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   Task_token* token = this->object_->token();
  60   if (token != NULL)
  61     tl->add(this, token);
  62 }
  63
  64 // Read the relocations and then start a Scan_relocs_task.
  65
  66 void
  67 Read_relocs::run(Workqueue* workqueue)
  68 {
  69   Read_relocs_data* rd = new Read_relocs_data;
  70   this->object_->read_relocs(rd);
  71   this->object_->set_relocs_data(rd);
  72   this->object_->release();
  73
  74   // If garbage collection or identical comdat folding is desired, we
  75   // process the relocs first before scanning them.  Scanning of relocs is
  76   // done only after garbage or identical sections is identified.
  77   if (parameters->options().gc_sections()
  78       || parameters->options().icf_enabled())
  79     {
  80       workqueue->queue_next(new Gc_process_relocs(this->symtab_,
  81                                                   this->layout_,
  82                                                   this->object_, rd,
  83                                                   this->this_blocker_,
  84                                                   this->next_blocker_));
  85     }
  86   else
  87     {
  88       workqueue->queue_next(new Scan_relocs(this->symtab_, this->layout_,
  89                                             this->object_, rd,
  90                                             this->this_blocker_,
  91                                             this->next_blocker_));
  92     }
  93 }
  94
  95 // Return a debugging name for the task.
  96
  97 std::string
  98 Read_relocs::get_name() const
  99 {
 100   return "Read_relocs " + this->object_->name();
 101 }
 102
 103 // Gc_process_relocs methods.
 104
 105 Gc_process_relocs::~Gc_process_relocs()
 106 {
 107   if (this->this_blocker_ != NULL)
 108     delete this->this_blocker_;
 109 }
 110
 111 // These tasks process the relocations read by Read_relocs and
 112 // determine which sections are referenced and which are garbage.
 113 // This task is done only when --gc-sections is used.  This is blocked
 114 // by THIS_BLOCKER_.  It unblocks NEXT_BLOCKER_.
 115
 116 Task_token*
 117 Gc_process_relocs::is_runnable()
 118 {
 119   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 120     return this->this_blocker_;
 121   if (this->object_->is_locked())
 122     return this->object_->token();
 123   return NULL;
 124 }
 125
 126 void
 127 Gc_process_relocs::locks(Task_locker* tl)
 128 {
 129   tl->add(this, this->object_->token());
 130   tl->add(this, this->next_blocker_);
 131 }
 132
 133 void
 134 Gc_process_relocs::run(Workqueue*)
 135 {
 136   this->object_->gc_process_relocs(this->symtab_, this->layout_, this->rd_);
 137   this->object_->release();
 138 }
 139
 140 // Return a debugging name for the task.
 141
 142 std::string
 143 Gc_process_relocs::get_name() const
 144 {
 145   return "Gc_process_relocs " + this->object_->name();
 146 }
 147
 148 // Scan_relocs methods.
 149
 150 Scan_relocs::~Scan_relocs()
 151 {
 152   if (this->this_blocker_ != NULL)
 153     delete this->this_blocker_;
 154 }
 155
 156 // These tasks scan the relocations read by Read_relocs and mark up
 157 // the symbol table to indicate which relocations are required.  We
 158 // use a lock on the symbol table to keep them from interfering with
 159 // each other.
 160
 161 Task_token*
 162 Scan_relocs::is_runnable()
 163 {
 164   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 165     return this->this_blocker_;
 166   if (this->object_->is_locked())
 167     return this->object_->token();
 168   return NULL;
 169 }
 170
 171 // Return the locks we hold: one on the file, one on the symbol table
 172 // and one blocker.
 173
 174 void
 175 Scan_relocs::locks(Task_locker* tl)
 176 {
 177   Task_token* token = this->object_->token();
 178   if (token != NULL)
 179     tl->add(this, token);
 180   tl->add(this, this->next_blocker_);
 181 }
 182
 183 // Scan the relocs.
 184
 185 void
 186 Scan_relocs::run(Workqueue*)
 187 {
 188   this->object_->scan_relocs(this->symtab_, this->layout_, this->rd_);
 189   delete this->rd_;
 190   this->rd_ = NULL;
 191   this->object_->release();
 192 }
 193
 194 // Return a debugging name for the task.
 195
 196 std::string
 197 Scan_relocs::get_name() const
 198 {
 199   return "Scan_relocs " + this->object_->name();
 200 }
 201
 202 // Relocate_task methods.
 203
 204 // We may have to wait for the output sections to be written.
 205
 206 Task_token*
 207 Relocate_task::is_runnable()
 208 {
 209   if (this->object_->relocs_must_follow_section_writes()
 210       && this->output_sections_blocker_->is_blocked())
 211     return this->output_sections_blocker_;
 212
 213   if (this->object_->is_locked())
 214     return this->object_->token();
 215
 216   return NULL;
 217 }
 218
 219 // We want to lock the file while we run.  We want to unblock
 220 // INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done.
 221 // INPUT_SECTIONS_BLOCKER may be NULL.
 222
 223 void
 224 Relocate_task::locks(Task_locker* tl)
 225 {
 226   if (this->input_sections_blocker_ != NULL)
 227     tl->add(this, this->input_sections_blocker_);
 228   tl->add(this, this->final_blocker_);
 229   Task_token* token = this->object_->token();
 230   if (token != NULL)
 231     tl->add(this, token);
 232 }
 233
 234 // Run the task.
 235
 236 void
 237 Relocate_task::run(Workqueue*)
 238 {
 239   this->object_->relocate(this->symtab_, this->layout_, this->of_);
 240
 241   // This is normally the last thing we will do with an object, so
 242   // uncache all views.
 243   this->object_->clear_view_cache_marks();
 244
 245   this->object_->release();
 246 }
 247
 248 // Return a debugging name for the task.
 249
 250 std::string
 251 Relocate_task::get_name() const
 252 {
 253   return "Relocate_task " + this->object_->name();
 254 }
 255
 256 // Read the relocs and local symbols from the object file and store
 257 // the information in RD.
 258
 259 template<int size, bool big_endian>
 260 void
 261 Sized_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd)
 262 {
 263   rd->relocs.clear();
 264
 265   unsigned int shnum = this->shnum();
 266   if (shnum == 0)
 267     return;
 268
 269   rd->relocs.reserve(shnum / 2);
 270
 271   const Output_sections& out_sections(this->output_sections());
 272   const std::vector<Address>& out_offsets(this->section_offsets_);
 273
 274   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 275                                                shnum * This::shdr_size,
 276                                                true, true);
 277   // Skip the first, dummy, section.
 278   const unsigned char* ps = pshdrs + This::shdr_size;
 279   for (unsigned int i = 1; i < shnum; ++i, ps += This::shdr_size)
 280     {
 281       typename This::Shdr shdr(ps);
 282
 283       unsigned int sh_type = shdr.get_sh_type();
 284       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 285         continue;
 286
 287       unsigned int shndx = this->adjust_shndx(shdr.get_sh_info());
 288       if (shndx >= shnum)
 289         {
 290           this->error(_("relocation section %u has bad info %u"),
 291                       i, shndx);
 292           continue;
 293         }
 294
 295       Output_section* os = out_sections[shndx];
 296       if (os == NULL)
 297         continue;
 298
 299       // We are scanning relocations in order to fill out the GOT and
 300       // PLT sections.  Relocations for sections which are not
 301       // allocated (typically debugging sections) should not add new
 302       // GOT and PLT entries.  So we skip them unless this is a
 303       // relocatable link or we need to emit relocations.  FIXME: What
 304       // should we do if a linker script maps a section with SHF_ALLOC
 305       // clear to a section with SHF_ALLOC set?
 306       typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
 307       bool is_section_allocated = ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC)
 308                                    != 0);
 309       if (!is_section_allocated
 310           && !parameters->options().relocatable()
 311           && !parameters->options().emit_relocs()
 312           && !parameters->incremental())
 313         continue;
 314
 315       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 316         {
 317           this->error(_("relocation section %u uses unexpected "
 318                         "symbol table %u"),
 319                       i, this->adjust_shndx(shdr.get_sh_link()));
 320           continue;
 321         }
 322
 323       off_t sh_size = shdr.get_sh_size();
 324
 325       unsigned int reloc_size;
 326       if (sh_type == elfcpp::SHT_REL)
 327         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 328       else
 329         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 330       if (reloc_size != shdr.get_sh_entsize())
 331         {
 332           this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
 333                       i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 334                       reloc_size);
 335           continue;
 336         }
 337
 338       size_t reloc_count = sh_size / reloc_size;
 339       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 340         {
 341           this->error(_("reloc section %u size %lu uneven"),
 342                       i, static_cast<unsigned long>(sh_size));
 343           continue;
 344         }
 345
 346       rd->relocs.push_back(Section_relocs());
 347       Section_relocs& sr(rd->relocs.back());
 348       sr.reloc_shndx = i;
 349       sr.data_shndx = shndx;
 350       sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
 351                                            true, true);
 352       sr.sh_type = sh_type;
 353       sr.reloc_count = reloc_count;
 354       sr.output_section = os;
 355       sr.needs_special_offset_handling = out_offsets[shndx] == invalid_address;
 356       sr.is_data_section_allocated = is_section_allocated;
 357     }
 358
 359   // Read the local symbols.
 360   gold_assert(this->symtab_shndx_ != -1U);
 361   if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
 362     rd->local_symbols = NULL;
 363   else
 364     {
 365       typename This::Shdr symtabshdr(pshdrs
 366                                      + this->symtab_shndx_ * This::shdr_size);
 367       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 368       const int sym_size = This::sym_size;
 369       const unsigned int loccount = this->local_symbol_count_;
 370       gold_assert(loccount == symtabshdr.get_sh_info());
 371       off_t locsize = loccount * sym_size;
 372       rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
 373                                                  locsize, true, true);
 374     }
 375 }
 376
 377 // Process the relocs to generate mappings from source sections to referenced
 378 // sections.  This is used during garbage collection to determine garbage
 379 // sections.
 380
 381 template<int size, bool big_endian>
 382 void
 383 Sized_relobj<size, big_endian>::do_gc_process_relocs(Symbol_table* symtab,
 384                                                      Layout* layout,
 385                                                      Read_relocs_data* rd)
 386 {
 387   Sized_target<size, big_endian>* target =
 388     parameters->sized_target<size, big_endian>();
 389
 390   const unsigned char* local_symbols;
 391   if (rd->local_symbols == NULL)
 392     local_symbols = NULL;
 393   else
 394     local_symbols = rd->local_symbols->data();
 395
 396   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 397        p != rd->relocs.end();
 398        ++p)
 399     {
 400       if (!parameters->options().relocatable())
 401           {
 402             // As noted above, when not generating an object file, we
 403             // only scan allocated sections.  We may see a non-allocated
 404             // section here if we are emitting relocs.
 405             if (p->is_data_section_allocated)
 406               target->gc_process_relocs(symtab, layout, this,
 407                                         p->data_shndx, p->sh_type,
 408                                         p->contents->data(), p->reloc_count,
 409                                         p->output_section,
 410                                         p->needs_special_offset_handling,
 411                                         this->local_symbol_count_,
 412                                         local_symbols);
 413         }
 414     }
 415 }
 416
 417
 418 // Scan the relocs and adjust the symbol table.  This looks for
 419 // relocations which require GOT/PLT/COPY relocations.
 420
 421 template<int size, bool big_endian>
 422 void
 423 Sized_relobj<size, big_endian>::do_scan_relocs(Symbol_table* symtab,
 424                                                Layout* layout,
 425                                                Read_relocs_data* rd)
 426 {
 427   Sized_target<size, big_endian>* target =
 428     parameters->sized_target<size, big_endian>();
 429
 430   const unsigned char* local_symbols;
 431   if (rd->local_symbols == NULL)
 432     local_symbols = NULL;
 433   else
 434     local_symbols = rd->local_symbols->data();
 435
 436   // For incremental links, allocate the counters for incremental relocations.
 437   if (layout->incremental_inputs() != NULL)
 438     this->allocate_incremental_reloc_counts();
 439
 440   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 441        p != rd->relocs.end();
 442        ++p)
 443     {
 444       // When garbage collection is on, unreferenced sections are not included
 445       // in the link that would have been included normally. This is known only
 446       // after Read_relocs hence this check has to be done again.
 447       if (parameters->options().gc_sections()
 448           || parameters->options().icf_enabled())
 449         {
 450           if (p->output_section == NULL)
 451             continue;
 452         }
 453       if (!parameters->options().relocatable())
 454         {
 455           // As noted above, when not generating an object file, we
 456           // only scan allocated sections.  We may see a non-allocated
 457           // section here if we are emitting relocs.
 458           if (p->is_data_section_allocated)
 459             target->scan_relocs(symtab, layout, this, p->data_shndx,
 460                                 p->sh_type, p->contents->data(),
 461                                 p->reloc_count, p->output_section,
 462                                 p->needs_special_offset_handling,
 463                                 this->local_symbol_count_,
 464                                 local_symbols);
 465           if (parameters->options().emit_relocs())
 466             this->emit_relocs_scan(symtab, layout, local_symbols, p);
 467           if (layout->incremental_inputs() != NULL)
 468             this->incremental_relocs_scan(p);
 469         }
 470       else
 471         {
 472           Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 473           gold_assert(rr != NULL);
 474           rr->set_reloc_count(p->reloc_count);
 475           target->scan_relocatable_relocs(symtab, layout, this,
 476                                           p->data_shndx, p->sh_type,
 477                                           p->contents->data(),
 478                                           p->reloc_count,
 479                                           p->output_section,
 480                                           p->needs_special_offset_handling,
 481                                           this->local_symbol_count_,
 482                                           local_symbols,
 483                                           rr);
 484         }
 485
 486       delete p->contents;
 487       p->contents = NULL;
 488     }
 489
 490   // For incremental links, finalize the allocation of relocations.
 491   if (layout->incremental_inputs() != NULL)
 492     this->finalize_incremental_relocs(layout, true);
 493
 494   if (rd->local_symbols != NULL)
 495     {
 496       delete rd->local_symbols;
 497       rd->local_symbols = NULL;
 498     }
 499 }
 500
 501 // This is a strategy class we use when scanning for --emit-relocs.
 502
 503 template<int sh_type>
 504 class Emit_relocs_strategy
 505 {
 506  public:
 507   // A local non-section symbol.
 508   inline Relocatable_relocs::Reloc_strategy
 509   local_non_section_strategy(unsigned int, Relobj*, unsigned int)
 510   { return Relocatable_relocs::RELOC_COPY; }
 511
 512   // A local section symbol.
 513   inline Relocatable_relocs::Reloc_strategy
 514   local_section_strategy(unsigned int, Relobj*)
 515   {
 516     if (sh_type == elfcpp::SHT_RELA)
 517       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
 518     else
 519       {
 520         // The addend is stored in the section contents.  Since this
 521         // is not a relocatable link, we are going to apply the
 522         // relocation contents to the section as usual.  This means
 523         // that we have no way to record the original addend.  If the
 524         // original addend is not zero, there is basically no way for
 525         // the user to handle this correctly.  Caveat emptor.
 526         return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
 527       }
 528   }
 529
 530   // A global symbol.
 531   inline Relocatable_relocs::Reloc_strategy
 532   global_strategy(unsigned int, Relobj*, unsigned int)
 533   { return Relocatable_relocs::RELOC_COPY; }
 534 };
 535
 536 // Scan the input relocations for --emit-relocs.
 537
 538 template<int size, bool big_endian>
 539 void
 540 Sized_relobj<size, big_endian>::emit_relocs_scan(
 541     Symbol_table* symtab,
 542     Layout* layout,
 543     const unsigned char* plocal_syms,
 544     const Read_relocs_data::Relocs_list::iterator& p)
 545 {
 546   Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 547   gold_assert(rr != NULL);
 548   rr->set_reloc_count(p->reloc_count);
 549
 550   if (p->sh_type == elfcpp::SHT_REL)
 551     this->emit_relocs_scan_reltype<elfcpp::SHT_REL>(symtab, layout,
 552                                                     plocal_syms, p, rr);
 553   else
 554     {
 555       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 556       this->emit_relocs_scan_reltype<elfcpp::SHT_RELA>(symtab, layout,
 557                                                        plocal_syms, p, rr);
 558     }
 559 }
 560
 561 // Scan the input relocation for --emit-relocs, templatized on the
 562 // type of the relocation section.
 563
 564 template<int size, bool big_endian>
 565 template<int sh_type>
 566 void
 567 Sized_relobj<size, big_endian>::emit_relocs_scan_reltype(
 568     Symbol_table* symtab,
 569     Layout* layout,
 570     const unsigned char* plocal_syms,
 571     const Read_relocs_data::Relocs_list::iterator& p,
 572     Relocatable_relocs* rr)
 573 {
 574   scan_relocatable_relocs<size, big_endian, sh_type,
 575                           Emit_relocs_strategy<sh_type> >(
 576     symtab,
 577     layout,
 578     this,
 579     p->data_shndx,
 580     p->contents->data(),
 581     p->reloc_count,
 582     p->output_section,
 583     p->needs_special_offset_handling,
 584     this->local_symbol_count_,
 585     plocal_syms,
 586     rr);
 587 }
 588
 589 // Scan the input relocations for --incremental.
 590
 591 template<int size, bool big_endian>
 592 void
 593 Sized_relobj<size, big_endian>::incremental_relocs_scan(
 594     const Read_relocs_data::Relocs_list::iterator& p)
 595 {
 596   if (p->sh_type == elfcpp::SHT_REL)
 597     this->incremental_relocs_scan_reltype<elfcpp::SHT_REL>(p);
 598   else
 599     {
 600       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 601       this->incremental_relocs_scan_reltype<elfcpp::SHT_RELA>(p);
 602     }
 603 }
 604
 605 // Scan the input relocation for --incremental, templatized on the
 606 // type of the relocation section.
 607
 608 template<int size, bool big_endian>
 609 template<int sh_type>
 610 void
 611 Sized_relobj<size, big_endian>::incremental_relocs_scan_reltype(
 612     const Read_relocs_data::Relocs_list::iterator& p)
 613 {
 614   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
 615   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
 616   const unsigned char* prelocs = p->contents->data();
 617   size_t reloc_count = p->reloc_count;
 618
 619   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
 620     {
 621       Reltype reloc(prelocs);
 622
 623       if (p->needs_special_offset_handling
 624           && !p->output_section->is_input_address_mapped(this, p->data_shndx,
 625                                                          reloc.get_r_offset()))
 626         continue;
 627
 628       typename elfcpp::Elf_types<size>::Elf_WXword r_info =
 629           reloc.get_r_info();
 630       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
 631
 632       if (r_sym >= this->local_symbol_count_)
 633         this->count_incremental_reloc(r_sym - this->local_symbol_count_);
 634     }
 635 }
 636
 637 // Relocate the input sections and write out the local symbols.
 638
 639 template<int size, bool big_endian>
 640 void
 641 Sized_relobj<size, big_endian>::do_relocate(const Symbol_table* symtab,
 642                                             const Layout* layout,
 643                                             Output_file* of)
 644 {
 645   unsigned int shnum = this->shnum();
 646
 647   // Read the section headers.
 648   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 649                                                shnum * This::shdr_size,
 650                                                true, true);
 651
 652   Views views;
 653   views.resize(shnum);
 654
 655   // Make two passes over the sections.  The first one copies the
 656   // section data to the output file.  The second one applies
 657   // relocations.
 658
 659   this->write_sections(pshdrs, of, &views);
 660
 661   // To speed up relocations, we set up hash tables for fast lookup of
 662   // input offsets to output addresses.
 663   this->initialize_input_to_output_maps();
 664
 665   // Apply relocations.
 666
 667   this->relocate_sections(symtab, layout, pshdrs, of, &views);
 668
 669   // After we've done the relocations, we release the hash tables,
 670   // since we no longer need them.
 671   this->free_input_to_output_maps();
 672
 673   // Write out the accumulated views.
 674   for (unsigned int i = 1; i < shnum; ++i)
 675     {
 676       if (views[i].view != NULL)
 677         {
 678           if (!views[i].is_postprocessing_view)
 679             {
 680               if (views[i].is_input_output_view)
 681                 of->write_input_output_view(views[i].offset,
 682                                             views[i].view_size,
 683                                             views[i].view);
 684               else
 685                 of->write_output_view(views[i].offset, views[i].view_size,
 686                                       views[i].view);
 687             }
 688         }
 689     }
 690
 691   // Write out the local symbols.
 692   this->write_local_symbols(of, layout->sympool(), layout->dynpool(),
 693                             layout->symtab_xindex(), layout->dynsym_xindex(),
 694                             layout->symtab_section_offset());
 695 }
 696
 697 // Sort a Read_multiple vector by file offset.
 698 struct Read_multiple_compare
 699 {
 700   inline bool
 701   operator()(const File_read::Read_multiple_entry& rme1,
 702              const File_read::Read_multiple_entry& rme2) const
 703   { return rme1.file_offset < rme2.file_offset; }
 704 };
 705
 706 // Write section data to the output file.  PSHDRS points to the
 707 // section headers.  Record the views in *PVIEWS for use when
 708 // relocating.
 709
 710 template<int size, bool big_endian>
 711 void
 712 Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
 713                                                Output_file* of,
 714                                                Views* pviews)
 715 {
 716   unsigned int shnum = this->shnum();
 717   const Output_sections& out_sections(this->output_sections());
 718   const std::vector<Address>& out_offsets(this->section_offsets_);
 719
 720   File_read::Read_multiple rm;
 721   bool is_sorted = true;
 722
 723   const unsigned char* p = pshdrs + This::shdr_size;
 724   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 725     {
 726       View_size* pvs = &(*pviews)[i];
 727
 728       pvs->view = NULL;
 729
 730       const Output_section* os = out_sections[i];
 731       if (os == NULL)
 732         continue;
 733       Address output_offset = out_offsets[i];
 734
 735       typename This::Shdr shdr(p);
 736
 737       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 738         continue;
 739
 740       if ((parameters->options().relocatable()
 741            || parameters->options().emit_relocs())
 742           && (shdr.get_sh_type() == elfcpp::SHT_REL
 743               || shdr.get_sh_type() == elfcpp::SHT_RELA)
 744           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 745         {
 746           // This is a reloc section in a relocatable link or when
 747           // emitting relocs.  We don't need to read the input file.
 748           // The size and file offset are stored in the
 749           // Relocatable_relocs structure.
 750           Relocatable_relocs* rr = this->relocatable_relocs(i);
 751           gold_assert(rr != NULL);
 752           Output_data* posd = rr->output_data();
 753           gold_assert(posd != NULL);
 754
 755           pvs->offset = posd->offset();
 756           pvs->view_size = posd->data_size();
 757           pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
 758           pvs->address = posd->address();
 759           pvs->is_input_output_view = false;
 760           pvs->is_postprocessing_view = false;
 761
 762           continue;
 763         }
 764
 765       // In the normal case, this input section is simply mapped to
 766       // the output section at offset OUTPUT_OFFSET.
 767
 768       // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is
 769       // handled specially--e.g., a .eh_frame section.  The relocation
 770       // routines need to check for each reloc where it should be
 771       // applied.  For this case, we need an input/output view for the
 772       // entire contents of the section in the output file.  We don't
 773       // want to copy the contents of the input section to the output
 774       // section; the output section contents were already written,
 775       // and we waited for them in Relocate_task::is_runnable because
 776       // relocs_must_follow_section_writes is set for the object.
 777
 778       // Regardless of which of the above cases is true, we have to
 779       // check requires_postprocessing of the output section.  If that
 780       // is false, then we work with views of the output file
 781       // directly.  If it is true, then we work with a separate
 782       // buffer, and the output section is responsible for writing the
 783       // final data to the output file.
 784
 785       off_t output_section_offset;
 786       Address output_section_size;
 787       if (!os->requires_postprocessing())
 788         {
 789           output_section_offset = os->offset();
 790           output_section_size = convert_types<Address, off_t>(os->data_size());
 791         }
 792       else
 793         {
 794           output_section_offset = 0;
 795           output_section_size =
 796               convert_types<Address, off_t>(os->postprocessing_buffer_size());
 797         }
 798
 799       off_t view_start;
 800       section_size_type view_size;
 801       bool must_decompress = false;
 802       if (output_offset != invalid_address)
 803         {
 804           view_start = output_section_offset + output_offset;
 805           view_size = convert_to_section_size_type(shdr.get_sh_size());
 806           section_size_type uncompressed_size;
 807           if (this->section_is_compressed(i, &uncompressed_size))
 808             {
 809               view_size = uncompressed_size;
 810               must_decompress = true;
 811             }
 812         }
 813       else
 814         {
 815           view_start = output_section_offset;
 816           view_size = convert_to_section_size_type(output_section_size);
 817         }
 818
 819       if (view_size == 0)
 820         continue;
 821
 822       gold_assert(output_offset == invalid_address
 823                   || output_offset + view_size <= output_section_size);
 824
 825       unsigned char* view;
 826       if (os->requires_postprocessing())
 827         {
 828           unsigned char* buffer = os->postprocessing_buffer();
 829           view = buffer + view_start;
 830           if (output_offset != invalid_address && !must_decompress)
 831             {
 832               off_t sh_offset = shdr.get_sh_offset();
 833               if (!rm.empty() && rm.back().file_offset > sh_offset)
 834                 is_sorted = false;
 835               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 836                                                           view_size, view));
 837             }
 838         }
 839       else
 840         {
 841           if (output_offset == invalid_address)
 842             view = of->get_input_output_view(view_start, view_size);
 843           else
 844             {
 845               view = of->get_output_view(view_start, view_size);
 846               if (!must_decompress)
 847                 {
 848                   off_t sh_offset = shdr.get_sh_offset();
 849                   if (!rm.empty() && rm.back().file_offset > sh_offset)
 850                     is_sorted = false;
 851                   rm.push_back(File_read::Read_multiple_entry(sh_offset,
 852                                                               view_size, view));
 853                 }
 854             }
 855         }
 856
 857       if (must_decompress)
 858         {
 859           // Read and decompress the section.
 860           section_size_type len;
 861           const unsigned char* p = this->section_contents(i, &len, false);
 862           if (!decompress_input_section(p, len, view, view_size))
 863             this->error(_("could not decompress section %s"),
 864                         this->section_name(i).c_str());
 865         }
 866
 867       pvs->view = view;
 868       pvs->address = os->address();
 869       if (output_offset != invalid_address)
 870         pvs->address += output_offset;
 871       pvs->offset = view_start;
 872       pvs->view_size = view_size;
 873       pvs->is_input_output_view = output_offset == invalid_address;
 874       pvs->is_postprocessing_view = os->requires_postprocessing();
 875     }
 876
 877   // Actually read the data.
 878   if (!rm.empty())
 879     {
 880       if (!is_sorted)
 881         std::sort(rm.begin(), rm.end(), Read_multiple_compare());
 882       this->read_multiple(rm);
 883     }
 884 }
 885
 886 // Relocate section data.  VIEWS points to the section data as views
 887 // in the output file.
 888
 889 template<int size, bool big_endian>
 890 void
 891 Sized_relobj<size, big_endian>::do_relocate_sections(
 892     const Symbol_table* symtab,
 893     const Layout* layout,
 894     const unsigned char* pshdrs,
 895     Output_file* of,
 896     Views* pviews)
 897 {
 898   unsigned int shnum = this->shnum();
 899   Sized_target<size, big_endian>* target =
 900     parameters->sized_target<size, big_endian>();
 901
 902   const Output_sections& out_sections(this->output_sections());
 903   const std::vector<Address>& out_offsets(this->section_offsets_);
 904
 905   Relocate_info<size, big_endian> relinfo;
 906   relinfo.symtab = symtab;
 907   relinfo.layout = layout;
 908   relinfo.object = this;
 909
 910   const unsigned char* p = pshdrs + This::shdr_size;
 911   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 912     {
 913       typename This::Shdr shdr(p);
 914
 915       unsigned int sh_type = shdr.get_sh_type();
 916       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 917         continue;
 918
 919       off_t sh_size = shdr.get_sh_size();
 920       if (sh_size == 0)
 921         continue;
 922
 923       unsigned int index = this->adjust_shndx(shdr.get_sh_info());
 924       if (index >= this->shnum())
 925         {
 926           this->error(_("relocation section %u has bad info %u"),
 927                       i, index);
 928           continue;
 929         }
 930
 931       Output_section* os = out_sections[index];
 932       if (os == NULL)
 933         {
 934           // This relocation section is against a section which we
 935           // discarded.
 936           continue;
 937         }
 938       Address output_offset = out_offsets[index];
 939
 940       gold_assert((*pviews)[index].view != NULL);
 941       if (parameters->options().relocatable())
 942         gold_assert((*pviews)[i].view != NULL);
 943
 944       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 945         {
 946           gold_error(_("relocation section %u uses unexpected "
 947                        "symbol table %u"),
 948                      i, this->adjust_shndx(shdr.get_sh_link()));
 949           continue;
 950         }
 951
 952       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 953                                                     sh_size, true, false);
 954
 955       unsigned int reloc_size;
 956       if (sh_type == elfcpp::SHT_REL)
 957         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 958       else
 959         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 960
 961       if (reloc_size != shdr.get_sh_entsize())
 962         {
 963           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 964                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 965                      reloc_size);
 966           continue;
 967         }
 968
 969       size_t reloc_count = sh_size / reloc_size;
 970       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 971         {
 972           gold_error(_("reloc section %u size %lu uneven"),
 973                      i, static_cast<unsigned long>(sh_size));
 974           continue;
 975         }
 976
 977       gold_assert(output_offset != invalid_address
 978                   || this->relocs_must_follow_section_writes());
 979
 980       relinfo.reloc_shndx = i;
 981       relinfo.reloc_shdr = p;
 982       relinfo.data_shndx = index;
 983       relinfo.data_shdr = pshdrs + index * This::shdr_size;
 984       unsigned char* view = (*pviews)[index].view;
 985       Address address = (*pviews)[index].address;
 986       section_size_type view_size = (*pviews)[index].view_size;
 987
 988       Reloc_symbol_changes* reloc_map = NULL;
 989       if (this->uses_split_stack() && output_offset != invalid_address)
 990         {
 991           typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
 992           if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
 993             this->split_stack_adjust(symtab, pshdrs, sh_type, index,
 994                                      prelocs, reloc_count, view, view_size,
 995                                      &reloc_map);
 996         }
 997
 998       if (!parameters->options().relocatable())
 999         {
1000           target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
1001                                    output_offset == invalid_address,
1002                                    view, address, view_size, reloc_map);
1003           if (parameters->options().emit_relocs())
1004             this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count,
1005                               os, output_offset, view, address, view_size,
1006                               (*pviews)[i].view, (*pviews)[i].view_size);
1007           if (parameters->incremental())
1008             this->incremental_relocs_write(&relinfo, sh_type, prelocs,
1009                                            reloc_count, os, output_offset, of);
1010         }
1011       else
1012         {
1013           Relocatable_relocs* rr = this->relocatable_relocs(i);
1014           target->relocate_for_relocatable(&relinfo, sh_type, prelocs,
1015                                            reloc_count, os, output_offset, rr,
1016                                            view, address, view_size,
1017                                            (*pviews)[i].view,
1018                                            (*pviews)[i].view_size);
1019         }
1020     }
1021 }
1022
1023 // Emit the relocs for --emit-relocs.
1024
1025 template<int size, bool big_endian>
1026 void
1027 Sized_relobj<size, big_endian>::emit_relocs(
1028     const Relocate_info<size, big_endian>* relinfo,
1029     unsigned int i,
1030     unsigned int sh_type,
1031     const unsigned char* prelocs,
1032     size_t reloc_count,
1033     Output_section* output_section,
1034     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
1035     unsigned char* view,
1036     typename elfcpp::Elf_types<size>::Elf_Addr address,
1037     section_size_type view_size,
1038     unsigned char* reloc_view,
1039     section_size_type reloc_view_size)
1040 {
1041   if (sh_type == elfcpp::SHT_REL)
1042     this->emit_relocs_reltype<elfcpp::SHT_REL>(relinfo, i, prelocs,
1043                                                reloc_count, output_section,
1044                                                offset_in_output_section,
1045                                                view, address, view_size,
1046                                                reloc_view, reloc_view_size);
1047   else
1048     {
1049       gold_assert(sh_type == elfcpp::SHT_RELA);
1050       this->emit_relocs_reltype<elfcpp::SHT_RELA>(relinfo, i, prelocs,
1051                                                   reloc_count, output_section,
1052                                                   offset_in_output_section,
1053                                                   view, address, view_size,
1054                                                   reloc_view, reloc_view_size);
1055     }
1056 }
1057
1058 // Emit the relocs for --emit-relocs, templatized on the type of the
1059 // relocation section.
1060
1061 template<int size, bool big_endian>
1062 template<int sh_type>
1063 void
1064 Sized_relobj<size, big_endian>::emit_relocs_reltype(
1065     const Relocate_info<size, big_endian>* relinfo,
1066     unsigned int i,
1067     const unsigned char* prelocs,
1068     size_t reloc_count,
1069     Output_section* output_section,
1070     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
1071     unsigned char* view,
1072     typename elfcpp::Elf_types<size>::Elf_Addr address,
1073     section_size_type view_size,
1074     unsigned char* reloc_view,
1075     section_size_type reloc_view_size)
1076 {
1077   const Relocatable_relocs* rr = this->relocatable_relocs(i);
1078   relocate_for_relocatable<size, big_endian, sh_type>(
1079     relinfo,
1080     prelocs,
1081     reloc_count,
1082     output_section,
1083     offset_in_output_section,
1084     rr,
1085     view,
1086     address,
1087     view_size,
1088     reloc_view,
1089     reloc_view_size);
1090 }
1091
1092 // Write the incremental relocs.
1093
1094 template<int size, bool big_endian>
1095 void
1096 Sized_relobj<size, big_endian>::incremental_relocs_write(
1097     const Relocate_info<size, big_endian>* relinfo,
1098     unsigned int sh_type,
1099     const unsigned char* prelocs,
1100     size_t reloc_count,
1101     Output_section* output_section,
1102     Address output_offset,
1103     Output_file* of)
1104 {
1105   if (sh_type == elfcpp::SHT_REL)
1106     this->incremental_relocs_write_reltype<elfcpp::SHT_REL>(
1107         relinfo,
1108         prelocs,
1109         reloc_count,
1110         output_section,
1111         output_offset,
1112         of);
1113   else
1114     {
1115       gold_assert(sh_type == elfcpp::SHT_RELA);
1116       this->incremental_relocs_write_reltype<elfcpp::SHT_RELA>(
1117           relinfo,
1118           prelocs,
1119           reloc_count,
1120           output_section,
1121           output_offset,
1122           of);
1123     }
1124 }
1125
1126 // Write the incremental relocs, templatized on the type of the
1127 // relocation section.
1128
1129 template<int size, bool big_endian>
1130 template<int sh_type>
1131 void
1132 Sized_relobj<size, big_endian>::incremental_relocs_write_reltype(
1133     const Relocate_info<size, big_endian>* relinfo,
1134     const unsigned char* prelocs,
1135     size_t reloc_count,
1136     Output_section* output_section,
1137     Address output_offset,
1138     Output_file* of)
1139 {
1140   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reloc;
1141   const unsigned int reloc_size =
1142       Reloc_types<sh_type, size, big_endian>::reloc_size;
1143   const unsigned int sizeof_addr = size / 8;
1144   const unsigned int incr_reloc_size =
1145       Incremental_relocs_reader<size, big_endian>::reloc_size;
1146
1147   unsigned int out_shndx = output_section->out_shndx();
1148
1149   // Get a view for the .gnu_incremental_relocs section.
1150
1151   Incremental_inputs* inputs = relinfo->layout->incremental_inputs();
1152   gold_assert(inputs != NULL);
1153   const off_t relocs_off = inputs->relocs_section()->offset();
1154   const off_t relocs_size = inputs->relocs_section()->data_size();
1155   unsigned char* const view = of->get_output_view(relocs_off, relocs_size);
1156
1157   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
1158     {
1159       Reloc reloc(prelocs);
1160
1161       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1162       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1163       const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
1164
1165       if (r_sym < this->local_symbol_count_)
1166         continue;
1167
1168       // Get the new offset--the location in the output section where
1169       // this relocation should be applied.
1170
1171       Address offset = reloc.get_r_offset();
1172       if (output_offset != invalid_address)
1173         offset += output_offset;
1174       else
1175         {
1176           section_offset_type sot_offset =
1177               convert_types<section_offset_type, Address>(offset);
1178           section_offset_type new_sot_offset =
1179               output_section->output_offset(relinfo->object,
1180                                             relinfo->data_shndx,
1181                                             sot_offset);
1182           gold_assert(new_sot_offset != -1);
1183           offset += new_sot_offset;
1184         }
1185
1186       // Get the addend.
1187       typename elfcpp::Elf_types<size>::Elf_Swxword addend;
1188       if (sh_type == elfcpp::SHT_RELA)
1189         addend =
1190             Reloc_types<sh_type, size, big_endian>::get_reloc_addend(&reloc);
1191       else
1192         {
1193           // FIXME: Get the addend for SHT_REL.
1194           addend = 0;
1195         }
1196
1197       // Get the index of the output relocation.
1198
1199       unsigned int reloc_index =
1200           this->next_incremental_reloc_index(r_sym - this->local_symbol_count_);
1201
1202       // Write the relocation.
1203
1204       unsigned char* pov = view + reloc_index * incr_reloc_size;
1205       elfcpp::Swap<32, big_endian>::writeval(pov, r_type);
1206       elfcpp::Swap<32, big_endian>::writeval(pov + 4, out_shndx);
1207       elfcpp::Swap<size, big_endian>::writeval(pov + 8, offset);
1208       elfcpp::Swap<size, big_endian>::writeval(pov + 8 + sizeof_addr, addend);
1209       of->write_output_view(pov - view, incr_reloc_size, view);
1210     }
1211 }
1212
1213 // Create merge hash tables for the local symbols.  These are used to
1214 // speed up relocations.
1215
1216 template<int size, bool big_endian>
1217 void
1218 Sized_relobj<size, big_endian>::initialize_input_to_output_maps()
1219 {
1220   const unsigned int loccount = this->local_symbol_count_;
1221   for (unsigned int i = 1; i < loccount; ++i)
1222     {
1223       Symbol_value<size>& lv(this->local_values_[i]);
1224       lv.initialize_input_to_output_map(this);
1225     }
1226 }
1227
1228 // Free merge hash tables for the local symbols.
1229
1230 template<int size, bool big_endian>
1231 void
1232 Sized_relobj<size, big_endian>::free_input_to_output_maps()
1233 {
1234   const unsigned int loccount = this->local_symbol_count_;
1235   for (unsigned int i = 1; i < loccount; ++i)
1236     {
1237       Symbol_value<size>& lv(this->local_values_[i]);
1238       lv.free_input_to_output_map();
1239     }
1240 }
1241
1242 // If an object was compiled with -fsplit-stack, this is called to
1243 // check whether any relocations refer to functions defined in objects
1244 // which were not compiled with -fsplit-stack.  If they were, then we
1245 // need to apply some target-specific adjustments to request
1246 // additional stack space.
1247
1248 template<int size, bool big_endian>
1249 void
1250 Sized_relobj<size, big_endian>::split_stack_adjust(
1251     const Symbol_table* symtab,
1252     const unsigned char* pshdrs,
1253     unsigned int sh_type,
1254     unsigned int shndx,
1255     const unsigned char* prelocs,
1256     size_t reloc_count,
1257     unsigned char* view,
1258     section_size_type view_size,
1259     Reloc_symbol_changes** reloc_map)
1260 {
1261   if (sh_type == elfcpp::SHT_REL)
1262     this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
1263                                                       prelocs, reloc_count,
1264                                                       view, view_size,
1265                                                       reloc_map);
1266   else
1267     {
1268       gold_assert(sh_type == elfcpp::SHT_RELA);
1269       this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
1270                                                          prelocs, reloc_count,
1271                                                          view, view_size,
1272                                                          reloc_map);
1273     }
1274 }
1275
1276 // Adjust for -fsplit-stack, templatized on the type of the relocation
1277 // section.
1278
1279 template<int size, bool big_endian>
1280 template<int sh_type>
1281 void
1282 Sized_relobj<size, big_endian>::split_stack_adjust_reltype(
1283     const Symbol_table* symtab,
1284     const unsigned char* pshdrs,
1285     unsigned int shndx,
1286     const unsigned char* prelocs,
1287     size_t reloc_count,
1288     unsigned char* view,
1289     section_size_type view_size,
1290     Reloc_symbol_changes** reloc_map)
1291 {
1292   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
1293   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
1294
1295   size_t local_count = this->local_symbol_count();
1296
1297   std::vector<section_offset_type> non_split_refs;
1298
1299   const unsigned char* pr = prelocs;
1300   for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1301     {
1302       Reltype reloc(pr);
1303
1304       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1305       unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1306       if (r_sym < local_count)
1307         continue;
1308
1309       const Symbol* gsym = this->global_symbol(r_sym);
1310       gold_assert(gsym != NULL);
1311       if (gsym->is_forwarder())
1312         gsym = symtab->resolve_forwards(gsym);
1313
1314       // See if this relocation refers to a function defined in an
1315       // object compiled without -fsplit-stack.  Note that we don't
1316       // care about the type of relocation--this means that in some
1317       // cases we will ask for a large stack unnecessarily, but this
1318       // is not fatal.  FIXME: Some targets have symbols which are
1319       // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
1320       if (!gsym->is_undefined()
1321           && gsym->source() == Symbol::FROM_OBJECT
1322           && !gsym->object()->uses_split_stack())
1323         {
1324           unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
1325           if (parameters->target().is_call_to_non_split(gsym, r_type))
1326             {
1327               section_offset_type offset =
1328                 convert_to_section_size_type(reloc.get_r_offset());
1329               non_split_refs.push_back(offset);
1330             }
1331         }
1332     }
1333
1334   if (non_split_refs.empty())
1335     return;
1336
1337   // At this point, every entry in NON_SPLIT_REFS indicates a
1338   // relocation which refers to a function in an object compiled
1339   // without -fsplit-stack.  We now have to convert that list into a
1340   // set of offsets to functions.  First, we find all the functions.
1341
1342   Function_offsets function_offsets;
1343   this->find_functions(pshdrs, shndx, &function_offsets);
1344   if (function_offsets.empty())
1345     return;
1346
1347   // Now get a list of the function with references to non split-stack
1348   // code.
1349
1350   Function_offsets calls_non_split;
1351   for (std::vector<section_offset_type>::const_iterator p
1352          = non_split_refs.begin();
1353        p != non_split_refs.end();
1354        ++p)
1355     {
1356       Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
1357       if (low == function_offsets.end())
1358         --low;
1359       else if (low->first == *p)
1360         ;
1361       else if (low == function_offsets.begin())
1362         continue;
1363       else
1364         --low;
1365
1366       calls_non_split.insert(*low);
1367     }
1368   if (calls_non_split.empty())
1369     return;
1370
1371   // Now we have a set of functions to adjust.  The adjustments are
1372   // target specific.  Besides changing the output section view
1373   // however, it likes, the target may request a relocation change
1374   // from one global symbol name to another.
1375
1376   for (Function_offsets::const_iterator p = calls_non_split.begin();
1377        p != calls_non_split.end();
1378        ++p)
1379     {
1380       std::string from;
1381       std::string to;
1382       parameters->target().calls_non_split(this, shndx, p->first, p->second,
1383                                            view, view_size, &from, &to);
1384       if (!from.empty())
1385         {
1386           gold_assert(!to.empty());
1387           Symbol* tosym = NULL;
1388
1389           // Find relocations in the relevant function which are for
1390           // FROM.
1391           pr = prelocs;
1392           for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1393             {
1394               Reltype reloc(pr);
1395
1396               typename elfcpp::Elf_types<size>::Elf_WXword r_info =
1397                 reloc.get_r_info();
1398               unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1399               if (r_sym < local_count)
1400                 continue;
1401
1402               section_offset_type offset =
1403                 convert_to_section_size_type(reloc.get_r_offset());
1404               if (offset < p->first
1405                   || (offset
1406                       >= (p->first
1407                           + static_cast<section_offset_type>(p->second))))
1408                 continue;
1409
1410               const Symbol* gsym = this->global_symbol(r_sym);
1411               if (from == gsym->name())
1412                 {
1413                   if (tosym == NULL)
1414                     {
1415                       tosym = symtab->lookup(to.c_str());
1416                       if (tosym == NULL)
1417                         {
1418                           this->error(_("could not convert call "
1419                                         "to '%s' to '%s'"),
1420                                       from.c_str(), to.c_str());
1421                           break;
1422                         }
1423                     }
1424
1425                   if (*reloc_map == NULL)
1426                     *reloc_map = new Reloc_symbol_changes(reloc_count);
1427                   (*reloc_map)->set(i, tosym);
1428                 }
1429             }
1430         }
1431     }
1432 }
1433
1434 // Find all the function in this object defined in section SHNDX.
1435 // Store their offsets in the section in FUNCTION_OFFSETS.
1436
1437 template<int size, bool big_endian>
1438 void
1439 Sized_relobj<size, big_endian>::find_functions(
1440     const unsigned char* pshdrs,
1441     unsigned int shndx,
1442     Sized_relobj<size, big_endian>::Function_offsets* function_offsets)
1443 {
1444   // We need to read the symbols to find the functions.  If we wanted
1445   // to, we could cache reading the symbols across all sections in the
1446   // object.
1447   const unsigned int symtab_shndx = this->symtab_shndx_;
1448   typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size);
1449   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1450
1451   typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
1452     symtabshdr.get_sh_size();
1453   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1454                                               sh_size, true, true);
1455
1456   const int sym_size = This::sym_size;
1457   const unsigned int symcount = sh_size / sym_size;
1458   for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size)
1459     {
1460       typename elfcpp::Sym<size, big_endian> isym(psyms);
1461
1462       // FIXME: Some targets can have functions which do not have type
1463       // STT_FUNC, e.g., STT_ARM_TFUNC.
1464       if (isym.get_st_type() != elfcpp::STT_FUNC
1465           || isym.get_st_size() == 0)
1466         continue;
1467
1468       bool is_ordinary;
1469       unsigned int sym_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1470                                                       &is_ordinary);
1471       if (!is_ordinary || sym_shndx != shndx)
1472         continue;
1473
1474       section_offset_type value =
1475         convert_to_section_size_type(isym.get_st_value());
1476       section_size_type fnsize =
1477         convert_to_section_size_type(isym.get_st_size());
1478
1479       (*function_offsets)[value] = fnsize;
1480     }
1481 }
1482
1483 // Class Merged_symbol_value.
1484
1485 template<int size>
1486 void
1487 Merged_symbol_value<size>::initialize_input_to_output_map(
1488     const Relobj* object,
1489     unsigned int input_shndx)
1490 {
1491   Object_merge_map* map = object->merge_map();
1492   map->initialize_input_to_output_map<size>(input_shndx,
1493                                             this->output_start_address_,
1494                                             &this->output_addresses_);
1495 }
1496
1497 // Get the output value corresponding to an input offset if we
1498 // couldn't find it in the hash table.
1499
1500 template<int size>
1501 typename elfcpp::Elf_types<size>::Elf_Addr
1502 Merged_symbol_value<size>::value_from_output_section(
1503     const Relobj* object,
1504     unsigned int input_shndx,
1505     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
1506 {
1507   section_offset_type output_offset;
1508   bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
1509                                                       input_offset,
1510                                                       &output_offset);
1511
1512   // If this assertion fails, it means that some relocation was
1513   // against a portion of an input merge section which we didn't map
1514   // to the output file and we didn't explicitly discard.  We should
1515   // always map all portions of input merge sections.
1516   gold_assert(found);
1517
1518   if (output_offset == -1)
1519     return 0;
1520   else
1521     return this->output_start_address_ + output_offset;
1522 }
1523
1524 // Track_relocs methods.
1525
1526 // Initialize the class to track the relocs.  This gets the object,
1527 // the reloc section index, and the type of the relocs.  This returns
1528 // false if something goes wrong.
1529
1530 template<int size, bool big_endian>
1531 bool
1532 Track_relocs<size, big_endian>::initialize(
1533     Object* object,
1534     unsigned int reloc_shndx,
1535     unsigned int reloc_type)
1536 {
1537   // If RELOC_SHNDX is -1U, it means there is more than one reloc
1538   // section for the .eh_frame section.  We can't handle that case.
1539   if (reloc_shndx == -1U)
1540     return false;
1541
1542   // If RELOC_SHNDX is 0, there is no reloc section.
1543   if (reloc_shndx == 0)
1544     return true;
1545
1546   // Get the contents of the reloc section.
1547   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
1548
1549   if (reloc_type == elfcpp::SHT_REL)
1550     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
1551   else if (reloc_type == elfcpp::SHT_RELA)
1552     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
1553   else
1554     gold_unreachable();
1555
1556   if (this->len_ % this->reloc_size_ != 0)
1557     {
1558       object->error(_("reloc section size %zu is not a multiple of "
1559                       "reloc size %d\n"),
1560                     static_cast<size_t>(this->len_),
1561                     this->reloc_size_);
1562       return false;
1563     }
1564
1565   return true;
1566 }
1567
1568 // Return the offset of the next reloc, or -1 if there isn't one.
1569
1570 template<int size, bool big_endian>
1571 off_t
1572 Track_relocs<size, big_endian>::next_offset() const
1573 {
1574   if (this->pos_ >= this->len_)
1575     return -1;
1576
1577   // Rel and Rela start out the same, so we can always use Rel to find
1578   // the r_offset value.
1579   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1580   return rel.get_r_offset();
1581 }
1582
1583 // Return the index of the symbol referenced by the next reloc, or -1U
1584 // if there aren't any more relocs.
1585
1586 template<int size, bool big_endian>
1587 unsigned int
1588 Track_relocs<size, big_endian>::next_symndx() const
1589 {
1590   if (this->pos_ >= this->len_)
1591     return -1U;
1592
1593   // Rel and Rela start out the same, so we can use Rel to find the
1594   // symbol index.
1595   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1596   return elfcpp::elf_r_sym<size>(rel.get_r_info());
1597 }
1598
1599 // Return the addend of the next reloc, or 0 if there isn't one.
1600
1601 template<int size, bool big_endian>
1602 uint64_t
1603 Track_relocs<size, big_endian>::next_addend() const
1604 {
1605   if (this->pos_ >= this->len_)
1606     return 0;
1607   if (this->reloc_size_ == elfcpp::Elf_sizes<size>::rel_size)
1608     return 0;
1609   elfcpp::Rela<size, big_endian> rela(this->prelocs_ + this->pos_);
1610   return rela.get_r_addend();
1611 }
1612
1613 // Advance to the next reloc whose r_offset is greater than or equal
1614 // to OFFSET.  Return the number of relocs we skip.
1615
1616 template<int size, bool big_endian>
1617 int
1618 Track_relocs<size, big_endian>::advance(off_t offset)
1619 {
1620   int ret = 0;
1621   while (this->pos_ < this->len_)
1622     {
1623       // Rel and Rela start out the same, so we can always use Rel to
1624       // find the r_offset value.
1625       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1626       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
1627         break;
1628       ++ret;
1629       this->pos_ += this->reloc_size_;
1630     }
1631   return ret;
1632 }
1633
1634 // Instantiate the templates we need.
1635
1636 #ifdef HAVE_TARGET_32_LITTLE
1637 template
1638 void
1639 Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd);
1640 #endif
1641
1642 #ifdef HAVE_TARGET_32_BIG
1643 template
1644 void
1645 Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd);
1646 #endif
1647
1648 #ifdef HAVE_TARGET_64_LITTLE
1649 template
1650 void
1651 Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd);
1652 #endif
1653
1654 #ifdef HAVE_TARGET_64_BIG
1655 template
1656 void
1657 Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
1658 #endif
1659
1660 #ifdef HAVE_TARGET_32_LITTLE
1661 template
1662 void
1663 Sized_relobj<32, false>::do_gc_process_relocs(Symbol_table* symtab,
1664                                               Layout* layout,
1665                                               Read_relocs_data* rd);
1666 #endif
1667
1668 #ifdef HAVE_TARGET_32_BIG
1669 template
1670 void
1671 Sized_relobj<32, true>::do_gc_process_relocs(Symbol_table* symtab,
1672                                              Layout* layout,
1673                                              Read_relocs_data* rd);
1674 #endif
1675
1676 #ifdef HAVE_TARGET_64_LITTLE
1677 template
1678 void
1679 Sized_relobj<64, false>::do_gc_process_relocs(Symbol_table* symtab,
1680                                               Layout* layout,
1681                                               Read_relocs_data* rd);
1682 #endif
1683
1684 #ifdef HAVE_TARGET_64_BIG
1685 template
1686 void
1687 Sized_relobj<64, true>::do_gc_process_relocs(Symbol_table* symtab,
1688                                              Layout* layout,
1689                                              Read_relocs_data* rd);
1690 #endif
1691
1692 #ifdef HAVE_TARGET_32_LITTLE
1693 template
1694 void
1695 Sized_relobj<32, false>::do_scan_relocs(Symbol_table* symtab,
1696                                         Layout* layout,
1697                                         Read_relocs_data* rd);
1698 #endif
1699
1700 #ifdef HAVE_TARGET_32_BIG
1701 template
1702 void
1703 Sized_relobj<32, true>::do_scan_relocs(Symbol_table* symtab,
1704                                        Layout* layout,
1705                                        Read_relocs_data* rd);
1706 #endif
1707
1708 #ifdef HAVE_TARGET_64_LITTLE
1709 template
1710 void
1711 Sized_relobj<64, false>::do_scan_relocs(Symbol_table* symtab,
1712                                         Layout* layout,
1713                                         Read_relocs_data* rd);
1714 #endif
1715
1716 #ifdef HAVE_TARGET_64_BIG
1717 template
1718 void
1719 Sized_relobj<64, true>::do_scan_relocs(Symbol_table* symtab,
1720                                        Layout* layout,
1721                                        Read_relocs_data* rd);
1722 #endif
1723
1724 #ifdef HAVE_TARGET_32_LITTLE
1725 template
1726 void
1727 Sized_relobj<32, false>::do_relocate(const Symbol_table* symtab,
1728                                      const Layout* layout,
1729                                      Output_file* of);
1730 #endif
1731
1732 #ifdef HAVE_TARGET_32_BIG
1733 template
1734 void
1735 Sized_relobj<32, true>::do_relocate(const Symbol_table* symtab,
1736                                     const Layout* layout,
1737                                     Output_file* of);
1738 #endif
1739
1740 #ifdef HAVE_TARGET_64_LITTLE
1741 template
1742 void
1743 Sized_relobj<64, false>::do_relocate(const Symbol_table* symtab,
1744                                      const Layout* layout,
1745                                      Output_file* of);
1746 #endif
1747
1748 #ifdef HAVE_TARGET_64_BIG
1749 template
1750 void
1751 Sized_relobj<64, true>::do_relocate(const Symbol_table* symtab,
1752                                     const Layout* layout,
1753                                     Output_file* of);
1754 #endif
1755
1756 #ifdef HAVE_TARGET_32_LITTLE
1757 template
1758 void
1759 Sized_relobj<32, 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_32_BIG
1768 template
1769 void
1770 Sized_relobj<32, 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_64_LITTLE
1779 template
1780 void
1781 Sized_relobj<64, false>::do_relocate_sections(
1782     const Symbol_table* symtab,
1783     const Layout* layout,
1784     const unsigned char* pshdrs,
1785     Output_file* of,
1786     Views* pviews);
1787 #endif
1788
1789 #ifdef HAVE_TARGET_64_BIG
1790 template
1791 void
1792 Sized_relobj<64, true>::do_relocate_sections(
1793     const Symbol_table* symtab,
1794     const Layout* layout,
1795     const unsigned char* pshdrs,
1796     Output_file* of,
1797     Views* pviews);
1798 #endif
1799
1800 #ifdef HAVE_TARGET_32_LITTLE
1801 template
1802 void
1803 Sized_relobj<32, false>::initialize_input_to_output_maps();
1804
1805 template
1806 void
1807 Sized_relobj<32, false>::free_input_to_output_maps();
1808 #endif
1809
1810 #ifdef HAVE_TARGET_32_BIG
1811 template
1812 void
1813 Sized_relobj<32, true>::initialize_input_to_output_maps();
1814
1815 template
1816 void
1817 Sized_relobj<32, true>::free_input_to_output_maps();
1818 #endif
1819
1820 #ifdef HAVE_TARGET_64_LITTLE
1821 template
1822 void
1823 Sized_relobj<64, false>::initialize_input_to_output_maps();
1824
1825 template
1826 void
1827 Sized_relobj<64, false>::free_input_to_output_maps();
1828 #endif
1829
1830 #ifdef HAVE_TARGET_64_BIG
1831 template
1832 void
1833 Sized_relobj<64, true>::initialize_input_to_output_maps();
1834
1835 template
1836 void
1837 Sized_relobj<64, true>::free_input_to_output_maps();
1838 #endif
1839
1840 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1841 template
1842 class Merged_symbol_value<32>;
1843 #endif
1844
1845 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1846 template
1847 class Merged_symbol_value<64>;
1848 #endif
1849
1850 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1851 template
1852 class Symbol_value<32>;
1853 #endif
1854
1855 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1856 template
1857 class Symbol_value<64>;
1858 #endif
1859
1860 #ifdef HAVE_TARGET_32_LITTLE
1861 template
1862 class Track_relocs<32, false>;
1863 #endif
1864
1865 #ifdef HAVE_TARGET_32_BIG
1866 template
1867 class Track_relocs<32, true>;
1868 #endif
1869
1870 #ifdef HAVE_TARGET_64_LITTLE
1871 template
1872 class Track_relocs<64, false>;
1873 #endif
1874
1875 #ifdef HAVE_TARGET_64_BIG
1876 template
1877 class Track_relocs<64, true>;
1878 #endif
1879
1880 } // End namespace gold.