gold/reloc.cc

   1 // reloc.cc -- relocate input files for gold.
   2
   3 // Copyright (C) 2006-2019 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   this->relocate_section_range(symtab, layout, pshdrs, of, pviews,
 875                                1, this->shnum() - 1);
 876 }
 877
 878 // Relocate section data for the range of sections START_SHNDX through
 879 // END_SHNDX.
 880
 881 template<int size, bool big_endian>
 882 void
 883 Sized_relobj_file<size, big_endian>::relocate_section_range(
 884     const Symbol_table* symtab,
 885     const Layout* layout,
 886     const unsigned char* pshdrs,
 887     Output_file* of,
 888     Views* pviews,
 889     unsigned int start_shndx,
 890     unsigned int end_shndx)
 891 {
 892   gold_assert(start_shndx >= 1);
 893   gold_assert(end_shndx < this->shnum());
 894
 895   if (end_shndx < start_shndx)
 896     return;
 897
 898   Sized_target<size, big_endian>* target =
 899     parameters->sized_target<size, big_endian>();
 900
 901   const Output_sections& out_sections(this->output_sections());
 902   const std::vector<Address>& out_offsets(this->section_offsets());
 903
 904   Relocate_info<size, big_endian> relinfo;
 905   relinfo.symtab = symtab;
 906   relinfo.layout = layout;
 907   relinfo.object = this;
 908
 909   const unsigned char* p = pshdrs + start_shndx * This::shdr_size;
 910   for (unsigned int i = start_shndx; i <= end_shndx; ++i, p += This::shdr_size)
 911     {
 912       typename This::Shdr shdr(p);
 913
 914       unsigned int sh_type = shdr.get_sh_type();
 915       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 916         continue;
 917
 918       off_t sh_size = shdr.get_sh_size();
 919       if (sh_size == 0)
 920         continue;
 921
 922       unsigned int index = this->adjust_shndx(shdr.get_sh_info());
 923       if (index >= this->shnum())
 924         {
 925           this->error(_("relocation section %u has bad info %u"),
 926                       i, index);
 927           continue;
 928         }
 929
 930       Output_section* os = out_sections[index];
 931       if (os == NULL)
 932         {
 933           // This relocation section is against a section which we
 934           // discarded.
 935           continue;
 936         }
 937       Address output_offset = out_offsets[index];
 938
 939       gold_assert((*pviews)[index].view != NULL);
 940       if (parameters->options().relocatable())
 941         gold_assert((*pviews)[i].view != NULL);
 942
 943       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 944         {
 945           gold_error(_("relocation section %u uses unexpected "
 946                        "symbol table %u"),
 947                      i, this->adjust_shndx(shdr.get_sh_link()));
 948           continue;
 949         }
 950
 951       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 952                                                     sh_size, true, false);
 953
 954       unsigned int reloc_size;
 955       if (sh_type == elfcpp::SHT_REL)
 956         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 957       else
 958         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 959
 960       if (reloc_size != shdr.get_sh_entsize())
 961         {
 962           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 963                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 964                      reloc_size);
 965           continue;
 966         }
 967
 968       size_t reloc_count = sh_size / reloc_size;
 969       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 970         {
 971           gold_error(_("reloc section %u size %lu uneven"),
 972                      i, static_cast<unsigned long>(sh_size));
 973           continue;
 974         }
 975
 976       gold_assert(output_offset != invalid_address
 977                   || this->relocs_must_follow_section_writes());
 978
 979       relinfo.reloc_shndx = i;
 980       relinfo.reloc_shdr = p;
 981       relinfo.data_shndx = index;
 982       relinfo.data_shdr = pshdrs + index * This::shdr_size;
 983       unsigned char* view = (*pviews)[index].view;
 984       Address address = (*pviews)[index].address;
 985       section_size_type view_size = (*pviews)[index].view_size;
 986
 987       Reloc_symbol_changes* reloc_map = NULL;
 988       if (this->uses_split_stack() && output_offset != invalid_address)
 989         {
 990           typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
 991           if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
 992             this->split_stack_adjust(symtab, pshdrs, sh_type, index,
 993                                      prelocs, reloc_count, view, view_size,
 994                                      &reloc_map, target);
 995         }
 996
 997       Relocatable_relocs* rr = NULL;
 998       if (parameters->options().emit_relocs()
 999           || parameters->options().relocatable())
1000         rr = this->relocatable_relocs(i);
1001       relinfo.rr = rr;
1002
1003       if (!parameters->options().relocatable())
1004         {
1005           target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
1006                                    output_offset == invalid_address,
1007                                    view, address, view_size, reloc_map);
1008           if (parameters->options().emit_relocs())
1009             target->relocate_relocs(&relinfo, sh_type, prelocs, reloc_count,
1010                                     os, output_offset,
1011                                     view, address, view_size,
1012                                     (*pviews)[i].view,
1013                                     (*pviews)[i].view_size);
1014           if (parameters->incremental())
1015             this->incremental_relocs_write(&relinfo, sh_type, prelocs,
1016                                            reloc_count, os, output_offset, of);
1017         }
1018       else
1019         target->relocate_relocs(&relinfo, sh_type, prelocs, reloc_count,
1020                                 os, output_offset,
1021                                 view, address, view_size,
1022                                 (*pviews)[i].view,
1023                                 (*pviews)[i].view_size);
1024     }
1025 }
1026
1027 // Return the output view for section SHNDX.
1028
1029 template<int size, bool big_endian>
1030 unsigned char*
1031 Sized_relobj_file<size, big_endian>::do_get_output_view(
1032     unsigned int shndx,
1033     section_size_type* plen) const
1034 {
1035   gold_assert(this->output_views_ != NULL);
1036   gold_assert(shndx < this->output_views_->size());
1037   const View_size& v = (*this->output_views_)[shndx];
1038   *plen = v.view_size;
1039   return v.view;
1040 }
1041
1042 // Write the incremental relocs.
1043
1044 template<int size, bool big_endian>
1045 void
1046 Sized_relobj_file<size, big_endian>::incremental_relocs_write(
1047     const Relocate_info<size, big_endian>* relinfo,
1048     unsigned int sh_type,
1049     const unsigned char* prelocs,
1050     size_t reloc_count,
1051     Output_section* output_section,
1052     Address output_offset,
1053     Output_file* of)
1054 {
1055   if (sh_type == elfcpp::SHT_REL)
1056     this->incremental_relocs_write_reltype<elfcpp::SHT_REL>(
1057         relinfo,
1058         prelocs,
1059         reloc_count,
1060         output_section,
1061         output_offset,
1062         of);
1063   else
1064     {
1065       gold_assert(sh_type == elfcpp::SHT_RELA);
1066       this->incremental_relocs_write_reltype<elfcpp::SHT_RELA>(
1067           relinfo,
1068           prelocs,
1069           reloc_count,
1070           output_section,
1071           output_offset,
1072           of);
1073     }
1074 }
1075
1076 // Write the incremental relocs, templatized on the type of the
1077 // relocation section.
1078
1079 template<int size, bool big_endian>
1080 template<int sh_type>
1081 void
1082 Sized_relobj_file<size, big_endian>::incremental_relocs_write_reltype(
1083     const Relocate_info<size, big_endian>* relinfo,
1084     const unsigned char* prelocs,
1085     size_t reloc_count,
1086     Output_section* output_section,
1087     Address output_offset,
1088     Output_file* of)
1089 {
1090   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reloc;
1091   const unsigned int reloc_size =
1092       Reloc_types<sh_type, size, big_endian>::reloc_size;
1093   const unsigned int sizeof_addr = size / 8;
1094   const unsigned int incr_reloc_size =
1095       Incremental_relocs_reader<size, big_endian>::reloc_size;
1096
1097   unsigned int out_shndx = output_section->out_shndx();
1098
1099   // Get a view for the .gnu_incremental_relocs section.
1100
1101   Incremental_inputs* inputs = relinfo->layout->incremental_inputs();
1102   gold_assert(inputs != NULL);
1103   const off_t relocs_off = inputs->relocs_section()->offset();
1104   const off_t relocs_size = inputs->relocs_section()->data_size();
1105   unsigned char* const view = of->get_output_view(relocs_off, relocs_size);
1106
1107   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
1108     {
1109       Reloc reloc(prelocs);
1110
1111       // FIXME: Some targets have a non-standard r_info field.
1112       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1113       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1114       const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
1115
1116       if (r_sym < this->local_symbol_count_)
1117         continue;
1118
1119       // Get the new offset--the location in the output section where
1120       // this relocation should be applied.
1121
1122       Address offset = reloc.get_r_offset();
1123       if (output_offset != invalid_address)
1124         offset += output_offset;
1125       else
1126         {
1127           section_offset_type sot_offset =
1128               convert_types<section_offset_type, Address>(offset);
1129           section_offset_type new_sot_offset =
1130               output_section->output_offset(relinfo->object,
1131                                             relinfo->data_shndx,
1132                                             sot_offset);
1133           gold_assert(new_sot_offset != -1);
1134           offset += new_sot_offset;
1135         }
1136
1137       // Get the addend.
1138       typename elfcpp::Elf_types<size>::Elf_Swxword addend;
1139       if (sh_type == elfcpp::SHT_RELA)
1140         addend =
1141             Reloc_types<sh_type, size, big_endian>::get_reloc_addend(&reloc);
1142       else
1143         {
1144           // FIXME: Get the addend for SHT_REL.
1145           addend = 0;
1146         }
1147
1148       // Get the index of the output relocation.
1149
1150       unsigned int reloc_index =
1151           this->next_incremental_reloc_index(r_sym - this->local_symbol_count_);
1152
1153       // Write the relocation.
1154
1155       unsigned char* pov = view + reloc_index * incr_reloc_size;
1156       elfcpp::Swap<32, big_endian>::writeval(pov, r_type);
1157       elfcpp::Swap<32, big_endian>::writeval(pov + 4, out_shndx);
1158       elfcpp::Swap<size, big_endian>::writeval(pov + 8, offset);
1159       elfcpp::Swap<size, big_endian>::writeval(pov + 8 + sizeof_addr, addend);
1160       of->write_output_view(pov - view, incr_reloc_size, view);
1161     }
1162 }
1163
1164 // Create merge hash tables for the local symbols.  These are used to
1165 // speed up relocations.
1166
1167 template<int size, bool big_endian>
1168 void
1169 Sized_relobj_file<size, big_endian>::initialize_input_to_output_maps()
1170 {
1171   const unsigned int loccount = this->local_symbol_count_;
1172   for (unsigned int i = 1; i < loccount; ++i)
1173     {
1174       Symbol_value<size>& lv(this->local_values_[i]);
1175       lv.initialize_input_to_output_map(this);
1176     }
1177 }
1178
1179 // Free merge hash tables for the local symbols.
1180
1181 template<int size, bool big_endian>
1182 void
1183 Sized_relobj_file<size, big_endian>::free_input_to_output_maps()
1184 {
1185   const unsigned int loccount = this->local_symbol_count_;
1186   for (unsigned int i = 1; i < loccount; ++i)
1187     {
1188       Symbol_value<size>& lv(this->local_values_[i]);
1189       lv.free_input_to_output_map();
1190     }
1191 }
1192
1193 // If an object was compiled with -fsplit-stack, this is called to
1194 // check whether any relocations refer to functions defined in objects
1195 // which were not compiled with -fsplit-stack.  If they were, then we
1196 // need to apply some target-specific adjustments to request
1197 // additional stack space.
1198
1199 template<int size, bool big_endian>
1200 void
1201 Sized_relobj_file<size, big_endian>::split_stack_adjust(
1202     const Symbol_table* symtab,
1203     const unsigned char* pshdrs,
1204     unsigned int sh_type,
1205     unsigned int shndx,
1206     const unsigned char* prelocs,
1207     size_t reloc_count,
1208     unsigned char* view,
1209     section_size_type view_size,
1210     Reloc_symbol_changes** reloc_map,
1211     const Sized_target<size, big_endian>* target)
1212 {
1213   if (sh_type == elfcpp::SHT_REL)
1214     this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
1215                                                       prelocs, reloc_count,
1216                                                       view, view_size,
1217                                                       reloc_map, target);
1218   else
1219     {
1220       gold_assert(sh_type == elfcpp::SHT_RELA);
1221       this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
1222                                                          prelocs, reloc_count,
1223                                                          view, view_size,
1224                                                          reloc_map, target);
1225     }
1226 }
1227
1228 // Adjust for -fsplit-stack, templatized on the type of the relocation
1229 // section.
1230
1231 template<int size, bool big_endian>
1232 template<int sh_type>
1233 void
1234 Sized_relobj_file<size, big_endian>::split_stack_adjust_reltype(
1235     const Symbol_table* symtab,
1236     const unsigned char* pshdrs,
1237     unsigned int shndx,
1238     const unsigned char* prelocs,
1239     size_t reloc_count,
1240     unsigned char* view,
1241     section_size_type view_size,
1242     Reloc_symbol_changes** reloc_map,
1243     const Sized_target<size, big_endian>* target)
1244 {
1245   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
1246   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
1247
1248   size_t local_count = this->local_symbol_count();
1249
1250   std::vector<section_offset_type> non_split_refs;
1251
1252   const unsigned char* pr = prelocs;
1253   for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1254     {
1255       // Some supported targets have a non-standard r_info field.
1256       // If this call is too slow, we can move this routine to
1257       // target-reloc.h and templatize it on Classify_reloc.
1258       unsigned int r_sym = target->get_r_sym(pr);
1259       if (r_sym < local_count)
1260         continue;
1261
1262       const Symbol* gsym = this->global_symbol(r_sym);
1263       gold_assert(gsym != NULL);
1264       if (gsym->is_forwarder())
1265         gsym = symtab->resolve_forwards(gsym);
1266
1267       // See if this relocation refers to a function defined in an
1268       // object compiled without -fsplit-stack.  Note that we don't
1269       // care about the type of relocation--this means that in some
1270       // cases we will ask for a large stack unnecessarily, but this
1271       // is not fatal.  FIXME: Some targets have symbols which are
1272       // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
1273       if (!gsym->is_undefined()
1274           && gsym->source() == Symbol::FROM_OBJECT
1275           && !gsym->object()->uses_split_stack())
1276         {
1277           if (parameters->target().is_call_to_non_split(gsym, pr, view,
1278                                                         view_size))
1279             {
1280               Reltype reloc(pr);
1281               section_offset_type offset =
1282                 convert_to_section_size_type(reloc.get_r_offset());
1283               non_split_refs.push_back(offset);
1284             }
1285         }
1286     }
1287
1288   if (non_split_refs.empty())
1289     return;
1290
1291   // At this point, every entry in NON_SPLIT_REFS indicates a
1292   // relocation which refers to a function in an object compiled
1293   // without -fsplit-stack.  We now have to convert that list into a
1294   // set of offsets to functions.  First, we find all the functions.
1295
1296   Function_offsets function_offsets;
1297   this->find_functions(pshdrs, shndx, &function_offsets);
1298   if (function_offsets.empty())
1299     return;
1300
1301   // Now get a list of the function with references to non split-stack
1302   // code.
1303
1304   Function_offsets calls_non_split;
1305   for (std::vector<section_offset_type>::const_iterator p
1306          = non_split_refs.begin();
1307        p != non_split_refs.end();
1308        ++p)
1309     {
1310       Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
1311       if (low == function_offsets.end())
1312         --low;
1313       else if (low->first == *p)
1314         ;
1315       else if (low == function_offsets.begin())
1316         continue;
1317       else
1318         --low;
1319
1320       calls_non_split.insert(*low);
1321     }
1322   if (calls_non_split.empty())
1323     return;
1324
1325   // Now we have a set of functions to adjust.  The adjustments are
1326   // target specific.  Besides changing the output section view
1327   // however, it likes, the target may request a relocation change
1328   // from one global symbol name to another.
1329
1330   for (Function_offsets::const_iterator p = calls_non_split.begin();
1331        p != calls_non_split.end();
1332        ++p)
1333     {
1334       std::string from;
1335       std::string to;
1336       parameters->target().calls_non_split(this, shndx, p->first, p->second,
1337                                            prelocs, reloc_count,
1338                                            view, view_size, &from, &to);
1339       if (!from.empty())
1340         {
1341           gold_assert(!to.empty());
1342           Symbol* tosym = NULL;
1343
1344           // Find relocations in the relevant function which are for
1345           // FROM.
1346           pr = prelocs;
1347           for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1348             {
1349               Reltype reloc(pr);
1350
1351               unsigned int r_sym = target->get_r_sym(pr);
1352               if (r_sym < local_count)
1353                 continue;
1354
1355               section_offset_type offset =
1356                 convert_to_section_size_type(reloc.get_r_offset());
1357               if (offset < p->first
1358                   || (offset
1359                       >= (p->first
1360                           + static_cast<section_offset_type>(p->second))))
1361                 continue;
1362
1363               const Symbol* gsym = this->global_symbol(r_sym);
1364               if (from == gsym->name())
1365                 {
1366                   if (tosym == NULL)
1367                     {
1368                       tosym = symtab->lookup(to.c_str());
1369                       if (tosym == NULL)
1370                         {
1371                           this->error(_("could not convert call "
1372                                         "to '%s' to '%s'"),
1373                                       from.c_str(), to.c_str());
1374                           break;
1375                         }
1376                     }
1377
1378                   if (*reloc_map == NULL)
1379                     *reloc_map = new Reloc_symbol_changes(reloc_count);
1380                   (*reloc_map)->set(i, tosym);
1381                 }
1382             }
1383         }
1384     }
1385 }
1386
1387 // Find all the function in this object defined in section SHNDX.
1388 // Store their offsets in the section in FUNCTION_OFFSETS.
1389
1390 template<int size, bool big_endian>
1391 void
1392 Sized_relobj_file<size, big_endian>::find_functions(
1393     const unsigned char* pshdrs,
1394     unsigned int shndx,
1395     Sized_relobj_file<size, big_endian>::Function_offsets* function_offsets)
1396 {
1397   // We need to read the symbols to find the functions.  If we wanted
1398   // to, we could cache reading the symbols across all sections in the
1399   // object.
1400   const unsigned int symtab_shndx = this->symtab_shndx_;
1401   typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size);
1402   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1403
1404   typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
1405     symtabshdr.get_sh_size();
1406   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1407                                               sh_size, true, true);
1408
1409   const int sym_size = This::sym_size;
1410   const unsigned int symcount = sh_size / sym_size;
1411   for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size)
1412     {
1413       typename elfcpp::Sym<size, big_endian> isym(psyms);
1414
1415       // FIXME: Some targets can have functions which do not have type
1416       // STT_FUNC, e.g., STT_ARM_TFUNC.
1417       if (isym.get_st_type() != elfcpp::STT_FUNC
1418           || isym.get_st_size() == 0)
1419         continue;
1420
1421       bool is_ordinary;
1422       Symbol_location loc;
1423       loc.shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1424                                          &is_ordinary);
1425       if (!is_ordinary)
1426         continue;
1427
1428       loc.object = this;
1429       loc.offset = isym.get_st_value();
1430       parameters->target().function_location(&loc);
1431
1432       if (loc.shndx != shndx)
1433         continue;
1434
1435       section_offset_type value =
1436         convert_to_section_size_type(loc.offset);
1437       section_size_type fnsize =
1438         convert_to_section_size_type(isym.get_st_size());
1439
1440       (*function_offsets)[value] = fnsize;
1441     }
1442 }
1443
1444 // Reverse the words in a section.  Used for .ctors sections mapped to
1445 // .init_array sections.  See ctors_sections_in_init_array in
1446 // layout.cc.
1447
1448 template<int size, bool big_endian>
1449 void
1450 Sized_relobj_file<size, big_endian>::reverse_words(unsigned char* view,
1451                                                    section_size_type view_size)
1452 {
1453   typedef typename elfcpp::Swap<size, big_endian>::Valtype Valtype;
1454   Valtype* vview = reinterpret_cast<Valtype*>(view);
1455   section_size_type vview_size = view_size / (size / 8);
1456   for (section_size_type i = 0; i < vview_size / 2; ++i)
1457     {
1458       Valtype tmp = vview[i];
1459       vview[i] = vview[vview_size - 1 - i];
1460       vview[vview_size - 1 - i] = tmp;
1461     }
1462 }
1463
1464 // Class Merged_symbol_value.
1465
1466 template<int size>
1467 void
1468 Merged_symbol_value<size>::initialize_input_to_output_map(
1469     const Relobj* object,
1470     unsigned int input_shndx)
1471 {
1472   object->initialize_input_to_output_map<size>(input_shndx,
1473                                                this->output_start_address_,
1474                                                &this->output_addresses_);
1475 }
1476
1477 // Get the output value corresponding to an input offset if we
1478 // couldn't find it in the hash table.
1479
1480 template<int size>
1481 typename elfcpp::Elf_types<size>::Elf_Addr
1482 Merged_symbol_value<size>::value_from_output_section(
1483     const Relobj* object,
1484     unsigned int input_shndx,
1485     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
1486 {
1487   section_offset_type output_offset;
1488   bool found = object->merge_output_offset(input_shndx, input_offset,
1489                                            &output_offset);
1490
1491   // If this assertion fails, it means that some relocation was
1492   // against a portion of an input merge section which we didn't map
1493   // to the output file and we didn't explicitly discard.  We should
1494   // always map all portions of input merge sections.
1495   gold_assert(found);
1496
1497   if (output_offset == -1)
1498     return 0;
1499   else
1500     return this->output_start_address_ + output_offset;
1501 }
1502
1503 // Track_relocs methods.
1504
1505 // Initialize the class to track the relocs.  This gets the object,
1506 // the reloc section index, and the type of the relocs.  This returns
1507 // false if something goes wrong.
1508
1509 template<int size, bool big_endian>
1510 bool
1511 Track_relocs<size, big_endian>::initialize(
1512     Object* object,
1513     unsigned int reloc_shndx,
1514     unsigned int reloc_type)
1515 {
1516   // If RELOC_SHNDX is -1U, it means there is more than one reloc
1517   // section for the .eh_frame section.  We can't handle that case.
1518   if (reloc_shndx == -1U)
1519     return false;
1520
1521   // If RELOC_SHNDX is 0, there is no reloc section.
1522   if (reloc_shndx == 0)
1523     return true;
1524
1525   // Get the contents of the reloc section.
1526   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
1527
1528   if (reloc_type == elfcpp::SHT_REL)
1529     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
1530   else if (reloc_type == elfcpp::SHT_RELA)
1531     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
1532   else
1533     gold_unreachable();
1534
1535   if (this->len_ % this->reloc_size_ != 0)
1536     {
1537       object->error(_("reloc section size %zu is not a multiple of "
1538                       "reloc size %d\n"),
1539                     static_cast<size_t>(this->len_),
1540                     this->reloc_size_);
1541       return false;
1542     }
1543
1544   return true;
1545 }
1546
1547 // Return the offset of the next reloc, or -1 if there isn't one.
1548
1549 template<int size, bool big_endian>
1550 off_t
1551 Track_relocs<size, big_endian>::next_offset() const
1552 {
1553   if (this->pos_ >= this->len_)
1554     return -1;
1555
1556   // Rel and Rela start out the same, so we can always use Rel to find
1557   // the r_offset value.
1558   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1559   return rel.get_r_offset();
1560 }
1561
1562 // Return the index of the symbol referenced by the next reloc, or -1U
1563 // if there aren't any more relocs.
1564
1565 template<int size, bool big_endian>
1566 unsigned int
1567 Track_relocs<size, big_endian>::next_symndx() const
1568 {
1569   if (this->pos_ >= this->len_)
1570     return -1U;
1571   Sized_target<size, big_endian>* target
1572       = parameters->sized_target<size, big_endian>();
1573   return target->get_r_sym(this->prelocs_ + this->pos_);
1574 }
1575
1576 // Return the addend of the next reloc, or 0 if there isn't one.
1577
1578 template<int size, bool big_endian>
1579 uint64_t
1580 Track_relocs<size, big_endian>::next_addend() const
1581 {
1582   if (this->pos_ >= this->len_)
1583     return 0;
1584   if (this->reloc_size_ == elfcpp::Elf_sizes<size>::rel_size)
1585     return 0;
1586   elfcpp::Rela<size, big_endian> rela(this->prelocs_ + this->pos_);
1587   return rela.get_r_addend();
1588 }
1589
1590 // Advance to the next reloc whose r_offset is greater than or equal
1591 // to OFFSET.  Return the number of relocs we skip.
1592
1593 template<int size, bool big_endian>
1594 int
1595 Track_relocs<size, big_endian>::advance(off_t offset)
1596 {
1597   int ret = 0;
1598   while (this->pos_ < this->len_)
1599     {
1600       // Rel and Rela start out the same, so we can always use Rel to
1601       // find the r_offset value.
1602       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1603       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
1604         break;
1605       ++ret;
1606       this->pos_ += this->reloc_size_;
1607     }
1608   return ret;
1609 }
1610
1611 // Instantiate the templates we need.
1612
1613 #ifdef HAVE_TARGET_32_LITTLE
1614 template
1615 void
1616 Sized_relobj_file<32, false>::do_read_relocs(Read_relocs_data* rd);
1617 #endif
1618
1619 #ifdef HAVE_TARGET_32_BIG
1620 template
1621 void
1622 Sized_relobj_file<32, true>::do_read_relocs(Read_relocs_data* rd);
1623 #endif
1624
1625 #ifdef HAVE_TARGET_64_LITTLE
1626 template
1627 void
1628 Sized_relobj_file<64, false>::do_read_relocs(Read_relocs_data* rd);
1629 #endif
1630
1631 #ifdef HAVE_TARGET_64_BIG
1632 template
1633 void
1634 Sized_relobj_file<64, true>::do_read_relocs(Read_relocs_data* rd);
1635 #endif
1636
1637 #ifdef HAVE_TARGET_32_LITTLE
1638 template
1639 void
1640 Sized_relobj_file<32, false>::do_gc_process_relocs(Symbol_table* symtab,
1641                                                    Layout* layout,
1642                                                    Read_relocs_data* rd);
1643 #endif
1644
1645 #ifdef HAVE_TARGET_32_BIG
1646 template
1647 void
1648 Sized_relobj_file<32, true>::do_gc_process_relocs(Symbol_table* symtab,
1649                                                   Layout* layout,
1650                                                   Read_relocs_data* rd);
1651 #endif
1652
1653 #ifdef HAVE_TARGET_64_LITTLE
1654 template
1655 void
1656 Sized_relobj_file<64, false>::do_gc_process_relocs(Symbol_table* symtab,
1657                                                    Layout* layout,
1658                                                    Read_relocs_data* rd);
1659 #endif
1660
1661 #ifdef HAVE_TARGET_64_BIG
1662 template
1663 void
1664 Sized_relobj_file<64, true>::do_gc_process_relocs(Symbol_table* symtab,
1665                                                   Layout* layout,
1666                                                   Read_relocs_data* rd);
1667 #endif
1668
1669 #ifdef HAVE_TARGET_32_LITTLE
1670 template
1671 void
1672 Sized_relobj_file<32, false>::do_scan_relocs(Symbol_table* symtab,
1673                                              Layout* layout,
1674                                              Read_relocs_data* rd);
1675 #endif
1676
1677 #ifdef HAVE_TARGET_32_BIG
1678 template
1679 void
1680 Sized_relobj_file<32, true>::do_scan_relocs(Symbol_table* symtab,
1681                                             Layout* layout,
1682                                             Read_relocs_data* rd);
1683 #endif
1684
1685 #ifdef HAVE_TARGET_64_LITTLE
1686 template
1687 void
1688 Sized_relobj_file<64, false>::do_scan_relocs(Symbol_table* symtab,
1689                                              Layout* layout,
1690                                              Read_relocs_data* rd);
1691 #endif
1692
1693 #ifdef HAVE_TARGET_64_BIG
1694 template
1695 void
1696 Sized_relobj_file<64, true>::do_scan_relocs(Symbol_table* symtab,
1697                                             Layout* layout,
1698                                             Read_relocs_data* rd);
1699 #endif
1700
1701 #ifdef HAVE_TARGET_32_LITTLE
1702 template
1703 void
1704 Sized_relobj_file<32, false>::do_relocate(const Symbol_table* symtab,
1705                                           const Layout* layout,
1706                                           Output_file* of);
1707 #endif
1708
1709 #ifdef HAVE_TARGET_32_BIG
1710 template
1711 void
1712 Sized_relobj_file<32, true>::do_relocate(const Symbol_table* symtab,
1713                                          const Layout* layout,
1714                                          Output_file* of);
1715 #endif
1716
1717 #ifdef HAVE_TARGET_64_LITTLE
1718 template
1719 void
1720 Sized_relobj_file<64, false>::do_relocate(const Symbol_table* symtab,
1721                                           const Layout* layout,
1722                                           Output_file* of);
1723 #endif
1724
1725 #ifdef HAVE_TARGET_64_BIG
1726 template
1727 void
1728 Sized_relobj_file<64, true>::do_relocate(const Symbol_table* symtab,
1729                                          const Layout* layout,
1730                                          Output_file* of);
1731 #endif
1732
1733 #ifdef HAVE_TARGET_32_LITTLE
1734 template
1735 void
1736 Sized_relobj_file<32, false>::do_relocate_sections(
1737     const Symbol_table* symtab,
1738     const Layout* layout,
1739     const unsigned char* pshdrs,
1740     Output_file* of,
1741     Views* pviews);
1742
1743 template
1744 void
1745 Sized_relobj_file<32, false>::relocate_section_range(
1746     const Symbol_table* symtab,
1747     const Layout* layout,
1748     const unsigned char* pshdrs,
1749     Output_file* of,
1750     Views* pviews,
1751     unsigned int start_shndx,
1752     unsigned int end_shndx);
1753
1754 template
1755 unsigned char*
1756 Sized_relobj_file<32, false>::do_get_output_view(
1757     unsigned int shndx,
1758     section_size_type* plen) const;
1759 #endif
1760
1761 #ifdef HAVE_TARGET_32_BIG
1762 template
1763 void
1764 Sized_relobj_file<32, 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 void
1773 Sized_relobj_file<32, true>::relocate_section_range(
1774     const Symbol_table* symtab,
1775     const Layout* layout,
1776     const unsigned char* pshdrs,
1777     Output_file* of,
1778     Views* pviews,
1779     unsigned int start_shndx,
1780     unsigned int end_shndx);
1781
1782 template
1783 unsigned char*
1784 Sized_relobj_file<32, true>::do_get_output_view(
1785     unsigned int shndx,
1786     section_size_type* plen) const;
1787 #endif
1788
1789 #ifdef HAVE_TARGET_64_LITTLE
1790 template
1791 void
1792 Sized_relobj_file<64, false>::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
1799 template
1800 void
1801 Sized_relobj_file<64, false>::relocate_section_range(
1802     const Symbol_table* symtab,
1803     const Layout* layout,
1804     const unsigned char* pshdrs,
1805     Output_file* of,
1806     Views* pviews,
1807     unsigned int start_shndx,
1808     unsigned int end_shndx);
1809
1810 template
1811 unsigned char*
1812 Sized_relobj_file<64, false>::do_get_output_view(
1813     unsigned int shndx,
1814     section_size_type* plen) const;
1815 #endif
1816
1817 #ifdef HAVE_TARGET_64_BIG
1818 template
1819 void
1820 Sized_relobj_file<64, true>::do_relocate_sections(
1821     const Symbol_table* symtab,
1822     const Layout* layout,
1823     const unsigned char* pshdrs,
1824     Output_file* of,
1825     Views* pviews);
1826
1827 template
1828 void
1829 Sized_relobj_file<64, true>::relocate_section_range(
1830     const Symbol_table* symtab,
1831     const Layout* layout,
1832     const unsigned char* pshdrs,
1833     Output_file* of,
1834     Views* pviews,
1835     unsigned int start_shndx,
1836     unsigned int end_shndx);
1837
1838 template
1839 unsigned char*
1840 Sized_relobj_file<64, true>::do_get_output_view(
1841     unsigned int shndx,
1842     section_size_type* plen) const;
1843 #endif
1844
1845 #ifdef HAVE_TARGET_32_LITTLE
1846 template
1847 void
1848 Sized_relobj_file<32, false>::initialize_input_to_output_maps();
1849
1850 template
1851 void
1852 Sized_relobj_file<32, false>::free_input_to_output_maps();
1853 #endif
1854
1855 #ifdef HAVE_TARGET_32_BIG
1856 template
1857 void
1858 Sized_relobj_file<32, true>::initialize_input_to_output_maps();
1859
1860 template
1861 void
1862 Sized_relobj_file<32, true>::free_input_to_output_maps();
1863 #endif
1864
1865 #ifdef HAVE_TARGET_64_LITTLE
1866 template
1867 void
1868 Sized_relobj_file<64, false>::initialize_input_to_output_maps();
1869
1870 template
1871 void
1872 Sized_relobj_file<64, false>::free_input_to_output_maps();
1873 #endif
1874
1875 #ifdef HAVE_TARGET_64_BIG
1876 template
1877 void
1878 Sized_relobj_file<64, true>::initialize_input_to_output_maps();
1879
1880 template
1881 void
1882 Sized_relobj_file<64, true>::free_input_to_output_maps();
1883 #endif
1884
1885 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1886 template
1887 class Merged_symbol_value<32>;
1888 #endif
1889
1890 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1891 template
1892 class Merged_symbol_value<64>;
1893 #endif
1894
1895 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1896 template
1897 class Symbol_value<32>;
1898 #endif
1899
1900 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1901 template
1902 class Symbol_value<64>;
1903 #endif
1904
1905 #ifdef HAVE_TARGET_32_LITTLE
1906 template
1907 class Track_relocs<32, false>;
1908 #endif
1909
1910 #ifdef HAVE_TARGET_32_BIG
1911 template
1912 class Track_relocs<32, true>;
1913 #endif
1914
1915 #ifdef HAVE_TARGET_64_LITTLE
1916 template
1917 class Track_relocs<64, false>;
1918 #endif
1919
1920 #ifdef HAVE_TARGET_64_BIG
1921 template
1922 class Track_relocs<64, true>;
1923 #endif
1924
1925 } // End namespace gold.