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