gold/reloc.cc

   1 // reloc.cc -- relocate input files for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 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 #include "compressed_output.h"
  36
  37 namespace gold
  38 {
  39
  40 // Read_relocs methods.
  41
  42 // These tasks just read the relocation information from the file.
  43 // After reading it, the start another task to process the
  44 // information.  These tasks requires access to the file.
  45
  46 Task_token*
  47 Read_relocs::is_runnable()
  48 {
  49   return this->object_->is_locked() ? this->object_->token() : NULL;
  50 }
  51
  52 // Lock the file.
  53
  54 void
  55 Read_relocs::locks(Task_locker* tl)
  56 {
  57   tl->add(this, this->object_->token());
  58 }
  59
  60 // Read the relocations and then start a Scan_relocs_task.
  61
  62 void
  63 Read_relocs::run(Workqueue* workqueue)
  64 {
  65   Read_relocs_data *rd = new Read_relocs_data;
  66   this->object_->read_relocs(rd);
  67   this->object_->set_relocs_data(rd);
  68   this->object_->release();
  69
  70   // If garbage collection or identical comdat folding is desired, we
  71   // process the relocs first before scanning them.  Scanning of relocs is
  72   // done only after garbage or identical sections is identified.
  73   if (parameters->options().gc_sections()
  74       || parameters->options().icf_enabled())
  75     {
  76       workqueue->queue_next(new Gc_process_relocs(this->symtab_,
  77                                                   this->layout_,
  78                                                   this->object_, rd,
  79                                                   this->this_blocker_,
  80                                                   this->next_blocker_));
  81     }
  82   else
  83     {
  84       workqueue->queue_next(new Scan_relocs(this->symtab_, this->layout_,
  85                                             this->object_, rd,
  86                                             this->this_blocker_,
  87                                             this->next_blocker_));
  88     }
  89 }
  90
  91 // Return a debugging name for the task.
  92
  93 std::string
  94 Read_relocs::get_name() const
  95 {
  96   return "Read_relocs " + this->object_->name();
  97 }
  98
  99 // Gc_process_relocs methods.
 100
 101 Gc_process_relocs::~Gc_process_relocs()
 102 {
 103   if (this->this_blocker_ != NULL)
 104     delete this->this_blocker_;
 105 }
 106
 107 // These tasks process the relocations read by Read_relocs and
 108 // determine which sections are referenced and which are garbage.
 109 // This task is done only when --gc-sections is used.  This is blocked
 110 // by THIS_BLOCKER_.  It unblocks NEXT_BLOCKER_.
 111
 112 Task_token*
 113 Gc_process_relocs::is_runnable()
 114 {
 115   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 116     return this->this_blocker_;
 117   if (this->object_->is_locked())
 118     return this->object_->token();
 119   return NULL;
 120 }
 121
 122 void
 123 Gc_process_relocs::locks(Task_locker* tl)
 124 {
 125   tl->add(this, this->object_->token());
 126   tl->add(this, this->next_blocker_);
 127 }
 128
 129 void
 130 Gc_process_relocs::run(Workqueue*)
 131 {
 132   this->object_->gc_process_relocs(this->symtab_, this->layout_, this->rd_);
 133   this->object_->release();
 134 }
 135
 136 // Return a debugging name for the task.
 137
 138 std::string
 139 Gc_process_relocs::get_name() const
 140 {
 141   return "Gc_process_relocs " + this->object_->name();
 142 }
 143
 144 // Scan_relocs methods.
 145
 146 Scan_relocs::~Scan_relocs()
 147 {
 148   if (this->this_blocker_ != NULL)
 149     delete this->this_blocker_;
 150 }
 151
 152 // These tasks scan the relocations read by Read_relocs and mark up
 153 // the symbol table to indicate which relocations are required.  We
 154 // use a lock on the symbol table to keep them from interfering with
 155 // each other.
 156
 157 Task_token*
 158 Scan_relocs::is_runnable()
 159 {
 160   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 161     return this->this_blocker_;
 162   if (this->object_->is_locked())
 163     return this->object_->token();
 164   return NULL;
 165 }
 166
 167 // Return the locks we hold: one on the file, one on the symbol table
 168 // and one blocker.
 169
 170 void
 171 Scan_relocs::locks(Task_locker* tl)
 172 {
 173   tl->add(this, this->object_->token());
 174   tl->add(this, this->next_blocker_);
 175 }
 176
 177 // Scan the relocs.
 178
 179 void
 180 Scan_relocs::run(Workqueue*)
 181 {
 182   this->object_->scan_relocs(this->symtab_, this->layout_, this->rd_);
 183   delete this->rd_;
 184   this->rd_ = NULL;
 185   this->object_->release();
 186 }
 187
 188 // Return a debugging name for the task.
 189
 190 std::string
 191 Scan_relocs::get_name() const
 192 {
 193   return "Scan_relocs " + this->object_->name();
 194 }
 195
 196 // Relocate_task methods.
 197
 198 // We may have to wait for the output sections to be written.
 199
 200 Task_token*
 201 Relocate_task::is_runnable()
 202 {
 203   if (this->object_->relocs_must_follow_section_writes()
 204       && this->output_sections_blocker_->is_blocked())
 205     return this->output_sections_blocker_;
 206
 207   if (this->object_->is_locked())
 208     return this->object_->token();
 209
 210   return NULL;
 211 }
 212
 213 // We want to lock the file while we run.  We want to unblock
 214 // INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done.
 215 // INPUT_SECTIONS_BLOCKER may be NULL.
 216
 217 void
 218 Relocate_task::locks(Task_locker* tl)
 219 {
 220   if (this->input_sections_blocker_ != NULL)
 221     tl->add(this, this->input_sections_blocker_);
 222   tl->add(this, this->final_blocker_);
 223   tl->add(this, this->object_->token());
 224 }
 225
 226 // Run the task.
 227
 228 void
 229 Relocate_task::run(Workqueue*)
 230 {
 231   this->object_->relocate(this->symtab_, this->layout_, this->of_);
 232
 233   // This is normally the last thing we will do with an object, so
 234   // uncache all views.
 235   this->object_->clear_view_cache_marks();
 236
 237   this->object_->release();
 238 }
 239
 240 // Return a debugging name for the task.
 241
 242 std::string
 243 Relocate_task::get_name() const
 244 {
 245   return "Relocate_task " + this->object_->name();
 246 }
 247
 248 // Read the relocs and local symbols from the object file and store
 249 // the information in RD.
 250
 251 template<int size, bool big_endian>
 252 void
 253 Sized_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd)
 254 {
 255   rd->relocs.clear();
 256
 257   unsigned int shnum = this->shnum();
 258   if (shnum == 0)
 259     return;
 260
 261   rd->relocs.reserve(shnum / 2);
 262
 263   const Output_sections& out_sections(this->output_sections());
 264   const std::vector<Address>& out_offsets(this->section_offsets_);
 265
 266   const unsigned char *pshdrs = this->get_view(this->elf_file_.shoff(),
 267                                                shnum * This::shdr_size,
 268                                                true, true);
 269   // Skip the first, dummy, section.
 270   const unsigned char *ps = pshdrs + This::shdr_size;
 271   for (unsigned int i = 1; i < shnum; ++i, ps += This::shdr_size)
 272     {
 273       typename This::Shdr shdr(ps);
 274
 275       unsigned int sh_type = shdr.get_sh_type();
 276       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 277         continue;
 278
 279       unsigned int shndx = this->adjust_shndx(shdr.get_sh_info());
 280       if (shndx >= shnum)
 281         {
 282           this->error(_("relocation section %u has bad info %u"),
 283                       i, shndx);
 284           continue;
 285         }
 286
 287       Output_section* os = out_sections[shndx];
 288       if (os == NULL)
 289         continue;
 290
 291       // We are scanning relocations in order to fill out the GOT and
 292       // PLT sections.  Relocations for sections which are not
 293       // allocated (typically debugging sections) should not add new
 294       // GOT and PLT entries.  So we skip them unless this is a
 295       // relocatable link or we need to emit relocations.  FIXME: What
 296       // should we do if a linker script maps a section with SHF_ALLOC
 297       // clear to a section with SHF_ALLOC set?
 298       typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
 299       bool is_section_allocated = ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC)
 300                                    != 0);
 301       if (!is_section_allocated
 302           && !parameters->options().relocatable()
 303           && !parameters->options().emit_relocs())
 304         continue;
 305
 306       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 307         {
 308           this->error(_("relocation section %u uses unexpected "
 309                         "symbol table %u"),
 310                       i, this->adjust_shndx(shdr.get_sh_link()));
 311           continue;
 312         }
 313
 314       off_t sh_size = shdr.get_sh_size();
 315
 316       unsigned int reloc_size;
 317       if (sh_type == elfcpp::SHT_REL)
 318         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 319       else
 320         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 321       if (reloc_size != shdr.get_sh_entsize())
 322         {
 323           this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
 324                       i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 325                       reloc_size);
 326           continue;
 327         }
 328
 329       size_t reloc_count = sh_size / reloc_size;
 330       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 331         {
 332           this->error(_("reloc section %u size %lu uneven"),
 333                       i, static_cast<unsigned long>(sh_size));
 334           continue;
 335         }
 336
 337       rd->relocs.push_back(Section_relocs());
 338       Section_relocs& sr(rd->relocs.back());
 339       sr.reloc_shndx = i;
 340       sr.data_shndx = shndx;
 341       sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
 342                                            true, true);
 343       sr.sh_type = sh_type;
 344       sr.reloc_count = reloc_count;
 345       sr.output_section = os;
 346       sr.needs_special_offset_handling = out_offsets[shndx] == invalid_address;
 347       sr.is_data_section_allocated = is_section_allocated;
 348     }
 349
 350   // Read the local symbols.
 351   gold_assert(this->symtab_shndx_ != -1U);
 352   if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
 353     rd->local_symbols = NULL;
 354   else
 355     {
 356       typename This::Shdr symtabshdr(pshdrs
 357                                      + this->symtab_shndx_ * This::shdr_size);
 358       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 359       const int sym_size = This::sym_size;
 360       const unsigned int loccount = this->local_symbol_count_;
 361       gold_assert(loccount == symtabshdr.get_sh_info());
 362       off_t locsize = loccount * sym_size;
 363       rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
 364                                                  locsize, true, true);
 365     }
 366 }
 367
 368 // Process the relocs to generate mappings from source sections to referenced
 369 // sections.  This is used during garbage colletion to determine garbage
 370 // sections.
 371
 372 template<int size, bool big_endian>
 373 void
 374 Sized_relobj<size, big_endian>::do_gc_process_relocs(Symbol_table* symtab,
 375                                                      Layout* layout,
 376                                                      Read_relocs_data* rd)
 377 {
 378   Sized_target<size, big_endian>* target =
 379     parameters->sized_target<size, big_endian>();
 380
 381   const unsigned char* local_symbols;
 382   if (rd->local_symbols == NULL)
 383     local_symbols = NULL;
 384   else
 385     local_symbols = rd->local_symbols->data();
 386
 387   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 388        p != rd->relocs.end();
 389        ++p)
 390     {
 391       if (!parameters->options().relocatable())
 392           {
 393             // As noted above, when not generating an object file, we
 394             // only scan allocated sections.  We may see a non-allocated
 395             // section here if we are emitting relocs.
 396             if (p->is_data_section_allocated)
 397               target->gc_process_relocs(symtab, layout, this,
 398                                         p->data_shndx, p->sh_type,
 399                                         p->contents->data(), p->reloc_count,
 400                                         p->output_section,
 401                                         p->needs_special_offset_handling,
 402                                         this->local_symbol_count_,
 403                                         local_symbols);
 404         }
 405     }
 406 }
 407
 408
 409 // Scan the relocs and adjust the symbol table.  This looks for
 410 // relocations which require GOT/PLT/COPY relocations.
 411
 412 template<int size, bool big_endian>
 413 void
 414 Sized_relobj<size, big_endian>::do_scan_relocs(Symbol_table* symtab,
 415                                                Layout* layout,
 416                                                Read_relocs_data* rd)
 417 {
 418   Sized_target<size, big_endian>* target =
 419     parameters->sized_target<size, big_endian>();
 420
 421   const unsigned char* local_symbols;
 422   if (rd->local_symbols == NULL)
 423     local_symbols = NULL;
 424   else
 425     local_symbols = rd->local_symbols->data();
 426
 427   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 428        p != rd->relocs.end();
 429        ++p)
 430     {
 431       // When garbage collection is on, unreferenced sections are not included
 432       // in the link that would have been included normally. This is known only
 433       // after Read_relocs hence this check has to be done again.
 434       if (parameters->options().gc_sections()
 435           || parameters->options().icf_enabled())
 436         {
 437           if (p->output_section == NULL)
 438             continue;
 439         }
 440       if (!parameters->options().relocatable())
 441         {
 442           // As noted above, when not generating an object file, we
 443           // only scan allocated sections.  We may see a non-allocated
 444           // section here if we are emitting relocs.
 445           if (p->is_data_section_allocated)
 446             target->scan_relocs(symtab, layout, this, p->data_shndx,
 447                                 p->sh_type, p->contents->data(),
 448                                 p->reloc_count, p->output_section,
 449                                 p->needs_special_offset_handling,
 450                                 this->local_symbol_count_,
 451                                 local_symbols);
 452           if (parameters->options().emit_relocs())
 453             this->emit_relocs_scan(symtab, layout, local_symbols, p);
 454         }
 455       else
 456         {
 457           Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 458           gold_assert(rr != NULL);
 459           rr->set_reloc_count(p->reloc_count);
 460           target->scan_relocatable_relocs(symtab, layout, this,
 461                                           p->data_shndx, p->sh_type,
 462                                           p->contents->data(),
 463                                           p->reloc_count,
 464                                           p->output_section,
 465                                           p->needs_special_offset_handling,
 466                                           this->local_symbol_count_,
 467                                           local_symbols,
 468                                           rr);
 469         }
 470
 471       delete p->contents;
 472       p->contents = NULL;
 473     }
 474
 475   if (rd->local_symbols != NULL)
 476     {
 477       delete rd->local_symbols;
 478       rd->local_symbols = NULL;
 479     }
 480 }
 481
 482 // This is a strategy class we use when scanning for --emit-relocs.
 483
 484 template<int sh_type>
 485 class Emit_relocs_strategy
 486 {
 487  public:
 488   // A local non-section symbol.
 489   inline Relocatable_relocs::Reloc_strategy
 490   local_non_section_strategy(unsigned int, Relobj*, unsigned int)
 491   { return Relocatable_relocs::RELOC_COPY; }
 492
 493   // A local section symbol.
 494   inline Relocatable_relocs::Reloc_strategy
 495   local_section_strategy(unsigned int, Relobj*)
 496   {
 497     if (sh_type == elfcpp::SHT_RELA)
 498       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
 499     else
 500       {
 501         // The addend is stored in the section contents.  Since this
 502         // is not a relocatable link, we are going to apply the
 503         // relocation contents to the section as usual.  This means
 504         // that we have no way to record the original addend.  If the
 505         // original addend is not zero, there is basically no way for
 506         // the user to handle this correctly.  Caveat emptor.
 507         return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
 508       }
 509   }
 510
 511   // A global symbol.
 512   inline Relocatable_relocs::Reloc_strategy
 513   global_strategy(unsigned int, Relobj*, unsigned int)
 514   { return Relocatable_relocs::RELOC_COPY; }
 515 };
 516
 517 // Scan the input relocations for --emit-relocs.
 518
 519 template<int size, bool big_endian>
 520 void
 521 Sized_relobj<size, big_endian>::emit_relocs_scan(
 522     Symbol_table* symtab,
 523     Layout* layout,
 524     const unsigned char* plocal_syms,
 525     const Read_relocs_data::Relocs_list::iterator& p)
 526 {
 527   Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 528   gold_assert(rr != NULL);
 529   rr->set_reloc_count(p->reloc_count);
 530
 531   if (p->sh_type == elfcpp::SHT_REL)
 532     this->emit_relocs_scan_reltype<elfcpp::SHT_REL>(symtab, layout,
 533                                                     plocal_syms, p, rr);
 534   else
 535     {
 536       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 537       this->emit_relocs_scan_reltype<elfcpp::SHT_RELA>(symtab, layout,
 538                                                        plocal_syms, p, rr);
 539     }
 540 }
 541
 542 // Scan the input relocation for --emit-relocs, templatized on the
 543 // type of the relocation section.
 544
 545 template<int size, bool big_endian>
 546 template<int sh_type>
 547 void
 548 Sized_relobj<size, big_endian>::emit_relocs_scan_reltype(
 549     Symbol_table* symtab,
 550     Layout* layout,
 551     const unsigned char* plocal_syms,
 552     const Read_relocs_data::Relocs_list::iterator& p,
 553     Relocatable_relocs* rr)
 554 {
 555   scan_relocatable_relocs<size, big_endian, sh_type,
 556                           Emit_relocs_strategy<sh_type> >(
 557     symtab,
 558     layout,
 559     this,
 560     p->data_shndx,
 561     p->contents->data(),
 562     p->reloc_count,
 563     p->output_section,
 564     p->needs_special_offset_handling,
 565     this->local_symbol_count_,
 566     plocal_syms,
 567     rr);
 568 }
 569
 570 // Relocate the input sections and write out the local symbols.
 571
 572 template<int size, bool big_endian>
 573 void
 574 Sized_relobj<size, big_endian>::do_relocate(const Symbol_table* symtab,
 575                                             const Layout* layout,
 576                                             Output_file* of)
 577 {
 578   unsigned int shnum = this->shnum();
 579
 580   // Read the section headers.
 581   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 582                                                shnum * This::shdr_size,
 583                                                true, true);
 584
 585   Views views;
 586   views.resize(shnum);
 587
 588   // Make two passes over the sections.  The first one copies the
 589   // section data to the output file.  The second one applies
 590   // relocations.
 591
 592   this->write_sections(pshdrs, of, &views);
 593
 594   // To speed up relocations, we set up hash tables for fast lookup of
 595   // input offsets to output addresses.
 596   this->initialize_input_to_output_maps();
 597
 598   // Apply relocations.
 599
 600   this->relocate_sections(symtab, layout, pshdrs, &views);
 601
 602   // After we've done the relocations, we release the hash tables,
 603   // since we no longer need them.
 604   this->free_input_to_output_maps();
 605
 606   // Write out the accumulated views.
 607   for (unsigned int i = 1; i < shnum; ++i)
 608     {
 609       if (views[i].view != NULL)
 610         {
 611           if (!views[i].is_postprocessing_view)
 612             {
 613               if (views[i].is_input_output_view)
 614                 of->write_input_output_view(views[i].offset,
 615                                             views[i].view_size,
 616                                             views[i].view);
 617               else
 618                 of->write_output_view(views[i].offset, views[i].view_size,
 619                                       views[i].view);
 620             }
 621         }
 622     }
 623
 624   // Write out the local symbols.
 625   this->write_local_symbols(of, layout->sympool(), layout->dynpool(),
 626                             layout->symtab_xindex(), layout->dynsym_xindex());
 627
 628   // We should no longer need the local symbol values.
 629   this->clear_local_symbols();
 630 }
 631
 632 // Sort a Read_multiple vector by file offset.
 633 struct Read_multiple_compare
 634 {
 635   inline bool
 636   operator()(const File_read::Read_multiple_entry& rme1,
 637              const File_read::Read_multiple_entry& rme2) const
 638   { return rme1.file_offset < rme2.file_offset; }
 639 };
 640
 641 // Write section data to the output file.  PSHDRS points to the
 642 // section headers.  Record the views in *PVIEWS for use when
 643 // relocating.
 644
 645 template<int size, bool big_endian>
 646 void
 647 Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
 648                                                Output_file* of,
 649                                                Views* pviews)
 650 {
 651   unsigned int shnum = this->shnum();
 652   const Output_sections& out_sections(this->output_sections());
 653   const std::vector<Address>& out_offsets(this->section_offsets_);
 654
 655   File_read::Read_multiple rm;
 656   bool is_sorted = true;
 657
 658   const unsigned char* p = pshdrs + This::shdr_size;
 659   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 660     {
 661       View_size* pvs = &(*pviews)[i];
 662
 663       pvs->view = NULL;
 664
 665       const Output_section* os = out_sections[i];
 666       if (os == NULL)
 667         continue;
 668       Address output_offset = out_offsets[i];
 669
 670       typename This::Shdr shdr(p);
 671
 672       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 673         continue;
 674
 675       if ((parameters->options().relocatable()
 676            || parameters->options().emit_relocs())
 677           && (shdr.get_sh_type() == elfcpp::SHT_REL
 678               || shdr.get_sh_type() == elfcpp::SHT_RELA)
 679           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 680         {
 681           // This is a reloc section in a relocatable link or when
 682           // emitting relocs.  We don't need to read the input file.
 683           // The size and file offset are stored in the
 684           // Relocatable_relocs structure.
 685           Relocatable_relocs* rr = this->relocatable_relocs(i);
 686           gold_assert(rr != NULL);
 687           Output_data* posd = rr->output_data();
 688           gold_assert(posd != NULL);
 689
 690           pvs->offset = posd->offset();
 691           pvs->view_size = posd->data_size();
 692           pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
 693           pvs->address = posd->address();
 694           pvs->is_input_output_view = false;
 695           pvs->is_postprocessing_view = false;
 696
 697           continue;
 698         }
 699
 700       // In the normal case, this input section is simply mapped to
 701       // the output section at offset OUTPUT_OFFSET.
 702
 703       // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is
 704       // handled specially--e.g., a .eh_frame section.  The relocation
 705       // routines need to check for each reloc where it should be
 706       // applied.  For this case, we need an input/output view for the
 707       // entire contents of the section in the output file.  We don't
 708       // want to copy the contents of the input section to the output
 709       // section; the output section contents were already written,
 710       // and we waited for them in Relocate_task::is_runnable because
 711       // relocs_must_follow_section_writes is set for the object.
 712
 713       // Regardless of which of the above cases is true, we have to
 714       // check requires_postprocessing of the output section.  If that
 715       // is false, then we work with views of the output file
 716       // directly.  If it is true, then we work with a separate
 717       // buffer, and the output section is responsible for writing the
 718       // final data to the output file.
 719
 720       off_t output_section_offset;
 721       Address output_section_size;
 722       if (!os->requires_postprocessing())
 723         {
 724           output_section_offset = os->offset();
 725           output_section_size = convert_types<Address, off_t>(os->data_size());
 726         }
 727       else
 728         {
 729           output_section_offset = 0;
 730           output_section_size =
 731               convert_types<Address, off_t>(os->postprocessing_buffer_size());
 732         }
 733
 734       off_t view_start;
 735       section_size_type view_size;
 736       bool must_decompress = false;
 737       if (output_offset != invalid_address)
 738         {
 739           view_start = output_section_offset + output_offset;
 740           view_size = convert_to_section_size_type(shdr.get_sh_size());
 741           section_size_type uncompressed_size;
 742           if (this->section_is_compressed(i, &uncompressed_size))
 743             {
 744               view_size = uncompressed_size;
 745               must_decompress = true;
 746             }
 747         }
 748       else
 749         {
 750           view_start = output_section_offset;
 751           view_size = convert_to_section_size_type(output_section_size);
 752         }
 753
 754       if (view_size == 0)
 755         continue;
 756
 757       gold_assert(output_offset == invalid_address
 758                   || output_offset + view_size <= output_section_size);
 759
 760       unsigned char* view;
 761       if (os->requires_postprocessing())
 762         {
 763           unsigned char* buffer = os->postprocessing_buffer();
 764           view = buffer + view_start;
 765           if (output_offset != invalid_address && !must_decompress)
 766             {
 767               off_t sh_offset = shdr.get_sh_offset();
 768               if (!rm.empty() && rm.back().file_offset > sh_offset)
 769                 is_sorted = false;
 770               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 771                                                           view_size, view));
 772             }
 773         }
 774       else
 775         {
 776           if (output_offset == invalid_address)
 777             view = of->get_input_output_view(view_start, view_size);
 778           else
 779             {
 780               view = of->get_output_view(view_start, view_size);
 781               if (!must_decompress)
 782                 {
 783                   off_t sh_offset = shdr.get_sh_offset();
 784                   if (!rm.empty() && rm.back().file_offset > sh_offset)
 785                     is_sorted = false;
 786                   rm.push_back(File_read::Read_multiple_entry(sh_offset,
 787                                                               view_size, view));
 788                 }
 789             }
 790         }
 791
 792       if (must_decompress)
 793         {
 794           // Read and decompress the section.
 795           section_size_type len;
 796           const unsigned char* p = this->section_contents(i, &len, false);
 797           if (!decompress_input_section(p, len, view, view_size))
 798             this->error(_("could not decompress section %s"),
 799                         this->section_name(i).c_str());
 800         }
 801
 802       pvs->view = view;
 803       pvs->address = os->address();
 804       if (output_offset != invalid_address)
 805         pvs->address += output_offset;
 806       pvs->offset = view_start;
 807       pvs->view_size = view_size;
 808       pvs->is_input_output_view = output_offset == invalid_address;
 809       pvs->is_postprocessing_view = os->requires_postprocessing();
 810     }
 811
 812   // Actually read the data.
 813   if (!rm.empty())
 814     {
 815       if (!is_sorted)
 816         std::sort(rm.begin(), rm.end(), Read_multiple_compare());
 817       this->read_multiple(rm);
 818     }
 819 }
 820
 821 // Relocate section data.  VIEWS points to the section data as views
 822 // in the output file.
 823
 824 template<int size, bool big_endian>
 825 void
 826 Sized_relobj<size, big_endian>::do_relocate_sections(
 827     const Symbol_table* symtab,
 828     const Layout* layout,
 829     const unsigned char* pshdrs,
 830     Views* pviews)
 831 {
 832   unsigned int shnum = this->shnum();
 833   Sized_target<size, big_endian>* target =
 834     parameters->sized_target<size, big_endian>();
 835
 836   const Output_sections& out_sections(this->output_sections());
 837   const std::vector<Address>& out_offsets(this->section_offsets_);
 838
 839   Relocate_info<size, big_endian> relinfo;
 840   relinfo.symtab = symtab;
 841   relinfo.layout = layout;
 842   relinfo.object = this;
 843
 844   const unsigned char* p = pshdrs + This::shdr_size;
 845   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 846     {
 847       typename This::Shdr shdr(p);
 848
 849       unsigned int sh_type = shdr.get_sh_type();
 850       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 851         continue;
 852
 853       off_t sh_size = shdr.get_sh_size();
 854       if (sh_size == 0)
 855         continue;
 856
 857       unsigned int index = this->adjust_shndx(shdr.get_sh_info());
 858       if (index >= this->shnum())
 859         {
 860           this->error(_("relocation section %u has bad info %u"),
 861                       i, index);
 862           continue;
 863         }
 864
 865       Output_section* os = out_sections[index];
 866       if (os == NULL)
 867         {
 868           // This relocation section is against a section which we
 869           // discarded.
 870           continue;
 871         }
 872       Address output_offset = out_offsets[index];
 873
 874       gold_assert((*pviews)[index].view != NULL);
 875       if (parameters->options().relocatable())
 876         gold_assert((*pviews)[i].view != NULL);
 877
 878       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 879         {
 880           gold_error(_("relocation section %u uses unexpected "
 881                        "symbol table %u"),
 882                      i, this->adjust_shndx(shdr.get_sh_link()));
 883           continue;
 884         }
 885
 886       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 887                                                     sh_size, true, false);
 888
 889       unsigned int reloc_size;
 890       if (sh_type == elfcpp::SHT_REL)
 891         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 892       else
 893         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 894
 895       if (reloc_size != shdr.get_sh_entsize())
 896         {
 897           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 898                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 899                      reloc_size);
 900           continue;
 901         }
 902
 903       size_t reloc_count = sh_size / reloc_size;
 904       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 905         {
 906           gold_error(_("reloc section %u size %lu uneven"),
 907                      i, static_cast<unsigned long>(sh_size));
 908           continue;
 909         }
 910
 911       gold_assert(output_offset != invalid_address
 912                   || this->relocs_must_follow_section_writes());
 913
 914       relinfo.reloc_shndx = i;
 915       relinfo.reloc_shdr = p;
 916       relinfo.data_shndx = index;
 917       relinfo.data_shdr = pshdrs + index * This::shdr_size;
 918       unsigned char* view = (*pviews)[index].view;
 919       Address address = (*pviews)[index].address;
 920       section_size_type view_size = (*pviews)[index].view_size;
 921
 922       Reloc_symbol_changes* reloc_map = NULL;
 923       if (this->uses_split_stack() && output_offset != invalid_address)
 924         {
 925           typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
 926           if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
 927             this->split_stack_adjust(symtab, pshdrs, sh_type, index,
 928                                      prelocs, reloc_count, view, view_size,
 929                                      &reloc_map);
 930         }
 931
 932       if (!parameters->options().relocatable())
 933         {
 934           target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
 935                                    output_offset == invalid_address,
 936                                    view, address, view_size, reloc_map);
 937           if (parameters->options().emit_relocs())
 938             this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count,
 939                               os, output_offset, view, address, view_size,
 940                               (*pviews)[i].view, (*pviews)[i].view_size);
 941         }
 942       else
 943         {
 944           Relocatable_relocs* rr = this->relocatable_relocs(i);
 945           target->relocate_for_relocatable(&relinfo, sh_type, prelocs,
 946                                            reloc_count, os, output_offset, rr,
 947                                            view, address, view_size,
 948                                            (*pviews)[i].view,
 949                                            (*pviews)[i].view_size);
 950         }
 951     }
 952 }
 953
 954 // Emit the relocs for --emit-relocs.
 955
 956 template<int size, bool big_endian>
 957 void
 958 Sized_relobj<size, big_endian>::emit_relocs(
 959     const Relocate_info<size, big_endian>* relinfo,
 960     unsigned int i,
 961     unsigned int sh_type,
 962     const unsigned char* prelocs,
 963     size_t reloc_count,
 964     Output_section* output_section,
 965     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
 966     unsigned char* view,
 967     typename elfcpp::Elf_types<size>::Elf_Addr address,
 968     section_size_type view_size,
 969     unsigned char* reloc_view,
 970     section_size_type reloc_view_size)
 971 {
 972   if (sh_type == elfcpp::SHT_REL)
 973     this->emit_relocs_reltype<elfcpp::SHT_REL>(relinfo, i, prelocs,
 974                                                reloc_count, output_section,
 975                                                offset_in_output_section,
 976                                                view, address, view_size,
 977                                                reloc_view, reloc_view_size);
 978   else
 979     {
 980       gold_assert(sh_type == elfcpp::SHT_RELA);
 981       this->emit_relocs_reltype<elfcpp::SHT_RELA>(relinfo, i, prelocs,
 982                                                   reloc_count, output_section,
 983                                                   offset_in_output_section,
 984                                                   view, address, view_size,
 985                                                   reloc_view, reloc_view_size);
 986     }
 987 }
 988
 989 // Emit the relocs for --emit-relocs, templatized on the type of the
 990 // relocation section.
 991
 992 template<int size, bool big_endian>
 993 template<int sh_type>
 994 void
 995 Sized_relobj<size, big_endian>::emit_relocs_reltype(
 996     const Relocate_info<size, big_endian>* relinfo,
 997     unsigned int i,
 998     const unsigned char* prelocs,
 999     size_t reloc_count,
1000     Output_section* output_section,
1001     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
1002     unsigned char* view,
1003     typename elfcpp::Elf_types<size>::Elf_Addr address,
1004     section_size_type view_size,
1005     unsigned char* reloc_view,
1006     section_size_type reloc_view_size)
1007 {
1008   const Relocatable_relocs* rr = this->relocatable_relocs(i);
1009   relocate_for_relocatable<size, big_endian, sh_type>(
1010     relinfo,
1011     prelocs,
1012     reloc_count,
1013     output_section,
1014     offset_in_output_section,
1015     rr,
1016     view,
1017     address,
1018     view_size,
1019     reloc_view,
1020     reloc_view_size);
1021 }
1022
1023 // Create merge hash tables for the local symbols.  These are used to
1024 // speed up relocations.
1025
1026 template<int size, bool big_endian>
1027 void
1028 Sized_relobj<size, big_endian>::initialize_input_to_output_maps()
1029 {
1030   const unsigned int loccount = this->local_symbol_count_;
1031   for (unsigned int i = 1; i < loccount; ++i)
1032     {
1033       Symbol_value<size>& lv(this->local_values_[i]);
1034       lv.initialize_input_to_output_map(this);
1035     }
1036 }
1037
1038 // Free merge hash tables for the local symbols.
1039
1040 template<int size, bool big_endian>
1041 void
1042 Sized_relobj<size, big_endian>::free_input_to_output_maps()
1043 {
1044   const unsigned int loccount = this->local_symbol_count_;
1045   for (unsigned int i = 1; i < loccount; ++i)
1046     {
1047       Symbol_value<size>& lv(this->local_values_[i]);
1048       lv.free_input_to_output_map();
1049     }
1050 }
1051
1052 // If an object was compiled with -fsplit-stack, this is called to
1053 // check whether any relocations refer to functions defined in objects
1054 // which were not compiled with -fsplit-stack.  If they were, then we
1055 // need to apply some target-specific adjustments to request
1056 // additional stack space.
1057
1058 template<int size, bool big_endian>
1059 void
1060 Sized_relobj<size, big_endian>::split_stack_adjust(
1061     const Symbol_table* symtab,
1062     const unsigned char* pshdrs,
1063     unsigned int sh_type,
1064     unsigned int shndx,
1065     const unsigned char* prelocs,
1066     size_t reloc_count,
1067     unsigned char* view,
1068     section_size_type view_size,
1069     Reloc_symbol_changes** reloc_map)
1070 {
1071   if (sh_type == elfcpp::SHT_REL)
1072     this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
1073                                                       prelocs, reloc_count,
1074                                                       view, view_size,
1075                                                       reloc_map);
1076   else
1077     {
1078       gold_assert(sh_type == elfcpp::SHT_RELA);
1079       this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
1080                                                          prelocs, reloc_count,
1081                                                          view, view_size,
1082                                                          reloc_map);
1083     }
1084 }
1085
1086 // Adjust for -fsplit-stack, templatized on the type of the relocation
1087 // section.
1088
1089 template<int size, bool big_endian>
1090 template<int sh_type>
1091 void
1092 Sized_relobj<size, big_endian>::split_stack_adjust_reltype(
1093     const Symbol_table* symtab,
1094     const unsigned char* pshdrs,
1095     unsigned int shndx,
1096     const unsigned char* prelocs,
1097     size_t reloc_count,
1098     unsigned char* view,
1099     section_size_type view_size,
1100     Reloc_symbol_changes** reloc_map)
1101 {
1102   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
1103   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
1104
1105   size_t local_count = this->local_symbol_count();
1106
1107   std::vector<section_offset_type> non_split_refs;
1108
1109   const unsigned char* pr = prelocs;
1110   for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1111     {
1112       Reltype reloc(pr);
1113
1114       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1115       unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1116       if (r_sym < local_count)
1117         continue;
1118
1119       const Symbol* gsym = this->global_symbol(r_sym);
1120       gold_assert(gsym != NULL);
1121       if (gsym->is_forwarder())
1122         gsym = symtab->resolve_forwards(gsym);
1123
1124       // See if this relocation refers to a function defined in an
1125       // object compiled without -fsplit-stack.  Note that we don't
1126       // care about the type of relocation--this means that in some
1127       // cases we will ask for a large stack unnecessarily, but this
1128       // is not fatal.  FIXME: Some targets have symbols which are
1129       // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
1130       if (!gsym->is_undefined()
1131           && gsym->source() == Symbol::FROM_OBJECT
1132           && !gsym->object()->uses_split_stack())
1133         {
1134           unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
1135           if (parameters->target().is_call_to_non_split(gsym, r_type))
1136             {
1137               section_offset_type offset =
1138                 convert_to_section_size_type(reloc.get_r_offset());
1139               non_split_refs.push_back(offset);
1140             }
1141         }
1142     }
1143
1144   if (non_split_refs.empty())
1145     return;
1146
1147   // At this point, every entry in NON_SPLIT_REFS indicates a
1148   // relocation which refers to a function in an object compiled
1149   // without -fsplit-stack.  We now have to convert that list into a
1150   // set of offsets to functions.  First, we find all the functions.
1151
1152   Function_offsets function_offsets;
1153   this->find_functions(pshdrs, shndx, &function_offsets);
1154   if (function_offsets.empty())
1155     return;
1156
1157   // Now get a list of the function with references to non split-stack
1158   // code.
1159
1160   Function_offsets calls_non_split;
1161   for (std::vector<section_offset_type>::const_iterator p
1162          = non_split_refs.begin();
1163        p != non_split_refs.end();
1164        ++p)
1165     {
1166       Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
1167       if (low == function_offsets.end())
1168         --low;
1169       else if (low->first == *p)
1170         ;
1171       else if (low == function_offsets.begin())
1172         continue;
1173       else
1174         --low;
1175
1176       calls_non_split.insert(*low);
1177     }
1178   if (calls_non_split.empty())
1179     return;
1180
1181   // Now we have a set of functions to adjust.  The adjustments are
1182   // target specific.  Besides changing the output section view
1183   // however, it likes, the target may request a relocation change
1184   // from one global symbol name to another.
1185
1186   for (Function_offsets::const_iterator p = calls_non_split.begin();
1187        p != calls_non_split.end();
1188        ++p)
1189     {
1190       std::string from;
1191       std::string to;
1192       parameters->target().calls_non_split(this, shndx, p->first, p->second,
1193                                            view, view_size, &from, &to);
1194       if (!from.empty())
1195         {
1196           gold_assert(!to.empty());
1197           Symbol* tosym = NULL;
1198
1199           // Find relocations in the relevant function which are for
1200           // FROM.
1201           pr = prelocs;
1202           for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1203             {
1204               Reltype reloc(pr);
1205
1206               typename elfcpp::Elf_types<size>::Elf_WXword r_info =
1207                 reloc.get_r_info();
1208               unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1209               if (r_sym < local_count)
1210                 continue;
1211
1212               section_offset_type offset =
1213                 convert_to_section_size_type(reloc.get_r_offset());
1214               if (offset < p->first
1215                   || (offset
1216                       >= (p->first
1217                           + static_cast<section_offset_type>(p->second))))
1218                 continue;
1219
1220               const Symbol* gsym = this->global_symbol(r_sym);
1221               if (from == gsym->name())
1222                 {
1223                   if (tosym == NULL)
1224                     {
1225                       tosym = symtab->lookup(to.c_str());
1226                       if (tosym == NULL)
1227                         {
1228                           this->error(_("could not convert call "
1229                                         "to '%s' to '%s'"),
1230                                       from.c_str(), to.c_str());
1231                           break;
1232                         }
1233                     }
1234
1235                   if (*reloc_map == NULL)
1236                     *reloc_map = new Reloc_symbol_changes(reloc_count);
1237                   (*reloc_map)->set(i, tosym);
1238                 }
1239             }
1240         }
1241     }
1242 }
1243
1244 // Find all the function in this object defined in section SHNDX.
1245 // Store their offsets in the section in FUNCTION_OFFSETS.
1246
1247 template<int size, bool big_endian>
1248 void
1249 Sized_relobj<size, big_endian>::find_functions(
1250     const unsigned char* pshdrs,
1251     unsigned int shndx,
1252     Sized_relobj<size, big_endian>::Function_offsets* function_offsets)
1253 {
1254   // We need to read the symbols to find the functions.  If we wanted
1255   // to, we could cache reading the symbols across all sections in the
1256   // object.
1257   const unsigned int symtab_shndx = this->symtab_shndx_;
1258   typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size);
1259   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1260
1261   typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
1262     symtabshdr.get_sh_size();
1263   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1264                                               sh_size, true, true);
1265
1266   const int sym_size = This::sym_size;
1267   const unsigned int symcount = sh_size / sym_size;
1268   for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size)
1269     {
1270       typename elfcpp::Sym<size, big_endian> isym(psyms);
1271
1272       // FIXME: Some targets can have functions which do not have type
1273       // STT_FUNC, e.g., STT_ARM_TFUNC.
1274       if (isym.get_st_type() != elfcpp::STT_FUNC
1275           || isym.get_st_size() == 0)
1276         continue;
1277
1278       bool is_ordinary;
1279       unsigned int sym_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1280                                                       &is_ordinary);
1281       if (!is_ordinary || sym_shndx != shndx)
1282         continue;
1283
1284       section_offset_type value =
1285         convert_to_section_size_type(isym.get_st_value());
1286       section_size_type fnsize =
1287         convert_to_section_size_type(isym.get_st_size());
1288
1289       (*function_offsets)[value] = fnsize;
1290     }
1291 }
1292
1293 // Class Merged_symbol_value.
1294
1295 template<int size>
1296 void
1297 Merged_symbol_value<size>::initialize_input_to_output_map(
1298     const Relobj* object,
1299     unsigned int input_shndx)
1300 {
1301   Object_merge_map* map = object->merge_map();
1302   map->initialize_input_to_output_map<size>(input_shndx,
1303                                             this->output_start_address_,
1304                                             &this->output_addresses_);
1305 }
1306
1307 // Get the output value corresponding to an input offset if we
1308 // couldn't find it in the hash table.
1309
1310 template<int size>
1311 typename elfcpp::Elf_types<size>::Elf_Addr
1312 Merged_symbol_value<size>::value_from_output_section(
1313     const Relobj* object,
1314     unsigned int input_shndx,
1315     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
1316 {
1317   section_offset_type output_offset;
1318   bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
1319                                                       input_offset,
1320                                                       &output_offset);
1321
1322   // If this assertion fails, it means that some relocation was
1323   // against a portion of an input merge section which we didn't map
1324   // to the output file and we didn't explicitly discard.  We should
1325   // always map all portions of input merge sections.
1326   gold_assert(found);
1327
1328   if (output_offset == -1)
1329     return 0;
1330   else
1331     return this->output_start_address_ + output_offset;
1332 }
1333
1334 // Track_relocs methods.
1335
1336 // Initialize the class to track the relocs.  This gets the object,
1337 // the reloc section index, and the type of the relocs.  This returns
1338 // false if something goes wrong.
1339
1340 template<int size, bool big_endian>
1341 bool
1342 Track_relocs<size, big_endian>::initialize(
1343     Object* object,
1344     unsigned int reloc_shndx,
1345     unsigned int reloc_type)
1346 {
1347   // If RELOC_SHNDX is -1U, it means there is more than one reloc
1348   // section for the .eh_frame section.  We can't handle that case.
1349   if (reloc_shndx == -1U)
1350     return false;
1351
1352   // If RELOC_SHNDX is 0, there is no reloc section.
1353   if (reloc_shndx == 0)
1354     return true;
1355
1356   // Get the contents of the reloc section.
1357   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
1358
1359   if (reloc_type == elfcpp::SHT_REL)
1360     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
1361   else if (reloc_type == elfcpp::SHT_RELA)
1362     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
1363   else
1364     gold_unreachable();
1365
1366   if (this->len_ % this->reloc_size_ != 0)
1367     {
1368       object->error(_("reloc section size %zu is not a multiple of "
1369                       "reloc size %d\n"),
1370                     static_cast<size_t>(this->len_),
1371                     this->reloc_size_);
1372       return false;
1373     }
1374
1375   return true;
1376 }
1377
1378 // Return the offset of the next reloc, or -1 if there isn't one.
1379
1380 template<int size, bool big_endian>
1381 off_t
1382 Track_relocs<size, big_endian>::next_offset() const
1383 {
1384   if (this->pos_ >= this->len_)
1385     return -1;
1386
1387   // Rel and Rela start out the same, so we can always use Rel to find
1388   // the r_offset value.
1389   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1390   return rel.get_r_offset();
1391 }
1392
1393 // Return the index of the symbol referenced by the next reloc, or -1U
1394 // if there aren't any more relocs.
1395
1396 template<int size, bool big_endian>
1397 unsigned int
1398 Track_relocs<size, big_endian>::next_symndx() const
1399 {
1400   if (this->pos_ >= this->len_)
1401     return -1U;
1402
1403   // Rel and Rela start out the same, so we can use Rel to find the
1404   // symbol index.
1405   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1406   return elfcpp::elf_r_sym<size>(rel.get_r_info());
1407 }
1408
1409 // Advance to the next reloc whose r_offset is greater than or equal
1410 // to OFFSET.  Return the number of relocs we skip.
1411
1412 template<int size, bool big_endian>
1413 int
1414 Track_relocs<size, big_endian>::advance(off_t offset)
1415 {
1416   int ret = 0;
1417   while (this->pos_ < this->len_)
1418     {
1419       // Rel and Rela start out the same, so we can always use Rel to
1420       // find the r_offset value.
1421       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1422       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
1423         break;
1424       ++ret;
1425       this->pos_ += this->reloc_size_;
1426     }
1427   return ret;
1428 }
1429
1430 // Instantiate the templates we need.
1431
1432 #ifdef HAVE_TARGET_32_LITTLE
1433 template
1434 void
1435 Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd);
1436 #endif
1437
1438 #ifdef HAVE_TARGET_32_BIG
1439 template
1440 void
1441 Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd);
1442 #endif
1443
1444 #ifdef HAVE_TARGET_64_LITTLE
1445 template
1446 void
1447 Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd);
1448 #endif
1449
1450 #ifdef HAVE_TARGET_64_BIG
1451 template
1452 void
1453 Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
1454 #endif
1455
1456 #ifdef HAVE_TARGET_32_LITTLE
1457 template
1458 void
1459 Sized_relobj<32, false>::do_gc_process_relocs(Symbol_table* symtab,
1460                                               Layout* layout,
1461                                               Read_relocs_data* rd);
1462 #endif
1463
1464 #ifdef HAVE_TARGET_32_BIG
1465 template
1466 void
1467 Sized_relobj<32, true>::do_gc_process_relocs(Symbol_table* symtab,
1468                                              Layout* layout,
1469                                              Read_relocs_data* rd);
1470 #endif
1471
1472 #ifdef HAVE_TARGET_64_LITTLE
1473 template
1474 void
1475 Sized_relobj<64, false>::do_gc_process_relocs(Symbol_table* symtab,
1476                                               Layout* layout,
1477                                               Read_relocs_data* rd);
1478 #endif
1479
1480 #ifdef HAVE_TARGET_64_BIG
1481 template
1482 void
1483 Sized_relobj<64, true>::do_gc_process_relocs(Symbol_table* symtab,
1484                                              Layout* layout,
1485                                              Read_relocs_data* rd);
1486 #endif
1487
1488 #ifdef HAVE_TARGET_32_LITTLE
1489 template
1490 void
1491 Sized_relobj<32, false>::do_scan_relocs(Symbol_table* symtab,
1492                                         Layout* layout,
1493                                         Read_relocs_data* rd);
1494 #endif
1495
1496 #ifdef HAVE_TARGET_32_BIG
1497 template
1498 void
1499 Sized_relobj<32, true>::do_scan_relocs(Symbol_table* symtab,
1500                                        Layout* layout,
1501                                        Read_relocs_data* rd);
1502 #endif
1503
1504 #ifdef HAVE_TARGET_64_LITTLE
1505 template
1506 void
1507 Sized_relobj<64, false>::do_scan_relocs(Symbol_table* symtab,
1508                                         Layout* layout,
1509                                         Read_relocs_data* rd);
1510 #endif
1511
1512 #ifdef HAVE_TARGET_64_BIG
1513 template
1514 void
1515 Sized_relobj<64, true>::do_scan_relocs(Symbol_table* symtab,
1516                                        Layout* layout,
1517                                        Read_relocs_data* rd);
1518 #endif
1519
1520 #ifdef HAVE_TARGET_32_LITTLE
1521 template
1522 void
1523 Sized_relobj<32, false>::do_relocate(const Symbol_table* symtab,
1524                                      const Layout* layout,
1525                                      Output_file* of);
1526 #endif
1527
1528 #ifdef HAVE_TARGET_32_BIG
1529 template
1530 void
1531 Sized_relobj<32, true>::do_relocate(const Symbol_table* symtab,
1532                                     const Layout* layout,
1533                                     Output_file* of);
1534 #endif
1535
1536 #ifdef HAVE_TARGET_64_LITTLE
1537 template
1538 void
1539 Sized_relobj<64, false>::do_relocate(const Symbol_table* symtab,
1540                                      const Layout* layout,
1541                                      Output_file* of);
1542 #endif
1543
1544 #ifdef HAVE_TARGET_64_BIG
1545 template
1546 void
1547 Sized_relobj<64, true>::do_relocate(const Symbol_table* symtab,
1548                                     const Layout* layout,
1549                                     Output_file* of);
1550 #endif
1551
1552 #ifdef HAVE_TARGET_32_LITTLE
1553 template
1554 void
1555 Sized_relobj<32, false>::do_relocate_sections(
1556     const Symbol_table* symtab,
1557     const Layout* layout,
1558     const unsigned char* pshdrs,
1559     Views* pviews);
1560 #endif
1561
1562 #ifdef HAVE_TARGET_32_BIG
1563 template
1564 void
1565 Sized_relobj<32, true>::do_relocate_sections(
1566     const Symbol_table* symtab,
1567     const Layout* layout,
1568     const unsigned char* pshdrs,
1569     Views* pviews);
1570 #endif
1571
1572 #ifdef HAVE_TARGET_64_LITTLE
1573 template
1574 void
1575 Sized_relobj<64, false>::do_relocate_sections(
1576     const Symbol_table* symtab,
1577     const Layout* layout,
1578     const unsigned char* pshdrs,
1579     Views* pviews);
1580 #endif
1581
1582 #ifdef HAVE_TARGET_64_BIG
1583 template
1584 void
1585 Sized_relobj<64, true>::do_relocate_sections(
1586     const Symbol_table* symtab,
1587     const Layout* layout,
1588     const unsigned char* pshdrs,
1589     Views* pviews);
1590 #endif
1591
1592 #ifdef HAVE_TARGET_32_LITTLE
1593 template
1594 void
1595 Sized_relobj<32, false>::initialize_input_to_output_maps();
1596
1597 template
1598 void
1599 Sized_relobj<32, false>::free_input_to_output_maps();
1600 #endif
1601
1602 #ifdef HAVE_TARGET_32_BIG
1603 template
1604 void
1605 Sized_relobj<32, true>::initialize_input_to_output_maps();
1606
1607 template
1608 void
1609 Sized_relobj<32, true>::free_input_to_output_maps();
1610 #endif
1611
1612 #ifdef HAVE_TARGET_64_LITTLE
1613 template
1614 void
1615 Sized_relobj<64, false>::initialize_input_to_output_maps();
1616
1617 template
1618 void
1619 Sized_relobj<64, false>::free_input_to_output_maps();
1620 #endif
1621
1622 #ifdef HAVE_TARGET_64_BIG
1623 template
1624 void
1625 Sized_relobj<64, true>::initialize_input_to_output_maps();
1626
1627 template
1628 void
1629 Sized_relobj<64, true>::free_input_to_output_maps();
1630 #endif
1631
1632 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1633 template
1634 class Merged_symbol_value<32>;
1635 #endif
1636
1637 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1638 template
1639 class Merged_symbol_value<64>;
1640 #endif
1641
1642 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1643 template
1644 class Symbol_value<32>;
1645 #endif
1646
1647 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1648 template
1649 class Symbol_value<64>;
1650 #endif
1651
1652 #ifdef HAVE_TARGET_32_LITTLE
1653 template
1654 class Track_relocs<32, false>;
1655 #endif
1656
1657 #ifdef HAVE_TARGET_32_BIG
1658 template
1659 class Track_relocs<32, true>;
1660 #endif
1661
1662 #ifdef HAVE_TARGET_64_LITTLE
1663 template
1664 class Track_relocs<64, false>;
1665 #endif
1666
1667 #ifdef HAVE_TARGET_64_BIG
1668 template
1669 class Track_relocs<64, true>;
1670 #endif
1671
1672 } // End namespace gold.