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.
34 #include "dwarf_reader.h"
38 #include "workqueue.h"
46 // Initialize fields in Symbol. This initializes everything except u_
50 Symbol::init_fields(const char* name, const char* version,
51 elfcpp::STT type, elfcpp::STB binding,
52 elfcpp::STV visibility, unsigned char nonvis)
55 this->version_ = version;
56 this->symtab_index_ = 0;
57 this->dynsym_index_ = 0;
58 this->got_offsets_.init();
59 this->plt_offset_ = 0;
61 this->binding_ = binding;
62 this->visibility_ = visibility;
63 this->nonvis_ = nonvis;
64 this->is_target_special_ = false;
65 this->is_def_ = false;
66 this->is_forwarder_ = false;
67 this->has_alias_ = false;
68 this->needs_dynsym_entry_ = false;
69 this->in_reg_ = false;
70 this->in_dyn_ = false;
71 this->has_plt_offset_ = false;
72 this->has_warning_ = false;
73 this->is_copied_from_dynobj_ = false;
74 this->is_forced_local_ = false;
77 // Return the demangled version of the symbol's name, but only
78 // if the --demangle flag was set.
81 demangle(const char* name)
83 if (!parameters->options().do_demangle())
86 // cplus_demangle allocates memory for the result it returns,
87 // and returns NULL if the name is already demangled.
88 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
89 if (demangled_name == NULL)
92 std::string retval(demangled_name);
98 Symbol::demangled_name() const
100 return demangle(this->name());
103 // Initialize the fields in the base class Symbol for SYM in OBJECT.
105 template<int size, bool big_endian>
107 Symbol::init_base(const char* name, const char* version, Object* object,
108 const elfcpp::Sym<size, big_endian>& sym)
110 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
111 sym.get_st_visibility(), sym.get_st_nonvis());
112 this->u_.from_object.object = object;
113 // FIXME: Handle SHN_XINDEX.
114 this->u_.from_object.shndx = sym.get_st_shndx();
115 this->source_ = FROM_OBJECT;
116 this->in_reg_ = !object->is_dynamic();
117 this->in_dyn_ = object->is_dynamic();
120 // Initialize the fields in the base class Symbol for a symbol defined
121 // in an Output_data.
124 Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type,
125 elfcpp::STB binding, elfcpp::STV visibility,
126 unsigned char nonvis, bool offset_is_from_end)
128 this->init_fields(name, NULL, type, binding, visibility, nonvis);
129 this->u_.in_output_data.output_data = od;
130 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
131 this->source_ = IN_OUTPUT_DATA;
132 this->in_reg_ = true;
135 // Initialize the fields in the base class Symbol for a symbol defined
136 // in an Output_segment.
139 Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type,
140 elfcpp::STB binding, elfcpp::STV visibility,
141 unsigned char nonvis, Segment_offset_base offset_base)
143 this->init_fields(name, NULL, type, binding, visibility, nonvis);
144 this->u_.in_output_segment.output_segment = os;
145 this->u_.in_output_segment.offset_base = offset_base;
146 this->source_ = IN_OUTPUT_SEGMENT;
147 this->in_reg_ = true;
150 // Initialize the fields in the base class Symbol for a symbol defined
154 Symbol::init_base(const char* name, elfcpp::STT type,
155 elfcpp::STB binding, elfcpp::STV visibility,
156 unsigned char nonvis)
158 this->init_fields(name, NULL, type, binding, visibility, nonvis);
159 this->source_ = CONSTANT;
160 this->in_reg_ = true;
163 // Allocate a common symbol in the base.
166 Symbol::allocate_base_common(Output_data* od)
168 gold_assert(this->is_common());
169 this->source_ = IN_OUTPUT_DATA;
170 this->u_.in_output_data.output_data = od;
171 this->u_.in_output_data.offset_is_from_end = false;
174 // Initialize the fields in Sized_symbol for SYM in OBJECT.
177 template<bool big_endian>
179 Sized_symbol<size>::init(const char* name, const char* version, Object* object,
180 const elfcpp::Sym<size, big_endian>& sym)
182 this->init_base(name, version, object, sym);
183 this->value_ = sym.get_st_value();
184 this->symsize_ = sym.get_st_size();
187 // Initialize the fields in Sized_symbol for a symbol defined in an
192 Sized_symbol<size>::init(const char* name, Output_data* od,
193 Value_type value, Size_type symsize,
194 elfcpp::STT type, elfcpp::STB binding,
195 elfcpp::STV visibility, unsigned char nonvis,
196 bool offset_is_from_end)
198 this->init_base(name, od, type, binding, visibility, nonvis,
200 this->value_ = value;
201 this->symsize_ = symsize;
204 // Initialize the fields in Sized_symbol for a symbol defined in an
209 Sized_symbol<size>::init(const char* name, Output_segment* os,
210 Value_type value, Size_type symsize,
211 elfcpp::STT type, elfcpp::STB binding,
212 elfcpp::STV visibility, unsigned char nonvis,
213 Segment_offset_base offset_base)
215 this->init_base(name, os, type, binding, visibility, nonvis, offset_base);
216 this->value_ = value;
217 this->symsize_ = symsize;
220 // Initialize the fields in Sized_symbol for a symbol defined as a
225 Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize,
226 elfcpp::STT type, elfcpp::STB binding,
227 elfcpp::STV visibility, unsigned char nonvis)
229 this->init_base(name, type, binding, visibility, nonvis);
230 this->value_ = value;
231 this->symsize_ = symsize;
234 // Allocate a common symbol.
238 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
240 this->allocate_base_common(od);
241 this->value_ = value;
244 // Return true if this symbol should be added to the dynamic symbol
248 Symbol::should_add_dynsym_entry() const
250 // If the symbol is used by a dynamic relocation, we need to add it.
251 if (this->needs_dynsym_entry())
254 // If the symbol was forced local in a version script, do not add it.
255 if (this->is_forced_local())
258 // If exporting all symbols or building a shared library,
259 // and the symbol is defined in a regular object and is
260 // externally visible, we need to add it.
261 if ((parameters->options().export_dynamic() || parameters->options().shared())
262 && !this->is_from_dynobj()
263 && this->is_externally_visible())
269 // Return true if the final value of this symbol is known at link
273 Symbol::final_value_is_known() const
275 // If we are not generating an executable, then no final values are
276 // known, since they will change at runtime.
277 if (parameters->options().shared() || parameters->options().relocatable())
280 // If the symbol is not from an object file, then it is defined, and
282 if (this->source_ != FROM_OBJECT)
285 // If the symbol is from a dynamic object, then the final value is
287 if (this->object()->is_dynamic())
290 // If the symbol is not undefined (it is defined or common), then
291 // the final value is known.
292 if (!this->is_undefined())
295 // If the symbol is undefined, then whether the final value is known
296 // depends on whether we are doing a static link. If we are doing a
297 // dynamic link, then the final value could be filled in at runtime.
298 // This could reasonably be the case for a weak undefined symbol.
299 return parameters->doing_static_link();
302 // Return the output section where this symbol is defined.
305 Symbol::output_section() const
307 switch (this->source_)
311 unsigned int shndx = this->u_.from_object.shndx;
312 if (shndx != elfcpp::SHN_UNDEF && shndx < elfcpp::SHN_LORESERVE)
314 gold_assert(!this->u_.from_object.object->is_dynamic());
315 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
316 section_offset_type dummy;
317 return relobj->output_section(shndx, &dummy);
323 return this->u_.in_output_data.output_data->output_section();
325 case IN_OUTPUT_SEGMENT:
334 // Set the symbol's output section. This is used for symbols defined
335 // in scripts. This should only be called after the symbol table has
339 Symbol::set_output_section(Output_section* os)
341 switch (this->source_)
345 gold_assert(this->output_section() == os);
348 this->source_ = IN_OUTPUT_DATA;
349 this->u_.in_output_data.output_data = os;
350 this->u_.in_output_data.offset_is_from_end = false;
352 case IN_OUTPUT_SEGMENT:
358 // Class Symbol_table.
360 Symbol_table::Symbol_table(unsigned int count,
361 const Version_script_info& version_script)
362 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
363 forwarders_(), commons_(), forced_locals_(), warnings_(),
364 version_script_(version_script)
366 namepool_.reserve(count);
369 Symbol_table::~Symbol_table()
373 // The hash function. The key values are Stringpool keys.
376 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
378 return key.first ^ key.second;
381 // The symbol table key equality function. This is called with
385 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
386 const Symbol_table_key& k2) const
388 return k1.first == k2.first && k1.second == k2.second;
391 // Make TO a symbol which forwards to FROM.
394 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
396 gold_assert(from != to);
397 gold_assert(!from->is_forwarder() && !to->is_forwarder());
398 this->forwarders_[from] = to;
399 from->set_forwarder();
402 // Resolve the forwards from FROM, returning the real symbol.
405 Symbol_table::resolve_forwards(const Symbol* from) const
407 gold_assert(from->is_forwarder());
408 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
409 this->forwarders_.find(from);
410 gold_assert(p != this->forwarders_.end());
414 // Look up a symbol by name.
417 Symbol_table::lookup(const char* name, const char* version) const
419 Stringpool::Key name_key;
420 name = this->namepool_.find(name, &name_key);
424 Stringpool::Key version_key = 0;
427 version = this->namepool_.find(version, &version_key);
432 Symbol_table_key key(name_key, version_key);
433 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
434 if (p == this->table_.end())
439 // Resolve a Symbol with another Symbol. This is only used in the
440 // unusual case where there are references to both an unversioned
441 // symbol and a symbol with a version, and we then discover that that
442 // version is the default version. Because this is unusual, we do
443 // this the slow way, by converting back to an ELF symbol.
445 template<int size, bool big_endian>
447 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
450 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
451 elfcpp::Sym_write<size, big_endian> esym(buf);
452 // We don't bother to set the st_name field.
453 esym.put_st_value(from->value());
454 esym.put_st_size(from->symsize());
455 esym.put_st_info(from->binding(), from->type());
456 esym.put_st_other(from->visibility(), from->nonvis());
457 esym.put_st_shndx(from->shndx());
458 this->resolve(to, esym.sym(), esym.sym(), from->object(), version);
465 // Record that a symbol is forced to be local by a version script.
468 Symbol_table::force_local(Symbol* sym)
470 if (!sym->is_defined() && !sym->is_common())
472 if (sym->is_forced_local())
474 // We already got this one.
477 sym->set_is_forced_local();
478 this->forced_locals_.push_back(sym);
481 // Add one symbol from OBJECT to the symbol table. NAME is symbol
482 // name and VERSION is the version; both are canonicalized. DEF is
483 // whether this is the default version.
485 // If DEF is true, then this is the definition of a default version of
486 // a symbol. That means that any lookup of NAME/NULL and any lookup
487 // of NAME/VERSION should always return the same symbol. This is
488 // obvious for references, but in particular we want to do this for
489 // definitions: overriding NAME/NULL should also override
490 // NAME/VERSION. If we don't do that, it would be very hard to
491 // override functions in a shared library which uses versioning.
493 // We implement this by simply making both entries in the hash table
494 // point to the same Symbol structure. That is easy enough if this is
495 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
496 // that we have seen both already, in which case they will both have
497 // independent entries in the symbol table. We can't simply change
498 // the symbol table entry, because we have pointers to the entries
499 // attached to the object files. So we mark the entry attached to the
500 // object file as a forwarder, and record it in the forwarders_ map.
501 // Note that entries in the hash table will never be marked as
504 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
505 // symbol exactly as it existed in the input file. SYM is usually
506 // that as well, but can be modified, for instance if we determine
507 // it's in a to-be-discarded section.
509 template<int size, bool big_endian>
511 Symbol_table::add_from_object(Object* object,
513 Stringpool::Key name_key,
515 Stringpool::Key version_key,
517 const elfcpp::Sym<size, big_endian>& sym,
518 const elfcpp::Sym<size, big_endian>& orig_sym)
520 Symbol* const snull = NULL;
521 std::pair<typename Symbol_table_type::iterator, bool> ins =
522 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
525 std::pair<typename Symbol_table_type::iterator, bool> insdef =
526 std::make_pair(this->table_.end(), false);
529 const Stringpool::Key vnull_key = 0;
530 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
535 // ins.first: an iterator, which is a pointer to a pair.
536 // ins.first->first: the key (a pair of name and version).
537 // ins.first->second: the value (Symbol*).
538 // ins.second: true if new entry was inserted, false if not.
540 Sized_symbol<size>* ret;
545 // We already have an entry for NAME/VERSION.
546 ret = this->get_sized_symbol<size>(ins.first->second);
547 gold_assert(ret != NULL);
549 was_undefined = ret->is_undefined();
550 was_common = ret->is_common();
552 this->resolve(ret, sym, orig_sym, object, version);
558 // This is the first time we have seen NAME/NULL. Make
559 // NAME/NULL point to NAME/VERSION.
560 insdef.first->second = ret;
562 else if (insdef.first->second != ret
563 && insdef.first->second->is_undefined())
565 // This is the unfortunate case where we already have
566 // entries for both NAME/VERSION and NAME/NULL. Note
567 // that we don't want to combine them if the existing
568 // symbol is going to override the new one. FIXME: We
569 // currently just test is_undefined, but this may not do
570 // the right thing if the existing symbol is from a
571 // shared library and the new one is from a regular
574 const Sized_symbol<size>* sym2;
575 sym2 = this->get_sized_symbol<size>(insdef.first->second);
576 Symbol_table::resolve<size, big_endian>(ret, sym2, version);
577 this->make_forwarder(insdef.first->second, ret);
578 insdef.first->second = ret;
584 // This is the first time we have seen NAME/VERSION.
585 gold_assert(ins.first->second == NULL);
587 was_undefined = false;
590 if (def && !insdef.second)
592 // We already have an entry for NAME/NULL. If we override
593 // it, then change it to NAME/VERSION.
594 ret = this->get_sized_symbol<size>(insdef.first->second);
595 this->resolve(ret, sym, orig_sym, object, version);
596 ins.first->second = ret;
600 Sized_target<size, big_endian>* target =
601 object->sized_target<size, big_endian>();
602 if (!target->has_make_symbol())
603 ret = new Sized_symbol<size>();
606 ret = target->make_symbol();
609 // This means that we don't want a symbol table
612 this->table_.erase(ins.first);
615 this->table_.erase(insdef.first);
616 // Inserting insdef invalidated ins.
617 this->table_.erase(std::make_pair(name_key,
624 ret->init(name, version, object, sym);
626 ins.first->second = ret;
629 // This is the first time we have seen NAME/NULL. Point
630 // it at the new entry for NAME/VERSION.
631 gold_assert(insdef.second);
632 insdef.first->second = ret;
637 // Record every time we see a new undefined symbol, to speed up
639 if (!was_undefined && ret->is_undefined())
640 ++this->saw_undefined_;
642 // Keep track of common symbols, to speed up common symbol
644 if (!was_common && ret->is_common())
645 this->commons_.push_back(ret);
648 ret->set_is_default();
652 // Add all the symbols in a relocatable object to the hash table.
654 template<int size, bool big_endian>
656 Symbol_table::add_from_relobj(
657 Sized_relobj<size, big_endian>* relobj,
658 const unsigned char* syms,
660 const char* sym_names,
661 size_t sym_name_size,
662 typename Sized_relobj<size, big_endian>::Symbols* sympointers)
664 gold_assert(size == relobj->target()->get_size());
665 gold_assert(size == parameters->target().get_size());
667 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
669 const bool just_symbols = relobj->just_symbols();
671 const unsigned char* p = syms;
672 for (size_t i = 0; i < count; ++i, p += sym_size)
674 elfcpp::Sym<size, big_endian> sym(p);
675 elfcpp::Sym<size, big_endian>* psym = &sym;
677 unsigned int st_name = psym->get_st_name();
678 if (st_name >= sym_name_size)
680 relobj->error(_("bad global symbol name offset %u at %zu"),
685 const char* name = sym_names + st_name;
687 // A symbol defined in a section which we are not including must
688 // be treated as an undefined symbol.
689 unsigned char symbuf[sym_size];
690 elfcpp::Sym<size, big_endian> sym2(symbuf);
691 unsigned int st_shndx = psym->get_st_shndx();
692 if (st_shndx != elfcpp::SHN_UNDEF
693 && st_shndx < elfcpp::SHN_LORESERVE
694 && !relobj->is_section_included(st_shndx))
696 memcpy(symbuf, p, sym_size);
697 elfcpp::Sym_write<size, big_endian> sw(symbuf);
698 sw.put_st_shndx(elfcpp::SHN_UNDEF);
702 // In an object file, an '@' in the name separates the symbol
703 // name from the version name. If there are two '@' characters,
704 // this is the default version.
705 const char* ver = strchr(name, '@');
707 // DEF: is the version default? LOCAL: is the symbol forced local?
713 // The symbol name is of the form foo@VERSION or foo@@VERSION
714 namelen = ver - name;
722 // We don't want to assign a version to an undefined symbol,
723 // even if it is listed in the version script. FIXME: What
724 // about a common symbol?
725 else if (!version_script_.empty()
726 && psym->get_st_shndx() != elfcpp::SHN_UNDEF)
728 // The symbol name did not have a version, but
729 // the version script may assign a version anyway.
730 namelen = strlen(name);
732 // Check the global: entries from the version script.
733 const std::string& version =
734 version_script_.get_symbol_version(name);
735 if (!version.empty())
736 ver = version.c_str();
737 // Check the local: entries from the version script
738 if (version_script_.symbol_is_local(name))
745 memcpy(symbuf, p, sym_size);
746 elfcpp::Sym_write<size, big_endian> sw(symbuf);
747 sw.put_st_shndx(elfcpp::SHN_ABS);
748 if (st_shndx != elfcpp::SHN_UNDEF
749 && st_shndx < elfcpp::SHN_LORESERVE)
751 // Symbol values in object files are section relative.
752 // This is normally what we want, but since here we are
753 // converting the symbol to absolute we need to add the
754 // section address. The section address in an object
755 // file is normally zero, but people can use a linker
756 // script to change it.
757 sw.put_st_value(sym2.get_st_value()
758 + relobj->section_address(st_shndx));
763 Sized_symbol<size>* res;
766 Stringpool::Key name_key;
767 name = this->namepool_.add(name, true, &name_key);
768 res = this->add_from_object(relobj, name, name_key, NULL, 0,
771 this->force_local(res);
775 Stringpool::Key name_key;
776 name = this->namepool_.add_with_length(name, namelen, true,
778 Stringpool::Key ver_key;
779 ver = this->namepool_.add(ver, true, &ver_key);
781 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
785 (*sympointers)[i] = res;
789 // Add all the symbols in a dynamic object to the hash table.
791 template<int size, bool big_endian>
793 Symbol_table::add_from_dynobj(
794 Sized_dynobj<size, big_endian>* dynobj,
795 const unsigned char* syms,
797 const char* sym_names,
798 size_t sym_name_size,
799 const unsigned char* versym,
801 const std::vector<const char*>* version_map)
803 gold_assert(size == dynobj->target()->get_size());
804 gold_assert(size == parameters->target().get_size());
806 if (dynobj->just_symbols())
808 gold_error(_("--just-symbols does not make sense with a shared object"));
812 if (versym != NULL && versym_size / 2 < count)
814 dynobj->error(_("too few symbol versions"));
818 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
820 // We keep a list of all STT_OBJECT symbols, so that we can resolve
821 // weak aliases. This is necessary because if the dynamic object
822 // provides the same variable under two names, one of which is a
823 // weak definition, and the regular object refers to the weak
824 // definition, we have to put both the weak definition and the
825 // strong definition into the dynamic symbol table. Given a weak
826 // definition, the only way that we can find the corresponding
827 // strong definition, if any, is to search the symbol table.
828 std::vector<Sized_symbol<size>*> object_symbols;
830 const unsigned char* p = syms;
831 const unsigned char* vs = versym;
832 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
834 elfcpp::Sym<size, big_endian> sym(p);
836 // Ignore symbols with local binding or that have
837 // internal or hidden visibility.
838 if (sym.get_st_bind() == elfcpp::STB_LOCAL
839 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
840 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
843 unsigned int st_name = sym.get_st_name();
844 if (st_name >= sym_name_size)
846 dynobj->error(_("bad symbol name offset %u at %zu"),
851 const char* name = sym_names + st_name;
853 Sized_symbol<size>* res;
857 Stringpool::Key name_key;
858 name = this->namepool_.add(name, true, &name_key);
859 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
864 // Read the version information.
866 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
868 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
869 v &= elfcpp::VERSYM_VERSION;
871 // The Sun documentation says that V can be VER_NDX_LOCAL,
872 // or VER_NDX_GLOBAL, or a version index. The meaning of
873 // VER_NDX_LOCAL is defined as "Symbol has local scope."
874 // The old GNU linker will happily generate VER_NDX_LOCAL
875 // for an undefined symbol. I don't know what the Sun
876 // linker will generate.
878 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
879 && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
881 // This symbol should not be visible outside the object.
885 // At this point we are definitely going to add this symbol.
886 Stringpool::Key name_key;
887 name = this->namepool_.add(name, true, &name_key);
889 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
890 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
892 // This symbol does not have a version.
893 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
898 if (v >= version_map->size())
900 dynobj->error(_("versym for symbol %zu out of range: %u"),
905 const char* version = (*version_map)[v];
908 dynobj->error(_("versym for symbol %zu has no name: %u"),
913 Stringpool::Key version_key;
914 version = this->namepool_.add(version, true, &version_key);
916 // If this is an absolute symbol, and the version name
917 // and symbol name are the same, then this is the
918 // version definition symbol. These symbols exist to
919 // support using -u to pull in particular versions. We
920 // do not want to record a version for them.
921 if (sym.get_st_shndx() == elfcpp::SHN_ABS
922 && name_key == version_key)
923 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
927 const bool def = (!hidden
928 && (sym.get_st_shndx()
929 != elfcpp::SHN_UNDEF));
930 res = this->add_from_object(dynobj, name, name_key, version,
931 version_key, def, sym, sym);
936 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
937 && sym.get_st_type() == elfcpp::STT_OBJECT)
938 object_symbols.push_back(res);
941 this->record_weak_aliases(&object_symbols);
944 // This is used to sort weak aliases. We sort them first by section
945 // index, then by offset, then by weak ahead of strong.
948 class Weak_alias_sorter
951 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
956 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
957 const Sized_symbol<size>* s2) const
959 if (s1->shndx() != s2->shndx())
960 return s1->shndx() < s2->shndx();
961 if (s1->value() != s2->value())
962 return s1->value() < s2->value();
963 if (s1->binding() != s2->binding())
965 if (s1->binding() == elfcpp::STB_WEAK)
967 if (s2->binding() == elfcpp::STB_WEAK)
970 return std::string(s1->name()) < std::string(s2->name());
973 // SYMBOLS is a list of object symbols from a dynamic object. Look
974 // for any weak aliases, and record them so that if we add the weak
975 // alias to the dynamic symbol table, we also add the corresponding
980 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
982 // Sort the vector by section index, then by offset, then by weak
984 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
986 // Walk through the vector. For each weak definition, record
988 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
993 if ((*p)->binding() != elfcpp::STB_WEAK)
996 // Build a circular list of weak aliases. Each symbol points to
997 // the next one in the circular list.
999 Sized_symbol<size>* from_sym = *p;
1000 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1001 for (q = p + 1; q != symbols->end(); ++q)
1003 if ((*q)->shndx() != from_sym->shndx()
1004 || (*q)->value() != from_sym->value())
1007 this->weak_aliases_[from_sym] = *q;
1008 from_sym->set_has_alias();
1014 this->weak_aliases_[from_sym] = *p;
1015 from_sym->set_has_alias();
1022 // Create and return a specially defined symbol. If ONLY_IF_REF is
1023 // true, then only create the symbol if there is a reference to it.
1024 // If this does not return NULL, it sets *POLDSYM to the existing
1025 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1027 template<int size, bool big_endian>
1029 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1031 Sized_symbol<size>** poldsym)
1034 Sized_symbol<size>* sym;
1035 bool add_to_table = false;
1036 typename Symbol_table_type::iterator add_loc = this->table_.end();
1038 // If the caller didn't give us a version, see if we get one from
1039 // the version script.
1040 if (*pversion == NULL)
1042 const std::string& v(this->version_script_.get_symbol_version(*pname));
1044 *pversion = v.c_str();
1049 oldsym = this->lookup(*pname, *pversion);
1050 if (oldsym == NULL || !oldsym->is_undefined())
1053 *pname = oldsym->name();
1054 *pversion = oldsym->version();
1058 // Canonicalize NAME and VERSION.
1059 Stringpool::Key name_key;
1060 *pname = this->namepool_.add(*pname, true, &name_key);
1062 Stringpool::Key version_key = 0;
1063 if (*pversion != NULL)
1064 *pversion = this->namepool_.add(*pversion, true, &version_key);
1066 Symbol* const snull = NULL;
1067 std::pair<typename Symbol_table_type::iterator, bool> ins =
1068 this->table_.insert(std::make_pair(std::make_pair(name_key,
1074 // We already have a symbol table entry for NAME/VERSION.
1075 oldsym = ins.first->second;
1076 gold_assert(oldsym != NULL);
1080 // We haven't seen this symbol before.
1081 gold_assert(ins.first->second == NULL);
1082 add_to_table = true;
1083 add_loc = ins.first;
1088 const Target& target = parameters->target();
1089 if (!target.has_make_symbol())
1090 sym = new Sized_symbol<size>();
1093 gold_assert(target.get_size() == size);
1094 gold_assert(target.is_big_endian() ? big_endian : !big_endian);
1095 typedef Sized_target<size, big_endian> My_target;
1096 const My_target* sized_target =
1097 static_cast<const My_target*>(&target);
1098 sym = sized_target->make_symbol();
1104 add_loc->second = sym;
1106 gold_assert(oldsym != NULL);
1108 *poldsym = this->get_sized_symbol<size>(oldsym);
1113 // Define a symbol based on an Output_data.
1116 Symbol_table::define_in_output_data(const char* name,
1117 const char* version,
1122 elfcpp::STB binding,
1123 elfcpp::STV visibility,
1124 unsigned char nonvis,
1125 bool offset_is_from_end,
1128 if (parameters->target().get_size() == 32)
1130 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1131 return this->do_define_in_output_data<32>(name, version, od,
1132 value, symsize, type, binding,
1140 else if (parameters->target().get_size() == 64)
1142 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1143 return this->do_define_in_output_data<64>(name, version, od,
1144 value, symsize, type, binding,
1156 // Define a symbol in an Output_data, sized version.
1160 Symbol_table::do_define_in_output_data(
1162 const char* version,
1164 typename elfcpp::Elf_types<size>::Elf_Addr value,
1165 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1167 elfcpp::STB binding,
1168 elfcpp::STV visibility,
1169 unsigned char nonvis,
1170 bool offset_is_from_end,
1173 Sized_symbol<size>* sym;
1174 Sized_symbol<size>* oldsym;
1176 if (parameters->target().is_big_endian())
1178 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1179 sym = this->define_special_symbol<size, true>(&name, &version,
1180 only_if_ref, &oldsym);
1187 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1188 sym = this->define_special_symbol<size, false>(&name, &version,
1189 only_if_ref, &oldsym);
1198 gold_assert(version == NULL || oldsym != NULL);
1199 sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1200 offset_is_from_end);
1204 if (binding == elfcpp::STB_LOCAL
1205 || this->version_script_.symbol_is_local(name))
1206 this->force_local(sym);
1210 if (Symbol_table::should_override_with_special(oldsym))
1211 this->override_with_special(oldsym, sym);
1216 // Define a symbol based on an Output_segment.
1219 Symbol_table::define_in_output_segment(const char* name,
1220 const char* version, Output_segment* os,
1224 elfcpp::STB binding,
1225 elfcpp::STV visibility,
1226 unsigned char nonvis,
1227 Symbol::Segment_offset_base offset_base,
1230 if (parameters->target().get_size() == 32)
1232 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1233 return this->do_define_in_output_segment<32>(name, version, os,
1234 value, symsize, type,
1235 binding, visibility, nonvis,
1236 offset_base, only_if_ref);
1241 else if (parameters->target().get_size() == 64)
1243 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1244 return this->do_define_in_output_segment<64>(name, version, os,
1245 value, symsize, type,
1246 binding, visibility, nonvis,
1247 offset_base, only_if_ref);
1256 // Define a symbol in an Output_segment, sized version.
1260 Symbol_table::do_define_in_output_segment(
1262 const char* version,
1264 typename elfcpp::Elf_types<size>::Elf_Addr value,
1265 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1267 elfcpp::STB binding,
1268 elfcpp::STV visibility,
1269 unsigned char nonvis,
1270 Symbol::Segment_offset_base offset_base,
1273 Sized_symbol<size>* sym;
1274 Sized_symbol<size>* oldsym;
1276 if (parameters->target().is_big_endian())
1278 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1279 sym = this->define_special_symbol<size, true>(&name, &version,
1280 only_if_ref, &oldsym);
1287 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1288 sym = this->define_special_symbol<size, false>(&name, &version,
1289 only_if_ref, &oldsym);
1298 gold_assert(version == NULL || oldsym != NULL);
1299 sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1304 if (binding == elfcpp::STB_LOCAL
1305 || this->version_script_.symbol_is_local(name))
1306 this->force_local(sym);
1310 if (Symbol_table::should_override_with_special(oldsym))
1311 this->override_with_special(oldsym, sym);
1316 // Define a special symbol with a constant value. It is a multiple
1317 // definition error if this symbol is already defined.
1320 Symbol_table::define_as_constant(const char* name,
1321 const char* version,
1325 elfcpp::STB binding,
1326 elfcpp::STV visibility,
1327 unsigned char nonvis,
1329 bool force_override)
1331 if (parameters->target().get_size() == 32)
1333 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1334 return this->do_define_as_constant<32>(name, version, value,
1335 symsize, type, binding,
1336 visibility, nonvis, only_if_ref,
1342 else if (parameters->target().get_size() == 64)
1344 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1345 return this->do_define_as_constant<64>(name, version, value,
1346 symsize, type, binding,
1347 visibility, nonvis, only_if_ref,
1357 // Define a symbol as a constant, sized version.
1361 Symbol_table::do_define_as_constant(
1363 const char* version,
1364 typename elfcpp::Elf_types<size>::Elf_Addr value,
1365 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1367 elfcpp::STB binding,
1368 elfcpp::STV visibility,
1369 unsigned char nonvis,
1371 bool force_override)
1373 Sized_symbol<size>* sym;
1374 Sized_symbol<size>* oldsym;
1376 if (parameters->target().is_big_endian())
1378 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1379 sym = this->define_special_symbol<size, true>(&name, &version,
1380 only_if_ref, &oldsym);
1387 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1388 sym = this->define_special_symbol<size, false>(&name, &version,
1389 only_if_ref, &oldsym);
1398 gold_assert(version == NULL || version == name || oldsym != NULL);
1399 sym->init(name, value, symsize, type, binding, visibility, nonvis);
1403 if (binding == elfcpp::STB_LOCAL
1404 || this->version_script_.symbol_is_local(name))
1405 this->force_local(sym);
1409 if (force_override || Symbol_table::should_override_with_special(oldsym))
1410 this->override_with_special(oldsym, sym);
1415 // Define a set of symbols in output sections.
1418 Symbol_table::define_symbols(const Layout* layout, int count,
1419 const Define_symbol_in_section* p,
1422 for (int i = 0; i < count; ++i, ++p)
1424 Output_section* os = layout->find_output_section(p->output_section);
1426 this->define_in_output_data(p->name, NULL, os, p->value,
1427 p->size, p->type, p->binding,
1428 p->visibility, p->nonvis,
1429 p->offset_is_from_end,
1430 only_if_ref || p->only_if_ref);
1432 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1433 p->binding, p->visibility, p->nonvis,
1434 only_if_ref || p->only_if_ref,
1439 // Define a set of symbols in output segments.
1442 Symbol_table::define_symbols(const Layout* layout, int count,
1443 const Define_symbol_in_segment* p,
1446 for (int i = 0; i < count; ++i, ++p)
1448 Output_segment* os = layout->find_output_segment(p->segment_type,
1449 p->segment_flags_set,
1450 p->segment_flags_clear);
1452 this->define_in_output_segment(p->name, NULL, os, p->value,
1453 p->size, p->type, p->binding,
1454 p->visibility, p->nonvis,
1456 only_if_ref || p->only_if_ref);
1458 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1459 p->binding, p->visibility, p->nonvis,
1460 only_if_ref || p->only_if_ref,
1465 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1466 // symbol should be defined--typically a .dyn.bss section. VALUE is
1467 // the offset within POSD.
1471 Symbol_table::define_with_copy_reloc(
1472 Sized_symbol<size>* csym,
1474 typename elfcpp::Elf_types<size>::Elf_Addr value)
1476 gold_assert(csym->is_from_dynobj());
1477 gold_assert(!csym->is_copied_from_dynobj());
1478 Object* object = csym->object();
1479 gold_assert(object->is_dynamic());
1480 Dynobj* dynobj = static_cast<Dynobj*>(object);
1482 // Our copied variable has to override any variable in a shared
1484 elfcpp::STB binding = csym->binding();
1485 if (binding == elfcpp::STB_WEAK)
1486 binding = elfcpp::STB_GLOBAL;
1488 this->define_in_output_data(csym->name(), csym->version(),
1489 posd, value, csym->symsize(),
1490 csym->type(), binding,
1491 csym->visibility(), csym->nonvis(),
1494 csym->set_is_copied_from_dynobj();
1495 csym->set_needs_dynsym_entry();
1497 this->copied_symbol_dynobjs_[csym] = dynobj;
1499 // We have now defined all aliases, but we have not entered them all
1500 // in the copied_symbol_dynobjs_ map.
1501 if (csym->has_alias())
1506 sym = this->weak_aliases_[sym];
1509 gold_assert(sym->output_data() == posd);
1511 sym->set_is_copied_from_dynobj();
1512 this->copied_symbol_dynobjs_[sym] = dynobj;
1517 // SYM is defined using a COPY reloc. Return the dynamic object where
1518 // the original definition was found.
1521 Symbol_table::get_copy_source(const Symbol* sym) const
1523 gold_assert(sym->is_copied_from_dynobj());
1524 Copied_symbol_dynobjs::const_iterator p =
1525 this->copied_symbol_dynobjs_.find(sym);
1526 gold_assert(p != this->copied_symbol_dynobjs_.end());
1530 // Set the dynamic symbol indexes. INDEX is the index of the first
1531 // global dynamic symbol. Pointers to the symbols are stored into the
1532 // vector SYMS. The names are added to DYNPOOL. This returns an
1533 // updated dynamic symbol index.
1536 Symbol_table::set_dynsym_indexes(unsigned int index,
1537 std::vector<Symbol*>* syms,
1538 Stringpool* dynpool,
1541 for (Symbol_table_type::iterator p = this->table_.begin();
1542 p != this->table_.end();
1545 Symbol* sym = p->second;
1547 // Note that SYM may already have a dynamic symbol index, since
1548 // some symbols appear more than once in the symbol table, with
1549 // and without a version.
1551 if (!sym->should_add_dynsym_entry())
1552 sym->set_dynsym_index(-1U);
1553 else if (!sym->has_dynsym_index())
1555 sym->set_dynsym_index(index);
1557 syms->push_back(sym);
1558 dynpool->add(sym->name(), false, NULL);
1560 // Record any version information.
1561 if (sym->version() != NULL)
1562 versions->record_version(this, dynpool, sym);
1566 // Finish up the versions. In some cases this may add new dynamic
1568 index = versions->finalize(this, index, syms);
1573 // Set the final values for all the symbols. The index of the first
1574 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1575 // file offset OFF. Add their names to POOL. Return the new file
1576 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1579 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
1580 size_t dyncount, Stringpool* pool,
1581 unsigned int *plocal_symcount)
1585 gold_assert(*plocal_symcount != 0);
1586 this->first_global_index_ = *plocal_symcount;
1588 this->dynamic_offset_ = dynoff;
1589 this->first_dynamic_global_index_ = dyn_global_index;
1590 this->dynamic_count_ = dyncount;
1592 if (parameters->target().get_size() == 32)
1594 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1595 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
1600 else if (parameters->target().get_size() == 64)
1602 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1603 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
1611 // Now that we have the final symbol table, we can reliably note
1612 // which symbols should get warnings.
1613 this->warnings_.note_warnings(this);
1618 // SYM is going into the symbol table at *PINDEX. Add the name to
1619 // POOL, update *PINDEX and *POFF.
1623 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
1624 unsigned int* pindex, off_t* poff)
1626 sym->set_symtab_index(*pindex);
1627 pool->add(sym->name(), false, NULL);
1629 *poff += elfcpp::Elf_sizes<size>::sym_size;
1632 // Set the final value for all the symbols. This is called after
1633 // Layout::finalize, so all the output sections have their final
1638 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
1639 unsigned int* plocal_symcount)
1641 off = align_address(off, size >> 3);
1642 this->offset_ = off;
1644 unsigned int index = *plocal_symcount;
1645 const unsigned int orig_index = index;
1647 // First do all the symbols which have been forced to be local, as
1648 // they must appear before all global symbols.
1649 for (Forced_locals::iterator p = this->forced_locals_.begin();
1650 p != this->forced_locals_.end();
1654 gold_assert(sym->is_forced_local());
1655 if (this->sized_finalize_symbol<size>(sym))
1657 this->add_to_final_symtab<size>(sym, pool, &index, &off);
1662 // Now do all the remaining symbols.
1663 for (Symbol_table_type::iterator p = this->table_.begin();
1664 p != this->table_.end();
1667 Symbol* sym = p->second;
1668 if (this->sized_finalize_symbol<size>(sym))
1669 this->add_to_final_symtab<size>(sym, pool, &index, &off);
1672 this->output_count_ = index - orig_index;
1677 // Finalize the symbol SYM. This returns true if the symbol should be
1678 // added to the symbol table, false otherwise.
1682 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
1684 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
1686 // The default version of a symbol may appear twice in the symbol
1687 // table. We only need to finalize it once.
1688 if (sym->has_symtab_index())
1693 gold_assert(!sym->has_symtab_index());
1694 sym->set_symtab_index(-1U);
1695 gold_assert(sym->dynsym_index() == -1U);
1699 typename Sized_symbol<size>::Value_type value;
1701 switch (sym->source())
1703 case Symbol::FROM_OBJECT:
1705 unsigned int shndx = sym->shndx();
1707 // FIXME: We need some target specific support here.
1708 if (shndx >= elfcpp::SHN_LORESERVE
1709 && shndx != elfcpp::SHN_ABS
1710 && shndx != elfcpp::SHN_COMMON)
1712 gold_error(_("%s: unsupported symbol section 0x%x"),
1713 sym->demangled_name().c_str(), shndx);
1714 shndx = elfcpp::SHN_UNDEF;
1717 Object* symobj = sym->object();
1718 if (symobj->is_dynamic())
1721 shndx = elfcpp::SHN_UNDEF;
1723 else if (shndx == elfcpp::SHN_UNDEF)
1725 else if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
1726 value = sym->value();
1729 Relobj* relobj = static_cast<Relobj*>(symobj);
1730 section_offset_type secoff;
1731 Output_section* os = relobj->output_section(shndx, &secoff);
1735 sym->set_symtab_index(-1U);
1736 gold_assert(sym->dynsym_index() == -1U);
1740 if (sym->type() == elfcpp::STT_TLS)
1741 value = sym->value() + os->tls_offset() + secoff;
1743 value = sym->value() + os->address() + secoff;
1748 case Symbol::IN_OUTPUT_DATA:
1750 Output_data* od = sym->output_data();
1751 value = sym->value() + od->address();
1752 if (sym->offset_is_from_end())
1753 value += od->data_size();
1757 case Symbol::IN_OUTPUT_SEGMENT:
1759 Output_segment* os = sym->output_segment();
1760 value = sym->value() + os->vaddr();
1761 switch (sym->offset_base())
1763 case Symbol::SEGMENT_START:
1765 case Symbol::SEGMENT_END:
1766 value += os->memsz();
1768 case Symbol::SEGMENT_BSS:
1769 value += os->filesz();
1777 case Symbol::CONSTANT:
1778 value = sym->value();
1785 sym->set_value(value);
1787 if (parameters->options().strip_all())
1789 sym->set_symtab_index(-1U);
1796 // Write out the global symbols.
1799 Symbol_table::write_globals(const Input_objects* input_objects,
1800 const Stringpool* sympool,
1801 const Stringpool* dynpool, Output_file* of) const
1803 switch (parameters->size_and_endianness())
1805 #ifdef HAVE_TARGET_32_LITTLE
1806 case Parameters::TARGET_32_LITTLE:
1807 this->sized_write_globals<32, false>(input_objects, sympool,
1811 #ifdef HAVE_TARGET_32_BIG
1812 case Parameters::TARGET_32_BIG:
1813 this->sized_write_globals<32, true>(input_objects, sympool,
1817 #ifdef HAVE_TARGET_64_LITTLE
1818 case Parameters::TARGET_64_LITTLE:
1819 this->sized_write_globals<64, false>(input_objects, sympool,
1823 #ifdef HAVE_TARGET_64_BIG
1824 case Parameters::TARGET_64_BIG:
1825 this->sized_write_globals<64, true>(input_objects, sympool,
1834 // Write out the global symbols.
1836 template<int size, bool big_endian>
1838 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1839 const Stringpool* sympool,
1840 const Stringpool* dynpool,
1841 Output_file* of) const
1843 const Target& target = parameters->target();
1845 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1847 const unsigned int output_count = this->output_count_;
1848 const section_size_type oview_size = output_count * sym_size;
1849 const unsigned int first_global_index = this->first_global_index_;
1850 unsigned char* psyms;
1851 if (this->offset_ == 0 || output_count == 0)
1854 psyms = of->get_output_view(this->offset_, oview_size);
1856 const unsigned int dynamic_count = this->dynamic_count_;
1857 const section_size_type dynamic_size = dynamic_count * sym_size;
1858 const unsigned int first_dynamic_global_index =
1859 this->first_dynamic_global_index_;
1860 unsigned char* dynamic_view;
1861 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
1862 dynamic_view = NULL;
1864 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1866 for (Symbol_table_type::const_iterator p = this->table_.begin();
1867 p != this->table_.end();
1870 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1872 // Possibly warn about unresolved symbols in shared libraries.
1873 this->warn_about_undefined_dynobj_symbol(input_objects, sym);
1875 unsigned int sym_index = sym->symtab_index();
1876 unsigned int dynsym_index;
1877 if (dynamic_view == NULL)
1880 dynsym_index = sym->dynsym_index();
1882 if (sym_index == -1U && dynsym_index == -1U)
1884 // This symbol is not included in the output file.
1889 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
1890 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
1891 switch (sym->source())
1893 case Symbol::FROM_OBJECT:
1895 unsigned int in_shndx = sym->shndx();
1897 // FIXME: We need some target specific support here.
1898 if (in_shndx >= elfcpp::SHN_LORESERVE
1899 && in_shndx != elfcpp::SHN_ABS
1900 && in_shndx != elfcpp::SHN_COMMON)
1902 gold_error(_("%s: unsupported symbol section 0x%x"),
1903 sym->demangled_name().c_str(), in_shndx);
1908 Object* symobj = sym->object();
1909 if (symobj->is_dynamic())
1911 if (sym->needs_dynsym_value())
1912 dynsym_value = target.dynsym_value(sym);
1913 shndx = elfcpp::SHN_UNDEF;
1915 else if (in_shndx == elfcpp::SHN_UNDEF
1916 || in_shndx == elfcpp::SHN_ABS
1917 || in_shndx == elfcpp::SHN_COMMON)
1921 Relobj* relobj = static_cast<Relobj*>(symobj);
1922 section_offset_type secoff;
1923 Output_section* os = relobj->output_section(in_shndx,
1925 gold_assert(os != NULL);
1926 shndx = os->out_shndx();
1928 // In object files symbol values are section
1930 if (parameters->options().relocatable())
1931 sym_value -= os->address();
1937 case Symbol::IN_OUTPUT_DATA:
1938 shndx = sym->output_data()->out_shndx();
1941 case Symbol::IN_OUTPUT_SEGMENT:
1942 shndx = elfcpp::SHN_ABS;
1945 case Symbol::CONSTANT:
1946 shndx = elfcpp::SHN_ABS;
1953 if (sym_index != -1U)
1955 sym_index -= first_global_index;
1956 gold_assert(sym_index < output_count);
1957 unsigned char* ps = psyms + (sym_index * sym_size);
1958 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
1962 if (dynsym_index != -1U)
1964 dynsym_index -= first_dynamic_global_index;
1965 gold_assert(dynsym_index < dynamic_count);
1966 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
1967 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
1972 of->write_output_view(this->offset_, oview_size, psyms);
1973 if (dynamic_view != NULL)
1974 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
1977 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1978 // strtab holding the name.
1980 template<int size, bool big_endian>
1982 Symbol_table::sized_write_symbol(
1983 Sized_symbol<size>* sym,
1984 typename elfcpp::Elf_types<size>::Elf_Addr value,
1986 const Stringpool* pool,
1987 unsigned char* p) const
1989 elfcpp::Sym_write<size, big_endian> osym(p);
1990 osym.put_st_name(pool->get_offset(sym->name()));
1991 osym.put_st_value(value);
1992 osym.put_st_size(sym->symsize());
1993 // A version script may have overridden the default binding.
1994 if (sym->is_forced_local())
1995 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
1997 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
1998 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
1999 osym.put_st_shndx(shndx);
2002 // Check for unresolved symbols in shared libraries. This is
2003 // controlled by the --allow-shlib-undefined option.
2005 // We only warn about libraries for which we have seen all the
2006 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2007 // which were not seen in this link. If we didn't see a DT_NEEDED
2008 // entry, we aren't going to be able to reliably report whether the
2009 // symbol is undefined.
2011 // We also don't warn about libraries found in the system library
2012 // directory (the directory were we find libc.so); we assume that
2013 // those libraries are OK. This heuristic avoids problems in
2014 // GNU/Linux, in which -ldl can have undefined references satisfied by
2018 Symbol_table::warn_about_undefined_dynobj_symbol(
2019 const Input_objects* input_objects,
2022 if (sym->source() == Symbol::FROM_OBJECT
2023 && sym->object()->is_dynamic()
2024 && sym->shndx() == elfcpp::SHN_UNDEF
2025 && sym->binding() != elfcpp::STB_WEAK
2026 && !parameters->options().allow_shlib_undefined()
2027 && !parameters->target().is_defined_by_abi(sym)
2028 && !input_objects->found_in_system_library_directory(sym->object()))
2030 // A very ugly cast.
2031 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2032 if (!dynobj->has_unknown_needed_entries())
2033 gold_error(_("%s: undefined reference to '%s'"),
2034 sym->object()->name().c_str(),
2035 sym->demangled_name().c_str());
2039 // Write out a section symbol. Return the update offset.
2042 Symbol_table::write_section_symbol(const Output_section *os,
2046 switch (parameters->size_and_endianness())
2048 #ifdef HAVE_TARGET_32_LITTLE
2049 case Parameters::TARGET_32_LITTLE:
2050 this->sized_write_section_symbol<32, false>(os, of, offset);
2053 #ifdef HAVE_TARGET_32_BIG
2054 case Parameters::TARGET_32_BIG:
2055 this->sized_write_section_symbol<32, true>(os, of, offset);
2058 #ifdef HAVE_TARGET_64_LITTLE
2059 case Parameters::TARGET_64_LITTLE:
2060 this->sized_write_section_symbol<64, false>(os, of, offset);
2063 #ifdef HAVE_TARGET_64_BIG
2064 case Parameters::TARGET_64_BIG:
2065 this->sized_write_section_symbol<64, true>(os, of, offset);
2073 // Write out a section symbol, specialized for size and endianness.
2075 template<int size, bool big_endian>
2077 Symbol_table::sized_write_section_symbol(const Output_section* os,
2081 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2083 unsigned char* pov = of->get_output_view(offset, sym_size);
2085 elfcpp::Sym_write<size, big_endian> osym(pov);
2086 osym.put_st_name(0);
2087 osym.put_st_value(os->address());
2088 osym.put_st_size(0);
2089 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2090 elfcpp::STT_SECTION));
2091 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2092 osym.put_st_shndx(os->out_shndx());
2094 of->write_output_view(offset, sym_size, pov);
2097 // Print statistical information to stderr. This is used for --stats.
2100 Symbol_table::print_stats() const
2102 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2103 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2104 program_name, this->table_.size(), this->table_.bucket_count());
2106 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2107 program_name, this->table_.size());
2109 this->namepool_.print_stats("symbol table stringpool");
2112 // We check for ODR violations by looking for symbols with the same
2113 // name for which the debugging information reports that they were
2114 // defined in different source locations. When comparing the source
2115 // location, we consider instances with the same base filename and
2116 // line number to be the same. This is because different object
2117 // files/shared libraries can include the same header file using
2118 // different paths, and we don't want to report an ODR violation in
2121 // This struct is used to compare line information, as returned by
2122 // Dwarf_line_info::one_addr2line. It implements a < comparison
2123 // operator used with std::set.
2125 struct Odr_violation_compare
2128 operator()(const std::string& s1, const std::string& s2) const
2130 std::string::size_type pos1 = s1.rfind('/');
2131 std::string::size_type pos2 = s2.rfind('/');
2132 if (pos1 == std::string::npos
2133 || pos2 == std::string::npos)
2135 return s1.compare(pos1, std::string::npos,
2136 s2, pos2, std::string::npos) < 0;
2140 // Check candidate_odr_violations_ to find symbols with the same name
2141 // but apparently different definitions (different source-file/line-no).
2144 Symbol_table::detect_odr_violations(const Task* task,
2145 const char* output_file_name) const
2147 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2148 it != candidate_odr_violations_.end();
2151 const char* symbol_name = it->first;
2152 // We use a sorted set so the output is deterministic.
2153 std::set<std::string, Odr_violation_compare> line_nums;
2155 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2156 locs = it->second.begin();
2157 locs != it->second.end();
2160 // We need to lock the object in order to read it. This
2161 // means that we have to run in a singleton Task. If we
2162 // want to run this in a general Task for better
2163 // performance, we will need one Task for object, plus
2164 // appropriate locking to ensure that we don't conflict with
2165 // other uses of the object.
2166 Task_lock_obj<Object> tl(task, locs->object);
2167 std::string lineno = Dwarf_line_info::one_addr2line(
2168 locs->object, locs->shndx, locs->offset);
2169 if (!lineno.empty())
2170 line_nums.insert(lineno);
2173 if (line_nums.size() > 1)
2175 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2176 "places (possible ODR violation):"),
2177 output_file_name, demangle(symbol_name).c_str());
2178 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
2179 it2 != line_nums.end();
2181 fprintf(stderr, " %s\n", it2->c_str());
2186 // Warnings functions.
2188 // Add a new warning.
2191 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
2192 const std::string& warning)
2194 name = symtab->canonicalize_name(name);
2195 this->warnings_[name].set(obj, warning);
2198 // Look through the warnings and mark the symbols for which we should
2199 // warn. This is called during Layout::finalize when we know the
2200 // sources for all the symbols.
2203 Warnings::note_warnings(Symbol_table* symtab)
2205 for (Warning_table::iterator p = this->warnings_.begin();
2206 p != this->warnings_.end();
2209 Symbol* sym = symtab->lookup(p->first, NULL);
2211 && sym->source() == Symbol::FROM_OBJECT
2212 && sym->object() == p->second.object)
2213 sym->set_has_warning();
2217 // Issue a warning. This is called when we see a relocation against a
2218 // symbol for which has a warning.
2220 template<int size, bool big_endian>
2222 Warnings::issue_warning(const Symbol* sym,
2223 const Relocate_info<size, big_endian>* relinfo,
2224 size_t relnum, off_t reloffset) const
2226 gold_assert(sym->has_warning());
2227 Warning_table::const_iterator p = this->warnings_.find(sym->name());
2228 gold_assert(p != this->warnings_.end());
2229 gold_warning_at_location(relinfo, relnum, reloffset,
2230 "%s", p->second.text.c_str());
2233 // Instantiate the templates we need. We could use the configure
2234 // script to restrict this to only the ones needed for implemented
2237 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2240 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2243 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2246 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2249 #ifdef HAVE_TARGET_32_LITTLE
2252 Symbol_table::add_from_relobj<32, false>(
2253 Sized_relobj<32, false>* relobj,
2254 const unsigned char* syms,
2256 const char* sym_names,
2257 size_t sym_name_size,
2258 Sized_relobj<32, true>::Symbols* sympointers);
2261 #ifdef HAVE_TARGET_32_BIG
2264 Symbol_table::add_from_relobj<32, true>(
2265 Sized_relobj<32, true>* relobj,
2266 const unsigned char* syms,
2268 const char* sym_names,
2269 size_t sym_name_size,
2270 Sized_relobj<32, false>::Symbols* sympointers);
2273 #ifdef HAVE_TARGET_64_LITTLE
2276 Symbol_table::add_from_relobj<64, false>(
2277 Sized_relobj<64, false>* relobj,
2278 const unsigned char* syms,
2280 const char* sym_names,
2281 size_t sym_name_size,
2282 Sized_relobj<64, true>::Symbols* sympointers);
2285 #ifdef HAVE_TARGET_64_BIG
2288 Symbol_table::add_from_relobj<64, true>(
2289 Sized_relobj<64, true>* relobj,
2290 const unsigned char* syms,
2292 const char* sym_names,
2293 size_t sym_name_size,
2294 Sized_relobj<64, false>::Symbols* sympointers);
2297 #ifdef HAVE_TARGET_32_LITTLE
2300 Symbol_table::add_from_dynobj<32, false>(
2301 Sized_dynobj<32, false>* dynobj,
2302 const unsigned char* syms,
2304 const char* sym_names,
2305 size_t sym_name_size,
2306 const unsigned char* versym,
2308 const std::vector<const char*>* version_map);
2311 #ifdef HAVE_TARGET_32_BIG
2314 Symbol_table::add_from_dynobj<32, true>(
2315 Sized_dynobj<32, true>* dynobj,
2316 const unsigned char* syms,
2318 const char* sym_names,
2319 size_t sym_name_size,
2320 const unsigned char* versym,
2322 const std::vector<const char*>* version_map);
2325 #ifdef HAVE_TARGET_64_LITTLE
2328 Symbol_table::add_from_dynobj<64, false>(
2329 Sized_dynobj<64, false>* dynobj,
2330 const unsigned char* syms,
2332 const char* sym_names,
2333 size_t sym_name_size,
2334 const unsigned char* versym,
2336 const std::vector<const char*>* version_map);
2339 #ifdef HAVE_TARGET_64_BIG
2342 Symbol_table::add_from_dynobj<64, true>(
2343 Sized_dynobj<64, true>* dynobj,
2344 const unsigned char* syms,
2346 const char* sym_names,
2347 size_t sym_name_size,
2348 const unsigned char* versym,
2350 const std::vector<const char*>* version_map);
2353 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2356 Symbol_table::define_with_copy_reloc<32>(
2357 Sized_symbol<32>* sym,
2359 elfcpp::Elf_types<32>::Elf_Addr value);
2362 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2365 Symbol_table::define_with_copy_reloc<64>(
2366 Sized_symbol<64>* sym,
2368 elfcpp::Elf_types<64>::Elf_Addr value);
2371 #ifdef HAVE_TARGET_32_LITTLE
2374 Warnings::issue_warning<32, false>(const Symbol* sym,
2375 const Relocate_info<32, false>* relinfo,
2376 size_t relnum, off_t reloffset) const;
2379 #ifdef HAVE_TARGET_32_BIG
2382 Warnings::issue_warning<32, true>(const Symbol* sym,
2383 const Relocate_info<32, true>* relinfo,
2384 size_t relnum, off_t reloffset) const;
2387 #ifdef HAVE_TARGET_64_LITTLE
2390 Warnings::issue_warning<64, false>(const Symbol* sym,
2391 const Relocate_info<64, false>* relinfo,
2392 size_t relnum, off_t reloffset) const;
2395 #ifdef HAVE_TARGET_64_BIG
2398 Warnings::issue_warning<64, true>(const Symbol* sym,
2399 const Relocate_info<64, true>* relinfo,
2400 size_t relnum, off_t reloffset) const;
2403 } // End namespace gold.