gold/i386.cc

   1 // i386.cc -- i386 target support for gold.
   2
   3 // Copyright 2006, 2007 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 <cstring>
  26
  27 #include "elfcpp.h"
  28 #include "parameters.h"
  29 #include "reloc.h"
  30 #include "i386.h"
  31 #include "object.h"
  32 #include "symtab.h"
  33 #include "layout.h"
  34 #include "output.h"
  35 #include "target.h"
  36 #include "target-reloc.h"
  37 #include "target-select.h"
  38 #include "tls.h"
  39
  40 namespace
  41 {
  42
  43 using namespace gold;
  44
  45 class Output_data_plt_i386;
  46
  47 // The i386 target class.
  48 // TLS info comes from
  49 //   http://people.redhat.com/drepper/tls.pdf
  50 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  51
  52 class Target_i386 : public Sized_target<32, false>
  53 {
  54  public:
  55   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
  56
  57   Target_i386()
  58     : Sized_target<32, false>(&i386_info),
  59       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
  60       copy_relocs_(NULL), dynbss_(NULL), got_mod_index_offset_(-1U)
  61   { }
  62
  63   // Scan the relocations to look for symbol adjustments.
  64   void
  65   scan_relocs(const General_options& options,
  66               Symbol_table* symtab,
  67               Layout* layout,
  68               Sized_relobj<32, false>* object,
  69               unsigned int data_shndx,
  70               unsigned int sh_type,
  71               const unsigned char* prelocs,
  72               size_t reloc_count,
  73               Output_section* output_section,
  74               bool needs_special_offset_handling,
  75               size_t local_symbol_count,
  76               const unsigned char* plocal_symbols);
  77
  78   // Finalize the sections.
  79   void
  80   do_finalize_sections(Layout*);
  81
  82   // Return the value to use for a dynamic which requires special
  83   // treatment.
  84   uint64_t
  85   do_dynsym_value(const Symbol*) const;
  86
  87   // Relocate a section.
  88   void
  89   relocate_section(const Relocate_info<32, false>*,
  90                    unsigned int sh_type,
  91                    const unsigned char* prelocs,
  92                    size_t reloc_count,
  93                    Output_section* output_section,
  94                    bool needs_special_offset_handling,
  95                    unsigned char* view,
  96                    elfcpp::Elf_types<32>::Elf_Addr view_address,
  97                    section_size_type view_size);
  98
  99   // Scan the relocs during a relocatable link.
 100   void
 101   scan_relocatable_relocs(const General_options& options,
 102                           Symbol_table* symtab,
 103                           Layout* layout,
 104                           Sized_relobj<32, false>* object,
 105                           unsigned int data_shndx,
 106                           unsigned int sh_type,
 107                           const unsigned char* prelocs,
 108                           size_t reloc_count,
 109                           Output_section* output_section,
 110                           bool needs_special_offset_handling,
 111                           size_t local_symbol_count,
 112                           const unsigned char* plocal_symbols,
 113                           Relocatable_relocs*);
 114
 115   // Relocate a section during a relocatable link.
 116   void
 117   relocate_for_relocatable(const Relocate_info<32, false>*,
 118                            unsigned int sh_type,
 119                            const unsigned char* prelocs,
 120                            size_t reloc_count,
 121                            Output_section* output_section,
 122                            off_t offset_in_output_section,
 123                            const Relocatable_relocs*,
 124                            unsigned char* view,
 125                            elfcpp::Elf_types<32>::Elf_Addr view_address,
 126                            section_size_type view_size,
 127                            unsigned char* reloc_view,
 128                            section_size_type reloc_view_size);
 129
 130   // Return a string used to fill a code section with nops.
 131   std::string
 132   do_code_fill(section_size_type length);
 133
 134   // Return whether SYM is defined by the ABI.
 135   bool
 136   do_is_defined_by_abi(Symbol* sym) const
 137   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
 138
 139   // Return the size of the GOT section.
 140   section_size_type
 141   got_size()
 142   {
 143     gold_assert(this->got_ != NULL);
 144     return this->got_->data_size();
 145   }
 146
 147  private:
 148   // The class which scans relocations.
 149   struct Scan
 150   {
 151     inline void
 152     local(const General_options& options, Symbol_table* symtab,
 153           Layout* layout, Target_i386* target,
 154           Sized_relobj<32, false>* object,
 155           unsigned int data_shndx,
 156           Output_section* output_section,
 157           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 158           const elfcpp::Sym<32, false>& lsym);
 159
 160     inline void
 161     global(const General_options& options, Symbol_table* symtab,
 162            Layout* layout, Target_i386* target,
 163            Sized_relobj<32, false>* object,
 164            unsigned int data_shndx,
 165            Output_section* output_section,
 166            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 167            Symbol* gsym);
 168
 169     static void
 170     unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
 171
 172     static void
 173     unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
 174                              Symbol*);
 175   };
 176
 177   // The class which implements relocation.
 178   class Relocate
 179   {
 180    public:
 181     Relocate()
 182       : skip_call_tls_get_addr_(false),
 183         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
 184     { }
 185
 186     ~Relocate()
 187     {
 188       if (this->skip_call_tls_get_addr_)
 189         {
 190           // FIXME: This needs to specify the location somehow.
 191           gold_error(_("missing expected TLS relocation"));
 192         }
 193     }
 194
 195     // Return whether the static relocation needs to be applied.
 196     inline bool
 197     should_apply_static_reloc(const Sized_symbol<32>* gsym,
 198                               int ref_flags,
 199                               bool is_32bit);
 200
 201     // Do a relocation.  Return false if the caller should not issue
 202     // any warnings about this relocation.
 203     inline bool
 204     relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
 205              const elfcpp::Rel<32, false>&,
 206              unsigned int r_type, const Sized_symbol<32>*,
 207              const Symbol_value<32>*,
 208              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 209              section_size_type);
 210
 211    private:
 212     // Do a TLS relocation.
 213     inline void
 214     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
 215                  size_t relnum, const elfcpp::Rel<32, false>&,
 216                  unsigned int r_type, const Sized_symbol<32>*,
 217                  const Symbol_value<32>*,
 218                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 219                  section_size_type);
 220
 221     // Do a TLS General-Dynamic to Initial-Exec transition.
 222     inline void
 223     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 224                  Output_segment* tls_segment,
 225                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 226                  elfcpp::Elf_types<32>::Elf_Addr value,
 227                  unsigned char* view,
 228                  section_size_type view_size);
 229
 230     // Do a TLS General-Dynamic to Local-Exec transition.
 231     inline void
 232     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 233                  Output_segment* tls_segment,
 234                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 235                  elfcpp::Elf_types<32>::Elf_Addr value,
 236                  unsigned char* view,
 237                  section_size_type view_size);
 238
 239     // Do a TLS Local-Dynamic to Local-Exec transition.
 240     inline void
 241     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
 242                  Output_segment* tls_segment,
 243                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 244                  elfcpp::Elf_types<32>::Elf_Addr value,
 245                  unsigned char* view,
 246                  section_size_type view_size);
 247
 248     // Do a TLS Initial-Exec to Local-Exec transition.
 249     static inline void
 250     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 251                  Output_segment* tls_segment,
 252                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 253                  elfcpp::Elf_types<32>::Elf_Addr value,
 254                  unsigned char* view,
 255                  section_size_type view_size);
 256
 257     // We need to keep track of which type of local dynamic relocation
 258     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
 259     enum Local_dynamic_type
 260     {
 261       LOCAL_DYNAMIC_NONE,
 262       LOCAL_DYNAMIC_SUN,
 263       LOCAL_DYNAMIC_GNU
 264     };
 265
 266     // This is set if we should skip the next reloc, which should be a
 267     // PLT32 reloc against ___tls_get_addr.
 268     bool skip_call_tls_get_addr_;
 269     // The type of local dynamic relocation we have seen in the section
 270     // being relocated, if any.
 271     Local_dynamic_type local_dynamic_type_;
 272   };
 273
 274   // A class which returns the size required for a relocation type,
 275   // used while scanning relocs during a relocatable link.
 276   class Relocatable_size_for_reloc
 277   {
 278    public:
 279     unsigned int
 280     get_size_for_reloc(unsigned int, Relobj*);
 281   };
 282
 283   // Adjust TLS relocation type based on the options and whether this
 284   // is a local symbol.
 285   static tls::Tls_optimization
 286   optimize_tls_reloc(bool is_final, int r_type);
 287
 288   // Get the GOT section, creating it if necessary.
 289   Output_data_got<32, false>*
 290   got_section(Symbol_table*, Layout*);
 291
 292   // Get the GOT PLT section.
 293   Output_data_space*
 294   got_plt_section() const
 295   {
 296     gold_assert(this->got_plt_ != NULL);
 297     return this->got_plt_;
 298   }
 299
 300   // Create a PLT entry for a global symbol.
 301   void
 302   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 303
 304   // Create a GOT entry for the TLS module index.
 305   unsigned int
 306   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 307                       Sized_relobj<32, false>* object);
 308
 309   // Get the PLT section.
 310   const Output_data_plt_i386*
 311   plt_section() const
 312   {
 313     gold_assert(this->plt_ != NULL);
 314     return this->plt_;
 315   }
 316
 317   // Get the dynamic reloc section, creating it if necessary.
 318   Reloc_section*
 319   rel_dyn_section(Layout*);
 320
 321   // Return true if the symbol may need a COPY relocation.
 322   // References from an executable object to non-function symbols
 323   // defined in a dynamic object may need a COPY relocation.
 324   bool
 325   may_need_copy_reloc(Symbol* gsym)
 326   {
 327     return (!parameters->output_is_shared()
 328             && gsym->is_from_dynobj()
 329             && gsym->type() != elfcpp::STT_FUNC);
 330   }
 331
 332   // Copy a relocation against a global symbol.
 333   void
 334   copy_reloc(const General_options*, Symbol_table*, Layout*,
 335              Sized_relobj<32, false>*, unsigned int,
 336              Output_section*, Symbol*, const elfcpp::Rel<32, false>&);
 337
 338   // Information about this specific target which we pass to the
 339   // general Target structure.
 340   static const Target::Target_info i386_info;
 341
 342   // The GOT section.
 343   Output_data_got<32, false>* got_;
 344   // The PLT section.
 345   Output_data_plt_i386* plt_;
 346   // The GOT PLT section.
 347   Output_data_space* got_plt_;
 348   // The dynamic reloc section.
 349   Reloc_section* rel_dyn_;
 350   // Relocs saved to avoid a COPY reloc.
 351   Copy_relocs<32, false>* copy_relocs_;
 352   // Space for variables copied with a COPY reloc.
 353   Output_data_space* dynbss_;
 354   // Offset of the GOT entry for the TLS module index;
 355   unsigned int got_mod_index_offset_;
 356 };
 357
 358 const Target::Target_info Target_i386::i386_info =
 359 {
 360   32,                   // size
 361   false,                // is_big_endian
 362   elfcpp::EM_386,       // machine_code
 363   false,                // has_make_symbol
 364   false,                // has_resolve
 365   true,                 // has_code_fill
 366   true,                 // is_default_stack_executable
 367   "/usr/lib/libc.so.1", // dynamic_linker
 368   0x08048000,           // default_text_segment_address
 369   0x1000,               // abi_pagesize
 370   0x1000                // common_pagesize
 371 };
 372
 373 // Get the GOT section, creating it if necessary.
 374
 375 Output_data_got<32, false>*
 376 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
 377 {
 378   if (this->got_ == NULL)
 379     {
 380       gold_assert(symtab != NULL && layout != NULL);
 381
 382       this->got_ = new Output_data_got<32, false>();
 383
 384       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 385                                       elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
 386                                       this->got_);
 387
 388       // The old GNU linker creates a .got.plt section.  We just
 389       // create another set of data in the .got section.  Note that we
 390       // always create a PLT if we create a GOT, although the PLT
 391       // might be empty.
 392       this->got_plt_ = new Output_data_space(4);
 393       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 394                                       elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
 395                                       this->got_plt_);
 396
 397       // The first three entries are reserved.
 398       this->got_plt_->set_current_data_size(3 * 4);
 399
 400       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 401       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 402                                     this->got_plt_,
 403                                     0, 0, elfcpp::STT_OBJECT,
 404                                     elfcpp::STB_LOCAL,
 405                                     elfcpp::STV_HIDDEN, 0,
 406                                     false, false);
 407     }
 408
 409   return this->got_;
 410 }
 411
 412 // Get the dynamic reloc section, creating it if necessary.
 413
 414 Target_i386::Reloc_section*
 415 Target_i386::rel_dyn_section(Layout* layout)
 416 {
 417   if (this->rel_dyn_ == NULL)
 418     {
 419       gold_assert(layout != NULL);
 420       this->rel_dyn_ = new Reloc_section();
 421       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 422                                       elfcpp::SHF_ALLOC, this->rel_dyn_);
 423     }
 424   return this->rel_dyn_;
 425 }
 426
 427 // A class to handle the PLT data.
 428
 429 class Output_data_plt_i386 : public Output_section_data
 430 {
 431  public:
 432   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 433
 434   Output_data_plt_i386(Layout*, Output_data_space*);
 435
 436   // Add an entry to the PLT.
 437   void
 438   add_entry(Symbol* gsym);
 439
 440   // Return the .rel.plt section data.
 441   const Reloc_section*
 442   rel_plt() const
 443   { return this->rel_; }
 444
 445  protected:
 446   void
 447   do_adjust_output_section(Output_section* os);
 448
 449  private:
 450   // The size of an entry in the PLT.
 451   static const int plt_entry_size = 16;
 452
 453   // The first entry in the PLT for an executable.
 454   static unsigned char exec_first_plt_entry[plt_entry_size];
 455
 456   // The first entry in the PLT for a shared object.
 457   static unsigned char dyn_first_plt_entry[plt_entry_size];
 458
 459   // Other entries in the PLT for an executable.
 460   static unsigned char exec_plt_entry[plt_entry_size];
 461
 462   // Other entries in the PLT for a shared object.
 463   static unsigned char dyn_plt_entry[plt_entry_size];
 464
 465   // Set the final size.
 466   void
 467   set_final_data_size()
 468   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
 469
 470   // Write out the PLT data.
 471   void
 472   do_write(Output_file*);
 473
 474   // The reloc section.
 475   Reloc_section* rel_;
 476   // The .got.plt section.
 477   Output_data_space* got_plt_;
 478   // The number of PLT entries.
 479   unsigned int count_;
 480 };
 481
 482 // Create the PLT section.  The ordinary .got section is an argument,
 483 // since we need to refer to the start.  We also create our own .got
 484 // section just for PLT entries.
 485
 486 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
 487                                            Output_data_space* got_plt)
 488   : Output_section_data(4), got_plt_(got_plt), count_(0)
 489 {
 490   this->rel_ = new Reloc_section();
 491   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 492                                   elfcpp::SHF_ALLOC, this->rel_);
 493 }
 494
 495 void
 496 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 497 {
 498   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 499   // linker, and so do we.
 500   os->set_entsize(4);
 501 }
 502
 503 // Add an entry to the PLT.
 504
 505 void
 506 Output_data_plt_i386::add_entry(Symbol* gsym)
 507 {
 508   gold_assert(!gsym->has_plt_offset());
 509
 510   // Note that when setting the PLT offset we skip the initial
 511   // reserved PLT entry.
 512   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 513
 514   ++this->count_;
 515
 516   section_offset_type got_offset = this->got_plt_->current_data_size();
 517
 518   // Every PLT entry needs a GOT entry which points back to the PLT
 519   // entry (this will be changed by the dynamic linker, normally
 520   // lazily when the function is called).
 521   this->got_plt_->set_current_data_size(got_offset + 4);
 522
 523   // Every PLT entry needs a reloc.
 524   gsym->set_needs_dynsym_entry();
 525   this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 526                          got_offset);
 527
 528   // Note that we don't need to save the symbol.  The contents of the
 529   // PLT are independent of which symbols are used.  The symbols only
 530   // appear in the relocations.
 531 }
 532
 533 // The first entry in the PLT for an executable.
 534
 535 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 536 {
 537   0xff, 0x35,   // pushl contents of memory address
 538   0, 0, 0, 0,   // replaced with address of .got + 4
 539   0xff, 0x25,   // jmp indirect
 540   0, 0, 0, 0,   // replaced with address of .got + 8
 541   0, 0, 0, 0    // unused
 542 };
 543
 544 // The first entry in the PLT for a shared object.
 545
 546 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
 547 {
 548   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
 549   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
 550   0, 0, 0, 0                    // unused
 551 };
 552
 553 // Subsequent entries in the PLT for an executable.
 554
 555 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
 556 {
 557   0xff, 0x25,   // jmp indirect
 558   0, 0, 0, 0,   // replaced with address of symbol in .got
 559   0x68,         // pushl immediate
 560   0, 0, 0, 0,   // replaced with offset into relocation table
 561   0xe9,         // jmp relative
 562   0, 0, 0, 0    // replaced with offset to start of .plt
 563 };
 564
 565 // Subsequent entries in the PLT for a shared object.
 566
 567 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
 568 {
 569   0xff, 0xa3,   // jmp *offset(%ebx)
 570   0, 0, 0, 0,   // replaced with offset of symbol in .got
 571   0x68,         // pushl immediate
 572   0, 0, 0, 0,   // replaced with offset into relocation table
 573   0xe9,         // jmp relative
 574   0, 0, 0, 0    // replaced with offset to start of .plt
 575 };
 576
 577 // Write out the PLT.  This uses the hand-coded instructions above,
 578 // and adjusts them as needed.  This is all specified by the i386 ELF
 579 // Processor Supplement.
 580
 581 void
 582 Output_data_plt_i386::do_write(Output_file* of)
 583 {
 584   const off_t offset = this->offset();
 585   const section_size_type oview_size =
 586     convert_to_section_size_type(this->data_size());
 587   unsigned char* const oview = of->get_output_view(offset, oview_size);
 588
 589   const off_t got_file_offset = this->got_plt_->offset();
 590   const section_size_type got_size =
 591     convert_to_section_size_type(this->got_plt_->data_size());
 592   unsigned char* const got_view = of->get_output_view(got_file_offset,
 593                                                       got_size);
 594
 595   unsigned char* pov = oview;
 596
 597   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
 598   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
 599
 600   if (parameters->output_is_shared())
 601     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
 602   else
 603     {
 604       memcpy(pov, exec_first_plt_entry, plt_entry_size);
 605       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
 606       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
 607     }
 608   pov += plt_entry_size;
 609
 610   unsigned char* got_pov = got_view;
 611
 612   memset(got_pov, 0, 12);
 613   got_pov += 12;
 614
 615   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
 616
 617   unsigned int plt_offset = plt_entry_size;
 618   unsigned int plt_rel_offset = 0;
 619   unsigned int got_offset = 12;
 620   const unsigned int count = this->count_;
 621   for (unsigned int i = 0;
 622        i < count;
 623        ++i,
 624          pov += plt_entry_size,
 625          got_pov += 4,
 626          plt_offset += plt_entry_size,
 627          plt_rel_offset += rel_size,
 628          got_offset += 4)
 629     {
 630       // Set and adjust the PLT entry itself.
 631
 632       if (parameters->output_is_shared())
 633         {
 634           memcpy(pov, dyn_plt_entry, plt_entry_size);
 635           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
 636         }
 637       else
 638         {
 639           memcpy(pov, exec_plt_entry, plt_entry_size);
 640           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 641                                                       (got_address
 642                                                        + got_offset));
 643         }
 644
 645       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
 646       elfcpp::Swap<32, false>::writeval(pov + 12,
 647                                         - (plt_offset + plt_entry_size));
 648
 649       // Set the entry in the GOT.
 650       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
 651     }
 652
 653   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 654   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 655
 656   of->write_output_view(offset, oview_size, oview);
 657   of->write_output_view(got_file_offset, got_size, got_view);
 658 }
 659
 660 // Create a PLT entry for a global symbol.
 661
 662 void
 663 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
 664 {
 665   if (gsym->has_plt_offset())
 666     return;
 667
 668   if (this->plt_ == NULL)
 669     {
 670       // Create the GOT sections first.
 671       this->got_section(symtab, layout);
 672
 673       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
 674       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 675                                       (elfcpp::SHF_ALLOC
 676                                        | elfcpp::SHF_EXECINSTR),
 677                                       this->plt_);
 678     }
 679
 680   this->plt_->add_entry(gsym);
 681 }
 682
 683 // Create a GOT entry for the TLS module index.
 684
 685 unsigned int
 686 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 687                                  Sized_relobj<32, false>* object)
 688 {
 689   if (this->got_mod_index_offset_ == -1U)
 690     {
 691       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 692       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
 693       Output_data_got<32, false>* got = this->got_section(symtab, layout);
 694       unsigned int got_offset = got->add_constant(0);
 695       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
 696                          got_offset);
 697       got->add_constant(0);
 698       this->got_mod_index_offset_ = got_offset;
 699     }
 700   return this->got_mod_index_offset_;
 701 }
 702
 703 // Handle a relocation against a non-function symbol defined in a
 704 // dynamic object.  The traditional way to handle this is to generate
 705 // a COPY relocation to copy the variable at runtime from the shared
 706 // object into the executable's data segment.  However, this is
 707 // undesirable in general, as if the size of the object changes in the
 708 // dynamic object, the executable will no longer work correctly.  If
 709 // this relocation is in a writable section, then we can create a
 710 // dynamic reloc and the dynamic linker will resolve it to the correct
 711 // address at runtime.  However, we do not want do that if the
 712 // relocation is in a read-only section, as it would prevent the
 713 // readonly segment from being shared.  And if we have to eventually
 714 // generate a COPY reloc, then any dynamic relocations will be
 715 // useless.  So this means that if this is a writable section, we need
 716 // to save the relocation until we see whether we have to create a
 717 // COPY relocation for this symbol for any other relocation.
 718
 719 void
 720 Target_i386::copy_reloc(const General_options* options,
 721                         Symbol_table* symtab,
 722                         Layout* layout,
 723                         Sized_relobj<32, false>* object,
 724                         unsigned int data_shndx,
 725                         Output_section* output_section,
 726                         Symbol* gsym,
 727                         const elfcpp::Rel<32, false>& rel)
 728 {
 729   Sized_symbol<32>* ssym;
 730   ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym
 731                                                         SELECT_SIZE(32));
 732
 733   if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
 734                                                data_shndx, ssym))
 735     {
 736       // So far we do not need a COPY reloc.  Save this relocation.
 737       // If it turns out that we never need a COPY reloc for this
 738       // symbol, then we will emit the relocation.
 739       if (this->copy_relocs_ == NULL)
 740         this->copy_relocs_ = new Copy_relocs<32, false>();
 741       this->copy_relocs_->save(ssym, object, data_shndx, output_section, rel);
 742     }
 743   else
 744     {
 745       // Allocate space for this symbol in the .bss section.
 746
 747       elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
 748
 749       // There is no defined way to determine the required alignment
 750       // of the symbol.  We pick the alignment based on the size.  We
 751       // set an arbitrary maximum of 256.
 752       unsigned int align;
 753       for (align = 1; align < 512; align <<= 1)
 754         if ((symsize & align) != 0)
 755           break;
 756
 757       if (this->dynbss_ == NULL)
 758         {
 759           this->dynbss_ = new Output_data_space(align);
 760           layout->add_output_section_data(".bss",
 761                                           elfcpp::SHT_NOBITS,
 762                                           (elfcpp::SHF_ALLOC
 763                                            | elfcpp::SHF_WRITE),
 764                                           this->dynbss_);
 765         }
 766
 767       Output_data_space* dynbss = this->dynbss_;
 768
 769       if (align > dynbss->addralign())
 770         dynbss->set_space_alignment(align);
 771
 772       section_size_type dynbss_size =
 773         convert_to_section_size_type(dynbss->current_data_size());
 774       dynbss_size = align_address(dynbss_size, align);
 775       section_size_type offset = dynbss_size;
 776       dynbss->set_current_data_size(dynbss_size + symsize);
 777
 778       symtab->define_with_copy_reloc(ssym, dynbss, offset);
 779
 780       // Add the COPY reloc.
 781       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
 782       rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
 783     }
 784 }
 785
 786 // Optimize the TLS relocation type based on what we know about the
 787 // symbol.  IS_FINAL is true if the final address of this symbol is
 788 // known at link time.
 789
 790 tls::Tls_optimization
 791 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
 792 {
 793   // If we are generating a shared library, then we can't do anything
 794   // in the linker.
 795   if (parameters->output_is_shared())
 796     return tls::TLSOPT_NONE;
 797
 798   switch (r_type)
 799     {
 800     case elfcpp::R_386_TLS_GD:
 801     case elfcpp::R_386_TLS_GOTDESC:
 802     case elfcpp::R_386_TLS_DESC_CALL:
 803       // These are General-Dynamic which permits fully general TLS
 804       // access.  Since we know that we are generating an executable,
 805       // we can convert this to Initial-Exec.  If we also know that
 806       // this is a local symbol, we can further switch to Local-Exec.
 807       if (is_final)
 808         return tls::TLSOPT_TO_LE;
 809       return tls::TLSOPT_TO_IE;
 810
 811     case elfcpp::R_386_TLS_LDM:
 812       // This is Local-Dynamic, which refers to a local symbol in the
 813       // dynamic TLS block.  Since we know that we generating an
 814       // executable, we can switch to Local-Exec.
 815       return tls::TLSOPT_TO_LE;
 816
 817     case elfcpp::R_386_TLS_LDO_32:
 818       // Another type of Local-Dynamic relocation.
 819       return tls::TLSOPT_TO_LE;
 820
 821     case elfcpp::R_386_TLS_IE:
 822     case elfcpp::R_386_TLS_GOTIE:
 823     case elfcpp::R_386_TLS_IE_32:
 824       // These are Initial-Exec relocs which get the thread offset
 825       // from the GOT.  If we know that we are linking against the
 826       // local symbol, we can switch to Local-Exec, which links the
 827       // thread offset into the instruction.
 828       if (is_final)
 829         return tls::TLSOPT_TO_LE;
 830       return tls::TLSOPT_NONE;
 831
 832     case elfcpp::R_386_TLS_LE:
 833     case elfcpp::R_386_TLS_LE_32:
 834       // When we already have Local-Exec, there is nothing further we
 835       // can do.
 836       return tls::TLSOPT_NONE;
 837
 838     default:
 839       gold_unreachable();
 840     }
 841 }
 842
 843 // Report an unsupported relocation against a local symbol.
 844
 845 void
 846 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
 847                                            unsigned int r_type)
 848 {
 849   gold_error(_("%s: unsupported reloc %u against local symbol"),
 850              object->name().c_str(), r_type);
 851 }
 852
 853 // Scan a relocation for a local symbol.
 854
 855 inline void
 856 Target_i386::Scan::local(const General_options&,
 857                          Symbol_table* symtab,
 858                          Layout* layout,
 859                          Target_i386* target,
 860                          Sized_relobj<32, false>* object,
 861                          unsigned int data_shndx,
 862                          Output_section* output_section,
 863                          const elfcpp::Rel<32, false>& reloc,
 864                          unsigned int r_type,
 865                          const elfcpp::Sym<32, false>& lsym)
 866 {
 867   switch (r_type)
 868     {
 869     case elfcpp::R_386_NONE:
 870     case elfcpp::R_386_GNU_VTINHERIT:
 871     case elfcpp::R_386_GNU_VTENTRY:
 872       break;
 873
 874     case elfcpp::R_386_32:
 875       // If building a shared library (or a position-independent
 876       // executable), we need to create a dynamic relocation for
 877       // this location. The relocation applied at link time will
 878       // apply the link-time value, so we flag the location with
 879       // an R_386_RELATIVE relocation so the dynamic loader can
 880       // relocate it easily.
 881       if (parameters->output_is_position_independent())
 882         {
 883           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 884           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 885           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
 886                                       output_section, data_shndx,
 887                                       reloc.get_r_offset());
 888         }
 889       break;
 890
 891     case elfcpp::R_386_16:
 892     case elfcpp::R_386_8:
 893       // If building a shared library (or a position-independent
 894       // executable), we need to create a dynamic relocation for
 895       // this location. Because the addend needs to remain in the
 896       // data section, we need to be careful not to apply this
 897       // relocation statically.
 898       if (parameters->output_is_position_independent())
 899         {
 900           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 901           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 902           rel_dyn->add_local(object, r_sym, r_type, output_section, data_shndx,
 903                              reloc.get_r_offset());
 904         }
 905       break;
 906
 907     case elfcpp::R_386_PC32:
 908     case elfcpp::R_386_PC16:
 909     case elfcpp::R_386_PC8:
 910       break;
 911
 912     case elfcpp::R_386_PLT32:
 913       // Since we know this is a local symbol, we can handle this as a
 914       // PC32 reloc.
 915       break;
 916
 917     case elfcpp::R_386_GOTOFF:
 918     case elfcpp::R_386_GOTPC:
 919       // We need a GOT section.
 920       target->got_section(symtab, layout);
 921       break;
 922
 923     case elfcpp::R_386_GOT32:
 924       {
 925         // The symbol requires a GOT entry.
 926         Output_data_got<32, false>* got = target->got_section(symtab, layout);
 927         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 928         if (got->add_local(object, r_sym))
 929           {
 930             // If we are generating a shared object, we need to add a
 931             // dynamic RELATIVE relocation for this symbol's GOT entry.
 932             if (parameters->output_is_position_independent())
 933               {
 934                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 935                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 936                 rel_dyn->add_local_relative(object, r_sym,
 937                                             elfcpp::R_386_RELATIVE,
 938                                             got,
 939                                             object->local_got_offset(r_sym));
 940               }
 941           }
 942       }
 943       break;
 944
 945       // These are relocations which should only be seen by the
 946       // dynamic linker, and should never be seen here.
 947     case elfcpp::R_386_COPY:
 948     case elfcpp::R_386_GLOB_DAT:
 949     case elfcpp::R_386_JUMP_SLOT:
 950     case elfcpp::R_386_RELATIVE:
 951     case elfcpp::R_386_TLS_TPOFF:
 952     case elfcpp::R_386_TLS_DTPMOD32:
 953     case elfcpp::R_386_TLS_DTPOFF32:
 954     case elfcpp::R_386_TLS_TPOFF32:
 955     case elfcpp::R_386_TLS_DESC:
 956       gold_error(_("%s: unexpected reloc %u in object file"),
 957                  object->name().c_str(), r_type);
 958       break;
 959
 960       // These are initial TLS relocs, which are expected when
 961       // linking.
 962     case elfcpp::R_386_TLS_GD:            // Global-dynamic
 963     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
 964     case elfcpp::R_386_TLS_DESC_CALL:
 965     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
 966     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
 967     case elfcpp::R_386_TLS_IE:            // Initial-exec
 968     case elfcpp::R_386_TLS_IE_32:
 969     case elfcpp::R_386_TLS_GOTIE:
 970     case elfcpp::R_386_TLS_LE:            // Local-exec
 971     case elfcpp::R_386_TLS_LE_32:
 972       {
 973         bool output_is_shared = parameters->output_is_shared();
 974         const tls::Tls_optimization optimized_type
 975             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
 976         switch (r_type)
 977           {
 978           case elfcpp::R_386_TLS_GD:          // Global-dynamic
 979             if (optimized_type == tls::TLSOPT_NONE)
 980               {
 981                 // Create a pair of GOT entries for the module index and
 982                 // dtv-relative offset.
 983                 Output_data_got<32, false>* got
 984                     = target->got_section(symtab, layout);
 985                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 986                 got->add_local_tls_with_rel(object, r_sym,
 987                                             lsym.get_st_shndx(), true,
 988                                             target->rel_dyn_section(layout),
 989                                             elfcpp::R_386_TLS_DTPMOD32);
 990               }
 991             else if (optimized_type != tls::TLSOPT_TO_LE)
 992               unsupported_reloc_local(object, r_type);
 993             break;
 994
 995           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
 996           case elfcpp::R_386_TLS_DESC_CALL:
 997             // FIXME: If not relaxing to LE, we need to generate
 998             // a GOT entry with an R_386_TLS_DESC reloc.
 999             if (optimized_type != tls::TLSOPT_TO_LE)
1000               unsupported_reloc_local(object, r_type);
1001             break;
1002
1003           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1004             if (optimized_type == tls::TLSOPT_NONE)
1005               {
1006                 // Create a GOT entry for the module index.
1007                 target->got_mod_index_entry(symtab, layout, object);
1008               }
1009             else if (optimized_type != tls::TLSOPT_TO_LE)
1010               unsupported_reloc_local(object, r_type);
1011             break;
1012
1013           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1014             break;
1015
1016           case elfcpp::R_386_TLS_IE:          // Initial-exec
1017           case elfcpp::R_386_TLS_IE_32:
1018           case elfcpp::R_386_TLS_GOTIE:
1019             layout->set_has_static_tls();
1020             if (optimized_type == tls::TLSOPT_NONE)
1021               {
1022                 // For the R_386_TLS_IE relocation, we need to create a
1023                 // dynamic relocation when building a shared library.
1024                 if (r_type == elfcpp::R_386_TLS_IE
1025                     && parameters->output_is_shared())
1026                   {
1027                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1028                     unsigned int r_sym
1029                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1030                     rel_dyn->add_local_relative(object, r_sym,
1031                                                 elfcpp::R_386_RELATIVE,
1032                                                 output_section, data_shndx,
1033                                                 reloc.get_r_offset());
1034                   }
1035                 // Create a GOT entry for the tp-relative offset.
1036                 Output_data_got<32, false>* got
1037                     = target->got_section(symtab, layout);
1038                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1039                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1040                                            ? elfcpp::R_386_TLS_TPOFF32
1041                                            : elfcpp::R_386_TLS_TPOFF);
1042                 got->add_local_with_rel(object, r_sym,
1043                                         target->rel_dyn_section(layout),
1044                                         dyn_r_type);
1045               }
1046             else if (optimized_type != tls::TLSOPT_TO_LE)
1047               unsupported_reloc_local(object, r_type);
1048             break;
1049
1050           case elfcpp::R_386_TLS_LE:          // Local-exec
1051           case elfcpp::R_386_TLS_LE_32:
1052             layout->set_has_static_tls();
1053             if (output_is_shared)
1054               {
1055                 // We need to create a dynamic relocation.
1056                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1057                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1058                                            ? elfcpp::R_386_TLS_TPOFF32
1059                                            : elfcpp::R_386_TLS_TPOFF);
1060                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1061                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1062                                    data_shndx, reloc.get_r_offset());
1063               }
1064             break;
1065
1066           default:
1067             gold_unreachable();
1068           }
1069       }
1070       break;
1071
1072     case elfcpp::R_386_32PLT:
1073     case elfcpp::R_386_TLS_GD_32:
1074     case elfcpp::R_386_TLS_GD_PUSH:
1075     case elfcpp::R_386_TLS_GD_CALL:
1076     case elfcpp::R_386_TLS_GD_POP:
1077     case elfcpp::R_386_TLS_LDM_32:
1078     case elfcpp::R_386_TLS_LDM_PUSH:
1079     case elfcpp::R_386_TLS_LDM_CALL:
1080     case elfcpp::R_386_TLS_LDM_POP:
1081     case elfcpp::R_386_USED_BY_INTEL_200:
1082     default:
1083       unsupported_reloc_local(object, r_type);
1084       break;
1085     }
1086 }
1087
1088 // Report an unsupported relocation against a global symbol.
1089
1090 void
1091 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1092                                             unsigned int r_type,
1093                                             Symbol* gsym)
1094 {
1095   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1096              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1097 }
1098
1099 // Scan a relocation for a global symbol.
1100
1101 inline void
1102 Target_i386::Scan::global(const General_options& options,
1103                           Symbol_table* symtab,
1104                           Layout* layout,
1105                           Target_i386* target,
1106                           Sized_relobj<32, false>* object,
1107                           unsigned int data_shndx,
1108                           Output_section* output_section,
1109                           const elfcpp::Rel<32, false>& reloc,
1110                           unsigned int r_type,
1111                           Symbol* gsym)
1112 {
1113   switch (r_type)
1114     {
1115     case elfcpp::R_386_NONE:
1116     case elfcpp::R_386_GNU_VTINHERIT:
1117     case elfcpp::R_386_GNU_VTENTRY:
1118       break;
1119
1120     case elfcpp::R_386_32:
1121     case elfcpp::R_386_16:
1122     case elfcpp::R_386_8:
1123       {
1124         // Make a PLT entry if necessary.
1125         if (gsym->needs_plt_entry())
1126           {
1127             target->make_plt_entry(symtab, layout, gsym);
1128             // Since this is not a PC-relative relocation, we may be
1129             // taking the address of a function. In that case we need to
1130             // set the entry in the dynamic symbol table to the address of
1131             // the PLT entry.
1132             if (gsym->is_from_dynobj() && !parameters->output_is_shared())
1133               gsym->set_needs_dynsym_value();
1134           }
1135         // Make a dynamic relocation if necessary.
1136         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1137           {
1138             if (target->may_need_copy_reloc(gsym))
1139               {
1140                 target->copy_reloc(&options, symtab, layout, object,
1141                                    data_shndx, output_section, gsym, reloc);
1142               }
1143             else if (r_type == elfcpp::R_386_32
1144                      && gsym->can_use_relative_reloc(false))
1145               {
1146                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1147                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1148                                              output_section, object,
1149                                              data_shndx, reloc.get_r_offset());
1150               }
1151             else
1152               {
1153                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1154                 rel_dyn->add_global(gsym, r_type, output_section, object,
1155                                     data_shndx, reloc.get_r_offset());
1156               }
1157           }
1158       }
1159       break;
1160
1161     case elfcpp::R_386_PC32:
1162     case elfcpp::R_386_PC16:
1163     case elfcpp::R_386_PC8:
1164       {
1165         // Make a PLT entry if necessary.
1166         if (gsym->needs_plt_entry())
1167           {
1168             // These relocations are used for function calls only in
1169             // non-PIC code.  For a 32-bit relocation in a shared library,
1170             // we'll need a text relocation anyway, so we can skip the
1171             // PLT entry and let the dynamic linker bind the call directly
1172             // to the target.  For smaller relocations, we should use a
1173             // PLT entry to ensure that the call can reach.
1174             if (!parameters->output_is_shared()
1175                 || r_type != elfcpp::R_386_PC32)
1176               target->make_plt_entry(symtab, layout, gsym);
1177           }
1178         // Make a dynamic relocation if necessary.
1179         int flags = Symbol::NON_PIC_REF;
1180         if (gsym->type() == elfcpp::STT_FUNC)
1181           flags |= Symbol::FUNCTION_CALL;
1182         if (gsym->needs_dynamic_reloc(flags))
1183           {
1184             if (target->may_need_copy_reloc(gsym))
1185               {
1186                 target->copy_reloc(&options, symtab, layout, object,
1187                                    data_shndx, output_section, gsym, reloc);
1188               }
1189             else
1190               {
1191                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1192                 rel_dyn->add_global(gsym, r_type, output_section, object,
1193                                     data_shndx, reloc.get_r_offset());
1194               }
1195           }
1196       }
1197       break;
1198
1199     case elfcpp::R_386_GOT32:
1200       {
1201         // The symbol requires a GOT entry.
1202         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1203         if (gsym->final_value_is_known())
1204           got->add_global(gsym);
1205         else
1206           {
1207             // If this symbol is not fully resolved, we need to add a
1208             // GOT entry with a dynamic relocation.
1209             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1210             if (gsym->is_from_dynobj() || gsym->is_preemptible())
1211               got->add_global_with_rel(gsym, rel_dyn, elfcpp::R_386_GLOB_DAT);
1212             else
1213               {
1214                 if (got->add_global(gsym))
1215                   rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1216                                                got, gsym->got_offset());
1217               }
1218           }
1219       }
1220       break;
1221
1222     case elfcpp::R_386_PLT32:
1223       // If the symbol is fully resolved, this is just a PC32 reloc.
1224       // Otherwise we need a PLT entry.
1225       if (gsym->final_value_is_known())
1226         break;
1227       // If building a shared library, we can also skip the PLT entry
1228       // if the symbol is defined in the output file and is protected
1229       // or hidden.
1230       if (gsym->is_defined()
1231           && !gsym->is_from_dynobj()
1232           && !gsym->is_preemptible())
1233         break;
1234       target->make_plt_entry(symtab, layout, gsym);
1235       break;
1236
1237     case elfcpp::R_386_GOTOFF:
1238     case elfcpp::R_386_GOTPC:
1239       // We need a GOT section.
1240       target->got_section(symtab, layout);
1241       break;
1242
1243       // These are relocations which should only be seen by the
1244       // dynamic linker, and should never be seen here.
1245     case elfcpp::R_386_COPY:
1246     case elfcpp::R_386_GLOB_DAT:
1247     case elfcpp::R_386_JUMP_SLOT:
1248     case elfcpp::R_386_RELATIVE:
1249     case elfcpp::R_386_TLS_TPOFF:
1250     case elfcpp::R_386_TLS_DTPMOD32:
1251     case elfcpp::R_386_TLS_DTPOFF32:
1252     case elfcpp::R_386_TLS_TPOFF32:
1253     case elfcpp::R_386_TLS_DESC:
1254       gold_error(_("%s: unexpected reloc %u in object file"),
1255                  object->name().c_str(), r_type);
1256       break;
1257
1258       // These are initial tls relocs, which are expected when
1259       // linking.
1260     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1261     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1262     case elfcpp::R_386_TLS_DESC_CALL:
1263     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1264     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1265     case elfcpp::R_386_TLS_IE:            // Initial-exec
1266     case elfcpp::R_386_TLS_IE_32:
1267     case elfcpp::R_386_TLS_GOTIE:
1268     case elfcpp::R_386_TLS_LE:            // Local-exec
1269     case elfcpp::R_386_TLS_LE_32:
1270       {
1271         const bool is_final = gsym->final_value_is_known();
1272         const tls::Tls_optimization optimized_type
1273             = Target_i386::optimize_tls_reloc(is_final, r_type);
1274         switch (r_type)
1275           {
1276           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1277             if (optimized_type == tls::TLSOPT_NONE)
1278               {
1279                 // Create a pair of GOT entries for the module index and
1280                 // dtv-relative offset.
1281                 Output_data_got<32, false>* got
1282                     = target->got_section(symtab, layout);
1283                 got->add_global_tls_with_rel(gsym,
1284                                              target->rel_dyn_section(layout),
1285                                              elfcpp::R_386_TLS_DTPMOD32,
1286                                              elfcpp::R_386_TLS_DTPOFF32);
1287               }
1288             else if (optimized_type == tls::TLSOPT_TO_IE)
1289               {
1290                 // Create a GOT entry for the tp-relative offset.
1291                 Output_data_got<32, false>* got
1292                     = target->got_section(symtab, layout);
1293                 got->add_global_with_rel(gsym, target->rel_dyn_section(layout),
1294                                          elfcpp::R_386_TLS_TPOFF32);
1295               }
1296             else if (optimized_type != tls::TLSOPT_TO_LE)
1297               unsupported_reloc_global(object, r_type, gsym);
1298             break;
1299
1300           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1301           case elfcpp::R_386_TLS_DESC_CALL:
1302             // FIXME: If not relaxing to LE, we need to generate
1303             // a GOT entry with an R_386_TLS_DESC reloc.
1304             if (optimized_type != tls::TLSOPT_TO_LE)
1305               unsupported_reloc_global(object, r_type, gsym);
1306             unsupported_reloc_global(object, r_type, gsym);
1307             break;
1308
1309           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1310             if (optimized_type == tls::TLSOPT_NONE)
1311               {
1312                 // Create a GOT entry for the module index.
1313                 target->got_mod_index_entry(symtab, layout, object);
1314               }
1315             else if (optimized_type != tls::TLSOPT_TO_LE)
1316               unsupported_reloc_global(object, r_type, gsym);
1317             break;
1318
1319           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1320             break;
1321
1322           case elfcpp::R_386_TLS_IE:          // Initial-exec
1323           case elfcpp::R_386_TLS_IE_32:
1324           case elfcpp::R_386_TLS_GOTIE:
1325             layout->set_has_static_tls();
1326             if (optimized_type == tls::TLSOPT_NONE)
1327               {
1328                 // For the R_386_TLS_IE relocation, we need to create a
1329                 // dynamic relocation when building a shared library.
1330                 if (r_type == elfcpp::R_386_TLS_IE
1331                     && parameters->output_is_shared())
1332                   {
1333                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1334                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1335                                                  output_section, object,
1336                                                  data_shndx,
1337                                                  reloc.get_r_offset());
1338                   }
1339                 // Create a GOT entry for the tp-relative offset.
1340                 Output_data_got<32, false>* got
1341                     = target->got_section(symtab, layout);
1342                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1343                                            ? elfcpp::R_386_TLS_TPOFF32
1344                                            : elfcpp::R_386_TLS_TPOFF);
1345                 got->add_global_with_rel(gsym,
1346                                          target->rel_dyn_section(layout),
1347                                          dyn_r_type);
1348               }
1349             else if (optimized_type != tls::TLSOPT_TO_LE)
1350               unsupported_reloc_global(object, r_type, gsym);
1351             break;
1352
1353           case elfcpp::R_386_TLS_LE:          // Local-exec
1354           case elfcpp::R_386_TLS_LE_32:
1355             layout->set_has_static_tls();
1356             if (parameters->output_is_shared())
1357               {
1358                 // We need to create a dynamic relocation.
1359                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1360                                            ? elfcpp::R_386_TLS_TPOFF32
1361                                            : elfcpp::R_386_TLS_TPOFF);
1362                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1363                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1364                                     data_shndx, reloc.get_r_offset());
1365               }
1366             break;
1367
1368           default:
1369             gold_unreachable();
1370           }
1371       }
1372       break;
1373
1374     case elfcpp::R_386_32PLT:
1375     case elfcpp::R_386_TLS_GD_32:
1376     case elfcpp::R_386_TLS_GD_PUSH:
1377     case elfcpp::R_386_TLS_GD_CALL:
1378     case elfcpp::R_386_TLS_GD_POP:
1379     case elfcpp::R_386_TLS_LDM_32:
1380     case elfcpp::R_386_TLS_LDM_PUSH:
1381     case elfcpp::R_386_TLS_LDM_CALL:
1382     case elfcpp::R_386_TLS_LDM_POP:
1383     case elfcpp::R_386_USED_BY_INTEL_200:
1384     default:
1385       unsupported_reloc_global(object, r_type, gsym);
1386       break;
1387     }
1388 }
1389
1390 // Scan relocations for a section.
1391
1392 void
1393 Target_i386::scan_relocs(const General_options& options,
1394                          Symbol_table* symtab,
1395                          Layout* layout,
1396                          Sized_relobj<32, false>* object,
1397                          unsigned int data_shndx,
1398                          unsigned int sh_type,
1399                          const unsigned char* prelocs,
1400                          size_t reloc_count,
1401                          Output_section* output_section,
1402                          bool needs_special_offset_handling,
1403                          size_t local_symbol_count,
1404                          const unsigned char* plocal_symbols)
1405 {
1406   if (sh_type == elfcpp::SHT_RELA)
1407     {
1408       gold_error(_("%s: unsupported RELA reloc section"),
1409                  object->name().c_str());
1410       return;
1411     }
1412
1413   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1414                     Target_i386::Scan>(
1415     options,
1416     symtab,
1417     layout,
1418     this,
1419     object,
1420     data_shndx,
1421     prelocs,
1422     reloc_count,
1423     output_section,
1424     needs_special_offset_handling,
1425     local_symbol_count,
1426     plocal_symbols);
1427 }
1428
1429 // Finalize the sections.
1430
1431 void
1432 Target_i386::do_finalize_sections(Layout* layout)
1433 {
1434   // Fill in some more dynamic tags.
1435   Output_data_dynamic* const odyn = layout->dynamic_data();
1436   if (odyn != NULL)
1437     {
1438       if (this->got_plt_ != NULL)
1439         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1440
1441       if (this->plt_ != NULL)
1442         {
1443           const Output_data* od = this->plt_->rel_plt();
1444           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1445           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1446           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1447         }
1448
1449       if (this->rel_dyn_ != NULL)
1450         {
1451           const Output_data* od = this->rel_dyn_;
1452           odyn->add_section_address(elfcpp::DT_REL, od);
1453           odyn->add_section_size(elfcpp::DT_RELSZ, od);
1454           odyn->add_constant(elfcpp::DT_RELENT,
1455                              elfcpp::Elf_sizes<32>::rel_size);
1456         }
1457
1458       if (!parameters->output_is_shared())
1459         {
1460           // The value of the DT_DEBUG tag is filled in by the dynamic
1461           // linker at run time, and used by the debugger.
1462           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1463         }
1464     }
1465
1466   // Emit any relocs we saved in an attempt to avoid generating COPY
1467   // relocs.
1468   if (this->copy_relocs_ == NULL)
1469     return;
1470   if (this->copy_relocs_->any_to_emit())
1471     {
1472       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1473       this->copy_relocs_->emit(rel_dyn);
1474     }
1475   delete this->copy_relocs_;
1476   this->copy_relocs_ = NULL;
1477 }
1478
1479 // Return whether a direct absolute static relocation needs to be applied.
1480 // In cases where Scan::local() or Scan::global() has created
1481 // a dynamic relocation other than R_386_RELATIVE, the addend
1482 // of the relocation is carried in the data, and we must not
1483 // apply the static relocation.
1484
1485 inline bool
1486 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1487                                                  int ref_flags,
1488                                                  bool is_32bit)
1489 {
1490   // For local symbols, we will have created a non-RELATIVE dynamic
1491   // relocation only if (a) the output is position independent,
1492   // (b) the relocation is absolute (not pc- or segment-relative), and
1493   // (c) the relocation is not 32 bits wide.
1494   if (gsym == NULL)
1495     return !(parameters->output_is_position_independent()
1496              && (ref_flags & Symbol::ABSOLUTE_REF)
1497              && !is_32bit);
1498
1499   // For global symbols, we use the same helper routines used in the
1500   // scan pass.  If we did not create a dynamic relocation, or if we
1501   // created a RELATIVE dynamic relocation, we should apply the static
1502   // relocation.
1503   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1504   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1505                 && gsym->can_use_relative_reloc(ref_flags
1506                                                 & Symbol::FUNCTION_CALL);
1507   return !has_dyn || is_rel;
1508 }
1509
1510 // Perform a relocation.
1511
1512 inline bool
1513 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1514                                 Target_i386* target,
1515                                 size_t relnum,
1516                                 const elfcpp::Rel<32, false>& rel,
1517                                 unsigned int r_type,
1518                                 const Sized_symbol<32>* gsym,
1519                                 const Symbol_value<32>* psymval,
1520                                 unsigned char* view,
1521                                 elfcpp::Elf_types<32>::Elf_Addr address,
1522                                 section_size_type view_size)
1523 {
1524   if (this->skip_call_tls_get_addr_)
1525     {
1526       if (r_type != elfcpp::R_386_PLT32
1527           || gsym == NULL
1528           || strcmp(gsym->name(), "___tls_get_addr") != 0)
1529         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1530                                _("missing expected TLS relocation"));
1531       else
1532         {
1533           this->skip_call_tls_get_addr_ = false;
1534           return false;
1535         }
1536     }
1537
1538   // Pick the value to use for symbols defined in shared objects.
1539   Symbol_value<32> symval;
1540   bool is_nonpic = (r_type == elfcpp::R_386_PC8
1541                     || r_type == elfcpp::R_386_PC16
1542                     || r_type == elfcpp::R_386_PC32);
1543   if (gsym != NULL
1544       && (gsym->is_from_dynobj()
1545           || (parameters->output_is_shared()
1546               && gsym->is_preemptible()))
1547       && gsym->has_plt_offset()
1548       && (!is_nonpic || !parameters->output_is_shared()))
1549     {
1550       symval.set_output_value(target->plt_section()->address()
1551                               + gsym->plt_offset());
1552       psymval = &symval;
1553     }
1554
1555   const Sized_relobj<32, false>* object = relinfo->object;
1556
1557   // Get the GOT offset if needed.
1558   // The GOT pointer points to the end of the GOT section.
1559   // We need to subtract the size of the GOT section to get
1560   // the actual offset to use in the relocation.
1561   bool have_got_offset = false;
1562   unsigned int got_offset = 0;
1563   switch (r_type)
1564     {
1565     case elfcpp::R_386_GOT32:
1566       if (gsym != NULL)
1567         {
1568           gold_assert(gsym->has_got_offset());
1569           got_offset = gsym->got_offset() - target->got_size();
1570         }
1571       else
1572         {
1573           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1574           gold_assert(object->local_has_got_offset(r_sym));
1575           got_offset = object->local_got_offset(r_sym) - target->got_size();
1576         }
1577       have_got_offset = true;
1578       break;
1579
1580     default:
1581       break;
1582     }
1583
1584   switch (r_type)
1585     {
1586     case elfcpp::R_386_NONE:
1587     case elfcpp::R_386_GNU_VTINHERIT:
1588     case elfcpp::R_386_GNU_VTENTRY:
1589       break;
1590
1591     case elfcpp::R_386_32:
1592       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true))
1593         Relocate_functions<32, false>::rel32(view, object, psymval);
1594       break;
1595
1596     case elfcpp::R_386_PC32:
1597       {
1598         int ref_flags = Symbol::NON_PIC_REF;
1599         if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1600           ref_flags |= Symbol::FUNCTION_CALL;
1601         if (should_apply_static_reloc(gsym, ref_flags, true))
1602           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1603       }
1604       break;
1605
1606     case elfcpp::R_386_16:
1607       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
1608         Relocate_functions<32, false>::rel16(view, object, psymval);
1609       break;
1610
1611     case elfcpp::R_386_PC16:
1612       {
1613         int ref_flags = Symbol::NON_PIC_REF;
1614         if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1615           ref_flags |= Symbol::FUNCTION_CALL;
1616         if (should_apply_static_reloc(gsym, ref_flags, false))
1617           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1618       }
1619       break;
1620
1621     case elfcpp::R_386_8:
1622       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
1623         Relocate_functions<32, false>::rel8(view, object, psymval);
1624       break;
1625
1626     case elfcpp::R_386_PC8:
1627       {
1628         int ref_flags = Symbol::NON_PIC_REF;
1629         if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1630           ref_flags |= Symbol::FUNCTION_CALL;
1631         if (should_apply_static_reloc(gsym, ref_flags, false))
1632           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1633       }
1634       break;
1635
1636     case elfcpp::R_386_PLT32:
1637       gold_assert(gsym == NULL
1638                   || gsym->has_plt_offset()
1639                   || gsym->final_value_is_known()
1640                   || (gsym->is_defined()
1641                       && !gsym->is_from_dynobj()
1642                       && !gsym->is_preemptible()));
1643       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1644       break;
1645
1646     case elfcpp::R_386_GOT32:
1647       gold_assert(have_got_offset);
1648       Relocate_functions<32, false>::rel32(view, got_offset);
1649       break;
1650
1651     case elfcpp::R_386_GOTOFF:
1652       {
1653         elfcpp::Elf_types<32>::Elf_Addr value;
1654         value = (psymval->value(object, 0)
1655                  - target->got_plt_section()->address());
1656         Relocate_functions<32, false>::rel32(view, value);
1657       }
1658       break;
1659
1660     case elfcpp::R_386_GOTPC:
1661       {
1662         elfcpp::Elf_types<32>::Elf_Addr value;
1663         value = target->got_plt_section()->address();
1664         Relocate_functions<32, false>::pcrel32(view, value, address);
1665       }
1666       break;
1667
1668     case elfcpp::R_386_COPY:
1669     case elfcpp::R_386_GLOB_DAT:
1670     case elfcpp::R_386_JUMP_SLOT:
1671     case elfcpp::R_386_RELATIVE:
1672       // These are outstanding tls relocs, which are unexpected when
1673       // linking.
1674     case elfcpp::R_386_TLS_TPOFF:
1675     case elfcpp::R_386_TLS_DTPMOD32:
1676     case elfcpp::R_386_TLS_DTPOFF32:
1677     case elfcpp::R_386_TLS_TPOFF32:
1678     case elfcpp::R_386_TLS_DESC:
1679       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1680                              _("unexpected reloc %u in object file"),
1681                              r_type);
1682       break;
1683
1684       // These are initial tls relocs, which are expected when
1685       // linking.
1686     case elfcpp::R_386_TLS_GD:             // Global-dynamic
1687     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
1688     case elfcpp::R_386_TLS_DESC_CALL:
1689     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
1690     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
1691     case elfcpp::R_386_TLS_IE:             // Initial-exec
1692     case elfcpp::R_386_TLS_IE_32:
1693     case elfcpp::R_386_TLS_GOTIE:
1694     case elfcpp::R_386_TLS_LE:             // Local-exec
1695     case elfcpp::R_386_TLS_LE_32:
1696       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1697                          view, address, view_size);
1698       break;
1699
1700     case elfcpp::R_386_32PLT:
1701     case elfcpp::R_386_TLS_GD_32:
1702     case elfcpp::R_386_TLS_GD_PUSH:
1703     case elfcpp::R_386_TLS_GD_CALL:
1704     case elfcpp::R_386_TLS_GD_POP:
1705     case elfcpp::R_386_TLS_LDM_32:
1706     case elfcpp::R_386_TLS_LDM_PUSH:
1707     case elfcpp::R_386_TLS_LDM_CALL:
1708     case elfcpp::R_386_TLS_LDM_POP:
1709     case elfcpp::R_386_USED_BY_INTEL_200:
1710     default:
1711       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1712                              _("unsupported reloc %u"),
1713                              r_type);
1714       break;
1715     }
1716
1717   return true;
1718 }
1719
1720 // Perform a TLS relocation.
1721
1722 inline void
1723 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1724                                     Target_i386* target,
1725                                     size_t relnum,
1726                                     const elfcpp::Rel<32, false>& rel,
1727                                     unsigned int r_type,
1728                                     const Sized_symbol<32>* gsym,
1729                                     const Symbol_value<32>* psymval,
1730                                     unsigned char* view,
1731                                     elfcpp::Elf_types<32>::Elf_Addr,
1732                                     section_size_type view_size)
1733 {
1734   Output_segment* tls_segment = relinfo->layout->tls_segment();
1735
1736   const Sized_relobj<32, false>* object = relinfo->object;
1737
1738   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1739
1740   const bool is_final = (gsym == NULL
1741                          ? !parameters->output_is_position_independent()
1742                          : gsym->final_value_is_known());
1743   const tls::Tls_optimization optimized_type
1744       = Target_i386::optimize_tls_reloc(is_final, r_type);
1745   switch (r_type)
1746     {
1747     case elfcpp::R_386_TLS_GD:           // Global-dynamic
1748       if (optimized_type == tls::TLSOPT_TO_LE)
1749         {
1750           gold_assert(tls_segment != NULL);
1751           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1752                              rel, r_type, value, view,
1753                              view_size);
1754           break;
1755         }
1756       else
1757         {
1758           unsigned int got_offset;
1759           if (gsym != NULL)
1760             {
1761               gold_assert(gsym->has_tls_got_offset(true));
1762               got_offset = gsym->tls_got_offset(true) - target->got_size();
1763             }
1764           else
1765             {
1766               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1767               gold_assert(object->local_has_tls_got_offset(r_sym, true));
1768               got_offset = (object->local_tls_got_offset(r_sym, true)
1769                             - target->got_size());
1770             }
1771           if (optimized_type == tls::TLSOPT_TO_IE)
1772             {
1773               gold_assert(tls_segment != NULL);
1774               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1775                                  got_offset, view, view_size);
1776               break;
1777             }
1778           else if (optimized_type == tls::TLSOPT_NONE)
1779             {
1780               // Relocate the field with the offset of the pair of GOT
1781               // entries.
1782               Relocate_functions<32, false>::rel32(view, got_offset);
1783               break;
1784             }
1785         }
1786       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1787                              _("unsupported reloc %u"),
1788                              r_type);
1789       break;
1790
1791     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
1792     case elfcpp::R_386_TLS_DESC_CALL:
1793       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1794                              _("unsupported reloc %u"),
1795                              r_type);
1796       break;
1797
1798     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
1799       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1800         {
1801           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1802                                  _("both SUN and GNU model "
1803                                    "TLS relocations"));
1804           break;
1805         }
1806       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1807       if (optimized_type == tls::TLSOPT_TO_LE)
1808         {
1809           gold_assert(tls_segment != NULL);
1810           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1811                              value, view, view_size);
1812           break;
1813         }
1814       else if (optimized_type == tls::TLSOPT_NONE)
1815         {
1816           // Relocate the field with the offset of the GOT entry for
1817           // the module index.
1818           unsigned int got_offset;
1819           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
1820                         - target->got_size());
1821           Relocate_functions<32, false>::rel32(view, got_offset);
1822           break;
1823         }
1824       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1825                              _("unsupported reloc %u"),
1826                              r_type);
1827       break;
1828
1829     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
1830       // This reloc can appear in debugging sections, in which case we
1831       // won't see the TLS_LDM reloc.  The local_dynamic_type field
1832       // tells us this.
1833       if (optimized_type == tls::TLSOPT_TO_LE)
1834         {
1835           gold_assert(tls_segment != NULL);
1836           value -= tls_segment->memsz();
1837         }
1838       Relocate_functions<32, false>::rel32(view, value);
1839       break;
1840
1841     case elfcpp::R_386_TLS_IE:           // Initial-exec
1842     case elfcpp::R_386_TLS_GOTIE:
1843     case elfcpp::R_386_TLS_IE_32:
1844       if (optimized_type == tls::TLSOPT_TO_LE)
1845         {
1846           gold_assert(tls_segment != NULL);
1847           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
1848                                               rel, r_type, value, view,
1849                                               view_size);
1850           break;
1851         }
1852       else if (optimized_type == tls::TLSOPT_NONE)
1853         {
1854           // Relocate the field with the offset of the GOT entry for
1855           // the tp-relative offset of the symbol.
1856           unsigned int got_offset;
1857           if (gsym != NULL)
1858             {
1859               gold_assert(gsym->has_got_offset());
1860               got_offset = gsym->got_offset();
1861             }
1862           else
1863             {
1864               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1865               gold_assert(object->local_has_got_offset(r_sym));
1866               got_offset = object->local_got_offset(r_sym);
1867             }
1868           // For the R_386_TLS_IE relocation, we need to apply the
1869           // absolute address of the GOT entry.
1870           if (r_type == elfcpp::R_386_TLS_IE)
1871             got_offset += target->got_plt_section()->address();
1872           // All GOT offsets are relative to the end of the GOT.
1873           got_offset -= target->got_size();
1874           Relocate_functions<32, false>::rel32(view, got_offset);
1875           break;
1876         }
1877       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1878                              _("unsupported reloc %u"),
1879                              r_type);
1880       break;
1881
1882     case elfcpp::R_386_TLS_LE:           // Local-exec
1883       // If we're creating a shared library, a dynamic relocation will
1884       // have been created for this location, so do not apply it now.
1885       if (!parameters->output_is_shared())
1886         {
1887           gold_assert(tls_segment != NULL);
1888           value -= tls_segment->memsz();
1889           Relocate_functions<32, false>::rel32(view, value);
1890         }
1891       break;
1892
1893     case elfcpp::R_386_TLS_LE_32:
1894       // If we're creating a shared library, a dynamic relocation will
1895       // have been created for this location, so do not apply it now.
1896       if (!parameters->output_is_shared())
1897         {
1898           gold_assert(tls_segment != NULL);
1899           value = tls_segment->memsz() - value;
1900           Relocate_functions<32, false>::rel32(view, value);
1901         }
1902       break;
1903     }
1904 }
1905
1906 // Do a relocation in which we convert a TLS General-Dynamic to a
1907 // Local-Exec.
1908
1909 inline void
1910 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
1911                                     size_t relnum,
1912                                     Output_segment* tls_segment,
1913                                     const elfcpp::Rel<32, false>& rel,
1914                                     unsigned int,
1915                                     elfcpp::Elf_types<32>::Elf_Addr value,
1916                                     unsigned char* view,
1917                                     section_size_type view_size)
1918 {
1919   // leal foo(,%reg,1),%eax; call ___tls_get_addr
1920   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1921   // leal foo(%reg),%eax; call ___tls_get_addr
1922   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1923
1924   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1925   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
1926
1927   unsigned char op1 = view[-1];
1928   unsigned char op2 = view[-2];
1929
1930   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1931                  op2 == 0x8d || op2 == 0x04);
1932   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
1933
1934   int roff = 5;
1935
1936   if (op2 == 0x04)
1937     {
1938       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
1939       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
1940       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1941                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
1942       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1943     }
1944   else
1945     {
1946       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1947                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
1948       if (rel.get_r_offset() + 9 < view_size
1949           && view[9] == 0x90)
1950         {
1951           // There is a trailing nop.  Use the size byte subl.
1952           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1953           roff = 6;
1954         }
1955       else
1956         {
1957           // Use the five byte subl.
1958           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1959         }
1960     }
1961
1962   value = tls_segment->memsz() - value;
1963   Relocate_functions<32, false>::rel32(view + roff, value);
1964
1965   // The next reloc should be a PLT32 reloc against __tls_get_addr.
1966   // We can skip it.
1967   this->skip_call_tls_get_addr_ = true;
1968 }
1969
1970 // Do a relocation in which we convert a TLS General-Dynamic to an
1971 // Initial-Exec.
1972
1973 inline void
1974 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
1975                                     size_t relnum,
1976                                     Output_segment* tls_segment,
1977                                     const elfcpp::Rel<32, false>& rel,
1978                                     unsigned int,
1979                                     elfcpp::Elf_types<32>::Elf_Addr value,
1980                                     unsigned char* view,
1981                                     section_size_type view_size)
1982 {
1983   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
1984   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
1985
1986   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1987   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
1988
1989   unsigned char op1 = view[-1];
1990   unsigned char op2 = view[-2];
1991
1992   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1993                  op2 == 0x8d || op2 == 0x04);
1994   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
1995
1996   int roff = 5;
1997
1998   // FIXME: For now, support only one form.
1999   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2000                  op1 == 0x8d && op2 == 0x04);
2001
2002   if (op2 == 0x04)
2003     {
2004       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2005       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2006       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2007                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2008       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2009     }
2010   else
2011     {
2012       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2013                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2014       if (rel.get_r_offset() + 9 < view_size
2015           && view[9] == 0x90)
2016         {
2017           // FIXME: This is not the right instruction sequence.
2018           // There is a trailing nop.  Use the size byte subl.
2019           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2020           roff = 6;
2021         }
2022       else
2023         {
2024           // FIXME: This is not the right instruction sequence.
2025           // Use the five byte subl.
2026           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2027         }
2028     }
2029
2030   value = tls_segment->memsz() - value;
2031   Relocate_functions<32, false>::rel32(view + roff, value);
2032
2033   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2034   // We can skip it.
2035   this->skip_call_tls_get_addr_ = true;
2036 }
2037
2038 // Do a relocation in which we convert a TLS Local-Dynamic to a
2039 // Local-Exec.
2040
2041 inline void
2042 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2043                                     size_t relnum,
2044                                     Output_segment*,
2045                                     const elfcpp::Rel<32, false>& rel,
2046                                     unsigned int,
2047                                     elfcpp::Elf_types<32>::Elf_Addr,
2048                                     unsigned char* view,
2049                                     section_size_type view_size)
2050 {
2051   // leal foo(%reg), %eax; call ___tls_get_addr
2052   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2053
2054   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2055   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2056
2057   // FIXME: Does this test really always pass?
2058   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2059                  view[-2] == 0x8d && view[-1] == 0x83);
2060
2061   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2062
2063   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2064
2065   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2066   // We can skip it.
2067   this->skip_call_tls_get_addr_ = true;
2068 }
2069
2070 // Do a relocation in which we convert a TLS Initial-Exec to a
2071 // Local-Exec.
2072
2073 inline void
2074 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2075                                     size_t relnum,
2076                                     Output_segment* tls_segment,
2077                                     const elfcpp::Rel<32, false>& rel,
2078                                     unsigned int r_type,
2079                                     elfcpp::Elf_types<32>::Elf_Addr value,
2080                                     unsigned char* view,
2081                                     section_size_type view_size)
2082 {
2083   // We have to actually change the instructions, which means that we
2084   // need to examine the opcodes to figure out which instruction we
2085   // are looking at.
2086   if (r_type == elfcpp::R_386_TLS_IE)
2087     {
2088       // movl %gs:XX,%eax  ==>  movl $YY,%eax
2089       // movl %gs:XX,%reg  ==>  movl $YY,%reg
2090       // addl %gs:XX,%reg  ==>  addl $YY,%reg
2091       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2092       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2093
2094       unsigned char op1 = view[-1];
2095       if (op1 == 0xa1)
2096         {
2097           // movl XX,%eax  ==>  movl $YY,%eax
2098           view[-1] = 0xb8;
2099         }
2100       else
2101         {
2102           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2103
2104           unsigned char op2 = view[-2];
2105           if (op2 == 0x8b)
2106             {
2107               // movl XX,%reg  ==>  movl $YY,%reg
2108               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2109                              (op1 & 0xc7) == 0x05);
2110               view[-2] = 0xc7;
2111               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2112             }
2113           else if (op2 == 0x03)
2114             {
2115               // addl XX,%reg  ==>  addl $YY,%reg
2116               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2117                              (op1 & 0xc7) == 0x05);
2118               view[-2] = 0x81;
2119               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2120             }
2121           else
2122             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2123         }
2124     }
2125   else
2126     {
2127       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2128       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2129       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2130       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2131       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2132
2133       unsigned char op1 = view[-1];
2134       unsigned char op2 = view[-2];
2135       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2136                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2137       if (op2 == 0x8b)
2138         {
2139           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2140           view[-2] = 0xc7;
2141           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2142         }
2143       else if (op2 == 0x2b)
2144         {
2145           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2146           view[-2] = 0x81;
2147           view[-1] = 0xe8 | ((op1 >> 3) & 7);
2148         }
2149       else if (op2 == 0x03)
2150         {
2151           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2152           view[-2] = 0x81;
2153           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2154         }
2155       else
2156         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2157     }
2158
2159   value = tls_segment->memsz() - value;
2160   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2161     value = - value;
2162
2163   Relocate_functions<32, false>::rel32(view, value);
2164 }
2165
2166 // Relocate section data.
2167
2168 void
2169 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2170                               unsigned int sh_type,
2171                               const unsigned char* prelocs,
2172                               size_t reloc_count,
2173                               Output_section* output_section,
2174                               bool needs_special_offset_handling,
2175                               unsigned char* view,
2176                               elfcpp::Elf_types<32>::Elf_Addr address,
2177                               section_size_type view_size)
2178 {
2179   gold_assert(sh_type == elfcpp::SHT_REL);
2180
2181   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2182                          Target_i386::Relocate>(
2183     relinfo,
2184     this,
2185     prelocs,
2186     reloc_count,
2187     output_section,
2188     needs_special_offset_handling,
2189     view,
2190     address,
2191     view_size);
2192 }
2193
2194 // Return the size of a relocation while scanning during a relocatable
2195 // link.
2196
2197 unsigned int
2198 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2199     unsigned int r_type,
2200     Relobj* object)
2201 {
2202   switch (r_type)
2203     {
2204     case elfcpp::R_386_NONE:
2205     case elfcpp::R_386_GNU_VTINHERIT:
2206     case elfcpp::R_386_GNU_VTENTRY:
2207     case elfcpp::R_386_TLS_GD:            // Global-dynamic
2208     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
2209     case elfcpp::R_386_TLS_DESC_CALL:
2210     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
2211     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
2212     case elfcpp::R_386_TLS_IE:            // Initial-exec
2213     case elfcpp::R_386_TLS_IE_32:
2214     case elfcpp::R_386_TLS_GOTIE:
2215     case elfcpp::R_386_TLS_LE:            // Local-exec
2216     case elfcpp::R_386_TLS_LE_32:
2217       return 0;
2218
2219     case elfcpp::R_386_32:
2220     case elfcpp::R_386_PC32:
2221     case elfcpp::R_386_GOT32:
2222     case elfcpp::R_386_PLT32:
2223     case elfcpp::R_386_GOTOFF:
2224     case elfcpp::R_386_GOTPC:
2225      return 4;
2226
2227     case elfcpp::R_386_16:
2228     case elfcpp::R_386_PC16:
2229       return 2;
2230
2231     case elfcpp::R_386_8:
2232     case elfcpp::R_386_PC8:
2233       return 1;
2234
2235       // These are relocations which should only be seen by the
2236       // dynamic linker, and should never be seen here.
2237     case elfcpp::R_386_COPY:
2238     case elfcpp::R_386_GLOB_DAT:
2239     case elfcpp::R_386_JUMP_SLOT:
2240     case elfcpp::R_386_RELATIVE:
2241     case elfcpp::R_386_TLS_TPOFF:
2242     case elfcpp::R_386_TLS_DTPMOD32:
2243     case elfcpp::R_386_TLS_DTPOFF32:
2244     case elfcpp::R_386_TLS_TPOFF32:
2245     case elfcpp::R_386_TLS_DESC:
2246       object->error(_("unexpected reloc %u in object file"), r_type);
2247       return 0;
2248
2249     case elfcpp::R_386_32PLT:
2250     case elfcpp::R_386_TLS_GD_32:
2251     case elfcpp::R_386_TLS_GD_PUSH:
2252     case elfcpp::R_386_TLS_GD_CALL:
2253     case elfcpp::R_386_TLS_GD_POP:
2254     case elfcpp::R_386_TLS_LDM_32:
2255     case elfcpp::R_386_TLS_LDM_PUSH:
2256     case elfcpp::R_386_TLS_LDM_CALL:
2257     case elfcpp::R_386_TLS_LDM_POP:
2258     case elfcpp::R_386_USED_BY_INTEL_200:
2259     default:
2260       object->error(_("unsupported reloc %u in object file"), r_type);
2261       return 0;
2262     }
2263 }
2264
2265 // Scan the relocs during a relocatable link.
2266
2267 void
2268 Target_i386::scan_relocatable_relocs(const General_options& options,
2269                                      Symbol_table* symtab,
2270                                      Layout* layout,
2271                                      Sized_relobj<32, false>* object,
2272                                      unsigned int data_shndx,
2273                                      unsigned int sh_type,
2274                                      const unsigned char* prelocs,
2275                                      size_t reloc_count,
2276                                      Output_section* output_section,
2277                                      bool needs_special_offset_handling,
2278                                      size_t local_symbol_count,
2279                                      const unsigned char* plocal_symbols,
2280                                      Relocatable_relocs* rr)
2281 {
2282   gold_assert(sh_type == elfcpp::SHT_REL);
2283
2284   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2285     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2286
2287   gold::scan_relocatable_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2288       Scan_relocatable_relocs>(
2289     options,
2290     symtab,
2291     layout,
2292     object,
2293     data_shndx,
2294     prelocs,
2295     reloc_count,
2296     output_section,
2297     needs_special_offset_handling,
2298     local_symbol_count,
2299     plocal_symbols,
2300     rr);
2301 }
2302
2303 // Relocate a section during a relocatable link.
2304
2305 void
2306 Target_i386::relocate_for_relocatable(
2307     const Relocate_info<32, false>* relinfo,
2308     unsigned int sh_type,
2309     const unsigned char* prelocs,
2310     size_t reloc_count,
2311     Output_section* output_section,
2312     off_t offset_in_output_section,
2313     const Relocatable_relocs* rr,
2314     unsigned char* view,
2315     elfcpp::Elf_types<32>::Elf_Addr view_address,
2316     section_size_type view_size,
2317     unsigned char* reloc_view,
2318     section_size_type reloc_view_size)
2319 {
2320   gold_assert(sh_type == elfcpp::SHT_REL);
2321
2322   gold::relocate_for_relocatable<32, false, Target_i386, elfcpp::SHT_REL>(
2323     relinfo,
2324     prelocs,
2325     reloc_count,
2326     output_section,
2327     offset_in_output_section,
2328     rr,
2329     view,
2330     view_address,
2331     view_size,
2332     reloc_view,
2333     reloc_view_size);
2334 }
2335
2336 // Return the value to use for a dynamic which requires special
2337 // treatment.  This is how we support equality comparisons of function
2338 // pointers across shared library boundaries, as described in the
2339 // processor specific ABI supplement.
2340
2341 uint64_t
2342 Target_i386::do_dynsym_value(const Symbol* gsym) const
2343 {
2344   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2345   return this->plt_section()->address() + gsym->plt_offset();
2346 }
2347
2348 // Return a string used to fill a code section with nops to take up
2349 // the specified length.
2350
2351 std::string
2352 Target_i386::do_code_fill(section_size_type length)
2353 {
2354   if (length >= 16)
2355     {
2356       // Build a jmp instruction to skip over the bytes.
2357       unsigned char jmp[5];
2358       jmp[0] = 0xe9;
2359       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2360       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2361               + std::string(length - 5, '\0'));
2362     }
2363
2364   // Nop sequences of various lengths.
2365   const char nop1[1] = { 0x90 };                   // nop
2366   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2367   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
2368   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
2369   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
2370                          0x00 };                   // leal 0(%esi,1),%esi
2371   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
2372                          0x00, 0x00 };
2373   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
2374                          0x00, 0x00, 0x00 };
2375   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
2376                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2377   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
2378                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
2379                          0x00 };
2380   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2381                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2382                            0x00, 0x00 };
2383   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2384                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2385                            0x00, 0x00, 0x00 };
2386   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2387                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2388                            0x00, 0x00, 0x00, 0x00 };
2389   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2390                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2391                            0x27, 0x00, 0x00, 0x00,
2392                            0x00 };
2393   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2394                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2395                            0xbc, 0x27, 0x00, 0x00,
2396                            0x00, 0x00 };
2397   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2398                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2399                            0x90, 0x90, 0x90, 0x90,
2400                            0x90, 0x90, 0x90 };
2401
2402   const char* nops[16] = {
2403     NULL,
2404     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2405     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2406   };
2407
2408   return std::string(nops[length], length);
2409 }
2410
2411 // The selector for i386 object files.
2412
2413 class Target_selector_i386 : public Target_selector
2414 {
2415 public:
2416   Target_selector_i386()
2417     : Target_selector(elfcpp::EM_386, 32, false)
2418   { }
2419
2420   Target*
2421   recognize(int machine, int osabi, int abiversion);
2422
2423  private:
2424   Target_i386* target_;
2425 };
2426
2427 // Recognize an i386 object file when we already know that the machine
2428 // number is EM_386.
2429
2430 Target*
2431 Target_selector_i386::recognize(int, int, int)
2432 {
2433   if (this->target_ == NULL)
2434     this->target_ = new Target_i386();
2435   return this->target_;
2436 }
2437
2438 Target_selector_i386 target_selector_i386;
2439
2440 } // End anonymous namespace.