gold/reloc.cc

   1 // reloc.cc -- relocate input files for gold.
   2
   3 // Copyright 2006, 2007 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <algorithm>
  26
  27 #include "workqueue.h"
  28 #include "symtab.h"
  29 #include "output.h"
  30 #include "merge.h"
  31 #include "object.h"
  32 #include "reloc.h"
  33
  34 namespace gold
  35 {
  36
  37 // Read_relocs methods.
  38
  39 // These tasks just read the relocation information from the file.
  40 // After reading it, the start another task to process the
  41 // information.  These tasks requires access to the file.
  42
  43 Task_token*
  44 Read_relocs::is_runnable()
  45 {
  46   return this->object_->is_locked() ? this->object_->token() : NULL;
  47 }
  48
  49 // Lock the file.
  50
  51 void
  52 Read_relocs::locks(Task_locker* tl)
  53 {
  54   tl->add(this, this->object_->token());
  55 }
  56
  57 // Read the relocations and then start a Scan_relocs_task.
  58
  59 void
  60 Read_relocs::run(Workqueue* workqueue)
  61 {
  62   Read_relocs_data *rd = new Read_relocs_data;
  63   this->object_->read_relocs(rd);
  64   this->object_->release();
  65
  66   workqueue->queue_front(new Scan_relocs(this->options_, this->symtab_,
  67                                          this->layout_, this->object_, rd,
  68                                          this->symtab_lock_, this->blocker_));
  69 }
  70
  71 // Return a debugging name for the task.
  72
  73 std::string
  74 Read_relocs::get_name() const
  75 {
  76   return "Read_relocs " + this->object_->name();
  77 }
  78
  79 // Scan_relocs methods.
  80
  81 // These tasks scan the relocations read by Read_relocs and mark up
  82 // the symbol table to indicate which relocations are required.  We
  83 // use a lock on the symbol table to keep them from interfering with
  84 // each other.
  85
  86 Task_token*
  87 Scan_relocs::is_runnable()
  88 {
  89   if (!this->symtab_lock_->is_writable())
  90     return this->symtab_lock_;
  91   if (this->object_->is_locked())
  92     return this->object_->token();
  93   return NULL;
  94 }
  95
  96 // Return the locks we hold: one on the file, one on the symbol table
  97 // and one blocker.
  98
  99 void
 100 Scan_relocs::locks(Task_locker* tl)
 101 {
 102   tl->add(this, this->object_->token());
 103   tl->add(this, this->symtab_lock_);
 104   tl->add(this, this->blocker_);
 105 }
 106
 107 // Scan the relocs.
 108
 109 void
 110 Scan_relocs::run(Workqueue*)
 111 {
 112   this->object_->scan_relocs(this->options_, this->symtab_, this->layout_,
 113                              this->rd_);
 114   this->object_->release();
 115   delete this->rd_;
 116   this->rd_ = NULL;
 117 }
 118
 119 // Return a debugging name for the task.
 120
 121 std::string
 122 Scan_relocs::get_name() const
 123 {
 124   return "Scan_relocs " + this->object_->name();
 125 }
 126
 127 // Relocate_task methods.
 128
 129 // We may have to wait for the output sections to be written.
 130
 131 Task_token*
 132 Relocate_task::is_runnable()
 133 {
 134   if (this->object_->relocs_must_follow_section_writes()
 135       && this->output_sections_blocker_->is_blocked())
 136     return this->output_sections_blocker_;
 137
 138   if (this->object_->is_locked())
 139     return this->object_->token();
 140
 141   return NULL;
 142 }
 143
 144 // We want to lock the file while we run.  We want to unblock
 145 // INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done.
 146 // INPUT_SECTIONS_BLOCKER may be NULL.
 147
 148 void
 149 Relocate_task::locks(Task_locker* tl)
 150 {
 151   if (this->input_sections_blocker_ != NULL)
 152     tl->add(this, this->input_sections_blocker_);
 153   tl->add(this, this->final_blocker_);
 154   tl->add(this, this->object_->token());
 155 }
 156
 157 // Run the task.
 158
 159 void
 160 Relocate_task::run(Workqueue*)
 161 {
 162   this->object_->relocate(this->options_, this->symtab_, this->layout_,
 163                           this->of_);
 164
 165   // This is normally the last thing we will do with an object, so
 166   // uncache all views.
 167   this->object_->clear_view_cache_marks();
 168
 169   this->object_->release();
 170 }
 171
 172 // Return a debugging name for the task.
 173
 174 std::string
 175 Relocate_task::get_name() const
 176 {
 177   return "Relocate_task " + this->object_->name();
 178 }
 179
 180 // Read the relocs and local symbols from the object file and store
 181 // the information in RD.
 182
 183 template<int size, bool big_endian>
 184 void
 185 Sized_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd)
 186 {
 187   rd->relocs.clear();
 188
 189   unsigned int shnum = this->shnum();
 190   if (shnum == 0)
 191     return;
 192
 193   rd->relocs.reserve(shnum / 2);
 194
 195   std::vector<Map_to_output>& map_sections(this->map_to_output());
 196
 197   const unsigned char *pshdrs = this->get_view(this->elf_file_.shoff(),
 198                                                shnum * This::shdr_size,
 199                                                true);
 200   // Skip the first, dummy, section.
 201   const unsigned char *ps = pshdrs + This::shdr_size;
 202   for (unsigned int i = 1; i < shnum; ++i, ps += This::shdr_size)
 203     {
 204       typename This::Shdr shdr(ps);
 205
 206       unsigned int sh_type = shdr.get_sh_type();
 207       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 208         continue;
 209
 210       unsigned int shndx = shdr.get_sh_info();
 211       if (shndx >= shnum)
 212         {
 213           this->error(_("relocation section %u has bad info %u"),
 214                       i, shndx);
 215           continue;
 216         }
 217
 218       Output_section* os = map_sections[shndx].output_section;
 219       if (os == NULL)
 220         continue;
 221
 222       // We are scanning relocations in order to fill out the GOT and
 223       // PLT sections.  Relocations for sections which are not
 224       // allocated (typically debugging sections) should not add new
 225       // GOT and PLT entries.  So we skip them unless this is a
 226       // relocatable link.
 227       if (!parameters->output_is_object())
 228         {
 229           typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
 230           if ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 231             continue;
 232         }
 233
 234       if (shdr.get_sh_link() != this->symtab_shndx_)
 235         {
 236           this->error(_("relocation section %u uses unexpected "
 237                         "symbol table %u"),
 238                       i, shdr.get_sh_link());
 239           continue;
 240         }
 241
 242       off_t sh_size = shdr.get_sh_size();
 243
 244       unsigned int reloc_size;
 245       if (sh_type == elfcpp::SHT_REL)
 246         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 247       else
 248         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 249       if (reloc_size != shdr.get_sh_entsize())
 250         {
 251           this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
 252                       i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 253                       reloc_size);
 254           continue;
 255         }
 256
 257       size_t reloc_count = sh_size / reloc_size;
 258       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 259         {
 260           this->error(_("reloc section %u size %lu uneven"),
 261                       i, static_cast<unsigned long>(sh_size));
 262           continue;
 263         }
 264
 265       rd->relocs.push_back(Section_relocs());
 266       Section_relocs& sr(rd->relocs.back());
 267       sr.reloc_shndx = i;
 268       sr.data_shndx = shndx;
 269       sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
 270                                            true);
 271       sr.sh_type = sh_type;
 272       sr.reloc_count = reloc_count;
 273       sr.output_section = os;
 274       sr.needs_special_offset_handling = map_sections[shndx].offset == -1;
 275     }
 276
 277   // Read the local symbols.
 278   gold_assert(this->symtab_shndx_ != -1U);
 279   if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
 280     rd->local_symbols = NULL;
 281   else
 282     {
 283       typename This::Shdr symtabshdr(pshdrs
 284                                      + this->symtab_shndx_ * This::shdr_size);
 285       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 286       const int sym_size = This::sym_size;
 287       const unsigned int loccount = this->local_symbol_count_;
 288       gold_assert(loccount == symtabshdr.get_sh_info());
 289       off_t locsize = loccount * sym_size;
 290       rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
 291                                                  locsize, true);
 292     }
 293 }
 294
 295 // Scan the relocs and adjust the symbol table.  This looks for
 296 // relocations which require GOT/PLT/COPY relocations.
 297
 298 template<int size, bool big_endian>
 299 void
 300 Sized_relobj<size, big_endian>::do_scan_relocs(const General_options& options,
 301                                                Symbol_table* symtab,
 302                                                Layout* layout,
 303                                                Read_relocs_data* rd)
 304 {
 305   Sized_target<size, big_endian>* target = this->sized_target();
 306
 307   const unsigned char* local_symbols;
 308   if (rd->local_symbols == NULL)
 309     local_symbols = NULL;
 310   else
 311     local_symbols = rd->local_symbols->data();
 312
 313   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 314        p != rd->relocs.end();
 315        ++p)
 316     {
 317       if (!parameters->output_is_object())
 318         target->scan_relocs(options, symtab, layout, this, p->data_shndx,
 319                             p->sh_type, p->contents->data(), p->reloc_count,
 320                             p->output_section,
 321                             p->needs_special_offset_handling,
 322                             this->local_symbol_count_,
 323                             local_symbols);
 324       else
 325         {
 326           Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 327           gold_assert(rr != NULL);
 328           rr->set_reloc_count(p->reloc_count);
 329           target->scan_relocatable_relocs(options, symtab, layout, this,
 330                                           p->data_shndx, p->sh_type,
 331                                           p->contents->data(),
 332                                           p->reloc_count,
 333                                           p->output_section,
 334                                           p->needs_special_offset_handling,
 335                                           this->local_symbol_count_,
 336                                           local_symbols,
 337                                           rr);
 338         }
 339
 340       delete p->contents;
 341       p->contents = NULL;
 342     }
 343
 344   if (rd->local_symbols != NULL)
 345     {
 346       delete rd->local_symbols;
 347       rd->local_symbols = NULL;
 348     }
 349 }
 350
 351 // Relocate the input sections and write out the local symbols.
 352
 353 template<int size, bool big_endian>
 354 void
 355 Sized_relobj<size, big_endian>::do_relocate(const General_options& options,
 356                                             const Symbol_table* symtab,
 357                                             const Layout* layout,
 358                                             Output_file* of)
 359 {
 360   unsigned int shnum = this->shnum();
 361
 362   // Read the section headers.
 363   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 364                                                shnum * This::shdr_size,
 365                                                true);
 366
 367   Views views;
 368   views.resize(shnum);
 369
 370   // Make two passes over the sections.  The first one copies the
 371   // section data to the output file.  The second one applies
 372   // relocations.
 373
 374   this->write_sections(pshdrs, of, &views);
 375
 376   // To speed up relocations, we set up hash tables for fast lookup of
 377   // input offsets to output addresses.
 378   this->initialize_input_to_output_maps();
 379
 380   // Apply relocations.
 381
 382   this->relocate_sections(options, symtab, layout, pshdrs, &views);
 383
 384   // After we've done the relocations, we release the hash tables,
 385   // since we no longer need them.
 386   this->free_input_to_output_maps();
 387
 388   // Write out the accumulated views.
 389   for (unsigned int i = 1; i < shnum; ++i)
 390     {
 391       if (views[i].view != NULL)
 392         {
 393           if (!views[i].is_postprocessing_view)
 394             {
 395               if (views[i].is_input_output_view)
 396                 of->write_input_output_view(views[i].offset,
 397                                             views[i].view_size,
 398                                             views[i].view);
 399               else
 400                 of->write_output_view(views[i].offset, views[i].view_size,
 401                                       views[i].view);
 402             }
 403         }
 404     }
 405
 406   // Write out the local symbols.
 407   this->write_local_symbols(of, layout->sympool(), layout->dynpool());
 408
 409   // We should no longer need the local symbol values.
 410   this->clear_local_symbols();
 411 }
 412
 413 // Sort a Read_multiple vector by file offset.
 414 struct Read_multiple_compare
 415 {
 416   inline bool
 417   operator()(const File_read::Read_multiple_entry& rme1,
 418              const File_read::Read_multiple_entry& rme2) const
 419   { return rme1.file_offset < rme2.file_offset; }
 420 };
 421
 422 // Write section data to the output file.  PSHDRS points to the
 423 // section headers.  Record the views in *PVIEWS for use when
 424 // relocating.
 425
 426 template<int size, bool big_endian>
 427 void
 428 Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
 429                                                Output_file* of,
 430                                                Views* pviews)
 431 {
 432   unsigned int shnum = this->shnum();
 433   const std::vector<Map_to_output>& map_sections(this->map_to_output());
 434
 435   File_read::Read_multiple rm;
 436   bool is_sorted = true;
 437
 438   const unsigned char* p = pshdrs + This::shdr_size;
 439   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 440     {
 441       View_size* pvs = &(*pviews)[i];
 442
 443       pvs->view = NULL;
 444
 445       const Output_section* os = map_sections[i].output_section;
 446       if (os == NULL)
 447         continue;
 448       off_t output_offset = map_sections[i].offset;
 449
 450       typename This::Shdr shdr(p);
 451
 452       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 453         continue;
 454
 455       if (parameters->output_is_object()
 456           && (shdr.get_sh_type() == elfcpp::SHT_REL
 457               || shdr.get_sh_type() == elfcpp::SHT_RELA)
 458           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 459         {
 460           // This is a reloc section in a relocatable link.  We don't
 461           // need to read the input file.  The size and file offset
 462           // are stored in the Relocatable_relocs structure.
 463           Relocatable_relocs* rr = this->relocatable_relocs(i);
 464           gold_assert(rr != NULL);
 465           Output_data* posd = rr->output_data();
 466           gold_assert(posd != NULL);
 467
 468           pvs->offset = posd->offset();
 469           pvs->view_size = posd->data_size();
 470           pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
 471           pvs->address = posd->address();
 472           pvs->is_input_output_view = false;
 473           pvs->is_postprocessing_view = false;
 474
 475           continue;
 476         }
 477
 478       // In the normal case, this input section is simply mapped to
 479       // the output section at offset OUTPUT_OFFSET.
 480
 481       // However, if OUTPUT_OFFSET == -1, then input data is handled
 482       // specially--e.g., a .eh_frame section.  The relocation
 483       // routines need to check for each reloc where it should be
 484       // applied.  For this case, we need an input/output view for the
 485       // entire contents of the section in the output file.  We don't
 486       // want to copy the contents of the input section to the output
 487       // section; the output section contents were already written,
 488       // and we waited for them in Relocate_task::is_runnable because
 489       // relocs_must_follow_section_writes is set for the object.
 490
 491       // Regardless of which of the above cases is true, we have to
 492       // check requires_postprocessing of the output section.  If that
 493       // is false, then we work with views of the output file
 494       // directly.  If it is true, then we work with a separate
 495       // buffer, and the output section is responsible for writing the
 496       // final data to the output file.
 497
 498       off_t output_section_offset;
 499       off_t output_section_size;
 500       if (!os->requires_postprocessing())
 501         {
 502           output_section_offset = os->offset();
 503           output_section_size = os->data_size();
 504         }
 505       else
 506         {
 507           output_section_offset = 0;
 508           output_section_size = os->postprocessing_buffer_size();
 509         }
 510
 511       off_t view_start;
 512       section_size_type view_size;
 513       if (output_offset != -1)
 514         {
 515           view_start = output_section_offset + output_offset;
 516           view_size = convert_to_section_size_type(shdr.get_sh_size());
 517         }
 518       else
 519         {
 520           view_start = output_section_offset;
 521           view_size = convert_to_section_size_type(output_section_size);
 522         }
 523
 524       if (view_size == 0)
 525         continue;
 526
 527       gold_assert(output_offset == -1
 528                   || (output_offset >= 0
 529                       && (output_offset + static_cast<off_t>(view_size)
 530                           <= output_section_size)));
 531
 532       unsigned char* view;
 533       if (os->requires_postprocessing())
 534         {
 535           unsigned char* buffer = os->postprocessing_buffer();
 536           view = buffer + view_start;
 537           if (output_offset != -1)
 538             {
 539               off_t sh_offset = shdr.get_sh_offset();
 540               if (!rm.empty() && rm.back().file_offset > sh_offset)
 541                 is_sorted = false;
 542               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 543                                                           view_size, view));
 544             }
 545         }
 546       else
 547         {
 548           if (output_offset == -1)
 549             view = of->get_input_output_view(view_start, view_size);
 550           else
 551             {
 552               view = of->get_output_view(view_start, view_size);
 553               off_t sh_offset = shdr.get_sh_offset();
 554               if (!rm.empty() && rm.back().file_offset > sh_offset)
 555                 is_sorted = false;
 556               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 557                                                           view_size, view));
 558             }
 559         }
 560
 561       pvs->view = view;
 562       pvs->address = os->address();
 563       if (output_offset != -1)
 564         pvs->address += output_offset;
 565       pvs->offset = view_start;
 566       pvs->view_size = view_size;
 567       pvs->is_input_output_view = output_offset == -1;
 568       pvs->is_postprocessing_view = os->requires_postprocessing();
 569     }
 570
 571   // Actually read the data.
 572   if (!rm.empty())
 573     {
 574       if (!is_sorted)
 575         std::sort(rm.begin(), rm.end(), Read_multiple_compare());
 576       this->read_multiple(rm);
 577     }
 578 }
 579
 580 // Relocate section data.  VIEWS points to the section data as views
 581 // in the output file.
 582
 583 template<int size, bool big_endian>
 584 void
 585 Sized_relobj<size, big_endian>::relocate_sections(
 586     const General_options& options,
 587     const Symbol_table* symtab,
 588     const Layout* layout,
 589     const unsigned char* pshdrs,
 590     Views* pviews)
 591 {
 592   unsigned int shnum = this->shnum();
 593   Sized_target<size, big_endian>* target = this->sized_target();
 594
 595   const std::vector<Map_to_output>& map_sections(this->map_to_output());
 596
 597   Relocate_info<size, big_endian> relinfo;
 598   relinfo.options = &options;
 599   relinfo.symtab = symtab;
 600   relinfo.layout = layout;
 601   relinfo.object = this;
 602
 603   const unsigned char* p = pshdrs + This::shdr_size;
 604   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 605     {
 606       typename This::Shdr shdr(p);
 607
 608       unsigned int sh_type = shdr.get_sh_type();
 609       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 610         continue;
 611
 612       unsigned int index = shdr.get_sh_info();
 613       if (index >= this->shnum())
 614         {
 615           this->error(_("relocation section %u has bad info %u"),
 616                       i, index);
 617           continue;
 618         }
 619
 620       Output_section* os = map_sections[index].output_section;
 621       if (os == NULL)
 622         {
 623           // This relocation section is against a section which we
 624           // discarded.
 625           continue;
 626         }
 627       off_t output_offset = map_sections[index].offset;
 628
 629       gold_assert((*pviews)[index].view != NULL);
 630       if (parameters->output_is_object())
 631         gold_assert((*pviews)[i].view != NULL);
 632
 633       if (shdr.get_sh_link() != this->symtab_shndx_)
 634         {
 635           gold_error(_("relocation section %u uses unexpected "
 636                        "symbol table %u"),
 637                      i, shdr.get_sh_link());
 638           continue;
 639         }
 640
 641       off_t sh_size = shdr.get_sh_size();
 642       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 643                                                     sh_size, false);
 644
 645       unsigned int reloc_size;
 646       if (sh_type == elfcpp::SHT_REL)
 647         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 648       else
 649         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 650
 651       if (reloc_size != shdr.get_sh_entsize())
 652         {
 653           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 654                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 655                      reloc_size);
 656           continue;
 657         }
 658
 659       size_t reloc_count = sh_size / reloc_size;
 660       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 661         {
 662           gold_error(_("reloc section %u size %lu uneven"),
 663                      i, static_cast<unsigned long>(sh_size));
 664           continue;
 665         }
 666
 667       gold_assert(output_offset != -1
 668                   || this->relocs_must_follow_section_writes());
 669
 670       relinfo.reloc_shndx = i;
 671       relinfo.data_shndx = index;
 672       if (!parameters->output_is_object())
 673         target->relocate_section(&relinfo,
 674                                  sh_type,
 675                                  prelocs,
 676                                  reloc_count,
 677                                  os,
 678                                  output_offset == -1,
 679                                  (*pviews)[index].view,
 680                                  (*pviews)[index].address,
 681                                  (*pviews)[index].view_size);
 682       else
 683         {
 684           Relocatable_relocs* rr = this->relocatable_relocs(i);
 685           target->relocate_for_relocatable(&relinfo,
 686                                            sh_type,
 687                                            prelocs,
 688                                            reloc_count,
 689                                            os,
 690                                            output_offset,
 691                                            rr,
 692                                            (*pviews)[index].view,
 693                                            (*pviews)[index].address,
 694                                            (*pviews)[index].view_size,
 695                                            (*pviews)[i].view,
 696                                            (*pviews)[i].view_size);
 697         }
 698     }
 699 }
 700
 701 // Create merge hash tables for the local symbols.  These are used to
 702 // speed up relocations.
 703
 704 template<int size, bool big_endian>
 705 void
 706 Sized_relobj<size, big_endian>::initialize_input_to_output_maps()
 707 {
 708   const unsigned int loccount = this->local_symbol_count_;
 709   for (unsigned int i = 1; i < loccount; ++i)
 710     {
 711       Symbol_value<size>& lv(this->local_values_[i]);
 712       lv.initialize_input_to_output_map(this);
 713     }
 714 }
 715
 716 // Free merge hash tables for the local symbols.
 717
 718 template<int size, bool big_endian>
 719 void
 720 Sized_relobj<size, big_endian>::free_input_to_output_maps()
 721 {
 722   const unsigned int loccount = this->local_symbol_count_;
 723   for (unsigned int i = 1; i < loccount; ++i)
 724     {
 725       Symbol_value<size>& lv(this->local_values_[i]);
 726       lv.free_input_to_output_map();
 727     }
 728 }
 729
 730 // Class Merged_symbol_value.
 731
 732 template<int size>
 733 void
 734 Merged_symbol_value<size>::initialize_input_to_output_map(
 735     const Relobj* object,
 736     unsigned int input_shndx)
 737 {
 738   Object_merge_map* map = object->merge_map();
 739   map->initialize_input_to_output_map<size>(input_shndx,
 740                                             this->output_start_address_,
 741                                             &this->output_addresses_);
 742 }
 743
 744 // Get the output value corresponding to an input offset if we
 745 // couldn't find it in the hash table.
 746
 747 template<int size>
 748 typename elfcpp::Elf_types<size>::Elf_Addr
 749 Merged_symbol_value<size>::value_from_output_section(
 750     const Relobj* object,
 751     unsigned int input_shndx,
 752     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
 753 {
 754   section_offset_type output_offset;
 755   bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
 756                                                       input_offset,
 757                                                       &output_offset);
 758
 759   // If this assertion fails, it means that some relocation was
 760   // against a portion of an input merge section which we didn't map
 761   // to the output file and we didn't explicitly discard.  We should
 762   // always map all portions of input merge sections.
 763   gold_assert(found);
 764
 765   if (output_offset == -1)
 766     return 0;
 767   else
 768     return this->output_start_address_ + output_offset;
 769 }
 770
 771 // Copy_relocs::Copy_reloc_entry methods.
 772
 773 // Return whether we should emit this reloc.  We should emit it if the
 774 // symbol is still defined in a dynamic object.  If we should not emit
 775 // it, we clear it, to save ourselves the test next time.
 776
 777 template<int size, bool big_endian>
 778 bool
 779 Copy_relocs<size, big_endian>::Copy_reloc_entry::should_emit()
 780 {
 781   if (this->sym_ == NULL)
 782     return false;
 783   if (this->sym_->is_from_dynobj())
 784     return true;
 785   this->sym_ = NULL;
 786   return false;
 787 }
 788
 789 // Emit a reloc into a SHT_REL section.
 790
 791 template<int size, bool big_endian>
 792 void
 793 Copy_relocs<size, big_endian>::Copy_reloc_entry::emit(
 794     Output_data_reloc<elfcpp::SHT_REL, true, size, big_endian>* reloc_data)
 795 {
 796   this->sym_->set_needs_dynsym_entry();
 797   reloc_data->add_global(this->sym_, this->reloc_type_, this->output_section_,
 798                          this->relobj_, this->shndx_, this->address_);
 799 }
 800
 801 // Emit a reloc into a SHT_RELA section.
 802
 803 template<int size, bool big_endian>
 804 void
 805 Copy_relocs<size, big_endian>::Copy_reloc_entry::emit(
 806     Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>* reloc_data)
 807 {
 808   this->sym_->set_needs_dynsym_entry();
 809   reloc_data->add_global(this->sym_, this->reloc_type_, this->output_section_,
 810                          this->relobj_, this->shndx_, this->address_,
 811                          this->addend_);
 812 }
 813
 814 // Copy_relocs methods.
 815
 816 // Return whether we need a COPY reloc for a relocation against GSYM.
 817 // The relocation is being applied to section SHNDX in OBJECT.
 818
 819 template<int size, bool big_endian>
 820 bool
 821 Copy_relocs<size, big_endian>::need_copy_reloc(
 822     const General_options*,
 823     Relobj* object,
 824     unsigned int shndx,
 825     Sized_symbol<size>* sym)
 826 {
 827   // FIXME: Handle -z nocopyrelocs.
 828
 829   if (sym->symsize() == 0)
 830     return false;
 831
 832   // If this is a readonly section, then we need a COPY reloc.
 833   // Otherwise we can use a dynamic reloc.
 834   if ((object->section_flags(shndx) & elfcpp::SHF_WRITE) == 0)
 835     return true;
 836
 837   return false;
 838 }
 839
 840 // Save a Rel reloc.
 841
 842 template<int size, bool big_endian>
 843 void
 844 Copy_relocs<size, big_endian>::save(
 845     Symbol* sym,
 846     Relobj* relobj,
 847     unsigned int shndx,
 848     Output_section* output_section,
 849     const elfcpp::Rel<size, big_endian>& rel)
 850 {
 851   unsigned int reloc_type = elfcpp::elf_r_type<size>(rel.get_r_info());
 852   this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, relobj, shndx,
 853                                             output_section,
 854                                             rel.get_r_offset(), 0));
 855 }
 856
 857 // Save a Rela reloc.
 858
 859 template<int size, bool big_endian>
 860 void
 861 Copy_relocs<size, big_endian>::save(
 862     Symbol* sym,
 863     Relobj* relobj,
 864     unsigned int shndx,
 865     Output_section* output_section,
 866     const elfcpp::Rela<size, big_endian>& rela)
 867 {
 868   unsigned int reloc_type = elfcpp::elf_r_type<size>(rela.get_r_info());
 869   this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, relobj, shndx,
 870                                             output_section,
 871                                             rela.get_r_offset(),
 872                                             rela.get_r_addend()));
 873 }
 874
 875 // Return whether there are any relocs to emit.  We don't want to emit
 876 // a reloc if the symbol is no longer defined in a dynamic object.
 877
 878 template<int size, bool big_endian>
 879 bool
 880 Copy_relocs<size, big_endian>::any_to_emit()
 881 {
 882   for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
 883        p != this->entries_.end();
 884        ++p)
 885     {
 886       if (p->should_emit())
 887         return true;
 888     }
 889   return false;
 890 }
 891
 892 // Emit relocs.
 893
 894 template<int size, bool big_endian>
 895 template<int sh_type>
 896 void
 897 Copy_relocs<size, big_endian>::emit(
 898     Output_data_reloc<sh_type, true, size, big_endian>* reloc_data)
 899 {
 900   for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
 901        p != this->entries_.end();
 902        ++p)
 903     {
 904       if (p->should_emit())
 905         p->emit(reloc_data);
 906     }
 907 }
 908
 909 // Track_relocs methods.
 910
 911 // Initialize the class to track the relocs.  This gets the object,
 912 // the reloc section index, and the type of the relocs.  This returns
 913 // false if something goes wrong.
 914
 915 template<int size, bool big_endian>
 916 bool
 917 Track_relocs<size, big_endian>::initialize(
 918     Object* object,
 919     unsigned int reloc_shndx,
 920     unsigned int reloc_type)
 921 {
 922   // If RELOC_SHNDX is -1U, it means there is more than one reloc
 923   // section for the .eh_frame section.  We can't handle that case.
 924   if (reloc_shndx == -1U)
 925     return false;
 926
 927   // If RELOC_SHNDX is 0, there is no reloc section.
 928   if (reloc_shndx == 0)
 929     return true;
 930
 931   // Get the contents of the reloc section.
 932   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
 933
 934   if (reloc_type == elfcpp::SHT_REL)
 935     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
 936   else if (reloc_type == elfcpp::SHT_RELA)
 937     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
 938   else
 939     gold_unreachable();
 940
 941   if (this->len_ % this->reloc_size_ != 0)
 942     {
 943       object->error(_("reloc section size %zu is not a multiple of "
 944                       "reloc size %d\n"),
 945                     static_cast<size_t>(this->len_),
 946                     this->reloc_size_);
 947       return false;
 948     }
 949
 950   return true;
 951 }
 952
 953 // Return the offset of the next reloc, or -1 if there isn't one.
 954
 955 template<int size, bool big_endian>
 956 off_t
 957 Track_relocs<size, big_endian>::next_offset() const
 958 {
 959   if (this->pos_ >= this->len_)
 960     return -1;
 961
 962   // Rel and Rela start out the same, so we can always use Rel to find
 963   // the r_offset value.
 964   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 965   return rel.get_r_offset();
 966 }
 967
 968 // Return the index of the symbol referenced by the next reloc, or -1U
 969 // if there aren't any more relocs.
 970
 971 template<int size, bool big_endian>
 972 unsigned int
 973 Track_relocs<size, big_endian>::next_symndx() const
 974 {
 975   if (this->pos_ >= this->len_)
 976     return -1U;
 977
 978   // Rel and Rela start out the same, so we can use Rel to find the
 979   // symbol index.
 980   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 981   return elfcpp::elf_r_sym<size>(rel.get_r_info());
 982 }
 983
 984 // Advance to the next reloc whose r_offset is greater than or equal
 985 // to OFFSET.  Return the number of relocs we skip.
 986
 987 template<int size, bool big_endian>
 988 int
 989 Track_relocs<size, big_endian>::advance(off_t offset)
 990 {
 991   int ret = 0;
 992   while (this->pos_ < this->len_)
 993     {
 994       // Rel and Rela start out the same, so we can always use Rel to
 995       // find the r_offset value.
 996       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 997       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
 998         break;
 999       ++ret;
1000       this->pos_ += this->reloc_size_;
1001     }
1002   return ret;
1003 }
1004
1005 // Instantiate the templates we need.  We could use the configure
1006 // script to restrict this to only the ones for implemented targets.
1007
1008 #ifdef HAVE_TARGET_32_LITTLE
1009 template
1010 void
1011 Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd);
1012 #endif
1013
1014 #ifdef HAVE_TARGET_32_BIG
1015 template
1016 void
1017 Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd);
1018 #endif
1019
1020 #ifdef HAVE_TARGET_64_LITTLE
1021 template
1022 void
1023 Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd);
1024 #endif
1025
1026 #ifdef HAVE_TARGET_64_BIG
1027 template
1028 void
1029 Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
1030 #endif
1031
1032 #ifdef HAVE_TARGET_32_LITTLE
1033 template
1034 void
1035 Sized_relobj<32, false>::do_scan_relocs(const General_options& options,
1036                                         Symbol_table* symtab,
1037                                         Layout* layout,
1038                                         Read_relocs_data* rd);
1039 #endif
1040
1041 #ifdef HAVE_TARGET_32_BIG
1042 template
1043 void
1044 Sized_relobj<32, true>::do_scan_relocs(const General_options& options,
1045                                        Symbol_table* symtab,
1046                                        Layout* layout,
1047                                        Read_relocs_data* rd);
1048 #endif
1049
1050 #ifdef HAVE_TARGET_64_LITTLE
1051 template
1052 void
1053 Sized_relobj<64, false>::do_scan_relocs(const General_options& options,
1054                                         Symbol_table* symtab,
1055                                         Layout* layout,
1056                                         Read_relocs_data* rd);
1057 #endif
1058
1059 #ifdef HAVE_TARGET_64_BIG
1060 template
1061 void
1062 Sized_relobj<64, true>::do_scan_relocs(const General_options& options,
1063                                        Symbol_table* symtab,
1064                                        Layout* layout,
1065                                        Read_relocs_data* rd);
1066 #endif
1067
1068 #ifdef HAVE_TARGET_32_LITTLE
1069 template
1070 void
1071 Sized_relobj<32, false>::do_relocate(const General_options& options,
1072                                      const Symbol_table* symtab,
1073                                      const Layout* layout,
1074                                      Output_file* of);
1075 #endif
1076
1077 #ifdef HAVE_TARGET_32_BIG
1078 template
1079 void
1080 Sized_relobj<32, true>::do_relocate(const General_options& options,
1081                                     const Symbol_table* symtab,
1082                                     const Layout* layout,
1083                                     Output_file* of);
1084 #endif
1085
1086 #ifdef HAVE_TARGET_64_LITTLE
1087 template
1088 void
1089 Sized_relobj<64, false>::do_relocate(const General_options& options,
1090                                      const Symbol_table* symtab,
1091                                      const Layout* layout,
1092                                      Output_file* of);
1093 #endif
1094
1095 #ifdef HAVE_TARGET_64_BIG
1096 template
1097 void
1098 Sized_relobj<64, true>::do_relocate(const General_options& options,
1099                                     const Symbol_table* symtab,
1100                                     const Layout* layout,
1101                                     Output_file* of);
1102 #endif
1103
1104 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1105 template
1106 class Merged_symbol_value<32>;
1107 #endif
1108
1109 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1110 template
1111 class Merged_symbol_value<64>;
1112 #endif
1113
1114 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1115 template
1116 class Symbol_value<32>;
1117 #endif
1118
1119 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1120 template
1121 class Symbol_value<64>;
1122 #endif
1123
1124 #ifdef HAVE_TARGET_32_LITTLE
1125 template
1126 class Copy_relocs<32, false>;
1127 #endif
1128
1129 #ifdef HAVE_TARGET_32_BIG
1130 template
1131 class Copy_relocs<32, true>;
1132 #endif
1133
1134 #ifdef HAVE_TARGET_64_LITTLE
1135 template
1136 class Copy_relocs<64, false>;
1137 #endif
1138
1139 #ifdef HAVE_TARGET_64_BIG
1140 template
1141 class Copy_relocs<64, true>;
1142 #endif
1143
1144 #ifdef HAVE_TARGET_32_LITTLE
1145 template
1146 void
1147 Copy_relocs<32, false>::emit<elfcpp::SHT_REL>(
1148     Output_data_reloc<elfcpp::SHT_REL, true, 32, false>*);
1149 #endif
1150
1151 #ifdef HAVE_TARGET_32_BIG
1152 template
1153 void
1154 Copy_relocs<32, true>::emit<elfcpp::SHT_REL>(
1155     Output_data_reloc<elfcpp::SHT_REL, true, 32, true>*);
1156 #endif
1157
1158 #ifdef HAVE_TARGET_64_LITTLE
1159 template
1160 void
1161 Copy_relocs<64, false>::emit<elfcpp::SHT_REL>(
1162     Output_data_reloc<elfcpp::SHT_REL, true, 64, false>*);
1163 #endif
1164
1165 #ifdef HAVE_TARGET_64_BIG
1166 template
1167 void
1168 Copy_relocs<64, true>::emit<elfcpp::SHT_REL>(
1169     Output_data_reloc<elfcpp::SHT_REL, true, 64, true>*);
1170 #endif
1171
1172 #ifdef HAVE_TARGET_32_LITTLE
1173 template
1174 void
1175 Copy_relocs<32, false>::emit<elfcpp::SHT_RELA>(
1176     Output_data_reloc<elfcpp::SHT_RELA , true, 32, false>*);
1177 #endif
1178
1179 #ifdef HAVE_TARGET_32_BIG
1180 template
1181 void
1182 Copy_relocs<32, true>::emit<elfcpp::SHT_RELA>(
1183     Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>*);
1184 #endif
1185
1186 #ifdef HAVE_TARGET_64_LITTLE
1187 template
1188 void
1189 Copy_relocs<64, false>::emit<elfcpp::SHT_RELA>(
1190     Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>*);
1191 #endif
1192
1193 #ifdef HAVE_TARGET_64_BIG
1194 template
1195 void
1196 Copy_relocs<64, true>::emit<elfcpp::SHT_RELA>(
1197     Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>*);
1198 #endif
1199
1200 #ifdef HAVE_TARGET_32_LITTLE
1201 template
1202 class Track_relocs<32, false>;
1203 #endif
1204
1205 #ifdef HAVE_TARGET_32_BIG
1206 template
1207 class Track_relocs<32, true>;
1208 #endif
1209
1210 #ifdef HAVE_TARGET_64_LITTLE
1211 template
1212 class Track_relocs<64, false>;
1213 #endif
1214
1215 #ifdef HAVE_TARGET_64_BIG
1216 template
1217 class Track_relocs<64, true>;
1218 #endif
1219
1220 } // End namespace gold.