1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
32 #include "dwarf_reader.h"
36 #include "workqueue.h"
44 // Initialize fields in Symbol. This initializes everything except u_
48 Symbol::init_fields(const char* name, const char* version,
49 elfcpp::STT type, elfcpp::STB binding,
50 elfcpp::STV visibility, unsigned char nonvis)
53 this->version_ = version;
54 this->symtab_index_ = 0;
55 this->dynsym_index_ = 0;
56 this->got_offset_ = 0;
57 this->plt_offset_ = 0;
59 this->binding_ = binding;
60 this->visibility_ = visibility;
61 this->nonvis_ = nonvis;
62 this->is_target_special_ = false;
63 this->is_def_ = false;
64 this->is_forwarder_ = false;
65 this->has_alias_ = false;
66 this->needs_dynsym_entry_ = false;
67 this->in_reg_ = false;
68 this->in_dyn_ = false;
69 this->has_got_offset_ = false;
70 this->has_plt_offset_ = false;
71 this->has_warning_ = false;
72 this->is_copied_from_dynobj_ = false;
73 this->needs_value_in_got_ = false;
76 // Return the demangled version of the symbol's name, but only
77 // if the --demangle flag was set.
80 demangle(const char* name)
82 if (!parameters->demangle())
85 // cplus_demangle allocates memory for the result it returns,
86 // and returns NULL if the name is already demangled.
87 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
88 if (demangled_name == NULL)
91 std::string retval(demangled_name);
97 Symbol::demangled_name() const
99 return demangle(this->name());
102 // Initialize the fields in the base class Symbol for SYM in OBJECT.
104 template<int size, bool big_endian>
106 Symbol::init_base(const char* name, const char* version, Object* object,
107 const elfcpp::Sym<size, big_endian>& sym)
109 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
110 sym.get_st_visibility(), sym.get_st_nonvis());
111 this->u_.from_object.object = object;
112 // FIXME: Handle SHN_XINDEX.
113 this->u_.from_object.shndx = sym.get_st_shndx();
114 this->source_ = FROM_OBJECT;
115 this->in_reg_ = !object->is_dynamic();
116 this->in_dyn_ = object->is_dynamic();
119 // Initialize the fields in the base class Symbol for a symbol defined
120 // in an Output_data.
123 Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type,
124 elfcpp::STB binding, elfcpp::STV visibility,
125 unsigned char nonvis, bool offset_is_from_end)
127 this->init_fields(name, NULL, type, binding, visibility, nonvis);
128 this->u_.in_output_data.output_data = od;
129 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
130 this->source_ = IN_OUTPUT_DATA;
131 this->in_reg_ = true;
134 // Initialize the fields in the base class Symbol for a symbol defined
135 // in an Output_segment.
138 Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type,
139 elfcpp::STB binding, elfcpp::STV visibility,
140 unsigned char nonvis, Segment_offset_base offset_base)
142 this->init_fields(name, NULL, type, binding, visibility, nonvis);
143 this->u_.in_output_segment.output_segment = os;
144 this->u_.in_output_segment.offset_base = offset_base;
145 this->source_ = IN_OUTPUT_SEGMENT;
146 this->in_reg_ = true;
149 // Initialize the fields in the base class Symbol for a symbol defined
153 Symbol::init_base(const char* name, elfcpp::STT type,
154 elfcpp::STB binding, elfcpp::STV visibility,
155 unsigned char nonvis)
157 this->init_fields(name, NULL, type, binding, visibility, nonvis);
158 this->source_ = CONSTANT;
159 this->in_reg_ = true;
162 // Allocate a common symbol in the base.
165 Symbol::allocate_base_common(Output_data* od)
167 gold_assert(this->is_common());
168 this->source_ = IN_OUTPUT_DATA;
169 this->u_.in_output_data.output_data = od;
170 this->u_.in_output_data.offset_is_from_end = false;
173 // Initialize the fields in Sized_symbol for SYM in OBJECT.
176 template<bool big_endian>
178 Sized_symbol<size>::init(const char* name, const char* version, Object* object,
179 const elfcpp::Sym<size, big_endian>& sym)
181 this->init_base(name, version, object, sym);
182 this->value_ = sym.get_st_value();
183 this->symsize_ = sym.get_st_size();
186 // Initialize the fields in Sized_symbol for a symbol defined in an
191 Sized_symbol<size>::init(const char* name, Output_data* od,
192 Value_type value, Size_type symsize,
193 elfcpp::STT type, elfcpp::STB binding,
194 elfcpp::STV visibility, unsigned char nonvis,
195 bool offset_is_from_end)
197 this->init_base(name, od, type, binding, visibility, nonvis,
199 this->value_ = value;
200 this->symsize_ = symsize;
203 // Initialize the fields in Sized_symbol for a symbol defined in an
208 Sized_symbol<size>::init(const char* name, Output_segment* os,
209 Value_type value, Size_type symsize,
210 elfcpp::STT type, elfcpp::STB binding,
211 elfcpp::STV visibility, unsigned char nonvis,
212 Segment_offset_base offset_base)
214 this->init_base(name, os, type, binding, visibility, nonvis, offset_base);
215 this->value_ = value;
216 this->symsize_ = symsize;
219 // Initialize the fields in Sized_symbol for a symbol defined as a
224 Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize,
225 elfcpp::STT type, elfcpp::STB binding,
226 elfcpp::STV visibility, unsigned char nonvis)
228 this->init_base(name, type, binding, visibility, nonvis);
229 this->value_ = value;
230 this->symsize_ = symsize;
233 // Allocate a common symbol.
237 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
239 this->allocate_base_common(od);
240 this->value_ = value;
243 // Return true if this symbol should be added to the dynamic symbol
247 Symbol::should_add_dynsym_entry() const
249 // If the symbol is used by a dynamic relocation, we need to add it.
250 if (this->needs_dynsym_entry())
253 // If exporting all symbols or building a shared library,
254 // and the symbol is defined in a regular object and is
255 // externally visible, we need to add it.
256 if ((parameters->export_dynamic() || parameters->output_is_shared())
257 && !this->is_from_dynobj()
258 && this->is_externally_visible())
264 // Return true if the final value of this symbol is known at link
268 Symbol::final_value_is_known() const
270 // If we are not generating an executable, then no final values are
271 // known, since they will change at runtime.
272 if (!parameters->output_is_executable())
275 // If the symbol is not from an object file, then it is defined, and
277 if (this->source_ != FROM_OBJECT)
280 // If the symbol is from a dynamic object, then the final value is
282 if (this->object()->is_dynamic())
285 // If the symbol is not undefined (it is defined or common), then
286 // the final value is known.
287 if (!this->is_undefined())
290 // If the symbol is undefined, then whether the final value is known
291 // depends on whether we are doing a static link. If we are doing a
292 // dynamic link, then the final value could be filled in at runtime.
293 // This could reasonably be the case for a weak undefined symbol.
294 return parameters->doing_static_link();
297 // Class Symbol_table.
299 Symbol_table::Symbol_table()
300 : saw_undefined_(0), offset_(0), table_(), namepool_(),
301 forwarders_(), commons_(), warnings_()
305 Symbol_table::~Symbol_table()
309 // The hash function. The key is always canonicalized, so we use a
310 // simple combination of the pointers.
313 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
315 return key.first ^ key.second;
318 // The symbol table key equality function. This is only called with
319 // canonicalized name and version strings, so we can use pointer
323 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
324 const Symbol_table_key& k2) const
326 return k1.first == k2.first && k1.second == k2.second;
329 // Make TO a symbol which forwards to FROM.
332 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
334 gold_assert(from != to);
335 gold_assert(!from->is_forwarder() && !to->is_forwarder());
336 this->forwarders_[from] = to;
337 from->set_forwarder();
340 // Resolve the forwards from FROM, returning the real symbol.
343 Symbol_table::resolve_forwards(const Symbol* from) const
345 gold_assert(from->is_forwarder());
346 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
347 this->forwarders_.find(from);
348 gold_assert(p != this->forwarders_.end());
352 // Look up a symbol by name.
355 Symbol_table::lookup(const char* name, const char* version) const
357 Stringpool::Key name_key;
358 name = this->namepool_.find(name, &name_key);
362 Stringpool::Key version_key = 0;
365 version = this->namepool_.find(version, &version_key);
370 Symbol_table_key key(name_key, version_key);
371 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
372 if (p == this->table_.end())
377 // Resolve a Symbol with another Symbol. This is only used in the
378 // unusual case where there are references to both an unversioned
379 // symbol and a symbol with a version, and we then discover that that
380 // version is the default version. Because this is unusual, we do
381 // this the slow way, by converting back to an ELF symbol.
383 template<int size, bool big_endian>
385 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
386 const char* version ACCEPT_SIZE_ENDIAN)
388 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
389 elfcpp::Sym_write<size, big_endian> esym(buf);
390 // We don't bother to set the st_name field.
391 esym.put_st_value(from->value());
392 esym.put_st_size(from->symsize());
393 esym.put_st_info(from->binding(), from->type());
394 esym.put_st_other(from->visibility(), from->nonvis());
395 esym.put_st_shndx(from->shndx());
396 this->resolve(to, esym.sym(), esym.sym(), from->object(), version);
403 // Add one symbol from OBJECT to the symbol table. NAME is symbol
404 // name and VERSION is the version; both are canonicalized. DEF is
405 // whether this is the default version.
407 // If DEF is true, then this is the definition of a default version of
408 // a symbol. That means that any lookup of NAME/NULL and any lookup
409 // of NAME/VERSION should always return the same symbol. This is
410 // obvious for references, but in particular we want to do this for
411 // definitions: overriding NAME/NULL should also override
412 // NAME/VERSION. If we don't do that, it would be very hard to
413 // override functions in a shared library which uses versioning.
415 // We implement this by simply making both entries in the hash table
416 // point to the same Symbol structure. That is easy enough if this is
417 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
418 // that we have seen both already, in which case they will both have
419 // independent entries in the symbol table. We can't simply change
420 // the symbol table entry, because we have pointers to the entries
421 // attached to the object files. So we mark the entry attached to the
422 // object file as a forwarder, and record it in the forwarders_ map.
423 // Note that entries in the hash table will never be marked as
426 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
427 // symbol exactly as it existed in the input file. SYM is usually
428 // that as well, but can be modified, for instance if we determine
429 // it's in a to-be-discarded section.
431 template<int size, bool big_endian>
433 Symbol_table::add_from_object(Object* object,
435 Stringpool::Key name_key,
437 Stringpool::Key version_key,
439 const elfcpp::Sym<size, big_endian>& sym,
440 const elfcpp::Sym<size, big_endian>& orig_sym)
442 Symbol* const snull = NULL;
443 std::pair<typename Symbol_table_type::iterator, bool> ins =
444 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
447 std::pair<typename Symbol_table_type::iterator, bool> insdef =
448 std::make_pair(this->table_.end(), false);
451 const Stringpool::Key vnull_key = 0;
452 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
457 // ins.first: an iterator, which is a pointer to a pair.
458 // ins.first->first: the key (a pair of name and version).
459 // ins.first->second: the value (Symbol*).
460 // ins.second: true if new entry was inserted, false if not.
462 Sized_symbol<size>* ret;
467 // We already have an entry for NAME/VERSION.
468 ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (ins.first->second
470 gold_assert(ret != NULL);
472 was_undefined = ret->is_undefined();
473 was_common = ret->is_common();
475 this->resolve(ret, sym, orig_sym, object, version);
481 // This is the first time we have seen NAME/NULL. Make
482 // NAME/NULL point to NAME/VERSION.
483 insdef.first->second = ret;
485 else if (insdef.first->second != ret)
487 // This is the unfortunate case where we already have
488 // entries for both NAME/VERSION and NAME/NULL.
489 const Sized_symbol<size>* sym2;
490 sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) (
493 Symbol_table::resolve SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
494 ret, sym2, version SELECT_SIZE_ENDIAN(size, big_endian));
495 this->make_forwarder(insdef.first->second, ret);
496 insdef.first->second = ret;
502 // This is the first time we have seen NAME/VERSION.
503 gold_assert(ins.first->second == NULL);
505 was_undefined = false;
508 if (def && !insdef.second)
510 // We already have an entry for NAME/NULL. If we override
511 // it, then change it to NAME/VERSION.
512 ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (
515 this->resolve(ret, sym, orig_sym, object, version);
516 ins.first->second = ret;
520 Sized_target<size, big_endian>* target =
521 object->sized_target SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
522 SELECT_SIZE_ENDIAN_ONLY(size, big_endian));
523 if (!target->has_make_symbol())
524 ret = new Sized_symbol<size>();
527 ret = target->make_symbol();
530 // This means that we don't want a symbol table
533 this->table_.erase(ins.first);
536 this->table_.erase(insdef.first);
537 // Inserting insdef invalidated ins.
538 this->table_.erase(std::make_pair(name_key,
545 ret->init(name, version, object, sym);
547 ins.first->second = ret;
550 // This is the first time we have seen NAME/NULL. Point
551 // it at the new entry for NAME/VERSION.
552 gold_assert(insdef.second);
553 insdef.first->second = ret;
558 // Record every time we see a new undefined symbol, to speed up
560 if (!was_undefined && ret->is_undefined())
561 ++this->saw_undefined_;
563 // Keep track of common symbols, to speed up common symbol
565 if (!was_common && ret->is_common())
566 this->commons_.push_back(ret);
571 // Add all the symbols in a relocatable object to the hash table.
573 template<int size, bool big_endian>
575 Symbol_table::add_from_relobj(
576 Sized_relobj<size, big_endian>* relobj,
577 const unsigned char* syms,
579 const char* sym_names,
580 size_t sym_name_size,
581 typename Sized_relobj<size, big_endian>::Symbols* sympointers)
583 gold_assert(size == relobj->target()->get_size());
584 gold_assert(size == parameters->get_size());
586 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
588 const unsigned char* p = syms;
589 for (size_t i = 0; i < count; ++i, p += sym_size)
591 elfcpp::Sym<size, big_endian> sym(p);
592 elfcpp::Sym<size, big_endian>* psym = &sym;
594 unsigned int st_name = psym->get_st_name();
595 if (st_name >= sym_name_size)
597 relobj->error(_("bad global symbol name offset %u at %zu"),
602 const char* name = sym_names + st_name;
604 // A symbol defined in a section which we are not including must
605 // be treated as an undefined symbol.
606 unsigned char symbuf[sym_size];
607 elfcpp::Sym<size, big_endian> sym2(symbuf);
608 unsigned int st_shndx = psym->get_st_shndx();
609 if (st_shndx != elfcpp::SHN_UNDEF
610 && st_shndx < elfcpp::SHN_LORESERVE
611 && !relobj->is_section_included(st_shndx))
613 memcpy(symbuf, p, sym_size);
614 elfcpp::Sym_write<size, big_endian> sw(symbuf);
615 sw.put_st_shndx(elfcpp::SHN_UNDEF);
619 // In an object file, an '@' in the name separates the symbol
620 // name from the version name. If there are two '@' characters,
621 // this is the default version.
622 const char* ver = strchr(name, '@');
624 Sized_symbol<size>* res;
627 Stringpool::Key name_key;
628 name = this->namepool_.add(name, true, &name_key);
629 res = this->add_from_object(relobj, name, name_key, NULL, 0,
634 Stringpool::Key name_key;
635 name = this->namepool_.add_prefix(name, ver - name, &name_key);
645 Stringpool::Key ver_key;
646 ver = this->namepool_.add(ver, true, &ver_key);
648 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
652 (*sympointers)[i] = res;
656 // Add all the symbols in a dynamic object to the hash table.
658 template<int size, bool big_endian>
660 Symbol_table::add_from_dynobj(
661 Sized_dynobj<size, big_endian>* dynobj,
662 const unsigned char* syms,
664 const char* sym_names,
665 size_t sym_name_size,
666 const unsigned char* versym,
668 const std::vector<const char*>* version_map)
670 gold_assert(size == dynobj->target()->get_size());
671 gold_assert(size == parameters->get_size());
673 if (versym != NULL && versym_size / 2 < count)
675 dynobj->error(_("too few symbol versions"));
679 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
681 // We keep a list of all STT_OBJECT symbols, so that we can resolve
682 // weak aliases. This is necessary because if the dynamic object
683 // provides the same variable under two names, one of which is a
684 // weak definition, and the regular object refers to the weak
685 // definition, we have to put both the weak definition and the
686 // strong definition into the dynamic symbol table. Given a weak
687 // definition, the only way that we can find the corresponding
688 // strong definition, if any, is to search the symbol table.
689 std::vector<Sized_symbol<size>*> object_symbols;
691 const unsigned char* p = syms;
692 const unsigned char* vs = versym;
693 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
695 elfcpp::Sym<size, big_endian> sym(p);
697 // Ignore symbols with local binding.
698 if (sym.get_st_bind() == elfcpp::STB_LOCAL)
701 unsigned int st_name = sym.get_st_name();
702 if (st_name >= sym_name_size)
704 dynobj->error(_("bad symbol name offset %u at %zu"),
709 const char* name = sym_names + st_name;
711 Sized_symbol<size>* res;
715 Stringpool::Key name_key;
716 name = this->namepool_.add(name, true, &name_key);
717 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
722 // Read the version information.
724 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
726 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
727 v &= elfcpp::VERSYM_VERSION;
729 // The Sun documentation says that V can be VER_NDX_LOCAL,
730 // or VER_NDX_GLOBAL, or a version index. The meaning of
731 // VER_NDX_LOCAL is defined as "Symbol has local scope."
732 // The old GNU linker will happily generate VER_NDX_LOCAL
733 // for an undefined symbol. I don't know what the Sun
734 // linker will generate.
736 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
737 && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
739 // This symbol should not be visible outside the object.
743 // At this point we are definitely going to add this symbol.
744 Stringpool::Key name_key;
745 name = this->namepool_.add(name, true, &name_key);
747 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
748 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
750 // This symbol does not have a version.
751 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
756 if (v >= version_map->size())
758 dynobj->error(_("versym for symbol %zu out of range: %u"),
763 const char* version = (*version_map)[v];
766 dynobj->error(_("versym for symbol %zu has no name: %u"),
771 Stringpool::Key version_key;
772 version = this->namepool_.add(version, true, &version_key);
774 // If this is an absolute symbol, and the version name
775 // and symbol name are the same, then this is the
776 // version definition symbol. These symbols exist to
777 // support using -u to pull in particular versions. We
778 // do not want to record a version for them.
779 if (sym.get_st_shndx() == elfcpp::SHN_ABS
780 && name_key == version_key)
781 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
785 const bool def = (!hidden
786 && (sym.get_st_shndx()
787 != elfcpp::SHN_UNDEF));
788 res = this->add_from_object(dynobj, name, name_key, version,
789 version_key, def, sym, sym);
794 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
795 && sym.get_st_type() == elfcpp::STT_OBJECT)
796 object_symbols.push_back(res);
799 this->record_weak_aliases(&object_symbols);
802 // This is used to sort weak aliases. We sort them first by section
803 // index, then by offset, then by weak ahead of strong.
806 class Weak_alias_sorter
809 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
814 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
815 const Sized_symbol<size>* s2) const
817 if (s1->shndx() != s2->shndx())
818 return s1->shndx() < s2->shndx();
819 if (s1->value() != s2->value())
820 return s1->value() < s2->value();
821 if (s1->binding() != s2->binding())
823 if (s1->binding() == elfcpp::STB_WEAK)
825 if (s2->binding() == elfcpp::STB_WEAK)
828 return std::string(s1->name()) < std::string(s2->name());
831 // SYMBOLS is a list of object symbols from a dynamic object. Look
832 // for any weak aliases, and record them so that if we add the weak
833 // alias to the dynamic symbol table, we also add the corresponding
838 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
840 // Sort the vector by section index, then by offset, then by weak
842 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
844 // Walk through the vector. For each weak definition, record
846 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
851 if ((*p)->binding() != elfcpp::STB_WEAK)
854 // Build a circular list of weak aliases. Each symbol points to
855 // the next one in the circular list.
857 Sized_symbol<size>* from_sym = *p;
858 typename std::vector<Sized_symbol<size>*>::const_iterator q;
859 for (q = p + 1; q != symbols->end(); ++q)
861 if ((*q)->shndx() != from_sym->shndx()
862 || (*q)->value() != from_sym->value())
865 this->weak_aliases_[from_sym] = *q;
866 from_sym->set_has_alias();
872 this->weak_aliases_[from_sym] = *p;
873 from_sym->set_has_alias();
880 // Create and return a specially defined symbol. If ONLY_IF_REF is
881 // true, then only create the symbol if there is a reference to it.
882 // If this does not return NULL, it sets *POLDSYM to the existing
883 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
885 template<int size, bool big_endian>
887 Symbol_table::define_special_symbol(const Target* target, const char** pname,
888 const char** pversion, bool only_if_ref,
889 Sized_symbol<size>** poldsym
893 Sized_symbol<size>* sym;
894 bool add_to_table = false;
895 typename Symbol_table_type::iterator add_loc = this->table_.end();
899 oldsym = this->lookup(*pname, *pversion);
900 if (oldsym == NULL || !oldsym->is_undefined())
903 *pname = oldsym->name();
904 *pversion = oldsym->version();
908 // Canonicalize NAME and VERSION.
909 Stringpool::Key name_key;
910 *pname = this->namepool_.add(*pname, true, &name_key);
912 Stringpool::Key version_key = 0;
913 if (*pversion != NULL)
914 *pversion = this->namepool_.add(*pversion, true, &version_key);
916 Symbol* const snull = NULL;
917 std::pair<typename Symbol_table_type::iterator, bool> ins =
918 this->table_.insert(std::make_pair(std::make_pair(name_key,
924 // We already have a symbol table entry for NAME/VERSION.
925 oldsym = ins.first->second;
926 gold_assert(oldsym != NULL);
930 // We haven't seen this symbol before.
931 gold_assert(ins.first->second == NULL);
938 if (!target->has_make_symbol())
939 sym = new Sized_symbol<size>();
942 gold_assert(target->get_size() == size);
943 gold_assert(target->is_big_endian() ? big_endian : !big_endian);
944 typedef Sized_target<size, big_endian> My_target;
945 const My_target* sized_target =
946 static_cast<const My_target*>(target);
947 sym = sized_target->make_symbol();
953 add_loc->second = sym;
955 gold_assert(oldsym != NULL);
957 *poldsym = this->get_sized_symbol SELECT_SIZE_NAME(size) (oldsym
963 // Define a symbol based on an Output_data.
966 Symbol_table::define_in_output_data(const Target* target, const char* name,
967 const char* version, Output_data* od,
968 uint64_t value, uint64_t symsize,
969 elfcpp::STT type, elfcpp::STB binding,
970 elfcpp::STV visibility,
971 unsigned char nonvis,
972 bool offset_is_from_end,
975 if (parameters->get_size() == 32)
977 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
978 return this->do_define_in_output_data<32>(target, name, version, od,
979 value, symsize, type, binding,
987 else if (parameters->get_size() == 64)
989 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
990 return this->do_define_in_output_data<64>(target, name, version, od,
991 value, symsize, type, binding,
1003 // Define a symbol in an Output_data, sized version.
1007 Symbol_table::do_define_in_output_data(
1008 const Target* target,
1010 const char* version,
1012 typename elfcpp::Elf_types<size>::Elf_Addr value,
1013 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1015 elfcpp::STB binding,
1016 elfcpp::STV visibility,
1017 unsigned char nonvis,
1018 bool offset_is_from_end,
1021 Sized_symbol<size>* sym;
1022 Sized_symbol<size>* oldsym;
1024 if (parameters->is_big_endian())
1026 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1027 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1028 target, &name, &version, only_if_ref, &oldsym
1029 SELECT_SIZE_ENDIAN(size, true));
1036 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1037 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1038 target, &name, &version, only_if_ref, &oldsym
1039 SELECT_SIZE_ENDIAN(size, false));
1048 gold_assert(version == NULL || oldsym != NULL);
1049 sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1050 offset_is_from_end);
1053 && Symbol_table::should_override_with_special(oldsym))
1054 this->override_with_special(oldsym, sym);
1059 // Define a symbol based on an Output_segment.
1062 Symbol_table::define_in_output_segment(const Target* target, const char* name,
1063 const char* version, Output_segment* os,
1064 uint64_t value, uint64_t symsize,
1065 elfcpp::STT type, elfcpp::STB binding,
1066 elfcpp::STV visibility,
1067 unsigned char nonvis,
1068 Symbol::Segment_offset_base offset_base,
1071 if (parameters->get_size() == 32)
1073 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1074 return this->do_define_in_output_segment<32>(target, name, version, os,
1075 value, symsize, type,
1076 binding, visibility, nonvis,
1077 offset_base, only_if_ref);
1082 else if (parameters->get_size() == 64)
1084 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1085 return this->do_define_in_output_segment<64>(target, name, version, os,
1086 value, symsize, type,
1087 binding, visibility, nonvis,
1088 offset_base, only_if_ref);
1097 // Define a symbol in an Output_segment, sized version.
1101 Symbol_table::do_define_in_output_segment(
1102 const Target* target,
1104 const char* version,
1106 typename elfcpp::Elf_types<size>::Elf_Addr value,
1107 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1109 elfcpp::STB binding,
1110 elfcpp::STV visibility,
1111 unsigned char nonvis,
1112 Symbol::Segment_offset_base offset_base,
1115 Sized_symbol<size>* sym;
1116 Sized_symbol<size>* oldsym;
1118 if (parameters->is_big_endian())
1120 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1121 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1122 target, &name, &version, only_if_ref, &oldsym
1123 SELECT_SIZE_ENDIAN(size, true));
1130 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1131 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1132 target, &name, &version, only_if_ref, &oldsym
1133 SELECT_SIZE_ENDIAN(size, false));
1142 gold_assert(version == NULL || oldsym != NULL);
1143 sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1147 && Symbol_table::should_override_with_special(oldsym))
1148 this->override_with_special(oldsym, sym);
1153 // Define a special symbol with a constant value. It is a multiple
1154 // definition error if this symbol is already defined.
1157 Symbol_table::define_as_constant(const Target* target, const char* name,
1158 const char* version, uint64_t value,
1159 uint64_t symsize, elfcpp::STT type,
1160 elfcpp::STB binding, elfcpp::STV visibility,
1161 unsigned char nonvis, bool only_if_ref)
1163 if (parameters->get_size() == 32)
1165 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1166 return this->do_define_as_constant<32>(target, name, version, value,
1167 symsize, type, binding,
1168 visibility, nonvis, only_if_ref);
1173 else if (parameters->get_size() == 64)
1175 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1176 return this->do_define_as_constant<64>(target, name, version, value,
1177 symsize, type, binding,
1178 visibility, nonvis, only_if_ref);
1187 // Define a symbol as a constant, sized version.
1191 Symbol_table::do_define_as_constant(
1192 const Target* target,
1194 const char* version,
1195 typename elfcpp::Elf_types<size>::Elf_Addr value,
1196 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1198 elfcpp::STB binding,
1199 elfcpp::STV visibility,
1200 unsigned char nonvis,
1203 Sized_symbol<size>* sym;
1204 Sized_symbol<size>* oldsym;
1206 if (parameters->is_big_endian())
1208 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1209 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1210 target, &name, &version, only_if_ref, &oldsym
1211 SELECT_SIZE_ENDIAN(size, true));
1218 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1219 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1220 target, &name, &version, only_if_ref, &oldsym
1221 SELECT_SIZE_ENDIAN(size, false));
1230 gold_assert(version == NULL || oldsym != NULL);
1231 sym->init(name, value, symsize, type, binding, visibility, nonvis);
1234 && Symbol_table::should_override_with_special(oldsym))
1235 this->override_with_special(oldsym, sym);
1240 // Define a set of symbols in output sections.
1243 Symbol_table::define_symbols(const Layout* layout, const Target* target,
1244 int count, const Define_symbol_in_section* p)
1246 for (int i = 0; i < count; ++i, ++p)
1248 Output_section* os = layout->find_output_section(p->output_section);
1250 this->define_in_output_data(target, p->name, NULL, os, p->value,
1251 p->size, p->type, p->binding,
1252 p->visibility, p->nonvis,
1253 p->offset_is_from_end, p->only_if_ref);
1255 this->define_as_constant(target, p->name, NULL, 0, p->size, p->type,
1256 p->binding, p->visibility, p->nonvis,
1261 // Define a set of symbols in output segments.
1264 Symbol_table::define_symbols(const Layout* layout, const Target* target,
1265 int count, const Define_symbol_in_segment* p)
1267 for (int i = 0; i < count; ++i, ++p)
1269 Output_segment* os = layout->find_output_segment(p->segment_type,
1270 p->segment_flags_set,
1271 p->segment_flags_clear);
1273 this->define_in_output_segment(target, p->name, NULL, os, p->value,
1274 p->size, p->type, p->binding,
1275 p->visibility, p->nonvis,
1276 p->offset_base, p->only_if_ref);
1278 this->define_as_constant(target, p->name, NULL, 0, p->size, p->type,
1279 p->binding, p->visibility, p->nonvis,
1284 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1285 // symbol should be defined--typically a .dyn.bss section. VALUE is
1286 // the offset within POSD.
1290 Symbol_table::define_with_copy_reloc(const Target* target,
1291 Sized_symbol<size>* csym,
1292 Output_data* posd, uint64_t value)
1294 gold_assert(csym->is_from_dynobj());
1295 gold_assert(!csym->is_copied_from_dynobj());
1296 Object* object = csym->object();
1297 gold_assert(object->is_dynamic());
1298 Dynobj* dynobj = static_cast<Dynobj*>(object);
1300 // Our copied variable has to override any variable in a shared
1302 elfcpp::STB binding = csym->binding();
1303 if (binding == elfcpp::STB_WEAK)
1304 binding = elfcpp::STB_GLOBAL;
1306 this->define_in_output_data(target, csym->name(), csym->version(),
1307 posd, value, csym->symsize(),
1308 csym->type(), binding,
1309 csym->visibility(), csym->nonvis(),
1312 csym->set_is_copied_from_dynobj();
1313 csym->set_needs_dynsym_entry();
1315 this->copied_symbol_dynobjs_[csym] = dynobj;
1317 // We have now defined all aliases, but we have not entered them all
1318 // in the copied_symbol_dynobjs_ map.
1319 if (csym->has_alias())
1324 sym = this->weak_aliases_[sym];
1327 gold_assert(sym->output_data() == posd);
1329 sym->set_is_copied_from_dynobj();
1330 this->copied_symbol_dynobjs_[sym] = dynobj;
1335 // SYM is defined using a COPY reloc. Return the dynamic object where
1336 // the original definition was found.
1339 Symbol_table::get_copy_source(const Symbol* sym) const
1341 gold_assert(sym->is_copied_from_dynobj());
1342 Copied_symbol_dynobjs::const_iterator p =
1343 this->copied_symbol_dynobjs_.find(sym);
1344 gold_assert(p != this->copied_symbol_dynobjs_.end());
1348 // Set the dynamic symbol indexes. INDEX is the index of the first
1349 // global dynamic symbol. Pointers to the symbols are stored into the
1350 // vector SYMS. The names are added to DYNPOOL. This returns an
1351 // updated dynamic symbol index.
1354 Symbol_table::set_dynsym_indexes(const Target* target,
1356 std::vector<Symbol*>* syms,
1357 Stringpool* dynpool,
1360 for (Symbol_table_type::iterator p = this->table_.begin();
1361 p != this->table_.end();
1364 Symbol* sym = p->second;
1366 // Note that SYM may already have a dynamic symbol index, since
1367 // some symbols appear more than once in the symbol table, with
1368 // and without a version.
1370 if (!sym->should_add_dynsym_entry())
1371 sym->set_dynsym_index(-1U);
1372 else if (!sym->has_dynsym_index())
1374 sym->set_dynsym_index(index);
1376 syms->push_back(sym);
1377 dynpool->add(sym->name(), false, NULL);
1379 // Record any version information.
1380 if (sym->version() != NULL)
1381 versions->record_version(this, dynpool, sym);
1385 // Finish up the versions. In some cases this may add new dynamic
1387 index = versions->finalize(target, this, index, syms);
1392 // Set the final values for all the symbols. The index of the first
1393 // global symbol in the output file is INDEX. Record the file offset
1394 // OFF. Add their names to POOL. Return the new file offset.
1397 Symbol_table::finalize(unsigned int index, off_t off, off_t dynoff,
1398 size_t dyn_global_index, size_t dyncount,
1403 gold_assert(index != 0);
1404 this->first_global_index_ = index;
1406 this->dynamic_offset_ = dynoff;
1407 this->first_dynamic_global_index_ = dyn_global_index;
1408 this->dynamic_count_ = dyncount;
1410 if (parameters->get_size() == 32)
1412 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1413 ret = this->sized_finalize<32>(index, off, pool);
1418 else if (parameters->get_size() == 64)
1420 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1421 ret = this->sized_finalize<64>(index, off, pool);
1429 // Now that we have the final symbol table, we can reliably note
1430 // which symbols should get warnings.
1431 this->warnings_.note_warnings(this);
1436 // Set the final value for all the symbols. This is called after
1437 // Layout::finalize, so all the output sections have their final
1442 Symbol_table::sized_finalize(unsigned index, off_t off, Stringpool* pool)
1444 off = align_address(off, size >> 3);
1445 this->offset_ = off;
1447 size_t orig_index = index;
1449 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1450 for (Symbol_table_type::iterator p = this->table_.begin();
1451 p != this->table_.end();
1454 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1456 // FIXME: Here we need to decide which symbols should go into
1457 // the output file, based on --strip.
1459 // The default version of a symbol may appear twice in the
1460 // symbol table. We only need to finalize it once.
1461 if (sym->has_symtab_index())
1466 gold_assert(!sym->has_symtab_index());
1467 sym->set_symtab_index(-1U);
1468 gold_assert(sym->dynsym_index() == -1U);
1472 typename Sized_symbol<size>::Value_type value;
1474 switch (sym->source())
1476 case Symbol::FROM_OBJECT:
1478 unsigned int shndx = sym->shndx();
1480 // FIXME: We need some target specific support here.
1481 if (shndx >= elfcpp::SHN_LORESERVE
1482 && shndx != elfcpp::SHN_ABS)
1484 gold_error(_("%s: unsupported symbol section 0x%x"),
1485 sym->demangled_name().c_str(), shndx);
1486 shndx = elfcpp::SHN_UNDEF;
1489 Object* symobj = sym->object();
1490 if (symobj->is_dynamic())
1493 shndx = elfcpp::SHN_UNDEF;
1495 else if (shndx == elfcpp::SHN_UNDEF)
1497 else if (shndx == elfcpp::SHN_ABS)
1498 value = sym->value();
1501 Relobj* relobj = static_cast<Relobj*>(symobj);
1503 Output_section* os = relobj->output_section(shndx, &secoff);
1507 sym->set_symtab_index(-1U);
1508 gold_assert(sym->dynsym_index() == -1U);
1512 value = sym->value() + os->address() + secoff;
1517 case Symbol::IN_OUTPUT_DATA:
1519 Output_data* od = sym->output_data();
1520 value = sym->value() + od->address();
1521 if (sym->offset_is_from_end())
1522 value += od->data_size();
1526 case Symbol::IN_OUTPUT_SEGMENT:
1528 Output_segment* os = sym->output_segment();
1529 value = sym->value() + os->vaddr();
1530 switch (sym->offset_base())
1532 case Symbol::SEGMENT_START:
1534 case Symbol::SEGMENT_END:
1535 value += os->memsz();
1537 case Symbol::SEGMENT_BSS:
1538 value += os->filesz();
1546 case Symbol::CONSTANT:
1547 value = sym->value();
1554 sym->set_value(value);
1556 if (parameters->strip_all())
1557 sym->set_symtab_index(-1U);
1560 sym->set_symtab_index(index);
1561 pool->add(sym->name(), false, NULL);
1567 this->output_count_ = index - orig_index;
1572 // Write out the global symbols.
1575 Symbol_table::write_globals(const Input_objects* input_objects,
1576 const Stringpool* sympool,
1577 const Stringpool* dynpool, Output_file* of) const
1579 if (parameters->get_size() == 32)
1581 if (parameters->is_big_endian())
1583 #ifdef HAVE_TARGET_32_BIG
1584 this->sized_write_globals<32, true>(input_objects, sympool,
1592 #ifdef HAVE_TARGET_32_LITTLE
1593 this->sized_write_globals<32, false>(input_objects, sympool,
1600 else if (parameters->get_size() == 64)
1602 if (parameters->is_big_endian())
1604 #ifdef HAVE_TARGET_64_BIG
1605 this->sized_write_globals<64, true>(input_objects, sympool,
1613 #ifdef HAVE_TARGET_64_LITTLE
1614 this->sized_write_globals<64, false>(input_objects, sympool,
1625 // Write out the global symbols.
1627 template<int size, bool big_endian>
1629 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1630 const Stringpool* sympool,
1631 const Stringpool* dynpool,
1632 Output_file* of) const
1634 const Target* const target = input_objects->target();
1636 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1637 unsigned int index = this->first_global_index_;
1638 const off_t oview_size = this->output_count_ * sym_size;
1639 unsigned char* const psyms = of->get_output_view(this->offset_, oview_size);
1641 unsigned int dynamic_count = this->dynamic_count_;
1642 off_t dynamic_size = dynamic_count * sym_size;
1643 unsigned int first_dynamic_global_index = this->first_dynamic_global_index_;
1644 unsigned char* dynamic_view;
1645 if (this->dynamic_offset_ == 0)
1646 dynamic_view = NULL;
1648 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1650 unsigned char* ps = psyms;
1651 for (Symbol_table_type::const_iterator p = this->table_.begin();
1652 p != this->table_.end();
1655 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1657 // Possibly warn about unresolved symbols in shared libraries.
1658 this->warn_about_undefined_dynobj_symbol(input_objects, sym);
1660 unsigned int sym_index = sym->symtab_index();
1661 unsigned int dynsym_index;
1662 if (dynamic_view == NULL)
1665 dynsym_index = sym->dynsym_index();
1667 if (sym_index == -1U && dynsym_index == -1U)
1669 // This symbol is not included in the output file.
1673 if (sym_index == index)
1675 else if (sym_index != -1U)
1677 // We have already seen this symbol, because it has a
1679 gold_assert(sym_index < index);
1680 if (dynsym_index == -1U)
1686 typename elfcpp::Elf_types<32>::Elf_Addr value = sym->value();
1687 switch (sym->source())
1689 case Symbol::FROM_OBJECT:
1691 unsigned int in_shndx = sym->shndx();
1693 // FIXME: We need some target specific support here.
1694 if (in_shndx >= elfcpp::SHN_LORESERVE
1695 && in_shndx != elfcpp::SHN_ABS)
1697 gold_error(_("%s: unsupported symbol section 0x%x"),
1698 sym->demangled_name().c_str(), in_shndx);
1703 Object* symobj = sym->object();
1704 if (symobj->is_dynamic())
1706 if (sym->needs_dynsym_value())
1707 value = target->dynsym_value(sym);
1708 shndx = elfcpp::SHN_UNDEF;
1710 else if (in_shndx == elfcpp::SHN_UNDEF
1711 || in_shndx == elfcpp::SHN_ABS)
1715 Relobj* relobj = static_cast<Relobj*>(symobj);
1717 Output_section* os = relobj->output_section(in_shndx,
1719 gold_assert(os != NULL);
1720 shndx = os->out_shndx();
1726 case Symbol::IN_OUTPUT_DATA:
1727 shndx = sym->output_data()->out_shndx();
1730 case Symbol::IN_OUTPUT_SEGMENT:
1731 shndx = elfcpp::SHN_ABS;
1734 case Symbol::CONSTANT:
1735 shndx = elfcpp::SHN_ABS;
1742 if (sym_index != -1U)
1744 this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1745 sym, sym->value(), shndx, sympool, ps
1746 SELECT_SIZE_ENDIAN(size, big_endian));
1750 if (dynsym_index != -1U)
1752 dynsym_index -= first_dynamic_global_index;
1753 gold_assert(dynsym_index < dynamic_count);
1754 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
1755 this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1756 sym, value, shndx, dynpool, pd
1757 SELECT_SIZE_ENDIAN(size, big_endian));
1761 gold_assert(ps - psyms == oview_size);
1763 of->write_output_view(this->offset_, oview_size, psyms);
1764 if (dynamic_view != NULL)
1765 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
1768 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1769 // strtab holding the name.
1771 template<int size, bool big_endian>
1773 Symbol_table::sized_write_symbol(
1774 Sized_symbol<size>* sym,
1775 typename elfcpp::Elf_types<size>::Elf_Addr value,
1777 const Stringpool* pool,
1779 ACCEPT_SIZE_ENDIAN) const
1781 elfcpp::Sym_write<size, big_endian> osym(p);
1782 osym.put_st_name(pool->get_offset(sym->name()));
1783 osym.put_st_value(value);
1784 osym.put_st_size(sym->symsize());
1785 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
1786 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
1787 osym.put_st_shndx(shndx);
1790 // Check for unresolved symbols in shared libraries. This is
1791 // controlled by the --allow-shlib-undefined option.
1793 // We only warn about libraries for which we have seen all the
1794 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
1795 // which were not seen in this link. If we didn't see a DT_NEEDED
1796 // entry, we aren't going to be able to reliably report whether the
1797 // symbol is undefined.
1799 // We also don't warn about libraries found in the system library
1800 // directory (the directory were we find libc.so); we assume that
1801 // those libraries are OK. This heuristic avoids problems in
1802 // GNU/Linux, in which -ldl can have undefined references satisfied by
1806 Symbol_table::warn_about_undefined_dynobj_symbol(
1807 const Input_objects* input_objects,
1810 if (sym->source() == Symbol::FROM_OBJECT
1811 && sym->object()->is_dynamic()
1812 && sym->shndx() == elfcpp::SHN_UNDEF
1813 && sym->binding() != elfcpp::STB_WEAK
1814 && !parameters->allow_shlib_undefined()
1815 && !input_objects->target()->is_defined_by_abi(sym)
1816 && !input_objects->found_in_system_library_directory(sym->object()))
1818 // A very ugly cast.
1819 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
1820 if (!dynobj->has_unknown_needed_entries())
1821 gold_error(_("%s: undefined reference to '%s'"),
1822 sym->object()->name().c_str(),
1823 sym->demangled_name().c_str());
1827 // Write out a section symbol. Return the update offset.
1830 Symbol_table::write_section_symbol(const Output_section *os,
1834 if (parameters->get_size() == 32)
1836 if (parameters->is_big_endian())
1838 #ifdef HAVE_TARGET_32_BIG
1839 this->sized_write_section_symbol<32, true>(os, of, offset);
1846 #ifdef HAVE_TARGET_32_LITTLE
1847 this->sized_write_section_symbol<32, false>(os, of, offset);
1853 else if (parameters->get_size() == 64)
1855 if (parameters->is_big_endian())
1857 #ifdef HAVE_TARGET_64_BIG
1858 this->sized_write_section_symbol<64, true>(os, of, offset);
1865 #ifdef HAVE_TARGET_64_LITTLE
1866 this->sized_write_section_symbol<64, false>(os, of, offset);
1876 // Write out a section symbol, specialized for size and endianness.
1878 template<int size, bool big_endian>
1880 Symbol_table::sized_write_section_symbol(const Output_section* os,
1884 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1886 unsigned char* pov = of->get_output_view(offset, sym_size);
1888 elfcpp::Sym_write<size, big_endian> osym(pov);
1889 osym.put_st_name(0);
1890 osym.put_st_value(os->address());
1891 osym.put_st_size(0);
1892 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
1893 elfcpp::STT_SECTION));
1894 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
1895 osym.put_st_shndx(os->out_shndx());
1897 of->write_output_view(offset, sym_size, pov);
1900 // Print statistical information to stderr. This is used for --stats.
1903 Symbol_table::print_stats() const
1905 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
1906 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
1907 program_name, this->table_.size(), this->table_.bucket_count());
1909 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
1910 program_name, this->table_.size());
1914 // We check for ODR violations by looking for symbols with the same
1915 // name for which the debugging information reports that they were
1916 // defined in different source locations. When comparing the source
1917 // location, we consider instances with the same base filename and
1918 // line number to be the same. This is because different object
1919 // files/shared libraries can include the same header file using
1920 // different paths, and we don't want to report an ODR violation in
1923 // This struct is used to compare line information, as returned by
1924 // Dwarf_line_info::one_addr2line. It imlements a < comparison
1925 // operator used with std::set.
1927 struct Odr_violation_compare
1930 operator()(const std::string& s1, const std::string& s2) const
1932 std::string::size_type pos1 = s1.rfind('/');
1933 std::string::size_type pos2 = s2.rfind('/');
1934 if (pos1 == std::string::npos
1935 || pos2 == std::string::npos)
1937 return s1.compare(pos1, std::string::npos,
1938 s2, pos2, std::string::npos) < 0;
1942 // Check candidate_odr_violations_ to find symbols with the same name
1943 // but apparently different definitions (different source-file/line-no).
1946 Symbol_table::detect_odr_violations(const char* output_file_name) const
1948 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
1949 it != candidate_odr_violations_.end();
1952 const char* symbol_name = it->first;
1953 // We use a sorted set so the output is deterministic.
1954 std::set<std::string, Odr_violation_compare> line_nums;
1956 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
1957 locs = it->second.begin();
1958 locs != it->second.end();
1961 // We need to lock the object in order to read it. This
1962 // means that we can not run inside a Task. If we want to
1963 // run this in a Task for better performance, we will need
1964 // one Task for object, plus appropriate locking to ensure
1965 // that we don't conflict with other uses of the object.
1966 locs->object->lock();
1967 std::string lineno = Dwarf_line_info::one_addr2line(
1968 locs->object, locs->shndx, locs->offset);
1969 locs->object->unlock();
1970 if (!lineno.empty())
1971 line_nums.insert(lineno);
1974 if (line_nums.size() > 1)
1976 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
1977 "places (possible ODR violation):"),
1978 output_file_name, demangle(symbol_name).c_str());
1979 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
1980 it2 != line_nums.end();
1982 fprintf(stderr, " %s\n", it2->c_str());
1987 // Warnings functions.
1989 // Add a new warning.
1992 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
1995 name = symtab->canonicalize_name(name);
1996 this->warnings_[name].set(obj, shndx);
1999 // Look through the warnings and mark the symbols for which we should
2000 // warn. This is called during Layout::finalize when we know the
2001 // sources for all the symbols.
2004 Warnings::note_warnings(Symbol_table* symtab)
2006 for (Warning_table::iterator p = this->warnings_.begin();
2007 p != this->warnings_.end();
2010 Symbol* sym = symtab->lookup(p->first, NULL);
2012 && sym->source() == Symbol::FROM_OBJECT
2013 && sym->object() == p->second.object)
2015 sym->set_has_warning();
2017 // Read the section contents to get the warning text. It
2018 // would be nicer if we only did this if we have to actually
2019 // issue a warning. Unfortunately, warnings are issued as
2020 // we relocate sections. That means that we can not lock
2021 // the object then, as we might try to issue the same
2022 // warning multiple times simultaneously.
2024 Task_locker_obj<Object> tl(*p->second.object);
2025 const unsigned char* c;
2027 c = p->second.object->section_contents(p->second.shndx, &len,
2029 p->second.set_text(reinterpret_cast<const char*>(c), len);
2035 // Issue a warning. This is called when we see a relocation against a
2036 // symbol for which has a warning.
2038 template<int size, bool big_endian>
2040 Warnings::issue_warning(const Symbol* sym,
2041 const Relocate_info<size, big_endian>* relinfo,
2042 size_t relnum, off_t reloffset) const
2044 gold_assert(sym->has_warning());
2045 Warning_table::const_iterator p = this->warnings_.find(sym->name());
2046 gold_assert(p != this->warnings_.end());
2047 gold_warning_at_location(relinfo, relnum, reloffset,
2048 "%s", p->second.text.c_str());
2051 // Instantiate the templates we need. We could use the configure
2052 // script to restrict this to only the ones needed for implemented
2055 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2058 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2061 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2064 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2067 #ifdef HAVE_TARGET_32_LITTLE
2070 Symbol_table::add_from_relobj<32, false>(
2071 Sized_relobj<32, false>* relobj,
2072 const unsigned char* syms,
2074 const char* sym_names,
2075 size_t sym_name_size,
2076 Sized_relobj<32, true>::Symbols* sympointers);
2079 #ifdef HAVE_TARGET_32_BIG
2082 Symbol_table::add_from_relobj<32, true>(
2083 Sized_relobj<32, true>* relobj,
2084 const unsigned char* syms,
2086 const char* sym_names,
2087 size_t sym_name_size,
2088 Sized_relobj<32, false>::Symbols* sympointers);
2091 #ifdef HAVE_TARGET_64_LITTLE
2094 Symbol_table::add_from_relobj<64, false>(
2095 Sized_relobj<64, false>* relobj,
2096 const unsigned char* syms,
2098 const char* sym_names,
2099 size_t sym_name_size,
2100 Sized_relobj<64, true>::Symbols* sympointers);
2103 #ifdef HAVE_TARGET_64_BIG
2106 Symbol_table::add_from_relobj<64, true>(
2107 Sized_relobj<64, true>* relobj,
2108 const unsigned char* syms,
2110 const char* sym_names,
2111 size_t sym_name_size,
2112 Sized_relobj<64, false>::Symbols* sympointers);
2115 #ifdef HAVE_TARGET_32_LITTLE
2118 Symbol_table::add_from_dynobj<32, false>(
2119 Sized_dynobj<32, false>* dynobj,
2120 const unsigned char* syms,
2122 const char* sym_names,
2123 size_t sym_name_size,
2124 const unsigned char* versym,
2126 const std::vector<const char*>* version_map);
2129 #ifdef HAVE_TARGET_32_BIG
2132 Symbol_table::add_from_dynobj<32, true>(
2133 Sized_dynobj<32, true>* dynobj,
2134 const unsigned char* syms,
2136 const char* sym_names,
2137 size_t sym_name_size,
2138 const unsigned char* versym,
2140 const std::vector<const char*>* version_map);
2143 #ifdef HAVE_TARGET_64_LITTLE
2146 Symbol_table::add_from_dynobj<64, false>(
2147 Sized_dynobj<64, false>* dynobj,
2148 const unsigned char* syms,
2150 const char* sym_names,
2151 size_t sym_name_size,
2152 const unsigned char* versym,
2154 const std::vector<const char*>* version_map);
2157 #ifdef HAVE_TARGET_64_BIG
2160 Symbol_table::add_from_dynobj<64, true>(
2161 Sized_dynobj<64, true>* dynobj,
2162 const unsigned char* syms,
2164 const char* sym_names,
2165 size_t sym_name_size,
2166 const unsigned char* versym,
2168 const std::vector<const char*>* version_map);
2171 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2174 Symbol_table::define_with_copy_reloc<32>(const Target* target,
2175 Sized_symbol<32>* sym,
2176 Output_data* posd, uint64_t value);
2179 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2182 Symbol_table::define_with_copy_reloc<64>(const Target* target,
2183 Sized_symbol<64>* sym,
2184 Output_data* posd, uint64_t value);
2187 #ifdef HAVE_TARGET_32_LITTLE
2190 Warnings::issue_warning<32, false>(const Symbol* sym,
2191 const Relocate_info<32, false>* relinfo,
2192 size_t relnum, off_t reloffset) const;
2195 #ifdef HAVE_TARGET_32_BIG
2198 Warnings::issue_warning<32, true>(const Symbol* sym,
2199 const Relocate_info<32, true>* relinfo,
2200 size_t relnum, off_t reloffset) const;
2203 #ifdef HAVE_TARGET_64_LITTLE
2206 Warnings::issue_warning<64, false>(const Symbol* sym,
2207 const Relocate_info<64, false>* relinfo,
2208 size_t relnum, off_t reloffset) const;
2211 #ifdef HAVE_TARGET_64_BIG
2214 Warnings::issue_warning<64, true>(const Symbol* sym,
2215 const Relocate_info<64, true>* relinfo,
2216 size_t relnum, off_t reloffset) const;
2219 } // End namespace gold.