gold/symtab.cc

   1 // symtab.cc -- the gold symbol table
   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 <stdint.h>
  26 #include <string>
  27 #include <utility>
  28
  29 #include "object.h"
  30 #include "dynobj.h"
  31 #include "output.h"
  32 #include "target.h"
  33 #include "workqueue.h"
  34 #include "symtab.h"
  35
  36 namespace gold
  37 {
  38
  39 // Class Symbol.
  40
  41 // Initialize fields in Symbol.  This initializes everything except u_
  42 // and source_.
  43
  44 void
  45 Symbol::init_fields(const char* name, const char* version,
  46                     elfcpp::STT type, elfcpp::STB binding,
  47                     elfcpp::STV visibility, unsigned char nonvis)
  48 {
  49   this->name_ = name;
  50   this->version_ = version;
  51   this->symtab_index_ = 0;
  52   this->dynsym_index_ = 0;
  53   this->got_offset_ = 0;
  54   this->plt_offset_ = 0;
  55   this->type_ = type;
  56   this->binding_ = binding;
  57   this->visibility_ = visibility;
  58   this->nonvis_ = nonvis;
  59   this->is_target_special_ = false;
  60   this->is_def_ = false;
  61   this->is_forwarder_ = false;
  62   this->needs_dynsym_entry_ = false;
  63   this->in_reg_ = false;
  64   this->in_dyn_ = false;
  65   this->has_got_offset_ = false;
  66   this->has_plt_offset_ = false;
  67   this->has_warning_ = false;
  68 }
  69
  70 // Initialize the fields in the base class Symbol for SYM in OBJECT.
  71
  72 template<int size, bool big_endian>
  73 void
  74 Symbol::init_base(const char* name, const char* version, Object* object,
  75                   const elfcpp::Sym<size, big_endian>& sym)
  76 {
  77   this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
  78                     sym.get_st_visibility(), sym.get_st_nonvis());
  79   this->u_.from_object.object = object;
  80   // FIXME: Handle SHN_XINDEX.
  81   this->u_.from_object.shndx = sym.get_st_shndx();
  82   this->source_ = FROM_OBJECT;
  83   this->in_reg_ = !object->is_dynamic();
  84   this->in_dyn_ = object->is_dynamic();
  85 }
  86
  87 // Initialize the fields in the base class Symbol for a symbol defined
  88 // in an Output_data.
  89
  90 void
  91 Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type,
  92                   elfcpp::STB binding, elfcpp::STV visibility,
  93                   unsigned char nonvis, bool offset_is_from_end)
  94 {
  95   this->init_fields(name, NULL, type, binding, visibility, nonvis);
  96   this->u_.in_output_data.output_data = od;
  97   this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
  98   this->source_ = IN_OUTPUT_DATA;
  99   this->in_reg_ = true;
 100 }
 101
 102 // Initialize the fields in the base class Symbol for a symbol defined
 103 // in an Output_segment.
 104
 105 void
 106 Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type,
 107                   elfcpp::STB binding, elfcpp::STV visibility,
 108                   unsigned char nonvis, Segment_offset_base offset_base)
 109 {
 110   this->init_fields(name, NULL, type, binding, visibility, nonvis);
 111   this->u_.in_output_segment.output_segment = os;
 112   this->u_.in_output_segment.offset_base = offset_base;
 113   this->source_ = IN_OUTPUT_SEGMENT;
 114   this->in_reg_ = true;
 115 }
 116
 117 // Initialize the fields in the base class Symbol for a symbol defined
 118 // as a constant.
 119
 120 void
 121 Symbol::init_base(const char* name, elfcpp::STT type,
 122                   elfcpp::STB binding, elfcpp::STV visibility,
 123                   unsigned char nonvis)
 124 {
 125   this->init_fields(name, NULL, type, binding, visibility, nonvis);
 126   this->source_ = CONSTANT;
 127   this->in_reg_ = true;
 128 }
 129
 130 // Initialize the fields in Sized_symbol for SYM in OBJECT.
 131
 132 template<int size>
 133 template<bool big_endian>
 134 void
 135 Sized_symbol<size>::init(const char* name, const char* version, Object* object,
 136                          const elfcpp::Sym<size, big_endian>& sym)
 137 {
 138   this->init_base(name, version, object, sym);
 139   this->value_ = sym.get_st_value();
 140   this->symsize_ = sym.get_st_size();
 141 }
 142
 143 // Initialize the fields in Sized_symbol for a symbol defined in an
 144 // Output_data.
 145
 146 template<int size>
 147 void
 148 Sized_symbol<size>::init(const char* name, Output_data* od,
 149                          Value_type value, Size_type symsize,
 150                          elfcpp::STT type, elfcpp::STB binding,
 151                          elfcpp::STV visibility, unsigned char nonvis,
 152                          bool offset_is_from_end)
 153 {
 154   this->init_base(name, od, type, binding, visibility, nonvis,
 155                   offset_is_from_end);
 156   this->value_ = value;
 157   this->symsize_ = symsize;
 158 }
 159
 160 // Initialize the fields in Sized_symbol for a symbol defined in an
 161 // Output_segment.
 162
 163 template<int size>
 164 void
 165 Sized_symbol<size>::init(const char* name, Output_segment* os,
 166                          Value_type value, Size_type symsize,
 167                          elfcpp::STT type, elfcpp::STB binding,
 168                          elfcpp::STV visibility, unsigned char nonvis,
 169                          Segment_offset_base offset_base)
 170 {
 171   this->init_base(name, os, type, binding, visibility, nonvis, offset_base);
 172   this->value_ = value;
 173   this->symsize_ = symsize;
 174 }
 175
 176 // Initialize the fields in Sized_symbol for a symbol defined as a
 177 // constant.
 178
 179 template<int size>
 180 void
 181 Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize,
 182                          elfcpp::STT type, elfcpp::STB binding,
 183                          elfcpp::STV visibility, unsigned char nonvis)
 184 {
 185   this->init_base(name, type, binding, visibility, nonvis);
 186   this->value_ = value;
 187   this->symsize_ = symsize;
 188 }
 189
 190 // Class Symbol_table.
 191
 192 Symbol_table::Symbol_table()
 193   : saw_undefined_(0), offset_(0), table_(), namepool_(),
 194     forwarders_(), commons_(), warnings_()
 195 {
 196 }
 197
 198 Symbol_table::~Symbol_table()
 199 {
 200 }
 201
 202 // The hash function.  The key is always canonicalized, so we use a
 203 // simple combination of the pointers.
 204
 205 size_t
 206 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
 207 {
 208   return key.first ^ key.second;
 209 }
 210
 211 // The symbol table key equality function.  This is only called with
 212 // canonicalized name and version strings, so we can use pointer
 213 // comparison.
 214
 215 bool
 216 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
 217                                           const Symbol_table_key& k2) const
 218 {
 219   return k1.first == k2.first && k1.second == k2.second;
 220 }
 221
 222 // Make TO a symbol which forwards to FROM.
 223
 224 void
 225 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
 226 {
 227   gold_assert(from != to);
 228   gold_assert(!from->is_forwarder() && !to->is_forwarder());
 229   this->forwarders_[from] = to;
 230   from->set_forwarder();
 231 }
 232
 233 // Resolve the forwards from FROM, returning the real symbol.
 234
 235 Symbol*
 236 Symbol_table::resolve_forwards(const Symbol* from) const
 237 {
 238   gold_assert(from->is_forwarder());
 239   Unordered_map<const Symbol*, Symbol*>::const_iterator p =
 240     this->forwarders_.find(from);
 241   gold_assert(p != this->forwarders_.end());
 242   return p->second;
 243 }
 244
 245 // Look up a symbol by name.
 246
 247 Symbol*
 248 Symbol_table::lookup(const char* name, const char* version) const
 249 {
 250   Stringpool::Key name_key;
 251   name = this->namepool_.find(name, &name_key);
 252   if (name == NULL)
 253     return NULL;
 254
 255   Stringpool::Key version_key = 0;
 256   if (version != NULL)
 257     {
 258       version = this->namepool_.find(version, &version_key);
 259       if (version == NULL)
 260         return NULL;
 261     }
 262
 263   Symbol_table_key key(name_key, version_key);
 264   Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
 265   if (p == this->table_.end())
 266     return NULL;
 267   return p->second;
 268 }
 269
 270 // Resolve a Symbol with another Symbol.  This is only used in the
 271 // unusual case where there are references to both an unversioned
 272 // symbol and a symbol with a version, and we then discover that that
 273 // version is the default version.  Because this is unusual, we do
 274 // this the slow way, by converting back to an ELF symbol.
 275
 276 template<int size, bool big_endian>
 277 void
 278 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
 279                       const char* version ACCEPT_SIZE_ENDIAN)
 280 {
 281   unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
 282   elfcpp::Sym_write<size, big_endian> esym(buf);
 283   // We don't bother to set the st_name field.
 284   esym.put_st_value(from->value());
 285   esym.put_st_size(from->symsize());
 286   esym.put_st_info(from->binding(), from->type());
 287   esym.put_st_other(from->visibility(), from->nonvis());
 288   esym.put_st_shndx(from->shndx());
 289   Symbol_table::resolve(to, esym.sym(), from->object(), version);
 290   if (from->in_reg())
 291     to->set_in_reg();
 292   if (from->in_dyn())
 293     to->set_in_dyn();
 294 }
 295
 296 // Add one symbol from OBJECT to the symbol table.  NAME is symbol
 297 // name and VERSION is the version; both are canonicalized.  DEF is
 298 // whether this is the default version.
 299
 300 // If DEF is true, then this is the definition of a default version of
 301 // a symbol.  That means that any lookup of NAME/NULL and any lookup
 302 // of NAME/VERSION should always return the same symbol.  This is
 303 // obvious for references, but in particular we want to do this for
 304 // definitions: overriding NAME/NULL should also override
 305 // NAME/VERSION.  If we don't do that, it would be very hard to
 306 // override functions in a shared library which uses versioning.
 307
 308 // We implement this by simply making both entries in the hash table
 309 // point to the same Symbol structure.  That is easy enough if this is
 310 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
 311 // that we have seen both already, in which case they will both have
 312 // independent entries in the symbol table.  We can't simply change
 313 // the symbol table entry, because we have pointers to the entries
 314 // attached to the object files.  So we mark the entry attached to the
 315 // object file as a forwarder, and record it in the forwarders_ map.
 316 // Note that entries in the hash table will never be marked as
 317 // forwarders.
 318
 319 template<int size, bool big_endian>
 320 Symbol*
 321 Symbol_table::add_from_object(Object* object,
 322                               const char *name,
 323                               Stringpool::Key name_key,
 324                               const char *version,
 325                               Stringpool::Key version_key,
 326                               bool def,
 327                               const elfcpp::Sym<size, big_endian>& sym)
 328 {
 329   Symbol* const snull = NULL;
 330   std::pair<typename Symbol_table_type::iterator, bool> ins =
 331     this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
 332                                        snull));
 333
 334   std::pair<typename Symbol_table_type::iterator, bool> insdef =
 335     std::make_pair(this->table_.end(), false);
 336   if (def)
 337     {
 338       const Stringpool::Key vnull_key = 0;
 339       insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
 340                                                                  vnull_key),
 341                                                   snull));
 342     }
 343
 344   // ins.first: an iterator, which is a pointer to a pair.
 345   // ins.first->first: the key (a pair of name and version).
 346   // ins.first->second: the value (Symbol*).
 347   // ins.second: true if new entry was inserted, false if not.
 348
 349   Sized_symbol<size>* ret;
 350   bool was_undefined;
 351   bool was_common;
 352   if (!ins.second)
 353     {
 354       // We already have an entry for NAME/VERSION.
 355       ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (ins.first->second
 356                                                            SELECT_SIZE(size));
 357       gold_assert(ret != NULL);
 358
 359       was_undefined = ret->is_undefined();
 360       was_common = ret->is_common();
 361
 362       Symbol_table::resolve(ret, sym, object, version);
 363
 364       if (def)
 365         {
 366           if (insdef.second)
 367             {
 368               // This is the first time we have seen NAME/NULL.  Make
 369               // NAME/NULL point to NAME/VERSION.
 370               insdef.first->second = ret;
 371             }
 372           else if (insdef.first->second != ret)
 373             {
 374               // This is the unfortunate case where we already have
 375               // entries for both NAME/VERSION and NAME/NULL.
 376               const Sized_symbol<size>* sym2;
 377               sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) (
 378                 insdef.first->second
 379                 SELECT_SIZE(size));
 380               Symbol_table::resolve SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
 381                 ret, sym2, version SELECT_SIZE_ENDIAN(size, big_endian));
 382               this->make_forwarder(insdef.first->second, ret);
 383               insdef.first->second = ret;
 384             }
 385         }
 386     }
 387   else
 388     {
 389       // This is the first time we have seen NAME/VERSION.
 390       gold_assert(ins.first->second == NULL);
 391
 392       was_undefined = false;
 393       was_common = false;
 394
 395       if (def && !insdef.second)
 396         {
 397           // We already have an entry for NAME/NULL.  If we override
 398           // it, then change it to NAME/VERSION.
 399           ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (
 400               insdef.first->second
 401               SELECT_SIZE(size));
 402           Symbol_table::resolve(ret, sym, object, version);
 403           ins.first->second = ret;
 404         }
 405       else
 406         {
 407           Sized_target<size, big_endian>* target =
 408             object->sized_target SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
 409                 SELECT_SIZE_ENDIAN_ONLY(size, big_endian));
 410           if (!target->has_make_symbol())
 411             ret = new Sized_symbol<size>();
 412           else
 413             {
 414               ret = target->make_symbol();
 415               if (ret == NULL)
 416                 {
 417                   // This means that we don't want a symbol table
 418                   // entry after all.
 419                   if (!def)
 420                     this->table_.erase(ins.first);
 421                   else
 422                     {
 423                       this->table_.erase(insdef.first);
 424                       // Inserting insdef invalidated ins.
 425                       this->table_.erase(std::make_pair(name_key,
 426                                                         version_key));
 427                     }
 428                   return NULL;
 429                 }
 430             }
 431
 432           ret->init(name, version, object, sym);
 433
 434           ins.first->second = ret;
 435           if (def)
 436             {
 437               // This is the first time we have seen NAME/NULL.  Point
 438               // it at the new entry for NAME/VERSION.
 439               gold_assert(insdef.second);
 440               insdef.first->second = ret;
 441             }
 442         }
 443     }
 444
 445   // Record every time we see a new undefined symbol, to speed up
 446   // archive groups.
 447   if (!was_undefined && ret->is_undefined())
 448     ++this->saw_undefined_;
 449
 450   // Keep track of common symbols, to speed up common symbol
 451   // allocation.
 452   if (!was_common && ret->is_common())
 453     this->commons_.push_back(ret);
 454
 455   return ret;
 456 }
 457
 458 // Add all the symbols in a relocatable object to the hash table.
 459
 460 template<int size, bool big_endian>
 461 void
 462 Symbol_table::add_from_relobj(
 463     Sized_relobj<size, big_endian>* relobj,
 464     const unsigned char* syms,
 465     size_t count,
 466     const char* sym_names,
 467     size_t sym_name_size,
 468     Symbol** sympointers)
 469 {
 470   gold_assert(size == relobj->target()->get_size());
 471   gold_assert(size == parameters->get_size());
 472
 473   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
 474
 475   const unsigned char* p = syms;
 476   for (size_t i = 0; i < count; ++i, p += sym_size)
 477     {
 478       elfcpp::Sym<size, big_endian> sym(p);
 479       elfcpp::Sym<size, big_endian>* psym = &sym;
 480
 481       unsigned int st_name = psym->get_st_name();
 482       if (st_name >= sym_name_size)
 483         {
 484           fprintf(stderr,
 485                   _("%s: %s: bad global symbol name offset %u at %lu\n"),
 486                   program_name, relobj->name().c_str(), st_name,
 487                   static_cast<unsigned long>(i));
 488           gold_exit(false);
 489         }
 490
 491       const char* name = sym_names + st_name;
 492
 493       // A symbol defined in a section which we are not including must
 494       // be treated as an undefined symbol.
 495       unsigned char symbuf[sym_size];
 496       elfcpp::Sym<size, big_endian> sym2(symbuf);
 497       unsigned int st_shndx = psym->get_st_shndx();
 498       if (st_shndx != elfcpp::SHN_UNDEF
 499           && st_shndx < elfcpp::SHN_LORESERVE
 500           && !relobj->is_section_included(st_shndx))
 501         {
 502           memcpy(symbuf, p, sym_size);
 503           elfcpp::Sym_write<size, big_endian> sw(symbuf);
 504           sw.put_st_shndx(elfcpp::SHN_UNDEF);
 505           psym = &sym2;
 506         }
 507
 508       // In an object file, an '@' in the name separates the symbol
 509       // name from the version name.  If there are two '@' characters,
 510       // this is the default version.
 511       const char* ver = strchr(name, '@');
 512
 513       Symbol* res;
 514       if (ver == NULL)
 515         {
 516           Stringpool::Key name_key;
 517           name = this->namepool_.add(name, &name_key);
 518           res = this->add_from_object(relobj, name, name_key, NULL, 0,
 519                                       false, *psym);
 520         }
 521       else
 522         {
 523           Stringpool::Key name_key;
 524           name = this->namepool_.add(name, ver - name, &name_key);
 525
 526           bool def = false;
 527           ++ver;
 528           if (*ver == '@')
 529             {
 530               def = true;
 531               ++ver;
 532             }
 533
 534           Stringpool::Key ver_key;
 535           ver = this->namepool_.add(ver, &ver_key);
 536
 537           res = this->add_from_object(relobj, name, name_key, ver, ver_key,
 538                                       def, *psym);
 539         }
 540
 541       *sympointers++ = res;
 542     }
 543 }
 544
 545 // Add all the symbols in a dynamic object to the hash table.
 546
 547 template<int size, bool big_endian>
 548 void
 549 Symbol_table::add_from_dynobj(
 550     Sized_dynobj<size, big_endian>* dynobj,
 551     const unsigned char* syms,
 552     size_t count,
 553     const char* sym_names,
 554     size_t sym_name_size,
 555     const unsigned char* versym,
 556     size_t versym_size,
 557     const std::vector<const char*>* version_map)
 558 {
 559   gold_assert(size == dynobj->target()->get_size());
 560   gold_assert(size == parameters->get_size());
 561
 562   if (versym != NULL && versym_size / 2 < count)
 563     {
 564       fprintf(stderr, _("%s: %s: too few symbol versions\n"),
 565               program_name, dynobj->name().c_str());
 566       gold_exit(false);
 567     }
 568
 569   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
 570
 571   const unsigned char* p = syms;
 572   const unsigned char* vs = versym;
 573   for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
 574     {
 575       elfcpp::Sym<size, big_endian> sym(p);
 576
 577       // Ignore symbols with local binding.
 578       if (sym.get_st_bind() == elfcpp::STB_LOCAL)
 579         continue;
 580
 581       unsigned int st_name = sym.get_st_name();
 582       if (st_name >= sym_name_size)
 583         {
 584           fprintf(stderr, _("%s: %s: bad symbol name offset %u at %lu\n"),
 585                   program_name, dynobj->name().c_str(), st_name,
 586                   static_cast<unsigned long>(i));
 587           gold_exit(false);
 588         }
 589
 590       const char* name = sym_names + st_name;
 591
 592       if (versym == NULL)
 593         {
 594           Stringpool::Key name_key;
 595           name = this->namepool_.add(name, &name_key);
 596           this->add_from_object(dynobj, name, name_key, NULL, 0,
 597                                 false, sym);
 598           continue;
 599         }
 600
 601       // Read the version information.
 602
 603       unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
 604
 605       bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
 606       v &= elfcpp::VERSYM_VERSION;
 607
 608       // The Sun documentation says that V can be VER_NDX_LOCAL, or
 609       // VER_NDX_GLOBAL, or a version index.  The meaning of
 610       // VER_NDX_LOCAL is defined as "Symbol has local scope."  The
 611       // old GNU linker will happily generate VER_NDX_LOCAL for an
 612       // undefined symbol.  I don't know what the Sun linker will
 613       // generate.
 614
 615       if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
 616           && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
 617         {
 618           // This symbol should not be visible outside the object.
 619           continue;
 620         }
 621
 622       // At this point we are definitely going to add this symbol.
 623       Stringpool::Key name_key;
 624       name = this->namepool_.add(name, &name_key);
 625
 626       if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
 627           || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
 628         {
 629           // This symbol does not have a version.
 630           this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym);
 631           continue;
 632         }
 633
 634       if (v >= version_map->size())
 635         {
 636           fprintf(stderr,
 637                   _("%s: %s: versym for symbol %zu out of range: %u\n"),
 638                   program_name, dynobj->name().c_str(), i, v);
 639           gold_exit(false);
 640         }
 641
 642       const char* version = (*version_map)[v];
 643       if (version == NULL)
 644         {
 645           fprintf(stderr, _("%s: %s: versym for symbol %zu has no name: %u\n"),
 646                   program_name, dynobj->name().c_str(), i, v);
 647           gold_exit(false);
 648         }
 649
 650       Stringpool::Key version_key;
 651       version = this->namepool_.add(version, &version_key);
 652
 653       // If this is an absolute symbol, and the version name and
 654       // symbol name are the same, then this is the version definition
 655       // symbol.  These symbols exist to support using -u to pull in
 656       // particular versions.  We do not want to record a version for
 657       // them.
 658       if (sym.get_st_shndx() == elfcpp::SHN_ABS && name_key == version_key)
 659         {
 660           this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym);
 661           continue;
 662         }
 663
 664       const bool def = !hidden && sym.get_st_shndx() != elfcpp::SHN_UNDEF;
 665
 666       this->add_from_object(dynobj, name, name_key, version, version_key,
 667                             def, sym);
 668     }
 669 }
 670
 671 // Create and return a specially defined symbol.  If ONLY_IF_REF is
 672 // true, then only create the symbol if there is a reference to it.
 673 // If this does not return NULL, it sets *POLDSYM to the existing
 674 // symbol if there is one.  This canonicalizes *PNAME and *PVERSION.
 675
 676 template<int size, bool big_endian>
 677 Sized_symbol<size>*
 678 Symbol_table::define_special_symbol(const Target* target, const char** pname,
 679                                     const char** pversion, bool only_if_ref,
 680                                     Sized_symbol<size>** poldsym
 681                                     ACCEPT_SIZE_ENDIAN)
 682 {
 683   Symbol* oldsym;
 684   Sized_symbol<size>* sym;
 685   bool add_to_table = false;
 686   typename Symbol_table_type::iterator add_loc = this->table_.end();
 687
 688   if (only_if_ref)
 689     {
 690       oldsym = this->lookup(*pname, *pversion);
 691       if (oldsym == NULL || !oldsym->is_undefined())
 692         return NULL;
 693
 694       *pname = oldsym->name();
 695       *pversion = oldsym->version();
 696     }
 697   else
 698     {
 699       // Canonicalize NAME and VERSION.
 700       Stringpool::Key name_key;
 701       *pname = this->namepool_.add(*pname, &name_key);
 702
 703       Stringpool::Key version_key = 0;
 704       if (*pversion != NULL)
 705         *pversion = this->namepool_.add(*pversion, &version_key);
 706
 707       Symbol* const snull = NULL;
 708       std::pair<typename Symbol_table_type::iterator, bool> ins =
 709         this->table_.insert(std::make_pair(std::make_pair(name_key,
 710                                                           version_key),
 711                                            snull));
 712
 713       if (!ins.second)
 714         {
 715           // We already have a symbol table entry for NAME/VERSION.
 716           oldsym = ins.first->second;
 717           gold_assert(oldsym != NULL);
 718         }
 719       else
 720         {
 721           // We haven't seen this symbol before.
 722           gold_assert(ins.first->second == NULL);
 723           add_to_table = true;
 724           add_loc = ins.first;
 725           oldsym = NULL;
 726         }
 727     }
 728
 729   if (!target->has_make_symbol())
 730     sym = new Sized_symbol<size>();
 731   else
 732     {
 733       gold_assert(target->get_size() == size);
 734       gold_assert(target->is_big_endian() ? big_endian : !big_endian);
 735       typedef Sized_target<size, big_endian> My_target;
 736       const My_target* sized_target =
 737           static_cast<const My_target*>(target);
 738       sym = sized_target->make_symbol();
 739       if (sym == NULL)
 740         return NULL;
 741     }
 742
 743   if (add_to_table)
 744     add_loc->second = sym;
 745   else
 746     gold_assert(oldsym != NULL);
 747
 748   *poldsym = this->get_sized_symbol SELECT_SIZE_NAME(size) (oldsym
 749                                                             SELECT_SIZE(size));
 750
 751   return sym;
 752 }
 753
 754 // Define a symbol based on an Output_data.
 755
 756 Symbol*
 757 Symbol_table::define_in_output_data(const Target* target, const char* name,
 758                                     const char* version, Output_data* od,
 759                                     uint64_t value, uint64_t symsize,
 760                                     elfcpp::STT type, elfcpp::STB binding,
 761                                     elfcpp::STV visibility,
 762                                     unsigned char nonvis,
 763                                     bool offset_is_from_end,
 764                                     bool only_if_ref)
 765 {
 766   if (parameters->get_size() == 32)
 767     {
 768 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
 769       return this->do_define_in_output_data<32>(target, name, version, od,
 770                                                 value, symsize, type, binding,
 771                                                 visibility, nonvis,
 772                                                 offset_is_from_end,
 773                                                 only_if_ref);
 774 #else
 775       gold_unreachable();
 776 #endif
 777     }
 778   else if (parameters->get_size() == 64)
 779     {
 780 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
 781       return this->do_define_in_output_data<64>(target, name, version, od,
 782                                                 value, symsize, type, binding,
 783                                                 visibility, nonvis,
 784                                                 offset_is_from_end,
 785                                                 only_if_ref);
 786 #else
 787       gold_unreachable();
 788 #endif
 789     }
 790   else
 791     gold_unreachable();
 792 }
 793
 794 // Define a symbol in an Output_data, sized version.
 795
 796 template<int size>
 797 Sized_symbol<size>*
 798 Symbol_table::do_define_in_output_data(
 799     const Target* target,
 800     const char* name,
 801     const char* version,
 802     Output_data* od,
 803     typename elfcpp::Elf_types<size>::Elf_Addr value,
 804     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
 805     elfcpp::STT type,
 806     elfcpp::STB binding,
 807     elfcpp::STV visibility,
 808     unsigned char nonvis,
 809     bool offset_is_from_end,
 810     bool only_if_ref)
 811 {
 812   Sized_symbol<size>* sym;
 813   Sized_symbol<size>* oldsym;
 814
 815   if (parameters->is_big_endian())
 816     {
 817 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
 818       sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
 819           target, &name, &version, only_if_ref, &oldsym
 820           SELECT_SIZE_ENDIAN(size, true));
 821 #else
 822       gold_unreachable();
 823 #endif
 824     }
 825   else
 826     {
 827 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
 828       sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
 829           target, &name, &version, only_if_ref, &oldsym
 830           SELECT_SIZE_ENDIAN(size, false));
 831 #else
 832       gold_unreachable();
 833 #endif
 834     }
 835
 836   if (sym == NULL)
 837     return NULL;
 838
 839   gold_assert(version == NULL || oldsym != NULL);
 840   sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
 841             offset_is_from_end);
 842
 843   if (oldsym != NULL
 844       && Symbol_table::should_override_with_special(oldsym))
 845     oldsym->override_with_special(sym);
 846
 847   return sym;
 848 }
 849
 850 // Define a symbol based on an Output_segment.
 851
 852 Symbol*
 853 Symbol_table::define_in_output_segment(const Target* target, const char* name,
 854                                        const char* version, Output_segment* os,
 855                                        uint64_t value, uint64_t symsize,
 856                                        elfcpp::STT type, elfcpp::STB binding,
 857                                        elfcpp::STV visibility,
 858                                        unsigned char nonvis,
 859                                        Symbol::Segment_offset_base offset_base,
 860                                        bool only_if_ref)
 861 {
 862   if (parameters->get_size() == 32)
 863     {
 864 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
 865       return this->do_define_in_output_segment<32>(target, name, version, os,
 866                                                    value, symsize, type,
 867                                                    binding, visibility, nonvis,
 868                                                    offset_base, only_if_ref);
 869 #else
 870       gold_unreachable();
 871 #endif
 872     }
 873   else if (parameters->get_size() == 64)
 874     {
 875 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
 876       return this->do_define_in_output_segment<64>(target, name, version, os,
 877                                                    value, symsize, type,
 878                                                    binding, visibility, nonvis,
 879                                                    offset_base, only_if_ref);
 880 #else
 881       gold_unreachable();
 882 #endif
 883     }
 884   else
 885     gold_unreachable();
 886 }
 887
 888 // Define a symbol in an Output_segment, sized version.
 889
 890 template<int size>
 891 Sized_symbol<size>*
 892 Symbol_table::do_define_in_output_segment(
 893     const Target* target,
 894     const char* name,
 895     const char* version,
 896     Output_segment* os,
 897     typename elfcpp::Elf_types<size>::Elf_Addr value,
 898     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
 899     elfcpp::STT type,
 900     elfcpp::STB binding,
 901     elfcpp::STV visibility,
 902     unsigned char nonvis,
 903     Symbol::Segment_offset_base offset_base,
 904     bool only_if_ref)
 905 {
 906   Sized_symbol<size>* sym;
 907   Sized_symbol<size>* oldsym;
 908
 909   if (parameters->is_big_endian())
 910     {
 911 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
 912       sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
 913           target, &name, &version, only_if_ref, &oldsym
 914           SELECT_SIZE_ENDIAN(size, true));
 915 #else
 916       gold_unreachable();
 917 #endif
 918     }
 919   else
 920     {
 921 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
 922       sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
 923           target, &name, &version, only_if_ref, &oldsym
 924           SELECT_SIZE_ENDIAN(size, false));
 925 #else
 926       gold_unreachable();
 927 #endif
 928     }
 929
 930   if (sym == NULL)
 931     return NULL;
 932
 933   gold_assert(version == NULL || oldsym != NULL);
 934   sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
 935             offset_base);
 936
 937   if (oldsym != NULL
 938       && Symbol_table::should_override_with_special(oldsym))
 939     oldsym->override_with_special(sym);
 940
 941   return sym;
 942 }
 943
 944 // Define a special symbol with a constant value.  It is a multiple
 945 // definition error if this symbol is already defined.
 946
 947 Symbol*
 948 Symbol_table::define_as_constant(const Target* target, const char* name,
 949                                  const char* version, uint64_t value,
 950                                  uint64_t symsize, elfcpp::STT type,
 951                                  elfcpp::STB binding, elfcpp::STV visibility,
 952                                  unsigned char nonvis, bool only_if_ref)
 953 {
 954   if (parameters->get_size() == 32)
 955     {
 956 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
 957       return this->do_define_as_constant<32>(target, name, version, value,
 958                                              symsize, type, binding,
 959                                              visibility, nonvis, only_if_ref);
 960 #else
 961       gold_unreachable();
 962 #endif
 963     }
 964   else if (parameters->get_size() == 64)
 965     {
 966 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
 967       return this->do_define_as_constant<64>(target, name, version, value,
 968                                              symsize, type, binding,
 969                                              visibility, nonvis, only_if_ref);
 970 #else
 971       gold_unreachable();
 972 #endif
 973     }
 974   else
 975     gold_unreachable();
 976 }
 977
 978 // Define a symbol as a constant, sized version.
 979
 980 template<int size>
 981 Sized_symbol<size>*
 982 Symbol_table::do_define_as_constant(
 983     const Target* target,
 984     const char* name,
 985     const char* version,
 986     typename elfcpp::Elf_types<size>::Elf_Addr value,
 987     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
 988     elfcpp::STT type,
 989     elfcpp::STB binding,
 990     elfcpp::STV visibility,
 991     unsigned char nonvis,
 992     bool only_if_ref)
 993 {
 994   Sized_symbol<size>* sym;
 995   Sized_symbol<size>* oldsym;
 996
 997   if (parameters->is_big_endian())
 998     {
 999 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1000       sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1001           target, &name, &version, only_if_ref, &oldsym
1002           SELECT_SIZE_ENDIAN(size, true));
1003 #else
1004       gold_unreachable();
1005 #endif
1006     }
1007   else
1008     {
1009 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1010       sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1011           target, &name, &version, only_if_ref, &oldsym
1012           SELECT_SIZE_ENDIAN(size, false));
1013 #else
1014       gold_unreachable();
1015 #endif
1016     }
1017
1018   if (sym == NULL)
1019     return NULL;
1020
1021   gold_assert(version == NULL || oldsym != NULL);
1022   sym->init(name, value, symsize, type, binding, visibility, nonvis);
1023
1024   if (oldsym != NULL
1025       && Symbol_table::should_override_with_special(oldsym))
1026     oldsym->override_with_special(sym);
1027
1028   return sym;
1029 }
1030
1031 // Define a set of symbols in output sections.
1032
1033 void
1034 Symbol_table::define_symbols(const Layout* layout, const Target* target,
1035                              int count, const Define_symbol_in_section* p)
1036 {
1037   for (int i = 0; i < count; ++i, ++p)
1038     {
1039       Output_section* os = layout->find_output_section(p->output_section);
1040       if (os != NULL)
1041         this->define_in_output_data(target, p->name, NULL, os, p->value,
1042                                     p->size, p->type, p->binding,
1043                                     p->visibility, p->nonvis,
1044                                     p->offset_is_from_end, p->only_if_ref);
1045       else
1046         this->define_as_constant(target, p->name, NULL, 0, p->size, p->type,
1047                                  p->binding, p->visibility, p->nonvis,
1048                                  p->only_if_ref);
1049     }
1050 }
1051
1052 // Define a set of symbols in output segments.
1053
1054 void
1055 Symbol_table::define_symbols(const Layout* layout, const Target* target,
1056                              int count, const Define_symbol_in_segment* p)
1057 {
1058   for (int i = 0; i < count; ++i, ++p)
1059     {
1060       Output_segment* os = layout->find_output_segment(p->segment_type,
1061                                                        p->segment_flags_set,
1062                                                        p->segment_flags_clear);
1063       if (os != NULL)
1064         this->define_in_output_segment(target, p->name, NULL, os, p->value,
1065                                        p->size, p->type, p->binding,
1066                                        p->visibility, p->nonvis,
1067                                        p->offset_base, p->only_if_ref);
1068       else
1069         this->define_as_constant(target, p->name, NULL, 0, p->size, p->type,
1070                                  p->binding, p->visibility, p->nonvis,
1071                                  p->only_if_ref);
1072     }
1073 }
1074
1075 // Set the dynamic symbol indexes.  INDEX is the index of the first
1076 // global dynamic symbol.  Pointers to the symbols are stored into the
1077 // vector SYMS.  The names are added to DYNPOOL.  This returns an
1078 // updated dynamic symbol index.
1079
1080 unsigned int
1081 Symbol_table::set_dynsym_indexes(const General_options* options,
1082                                  const Target* target,
1083                                  unsigned int index,
1084                                  std::vector<Symbol*>* syms,
1085                                  Stringpool* dynpool,
1086                                  Versions* versions)
1087 {
1088   for (Symbol_table_type::iterator p = this->table_.begin();
1089        p != this->table_.end();
1090        ++p)
1091     {
1092       Symbol* sym = p->second;
1093
1094       // Note that SYM may already have a dynamic symbol index, since
1095       // some symbols appear more than once in the symbol table, with
1096       // and without a version.
1097
1098       if (!sym->needs_dynsym_entry()
1099           && (!options->export_dynamic()
1100               || !sym->in_reg()
1101               || !sym->is_externally_visible()))
1102         sym->set_dynsym_index(-1U);
1103       else if (!sym->has_dynsym_index())
1104         {
1105           sym->set_dynsym_index(index);
1106           ++index;
1107           syms->push_back(sym);
1108           dynpool->add(sym->name(), NULL);
1109
1110           // Record any version information.
1111           if (sym->version() != NULL)
1112             versions->record_version(options, dynpool, sym);
1113         }
1114     }
1115
1116   // Finish up the versions.  In some cases this may add new dynamic
1117   // symbols.
1118   index = versions->finalize(target, this, index, syms);
1119
1120   return index;
1121 }
1122
1123 // Set the final values for all the symbols.  The index of the first
1124 // global symbol in the output file is INDEX.  Record the file offset
1125 // OFF.  Add their names to POOL.  Return the new file offset.
1126
1127 off_t
1128 Symbol_table::finalize(unsigned int index, off_t off, off_t dynoff,
1129                        size_t dyn_global_index, size_t dyncount,
1130                        Stringpool* pool)
1131 {
1132   off_t ret;
1133
1134   gold_assert(index != 0);
1135   this->first_global_index_ = index;
1136
1137   this->dynamic_offset_ = dynoff;
1138   this->first_dynamic_global_index_ = dyn_global_index;
1139   this->dynamic_count_ = dyncount;
1140
1141   if (parameters->get_size() == 32)
1142     {
1143 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1144       ret = this->sized_finalize<32>(index, off, pool);
1145 #else
1146       gold_unreachable();
1147 #endif
1148     }
1149   else if (parameters->get_size() == 64)
1150     {
1151 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1152       ret = this->sized_finalize<64>(index, off, pool);
1153 #else
1154       gold_unreachable();
1155 #endif
1156     }
1157   else
1158     gold_unreachable();
1159
1160   // Now that we have the final symbol table, we can reliably note
1161   // which symbols should get warnings.
1162   this->warnings_.note_warnings(this);
1163
1164   return ret;
1165 }
1166
1167 // Set the final value for all the symbols.  This is called after
1168 // Layout::finalize, so all the output sections have their final
1169 // address.
1170
1171 template<int size>
1172 off_t
1173 Symbol_table::sized_finalize(unsigned index, off_t off, Stringpool* pool)
1174 {
1175   off = align_address(off, size >> 3);
1176   this->offset_ = off;
1177
1178   size_t orig_index = index;
1179
1180   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1181   for (Symbol_table_type::iterator p = this->table_.begin();
1182        p != this->table_.end();
1183        ++p)
1184     {
1185       Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1186
1187       // FIXME: Here we need to decide which symbols should go into
1188       // the output file, based on --strip.
1189
1190       // The default version of a symbol may appear twice in the
1191       // symbol table.  We only need to finalize it once.
1192       if (sym->has_symtab_index())
1193         continue;
1194
1195       if (!sym->in_reg())
1196         {
1197           gold_assert(!sym->has_symtab_index());
1198           sym->set_symtab_index(-1U);
1199           gold_assert(sym->dynsym_index() == -1U);
1200           continue;
1201         }
1202
1203       typename Sized_symbol<size>::Value_type value;
1204
1205       switch (sym->source())
1206         {
1207         case Symbol::FROM_OBJECT:
1208           {
1209             unsigned int shndx = sym->shndx();
1210
1211             // FIXME: We need some target specific support here.
1212             if (shndx >= elfcpp::SHN_LORESERVE
1213                 && shndx != elfcpp::SHN_ABS)
1214               {
1215                 fprintf(stderr, _("%s: %s: unsupported symbol section 0x%x\n"),
1216                         program_name, sym->name(), shndx);
1217                 gold_exit(false);
1218               }
1219
1220             Object* symobj = sym->object();
1221             if (symobj->is_dynamic())
1222               {
1223                 value = 0;
1224                 shndx = elfcpp::SHN_UNDEF;
1225               }
1226             else if (shndx == elfcpp::SHN_UNDEF)
1227               value = 0;
1228             else if (shndx == elfcpp::SHN_ABS)
1229               value = sym->value();
1230             else
1231               {
1232                 Relobj* relobj = static_cast<Relobj*>(symobj);
1233                 off_t secoff;
1234                 Output_section* os = relobj->output_section(shndx, &secoff);
1235
1236                 if (os == NULL)
1237                   {
1238                     sym->set_symtab_index(-1U);
1239                     gold_assert(sym->dynsym_index() == -1U);
1240                     continue;
1241                   }
1242
1243                 value = sym->value() + os->address() + secoff;
1244               }
1245           }
1246           break;
1247
1248         case Symbol::IN_OUTPUT_DATA:
1249           {
1250             Output_data* od = sym->output_data();
1251             value = sym->value() + od->address();
1252             if (sym->offset_is_from_end())
1253               value += od->data_size();
1254           }
1255           break;
1256
1257         case Symbol::IN_OUTPUT_SEGMENT:
1258           {
1259             Output_segment* os = sym->output_segment();
1260             value = sym->value() + os->vaddr();
1261             switch (sym->offset_base())
1262               {
1263               case Symbol::SEGMENT_START:
1264                 break;
1265               case Symbol::SEGMENT_END:
1266                 value += os->memsz();
1267                 break;
1268               case Symbol::SEGMENT_BSS:
1269                 value += os->filesz();
1270                 break;
1271               default:
1272                 gold_unreachable();
1273               }
1274           }
1275           break;
1276
1277         case Symbol::CONSTANT:
1278           value = sym->value();
1279           break;
1280
1281         default:
1282           gold_unreachable();
1283         }
1284
1285       sym->set_value(value);
1286       sym->set_symtab_index(index);
1287       pool->add(sym->name(), NULL);
1288       ++index;
1289       off += sym_size;
1290     }
1291
1292   this->output_count_ = index - orig_index;
1293
1294   return off;
1295 }
1296
1297 // Write out the global symbols.
1298
1299 void
1300 Symbol_table::write_globals(const Target* target, const Stringpool* sympool,
1301                             const Stringpool* dynpool, Output_file* of) const
1302 {
1303   if (parameters->get_size() == 32)
1304     {
1305       if (parameters->is_big_endian())
1306         {
1307 #ifdef HAVE_TARGET_32_BIG
1308           this->sized_write_globals<32, true>(target, sympool, dynpool, of);
1309 #else
1310           gold_unreachable();
1311 #endif
1312         }
1313       else
1314         {
1315 #ifdef HAVE_TARGET_32_LITTLE
1316           this->sized_write_globals<32, false>(target, sympool, dynpool, of);
1317 #else
1318           gold_unreachable();
1319 #endif
1320         }
1321     }
1322   else if (parameters->get_size() == 64)
1323     {
1324       if (parameters->is_big_endian())
1325         {
1326 #ifdef HAVE_TARGET_64_BIG
1327           this->sized_write_globals<64, true>(target, sympool, dynpool, of);
1328 #else
1329           gold_unreachable();
1330 #endif
1331         }
1332       else
1333         {
1334 #ifdef HAVE_TARGET_64_LITTLE
1335           this->sized_write_globals<64, false>(target, sympool, dynpool, of);
1336 #else
1337           gold_unreachable();
1338 #endif
1339         }
1340     }
1341   else
1342     gold_unreachable();
1343 }
1344
1345 // Write out the global symbols.
1346
1347 template<int size, bool big_endian>
1348 void
1349 Symbol_table::sized_write_globals(const Target* target,
1350                                   const Stringpool* sympool,
1351                                   const Stringpool* dynpool,
1352                                   Output_file* of) const
1353 {
1354   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1355   unsigned int index = this->first_global_index_;
1356   const off_t oview_size = this->output_count_ * sym_size;
1357   unsigned char* const psyms = of->get_output_view(this->offset_, oview_size);
1358
1359   unsigned int dynamic_count = this->dynamic_count_;
1360   off_t dynamic_size = dynamic_count * sym_size;
1361   unsigned int first_dynamic_global_index = this->first_dynamic_global_index_;
1362   unsigned char* dynamic_view;
1363   if (this->dynamic_offset_ == 0)
1364     dynamic_view = NULL;
1365   else
1366     dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1367
1368   unsigned char* ps = psyms;
1369   for (Symbol_table_type::const_iterator p = this->table_.begin();
1370        p != this->table_.end();
1371        ++p)
1372     {
1373       Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1374
1375       unsigned int sym_index = sym->symtab_index();
1376       unsigned int dynsym_index;
1377       if (dynamic_view == NULL)
1378         dynsym_index = -1U;
1379       else
1380         dynsym_index = sym->dynsym_index();
1381
1382       if (sym_index == -1U && dynsym_index == -1U)
1383         {
1384           // This symbol is not included in the output file.
1385           continue;
1386         }
1387
1388       if (sym_index == index)
1389         ++index;
1390       else if (sym_index != -1U)
1391         {
1392           // We have already seen this symbol, because it has a
1393           // default version.
1394           gold_assert(sym_index < index);
1395           if (dynsym_index == -1U)
1396             continue;
1397           sym_index = -1U;
1398         }
1399
1400       unsigned int shndx;
1401       typename elfcpp::Elf_types<32>::Elf_Addr value = sym->value();
1402       switch (sym->source())
1403         {
1404         case Symbol::FROM_OBJECT:
1405           {
1406             unsigned int in_shndx = sym->shndx();
1407
1408             // FIXME: We need some target specific support here.
1409             if (in_shndx >= elfcpp::SHN_LORESERVE
1410                 && in_shndx != elfcpp::SHN_ABS)
1411               {
1412                 fprintf(stderr, _("%s: %s: unsupported symbol section 0x%x\n"),
1413                         program_name, sym->name(), in_shndx);
1414                 gold_exit(false);
1415               }
1416
1417             Object* symobj = sym->object();
1418             if (symobj->is_dynamic())
1419               {
1420                 if (sym->needs_dynsym_value())
1421                   value = target->dynsym_value(sym);
1422                 shndx = elfcpp::SHN_UNDEF;
1423               }
1424             else if (in_shndx == elfcpp::SHN_UNDEF
1425                      || in_shndx == elfcpp::SHN_ABS)
1426               shndx = in_shndx;
1427             else
1428               {
1429                 Relobj* relobj = static_cast<Relobj*>(symobj);
1430                 off_t secoff;
1431                 Output_section* os = relobj->output_section(in_shndx, &secoff);
1432                 gold_assert(os != NULL);
1433                 shndx = os->out_shndx();
1434               }
1435           }
1436           break;
1437
1438         case Symbol::IN_OUTPUT_DATA:
1439           shndx = sym->output_data()->out_shndx();
1440           break;
1441
1442         case Symbol::IN_OUTPUT_SEGMENT:
1443           shndx = elfcpp::SHN_ABS;
1444           break;
1445
1446         case Symbol::CONSTANT:
1447           shndx = elfcpp::SHN_ABS;
1448           break;
1449
1450         default:
1451           gold_unreachable();
1452         }
1453
1454       if (sym_index != -1U)
1455         {
1456           this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1457               sym, sym->value(), shndx, sympool, ps
1458               SELECT_SIZE_ENDIAN(size, big_endian));
1459           ps += sym_size;
1460         }
1461
1462       if (dynsym_index != -1U)
1463         {
1464           dynsym_index -= first_dynamic_global_index;
1465           gold_assert(dynsym_index < dynamic_count);
1466           unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
1467           this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1468               sym, value, shndx, dynpool, pd
1469               SELECT_SIZE_ENDIAN(size, big_endian));
1470         }
1471     }
1472
1473   gold_assert(ps - psyms == oview_size);
1474
1475   of->write_output_view(this->offset_, oview_size, psyms);
1476   if (dynamic_view != NULL)
1477     of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
1478 }
1479
1480 // Write out the symbol SYM, in section SHNDX, to P.  POOL is the
1481 // strtab holding the name.
1482
1483 template<int size, bool big_endian>
1484 void
1485 Symbol_table::sized_write_symbol(
1486     Sized_symbol<size>* sym,
1487     typename elfcpp::Elf_types<size>::Elf_Addr value,
1488     unsigned int shndx,
1489     const Stringpool* pool,
1490     unsigned char* p
1491     ACCEPT_SIZE_ENDIAN) const
1492 {
1493   elfcpp::Sym_write<size, big_endian> osym(p);
1494   osym.put_st_name(pool->get_offset(sym->name()));
1495   osym.put_st_value(value);
1496   osym.put_st_size(sym->symsize());
1497   osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
1498   osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
1499   osym.put_st_shndx(shndx);
1500 }
1501
1502 // Write out a section symbol.  Return the update offset.
1503
1504 void
1505 Symbol_table::write_section_symbol(const Output_section *os,
1506                                    Output_file* of,
1507                                    off_t offset) const
1508 {
1509   if (parameters->get_size() == 32)
1510     {
1511       if (parameters->is_big_endian())
1512         {
1513 #ifdef HAVE_TARGET_32_BIG
1514           this->sized_write_section_symbol<32, true>(os, of, offset);
1515 #else
1516           gold_unreachable();
1517 #endif
1518         }
1519       else
1520         {
1521 #ifdef HAVE_TARGET_32_LITTLE
1522           this->sized_write_section_symbol<32, false>(os, of, offset);
1523 #else
1524           gold_unreachable();
1525 #endif
1526         }
1527     }
1528   else if (parameters->get_size() == 64)
1529     {
1530       if (parameters->is_big_endian())
1531         {
1532 #ifdef HAVE_TARGET_64_BIG
1533           this->sized_write_section_symbol<64, true>(os, of, offset);
1534 #else
1535           gold_unreachable();
1536 #endif
1537         }
1538       else
1539         {
1540 #ifdef HAVE_TARGET_64_LITTLE
1541           this->sized_write_section_symbol<64, false>(os, of, offset);
1542 #else
1543           gold_unreachable();
1544 #endif
1545         }
1546     }
1547   else
1548     gold_unreachable();
1549 }
1550
1551 // Write out a section symbol, specialized for size and endianness.
1552
1553 template<int size, bool big_endian>
1554 void
1555 Symbol_table::sized_write_section_symbol(const Output_section* os,
1556                                          Output_file* of,
1557                                          off_t offset) const
1558 {
1559   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1560
1561   unsigned char* pov = of->get_output_view(offset, sym_size);
1562
1563   elfcpp::Sym_write<size, big_endian> osym(pov);
1564   osym.put_st_name(0);
1565   osym.put_st_value(os->address());
1566   osym.put_st_size(0);
1567   osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
1568                                        elfcpp::STT_SECTION));
1569   osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
1570   osym.put_st_shndx(os->out_shndx());
1571
1572   of->write_output_view(offset, sym_size, pov);
1573 }
1574
1575 // Warnings functions.
1576
1577 // Add a new warning.
1578
1579 void
1580 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
1581                       unsigned int shndx)
1582 {
1583   name = symtab->canonicalize_name(name);
1584   this->warnings_[name].set(obj, shndx);
1585 }
1586
1587 // Look through the warnings and mark the symbols for which we should
1588 // warn.  This is called during Layout::finalize when we know the
1589 // sources for all the symbols.
1590
1591 void
1592 Warnings::note_warnings(Symbol_table* symtab)
1593 {
1594   for (Warning_table::iterator p = this->warnings_.begin();
1595        p != this->warnings_.end();
1596        ++p)
1597     {
1598       Symbol* sym = symtab->lookup(p->first, NULL);
1599       if (sym != NULL
1600           && sym->source() == Symbol::FROM_OBJECT
1601           && sym->object() == p->second.object)
1602         {
1603           sym->set_has_warning();
1604
1605           // Read the section contents to get the warning text.  It
1606           // would be nicer if we only did this if we have to actually
1607           // issue a warning.  Unfortunately, warnings are issued as
1608           // we relocate sections.  That means that we can not lock
1609           // the object then, as we might try to issue the same
1610           // warning multiple times simultaneously.
1611           {
1612             Task_locker_obj<Object> tl(*p->second.object);
1613             const unsigned char* c;
1614             off_t len;
1615             c = p->second.object->section_contents(p->second.shndx, &len,
1616                                                    false);
1617             p->second.set_text(reinterpret_cast<const char*>(c), len);
1618           }
1619         }
1620     }
1621 }
1622
1623 // Issue a warning.  This is called when we see a relocation against a
1624 // symbol for which has a warning.
1625
1626 void
1627 Warnings::issue_warning(const Symbol* sym, const std::string& location) const
1628 {
1629   gold_assert(sym->has_warning());
1630   Warning_table::const_iterator p = this->warnings_.find(sym->name());
1631   gold_assert(p != this->warnings_.end());
1632   fprintf(stderr, _("%s: %s: warning: %s\n"), program_name, location.c_str(),
1633           p->second.text.c_str());
1634 }
1635
1636 // Instantiate the templates we need.  We could use the configure
1637 // script to restrict this to only the ones needed for implemented
1638 // targets.
1639
1640 #ifdef HAVE_TARGET_32_LITTLE
1641 template
1642 void
1643 Symbol_table::add_from_relobj<32, false>(
1644     Sized_relobj<32, false>* relobj,
1645     const unsigned char* syms,
1646     size_t count,
1647     const char* sym_names,
1648     size_t sym_name_size,
1649     Symbol** sympointers);
1650 #endif
1651
1652 #ifdef HAVE_TARGET_32_BIG
1653 template
1654 void
1655 Symbol_table::add_from_relobj<32, true>(
1656     Sized_relobj<32, true>* relobj,
1657     const unsigned char* syms,
1658     size_t count,
1659     const char* sym_names,
1660     size_t sym_name_size,
1661     Symbol** sympointers);
1662 #endif
1663
1664 #ifdef HAVE_TARGET_64_LITTLE
1665 template
1666 void
1667 Symbol_table::add_from_relobj<64, false>(
1668     Sized_relobj<64, false>* relobj,
1669     const unsigned char* syms,
1670     size_t count,
1671     const char* sym_names,
1672     size_t sym_name_size,
1673     Symbol** sympointers);
1674 #endif
1675
1676 #ifdef HAVE_TARGET_64_BIG
1677 template
1678 void
1679 Symbol_table::add_from_relobj<64, true>(
1680     Sized_relobj<64, true>* relobj,
1681     const unsigned char* syms,
1682     size_t count,
1683     const char* sym_names,
1684     size_t sym_name_size,
1685     Symbol** sympointers);
1686 #endif
1687
1688 #ifdef HAVE_TARGET_32_LITTLE
1689 template
1690 void
1691 Symbol_table::add_from_dynobj<32, false>(
1692     Sized_dynobj<32, false>* dynobj,
1693     const unsigned char* syms,
1694     size_t count,
1695     const char* sym_names,
1696     size_t sym_name_size,
1697     const unsigned char* versym,
1698     size_t versym_size,
1699     const std::vector<const char*>* version_map);
1700 #endif
1701
1702 #ifdef HAVE_TARGET_32_BIG
1703 template
1704 void
1705 Symbol_table::add_from_dynobj<32, true>(
1706     Sized_dynobj<32, true>* dynobj,
1707     const unsigned char* syms,
1708     size_t count,
1709     const char* sym_names,
1710     size_t sym_name_size,
1711     const unsigned char* versym,
1712     size_t versym_size,
1713     const std::vector<const char*>* version_map);
1714 #endif
1715
1716 #ifdef HAVE_TARGET_64_LITTLE
1717 template
1718 void
1719 Symbol_table::add_from_dynobj<64, false>(
1720     Sized_dynobj<64, false>* dynobj,
1721     const unsigned char* syms,
1722     size_t count,
1723     const char* sym_names,
1724     size_t sym_name_size,
1725     const unsigned char* versym,
1726     size_t versym_size,
1727     const std::vector<const char*>* version_map);
1728 #endif
1729
1730 #ifdef HAVE_TARGET_64_BIG
1731 template
1732 void
1733 Symbol_table::add_from_dynobj<64, true>(
1734     Sized_dynobj<64, true>* dynobj,
1735     const unsigned char* syms,
1736     size_t count,
1737     const char* sym_names,
1738     size_t sym_name_size,
1739     const unsigned char* versym,
1740     size_t versym_size,
1741     const std::vector<const char*>* version_map);
1742 #endif
1743
1744 } // End namespace gold.