
1181
1182               const Symbol* gsym = this->global_symbol(r_sym);
1183               if (from == gsym->name())
1184                 {
1185                   if (tosym == NULL)
1186                     {
1187                       tosym = symtab->lookup(to.c_str());
1188                       if (tosym == NULL)
1189                         {
1190                           this->error(_("could not convert call "
1191                                         "to '%s' to '%s'"),
1192                                       from.c_str(), to.c_str());
1193                           break;
1194                         }
1195                     }
1196
1197                   if (*reloc_map == NULL)
1198                     *reloc_map = new Reloc_symbol_changes(reloc_count);
1199                   (*reloc_map)->set(i, tosym);
1200                 }
1201             }
1202         }
1203     }
1204 }
1205
1206 // Find all the function in this object defined in section SHNDX.
1207 // Store their offsets in the section in FUNCTION_OFFSETS.
1208
1209 template<int size, bool big_endian>
1210 void
1211 Sized_relobj<size, big_endian>::find_functions(
1212     const unsigned char* pshdrs,
1213     unsigned int shndx,
1214     Sized_relobj<size, big_endian>::Function_offsets* function_offsets)
1215 {
1216   // We need to read the symbols to find the functions.  If we wanted
1217   // to, we could cache reading the symbols across all sections in the
1218   // object.
1219   const unsigned int sym_tab_shndx = this->symtab_shndx_;
1220   typename This::Shdr symtabshdr(pshdrs + sym_tab_shndx * This::shdr_size);
1221   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1222
1223   typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
1224     symtabshdr.get_sh_size();
1225   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1226                                               sh_size, true, true);
1227
1228   const int symsize = This::sym_size;
1229   const unsigned int symcount = sh_size / symsize;
1230   for (unsigned int i = 0; i < symcount; ++i, psyms += symsize)
1231     {
1232       typename elfcpp::Sym<size, big_endian> isym(psyms);
1233
1234       // FIXME: Some targets can have functions which do not have type
1235       // STT_FUNC, e.g., STT_ARM_TFUNC.
1236       if (isym.get_st_type() != elfcpp::STT_FUNC
1237           || isym.get_st_size() == 0)
1238         continue;
1239
1240       bool is_ordinary;
1241       unsigned int sym_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1242                                                       &is_ordinary);
1243       if (!is_ordinary || sym_shndx != shndx)
1244         continue;
1245
1246       section_offset_type value =
1247         convert_to_section_size_type(isym.get_st_value());
1248       section_size_type fnsize =
1249         convert_to_section_size_type(isym.get_st_size());
1250
1251       (*function_offsets)[value] = fnsize;
1252     }
1253 }
1254
1255 // Class Merged_symbol_value.
1256
1257 template<int size>
1258 void
1259 Merged_symbol_value<size>::initialize_input_to_output_map(
1260     const Relobj* object,
1261     unsigned int input_shndx)
1262 {
1263   Object_merge_map* map = object->merge_map();
1264   map->initialize_input_to_output_map<size>(input_shndx,
1265                                             this->output_start_address_,
1266                                             &this->output_addresses_);
1267 }
1268
1269 // Get the output value corresponding to an input offset if we
1270 // couldn't find it in the hash table.
1271
1272 template<int size>
1273 typename elfcpp::Elf_types<size>::Elf_Addr
1274 Merged_symbol_value<size>::value_from_output_section(
1275     const Relobj* object,
1276     unsigned int input_shndx,
1277     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
1278 {
1279   section_offset_type output_offset;
1280   bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
1281                                                       input_offset,
1282                                                       &output_offset);
1283
1284   // If this assertion fails, it means that some relocation was
1285   // against a portion of an input merge section which we didn't map
1286   // to the output file and we didn't explicitly discard.  We should
1287   // always map all portions of input merge sections.
1288   gold_assert(found);
1289
1290   if (output_offset == -1)
1291     return 0;
1292   else
1293     return this->output_start_address_ + output_offset;
1294 }
1295
1296 // Track_relocs methods.
1297
1298 // Initialize the class to track the relocs.  This gets the object,
1299 // the reloc section index, and the type of the relocs.  This returns
1300 // false if something goes wrong.
1301
1302 template<int size, bool big_endian>
1303 bool
1304 Track_relocs<size, big_endian>::initialize(
1305     Object* object,
1306     unsigned int reloc_shndx,
1307     unsigned int reloc_type)
1308 {
1309   // If RELOC_SHNDX is -1U, it means there is more than one reloc
1310   // section for the .eh_frame section.  We can't handle that case.
1311   if (reloc_shndx == -1U)
1312     return false;
1313
1314   // If RELOC_SHNDX is 0, there is no reloc section.
1315   if (reloc_shndx == 0)
1316     return true;
1317
1318   // Get the contents of the reloc section.
1319   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
1320
1321   if (reloc_type == elfcpp::SHT_REL)
1322     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
1323   else if (reloc_type == elfcpp::SHT_RELA)
1324     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
1325   else
1326     gold_unreachable();
1327
1328   if (this->len_ % this->reloc_size_ != 0)
1329     {
1330       object->error(_("reloc section size %zu is not a multiple of "
1331                       "reloc size %d\n"),
1332                     static_cast<size_t>(this->len_),
1333                     this->reloc_size_);
1334       return false;
1335     }
1336
1337   return true;
1338 }
1339
1340 // Return the offset of the next reloc, or -1 if there isn't one.
1341
1342 template<int size, bool big_endian>
1343 off_t
1344 Track_relocs<size, big_endian>::next_offset() const
1345 {
1346   if (this->pos_ >= this->len_)
1347     return -1;
1348
1349   // Rel and Rela start out the same, so we can always use Rel to find
1350   // the r_offset value.
1351   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1352   return rel.get_r_offset();
1353 }
1354
1355 // Return the index of the symbol referenced by the next reloc, or -1U
1356 // if there aren't any more relocs.
1357
1358 template<int size, bool big_endian>
1359 unsigned int
1360 Track_relocs<size, big_endian>::next_symndx() const
1361 {
1362   if (this->pos_ >= this->len_)
1363     return -1U;
1364
1365   // Rel and Rela start out the same, so we can use Rel to find the
1366   // symbol index.
1367   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1368   return elfcpp::elf_r_sym<size>(rel.get_r_info());
1369 }
1370
1371 // Advance to the next reloc whose r_offset is greater than or equal
1372 // to OFFSET.  Return the number of relocs we skip.
1373
1374 template<int size, bool big_endian>
1375 int
1376 Track_relocs<size, big_endian>::advance(off_t offset)
1377 {
1378   int ret = 0;
1379   while (this->pos_ < this->len_)
1380     {
1381       // Rel and Rela start out the same, so we can always use Rel to
1382       // find the r_offset value.
1383       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1384       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
1385         break;
1386       ++ret;
1387       this->pos_ += this->reloc_size_;
1388     }
1389   return ret;
1390 }
1391
1392 // Instantiate the templates we need.
1393
1394 #ifdef HAVE_TARGET_32_LITTLE
1395 template
1396 void
1397 Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd);
1398 #endif
1399
1400 #ifdef HAVE_TARGET_32_BIG
1401 template
1402 void
1403 Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd);
1404 #endif
1405
1406 #ifdef HAVE_TARGET_64_LITTLE
1407 template
1408 void
1409 Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd);
1410 #endif
1411
1412 #ifdef HAVE_TARGET_64_BIG
1413 template
1414 void
1415 Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
1416 #endif
1417
1418 #ifdef HAVE_TARGET_32_LITTLE
1419 template
1420 void
1421 Sized_relobj<32, false>::do_gc_process_relocs(Symbol_table* symtab,
1422                                               Layout* alayout,
1423                                               Read_relocs_data* rd);
1424 #endif
1425
1426 #ifdef HAVE_TARGET_32_BIG
1427 template
1428 void
1429 Sized_relobj<32, true>::do_gc_process_relocs(Symbol_table* symtab,
1430                                              Layout* alayout,
1431                                              Read_relocs_data* rd);
1432 #endif
1433
1434 #ifdef HAVE_TARGET_64_LITTLE
1435 template
1436 void
1437 Sized_relobj<64, false>::do_gc_process_relocs(Symbol_table* symtab,
1438                                               Layout* alayout,
1439                                               Read_relocs_data* rd);
1440 #endif
1441
1442 #ifdef HAVE_TARGET_64_BIG
1443 template
1444 void
1445 Sized_relobj<64, true>::do_gc_process_relocs(Symbol_table* symtab,
1446                                              Layout* alayout,
1447                                              Read_relocs_data* rd);
1448 #endif
1449
1450 #ifdef HAVE_TARGET_32_LITTLE
1451 template
1452 void
1453 Sized_relobj<32, false>::do_scan_relocs(Symbol_table* symtab,
1454                                         Layout* alayout,
1455                                         Read_relocs_data* rd);
1456 #endif
1457
1458 #ifdef HAVE_TARGET_32_BIG
1459 template
1460 void
1461 Sized_relobj<32, true>::do_scan_relocs(Symbol_table* symtab,
1462                                        Layout* alayout,
1463                                        Read_relocs_data* rd);
1464 #endif
1465
1466 #ifdef HAVE_TARGET_64_LITTLE
1467 template
1468 void
1469 Sized_relobj<64, false>::do_scan_relocs(Symbol_table* symtab,
1470                                         Layout* alayout,
1471                                         Read_relocs_data* rd);
1472 #endif
1473
1474 #ifdef HAVE_TARGET_64_BIG
1475 template
1476 void
1477 Sized_relobj<64, true>::do_scan_relocs(Symbol_table* symtab,
1478                                        Layout* alayout,
1479                                        Read_relocs_data* rd);
1480 #endif
1481
1482 #ifdef HAVE_TARGET_32_LITTLE
1483 template
1484 void
1485 Sized_relobj<32, false>::do_relocate(const Symbol_table* symtab,
1486                                      const Layout* alayout,
1487                                      Output_file* of);
1488 #endif
1489
1490 #ifdef HAVE_TARGET_32_BIG
1491 template
1492 void
1493 Sized_relobj<32, true>::do_relocate(const Symbol_table* symtab,
1494                                     const Layout* alayout,
1495                                     Output_file* of);
1496 #endif
1497
1498 #ifdef HAVE_TARGET_64_LITTLE
1499 template
1500 void
1501 Sized_relobj<64, false>::do_relocate(const Symbol_table* symtab,
1502                                      const Layout* alayout,
1503                                      Output_file* of);
1504 #endif
1505
1506 #ifdef HAVE_TARGET_64_BIG
1507 template
1508 void
1509 Sized_relobj<64, true>::do_relocate(const Symbol_table* symtab,
1510                                     const Layout* alayout,
1511                                     Output_file* of);
1512 #endif
1513
1514 #ifdef HAVE_TARGET_32_LITTLE
1515 template
1516 void
1517 Sized_relobj<32, false>::do_relocate_sections(
1518     const Symbol_table* symtab,
1519     const Layout* alayout,
1520     const unsigned char* pshdrs,
1521     Views* pviews);
1522 #endif
1523
1524 #ifdef HAVE_TARGET_32_BIG
1525 template
1526 void
1527 Sized_relobj<32, true>::do_relocate_sections(
1528     const Symbol_table* symtab,
1529     const Layout* alayout,
1530     const unsigned char* pshdrs,
1531     Views* pviews);
1532 #endif
1533
1534 #ifdef HAVE_TARGET_64_LITTLE
1535 template
1536 void
1537 Sized_relobj<64, false>::do_relocate_sections(
1538     const Symbol_table* symtab,
1539     const Layout* alayout,
1540     const unsigned char* pshdrs,
1541     Views* pviews);
1542 #endif
1543
1544 #ifdef HAVE_TARGET_64_BIG
1545 template
1546 void
1547 Sized_relobj<64, true>::do_relocate_sections(
1548     const Symbol_table* symtab,
1549     const Layout* layout,
1550     const unsigned char* pshdrs,
1551     Views* pviews);
1552 #endif
1553
1554 #ifdef HAVE_TARGET_32_LITTLE
1555 template
1556 void
1557 Sized_relobj<32, false>::initialize_input_to_output_maps();
1558
1559 template
1560 void
1561 Sized_relobj<32, false>::free_input_to_output_maps();
1562 #endif
1563
1564 #ifdef HAVE_TARGET_32_BIG
1565 template
1566 void
1567 Sized_relobj<32, true>::initialize_input_to_output_maps();
1568
1569 template
1570 void
1571 Sized_relobj<32, true>::free_input_to_output_maps();
1572 #endif
1573
1574 #ifdef HAVE_TARGET_64_LITTLE
1575 template
1576 void
1577 Sized_relobj<64, false>::initialize_input_to_output_maps();
1578
1579 template
1580 void
1581 Sized_relobj<64, false>::free_input_to_output_maps();
1582 #endif
1583
1584 #ifdef HAVE_TARGET_64_BIG
1585 template
1586 void
1587 Sized_relobj<64, true>::initialize_input_to_output_maps();
1588
1589 template
1590 void
1591 Sized_relobj<64, true>::free_input_to_output_maps();
1592 #endif
1593
1594 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1595 template
1596 class Merged_symbol_value<32>;
1597 #endif
1598
1599 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1600 template
1601 class Merged_symbol_value<64>;
1602 #endif
1603
1604 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1605 template
1606 class Symbol_value<32>;
1607 #endif
1608
1609 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1610 template
1611 class Symbol_value<64>;
1612 #endif
1613
1614 #ifdef HAVE_TARGET_32_LITTLE
1615 template
1616 class Track_relocs<32, false>;
1617 #endif
1618
1619 #ifdef HAVE_TARGET_32_BIG
1620 template
1621 class Track_relocs<32, true>;
1622 #endif
1623
1624 #ifdef HAVE_TARGET_64_LITTLE
1625 template
1626 class Track_relocs<64, false>;
1627 #endif
1628
1629 #ifdef HAVE_TARGET_64_BIG
1630 template
1631 class Track_relocs<64, true>;
1632 #endif
1633
1634 } // End namespace gold.