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 "workqueue.h"
  26 #include "object.h"
  27 #include "symtab.h"
  28 #include "output.h"
  29 #include "reloc.h"
  30
  31 namespace gold
  32 {
  33
  34 // Read_relocs methods.
  35
  36 // These tasks just read the relocation information from the file.
  37 // After reading it, the start another task to process the
  38 // information.  These tasks requires access to the file.
  39
  40 Task::Is_runnable_type
  41 Read_relocs::is_runnable(Workqueue*)
  42 {
  43   return this->object_->is_locked() ? IS_LOCKED : IS_RUNNABLE;
  44 }
  45
  46 // Lock the file.
  47
  48 Task_locker*
  49 Read_relocs::locks(Workqueue*)
  50 {
  51   return new Task_locker_obj<Object>(*this->object_);
  52 }
  53
  54 // Read the relocations and then start a Scan_relocs_task.
  55
  56 void
  57 Read_relocs::run(Workqueue* workqueue)
  58 {
  59   Read_relocs_data *rd = new Read_relocs_data;
  60   this->object_->read_relocs(rd);
  61   workqueue->queue_front(new Scan_relocs(this->options_, this->symtab_,
  62                                          this->layout_, this->object_, rd,
  63                                          this->symtab_lock_, this->blocker_));
  64 }
  65
  66 // Return a debugging name for the task.
  67
  68 std::string
  69 Read_relocs::get_name() const
  70 {
  71   return "Read_relocs " + this->object_->name();
  72 }
  73
  74 // Scan_relocs methods.
  75
  76 // These tasks scan the relocations read by Read_relocs and mark up
  77 // the symbol table to indicate which relocations are required.  We
  78 // use a lock on the symbol table to keep them from interfering with
  79 // each other.
  80
  81 Task::Is_runnable_type
  82 Scan_relocs::is_runnable(Workqueue*)
  83 {
  84   if (!this->symtab_lock_->is_writable() || this->object_->is_locked())
  85     return IS_LOCKED;
  86   return IS_RUNNABLE;
  87 }
  88
  89 // Return the locks we hold: one on the file, one on the symbol table
  90 // and one blocker.
  91
  92 class Scan_relocs::Scan_relocs_locker : public Task_locker
  93 {
  94  public:
  95   Scan_relocs_locker(Object* object, Task_token& symtab_lock, Task* task,
  96                      Task_token& blocker, Workqueue* workqueue)
  97     : objlock_(*object), symtab_locker_(symtab_lock, task),
  98       blocker_(blocker, workqueue)
  99   { }
 100
 101  private:
 102   Task_locker_obj<Object> objlock_;
 103   Task_locker_write symtab_locker_;
 104   Task_locker_block blocker_;
 105 };
 106
 107 Task_locker*
 108 Scan_relocs::locks(Workqueue* workqueue)
 109 {
 110   return new Scan_relocs_locker(this->object_, *this->symtab_lock_, this,
 111                                 *this->blocker_, workqueue);
 112 }
 113
 114 // Scan the relocs.
 115
 116 void
 117 Scan_relocs::run(Workqueue*)
 118 {
 119   this->object_->scan_relocs(this->options_, this->symtab_, this->layout_,
 120                              this->rd_);
 121   delete this->rd_;
 122   this->rd_ = NULL;
 123 }
 124
 125 // Return a debugging name for the task.
 126
 127 std::string
 128 Scan_relocs::get_name() const
 129 {
 130   return "Scan_relocs " + this->object_->name();
 131 }
 132
 133 // Relocate_task methods.
 134
 135 // We may have to wait for the output sections to be written.
 136
 137 Task::Is_runnable_type
 138 Relocate_task::is_runnable(Workqueue*)
 139 {
 140   if (this->object_->relocs_must_follow_section_writes()
 141       && this->output_sections_blocker_->is_blocked())
 142     return IS_BLOCKED;
 143
 144   if (this->object_->is_locked())
 145     return IS_LOCKED;
 146
 147   return IS_RUNNABLE;
 148 }
 149
 150 // We want to lock the file while we run.  We want to unblock
 151 // INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done.
 152
 153 class Relocate_task::Relocate_locker : public Task_locker
 154 {
 155  public:
 156   Relocate_locker(Task_token& input_sections_blocker,
 157                   Task_token& final_blocker, Workqueue* workqueue,
 158                   Object* object)
 159     : input_sections_blocker_(input_sections_blocker, workqueue),
 160       final_blocker_(final_blocker, workqueue),
 161       objlock_(*object)
 162   { }
 163
 164  private:
 165   Task_block_token input_sections_blocker_;
 166   Task_block_token final_blocker_;
 167   Task_locker_obj<Object> objlock_;
 168 };
 169
 170 Task_locker*
 171 Relocate_task::locks(Workqueue* workqueue)
 172 {
 173   return new Relocate_locker(*this->input_sections_blocker_,
 174                              *this->final_blocker_,
 175                              workqueue,
 176                              this->object_);
 177 }
 178
 179 // Run the task.
 180
 181 void
 182 Relocate_task::run(Workqueue*)
 183 {
 184   this->object_->relocate(this->options_, this->symtab_, this->layout_,
 185                           this->of_);
 186 }
 187
 188 // Return a debugging name for the task.
 189
 190 std::string
 191 Relocate_task::get_name() const
 192 {
 193   return "Relocate_task " + this->object_->name();
 194 }
 195
 196 // Read the relocs and local symbols from the object file and store
 197 // the information in RD.
 198
 199 template<int size, bool big_endian>
 200 void
 201 Sized_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd)
 202 {
 203   rd->relocs.clear();
 204
 205   unsigned int shnum = this->shnum();
 206   if (shnum == 0)
 207     return;
 208
 209   rd->relocs.reserve(shnum / 2);
 210
 211   std::vector<Map_to_output>& map_sections(this->map_to_output());
 212
 213   const unsigned char *pshdrs = this->get_view(this->elf_file_.shoff(),
 214                                                shnum * This::shdr_size,
 215                                                true);
 216   // Skip the first, dummy, section.
 217   const unsigned char *ps = pshdrs + This::shdr_size;
 218   for (unsigned int i = 1; i < shnum; ++i, ps += This::shdr_size)
 219     {
 220       typename This::Shdr shdr(ps);
 221
 222       unsigned int sh_type = shdr.get_sh_type();
 223       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 224         continue;
 225
 226       unsigned int shndx = shdr.get_sh_info();
 227       if (shndx >= shnum)
 228         {
 229           this->error(_("relocation section %u has bad info %u"),
 230                       i, shndx);
 231           continue;
 232         }
 233
 234       Output_section* os = map_sections[shndx].output_section;
 235       if (os == NULL)
 236         continue;
 237
 238       // We are scanning relocations in order to fill out the GOT and
 239       // PLT sections.  Relocations for sections which are not
 240       // allocated (typically debugging sections) should not add new
 241       // GOT and PLT entries.  So we skip them.
 242       typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
 243       if ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 244         continue;
 245
 246       if (shdr.get_sh_link() != this->symtab_shndx_)
 247         {
 248           this->error(_("relocation section %u uses unexpected "
 249                         "symbol table %u"),
 250                       i, shdr.get_sh_link());
 251           continue;
 252         }
 253
 254       off_t sh_size = shdr.get_sh_size();
 255
 256       unsigned int reloc_size;
 257       if (sh_type == elfcpp::SHT_REL)
 258         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 259       else
 260         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 261       if (reloc_size != shdr.get_sh_entsize())
 262         {
 263           this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
 264                       i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 265                       reloc_size);
 266           continue;
 267         }
 268
 269       size_t reloc_count = sh_size / reloc_size;
 270       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 271         {
 272           this->error(_("reloc section %u size %lu uneven"),
 273                       i, static_cast<unsigned long>(sh_size));
 274           continue;
 275         }
 276
 277       rd->relocs.push_back(Section_relocs());
 278       Section_relocs& sr(rd->relocs.back());
 279       sr.reloc_shndx = i;
 280       sr.data_shndx = shndx;
 281       sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
 282                                            true);
 283       sr.sh_type = sh_type;
 284       sr.reloc_count = reloc_count;
 285       sr.output_section = os;
 286       sr.needs_special_offset_handling = map_sections[shndx].offset == -1;
 287     }
 288
 289   // Read the local symbols.
 290   gold_assert(this->symtab_shndx_ != -1U);
 291   if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
 292     rd->local_symbols = NULL;
 293   else
 294     {
 295       typename This::Shdr symtabshdr(pshdrs
 296                                      + this->symtab_shndx_ * This::shdr_size);
 297       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 298       const int sym_size = This::sym_size;
 299       const unsigned int loccount = this->local_symbol_count_;
 300       gold_assert(loccount == symtabshdr.get_sh_info());
 301       off_t locsize = loccount * sym_size;
 302       rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
 303                                                  locsize, true);
 304     }
 305 }
 306
 307 // Scan the relocs and adjust the symbol table.  This looks for
 308 // relocations which require GOT/PLT/COPY relocations.
 309
 310 template<int size, bool big_endian>
 311 void
 312 Sized_relobj<size, big_endian>::do_scan_relocs(const General_options& options,
 313                                                Symbol_table* symtab,
 314                                                Layout* layout,
 315                                                Read_relocs_data* rd)
 316 {
 317   Sized_target<size, big_endian>* target = this->sized_target();
 318
 319   const unsigned char* local_symbols;
 320   if (rd->local_symbols == NULL)
 321     local_symbols = NULL;
 322   else
 323     local_symbols = rd->local_symbols->data();
 324
 325   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 326        p != rd->relocs.end();
 327        ++p)
 328     {
 329       target->scan_relocs(options, symtab, layout, this, p->data_shndx,
 330                           p->sh_type, p->contents->data(), p->reloc_count,
 331                           p->output_section, p->needs_special_offset_handling,
 332                           this->local_symbol_count_,
 333                           local_symbols);
 334       delete p->contents;
 335       p->contents = NULL;
 336     }
 337
 338   if (rd->local_symbols != NULL)
 339     {
 340       delete rd->local_symbols;
 341       rd->local_symbols = NULL;
 342     }
 343 }
 344
 345 // Relocate the input sections and write out the local symbols.
 346
 347 template<int size, bool big_endian>
 348 void
 349 Sized_relobj<size, big_endian>::do_relocate(const General_options& options,
 350                                             const Symbol_table* symtab,
 351                                             const Layout* layout,
 352                                             Output_file* of)
 353 {
 354   unsigned int shnum = this->shnum();
 355
 356   // Read the section headers.
 357   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 358                                                shnum * This::shdr_size,
 359                                                true);
 360
 361   Views views;
 362   views.resize(shnum);
 363
 364   // Make two passes over the sections.  The first one copies the
 365   // section data to the output file.  The second one applies
 366   // relocations.
 367
 368   this->write_sections(pshdrs, of, &views);
 369
 370   // Apply relocations.
 371
 372   this->relocate_sections(options, symtab, layout, pshdrs, &views);
 373
 374   // Write out the accumulated views.
 375   for (unsigned int i = 1; i < shnum; ++i)
 376     {
 377       if (views[i].view != NULL)
 378         {
 379           if (!views[i].is_postprocessing_view)
 380             {
 381               if (views[i].is_input_output_view)
 382                 of->write_input_output_view(views[i].offset,
 383                                             views[i].view_size,
 384                                             views[i].view);
 385               else
 386                 of->write_output_view(views[i].offset, views[i].view_size,
 387                                       views[i].view);
 388             }
 389         }
 390     }
 391
 392   // Write out the local symbols.
 393   this->write_local_symbols(of, layout->sympool());
 394 }
 395
 396 // Write section data to the output file.  PSHDRS points to the
 397 // section headers.  Record the views in *PVIEWS for use when
 398 // relocating.
 399
 400 template<int size, bool big_endian>
 401 void
 402 Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
 403                                                Output_file* of,
 404                                                Views* pviews)
 405 {
 406   unsigned int shnum = this->shnum();
 407   std::vector<Map_to_output>& map_sections(this->map_to_output());
 408
 409   const unsigned char* p = pshdrs + This::shdr_size;
 410   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 411     {
 412       View_size* pvs = &(*pviews)[i];
 413
 414       pvs->view = NULL;
 415
 416       const Output_section* os = map_sections[i].output_section;
 417       if (os == NULL)
 418         continue;
 419       off_t output_offset = map_sections[i].offset;
 420
 421       typename This::Shdr shdr(p);
 422
 423       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 424         continue;
 425
 426       // In the normal case, this input section is simply mapped to
 427       // the output section at offset OUTPUT_OFFSET.
 428
 429       // However, if OUTPUT_OFFSET == -1, then input data is handled
 430       // specially--e.g., a .eh_frame section.  The relocation
 431       // routines need to check for each reloc where it should be
 432       // applied.  For this case, we need an input/output view for the
 433       // entire contents of the section in the output file.  We don't
 434       // want to copy the contents of the input section to the output
 435       // section; the output section contents were already written,
 436       // and we waited for them in Relocate_task::is_runnable because
 437       // relocs_must_follow_section_writes is set for the object.
 438
 439       // Regardless of which of the above cases is true, we have to
 440       // check requires_postprocessing of the output section.  If that
 441       // is false, then we work with views of the output file
 442       // directly.  If it is true, then we work with a separate
 443       // buffer, and the output section is responsible for writing the
 444       // final data to the output file.
 445
 446       off_t output_section_offset;
 447       off_t output_section_size;
 448       if (!os->requires_postprocessing())
 449         {
 450           output_section_offset = os->offset();
 451           output_section_size = os->data_size();
 452         }
 453       else
 454         {
 455           output_section_offset = 0;
 456           output_section_size = os->postprocessing_buffer_size();
 457         }
 458
 459       off_t view_start;
 460       off_t view_size;
 461       if (output_offset != -1)
 462         {
 463           view_start = output_section_offset + output_offset;
 464           view_size = shdr.get_sh_size();
 465         }
 466       else
 467         {
 468           view_start = output_section_offset;
 469           view_size = output_section_size;
 470         }
 471
 472       if (view_size == 0)
 473         continue;
 474
 475       gold_assert(output_offset == -1
 476                   || (output_offset >= 0
 477                       && output_offset + view_size <= output_section_size));
 478
 479       unsigned char* view;
 480       if (os->requires_postprocessing())
 481         {
 482           unsigned char* buffer = os->postprocessing_buffer();
 483           view = buffer + view_start;
 484           if (output_offset != -1)
 485             this->read(shdr.get_sh_offset(), view_size, view);
 486         }
 487       else
 488         {
 489           if (output_offset == -1)
 490             view = of->get_input_output_view(view_start, view_size);
 491           else
 492             {
 493               view = of->get_output_view(view_start, view_size);
 494               this->read(shdr.get_sh_offset(), view_size, view);
 495             }
 496         }
 497
 498       pvs->view = view;
 499       pvs->address = os->address();
 500       if (output_offset != -1)
 501         pvs->address += output_offset;
 502       pvs->offset = view_start;
 503       pvs->view_size = view_size;
 504       pvs->is_input_output_view = output_offset == -1;
 505       pvs->is_postprocessing_view = os->requires_postprocessing();
 506     }
 507 }
 508
 509 // Relocate section data.  VIEWS points to the section data as views
 510 // in the output file.
 511
 512 template<int size, bool big_endian>
 513 void
 514 Sized_relobj<size, big_endian>::relocate_sections(
 515     const General_options& options,
 516     const Symbol_table* symtab,
 517     const Layout* layout,
 518     const unsigned char* pshdrs,
 519     Views* pviews)
 520 {
 521   unsigned int shnum = this->shnum();
 522   Sized_target<size, big_endian>* target = this->sized_target();
 523
 524   std::vector<Map_to_output>& map_sections(this->map_to_output());
 525
 526   Relocate_info<size, big_endian> relinfo;
 527   relinfo.options = &options;
 528   relinfo.symtab = symtab;
 529   relinfo.layout = layout;
 530   relinfo.object = this;
 531
 532   const unsigned char* p = pshdrs + This::shdr_size;
 533   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 534     {
 535       typename This::Shdr shdr(p);
 536
 537       unsigned int sh_type = shdr.get_sh_type();
 538       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 539         continue;
 540
 541       unsigned int index = shdr.get_sh_info();
 542       if (index >= this->shnum())
 543         {
 544           this->error(_("relocation section %u has bad info %u"),
 545                       i, index);
 546           continue;
 547         }
 548
 549       Output_section* os = map_sections[index].output_section;
 550       if (os == NULL)
 551         {
 552           // This relocation section is against a section which we
 553           // discarded.
 554           continue;
 555         }
 556       off_t output_offset = map_sections[index].offset;
 557
 558       gold_assert((*pviews)[index].view != NULL);
 559
 560       if (shdr.get_sh_link() != this->symtab_shndx_)
 561         {
 562           gold_error(_("relocation section %u uses unexpected "
 563                        "symbol table %u"),
 564                      i, shdr.get_sh_link());
 565           continue;
 566         }
 567
 568       off_t sh_size = shdr.get_sh_size();
 569       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 570                                                     sh_size, false);
 571
 572       unsigned int reloc_size;
 573       if (sh_type == elfcpp::SHT_REL)
 574         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 575       else
 576         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 577
 578       if (reloc_size != shdr.get_sh_entsize())
 579         {
 580           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 581                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 582                      reloc_size);
 583           continue;
 584         }
 585
 586       size_t reloc_count = sh_size / reloc_size;
 587       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 588         {
 589           gold_error(_("reloc section %u size %lu uneven"),
 590                      i, static_cast<unsigned long>(sh_size));
 591           continue;
 592         }
 593
 594       gold_assert(output_offset != -1
 595                   || this->relocs_must_follow_section_writes());
 596
 597       relinfo.reloc_shndx = i;
 598       relinfo.data_shndx = index;
 599       target->relocate_section(&relinfo,
 600                                sh_type,
 601                                prelocs,
 602                                reloc_count,
 603                                os,
 604                                output_offset == -1,
 605                                (*pviews)[index].view,
 606                                (*pviews)[index].address,
 607                                (*pviews)[index].view_size);
 608     }
 609 }
 610
 611 // Copy_relocs::Copy_reloc_entry methods.
 612
 613 // Return whether we should emit this reloc.  We should emit it if the
 614 // symbol is still defined in a dynamic object.  If we should not emit
 615 // it, we clear it, to save ourselves the test next time.
 616
 617 template<int size, bool big_endian>
 618 bool
 619 Copy_relocs<size, big_endian>::Copy_reloc_entry::should_emit()
 620 {
 621   if (this->sym_ == NULL)
 622     return false;
 623   if (this->sym_->is_from_dynobj())
 624     return true;
 625   this->sym_ = NULL;
 626   return false;
 627 }
 628
 629 // Emit a reloc into a SHT_REL section.
 630
 631 template<int size, bool big_endian>
 632 void
 633 Copy_relocs<size, big_endian>::Copy_reloc_entry::emit(
 634     Output_data_reloc<elfcpp::SHT_REL, true, size, big_endian>* reloc_data)
 635 {
 636   this->sym_->set_needs_dynsym_entry();
 637   reloc_data->add_global(this->sym_, this->reloc_type_, this->output_section_,
 638                          this->relobj_, this->shndx_, this->address_);
 639 }
 640
 641 // Emit a reloc into a SHT_RELA section.
 642
 643 template<int size, bool big_endian>
 644 void
 645 Copy_relocs<size, big_endian>::Copy_reloc_entry::emit(
 646     Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>* reloc_data)
 647 {
 648   this->sym_->set_needs_dynsym_entry();
 649   reloc_data->add_global(this->sym_, this->reloc_type_, this->output_section_,
 650                          this->relobj_, this->shndx_, this->address_,
 651                          this->addend_);
 652 }
 653
 654 // Copy_relocs methods.
 655
 656 // Return whether we need a COPY reloc for a relocation against GSYM.
 657 // The relocation is being applied to section SHNDX in OBJECT.
 658
 659 template<int size, bool big_endian>
 660 bool
 661 Copy_relocs<size, big_endian>::need_copy_reloc(
 662     const General_options*,
 663     Relobj* object,
 664     unsigned int shndx,
 665     Sized_symbol<size>* sym)
 666 {
 667   // FIXME: Handle -z nocopyrelocs.
 668
 669   if (sym->symsize() == 0)
 670     return false;
 671
 672   // If this is a readonly section, then we need a COPY reloc.
 673   // Otherwise we can use a dynamic reloc.
 674   if ((object->section_flags(shndx) & elfcpp::SHF_WRITE) == 0)
 675     return true;
 676
 677   return false;
 678 }
 679
 680 // Save a Rel reloc.
 681
 682 template<int size, bool big_endian>
 683 void
 684 Copy_relocs<size, big_endian>::save(
 685     Symbol* sym,
 686     Relobj* relobj,
 687     unsigned int shndx,
 688     Output_section* output_section,
 689     const elfcpp::Rel<size, big_endian>& rel)
 690 {
 691   unsigned int reloc_type = elfcpp::elf_r_type<size>(rel.get_r_info());
 692   this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, relobj, shndx,
 693                                             output_section,
 694                                             rel.get_r_offset(), 0));
 695 }
 696
 697 // Save a Rela reloc.
 698
 699 template<int size, bool big_endian>
 700 void
 701 Copy_relocs<size, big_endian>::save(
 702     Symbol* sym,
 703     Relobj* relobj,
 704     unsigned int shndx,
 705     Output_section* output_section,
 706     const elfcpp::Rela<size, big_endian>& rela)
 707 {
 708   unsigned int reloc_type = elfcpp::elf_r_type<size>(rela.get_r_info());
 709   this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, relobj, shndx,
 710                                             output_section,
 711                                             rela.get_r_offset(),
 712                                             rela.get_r_addend()));
 713 }
 714
 715 // Return whether there are any relocs to emit.  We don't want to emit
 716 // a reloc if the symbol is no longer defined in a dynamic object.
 717
 718 template<int size, bool big_endian>
 719 bool
 720 Copy_relocs<size, big_endian>::any_to_emit()
 721 {
 722   for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
 723        p != this->entries_.end();
 724        ++p)
 725     {
 726       if (p->should_emit())
 727         return true;
 728     }
 729   return false;
 730 }
 731
 732 // Emit relocs.
 733
 734 template<int size, bool big_endian>
 735 template<int sh_type>
 736 void
 737 Copy_relocs<size, big_endian>::emit(
 738     Output_data_reloc<sh_type, true, size, big_endian>* reloc_data)
 739 {
 740   for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
 741        p != this->entries_.end();
 742        ++p)
 743     {
 744       if (p->should_emit())
 745         p->emit(reloc_data);
 746     }
 747 }
 748
 749 // Track_relocs methods.
 750
 751 // Initialize the class to track the relocs.  This gets the object,
 752 // the reloc section index, and the type of the relocs.  This returns
 753 // false if something goes wrong.
 754
 755 template<int size, bool big_endian>
 756 bool
 757 Track_relocs<size, big_endian>::initialize(
 758     Object* object,
 759     unsigned int reloc_shndx,
 760     unsigned int reloc_type)
 761 {
 762   // If RELOC_SHNDX is -1U, it means there is more than one reloc
 763   // section for the .eh_frame section.  We can't handle that case.
 764   if (reloc_shndx == -1U)
 765     return false;
 766
 767   // If RELOC_SHNDX is 0, there is no reloc section.
 768   if (reloc_shndx == 0)
 769     return true;
 770
 771   // Get the contents of the reloc section.
 772   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
 773
 774   if (reloc_type == elfcpp::SHT_REL)
 775     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
 776   else if (reloc_type == elfcpp::SHT_RELA)
 777     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
 778   else
 779     gold_unreachable();
 780
 781   if (this->len_ % this->reloc_size_ != 0)
 782     {
 783       object->error(_("reloc section size %zu is not a multiple of "
 784                       "reloc size %d\n"),
 785                     static_cast<size_t>(this->len_),
 786                     this->reloc_size_);
 787       return false;
 788     }
 789
 790   return true;
 791 }
 792
 793 // Return the offset of the next reloc, or -1 if there isn't one.
 794
 795 template<int size, bool big_endian>
 796 off_t
 797 Track_relocs<size, big_endian>::next_offset() const
 798 {
 799   if (this->pos_ >= this->len_)
 800     return -1;
 801
 802   // Rel and Rela start out the same, so we can always use Rel to find
 803   // the r_offset value.
 804   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 805   return rel.get_r_offset();
 806 }
 807
 808 // Return the index of the symbol referenced by the next reloc, or -1U
 809 // if there aren't any more relocs.
 810
 811 template<int size, bool big_endian>
 812 unsigned int
 813 Track_relocs<size, big_endian>::next_symndx() const
 814 {
 815   if (this->pos_ >= this->len_)
 816     return -1U;
 817
 818   // Rel and Rela start out the same, so we can use Rel to find the
 819   // symbol index.
 820   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 821   return elfcpp::elf_r_sym<size>(rel.get_r_info());
 822 }
 823
 824 // Advance to the next reloc whose r_offset is greater than or equal
 825 // to OFFSET.  Return the number of relocs we skip.
 826
 827 template<int size, bool big_endian>
 828 int
 829 Track_relocs<size, big_endian>::advance(off_t offset)
 830 {
 831   int ret = 0;
 832   while (this->pos_ < this->len_)
 833     {
 834       // Rel and Rela start out the same, so we can always use Rel to
 835       // find the r_offset value.
 836       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
 837       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
 838         break;
 839       ++ret;
 840       this->pos_ += this->reloc_size_;
 841     }
 842   return ret;
 843 }
 844
 845 // Instantiate the templates we need.  We could use the configure
 846 // script to restrict this to only the ones for implemented targets.
 847
 848 #ifdef HAVE_TARGET_32_LITTLE
 849 template
 850 void
 851 Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd);
 852 #endif
 853
 854 #ifdef HAVE_TARGET_32_BIG
 855 template
 856 void
 857 Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd);
 858 #endif
 859
 860 #ifdef HAVE_TARGET_64_LITTLE
 861 template
 862 void
 863 Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd);
 864 #endif
 865
 866 #ifdef HAVE_TARGET_64_BIG
 867 template
 868 void
 869 Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
 870 #endif
 871
 872 #ifdef HAVE_TARGET_32_LITTLE
 873 template
 874 void
 875 Sized_relobj<32, false>::do_scan_relocs(const General_options& options,
 876                                         Symbol_table* symtab,
 877                                         Layout* layout,
 878                                         Read_relocs_data* rd);
 879 #endif
 880
 881 #ifdef HAVE_TARGET_32_BIG
 882 template
 883 void
 884 Sized_relobj<32, true>::do_scan_relocs(const General_options& options,
 885                                        Symbol_table* symtab,
 886                                        Layout* layout,
 887                                        Read_relocs_data* rd);
 888 #endif
 889
 890 #ifdef HAVE_TARGET_64_LITTLE
 891 template
 892 void
 893 Sized_relobj<64, false>::do_scan_relocs(const General_options& options,
 894                                         Symbol_table* symtab,
 895                                         Layout* layout,
 896                                         Read_relocs_data* rd);
 897 #endif
 898
 899 #ifdef HAVE_TARGET_64_BIG
 900 template
 901 void
 902 Sized_relobj<64, true>::do_scan_relocs(const General_options& options,
 903                                        Symbol_table* symtab,
 904                                        Layout* layout,
 905                                        Read_relocs_data* rd);
 906 #endif
 907
 908 #ifdef HAVE_TARGET_32_LITTLE
 909 template
 910 void
 911 Sized_relobj<32, false>::do_relocate(const General_options& options,
 912                                      const Symbol_table* symtab,
 913                                      const Layout* layout,
 914                                      Output_file* of);
 915 #endif
 916
 917 #ifdef HAVE_TARGET_32_BIG
 918 template
 919 void
 920 Sized_relobj<32, true>::do_relocate(const General_options& options,
 921                                     const Symbol_table* symtab,
 922                                     const Layout* layout,
 923                                     Output_file* of);
 924 #endif
 925
 926 #ifdef HAVE_TARGET_64_LITTLE
 927 template
 928 void
 929 Sized_relobj<64, false>::do_relocate(const General_options& options,
 930                                      const Symbol_table* symtab,
 931                                      const Layout* layout,
 932                                      Output_file* of);
 933 #endif
 934
 935 #ifdef HAVE_TARGET_64_BIG
 936 template
 937 void
 938 Sized_relobj<64, true>::do_relocate(const General_options& options,
 939                                     const Symbol_table* symtab,
 940                                     const Layout* layout,
 941                                     Output_file* of);
 942 #endif
 943
 944 #ifdef HAVE_TARGET_32_LITTLE
 945 template
 946 class Copy_relocs<32, false>;
 947 #endif
 948
 949 #ifdef HAVE_TARGET_32_BIG
 950 template
 951 class Copy_relocs<32, true>;
 952 #endif
 953
 954 #ifdef HAVE_TARGET_64_LITTLE
 955 template
 956 class Copy_relocs<64, false>;
 957 #endif
 958
 959 #ifdef HAVE_TARGET_64_BIG
 960 template
 961 class Copy_relocs<64, true>;
 962 #endif
 963
 964 #ifdef HAVE_TARGET_32_LITTLE
 965 template
 966 void
 967 Copy_relocs<32, false>::emit<elfcpp::SHT_REL>(
 968     Output_data_reloc<elfcpp::SHT_REL, true, 32, false>*);
 969 #endif
 970
 971 #ifdef HAVE_TARGET_32_BIG
 972 template
 973 void
 974 Copy_relocs<32, true>::emit<elfcpp::SHT_REL>(
 975     Output_data_reloc<elfcpp::SHT_REL, true, 32, true>*);
 976 #endif
 977
 978 #ifdef HAVE_TARGET_64_LITTLE
 979 template
 980 void
 981 Copy_relocs<64, false>::emit<elfcpp::SHT_REL>(
 982     Output_data_reloc<elfcpp::SHT_REL, true, 64, false>*);
 983 #endif
 984
 985 #ifdef HAVE_TARGET_64_BIG
 986 template
 987 void
 988 Copy_relocs<64, true>::emit<elfcpp::SHT_REL>(
 989     Output_data_reloc<elfcpp::SHT_REL, true, 64, true>*);
 990 #endif
 991
 992 #ifdef HAVE_TARGET_32_LITTLE
 993 template
 994 void
 995 Copy_relocs<32, false>::emit<elfcpp::SHT_RELA>(
 996     Output_data_reloc<elfcpp::SHT_RELA , true, 32, false>*);
 997 #endif
 998
 999 #ifdef HAVE_TARGET_32_BIG
1000 template
1001 void
1002 Copy_relocs<32, true>::emit<elfcpp::SHT_RELA>(
1003     Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>*);
1004 #endif
1005
1006 #ifdef HAVE_TARGET_64_LITTLE
1007 template
1008 void
1009 Copy_relocs<64, false>::emit<elfcpp::SHT_RELA>(
1010     Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>*);
1011 #endif
1012
1013 #ifdef HAVE_TARGET_64_BIG
1014 template
1015 void
1016 Copy_relocs<64, true>::emit<elfcpp::SHT_RELA>(
1017     Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>*);
1018 #endif
1019
1020 #ifdef HAVE_TARGET_32_LITTLE
1021 template
1022 class Track_relocs<32, false>;
1023 #endif
1024
1025 #ifdef HAVE_TARGET_32_BIG
1026 template
1027 class Track_relocs<32, true>;
1028 #endif
1029
1030 #ifdef HAVE_TARGET_64_LITTLE
1031 template
1032 class Track_relocs<64, false>;
1033 #endif
1034
1035 #ifdef HAVE_TARGET_64_BIG
1036 template
1037 class Track_relocs<64, true>;
1038 #endif
1039
1040 } // End namespace gold.