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)
  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               size_t local_symbol_count,
  74               const unsigned char* plocal_symbols,
  75               Symbol** global_symbols);
  76
  77   // Finalize the sections.
  78   void
  79   do_finalize_sections(Layout*);
  80
  81   // Return the value to use for a dynamic which requires special
  82   // treatment.
  83   uint64_t
  84   do_dynsym_value(const Symbol*) const;
  85
  86   // Relocate a section.
  87   void
  88   relocate_section(const Relocate_info<32, false>*,
  89                    unsigned int sh_type,
  90                    const unsigned char* prelocs,
  91                    size_t reloc_count,
  92                    unsigned char* view,
  93                    elfcpp::Elf_types<32>::Elf_Addr view_address,
  94                    off_t view_size);
  95
  96   // Return a string used to fill a code section with nops.
  97   std::string
  98   do_code_fill(off_t length);
  99
 100   // Return the size of the GOT section.
 101   off_t
 102   got_size()
 103   {
 104     gold_assert(this->got_ != NULL);
 105     return this->got_->data_size();
 106   }
 107
 108  private:
 109   // The class which scans relocations.
 110   struct Scan
 111   {
 112     inline void
 113     local(const General_options& options, Symbol_table* symtab,
 114           Layout* layout, Target_i386* target,
 115           Sized_relobj<32, false>* object,
 116           unsigned int data_shndx,
 117           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 118           const elfcpp::Sym<32, false>& lsym);
 119
 120     inline void
 121     global(const General_options& options, Symbol_table* symtab,
 122            Layout* layout, Target_i386* target,
 123            Sized_relobj<32, false>* object,
 124            unsigned int data_shndx,
 125            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 126            Symbol* gsym);
 127
 128     static void
 129     unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
 130
 131     static void
 132     unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
 133                              Symbol*);
 134   };
 135
 136   // The class which implements relocation.
 137   class Relocate
 138   {
 139    public:
 140     Relocate()
 141       : skip_call_tls_get_addr_(false),
 142         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
 143     { }
 144
 145     ~Relocate()
 146     {
 147       if (this->skip_call_tls_get_addr_)
 148         {
 149           // FIXME: This needs to specify the location somehow.
 150           gold_error(_("missing expected TLS relocation"));
 151         }
 152     }
 153
 154     // Do a relocation.  Return false if the caller should not issue
 155     // any warnings about this relocation.
 156     inline bool
 157     relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
 158              const elfcpp::Rel<32, false>&,
 159              unsigned int r_type, const Sized_symbol<32>*,
 160              const Symbol_value<32>*,
 161              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 162              off_t);
 163
 164    private:
 165     // Do a TLS relocation.
 166     inline void
 167     relocate_tls(const Relocate_info<32, false>*, size_t relnum,
 168                  const elfcpp::Rel<32, false>&,
 169                  unsigned int r_type, const Sized_symbol<32>*,
 170                  const Symbol_value<32>*,
 171                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t);
 172
 173     // Do a TLS General-Dynamic to Local-Exec transition.
 174     inline void
 175     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 176                  Output_segment* tls_segment,
 177                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 178                  elfcpp::Elf_types<32>::Elf_Addr value,
 179                  unsigned char* view,
 180                  off_t view_size);
 181
 182     // Do a TLS Local-Dynamic to Local-Exec transition.
 183     inline void
 184     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
 185                  Output_segment* tls_segment,
 186                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 187                  elfcpp::Elf_types<32>::Elf_Addr value,
 188                  unsigned char* view,
 189                  off_t view_size);
 190
 191     // Do a TLS Initial-Exec to Local-Exec transition.
 192     static inline void
 193     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 194                  Output_segment* tls_segment,
 195                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 196                  elfcpp::Elf_types<32>::Elf_Addr value,
 197                  unsigned char* view,
 198                  off_t view_size);
 199
 200     // We need to keep track of which type of local dynamic relocation
 201     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
 202     enum Local_dynamic_type
 203     {
 204       LOCAL_DYNAMIC_NONE,
 205       LOCAL_DYNAMIC_SUN,
 206       LOCAL_DYNAMIC_GNU
 207     };
 208
 209     // This is set if we should skip the next reloc, which should be a
 210     // PLT32 reloc against ___tls_get_addr.
 211     bool skip_call_tls_get_addr_;
 212     // The type of local dynamic relocation we have seen in the section
 213     // being relocated, if any.
 214     Local_dynamic_type local_dynamic_type_;
 215   };
 216
 217   // Adjust TLS relocation type based on the options and whether this
 218   // is a local symbol.
 219   static tls::Tls_optimization
 220   optimize_tls_reloc(bool is_final, int r_type);
 221
 222   // Get the GOT section, creating it if necessary.
 223   Output_data_got<32, false>*
 224   got_section(Symbol_table*, Layout*);
 225
 226   // Get the GOT PLT section.
 227   Output_data_space*
 228   got_plt_section() const
 229   {
 230     gold_assert(this->got_plt_ != NULL);
 231     return this->got_plt_;
 232   }
 233
 234   // Create a PLT entry for a global symbol.
 235   void
 236   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 237
 238   // Get the PLT section.
 239   const Output_data_plt_i386*
 240   plt_section() const
 241   {
 242     gold_assert(this->plt_ != NULL);
 243     return this->plt_;
 244   }
 245
 246   // Get the dynamic reloc section, creating it if necessary.
 247   Reloc_section*
 248   rel_dyn_section(Layout*);
 249
 250   // Copy a relocation against a global symbol.
 251   void
 252   copy_reloc(const General_options*, Symbol_table*, Layout*,
 253              Sized_relobj<32, false>*, unsigned int,
 254              Symbol*, const elfcpp::Rel<32, false>&);
 255
 256   // Information about this specific target which we pass to the
 257   // general Target structure.
 258   static const Target::Target_info i386_info;
 259
 260   // The GOT section.
 261   Output_data_got<32, false>* got_;
 262   // The PLT section.
 263   Output_data_plt_i386* plt_;
 264   // The GOT PLT section.
 265   Output_data_space* got_plt_;
 266   // The dynamic reloc section.
 267   Reloc_section* rel_dyn_;
 268   // Relocs saved to avoid a COPY reloc.
 269   Copy_relocs<32, false>* copy_relocs_;
 270   // Space for variables copied with a COPY reloc.
 271   Output_data_space* dynbss_;
 272 };
 273
 274 const Target::Target_info Target_i386::i386_info =
 275 {
 276   32,                   // size
 277   false,                // is_big_endian
 278   elfcpp::EM_386,       // machine_code
 279   false,                // has_make_symbol
 280   false,                // has_resolve
 281   true,                 // has_code_fill
 282   true,                 // is_default_stack_executable
 283   "/usr/lib/libc.so.1", // dynamic_linker
 284   0x08048000,           // default_text_segment_address
 285   0x1000,               // abi_pagesize
 286   0x1000                // common_pagesize
 287 };
 288
 289 // Get the GOT section, creating it if necessary.
 290
 291 Output_data_got<32, false>*
 292 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
 293 {
 294   if (this->got_ == NULL)
 295     {
 296       gold_assert(symtab != NULL && layout != NULL);
 297
 298       this->got_ = new Output_data_got<32, false>();
 299
 300       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 301                                       elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
 302                                       this->got_);
 303
 304       // The old GNU linker creates a .got.plt section.  We just
 305       // create another set of data in the .got section.  Note that we
 306       // always create a PLT if we create a GOT, although the PLT
 307       // might be empty.
 308       this->got_plt_ = new Output_data_space(4);
 309       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 310                                       elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
 311                                       this->got_plt_);
 312
 313       // The first three entries are reserved.
 314       this->got_plt_->set_space_size(3 * 4);
 315
 316       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 317       symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL,
 318                                     this->got_plt_,
 319                                     0, 0, elfcpp::STT_OBJECT,
 320                                     elfcpp::STB_LOCAL,
 321                                     elfcpp::STV_HIDDEN, 0,
 322                                     false, false);
 323     }
 324
 325   return this->got_;
 326 }
 327
 328 // Get the dynamic reloc section, creating it if necessary.
 329
 330 Target_i386::Reloc_section*
 331 Target_i386::rel_dyn_section(Layout* layout)
 332 {
 333   if (this->rel_dyn_ == NULL)
 334     {
 335       gold_assert(layout != NULL);
 336       this->rel_dyn_ = new Reloc_section();
 337       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 338                                       elfcpp::SHF_ALLOC, this->rel_dyn_);
 339     }
 340   return this->rel_dyn_;
 341 }
 342
 343 // A class to handle the PLT data.
 344
 345 class Output_data_plt_i386 : public Output_section_data
 346 {
 347  public:
 348   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 349
 350   Output_data_plt_i386(Layout*, Output_data_space*);
 351
 352   // Add an entry to the PLT.
 353   void
 354   add_entry(Symbol* gsym);
 355
 356   // Return the .rel.plt section data.
 357   const Reloc_section*
 358   rel_plt() const
 359   { return this->rel_; }
 360
 361  protected:
 362   void
 363   do_adjust_output_section(Output_section* os);
 364
 365  private:
 366   // The size of an entry in the PLT.
 367   static const int plt_entry_size = 16;
 368
 369   // The first entry in the PLT for an executable.
 370   static unsigned char exec_first_plt_entry[plt_entry_size];
 371
 372   // The first entry in the PLT for a shared object.
 373   static unsigned char dyn_first_plt_entry[plt_entry_size];
 374
 375   // Other entries in the PLT for an executable.
 376   static unsigned char exec_plt_entry[plt_entry_size];
 377
 378   // Other entries in the PLT for a shared object.
 379   static unsigned char dyn_plt_entry[plt_entry_size];
 380
 381   // Set the final size.
 382   void
 383   do_set_address(uint64_t, off_t)
 384   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
 385
 386   // Write out the PLT data.
 387   void
 388   do_write(Output_file*);
 389
 390   // The reloc section.
 391   Reloc_section* rel_;
 392   // The .got.plt section.
 393   Output_data_space* got_plt_;
 394   // The number of PLT entries.
 395   unsigned int count_;
 396 };
 397
 398 // Create the PLT section.  The ordinary .got section is an argument,
 399 // since we need to refer to the start.  We also create our own .got
 400 // section just for PLT entries.
 401
 402 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
 403                                            Output_data_space* got_plt)
 404   : Output_section_data(4), got_plt_(got_plt), count_(0)
 405 {
 406   this->rel_ = new Reloc_section();
 407   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 408                                   elfcpp::SHF_ALLOC, this->rel_);
 409 }
 410
 411 void
 412 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 413 {
 414   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 415   // linker, and so do we.
 416   os->set_entsize(4);
 417 }
 418
 419 // Add an entry to the PLT.
 420
 421 void
 422 Output_data_plt_i386::add_entry(Symbol* gsym)
 423 {
 424   gold_assert(!gsym->has_plt_offset());
 425
 426   // Note that when setting the PLT offset we skip the initial
 427   // reserved PLT entry.
 428   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 429
 430   ++this->count_;
 431
 432   off_t got_offset = this->got_plt_->data_size();
 433
 434   // Every PLT entry needs a GOT entry which points back to the PLT
 435   // entry (this will be changed by the dynamic linker, normally
 436   // lazily when the function is called).
 437   this->got_plt_->set_space_size(got_offset + 4);
 438
 439   // Every PLT entry needs a reloc.
 440   gsym->set_needs_dynsym_entry();
 441   this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 442                          got_offset);
 443
 444   // Note that we don't need to save the symbol.  The contents of the
 445   // PLT are independent of which symbols are used.  The symbols only
 446   // appear in the relocations.
 447 }
 448
 449 // The first entry in the PLT for an executable.
 450
 451 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 452 {
 453   0xff, 0x35,   // pushl contents of memory address
 454   0, 0, 0, 0,   // replaced with address of .got + 4
 455   0xff, 0x25,   // jmp indirect
 456   0, 0, 0, 0,   // replaced with address of .got + 8
 457   0, 0, 0, 0    // unused
 458 };
 459
 460 // The first entry in the PLT for a shared object.
 461
 462 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
 463 {
 464   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
 465   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
 466   0, 0, 0, 0                    // unused
 467 };
 468
 469 // Subsequent entries in the PLT for an executable.
 470
 471 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
 472 {
 473   0xff, 0x25,   // jmp indirect
 474   0, 0, 0, 0,   // replaced with address of symbol in .got
 475   0x68,         // pushl immediate
 476   0, 0, 0, 0,   // replaced with offset into relocation table
 477   0xe9,         // jmp relative
 478   0, 0, 0, 0    // replaced with offset to start of .plt
 479 };
 480
 481 // Subsequent entries in the PLT for a shared object.
 482
 483 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
 484 {
 485   0xff, 0xa3,   // jmp *offset(%ebx)
 486   0, 0, 0, 0,   // replaced with offset of symbol in .got
 487   0x68,         // pushl immediate
 488   0, 0, 0, 0,   // replaced with offset into relocation table
 489   0xe9,         // jmp relative
 490   0, 0, 0, 0    // replaced with offset to start of .plt
 491 };
 492
 493 // Write out the PLT.  This uses the hand-coded instructions above,
 494 // and adjusts them as needed.  This is all specified by the i386 ELF
 495 // Processor Supplement.
 496
 497 void
 498 Output_data_plt_i386::do_write(Output_file* of)
 499 {
 500   const off_t offset = this->offset();
 501   const off_t oview_size = this->data_size();
 502   unsigned char* const oview = of->get_output_view(offset, oview_size);
 503
 504   const off_t got_file_offset = this->got_plt_->offset();
 505   const off_t got_size = this->got_plt_->data_size();
 506   unsigned char* const got_view = of->get_output_view(got_file_offset,
 507                                                       got_size);
 508
 509   unsigned char* pov = oview;
 510
 511   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
 512   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
 513
 514   if (parameters->output_is_shared())
 515     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
 516   else
 517     {
 518       memcpy(pov, exec_first_plt_entry, plt_entry_size);
 519       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
 520       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
 521     }
 522   pov += plt_entry_size;
 523
 524   unsigned char* got_pov = got_view;
 525
 526   memset(got_pov, 0, 12);
 527   got_pov += 12;
 528
 529   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
 530
 531   unsigned int plt_offset = plt_entry_size;
 532   unsigned int plt_rel_offset = 0;
 533   unsigned int got_offset = 12;
 534   const unsigned int count = this->count_;
 535   for (unsigned int i = 0;
 536        i < count;
 537        ++i,
 538          pov += plt_entry_size,
 539          got_pov += 4,
 540          plt_offset += plt_entry_size,
 541          plt_rel_offset += rel_size,
 542          got_offset += 4)
 543     {
 544       // Set and adjust the PLT entry itself.
 545
 546       if (parameters->output_is_shared())
 547         {
 548           memcpy(pov, dyn_plt_entry, plt_entry_size);
 549           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
 550         }
 551       else
 552         {
 553           memcpy(pov, exec_plt_entry, plt_entry_size);
 554           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 555                                                       (got_address
 556                                                        + got_offset));
 557         }
 558
 559       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
 560       elfcpp::Swap<32, false>::writeval(pov + 12,
 561                                         - (plt_offset + plt_entry_size));
 562
 563       // Set the entry in the GOT.
 564       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
 565     }
 566
 567   gold_assert(pov - oview == oview_size);
 568   gold_assert(got_pov - got_view == got_size);
 569
 570   of->write_output_view(offset, oview_size, oview);
 571   of->write_output_view(got_file_offset, got_size, got_view);
 572 }
 573
 574 // Create a PLT entry for a global symbol.
 575
 576 void
 577 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
 578 {
 579   if (gsym->has_plt_offset())
 580     return;
 581
 582   if (this->plt_ == NULL)
 583     {
 584       // Create the GOT sections first.
 585       this->got_section(symtab, layout);
 586
 587       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
 588       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 589                                       (elfcpp::SHF_ALLOC
 590                                        | elfcpp::SHF_EXECINSTR),
 591                                       this->plt_);
 592     }
 593
 594   this->plt_->add_entry(gsym);
 595 }
 596
 597 // Handle a relocation against a non-function symbol defined in a
 598 // dynamic object.  The traditional way to handle this is to generate
 599 // a COPY relocation to copy the variable at runtime from the shared
 600 // object into the executable's data segment.  However, this is
 601 // undesirable in general, as if the size of the object changes in the
 602 // dynamic object, the executable will no longer work correctly.  If
 603 // this relocation is in a writable section, then we can create a
 604 // dynamic reloc and the dynamic linker will resolve it to the correct
 605 // address at runtime.  However, we do not want do that if the
 606 // relocation is in a read-only section, as it would prevent the
 607 // readonly segment from being shared.  And if we have to eventually
 608 // generate a COPY reloc, then any dynamic relocations will be
 609 // useless.  So this means that if this is a writable section, we need
 610 // to save the relocation until we see whether we have to create a
 611 // COPY relocation for this symbol for any other relocation.
 612
 613 void
 614 Target_i386::copy_reloc(const General_options* options,
 615                         Symbol_table* symtab,
 616                         Layout* layout,
 617                         Sized_relobj<32, false>* object,
 618                         unsigned int data_shndx, Symbol* gsym,
 619                         const elfcpp::Rel<32, false>& rel)
 620 {
 621   Sized_symbol<32>* ssym;
 622   ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym
 623                                                         SELECT_SIZE(32));
 624
 625   if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
 626                                                data_shndx, ssym))
 627     {
 628       // So far we do not need a COPY reloc.  Save this relocation.
 629       // If it turns out that we never need a COPY reloc for this
 630       // symbol, then we will emit the relocation.
 631       if (this->copy_relocs_ == NULL)
 632         this->copy_relocs_ = new Copy_relocs<32, false>();
 633       this->copy_relocs_->save(ssym, object, data_shndx, rel);
 634     }
 635   else
 636     {
 637       // Allocate space for this symbol in the .bss section.
 638
 639       elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
 640
 641       // There is no defined way to determine the required alignment
 642       // of the symbol.  We pick the alignment based on the size.  We
 643       // set an arbitrary maximum of 256.
 644       unsigned int align;
 645       for (align = 1; align < 512; align <<= 1)
 646         if ((symsize & align) != 0)
 647           break;
 648
 649       if (this->dynbss_ == NULL)
 650         {
 651           this->dynbss_ = new Output_data_space(align);
 652           layout->add_output_section_data(".bss",
 653                                           elfcpp::SHT_NOBITS,
 654                                           (elfcpp::SHF_ALLOC
 655                                            | elfcpp::SHF_WRITE),
 656                                           this->dynbss_);
 657         }
 658
 659       Output_data_space* dynbss = this->dynbss_;
 660
 661       if (align > dynbss->addralign())
 662         dynbss->set_space_alignment(align);
 663
 664       off_t dynbss_size = dynbss->data_size();
 665       dynbss_size = align_address(dynbss_size, align);
 666       off_t offset = dynbss_size;
 667       dynbss->set_space_size(dynbss_size + symsize);
 668
 669       symtab->define_with_copy_reloc(this, ssym, dynbss, offset);
 670
 671       // Add the COPY reloc.
 672       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
 673       rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
 674     }
 675 }
 676
 677 // Optimize the TLS relocation type based on what we know about the
 678 // symbol.  IS_FINAL is true if the final address of this symbol is
 679 // known at link time.
 680
 681 tls::Tls_optimization
 682 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
 683 {
 684   // If we are generating a shared library, then we can't do anything
 685   // in the linker.
 686   if (parameters->output_is_shared())
 687     return tls::TLSOPT_NONE;
 688
 689   switch (r_type)
 690     {
 691     case elfcpp::R_386_TLS_GD:
 692     case elfcpp::R_386_TLS_GOTDESC:
 693     case elfcpp::R_386_TLS_DESC_CALL:
 694       // These are General-Dynamic which permits fully general TLS
 695       // access.  Since we know that we are generating an executable,
 696       // we can convert this to Initial-Exec.  If we also know that
 697       // this is a local symbol, we can further switch to Local-Exec.
 698       if (is_final)
 699         return tls::TLSOPT_TO_LE;
 700       return tls::TLSOPT_TO_IE;
 701
 702     case elfcpp::R_386_TLS_LDM:
 703       // This is Local-Dynamic, which refers to a local symbol in the
 704       // dynamic TLS block.  Since we know that we generating an
 705       // executable, we can switch to Local-Exec.
 706       return tls::TLSOPT_TO_LE;
 707
 708     case elfcpp::R_386_TLS_LDO_32:
 709       // Another type of Local-Dynamic relocation.
 710       return tls::TLSOPT_TO_LE;
 711
 712     case elfcpp::R_386_TLS_IE:
 713     case elfcpp::R_386_TLS_GOTIE:
 714     case elfcpp::R_386_TLS_IE_32:
 715       // These are Initial-Exec relocs which get the thread offset
 716       // from the GOT.  If we know that we are linking against the
 717       // local symbol, we can switch to Local-Exec, which links the
 718       // thread offset into the instruction.
 719       if (is_final)
 720         return tls::TLSOPT_TO_LE;
 721       return tls::TLSOPT_NONE;
 722
 723     case elfcpp::R_386_TLS_LE:
 724     case elfcpp::R_386_TLS_LE_32:
 725       // When we already have Local-Exec, there is nothing further we
 726       // can do.
 727       return tls::TLSOPT_NONE;
 728
 729     default:
 730       gold_unreachable();
 731     }
 732 }
 733
 734 // Report an unsupported relocation against a local symbol.
 735
 736 void
 737 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
 738                                            unsigned int r_type)
 739 {
 740   gold_error(_("%s: unsupported reloc %u against local symbol"),
 741              object->name().c_str(), r_type);
 742 }
 743
 744 // Scan a relocation for a local symbol.
 745
 746 inline void
 747 Target_i386::Scan::local(const General_options&,
 748                          Symbol_table* symtab,
 749                          Layout* layout,
 750                          Target_i386* target,
 751                          Sized_relobj<32, false>* object,
 752                          unsigned int data_shndx,
 753                          const elfcpp::Rel<32, false>& reloc,
 754                          unsigned int r_type,
 755                          const elfcpp::Sym<32, false>&)
 756 {
 757   switch (r_type)
 758     {
 759     case elfcpp::R_386_NONE:
 760     case elfcpp::R_386_GNU_VTINHERIT:
 761     case elfcpp::R_386_GNU_VTENTRY:
 762       break;
 763
 764     case elfcpp::R_386_32:
 765     case elfcpp::R_386_16:
 766     case elfcpp::R_386_8:
 767       // If building a shared library (or a position-independent
 768       // executable), we need to create a dynamic relocation for
 769       // this location. The relocation applied at link time will
 770       // apply the link-time value, so we flag the location with
 771       // an R_386_RELATIVE relocation so the dynamic loader can
 772       // relocate it easily.
 773       if (parameters->output_is_position_independent())
 774         {
 775           // FIXME: R_386_RELATIVE only works for a 32-bit relocation.
 776           gold_assert(r_type != elfcpp::R_386_16 && r_type != elfcpp::R_386_8);
 777
 778           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 779           rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE, data_shndx,
 780                              reloc.get_r_offset());
 781         }
 782       break;
 783
 784     case elfcpp::R_386_PC32:
 785     case elfcpp::R_386_PC16:
 786     case elfcpp::R_386_PC8:
 787       break;
 788
 789     case elfcpp::R_386_PLT32:
 790       // Since we know this is a local symbol, we can handle this as a
 791       // PC32 reloc.
 792       break;
 793
 794     case elfcpp::R_386_GOTOFF:
 795     case elfcpp::R_386_GOTPC:
 796       // We need a GOT section.
 797       target->got_section(symtab, layout);
 798       break;
 799
 800     case elfcpp::R_386_GOT32:
 801       {
 802         // The symbol requires a GOT entry.
 803         Output_data_got<32, false>* got = target->got_section(symtab, layout);
 804         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 805         if (got->add_local(object, r_sym))
 806           {
 807             // If we are generating a shared object, we need to add a
 808             // dynamic RELATIVE relocation for this symbol.
 809             if (parameters->output_is_position_independent())
 810               {
 811                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 812                 rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE,
 813                                    data_shndx, reloc.get_r_offset());
 814               }
 815           }
 816       }
 817       break;
 818
 819       // These are relocations which should only be seen by the
 820       // dynamic linker, and should never be seen here.
 821     case elfcpp::R_386_COPY:
 822     case elfcpp::R_386_GLOB_DAT:
 823     case elfcpp::R_386_JUMP_SLOT:
 824     case elfcpp::R_386_RELATIVE:
 825     case elfcpp::R_386_TLS_TPOFF:
 826     case elfcpp::R_386_TLS_DTPMOD32:
 827     case elfcpp::R_386_TLS_DTPOFF32:
 828     case elfcpp::R_386_TLS_TPOFF32:
 829     case elfcpp::R_386_TLS_DESC:
 830       gold_error(_("%s: unexpected reloc %u in object file"),
 831                  object->name().c_str(), r_type);
 832       break;
 833
 834       // These are initial TLS relocs, which are expected when
 835       // linking.
 836     case elfcpp::R_386_TLS_GD:            // Global-dynamic
 837     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
 838     case elfcpp::R_386_TLS_DESC_CALL:
 839     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
 840     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
 841     case elfcpp::R_386_TLS_IE:            // Initial-exec
 842     case elfcpp::R_386_TLS_IE_32:
 843     case elfcpp::R_386_TLS_GOTIE:
 844     case elfcpp::R_386_TLS_LE:            // Local-exec
 845     case elfcpp::R_386_TLS_LE_32:
 846       {
 847         bool output_is_shared = parameters->output_is_shared();
 848         const tls::Tls_optimization optimized_type
 849             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
 850         switch (r_type)
 851           {
 852           case elfcpp::R_386_TLS_GD:          // Global-dynamic
 853           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
 854           case elfcpp::R_386_TLS_DESC_CALL:
 855             // FIXME: If not relaxing to LE, we need to generate
 856             // DTPMOD32 and DTPOFF32 relocs.
 857             if (optimized_type != tls::TLSOPT_TO_LE)
 858               unsupported_reloc_local(object, r_type);
 859             break;
 860
 861           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
 862             // FIXME: If not relaxing to LE, we need to generate a
 863             // DTPMOD32 reloc.
 864             if (optimized_type != tls::TLSOPT_TO_LE)
 865               unsupported_reloc_local(object, r_type);
 866             break;
 867
 868           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
 869             break;
 870
 871           case elfcpp::R_386_TLS_IE:          // Initial-exec
 872           case elfcpp::R_386_TLS_IE_32:
 873           case elfcpp::R_386_TLS_GOTIE:
 874             // FIXME: If not relaxing to LE, we need to generate a
 875             // TPOFF or TPOFF32 reloc.
 876             if (optimized_type != tls::TLSOPT_TO_LE)
 877               unsupported_reloc_local(object, r_type);
 878             break;
 879
 880           case elfcpp::R_386_TLS_LE:          // Local-exec
 881           case elfcpp::R_386_TLS_LE_32:
 882             // FIXME: If generating a shared object, we need to copy
 883             // this relocation into the object.
 884             gold_assert(!output_is_shared);
 885             break;
 886
 887           default:
 888             gold_unreachable();
 889           }
 890       }
 891       break;
 892
 893     case elfcpp::R_386_32PLT:
 894     case elfcpp::R_386_TLS_GD_32:
 895     case elfcpp::R_386_TLS_GD_PUSH:
 896     case elfcpp::R_386_TLS_GD_CALL:
 897     case elfcpp::R_386_TLS_GD_POP:
 898     case elfcpp::R_386_TLS_LDM_32:
 899     case elfcpp::R_386_TLS_LDM_PUSH:
 900     case elfcpp::R_386_TLS_LDM_CALL:
 901     case elfcpp::R_386_TLS_LDM_POP:
 902     case elfcpp::R_386_USED_BY_INTEL_200:
 903     default:
 904       unsupported_reloc_local(object, r_type);
 905       break;
 906     }
 907 }
 908
 909 // Report an unsupported relocation against a global symbol.
 910
 911 void
 912 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
 913                                             unsigned int r_type,
 914                                             Symbol* gsym)
 915 {
 916   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
 917              object->name().c_str(), r_type, gsym->name());
 918 }
 919
 920 // Scan a relocation for a global symbol.
 921
 922 inline void
 923 Target_i386::Scan::global(const General_options& options,
 924                           Symbol_table* symtab,
 925                           Layout* layout,
 926                           Target_i386* target,
 927                           Sized_relobj<32, false>* object,
 928                           unsigned int data_shndx,
 929                           const elfcpp::Rel<32, false>& reloc,
 930                           unsigned int r_type,
 931                           Symbol* gsym)
 932 {
 933   switch (r_type)
 934     {
 935     case elfcpp::R_386_NONE:
 936     case elfcpp::R_386_GNU_VTINHERIT:
 937     case elfcpp::R_386_GNU_VTENTRY:
 938       break;
 939
 940     case elfcpp::R_386_32:
 941     case elfcpp::R_386_PC32:
 942     case elfcpp::R_386_16:
 943     case elfcpp::R_386_PC16:
 944     case elfcpp::R_386_8:
 945     case elfcpp::R_386_PC8:
 946       {
 947         bool is_pcrel = (r_type == elfcpp::R_386_PC32
 948                          || r_type == elfcpp::R_386_PC16
 949                          || r_type == elfcpp::R_386_PC8);
 950
 951         if (gsym->is_from_dynobj()
 952             || (parameters->output_is_shared()
 953                 && gsym->is_preemptible()))
 954           {
 955             // (a) This symbol is defined in a dynamic object.  If it is a
 956             // function, we make a PLT entry.  Otherwise we need to
 957             // either generate a COPY reloc or copy this reloc.
 958             // (b) We are building a shared object and this symbol is
 959             // preemptible. If it is a function, we make a PLT entry.
 960             // Otherwise, we copy the reloc.
 961             if (gsym->type() == elfcpp::STT_FUNC)
 962               {
 963                 target->make_plt_entry(symtab, layout, gsym);
 964
 965                 // If this is not a PC relative reference, then we may
 966                 // be taking the address of the function.  In that case
 967                 // we need to set the entry in the dynamic symbol table
 968                 // to the address of the PLT entry. We will also need to
 969                 // create a dynamic relocation.
 970                 if (!is_pcrel)
 971                   {
 972                     if (gsym->is_from_dynobj())
 973                       gsym->set_needs_dynsym_value();
 974                     if (parameters->output_is_position_independent())
 975                       {
 976                         // FIXME: If this is an 8-bit or 16-bit
 977                         // relocation, R_386_RELATIVE won't work.
 978                         gold_assert(r_type != elfcpp::R_386_16
 979                                     && r_type != elfcpp::R_386_8);
 980
 981                         Reloc_section* rel_dyn =
 982                           target->rel_dyn_section(layout);
 983                         rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE,
 984                                            data_shndx, reloc.get_r_offset());
 985                       }
 986                   }
 987               }
 988             else if (parameters->output_is_shared())
 989               {
 990                 // We do not make COPY relocs in shared objects.
 991                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 992                 rel_dyn->add_global(gsym, r_type, object, data_shndx,
 993                                     reloc.get_r_offset());
 994               }
 995             else
 996               target->copy_reloc(&options, symtab, layout, object, data_shndx,
 997                                  gsym, reloc);
 998           }
 999         else if (!is_pcrel && parameters->output_is_position_independent())
1000           {
1001             // FIXME: If this is an 8-bit or 16-bit relocation,
1002             // R_386_RELATIVE won't work.
1003             gold_assert(r_type != elfcpp::R_386_16
1004                         && r_type != elfcpp::R_386_8);
1005
1006             // This is not a PC-relative reference, so we need to generate
1007             // a dynamic relocation.
1008             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1009             rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE, data_shndx,
1010                                reloc.get_r_offset());
1011           }
1012       }
1013       break;
1014
1015     case elfcpp::R_386_GOT32:
1016       {
1017         // The symbol requires a GOT entry.
1018         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1019         if (got->add_global(gsym))
1020           {
1021             // If this symbol is not fully resolved, we need to add a
1022             // dynamic relocation for it.
1023             if (!gsym->final_value_is_known())
1024               {
1025                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1026                 rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got,
1027                                     gsym->got_offset());
1028               }
1029           }
1030       }
1031       break;
1032
1033     case elfcpp::R_386_PLT32:
1034       // If the symbol is fully resolved, this is just a PC32 reloc.
1035       // Otherwise we need a PLT entry.
1036       if (gsym->final_value_is_known())
1037         break;
1038       // If building a shared library, we can also skip the PLT entry
1039       // if the symbol is defined in the output file and is protected
1040       // or hidden.
1041       if (gsym->is_defined()
1042           && !gsym->is_from_dynobj()
1043           && !gsym->is_preemptible())
1044         break;
1045       target->make_plt_entry(symtab, layout, gsym);
1046       break;
1047
1048     case elfcpp::R_386_GOTOFF:
1049     case elfcpp::R_386_GOTPC:
1050       // We need a GOT section.
1051       target->got_section(symtab, layout);
1052       break;
1053
1054       // These are relocations which should only be seen by the
1055       // dynamic linker, and should never be seen here.
1056     case elfcpp::R_386_COPY:
1057     case elfcpp::R_386_GLOB_DAT:
1058     case elfcpp::R_386_JUMP_SLOT:
1059     case elfcpp::R_386_RELATIVE:
1060     case elfcpp::R_386_TLS_TPOFF:
1061     case elfcpp::R_386_TLS_DTPMOD32:
1062     case elfcpp::R_386_TLS_DTPOFF32:
1063     case elfcpp::R_386_TLS_TPOFF32:
1064     case elfcpp::R_386_TLS_DESC:
1065       gold_error(_("%s: unexpected reloc %u in object file"),
1066                  object->name().c_str(), r_type);
1067       break;
1068
1069       // These are initial tls relocs, which are expected when
1070       // linking.
1071     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1072     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1073     case elfcpp::R_386_TLS_DESC_CALL:
1074     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1075     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1076     case elfcpp::R_386_TLS_IE:            // Initial-exec
1077     case elfcpp::R_386_TLS_IE_32:
1078     case elfcpp::R_386_TLS_GOTIE:
1079     case elfcpp::R_386_TLS_LE:            // Local-exec
1080     case elfcpp::R_386_TLS_LE_32:
1081       {
1082         const bool is_final = gsym->final_value_is_known();
1083         const tls::Tls_optimization optimized_type
1084             = Target_i386::optimize_tls_reloc(is_final, r_type);
1085         switch (r_type)
1086           {
1087           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1088           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1089           case elfcpp::R_386_TLS_DESC_CALL:
1090             // FIXME: If not relaxing to LE, we need to generate
1091             // DTPMOD32 and DTPOFF32 relocs.
1092             if (optimized_type != tls::TLSOPT_TO_LE)
1093               unsupported_reloc_global(object, r_type, gsym);
1094             break;
1095
1096           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1097             // FIXME: If not relaxing to LE, we need to generate a
1098             // DTPMOD32 reloc.
1099             if (optimized_type != tls::TLSOPT_TO_LE)
1100               unsupported_reloc_global(object, r_type, gsym);
1101             break;
1102
1103           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1104             break;
1105
1106           case elfcpp::R_386_TLS_IE:          // Initial-exec
1107           case elfcpp::R_386_TLS_IE_32:
1108           case elfcpp::R_386_TLS_GOTIE:
1109             // FIXME: If not relaxing to LE, we need to generate a
1110             // TPOFF or TPOFF32 reloc.
1111             if (optimized_type != tls::TLSOPT_TO_LE)
1112               unsupported_reloc_global(object, r_type, gsym);
1113             break;
1114
1115           case elfcpp::R_386_TLS_LE:          // Local-exec
1116           case elfcpp::R_386_TLS_LE_32:
1117             // FIXME: If generating a shared object, we need to copy
1118             // this relocation into the object.
1119             gold_assert(!parameters->output_is_shared());
1120             break;
1121
1122           default:
1123             gold_unreachable();
1124           }
1125       }
1126       break;
1127
1128     case elfcpp::R_386_32PLT:
1129     case elfcpp::R_386_TLS_GD_32:
1130     case elfcpp::R_386_TLS_GD_PUSH:
1131     case elfcpp::R_386_TLS_GD_CALL:
1132     case elfcpp::R_386_TLS_GD_POP:
1133     case elfcpp::R_386_TLS_LDM_32:
1134     case elfcpp::R_386_TLS_LDM_PUSH:
1135     case elfcpp::R_386_TLS_LDM_CALL:
1136     case elfcpp::R_386_TLS_LDM_POP:
1137     case elfcpp::R_386_USED_BY_INTEL_200:
1138     default:
1139       unsupported_reloc_global(object, r_type, gsym);
1140       break;
1141     }
1142 }
1143
1144 // Scan relocations for a section.
1145
1146 void
1147 Target_i386::scan_relocs(const General_options& options,
1148                          Symbol_table* symtab,
1149                          Layout* layout,
1150                          Sized_relobj<32, false>* object,
1151                          unsigned int data_shndx,
1152                          unsigned int sh_type,
1153                          const unsigned char* prelocs,
1154                          size_t reloc_count,
1155                          size_t local_symbol_count,
1156                          const unsigned char* plocal_symbols,
1157                          Symbol** global_symbols)
1158 {
1159   if (sh_type == elfcpp::SHT_RELA)
1160     {
1161       gold_error(_("%s: unsupported RELA reloc section"),
1162                  object->name().c_str());
1163       return;
1164     }
1165
1166   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1167                     Target_i386::Scan>(
1168     options,
1169     symtab,
1170     layout,
1171     this,
1172     object,
1173     data_shndx,
1174     prelocs,
1175     reloc_count,
1176     local_symbol_count,
1177     plocal_symbols,
1178     global_symbols);
1179 }
1180
1181 // Finalize the sections.
1182
1183 void
1184 Target_i386::do_finalize_sections(Layout* layout)
1185 {
1186   // Fill in some more dynamic tags.
1187   Output_data_dynamic* const odyn = layout->dynamic_data();
1188   if (odyn != NULL)
1189     {
1190       if (this->got_plt_ != NULL)
1191         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1192
1193       if (this->plt_ != NULL)
1194         {
1195           const Output_data* od = this->plt_->rel_plt();
1196           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1197           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1198           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1199         }
1200
1201       if (this->rel_dyn_ != NULL)
1202         {
1203           const Output_data* od = this->rel_dyn_;
1204           odyn->add_section_address(elfcpp::DT_REL, od);
1205           odyn->add_section_size(elfcpp::DT_RELSZ, od);
1206           odyn->add_constant(elfcpp::DT_RELENT,
1207                              elfcpp::Elf_sizes<32>::rel_size);
1208         }
1209
1210       if (!parameters->output_is_shared())
1211         {
1212           // The value of the DT_DEBUG tag is filled in by the dynamic
1213           // linker at run time, and used by the debugger.
1214           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1215         }
1216     }
1217
1218   // Emit any relocs we saved in an attempt to avoid generating COPY
1219   // relocs.
1220   if (this->copy_relocs_ == NULL)
1221     return;
1222   if (this->copy_relocs_->any_to_emit())
1223     {
1224       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1225       this->copy_relocs_->emit(rel_dyn);
1226     }
1227   delete this->copy_relocs_;
1228   this->copy_relocs_ = NULL;
1229 }
1230
1231 // Perform a relocation.
1232
1233 inline bool
1234 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1235                                 Target_i386* target,
1236                                 size_t relnum,
1237                                 const elfcpp::Rel<32, false>& rel,
1238                                 unsigned int r_type,
1239                                 const Sized_symbol<32>* gsym,
1240                                 const Symbol_value<32>* psymval,
1241                                 unsigned char* view,
1242                                 elfcpp::Elf_types<32>::Elf_Addr address,
1243                                 off_t view_size)
1244 {
1245   if (this->skip_call_tls_get_addr_)
1246     {
1247       if (r_type != elfcpp::R_386_PLT32
1248           || gsym == NULL
1249           || strcmp(gsym->name(), "___tls_get_addr") != 0)
1250         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1251                                _("missing expected TLS relocation"));
1252       else
1253         {
1254           this->skip_call_tls_get_addr_ = false;
1255           return false;
1256         }
1257     }
1258
1259   // Pick the value to use for symbols defined in shared objects.
1260   Symbol_value<32> symval;
1261   if (gsym != NULL
1262       && (gsym->is_from_dynobj()
1263           || (parameters->output_is_shared()
1264               && gsym->is_preemptible()))
1265       && gsym->has_plt_offset())
1266     {
1267       symval.set_output_value(target->plt_section()->address()
1268                               + gsym->plt_offset());
1269       psymval = &symval;
1270     }
1271
1272   const Sized_relobj<32, false>* object = relinfo->object;
1273
1274   // Get the GOT offset if needed.
1275   // The GOT pointer points to the end of the GOT section.
1276   // We need to subtract the size of the GOT section to get
1277   // the actual offset to use in the relocation.
1278   bool have_got_offset = false;
1279   unsigned int got_offset = 0;
1280   switch (r_type)
1281     {
1282     case elfcpp::R_386_GOT32:
1283       if (gsym != NULL)
1284         {
1285           gold_assert(gsym->has_got_offset());
1286           got_offset = gsym->got_offset() - target->got_size();
1287         }
1288       else
1289         {
1290           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1291           got_offset = object->local_got_offset(r_sym) - target->got_size();
1292         }
1293       have_got_offset = true;
1294       break;
1295
1296     default:
1297       break;
1298     }
1299
1300   switch (r_type)
1301     {
1302     case elfcpp::R_386_NONE:
1303     case elfcpp::R_386_GNU_VTINHERIT:
1304     case elfcpp::R_386_GNU_VTENTRY:
1305       break;
1306
1307     case elfcpp::R_386_32:
1308       Relocate_functions<32, false>::rel32(view, object, psymval);
1309       break;
1310
1311     case elfcpp::R_386_PC32:
1312       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1313       break;
1314
1315     case elfcpp::R_386_16:
1316       Relocate_functions<32, false>::rel16(view, object, psymval);
1317       break;
1318
1319     case elfcpp::R_386_PC16:
1320       Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1321       break;
1322
1323     case elfcpp::R_386_8:
1324       Relocate_functions<32, false>::rel8(view, object, psymval);
1325       break;
1326
1327     case elfcpp::R_386_PC8:
1328       Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1329       break;
1330
1331     case elfcpp::R_386_PLT32:
1332       gold_assert(gsym == NULL
1333                   || gsym->has_plt_offset()
1334                   || gsym->final_value_is_known());
1335       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1336       break;
1337
1338     case elfcpp::R_386_GOT32:
1339       gold_assert(have_got_offset);
1340       Relocate_functions<32, false>::rel32(view, got_offset);
1341       break;
1342
1343     case elfcpp::R_386_GOTOFF:
1344       {
1345         elfcpp::Elf_types<32>::Elf_Addr value;
1346         value = (psymval->value(object, 0)
1347                  - target->got_plt_section()->address());
1348         Relocate_functions<32, false>::rel32(view, value);
1349       }
1350       break;
1351
1352     case elfcpp::R_386_GOTPC:
1353       {
1354         elfcpp::Elf_types<32>::Elf_Addr value;
1355         value = target->got_plt_section()->address();
1356         Relocate_functions<32, false>::pcrel32(view, value, address);
1357       }
1358       break;
1359
1360     case elfcpp::R_386_COPY:
1361     case elfcpp::R_386_GLOB_DAT:
1362     case elfcpp::R_386_JUMP_SLOT:
1363     case elfcpp::R_386_RELATIVE:
1364       // These are outstanding tls relocs, which are unexpected when
1365       // linking.
1366     case elfcpp::R_386_TLS_TPOFF:
1367     case elfcpp::R_386_TLS_DTPMOD32:
1368     case elfcpp::R_386_TLS_DTPOFF32:
1369     case elfcpp::R_386_TLS_TPOFF32:
1370     case elfcpp::R_386_TLS_DESC:
1371       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1372                              _("unexpected reloc %u in object file"),
1373                              r_type);
1374       break;
1375
1376       // These are initial tls relocs, which are expected when
1377       // linking.
1378     case elfcpp::R_386_TLS_GD:             // Global-dynamic
1379     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
1380     case elfcpp::R_386_TLS_DESC_CALL:
1381     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
1382     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
1383     case elfcpp::R_386_TLS_IE:             // Initial-exec
1384     case elfcpp::R_386_TLS_IE_32:
1385     case elfcpp::R_386_TLS_GOTIE:
1386     case elfcpp::R_386_TLS_LE:             // Local-exec
1387     case elfcpp::R_386_TLS_LE_32:
1388       this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view,
1389                          address, view_size);
1390       break;
1391
1392     case elfcpp::R_386_32PLT:
1393     case elfcpp::R_386_TLS_GD_32:
1394     case elfcpp::R_386_TLS_GD_PUSH:
1395     case elfcpp::R_386_TLS_GD_CALL:
1396     case elfcpp::R_386_TLS_GD_POP:
1397     case elfcpp::R_386_TLS_LDM_32:
1398     case elfcpp::R_386_TLS_LDM_PUSH:
1399     case elfcpp::R_386_TLS_LDM_CALL:
1400     case elfcpp::R_386_TLS_LDM_POP:
1401     case elfcpp::R_386_USED_BY_INTEL_200:
1402     default:
1403       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1404                              _("unsupported reloc %u"),
1405                              r_type);
1406       break;
1407     }
1408
1409   return true;
1410 }
1411
1412 // Perform a TLS relocation.
1413
1414 inline void
1415 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1416                                     size_t relnum,
1417                                     const elfcpp::Rel<32, false>& rel,
1418                                     unsigned int r_type,
1419                                     const Sized_symbol<32>* gsym,
1420                                     const Symbol_value<32>* psymval,
1421                                     unsigned char* view,
1422                                     elfcpp::Elf_types<32>::Elf_Addr,
1423                                     off_t view_size)
1424 {
1425   Output_segment* tls_segment = relinfo->layout->tls_segment();
1426   if (tls_segment == NULL)
1427     {
1428       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1429                              _("TLS reloc but no TLS segment"));
1430       return;
1431     }
1432
1433   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(relinfo->object, 0);
1434
1435   const bool is_final = (gsym == NULL
1436                          ? !parameters->output_is_position_independent()
1437                          : gsym->final_value_is_known());
1438   const tls::Tls_optimization optimized_type
1439       = Target_i386::optimize_tls_reloc(is_final, r_type);
1440   switch (r_type)
1441     {
1442     case elfcpp::R_386_TLS_GD:           // Global-dynamic
1443       if (optimized_type == tls::TLSOPT_TO_LE)
1444         {
1445           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1446                              rel, r_type, value, view,
1447                              view_size);
1448           break;
1449         }
1450       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1451                              _("unsupported reloc %u"),
1452                              r_type);
1453       break;
1454
1455     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
1456     case elfcpp::R_386_TLS_DESC_CALL:
1457       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1458                              _("unsupported reloc %u"),
1459                              r_type);
1460       break;
1461
1462     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
1463       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1464         {
1465           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1466                                  _("both SUN and GNU model "
1467                                    "TLS relocations"));
1468           break;
1469         }
1470       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1471       if (optimized_type == tls::TLSOPT_TO_LE)
1472         {
1473           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1474                              value, view, view_size);
1475           break;
1476         }
1477       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1478                              _("unsupported reloc %u"),
1479                              r_type);
1480       break;
1481
1482     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
1483       // This reloc can appear in debugging sections, in which case we
1484       // won't see the TLS_LDM reloc.  The local_dynamic_type field
1485       // tells us this.
1486       if (optimized_type != tls::TLSOPT_TO_LE
1487           || this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE)
1488         value = value - tls_segment->vaddr();
1489       else if (this->local_dynamic_type_ == LOCAL_DYNAMIC_GNU)
1490         value = value - (tls_segment->vaddr() + tls_segment->memsz());
1491       else
1492         value = tls_segment->vaddr() + tls_segment->memsz() - value;
1493       Relocate_functions<32, false>::rel32(view, value);
1494       break;
1495
1496     case elfcpp::R_386_TLS_IE:           // Initial-exec
1497     case elfcpp::R_386_TLS_GOTIE:
1498     case elfcpp::R_386_TLS_IE_32:
1499       if (optimized_type == tls::TLSOPT_TO_LE)
1500         {
1501           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
1502                                               rel, r_type, value, view,
1503                                               view_size);
1504           break;
1505         }
1506       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1507                              _("unsupported reloc %u"),
1508                              r_type);
1509       break;
1510
1511     case elfcpp::R_386_TLS_LE:           // Local-exec
1512       value = value - (tls_segment->vaddr() + tls_segment->memsz());
1513       Relocate_functions<32, false>::rel32(view, value);
1514       break;
1515
1516     case elfcpp::R_386_TLS_LE_32:
1517       value = tls_segment->vaddr() + tls_segment->memsz() - value;
1518       Relocate_functions<32, false>::rel32(view, value);
1519       break;
1520     }
1521 }
1522
1523 // Do a relocation in which we convert a TLS General-Dynamic to a
1524 // Local-Exec.
1525
1526 inline void
1527 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
1528                                     size_t relnum,
1529                                     Output_segment* tls_segment,
1530                                     const elfcpp::Rel<32, false>& rel,
1531                                     unsigned int,
1532                                     elfcpp::Elf_types<32>::Elf_Addr value,
1533                                     unsigned char* view,
1534                                     off_t view_size)
1535 {
1536   // leal foo(,%reg,1),%eax; call ___tls_get_addr
1537   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1538   // leal foo(%reg),%eax; call ___tls_get_addr
1539   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1540
1541   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1542   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
1543
1544   unsigned char op1 = view[-1];
1545   unsigned char op2 = view[-2];
1546
1547   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1548                  op2 == 0x8d || op2 == 0x04);
1549   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
1550
1551   int roff = 5;
1552
1553   if (op2 == 0x04)
1554     {
1555       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
1556       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
1557       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1558                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
1559       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1560     }
1561   else
1562     {
1563       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1564                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
1565       if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size
1566           && view[9] == 0x90)
1567         {
1568           // There is a trailing nop.  Use the size byte subl.
1569           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1570           roff = 6;
1571         }
1572       else
1573         {
1574           // Use the five byte subl.
1575           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1576         }
1577     }
1578
1579   value = tls_segment->vaddr() + tls_segment->memsz() - value;
1580   Relocate_functions<32, false>::rel32(view + roff, value);
1581
1582   // The next reloc should be a PLT32 reloc against __tls_get_addr.
1583   // We can skip it.
1584   this->skip_call_tls_get_addr_ = true;
1585 }
1586
1587 // Do a relocation in which we convert a TLS Local-Dynamic to a
1588 // Local-Exec.
1589
1590 inline void
1591 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
1592                                     size_t relnum,
1593                                     Output_segment*,
1594                                     const elfcpp::Rel<32, false>& rel,
1595                                     unsigned int,
1596                                     elfcpp::Elf_types<32>::Elf_Addr,
1597                                     unsigned char* view,
1598                                     off_t view_size)
1599 {
1600   // leal foo(%reg), %eax; call ___tls_get_addr
1601   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
1602
1603   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1604   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
1605
1606   // FIXME: Does this test really always pass?
1607   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1608                  view[-2] == 0x8d && view[-1] == 0x83);
1609
1610   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
1611
1612   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
1613
1614   // The next reloc should be a PLT32 reloc against __tls_get_addr.
1615   // We can skip it.
1616   this->skip_call_tls_get_addr_ = true;
1617 }
1618
1619 // Do a relocation in which we convert a TLS Initial-Exec to a
1620 // Local-Exec.
1621
1622 inline void
1623 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
1624                                     size_t relnum,
1625                                     Output_segment* tls_segment,
1626                                     const elfcpp::Rel<32, false>& rel,
1627                                     unsigned int r_type,
1628                                     elfcpp::Elf_types<32>::Elf_Addr value,
1629                                     unsigned char* view,
1630                                     off_t view_size)
1631 {
1632   // We have to actually change the instructions, which means that we
1633   // need to examine the opcodes to figure out which instruction we
1634   // are looking at.
1635   if (r_type == elfcpp::R_386_TLS_IE)
1636     {
1637       // movl %gs:XX,%eax  ==>  movl $YY,%eax
1638       // movl %gs:XX,%reg  ==>  movl $YY,%reg
1639       // addl %gs:XX,%reg  ==>  addl $YY,%reg
1640       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
1641       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
1642
1643       unsigned char op1 = view[-1];
1644       if (op1 == 0xa1)
1645         {
1646           // movl XX,%eax  ==>  movl $YY,%eax
1647           view[-1] = 0xb8;
1648         }
1649       else
1650         {
1651           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1652
1653           unsigned char op2 = view[-2];
1654           if (op2 == 0x8b)
1655             {
1656               // movl XX,%reg  ==>  movl $YY,%reg
1657               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1658                              (op1 & 0xc7) == 0x05);
1659               view[-2] = 0xc7;
1660               view[-1] = 0xc0 | ((op1 >> 3) & 7);
1661             }
1662           else if (op2 == 0x03)
1663             {
1664               // addl XX,%reg  ==>  addl $YY,%reg
1665               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1666                              (op1 & 0xc7) == 0x05);
1667               view[-2] = 0x81;
1668               view[-1] = 0xc0 | ((op1 >> 3) & 7);
1669             }
1670           else
1671             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
1672         }
1673     }
1674   else
1675     {
1676       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
1677       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
1678       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
1679       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1680       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
1681
1682       unsigned char op1 = view[-1];
1683       unsigned char op2 = view[-2];
1684       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1685                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
1686       if (op2 == 0x8b)
1687         {
1688           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
1689           view[-2] = 0xc7;
1690           view[-1] = 0xc0 | ((op1 >> 3) & 7);
1691         }
1692       else if (op2 == 0x2b)
1693         {
1694           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
1695           view[-2] = 0x81;
1696           view[-1] = 0xe8 | ((op1 >> 3) & 7);
1697         }
1698       else if (op2 == 0x03)
1699         {
1700           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
1701           view[-2] = 0x81;
1702           view[-1] = 0xc0 | ((op1 >> 3) & 7);
1703         }
1704       else
1705         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
1706     }
1707
1708   value = tls_segment->vaddr() + tls_segment->memsz() - value;
1709   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
1710     value = - value;
1711
1712   Relocate_functions<32, false>::rel32(view, value);
1713 }
1714
1715 // Relocate section data.
1716
1717 void
1718 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
1719                               unsigned int sh_type,
1720                               const unsigned char* prelocs,
1721                               size_t reloc_count,
1722                               unsigned char* view,
1723                               elfcpp::Elf_types<32>::Elf_Addr address,
1724                               off_t view_size)
1725 {
1726   gold_assert(sh_type == elfcpp::SHT_REL);
1727
1728   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
1729                          Target_i386::Relocate>(
1730     relinfo,
1731     this,
1732     prelocs,
1733     reloc_count,
1734     view,
1735     address,
1736     view_size);
1737 }
1738
1739 // Return the value to use for a dynamic which requires special
1740 // treatment.  This is how we support equality comparisons of function
1741 // pointers across shared library boundaries, as described in the
1742 // processor specific ABI supplement.
1743
1744 uint64_t
1745 Target_i386::do_dynsym_value(const Symbol* gsym) const
1746 {
1747   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
1748   return this->plt_section()->address() + gsym->plt_offset();
1749 }
1750
1751 // Return a string used to fill a code section with nops to take up
1752 // the specified length.
1753
1754 std::string
1755 Target_i386::do_code_fill(off_t length)
1756 {
1757   if (length >= 16)
1758     {
1759       // Build a jmp instruction to skip over the bytes.
1760       unsigned char jmp[5];
1761       jmp[0] = 0xe9;
1762       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
1763       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
1764               + std::string(length - 5, '\0'));
1765     }
1766
1767   // Nop sequences of various lengths.
1768   const char nop1[1] = { 0x90 };                   // nop
1769   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
1770   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
1771   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
1772   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
1773                          0x00 };                   // leal 0(%esi,1),%esi
1774   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
1775                          0x00, 0x00 };
1776   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
1777                          0x00, 0x00, 0x00 };
1778   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
1779                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1780   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
1781                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
1782                          0x00 };
1783   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1784                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1785                            0x00, 0x00 };
1786   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1787                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1788                            0x00, 0x00, 0x00 };
1789   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1790                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1791                            0x00, 0x00, 0x00, 0x00 };
1792   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1793                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1794                            0x27, 0x00, 0x00, 0x00,
1795                            0x00 };
1796   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1797                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1798                            0xbc, 0x27, 0x00, 0x00,
1799                            0x00, 0x00 };
1800   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1801                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1802                            0x90, 0x90, 0x90, 0x90,
1803                            0x90, 0x90, 0x90 };
1804
1805   const char* nops[16] = {
1806     NULL,
1807     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
1808     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
1809   };
1810
1811   return std::string(nops[length], length);
1812 }
1813
1814 // The selector for i386 object files.
1815
1816 class Target_selector_i386 : public Target_selector
1817 {
1818 public:
1819   Target_selector_i386()
1820     : Target_selector(elfcpp::EM_386, 32, false)
1821   { }
1822
1823   Target*
1824   recognize(int machine, int osabi, int abiversion);
1825
1826  private:
1827   Target_i386* target_;
1828 };
1829
1830 // Recognize an i386 object file when we already know that the machine
1831 // number is EM_386.
1832
1833 Target*
1834 Target_selector_i386::recognize(int, int, int)
1835 {
1836   if (this->target_ == NULL)
1837     this->target_ = new Target_i386();
1838   return this->target_;
1839 }
1840
1841 Target_selector_i386 target_selector_i386;
1842
1843 } // End anonymous namespace.