1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007, 2008 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->is_forced_local_ = 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 the symbol was forced local in a version script, do not add it.
254 if (this->is_forced_local())
257 // If exporting all symbols or building a shared library,
258 // and the symbol is defined in a regular object and is
259 // externally visible, we need to add it.
260 if ((parameters->export_dynamic() || parameters->output_is_shared())
261 && !this->is_from_dynobj()
262 && this->is_externally_visible())
268 // Return true if the final value of this symbol is known at link
272 Symbol::final_value_is_known() const
274 // If we are not generating an executable, then no final values are
275 // known, since they will change at runtime.
276 if (!parameters->output_is_executable())
279 // If the symbol is not from an object file, then it is defined, and
281 if (this->source_ != FROM_OBJECT)
284 // If the symbol is from a dynamic object, then the final value is
286 if (this->object()->is_dynamic())
289 // If the symbol is not undefined (it is defined or common), then
290 // the final value is known.
291 if (!this->is_undefined())
294 // If the symbol is undefined, then whether the final value is known
295 // depends on whether we are doing a static link. If we are doing a
296 // dynamic link, then the final value could be filled in at runtime.
297 // This could reasonably be the case for a weak undefined symbol.
298 return parameters->doing_static_link();
301 // Class Symbol_table.
303 Symbol_table::Symbol_table(unsigned int count,
304 const Version_script_info& version_script)
305 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
306 forwarders_(), commons_(), forced_locals_(), warnings_(),
307 version_script_(version_script)
309 namepool_.reserve(count);
312 Symbol_table::~Symbol_table()
316 // The hash function. The key values are Stringpool keys.
319 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
321 return key.first ^ key.second;
324 // The symbol table key equality function. This is called with
328 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
329 const Symbol_table_key& k2) const
331 return k1.first == k2.first && k1.second == k2.second;
334 // Make TO a symbol which forwards to FROM.
337 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
339 gold_assert(from != to);
340 gold_assert(!from->is_forwarder() && !to->is_forwarder());
341 this->forwarders_[from] = to;
342 from->set_forwarder();
345 // Resolve the forwards from FROM, returning the real symbol.
348 Symbol_table::resolve_forwards(const Symbol* from) const
350 gold_assert(from->is_forwarder());
351 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
352 this->forwarders_.find(from);
353 gold_assert(p != this->forwarders_.end());
357 // Look up a symbol by name.
360 Symbol_table::lookup(const char* name, const char* version) const
362 Stringpool::Key name_key;
363 name = this->namepool_.find(name, &name_key);
367 Stringpool::Key version_key = 0;
370 version = this->namepool_.find(version, &version_key);
375 Symbol_table_key key(name_key, version_key);
376 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
377 if (p == this->table_.end())
382 // Resolve a Symbol with another Symbol. This is only used in the
383 // unusual case where there are references to both an unversioned
384 // symbol and a symbol with a version, and we then discover that that
385 // version is the default version. Because this is unusual, we do
386 // this the slow way, by converting back to an ELF symbol.
388 template<int size, bool big_endian>
390 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
391 const char* version ACCEPT_SIZE_ENDIAN)
393 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
394 elfcpp::Sym_write<size, big_endian> esym(buf);
395 // We don't bother to set the st_name field.
396 esym.put_st_value(from->value());
397 esym.put_st_size(from->symsize());
398 esym.put_st_info(from->binding(), from->type());
399 esym.put_st_other(from->visibility(), from->nonvis());
400 esym.put_st_shndx(from->shndx());
401 this->resolve(to, esym.sym(), esym.sym(), from->object(), version);
408 // Record that a symbol is forced to be local by a version script.
411 Symbol_table::force_local(Symbol* sym)
413 if (!sym->is_defined() && !sym->is_common())
415 if (sym->is_forced_local())
417 // We already got this one.
420 sym->set_is_forced_local();
421 this->forced_locals_.push_back(sym);
424 // Add one symbol from OBJECT to the symbol table. NAME is symbol
425 // name and VERSION is the version; both are canonicalized. DEF is
426 // whether this is the default version.
428 // If DEF is true, then this is the definition of a default version of
429 // a symbol. That means that any lookup of NAME/NULL and any lookup
430 // of NAME/VERSION should always return the same symbol. This is
431 // obvious for references, but in particular we want to do this for
432 // definitions: overriding NAME/NULL should also override
433 // NAME/VERSION. If we don't do that, it would be very hard to
434 // override functions in a shared library which uses versioning.
436 // We implement this by simply making both entries in the hash table
437 // point to the same Symbol structure. That is easy enough if this is
438 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
439 // that we have seen both already, in which case they will both have
440 // independent entries in the symbol table. We can't simply change
441 // the symbol table entry, because we have pointers to the entries
442 // attached to the object files. So we mark the entry attached to the
443 // object file as a forwarder, and record it in the forwarders_ map.
444 // Note that entries in the hash table will never be marked as
447 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
448 // symbol exactly as it existed in the input file. SYM is usually
449 // that as well, but can be modified, for instance if we determine
450 // it's in a to-be-discarded section.
452 template<int size, bool big_endian>
454 Symbol_table::add_from_object(Object* object,
456 Stringpool::Key name_key,
458 Stringpool::Key version_key,
460 const elfcpp::Sym<size, big_endian>& sym,
461 const elfcpp::Sym<size, big_endian>& orig_sym)
463 Symbol* const snull = NULL;
464 std::pair<typename Symbol_table_type::iterator, bool> ins =
465 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
468 std::pair<typename Symbol_table_type::iterator, bool> insdef =
469 std::make_pair(this->table_.end(), false);
472 const Stringpool::Key vnull_key = 0;
473 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
478 // ins.first: an iterator, which is a pointer to a pair.
479 // ins.first->first: the key (a pair of name and version).
480 // ins.first->second: the value (Symbol*).
481 // ins.second: true if new entry was inserted, false if not.
483 Sized_symbol<size>* ret;
488 // We already have an entry for NAME/VERSION.
489 ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (ins.first->second
491 gold_assert(ret != NULL);
493 was_undefined = ret->is_undefined();
494 was_common = ret->is_common();
496 this->resolve(ret, sym, orig_sym, object, version);
502 // This is the first time we have seen NAME/NULL. Make
503 // NAME/NULL point to NAME/VERSION.
504 insdef.first->second = ret;
506 else if (insdef.first->second != ret
507 && insdef.first->second->is_undefined())
509 // This is the unfortunate case where we already have
510 // entries for both NAME/VERSION and NAME/NULL. Note
511 // that we don't want to combine them if the existing
512 // symbol is going to override the new one. FIXME: We
513 // currently just test is_undefined, but this may not do
514 // the right thing if the existing symbol is from a
515 // shared library and the new one is from a regular
518 const Sized_symbol<size>* sym2;
519 sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) (
522 Symbol_table::resolve SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
523 ret, sym2, version SELECT_SIZE_ENDIAN(size, big_endian));
524 this->make_forwarder(insdef.first->second, ret);
525 insdef.first->second = ret;
531 // This is the first time we have seen NAME/VERSION.
532 gold_assert(ins.first->second == NULL);
534 was_undefined = false;
537 if (def && !insdef.second)
539 // We already have an entry for NAME/NULL. If we override
540 // it, then change it to NAME/VERSION.
541 ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (
544 this->resolve(ret, sym, orig_sym, object, version);
545 ins.first->second = ret;
549 Sized_target<size, big_endian>* target =
550 object->sized_target SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
551 SELECT_SIZE_ENDIAN_ONLY(size, big_endian));
552 if (!target->has_make_symbol())
553 ret = new Sized_symbol<size>();
556 ret = target->make_symbol();
559 // This means that we don't want a symbol table
562 this->table_.erase(ins.first);
565 this->table_.erase(insdef.first);
566 // Inserting insdef invalidated ins.
567 this->table_.erase(std::make_pair(name_key,
574 ret->init(name, version, object, sym);
576 ins.first->second = ret;
579 // This is the first time we have seen NAME/NULL. Point
580 // it at the new entry for NAME/VERSION.
581 gold_assert(insdef.second);
582 insdef.first->second = ret;
587 // Record every time we see a new undefined symbol, to speed up
589 if (!was_undefined && ret->is_undefined())
590 ++this->saw_undefined_;
592 // Keep track of common symbols, to speed up common symbol
594 if (!was_common && ret->is_common())
595 this->commons_.push_back(ret);
597 ret->set_is_default(def);
601 // Add all the symbols in a relocatable object to the hash table.
603 template<int size, bool big_endian>
605 Symbol_table::add_from_relobj(
606 Sized_relobj<size, big_endian>* relobj,
607 const unsigned char* syms,
609 const char* sym_names,
610 size_t sym_name_size,
611 typename Sized_relobj<size, big_endian>::Symbols* sympointers)
613 gold_assert(size == relobj->target()->get_size());
614 gold_assert(size == parameters->get_size());
616 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
618 const unsigned char* p = syms;
619 for (size_t i = 0; i < count; ++i, p += sym_size)
621 elfcpp::Sym<size, big_endian> sym(p);
622 elfcpp::Sym<size, big_endian>* psym = &sym;
624 unsigned int st_name = psym->get_st_name();
625 if (st_name >= sym_name_size)
627 relobj->error(_("bad global symbol name offset %u at %zu"),
632 const char* name = sym_names + st_name;
634 // A symbol defined in a section which we are not including must
635 // be treated as an undefined symbol.
636 unsigned char symbuf[sym_size];
637 elfcpp::Sym<size, big_endian> sym2(symbuf);
638 unsigned int st_shndx = psym->get_st_shndx();
639 if (st_shndx != elfcpp::SHN_UNDEF
640 && st_shndx < elfcpp::SHN_LORESERVE
641 && !relobj->is_section_included(st_shndx))
643 memcpy(symbuf, p, sym_size);
644 elfcpp::Sym_write<size, big_endian> sw(symbuf);
645 sw.put_st_shndx(elfcpp::SHN_UNDEF);
649 // In an object file, an '@' in the name separates the symbol
650 // name from the version name. If there are two '@' characters,
651 // this is the default version.
652 const char* ver = strchr(name, '@');
654 // DEF: is the version default? LOCAL: is the symbol forced local?
660 // The symbol name is of the form foo@VERSION or foo@@VERSION
661 namelen = ver - name;
669 else if (!version_script_.empty())
671 // The symbol name did not have a version, but
672 // the version script may assign a version anyway.
673 namelen = strlen(name);
675 // Check the global: entries from the version script.
676 const std::string& version =
677 version_script_.get_symbol_version(name);
678 if (!version.empty())
679 ver = version.c_str();
680 // Check the local: entries from the version script
681 if (version_script_.symbol_is_local(name))
685 Sized_symbol<size>* res;
688 Stringpool::Key name_key;
689 name = this->namepool_.add(name, true, &name_key);
690 res = this->add_from_object(relobj, name, name_key, NULL, 0,
693 this->force_local(res);
697 Stringpool::Key name_key;
698 name = this->namepool_.add_with_length(name, namelen, true,
700 Stringpool::Key ver_key;
701 ver = this->namepool_.add(ver, true, &ver_key);
703 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
707 (*sympointers)[i] = res;
711 // Add all the symbols in a dynamic object to the hash table.
713 template<int size, bool big_endian>
715 Symbol_table::add_from_dynobj(
716 Sized_dynobj<size, big_endian>* dynobj,
717 const unsigned char* syms,
719 const char* sym_names,
720 size_t sym_name_size,
721 const unsigned char* versym,
723 const std::vector<const char*>* version_map)
725 gold_assert(size == dynobj->target()->get_size());
726 gold_assert(size == parameters->get_size());
728 if (versym != NULL && versym_size / 2 < count)
730 dynobj->error(_("too few symbol versions"));
734 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
736 // We keep a list of all STT_OBJECT symbols, so that we can resolve
737 // weak aliases. This is necessary because if the dynamic object
738 // provides the same variable under two names, one of which is a
739 // weak definition, and the regular object refers to the weak
740 // definition, we have to put both the weak definition and the
741 // strong definition into the dynamic symbol table. Given a weak
742 // definition, the only way that we can find the corresponding
743 // strong definition, if any, is to search the symbol table.
744 std::vector<Sized_symbol<size>*> object_symbols;
746 const unsigned char* p = syms;
747 const unsigned char* vs = versym;
748 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
750 elfcpp::Sym<size, big_endian> sym(p);
752 // Ignore symbols with local binding or that have
753 // internal or hidden visibility.
754 if (sym.get_st_bind() == elfcpp::STB_LOCAL
755 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
756 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
759 unsigned int st_name = sym.get_st_name();
760 if (st_name >= sym_name_size)
762 dynobj->error(_("bad symbol name offset %u at %zu"),
767 const char* name = sym_names + st_name;
769 Sized_symbol<size>* res;
773 Stringpool::Key name_key;
774 name = this->namepool_.add(name, true, &name_key);
775 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
780 // Read the version information.
782 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
784 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
785 v &= elfcpp::VERSYM_VERSION;
787 // The Sun documentation says that V can be VER_NDX_LOCAL,
788 // or VER_NDX_GLOBAL, or a version index. The meaning of
789 // VER_NDX_LOCAL is defined as "Symbol has local scope."
790 // The old GNU linker will happily generate VER_NDX_LOCAL
791 // for an undefined symbol. I don't know what the Sun
792 // linker will generate.
794 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
795 && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
797 // This symbol should not be visible outside the object.
801 // At this point we are definitely going to add this symbol.
802 Stringpool::Key name_key;
803 name = this->namepool_.add(name, true, &name_key);
805 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
806 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
808 // This symbol does not have a version.
809 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
814 if (v >= version_map->size())
816 dynobj->error(_("versym for symbol %zu out of range: %u"),
821 const char* version = (*version_map)[v];
824 dynobj->error(_("versym for symbol %zu has no name: %u"),
829 Stringpool::Key version_key;
830 version = this->namepool_.add(version, true, &version_key);
832 // If this is an absolute symbol, and the version name
833 // and symbol name are the same, then this is the
834 // version definition symbol. These symbols exist to
835 // support using -u to pull in particular versions. We
836 // do not want to record a version for them.
837 if (sym.get_st_shndx() == elfcpp::SHN_ABS
838 && name_key == version_key)
839 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
843 const bool def = (!hidden
844 && (sym.get_st_shndx()
845 != elfcpp::SHN_UNDEF));
846 res = this->add_from_object(dynobj, name, name_key, version,
847 version_key, def, sym, sym);
852 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
853 && sym.get_st_type() == elfcpp::STT_OBJECT)
854 object_symbols.push_back(res);
857 this->record_weak_aliases(&object_symbols);
860 // This is used to sort weak aliases. We sort them first by section
861 // index, then by offset, then by weak ahead of strong.
864 class Weak_alias_sorter
867 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
872 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
873 const Sized_symbol<size>* s2) const
875 if (s1->shndx() != s2->shndx())
876 return s1->shndx() < s2->shndx();
877 if (s1->value() != s2->value())
878 return s1->value() < s2->value();
879 if (s1->binding() != s2->binding())
881 if (s1->binding() == elfcpp::STB_WEAK)
883 if (s2->binding() == elfcpp::STB_WEAK)
886 return std::string(s1->name()) < std::string(s2->name());
889 // SYMBOLS is a list of object symbols from a dynamic object. Look
890 // for any weak aliases, and record them so that if we add the weak
891 // alias to the dynamic symbol table, we also add the corresponding
896 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
898 // Sort the vector by section index, then by offset, then by weak
900 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
902 // Walk through the vector. For each weak definition, record
904 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
909 if ((*p)->binding() != elfcpp::STB_WEAK)
912 // Build a circular list of weak aliases. Each symbol points to
913 // the next one in the circular list.
915 Sized_symbol<size>* from_sym = *p;
916 typename std::vector<Sized_symbol<size>*>::const_iterator q;
917 for (q = p + 1; q != symbols->end(); ++q)
919 if ((*q)->shndx() != from_sym->shndx()
920 || (*q)->value() != from_sym->value())
923 this->weak_aliases_[from_sym] = *q;
924 from_sym->set_has_alias();
930 this->weak_aliases_[from_sym] = *p;
931 from_sym->set_has_alias();
938 // Create and return a specially defined symbol. If ONLY_IF_REF is
939 // true, then only create the symbol if there is a reference to it.
940 // If this does not return NULL, it sets *POLDSYM to the existing
941 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
943 template<int size, bool big_endian>
945 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
947 Sized_symbol<size>** poldsym
951 Sized_symbol<size>* sym;
952 bool add_to_table = false;
953 typename Symbol_table_type::iterator add_loc = this->table_.end();
955 // If the caller didn't give us a version, see if we get one from
956 // the version script.
957 if (*pversion == NULL)
959 const std::string& v(this->version_script_.get_symbol_version(*pname));
961 *pversion = v.c_str();
966 oldsym = this->lookup(*pname, *pversion);
967 if (oldsym == NULL || !oldsym->is_undefined())
970 *pname = oldsym->name();
971 *pversion = oldsym->version();
975 // Canonicalize NAME and VERSION.
976 Stringpool::Key name_key;
977 *pname = this->namepool_.add(*pname, true, &name_key);
979 Stringpool::Key version_key = 0;
980 if (*pversion != NULL)
981 *pversion = this->namepool_.add(*pversion, true, &version_key);
983 Symbol* const snull = NULL;
984 std::pair<typename Symbol_table_type::iterator, bool> ins =
985 this->table_.insert(std::make_pair(std::make_pair(name_key,
991 // We already have a symbol table entry for NAME/VERSION.
992 oldsym = ins.first->second;
993 gold_assert(oldsym != NULL);
997 // We haven't seen this symbol before.
998 gold_assert(ins.first->second == NULL);
1000 add_loc = ins.first;
1005 const Target* target = parameters->target();
1006 if (!target->has_make_symbol())
1007 sym = new Sized_symbol<size>();
1010 gold_assert(target->get_size() == size);
1011 gold_assert(target->is_big_endian() ? big_endian : !big_endian);
1012 typedef Sized_target<size, big_endian> My_target;
1013 const My_target* sized_target =
1014 static_cast<const My_target*>(target);
1015 sym = sized_target->make_symbol();
1021 add_loc->second = sym;
1023 gold_assert(oldsym != NULL);
1025 *poldsym = this->get_sized_symbol SELECT_SIZE_NAME(size) (oldsym
1031 // Define a symbol based on an Output_data.
1034 Symbol_table::define_in_output_data(const char* name,
1035 const char* version,
1040 elfcpp::STB binding,
1041 elfcpp::STV visibility,
1042 unsigned char nonvis,
1043 bool offset_is_from_end,
1046 if (parameters->get_size() == 32)
1048 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1049 return this->do_define_in_output_data<32>(name, version, od,
1050 value, symsize, type, binding,
1058 else if (parameters->get_size() == 64)
1060 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1061 return this->do_define_in_output_data<64>(name, version, od,
1062 value, symsize, type, binding,
1074 // Define a symbol in an Output_data, sized version.
1078 Symbol_table::do_define_in_output_data(
1080 const char* version,
1082 typename elfcpp::Elf_types<size>::Elf_Addr value,
1083 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1085 elfcpp::STB binding,
1086 elfcpp::STV visibility,
1087 unsigned char nonvis,
1088 bool offset_is_from_end,
1091 Sized_symbol<size>* sym;
1092 Sized_symbol<size>* oldsym;
1094 if (parameters->is_big_endian())
1096 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1097 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1098 &name, &version, only_if_ref, &oldsym
1099 SELECT_SIZE_ENDIAN(size, true));
1106 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1107 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1108 &name, &version, only_if_ref, &oldsym
1109 SELECT_SIZE_ENDIAN(size, false));
1118 gold_assert(version == NULL || oldsym != NULL);
1119 sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1120 offset_is_from_end);
1124 if (binding == elfcpp::STB_LOCAL
1125 || this->version_script_.symbol_is_local(name))
1126 this->force_local(sym);
1130 if (Symbol_table::should_override_with_special(oldsym))
1131 this->override_with_special(oldsym, sym);
1136 // Define a symbol based on an Output_segment.
1139 Symbol_table::define_in_output_segment(const char* name,
1140 const char* version, Output_segment* os,
1144 elfcpp::STB binding,
1145 elfcpp::STV visibility,
1146 unsigned char nonvis,
1147 Symbol::Segment_offset_base offset_base,
1150 if (parameters->get_size() == 32)
1152 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1153 return this->do_define_in_output_segment<32>(name, version, os,
1154 value, symsize, type,
1155 binding, visibility, nonvis,
1156 offset_base, only_if_ref);
1161 else if (parameters->get_size() == 64)
1163 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1164 return this->do_define_in_output_segment<64>(name, version, os,
1165 value, symsize, type,
1166 binding, visibility, nonvis,
1167 offset_base, only_if_ref);
1176 // Define a symbol in an Output_segment, sized version.
1180 Symbol_table::do_define_in_output_segment(
1182 const char* version,
1184 typename elfcpp::Elf_types<size>::Elf_Addr value,
1185 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1187 elfcpp::STB binding,
1188 elfcpp::STV visibility,
1189 unsigned char nonvis,
1190 Symbol::Segment_offset_base offset_base,
1193 Sized_symbol<size>* sym;
1194 Sized_symbol<size>* oldsym;
1196 if (parameters->is_big_endian())
1198 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1199 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1200 &name, &version, only_if_ref, &oldsym
1201 SELECT_SIZE_ENDIAN(size, true));
1208 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1209 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1210 &name, &version, only_if_ref, &oldsym
1211 SELECT_SIZE_ENDIAN(size, false));
1220 gold_assert(version == NULL || oldsym != NULL);
1221 sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1226 if (binding == elfcpp::STB_LOCAL
1227 || this->version_script_.symbol_is_local(name))
1228 this->force_local(sym);
1232 if (Symbol_table::should_override_with_special(oldsym))
1233 this->override_with_special(oldsym, sym);
1238 // Define a special symbol with a constant value. It is a multiple
1239 // definition error if this symbol is already defined.
1242 Symbol_table::define_as_constant(const char* name,
1243 const char* version,
1247 elfcpp::STB binding,
1248 elfcpp::STV visibility,
1249 unsigned char nonvis,
1252 if (parameters->get_size() == 32)
1254 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1255 return this->do_define_as_constant<32>(name, version, value,
1256 symsize, type, binding,
1257 visibility, nonvis, only_if_ref);
1262 else if (parameters->get_size() == 64)
1264 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1265 return this->do_define_as_constant<64>(name, version, value,
1266 symsize, type, binding,
1267 visibility, nonvis, only_if_ref);
1276 // Define a symbol as a constant, sized version.
1280 Symbol_table::do_define_as_constant(
1282 const char* version,
1283 typename elfcpp::Elf_types<size>::Elf_Addr value,
1284 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1286 elfcpp::STB binding,
1287 elfcpp::STV visibility,
1288 unsigned char nonvis,
1291 Sized_symbol<size>* sym;
1292 Sized_symbol<size>* oldsym;
1294 if (parameters->is_big_endian())
1296 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1297 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1298 &name, &version, only_if_ref, &oldsym
1299 SELECT_SIZE_ENDIAN(size, true));
1306 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1307 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1308 &name, &version, only_if_ref, &oldsym
1309 SELECT_SIZE_ENDIAN(size, false));
1318 gold_assert(version == NULL || version == name || oldsym != NULL);
1319 sym->init(name, value, symsize, type, binding, visibility, nonvis);
1323 if (binding == elfcpp::STB_LOCAL
1324 || this->version_script_.symbol_is_local(name))
1325 this->force_local(sym);
1329 if (Symbol_table::should_override_with_special(oldsym))
1330 this->override_with_special(oldsym, sym);
1335 // Define a set of symbols in output sections.
1338 Symbol_table::define_symbols(const Layout* layout, int count,
1339 const Define_symbol_in_section* p)
1341 for (int i = 0; i < count; ++i, ++p)
1343 Output_section* os = layout->find_output_section(p->output_section);
1345 this->define_in_output_data(p->name, NULL, os, p->value,
1346 p->size, p->type, p->binding,
1347 p->visibility, p->nonvis,
1348 p->offset_is_from_end, p->only_if_ref);
1350 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1351 p->binding, p->visibility, p->nonvis,
1356 // Define a set of symbols in output segments.
1359 Symbol_table::define_symbols(const Layout* layout, int count,
1360 const Define_symbol_in_segment* p)
1362 for (int i = 0; i < count; ++i, ++p)
1364 Output_segment* os = layout->find_output_segment(p->segment_type,
1365 p->segment_flags_set,
1366 p->segment_flags_clear);
1368 this->define_in_output_segment(p->name, NULL, os, p->value,
1369 p->size, p->type, p->binding,
1370 p->visibility, p->nonvis,
1371 p->offset_base, p->only_if_ref);
1373 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1374 p->binding, p->visibility, p->nonvis,
1379 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1380 // symbol should be defined--typically a .dyn.bss section. VALUE is
1381 // the offset within POSD.
1385 Symbol_table::define_with_copy_reloc(
1386 Sized_symbol<size>* csym,
1388 typename elfcpp::Elf_types<size>::Elf_Addr value)
1390 gold_assert(csym->is_from_dynobj());
1391 gold_assert(!csym->is_copied_from_dynobj());
1392 Object* object = csym->object();
1393 gold_assert(object->is_dynamic());
1394 Dynobj* dynobj = static_cast<Dynobj*>(object);
1396 // Our copied variable has to override any variable in a shared
1398 elfcpp::STB binding = csym->binding();
1399 if (binding == elfcpp::STB_WEAK)
1400 binding = elfcpp::STB_GLOBAL;
1402 this->define_in_output_data(csym->name(), csym->version(),
1403 posd, value, csym->symsize(),
1404 csym->type(), binding,
1405 csym->visibility(), csym->nonvis(),
1408 csym->set_is_copied_from_dynobj();
1409 csym->set_needs_dynsym_entry();
1411 this->copied_symbol_dynobjs_[csym] = dynobj;
1413 // We have now defined all aliases, but we have not entered them all
1414 // in the copied_symbol_dynobjs_ map.
1415 if (csym->has_alias())
1420 sym = this->weak_aliases_[sym];
1423 gold_assert(sym->output_data() == posd);
1425 sym->set_is_copied_from_dynobj();
1426 this->copied_symbol_dynobjs_[sym] = dynobj;
1431 // SYM is defined using a COPY reloc. Return the dynamic object where
1432 // the original definition was found.
1435 Symbol_table::get_copy_source(const Symbol* sym) const
1437 gold_assert(sym->is_copied_from_dynobj());
1438 Copied_symbol_dynobjs::const_iterator p =
1439 this->copied_symbol_dynobjs_.find(sym);
1440 gold_assert(p != this->copied_symbol_dynobjs_.end());
1444 // Set the dynamic symbol indexes. INDEX is the index of the first
1445 // global dynamic symbol. Pointers to the symbols are stored into the
1446 // vector SYMS. The names are added to DYNPOOL. This returns an
1447 // updated dynamic symbol index.
1450 Symbol_table::set_dynsym_indexes(unsigned int index,
1451 std::vector<Symbol*>* syms,
1452 Stringpool* dynpool,
1455 for (Symbol_table_type::iterator p = this->table_.begin();
1456 p != this->table_.end();
1459 Symbol* sym = p->second;
1461 // Note that SYM may already have a dynamic symbol index, since
1462 // some symbols appear more than once in the symbol table, with
1463 // and without a version.
1465 if (!sym->should_add_dynsym_entry())
1466 sym->set_dynsym_index(-1U);
1467 else if (!sym->has_dynsym_index())
1469 sym->set_dynsym_index(index);
1471 syms->push_back(sym);
1472 dynpool->add(sym->name(), false, NULL);
1474 // Record any version information.
1475 if (sym->version() != NULL)
1476 versions->record_version(this, dynpool, sym);
1480 // Finish up the versions. In some cases this may add new dynamic
1482 index = versions->finalize(this, index, syms);
1487 // Set the final values for all the symbols. The index of the first
1488 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1489 // file offset OFF. Add their names to POOL. Return the new file
1490 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1493 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
1494 size_t dyncount, Stringpool* pool,
1495 unsigned int *plocal_symcount)
1499 gold_assert(*plocal_symcount != 0);
1500 this->first_global_index_ = *plocal_symcount;
1502 this->dynamic_offset_ = dynoff;
1503 this->first_dynamic_global_index_ = dyn_global_index;
1504 this->dynamic_count_ = dyncount;
1506 if (parameters->get_size() == 32)
1508 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1509 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
1514 else if (parameters->get_size() == 64)
1516 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1517 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
1525 // Now that we have the final symbol table, we can reliably note
1526 // which symbols should get warnings.
1527 this->warnings_.note_warnings(this);
1532 // SYM is going into the symbol table at *PINDEX. Add the name to
1533 // POOL, update *PINDEX and *POFF.
1537 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
1538 unsigned int* pindex, off_t* poff)
1540 sym->set_symtab_index(*pindex);
1541 pool->add(sym->name(), false, NULL);
1543 *poff += elfcpp::Elf_sizes<size>::sym_size;
1546 // Set the final value for all the symbols. This is called after
1547 // Layout::finalize, so all the output sections have their final
1552 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
1553 unsigned int* plocal_symcount)
1555 off = align_address(off, size >> 3);
1556 this->offset_ = off;
1558 unsigned int index = *plocal_symcount;
1559 const unsigned int orig_index = index;
1561 // First do all the symbols which have been forced to be local, as
1562 // they must appear before all global symbols.
1563 for (Forced_locals::iterator p = this->forced_locals_.begin();
1564 p != this->forced_locals_.end();
1568 gold_assert(sym->is_forced_local());
1569 if (this->sized_finalize_symbol<size>(sym))
1571 this->add_to_final_symtab<size>(sym, pool, &index, &off);
1576 // Now do all the remaining symbols.
1577 for (Symbol_table_type::iterator p = this->table_.begin();
1578 p != this->table_.end();
1581 Symbol* sym = p->second;
1582 if (this->sized_finalize_symbol<size>(sym))
1583 this->add_to_final_symtab<size>(sym, pool, &index, &off);
1586 this->output_count_ = index - orig_index;
1591 // Finalize the symbol SYM. This returns true if the symbol should be
1592 // added to the symbol table, false otherwise.
1596 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
1598 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
1600 // The default version of a symbol may appear twice in the symbol
1601 // table. We only need to finalize it once.
1602 if (sym->has_symtab_index())
1607 gold_assert(!sym->has_symtab_index());
1608 sym->set_symtab_index(-1U);
1609 gold_assert(sym->dynsym_index() == -1U);
1613 typename Sized_symbol<size>::Value_type value;
1615 switch (sym->source())
1617 case Symbol::FROM_OBJECT:
1619 unsigned int shndx = sym->shndx();
1621 // FIXME: We need some target specific support here.
1622 if (shndx >= elfcpp::SHN_LORESERVE
1623 && shndx != elfcpp::SHN_ABS)
1625 gold_error(_("%s: unsupported symbol section 0x%x"),
1626 sym->demangled_name().c_str(), shndx);
1627 shndx = elfcpp::SHN_UNDEF;
1630 Object* symobj = sym->object();
1631 if (symobj->is_dynamic())
1634 shndx = elfcpp::SHN_UNDEF;
1636 else if (shndx == elfcpp::SHN_UNDEF)
1638 else if (shndx == elfcpp::SHN_ABS)
1639 value = sym->value();
1642 Relobj* relobj = static_cast<Relobj*>(symobj);
1643 section_offset_type secoff;
1644 Output_section* os = relobj->output_section(shndx, &secoff);
1648 sym->set_symtab_index(-1U);
1649 gold_assert(sym->dynsym_index() == -1U);
1653 if (sym->type() == elfcpp::STT_TLS)
1654 value = sym->value() + os->tls_offset() + secoff;
1656 value = sym->value() + os->address() + secoff;
1661 case Symbol::IN_OUTPUT_DATA:
1663 Output_data* od = sym->output_data();
1664 value = sym->value() + od->address();
1665 if (sym->offset_is_from_end())
1666 value += od->data_size();
1670 case Symbol::IN_OUTPUT_SEGMENT:
1672 Output_segment* os = sym->output_segment();
1673 value = sym->value() + os->vaddr();
1674 switch (sym->offset_base())
1676 case Symbol::SEGMENT_START:
1678 case Symbol::SEGMENT_END:
1679 value += os->memsz();
1681 case Symbol::SEGMENT_BSS:
1682 value += os->filesz();
1690 case Symbol::CONSTANT:
1691 value = sym->value();
1698 sym->set_value(value);
1700 if (parameters->strip_all())
1702 sym->set_symtab_index(-1U);
1709 // Write out the global symbols.
1712 Symbol_table::write_globals(const Input_objects* input_objects,
1713 const Stringpool* sympool,
1714 const Stringpool* dynpool, Output_file* of) const
1716 if (parameters->get_size() == 32)
1718 if (parameters->is_big_endian())
1720 #ifdef HAVE_TARGET_32_BIG
1721 this->sized_write_globals<32, true>(input_objects, sympool,
1729 #ifdef HAVE_TARGET_32_LITTLE
1730 this->sized_write_globals<32, false>(input_objects, sympool,
1737 else if (parameters->get_size() == 64)
1739 if (parameters->is_big_endian())
1741 #ifdef HAVE_TARGET_64_BIG
1742 this->sized_write_globals<64, true>(input_objects, sympool,
1750 #ifdef HAVE_TARGET_64_LITTLE
1751 this->sized_write_globals<64, false>(input_objects, sympool,
1762 // Write out the global symbols.
1764 template<int size, bool big_endian>
1766 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1767 const Stringpool* sympool,
1768 const Stringpool* dynpool,
1769 Output_file* of) const
1771 const Target* const target = input_objects->target();
1773 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1775 const unsigned int output_count = this->output_count_;
1776 const section_size_type oview_size = output_count * sym_size;
1777 const unsigned int first_global_index = this->first_global_index_;
1778 unsigned char* const psyms = of->get_output_view(this->offset_, oview_size);
1780 const unsigned int dynamic_count = this->dynamic_count_;
1781 const section_size_type dynamic_size = dynamic_count * sym_size;
1782 const unsigned int first_dynamic_global_index =
1783 this->first_dynamic_global_index_;
1784 unsigned char* dynamic_view;
1785 if (this->dynamic_offset_ == 0)
1786 dynamic_view = NULL;
1788 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1790 for (Symbol_table_type::const_iterator p = this->table_.begin();
1791 p != this->table_.end();
1794 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1796 // Possibly warn about unresolved symbols in shared libraries.
1797 this->warn_about_undefined_dynobj_symbol(input_objects, sym);
1799 unsigned int sym_index = sym->symtab_index();
1800 unsigned int dynsym_index;
1801 if (dynamic_view == NULL)
1804 dynsym_index = sym->dynsym_index();
1806 if (sym_index == -1U && dynsym_index == -1U)
1808 // This symbol is not included in the output file.
1813 typename elfcpp::Elf_types<32>::Elf_Addr value = sym->value();
1814 switch (sym->source())
1816 case Symbol::FROM_OBJECT:
1818 unsigned int in_shndx = sym->shndx();
1820 // FIXME: We need some target specific support here.
1821 if (in_shndx >= elfcpp::SHN_LORESERVE
1822 && in_shndx != elfcpp::SHN_ABS)
1824 gold_error(_("%s: unsupported symbol section 0x%x"),
1825 sym->demangled_name().c_str(), in_shndx);
1830 Object* symobj = sym->object();
1831 if (symobj->is_dynamic())
1833 if (sym->needs_dynsym_value())
1834 value = target->dynsym_value(sym);
1835 shndx = elfcpp::SHN_UNDEF;
1837 else if (in_shndx == elfcpp::SHN_UNDEF
1838 || in_shndx == elfcpp::SHN_ABS)
1842 Relobj* relobj = static_cast<Relobj*>(symobj);
1843 section_offset_type secoff;
1844 Output_section* os = relobj->output_section(in_shndx,
1846 gold_assert(os != NULL);
1847 shndx = os->out_shndx();
1853 case Symbol::IN_OUTPUT_DATA:
1854 shndx = sym->output_data()->out_shndx();
1857 case Symbol::IN_OUTPUT_SEGMENT:
1858 shndx = elfcpp::SHN_ABS;
1861 case Symbol::CONSTANT:
1862 shndx = elfcpp::SHN_ABS;
1869 if (sym_index != -1U)
1871 sym_index -= first_global_index;
1872 gold_assert(sym_index < output_count);
1873 unsigned char* ps = psyms + (sym_index * sym_size);
1874 this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1875 sym, sym->value(), shndx, sympool, ps
1876 SELECT_SIZE_ENDIAN(size, big_endian));
1879 if (dynsym_index != -1U)
1881 dynsym_index -= first_dynamic_global_index;
1882 gold_assert(dynsym_index < dynamic_count);
1883 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
1884 this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1885 sym, value, shndx, dynpool, pd
1886 SELECT_SIZE_ENDIAN(size, big_endian));
1890 of->write_output_view(this->offset_, oview_size, psyms);
1891 if (dynamic_view != NULL)
1892 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
1895 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1896 // strtab holding the name.
1898 template<int size, bool big_endian>
1900 Symbol_table::sized_write_symbol(
1901 Sized_symbol<size>* sym,
1902 typename elfcpp::Elf_types<size>::Elf_Addr value,
1904 const Stringpool* pool,
1906 ACCEPT_SIZE_ENDIAN) const
1908 elfcpp::Sym_write<size, big_endian> osym(p);
1909 osym.put_st_name(pool->get_offset(sym->name()));
1910 osym.put_st_value(value);
1911 osym.put_st_size(sym->symsize());
1912 // A version script may have overridden the default binding.
1913 if (sym->is_forced_local())
1914 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
1916 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
1917 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
1918 osym.put_st_shndx(shndx);
1921 // Check for unresolved symbols in shared libraries. This is
1922 // controlled by the --allow-shlib-undefined option.
1924 // We only warn about libraries for which we have seen all the
1925 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
1926 // which were not seen in this link. If we didn't see a DT_NEEDED
1927 // entry, we aren't going to be able to reliably report whether the
1928 // symbol is undefined.
1930 // We also don't warn about libraries found in the system library
1931 // directory (the directory were we find libc.so); we assume that
1932 // those libraries are OK. This heuristic avoids problems in
1933 // GNU/Linux, in which -ldl can have undefined references satisfied by
1937 Symbol_table::warn_about_undefined_dynobj_symbol(
1938 const Input_objects* input_objects,
1941 if (sym->source() == Symbol::FROM_OBJECT
1942 && sym->object()->is_dynamic()
1943 && sym->shndx() == elfcpp::SHN_UNDEF
1944 && sym->binding() != elfcpp::STB_WEAK
1945 && !parameters->allow_shlib_undefined()
1946 && !input_objects->target()->is_defined_by_abi(sym)
1947 && !input_objects->found_in_system_library_directory(sym->object()))
1949 // A very ugly cast.
1950 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
1951 if (!dynobj->has_unknown_needed_entries())
1952 gold_error(_("%s: undefined reference to '%s'"),
1953 sym->object()->name().c_str(),
1954 sym->demangled_name().c_str());
1958 // Write out a section symbol. Return the update offset.
1961 Symbol_table::write_section_symbol(const Output_section *os,
1965 if (parameters->get_size() == 32)
1967 if (parameters->is_big_endian())
1969 #ifdef HAVE_TARGET_32_BIG
1970 this->sized_write_section_symbol<32, true>(os, of, offset);
1977 #ifdef HAVE_TARGET_32_LITTLE
1978 this->sized_write_section_symbol<32, false>(os, of, offset);
1984 else if (parameters->get_size() == 64)
1986 if (parameters->is_big_endian())
1988 #ifdef HAVE_TARGET_64_BIG
1989 this->sized_write_section_symbol<64, true>(os, of, offset);
1996 #ifdef HAVE_TARGET_64_LITTLE
1997 this->sized_write_section_symbol<64, false>(os, of, offset);
2007 // Write out a section symbol, specialized for size and endianness.
2009 template<int size, bool big_endian>
2011 Symbol_table::sized_write_section_symbol(const Output_section* os,
2015 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2017 unsigned char* pov = of->get_output_view(offset, sym_size);
2019 elfcpp::Sym_write<size, big_endian> osym(pov);
2020 osym.put_st_name(0);
2021 osym.put_st_value(os->address());
2022 osym.put_st_size(0);
2023 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2024 elfcpp::STT_SECTION));
2025 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2026 osym.put_st_shndx(os->out_shndx());
2028 of->write_output_view(offset, sym_size, pov);
2031 // Print statistical information to stderr. This is used for --stats.
2034 Symbol_table::print_stats() const
2036 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2037 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2038 program_name, this->table_.size(), this->table_.bucket_count());
2040 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2041 program_name, this->table_.size());
2043 this->namepool_.print_stats("symbol table stringpool");
2046 // We check for ODR violations by looking for symbols with the same
2047 // name for which the debugging information reports that they were
2048 // defined in different source locations. When comparing the source
2049 // location, we consider instances with the same base filename and
2050 // line number to be the same. This is because different object
2051 // files/shared libraries can include the same header file using
2052 // different paths, and we don't want to report an ODR violation in
2055 // This struct is used to compare line information, as returned by
2056 // Dwarf_line_info::one_addr2line. It implements a < comparison
2057 // operator used with std::set.
2059 struct Odr_violation_compare
2062 operator()(const std::string& s1, const std::string& s2) const
2064 std::string::size_type pos1 = s1.rfind('/');
2065 std::string::size_type pos2 = s2.rfind('/');
2066 if (pos1 == std::string::npos
2067 || pos2 == std::string::npos)
2069 return s1.compare(pos1, std::string::npos,
2070 s2, pos2, std::string::npos) < 0;
2074 // Check candidate_odr_violations_ to find symbols with the same name
2075 // but apparently different definitions (different source-file/line-no).
2078 Symbol_table::detect_odr_violations(const Task* task,
2079 const char* output_file_name) const
2081 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2082 it != candidate_odr_violations_.end();
2085 const char* symbol_name = it->first;
2086 // We use a sorted set so the output is deterministic.
2087 std::set<std::string, Odr_violation_compare> line_nums;
2089 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2090 locs = it->second.begin();
2091 locs != it->second.end();
2094 // We need to lock the object in order to read it. This
2095 // means that we have to run in a singleton Task. If we
2096 // want to run this in a general Task for better
2097 // performance, we will need one Task for object, plus
2098 // appropriate locking to ensure that we don't conflict with
2099 // other uses of the object.
2100 Task_lock_obj<Object> tl(task, locs->object);
2101 std::string lineno = Dwarf_line_info::one_addr2line(
2102 locs->object, locs->shndx, locs->offset);
2103 if (!lineno.empty())
2104 line_nums.insert(lineno);
2107 if (line_nums.size() > 1)
2109 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2110 "places (possible ODR violation):"),
2111 output_file_name, demangle(symbol_name).c_str());
2112 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
2113 it2 != line_nums.end();
2115 fprintf(stderr, " %s\n", it2->c_str());
2120 // Warnings functions.
2122 // Add a new warning.
2125 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
2126 const std::string& warning)
2128 name = symtab->canonicalize_name(name);
2129 this->warnings_[name].set(obj, warning);
2132 // Look through the warnings and mark the symbols for which we should
2133 // warn. This is called during Layout::finalize when we know the
2134 // sources for all the symbols.
2137 Warnings::note_warnings(Symbol_table* symtab)
2139 for (Warning_table::iterator p = this->warnings_.begin();
2140 p != this->warnings_.end();
2143 Symbol* sym = symtab->lookup(p->first, NULL);
2145 && sym->source() == Symbol::FROM_OBJECT
2146 && sym->object() == p->second.object)
2147 sym->set_has_warning();
2151 // Issue a warning. This is called when we see a relocation against a
2152 // symbol for which has a warning.
2154 template<int size, bool big_endian>
2156 Warnings::issue_warning(const Symbol* sym,
2157 const Relocate_info<size, big_endian>* relinfo,
2158 size_t relnum, off_t reloffset) const
2160 gold_assert(sym->has_warning());
2161 Warning_table::const_iterator p = this->warnings_.find(sym->name());
2162 gold_assert(p != this->warnings_.end());
2163 gold_warning_at_location(relinfo, relnum, reloffset,
2164 "%s", p->second.text.c_str());
2167 // Instantiate the templates we need. We could use the configure
2168 // script to restrict this to only the ones needed for implemented
2171 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2174 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2177 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2180 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2183 #ifdef HAVE_TARGET_32_LITTLE
2186 Symbol_table::add_from_relobj<32, false>(
2187 Sized_relobj<32, false>* relobj,
2188 const unsigned char* syms,
2190 const char* sym_names,
2191 size_t sym_name_size,
2192 Sized_relobj<32, true>::Symbols* sympointers);
2195 #ifdef HAVE_TARGET_32_BIG
2198 Symbol_table::add_from_relobj<32, true>(
2199 Sized_relobj<32, true>* relobj,
2200 const unsigned char* syms,
2202 const char* sym_names,
2203 size_t sym_name_size,
2204 Sized_relobj<32, false>::Symbols* sympointers);
2207 #ifdef HAVE_TARGET_64_LITTLE
2210 Symbol_table::add_from_relobj<64, false>(
2211 Sized_relobj<64, false>* relobj,
2212 const unsigned char* syms,
2214 const char* sym_names,
2215 size_t sym_name_size,
2216 Sized_relobj<64, true>::Symbols* sympointers);
2219 #ifdef HAVE_TARGET_64_BIG
2222 Symbol_table::add_from_relobj<64, true>(
2223 Sized_relobj<64, true>* relobj,
2224 const unsigned char* syms,
2226 const char* sym_names,
2227 size_t sym_name_size,
2228 Sized_relobj<64, false>::Symbols* sympointers);
2231 #ifdef HAVE_TARGET_32_LITTLE
2234 Symbol_table::add_from_dynobj<32, false>(
2235 Sized_dynobj<32, false>* dynobj,
2236 const unsigned char* syms,
2238 const char* sym_names,
2239 size_t sym_name_size,
2240 const unsigned char* versym,
2242 const std::vector<const char*>* version_map);
2245 #ifdef HAVE_TARGET_32_BIG
2248 Symbol_table::add_from_dynobj<32, true>(
2249 Sized_dynobj<32, true>* dynobj,
2250 const unsigned char* syms,
2252 const char* sym_names,
2253 size_t sym_name_size,
2254 const unsigned char* versym,
2256 const std::vector<const char*>* version_map);
2259 #ifdef HAVE_TARGET_64_LITTLE
2262 Symbol_table::add_from_dynobj<64, false>(
2263 Sized_dynobj<64, false>* dynobj,
2264 const unsigned char* syms,
2266 const char* sym_names,
2267 size_t sym_name_size,
2268 const unsigned char* versym,
2270 const std::vector<const char*>* version_map);
2273 #ifdef HAVE_TARGET_64_BIG
2276 Symbol_table::add_from_dynobj<64, true>(
2277 Sized_dynobj<64, true>* dynobj,
2278 const unsigned char* syms,
2280 const char* sym_names,
2281 size_t sym_name_size,
2282 const unsigned char* versym,
2284 const std::vector<const char*>* version_map);
2287 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2290 Symbol_table::define_with_copy_reloc<32>(
2291 Sized_symbol<32>* sym,
2293 elfcpp::Elf_types<32>::Elf_Addr value);
2296 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2299 Symbol_table::define_with_copy_reloc<64>(
2300 Sized_symbol<64>* sym,
2302 elfcpp::Elf_types<64>::Elf_Addr value);
2305 #ifdef HAVE_TARGET_32_LITTLE
2308 Warnings::issue_warning<32, false>(const Symbol* sym,
2309 const Relocate_info<32, false>* relinfo,
2310 size_t relnum, off_t reloffset) const;
2313 #ifdef HAVE_TARGET_32_BIG
2316 Warnings::issue_warning<32, true>(const Symbol* sym,
2317 const Relocate_info<32, true>* relinfo,
2318 size_t relnum, off_t reloffset) const;
2321 #ifdef HAVE_TARGET_64_LITTLE
2324 Warnings::issue_warning<64, false>(const Symbol* sym,
2325 const Relocate_info<64, false>* relinfo,
2326 size_t relnum, off_t reloffset) const;
2329 #ifdef HAVE_TARGET_64_BIG
2332 Warnings::issue_warning<64, true>(const Symbol* sym,
2333 const Relocate_info<64, true>* relinfo,
2334 size_t relnum, off_t reloffset) const;
2337 } // End namespace gold.