gold/dynobj.cc

   1 // dynobj.cc -- dynamic object support for gold
   2
   3 #include "gold.h"
   4
   5 #include <vector>
   6 #include <cstring>
   7
   8 #include "elfcpp.h"
   9 #include "symtab.h"
  10 #include "dynobj.h"
  11
  12 namespace gold
  13 {
  14
  15 // Class Dynobj.
  16
  17 // Return the string to use in a DT_NEEDED entry.
  18
  19 const char*
  20 Dynobj::soname() const
  21 {
  22   if (!this->soname_.empty())
  23     return this->soname_.c_str();
  24   return this->name().c_str();
  25 }
  26
  27 // Class Sized_dynobj.
  28
  29 template<int size, bool big_endian>
  30 Sized_dynobj<size, big_endian>::Sized_dynobj(
  31     const std::string& name,
  32     Input_file* input_file,
  33     off_t offset,
  34     const elfcpp::Ehdr<size, big_endian>& ehdr)
  35   : Dynobj(name, input_file, offset),
  36     elf_file_(this, ehdr)
  37 {
  38 }
  39
  40 // Set up the object.
  41
  42 template<int size, bool big_endian>
  43 void
  44 Sized_dynobj<size, big_endian>::setup(
  45     const elfcpp::Ehdr<size, big_endian>& ehdr)
  46 {
  47   this->set_target(ehdr.get_e_machine(), size, big_endian,
  48                    ehdr.get_e_ident()[elfcpp::EI_OSABI],
  49                    ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
  50
  51   const unsigned int shnum = this->elf_file_.shnum();
  52   this->set_shnum(shnum);
  53 }
  54
  55 // Find the SHT_DYNSYM section and the various version sections, and
  56 // the dynamic section, given the section headers.
  57
  58 template<int size, bool big_endian>
  59 void
  60 Sized_dynobj<size, big_endian>::find_dynsym_sections(
  61     const unsigned char* pshdrs,
  62     unsigned int* pdynsym_shndx,
  63     unsigned int* pversym_shndx,
  64     unsigned int* pverdef_shndx,
  65     unsigned int* pverneed_shndx,
  66     unsigned int* pdynamic_shndx)
  67 {
  68   *pdynsym_shndx = -1U;
  69   *pversym_shndx = -1U;
  70   *pverdef_shndx = -1U;
  71   *pverneed_shndx = -1U;
  72   *pdynamic_shndx = -1U;
  73
  74   const unsigned int shnum = this->shnum();
  75   const unsigned char* p = pshdrs;
  76   for (unsigned int i = 0; i < shnum; ++i, p += This::shdr_size)
  77     {
  78       typename This::Shdr shdr(p);
  79
  80       unsigned int* pi;
  81       switch (shdr.get_sh_type())
  82         {
  83         case elfcpp::SHT_DYNSYM:
  84           pi = pdynsym_shndx;
  85           break;
  86         case elfcpp::SHT_GNU_versym:
  87           pi = pversym_shndx;
  88           break;
  89         case elfcpp::SHT_GNU_verdef:
  90           pi = pverdef_shndx;
  91           break;
  92         case elfcpp::SHT_GNU_verneed:
  93           pi = pverneed_shndx;
  94           break;
  95         case elfcpp::SHT_DYNAMIC:
  96           pi = pdynamic_shndx;
  97           break;
  98         default:
  99           pi = NULL;
 100           break;
 101         }
 102
 103       if (pi == NULL)
 104         continue;
 105
 106       if (*pi != -1U)
 107         {
 108           fprintf(stderr,
 109                   _("%s: %s: unexpected duplicate type %u section: %u, %u\n"),
 110                   program_name, this->name().c_str(), shdr.get_sh_type(),
 111                   *pi, i);
 112           gold_exit(false);
 113         }
 114
 115       *pi = i;
 116     }
 117 }
 118
 119 // Read the contents of section SHNDX.  PSHDRS points to the section
 120 // headers.  TYPE is the expected section type.  LINK is the expected
 121 // section link.  Store the data in *VIEW and *VIEW_SIZE.  The
 122 // section's sh_info field is stored in *VIEW_INFO.
 123
 124 template<int size, bool big_endian>
 125 void
 126 Sized_dynobj<size, big_endian>::read_dynsym_section(
 127     const unsigned char* pshdrs,
 128     unsigned int shndx,
 129     elfcpp::SHT type,
 130     unsigned int link,
 131     File_view** view,
 132     off_t* view_size,
 133     unsigned int* view_info)
 134 {
 135   if (shndx == -1U)
 136     {
 137       *view = NULL;
 138       *view_size = 0;
 139       *view_info = 0;
 140       return;
 141     }
 142
 143   typename This::Shdr shdr(pshdrs + shndx * This::shdr_size);
 144
 145   gold_assert(shdr.get_sh_type() == type);
 146
 147   if (shdr.get_sh_link() != link)
 148     {
 149       fprintf(stderr,
 150               _("%s: %s: unexpected link in section %u header: %u != %u\n"),
 151               program_name, this->name().c_str(), shndx,
 152               shdr.get_sh_link(), link);
 153       gold_exit(false);
 154     }
 155
 156   *view = this->get_lasting_view(shdr.get_sh_offset(), shdr.get_sh_size());
 157   *view_size = shdr.get_sh_size();
 158   *view_info = shdr.get_sh_info();
 159 }
 160
 161 // Set the soname field if this shared object has a DT_SONAME tag.
 162 // PSHDRS points to the section headers.  DYNAMIC_SHNDX is the section
 163 // index of the SHT_DYNAMIC section.  STRTAB_SHNDX, STRTAB, and
 164 // STRTAB_SIZE are the section index and contents of a string table
 165 // which may be the one associated with the SHT_DYNAMIC section.
 166
 167 template<int size, bool big_endian>
 168 void
 169 Sized_dynobj<size, big_endian>::set_soname(const unsigned char* pshdrs,
 170                                            unsigned int dynamic_shndx,
 171                                            unsigned int strtab_shndx,
 172                                            const unsigned char* strtabu,
 173                                            off_t strtab_size)
 174 {
 175   typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size);
 176   gold_assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC);
 177
 178   const off_t dynamic_size = dynamicshdr.get_sh_size();
 179   const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(),
 180                                                  dynamic_size);
 181
 182   const unsigned int link = dynamicshdr.get_sh_link();
 183   if (link != strtab_shndx)
 184     {
 185       if (link >= this->shnum())
 186         {
 187           fprintf(stderr,
 188                   _("%s: %s: DYNAMIC section %u link out of range: %u\n"),
 189                   program_name, this->name().c_str(),
 190                   dynamic_shndx, link);
 191           gold_exit(false);
 192         }
 193
 194       typename This::Shdr strtabshdr(pshdrs + link * This::shdr_size);
 195       if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
 196         {
 197           fprintf(stderr,
 198                   _("%s: %s: DYNAMIC section %u link %u is not a strtab\n"),
 199                   program_name, this->name().c_str(),
 200                   dynamic_shndx, link);
 201           gold_exit(false);
 202         }
 203
 204       strtab_size = strtabshdr.get_sh_size();
 205       strtabu = this->get_view(strtabshdr.get_sh_offset(), strtab_size);
 206     }
 207
 208   for (const unsigned char* p = pdynamic;
 209        p < pdynamic + dynamic_size;
 210        p += This::dyn_size)
 211     {
 212       typename This::Dyn dyn(p);
 213
 214       if (dyn.get_d_tag() == elfcpp::DT_SONAME)
 215         {
 216           off_t val = dyn.get_d_val();
 217           if (val >= strtab_size)
 218             {
 219               fprintf(stderr,
 220                       _("%s: %s: DT_SONAME value out of range: "
 221                         "%lld >= %lld\n"),
 222                       program_name, this->name().c_str(),
 223                       static_cast<long long>(val),
 224                       static_cast<long long>(strtab_size));
 225               gold_exit(false);
 226             }
 227
 228           const char* strtab = reinterpret_cast<const char*>(strtabu);
 229           this->set_soname_string(strtab + val);
 230           return;
 231         }
 232
 233       if (dyn.get_d_tag() == elfcpp::DT_NULL)
 234         return;
 235     }
 236
 237   fprintf(stderr, _("%s: %s: missing DT_NULL in dynamic segment\n"),
 238           program_name, this->name().c_str());
 239   gold_exit(false);
 240 }
 241
 242 // Read the symbols and sections from a dynamic object.  We read the
 243 // dynamic symbols, not the normal symbols.
 244
 245 template<int size, bool big_endian>
 246 void
 247 Sized_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
 248 {
 249   this->read_section_data(&this->elf_file_, sd);
 250
 251   const unsigned char* const pshdrs = sd->section_headers->data();
 252
 253   unsigned int dynsym_shndx;
 254   unsigned int versym_shndx;
 255   unsigned int verdef_shndx;
 256   unsigned int verneed_shndx;
 257   unsigned int dynamic_shndx;
 258   this->find_dynsym_sections(pshdrs, &dynsym_shndx, &versym_shndx,
 259                              &verdef_shndx, &verneed_shndx, &dynamic_shndx);
 260
 261   unsigned int strtab_shndx = -1U;
 262
 263   if (dynsym_shndx == -1U)
 264     {
 265       sd->symbols = NULL;
 266       sd->symbols_size = 0;
 267       sd->symbol_names = NULL;
 268       sd->symbol_names_size = 0;
 269     }
 270   else
 271     {
 272       // Get the dynamic symbols.
 273       typename This::Shdr dynsymshdr(pshdrs + dynsym_shndx * This::shdr_size);
 274       gold_assert(dynsymshdr.get_sh_type() == elfcpp::SHT_DYNSYM);
 275
 276       sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(),
 277                                            dynsymshdr.get_sh_size());
 278       sd->symbols_size = dynsymshdr.get_sh_size();
 279
 280       // Get the symbol names.
 281       strtab_shndx = dynsymshdr.get_sh_link();
 282       if (strtab_shndx >= this->shnum())
 283         {
 284           fprintf(stderr,
 285                   _("%s: %s: invalid dynamic symbol table name index: %u\n"),
 286                   program_name, this->name().c_str(), strtab_shndx);
 287           gold_exit(false);
 288         }
 289       typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
 290       if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
 291         {
 292           fprintf(stderr,
 293                   _("%s: %s: dynamic symbol table name section "
 294                     "has wrong type: %u\n"),
 295                   program_name, this->name().c_str(),
 296                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
 297           gold_exit(false);
 298         }
 299
 300       sd->symbol_names = this->get_lasting_view(strtabshdr.get_sh_offset(),
 301                                                 strtabshdr.get_sh_size());
 302       sd->symbol_names_size = strtabshdr.get_sh_size();
 303
 304       // Get the version information.
 305
 306       unsigned int dummy;
 307       this->read_dynsym_section(pshdrs, versym_shndx, elfcpp::SHT_GNU_versym,
 308                                 dynsym_shndx, &sd->versym, &sd->versym_size,
 309                                 &dummy);
 310
 311       // We require that the version definition and need section link
 312       // to the same string table as the dynamic symbol table.  This
 313       // is not a technical requirement, but it always happens in
 314       // practice.  We could change this if necessary.
 315
 316       this->read_dynsym_section(pshdrs, verdef_shndx, elfcpp::SHT_GNU_verdef,
 317                                 strtab_shndx, &sd->verdef, &sd->verdef_size,
 318                                 &sd->verdef_info);
 319
 320       this->read_dynsym_section(pshdrs, verneed_shndx, elfcpp::SHT_GNU_verneed,
 321                                 strtab_shndx, &sd->verneed, &sd->verneed_size,
 322                                 &sd->verneed_info);
 323     }
 324
 325   // Read the SHT_DYNAMIC section to find whether this shared object
 326   // has a DT_SONAME tag.  This doesn't really have anything to do
 327   // with reading the symbols, but this is a convenient place to do
 328   // it.
 329   if (dynamic_shndx != -1U)
 330     this->set_soname(pshdrs, dynamic_shndx, strtab_shndx,
 331                      (sd->symbol_names == NULL
 332                       ? NULL
 333                       : sd->symbol_names->data()),
 334                      sd->symbol_names_size);
 335 }
 336
 337 // Lay out the input sections for a dynamic object.  We don't want to
 338 // include sections from a dynamic object, so all that we actually do
 339 // here is check for .gnu.warning sections.
 340
 341 template<int size, bool big_endian>
 342 void
 343 Sized_dynobj<size, big_endian>::do_layout(const General_options&,
 344                                           Symbol_table* symtab,
 345                                           Layout*,
 346                                           Read_symbols_data* sd)
 347 {
 348   const unsigned int shnum = this->shnum();
 349   if (shnum == 0)
 350     return;
 351
 352   // Get the section headers.
 353   const unsigned char* pshdrs = sd->section_headers->data();
 354
 355   // Get the section names.
 356   const unsigned char* pnamesu = sd->section_names->data();
 357   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 358
 359   // Skip the first, dummy, section.
 360   pshdrs += This::shdr_size;
 361   for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
 362     {
 363       typename This::Shdr shdr(pshdrs);
 364
 365       if (shdr.get_sh_name() >= sd->section_names_size)
 366         {
 367           fprintf(stderr,
 368                   _("%s: %s: bad section name offset for section %u: %lu\n"),
 369                   program_name, this->name().c_str(), i,
 370                   static_cast<unsigned long>(shdr.get_sh_name()));
 371           gold_exit(false);
 372         }
 373
 374       const char* name = pnames + shdr.get_sh_name();
 375
 376       this->handle_gnu_warning_section(name, i, symtab);
 377     }
 378
 379   delete sd->section_headers;
 380   sd->section_headers = NULL;
 381   delete sd->section_names;
 382   sd->section_names = NULL;
 383 }
 384
 385 // Add an entry to the vector mapping version numbers to version
 386 // strings.
 387
 388 template<int size, bool big_endian>
 389 void
 390 Sized_dynobj<size, big_endian>::set_version_map(
 391     Version_map* version_map,
 392     unsigned int ndx,
 393     const char* name) const
 394 {
 395   if (ndx >= version_map->size())
 396     version_map->resize(ndx + 1);
 397   if ((*version_map)[ndx] != NULL)
 398     {
 399       fprintf(stderr, _("%s: %s: duplicate definition for version %u\n"),
 400               program_name, this->name().c_str(), ndx);
 401       gold_exit(false);
 402     }
 403   (*version_map)[ndx] = name;
 404 }
 405
 406 // Add mappings for the version definitions to VERSION_MAP.
 407
 408 template<int size, bool big_endian>
 409 void
 410 Sized_dynobj<size, big_endian>::make_verdef_map(
 411     Read_symbols_data* sd,
 412     Version_map* version_map) const
 413 {
 414   if (sd->verdef == NULL)
 415     return;
 416
 417   const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
 418   off_t names_size = sd->symbol_names_size;
 419
 420   const unsigned char* pverdef = sd->verdef->data();
 421   off_t verdef_size = sd->verdef_size;
 422   const unsigned int count = sd->verdef_info;
 423
 424   const unsigned char* p = pverdef;
 425   for (unsigned int i = 0; i < count; ++i)
 426     {
 427       elfcpp::Verdef<size, big_endian> verdef(p);
 428
 429       if (verdef.get_vd_version() != elfcpp::VER_DEF_CURRENT)
 430         {
 431           fprintf(stderr, _("%s: %s: unexpected verdef version %u\n"),
 432                   program_name, this->name().c_str(), verdef.get_vd_version());
 433           gold_exit(false);
 434         }
 435
 436       const unsigned int vd_ndx = verdef.get_vd_ndx();
 437
 438       // The GNU linker clears the VERSYM_HIDDEN bit.  I'm not
 439       // sure why.
 440
 441       // The first Verdaux holds the name of this version.  Subsequent
 442       // ones are versions that this one depends upon, which we don't
 443       // care about here.
 444       const unsigned int vd_cnt = verdef.get_vd_cnt();
 445       if (vd_cnt < 1)
 446         {
 447           fprintf(stderr, _("%s: %s: verdef vd_cnt field too small: %u\n"),
 448                   program_name, this->name().c_str(), vd_cnt);
 449           gold_exit(false);
 450         }
 451
 452       const unsigned int vd_aux = verdef.get_vd_aux();
 453       if ((p - pverdef) + vd_aux >= verdef_size)
 454         {
 455           fprintf(stderr,
 456                   _("%s: %s: verdef vd_aux field out of range: %u\n"),
 457                   program_name, this->name().c_str(), vd_aux);
 458           gold_exit(false);
 459         }
 460
 461       const unsigned char* pvda = p + vd_aux;
 462       elfcpp::Verdaux<size, big_endian> verdaux(pvda);
 463
 464       const unsigned int vda_name = verdaux.get_vda_name();
 465       if (vda_name >= names_size)
 466         {
 467           fprintf(stderr,
 468                   _("%s: %s: verdaux vda_name field out of range: %u\n"),
 469                   program_name, this->name().c_str(), vda_name);
 470           gold_exit(false);
 471         }
 472
 473       this->set_version_map(version_map, vd_ndx, names + vda_name);
 474
 475       const unsigned int vd_next = verdef.get_vd_next();
 476       if ((p - pverdef) + vd_next >= verdef_size)
 477         {
 478           fprintf(stderr,
 479                   _("%s: %s: verdef vd_next field out of range: %u\n"),
 480                   program_name, this->name().c_str(), vd_next);
 481           gold_exit(false);
 482         }
 483
 484       p += vd_next;
 485     }
 486 }
 487
 488 // Add mappings for the required versions to VERSION_MAP.
 489
 490 template<int size, bool big_endian>
 491 void
 492 Sized_dynobj<size, big_endian>::make_verneed_map(
 493     Read_symbols_data* sd,
 494     Version_map* version_map) const
 495 {
 496   if (sd->verneed == NULL)
 497     return;
 498
 499   const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
 500   off_t names_size = sd->symbol_names_size;
 501
 502   const unsigned char* pverneed = sd->verneed->data();
 503   const off_t verneed_size = sd->verneed_size;
 504   const unsigned int count = sd->verneed_info;
 505
 506   const unsigned char* p = pverneed;
 507   for (unsigned int i = 0; i < count; ++i)
 508     {
 509       elfcpp::Verneed<size, big_endian> verneed(p);
 510
 511       if (verneed.get_vn_version() != elfcpp::VER_NEED_CURRENT)
 512         {
 513           fprintf(stderr, _("%s: %s: unexpected verneed version %u\n"),
 514                   program_name, this->name().c_str(),
 515                   verneed.get_vn_version());
 516           gold_exit(false);
 517         }
 518
 519       const unsigned int vn_aux = verneed.get_vn_aux();
 520
 521       if ((p - pverneed) + vn_aux >= verneed_size)
 522         {
 523           fprintf(stderr,
 524                   _("%s: %s: verneed vn_aux field out of range: %u\n"),
 525                   program_name, this->name().c_str(), vn_aux);
 526           gold_exit(false);
 527         }
 528
 529       const unsigned int vn_cnt = verneed.get_vn_cnt();
 530       const unsigned char* pvna = p + vn_aux;
 531       for (unsigned int j = 0; j < vn_cnt; ++j)
 532         {
 533           elfcpp::Vernaux<size, big_endian> vernaux(pvna);
 534
 535           const unsigned int vna_name = vernaux.get_vna_name();
 536           if (vna_name >= names_size)
 537             {
 538               fprintf(stderr,
 539                       _("%s: %s: vernaux vna_name field "
 540                         "out of range: %u\n"),
 541                       program_name, this->name().c_str(), vna_name);
 542               gold_exit(false);
 543             }
 544
 545           this->set_version_map(version_map, vernaux.get_vna_other(),
 546                                 names + vna_name);
 547
 548           const unsigned int vna_next = vernaux.get_vna_next();
 549           if ((pvna - pverneed) + vna_next >= verneed_size)
 550             {
 551               fprintf(stderr,
 552                       _("%s: %s: verneed vna_next field "
 553                         "out of range: %u\n"),
 554                       program_name, this->name().c_str(), vna_next);
 555               gold_exit(false);
 556             }
 557
 558           pvna += vna_next;
 559         }
 560
 561       const unsigned int vn_next = verneed.get_vn_next();
 562       if ((p - pverneed) + vn_next >= verneed_size)
 563         {
 564           fprintf(stderr,
 565                   _("%s: %s: verneed vn_next field out of range: %u\n"),
 566                   program_name, this->name().c_str(), vn_next);
 567           gold_exit(false);
 568         }
 569
 570       p += vn_next;
 571     }
 572 }
 573
 574 // Create a vector mapping version numbers to version strings.
 575
 576 template<int size, bool big_endian>
 577 void
 578 Sized_dynobj<size, big_endian>::make_version_map(
 579     Read_symbols_data* sd,
 580     Version_map* version_map) const
 581 {
 582   if (sd->verdef == NULL && sd->verneed == NULL)
 583     return;
 584
 585   // A guess at the maximum version number we will see.  If this is
 586   // wrong we will be less efficient but still correct.
 587   version_map->reserve(sd->verdef_info + sd->verneed_info * 10);
 588
 589   this->make_verdef_map(sd, version_map);
 590   this->make_verneed_map(sd, version_map);
 591 }
 592
 593 // Add the dynamic symbols to the symbol table.
 594
 595 template<int size, bool big_endian>
 596 void
 597 Sized_dynobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
 598                                                Read_symbols_data* sd)
 599 {
 600   if (sd->symbols == NULL)
 601     {
 602       gold_assert(sd->symbol_names == NULL);
 603       gold_assert(sd->versym == NULL && sd->verdef == NULL
 604                   && sd->verneed == NULL);
 605       return;
 606     }
 607
 608   const int sym_size = This::sym_size;
 609   const size_t symcount = sd->symbols_size / sym_size;
 610   if (symcount * sym_size != sd->symbols_size)
 611     {
 612       fprintf(stderr,
 613               _("%s: %s: size of dynamic symbols is not "
 614                 "multiple of symbol size\n"),
 615               program_name, this->name().c_str());
 616       gold_exit(false);
 617     }
 618
 619   Version_map version_map;
 620   this->make_version_map(sd, &version_map);
 621
 622   const char* sym_names =
 623     reinterpret_cast<const char*>(sd->symbol_names->data());
 624   symtab->add_from_dynobj(this, sd->symbols->data(), symcount,
 625                           sym_names, sd->symbol_names_size,
 626                           (sd->versym == NULL
 627                            ? NULL
 628                            : sd->versym->data()),
 629                           sd->versym_size,
 630                           &version_map);
 631
 632   delete sd->symbols;
 633   sd->symbols = NULL;
 634   delete sd->symbol_names;
 635   sd->symbol_names = NULL;
 636   if (sd->versym != NULL)
 637     {
 638       delete sd->versym;
 639       sd->versym = NULL;
 640     }
 641   if (sd->verdef != NULL)
 642     {
 643       delete sd->verdef;
 644       sd->verdef = NULL;
 645     }
 646   if (sd->verneed != NULL)
 647     {
 648       delete sd->verneed;
 649       sd->verneed = NULL;
 650     }
 651 }
 652
 653 // Given a vector of hash codes, compute the number of hash buckets to
 654 // use.
 655
 656 unsigned int
 657 Dynobj::compute_bucket_count(const std::vector<uint32_t>& hashcodes,
 658                              bool for_gnu_hash_table)
 659 {
 660   // FIXME: Implement optional hash table optimization.
 661
 662   // Array used to determine the number of hash table buckets to use
 663   // based on the number of symbols there are.  If there are fewer
 664   // than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3
 665   // buckets, fewer than 37 we use 17 buckets, and so forth.  We never
 666   // use more than 32771 buckets.  This is straight from the old GNU
 667   // linker.
 668   static const unsigned int buckets[] =
 669   {
 670     1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
 671     16411, 32771
 672   };
 673   const int buckets_count = sizeof buckets / sizeof buckets[0];
 674
 675   unsigned int symcount = hashcodes.size();
 676   unsigned int ret = 1;
 677   for (int i = 0; i < buckets_count; ++i)
 678     {
 679       if (symcount < buckets[i])
 680         break;
 681       ret = buckets[i];
 682     }
 683
 684   if (for_gnu_hash_table && ret < 2)
 685     ret = 2;
 686
 687   return ret;
 688 }
 689
 690 // The standard ELF hash function.  This hash function must not
 691 // change, as the dynamic linker uses it also.
 692
 693 uint32_t
 694 Dynobj::elf_hash(const char* name)
 695 {
 696   const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
 697   uint32_t h = 0;
 698   unsigned char c;
 699   while ((c = *nameu++) != '\0')
 700     {
 701       h = (h << 4) + c;
 702       uint32_t g = h & 0xf0000000;
 703       if (g != 0)
 704         {
 705           h ^= g >> 24;
 706           // The ELF ABI says h &= ~g, but using xor is equivalent in
 707           // this case (since g was set from h) and may save one
 708           // instruction.
 709           h ^= g;
 710         }
 711     }
 712   return h;
 713 }
 714
 715 // Create a standard ELF hash table, setting *PPHASH and *PHASHLEN.
 716 // DYNSYMS is a vector with all the global dynamic symbols.
 717 // LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
 718 // symbol table.
 719
 720 void
 721 Dynobj::create_elf_hash_table(const Target* target,
 722                               const std::vector<Symbol*>& dynsyms,
 723                               unsigned int local_dynsym_count,
 724                               unsigned char** pphash,
 725                               unsigned int* phashlen)
 726 {
 727   unsigned int dynsym_count = dynsyms.size();
 728
 729   // Get the hash values for all the symbols.
 730   std::vector<uint32_t> dynsym_hashvals(dynsym_count);
 731   for (unsigned int i = 0; i < dynsym_count; ++i)
 732     dynsym_hashvals[i] = Dynobj::elf_hash(dynsyms[i]->name());
 733
 734   const unsigned int bucketcount =
 735     Dynobj::compute_bucket_count(dynsym_hashvals, false);
 736
 737   std::vector<uint32_t> bucket(bucketcount);
 738   std::vector<uint32_t> chain(local_dynsym_count + dynsym_count);
 739
 740   for (unsigned int i = 0; i < dynsym_count; ++i)
 741     {
 742       unsigned int dynsym_index = dynsyms[i]->dynsym_index();
 743       unsigned int bucketpos = dynsym_hashvals[i] % bucketcount;
 744       chain[dynsym_index] = bucket[bucketpos];
 745       bucket[bucketpos] = dynsym_index;
 746     }
 747
 748   unsigned int hashlen = ((2
 749                            + bucketcount
 750                            + local_dynsym_count
 751                            + dynsym_count)
 752                           * 4);
 753   unsigned char* phash = new unsigned char[hashlen];
 754
 755   if (target->is_big_endian())
 756     Dynobj::sized_create_elf_hash_table<true>(bucket, chain, phash, hashlen);
 757   else
 758     Dynobj::sized_create_elf_hash_table<false>(bucket, chain, phash, hashlen);
 759
 760   *pphash = phash;
 761   *phashlen = hashlen;
 762 }
 763
 764 // Fill in an ELF hash table.
 765
 766 template<bool big_endian>
 767 void
 768 Dynobj::sized_create_elf_hash_table(const std::vector<uint32_t>& bucket,
 769                                     const std::vector<uint32_t>& chain,
 770                                     unsigned char* phash,
 771                                     unsigned int hashlen)
 772 {
 773   unsigned char* p = phash;
 774
 775   const unsigned int bucketcount = bucket.size();
 776   const unsigned int chaincount = chain.size();
 777
 778   elfcpp::Swap<32, big_endian>::writeval(p, bucketcount);
 779   p += 4;
 780   elfcpp::Swap<32, big_endian>::writeval(p, chaincount);
 781   p += 4;
 782
 783   for (unsigned int i = 0; i < bucketcount; ++i)
 784     {
 785       elfcpp::Swap<32, big_endian>::writeval(p, bucket[i]);
 786       p += 4;
 787     }
 788
 789   for (unsigned int i = 0; i < chaincount; ++i)
 790     {
 791       elfcpp::Swap<32, big_endian>::writeval(p, chain[i]);
 792       p += 4;
 793     }
 794
 795   gold_assert(static_cast<unsigned int>(p - phash) == hashlen);
 796 }
 797
 798 // The hash function used for the GNU hash table.  This hash function
 799 // must not change, as the dynamic linker uses it also.
 800
 801 uint32_t
 802 Dynobj::gnu_hash(const char* name)
 803 {
 804   const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
 805   uint32_t h = 5381;
 806   unsigned char c;
 807   while ((c = *nameu++) != '\0')
 808     h = (h << 5) + h + c;
 809   return h;
 810 }
 811
 812 // Create a GNU hash table, setting *PPHASH and *PHASHLEN.  GNU hash
 813 // tables are an extension to ELF which are recognized by the GNU
 814 // dynamic linker.  They are referenced using dynamic tag DT_GNU_HASH.
 815 // TARGET is the target.  DYNSYMS is a vector with all the global
 816 // symbols which will be going into the dynamic symbol table.
 817 // LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
 818 // symbol table.
 819
 820 void
 821 Dynobj::create_gnu_hash_table(const Target* target,
 822                               const std::vector<Symbol*>& dynsyms,
 823                               unsigned int local_dynsym_count,
 824                               unsigned char** pphash,
 825                               unsigned int* phashlen)
 826 {
 827   const unsigned int count = dynsyms.size();
 828
 829   // Sort the dynamic symbols into two vectors.  Symbols which we do
 830   // not want to put into the hash table we store into
 831   // UNHASHED_DYNSYMS.  Symbols which we do want to store we put into
 832   // HASHED_DYNSYMS.  DYNSYM_HASHVALS is parallel to HASHED_DYNSYMS,
 833   // and records the hash codes.
 834
 835   std::vector<Symbol*> unhashed_dynsyms;
 836   unhashed_dynsyms.reserve(count);
 837
 838   std::vector<Symbol*> hashed_dynsyms;
 839   hashed_dynsyms.reserve(count);
 840
 841   std::vector<uint32_t> dynsym_hashvals;
 842   dynsym_hashvals.reserve(count);
 843
 844   for (unsigned int i = 0; i < count; ++i)
 845     {
 846       Symbol* sym = dynsyms[i];
 847
 848       // FIXME: Should put on unhashed_dynsyms if the symbol is
 849       // hidden.
 850       if (sym->is_undefined())
 851         unhashed_dynsyms.push_back(sym);
 852       else
 853         {
 854           hashed_dynsyms.push_back(sym);
 855           dynsym_hashvals.push_back(Dynobj::gnu_hash(sym->name()));
 856         }
 857     }
 858
 859   // Put the unhashed symbols at the start of the global portion of
 860   // the dynamic symbol table.
 861   const unsigned int unhashed_count = unhashed_dynsyms.size();
 862   unsigned int unhashed_dynsym_index = local_dynsym_count;
 863   for (unsigned int i = 0; i < unhashed_count; ++i)
 864     {
 865       unhashed_dynsyms[i]->set_dynsym_index(unhashed_dynsym_index);
 866       ++unhashed_dynsym_index;
 867     }
 868
 869   // For the actual data generation we call out to a templatized
 870   // function.
 871   int size = target->get_size();
 872   bool big_endian = target->is_big_endian();
 873   if (size == 32)
 874     {
 875       if (big_endian)
 876         Dynobj::sized_create_gnu_hash_table<32, true>(hashed_dynsyms,
 877                                                       dynsym_hashvals,
 878                                                       unhashed_dynsym_index,
 879                                                       pphash,
 880                                                       phashlen);
 881       else
 882         Dynobj::sized_create_gnu_hash_table<32, false>(hashed_dynsyms,
 883                                                        dynsym_hashvals,
 884                                                        unhashed_dynsym_index,
 885                                                        pphash,
 886                                                        phashlen);
 887     }
 888   else if (size == 64)
 889     {
 890       if (big_endian)
 891         Dynobj::sized_create_gnu_hash_table<64, true>(hashed_dynsyms,
 892                                                       dynsym_hashvals,
 893                                                       unhashed_dynsym_index,
 894                                                       pphash,
 895                                                       phashlen);
 896       else
 897         Dynobj::sized_create_gnu_hash_table<64, false>(hashed_dynsyms,
 898                                                        dynsym_hashvals,
 899                                                        unhashed_dynsym_index,
 900                                                        pphash,
 901                                                        phashlen);
 902     }
 903   else
 904     gold_unreachable();
 905 }
 906
 907 // Create the actual data for a GNU hash table.  This is just a copy
 908 // of the code from the old GNU linker.
 909
 910 template<int size, bool big_endian>
 911 void
 912 Dynobj::sized_create_gnu_hash_table(
 913     const std::vector<Symbol*>& hashed_dynsyms,
 914     const std::vector<uint32_t>& dynsym_hashvals,
 915     unsigned int unhashed_dynsym_count,
 916     unsigned char** pphash,
 917     unsigned int* phashlen)
 918 {
 919   if (hashed_dynsyms.empty())
 920     {
 921       // Special case for the empty hash table.
 922       unsigned int hashlen = 5 * 4 + size / 8;
 923       unsigned char* phash = new unsigned char[hashlen];
 924       // One empty bucket.
 925       elfcpp::Swap<32, big_endian>::writeval(phash, 1);
 926       // Symbol index above unhashed symbols.
 927       elfcpp::Swap<32, big_endian>::writeval(phash + 4, unhashed_dynsym_count);
 928       // One word for bitmask.
 929       elfcpp::Swap<32, big_endian>::writeval(phash + 8, 1);
 930       // Only bloom filter.
 931       elfcpp::Swap<32, big_endian>::writeval(phash + 12, 0);
 932       // No valid hashes.
 933       elfcpp::Swap<size, big_endian>::writeval(phash + 16, 0);
 934       // No hashes in only bucket.
 935       elfcpp::Swap<32, big_endian>::writeval(phash + 16 + size / 8, 0);
 936
 937       *phashlen = hashlen;
 938       *pphash = phash;
 939
 940       return;
 941     }
 942
 943   const unsigned int bucketcount =
 944     Dynobj::compute_bucket_count(dynsym_hashvals, true);
 945
 946   const unsigned int nsyms = hashed_dynsyms.size();
 947
 948   uint32_t maskbitslog2 = 1;
 949   uint32_t x = nsyms >> 1;
 950   while (x != 0)
 951     {
 952       ++maskbitslog2;
 953       x >>= 1;
 954     }
 955   if (maskbitslog2 < 3)
 956     maskbitslog2 = 5;
 957   else if (((1U << (maskbitslog2 - 2)) & nsyms) != 0)
 958     maskbitslog2 += 3;
 959   else
 960     maskbitslog2 += 2;
 961
 962   uint32_t shift1;
 963   if (size == 32)
 964     shift1 = 5;
 965   else
 966     {
 967       if (maskbitslog2 == 5)
 968         maskbitslog2 = 6;
 969       shift1 = 6;
 970     }
 971   uint32_t mask = (1U << shift1) - 1U;
 972   uint32_t shift2 = maskbitslog2;
 973   uint32_t maskbits = 1U << maskbitslog2;
 974   uint32_t maskwords = 1U << (maskbitslog2 - shift1);
 975
 976   typedef typename elfcpp::Elf_types<size>::Elf_WXword Word;
 977   std::vector<Word> bitmask(maskwords);
 978   std::vector<uint32_t> counts(bucketcount);
 979   std::vector<uint32_t> indx(bucketcount);
 980   uint32_t symindx = unhashed_dynsym_count;
 981
 982   // Count the number of times each hash bucket is used.
 983   for (unsigned int i = 0; i < nsyms; ++i)
 984     ++counts[dynsym_hashvals[i] % bucketcount];
 985
 986   unsigned int cnt = symindx;
 987   for (unsigned int i = 0; i < bucketcount; ++i)
 988     {
 989       indx[i] = cnt;
 990       cnt += counts[i];
 991     }
 992
 993   unsigned int hashlen = (4 + bucketcount + nsyms) * 4;
 994   hashlen += maskbits / 8;
 995   unsigned char* phash = new unsigned char[hashlen];
 996
 997   elfcpp::Swap<32, big_endian>::writeval(phash, bucketcount);
 998   elfcpp::Swap<32, big_endian>::writeval(phash + 4, symindx);
 999   elfcpp::Swap<32, big_endian>::writeval(phash + 8, maskwords);
1000   elfcpp::Swap<32, big_endian>::writeval(phash + 12, shift2);
1001
1002   unsigned char* p = phash + 16 + maskbits / 8;
1003   for (unsigned int i = 0; i < bucketcount; ++i)
1004     {
1005       if (counts[i] == 0)
1006         elfcpp::Swap<32, big_endian>::writeval(p, 0);
1007       else
1008         elfcpp::Swap<32, big_endian>::writeval(p, indx[i]);
1009       p += 4;
1010     }
1011
1012   for (unsigned int i = 0; i < nsyms; ++i)
1013     {
1014       Symbol* sym = hashed_dynsyms[i];
1015       uint32_t hashval = dynsym_hashvals[i];
1016
1017       unsigned int bucket = hashval % bucketcount;
1018       unsigned int val = ((hashval >> shift1)
1019                           & ((maskbits >> shift1) - 1));
1020       bitmask[val] |= (static_cast<Word>(1U)) << (hashval & mask);
1021       bitmask[val] |= (static_cast<Word>(1U)) << ((hashval >> shift2) & mask);
1022       val = hashval & ~ 1U;
1023       if (counts[bucket] == 1)
1024         {
1025           // Last element terminates the chain.
1026           val |= 1;
1027         }
1028       elfcpp::Swap<32, big_endian>::writeval(p + (indx[bucket] - symindx) * 4,
1029                                              val);
1030       --counts[bucket];
1031
1032       sym->set_dynsym_index(indx[bucket]);
1033       ++indx[bucket];
1034     }
1035
1036   p = phash + 16;
1037   for (unsigned int i = 0; i < maskwords; ++i)
1038     {
1039       elfcpp::Swap<size, big_endian>::writeval(p, bitmask[i]);
1040       p += size / 8;
1041     }
1042
1043   *phashlen = hashlen;
1044   *pphash = phash;
1045 }
1046
1047 // Verdef methods.
1048
1049 // Write this definition to a buffer for the output section.
1050
1051 template<int size, bool big_endian>
1052 unsigned char*
1053 Verdef::write(const Stringpool* dynpool, bool is_last, unsigned char* pb
1054               ACCEPT_SIZE_ENDIAN) const
1055 {
1056   const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size;
1057   const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size;
1058
1059   elfcpp::Verdef_write<size, big_endian> vd(pb);
1060   vd.set_vd_version(elfcpp::VER_DEF_CURRENT);
1061   vd.set_vd_flags((this->is_base_ ? elfcpp::VER_FLG_BASE : 0)
1062                   | (this->is_weak_ ? elfcpp::VER_FLG_WEAK : 0));
1063   vd.set_vd_ndx(this->index());
1064   vd.set_vd_cnt(1 + this->deps_.size());
1065   vd.set_vd_hash(Dynobj::elf_hash(this->name()));
1066   vd.set_vd_aux(verdef_size);
1067   vd.set_vd_next(is_last
1068                  ? 0
1069                  : verdef_size + (1 + this->deps_.size()) * verdaux_size);
1070   pb += verdef_size;
1071
1072   elfcpp::Verdaux_write<size, big_endian> vda(pb);
1073   vda.set_vda_name(dynpool->get_offset(this->name()));
1074   vda.set_vda_next(this->deps_.empty() ? 0 : verdaux_size);
1075   pb += verdaux_size;
1076
1077   Deps::const_iterator p;
1078   unsigned int i;
1079   for (p = this->deps_.begin(), i = 0;
1080        p != this->deps_.end();
1081        ++p, ++i)
1082     {
1083       elfcpp::Verdaux_write<size, big_endian> vda(pb);
1084       vda.set_vda_name(dynpool->get_offset(*p));
1085       vda.set_vda_next(i + 1 >= this->deps_.size() ? 0 : verdaux_size);
1086       pb += verdaux_size;
1087     }
1088
1089   return pb;
1090 }
1091
1092 // Verneed methods.
1093
1094 Verneed::~Verneed()
1095 {
1096   for (Need_versions::iterator p = this->need_versions_.begin();
1097        p != this->need_versions_.end();
1098        ++p)
1099     delete *p;
1100 }
1101
1102 // Add a new version to this file reference.
1103
1104 Verneed_version*
1105 Verneed::add_name(const char* name)
1106 {
1107   Verneed_version* vv = new Verneed_version(name);
1108   this->need_versions_.push_back(vv);
1109   return vv;
1110 }
1111
1112 // Set the version indexes starting at INDEX.
1113
1114 unsigned int
1115 Verneed::finalize(unsigned int index)
1116 {
1117   for (Need_versions::iterator p = this->need_versions_.begin();
1118        p != this->need_versions_.end();
1119        ++p)
1120     {
1121       (*p)->set_index(index);
1122       ++index;
1123     }
1124   return index;
1125 }
1126
1127 // Write this list of referenced versions to a buffer for the output
1128 // section.
1129
1130 template<int size, bool big_endian>
1131 unsigned char*
1132 Verneed::write(const Stringpool* dynpool, bool is_last,
1133                unsigned char* pb ACCEPT_SIZE_ENDIAN) const
1134 {
1135   const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size;
1136   const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size;
1137
1138   elfcpp::Verneed_write<size, big_endian> vn(pb);
1139   vn.set_vn_version(elfcpp::VER_NEED_CURRENT);
1140   vn.set_vn_cnt(this->need_versions_.size());
1141   vn.set_vn_file(dynpool->get_offset(this->filename()));
1142   vn.set_vn_aux(verneed_size);
1143   vn.set_vn_next(is_last
1144                  ? 0
1145                  : verneed_size + this->need_versions_.size() * vernaux_size);
1146   pb += verneed_size;
1147
1148   Need_versions::const_iterator p;
1149   unsigned int i;
1150   for (p = this->need_versions_.begin(), i = 0;
1151        p != this->need_versions_.end();
1152        ++p, ++i)
1153     {
1154       elfcpp::Vernaux_write<size, big_endian> vna(pb);
1155       vna.set_vna_hash(Dynobj::elf_hash((*p)->version()));
1156       // FIXME: We need to sometimes set VER_FLG_WEAK here.
1157       vna.set_vna_flags(0);
1158       vna.set_vna_other((*p)->index());
1159       vna.set_vna_name(dynpool->get_offset((*p)->version()));
1160       vna.set_vna_next(i + 1 >= this->need_versions_.size()
1161                        ? 0
1162                        : vernaux_size);
1163       pb += vernaux_size;
1164     }
1165
1166   return pb;
1167 }
1168
1169 // Versions methods.
1170
1171 Versions::~Versions()
1172 {
1173   for (Defs::iterator p = this->defs_.begin();
1174        p != this->defs_.end();
1175        ++p)
1176     delete *p;
1177
1178   for (Needs::iterator p = this->needs_.begin();
1179        p != this->needs_.end();
1180        ++p)
1181     delete *p;
1182 }
1183
1184 // Record version information for a symbol going into the dynamic
1185 // symbol table.
1186
1187 void
1188 Versions::record_version(const General_options* options,
1189                          Stringpool* dynpool, const Symbol* sym)
1190 {
1191   gold_assert(!this->is_finalized_);
1192   gold_assert(sym->version() != NULL);
1193
1194   Stringpool::Key version_key;
1195   const char* version = dynpool->add(sym->version(), &version_key);
1196
1197   if (!sym->is_from_dynobj())
1198     this->add_def(options, sym, version, version_key);
1199   else
1200     {
1201       // This is a version reference.
1202
1203       Object* object = sym->object();
1204       gold_assert(object->is_dynamic());
1205       Dynobj* dynobj = static_cast<Dynobj*>(object);
1206
1207       this->add_need(dynpool, dynobj->soname(), version, version_key);
1208     }
1209 }
1210
1211 // We've found a symbol SYM defined in version VERSION.
1212
1213 void
1214 Versions::add_def(const General_options* options, const Symbol* sym,
1215                   const char* version, Stringpool::Key version_key)
1216 {
1217   Key k(version_key, 0);
1218   Version_base* const vbnull = NULL;
1219   std::pair<Version_table::iterator, bool> ins =
1220     this->version_table_.insert(std::make_pair(k, vbnull));
1221
1222   if (!ins.second)
1223     {
1224       // We already have an entry for this version.
1225       Version_base* vb = ins.first->second;
1226
1227       // We have now seen a symbol in this version, so it is not
1228       // weak.
1229       vb->clear_weak();
1230
1231       // FIXME: When we support version scripts, we will need to
1232       // check whether this symbol should be forced local.
1233     }
1234   else
1235     {
1236       // If we are creating a shared object, it is an error to
1237       // find a definition of a symbol with a version which is not
1238       // in the version script.
1239       if (options->is_shared())
1240         {
1241           fprintf(stderr, _("%s: symbol %s has undefined version %s\n"),
1242                   program_name, sym->name(), version);
1243           gold_exit(false);
1244         }
1245
1246       // If this is the first version we are defining, first define
1247       // the base version.  FIXME: Should use soname here when
1248       // creating a shared object.
1249       Verdef* vdbase = new Verdef(options->output_file_name(), true, false,
1250                                   true);
1251       this->defs_.push_back(vdbase);
1252
1253       // When creating a regular executable, automatically define
1254       // a new version.
1255       Verdef* vd = new Verdef(version, false, false, false);
1256       this->defs_.push_back(vd);
1257       ins.first->second = vd;
1258     }
1259 }
1260
1261 // Add a reference to version NAME in file FILENAME.
1262
1263 void
1264 Versions::add_need(Stringpool* dynpool, const char* filename, const char* name,
1265                    Stringpool::Key name_key)
1266 {
1267   Stringpool::Key filename_key;
1268   filename = dynpool->add(filename, &filename_key);
1269
1270   Key k(name_key, filename_key);
1271   Version_base* const vbnull = NULL;
1272   std::pair<Version_table::iterator, bool> ins =
1273     this->version_table_.insert(std::make_pair(k, vbnull));
1274
1275   if (!ins.second)
1276     {
1277       // We already have an entry for this filename/version.
1278       return;
1279     }
1280
1281   // See whether we already have this filename.  We don't expect many
1282   // version references, so we just do a linear search.  This could be
1283   // replaced by a hash table.
1284   Verneed* vn = NULL;
1285   for (Needs::iterator p = this->needs_.begin();
1286        p != this->needs_.end();
1287        ++p)
1288     {
1289       if ((*p)->filename() == filename)
1290         {
1291           vn = *p;
1292           break;
1293         }
1294     }
1295
1296   if (vn == NULL)
1297     {
1298       // We have a new filename.
1299       vn = new Verneed(filename);
1300       this->needs_.push_back(vn);
1301     }
1302
1303   ins.first->second = vn->add_name(name);
1304 }
1305
1306 // Set the version indexes.  Create a new dynamic version symbol for
1307 // each new version definition.
1308
1309 unsigned int
1310 Versions::finalize(const Target* target, Symbol_table* symtab,
1311                    unsigned int dynsym_index, std::vector<Symbol*>* syms)
1312 {
1313   gold_assert(!this->is_finalized_);
1314
1315   unsigned int vi = 1;
1316
1317   for (Defs::iterator p = this->defs_.begin();
1318        p != this->defs_.end();
1319        ++p)
1320     {
1321       (*p)->set_index(vi);
1322       ++vi;
1323
1324       // Create a version symbol if necessary.
1325       if (!(*p)->is_symbol_created())
1326         {
1327           Symbol* vsym = symtab->define_as_constant(target, (*p)->name(),
1328                                                     (*p)->name(), 0, 0,
1329                                                     elfcpp::STT_OBJECT,
1330                                                     elfcpp::STB_GLOBAL,
1331                                                     elfcpp::STV_DEFAULT, 0,
1332                                                     false);
1333           vsym->set_needs_dynsym_entry();
1334           ++dynsym_index;
1335           syms->push_back(vsym);
1336           // The name is already in the dynamic pool.
1337         }
1338     }
1339
1340   // Index 1 is used for global symbols.
1341   if (vi == 1)
1342     {
1343       gold_assert(this->defs_.empty());
1344       vi = 2;
1345     }
1346
1347   for (Needs::iterator p = this->needs_.begin();
1348        p != this->needs_.end();
1349        ++p)
1350     vi = (*p)->finalize(vi);
1351
1352   this->is_finalized_ = true;
1353
1354   return dynsym_index;
1355 }
1356
1357 // Return the version index to use for a symbol.  This does two hash
1358 // table lookups: one in DYNPOOL and one in this->version_table_.
1359 // Another approach alternative would be store a pointer in SYM, which
1360 // would increase the size of the symbol table.  Or perhaps we could
1361 // use a hash table from dynamic symbol pointer values to Version_base
1362 // pointers.
1363
1364 unsigned int
1365 Versions::version_index(const Stringpool* dynpool, const Symbol* sym) const
1366 {
1367   Stringpool::Key version_key;
1368   const char* version = dynpool->find(sym->version(), &version_key);
1369   gold_assert(version != NULL);
1370
1371   Key k;
1372   if (!sym->is_from_dynobj())
1373     k = Key(version_key, 0);
1374   else
1375     {
1376       Object* object = sym->object();
1377       gold_assert(object->is_dynamic());
1378       Dynobj* dynobj = static_cast<Dynobj*>(object);
1379
1380       Stringpool::Key filename_key;
1381       const char* filename = dynpool->find(dynobj->soname(), &filename_key);
1382       gold_assert(filename != NULL);
1383
1384       k = Key(version_key, filename_key);
1385     }
1386
1387   Version_table::const_iterator p = this->version_table_.find(k);
1388   gold_assert(p != this->version_table_.end());
1389
1390   return p->second->index();
1391 }
1392
1393 // Return an allocated buffer holding the contents of the symbol
1394 // version section.
1395
1396 template<int size, bool big_endian>
1397 void
1398 Versions::symbol_section_contents(const Stringpool* dynpool,
1399                                   unsigned int local_symcount,
1400                                   const std::vector<Symbol*>& syms,
1401                                   unsigned char** pp,
1402                                   unsigned int* psize
1403                                   ACCEPT_SIZE_ENDIAN) const
1404 {
1405   gold_assert(this->is_finalized_);
1406
1407   unsigned int sz = (local_symcount + syms.size()) * 2;
1408   unsigned char* pbuf = new unsigned char[sz];
1409
1410   for (unsigned int i = 0; i < local_symcount; ++i)
1411     elfcpp::Swap<16, big_endian>::writeval(pbuf + i * 2,
1412                                            elfcpp::VER_NDX_LOCAL);
1413
1414   for (std::vector<Symbol*>::const_iterator p = syms.begin();
1415        p != syms.end();
1416        ++p)
1417     {
1418       unsigned int version_index;
1419       const char* version = (*p)->version();
1420       if (version == NULL)
1421         version_index = elfcpp::VER_NDX_GLOBAL;
1422       else
1423         version_index = this->version_index(dynpool, *p);
1424       elfcpp::Swap<16, big_endian>::writeval(pbuf + (*p)->dynsym_index() * 2,
1425                                              version_index);
1426     }
1427
1428   *pp = pbuf;
1429   *psize = sz;
1430 }
1431
1432 // Return an allocated buffer holding the contents of the version
1433 // definition section.
1434
1435 template<int size, bool big_endian>
1436 void
1437 Versions::def_section_contents(const Stringpool* dynpool,
1438                                unsigned char** pp, unsigned int* psize,
1439                                unsigned int* pentries
1440                                ACCEPT_SIZE_ENDIAN) const
1441 {
1442   gold_assert(this->is_finalized_);
1443   gold_assert(!this->defs_.empty());
1444
1445   const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size;
1446   const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size;
1447
1448   unsigned int sz = 0;
1449   for (Defs::const_iterator p = this->defs_.begin();
1450        p != this->defs_.end();
1451        ++p)
1452     {
1453       sz += verdef_size + verdaux_size;
1454       sz += (*p)->count_dependencies() * verdaux_size;
1455     }
1456
1457   unsigned char* pbuf = new unsigned char[sz];
1458
1459   unsigned char* pb = pbuf;
1460   Defs::const_iterator p;
1461   unsigned int i;
1462   for (p = this->defs_.begin(), i = 0;
1463        p != this->defs_.end();
1464        ++p, ++i)
1465     pb = (*p)->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
1466             dynpool, i + 1 >= this->defs_.size(), pb
1467             SELECT_SIZE_ENDIAN(size, big_endian));
1468
1469   gold_assert(static_cast<unsigned int>(pb - pbuf) == sz);
1470
1471   *pp = pbuf;
1472   *psize = sz;
1473   *pentries = this->defs_.size();
1474 }
1475
1476 // Return an allocated buffer holding the contents of the version
1477 // reference section.
1478
1479 template<int size, bool big_endian>
1480 void
1481 Versions::need_section_contents(const Stringpool* dynpool,
1482                                 unsigned char** pp, unsigned int *psize,
1483                                 unsigned int *pentries
1484                                 ACCEPT_SIZE_ENDIAN) const
1485 {
1486   gold_assert(this->is_finalized_);
1487   gold_assert(!this->needs_.empty());
1488
1489   const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size;
1490   const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size;
1491
1492   unsigned int sz = 0;
1493   for (Needs::const_iterator p = this->needs_.begin();
1494        p != this->needs_.end();
1495        ++p)
1496     {
1497       sz += verneed_size;
1498       sz += (*p)->count_versions() * vernaux_size;
1499     }
1500
1501   unsigned char* pbuf = new unsigned char[sz];
1502
1503   unsigned char* pb = pbuf;
1504   Needs::const_iterator p;
1505   unsigned int i;
1506   for (p = this->needs_.begin(), i = 0;
1507        p != this->needs_.end();
1508        ++p, ++i)
1509     pb = (*p)->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
1510             dynpool, i + 1 >= this->needs_.size(), pb
1511             SELECT_SIZE_ENDIAN(size, big_endian));
1512
1513   gold_assert(static_cast<unsigned int>(pb - pbuf) == sz);
1514
1515   *pp = pbuf;
1516   *psize = sz;
1517   *pentries = this->needs_.size();
1518 }
1519
1520 // Instantiate the templates we need.  We could use the configure
1521 // script to restrict this to only the ones for implemented targets.
1522
1523 template
1524 class Sized_dynobj<32, false>;
1525
1526 template
1527 class Sized_dynobj<32, true>;
1528
1529 template
1530 class Sized_dynobj<64, false>;
1531
1532 template
1533 class Sized_dynobj<64, true>;
1534
1535 template
1536 void
1537 Versions::symbol_section_contents<32, false>(
1538     const Stringpool*,
1539     unsigned int,
1540     const std::vector<Symbol*>&,
1541     unsigned char**,
1542     unsigned int*
1543     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
1544
1545 template
1546 void
1547 Versions::symbol_section_contents<32, true>(
1548     const Stringpool*,
1549     unsigned int,
1550     const std::vector<Symbol*>&,
1551     unsigned char**,
1552     unsigned int*
1553     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
1554
1555 template
1556 void
1557 Versions::symbol_section_contents<64, false>(
1558     const Stringpool*,
1559     unsigned int,
1560     const std::vector<Symbol*>&,
1561     unsigned char**,
1562     unsigned int*
1563     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
1564
1565 template
1566 void
1567 Versions::symbol_section_contents<64, true>(
1568     const Stringpool*,
1569     unsigned int,
1570     const std::vector<Symbol*>&,
1571     unsigned char**,
1572     unsigned int*
1573     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
1574
1575 template
1576 void
1577 Versions::def_section_contents<32, false>(
1578     const Stringpool*,
1579     unsigned char**,
1580     unsigned int*,
1581     unsigned int*
1582     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
1583
1584 template
1585 void
1586 Versions::def_section_contents<32, true>(
1587     const Stringpool*,
1588     unsigned char**,
1589     unsigned int*,
1590     unsigned int*
1591     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
1592
1593 template
1594 void
1595 Versions::def_section_contents<64, false>(
1596     const Stringpool*,
1597     unsigned char**,
1598     unsigned int*,
1599     unsigned int*
1600     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
1601
1602 template
1603 void
1604 Versions::def_section_contents<64, true>(
1605     const Stringpool*,
1606     unsigned char**,
1607     unsigned int*,
1608     unsigned int*
1609     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
1610
1611 template
1612 void
1613 Versions::need_section_contents<32, false>(
1614     const Stringpool*,
1615     unsigned char**,
1616     unsigned int*,
1617     unsigned int*
1618     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
1619
1620 template
1621 void
1622 Versions::need_section_contents<32, true>(
1623     const Stringpool*,
1624     unsigned char**,
1625     unsigned int*,
1626     unsigned int*
1627     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
1628
1629 template
1630 void
1631 Versions::need_section_contents<64, false>(
1632     const Stringpool*,
1633     unsigned char**,
1634     unsigned int*,
1635     unsigned int*
1636     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
1637
1638 template
1639 void
1640 Versions::need_section_contents<64, true>(
1641     const Stringpool*,
1642     unsigned char**,
1643     unsigned int*,
1644     unsigned int*
1645     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
1646
1647 } // End namespace gold.