contrib/binutils-2.21/gold/reloc.cc

   1 // reloc.cc -- relocate input files for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 "layout.h"
  29 #include "symtab.h"
  30 #include "output.h"
  31 #include "merge.h"
  32 #include "object.h"
  33 #include "target-reloc.h"
  34 #include "reloc.h"
  35 #include "icf.h"
  36 #include "compressed_output.h"
  37 #include "incremental.h"
  38
  39 namespace gold
  40 {
  41
  42 // Read_relocs methods.
  43
  44 // These tasks just read the relocation information from the file.
  45 // After reading it, the start another task to process the
  46 // information.  These tasks requires access to the file.
  47
  48 Task_token*
  49 Read_relocs::is_runnable()
  50 {
  51   return this->object_->is_locked() ? this->object_->token() : NULL;
  52 }
  53
  54 // Lock the file.
  55
  56 void
  57 Read_relocs::locks(Task_locker* tl)
  58 {
  59   tl->add(this, this->object_->token());
  60 }
  61
  62 // Read the relocations and then start a Scan_relocs_task.
  63
  64 void
  65 Read_relocs::run(Workqueue* workqueue)
  66 {
  67   Read_relocs_data* rd = new Read_relocs_data;
  68   this->object_->read_relocs(rd);
  69   this->object_->set_relocs_data(rd);
  70   this->object_->release();
  71
  72   // If garbage collection or identical comdat folding is desired, we
  73   // process the relocs first before scanning them.  Scanning of relocs is
  74   // done only after garbage or identical sections is identified.
  75   if (parameters->options().gc_sections()
  76       || parameters->options().icf_enabled())
  77     {
  78       workqueue->queue_next(new Gc_process_relocs(this->symtab_,
  79                                                   this->layout_,
  80                                                   this->object_, rd,
  81                                                   this->this_blocker_,
  82                                                   this->next_blocker_));
  83     }
  84   else
  85     {
  86       workqueue->queue_next(new Scan_relocs(this->symtab_, this->layout_,
  87                                             this->object_, rd,
  88                                             this->this_blocker_,
  89                                             this->next_blocker_));
  90     }
  91 }
  92
  93 // Return a debugging name for the task.
  94
  95 std::string
  96 Read_relocs::get_name() const
  97 {
  98   return "Read_relocs " + this->object_->name();
  99 }
 100
 101 // Gc_process_relocs methods.
 102
 103 Gc_process_relocs::~Gc_process_relocs()
 104 {
 105   if (this->this_blocker_ != NULL)
 106     delete this->this_blocker_;
 107 }
 108
 109 // These tasks process the relocations read by Read_relocs and
 110 // determine which sections are referenced and which are garbage.
 111 // This task is done only when --gc-sections is used.  This is blocked
 112 // by THIS_BLOCKER_.  It unblocks NEXT_BLOCKER_.
 113
 114 Task_token*
 115 Gc_process_relocs::is_runnable()
 116 {
 117   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 118     return this->this_blocker_;
 119   if (this->object_->is_locked())
 120     return this->object_->token();
 121   return NULL;
 122 }
 123
 124 void
 125 Gc_process_relocs::locks(Task_locker* tl)
 126 {
 127   tl->add(this, this->object_->token());
 128   tl->add(this, this->next_blocker_);
 129 }
 130
 131 void
 132 Gc_process_relocs::run(Workqueue*)
 133 {
 134   this->object_->gc_process_relocs(this->symtab_, this->layout_, this->rd_);
 135   this->object_->release();
 136 }
 137
 138 // Return a debugging name for the task.
 139
 140 std::string
 141 Gc_process_relocs::get_name() const
 142 {
 143   return "Gc_process_relocs " + this->object_->name();
 144 }
 145
 146 // Scan_relocs methods.
 147
 148 Scan_relocs::~Scan_relocs()
 149 {
 150   if (this->this_blocker_ != NULL)
 151     delete this->this_blocker_;
 152 }
 153
 154 // These tasks scan the relocations read by Read_relocs and mark up
 155 // the symbol table to indicate which relocations are required.  We
 156 // use a lock on the symbol table to keep them from interfering with
 157 // each other.
 158
 159 Task_token*
 160 Scan_relocs::is_runnable()
 161 {
 162   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 163     return this->this_blocker_;
 164   if (this->object_->is_locked())
 165     return this->object_->token();
 166   return NULL;
 167 }
 168
 169 // Return the locks we hold: one on the file, one on the symbol table
 170 // and one blocker.
 171
 172 void
 173 Scan_relocs::locks(Task_locker* tl)
 174 {
 175   tl->add(this, this->object_->token());
 176   tl->add(this, this->next_blocker_);
 177 }
 178
 179 // Scan the relocs.
 180
 181 void
 182 Scan_relocs::run(Workqueue*)
 183 {
 184   this->object_->scan_relocs(this->symtab_, this->layout_, this->rd_);
 185   delete this->rd_;
 186   this->rd_ = NULL;
 187   this->object_->release();
 188 }
 189
 190 // Return a debugging name for the task.
 191
 192 std::string
 193 Scan_relocs::get_name() const
 194 {
 195   return "Scan_relocs " + this->object_->name();
 196 }
 197
 198 // Relocate_task methods.
 199
 200 // We may have to wait for the output sections to be written.
 201
 202 Task_token*
 203 Relocate_task::is_runnable()
 204 {
 205   if (this->object_->relocs_must_follow_section_writes()
 206       && this->output_sections_blocker_->is_blocked())
 207     return this->output_sections_blocker_;
 208
 209   if (this->object_->is_locked())
 210     return this->object_->token();
 211
 212   return NULL;
 213 }
 214
 215 // We want to lock the file while we run.  We want to unblock
 216 // INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done.
 217 // INPUT_SECTIONS_BLOCKER may be NULL.
 218
 219 void
 220 Relocate_task::locks(Task_locker* tl)
 221 {
 222   if (this->input_sections_blocker_ != NULL)
 223     tl->add(this, this->input_sections_blocker_);
 224   tl->add(this, this->final_blocker_);
 225   tl->add(this, this->object_->token());
 226 }
 227
 228 // Run the task.
 229
 230 void
 231 Relocate_task::run(Workqueue*)
 232 {
 233   this->object_->relocate(this->symtab_, this->layout_, this->of_);
 234
 235   // This is normally the last thing we will do with an object, so
 236   // uncache all views.
 237   this->object_->clear_view_cache_marks();
 238
 239   this->object_->release();
 240 }
 241
 242 // Return a debugging name for the task.
 243
 244 std::string
 245 Relocate_task::get_name() const
 246 {
 247   return "Relocate_task " + this->object_->name();
 248 }
 249
 250 // Read the relocs and local symbols from the object file and store
 251 // the information in RD.
 252
 253 template<int size, bool big_endian>
 254 void
 255 Sized_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd)
 256 {
 257   rd->relocs.clear();
 258
 259   unsigned int shnum = this->shnum();
 260   if (shnum == 0)
 261     return;
 262
 263   rd->relocs.reserve(shnum / 2);
 264
 265   const Output_sections& out_sections(this->output_sections());
 266   const std::vector<Address>& out_offsets(this->section_offsets_);
 267
 268   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 269                                                shnum * This::shdr_size,
 270                                                true, true);
 271   // Skip the first, dummy, section.
 272   const unsigned char* ps = pshdrs + This::shdr_size;
 273   for (unsigned int i = 1; i < shnum; ++i, ps += This::shdr_size)
 274     {
 275       typename This::Shdr shdr(ps);
 276
 277       unsigned int sh_type = shdr.get_sh_type();
 278       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 279         continue;
 280
 281       unsigned int shndx = this->adjust_shndx(shdr.get_sh_info());
 282       if (shndx >= shnum)
 283         {
 284           this->error(_("relocation section %u has bad info %u"),
 285                       i, shndx);
 286           continue;
 287         }
 288
 289       Output_section* os = out_sections[shndx];
 290       if (os == NULL)
 291         continue;
 292
 293       // We are scanning relocations in order to fill out the GOT and
 294       // PLT sections.  Relocations for sections which are not
 295       // allocated (typically debugging sections) should not add new
 296       // GOT and PLT entries.  So we skip them unless this is a
 297       // relocatable link or we need to emit relocations.  FIXME: What
 298       // should we do if a linker script maps a section with SHF_ALLOC
 299       // clear to a section with SHF_ALLOC set?
 300       typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
 301       bool is_section_allocated = ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC)
 302                                    != 0);
 303       if (!is_section_allocated
 304           && !parameters->options().relocatable()
 305           && !parameters->options().emit_relocs()
 306           && !parameters->incremental())
 307         continue;
 308
 309       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 310         {
 311           this->error(_("relocation section %u uses unexpected "
 312                         "symbol table %u"),
 313                       i, this->adjust_shndx(shdr.get_sh_link()));
 314           continue;
 315         }
 316
 317       off_t sh_size = shdr.get_sh_size();
 318
 319       unsigned int reloc_size;
 320       if (sh_type == elfcpp::SHT_REL)
 321         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 322       else
 323         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 324       if (reloc_size != shdr.get_sh_entsize())
 325         {
 326           this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
 327                       i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 328                       reloc_size);
 329           continue;
 330         }
 331
 332       size_t reloc_count = sh_size / reloc_size;
 333       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 334         {
 335           this->error(_("reloc section %u size %lu uneven"),
 336                       i, static_cast<unsigned long>(sh_size));
 337           continue;
 338         }
 339
 340       rd->relocs.push_back(Section_relocs());
 341       Section_relocs& sr(rd->relocs.back());
 342       sr.reloc_shndx = i;
 343       sr.data_shndx = shndx;
 344       sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
 345                                            true, true);
 346       sr.sh_type = sh_type;
 347       sr.reloc_count = reloc_count;
 348       sr.output_section = os;
 349       sr.needs_special_offset_handling = out_offsets[shndx] == invalid_address;
 350       sr.is_data_section_allocated = is_section_allocated;
 351     }
 352
 353   // Read the local symbols.
 354   gold_assert(this->symtab_shndx_ != -1U);
 355   if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
 356     rd->local_symbols = NULL;
 357   else
 358     {
 359       typename This::Shdr symtabshdr(pshdrs
 360                                      + this->symtab_shndx_ * This::shdr_size);
 361       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 362       const int sym_size = This::sym_size;
 363       const unsigned int loccount = this->local_symbol_count_;
 364       gold_assert(loccount == symtabshdr.get_sh_info());
 365       off_t locsize = loccount * sym_size;
 366       rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
 367                                                  locsize, true, true);
 368     }
 369 }
 370
 371 // Process the relocs to generate mappings from source sections to referenced
 372 // sections.  This is used during garbage colletion to determine garbage
 373 // sections.
 374
 375 template<int size, bool big_endian>
 376 void
 377 Sized_relobj<size, big_endian>::do_gc_process_relocs(Symbol_table* symtab,
 378                                                      Layout* layout,
 379                                                      Read_relocs_data* rd)
 380 {
 381   Sized_target<size, big_endian>* target =
 382     parameters->sized_target<size, big_endian>();
 383
 384   const unsigned char* local_symbols;
 385   if (rd->local_symbols == NULL)
 386     local_symbols = NULL;
 387   else
 388     local_symbols = rd->local_symbols->data();
 389
 390   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 391        p != rd->relocs.end();
 392        ++p)
 393     {
 394       if (!parameters->options().relocatable())
 395           {
 396             // As noted above, when not generating an object file, we
 397             // only scan allocated sections.  We may see a non-allocated
 398             // section here if we are emitting relocs.
 399             if (p->is_data_section_allocated)
 400               target->gc_process_relocs(symtab, layout, this,
 401                                         p->data_shndx, p->sh_type,
 402                                         p->contents->data(), p->reloc_count,
 403                                         p->output_section,
 404                                         p->needs_special_offset_handling,
 405                                         this->local_symbol_count_,
 406                                         local_symbols);
 407         }
 408     }
 409 }
 410
 411
 412 // Scan the relocs and adjust the symbol table.  This looks for
 413 // relocations which require GOT/PLT/COPY relocations.
 414
 415 template<int size, bool big_endian>
 416 void
 417 Sized_relobj<size, big_endian>::do_scan_relocs(Symbol_table* symtab,
 418                                                Layout* layout,
 419                                                Read_relocs_data* rd)
 420 {
 421   Sized_target<size, big_endian>* target =
 422     parameters->sized_target<size, big_endian>();
 423
 424   const unsigned char* local_symbols;
 425   if (rd->local_symbols == NULL)
 426     local_symbols = NULL;
 427   else
 428     local_symbols = rd->local_symbols->data();
 429
 430   // For incremental links, allocate the counters for incremental relocations.
 431   if (layout->incremental_inputs() != NULL)
 432     this->allocate_incremental_reloc_counts();
 433
 434   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 435        p != rd->relocs.end();
 436        ++p)
 437     {
 438       // When garbage collection is on, unreferenced sections are not included
 439       // in the link that would have been included normally. This is known only
 440       // after Read_relocs hence this check has to be done again.
 441       if (parameters->options().gc_sections()
 442           || parameters->options().icf_enabled())
 443         {
 444           if (p->output_section == NULL)
 445             continue;
 446         }
 447       if (!parameters->options().relocatable())
 448         {
 449           // As noted above, when not generating an object file, we
 450           // only scan allocated sections.  We may see a non-allocated
 451           // section here if we are emitting relocs.
 452           if (p->is_data_section_allocated)
 453             target->scan_relocs(symtab, layout, this, p->data_shndx,
 454                                 p->sh_type, p->contents->data(),
 455                                 p->reloc_count, p->output_section,
 456                                 p->needs_special_offset_handling,
 457                                 this->local_symbol_count_,
 458                                 local_symbols);
 459           if (parameters->options().emit_relocs())
 460             this->emit_relocs_scan(symtab, layout, local_symbols, p);
 461           if (layout->incremental_inputs() != NULL)
 462             this->incremental_relocs_scan(p);
 463         }
 464       else
 465         {
 466           Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 467           gold_assert(rr != NULL);
 468           rr->set_reloc_count(p->reloc_count);
 469           target->scan_relocatable_relocs(symtab, layout, this,
 470                                           p->data_shndx, p->sh_type,
 471                                           p->contents->data(),
 472                                           p->reloc_count,
 473                                           p->output_section,
 474                                           p->needs_special_offset_handling,
 475                                           this->local_symbol_count_,
 476                                           local_symbols,
 477                                           rr);
 478         }
 479
 480       delete p->contents;
 481       p->contents = NULL;
 482     }
 483
 484   // For incremental links, finalize the allocation of relocations.
 485   if (layout->incremental_inputs() != NULL)
 486     this->finalize_incremental_relocs(layout);
 487
 488   if (rd->local_symbols != NULL)
 489     {
 490       delete rd->local_symbols;
 491       rd->local_symbols = NULL;
 492     }
 493 }
 494
 495 // This is a strategy class we use when scanning for --emit-relocs.
 496
 497 template<int sh_type>
 498 class Emit_relocs_strategy
 499 {
 500  public:
 501   // A local non-section symbol.
 502   inline Relocatable_relocs::Reloc_strategy
 503   local_non_section_strategy(unsigned int, Relobj*, unsigned int)
 504   { return Relocatable_relocs::RELOC_COPY; }
 505
 506   // A local section symbol.
 507   inline Relocatable_relocs::Reloc_strategy
 508   local_section_strategy(unsigned int, Relobj*)
 509   {
 510     if (sh_type == elfcpp::SHT_RELA)
 511       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
 512     else
 513       {
 514         // The addend is stored in the section contents.  Since this
 515         // is not a relocatable link, we are going to apply the
 516         // relocation contents to the section as usual.  This means
 517         // that we have no way to record the original addend.  If the
 518         // original addend is not zero, there is basically no way for
 519         // the user to handle this correctly.  Caveat emptor.
 520         return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
 521       }
 522   }
 523
 524   // A global symbol.
 525   inline Relocatable_relocs::Reloc_strategy
 526   global_strategy(unsigned int, Relobj*, unsigned int)
 527   { return Relocatable_relocs::RELOC_COPY; }
 528 };
 529
 530 // Scan the input relocations for --emit-relocs.
 531
 532 template<int size, bool big_endian>
 533 void
 534 Sized_relobj<size, big_endian>::emit_relocs_scan(
 535     Symbol_table* symtab,
 536     Layout* layout,
 537     const unsigned char* plocal_syms,
 538     const Read_relocs_data::Relocs_list::iterator& p)
 539 {
 540   Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 541   gold_assert(rr != NULL);
 542   rr->set_reloc_count(p->reloc_count);
 543
 544   if (p->sh_type == elfcpp::SHT_REL)
 545     this->emit_relocs_scan_reltype<elfcpp::SHT_REL>(symtab, layout,
 546                                                     plocal_syms, p, rr);
 547   else
 548     {
 549       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 550       this->emit_relocs_scan_reltype<elfcpp::SHT_RELA>(symtab, layout,
 551                                                        plocal_syms, p, rr);
 552     }
 553 }
 554
 555 // Scan the input relocation for --emit-relocs, templatized on the
 556 // type of the relocation section.
 557
 558 template<int size, bool big_endian>
 559 template<int sh_type>
 560 void
 561 Sized_relobj<size, big_endian>::emit_relocs_scan_reltype(
 562     Symbol_table* symtab,
 563     Layout* layout,
 564     const unsigned char* plocal_syms,
 565     const Read_relocs_data::Relocs_list::iterator& p,
 566     Relocatable_relocs* rr)
 567 {
 568   scan_relocatable_relocs<size, big_endian, sh_type,
 569                           Emit_relocs_strategy<sh_type> >(
 570     symtab,
 571     layout,
 572     this,
 573     p->data_shndx,
 574     p->contents->data(),
 575     p->reloc_count,
 576     p->output_section,
 577     p->needs_special_offset_handling,
 578     this->local_symbol_count_,
 579     plocal_syms,
 580     rr);
 581 }
 582
 583 // Scan the input relocations for --incremental.
 584
 585 template<int size, bool big_endian>
 586 void
 587 Sized_relobj<size, big_endian>::incremental_relocs_scan(
 588     const Read_relocs_data::Relocs_list::iterator& p)
 589 {
 590   if (p->sh_type == elfcpp::SHT_REL)
 591     this->incremental_relocs_scan_reltype<elfcpp::SHT_REL>(p);
 592   else
 593     {
 594       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 595       this->incremental_relocs_scan_reltype<elfcpp::SHT_RELA>(p);
 596     }
 597 }
 598
 599 // Scan the input relocation for --emit-relocs, templatized on the
 600 // type of the relocation section.
 601
 602 template<int size, bool big_endian>
 603 template<int sh_type>
 604 void
 605 Sized_relobj<size, big_endian>::incremental_relocs_scan_reltype(
 606     const Read_relocs_data::Relocs_list::iterator& p)
 607 {
 608   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
 609   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
 610   const unsigned char* prelocs = p->contents->data();
 611   size_t reloc_count = p->reloc_count;
 612
 613   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
 614     {
 615       Reltype reloc(prelocs);
 616
 617       if (p->needs_special_offset_handling
 618           && !p->output_section->is_input_address_mapped(this, p->data_shndx,
 619                                                          reloc.get_r_offset()))
 620         continue;
 621
 622       typename elfcpp::Elf_types<size>::Elf_WXword r_info =
 623           reloc.get_r_info();
 624       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
 625
 626       if (r_sym >= this->local_symbol_count_)
 627         this->count_incremental_reloc(r_sym - this->local_symbol_count_);
 628     }
 629 }
 630
 631 // Relocate the input sections and write out the local symbols.
 632
 633 template<int size, bool big_endian>
 634 void
 635 Sized_relobj<size, big_endian>::do_relocate(const Symbol_table* symtab,
 636                                             const Layout* layout,
 637                                             Output_file* of)
 638 {
 639   unsigned int shnum = this->shnum();
 640
 641   // Read the section headers.
 642   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 643                                                shnum * This::shdr_size,
 644                                                true, true);
 645
 646   Views views;
 647   views.resize(shnum);
 648
 649   // Make two passes over the sections.  The first one copies the
 650   // section data to the output file.  The second one applies
 651   // relocations.
 652
 653   this->write_sections(pshdrs, of, &views);
 654
 655   // To speed up relocations, we set up hash tables for fast lookup of
 656   // input offsets to output addresses.
 657   this->initialize_input_to_output_maps();
 658
 659   // Apply relocations.
 660
 661   this->relocate_sections(symtab, layout, pshdrs, of, &views);
 662
 663   // After we've done the relocations, we release the hash tables,
 664   // since we no longer need them.
 665   this->free_input_to_output_maps();
 666
 667   // Write out the accumulated views.
 668   for (unsigned int i = 1; i < shnum; ++i)
 669     {
 670       if (views[i].view != NULL)
 671         {
 672           if (!views[i].is_postprocessing_view)
 673             {
 674               if (views[i].is_input_output_view)
 675                 of->write_input_output_view(views[i].offset,
 676                                             views[i].view_size,
 677                                             views[i].view);
 678               else
 679                 of->write_output_view(views[i].offset, views[i].view_size,
 680                                       views[i].view);
 681             }
 682         }
 683     }
 684
 685   // Write out the local symbols.
 686   this->write_local_symbols(of, layout->sympool(), layout->dynpool(),
 687                             layout->symtab_xindex(), layout->dynsym_xindex());
 688 }
 689
 690 // Sort a Read_multiple vector by file offset.
 691 struct Read_multiple_compare
 692 {
 693   inline bool
 694   operator()(const File_read::Read_multiple_entry& rme1,
 695              const File_read::Read_multiple_entry& rme2) const
 696   { return rme1.file_offset < rme2.file_offset; }
 697 };
 698
 699 // Write section data to the output file.  PSHDRS points to the
 700 // section headers.  Record the views in *PVIEWS for use when
 701 // relocating.
 702
 703 template<int size, bool big_endian>
 704 void
 705 Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
 706                                                Output_file* of,
 707                                                Views* pviews)
 708 {
 709   unsigned int shnum = this->shnum();
 710   const Output_sections& out_sections(this->output_sections());
 711   const std::vector<Address>& out_offsets(this->section_offsets_);
 712
 713   File_read::Read_multiple rm;
 714   bool is_sorted = true;
 715
 716   const unsigned char* p = pshdrs + This::shdr_size;
 717   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 718     {
 719       View_size* pvs = &(*pviews)[i];
 720
 721       pvs->view = NULL;
 722
 723       const Output_section* os = out_sections[i];
 724       if (os == NULL)
 725         continue;
 726       Address output_offset = out_offsets[i];
 727
 728       typename This::Shdr shdr(p);
 729
 730       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 731         continue;
 732
 733       if ((parameters->options().relocatable()
 734            || parameters->options().emit_relocs())
 735           && (shdr.get_sh_type() == elfcpp::SHT_REL
 736               || shdr.get_sh_type() == elfcpp::SHT_RELA)
 737           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 738         {
 739           // This is a reloc section in a relocatable link or when
 740           // emitting relocs.  We don't need to read the input file.
 741           // The size and file offset are stored in the
 742           // Relocatable_relocs structure.
 743           Relocatable_relocs* rr = this->relocatable_relocs(i);
 744           gold_assert(rr != NULL);
 745           Output_data* posd = rr->output_data();
 746           gold_assert(posd != NULL);
 747
 748           pvs->offset = posd->offset();
 749           pvs->view_size = posd->data_size();
 750           pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
 751           pvs->address = posd->address();
 752           pvs->is_input_output_view = false;
 753           pvs->is_postprocessing_view = false;
 754
 755           continue;
 756         }
 757
 758       // In the normal case, this input section is simply mapped to
 759       // the output section at offset OUTPUT_OFFSET.
 760
 761       // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is
 762       // handled specially--e.g., a .eh_frame section.  The relocation
 763       // routines need to check for each reloc where it should be
 764       // applied.  For this case, we need an input/output view for the
 765       // entire contents of the section in the output file.  We don't
 766       // want to copy the contents of the input section to the output
 767       // section; the output section contents were already written,
 768       // and we waited for them in Relocate_task::is_runnable because
 769       // relocs_must_follow_section_writes is set for the object.
 770
 771       // Regardless of which of the above cases is true, we have to
 772       // check requires_postprocessing of the output section.  If that
 773       // is false, then we work with views of the output file
 774       // directly.  If it is true, then we work with a separate
 775       // buffer, and the output section is responsible for writing the
 776       // final data to the output file.
 777
 778       off_t output_section_offset;
 779       Address output_section_size;
 780       if (!os->requires_postprocessing())
 781         {
 782           output_section_offset = os->offset();
 783           output_section_size = convert_types<Address, off_t>(os->data_size());
 784         }
 785       else
 786         {
 787           output_section_offset = 0;
 788           output_section_size =
 789               convert_types<Address, off_t>(os->postprocessing_buffer_size());
 790         }
 791
 792       off_t view_start;
 793       section_size_type view_size;
 794       bool must_decompress = false;
 795       if (output_offset != invalid_address)
 796         {
 797           view_start = output_section_offset + output_offset;
 798           view_size = convert_to_section_size_type(shdr.get_sh_size());
 799           section_size_type uncompressed_size;
 800           if (this->section_is_compressed(i, &uncompressed_size))
 801             {
 802               view_size = uncompressed_size;
 803               must_decompress = true;
 804             }
 805         }
 806       else
 807         {
 808           view_start = output_section_offset;
 809           view_size = convert_to_section_size_type(output_section_size);
 810         }
 811
 812       if (view_size == 0)
 813         continue;
 814
 815       gold_assert(output_offset == invalid_address
 816                   || output_offset + view_size <= output_section_size);
 817
 818       unsigned char* view;
 819       if (os->requires_postprocessing())
 820         {
 821           unsigned char* buffer = os->postprocessing_buffer();
 822           view = buffer + view_start;
 823           if (output_offset != invalid_address && !must_decompress)
 824             {
 825               off_t sh_offset = shdr.get_sh_offset();
 826               if (!rm.empty() && rm.back().file_offset > sh_offset)
 827                 is_sorted = false;
 828               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 829                                                           view_size, view));
 830             }
 831         }
 832       else
 833         {
 834           if (output_offset == invalid_address)
 835             view = of->get_input_output_view(view_start, view_size);
 836           else
 837             {
 838               view = of->get_output_view(view_start, view_size);
 839               if (!must_decompress)
 840                 {
 841                   off_t sh_offset = shdr.get_sh_offset();
 842                   if (!rm.empty() && rm.back().file_offset > sh_offset)
 843                     is_sorted = false;
 844                   rm.push_back(File_read::Read_multiple_entry(sh_offset,
 845                                                               view_size, view));
 846                 }
 847             }
 848         }
 849
 850       if (must_decompress)
 851         {
 852           // Read and decompress the section.
 853           section_size_type len;
 854           const unsigned char* p = this->section_contents(i, &len, false);
 855           if (!decompress_input_section(p, len, view, view_size))
 856             this->error(_("could not decompress section %s"),
 857                         this->section_name(i).c_str());
 858         }
 859
 860       pvs->view = view;
 861       pvs->address = os->address();
 862       if (output_offset != invalid_address)
 863         pvs->address += output_offset;
 864       pvs->offset = view_start;
 865       pvs->view_size = view_size;
 866       pvs->is_input_output_view = output_offset == invalid_address;
 867       pvs->is_postprocessing_view = os->requires_postprocessing();
 868     }
 869
 870   // Actually read the data.
 871   if (!rm.empty())
 872     {
 873       if (!is_sorted)
 874         std::sort(rm.begin(), rm.end(), Read_multiple_compare());
 875       this->read_multiple(rm);
 876     }
 877 }
 878
 879 // Relocate section data.  VIEWS points to the section data as views
 880 // in the output file.
 881
 882 template<int size, bool big_endian>
 883 void
 884 Sized_relobj<size, big_endian>::do_relocate_sections(
 885     const Symbol_table* symtab,
 886     const Layout* layout,
 887     const unsigned char* pshdrs,
 888     Output_file* of,
 889     Views* pviews)
 890 {
 891   unsigned int shnum = this->shnum();
 892   Sized_target<size, big_endian>* target =
 893     parameters->sized_target<size, big_endian>();
 894
 895   const Output_sections& out_sections(this->output_sections());
 896   const std::vector<Address>& out_offsets(this->section_offsets_);
 897
 898   Relocate_info<size, big_endian> relinfo;
 899   relinfo.symtab = symtab;
 900   relinfo.layout = layout;
 901   relinfo.object = this;
 902
 903   const unsigned char* p = pshdrs + This::shdr_size;
 904   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 905     {
 906       typename This::Shdr shdr(p);
 907
 908       unsigned int sh_type = shdr.get_sh_type();
 909       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 910         continue;
 911
 912       off_t sh_size = shdr.get_sh_size();
 913       if (sh_size == 0)
 914         continue;
 915
 916       unsigned int index = this->adjust_shndx(shdr.get_sh_info());
 917       if (index >= this->shnum())
 918         {
 919           this->error(_("relocation section %u has bad info %u"),
 920                       i, index);
 921           continue;
 922         }
 923
 924       Output_section* os = out_sections[index];
 925       if (os == NULL)
 926         {
 927           // This relocation section is against a section which we
 928           // discarded.
 929           continue;
 930         }
 931       Address output_offset = out_offsets[index];
 932
 933       gold_assert((*pviews)[index].view != NULL);
 934       if (parameters->options().relocatable())
 935         gold_assert((*pviews)[i].view != NULL);
 936
 937       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 938         {
 939           gold_error(_("relocation section %u uses unexpected "
 940                        "symbol table %u"),
 941                      i, this->adjust_shndx(shdr.get_sh_link()));
 942           continue;
 943         }
 944
 945       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 946                                                     sh_size, true, false);
 947
 948       unsigned int reloc_size;
 949       if (sh_type == elfcpp::SHT_REL)
 950         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 951       else
 952         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 953
 954       if (reloc_size != shdr.get_sh_entsize())
 955         {
 956           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 957                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 958                      reloc_size);
 959           continue;
 960         }
 961
 962       size_t reloc_count = sh_size / reloc_size;
 963       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 964         {
 965           gold_error(_("reloc section %u size %lu uneven"),
 966                      i, static_cast<unsigned long>(sh_size));
 967           continue;
 968         }
 969
 970       gold_assert(output_offset != invalid_address
 971                   || this->relocs_must_follow_section_writes());
 972
 973       relinfo.reloc_shndx = i;
 974       relinfo.reloc_shdr = p;
 975       relinfo.data_shndx = index;
 976       relinfo.data_shdr = pshdrs + index * This::shdr_size;
 977       unsigned char* view = (*pviews)[index].view;
 978       Address address = (*pviews)[index].address;
 979       section_size_type view_size = (*pviews)[index].view_size;
 980
 981       Reloc_symbol_changes* reloc_map = NULL;
 982       if (this->uses_split_stack() && output_offset != invalid_address)
 983         {
 984           typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
 985           if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
 986             this->split_stack_adjust(symtab, pshdrs, sh_type, index,
 987                                      prelocs, reloc_count, view, view_size,
 988                                      &reloc_map);
 989         }
 990
 991       if (!parameters->options().relocatable())
 992         {
 993           target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
 994                                    output_offset == invalid_address,
 995                                    view, address, view_size, reloc_map);
 996           if (parameters->options().emit_relocs())
 997             this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count,
 998                               os, output_offset, view, address, view_size,
 999                               (*pviews)[i].view, (*pviews)[i].view_size);
1000           if (parameters->incremental())
1001             this->incremental_relocs_write(&relinfo, sh_type, prelocs,
1002                                            reloc_count, os, output_offset, of);
1003         }
1004       else
1005         {
1006           Relocatable_relocs* rr = this->relocatable_relocs(i);
1007           target->relocate_for_relocatable(&relinfo, sh_type, prelocs,
1008                                            reloc_count, os, output_offset, rr,
1009                                            view, address, view_size,
1010                                            (*pviews)[i].view,
1011                                            (*pviews)[i].view_size);
1012         }
1013     }
1014 }
1015
1016 // Emit the relocs for --emit-relocs.
1017
1018 template<int size, bool big_endian>
1019 void
1020 Sized_relobj<size, big_endian>::emit_relocs(
1021     const Relocate_info<size, big_endian>* relinfo,
1022     unsigned int i,
1023     unsigned int sh_type,
1024     const unsigned char* prelocs,
1025     size_t reloc_count,
1026     Output_section* output_section,
1027     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
1028     unsigned char* view,
1029     typename elfcpp::Elf_types<size>::Elf_Addr address,
1030     section_size_type view_size,
1031     unsigned char* reloc_view,
1032     section_size_type reloc_view_size)
1033 {
1034   if (sh_type == elfcpp::SHT_REL)
1035     this->emit_relocs_reltype<elfcpp::SHT_REL>(relinfo, i, prelocs,
1036                                                reloc_count, output_section,
1037                                                offset_in_output_section,
1038                                                view, address, view_size,
1039                                                reloc_view, reloc_view_size);
1040   else
1041     {
1042       gold_assert(sh_type == elfcpp::SHT_RELA);
1043       this->emit_relocs_reltype<elfcpp::SHT_RELA>(relinfo, i, prelocs,
1044                                                   reloc_count, output_section,
1045                                                   offset_in_output_section,
1046                                                   view, address, view_size,
1047                                                   reloc_view, reloc_view_size);
1048     }
1049 }
1050
1051 // Emit the relocs for --emit-relocs, templatized on the type of the
1052 // relocation section.
1053
1054 template<int size, bool big_endian>
1055 template<int sh_type>
1056 void
1057 Sized_relobj<size, big_endian>::emit_relocs_reltype(
1058     const Relocate_info<size, big_endian>* relinfo,
1059     unsigned int i,
1060     const unsigned char* prelocs,
1061     size_t reloc_count,
1062     Output_section* output_section,
1063     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
1064     unsigned char* view,
1065     typename elfcpp::Elf_types<size>::Elf_Addr address,
1066     section_size_type view_size,
1067     unsigned char* reloc_view,
1068     section_size_type reloc_view_size)
1069 {
1070   const Relocatable_relocs* rr = this->relocatable_relocs(i);
1071   relocate_for_relocatable<size, big_endian, sh_type>(
1072     relinfo,
1073     prelocs,
1074     reloc_count,
1075     output_section,
1076     offset_in_output_section,
1077     rr,
1078     view,
1079     address,
1080     view_size,
1081     reloc_view,
1082     reloc_view_size);
1083 }
1084
1085 // Write the incremental relocs.
1086
1087 template<int size, bool big_endian>
1088 void
1089 Sized_relobj<size, big_endian>::incremental_relocs_write(
1090     const Relocate_info<size, big_endian>* relinfo,
1091     unsigned int sh_type,
1092     const unsigned char* prelocs,
1093     size_t reloc_count,
1094     Output_section* output_section,
1095     Address output_offset,
1096     Output_file* of)
1097 {
1098   if (sh_type == elfcpp::SHT_REL)
1099     this->incremental_relocs_write_reltype<elfcpp::SHT_REL>(
1100         relinfo,
1101         prelocs,
1102         reloc_count,
1103         output_section,
1104         output_offset,
1105         of);
1106   else
1107     {
1108       gold_assert(sh_type == elfcpp::SHT_RELA);
1109       this->incremental_relocs_write_reltype<elfcpp::SHT_RELA>(
1110           relinfo,
1111           prelocs,
1112           reloc_count,
1113           output_section,
1114           output_offset,
1115           of);
1116     }
1117 }
1118
1119 // Write the incremental relocs, templatized on the type of the
1120 // relocation section.
1121
1122 template<int size, bool big_endian>
1123 template<int sh_type>
1124 void
1125 Sized_relobj<size, big_endian>::incremental_relocs_write_reltype(
1126     const Relocate_info<size, big_endian>* relinfo,
1127     const unsigned char* prelocs,
1128     size_t reloc_count,
1129     Output_section* output_section,
1130     Address output_offset,
1131     Output_file* of)
1132 {
1133   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reloc;
1134   const unsigned int reloc_size =
1135       Reloc_types<sh_type, size, big_endian>::reloc_size;
1136   const unsigned int sizeof_addr = size / 8;
1137   const unsigned int incr_reloc_size = 8 + 2 * sizeof_addr;
1138
1139   unsigned int out_shndx = output_section->out_shndx();
1140
1141   // Get a view for the .gnu_incremental_relocs section.
1142
1143   Incremental_inputs* inputs = relinfo->layout->incremental_inputs();
1144   gold_assert(inputs != NULL);
1145   const off_t relocs_off = inputs->relocs_section()->offset();
1146   const off_t relocs_size = inputs->relocs_section()->data_size();
1147   unsigned char* const view = of->get_output_view(relocs_off, relocs_size);
1148
1149   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
1150     {
1151       Reloc reloc(prelocs);
1152
1153       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1154       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1155       const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
1156
1157       if (r_sym < this->local_symbol_count_)
1158         continue;
1159
1160       // Get the new offset--the location in the output section where
1161       // this relocation should be applied.
1162
1163       Address offset = reloc.get_r_offset();
1164       if (output_offset != invalid_address)
1165         offset += output_offset;
1166       else
1167         {
1168           section_offset_type sot_offset =
1169               convert_types<section_offset_type, Address>(offset);
1170           section_offset_type new_sot_offset =
1171               output_section->output_offset(relinfo->object,
1172                                             relinfo->data_shndx,
1173                                             sot_offset);
1174           gold_assert(new_sot_offset != -1);
1175           offset += new_sot_offset;
1176         }
1177
1178       // Get the addend.
1179       typename elfcpp::Elf_types<size>::Elf_Swxword addend;
1180       if (sh_type == elfcpp::SHT_RELA)
1181         addend =
1182             Reloc_types<sh_type, size, big_endian>::get_reloc_addend(&reloc);
1183       else
1184         {
1185           // FIXME: Get the addend for SHT_REL.
1186           addend = 0;
1187         }
1188
1189       // Get the index of the output relocation.
1190
1191       unsigned int reloc_index =
1192           this->next_incremental_reloc_index(r_sym - this->local_symbol_count_);
1193
1194       // Write the relocation.
1195
1196       unsigned char* pov = view + reloc_index * incr_reloc_size;
1197       elfcpp::Swap<32, big_endian>::writeval(pov, r_type);
1198       elfcpp::Swap<32, big_endian>::writeval(pov + 4, out_shndx);
1199       elfcpp::Swap<size, big_endian>::writeval(pov + 8, offset);
1200       elfcpp::Swap<size, big_endian>::writeval(pov + 8 + sizeof_addr, addend);
1201       of->write_output_view(pov - view, incr_reloc_size, view);
1202     }
1203 }
1204
1205 // Create merge hash tables for the local symbols.  These are used to
1206 // speed up relocations.
1207
1208 template<int size, bool big_endian>
1209 void
1210 Sized_relobj<size, big_endian>::initialize_input_to_output_maps()
1211 {
1212   const unsigned int loccount = this->local_symbol_count_;
1213   for (unsigned int i = 1; i < loccount; ++i)
1214     {
1215       Symbol_value<size>& lv(this->local_values_[i]);
1216       lv.initialize_input_to_output_map(this);
1217     }
1218 }
1219
1220 // Free merge hash tables for the local symbols.
1221
1222 template<int size, bool big_endian>
1223 void
1224 Sized_relobj<size, big_endian>::free_input_to_output_maps()
1225 {
1226   const unsigned int loccount = this->local_symbol_count_;
1227   for (unsigned int i = 1; i < loccount; ++i)
1228     {
1229       Symbol_value<size>& lv(this->local_values_[i]);
1230       lv.free_input_to_output_map();
1231     }
1232 }
1233
1234 // If an object was compiled with -fsplit-stack, this is called to
1235 // check whether any relocations refer to functions defined in objects
1236 // which were not compiled with -fsplit-stack.  If they were, then we
1237 // need to apply some target-specific adjustments to request
1238 // additional stack space.
1239
1240 template<int size, bool big_endian>
1241 void
1242 Sized_relobj<size, big_endian>::split_stack_adjust(
1243     const Symbol_table* symtab,
1244     const unsigned char* pshdrs,
1245     unsigned int sh_type,
1246     unsigned int shndx,
1247     const unsigned char* prelocs,
1248     size_t reloc_count,
1249     unsigned char* view,
1250     section_size_type view_size,
1251     Reloc_symbol_changes** reloc_map)
1252 {
1253   if (sh_type == elfcpp::SHT_REL)
1254     this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
1255                                                       prelocs, reloc_count,
1256                                                       view, view_size,
1257                                                       reloc_map);
1258   else
1259     {
1260       gold_assert(sh_type == elfcpp::SHT_RELA);
1261       this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
1262                                                          prelocs, reloc_count,
1263                                                          view, view_size,
1264                                                          reloc_map);
1265     }
1266 }
1267
1268 // Adjust for -fsplit-stack, templatized on the type of the relocation
1269 // section.
1270
1271 template<int size, bool big_endian>
1272 template<int sh_type>
1273 void
1274 Sized_relobj<size, big_endian>::split_stack_adjust_reltype(
1275     const Symbol_table* symtab,
1276     const unsigned char* pshdrs,
1277     unsigned int shndx,
1278     const unsigned char* prelocs,
1279     size_t reloc_count,
1280     unsigned char* view,
1281     section_size_type view_size,
1282     Reloc_symbol_changes** reloc_map)
1283 {
1284   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
1285   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
1286
1287   size_t local_count = this->local_symbol_count();
1288
1289   std::vector<section_offset_type> non_split_refs;
1290
1291   const unsigned char* pr = prelocs;
1292   for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1293     {
1294       Reltype reloc(pr);
1295
1296       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1297       unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1298       if (r_sym < local_count)
1299         continue;
1300
1301       const Symbol* gsym = this->global_symbol(r_sym);
1302       gold_assert(gsym != NULL);
1303       if (gsym->is_forwarder())
1304         gsym = symtab->resolve_forwards(gsym);
1305
1306       // See if this relocation refers to a function defined in an
1307       // object compiled without -fsplit-stack.  Note that we don't
1308       // care about the type of relocation--this means that in some
1309       // cases we will ask for a large stack unnecessarily, but this
1310       // is not fatal.  FIXME: Some targets have symbols which are
1311       // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
1312       if (!gsym->is_undefined()
1313           && gsym->source() == Symbol::FROM_OBJECT
1314           && !gsym->object()->uses_split_stack())
1315         {
1316           unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
1317           if (parameters->target().is_call_to_non_split(gsym, r_type))
1318             {
1319               section_offset_type offset =
1320                 convert_to_section_size_type(reloc.get_r_offset());
1321               non_split_refs.push_back(offset);
1322             }
1323         }
1324     }
1325
1326   if (non_split_refs.empty())
1327     return;
1328
1329   // At this point, every entry in NON_SPLIT_REFS indicates a
1330   // relocation which refers to a function in an object compiled
1331   // without -fsplit-stack.  We now have to convert that list into a
1332   // set of offsets to functions.  First, we find all the functions.
1333
1334   Function_offsets function_offsets;
1335   this->find_functions(pshdrs, shndx, &function_offsets);
1336   if (function_offsets.empty())
1337     return;
1338
1339   // Now get a list of the function with references to non split-stack
1340   // code.
1341
1342   Function_offsets calls_non_split;
1343   for (std::vector<section_offset_type>::const_iterator p
1344          = non_split_refs.begin();
1345        p != non_split_refs.end();
1346        ++p)
1347     {
1348       Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
1349       if (low == function_offsets.end())
1350         --low;
1351       else if (low->first == *p)
1352         ;
1353       else if (low == function_offsets.begin())
1354         continue;
1355       else
1356         --low;
1357
1358       calls_non_split.insert(*low);
1359     }
1360   if (calls_non_split.empty())
1361     return;
1362
1363   // Now we have a set of functions to adjust.  The adjustments are
1364   // target specific.  Besides changing the output section view
1365   // however, it likes, the target may request a relocation change
1366   // from one global symbol name to another.
1367
1368   for (Function_offsets::const_iterator p = calls_non_split.begin();
1369        p != calls_non_split.end();
1370        ++p)
1371     {
1372       std::string from;
1373       std::string to;
1374       parameters->target().calls_non_split(this, shndx, p->first, p->second,
1375                                            view, view_size, &from, &to);
1376       if (!from.empty())
1377         {
1378           gold_assert(!to.empty());
1379           Symbol* tosym = NULL;
1380
1381           // Find relocations in the relevant function which are for
1382           // FROM.
1383           pr = prelocs;
1384           for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1385             {
1386               Reltype reloc(pr);
1387
1388               typename elfcpp::Elf_types<size>::Elf_WXword r_info =
1389                 reloc.get_r_info();
1390               unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1391               if (r_sym < local_count)
1392                 continue;
1393
1394               section_offset_type offset =
1395                 convert_to_section_size_type(reloc.get_r_offset());
1396               if (offset < p->first
1397                   || (offset
1398                       >= (p->first
1399                           + static_cast<section_offset_type>(p->second))))
1400                 continue;
1401
1402               const Symbol* gsym = this->global_symbol(r_sym);
1403               if (from == gsym->name())
1404                 {
1405                   if (tosym == NULL)
1406                     {
1407                       tosym = symtab->lookup(to.c_str());
1408                       if (tosym == NULL)
1409                         {
1410                           this->error(_("could not convert call "
1411                                         "to '%s' to '%s'"),
1412                                       from.c_str(), to.c_str());
1413                           break;
1414                         }
1415                     }
1416
1417                   if (*reloc_map == NULL)
1418                     *reloc_map = new Reloc_symbol_changes(reloc_count);
1419                   (*reloc_map)->set(i, tosym);
1420                 }
1421             }
1422         }
1423     }
1424 }
1425
1426 // Find all the function in this object defined in section SHNDX.
1427 // Store their offsets in the section in FUNCTION_OFFSETS.
1428
1429 template<int size, bool big_endian>
1430 void
1431 Sized_relobj<size, big_endian>::find_functions(
1432     const unsigned char* pshdrs,
1433     unsigned int shndx,
1434     Sized_relobj<size, big_endian>::Function_offsets* function_offsets)
1435 {
1436   // We need to read the symbols to find the functions.  If we wanted
1437   // to, we could cache reading the symbols across all sections in the
1438   // object.
1439   const unsigned int symtab_shndx = this->symtab_shndx_;
1440   typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size);
1441   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1442
1443   typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
1444     symtabshdr.get_sh_size();
1445   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1446                                               sh_size, true, true);
1447
1448   const int sym_size = This::sym_size;
1449   const unsigned int symcount = sh_size / sym_size;
1450   for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size)
1451     {
1452       typename elfcpp::Sym<size, big_endian> isym(psyms);
1453
1454       // FIXME: Some targets can have functions which do not have type
1455       // STT_FUNC, e.g., STT_ARM_TFUNC.
1456       if (isym.get_st_type() != elfcpp::STT_FUNC
1457           || isym.get_st_size() == 0)
1458         continue;
1459
1460       bool is_ordinary;
1461       unsigned int sym_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1462                                                       &is_ordinary);
1463       if (!is_ordinary || sym_shndx != shndx)
1464         continue;
1465
1466       section_offset_type value =
1467         convert_to_section_size_type(isym.get_st_value());
1468       section_size_type fnsize =
1469         convert_to_section_size_type(isym.get_st_size());
1470
1471       (*function_offsets)[value] = fnsize;
1472     }
1473 }
1474
1475 // Class Merged_symbol_value.
1476
1477 template<int size>
1478 void
1479 Merged_symbol_value<size>::initialize_input_to_output_map(
1480     const Relobj* object,
1481     unsigned int input_shndx)
1482 {
1483   Object_merge_map* map = object->merge_map();
1484   map->initialize_input_to_output_map<size>(input_shndx,
1485                                             this->output_start_address_,
1486                                             &this->output_addresses_);
1487 }
1488
1489 // Get the output value corresponding to an input offset if we
1490 // couldn't find it in the hash table.
1491
1492 template<int size>
1493 typename elfcpp::Elf_types<size>::Elf_Addr
1494 Merged_symbol_value<size>::value_from_output_section(
1495     const Relobj* object,
1496     unsigned int input_shndx,
1497     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
1498 {
1499   section_offset_type output_offset;
1500   bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
1501                                                       input_offset,
1502                                                       &output_offset);
1503
1504   // If this assertion fails, it means that some relocation was
1505   // against a portion of an input merge section which we didn't map
1506   // to the output file and we didn't explicitly discard.  We should
1507   // always map all portions of input merge sections.
1508   gold_assert(found);
1509
1510   if (output_offset == -1)
1511     return 0;
1512   else
1513     return this->output_start_address_ + output_offset;
1514 }
1515
1516 // Track_relocs methods.
1517
1518 // Initialize the class to track the relocs.  This gets the object,
1519 // the reloc section index, and the type of the relocs.  This returns
1520 // false if something goes wrong.
1521
1522 template<int size, bool big_endian>
1523 bool
1524 Track_relocs<size, big_endian>::initialize(
1525     Object* object,
1526     unsigned int reloc_shndx,
1527     unsigned int reloc_type)
1528 {
1529   // If RELOC_SHNDX is -1U, it means there is more than one reloc
1530   // section for the .eh_frame section.  We can't handle that case.
1531   if (reloc_shndx == -1U)
1532     return false;
1533
1534   // If RELOC_SHNDX is 0, there is no reloc section.
1535   if (reloc_shndx == 0)
1536     return true;
1537
1538   // Get the contents of the reloc section.
1539   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
1540
1541   if (reloc_type == elfcpp::SHT_REL)
1542     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
1543   else if (reloc_type == elfcpp::SHT_RELA)
1544     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
1545   else
1546     gold_unreachable();
1547
1548   if (this->len_ % this->reloc_size_ != 0)
1549     {
1550       object->error(_("reloc section size %zu is not a multiple of "
1551                       "reloc size %d\n"),
1552                     static_cast<size_t>(this->len_),
1553                     this->reloc_size_);
1554       return false;
1555     }
1556
1557   return true;
1558 }
1559
1560 // Return the offset of the next reloc, or -1 if there isn't one.
1561
1562 template<int size, bool big_endian>
1563 off_t
1564 Track_relocs<size, big_endian>::next_offset() const
1565 {
1566   if (this->pos_ >= this->len_)
1567     return -1;
1568
1569   // Rel and Rela start out the same, so we can always use Rel to find
1570   // the r_offset value.
1571   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1572   return rel.get_r_offset();
1573 }
1574
1575 // Return the index of the symbol referenced by the next reloc, or -1U
1576 // if there aren't any more relocs.
1577
1578 template<int size, bool big_endian>
1579 unsigned int
1580 Track_relocs<size, big_endian>::next_symndx() const
1581 {
1582   if (this->pos_ >= this->len_)
1583     return -1U;
1584
1585   // Rel and Rela start out the same, so we can use Rel to find the
1586   // symbol index.
1587   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1588   return elfcpp::elf_r_sym<size>(rel.get_r_info());
1589 }
1590
1591 // Advance to the next reloc whose r_offset is greater than or equal
1592 // to OFFSET.  Return the number of relocs we skip.
1593
1594 template<int size, bool big_endian>
1595 int
1596 Track_relocs<size, big_endian>::advance(off_t offset)
1597 {
1598   int ret = 0;
1599   while (this->pos_ < this->len_)
1600     {
1601       // Rel and Rela start out the same, so we can always use Rel to
1602       // find the r_offset value.
1603       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1604       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
1605         break;
1606       ++ret;
1607       this->pos_ += this->reloc_size_;
1608     }
1609   return ret;
1610 }
1611
1612 // Instantiate the templates we need.
1613
1614 #ifdef HAVE_TARGET_32_LITTLE
1615 template
1616 void
1617 Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd);
1618 #endif
1619
1620 #ifdef HAVE_TARGET_32_BIG
1621 template
1622 void
1623 Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd);
1624 #endif
1625
1626 #ifdef HAVE_TARGET_64_LITTLE
1627 template
1628 void
1629 Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd);
1630 #endif
1631
1632 #ifdef HAVE_TARGET_64_BIG
1633 template
1634 void
1635 Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
1636 #endif
1637
1638 #ifdef HAVE_TARGET_32_LITTLE
1639 template
1640 void
1641 Sized_relobj<32, false>::do_gc_process_relocs(Symbol_table* symtab,
1642                                               Layout* layout,
1643                                               Read_relocs_data* rd);
1644 #endif
1645
1646 #ifdef HAVE_TARGET_32_BIG
1647 template
1648 void
1649 Sized_relobj<32, true>::do_gc_process_relocs(Symbol_table* symtab,
1650                                              Layout* layout,
1651                                              Read_relocs_data* rd);
1652 #endif
1653
1654 #ifdef HAVE_TARGET_64_LITTLE
1655 template
1656 void
1657 Sized_relobj<64, false>::do_gc_process_relocs(Symbol_table* symtab,
1658                                               Layout* layout,
1659                                               Read_relocs_data* rd);
1660 #endif
1661
1662 #ifdef HAVE_TARGET_64_BIG
1663 template
1664 void
1665 Sized_relobj<64, true>::do_gc_process_relocs(Symbol_table* symtab,
1666                                              Layout* layout,
1667                                              Read_relocs_data* rd);
1668 #endif
1669
1670 #ifdef HAVE_TARGET_32_LITTLE
1671 template
1672 void
1673 Sized_relobj<32, false>::do_scan_relocs(Symbol_table* symtab,
1674                                         Layout* layout,
1675                                         Read_relocs_data* rd);
1676 #endif
1677
1678 #ifdef HAVE_TARGET_32_BIG
1679 template
1680 void
1681 Sized_relobj<32, true>::do_scan_relocs(Symbol_table* symtab,
1682                                        Layout* layout,
1683                                        Read_relocs_data* rd);
1684 #endif
1685
1686 #ifdef HAVE_TARGET_64_LITTLE
1687 template
1688 void
1689 Sized_relobj<64, false>::do_scan_relocs(Symbol_table* symtab,
1690                                         Layout* layout,
1691                                         Read_relocs_data* rd);
1692 #endif
1693
1694 #ifdef HAVE_TARGET_64_BIG
1695 template
1696 void
1697 Sized_relobj<64, true>::do_scan_relocs(Symbol_table* symtab,
1698                                        Layout* layout,
1699                                        Read_relocs_data* rd);
1700 #endif
1701
1702 #ifdef HAVE_TARGET_32_LITTLE
1703 template
1704 void
1705 Sized_relobj<32, false>::do_relocate(const Symbol_table* symtab,
1706                                      const Layout* layout,
1707                                      Output_file* of);
1708 #endif
1709
1710 #ifdef HAVE_TARGET_32_BIG
1711 template
1712 void
1713 Sized_relobj<32, true>::do_relocate(const Symbol_table* symtab,
1714                                     const Layout* layout,
1715                                     Output_file* of);
1716 #endif
1717
1718 #ifdef HAVE_TARGET_64_LITTLE
1719 template
1720 void
1721 Sized_relobj<64, false>::do_relocate(const Symbol_table* symtab,
1722                                      const Layout* layout,
1723                                      Output_file* of);
1724 #endif
1725
1726 #ifdef HAVE_TARGET_64_BIG
1727 template
1728 void
1729 Sized_relobj<64, true>::do_relocate(const Symbol_table* symtab,
1730                                     const Layout* layout,
1731                                     Output_file* of);
1732 #endif
1733
1734 #ifdef HAVE_TARGET_32_LITTLE
1735 template
1736 void
1737 Sized_relobj<32, false>::do_relocate_sections(
1738     const Symbol_table* symtab,
1739     const Layout* layout,
1740     const unsigned char* pshdrs,
1741     Output_file* of,
1742     Views* pviews);
1743 #endif
1744
1745 #ifdef HAVE_TARGET_32_BIG
1746 template
1747 void
1748 Sized_relobj<32, true>::do_relocate_sections(
1749     const Symbol_table* symtab,
1750     const Layout* layout,
1751     const unsigned char* pshdrs,
1752     Output_file* of,
1753     Views* pviews);
1754 #endif
1755
1756 #ifdef HAVE_TARGET_64_LITTLE
1757 template
1758 void
1759 Sized_relobj<64, false>::do_relocate_sections(
1760     const Symbol_table* symtab,
1761     const Layout* layout,
1762     const unsigned char* pshdrs,
1763     Output_file* of,
1764     Views* pviews);
1765 #endif
1766
1767 #ifdef HAVE_TARGET_64_BIG
1768 template
1769 void
1770 Sized_relobj<64, true>::do_relocate_sections(
1771     const Symbol_table* symtab,
1772     const Layout* layout,
1773     const unsigned char* pshdrs,
1774     Output_file* of,
1775     Views* pviews);
1776 #endif
1777
1778 #ifdef HAVE_TARGET_32_LITTLE
1779 template
1780 void
1781 Sized_relobj<32, false>::initialize_input_to_output_maps();
1782
1783 template
1784 void
1785 Sized_relobj<32, false>::free_input_to_output_maps();
1786 #endif
1787
1788 #ifdef HAVE_TARGET_32_BIG
1789 template
1790 void
1791 Sized_relobj<32, true>::initialize_input_to_output_maps();
1792
1793 template
1794 void
1795 Sized_relobj<32, true>::free_input_to_output_maps();
1796 #endif
1797
1798 #ifdef HAVE_TARGET_64_LITTLE
1799 template
1800 void
1801 Sized_relobj<64, false>::initialize_input_to_output_maps();
1802
1803 template
1804 void
1805 Sized_relobj<64, false>::free_input_to_output_maps();
1806 #endif
1807
1808 #ifdef HAVE_TARGET_64_BIG
1809 template
1810 void
1811 Sized_relobj<64, true>::initialize_input_to_output_maps();
1812
1813 template
1814 void
1815 Sized_relobj<64, true>::free_input_to_output_maps();
1816 #endif
1817
1818 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1819 template
1820 class Merged_symbol_value<32>;
1821 #endif
1822
1823 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1824 template
1825 class Merged_symbol_value<64>;
1826 #endif
1827
1828 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1829 template
1830 class Symbol_value<32>;
1831 #endif
1832
1833 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1834 template
1835 class Symbol_value<64>;
1836 #endif
1837
1838 #ifdef HAVE_TARGET_32_LITTLE
1839 template
1840 class Track_relocs<32, false>;
1841 #endif
1842
1843 #ifdef HAVE_TARGET_32_BIG
1844 template
1845 class Track_relocs<32, true>;
1846 #endif
1847
1848 #ifdef HAVE_TARGET_64_LITTLE
1849 template
1850 class Track_relocs<64, false>;
1851 #endif
1852
1853 #ifdef HAVE_TARGET_64_BIG
1854 template
1855 class Track_relocs<64, true>;
1856 #endif
1857
1858 } // End namespace gold.