contrib/binutils-2.27/gold/reloc.cc

   1 // reloc.cc -- relocate input files for gold.
   2
   3 // Copyright (C) 2006-2016 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_file<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       if (sh_size == 0)
 326         continue;
 327
 328       unsigned int reloc_size;
 329       if (sh_type == elfcpp::SHT_REL)
 330         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 331       else
 332         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 333       if (reloc_size != shdr.get_sh_entsize())
 334         {
 335           this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
 336                       i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 337                       reloc_size);
 338           continue;
 339         }
 340
 341       size_t reloc_count = sh_size / reloc_size;
 342       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 343         {
 344           this->error(_("reloc section %u size %lu uneven"),
 345                       i, static_cast<unsigned long>(sh_size));
 346           continue;
 347         }
 348
 349       rd->relocs.push_back(Section_relocs());
 350       Section_relocs& sr(rd->relocs.back());
 351       sr.reloc_shndx = i;
 352       sr.data_shndx = shndx;
 353       sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
 354                                            true, true);
 355       sr.sh_type = sh_type;
 356       sr.reloc_count = reloc_count;
 357       sr.output_section = os;
 358       sr.needs_special_offset_handling = out_offsets[shndx] == invalid_address;
 359       sr.is_data_section_allocated = is_section_allocated;
 360     }
 361
 362   // Read the local symbols.
 363   gold_assert(this->symtab_shndx_ != -1U);
 364   if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
 365     rd->local_symbols = NULL;
 366   else
 367     {
 368       typename This::Shdr symtabshdr(pshdrs
 369                                      + this->symtab_shndx_ * This::shdr_size);
 370       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 371       const int sym_size = This::sym_size;
 372       const unsigned int loccount = this->local_symbol_count_;
 373       gold_assert(loccount == symtabshdr.get_sh_info());
 374       off_t locsize = loccount * sym_size;
 375       rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
 376                                                  locsize, true, true);
 377     }
 378 }
 379
 380 // Process the relocs to generate mappings from source sections to referenced
 381 // sections.  This is used during garbage collection to determine garbage
 382 // sections.
 383
 384 template<int size, bool big_endian>
 385 void
 386 Sized_relobj_file<size, big_endian>::do_gc_process_relocs(Symbol_table* symtab,
 387                                                           Layout* layout,
 388                                                           Read_relocs_data* rd)
 389 {
 390   Sized_target<size, big_endian>* target =
 391     parameters->sized_target<size, big_endian>();
 392
 393   const unsigned char* local_symbols;
 394   if (rd->local_symbols == NULL)
 395     local_symbols = NULL;
 396   else
 397     local_symbols = rd->local_symbols->data();
 398
 399   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 400        p != rd->relocs.end();
 401        ++p)
 402     {
 403       if (!parameters->options().relocatable())
 404           {
 405             // As noted above, when not generating an object file, we
 406             // only scan allocated sections.  We may see a non-allocated
 407             // section here if we are emitting relocs.
 408             if (p->is_data_section_allocated)
 409               target->gc_process_relocs(symtab, layout, this,
 410                                         p->data_shndx, p->sh_type,
 411                                         p->contents->data(), p->reloc_count,
 412                                         p->output_section,
 413                                         p->needs_special_offset_handling,
 414                                         this->local_symbol_count_,
 415                                         local_symbols);
 416         }
 417     }
 418 }
 419
 420
 421 // Scan the relocs and adjust the symbol table.  This looks for
 422 // relocations which require GOT/PLT/COPY relocations.
 423
 424 template<int size, bool big_endian>
 425 void
 426 Sized_relobj_file<size, big_endian>::do_scan_relocs(Symbol_table* symtab,
 427                                                     Layout* layout,
 428                                                     Read_relocs_data* rd)
 429 {
 430   Sized_target<size, big_endian>* target =
 431     parameters->sized_target<size, big_endian>();
 432
 433   const unsigned char* local_symbols;
 434   if (rd->local_symbols == NULL)
 435     local_symbols = NULL;
 436   else
 437     local_symbols = rd->local_symbols->data();
 438
 439   // For incremental links, allocate the counters for incremental relocations.
 440   if (layout->incremental_inputs() != NULL)
 441     this->allocate_incremental_reloc_counts();
 442
 443   for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
 444        p != rd->relocs.end();
 445        ++p)
 446     {
 447       // When garbage collection is on, unreferenced sections are not included
 448       // in the link that would have been included normally. This is known only
 449       // after Read_relocs hence this check has to be done again.
 450       if (parameters->options().gc_sections()
 451           || parameters->options().icf_enabled())
 452         {
 453           if (p->output_section == NULL)
 454             continue;
 455         }
 456       if (!parameters->options().relocatable())
 457         {
 458           // As noted above, when not generating an object file, we
 459           // only scan allocated sections.  We may see a non-allocated
 460           // section here if we are emitting relocs.
 461           if (p->is_data_section_allocated)
 462             target->scan_relocs(symtab, layout, this, p->data_shndx,
 463                                 p->sh_type, p->contents->data(),
 464                                 p->reloc_count, p->output_section,
 465                                 p->needs_special_offset_handling,
 466                                 this->local_symbol_count_,
 467                                 local_symbols);
 468           if (parameters->options().emit_relocs())
 469             this->emit_relocs_scan(symtab, layout, local_symbols, p);
 470           if (layout->incremental_inputs() != NULL)
 471             this->incremental_relocs_scan(p);
 472         }
 473       else
 474         {
 475           Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 476           gold_assert(rr != NULL);
 477           rr->set_reloc_count(p->reloc_count);
 478           target->scan_relocatable_relocs(symtab, layout, this,
 479                                           p->data_shndx, p->sh_type,
 480                                           p->contents->data(),
 481                                           p->reloc_count,
 482                                           p->output_section,
 483                                           p->needs_special_offset_handling,
 484                                           this->local_symbol_count_,
 485                                           local_symbols,
 486                                           rr);
 487         }
 488
 489       delete p->contents;
 490       p->contents = NULL;
 491     }
 492
 493   // For incremental links, finalize the allocation of relocations.
 494   if (layout->incremental_inputs() != NULL)
 495     this->finalize_incremental_relocs(layout, true);
 496
 497   if (rd->local_symbols != NULL)
 498     {
 499       delete rd->local_symbols;
 500       rd->local_symbols = NULL;
 501     }
 502 }
 503
 504 // Scan the input relocations for --emit-relocs.
 505
 506 template<int size, bool big_endian>
 507 void
 508 Sized_relobj_file<size, big_endian>::emit_relocs_scan(
 509     Symbol_table* symtab,
 510     Layout* layout,
 511     const unsigned char* plocal_syms,
 512     const Read_relocs_data::Relocs_list::iterator& p)
 513 {
 514   Sized_target<size, big_endian>* target =
 515       parameters->sized_target<size, big_endian>();
 516
 517   Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 518   gold_assert(rr != NULL);
 519   rr->set_reloc_count(p->reloc_count);
 520   target->emit_relocs_scan(
 521     symtab,
 522     layout,
 523     this,
 524     p->data_shndx,
 525     p->sh_type,
 526     p->contents->data(),
 527     p->reloc_count,
 528     p->output_section,
 529     p->needs_special_offset_handling,
 530     this->local_symbol_count_,
 531     plocal_syms,
 532     rr);
 533 }
 534
 535 // Scan the input relocations for --incremental.
 536
 537 template<int size, bool big_endian>
 538 void
 539 Sized_relobj_file<size, big_endian>::incremental_relocs_scan(
 540     const Read_relocs_data::Relocs_list::iterator& p)
 541 {
 542   if (p->sh_type == elfcpp::SHT_REL)
 543     this->incremental_relocs_scan_reltype<elfcpp::SHT_REL>(p);
 544   else
 545     {
 546       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 547       this->incremental_relocs_scan_reltype<elfcpp::SHT_RELA>(p);
 548     }
 549 }
 550
 551 // Scan the input relocation for --incremental, templatized on the
 552 // type of the relocation section.
 553
 554 template<int size, bool big_endian>
 555 template<int sh_type>
 556 void
 557 Sized_relobj_file<size, big_endian>::incremental_relocs_scan_reltype(
 558     const Read_relocs_data::Relocs_list::iterator& p)
 559 {
 560   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
 561   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
 562   const unsigned char* prelocs = p->contents->data();
 563   size_t reloc_count = p->reloc_count;
 564
 565   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
 566     {
 567       Reltype reloc(prelocs);
 568
 569       if (p->needs_special_offset_handling
 570           && !p->output_section->is_input_address_mapped(this, p->data_shndx,
 571                                                          reloc.get_r_offset()))
 572         continue;
 573
 574       // FIXME: Some targets have a non-standard r_info field.
 575       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
 576       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
 577
 578       if (r_sym >= this->local_symbol_count_)
 579         this->count_incremental_reloc(r_sym - this->local_symbol_count_);
 580     }
 581 }
 582
 583 // Relocate the input sections and write out the local symbols.
 584
 585 template<int size, bool big_endian>
 586 void
 587 Sized_relobj_file<size, big_endian>::do_relocate(const Symbol_table* symtab,
 588                                                  const Layout* layout,
 589                                                  Output_file* of)
 590 {
 591   unsigned int shnum = this->shnum();
 592
 593   // Read the section headers.
 594   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 595                                                shnum * This::shdr_size,
 596                                                true, true);
 597
 598   Views views;
 599   views.resize(shnum);
 600
 601   // Make two passes over the sections.  The first one copies the
 602   // section data to the output file.  The second one applies
 603   // relocations.
 604
 605   this->write_sections(layout, pshdrs, of, &views);
 606
 607   // To speed up relocations, we set up hash tables for fast lookup of
 608   // input offsets to output addresses.
 609   this->initialize_input_to_output_maps();
 610
 611   // Make the views available through get_output_view() for the duration
 612   // of this routine.  This RAII class will reset output_views_ to NULL
 613   // when the views go out of scope.
 614   struct Set_output_views
 615   {
 616     Set_output_views(const Views** ppviews, const Views* pviews)
 617     {
 618       ppviews_ = ppviews;
 619       *ppviews = pviews;
 620     }
 621
 622     ~Set_output_views()
 623     { *ppviews_ = NULL; }
 624
 625     const Views** ppviews_;
 626   };
 627   Set_output_views set_output_views(&this->output_views_, &views);
 628
 629   // Apply relocations.
 630
 631   this->relocate_sections(symtab, layout, pshdrs, of, &views);
 632
 633   // After we've done the relocations, we release the hash tables,
 634   // since we no longer need them.
 635   this->free_input_to_output_maps();
 636
 637   // Write out the accumulated views.
 638   for (unsigned int i = 1; i < shnum; ++i)
 639     {
 640       if (views[i].view != NULL)
 641         {
 642           if (views[i].is_ctors_reverse_view)
 643             this->reverse_words(views[i].view, views[i].view_size);
 644           if (!views[i].is_postprocessing_view)
 645             {
 646               if (views[i].is_input_output_view)
 647                 of->write_input_output_view(views[i].offset,
 648                                             views[i].view_size,
 649                                             views[i].view);
 650               else
 651                 of->write_output_view(views[i].offset, views[i].view_size,
 652                                       views[i].view);
 653             }
 654         }
 655     }
 656
 657   // Write out the local symbols.
 658   this->write_local_symbols(of, layout->sympool(), layout->dynpool(),
 659                             layout->symtab_xindex(), layout->dynsym_xindex(),
 660                             layout->symtab_section_offset());
 661 }
 662
 663 // Sort a Read_multiple vector by file offset.
 664 struct Read_multiple_compare
 665 {
 666   inline bool
 667   operator()(const File_read::Read_multiple_entry& rme1,
 668              const File_read::Read_multiple_entry& rme2) const
 669   { return rme1.file_offset < rme2.file_offset; }
 670 };
 671
 672 // Write section data to the output file.  PSHDRS points to the
 673 // section headers.  Record the views in *PVIEWS for use when
 674 // relocating.
 675
 676 template<int size, bool big_endian>
 677 void
 678 Sized_relobj_file<size, big_endian>::write_sections(const Layout* layout,
 679                                                     const unsigned char* pshdrs,
 680                                                     Output_file* of,
 681                                                     Views* pviews)
 682 {
 683   unsigned int shnum = this->shnum();
 684   const Output_sections& out_sections(this->output_sections());
 685   const std::vector<Address>& out_offsets(this->section_offsets());
 686
 687   File_read::Read_multiple rm;
 688   bool is_sorted = true;
 689
 690   const unsigned char* p = pshdrs + This::shdr_size;
 691   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 692     {
 693       View_size* pvs = &(*pviews)[i];
 694
 695       pvs->view = NULL;
 696
 697       const Output_section* os = out_sections[i];
 698       if (os == NULL)
 699         continue;
 700       Address output_offset = out_offsets[i];
 701
 702       typename This::Shdr shdr(p);
 703
 704       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 705         continue;
 706
 707       if ((parameters->options().relocatable()
 708            || parameters->options().emit_relocs())
 709           && (shdr.get_sh_type() == elfcpp::SHT_REL
 710               || shdr.get_sh_type() == elfcpp::SHT_RELA)
 711           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 712         {
 713           // This is a reloc section in a relocatable link or when
 714           // emitting relocs.  We don't need to read the input file.
 715           // The size and file offset are stored in the
 716           // Relocatable_relocs structure.
 717           Relocatable_relocs* rr = this->relocatable_relocs(i);
 718           gold_assert(rr != NULL);
 719           Output_data* posd = rr->output_data();
 720           gold_assert(posd != NULL);
 721
 722           pvs->offset = posd->offset();
 723           pvs->view_size = posd->data_size();
 724           pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
 725           pvs->address = posd->address();
 726           pvs->is_input_output_view = false;
 727           pvs->is_postprocessing_view = false;
 728           pvs->is_ctors_reverse_view = false;
 729
 730           continue;
 731         }
 732
 733       // In the normal case, this input section is simply mapped to
 734       // the output section at offset OUTPUT_OFFSET.
 735
 736       // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is
 737       // handled specially--e.g., a .eh_frame section.  The relocation
 738       // routines need to check for each reloc where it should be
 739       // applied.  For this case, we need an input/output view for the
 740       // entire contents of the section in the output file.  We don't
 741       // want to copy the contents of the input section to the output
 742       // section; the output section contents were already written,
 743       // and we waited for them in Relocate_task::is_runnable because
 744       // relocs_must_follow_section_writes is set for the object.
 745
 746       // Regardless of which of the above cases is true, we have to
 747       // check requires_postprocessing of the output section.  If that
 748       // is false, then we work with views of the output file
 749       // directly.  If it is true, then we work with a separate
 750       // buffer, and the output section is responsible for writing the
 751       // final data to the output file.
 752
 753       off_t output_section_offset;
 754       Address output_section_size;
 755       if (!os->requires_postprocessing())
 756         {
 757           output_section_offset = os->offset();
 758           output_section_size = convert_types<Address, off_t>(os->data_size());
 759         }
 760       else
 761         {
 762           output_section_offset = 0;
 763           output_section_size =
 764               convert_types<Address, off_t>(os->postprocessing_buffer_size());
 765         }
 766
 767       off_t view_start;
 768       section_size_type view_size;
 769       bool must_decompress = false;
 770       if (output_offset != invalid_address)
 771         {
 772           view_start = output_section_offset + output_offset;
 773           view_size = convert_to_section_size_type(shdr.get_sh_size());
 774           section_size_type uncompressed_size;
 775           if (this->section_is_compressed(i, &uncompressed_size))
 776             {
 777               view_size = uncompressed_size;
 778               must_decompress = true;
 779             }
 780         }
 781       else
 782         {
 783           view_start = output_section_offset;
 784           view_size = convert_to_section_size_type(output_section_size);
 785         }
 786
 787       if (view_size == 0)
 788         continue;
 789
 790       gold_assert(output_offset == invalid_address
 791                   || output_offset + view_size <= output_section_size);
 792
 793       unsigned char* view;
 794       if (os->requires_postprocessing())
 795         {
 796           unsigned char* buffer = os->postprocessing_buffer();
 797           view = buffer + view_start;
 798           if (output_offset != invalid_address && !must_decompress)
 799             {
 800               off_t sh_offset = shdr.get_sh_offset();
 801               if (!rm.empty() && rm.back().file_offset > sh_offset)
 802                 is_sorted = false;
 803               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 804                                                           view_size, view));
 805             }
 806         }
 807       else
 808         {
 809           if (output_offset == invalid_address)
 810             view = of->get_input_output_view(view_start, view_size);
 811           else
 812             {
 813               view = of->get_output_view(view_start, view_size);
 814               if (!must_decompress)
 815                 {
 816                   off_t sh_offset = shdr.get_sh_offset();
 817                   if (!rm.empty() && rm.back().file_offset > sh_offset)
 818                     is_sorted = false;
 819                   rm.push_back(File_read::Read_multiple_entry(sh_offset,
 820                                                               view_size, view));
 821                 }
 822             }
 823         }
 824
 825       if (must_decompress)
 826         {
 827           // Read and decompress the section.
 828           section_size_type len;
 829           const unsigned char* p = this->section_contents(i, &len, false);
 830           if (!decompress_input_section(p, len, view, view_size,
 831                                         size, big_endian,
 832                                         shdr.get_sh_flags()))
 833             this->error(_("could not decompress section %s"),
 834                         this->section_name(i).c_str());
 835         }
 836
 837       pvs->view = view;
 838       pvs->address = os->address();
 839       if (output_offset != invalid_address)
 840         pvs->address += output_offset;
 841       pvs->offset = view_start;
 842       pvs->view_size = view_size;
 843       pvs->is_input_output_view = output_offset == invalid_address;
 844       pvs->is_postprocessing_view = os->requires_postprocessing();
 845       pvs->is_ctors_reverse_view =
 846         (!parameters->options().relocatable()
 847          && view_size > size / 8
 848          && (strcmp(os->name(), ".init_array") == 0
 849              || strcmp(os->name(), ".fini_array") == 0)
 850          && layout->is_ctors_in_init_array(this, i));
 851     }
 852
 853   // Actually read the data.
 854   if (!rm.empty())
 855     {
 856       if (!is_sorted)
 857         std::sort(rm.begin(), rm.end(), Read_multiple_compare());
 858       this->read_multiple(rm);
 859     }
 860 }
 861
 862 // Relocate section data.  VIEWS points to the section data as views
 863 // in the output file.
 864
 865 template<int size, bool big_endian>
 866 void
 867 Sized_relobj_file<size, big_endian>::do_relocate_sections(
 868     const Symbol_table* symtab,
 869     const Layout* layout,
 870     const unsigned char* pshdrs,
 871     Output_file* of,
 872     Views* pviews)
 873 {
 874   unsigned int shnum = this->shnum();
 875   Sized_target<size, big_endian>* target =
 876     parameters->sized_target<size, big_endian>();
 877
 878   const Output_sections& out_sections(this->output_sections());
 879   const std::vector<Address>& out_offsets(this->section_offsets());
 880
 881   Relocate_info<size, big_endian> relinfo;
 882   relinfo.symtab = symtab;
 883   relinfo.layout = layout;
 884   relinfo.object = this;
 885
 886   const unsigned char* p = pshdrs + This::shdr_size;
 887   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 888     {
 889       typename This::Shdr shdr(p);
 890
 891       unsigned int sh_type = shdr.get_sh_type();
 892       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 893         continue;
 894
 895       off_t sh_size = shdr.get_sh_size();
 896       if (sh_size == 0)
 897         continue;
 898
 899       unsigned int index = this->adjust_shndx(shdr.get_sh_info());
 900       if (index >= this->shnum())
 901         {
 902           this->error(_("relocation section %u has bad info %u"),
 903                       i, index);
 904           continue;
 905         }
 906
 907       Output_section* os = out_sections[index];
 908       if (os == NULL)
 909         {
 910           // This relocation section is against a section which we
 911           // discarded.
 912           continue;
 913         }
 914       Address output_offset = out_offsets[index];
 915
 916       gold_assert((*pviews)[index].view != NULL);
 917       if (parameters->options().relocatable())
 918         gold_assert((*pviews)[i].view != NULL);
 919
 920       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 921         {
 922           gold_error(_("relocation section %u uses unexpected "
 923                        "symbol table %u"),
 924                      i, this->adjust_shndx(shdr.get_sh_link()));
 925           continue;
 926         }
 927
 928       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 929                                                     sh_size, true, false);
 930
 931       unsigned int reloc_size;
 932       if (sh_type == elfcpp::SHT_REL)
 933         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 934       else
 935         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 936
 937       if (reloc_size != shdr.get_sh_entsize())
 938         {
 939           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 940                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 941                      reloc_size);
 942           continue;
 943         }
 944
 945       size_t reloc_count = sh_size / reloc_size;
 946       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 947         {
 948           gold_error(_("reloc section %u size %lu uneven"),
 949                      i, static_cast<unsigned long>(sh_size));
 950           continue;
 951         }
 952
 953       gold_assert(output_offset != invalid_address
 954                   || this->relocs_must_follow_section_writes());
 955
 956       relinfo.reloc_shndx = i;
 957       relinfo.reloc_shdr = p;
 958       relinfo.data_shndx = index;
 959       relinfo.data_shdr = pshdrs + index * This::shdr_size;
 960       unsigned char* view = (*pviews)[index].view;
 961       Address address = (*pviews)[index].address;
 962       section_size_type view_size = (*pviews)[index].view_size;
 963
 964       Reloc_symbol_changes* reloc_map = NULL;
 965       if (this->uses_split_stack() && output_offset != invalid_address)
 966         {
 967           typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
 968           if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
 969             this->split_stack_adjust(symtab, pshdrs, sh_type, index,
 970                                      prelocs, reloc_count, view, view_size,
 971                                      &reloc_map, target);
 972         }
 973
 974       Relocatable_relocs* rr = NULL;
 975       if (parameters->options().emit_relocs()
 976           || parameters->options().relocatable())
 977         rr = this->relocatable_relocs(i);
 978       relinfo.rr = rr;
 979
 980       if (!parameters->options().relocatable())
 981         {
 982           target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
 983                                    output_offset == invalid_address,
 984                                    view, address, view_size, reloc_map);
 985           if (parameters->options().emit_relocs())
 986             target->relocate_relocs(&relinfo, sh_type, prelocs, reloc_count,
 987                                     os, output_offset,
 988                                     view, address, view_size,
 989                                     (*pviews)[i].view,
 990                                     (*pviews)[i].view_size);
 991           if (parameters->incremental())
 992             this->incremental_relocs_write(&relinfo, sh_type, prelocs,
 993                                            reloc_count, os, output_offset, of);
 994         }
 995       else
 996         target->relocate_relocs(&relinfo, sh_type, prelocs, reloc_count,
 997                                 os, output_offset,
 998                                 view, address, view_size,
 999                                 (*pviews)[i].view,
1000                                 (*pviews)[i].view_size);
1001     }
1002 }
1003
1004 // Return the output view for section SHNDX.
1005
1006 template<int size, bool big_endian>
1007 unsigned char*
1008 Sized_relobj_file<size, big_endian>::do_get_output_view(
1009     unsigned int shndx,
1010     section_size_type* plen) const
1011 {
1012   gold_assert(this->output_views_ != NULL);
1013   gold_assert(shndx < this->output_views_->size());
1014   const View_size& v = (*this->output_views_)[shndx];
1015   *plen = v.view_size;
1016   return v.view;
1017 }
1018
1019 // Write the incremental relocs.
1020
1021 template<int size, bool big_endian>
1022 void
1023 Sized_relobj_file<size, big_endian>::incremental_relocs_write(
1024     const Relocate_info<size, big_endian>* relinfo,
1025     unsigned int sh_type,
1026     const unsigned char* prelocs,
1027     size_t reloc_count,
1028     Output_section* output_section,
1029     Address output_offset,
1030     Output_file* of)
1031 {
1032   if (sh_type == elfcpp::SHT_REL)
1033     this->incremental_relocs_write_reltype<elfcpp::SHT_REL>(
1034         relinfo,
1035         prelocs,
1036         reloc_count,
1037         output_section,
1038         output_offset,
1039         of);
1040   else
1041     {
1042       gold_assert(sh_type == elfcpp::SHT_RELA);
1043       this->incremental_relocs_write_reltype<elfcpp::SHT_RELA>(
1044           relinfo,
1045           prelocs,
1046           reloc_count,
1047           output_section,
1048           output_offset,
1049           of);
1050     }
1051 }
1052
1053 // Write the incremental relocs, templatized on the type of the
1054 // relocation section.
1055
1056 template<int size, bool big_endian>
1057 template<int sh_type>
1058 void
1059 Sized_relobj_file<size, big_endian>::incremental_relocs_write_reltype(
1060     const Relocate_info<size, big_endian>* relinfo,
1061     const unsigned char* prelocs,
1062     size_t reloc_count,
1063     Output_section* output_section,
1064     Address output_offset,
1065     Output_file* of)
1066 {
1067   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reloc;
1068   const unsigned int reloc_size =
1069       Reloc_types<sh_type, size, big_endian>::reloc_size;
1070   const unsigned int sizeof_addr = size / 8;
1071   const unsigned int incr_reloc_size =
1072       Incremental_relocs_reader<size, big_endian>::reloc_size;
1073
1074   unsigned int out_shndx = output_section->out_shndx();
1075
1076   // Get a view for the .gnu_incremental_relocs section.
1077
1078   Incremental_inputs* inputs = relinfo->layout->incremental_inputs();
1079   gold_assert(inputs != NULL);
1080   const off_t relocs_off = inputs->relocs_section()->offset();
1081   const off_t relocs_size = inputs->relocs_section()->data_size();
1082   unsigned char* const view = of->get_output_view(relocs_off, relocs_size);
1083
1084   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
1085     {
1086       Reloc reloc(prelocs);
1087
1088       // FIXME: Some targets have a non-standard r_info field.
1089       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1090       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1091       const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
1092
1093       if (r_sym < this->local_symbol_count_)
1094         continue;
1095
1096       // Get the new offset--the location in the output section where
1097       // this relocation should be applied.
1098
1099       Address offset = reloc.get_r_offset();
1100       if (output_offset != invalid_address)
1101         offset += output_offset;
1102       else
1103         {
1104           section_offset_type sot_offset =
1105               convert_types<section_offset_type, Address>(offset);
1106           section_offset_type new_sot_offset =
1107               output_section->output_offset(relinfo->object,
1108                                             relinfo->data_shndx,
1109                                             sot_offset);
1110           gold_assert(new_sot_offset != -1);
1111           offset += new_sot_offset;
1112         }
1113
1114       // Get the addend.
1115       typename elfcpp::Elf_types<size>::Elf_Swxword addend;
1116       if (sh_type == elfcpp::SHT_RELA)
1117         addend =
1118             Reloc_types<sh_type, size, big_endian>::get_reloc_addend(&reloc);
1119       else
1120         {
1121           // FIXME: Get the addend for SHT_REL.
1122           addend = 0;
1123         }
1124
1125       // Get the index of the output relocation.
1126
1127       unsigned int reloc_index =
1128           this->next_incremental_reloc_index(r_sym - this->local_symbol_count_);
1129
1130       // Write the relocation.
1131
1132       unsigned char* pov = view + reloc_index * incr_reloc_size;
1133       elfcpp::Swap<32, big_endian>::writeval(pov, r_type);
1134       elfcpp::Swap<32, big_endian>::writeval(pov + 4, out_shndx);
1135       elfcpp::Swap<size, big_endian>::writeval(pov + 8, offset);
1136       elfcpp::Swap<size, big_endian>::writeval(pov + 8 + sizeof_addr, addend);
1137       of->write_output_view(pov - view, incr_reloc_size, view);
1138     }
1139 }
1140
1141 // Create merge hash tables for the local symbols.  These are used to
1142 // speed up relocations.
1143
1144 template<int size, bool big_endian>
1145 void
1146 Sized_relobj_file<size, big_endian>::initialize_input_to_output_maps()
1147 {
1148   const unsigned int loccount = this->local_symbol_count_;
1149   for (unsigned int i = 1; i < loccount; ++i)
1150     {
1151       Symbol_value<size>& lv(this->local_values_[i]);
1152       lv.initialize_input_to_output_map(this);
1153     }
1154 }
1155
1156 // Free merge hash tables for the local symbols.
1157
1158 template<int size, bool big_endian>
1159 void
1160 Sized_relobj_file<size, big_endian>::free_input_to_output_maps()
1161 {
1162   const unsigned int loccount = this->local_symbol_count_;
1163   for (unsigned int i = 1; i < loccount; ++i)
1164     {
1165       Symbol_value<size>& lv(this->local_values_[i]);
1166       lv.free_input_to_output_map();
1167     }
1168 }
1169
1170 // If an object was compiled with -fsplit-stack, this is called to
1171 // check whether any relocations refer to functions defined in objects
1172 // which were not compiled with -fsplit-stack.  If they were, then we
1173 // need to apply some target-specific adjustments to request
1174 // additional stack space.
1175
1176 template<int size, bool big_endian>
1177 void
1178 Sized_relobj_file<size, big_endian>::split_stack_adjust(
1179     const Symbol_table* symtab,
1180     const unsigned char* pshdrs,
1181     unsigned int sh_type,
1182     unsigned int shndx,
1183     const unsigned char* prelocs,
1184     size_t reloc_count,
1185     unsigned char* view,
1186     section_size_type view_size,
1187     Reloc_symbol_changes** reloc_map,
1188     const Sized_target<size, big_endian>* target)
1189 {
1190   if (sh_type == elfcpp::SHT_REL)
1191     this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
1192                                                       prelocs, reloc_count,
1193                                                       view, view_size,
1194                                                       reloc_map, target);
1195   else
1196     {
1197       gold_assert(sh_type == elfcpp::SHT_RELA);
1198       this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
1199                                                          prelocs, reloc_count,
1200                                                          view, view_size,
1201                                                          reloc_map, target);
1202     }
1203 }
1204
1205 // Adjust for -fsplit-stack, templatized on the type of the relocation
1206 // section.
1207
1208 template<int size, bool big_endian>
1209 template<int sh_type>
1210 void
1211 Sized_relobj_file<size, big_endian>::split_stack_adjust_reltype(
1212     const Symbol_table* symtab,
1213     const unsigned char* pshdrs,
1214     unsigned int shndx,
1215     const unsigned char* prelocs,
1216     size_t reloc_count,
1217     unsigned char* view,
1218     section_size_type view_size,
1219     Reloc_symbol_changes** reloc_map,
1220     const Sized_target<size, big_endian>* target)
1221 {
1222   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
1223   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
1224
1225   size_t local_count = this->local_symbol_count();
1226
1227   std::vector<section_offset_type> non_split_refs;
1228
1229   const unsigned char* pr = prelocs;
1230   for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1231     {
1232       // Some supported targets have a non-standard r_info field.
1233       // If this call is too slow, we can move this routine to
1234       // target-reloc.h and templatize it on Classify_reloc.
1235       unsigned int r_sym = target->get_r_sym(pr);
1236       if (r_sym < local_count)
1237         continue;
1238
1239       const Symbol* gsym = this->global_symbol(r_sym);
1240       gold_assert(gsym != NULL);
1241       if (gsym->is_forwarder())
1242         gsym = symtab->resolve_forwards(gsym);
1243
1244       // See if this relocation refers to a function defined in an
1245       // object compiled without -fsplit-stack.  Note that we don't
1246       // care about the type of relocation--this means that in some
1247       // cases we will ask for a large stack unnecessarily, but this
1248       // is not fatal.  FIXME: Some targets have symbols which are
1249       // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
1250       if (!gsym->is_undefined()
1251           && gsym->source() == Symbol::FROM_OBJECT
1252           && !gsym->object()->uses_split_stack())
1253         {
1254           if (parameters->target().is_call_to_non_split(gsym, pr, view,
1255                                                         view_size))
1256             {
1257               Reltype reloc(pr);
1258               section_offset_type offset =
1259                 convert_to_section_size_type(reloc.get_r_offset());
1260               non_split_refs.push_back(offset);
1261             }
1262         }
1263     }
1264
1265   if (non_split_refs.empty())
1266     return;
1267
1268   // At this point, every entry in NON_SPLIT_REFS indicates a
1269   // relocation which refers to a function in an object compiled
1270   // without -fsplit-stack.  We now have to convert that list into a
1271   // set of offsets to functions.  First, we find all the functions.
1272
1273   Function_offsets function_offsets;
1274   this->find_functions(pshdrs, shndx, &function_offsets);
1275   if (function_offsets.empty())
1276     return;
1277
1278   // Now get a list of the function with references to non split-stack
1279   // code.
1280
1281   Function_offsets calls_non_split;
1282   for (std::vector<section_offset_type>::const_iterator p
1283          = non_split_refs.begin();
1284        p != non_split_refs.end();
1285        ++p)
1286     {
1287       Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
1288       if (low == function_offsets.end())
1289         --low;
1290       else if (low->first == *p)
1291         ;
1292       else if (low == function_offsets.begin())
1293         continue;
1294       else
1295         --low;
1296
1297       calls_non_split.insert(*low);
1298     }
1299   if (calls_non_split.empty())
1300     return;
1301
1302   // Now we have a set of functions to adjust.  The adjustments are
1303   // target specific.  Besides changing the output section view
1304   // however, it likes, the target may request a relocation change
1305   // from one global symbol name to another.
1306
1307   for (Function_offsets::const_iterator p = calls_non_split.begin();
1308        p != calls_non_split.end();
1309        ++p)
1310     {
1311       std::string from;
1312       std::string to;
1313       parameters->target().calls_non_split(this, shndx, p->first, p->second,
1314                                            prelocs, reloc_count,
1315                                            view, view_size, &from, &to);
1316       if (!from.empty())
1317         {
1318           gold_assert(!to.empty());
1319           Symbol* tosym = NULL;
1320
1321           // Find relocations in the relevant function which are for
1322           // FROM.
1323           pr = prelocs;
1324           for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1325             {
1326               Reltype reloc(pr);
1327
1328               unsigned int r_sym = target->get_r_sym(pr);
1329               if (r_sym < local_count)
1330                 continue;
1331
1332               section_offset_type offset =
1333                 convert_to_section_size_type(reloc.get_r_offset());
1334               if (offset < p->first
1335                   || (offset
1336                       >= (p->first
1337                           + static_cast<section_offset_type>(p->second))))
1338                 continue;
1339
1340               const Symbol* gsym = this->global_symbol(r_sym);
1341               if (from == gsym->name())
1342                 {
1343                   if (tosym == NULL)
1344                     {
1345                       tosym = symtab->lookup(to.c_str());
1346                       if (tosym == NULL)
1347                         {
1348                           this->error(_("could not convert call "
1349                                         "to '%s' to '%s'"),
1350                                       from.c_str(), to.c_str());
1351                           break;
1352                         }
1353                     }
1354
1355                   if (*reloc_map == NULL)
1356                     *reloc_map = new Reloc_symbol_changes(reloc_count);
1357                   (*reloc_map)->set(i, tosym);
1358                 }
1359             }
1360         }
1361     }
1362 }
1363
1364 // Find all the function in this object defined in section SHNDX.
1365 // Store their offsets in the section in FUNCTION_OFFSETS.
1366
1367 template<int size, bool big_endian>
1368 void
1369 Sized_relobj_file<size, big_endian>::find_functions(
1370     const unsigned char* pshdrs,
1371     unsigned int shndx,
1372     Sized_relobj_file<size, big_endian>::Function_offsets* function_offsets)
1373 {
1374   // We need to read the symbols to find the functions.  If we wanted
1375   // to, we could cache reading the symbols across all sections in the
1376   // object.
1377   const unsigned int symtab_shndx = this->symtab_shndx_;
1378   typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size);
1379   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1380
1381   typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
1382     symtabshdr.get_sh_size();
1383   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1384                                               sh_size, true, true);
1385
1386   const int sym_size = This::sym_size;
1387   const unsigned int symcount = sh_size / sym_size;
1388   for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size)
1389     {
1390       typename elfcpp::Sym<size, big_endian> isym(psyms);
1391
1392       // FIXME: Some targets can have functions which do not have type
1393       // STT_FUNC, e.g., STT_ARM_TFUNC.
1394       if (isym.get_st_type() != elfcpp::STT_FUNC
1395           || isym.get_st_size() == 0)
1396         continue;
1397
1398       bool is_ordinary;
1399       Symbol_location loc;
1400       loc.shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1401                                          &is_ordinary);
1402       if (!is_ordinary)
1403         continue;
1404
1405       loc.object = this;
1406       loc.offset = isym.get_st_value();
1407       parameters->target().function_location(&loc);
1408
1409       if (loc.shndx != shndx)
1410         continue;
1411
1412       section_offset_type value =
1413         convert_to_section_size_type(loc.offset);
1414       section_size_type fnsize =
1415         convert_to_section_size_type(isym.get_st_size());
1416
1417       (*function_offsets)[value] = fnsize;
1418     }
1419 }
1420
1421 // Reverse the words in a section.  Used for .ctors sections mapped to
1422 // .init_array sections.  See ctors_sections_in_init_array in
1423 // layout.cc.
1424
1425 template<int size, bool big_endian>
1426 void
1427 Sized_relobj_file<size, big_endian>::reverse_words(unsigned char* view,
1428                                                    section_size_type view_size)
1429 {
1430   typedef typename elfcpp::Swap<size, big_endian>::Valtype Valtype;
1431   Valtype* vview = reinterpret_cast<Valtype*>(view);
1432   section_size_type vview_size = view_size / (size / 8);
1433   for (section_size_type i = 0; i < vview_size / 2; ++i)
1434     {
1435       Valtype tmp = vview[i];
1436       vview[i] = vview[vview_size - 1 - i];
1437       vview[vview_size - 1 - i] = tmp;
1438     }
1439 }
1440
1441 // Class Merged_symbol_value.
1442
1443 template<int size>
1444 void
1445 Merged_symbol_value<size>::initialize_input_to_output_map(
1446     const Relobj* object,
1447     unsigned int input_shndx)
1448 {
1449   object->initialize_input_to_output_map<size>(input_shndx,
1450                                                this->output_start_address_,
1451                                                &this->output_addresses_);
1452 }
1453
1454 // Get the output value corresponding to an input offset if we
1455 // couldn't find it in the hash table.
1456
1457 template<int size>
1458 typename elfcpp::Elf_types<size>::Elf_Addr
1459 Merged_symbol_value<size>::value_from_output_section(
1460     const Relobj* object,
1461     unsigned int input_shndx,
1462     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
1463 {
1464   section_offset_type output_offset;
1465   bool found = object->merge_output_offset(input_shndx, input_offset,
1466                                            &output_offset);
1467
1468   // If this assertion fails, it means that some relocation was
1469   // against a portion of an input merge section which we didn't map
1470   // to the output file and we didn't explicitly discard.  We should
1471   // always map all portions of input merge sections.
1472   gold_assert(found);
1473
1474   if (output_offset == -1)
1475     return 0;
1476   else
1477     return this->output_start_address_ + output_offset;
1478 }
1479
1480 // Track_relocs methods.
1481
1482 // Initialize the class to track the relocs.  This gets the object,
1483 // the reloc section index, and the type of the relocs.  This returns
1484 // false if something goes wrong.
1485
1486 template<int size, bool big_endian>
1487 bool
1488 Track_relocs<size, big_endian>::initialize(
1489     Object* object,
1490     unsigned int reloc_shndx,
1491     unsigned int reloc_type)
1492 {
1493   // If RELOC_SHNDX is -1U, it means there is more than one reloc
1494   // section for the .eh_frame section.  We can't handle that case.
1495   if (reloc_shndx == -1U)
1496     return false;
1497
1498   // If RELOC_SHNDX is 0, there is no reloc section.
1499   if (reloc_shndx == 0)
1500     return true;
1501
1502   // Get the contents of the reloc section.
1503   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
1504
1505   if (reloc_type == elfcpp::SHT_REL)
1506     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
1507   else if (reloc_type == elfcpp::SHT_RELA)
1508     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
1509   else
1510     gold_unreachable();
1511
1512   if (this->len_ % this->reloc_size_ != 0)
1513     {
1514       object->error(_("reloc section size %zu is not a multiple of "
1515                       "reloc size %d\n"),
1516                     static_cast<size_t>(this->len_),
1517                     this->reloc_size_);
1518       return false;
1519     }
1520
1521   return true;
1522 }
1523
1524 // Return the offset of the next reloc, or -1 if there isn't one.
1525
1526 template<int size, bool big_endian>
1527 off_t
1528 Track_relocs<size, big_endian>::next_offset() const
1529 {
1530   if (this->pos_ >= this->len_)
1531     return -1;
1532
1533   // Rel and Rela start out the same, so we can always use Rel to find
1534   // the r_offset value.
1535   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1536   return rel.get_r_offset();
1537 }
1538
1539 // Return the index of the symbol referenced by the next reloc, or -1U
1540 // if there aren't any more relocs.
1541
1542 template<int size, bool big_endian>
1543 unsigned int
1544 Track_relocs<size, big_endian>::next_symndx() const
1545 {
1546   if (this->pos_ >= this->len_)
1547     return -1U;
1548   Sized_target<size, big_endian>* target
1549       = parameters->sized_target<size, big_endian>();
1550   return target->get_r_sym(this->prelocs_ + this->pos_);
1551 }
1552
1553 // Return the addend of the next reloc, or 0 if there isn't one.
1554
1555 template<int size, bool big_endian>
1556 uint64_t
1557 Track_relocs<size, big_endian>::next_addend() const
1558 {
1559   if (this->pos_ >= this->len_)
1560     return 0;
1561   if (this->reloc_size_ == elfcpp::Elf_sizes<size>::rel_size)
1562     return 0;
1563   elfcpp::Rela<size, big_endian> rela(this->prelocs_ + this->pos_);
1564   return rela.get_r_addend();
1565 }
1566
1567 // Advance to the next reloc whose r_offset is greater than or equal
1568 // to OFFSET.  Return the number of relocs we skip.
1569
1570 template<int size, bool big_endian>
1571 int
1572 Track_relocs<size, big_endian>::advance(off_t offset)
1573 {
1574   int ret = 0;
1575   while (this->pos_ < this->len_)
1576     {
1577       // Rel and Rela start out the same, so we can always use Rel to
1578       // find the r_offset value.
1579       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1580       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
1581         break;
1582       ++ret;
1583       this->pos_ += this->reloc_size_;
1584     }
1585   return ret;
1586 }
1587
1588 // Instantiate the templates we need.
1589
1590 #ifdef HAVE_TARGET_32_LITTLE
1591 template
1592 void
1593 Sized_relobj_file<32, false>::do_read_relocs(Read_relocs_data* rd);
1594 #endif
1595
1596 #ifdef HAVE_TARGET_32_BIG
1597 template
1598 void
1599 Sized_relobj_file<32, true>::do_read_relocs(Read_relocs_data* rd);
1600 #endif
1601
1602 #ifdef HAVE_TARGET_64_LITTLE
1603 template
1604 void
1605 Sized_relobj_file<64, false>::do_read_relocs(Read_relocs_data* rd);
1606 #endif
1607
1608 #ifdef HAVE_TARGET_64_BIG
1609 template
1610 void
1611 Sized_relobj_file<64, true>::do_read_relocs(Read_relocs_data* rd);
1612 #endif
1613
1614 #ifdef HAVE_TARGET_32_LITTLE
1615 template
1616 void
1617 Sized_relobj_file<32, false>::do_gc_process_relocs(Symbol_table* symtab,
1618                                                    Layout* layout,
1619                                                    Read_relocs_data* rd);
1620 #endif
1621
1622 #ifdef HAVE_TARGET_32_BIG
1623 template
1624 void
1625 Sized_relobj_file<32, true>::do_gc_process_relocs(Symbol_table* symtab,
1626                                                   Layout* layout,
1627                                                   Read_relocs_data* rd);
1628 #endif
1629
1630 #ifdef HAVE_TARGET_64_LITTLE
1631 template
1632 void
1633 Sized_relobj_file<64, false>::do_gc_process_relocs(Symbol_table* symtab,
1634                                                    Layout* layout,
1635                                                    Read_relocs_data* rd);
1636 #endif
1637
1638 #ifdef HAVE_TARGET_64_BIG
1639 template
1640 void
1641 Sized_relobj_file<64, true>::do_gc_process_relocs(Symbol_table* symtab,
1642                                                   Layout* layout,
1643                                                   Read_relocs_data* rd);
1644 #endif
1645
1646 #ifdef HAVE_TARGET_32_LITTLE
1647 template
1648 void
1649 Sized_relobj_file<32, false>::do_scan_relocs(Symbol_table* symtab,
1650                                              Layout* layout,
1651                                              Read_relocs_data* rd);
1652 #endif
1653
1654 #ifdef HAVE_TARGET_32_BIG
1655 template
1656 void
1657 Sized_relobj_file<32, true>::do_scan_relocs(Symbol_table* symtab,
1658                                             Layout* layout,
1659                                             Read_relocs_data* rd);
1660 #endif
1661
1662 #ifdef HAVE_TARGET_64_LITTLE
1663 template
1664 void
1665 Sized_relobj_file<64, false>::do_scan_relocs(Symbol_table* symtab,
1666                                              Layout* layout,
1667                                              Read_relocs_data* rd);
1668 #endif
1669
1670 #ifdef HAVE_TARGET_64_BIG
1671 template
1672 void
1673 Sized_relobj_file<64, true>::do_scan_relocs(Symbol_table* symtab,
1674                                             Layout* layout,
1675                                             Read_relocs_data* rd);
1676 #endif
1677
1678 #ifdef HAVE_TARGET_32_LITTLE
1679 template
1680 void
1681 Sized_relobj_file<32, false>::do_relocate(const Symbol_table* symtab,
1682                                           const Layout* layout,
1683                                           Output_file* of);
1684 #endif
1685
1686 #ifdef HAVE_TARGET_32_BIG
1687 template
1688 void
1689 Sized_relobj_file<32, true>::do_relocate(const Symbol_table* symtab,
1690                                          const Layout* layout,
1691                                          Output_file* of);
1692 #endif
1693
1694 #ifdef HAVE_TARGET_64_LITTLE
1695 template
1696 void
1697 Sized_relobj_file<64, false>::do_relocate(const Symbol_table* symtab,
1698                                           const Layout* layout,
1699                                           Output_file* of);
1700 #endif
1701
1702 #ifdef HAVE_TARGET_64_BIG
1703 template
1704 void
1705 Sized_relobj_file<64, true>::do_relocate(const Symbol_table* symtab,
1706                                          const Layout* layout,
1707                                          Output_file* of);
1708 #endif
1709
1710 #ifdef HAVE_TARGET_32_LITTLE
1711 template
1712 void
1713 Sized_relobj_file<32, false>::do_relocate_sections(
1714     const Symbol_table* symtab,
1715     const Layout* layout,
1716     const unsigned char* pshdrs,
1717     Output_file* of,
1718     Views* pviews);
1719
1720 template
1721 unsigned char*
1722 Sized_relobj_file<32, false>::do_get_output_view(
1723     unsigned int shndx,
1724     section_size_type* plen) const;
1725 #endif
1726
1727 #ifdef HAVE_TARGET_32_BIG
1728 template
1729 void
1730 Sized_relobj_file<32, true>::do_relocate_sections(
1731     const Symbol_table* symtab,
1732     const Layout* layout,
1733     const unsigned char* pshdrs,
1734     Output_file* of,
1735     Views* pviews);
1736
1737 template
1738 unsigned char*
1739 Sized_relobj_file<32, true>::do_get_output_view(
1740     unsigned int shndx,
1741     section_size_type* plen) const;
1742 #endif
1743
1744 #ifdef HAVE_TARGET_64_LITTLE
1745 template
1746 void
1747 Sized_relobj_file<64, false>::do_relocate_sections(
1748     const Symbol_table* symtab,
1749     const Layout* layout,
1750     const unsigned char* pshdrs,
1751     Output_file* of,
1752     Views* pviews);
1753
1754 template
1755 unsigned char*
1756 Sized_relobj_file<64, false>::do_get_output_view(
1757     unsigned int shndx,
1758     section_size_type* plen) const;
1759 #endif
1760
1761 #ifdef HAVE_TARGET_64_BIG
1762 template
1763 void
1764 Sized_relobj_file<64, true>::do_relocate_sections(
1765     const Symbol_table* symtab,
1766     const Layout* layout,
1767     const unsigned char* pshdrs,
1768     Output_file* of,
1769     Views* pviews);
1770
1771 template
1772 unsigned char*
1773 Sized_relobj_file<64, true>::do_get_output_view(
1774     unsigned int shndx,
1775     section_size_type* plen) const;
1776 #endif
1777
1778 #ifdef HAVE_TARGET_32_LITTLE
1779 template
1780 void
1781 Sized_relobj_file<32, false>::initialize_input_to_output_maps();
1782
1783 template
1784 void
1785 Sized_relobj_file<32, false>::free_input_to_output_maps();
1786 #endif
1787
1788 #ifdef HAVE_TARGET_32_BIG
1789 template
1790 void
1791 Sized_relobj_file<32, true>::initialize_input_to_output_maps();
1792
1793 template
1794 void
1795 Sized_relobj_file<32, true>::free_input_to_output_maps();
1796 #endif
1797
1798 #ifdef HAVE_TARGET_64_LITTLE
1799 template
1800 void
1801 Sized_relobj_file<64, false>::initialize_input_to_output_maps();
1802
1803 template
1804 void
1805 Sized_relobj_file<64, false>::free_input_to_output_maps();
1806 #endif
1807
1808 #ifdef HAVE_TARGET_64_BIG
1809 template
1810 void
1811 Sized_relobj_file<64, true>::initialize_input_to_output_maps();
1812
1813 template
1814 void
1815 Sized_relobj_file<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.