gold/dynobj.cc

   1 // dynobj.cc -- dynamic object 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 <vector>
  26 #include <cstring>
  27
  28 #include "elfcpp.h"
  29 #include "parameters.h"
  30 #include "symtab.h"
  31 #include "dynobj.h"
  32
  33 namespace gold
  34 {
  35
  36 // Class Dynobj.
  37
  38 // Return the string to use in a DT_NEEDED entry.
  39
  40 const char*
  41 Dynobj::soname() const
  42 {
  43   if (!this->soname_.empty())
  44     return this->soname_.c_str();
  45   return this->name().c_str();
  46 }
  47
  48 // Class Sized_dynobj.
  49
  50 template<int size, bool big_endian>
  51 Sized_dynobj<size, big_endian>::Sized_dynobj(
  52     const std::string& name,
  53     Input_file* input_file,
  54     off_t offset,
  55     const elfcpp::Ehdr<size, big_endian>& ehdr)
  56   : Dynobj(name, input_file, offset),
  57     elf_file_(this, ehdr)
  58 {
  59 }
  60
  61 // Set up the object.
  62
  63 template<int size, bool big_endian>
  64 void
  65 Sized_dynobj<size, big_endian>::setup(
  66     const elfcpp::Ehdr<size, big_endian>& ehdr)
  67 {
  68   this->set_target(ehdr.get_e_machine(), size, big_endian,
  69                    ehdr.get_e_ident()[elfcpp::EI_OSABI],
  70                    ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
  71
  72   const unsigned int shnum = this->elf_file_.shnum();
  73   this->set_shnum(shnum);
  74 }
  75
  76 // Find the SHT_DYNSYM section and the various version sections, and
  77 // the dynamic section, given the section headers.
  78
  79 template<int size, bool big_endian>
  80 void
  81 Sized_dynobj<size, big_endian>::find_dynsym_sections(
  82     const unsigned char* pshdrs,
  83     unsigned int* pdynsym_shndx,
  84     unsigned int* pversym_shndx,
  85     unsigned int* pverdef_shndx,
  86     unsigned int* pverneed_shndx,
  87     unsigned int* pdynamic_shndx)
  88 {
  89   *pdynsym_shndx = -1U;
  90   *pversym_shndx = -1U;
  91   *pverdef_shndx = -1U;
  92   *pverneed_shndx = -1U;
  93   *pdynamic_shndx = -1U;
  94
  95   const unsigned int shnum = this->shnum();
  96   const unsigned char* p = pshdrs;
  97   for (unsigned int i = 0; i < shnum; ++i, p += This::shdr_size)
  98     {
  99       typename This::Shdr shdr(p);
 100
 101       unsigned int* pi;
 102       switch (shdr.get_sh_type())
 103         {
 104         case elfcpp::SHT_DYNSYM:
 105           pi = pdynsym_shndx;
 106           break;
 107         case elfcpp::SHT_GNU_versym:
 108           pi = pversym_shndx;
 109           break;
 110         case elfcpp::SHT_GNU_verdef:
 111           pi = pverdef_shndx;
 112           break;
 113         case elfcpp::SHT_GNU_verneed:
 114           pi = pverneed_shndx;
 115           break;
 116         case elfcpp::SHT_DYNAMIC:
 117           pi = pdynamic_shndx;
 118           break;
 119         default:
 120           pi = NULL;
 121           break;
 122         }
 123
 124       if (pi == NULL)
 125         continue;
 126
 127       if (*pi != -1U)
 128         {
 129           fprintf(stderr,
 130                   _("%s: %s: unexpected duplicate type %u section: %u, %u\n"),
 131                   program_name, this->name().c_str(), shdr.get_sh_type(),
 132                   *pi, i);
 133           gold_exit(false);
 134         }
 135
 136       *pi = i;
 137     }
 138 }
 139
 140 // Read the contents of section SHNDX.  PSHDRS points to the section
 141 // headers.  TYPE is the expected section type.  LINK is the expected
 142 // section link.  Store the data in *VIEW and *VIEW_SIZE.  The
 143 // section's sh_info field is stored in *VIEW_INFO.
 144
 145 template<int size, bool big_endian>
 146 void
 147 Sized_dynobj<size, big_endian>::read_dynsym_section(
 148     const unsigned char* pshdrs,
 149     unsigned int shndx,
 150     elfcpp::SHT type,
 151     unsigned int link,
 152     File_view** view,
 153     off_t* view_size,
 154     unsigned int* view_info)
 155 {
 156   if (shndx == -1U)
 157     {
 158       *view = NULL;
 159       *view_size = 0;
 160       *view_info = 0;
 161       return;
 162     }
 163
 164   typename This::Shdr shdr(pshdrs + shndx * This::shdr_size);
 165
 166   gold_assert(shdr.get_sh_type() == type);
 167
 168   if (shdr.get_sh_link() != link)
 169     {
 170       fprintf(stderr,
 171               _("%s: %s: unexpected link in section %u header: %u != %u\n"),
 172               program_name, this->name().c_str(), shndx,
 173               shdr.get_sh_link(), link);
 174       gold_exit(false);
 175     }
 176
 177   *view = this->get_lasting_view(shdr.get_sh_offset(), shdr.get_sh_size());
 178   *view_size = shdr.get_sh_size();
 179   *view_info = shdr.get_sh_info();
 180 }
 181
 182 // Set the soname field if this shared object has a DT_SONAME tag.
 183 // PSHDRS points to the section headers.  DYNAMIC_SHNDX is the section
 184 // index of the SHT_DYNAMIC section.  STRTAB_SHNDX, STRTAB, and
 185 // STRTAB_SIZE are the section index and contents of a string table
 186 // which may be the one associated with the SHT_DYNAMIC section.
 187
 188 template<int size, bool big_endian>
 189 void
 190 Sized_dynobj<size, big_endian>::set_soname(const unsigned char* pshdrs,
 191                                            unsigned int dynamic_shndx,
 192                                            unsigned int strtab_shndx,
 193                                            const unsigned char* strtabu,
 194                                            off_t strtab_size)
 195 {
 196   typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size);
 197   gold_assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC);
 198
 199   const off_t dynamic_size = dynamicshdr.get_sh_size();
 200   const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(),
 201                                                  dynamic_size);
 202
 203   const unsigned int link = dynamicshdr.get_sh_link();
 204   if (link != strtab_shndx)
 205     {
 206       if (link >= this->shnum())
 207         {
 208           fprintf(stderr,
 209                   _("%s: %s: DYNAMIC section %u link out of range: %u\n"),
 210                   program_name, this->name().c_str(),
 211                   dynamic_shndx, link);
 212           gold_exit(false);
 213         }
 214
 215       typename This::Shdr strtabshdr(pshdrs + link * This::shdr_size);
 216       if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
 217         {
 218           fprintf(stderr,
 219                   _("%s: %s: DYNAMIC section %u link %u is not a strtab\n"),
 220                   program_name, this->name().c_str(),
 221                   dynamic_shndx, link);
 222           gold_exit(false);
 223         }
 224
 225       strtab_size = strtabshdr.get_sh_size();
 226       strtabu = this->get_view(strtabshdr.get_sh_offset(), strtab_size);
 227     }
 228
 229   for (const unsigned char* p = pdynamic;
 230        p < pdynamic + dynamic_size;
 231        p += This::dyn_size)
 232     {
 233       typename This::Dyn dyn(p);
 234
 235       if (dyn.get_d_tag() == elfcpp::DT_SONAME)
 236         {
 237           off_t val = dyn.get_d_val();
 238           if (val >= strtab_size)
 239             {
 240               fprintf(stderr,
 241                       _("%s: %s: DT_SONAME value out of range: "
 242                         "%lld >= %lld\n"),
 243                       program_name, this->name().c_str(),
 244                       static_cast<long long>(val),
 245                       static_cast<long long>(strtab_size));
 246               gold_exit(false);
 247             }
 248
 249           const char* strtab = reinterpret_cast<const char*>(strtabu);
 250           this->set_soname_string(strtab + val);
 251           return;
 252         }
 253
 254       if (dyn.get_d_tag() == elfcpp::DT_NULL)
 255         return;
 256     }
 257
 258   fprintf(stderr, _("%s: %s: missing DT_NULL in dynamic segment\n"),
 259           program_name, this->name().c_str());
 260   gold_exit(false);
 261 }
 262
 263 // Read the symbols and sections from a dynamic object.  We read the
 264 // dynamic symbols, not the normal symbols.
 265
 266 template<int size, bool big_endian>
 267 void
 268 Sized_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
 269 {
 270   this->read_section_data(&this->elf_file_, sd);
 271
 272   const unsigned char* const pshdrs = sd->section_headers->data();
 273
 274   unsigned int dynsym_shndx;
 275   unsigned int versym_shndx;
 276   unsigned int verdef_shndx;
 277   unsigned int verneed_shndx;
 278   unsigned int dynamic_shndx;
 279   this->find_dynsym_sections(pshdrs, &dynsym_shndx, &versym_shndx,
 280                              &verdef_shndx, &verneed_shndx, &dynamic_shndx);
 281
 282   unsigned int strtab_shndx = -1U;
 283
 284   if (dynsym_shndx == -1U)
 285     {
 286       sd->symbols = NULL;
 287       sd->symbols_size = 0;
 288       sd->symbol_names = NULL;
 289       sd->symbol_names_size = 0;
 290     }
 291   else
 292     {
 293       // Get the dynamic symbols.
 294       typename This::Shdr dynsymshdr(pshdrs + dynsym_shndx * This::shdr_size);
 295       gold_assert(dynsymshdr.get_sh_type() == elfcpp::SHT_DYNSYM);
 296
 297       sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(),
 298                                            dynsymshdr.get_sh_size());
 299       sd->symbols_size = dynsymshdr.get_sh_size();
 300
 301       // Get the symbol names.
 302       strtab_shndx = dynsymshdr.get_sh_link();
 303       if (strtab_shndx >= this->shnum())
 304         {
 305           fprintf(stderr,
 306                   _("%s: %s: invalid dynamic symbol table name index: %u\n"),
 307                   program_name, this->name().c_str(), strtab_shndx);
 308           gold_exit(false);
 309         }
 310       typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
 311       if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
 312         {
 313           fprintf(stderr,
 314                   _("%s: %s: dynamic symbol table name section "
 315                     "has wrong type: %u\n"),
 316                   program_name, this->name().c_str(),
 317                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
 318           gold_exit(false);
 319         }
 320
 321       sd->symbol_names = this->get_lasting_view(strtabshdr.get_sh_offset(),
 322                                                 strtabshdr.get_sh_size());
 323       sd->symbol_names_size = strtabshdr.get_sh_size();
 324
 325       // Get the version information.
 326
 327       unsigned int dummy;
 328       this->read_dynsym_section(pshdrs, versym_shndx, elfcpp::SHT_GNU_versym,
 329                                 dynsym_shndx, &sd->versym, &sd->versym_size,
 330                                 &dummy);
 331
 332       // We require that the version definition and need section link
 333       // to the same string table as the dynamic symbol table.  This
 334       // is not a technical requirement, but it always happens in
 335       // practice.  We could change this if necessary.
 336
 337       this->read_dynsym_section(pshdrs, verdef_shndx, elfcpp::SHT_GNU_verdef,
 338                                 strtab_shndx, &sd->verdef, &sd->verdef_size,
 339                                 &sd->verdef_info);
 340
 341       this->read_dynsym_section(pshdrs, verneed_shndx, elfcpp::SHT_GNU_verneed,
 342                                 strtab_shndx, &sd->verneed, &sd->verneed_size,
 343                                 &sd->verneed_info);
 344     }
 345
 346   // Read the SHT_DYNAMIC section to find whether this shared object
 347   // has a DT_SONAME tag.  This doesn't really have anything to do
 348   // with reading the symbols, but this is a convenient place to do
 349   // it.
 350   if (dynamic_shndx != -1U)
 351     this->set_soname(pshdrs, dynamic_shndx, strtab_shndx,
 352                      (sd->symbol_names == NULL
 353                       ? NULL
 354                       : sd->symbol_names->data()),
 355                      sd->symbol_names_size);
 356 }
 357
 358 // Lay out the input sections for a dynamic object.  We don't want to
 359 // include sections from a dynamic object, so all that we actually do
 360 // here is check for .gnu.warning sections.
 361
 362 template<int size, bool big_endian>
 363 void
 364 Sized_dynobj<size, big_endian>::do_layout(Symbol_table* symtab,
 365                                           Layout*,
 366                                           Read_symbols_data* sd)
 367 {
 368   const unsigned int shnum = this->shnum();
 369   if (shnum == 0)
 370     return;
 371
 372   // Get the section headers.
 373   const unsigned char* pshdrs = sd->section_headers->data();
 374
 375   // Get the section names.
 376   const unsigned char* pnamesu = sd->section_names->data();
 377   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 378
 379   // Skip the first, dummy, section.
 380   pshdrs += This::shdr_size;
 381   for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
 382     {
 383       typename This::Shdr shdr(pshdrs);
 384
 385       if (shdr.get_sh_name() >= sd->section_names_size)
 386         {
 387           fprintf(stderr,
 388                   _("%s: %s: bad section name offset for section %u: %lu\n"),
 389                   program_name, this->name().c_str(), i,
 390                   static_cast<unsigned long>(shdr.get_sh_name()));
 391           gold_exit(false);
 392         }
 393
 394       const char* name = pnames + shdr.get_sh_name();
 395
 396       this->handle_gnu_warning_section(name, i, symtab);
 397     }
 398
 399   delete sd->section_headers;
 400   sd->section_headers = NULL;
 401   delete sd->section_names;
 402   sd->section_names = NULL;
 403 }
 404
 405 // Add an entry to the vector mapping version numbers to version
 406 // strings.
 407
 408 template<int size, bool big_endian>
 409 void
 410 Sized_dynobj<size, big_endian>::set_version_map(
 411     Version_map* version_map,
 412     unsigned int ndx,
 413     const char* name) const
 414 {
 415   if (ndx >= version_map->size())
 416     version_map->resize(ndx + 1);
 417   if ((*version_map)[ndx] != NULL)
 418     {
 419       fprintf(stderr, _("%s: %s: duplicate definition for version %u\n"),
 420               program_name, this->name().c_str(), ndx);
 421       gold_exit(false);
 422     }
 423   (*version_map)[ndx] = name;
 424 }
 425
 426 // Add mappings for the version definitions to VERSION_MAP.
 427
 428 template<int size, bool big_endian>
 429 void
 430 Sized_dynobj<size, big_endian>::make_verdef_map(
 431     Read_symbols_data* sd,
 432     Version_map* version_map) const
 433 {
 434   if (sd->verdef == NULL)
 435     return;
 436
 437   const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
 438   off_t names_size = sd->symbol_names_size;
 439
 440   const unsigned char* pverdef = sd->verdef->data();
 441   off_t verdef_size = sd->verdef_size;
 442   const unsigned int count = sd->verdef_info;
 443
 444   const unsigned char* p = pverdef;
 445   for (unsigned int i = 0; i < count; ++i)
 446     {
 447       elfcpp::Verdef<size, big_endian> verdef(p);
 448
 449       if (verdef.get_vd_version() != elfcpp::VER_DEF_CURRENT)
 450         {
 451           fprintf(stderr, _("%s: %s: unexpected verdef version %u\n"),
 452                   program_name, this->name().c_str(), verdef.get_vd_version());
 453           gold_exit(false);
 454         }
 455
 456       const unsigned int vd_ndx = verdef.get_vd_ndx();
 457
 458       // The GNU linker clears the VERSYM_HIDDEN bit.  I'm not
 459       // sure why.
 460
 461       // The first Verdaux holds the name of this version.  Subsequent
 462       // ones are versions that this one depends upon, which we don't
 463       // care about here.
 464       const unsigned int vd_cnt = verdef.get_vd_cnt();
 465       if (vd_cnt < 1)
 466         {
 467           fprintf(stderr, _("%s: %s: verdef vd_cnt field too small: %u\n"),
 468                   program_name, this->name().c_str(), vd_cnt);
 469           gold_exit(false);
 470         }
 471
 472       const unsigned int vd_aux = verdef.get_vd_aux();
 473       if ((p - pverdef) + vd_aux >= verdef_size)
 474         {
 475           fprintf(stderr,
 476                   _("%s: %s: verdef vd_aux field out of range: %u\n"),
 477                   program_name, this->name().c_str(), vd_aux);
 478           gold_exit(false);
 479         }
 480
 481       const unsigned char* pvda = p + vd_aux;
 482       elfcpp::Verdaux<size, big_endian> verdaux(pvda);
 483
 484       const unsigned int vda_name = verdaux.get_vda_name();
 485       if (vda_name >= names_size)
 486         {
 487           fprintf(stderr,
 488                   _("%s: %s: verdaux vda_name field out of range: %u\n"),
 489                   program_name, this->name().c_str(), vda_name);
 490           gold_exit(false);
 491         }
 492
 493       this->set_version_map(version_map, vd_ndx, names + vda_name);
 494
 495       const unsigned int vd_next = verdef.get_vd_next();
 496       if ((p - pverdef) + vd_next >= verdef_size)
 497         {
 498           fprintf(stderr,
 499                   _("%s: %s: verdef vd_next field out of range: %u\n"),
 500                   program_name, this->name().c_str(), vd_next);
 501           gold_exit(false);
 502         }
 503
 504       p += vd_next;
 505     }
 506 }
 507
 508 // Add mappings for the required versions to VERSION_MAP.
 509
 510 template<int size, bool big_endian>
 511 void
 512 Sized_dynobj<size, big_endian>::make_verneed_map(
 513     Read_symbols_data* sd,
 514     Version_map* version_map) const
 515 {
 516   if (sd->verneed == NULL)
 517     return;
 518
 519   const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
 520   off_t names_size = sd->symbol_names_size;
 521
 522   const unsigned char* pverneed = sd->verneed->data();
 523   const off_t verneed_size = sd->verneed_size;
 524   const unsigned int count = sd->verneed_info;
 525
 526   const unsigned char* p = pverneed;
 527   for (unsigned int i = 0; i < count; ++i)
 528     {
 529       elfcpp::Verneed<size, big_endian> verneed(p);
 530
 531       if (verneed.get_vn_version() != elfcpp::VER_NEED_CURRENT)
 532         {
 533           fprintf(stderr, _("%s: %s: unexpected verneed version %u\n"),
 534                   program_name, this->name().c_str(),
 535                   verneed.get_vn_version());
 536           gold_exit(false);
 537         }
 538
 539       const unsigned int vn_aux = verneed.get_vn_aux();
 540
 541       if ((p - pverneed) + vn_aux >= verneed_size)
 542         {
 543           fprintf(stderr,
 544                   _("%s: %s: verneed vn_aux field out of range: %u\n"),
 545                   program_name, this->name().c_str(), vn_aux);
 546           gold_exit(false);
 547         }
 548
 549       const unsigned int vn_cnt = verneed.get_vn_cnt();
 550       const unsigned char* pvna = p + vn_aux;
 551       for (unsigned int j = 0; j < vn_cnt; ++j)
 552         {
 553           elfcpp::Vernaux<size, big_endian> vernaux(pvna);
 554
 555           const unsigned int vna_name = vernaux.get_vna_name();
 556           if (vna_name >= names_size)
 557             {
 558               fprintf(stderr,
 559                       _("%s: %s: vernaux vna_name field "
 560                         "out of range: %u\n"),
 561                       program_name, this->name().c_str(), vna_name);
 562               gold_exit(false);
 563             }
 564
 565           this->set_version_map(version_map, vernaux.get_vna_other(),
 566                                 names + vna_name);
 567
 568           const unsigned int vna_next = vernaux.get_vna_next();
 569           if ((pvna - pverneed) + vna_next >= verneed_size)
 570             {
 571               fprintf(stderr,
 572                       _("%s: %s: verneed vna_next field "
 573                         "out of range: %u\n"),
 574                       program_name, this->name().c_str(), vna_next);
 575               gold_exit(false);
 576             }
 577
 578           pvna += vna_next;
 579         }
 580
 581       const unsigned int vn_next = verneed.get_vn_next();
 582       if ((p - pverneed) + vn_next >= verneed_size)
 583         {
 584           fprintf(stderr,
 585                   _("%s: %s: verneed vn_next field out of range: %u\n"),
 586                   program_name, this->name().c_str(), vn_next);
 587           gold_exit(false);
 588         }
 589
 590       p += vn_next;
 591     }
 592 }
 593
 594 // Create a vector mapping version numbers to version strings.
 595
 596 template<int size, bool big_endian>
 597 void
 598 Sized_dynobj<size, big_endian>::make_version_map(
 599     Read_symbols_data* sd,
 600     Version_map* version_map) const
 601 {
 602   if (sd->verdef == NULL && sd->verneed == NULL)
 603     return;
 604
 605   // A guess at the maximum version number we will see.  If this is
 606   // wrong we will be less efficient but still correct.
 607   version_map->reserve(sd->verdef_info + sd->verneed_info * 10);
 608
 609   this->make_verdef_map(sd, version_map);
 610   this->make_verneed_map(sd, version_map);
 611 }
 612
 613 // Add the dynamic symbols to the symbol table.
 614
 615 template<int size, bool big_endian>
 616 void
 617 Sized_dynobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
 618                                                Read_symbols_data* sd)
 619 {
 620   if (sd->symbols == NULL)
 621     {
 622       gold_assert(sd->symbol_names == NULL);
 623       gold_assert(sd->versym == NULL && sd->verdef == NULL
 624                   && sd->verneed == NULL);
 625       return;
 626     }
 627
 628   const int sym_size = This::sym_size;
 629   const size_t symcount = sd->symbols_size / sym_size;
 630   if (symcount * sym_size != sd->symbols_size)
 631     {
 632       fprintf(stderr,
 633               _("%s: %s: size of dynamic symbols is not "
 634                 "multiple of symbol size\n"),
 635               program_name, this->name().c_str());
 636       gold_exit(false);
 637     }
 638
 639   Version_map version_map;
 640   this->make_version_map(sd, &version_map);
 641
 642   const char* sym_names =
 643     reinterpret_cast<const char*>(sd->symbol_names->data());
 644   symtab->add_from_dynobj(this, sd->symbols->data(), symcount,
 645                           sym_names, sd->symbol_names_size,
 646                           (sd->versym == NULL
 647                            ? NULL
 648                            : sd->versym->data()),
 649                           sd->versym_size,
 650                           &version_map);
 651
 652   delete sd->symbols;
 653   sd->symbols = NULL;
 654   delete sd->symbol_names;
 655   sd->symbol_names = NULL;
 656   if (sd->versym != NULL)
 657     {
 658       delete sd->versym;
 659       sd->versym = NULL;
 660     }
 661   if (sd->verdef != NULL)
 662     {
 663       delete sd->verdef;
 664       sd->verdef = NULL;
 665     }
 666   if (sd->verneed != NULL)
 667     {
 668       delete sd->verneed;
 669       sd->verneed = NULL;
 670     }
 671 }
 672
 673 // Given a vector of hash codes, compute the number of hash buckets to
 674 // use.
 675
 676 unsigned int
 677 Dynobj::compute_bucket_count(const std::vector<uint32_t>& hashcodes,
 678                              bool for_gnu_hash_table)
 679 {
 680   // FIXME: Implement optional hash table optimization.
 681
 682   // Array used to determine the number of hash table buckets to use
 683   // based on the number of symbols there are.  If there are fewer
 684   // than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3
 685   // buckets, fewer than 37 we use 17 buckets, and so forth.  We never
 686   // use more than 32771 buckets.  This is straight from the old GNU
 687   // linker.
 688   static const unsigned int buckets[] =
 689   {
 690     1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
 691     16411, 32771
 692   };
 693   const int buckets_count = sizeof buckets / sizeof buckets[0];
 694
 695   unsigned int symcount = hashcodes.size();
 696   unsigned int ret = 1;
 697   for (int i = 0; i < buckets_count; ++i)
 698     {
 699       if (symcount < buckets[i])
 700         break;
 701       ret = buckets[i];
 702     }
 703
 704   if (for_gnu_hash_table && ret < 2)
 705     ret = 2;
 706
 707   return ret;
 708 }
 709
 710 // The standard ELF hash function.  This hash function must not
 711 // change, as the dynamic linker uses it also.
 712
 713 uint32_t
 714 Dynobj::elf_hash(const char* name)
 715 {
 716   const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
 717   uint32_t h = 0;
 718   unsigned char c;
 719   while ((c = *nameu++) != '\0')
 720     {
 721       h = (h << 4) + c;
 722       uint32_t g = h & 0xf0000000;
 723       if (g != 0)
 724         {
 725           h ^= g >> 24;
 726           // The ELF ABI says h &= ~g, but using xor is equivalent in
 727           // this case (since g was set from h) and may save one
 728           // instruction.
 729           h ^= g;
 730         }
 731     }
 732   return h;
 733 }
 734
 735 // Create a standard ELF hash table, setting *PPHASH and *PHASHLEN.
 736 // DYNSYMS is a vector with all the global dynamic symbols.
 737 // LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
 738 // symbol table.
 739
 740 void
 741 Dynobj::create_elf_hash_table(const Target* target,
 742                               const std::vector<Symbol*>& dynsyms,
 743                               unsigned int local_dynsym_count,
 744                               unsigned char** pphash,
 745                               unsigned int* phashlen)
 746 {
 747   unsigned int dynsym_count = dynsyms.size();
 748
 749   // Get the hash values for all the symbols.
 750   std::vector<uint32_t> dynsym_hashvals(dynsym_count);
 751   for (unsigned int i = 0; i < dynsym_count; ++i)
 752     dynsym_hashvals[i] = Dynobj::elf_hash(dynsyms[i]->name());
 753
 754   const unsigned int bucketcount =
 755     Dynobj::compute_bucket_count(dynsym_hashvals, false);
 756
 757   std::vector<uint32_t> bucket(bucketcount);
 758   std::vector<uint32_t> chain(local_dynsym_count + dynsym_count);
 759
 760   for (unsigned int i = 0; i < dynsym_count; ++i)
 761     {
 762       unsigned int dynsym_index = dynsyms[i]->dynsym_index();
 763       unsigned int bucketpos = dynsym_hashvals[i] % bucketcount;
 764       chain[dynsym_index] = bucket[bucketpos];
 765       bucket[bucketpos] = dynsym_index;
 766     }
 767
 768   unsigned int hashlen = ((2
 769                            + bucketcount
 770                            + local_dynsym_count
 771                            + dynsym_count)
 772                           * 4);
 773   unsigned char* phash = new unsigned char[hashlen];
 774
 775   if (target->is_big_endian())
 776     Dynobj::sized_create_elf_hash_table<true>(bucket, chain, phash, hashlen);
 777   else
 778     Dynobj::sized_create_elf_hash_table<false>(bucket, chain, phash, hashlen);
 779
 780   *pphash = phash;
 781   *phashlen = hashlen;
 782 }
 783
 784 // Fill in an ELF hash table.
 785
 786 template<bool big_endian>
 787 void
 788 Dynobj::sized_create_elf_hash_table(const std::vector<uint32_t>& bucket,
 789                                     const std::vector<uint32_t>& chain,
 790                                     unsigned char* phash,
 791                                     unsigned int hashlen)
 792 {
 793   unsigned char* p = phash;
 794
 795   const unsigned int bucketcount = bucket.size();
 796   const unsigned int chaincount = chain.size();
 797
 798   elfcpp::Swap<32, big_endian>::writeval(p, bucketcount);
 799   p += 4;
 800   elfcpp::Swap<32, big_endian>::writeval(p, chaincount);
 801   p += 4;
 802
 803   for (unsigned int i = 0; i < bucketcount; ++i)
 804     {
 805       elfcpp::Swap<32, big_endian>::writeval(p, bucket[i]);
 806       p += 4;
 807     }
 808
 809   for (unsigned int i = 0; i < chaincount; ++i)
 810     {
 811       elfcpp::Swap<32, big_endian>::writeval(p, chain[i]);
 812       p += 4;
 813     }
 814
 815   gold_assert(static_cast<unsigned int>(p - phash) == hashlen);
 816 }
 817
 818 // The hash function used for the GNU hash table.  This hash function
 819 // must not change, as the dynamic linker uses it also.
 820
 821 uint32_t
 822 Dynobj::gnu_hash(const char* name)
 823 {
 824   const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
 825   uint32_t h = 5381;
 826   unsigned char c;
 827   while ((c = *nameu++) != '\0')
 828     h = (h << 5) + h + c;
 829   return h;
 830 }
 831
 832 // Create a GNU hash table, setting *PPHASH and *PHASHLEN.  GNU hash
 833 // tables are an extension to ELF which are recognized by the GNU
 834 // dynamic linker.  They are referenced using dynamic tag DT_GNU_HASH.
 835 // TARGET is the target.  DYNSYMS is a vector with all the global
 836 // symbols which will be going into the dynamic symbol table.
 837 // LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
 838 // symbol table.
 839
 840 void
 841 Dynobj::create_gnu_hash_table(const Target* target,
 842                               const std::vector<Symbol*>& dynsyms,
 843                               unsigned int local_dynsym_count,
 844                               unsigned char** pphash,
 845                               unsigned int* phashlen)
 846 {
 847   const unsigned int count = dynsyms.size();
 848
 849   // Sort the dynamic symbols into two vectors.  Symbols which we do
 850   // not want to put into the hash table we store into
 851   // UNHASHED_DYNSYMS.  Symbols which we do want to store we put into
 852   // HASHED_DYNSYMS.  DYNSYM_HASHVALS is parallel to HASHED_DYNSYMS,
 853   // and records the hash codes.
 854
 855   std::vector<Symbol*> unhashed_dynsyms;
 856   unhashed_dynsyms.reserve(count);
 857
 858   std::vector<Symbol*> hashed_dynsyms;
 859   hashed_dynsyms.reserve(count);
 860
 861   std::vector<uint32_t> dynsym_hashvals;
 862   dynsym_hashvals.reserve(count);
 863
 864   for (unsigned int i = 0; i < count; ++i)
 865     {
 866       Symbol* sym = dynsyms[i];
 867
 868       // FIXME: Should put on unhashed_dynsyms if the symbol is
 869       // hidden.
 870       if (sym->is_undefined())
 871         unhashed_dynsyms.push_back(sym);
 872       else
 873         {
 874           hashed_dynsyms.push_back(sym);
 875           dynsym_hashvals.push_back(Dynobj::gnu_hash(sym->name()));
 876         }
 877     }
 878
 879   // Put the unhashed symbols at the start of the global portion of
 880   // the dynamic symbol table.
 881   const unsigned int unhashed_count = unhashed_dynsyms.size();
 882   unsigned int unhashed_dynsym_index = local_dynsym_count;
 883   for (unsigned int i = 0; i < unhashed_count; ++i)
 884     {
 885       unhashed_dynsyms[i]->set_dynsym_index(unhashed_dynsym_index);
 886       ++unhashed_dynsym_index;
 887     }
 888
 889   // For the actual data generation we call out to a templatized
 890   // function.
 891   int size = target->get_size();
 892   bool big_endian = target->is_big_endian();
 893   if (size == 32)
 894     {
 895       if (big_endian)
 896         Dynobj::sized_create_gnu_hash_table<32, true>(hashed_dynsyms,
 897                                                       dynsym_hashvals,
 898                                                       unhashed_dynsym_index,
 899                                                       pphash,
 900                                                       phashlen);
 901       else
 902         Dynobj::sized_create_gnu_hash_table<32, false>(hashed_dynsyms,
 903                                                        dynsym_hashvals,
 904                                                        unhashed_dynsym_index,
 905                                                        pphash,
 906                                                        phashlen);
 907     }
 908   else if (size == 64)
 909     {
 910       if (big_endian)
 911         Dynobj::sized_create_gnu_hash_table<64, true>(hashed_dynsyms,
 912                                                       dynsym_hashvals,
 913                                                       unhashed_dynsym_index,
 914                                                       pphash,
 915                                                       phashlen);
 916       else
 917         Dynobj::sized_create_gnu_hash_table<64, false>(hashed_dynsyms,
 918                                                        dynsym_hashvals,
 919                                                        unhashed_dynsym_index,
 920                                                        pphash,
 921                                                        phashlen);
 922     }
 923   else
 924     gold_unreachable();
 925 }
 926
 927 // Create the actual data for a GNU hash table.  This is just a copy
 928 // of the code from the old GNU linker.
 929
 930 template<int size, bool big_endian>
 931 void
 932 Dynobj::sized_create_gnu_hash_table(
 933     const std::vector<Symbol*>& hashed_dynsyms,
 934     const std::vector<uint32_t>& dynsym_hashvals,
 935     unsigned int unhashed_dynsym_count,
 936     unsigned char** pphash,
 937     unsigned int* phashlen)
 938 {
 939   if (hashed_dynsyms.empty())
 940     {
 941       // Special case for the empty hash table.
 942       unsigned int hashlen = 5 * 4 + size / 8;
 943       unsigned char* phash = new unsigned char[hashlen];
 944       // One empty bucket.
 945       elfcpp::Swap<32, big_endian>::writeval(phash, 1);
 946       // Symbol index above unhashed symbols.
 947       elfcpp::Swap<32, big_endian>::writeval(phash + 4, unhashed_dynsym_count);
 948       // One word for bitmask.
 949       elfcpp::Swap<32, big_endian>::writeval(phash + 8, 1);
 950       // Only bloom filter.
 951       elfcpp::Swap<32, big_endian>::writeval(phash + 12, 0);
 952       // No valid hashes.
 953       elfcpp::Swap<size, big_endian>::writeval(phash + 16, 0);
 954       // No hashes in only bucket.
 955       elfcpp::Swap<32, big_endian>::writeval(phash + 16 + size / 8, 0);
 956
 957       *phashlen = hashlen;
 958       *pphash = phash;
 959
 960       return;
 961     }
 962
 963   const unsigned int bucketcount =
 964     Dynobj::compute_bucket_count(dynsym_hashvals, true);
 965
 966   const unsigned int nsyms = hashed_dynsyms.size();
 967
 968   uint32_t maskbitslog2 = 1;
 969   uint32_t x = nsyms >> 1;
 970   while (x != 0)
 971     {
 972       ++maskbitslog2;
 973       x >>= 1;
 974     }
 975   if (maskbitslog2 < 3)
 976     maskbitslog2 = 5;
 977   else if (((1U << (maskbitslog2 - 2)) & nsyms) != 0)
 978     maskbitslog2 += 3;
 979   else
 980     maskbitslog2 += 2;
 981
 982   uint32_t shift1;
 983   if (size == 32)
 984     shift1 = 5;
 985   else
 986     {
 987       if (maskbitslog2 == 5)
 988         maskbitslog2 = 6;
 989       shift1 = 6;
 990     }
 991   uint32_t mask = (1U << shift1) - 1U;
 992   uint32_t shift2 = maskbitslog2;
 993   uint32_t maskbits = 1U << maskbitslog2;
 994   uint32_t maskwords = 1U << (maskbitslog2 - shift1);
 995
 996   typedef typename elfcpp::Elf_types<size>::Elf_WXword Word;
 997   std::vector<Word> bitmask(maskwords);
 998   std::vector<uint32_t> counts(bucketcount);
 999   std::vector<uint32_t> indx(bucketcount);
1000   uint32_t symindx = unhashed_dynsym_count;
1001
1002   // Count the number of times each hash bucket is used.
1003   for (unsigned int i = 0; i < nsyms; ++i)
1004     ++counts[dynsym_hashvals[i] % bucketcount];
1005
1006   unsigned int cnt = symindx;
1007   for (unsigned int i = 0; i < bucketcount; ++i)
1008     {
1009       indx[i] = cnt;
1010       cnt += counts[i];
1011     }
1012
1013   unsigned int hashlen = (4 + bucketcount + nsyms) * 4;
1014   hashlen += maskbits / 8;
1015   unsigned char* phash = new unsigned char[hashlen];
1016
1017   elfcpp::Swap<32, big_endian>::writeval(phash, bucketcount);
1018   elfcpp::Swap<32, big_endian>::writeval(phash + 4, symindx);
1019   elfcpp::Swap<32, big_endian>::writeval(phash + 8, maskwords);
1020   elfcpp::Swap<32, big_endian>::writeval(phash + 12, shift2);
1021
1022   unsigned char* p = phash + 16 + maskbits / 8;
1023   for (unsigned int i = 0; i < bucketcount; ++i)
1024     {
1025       if (counts[i] == 0)
1026         elfcpp::Swap<32, big_endian>::writeval(p, 0);
1027       else
1028         elfcpp::Swap<32, big_endian>::writeval(p, indx[i]);
1029       p += 4;
1030     }
1031
1032   for (unsigned int i = 0; i < nsyms; ++i)
1033     {
1034       Symbol* sym = hashed_dynsyms[i];
1035       uint32_t hashval = dynsym_hashvals[i];
1036
1037       unsigned int bucket = hashval % bucketcount;
1038       unsigned int val = ((hashval >> shift1)
1039                           & ((maskbits >> shift1) - 1));
1040       bitmask[val] |= (static_cast<Word>(1U)) << (hashval & mask);
1041       bitmask[val] |= (static_cast<Word>(1U)) << ((hashval >> shift2) & mask);
1042       val = hashval & ~ 1U;
1043       if (counts[bucket] == 1)
1044         {
1045           // Last element terminates the chain.
1046           val |= 1;
1047         }
1048       elfcpp::Swap<32, big_endian>::writeval(p + (indx[bucket] - symindx) * 4,
1049                                              val);
1050       --counts[bucket];
1051
1052       sym->set_dynsym_index(indx[bucket]);
1053       ++indx[bucket];
1054     }
1055
1056   p = phash + 16;
1057   for (unsigned int i = 0; i < maskwords; ++i)
1058     {
1059       elfcpp::Swap<size, big_endian>::writeval(p, bitmask[i]);
1060       p += size / 8;
1061     }
1062
1063   *phashlen = hashlen;
1064   *pphash = phash;
1065 }
1066
1067 // Verdef methods.
1068
1069 // Write this definition to a buffer for the output section.
1070
1071 template<int size, bool big_endian>
1072 unsigned char*
1073 Verdef::write(const Stringpool* dynpool, bool is_last, unsigned char* pb
1074               ACCEPT_SIZE_ENDIAN) const
1075 {
1076   const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size;
1077   const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size;
1078
1079   elfcpp::Verdef_write<size, big_endian> vd(pb);
1080   vd.set_vd_version(elfcpp::VER_DEF_CURRENT);
1081   vd.set_vd_flags((this->is_base_ ? elfcpp::VER_FLG_BASE : 0)
1082                   | (this->is_weak_ ? elfcpp::VER_FLG_WEAK : 0));
1083   vd.set_vd_ndx(this->index());
1084   vd.set_vd_cnt(1 + this->deps_.size());
1085   vd.set_vd_hash(Dynobj::elf_hash(this->name()));
1086   vd.set_vd_aux(verdef_size);
1087   vd.set_vd_next(is_last
1088                  ? 0
1089                  : verdef_size + (1 + this->deps_.size()) * verdaux_size);
1090   pb += verdef_size;
1091
1092   elfcpp::Verdaux_write<size, big_endian> vda(pb);
1093   vda.set_vda_name(dynpool->get_offset(this->name()));
1094   vda.set_vda_next(this->deps_.empty() ? 0 : verdaux_size);
1095   pb += verdaux_size;
1096
1097   Deps::const_iterator p;
1098   unsigned int i;
1099   for (p = this->deps_.begin(), i = 0;
1100        p != this->deps_.end();
1101        ++p, ++i)
1102     {
1103       elfcpp::Verdaux_write<size, big_endian> vda(pb);
1104       vda.set_vda_name(dynpool->get_offset(*p));
1105       vda.set_vda_next(i + 1 >= this->deps_.size() ? 0 : verdaux_size);
1106       pb += verdaux_size;
1107     }
1108
1109   return pb;
1110 }
1111
1112 // Verneed methods.
1113
1114 Verneed::~Verneed()
1115 {
1116   for (Need_versions::iterator p = this->need_versions_.begin();
1117        p != this->need_versions_.end();
1118        ++p)
1119     delete *p;
1120 }
1121
1122 // Add a new version to this file reference.
1123
1124 Verneed_version*
1125 Verneed::add_name(const char* name)
1126 {
1127   Verneed_version* vv = new Verneed_version(name);
1128   this->need_versions_.push_back(vv);
1129   return vv;
1130 }
1131
1132 // Set the version indexes starting at INDEX.
1133
1134 unsigned int
1135 Verneed::finalize(unsigned int index)
1136 {
1137   for (Need_versions::iterator p = this->need_versions_.begin();
1138        p != this->need_versions_.end();
1139        ++p)
1140     {
1141       (*p)->set_index(index);
1142       ++index;
1143     }
1144   return index;
1145 }
1146
1147 // Write this list of referenced versions to a buffer for the output
1148 // section.
1149
1150 template<int size, bool big_endian>
1151 unsigned char*
1152 Verneed::write(const Stringpool* dynpool, bool is_last,
1153                unsigned char* pb ACCEPT_SIZE_ENDIAN) const
1154 {
1155   const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size;
1156   const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size;
1157
1158   elfcpp::Verneed_write<size, big_endian> vn(pb);
1159   vn.set_vn_version(elfcpp::VER_NEED_CURRENT);
1160   vn.set_vn_cnt(this->need_versions_.size());
1161   vn.set_vn_file(dynpool->get_offset(this->filename()));
1162   vn.set_vn_aux(verneed_size);
1163   vn.set_vn_next(is_last
1164                  ? 0
1165                  : verneed_size + this->need_versions_.size() * vernaux_size);
1166   pb += verneed_size;
1167
1168   Need_versions::const_iterator p;
1169   unsigned int i;
1170   for (p = this->need_versions_.begin(), i = 0;
1171        p != this->need_versions_.end();
1172        ++p, ++i)
1173     {
1174       elfcpp::Vernaux_write<size, big_endian> vna(pb);
1175       vna.set_vna_hash(Dynobj::elf_hash((*p)->version()));
1176       // FIXME: We need to sometimes set VER_FLG_WEAK here.
1177       vna.set_vna_flags(0);
1178       vna.set_vna_other((*p)->index());
1179       vna.set_vna_name(dynpool->get_offset((*p)->version()));
1180       vna.set_vna_next(i + 1 >= this->need_versions_.size()
1181                        ? 0
1182                        : vernaux_size);
1183       pb += vernaux_size;
1184     }
1185
1186   return pb;
1187 }
1188
1189 // Versions methods.
1190
1191 Versions::~Versions()
1192 {
1193   for (Defs::iterator p = this->defs_.begin();
1194        p != this->defs_.end();
1195        ++p)
1196     delete *p;
1197
1198   for (Needs::iterator p = this->needs_.begin();
1199        p != this->needs_.end();
1200        ++p)
1201     delete *p;
1202 }
1203
1204 // Record version information for a symbol going into the dynamic
1205 // symbol table.
1206
1207 void
1208 Versions::record_version(const General_options* options,
1209                          Stringpool* dynpool, const Symbol* sym)
1210 {
1211   gold_assert(!this->is_finalized_);
1212   gold_assert(sym->version() != NULL);
1213
1214   Stringpool::Key version_key;
1215   const char* version = dynpool->add(sym->version(), &version_key);
1216
1217   if (!sym->is_from_dynobj())
1218     {
1219       if (parameters->output_is_shared())
1220         this->add_def(options, sym, version, version_key);
1221     }
1222   else
1223     {
1224       // This is a version reference.
1225
1226       Object* object = sym->object();
1227       gold_assert(object->is_dynamic());
1228       Dynobj* dynobj = static_cast<Dynobj*>(object);
1229
1230       this->add_need(dynpool, dynobj->soname(), version, version_key);
1231     }
1232 }
1233
1234 // We've found a symbol SYM defined in version VERSION.
1235
1236 void
1237 Versions::add_def(const General_options* options, const Symbol* sym,
1238                   const char* version, Stringpool::Key version_key)
1239 {
1240   Key k(version_key, 0);
1241   Version_base* const vbnull = NULL;
1242   std::pair<Version_table::iterator, bool> ins =
1243     this->version_table_.insert(std::make_pair(k, vbnull));
1244
1245   if (!ins.second)
1246     {
1247       // We already have an entry for this version.
1248       Version_base* vb = ins.first->second;
1249
1250       // We have now seen a symbol in this version, so it is not
1251       // weak.
1252       vb->clear_weak();
1253
1254       // FIXME: When we support version scripts, we will need to
1255       // check whether this symbol should be forced local.
1256     }
1257   else
1258     {
1259       // If we are creating a shared object, it is an error to
1260       // find a definition of a symbol with a version which is not
1261       // in the version script.
1262       if (parameters->output_is_shared())
1263         {
1264           fprintf(stderr, _("%s: symbol %s has undefined version %s\n"),
1265                   program_name, sym->name(), version);
1266           gold_exit(false);
1267         }
1268
1269       // If this is the first version we are defining, first define
1270       // the base version.  FIXME: Should use soname here when
1271       // creating a shared object.
1272       Verdef* vdbase = new Verdef(options->output_file_name(), true, false,
1273                                   true);
1274       this->defs_.push_back(vdbase);
1275
1276       // When creating a regular executable, automatically define
1277       // a new version.
1278       Verdef* vd = new Verdef(version, false, false, false);
1279       this->defs_.push_back(vd);
1280       ins.first->second = vd;
1281     }
1282 }
1283
1284 // Add a reference to version NAME in file FILENAME.
1285
1286 void
1287 Versions::add_need(Stringpool* dynpool, const char* filename, const char* name,
1288                    Stringpool::Key name_key)
1289 {
1290   Stringpool::Key filename_key;
1291   filename = dynpool->add(filename, &filename_key);
1292
1293   Key k(name_key, filename_key);
1294   Version_base* const vbnull = NULL;
1295   std::pair<Version_table::iterator, bool> ins =
1296     this->version_table_.insert(std::make_pair(k, vbnull));
1297
1298   if (!ins.second)
1299     {
1300       // We already have an entry for this filename/version.
1301       return;
1302     }
1303
1304   // See whether we already have this filename.  We don't expect many
1305   // version references, so we just do a linear search.  This could be
1306   // replaced by a hash table.
1307   Verneed* vn = NULL;
1308   for (Needs::iterator p = this->needs_.begin();
1309        p != this->needs_.end();
1310        ++p)
1311     {
1312       if ((*p)->filename() == filename)
1313         {
1314           vn = *p;
1315           break;
1316         }
1317     }
1318
1319   if (vn == NULL)
1320     {
1321       // We have a new filename.
1322       vn = new Verneed(filename);
1323       this->needs_.push_back(vn);
1324     }
1325
1326   ins.first->second = vn->add_name(name);
1327 }
1328
1329 // Set the version indexes.  Create a new dynamic version symbol for
1330 // each new version definition.
1331
1332 unsigned int
1333 Versions::finalize(const Target* target, Symbol_table* symtab,
1334                    unsigned int dynsym_index, std::vector<Symbol*>* syms)
1335 {
1336   gold_assert(!this->is_finalized_);
1337
1338   unsigned int vi = 1;
1339
1340   for (Defs::iterator p = this->defs_.begin();
1341        p != this->defs_.end();
1342        ++p)
1343     {
1344       (*p)->set_index(vi);
1345       ++vi;
1346
1347       // Create a version symbol if necessary.
1348       if (!(*p)->is_symbol_created())
1349         {
1350           Symbol* vsym = symtab->define_as_constant(target, (*p)->name(),
1351                                                     (*p)->name(), 0, 0,
1352                                                     elfcpp::STT_OBJECT,
1353                                                     elfcpp::STB_GLOBAL,
1354                                                     elfcpp::STV_DEFAULT, 0,
1355                                                     false);
1356           vsym->set_needs_dynsym_entry();
1357           vsym->set_dynsym_index(dynsym_index);
1358           ++dynsym_index;
1359           syms->push_back(vsym);
1360           // The name is already in the dynamic pool.
1361         }
1362     }
1363
1364   // Index 1 is used for global symbols.
1365   if (vi == 1)
1366     {
1367       gold_assert(this->defs_.empty());
1368       vi = 2;
1369     }
1370
1371   for (Needs::iterator p = this->needs_.begin();
1372        p != this->needs_.end();
1373        ++p)
1374     vi = (*p)->finalize(vi);
1375
1376   this->is_finalized_ = true;
1377
1378   return dynsym_index;
1379 }
1380
1381 // Return the version index to use for a symbol.  This does two hash
1382 // table lookups: one in DYNPOOL and one in this->version_table_.
1383 // Another approach alternative would be store a pointer in SYM, which
1384 // would increase the size of the symbol table.  Or perhaps we could
1385 // use a hash table from dynamic symbol pointer values to Version_base
1386 // pointers.
1387
1388 unsigned int
1389 Versions::version_index(const Stringpool* dynpool, const Symbol* sym) const
1390 {
1391   Stringpool::Key version_key;
1392   const char* version = dynpool->find(sym->version(), &version_key);
1393   gold_assert(version != NULL);
1394
1395   Key k;
1396   if (!sym->is_from_dynobj())
1397     {
1398       if (!parameters->output_is_shared())
1399         return elfcpp::VER_NDX_GLOBAL;
1400       k = Key(version_key, 0);
1401     }
1402   else
1403     {
1404       Object* object = sym->object();
1405       gold_assert(object->is_dynamic());
1406       Dynobj* dynobj = static_cast<Dynobj*>(object);
1407
1408       Stringpool::Key filename_key;
1409       const char* filename = dynpool->find(dynobj->soname(), &filename_key);
1410       gold_assert(filename != NULL);
1411
1412       k = Key(version_key, filename_key);
1413     }
1414
1415   Version_table::const_iterator p = this->version_table_.find(k);
1416   gold_assert(p != this->version_table_.end());
1417
1418   return p->second->index();
1419 }
1420
1421 // Return an allocated buffer holding the contents of the symbol
1422 // version section.
1423
1424 template<int size, bool big_endian>
1425 void
1426 Versions::symbol_section_contents(const Stringpool* dynpool,
1427                                   unsigned int local_symcount,
1428                                   const std::vector<Symbol*>& syms,
1429                                   unsigned char** pp,
1430                                   unsigned int* psize
1431                                   ACCEPT_SIZE_ENDIAN) const
1432 {
1433   gold_assert(this->is_finalized_);
1434
1435   unsigned int sz = (local_symcount + syms.size()) * 2;
1436   unsigned char* pbuf = new unsigned char[sz];
1437
1438   for (unsigned int i = 0; i < local_symcount; ++i)
1439     elfcpp::Swap<16, big_endian>::writeval(pbuf + i * 2,
1440                                            elfcpp::VER_NDX_LOCAL);
1441
1442   for (std::vector<Symbol*>::const_iterator p = syms.begin();
1443        p != syms.end();
1444        ++p)
1445     {
1446       unsigned int version_index;
1447       const char* version = (*p)->version();
1448       if (version == NULL)
1449         version_index = elfcpp::VER_NDX_GLOBAL;
1450       else
1451         version_index = this->version_index(dynpool, *p);
1452       elfcpp::Swap<16, big_endian>::writeval(pbuf + (*p)->dynsym_index() * 2,
1453                                              version_index);
1454     }
1455
1456   *pp = pbuf;
1457   *psize = sz;
1458 }
1459
1460 // Return an allocated buffer holding the contents of the version
1461 // definition section.
1462
1463 template<int size, bool big_endian>
1464 void
1465 Versions::def_section_contents(const Stringpool* dynpool,
1466                                unsigned char** pp, unsigned int* psize,
1467                                unsigned int* pentries
1468                                ACCEPT_SIZE_ENDIAN) const
1469 {
1470   gold_assert(this->is_finalized_);
1471   gold_assert(!this->defs_.empty());
1472
1473   const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size;
1474   const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size;
1475
1476   unsigned int sz = 0;
1477   for (Defs::const_iterator p = this->defs_.begin();
1478        p != this->defs_.end();
1479        ++p)
1480     {
1481       sz += verdef_size + verdaux_size;
1482       sz += (*p)->count_dependencies() * verdaux_size;
1483     }
1484
1485   unsigned char* pbuf = new unsigned char[sz];
1486
1487   unsigned char* pb = pbuf;
1488   Defs::const_iterator p;
1489   unsigned int i;
1490   for (p = this->defs_.begin(), i = 0;
1491        p != this->defs_.end();
1492        ++p, ++i)
1493     pb = (*p)->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
1494             dynpool, i + 1 >= this->defs_.size(), pb
1495             SELECT_SIZE_ENDIAN(size, big_endian));
1496
1497   gold_assert(static_cast<unsigned int>(pb - pbuf) == sz);
1498
1499   *pp = pbuf;
1500   *psize = sz;
1501   *pentries = this->defs_.size();
1502 }
1503
1504 // Return an allocated buffer holding the contents of the version
1505 // reference section.
1506
1507 template<int size, bool big_endian>
1508 void
1509 Versions::need_section_contents(const Stringpool* dynpool,
1510                                 unsigned char** pp, unsigned int *psize,
1511                                 unsigned int *pentries
1512                                 ACCEPT_SIZE_ENDIAN) const
1513 {
1514   gold_assert(this->is_finalized_);
1515   gold_assert(!this->needs_.empty());
1516
1517   const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size;
1518   const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size;
1519
1520   unsigned int sz = 0;
1521   for (Needs::const_iterator p = this->needs_.begin();
1522        p != this->needs_.end();
1523        ++p)
1524     {
1525       sz += verneed_size;
1526       sz += (*p)->count_versions() * vernaux_size;
1527     }
1528
1529   unsigned char* pbuf = new unsigned char[sz];
1530
1531   unsigned char* pb = pbuf;
1532   Needs::const_iterator p;
1533   unsigned int i;
1534   for (p = this->needs_.begin(), i = 0;
1535        p != this->needs_.end();
1536        ++p, ++i)
1537     pb = (*p)->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
1538             dynpool, i + 1 >= this->needs_.size(), pb
1539             SELECT_SIZE_ENDIAN(size, big_endian));
1540
1541   gold_assert(static_cast<unsigned int>(pb - pbuf) == sz);
1542
1543   *pp = pbuf;
1544   *psize = sz;
1545   *pentries = this->needs_.size();
1546 }
1547
1548 // Instantiate the templates we need.  We could use the configure
1549 // script to restrict this to only the ones for implemented targets.
1550
1551 #ifdef HAVE_TARGET_32_LITTLE
1552 template
1553 class Sized_dynobj<32, false>;
1554 #endif
1555
1556 #ifdef HAVE_TARGET_32_BIG
1557 template
1558 class Sized_dynobj<32, true>;
1559 #endif
1560
1561 #ifdef HAVE_TARGET_64_LITTLE
1562 template
1563 class Sized_dynobj<64, false>;
1564 #endif
1565
1566 #ifdef HAVE_TARGET_64_BIG
1567 template
1568 class Sized_dynobj<64, true>;
1569 #endif
1570
1571 #ifdef HAVE_TARGET_32_LITTLE
1572 template
1573 void
1574 Versions::symbol_section_contents<32, false>(
1575     const Stringpool*,
1576     unsigned int,
1577     const std::vector<Symbol*>&,
1578     unsigned char**,
1579     unsigned int*
1580     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
1581 #endif
1582
1583 #ifdef HAVE_TARGET_32_BIG
1584 template
1585 void
1586 Versions::symbol_section_contents<32, true>(
1587     const Stringpool*,
1588     unsigned int,
1589     const std::vector<Symbol*>&,
1590     unsigned char**,
1591     unsigned int*
1592     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
1593 #endif
1594
1595 #ifdef HAVE_TARGET_64_LITTLE
1596 template
1597 void
1598 Versions::symbol_section_contents<64, false>(
1599     const Stringpool*,
1600     unsigned int,
1601     const std::vector<Symbol*>&,
1602     unsigned char**,
1603     unsigned int*
1604     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
1605 #endif
1606
1607 #ifdef HAVE_TARGET_64_BIG
1608 template
1609 void
1610 Versions::symbol_section_contents<64, true>(
1611     const Stringpool*,
1612     unsigned int,
1613     const std::vector<Symbol*>&,
1614     unsigned char**,
1615     unsigned int*
1616     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
1617 #endif
1618
1619 #ifdef HAVE_TARGET_32_LITTLE
1620 template
1621 void
1622 Versions::def_section_contents<32, false>(
1623     const Stringpool*,
1624     unsigned char**,
1625     unsigned int*,
1626     unsigned int*
1627     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
1628 #endif
1629
1630 #ifdef HAVE_TARGET_32_BIG
1631 template
1632 void
1633 Versions::def_section_contents<32, true>(
1634     const Stringpool*,
1635     unsigned char**,
1636     unsigned int*,
1637     unsigned int*
1638     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
1639 #endif
1640
1641 #ifdef HAVE_TARGET_64_LITTLE
1642 template
1643 void
1644 Versions::def_section_contents<64, false>(
1645     const Stringpool*,
1646     unsigned char**,
1647     unsigned int*,
1648     unsigned int*
1649     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
1650 #endif
1651
1652 #ifdef HAVE_TARGET_64_BIG
1653 template
1654 void
1655 Versions::def_section_contents<64, true>(
1656     const Stringpool*,
1657     unsigned char**,
1658     unsigned int*,
1659     unsigned int*
1660     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
1661 #endif
1662
1663 #ifdef HAVE_TARGET_32_LITTLE
1664 template
1665 void
1666 Versions::need_section_contents<32, false>(
1667     const Stringpool*,
1668     unsigned char**,
1669     unsigned int*,
1670     unsigned int*
1671     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
1672 #endif
1673
1674 #ifdef HAVE_TARGET_32_BIG
1675 template
1676 void
1677 Versions::need_section_contents<32, true>(
1678     const Stringpool*,
1679     unsigned char**,
1680     unsigned int*,
1681     unsigned int*
1682     ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
1683 #endif
1684
1685 #ifdef HAVE_TARGET_64_LITTLE
1686 template
1687 void
1688 Versions::need_section_contents<64, false>(
1689     const Stringpool*,
1690     unsigned char**,
1691     unsigned int*,
1692     unsigned int*
1693     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
1694 #endif
1695
1696 #ifdef HAVE_TARGET_64_BIG
1697 template
1698 void
1699 Versions::need_section_contents<64, true>(
1700     const Stringpool*,
1701     unsigned char**,
1702     unsigned int*,
1703     unsigned int*
1704     ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
1705 #endif
1706
1707 } // End namespace gold.