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.
 226       typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
 227       if ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 228         continue;
 229
 230       if (shdr.get_sh_link() != this->symtab_shndx_)
 231         {
 232           this->error(_("relocation section %u uses unexpected "
 233                         "symbol table %u"),
 234                       i, shdr.get_sh_link());
 235           continue;
 236         }
 237
 238       off_t sh_size = shdr.get_sh_size();
 239
 240       unsigned int reloc_size;
 241       if (sh_type == elfcpp::SHT_REL)
 242         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 243       else
 244         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 245       if (reloc_size != shdr.get_sh_entsize())
 246         {
 247           this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
 248                       i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 249                       reloc_size);
 250           continue;
 251         }
 252
 253       size_t reloc_count = sh_size / reloc_size;
 254       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 255         {
 256           this->error(_("reloc section %u size %lu uneven"),
 257                       i, static_cast<unsigned long>(sh_size));
 258           continue;
 259         }
 260
 261       rd->relocs.push_back(Section_relocs());
 262       Section_relocs& sr(rd->relocs.back());
 263       sr.reloc_shndx = i;
 264       sr.data_shndx = shndx;
 265       sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
 266                                            true);
 267       sr.sh_type = sh_type;
 268       sr.reloc_count = reloc_count;
 269       sr.output_section = os;
 270       sr.needs_special_offset_handling = map_sections[shndx].offset == -1;
 271     }
 272
 273   // Read the local symbols.
 274   gold_assert(this->symtab_shndx_ != -1U);
 275   if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
 276     rd->local_symbols = NULL;
 277   else
 278     {
 279       typename This::Shdr symtabshdr(pshdrs
 280                                      + this->symtab_shndx_ * This::shdr_size);
 281       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 282       const int sym_size = This::sym_size;
 283       const unsigned int loccount = this->local_symbol_count_;
 284       gold_assert(loccount == symtabshdr.get_sh_info());
 285       off_t locsize = loccount * sym_size;
 286       rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
 287                                                  locsize, true);
 288     }
 289 }
 290
 291 // Scan the relocs and adjust the symbol table.  This looks for
 292 // relocations which require GOT/PLT/COPY relocations.
 293
 294 template<int size, bool big_endian>
 295 void
 296 Sized_relobj<size, big_endian>::do_scan_relocs(const General_options& options,
 297                                                Symbol_table* symtab,
 298                                                Layout* layout,
 299                                                Read_relocs_data* rd)
 300 {
 301   Sized_target<size, big_endian>* target = this->sized_target();
 302
 303   const unsigned char* local_symbols;
 304   if (rd->local_symbols == NULL)
 305     local_symbols = NULL;
 306   else
 307     local_symbols = rd->local_symbols->data();
 308
 309   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 310        p != rd->relocs.end();
 311        ++p)
 312     {
 313       target->scan_relocs(options, symtab, layout, this, p->data_shndx,
 314                           p->sh_type, p->contents->data(), p->reloc_count,
 315                           p->output_section, p->needs_special_offset_handling,
 316                           this->local_symbol_count_,
 317                           local_symbols);
 318       delete p->contents;
 319       p->contents = NULL;
 320     }
 321
 322   if (rd->local_symbols != NULL)
 323     {
 324       delete rd->local_symbols;
 325       rd->local_symbols = NULL;
 326     }
 327 }
 328
 329 // Relocate the input sections and write out the local symbols.
 330
 331 template<int size, bool big_endian>
 332 void
 333 Sized_relobj<size, big_endian>::do_relocate(const General_options& options,
 334                                             const Symbol_table* symtab,
 335                                             const Layout* layout,
 336                                             Output_file* of)
 337 {
 338   unsigned int shnum = this->shnum();
 339
 340   // Read the section headers.
 341   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 342                                                shnum * This::shdr_size,
 343                                                true);
 344
 345   Views views;
 346   views.resize(shnum);
 347
 348   // Make two passes over the sections.  The first one copies the
 349   // section data to the output file.  The second one applies
 350   // relocations.
 351
 352   this->write_sections(pshdrs, of, &views);
 353
 354   // To speed up relocations, we set up hash tables for fast lookup of
 355   // input offsets to output addresses.
 356   this->initialize_input_to_output_maps();
 357
 358   // Apply relocations.
 359
 360   this->relocate_sections(options, symtab, layout, pshdrs, &views);
 361
 362   // After we've done the relocations, we release the hash tables,
 363   // since we no longer need them.
 364   this->free_input_to_output_maps();
 365
 366   // Write out the accumulated views.
 367   for (unsigned int i = 1; i < shnum; ++i)
 368     {
 369       if (views[i].view != NULL)
 370         {
 371           if (!views[i].is_postprocessing_view)
 372             {
 373               if (views[i].is_input_output_view)
 374                 of->write_input_output_view(views[i].offset,
 375                                             views[i].view_size,
 376                                             views[i].view);
 377               else
 378                 of->write_output_view(views[i].offset, views[i].view_size,
 379                                       views[i].view);
 380             }
 381         }
 382     }
 383
 384   // Write out the local symbols.
 385   this->write_local_symbols(of, layout->sympool(), layout->dynpool());
 386
 387   // We should no longer need the local symbol values.
 388   this->clear_local_symbols();
 389 }
 390
 391 // Sort a Read_multiple vector by file offset.
 392 struct Read_multiple_compare
 393 {
 394   inline bool
 395   operator()(const File_read::Read_multiple_entry& rme1,
 396              const File_read::Read_multiple_entry& rme2) const
 397   { return rme1.file_offset < rme2.file_offset; }
 398 };
 399
 400 // Write section data to the output file.  PSHDRS points to the
 401 // section headers.  Record the views in *PVIEWS for use when
 402 // relocating.
 403
 404 template<int size, bool big_endian>
 405 void
 406 Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
 407                                                Output_file* of,
 408                                                Views* pviews)
 409 {
 410   unsigned int shnum = this->shnum();
 411   const std::vector<Map_to_output>& map_sections(this->map_to_output());
 412
 413   File_read::Read_multiple rm;
 414   bool is_sorted = true;
 415
 416   const unsigned char* p = pshdrs + This::shdr_size;
 417   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 418     {
 419       View_size* pvs = &(*pviews)[i];
 420
 421       pvs->view = NULL;
 422
 423       const Output_section* os = map_sections[i].output_section;
 424       if (os == NULL)
 425         continue;
 426       off_t output_offset = map_sections[i].offset;
 427
 428       typename This::Shdr shdr(p);
 429
 430       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 431         continue;
 432
 433       // In the normal case, this input section is simply mapped to
 434       // the output section at offset OUTPUT_OFFSET.
 435
 436       // However, if OUTPUT_OFFSET == -1, then input data is handled
 437       // specially--e.g., a .eh_frame section.  The relocation
 438       // routines need to check for each reloc where it should be
 439       // applied.  For this case, we need an input/output view for the
 440       // entire contents of the section in the output file.  We don't
 441       // want to copy the contents of the input section to the output
 442       // section; the output section contents were already written,
 443       // and we waited for them in Relocate_task::is_runnable because
 444       // relocs_must_follow_section_writes is set for the object.
 445
 446       // Regardless of which of the above cases is true, we have to
 447       // check requires_postprocessing of the output section.  If that
 448       // is false, then we work with views of the output file
 449       // directly.  If it is true, then we work with a separate
 450       // buffer, and the output section is responsible for writing the
 451       // final data to the output file.
 452
 453       off_t output_section_offset;
 454       off_t output_section_size;
 455       if (!os->requires_postprocessing())
 456         {
 457           output_section_offset = os->offset();
 458           output_section_size = os->data_size();
 459         }
 460       else
 461         {
 462           output_section_offset = 0;
 463           output_section_size = os->postprocessing_buffer_size();
 464         }
 465
 466       off_t view_start;
 467       section_size_type view_size;
 468       if (output_offset != -1)
 469         {
 470           view_start = output_section_offset + output_offset;
 471           view_size = convert_to_section_size_type(shdr.get_sh_size());
 472         }
 473       else
 474         {
 475           view_start = output_section_offset;
 476           view_size = convert_to_section_size_type(output_section_size);
 477         }
 478
 479       if (view_size == 0)
 480         continue;
 481
 482       gold_assert(output_offset == -1
 483                   || (output_offset >= 0
 484                       && (output_offset + static_cast<off_t>(view_size)
 485                           <= output_section_size)));
 486
 487       unsigned char* view;
 488       if (os->requires_postprocessing())
 489         {
 490           unsigned char* buffer = os->postprocessing_buffer();
 491           view = buffer + view_start;
 492           if (output_offset != -1)
 493             {
 494               off_t sh_offset = shdr.get_sh_offset();
 495               if (!rm.empty() && rm.back().file_offset > sh_offset)
 496                 is_sorted = false;
 497               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 498                                                           view_size, view));
 499             }
 500         }
 501       else
 502         {
 503           if (output_offset == -1)
 504             view = of->get_input_output_view(view_start, view_size);
 505           else
 506             {
 507               view = of->get_output_view(view_start, view_size);
 508               off_t sh_offset = shdr.get_sh_offset();
 509               if (!rm.empty() && rm.back().file_offset > sh_offset)
 510                 is_sorted = false;
 511               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 512                                                           view_size, view));
 513             }
 514         }
 515
 516       pvs->view = view;
 517       pvs->address = os->address();
 518       if (output_offset != -1)
 519         pvs->address += output_offset;
 520       pvs->offset = view_start;
 521       pvs->view_size = view_size;
 522       pvs->is_input_output_view = output_offset == -1;
 523       pvs->is_postprocessing_view = os->requires_postprocessing();
 524     }
 525
 526   // Actually read the data.
 527   if (!rm.empty())
 528     {
 529       if (!is_sorted)
 530         std::sort(rm.begin(), rm.end(), Read_multiple_compare());
 531       this->read_multiple(rm);
 532     }
 533 }
 534
 535 // Relocate section data.  VIEWS points to the section data as views
 536 // in the output file.
 537
 538 template<int size, bool big_endian>
 539 void
 540 Sized_relobj<size, big_endian>::relocate_sections(
 541     const General_options& options,
 542     const Symbol_table* symtab,
 543     const Layout* layout,
 544     const unsigned char* pshdrs,
 545     Views* pviews)
 546 {
 547   unsigned int shnum = this->shnum();
 548   Sized_target<size, big_endian>* target = this->sized_target();
 549
 550   const std::vector<Map_to_output>& map_sections(this->map_to_output());
 551
 552   Relocate_info<size, big_endian> relinfo;
 553   relinfo.options = &options;
 554   relinfo.symtab = symtab;
 555   relinfo.layout = layout;
 556   relinfo.object = this;
 557
 558   const unsigned char* p = pshdrs + This::shdr_size;
 559   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 560     {
 561       typename This::Shdr shdr(p);
 562
 563       unsigned int sh_type = shdr.get_sh_type();
 564       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 565         continue;
 566
 567       unsigned int index = shdr.get_sh_info();
 568       if (index >= this->shnum())
 569         {
 570           this->error(_("relocation section %u has bad info %u"),
 571                       i, index);
 572           continue;
 573         }
 574
 575       Output_section* os = map_sections[index].output_section;
 576       if (os == NULL)
 577         {
 578           // This relocation section is against a section which we
 579           // discarded.
 580           continue;
 581         }
 582       off_t output_offset = map_sections[index].offset;
 583
 584       gold_assert((*pviews)[index].view != NULL);
 585
 586       if (shdr.get_sh_link() != this->symtab_shndx_)
 587         {
 588           gold_error(_("relocation section %u uses unexpected "
 589                        "symbol table %u"),
 590                      i, shdr.get_sh_link());
 591           continue;
 592         }
 593
 594       off_t sh_size = shdr.get_sh_size();
 595       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 596                                                     sh_size, false);
 597
 598       unsigned int reloc_size;
 599       if (sh_type == elfcpp::SHT_REL)
 600         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 601       else
 602         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 603
 604       if (reloc_size != shdr.get_sh_entsize())
 605         {
 606           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 607                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 608                      reloc_size);
 609           continue;
 610         }
 611
 612       size_t reloc_count = sh_size / reloc_size;
 613       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 614         {
 615           gold_error(_("reloc section %u size %lu uneven"),
 616                      i, static_cast<unsigned long>(sh_size));
 617           continue;
 618         }
 619
 620       gold_assert(output_offset != -1
 621                   || this->relocs_must_follow_section_writes());
 622
 623       relinfo.reloc_shndx = i;
 624       relinfo.data_shndx = index;
 625       target->relocate_section(&relinfo,
 626                                sh_type,
 627                                prelocs,
 628                                reloc_count,
 629                                os,
 630                                output_offset == -1,
 631                                (*pviews)[index].view,
 632                                (*pviews)[index].address,
 633                                (*pviews)[index].view_size);
 634     }
 635 }
 636
 637 // Create merge hash tables for the local symbols.  These are used to
 638 // speed up relocations.
 639
 640 template<int size, bool big_endian>
 641 void
 642 Sized_relobj<size, big_endian>::initialize_input_to_output_maps()
 643 {
 644   const unsigned int loccount = this->local_symbol_count_;
 645   for (unsigned int i = 1; i < loccount; ++i)
 646     {
 647       Symbol_value<size>& lv(this->local_values_[i]);
 648       lv.initialize_input_to_output_map(this);
 649     }
 650 }
 651
 652 // Free merge hash tables for the local symbols.
 653
 654 template<int size, bool big_endian>
 655 void
 656 Sized_relobj<size, big_endian>::free_input_to_output_maps()
 657 {
 658   const unsigned int loccount = this->local_symbol_count_;
 659   for (unsigned int i = 1; i < loccount; ++i)
 660     {
 661       Symbol_value<size>& lv(this->local_values_[i]);
 662       lv.free_input_to_output_map();
 663     }
 664 }
 665
 666 // Class Merged_symbol_value.
 667
 668 template<int size>
 669 void
 670 Merged_symbol_value<size>::initialize_input_to_output_map(
 671     const Relobj* object,
 672     unsigned int input_shndx)
 673 {
 674   Object_merge_map* map = object->merge_map();
 675   map->initialize_input_to_output_map<size>(input_shndx,
 676                                             this->output_start_address_,
 677                                             &this->output_addresses_);
 678 }
 679
 680 // Get the output value corresponding to an input offset if we
 681 // couldn't find it in the hash table.
 682
 683 template<int size>
 684 typename elfcpp::Elf_types<size>::Elf_Addr
 685 Merged_symbol_value<size>::value_from_output_section(
 686     const Relobj* object,
 687     unsigned int input_shndx,
 688     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
 689 {
 690   section_offset_type output_offset;
 691   bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
 692                                                       input_offset,
 693                                                       &output_offset);
 694
 695   // If this assertion fails, it means that some relocation was
 696   // against a portion of an input merge section which we didn't map
 697   // to the output file and we didn't explicitly discard.  We should
 698   // always map all portions of input merge sections.
 699   gold_assert(found);
 700
 701   if (output_offset == -1)
 702     return 0;
 703   else
 704     return this->output_start_address_ + output_offset;
 705 }
 706
 707 // Copy_relocs::Copy_reloc_entry methods.
 708
 709 // Return whether we should emit this reloc.  We should emit it if the
 710 // symbol is still defined in a dynamic object.  If we should not emit
 711 // it, we clear it, to save ourselves the test next time.
 712
 713 template<int size, bool big_endian>
 714 bool
 715 Copy_relocs<size, big_endian>::Copy_reloc_entry::should_emit()
 716 {
 717   if (this->sym_ == NULL)
 718     return false;
 719   if (this->sym_->is_from_dynobj())
 720     return true;
 721   this->sym_ = NULL;
 722   return false;
 723 }
 724
 725 // Emit a reloc into a SHT_REL section.
 726
 727 template<int size, bool big_endian>
 728 void
 729 Copy_relocs<size, big_endian>::Copy_reloc_entry::emit(
 730     Output_data_reloc<elfcpp::SHT_REL, true, size, big_endian>* reloc_data)
 731 {
 732   this->sym_->set_needs_dynsym_entry();
 733   reloc_data->add_global(this->sym_, this->reloc_type_, this->output_section_,
 734                          this->relobj_, this->shndx_, this->address_);
 735 }
 736
 737 // Emit a reloc into a SHT_RELA section.
 738
 739 template<int size, bool big_endian>
 740 void
 741 Copy_relocs<size, big_endian>::Copy_reloc_entry::emit(
 742     Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>* reloc_data)
 743 {
 744   this->sym_->set_needs_dynsym_entry();
 745   reloc_data->add_global(this->sym_, this->reloc_type_, this->output_section_,
 746                          this->relobj_, this->shndx_, this->address_,
 747                          this->addend_);
 748 }
 749
 750 // Copy_relocs methods.
 751
 752 // Return whether we need a COPY reloc for a relocation against GSYM.
 753 // The relocation is being applied to section SHNDX in OBJECT.
 754
 755 template<int size, bool big_endian>
 756 bool
 757 Copy_relocs<size, big_endian>::need_copy_reloc(
 758     const General_options*,
 759     Relobj* object,
 760     unsigned int shndx,
 761     Sized_symbol<size>* sym)
 762 {
 763   // FIXME: Handle -z nocopyrelocs.
 764
 765   if (sym->symsize() == 0)
 766     return false;
 767
 768   // If this is a readonly section, then we need a COPY reloc.
 769   // Otherwise we can use a dynamic reloc.
 770   if ((object->section_flags(shndx) & elfcpp::SHF_WRITE) == 0)
 771     return true;
 772
 773   return false;
 774 }
 775
 776 // Save a Rel reloc.
 777
 778 template<int size, bool big_endian>
 779 void
 780 Copy_relocs<size, big_endian>::save(
 781     Symbol* sym,
 782     Relobj* relobj,
 783     unsigned int shndx,
 784     Output_section* output_section,
 785     const elfcpp::Rel<size, big_endian>& rel)
 786 {
 787   unsigned int reloc_type = elfcpp::elf_r_type<size>(rel.get_r_info());
 788   this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, relobj, shndx,
 789                                             output_section,
 790                                             rel.get_r_offset(), 0));
 791 }
 792
 793 // Save a Rela reloc.
 794
 795 template<int size, bool big_endian>
 796 void
 797 Copy_relocs<size, big_endian>::save(
 798     Symbol* sym,
 799     Relobj* relobj,
 800     unsigned int shndx,
 801     Output_section* output_section,
 802     const elfcpp::Rela<size, big_endian>& rela)
 803 {
 804   unsigned int reloc_type = elfcpp::elf_r_type<size>(rela.get_r_info());
 805   this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, relobj, shndx,
 806                                             output_section,
 807                                             rela.get_r_offset(),
 808                                             rela.get_r_addend()));
 809 }
 810
 811 // Return whether there are any relocs to emit.  We don't want to emit
 812 // a reloc if the symbol is no longer defined in a dynamic object.
 813
 814 template<int size, bool big_endian>
 815 bool
 816 Copy_relocs<size, big_endian>::any_to_emit()
 817 {
 818   for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
 819        p != this->entries_.end();
 820        ++p)
 821     {
 822       if (p->should_emit())
 823         return true;
 824     }
 825   return false;
 826 }
 827
 828 // Emit relocs.
 829
 830 template<int size, bool big_endian>
 831 template<int sh_type>
 832 void
 833 Copy_relocs<size, big_endian>::emit(
 834     Output_data_reloc<sh_type, true, size, big_endian>* reloc_data)
 835 {
 836   for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
 837        p != this->entries_.end();
 838        ++p)
 839     {
 840       if (p->should_emit())
 841         p->emit(reloc_data);
 842     }
 843 }
 844
 845 // Track_relocs methods.
 846
 847 // Initialize the class to track the relocs.  This gets the object,
 848 // the reloc section index, and the type of the relocs.  This returns
 849 // false if something goes wrong.
 850
 851 template<int size, bool big_endian>
 852 bool
 853 Track_relocs<size, big_endian>::initialize(
 854     Object* object,
 855     unsigned int reloc_shndx,
 856     unsigned int reloc_type)
 857 {
 858   // If RELOC_SHNDX is -1U, it means there is more than one reloc
 859   // section for the .eh_frame section.  We can't handle that case.
 860   if (reloc_shndx == -1U)
 861     return false;
 862
 863   // If RELOC_SHNDX is 0, there is no reloc section.
 864   if (reloc_shndx == 0)
 865     return true;
 866
 867   // Get the contents of the reloc section.
 868   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
 869
 870   if (reloc_type == elfcpp::SHT_REL)
 871     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
 872   else if (reloc_type == elfcpp::SHT_RELA)
 873     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
 874   else
 875     gold_unreachable();
 876
 877   if (this->len_ % this->reloc_size_ != 0)
 878     {
 879       object->error(_("reloc section size %zu is not a multiple of "
 880                       "reloc size %d\n"),
 881                     static_cast<size_t>(this->len_),
 882                     this->reloc_size_);
 883       return false;
 884     }
 885
 886   return true;
 887 }
 888
 889 // Return the offset of the next reloc, or -1 if there isn't one.
 890
 891 template<int size, bool big_endian>
 892 off_t
 893 Track_relocs<size, big_endian>::next_offset() const
 894 {
 895   if (this->pos_ >= this->len_)
 896     return -1;
 897
 898   // Rel and Rela start out the same, so we can always use Rel to find
 899   // the r_offset value.
 900   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 901   return rel.get_r_offset();
 902 }
 903
 904 // Return the index of the symbol referenced by the next reloc, or -1U
 905 // if there aren't any more relocs.
 906
 907 template<int size, bool big_endian>
 908 unsigned int
 909 Track_relocs<size, big_endian>::next_symndx() const
 910 {
 911   if (this->pos_ >= this->len_)
 912     return -1U;
 913
 914   // Rel and Rela start out the same, so we can use Rel to find the
 915   // symbol index.
 916   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 917   return elfcpp::elf_r_sym<size>(rel.get_r_info());
 918 }
 919
 920 // Advance to the next reloc whose r_offset is greater than or equal
 921 // to OFFSET.  Return the number of relocs we skip.
 922
 923 template<int size, bool big_endian>
 924 int
 925 Track_relocs<size, big_endian>::advance(off_t offset)
 926 {
 927   int ret = 0;
 928   while (this->pos_ < this->len_)
 929     {
 930       // Rel and Rela start out the same, so we can always use Rel to
 931       // find the r_offset value.
 932       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 933       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
 934         break;
 935       ++ret;
 936       this->pos_ += this->reloc_size_;
 937     }
 938   return ret;
 939 }
 940
 941 // Instantiate the templates we need.  We could use the configure
 942 // script to restrict this to only the ones for implemented targets.
 943
 944 #ifdef HAVE_TARGET_32_LITTLE
 945 template
 946 void
 947 Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd);
 948 #endif
 949
 950 #ifdef HAVE_TARGET_32_BIG
 951 template
 952 void
 953 Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd);
 954 #endif
 955
 956 #ifdef HAVE_TARGET_64_LITTLE
 957 template
 958 void
 959 Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd);
 960 #endif
 961
 962 #ifdef HAVE_TARGET_64_BIG
 963 template
 964 void
 965 Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
 966 #endif
 967
 968 #ifdef HAVE_TARGET_32_LITTLE
 969 template
 970 void
 971 Sized_relobj<32, false>::do_scan_relocs(const General_options& options,
 972                                         Symbol_table* symtab,
 973                                         Layout* layout,
 974                                         Read_relocs_data* rd);
 975 #endif
 976
 977 #ifdef HAVE_TARGET_32_BIG
 978 template
 979 void
 980 Sized_relobj<32, true>::do_scan_relocs(const General_options& options,
 981                                        Symbol_table* symtab,
 982                                        Layout* layout,
 983                                        Read_relocs_data* rd);
 984 #endif
 985
 986 #ifdef HAVE_TARGET_64_LITTLE
 987 template
 988 void
 989 Sized_relobj<64, false>::do_scan_relocs(const General_options& options,
 990                                         Symbol_table* symtab,
 991                                         Layout* layout,
 992                                         Read_relocs_data* rd);
 993 #endif
 994
 995 #ifdef HAVE_TARGET_64_BIG
 996 template
 997 void
 998 Sized_relobj<64, true>::do_scan_relocs(const General_options& options,
 999                                        Symbol_table* symtab,
1000                                        Layout* layout,
1001                                        Read_relocs_data* rd);
1002 #endif
1003
1004 #ifdef HAVE_TARGET_32_LITTLE
1005 template
1006 void
1007 Sized_relobj<32, false>::do_relocate(const General_options& options,
1008                                      const Symbol_table* symtab,
1009                                      const Layout* layout,
1010                                      Output_file* of);
1011 #endif
1012
1013 #ifdef HAVE_TARGET_32_BIG
1014 template
1015 void
1016 Sized_relobj<32, true>::do_relocate(const General_options& options,
1017                                     const Symbol_table* symtab,
1018                                     const Layout* layout,
1019                                     Output_file* of);
1020 #endif
1021
1022 #ifdef HAVE_TARGET_64_LITTLE
1023 template
1024 void
1025 Sized_relobj<64, false>::do_relocate(const General_options& options,
1026                                      const Symbol_table* symtab,
1027                                      const Layout* layout,
1028                                      Output_file* of);
1029 #endif
1030
1031 #ifdef HAVE_TARGET_64_BIG
1032 template
1033 void
1034 Sized_relobj<64, true>::do_relocate(const General_options& options,
1035                                     const Symbol_table* symtab,
1036                                     const Layout* layout,
1037                                     Output_file* of);
1038 #endif
1039
1040 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1041 template
1042 class Merged_symbol_value<32>;
1043 #endif
1044
1045 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1046 template
1047 class Merged_symbol_value<64>;
1048 #endif
1049
1050 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1051 template
1052 class Symbol_value<32>;
1053 #endif
1054
1055 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1056 template
1057 class Symbol_value<64>;
1058 #endif
1059
1060 #ifdef HAVE_TARGET_32_LITTLE
1061 template
1062 class Copy_relocs<32, false>;
1063 #endif
1064
1065 #ifdef HAVE_TARGET_32_BIG
1066 template
1067 class Copy_relocs<32, true>;
1068 #endif
1069
1070 #ifdef HAVE_TARGET_64_LITTLE
1071 template
1072 class Copy_relocs<64, false>;
1073 #endif
1074
1075 #ifdef HAVE_TARGET_64_BIG
1076 template
1077 class Copy_relocs<64, true>;
1078 #endif
1079
1080 #ifdef HAVE_TARGET_32_LITTLE
1081 template
1082 void
1083 Copy_relocs<32, false>::emit<elfcpp::SHT_REL>(
1084     Output_data_reloc<elfcpp::SHT_REL, true, 32, false>*);
1085 #endif
1086
1087 #ifdef HAVE_TARGET_32_BIG
1088 template
1089 void
1090 Copy_relocs<32, true>::emit<elfcpp::SHT_REL>(
1091     Output_data_reloc<elfcpp::SHT_REL, true, 32, true>*);
1092 #endif
1093
1094 #ifdef HAVE_TARGET_64_LITTLE
1095 template
1096 void
1097 Copy_relocs<64, false>::emit<elfcpp::SHT_REL>(
1098     Output_data_reloc<elfcpp::SHT_REL, true, 64, false>*);
1099 #endif
1100
1101 #ifdef HAVE_TARGET_64_BIG
1102 template
1103 void
1104 Copy_relocs<64, true>::emit<elfcpp::SHT_REL>(
1105     Output_data_reloc<elfcpp::SHT_REL, true, 64, true>*);
1106 #endif
1107
1108 #ifdef HAVE_TARGET_32_LITTLE
1109 template
1110 void
1111 Copy_relocs<32, false>::emit<elfcpp::SHT_RELA>(
1112     Output_data_reloc<elfcpp::SHT_RELA , true, 32, false>*);
1113 #endif
1114
1115 #ifdef HAVE_TARGET_32_BIG
1116 template
1117 void
1118 Copy_relocs<32, true>::emit<elfcpp::SHT_RELA>(
1119     Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>*);
1120 #endif
1121
1122 #ifdef HAVE_TARGET_64_LITTLE
1123 template
1124 void
1125 Copy_relocs<64, false>::emit<elfcpp::SHT_RELA>(
1126     Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>*);
1127 #endif
1128
1129 #ifdef HAVE_TARGET_64_BIG
1130 template
1131 void
1132 Copy_relocs<64, true>::emit<elfcpp::SHT_RELA>(
1133     Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>*);
1134 #endif
1135
1136 #ifdef HAVE_TARGET_32_LITTLE
1137 template
1138 class Track_relocs<32, false>;
1139 #endif
1140
1141 #ifdef HAVE_TARGET_32_BIG
1142 template
1143 class Track_relocs<32, true>;
1144 #endif
1145
1146 #ifdef HAVE_TARGET_64_LITTLE
1147 template
1148 class Track_relocs<64, false>;
1149 #endif
1150
1151 #ifdef HAVE_TARGET_64_BIG
1152 template
1153 class Track_relocs<64, true>;
1154 #endif
1155
1156 } // End namespace gold.