gold/symtab.cc

   1 // symtab.cc -- the gold symbol table
   2
   3 #include "gold.h"
   4
   5 #include <stdint.h>
   6 #include <string>
   7 #include <utility>
   8
   9 #include "object.h"
  10 #include "dynobj.h"
  11 #include "output.h"
  12 #include "target.h"
  13 #include "workqueue.h"
  14 #include "symtab.h"
  15
  16 namespace gold
  17 {
  18
  19 // Class Symbol.
  20
  21 // Initialize fields in Symbol.  This initializes everything except u_
  22 // and source_.
  23
  24 void
  25 Symbol::init_fields(const char* name, const char* version,
  26                     elfcpp::STT type, elfcpp::STB binding,
  27                     elfcpp::STV visibility, unsigned char nonvis)
  28 {
  29   this->name_ = name;
  30   this->version_ = version;
  31   this->symtab_index_ = 0;
  32   this->dynsym_index_ = 0;
  33   this->got_offset_ = 0;
  34   this->plt_offset_ = 0;
  35   this->type_ = type;
  36   this->binding_ = binding;
  37   this->visibility_ = visibility;
  38   this->nonvis_ = nonvis;
  39   this->is_target_special_ = false;
  40   this->is_def_ = false;
  41   this->is_forwarder_ = false;
  42   this->needs_dynsym_entry_ = false;
  43   this->in_reg_ = false;
  44   this->in_dyn_ = false;
  45   this->has_got_offset_ = false;
  46   this->has_plt_offset_ = false;
  47   this->has_warning_ = false;
  48 }
  49
  50 // Initialize the fields in the base class Symbol for SYM in OBJECT.
  51
  52 template<int size, bool big_endian>
  53 void
  54 Symbol::init_base(const char* name, const char* version, Object* object,
  55                   const elfcpp::Sym<size, big_endian>& sym)
  56 {
  57   this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
  58                     sym.get_st_visibility(), sym.get_st_nonvis());
  59   this->u_.from_object.object = object;
  60   // FIXME: Handle SHN_XINDEX.
  61   this->u_.from_object.shndx = sym.get_st_shndx();
  62   this->source_ = FROM_OBJECT;
  63   this->in_reg_ = !object->is_dynamic();
  64   this->in_dyn_ = object->is_dynamic();
  65 }
  66
  67 // Initialize the fields in the base class Symbol for a symbol defined
  68 // in an Output_data.
  69
  70 void
  71 Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type,
  72                   elfcpp::STB binding, elfcpp::STV visibility,
  73                   unsigned char nonvis, bool offset_is_from_end)
  74 {
  75   this->init_fields(name, NULL, type, binding, visibility, nonvis);
  76   this->u_.in_output_data.output_data = od;
  77   this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
  78   this->source_ = IN_OUTPUT_DATA;
  79   this->in_reg_ = true;
  80 }
  81
  82 // Initialize the fields in the base class Symbol for a symbol defined
  83 // in an Output_segment.
  84
  85 void
  86 Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type,
  87                   elfcpp::STB binding, elfcpp::STV visibility,
  88                   unsigned char nonvis, Segment_offset_base offset_base)
  89 {
  90   this->init_fields(name, NULL, type, binding, visibility, nonvis);
  91   this->u_.in_output_segment.output_segment = os;
  92   this->u_.in_output_segment.offset_base = offset_base;
  93   this->source_ = IN_OUTPUT_SEGMENT;
  94   this->in_reg_ = true;
  95 }
  96
  97 // Initialize the fields in the base class Symbol for a symbol defined
  98 // as a constant.
  99
 100 void
 101 Symbol::init_base(const char* name, elfcpp::STT type,
 102                   elfcpp::STB binding, elfcpp::STV visibility,
 103                   unsigned char nonvis)
 104 {
 105   this->init_fields(name, NULL, type, binding, visibility, nonvis);
 106   this->source_ = CONSTANT;
 107   this->in_reg_ = true;
 108 }
 109
 110 // Initialize the fields in Sized_symbol for SYM in OBJECT.
 111
 112 template<int size>
 113 template<bool big_endian>
 114 void
 115 Sized_symbol<size>::init(const char* name, const char* version, Object* object,
 116                          const elfcpp::Sym<size, big_endian>& sym)
 117 {
 118   this->init_base(name, version, object, sym);
 119   this->value_ = sym.get_st_value();
 120   this->symsize_ = sym.get_st_size();
 121 }
 122
 123 // Initialize the fields in Sized_symbol for a symbol defined in an
 124 // Output_data.
 125
 126 template<int size>
 127 void
 128 Sized_symbol<size>::init(const char* name, Output_data* od,
 129                          Value_type value, Size_type symsize,
 130                          elfcpp::STT type, elfcpp::STB binding,
 131                          elfcpp::STV visibility, unsigned char nonvis,
 132                          bool offset_is_from_end)
 133 {
 134   this->init_base(name, od, type, binding, visibility, nonvis,
 135                   offset_is_from_end);
 136   this->value_ = value;
 137   this->symsize_ = symsize;
 138 }
 139
 140 // Initialize the fields in Sized_symbol for a symbol defined in an
 141 // Output_segment.
 142
 143 template<int size>
 144 void
 145 Sized_symbol<size>::init(const char* name, Output_segment* os,
 146                          Value_type value, Size_type symsize,
 147                          elfcpp::STT type, elfcpp::STB binding,
 148                          elfcpp::STV visibility, unsigned char nonvis,
 149                          Segment_offset_base offset_base)
 150 {
 151   this->init_base(name, os, type, binding, visibility, nonvis, offset_base);
 152   this->value_ = value;
 153   this->symsize_ = symsize;
 154 }
 155
 156 // Initialize the fields in Sized_symbol for a symbol defined as a
 157 // constant.
 158
 159 template<int size>
 160 void
 161 Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize,
 162                          elfcpp::STT type, elfcpp::STB binding,
 163                          elfcpp::STV visibility, unsigned char nonvis)
 164 {
 165   this->init_base(name, type, binding, visibility, nonvis);
 166   this->value_ = value;
 167   this->symsize_ = symsize;
 168 }
 169
 170 // Class Symbol_table.
 171
 172 Symbol_table::Symbol_table()
 173   : size_(0), saw_undefined_(0), offset_(0), table_(), namepool_(),
 174     forwarders_(), commons_(), warnings_()
 175 {
 176 }
 177
 178 Symbol_table::~Symbol_table()
 179 {
 180 }
 181
 182 // The hash function.  The key is always canonicalized, so we use a
 183 // simple combination of the pointers.
 184
 185 size_t
 186 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
 187 {
 188   return key.first ^ key.second;
 189 }
 190
 191 // The symbol table key equality function.  This is only called with
 192 // canonicalized name and version strings, so we can use pointer
 193 // comparison.
 194
 195 bool
 196 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
 197                                           const Symbol_table_key& k2) const
 198 {
 199   return k1.first == k2.first && k1.second == k2.second;
 200 }
 201
 202 // Make TO a symbol which forwards to FROM.
 203
 204 void
 205 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
 206 {
 207   gold_assert(from != to);
 208   gold_assert(!from->is_forwarder() && !to->is_forwarder());
 209   this->forwarders_[from] = to;
 210   from->set_forwarder();
 211 }
 212
 213 // Resolve the forwards from FROM, returning the real symbol.
 214
 215 Symbol*
 216 Symbol_table::resolve_forwards(const Symbol* from) const
 217 {
 218   gold_assert(from->is_forwarder());
 219   Unordered_map<const Symbol*, Symbol*>::const_iterator p =
 220     this->forwarders_.find(from);
 221   gold_assert(p != this->forwarders_.end());
 222   return p->second;
 223 }
 224
 225 // Look up a symbol by name.
 226
 227 Symbol*
 228 Symbol_table::lookup(const char* name, const char* version) const
 229 {
 230   Stringpool::Key name_key;
 231   name = this->namepool_.find(name, &name_key);
 232   if (name == NULL)
 233     return NULL;
 234
 235   Stringpool::Key version_key = 0;
 236   if (version != NULL)
 237     {
 238       version = this->namepool_.find(version, &version_key);
 239       if (version == NULL)
 240         return NULL;
 241     }
 242
 243   Symbol_table_key key(name_key, version_key);
 244   Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
 245   if (p == this->table_.end())
 246     return NULL;
 247   return p->second;
 248 }
 249
 250 // Resolve a Symbol with another Symbol.  This is only used in the
 251 // unusual case where there are references to both an unversioned
 252 // symbol and a symbol with a version, and we then discover that that
 253 // version is the default version.  Because this is unusual, we do
 254 // this the slow way, by converting back to an ELF symbol.
 255
 256 template<int size, bool big_endian>
 257 void
 258 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
 259                       const char* version ACCEPT_SIZE_ENDIAN)
 260 {
 261   unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
 262   elfcpp::Sym_write<size, big_endian> esym(buf);
 263   // We don't bother to set the st_name field.
 264   esym.put_st_value(from->value());
 265   esym.put_st_size(from->symsize());
 266   esym.put_st_info(from->binding(), from->type());
 267   esym.put_st_other(from->visibility(), from->nonvis());
 268   esym.put_st_shndx(from->shndx());
 269   Symbol_table::resolve(to, esym.sym(), from->object(), version);
 270   if (from->in_reg())
 271     to->set_in_reg();
 272   if (from->in_dyn())
 273     to->set_in_dyn();
 274 }
 275
 276 // Add one symbol from OBJECT to the symbol table.  NAME is symbol
 277 // name and VERSION is the version; both are canonicalized.  DEF is
 278 // whether this is the default version.
 279
 280 // If DEF is true, then this is the definition of a default version of
 281 // a symbol.  That means that any lookup of NAME/NULL and any lookup
 282 // of NAME/VERSION should always return the same symbol.  This is
 283 // obvious for references, but in particular we want to do this for
 284 // definitions: overriding NAME/NULL should also override
 285 // NAME/VERSION.  If we don't do that, it would be very hard to
 286 // override functions in a shared library which uses versioning.
 287
 288 // We implement this by simply making both entries in the hash table
 289 // point to the same Symbol structure.  That is easy enough if this is
 290 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
 291 // that we have seen both already, in which case they will both have
 292 // independent entries in the symbol table.  We can't simply change
 293 // the symbol table entry, because we have pointers to the entries
 294 // attached to the object files.  So we mark the entry attached to the
 295 // object file as a forwarder, and record it in the forwarders_ map.
 296 // Note that entries in the hash table will never be marked as
 297 // forwarders.
 298
 299 template<int size, bool big_endian>
 300 Symbol*
 301 Symbol_table::add_from_object(Object* object,
 302                               const char *name,
 303                               Stringpool::Key name_key,
 304                               const char *version,
 305                               Stringpool::Key version_key,
 306                               bool def,
 307                               const elfcpp::Sym<size, big_endian>& sym)
 308 {
 309   Symbol* const snull = NULL;
 310   std::pair<typename Symbol_table_type::iterator, bool> ins =
 311     this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
 312                                        snull));
 313
 314   std::pair<typename Symbol_table_type::iterator, bool> insdef =
 315     std::make_pair(this->table_.end(), false);
 316   if (def)
 317     {
 318       const Stringpool::Key vnull_key = 0;
 319       insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
 320                                                                  vnull_key),
 321                                                   snull));
 322     }
 323
 324   // ins.first: an iterator, which is a pointer to a pair.
 325   // ins.first->first: the key (a pair of name and version).
 326   // ins.first->second: the value (Symbol*).
 327   // ins.second: true if new entry was inserted, false if not.
 328
 329   Sized_symbol<size>* ret;
 330   bool was_undefined;
 331   bool was_common;
 332   if (!ins.second)
 333     {
 334       // We already have an entry for NAME/VERSION.
 335       ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (ins.first->second
 336                                                            SELECT_SIZE(size));
 337       gold_assert(ret != NULL);
 338
 339       was_undefined = ret->is_undefined();
 340       was_common = ret->is_common();
 341
 342       Symbol_table::resolve(ret, sym, object, version);
 343
 344       if (def)
 345         {
 346           if (insdef.second)
 347             {
 348               // This is the first time we have seen NAME/NULL.  Make
 349               // NAME/NULL point to NAME/VERSION.
 350               insdef.first->second = ret;
 351             }
 352           else if (insdef.first->second != ret)
 353             {
 354               // This is the unfortunate case where we already have
 355               // entries for both NAME/VERSION and NAME/NULL.
 356               const Sized_symbol<size>* sym2;
 357               sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) (
 358                 insdef.first->second
 359                 SELECT_SIZE(size));
 360               Symbol_table::resolve SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
 361                 ret, sym2, version SELECT_SIZE_ENDIAN(size, big_endian));
 362               this->make_forwarder(insdef.first->second, ret);
 363               insdef.first->second = ret;
 364             }
 365         }
 366     }
 367   else
 368     {
 369       // This is the first time we have seen NAME/VERSION.
 370       gold_assert(ins.first->second == NULL);
 371
 372       was_undefined = false;
 373       was_common = false;
 374
 375       if (def && !insdef.second)
 376         {
 377           // We already have an entry for NAME/NULL.  If we override
 378           // it, then change it to NAME/VERSION.
 379           ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (
 380               insdef.first->second
 381               SELECT_SIZE(size));
 382           Symbol_table::resolve(ret, sym, object, version);
 383           ins.first->second = ret;
 384         }
 385       else
 386         {
 387           Sized_target<size, big_endian>* target =
 388             object->sized_target SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
 389                 SELECT_SIZE_ENDIAN_ONLY(size, big_endian));
 390           if (!target->has_make_symbol())
 391             ret = new Sized_symbol<size>();
 392           else
 393             {
 394               ret = target->make_symbol();
 395               if (ret == NULL)
 396                 {
 397                   // This means that we don't want a symbol table
 398                   // entry after all.
 399                   if (!def)
 400                     this->table_.erase(ins.first);
 401                   else
 402                     {
 403                       this->table_.erase(insdef.first);
 404                       // Inserting insdef invalidated ins.
 405                       this->table_.erase(std::make_pair(name_key,
 406                                                         version_key));
 407                     }
 408                   return NULL;
 409                 }
 410             }
 411
 412           ret->init(name, version, object, sym);
 413
 414           ins.first->second = ret;
 415           if (def)
 416             {
 417               // This is the first time we have seen NAME/NULL.  Point
 418               // it at the new entry for NAME/VERSION.
 419               gold_assert(insdef.second);
 420               insdef.first->second = ret;
 421             }
 422         }
 423     }
 424
 425   // Record every time we see a new undefined symbol, to speed up
 426   // archive groups.
 427   if (!was_undefined && ret->is_undefined())
 428     ++this->saw_undefined_;
 429
 430   // Keep track of common symbols, to speed up common symbol
 431   // allocation.
 432   if (!was_common && ret->is_common())
 433     this->commons_.push_back(ret);
 434
 435   return ret;
 436 }
 437
 438 // Add all the symbols in a relocatable object to the hash table.
 439
 440 template<int size, bool big_endian>
 441 void
 442 Symbol_table::add_from_relobj(
 443     Sized_relobj<size, big_endian>* relobj,
 444     const unsigned char* syms,
 445     size_t count,
 446     const char* sym_names,
 447     size_t sym_name_size,
 448     Symbol** sympointers)
 449 {
 450   // We take the size from the first object we see.
 451   if (this->get_size() == 0)
 452     this->set_size(size);
 453
 454   if (size != this->get_size() || size != relobj->target()->get_size())
 455     {
 456       fprintf(stderr, _("%s: %s: mixing 32-bit and 64-bit ELF objects\n"),
 457               program_name, relobj->name().c_str());
 458       gold_exit(false);
 459     }
 460
 461   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
 462
 463   const unsigned char* p = syms;
 464   for (size_t i = 0; i < count; ++i, p += sym_size)
 465     {
 466       elfcpp::Sym<size, big_endian> sym(p);
 467       elfcpp::Sym<size, big_endian>* psym = &sym;
 468
 469       unsigned int st_name = psym->get_st_name();
 470       if (st_name >= sym_name_size)
 471         {
 472           fprintf(stderr,
 473                   _("%s: %s: bad global symbol name offset %u at %lu\n"),
 474                   program_name, relobj->name().c_str(), st_name,
 475                   static_cast<unsigned long>(i));
 476           gold_exit(false);
 477         }
 478
 479       const char* name = sym_names + st_name;
 480
 481       // A symbol defined in a section which we are not including must
 482       // be treated as an undefined symbol.
 483       unsigned char symbuf[sym_size];
 484       elfcpp::Sym<size, big_endian> sym2(symbuf);
 485       unsigned int st_shndx = psym->get_st_shndx();
 486       if (st_shndx != elfcpp::SHN_UNDEF
 487           && st_shndx < elfcpp::SHN_LORESERVE
 488           && !relobj->is_section_included(st_shndx))
 489         {
 490           memcpy(symbuf, p, sym_size);
 491           elfcpp::Sym_write<size, big_endian> sw(symbuf);
 492           sw.put_st_shndx(elfcpp::SHN_UNDEF);
 493           psym = &sym2;
 494         }
 495
 496       // In an object file, an '@' in the name separates the symbol
 497       // name from the version name.  If there are two '@' characters,
 498       // this is the default version.
 499       const char* ver = strchr(name, '@');
 500
 501       Symbol* res;
 502       if (ver == NULL)
 503         {
 504           Stringpool::Key name_key;
 505           name = this->namepool_.add(name, &name_key);
 506           res = this->add_from_object(relobj, name, name_key, NULL, 0,
 507                                       false, *psym);
 508         }
 509       else
 510         {
 511           Stringpool::Key name_key;
 512           name = this->namepool_.add(name, ver - name, &name_key);
 513
 514           bool def = false;
 515           ++ver;
 516           if (*ver == '@')
 517             {
 518               def = true;
 519               ++ver;
 520             }
 521
 522           Stringpool::Key ver_key;
 523           ver = this->namepool_.add(ver, &ver_key);
 524
 525           res = this->add_from_object(relobj, name, name_key, ver, ver_key,
 526                                       def, *psym);
 527         }
 528
 529       *sympointers++ = res;
 530     }
 531 }
 532
 533 // Add all the symbols in a dynamic object to the hash table.
 534
 535 template<int size, bool big_endian>
 536 void
 537 Symbol_table::add_from_dynobj(
 538     Sized_dynobj<size, big_endian>* dynobj,
 539     const unsigned char* syms,
 540     size_t count,
 541     const char* sym_names,
 542     size_t sym_name_size,
 543     const unsigned char* versym,
 544     size_t versym_size,
 545     const std::vector<const char*>* version_map)
 546 {
 547   // We take the size from the first object we see.
 548   if (this->get_size() == 0)
 549     this->set_size(size);
 550
 551   if (size != this->get_size() || size != dynobj->target()->get_size())
 552     {
 553       fprintf(stderr, _("%s: %s: mixing 32-bit and 64-bit ELF objects\n"),
 554               program_name, dynobj->name().c_str());
 555       gold_exit(false);
 556     }
 557
 558   if (versym != NULL && versym_size / 2 < count)
 559     {
 560       fprintf(stderr, _("%s: %s: too few symbol versions\n"),
 561               program_name, dynobj->name().c_str());
 562       gold_exit(false);
 563     }
 564
 565   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
 566
 567   const unsigned char* p = syms;
 568   const unsigned char* vs = versym;
 569   for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
 570     {
 571       elfcpp::Sym<size, big_endian> sym(p);
 572
 573       // Ignore symbols with local binding.
 574       if (sym.get_st_bind() == elfcpp::STB_LOCAL)
 575         continue;
 576
 577       unsigned int st_name = sym.get_st_name();
 578       if (st_name >= sym_name_size)
 579         {
 580           fprintf(stderr, _("%s: %s: bad symbol name offset %u at %lu\n"),
 581                   program_name, dynobj->name().c_str(), st_name,
 582                   static_cast<unsigned long>(i));
 583           gold_exit(false);
 584         }
 585
 586       const char* name = sym_names + st_name;
 587
 588       if (versym == NULL)
 589         {
 590           Stringpool::Key name_key;
 591           name = this->namepool_.add(name, &name_key);
 592           this->add_from_object(dynobj, name, name_key, NULL, 0,
 593                                 false, sym);
 594           continue;
 595         }
 596
 597       // Read the version information.
 598
 599       unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
 600
 601       bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
 602       v &= elfcpp::VERSYM_VERSION;
 603
 604       if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL))
 605         {
 606           // This symbol should not be visible outside the object.
 607           continue;
 608         }
 609
 610       // At this point we are definitely going to add this symbol.
 611       Stringpool::Key name_key;
 612       name = this->namepool_.add(name, &name_key);
 613
 614       if (v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
 615         {
 616           // This symbol does not have a version.
 617           this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym);
 618           continue;
 619         }
 620
 621       if (v >= version_map->size())
 622         {
 623           fprintf(stderr,
 624                   _("%s: %s: versym for symbol %zu out of range: %u\n"),
 625                   program_name, dynobj->name().c_str(), i, v);
 626           gold_exit(false);
 627         }
 628
 629       const char* version = (*version_map)[v];
 630       if (version == NULL)
 631         {
 632           fprintf(stderr, _("%s: %s: versym for symbol %zu has no name: %u\n"),
 633                   program_name, dynobj->name().c_str(), i, v);
 634           gold_exit(false);
 635         }
 636
 637       Stringpool::Key version_key;
 638       version = this->namepool_.add(version, &version_key);
 639
 640       // If this is an absolute symbol, and the version name and
 641       // symbol name are the same, then this is the version definition
 642       // symbol.  These symbols exist to support using -u to pull in
 643       // particular versions.  We do not want to record a version for
 644       // them.
 645       if (sym.get_st_shndx() == elfcpp::SHN_ABS && name_key == version_key)
 646         {
 647           this->add_from_object(dynobj, name, name_key, NULL, 0, false, sym);
 648           continue;
 649         }
 650
 651       const bool def = !hidden && sym.get_st_shndx() != elfcpp::SHN_UNDEF;
 652
 653       this->add_from_object(dynobj, name, name_key, version, version_key,
 654                             def, sym);
 655     }
 656 }
 657
 658 // Create and return a specially defined symbol.  If ONLY_IF_REF is
 659 // true, then only create the symbol if there is a reference to it.
 660
 661 template<int size, bool big_endian>
 662 Sized_symbol<size>*
 663 Symbol_table::define_special_symbol(const Target* target, const char* name,
 664                                     const char* version, bool only_if_ref
 665                                     ACCEPT_SIZE_ENDIAN)
 666 {
 667   gold_assert(this->size_ == size);
 668
 669   Symbol* oldsym;
 670   Sized_symbol<size>* sym;
 671
 672   if (only_if_ref)
 673     {
 674       oldsym = this->lookup(name, version);
 675       if (oldsym == NULL || !oldsym->is_undefined())
 676         return NULL;
 677       sym = NULL;
 678
 679       // Canonicalize NAME and VERSION.
 680       name = oldsym->name();
 681       version = oldsym->version();
 682     }
 683   else
 684     {
 685       // Canonicalize NAME and VERSION.
 686       Stringpool::Key name_key;
 687       name = this->namepool_.add(name, &name_key);
 688
 689       Stringpool::Key version_key = 0;
 690       if (version != NULL)
 691         version = this->namepool_.add(version, &version_key);
 692
 693       Symbol* const snull = NULL;
 694       std::pair<typename Symbol_table_type::iterator, bool> ins =
 695         this->table_.insert(std::make_pair(std::make_pair(name_key,
 696                                                           version_key),
 697                                            snull));
 698
 699       if (!ins.second)
 700         {
 701           // We already have a symbol table entry for NAME/VERSION.
 702           oldsym = ins.first->second;
 703           gold_assert(oldsym != NULL);
 704           sym = NULL;
 705         }
 706       else
 707         {
 708           // We haven't seen this symbol before.
 709           gold_assert(ins.first->second == NULL);
 710
 711           if (!target->has_make_symbol())
 712             sym = new Sized_symbol<size>();
 713           else
 714             {
 715               gold_assert(target->get_size() == size);
 716               gold_assert(target->is_big_endian() ? big_endian : !big_endian);
 717               typedef Sized_target<size, big_endian> My_target;
 718               const My_target* sized_target =
 719                 static_cast<const My_target*>(target);
 720               sym = sized_target->make_symbol();
 721               if (sym == NULL)
 722                 return NULL;
 723             }
 724
 725           ins.first->second = sym;
 726           oldsym = NULL;
 727         }
 728     }
 729
 730   if (oldsym != NULL)
 731     {
 732       gold_assert(sym == NULL);
 733
 734       sym = this->get_sized_symbol SELECT_SIZE_NAME(size) (oldsym
 735                                                            SELECT_SIZE(size));
 736       gold_assert(sym->source() == Symbol::FROM_OBJECT);
 737       const int old_shndx = sym->shndx();
 738       if (old_shndx != elfcpp::SHN_UNDEF
 739           && old_shndx != elfcpp::SHN_COMMON
 740           && !sym->object()->is_dynamic())
 741         {
 742           fprintf(stderr, "%s: linker defined: multiple definition of %s\n",
 743                   program_name, name);
 744           // FIXME: Report old location.  Record that we have seen an
 745           // error.
 746           return NULL;
 747         }
 748
 749       // Our new definition is going to override the old reference.
 750     }
 751
 752   return sym;
 753 }
 754
 755 // Define a symbol based on an Output_data.
 756
 757 Symbol*
 758 Symbol_table::define_in_output_data(const Target* target, const char* name,
 759                                     const char* version, Output_data* od,
 760                                     uint64_t value, uint64_t symsize,
 761                                     elfcpp::STT type, elfcpp::STB binding,
 762                                     elfcpp::STV visibility,
 763                                     unsigned char nonvis,
 764                                     bool offset_is_from_end,
 765                                     bool only_if_ref)
 766 {
 767   gold_assert(target->get_size() == this->size_);
 768   if (this->size_ == 32)
 769     return this->do_define_in_output_data<32>(target, name, version, od, value,
 770                                               symsize, type, binding,
 771                                               visibility, nonvis,
 772                                               offset_is_from_end, only_if_ref);
 773   else if (this->size_ == 64)
 774     return this->do_define_in_output_data<64>(target, name, version, od, value,
 775                                               symsize, type, binding,
 776                                               visibility, nonvis,
 777                                               offset_is_from_end, only_if_ref);
 778   else
 779     gold_unreachable();
 780 }
 781
 782 // Define a symbol in an Output_data, sized version.
 783
 784 template<int size>
 785 Sized_symbol<size>*
 786 Symbol_table::do_define_in_output_data(
 787     const Target* target,
 788     const char* name,
 789     const char* version,
 790     Output_data* od,
 791     typename elfcpp::Elf_types<size>::Elf_Addr value,
 792     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
 793     elfcpp::STT type,
 794     elfcpp::STB binding,
 795     elfcpp::STV visibility,
 796     unsigned char nonvis,
 797     bool offset_is_from_end,
 798     bool only_if_ref)
 799 {
 800   Sized_symbol<size>* sym;
 801
 802   if (target->is_big_endian())
 803     sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
 804         target, name, version, only_if_ref
 805         SELECT_SIZE_ENDIAN(size, true));
 806   else
 807     sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
 808         target, name, version, only_if_ref
 809         SELECT_SIZE_ENDIAN(size, false));
 810
 811   if (sym == NULL)
 812     return NULL;
 813
 814   sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
 815             offset_is_from_end);
 816
 817   return sym;
 818 }
 819
 820 // Define a symbol based on an Output_segment.
 821
 822 Symbol*
 823 Symbol_table::define_in_output_segment(const Target* target, const char* name,
 824                                        const char* version, Output_segment* os,
 825                                        uint64_t value, uint64_t symsize,
 826                                        elfcpp::STT type, elfcpp::STB binding,
 827                                        elfcpp::STV visibility,
 828                                        unsigned char nonvis,
 829                                        Symbol::Segment_offset_base offset_base,
 830                                        bool only_if_ref)
 831 {
 832   gold_assert(target->get_size() == this->size_);
 833   if (this->size_ == 32)
 834     return this->do_define_in_output_segment<32>(target, name, version, os,
 835                                                  value, symsize, type, binding,
 836                                                  visibility, nonvis,
 837                                                  offset_base, only_if_ref);
 838   else if (this->size_ == 64)
 839     return this->do_define_in_output_segment<64>(target, name, version, os,
 840                                                  value, symsize, type, binding,
 841                                                  visibility, nonvis,
 842                                                  offset_base, only_if_ref);
 843   else
 844     gold_unreachable();
 845 }
 846
 847 // Define a symbol in an Output_segment, sized version.
 848
 849 template<int size>
 850 Sized_symbol<size>*
 851 Symbol_table::do_define_in_output_segment(
 852     const Target* target,
 853     const char* name,
 854     const char* version,
 855     Output_segment* os,
 856     typename elfcpp::Elf_types<size>::Elf_Addr value,
 857     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
 858     elfcpp::STT type,
 859     elfcpp::STB binding,
 860     elfcpp::STV visibility,
 861     unsigned char nonvis,
 862     Symbol::Segment_offset_base offset_base,
 863     bool only_if_ref)
 864 {
 865   Sized_symbol<size>* sym;
 866
 867   if (target->is_big_endian())
 868     sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
 869         target, name, version, only_if_ref
 870         SELECT_SIZE_ENDIAN(size, true));
 871   else
 872     sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
 873         target, name, version, only_if_ref
 874         SELECT_SIZE_ENDIAN(size, false));
 875
 876   if (sym == NULL)
 877     return NULL;
 878
 879   sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
 880             offset_base);
 881
 882   return sym;
 883 }
 884
 885 // Define a special symbol with a constant value.  It is a multiple
 886 // definition error if this symbol is already defined.
 887
 888 Symbol*
 889 Symbol_table::define_as_constant(const Target* target, const char* name,
 890                                  const char* version, uint64_t value,
 891                                  uint64_t symsize, elfcpp::STT type,
 892                                  elfcpp::STB binding, elfcpp::STV visibility,
 893                                  unsigned char nonvis, bool only_if_ref)
 894 {
 895   gold_assert(target->get_size() == this->size_);
 896   if (this->size_ == 32)
 897     return this->do_define_as_constant<32>(target, name, version, value,
 898                                            symsize, type, binding, visibility,
 899                                            nonvis, only_if_ref);
 900   else if (this->size_ == 64)
 901     return this->do_define_as_constant<64>(target, name, version, value,
 902                                            symsize, type, binding, visibility,
 903                                            nonvis, only_if_ref);
 904   else
 905     gold_unreachable();
 906 }
 907
 908 // Define a symbol as a constant, sized version.
 909
 910 template<int size>
 911 Sized_symbol<size>*
 912 Symbol_table::do_define_as_constant(
 913     const Target* target,
 914     const char* name,
 915     const char* version,
 916     typename elfcpp::Elf_types<size>::Elf_Addr value,
 917     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
 918     elfcpp::STT type,
 919     elfcpp::STB binding,
 920     elfcpp::STV visibility,
 921     unsigned char nonvis,
 922     bool only_if_ref)
 923 {
 924   Sized_symbol<size>* sym;
 925
 926   if (target->is_big_endian())
 927     sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
 928         target, name, version, only_if_ref
 929         SELECT_SIZE_ENDIAN(size, true));
 930   else
 931     sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
 932         target, name, version, only_if_ref
 933         SELECT_SIZE_ENDIAN(size, false));
 934
 935   if (sym == NULL)
 936     return NULL;
 937
 938   sym->init(name, value, symsize, type, binding, visibility, nonvis);
 939
 940   return sym;
 941 }
 942
 943 // Define a set of symbols in output sections.
 944
 945 void
 946 Symbol_table::define_symbols(const Layout* layout, const Target* target,
 947                              int count, const Define_symbol_in_section* p)
 948 {
 949   for (int i = 0; i < count; ++i, ++p)
 950     {
 951       Output_section* os = layout->find_output_section(p->output_section);
 952       if (os != NULL)
 953         this->define_in_output_data(target, p->name, NULL, os, p->value,
 954                                     p->size, p->type, p->binding,
 955                                     p->visibility, p->nonvis,
 956                                     p->offset_is_from_end, p->only_if_ref);
 957       else
 958         this->define_as_constant(target, p->name, NULL, 0, p->size, p->type,
 959                                  p->binding, p->visibility, p->nonvis,
 960                                  p->only_if_ref);
 961     }
 962 }
 963
 964 // Define a set of symbols in output segments.
 965
 966 void
 967 Symbol_table::define_symbols(const Layout* layout, const Target* target,
 968                              int count, const Define_symbol_in_segment* p)
 969 {
 970   for (int i = 0; i < count; ++i, ++p)
 971     {
 972       Output_segment* os = layout->find_output_segment(p->segment_type,
 973                                                        p->segment_flags_set,
 974                                                        p->segment_flags_clear);
 975       if (os != NULL)
 976         this->define_in_output_segment(target, p->name, NULL, os, p->value,
 977                                        p->size, p->type, p->binding,
 978                                        p->visibility, p->nonvis,
 979                                        p->offset_base, p->only_if_ref);
 980       else
 981         this->define_as_constant(target, p->name, NULL, 0, p->size, p->type,
 982                                  p->binding, p->visibility, p->nonvis,
 983                                  p->only_if_ref);
 984     }
 985 }
 986
 987 // Set the dynamic symbol indexes.  INDEX is the index of the first
 988 // global dynamic symbol.  Pointers to the symbols are stored into the
 989 // vector SYMS.  The names are added to DYNPOOL.  This returns an
 990 // updated dynamic symbol index.
 991
 992 unsigned int
 993 Symbol_table::set_dynsym_indexes(const General_options* options,
 994                                  const Target* target,
 995                                  unsigned int index,
 996                                  std::vector<Symbol*>* syms,
 997                                  Stringpool* dynpool,
 998                                  Versions* versions)
 999 {
1000   for (Symbol_table_type::iterator p = this->table_.begin();
1001        p != this->table_.end();
1002        ++p)
1003     {
1004       Symbol* sym = p->second;
1005
1006       // Note that SYM may already have a dynamic symbol index, since
1007       // some symbols appear more than once in the symbol table, with
1008       // and without a version.
1009
1010       if (!sym->needs_dynsym_entry()
1011           && (!options->export_dynamic()
1012               || !sym->in_reg()
1013               || !sym->is_externally_visible()))
1014         sym->set_dynsym_index(-1U);
1015       else if (!sym->has_dynsym_index())
1016         {
1017           sym->set_dynsym_index(index);
1018           ++index;
1019           syms->push_back(sym);
1020           dynpool->add(sym->name(), NULL);
1021
1022           // Record any version information.
1023           if (sym->version() != NULL)
1024             versions->record_version(options, dynpool, sym);
1025         }
1026     }
1027
1028   // Finish up the versions.  In some cases this may add new dynamic
1029   // symbols.
1030   index = versions->finalize(target, this, index, syms);
1031
1032   return index;
1033 }
1034
1035 // Set the final values for all the symbols.  The index of the first
1036 // global symbol in the output file is INDEX.  Record the file offset
1037 // OFF.  Add their names to POOL.  Return the new file offset.
1038
1039 off_t
1040 Symbol_table::finalize(unsigned int index, off_t off, off_t dynoff,
1041                        size_t dyn_global_index, size_t dyncount,
1042                        Stringpool* pool)
1043 {
1044   off_t ret;
1045
1046   gold_assert(index != 0);
1047   this->first_global_index_ = index;
1048
1049   this->dynamic_offset_ = dynoff;
1050   this->first_dynamic_global_index_ = dyn_global_index;
1051   this->dynamic_count_ = dyncount;
1052
1053   if (this->size_ == 32)
1054     ret = this->sized_finalize<32>(index, off, pool);
1055   else if (this->size_ == 64)
1056     ret = this->sized_finalize<64>(index, off, pool);
1057   else
1058     gold_unreachable();
1059
1060   // Now that we have the final symbol table, we can reliably note
1061   // which symbols should get warnings.
1062   this->warnings_.note_warnings(this);
1063
1064   return ret;
1065 }
1066
1067 // Set the final value for all the symbols.  This is called after
1068 // Layout::finalize, so all the output sections have their final
1069 // address.
1070
1071 template<int size>
1072 off_t
1073 Symbol_table::sized_finalize(unsigned index, off_t off, Stringpool* pool)
1074 {
1075   off = align_address(off, size >> 3);
1076   this->offset_ = off;
1077
1078   size_t orig_index = index;
1079
1080   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1081   for (Symbol_table_type::iterator p = this->table_.begin();
1082        p != this->table_.end();
1083        ++p)
1084     {
1085       Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1086
1087       // FIXME: Here we need to decide which symbols should go into
1088       // the output file, based on --strip.
1089
1090       // The default version of a symbol may appear twice in the
1091       // symbol table.  We only need to finalize it once.
1092       if (sym->has_symtab_index())
1093         continue;
1094
1095       if (!sym->in_reg())
1096         {
1097           gold_assert(!sym->has_symtab_index());
1098           sym->set_symtab_index(-1U);
1099           gold_assert(sym->dynsym_index() == -1U);
1100           continue;
1101         }
1102
1103       typename Sized_symbol<size>::Value_type value;
1104
1105       switch (sym->source())
1106         {
1107         case Symbol::FROM_OBJECT:
1108           {
1109             unsigned int shndx = sym->shndx();
1110
1111             // FIXME: We need some target specific support here.
1112             if (shndx >= elfcpp::SHN_LORESERVE
1113                 && shndx != elfcpp::SHN_ABS)
1114               {
1115                 fprintf(stderr, _("%s: %s: unsupported symbol section 0x%x\n"),
1116                         program_name, sym->name(), shndx);
1117                 gold_exit(false);
1118               }
1119
1120             Object* symobj = sym->object();
1121             if (symobj->is_dynamic())
1122               {
1123                 value = 0;
1124                 shndx = elfcpp::SHN_UNDEF;
1125               }
1126             else if (shndx == elfcpp::SHN_UNDEF)
1127               value = 0;
1128             else if (shndx == elfcpp::SHN_ABS)
1129               value = sym->value();
1130             else
1131               {
1132                 Relobj* relobj = static_cast<Relobj*>(symobj);
1133                 off_t secoff;
1134                 Output_section* os = relobj->output_section(shndx, &secoff);
1135
1136                 if (os == NULL)
1137                   {
1138                     sym->set_symtab_index(-1U);
1139                     gold_assert(sym->dynsym_index() == -1U);
1140                     continue;
1141                   }
1142
1143                 value = sym->value() + os->address() + secoff;
1144               }
1145           }
1146           break;
1147
1148         case Symbol::IN_OUTPUT_DATA:
1149           {
1150             Output_data* od = sym->output_data();
1151             value = sym->value() + od->address();
1152             if (sym->offset_is_from_end())
1153               value += od->data_size();
1154           }
1155           break;
1156
1157         case Symbol::IN_OUTPUT_SEGMENT:
1158           {
1159             Output_segment* os = sym->output_segment();
1160             value = sym->value() + os->vaddr();
1161             switch (sym->offset_base())
1162               {
1163               case Symbol::SEGMENT_START:
1164                 break;
1165               case Symbol::SEGMENT_END:
1166                 value += os->memsz();
1167                 break;
1168               case Symbol::SEGMENT_BSS:
1169                 value += os->filesz();
1170                 break;
1171               default:
1172                 gold_unreachable();
1173               }
1174           }
1175           break;
1176
1177         case Symbol::CONSTANT:
1178           value = sym->value();
1179           break;
1180
1181         default:
1182           gold_unreachable();
1183         }
1184
1185       sym->set_value(value);
1186       sym->set_symtab_index(index);
1187       pool->add(sym->name(), NULL);
1188       ++index;
1189       off += sym_size;
1190     }
1191
1192   this->output_count_ = index - orig_index;
1193
1194   return off;
1195 }
1196
1197 // Write out the global symbols.
1198
1199 void
1200 Symbol_table::write_globals(const Target* target, const Stringpool* sympool,
1201                             const Stringpool* dynpool, Output_file* of) const
1202 {
1203   if (this->size_ == 32)
1204     {
1205       if (target->is_big_endian())
1206         this->sized_write_globals<32, true>(target, sympool, dynpool, of);
1207       else
1208         this->sized_write_globals<32, false>(target, sympool, dynpool, of);
1209     }
1210   else if (this->size_ == 64)
1211     {
1212       if (target->is_big_endian())
1213         this->sized_write_globals<64, true>(target, sympool, dynpool, of);
1214       else
1215         this->sized_write_globals<64, false>(target, sympool, dynpool, of);
1216     }
1217   else
1218     gold_unreachable();
1219 }
1220
1221 // Write out the global symbols.
1222
1223 template<int size, bool big_endian>
1224 void
1225 Symbol_table::sized_write_globals(const Target*,
1226                                   const Stringpool* sympool,
1227                                   const Stringpool* dynpool,
1228                                   Output_file* of) const
1229 {
1230   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1231   unsigned int index = this->first_global_index_;
1232   const off_t oview_size = this->output_count_ * sym_size;
1233   unsigned char* const psyms = of->get_output_view(this->offset_, oview_size);
1234
1235   unsigned int dynamic_count = this->dynamic_count_;
1236   off_t dynamic_size = dynamic_count * sym_size;
1237   unsigned int first_dynamic_global_index = this->first_dynamic_global_index_;
1238   unsigned char* dynamic_view;
1239   if (this->dynamic_offset_ == 0)
1240     dynamic_view = NULL;
1241   else
1242     dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1243
1244   unsigned char* ps = psyms;
1245   for (Symbol_table_type::const_iterator p = this->table_.begin();
1246        p != this->table_.end();
1247        ++p)
1248     {
1249       Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1250
1251       unsigned int sym_index = sym->symtab_index();
1252       unsigned int dynsym_index;
1253       if (dynamic_view == NULL)
1254         dynsym_index = -1U;
1255       else
1256         dynsym_index = sym->dynsym_index();
1257
1258       if (sym_index == -1U && dynsym_index == -1U)
1259         {
1260           // This symbol is not included in the output file.
1261           continue;
1262         }
1263
1264       if (sym_index == index)
1265         ++index;
1266       else if (sym_index != -1U)
1267         {
1268           // We have already seen this symbol, because it has a
1269           // default version.
1270           gold_assert(sym_index < index);
1271           if (dynsym_index == -1U)
1272             continue;
1273           sym_index = -1U;
1274         }
1275
1276       unsigned int shndx;
1277       switch (sym->source())
1278         {
1279         case Symbol::FROM_OBJECT:
1280           {
1281             unsigned int in_shndx = sym->shndx();
1282
1283             // FIXME: We need some target specific support here.
1284             if (in_shndx >= elfcpp::SHN_LORESERVE
1285                 && in_shndx != elfcpp::SHN_ABS)
1286               {
1287                 fprintf(stderr, _("%s: %s: unsupported symbol section 0x%x\n"),
1288                         program_name, sym->name(), in_shndx);
1289                 gold_exit(false);
1290               }
1291
1292             Object* symobj = sym->object();
1293             if (symobj->is_dynamic())
1294               {
1295                 // FIXME.
1296                 shndx = elfcpp::SHN_UNDEF;
1297               }
1298             else if (in_shndx == elfcpp::SHN_UNDEF
1299                      || in_shndx == elfcpp::SHN_ABS)
1300               shndx = in_shndx;
1301             else
1302               {
1303                 Relobj* relobj = static_cast<Relobj*>(symobj);
1304                 off_t secoff;
1305                 Output_section* os = relobj->output_section(in_shndx, &secoff);
1306                 gold_assert(os != NULL);
1307                 shndx = os->out_shndx();
1308               }
1309           }
1310           break;
1311
1312         case Symbol::IN_OUTPUT_DATA:
1313           shndx = sym->output_data()->out_shndx();
1314           break;
1315
1316         case Symbol::IN_OUTPUT_SEGMENT:
1317           shndx = elfcpp::SHN_ABS;
1318           break;
1319
1320         case Symbol::CONSTANT:
1321           shndx = elfcpp::SHN_ABS;
1322           break;
1323
1324         default:
1325           gold_unreachable();
1326         }
1327
1328       if (sym_index != -1U)
1329         {
1330           this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1331               sym, shndx, sympool, ps
1332               SELECT_SIZE_ENDIAN(size, big_endian));
1333           ps += sym_size;
1334         }
1335
1336       if (dynsym_index != -1U)
1337         {
1338           dynsym_index -= first_dynamic_global_index;
1339           gold_assert(dynsym_index < dynamic_count);
1340           unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
1341           this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1342               sym, shndx, dynpool, pd
1343               SELECT_SIZE_ENDIAN(size, big_endian));
1344         }
1345     }
1346
1347   gold_assert(ps - psyms == oview_size);
1348
1349   of->write_output_view(this->offset_, oview_size, psyms);
1350   if (dynamic_view != NULL)
1351     of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
1352 }
1353
1354 // Write out the symbol SYM, in section SHNDX, to P.  POOL is the
1355 // strtab holding the name.
1356
1357 template<int size, bool big_endian>
1358 void
1359 Symbol_table::sized_write_symbol(Sized_symbol<size>* sym,
1360                                  unsigned int shndx,
1361                                  const Stringpool* pool,
1362                                  unsigned char* p
1363                                  ACCEPT_SIZE_ENDIAN) const
1364 {
1365   elfcpp::Sym_write<size, big_endian> osym(p);
1366   osym.put_st_name(pool->get_offset(sym->name()));
1367   osym.put_st_value(sym->value());
1368   osym.put_st_size(sym->symsize());
1369   osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
1370   osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
1371   osym.put_st_shndx(shndx);
1372 }
1373
1374 // Write out a section symbol.  Return the update offset.
1375
1376 void
1377 Symbol_table::write_section_symbol(const Target* target,
1378                                    const Output_section *os,
1379                                    Output_file* of,
1380                                    off_t offset) const
1381 {
1382   if (this->size_ == 32)
1383     {
1384       if (target->is_big_endian())
1385         this->sized_write_section_symbol<32, true>(os, of, offset);
1386       else
1387         this->sized_write_section_symbol<32, false>(os, of, offset);
1388     }
1389   else if (this->size_ == 64)
1390     {
1391       if (target->is_big_endian())
1392         this->sized_write_section_symbol<64, true>(os, of, offset);
1393       else
1394         this->sized_write_section_symbol<64, false>(os, of, offset);
1395     }
1396   else
1397     gold_unreachable();
1398 }
1399
1400 // Write out a section symbol, specialized for size and endianness.
1401
1402 template<int size, bool big_endian>
1403 void
1404 Symbol_table::sized_write_section_symbol(const Output_section* os,
1405                                          Output_file* of,
1406                                          off_t offset) const
1407 {
1408   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1409
1410   unsigned char* pov = of->get_output_view(offset, sym_size);
1411
1412   elfcpp::Sym_write<size, big_endian> osym(pov);
1413   osym.put_st_name(0);
1414   osym.put_st_value(os->address());
1415   osym.put_st_size(0);
1416   osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
1417                                        elfcpp::STT_SECTION));
1418   osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
1419   osym.put_st_shndx(os->out_shndx());
1420
1421   of->write_output_view(offset, sym_size, pov);
1422 }
1423
1424 // Warnings functions.
1425
1426 // Add a new warning.
1427
1428 void
1429 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
1430                       unsigned int shndx)
1431 {
1432   name = symtab->canonicalize_name(name);
1433   this->warnings_[name].set(obj, shndx);
1434 }
1435
1436 // Look through the warnings and mark the symbols for which we should
1437 // warn.  This is called during Layout::finalize when we know the
1438 // sources for all the symbols.
1439
1440 void
1441 Warnings::note_warnings(Symbol_table* symtab)
1442 {
1443   for (Warning_table::iterator p = this->warnings_.begin();
1444        p != this->warnings_.end();
1445        ++p)
1446     {
1447       Symbol* sym = symtab->lookup(p->first, NULL);
1448       if (sym != NULL
1449           && sym->source() == Symbol::FROM_OBJECT
1450           && sym->object() == p->second.object)
1451         {
1452           sym->set_has_warning();
1453
1454           // Read the section contents to get the warning text.  It
1455           // would be nicer if we only did this if we have to actually
1456           // issue a warning.  Unfortunately, warnings are issued as
1457           // we relocate sections.  That means that we can not lock
1458           // the object then, as we might try to issue the same
1459           // warning multiple times simultaneously.
1460           {
1461             Task_locker_obj<Object> tl(*p->second.object);
1462             const unsigned char* c;
1463             off_t len;
1464             c = p->second.object->section_contents(p->second.shndx, &len);
1465             p->second.set_text(reinterpret_cast<const char*>(c), len);
1466           }
1467         }
1468     }
1469 }
1470
1471 // Issue a warning.  This is called when we see a relocation against a
1472 // symbol for which has a warning.
1473
1474 void
1475 Warnings::issue_warning(const Symbol* sym, const std::string& location) const
1476 {
1477   gold_assert(sym->has_warning());
1478   Warning_table::const_iterator p = this->warnings_.find(sym->name());
1479   gold_assert(p != this->warnings_.end());
1480   fprintf(stderr, _("%s: %s: warning: %s\n"), program_name, location.c_str(),
1481           p->second.text.c_str());
1482 }
1483
1484 // Instantiate the templates we need.  We could use the configure
1485 // script to restrict this to only the ones needed for implemented
1486 // targets.
1487
1488 template
1489 void
1490 Symbol_table::add_from_relobj<32, true>(
1491     Sized_relobj<32, true>* relobj,
1492     const unsigned char* syms,
1493     size_t count,
1494     const char* sym_names,
1495     size_t sym_name_size,
1496     Symbol** sympointers);
1497
1498 template
1499 void
1500 Symbol_table::add_from_relobj<32, false>(
1501     Sized_relobj<32, false>* relobj,
1502     const unsigned char* syms,
1503     size_t count,
1504     const char* sym_names,
1505     size_t sym_name_size,
1506     Symbol** sympointers);
1507
1508 template
1509 void
1510 Symbol_table::add_from_relobj<64, true>(
1511     Sized_relobj<64, true>* relobj,
1512     const unsigned char* syms,
1513     size_t count,
1514     const char* sym_names,
1515     size_t sym_name_size,
1516     Symbol** sympointers);
1517
1518 template
1519 void
1520 Symbol_table::add_from_relobj<64, false>(
1521     Sized_relobj<64, false>* relobj,
1522     const unsigned char* syms,
1523     size_t count,
1524     const char* sym_names,
1525     size_t sym_name_size,
1526     Symbol** sympointers);
1527
1528 template
1529 void
1530 Symbol_table::add_from_dynobj<32, true>(
1531     Sized_dynobj<32, true>* dynobj,
1532     const unsigned char* syms,
1533     size_t count,
1534     const char* sym_names,
1535     size_t sym_name_size,
1536     const unsigned char* versym,
1537     size_t versym_size,
1538     const std::vector<const char*>* version_map);
1539
1540 template
1541 void
1542 Symbol_table::add_from_dynobj<32, false>(
1543     Sized_dynobj<32, false>* dynobj,
1544     const unsigned char* syms,
1545     size_t count,
1546     const char* sym_names,
1547     size_t sym_name_size,
1548     const unsigned char* versym,
1549     size_t versym_size,
1550     const std::vector<const char*>* version_map);
1551
1552 template
1553 void
1554 Symbol_table::add_from_dynobj<64, true>(
1555     Sized_dynobj<64, true>* dynobj,
1556     const unsigned char* syms,
1557     size_t count,
1558     const char* sym_names,
1559     size_t sym_name_size,
1560     const unsigned char* versym,
1561     size_t versym_size,
1562     const std::vector<const char*>* version_map);
1563
1564 template
1565 void
1566 Symbol_table::add_from_dynobj<64, false>(
1567     Sized_dynobj<64, false>* dynobj,
1568     const unsigned char* syms,
1569     size_t count,
1570     const char* sym_names,
1571     size_t sym_name_size,
1572     const unsigned char* versym,
1573     size_t versym_size,
1574     const std::vector<const char*>* version_map);
1575
1576 } // End namespace gold.