contrib/binutils-2.22/gold/reloc.cc

   1 // reloc.cc -- relocate input files for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <algorithm>
  26
  27 #include "workqueue.h"
  28 #include "layout.h"
  29 #include "symtab.h"
  30 #include "output.h"
  31 #include "merge.h"
  32 #include "object.h"
  33 #include "target-reloc.h"
  34 #include "reloc.h"
  35 #include "icf.h"
  36 #include "compressed_output.h"
  37 #include "incremental.h"
  38
  39 namespace gold
  40 {
  41
  42 // Read_relocs methods.
  43
  44 // These tasks just read the relocation information from the file.
  45 // After reading it, the start another task to process the
  46 // information.  These tasks requires access to the file.
  47
  48 Task_token*
  49 Read_relocs::is_runnable()
  50 {
  51   return this->object_->is_locked() ? this->object_->token() : NULL;
  52 }
  53
  54 // Lock the file.
  55
  56 void
  57 Read_relocs::locks(Task_locker* tl)
  58 {
  59   Task_token* token = this->object_->token();
  60   if (token != NULL)
  61     tl->add(this, token);
  62 }
  63
  64 // Read the relocations and then start a Scan_relocs_task.
  65
  66 void
  67 Read_relocs::run(Workqueue* workqueue)
  68 {
  69   Read_relocs_data* rd = new Read_relocs_data;
  70   this->object_->read_relocs(rd);
  71   this->object_->set_relocs_data(rd);
  72   this->object_->release();
  73
  74   // If garbage collection or identical comdat folding is desired, we
  75   // process the relocs first before scanning them.  Scanning of relocs is
  76   // done only after garbage or identical sections is identified.
  77   if (parameters->options().gc_sections()
  78       || parameters->options().icf_enabled())
  79     {
  80       workqueue->queue_next(new Gc_process_relocs(this->symtab_,
  81                                                   this->layout_,
  82                                                   this->object_, rd,
  83                                                   this->this_blocker_,
  84                                                   this->next_blocker_));
  85     }
  86   else
  87     {
  88       workqueue->queue_next(new Scan_relocs(this->symtab_, this->layout_,
  89                                             this->object_, rd,
  90                                             this->this_blocker_,
  91                                             this->next_blocker_));
  92     }
  93 }
  94
  95 // Return a debugging name for the task.
  96
  97 std::string
  98 Read_relocs::get_name() const
  99 {
 100   return "Read_relocs " + this->object_->name();
 101 }
 102
 103 // Gc_process_relocs methods.
 104
 105 Gc_process_relocs::~Gc_process_relocs()
 106 {
 107   if (this->this_blocker_ != NULL)
 108     delete this->this_blocker_;
 109 }
 110
 111 // These tasks process the relocations read by Read_relocs and
 112 // determine which sections are referenced and which are garbage.
 113 // This task is done only when --gc-sections is used.  This is blocked
 114 // by THIS_BLOCKER_.  It unblocks NEXT_BLOCKER_.
 115
 116 Task_token*
 117 Gc_process_relocs::is_runnable()
 118 {
 119   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 120     return this->this_blocker_;
 121   if (this->object_->is_locked())
 122     return this->object_->token();
 123   return NULL;
 124 }
 125
 126 void
 127 Gc_process_relocs::locks(Task_locker* tl)
 128 {
 129   tl->add(this, this->object_->token());
 130   tl->add(this, this->next_blocker_);
 131 }
 132
 133 void
 134 Gc_process_relocs::run(Workqueue*)
 135 {
 136   this->object_->gc_process_relocs(this->symtab_, this->layout_, this->rd_);
 137   this->object_->release();
 138 }
 139
 140 // Return a debugging name for the task.
 141
 142 std::string
 143 Gc_process_relocs::get_name() const
 144 {
 145   return "Gc_process_relocs " + this->object_->name();
 146 }
 147
 148 // Scan_relocs methods.
 149
 150 Scan_relocs::~Scan_relocs()
 151 {
 152   if (this->this_blocker_ != NULL)
 153     delete this->this_blocker_;
 154 }
 155
 156 // These tasks scan the relocations read by Read_relocs and mark up
 157 // the symbol table to indicate which relocations are required.  We
 158 // use a lock on the symbol table to keep them from interfering with
 159 // each other.
 160
 161 Task_token*
 162 Scan_relocs::is_runnable()
 163 {
 164   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 165     return this->this_blocker_;
 166   if (this->object_->is_locked())
 167     return this->object_->token();
 168   return NULL;
 169 }
 170
 171 // Return the locks we hold: one on the file, one on the symbol table
 172 // and one blocker.
 173
 174 void
 175 Scan_relocs::locks(Task_locker* tl)
 176 {
 177   Task_token* token = this->object_->token();
 178   if (token != NULL)
 179     tl->add(this, token);
 180   tl->add(this, this->next_blocker_);
 181 }
 182
 183 // Scan the relocs.
 184
 185 void
 186 Scan_relocs::run(Workqueue*)
 187 {
 188   this->object_->scan_relocs(this->symtab_, this->layout_, this->rd_);
 189   delete this->rd_;
 190   this->rd_ = NULL;
 191   this->object_->release();
 192 }
 193
 194 // Return a debugging name for the task.
 195
 196 std::string
 197 Scan_relocs::get_name() const
 198 {
 199   return "Scan_relocs " + this->object_->name();
 200 }
 201
 202 // Relocate_task methods.
 203
 204 // We may have to wait for the output sections to be written.
 205
 206 Task_token*
 207 Relocate_task::is_runnable()
 208 {
 209   if (this->object_->relocs_must_follow_section_writes()
 210       && this->output_sections_blocker_->is_blocked())
 211     return this->output_sections_blocker_;
 212
 213   if (this->object_->is_locked())
 214     return this->object_->token();
 215
 216   return NULL;
 217 }
 218
 219 // We want to lock the file while we run.  We want to unblock
 220 // INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done.
 221 // INPUT_SECTIONS_BLOCKER may be NULL.
 222
 223 void
 224 Relocate_task::locks(Task_locker* tl)
 225 {
 226   if (this->input_sections_blocker_ != NULL)
 227     tl->add(this, this->input_sections_blocker_);
 228   tl->add(this, this->final_blocker_);
 229   Task_token* token = this->object_->token();
 230   if (token != NULL)
 231     tl->add(this, token);
 232 }
 233
 234 // Run the task.
 235
 236 void
 237 Relocate_task::run(Workqueue*)
 238 {
 239   this->object_->relocate(this->symtab_, this->layout_, this->of_);
 240
 241   // This is normally the last thing we will do with an object, so
 242   // uncache all views.
 243   this->object_->clear_view_cache_marks();
 244
 245   this->object_->release();
 246 }
 247
 248 // Return a debugging name for the task.
 249
 250 std::string
 251 Relocate_task::get_name() const
 252 {
 253   return "Relocate_task " + this->object_->name();
 254 }
 255
 256 // Read the relocs and local symbols from the object file and store
 257 // the information in RD.
 258
 259 template<int size, bool big_endian>
 260 void
 261 Sized_relobj_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 // This is a strategy class we use when scanning for --emit-relocs.
 505
 506 template<int sh_type>
 507 class Emit_relocs_strategy
 508 {
 509  public:
 510   // A local non-section symbol.
 511   inline Relocatable_relocs::Reloc_strategy
 512   local_non_section_strategy(unsigned int, Relobj*, unsigned int)
 513   { return Relocatable_relocs::RELOC_COPY; }
 514
 515   // A local section symbol.
 516   inline Relocatable_relocs::Reloc_strategy
 517   local_section_strategy(unsigned int, Relobj*)
 518   {
 519     if (sh_type == elfcpp::SHT_RELA)
 520       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
 521     else
 522       {
 523         // The addend is stored in the section contents.  Since this
 524         // is not a relocatable link, we are going to apply the
 525         // relocation contents to the section as usual.  This means
 526         // that we have no way to record the original addend.  If the
 527         // original addend is not zero, there is basically no way for
 528         // the user to handle this correctly.  Caveat emptor.
 529         return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
 530       }
 531   }
 532
 533   // A global symbol.
 534   inline Relocatable_relocs::Reloc_strategy
 535   global_strategy(unsigned int, Relobj*, unsigned int)
 536   { return Relocatable_relocs::RELOC_COPY; }
 537 };
 538
 539 // Scan the input relocations for --emit-relocs.
 540
 541 template<int size, bool big_endian>
 542 void
 543 Sized_relobj_file<size, big_endian>::emit_relocs_scan(
 544     Symbol_table* symtab,
 545     Layout* layout,
 546     const unsigned char* plocal_syms,
 547     const Read_relocs_data::Relocs_list::iterator& p)
 548 {
 549   Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
 550   gold_assert(rr != NULL);
 551   rr->set_reloc_count(p->reloc_count);
 552
 553   if (p->sh_type == elfcpp::SHT_REL)
 554     this->emit_relocs_scan_reltype<elfcpp::SHT_REL>(symtab, layout,
 555                                                     plocal_syms, p, rr);
 556   else
 557     {
 558       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 559       this->emit_relocs_scan_reltype<elfcpp::SHT_RELA>(symtab, layout,
 560                                                        plocal_syms, p, rr);
 561     }
 562 }
 563
 564 // Scan the input relocation for --emit-relocs, templatized on the
 565 // type of the relocation section.
 566
 567 template<int size, bool big_endian>
 568 template<int sh_type>
 569 void
 570 Sized_relobj_file<size, big_endian>::emit_relocs_scan_reltype(
 571     Symbol_table* symtab,
 572     Layout* layout,
 573     const unsigned char* plocal_syms,
 574     const Read_relocs_data::Relocs_list::iterator& p,
 575     Relocatable_relocs* rr)
 576 {
 577   scan_relocatable_relocs<size, big_endian, sh_type,
 578                           Emit_relocs_strategy<sh_type> >(
 579     symtab,
 580     layout,
 581     this,
 582     p->data_shndx,
 583     p->contents->data(),
 584     p->reloc_count,
 585     p->output_section,
 586     p->needs_special_offset_handling,
 587     this->local_symbol_count_,
 588     plocal_syms,
 589     rr);
 590 }
 591
 592 // Scan the input relocations for --incremental.
 593
 594 template<int size, bool big_endian>
 595 void
 596 Sized_relobj_file<size, big_endian>::incremental_relocs_scan(
 597     const Read_relocs_data::Relocs_list::iterator& p)
 598 {
 599   if (p->sh_type == elfcpp::SHT_REL)
 600     this->incremental_relocs_scan_reltype<elfcpp::SHT_REL>(p);
 601   else
 602     {
 603       gold_assert(p->sh_type == elfcpp::SHT_RELA);
 604       this->incremental_relocs_scan_reltype<elfcpp::SHT_RELA>(p);
 605     }
 606 }
 607
 608 // Scan the input relocation for --incremental, templatized on the
 609 // type of the relocation section.
 610
 611 template<int size, bool big_endian>
 612 template<int sh_type>
 613 void
 614 Sized_relobj_file<size, big_endian>::incremental_relocs_scan_reltype(
 615     const Read_relocs_data::Relocs_list::iterator& p)
 616 {
 617   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
 618   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
 619   const unsigned char* prelocs = p->contents->data();
 620   size_t reloc_count = p->reloc_count;
 621
 622   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
 623     {
 624       Reltype reloc(prelocs);
 625
 626       if (p->needs_special_offset_handling
 627           && !p->output_section->is_input_address_mapped(this, p->data_shndx,
 628                                                          reloc.get_r_offset()))
 629         continue;
 630
 631       typename elfcpp::Elf_types<size>::Elf_WXword r_info =
 632           reloc.get_r_info();
 633       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
 634
 635       if (r_sym >= this->local_symbol_count_)
 636         this->count_incremental_reloc(r_sym - this->local_symbol_count_);
 637     }
 638 }
 639
 640 // Relocate the input sections and write out the local symbols.
 641
 642 template<int size, bool big_endian>
 643 void
 644 Sized_relobj_file<size, big_endian>::do_relocate(const Symbol_table* symtab,
 645                                                  const Layout* layout,
 646                                                  Output_file* of)
 647 {
 648   unsigned int shnum = this->shnum();
 649
 650   // Read the section headers.
 651   const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
 652                                                shnum * This::shdr_size,
 653                                                true, true);
 654
 655   Views views;
 656   views.resize(shnum);
 657
 658   // Make two passes over the sections.  The first one copies the
 659   // section data to the output file.  The second one applies
 660   // relocations.
 661
 662   this->write_sections(layout, pshdrs, of, &views);
 663
 664   // To speed up relocations, we set up hash tables for fast lookup of
 665   // input offsets to output addresses.
 666   this->initialize_input_to_output_maps();
 667
 668   // Apply relocations.
 669
 670   this->relocate_sections(symtab, layout, pshdrs, of, &views);
 671
 672   // After we've done the relocations, we release the hash tables,
 673   // since we no longer need them.
 674   this->free_input_to_output_maps();
 675
 676   // Write out the accumulated views.
 677   for (unsigned int i = 1; i < shnum; ++i)
 678     {
 679       if (views[i].view != NULL)
 680         {
 681           if (views[i].is_ctors_reverse_view)
 682             this->reverse_words(views[i].view, views[i].view_size);
 683           if (!views[i].is_postprocessing_view)
 684             {
 685               if (views[i].is_input_output_view)
 686                 of->write_input_output_view(views[i].offset,
 687                                             views[i].view_size,
 688                                             views[i].view);
 689               else
 690                 of->write_output_view(views[i].offset, views[i].view_size,
 691                                       views[i].view);
 692             }
 693         }
 694     }
 695
 696   // Write out the local symbols.
 697   this->write_local_symbols(of, layout->sympool(), layout->dynpool(),
 698                             layout->symtab_xindex(), layout->dynsym_xindex(),
 699                             layout->symtab_section_offset());
 700 }
 701
 702 // Sort a Read_multiple vector by file offset.
 703 struct Read_multiple_compare
 704 {
 705   inline bool
 706   operator()(const File_read::Read_multiple_entry& rme1,
 707              const File_read::Read_multiple_entry& rme2) const
 708   { return rme1.file_offset < rme2.file_offset; }
 709 };
 710
 711 // Write section data to the output file.  PSHDRS points to the
 712 // section headers.  Record the views in *PVIEWS for use when
 713 // relocating.
 714
 715 template<int size, bool big_endian>
 716 void
 717 Sized_relobj_file<size, big_endian>::write_sections(const Layout* layout,
 718                                                     const unsigned char* pshdrs,
 719                                                     Output_file* of,
 720                                                     Views* pviews)
 721 {
 722   unsigned int shnum = this->shnum();
 723   const Output_sections& out_sections(this->output_sections());
 724   const std::vector<Address>& out_offsets(this->section_offsets());
 725
 726   File_read::Read_multiple rm;
 727   bool is_sorted = true;
 728
 729   const unsigned char* p = pshdrs + This::shdr_size;
 730   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 731     {
 732       View_size* pvs = &(*pviews)[i];
 733
 734       pvs->view = NULL;
 735
 736       const Output_section* os = out_sections[i];
 737       if (os == NULL)
 738         continue;
 739       Address output_offset = out_offsets[i];
 740
 741       typename This::Shdr shdr(p);
 742
 743       if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
 744         continue;
 745
 746       if ((parameters->options().relocatable()
 747            || parameters->options().emit_relocs())
 748           && (shdr.get_sh_type() == elfcpp::SHT_REL
 749               || shdr.get_sh_type() == elfcpp::SHT_RELA)
 750           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
 751         {
 752           // This is a reloc section in a relocatable link or when
 753           // emitting relocs.  We don't need to read the input file.
 754           // The size and file offset are stored in the
 755           // Relocatable_relocs structure.
 756           Relocatable_relocs* rr = this->relocatable_relocs(i);
 757           gold_assert(rr != NULL);
 758           Output_data* posd = rr->output_data();
 759           gold_assert(posd != NULL);
 760
 761           pvs->offset = posd->offset();
 762           pvs->view_size = posd->data_size();
 763           pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
 764           pvs->address = posd->address();
 765           pvs->is_input_output_view = false;
 766           pvs->is_postprocessing_view = false;
 767           pvs->is_ctors_reverse_view = false;
 768
 769           continue;
 770         }
 771
 772       // In the normal case, this input section is simply mapped to
 773       // the output section at offset OUTPUT_OFFSET.
 774
 775       // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is
 776       // handled specially--e.g., a .eh_frame section.  The relocation
 777       // routines need to check for each reloc where it should be
 778       // applied.  For this case, we need an input/output view for the
 779       // entire contents of the section in the output file.  We don't
 780       // want to copy the contents of the input section to the output
 781       // section; the output section contents were already written,
 782       // and we waited for them in Relocate_task::is_runnable because
 783       // relocs_must_follow_section_writes is set for the object.
 784
 785       // Regardless of which of the above cases is true, we have to
 786       // check requires_postprocessing of the output section.  If that
 787       // is false, then we work with views of the output file
 788       // directly.  If it is true, then we work with a separate
 789       // buffer, and the output section is responsible for writing the
 790       // final data to the output file.
 791
 792       off_t output_section_offset;
 793       Address output_section_size;
 794       if (!os->requires_postprocessing())
 795         {
 796           output_section_offset = os->offset();
 797           output_section_size = convert_types<Address, off_t>(os->data_size());
 798         }
 799       else
 800         {
 801           output_section_offset = 0;
 802           output_section_size =
 803               convert_types<Address, off_t>(os->postprocessing_buffer_size());
 804         }
 805
 806       off_t view_start;
 807       section_size_type view_size;
 808       bool must_decompress = false;
 809       if (output_offset != invalid_address)
 810         {
 811           view_start = output_section_offset + output_offset;
 812           view_size = convert_to_section_size_type(shdr.get_sh_size());
 813           section_size_type uncompressed_size;
 814           if (this->section_is_compressed(i, &uncompressed_size))
 815             {
 816               view_size = uncompressed_size;
 817               must_decompress = true;
 818             }
 819         }
 820       else
 821         {
 822           view_start = output_section_offset;
 823           view_size = convert_to_section_size_type(output_section_size);
 824         }
 825
 826       if (view_size == 0)
 827         continue;
 828
 829       gold_assert(output_offset == invalid_address
 830                   || output_offset + view_size <= output_section_size);
 831
 832       unsigned char* view;
 833       if (os->requires_postprocessing())
 834         {
 835           unsigned char* buffer = os->postprocessing_buffer();
 836           view = buffer + view_start;
 837           if (output_offset != invalid_address && !must_decompress)
 838             {
 839               off_t sh_offset = shdr.get_sh_offset();
 840               if (!rm.empty() && rm.back().file_offset > sh_offset)
 841                 is_sorted = false;
 842               rm.push_back(File_read::Read_multiple_entry(sh_offset,
 843                                                           view_size, view));
 844             }
 845         }
 846       else
 847         {
 848           if (output_offset == invalid_address)
 849             view = of->get_input_output_view(view_start, view_size);
 850           else
 851             {
 852               view = of->get_output_view(view_start, view_size);
 853               if (!must_decompress)
 854                 {
 855                   off_t sh_offset = shdr.get_sh_offset();
 856                   if (!rm.empty() && rm.back().file_offset > sh_offset)
 857                     is_sorted = false;
 858                   rm.push_back(File_read::Read_multiple_entry(sh_offset,
 859                                                               view_size, view));
 860                 }
 861             }
 862         }
 863
 864       if (must_decompress)
 865         {
 866           // Read and decompress the section.
 867           section_size_type len;
 868           const unsigned char* p = this->section_contents(i, &len, false);
 869           if (!decompress_input_section(p, len, view, view_size))
 870             this->error(_("could not decompress section %s"),
 871                         this->section_name(i).c_str());
 872         }
 873
 874       pvs->view = view;
 875       pvs->address = os->address();
 876       if (output_offset != invalid_address)
 877         pvs->address += output_offset;
 878       pvs->offset = view_start;
 879       pvs->view_size = view_size;
 880       pvs->is_input_output_view = output_offset == invalid_address;
 881       pvs->is_postprocessing_view = os->requires_postprocessing();
 882       pvs->is_ctors_reverse_view =
 883         (!parameters->options().relocatable()
 884          && view_size > size / 8
 885          && (strcmp(os->name(), ".init_array") == 0
 886              || strcmp(os->name(), ".fini_array") == 0)
 887          && layout->is_ctors_in_init_array(this, i));
 888     }
 889
 890   // Actually read the data.
 891   if (!rm.empty())
 892     {
 893       if (!is_sorted)
 894         std::sort(rm.begin(), rm.end(), Read_multiple_compare());
 895       this->read_multiple(rm);
 896     }
 897 }
 898
 899 // Relocate section data.  VIEWS points to the section data as views
 900 // in the output file.
 901
 902 template<int size, bool big_endian>
 903 void
 904 Sized_relobj_file<size, big_endian>::do_relocate_sections(
 905     const Symbol_table* symtab,
 906     const Layout* layout,
 907     const unsigned char* pshdrs,
 908     Output_file* of,
 909     Views* pviews)
 910 {
 911   unsigned int shnum = this->shnum();
 912   Sized_target<size, big_endian>* target =
 913     parameters->sized_target<size, big_endian>();
 914
 915   const Output_sections& out_sections(this->output_sections());
 916   const std::vector<Address>& out_offsets(this->section_offsets());
 917
 918   Relocate_info<size, big_endian> relinfo;
 919   relinfo.symtab = symtab;
 920   relinfo.layout = layout;
 921   relinfo.object = this;
 922
 923   const unsigned char* p = pshdrs + This::shdr_size;
 924   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 925     {
 926       typename This::Shdr shdr(p);
 927
 928       unsigned int sh_type = shdr.get_sh_type();
 929       if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
 930         continue;
 931
 932       off_t sh_size = shdr.get_sh_size();
 933       if (sh_size == 0)
 934         continue;
 935
 936       unsigned int index = this->adjust_shndx(shdr.get_sh_info());
 937       if (index >= this->shnum())
 938         {
 939           this->error(_("relocation section %u has bad info %u"),
 940                       i, index);
 941           continue;
 942         }
 943
 944       Output_section* os = out_sections[index];
 945       if (os == NULL)
 946         {
 947           // This relocation section is against a section which we
 948           // discarded.
 949           continue;
 950         }
 951       Address output_offset = out_offsets[index];
 952
 953       gold_assert((*pviews)[index].view != NULL);
 954       if (parameters->options().relocatable())
 955         gold_assert((*pviews)[i].view != NULL);
 956
 957       if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
 958         {
 959           gold_error(_("relocation section %u uses unexpected "
 960                        "symbol table %u"),
 961                      i, this->adjust_shndx(shdr.get_sh_link()));
 962           continue;
 963         }
 964
 965       const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
 966                                                     sh_size, true, false);
 967
 968       unsigned int reloc_size;
 969       if (sh_type == elfcpp::SHT_REL)
 970         reloc_size = elfcpp::Elf_sizes<size>::rel_size;
 971       else
 972         reloc_size = elfcpp::Elf_sizes<size>::rela_size;
 973
 974       if (reloc_size != shdr.get_sh_entsize())
 975         {
 976           gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
 977                      i, static_cast<unsigned long>(shdr.get_sh_entsize()),
 978                      reloc_size);
 979           continue;
 980         }
 981
 982       size_t reloc_count = sh_size / reloc_size;
 983       if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
 984         {
 985           gold_error(_("reloc section %u size %lu uneven"),
 986                      i, static_cast<unsigned long>(sh_size));
 987           continue;
 988         }
 989
 990       gold_assert(output_offset != invalid_address
 991                   || this->relocs_must_follow_section_writes());
 992
 993       relinfo.reloc_shndx = i;
 994       relinfo.reloc_shdr = p;
 995       relinfo.data_shndx = index;
 996       relinfo.data_shdr = pshdrs + index * This::shdr_size;
 997       unsigned char* view = (*pviews)[index].view;
 998       Address address = (*pviews)[index].address;
 999       section_size_type view_size = (*pviews)[index].view_size;
1000
1001       Reloc_symbol_changes* reloc_map = NULL;
1002       if (this->uses_split_stack() && output_offset != invalid_address)
1003         {
1004           typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
1005           if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
1006             this->split_stack_adjust(symtab, pshdrs, sh_type, index,
1007                                      prelocs, reloc_count, view, view_size,
1008                                      &reloc_map);
1009         }
1010
1011       if (!parameters->options().relocatable())
1012         {
1013           target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
1014                                    output_offset == invalid_address,
1015                                    view, address, view_size, reloc_map);
1016           if (parameters->options().emit_relocs())
1017             this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count,
1018                               os, output_offset, view, address, view_size,
1019                               (*pviews)[i].view, (*pviews)[i].view_size);
1020           if (parameters->incremental())
1021             this->incremental_relocs_write(&relinfo, sh_type, prelocs,
1022                                            reloc_count, os, output_offset, of);
1023         }
1024       else
1025         {
1026           Relocatable_relocs* rr = this->relocatable_relocs(i);
1027           target->relocate_for_relocatable(&relinfo, sh_type, prelocs,
1028                                            reloc_count, os, output_offset, rr,
1029                                            view, address, view_size,
1030                                            (*pviews)[i].view,
1031                                            (*pviews)[i].view_size);
1032         }
1033     }
1034 }
1035
1036 // Emit the relocs for --emit-relocs.
1037
1038 template<int size, bool big_endian>
1039 void
1040 Sized_relobj_file<size, big_endian>::emit_relocs(
1041     const Relocate_info<size, big_endian>* relinfo,
1042     unsigned int i,
1043     unsigned int sh_type,
1044     const unsigned char* prelocs,
1045     size_t reloc_count,
1046     Output_section* output_section,
1047     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
1048     unsigned char* view,
1049     typename elfcpp::Elf_types<size>::Elf_Addr address,
1050     section_size_type view_size,
1051     unsigned char* reloc_view,
1052     section_size_type reloc_view_size)
1053 {
1054   if (sh_type == elfcpp::SHT_REL)
1055     this->emit_relocs_reltype<elfcpp::SHT_REL>(relinfo, i, prelocs,
1056                                                reloc_count, output_section,
1057                                                offset_in_output_section,
1058                                                view, address, view_size,
1059                                                reloc_view, reloc_view_size);
1060   else
1061     {
1062       gold_assert(sh_type == elfcpp::SHT_RELA);
1063       this->emit_relocs_reltype<elfcpp::SHT_RELA>(relinfo, i, prelocs,
1064                                                   reloc_count, output_section,
1065                                                   offset_in_output_section,
1066                                                   view, address, view_size,
1067                                                   reloc_view, reloc_view_size);
1068     }
1069 }
1070
1071 // Emit the relocs for --emit-relocs, templatized on the type of the
1072 // relocation section.
1073
1074 template<int size, bool big_endian>
1075 template<int sh_type>
1076 void
1077 Sized_relobj_file<size, big_endian>::emit_relocs_reltype(
1078     const Relocate_info<size, big_endian>* relinfo,
1079     unsigned int i,
1080     const unsigned char* prelocs,
1081     size_t reloc_count,
1082     Output_section* output_section,
1083     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
1084     unsigned char* view,
1085     typename elfcpp::Elf_types<size>::Elf_Addr address,
1086     section_size_type view_size,
1087     unsigned char* reloc_view,
1088     section_size_type reloc_view_size)
1089 {
1090   const Relocatable_relocs* rr = this->relocatable_relocs(i);
1091   relocate_for_relocatable<size, big_endian, sh_type>(
1092     relinfo,
1093     prelocs,
1094     reloc_count,
1095     output_section,
1096     offset_in_output_section,
1097     rr,
1098     view,
1099     address,
1100     view_size,
1101     reloc_view,
1102     reloc_view_size);
1103 }
1104
1105 // Write the incremental relocs.
1106
1107 template<int size, bool big_endian>
1108 void
1109 Sized_relobj_file<size, big_endian>::incremental_relocs_write(
1110     const Relocate_info<size, big_endian>* relinfo,
1111     unsigned int sh_type,
1112     const unsigned char* prelocs,
1113     size_t reloc_count,
1114     Output_section* output_section,
1115     Address output_offset,
1116     Output_file* of)
1117 {
1118   if (sh_type == elfcpp::SHT_REL)
1119     this->incremental_relocs_write_reltype<elfcpp::SHT_REL>(
1120         relinfo,
1121         prelocs,
1122         reloc_count,
1123         output_section,
1124         output_offset,
1125         of);
1126   else
1127     {
1128       gold_assert(sh_type == elfcpp::SHT_RELA);
1129       this->incremental_relocs_write_reltype<elfcpp::SHT_RELA>(
1130           relinfo,
1131           prelocs,
1132           reloc_count,
1133           output_section,
1134           output_offset,
1135           of);
1136     }
1137 }
1138
1139 // Write the incremental relocs, templatized on the type of the
1140 // relocation section.
1141
1142 template<int size, bool big_endian>
1143 template<int sh_type>
1144 void
1145 Sized_relobj_file<size, big_endian>::incremental_relocs_write_reltype(
1146     const Relocate_info<size, big_endian>* relinfo,
1147     const unsigned char* prelocs,
1148     size_t reloc_count,
1149     Output_section* output_section,
1150     Address output_offset,
1151     Output_file* of)
1152 {
1153   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reloc;
1154   const unsigned int reloc_size =
1155       Reloc_types<sh_type, size, big_endian>::reloc_size;
1156   const unsigned int sizeof_addr = size / 8;
1157   const unsigned int incr_reloc_size =
1158       Incremental_relocs_reader<size, big_endian>::reloc_size;
1159
1160   unsigned int out_shndx = output_section->out_shndx();
1161
1162   // Get a view for the .gnu_incremental_relocs section.
1163
1164   Incremental_inputs* inputs = relinfo->layout->incremental_inputs();
1165   gold_assert(inputs != NULL);
1166   const off_t relocs_off = inputs->relocs_section()->offset();
1167   const off_t relocs_size = inputs->relocs_section()->data_size();
1168   unsigned char* const view = of->get_output_view(relocs_off, relocs_size);
1169
1170   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
1171     {
1172       Reloc reloc(prelocs);
1173
1174       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1175       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1176       const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
1177
1178       if (r_sym < this->local_symbol_count_)
1179         continue;
1180
1181       // Get the new offset--the location in the output section where
1182       // this relocation should be applied.
1183
1184       Address offset = reloc.get_r_offset();
1185       if (output_offset != invalid_address)
1186         offset += output_offset;
1187       else
1188         {
1189           section_offset_type sot_offset =
1190               convert_types<section_offset_type, Address>(offset);
1191           section_offset_type new_sot_offset =
1192               output_section->output_offset(relinfo->object,
1193                                             relinfo->data_shndx,
1194                                             sot_offset);
1195           gold_assert(new_sot_offset != -1);
1196           offset += new_sot_offset;
1197         }
1198
1199       // Get the addend.
1200       typename elfcpp::Elf_types<size>::Elf_Swxword addend;
1201       if (sh_type == elfcpp::SHT_RELA)
1202         addend =
1203             Reloc_types<sh_type, size, big_endian>::get_reloc_addend(&reloc);
1204       else
1205         {
1206           // FIXME: Get the addend for SHT_REL.
1207           addend = 0;
1208         }
1209
1210       // Get the index of the output relocation.
1211
1212       unsigned int reloc_index =
1213           this->next_incremental_reloc_index(r_sym - this->local_symbol_count_);
1214
1215       // Write the relocation.
1216
1217       unsigned char* pov = view + reloc_index * incr_reloc_size;
1218       elfcpp::Swap<32, big_endian>::writeval(pov, r_type);
1219       elfcpp::Swap<32, big_endian>::writeval(pov + 4, out_shndx);
1220       elfcpp::Swap<size, big_endian>::writeval(pov + 8, offset);
1221       elfcpp::Swap<size, big_endian>::writeval(pov + 8 + sizeof_addr, addend);
1222       of->write_output_view(pov - view, incr_reloc_size, view);
1223     }
1224 }
1225
1226 // Create merge hash tables for the local symbols.  These are used to
1227 // speed up relocations.
1228
1229 template<int size, bool big_endian>
1230 void
1231 Sized_relobj_file<size, big_endian>::initialize_input_to_output_maps()
1232 {
1233   const unsigned int loccount = this->local_symbol_count_;
1234   for (unsigned int i = 1; i < loccount; ++i)
1235     {
1236       Symbol_value<size>& lv(this->local_values_[i]);
1237       lv.initialize_input_to_output_map(this);
1238     }
1239 }
1240
1241 // Free merge hash tables for the local symbols.
1242
1243 template<int size, bool big_endian>
1244 void
1245 Sized_relobj_file<size, big_endian>::free_input_to_output_maps()
1246 {
1247   const unsigned int loccount = this->local_symbol_count_;
1248   for (unsigned int i = 1; i < loccount; ++i)
1249     {
1250       Symbol_value<size>& lv(this->local_values_[i]);
1251       lv.free_input_to_output_map();
1252     }
1253 }
1254
1255 // If an object was compiled with -fsplit-stack, this is called to
1256 // check whether any relocations refer to functions defined in objects
1257 // which were not compiled with -fsplit-stack.  If they were, then we
1258 // need to apply some target-specific adjustments to request
1259 // additional stack space.
1260
1261 template<int size, bool big_endian>
1262 void
1263 Sized_relobj_file<size, big_endian>::split_stack_adjust(
1264     const Symbol_table* symtab,
1265     const unsigned char* pshdrs,
1266     unsigned int sh_type,
1267     unsigned int shndx,
1268     const unsigned char* prelocs,
1269     size_t reloc_count,
1270     unsigned char* view,
1271     section_size_type view_size,
1272     Reloc_symbol_changes** reloc_map)
1273 {
1274   if (sh_type == elfcpp::SHT_REL)
1275     this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
1276                                                       prelocs, reloc_count,
1277                                                       view, view_size,
1278                                                       reloc_map);
1279   else
1280     {
1281       gold_assert(sh_type == elfcpp::SHT_RELA);
1282       this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
1283                                                          prelocs, reloc_count,
1284                                                          view, view_size,
1285                                                          reloc_map);
1286     }
1287 }
1288
1289 // Adjust for -fsplit-stack, templatized on the type of the relocation
1290 // section.
1291
1292 template<int size, bool big_endian>
1293 template<int sh_type>
1294 void
1295 Sized_relobj_file<size, big_endian>::split_stack_adjust_reltype(
1296     const Symbol_table* symtab,
1297     const unsigned char* pshdrs,
1298     unsigned int shndx,
1299     const unsigned char* prelocs,
1300     size_t reloc_count,
1301     unsigned char* view,
1302     section_size_type view_size,
1303     Reloc_symbol_changes** reloc_map)
1304 {
1305   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
1306   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
1307
1308   size_t local_count = this->local_symbol_count();
1309
1310   std::vector<section_offset_type> non_split_refs;
1311
1312   const unsigned char* pr = prelocs;
1313   for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1314     {
1315       Reltype reloc(pr);
1316
1317       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1318       unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1319       if (r_sym < local_count)
1320         continue;
1321
1322       const Symbol* gsym = this->global_symbol(r_sym);
1323       gold_assert(gsym != NULL);
1324       if (gsym->is_forwarder())
1325         gsym = symtab->resolve_forwards(gsym);
1326
1327       // See if this relocation refers to a function defined in an
1328       // object compiled without -fsplit-stack.  Note that we don't
1329       // care about the type of relocation--this means that in some
1330       // cases we will ask for a large stack unnecessarily, but this
1331       // is not fatal.  FIXME: Some targets have symbols which are
1332       // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
1333       if (!gsym->is_undefined()
1334           && gsym->source() == Symbol::FROM_OBJECT
1335           && !gsym->object()->uses_split_stack())
1336         {
1337           unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
1338           if (parameters->target().is_call_to_non_split(gsym, r_type))
1339             {
1340               section_offset_type offset =
1341                 convert_to_section_size_type(reloc.get_r_offset());
1342               non_split_refs.push_back(offset);
1343             }
1344         }
1345     }
1346
1347   if (non_split_refs.empty())
1348     return;
1349
1350   // At this point, every entry in NON_SPLIT_REFS indicates a
1351   // relocation which refers to a function in an object compiled
1352   // without -fsplit-stack.  We now have to convert that list into a
1353   // set of offsets to functions.  First, we find all the functions.
1354
1355   Function_offsets function_offsets;
1356   this->find_functions(pshdrs, shndx, &function_offsets);
1357   if (function_offsets.empty())
1358     return;
1359
1360   // Now get a list of the function with references to non split-stack
1361   // code.
1362
1363   Function_offsets calls_non_split;
1364   for (std::vector<section_offset_type>::const_iterator p
1365          = non_split_refs.begin();
1366        p != non_split_refs.end();
1367        ++p)
1368     {
1369       Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
1370       if (low == function_offsets.end())
1371         --low;
1372       else if (low->first == *p)
1373         ;
1374       else if (low == function_offsets.begin())
1375         continue;
1376       else
1377         --low;
1378
1379       calls_non_split.insert(*low);
1380     }
1381   if (calls_non_split.empty())
1382     return;
1383
1384   // Now we have a set of functions to adjust.  The adjustments are
1385   // target specific.  Besides changing the output section view
1386   // however, it likes, the target may request a relocation change
1387   // from one global symbol name to another.
1388
1389   for (Function_offsets::const_iterator p = calls_non_split.begin();
1390        p != calls_non_split.end();
1391        ++p)
1392     {
1393       std::string from;
1394       std::string to;
1395       parameters->target().calls_non_split(this, shndx, p->first, p->second,
1396                                            view, view_size, &from, &to);
1397       if (!from.empty())
1398         {
1399           gold_assert(!to.empty());
1400           Symbol* tosym = NULL;
1401
1402           // Find relocations in the relevant function which are for
1403           // FROM.
1404           pr = prelocs;
1405           for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1406             {
1407               Reltype reloc(pr);
1408
1409               typename elfcpp::Elf_types<size>::Elf_WXword r_info =
1410                 reloc.get_r_info();
1411               unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1412               if (r_sym < local_count)
1413                 continue;
1414
1415               section_offset_type offset =
1416                 convert_to_section_size_type(reloc.get_r_offset());
1417               if (offset < p->first
1418                   || (offset
1419                       >= (p->first
1420                           + static_cast<section_offset_type>(p->second))))
1421                 continue;
1422
1423               const Symbol* gsym = this->global_symbol(r_sym);
1424               if (from == gsym->name())
1425                 {
1426                   if (tosym == NULL)
1427                     {
1428                       tosym = symtab->lookup(to.c_str());
1429                       if (tosym == NULL)
1430                         {
1431                           this->error(_("could not convert call "
1432                                         "to '%s' to '%s'"),
1433                                       from.c_str(), to.c_str());
1434                           break;
1435                         }
1436                     }
1437
1438                   if (*reloc_map == NULL)
1439                     *reloc_map = new Reloc_symbol_changes(reloc_count);
1440                   (*reloc_map)->set(i, tosym);
1441                 }
1442             }
1443         }
1444     }
1445 }
1446
1447 // Find all the function in this object defined in section SHNDX.
1448 // Store their offsets in the section in FUNCTION_OFFSETS.
1449
1450 template<int size, bool big_endian>
1451 void
1452 Sized_relobj_file<size, big_endian>::find_functions(
1453     const unsigned char* pshdrs,
1454     unsigned int shndx,
1455     Sized_relobj_file<size, big_endian>::Function_offsets* function_offsets)
1456 {
1457   // We need to read the symbols to find the functions.  If we wanted
1458   // to, we could cache reading the symbols across all sections in the
1459   // object.
1460   const unsigned int symtab_shndx = this->symtab_shndx_;
1461   typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size);
1462   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1463
1464   typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
1465     symtabshdr.get_sh_size();
1466   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1467                                               sh_size, true, true);
1468
1469   const int sym_size = This::sym_size;
1470   const unsigned int symcount = sh_size / sym_size;
1471   for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size)
1472     {
1473       typename elfcpp::Sym<size, big_endian> isym(psyms);
1474
1475       // FIXME: Some targets can have functions which do not have type
1476       // STT_FUNC, e.g., STT_ARM_TFUNC.
1477       if (isym.get_st_type() != elfcpp::STT_FUNC
1478           || isym.get_st_size() == 0)
1479         continue;
1480
1481       bool is_ordinary;
1482       unsigned int sym_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1483                                                       &is_ordinary);
1484       if (!is_ordinary || sym_shndx != shndx)
1485         continue;
1486
1487       section_offset_type value =
1488         convert_to_section_size_type(isym.get_st_value());
1489       section_size_type fnsize =
1490         convert_to_section_size_type(isym.get_st_size());
1491
1492       (*function_offsets)[value] = fnsize;
1493     }
1494 }
1495
1496 // Reverse the words in a section.  Used for .ctors sections mapped to
1497 // .init_array sections.  See ctors_sections_in_init_array in
1498 // layout.cc.
1499
1500 template<int size, bool big_endian>
1501 void
1502 Sized_relobj_file<size, big_endian>::reverse_words(unsigned char* view,
1503                                                    section_size_type view_size)
1504 {
1505   typedef typename elfcpp::Swap<size, big_endian>::Valtype Valtype;
1506   Valtype* vview = reinterpret_cast<Valtype*>(view);
1507   section_size_type vview_size = view_size / (size / 8);
1508   for (section_size_type i = 0; i < vview_size / 2; ++i)
1509     {
1510       Valtype tmp = vview[i];
1511       vview[i] = vview[vview_size - 1 - i];
1512       vview[vview_size - 1 - i] = tmp;
1513     }
1514 }
1515
1516 // Class Merged_symbol_value.
1517
1518 template<int size>
1519 void
1520 Merged_symbol_value<size>::initialize_input_to_output_map(
1521     const Relobj* object,
1522     unsigned int input_shndx)
1523 {
1524   Object_merge_map* map = object->merge_map();
1525   map->initialize_input_to_output_map<size>(input_shndx,
1526                                             this->output_start_address_,
1527                                             &this->output_addresses_);
1528 }
1529
1530 // Get the output value corresponding to an input offset if we
1531 // couldn't find it in the hash table.
1532
1533 template<int size>
1534 typename elfcpp::Elf_types<size>::Elf_Addr
1535 Merged_symbol_value<size>::value_from_output_section(
1536     const Relobj* object,
1537     unsigned int input_shndx,
1538     typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
1539 {
1540   section_offset_type output_offset;
1541   bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
1542                                                       input_offset,
1543                                                       &output_offset);
1544
1545   // If this assertion fails, it means that some relocation was
1546   // against a portion of an input merge section which we didn't map
1547   // to the output file and we didn't explicitly discard.  We should
1548   // always map all portions of input merge sections.
1549   gold_assert(found);
1550
1551   if (output_offset == -1)
1552     return 0;
1553   else
1554     return this->output_start_address_ + output_offset;
1555 }
1556
1557 // Track_relocs methods.
1558
1559 // Initialize the class to track the relocs.  This gets the object,
1560 // the reloc section index, and the type of the relocs.  This returns
1561 // false if something goes wrong.
1562
1563 template<int size, bool big_endian>
1564 bool
1565 Track_relocs<size, big_endian>::initialize(
1566     Object* object,
1567     unsigned int reloc_shndx,
1568     unsigned int reloc_type)
1569 {
1570   // If RELOC_SHNDX is -1U, it means there is more than one reloc
1571   // section for the .eh_frame section.  We can't handle that case.
1572   if (reloc_shndx == -1U)
1573     return false;
1574
1575   // If RELOC_SHNDX is 0, there is no reloc section.
1576   if (reloc_shndx == 0)
1577     return true;
1578
1579   // Get the contents of the reloc section.
1580   this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
1581
1582   if (reloc_type == elfcpp::SHT_REL)
1583     this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
1584   else if (reloc_type == elfcpp::SHT_RELA)
1585     this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
1586   else
1587     gold_unreachable();
1588
1589   if (this->len_ % this->reloc_size_ != 0)
1590     {
1591       object->error(_("reloc section size %zu is not a multiple of "
1592                       "reloc size %d\n"),
1593                     static_cast<size_t>(this->len_),
1594                     this->reloc_size_);
1595       return false;
1596     }
1597
1598   return true;
1599 }
1600
1601 // Return the offset of the next reloc, or -1 if there isn't one.
1602
1603 template<int size, bool big_endian>
1604 off_t
1605 Track_relocs<size, big_endian>::next_offset() const
1606 {
1607   if (this->pos_ >= this->len_)
1608     return -1;
1609
1610   // Rel and Rela start out the same, so we can always use Rel to find
1611   // the r_offset value.
1612   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1613   return rel.get_r_offset();
1614 }
1615
1616 // Return the index of the symbol referenced by the next reloc, or -1U
1617 // if there aren't any more relocs.
1618
1619 template<int size, bool big_endian>
1620 unsigned int
1621 Track_relocs<size, big_endian>::next_symndx() const
1622 {
1623   if (this->pos_ >= this->len_)
1624     return -1U;
1625
1626   // Rel and Rela start out the same, so we can use Rel to find the
1627   // symbol index.
1628   elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1629   return elfcpp::elf_r_sym<size>(rel.get_r_info());
1630 }
1631
1632 // Return the addend of the next reloc, or 0 if there isn't one.
1633
1634 template<int size, bool big_endian>
1635 uint64_t
1636 Track_relocs<size, big_endian>::next_addend() const
1637 {
1638   if (this->pos_ >= this->len_)
1639     return 0;
1640   if (this->reloc_size_ == elfcpp::Elf_sizes<size>::rel_size)
1641     return 0;
1642   elfcpp::Rela<size, big_endian> rela(this->prelocs_ + this->pos_);
1643   return rela.get_r_addend();
1644 }
1645
1646 // Advance to the next reloc whose r_offset is greater than or equal
1647 // to OFFSET.  Return the number of relocs we skip.
1648
1649 template<int size, bool big_endian>
1650 int
1651 Track_relocs<size, big_endian>::advance(off_t offset)
1652 {
1653   int ret = 0;
1654   while (this->pos_ < this->len_)
1655     {
1656       // Rel and Rela start out the same, so we can always use Rel to
1657       // find the r_offset value.
1658       elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1659       if (static_cast<off_t>(rel.get_r_offset()) >= offset)
1660         break;
1661       ++ret;
1662       this->pos_ += this->reloc_size_;
1663     }
1664   return ret;
1665 }
1666
1667 // Instantiate the templates we need.
1668
1669 #ifdef HAVE_TARGET_32_LITTLE
1670 template
1671 void
1672 Sized_relobj_file<32, false>::do_read_relocs(Read_relocs_data* rd);
1673 #endif
1674
1675 #ifdef HAVE_TARGET_32_BIG
1676 template
1677 void
1678 Sized_relobj_file<32, true>::do_read_relocs(Read_relocs_data* rd);
1679 #endif
1680
1681 #ifdef HAVE_TARGET_64_LITTLE
1682 template
1683 void
1684 Sized_relobj_file<64, false>::do_read_relocs(Read_relocs_data* rd);
1685 #endif
1686
1687 #ifdef HAVE_TARGET_64_BIG
1688 template
1689 void
1690 Sized_relobj_file<64, true>::do_read_relocs(Read_relocs_data* rd);
1691 #endif
1692
1693 #ifdef HAVE_TARGET_32_LITTLE
1694 template
1695 void
1696 Sized_relobj_file<32, false>::do_gc_process_relocs(Symbol_table* symtab,
1697                                                    Layout* layout,
1698                                                    Read_relocs_data* rd);
1699 #endif
1700
1701 #ifdef HAVE_TARGET_32_BIG
1702 template
1703 void
1704 Sized_relobj_file<32, true>::do_gc_process_relocs(Symbol_table* symtab,
1705                                                   Layout* layout,
1706                                                   Read_relocs_data* rd);
1707 #endif
1708
1709 #ifdef HAVE_TARGET_64_LITTLE
1710 template
1711 void
1712 Sized_relobj_file<64, false>::do_gc_process_relocs(Symbol_table* symtab,
1713                                                    Layout* layout,
1714                                                    Read_relocs_data* rd);
1715 #endif
1716
1717 #ifdef HAVE_TARGET_64_BIG
1718 template
1719 void
1720 Sized_relobj_file<64, true>::do_gc_process_relocs(Symbol_table* symtab,
1721                                                   Layout* layout,
1722                                                   Read_relocs_data* rd);
1723 #endif
1724
1725 #ifdef HAVE_TARGET_32_LITTLE
1726 template
1727 void
1728 Sized_relobj_file<32, false>::do_scan_relocs(Symbol_table* symtab,
1729                                              Layout* layout,
1730                                              Read_relocs_data* rd);
1731 #endif
1732
1733 #ifdef HAVE_TARGET_32_BIG
1734 template
1735 void
1736 Sized_relobj_file<32, true>::do_scan_relocs(Symbol_table* symtab,
1737                                             Layout* layout,
1738                                             Read_relocs_data* rd);
1739 #endif
1740
1741 #ifdef HAVE_TARGET_64_LITTLE
1742 template
1743 void
1744 Sized_relobj_file<64, false>::do_scan_relocs(Symbol_table* symtab,
1745                                              Layout* layout,
1746                                              Read_relocs_data* rd);
1747 #endif
1748
1749 #ifdef HAVE_TARGET_64_BIG
1750 template
1751 void
1752 Sized_relobj_file<64, true>::do_scan_relocs(Symbol_table* symtab,
1753                                             Layout* layout,
1754                                             Read_relocs_data* rd);
1755 #endif
1756
1757 #ifdef HAVE_TARGET_32_LITTLE
1758 template
1759 void
1760 Sized_relobj_file<32, false>::do_relocate(const Symbol_table* symtab,
1761                                           const Layout* layout,
1762                                           Output_file* of);
1763 #endif
1764
1765 #ifdef HAVE_TARGET_32_BIG
1766 template
1767 void
1768 Sized_relobj_file<32, true>::do_relocate(const Symbol_table* symtab,
1769                                          const Layout* layout,
1770                                          Output_file* of);
1771 #endif
1772
1773 #ifdef HAVE_TARGET_64_LITTLE
1774 template
1775 void
1776 Sized_relobj_file<64, false>::do_relocate(const Symbol_table* symtab,
1777                                           const Layout* layout,
1778                                           Output_file* of);
1779 #endif
1780
1781 #ifdef HAVE_TARGET_64_BIG
1782 template
1783 void
1784 Sized_relobj_file<64, true>::do_relocate(const Symbol_table* symtab,
1785                                          const Layout* layout,
1786                                          Output_file* of);
1787 #endif
1788
1789 #ifdef HAVE_TARGET_32_LITTLE
1790 template
1791 void
1792 Sized_relobj_file<32, 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 #endif
1799
1800 #ifdef HAVE_TARGET_32_BIG
1801 template
1802 void
1803 Sized_relobj_file<32, true>::do_relocate_sections(
1804     const Symbol_table* symtab,
1805     const Layout* layout,
1806     const unsigned char* pshdrs,
1807     Output_file* of,
1808     Views* pviews);
1809 #endif
1810
1811 #ifdef HAVE_TARGET_64_LITTLE
1812 template
1813 void
1814 Sized_relobj_file<64, false>::do_relocate_sections(
1815     const Symbol_table* symtab,
1816     const Layout* layout,
1817     const unsigned char* pshdrs,
1818     Output_file* of,
1819     Views* pviews);
1820 #endif
1821
1822 #ifdef HAVE_TARGET_64_BIG
1823 template
1824 void
1825 Sized_relobj_file<64, true>::do_relocate_sections(
1826     const Symbol_table* symtab,
1827     const Layout* layout,
1828     const unsigned char* pshdrs,
1829     Output_file* of,
1830     Views* pviews);
1831 #endif
1832
1833 #ifdef HAVE_TARGET_32_LITTLE
1834 template
1835 void
1836 Sized_relobj_file<32, false>::initialize_input_to_output_maps();
1837
1838 template
1839 void
1840 Sized_relobj_file<32, false>::free_input_to_output_maps();
1841 #endif
1842
1843 #ifdef HAVE_TARGET_32_BIG
1844 template
1845 void
1846 Sized_relobj_file<32, true>::initialize_input_to_output_maps();
1847
1848 template
1849 void
1850 Sized_relobj_file<32, true>::free_input_to_output_maps();
1851 #endif
1852
1853 #ifdef HAVE_TARGET_64_LITTLE
1854 template
1855 void
1856 Sized_relobj_file<64, false>::initialize_input_to_output_maps();
1857
1858 template
1859 void
1860 Sized_relobj_file<64, false>::free_input_to_output_maps();
1861 #endif
1862
1863 #ifdef HAVE_TARGET_64_BIG
1864 template
1865 void
1866 Sized_relobj_file<64, true>::initialize_input_to_output_maps();
1867
1868 template
1869 void
1870 Sized_relobj_file<64, true>::free_input_to_output_maps();
1871 #endif
1872
1873 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1874 template
1875 class Merged_symbol_value<32>;
1876 #endif
1877
1878 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1879 template
1880 class Merged_symbol_value<64>;
1881 #endif
1882
1883 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1884 template
1885 class Symbol_value<32>;
1886 #endif
1887
1888 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1889 template
1890 class Symbol_value<64>;
1891 #endif
1892
1893 #ifdef HAVE_TARGET_32_LITTLE
1894 template
1895 class Track_relocs<32, false>;
1896 #endif
1897
1898 #ifdef HAVE_TARGET_32_BIG
1899 template
1900 class Track_relocs<32, true>;
1901 #endif
1902
1903 #ifdef HAVE_TARGET_64_LITTLE
1904 template
1905 class Track_relocs<64, false>;
1906 #endif
1907
1908 #ifdef HAVE_TARGET_64_BIG
1909 template
1910 class Track_relocs<64, true>;
1911 #endif
1912
1913 } // End namespace gold.