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_(), tls_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 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
482 // is only called for undefined symbols, when at least one --wrap
486 Symbol_table::wrap_symbol(Object* object, const char* name,
487 Stringpool::Key* name_key)
489 // For some targets, we need to ignore a specific character when
490 // wrapping, and add it back later.
492 if (name[0] == object->target()->wrap_char())
498 if (parameters->options().is_wrap(name))
500 // Turn NAME into __wrap_NAME.
507 // This will give us both the old and new name in NAMEPOOL_, but
508 // that is OK. Only the versions we need will wind up in the
509 // real string table in the output file.
510 return this->namepool_.add(s.c_str(), true, name_key);
513 const char* const real_prefix = "__real_";
514 const size_t real_prefix_length = strlen(real_prefix);
515 if (strncmp(name, real_prefix, real_prefix_length) == 0
516 && parameters->options().is_wrap(name + real_prefix_length))
518 // Turn __real_NAME into NAME.
522 s += name + real_prefix_length;
523 return this->namepool_.add(s.c_str(), true, name_key);
529 // Add one symbol from OBJECT to the symbol table. NAME is symbol
530 // name and VERSION is the version; both are canonicalized. DEF is
531 // whether this is the default version.
533 // If DEF is true, then this is the definition of a default version of
534 // a symbol. That means that any lookup of NAME/NULL and any lookup
535 // of NAME/VERSION should always return the same symbol. This is
536 // obvious for references, but in particular we want to do this for
537 // definitions: overriding NAME/NULL should also override
538 // NAME/VERSION. If we don't do that, it would be very hard to
539 // override functions in a shared library which uses versioning.
541 // We implement this by simply making both entries in the hash table
542 // point to the same Symbol structure. That is easy enough if this is
543 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
544 // that we have seen both already, in which case they will both have
545 // independent entries in the symbol table. We can't simply change
546 // the symbol table entry, because we have pointers to the entries
547 // attached to the object files. So we mark the entry attached to the
548 // object file as a forwarder, and record it in the forwarders_ map.
549 // Note that entries in the hash table will never be marked as
552 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
553 // symbol exactly as it existed in the input file. SYM is usually
554 // that as well, but can be modified, for instance if we determine
555 // it's in a to-be-discarded section.
557 template<int size, bool big_endian>
559 Symbol_table::add_from_object(Object* object,
561 Stringpool::Key name_key,
563 Stringpool::Key version_key,
565 const elfcpp::Sym<size, big_endian>& sym,
566 const elfcpp::Sym<size, big_endian>& orig_sym)
568 // Print a message if this symbol is being traced.
569 if (parameters->options().is_trace_symbol(name))
571 if (orig_sym.get_st_shndx() == elfcpp::SHN_UNDEF)
572 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
574 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
577 // For an undefined symbol, we may need to adjust the name using
579 if (orig_sym.get_st_shndx() == elfcpp::SHN_UNDEF
580 && parameters->options().any_wrap())
582 const char* wrap_name = this->wrap_symbol(object, name, &name_key);
583 if (wrap_name != name)
585 // If we see a reference to malloc with version GLIBC_2.0,
586 // and we turn it into a reference to __wrap_malloc, then we
587 // discard the version number. Otherwise the user would be
588 // required to specify the correct version for
596 Symbol* const snull = NULL;
597 std::pair<typename Symbol_table_type::iterator, bool> ins =
598 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
601 std::pair<typename Symbol_table_type::iterator, bool> insdef =
602 std::make_pair(this->table_.end(), false);
605 const Stringpool::Key vnull_key = 0;
606 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
611 // ins.first: an iterator, which is a pointer to a pair.
612 // ins.first->first: the key (a pair of name and version).
613 // ins.first->second: the value (Symbol*).
614 // ins.second: true if new entry was inserted, false if not.
616 Sized_symbol<size>* ret;
621 // We already have an entry for NAME/VERSION.
622 ret = this->get_sized_symbol<size>(ins.first->second);
623 gold_assert(ret != NULL);
625 was_undefined = ret->is_undefined();
626 was_common = ret->is_common();
628 this->resolve(ret, sym, orig_sym, object, version);
634 // This is the first time we have seen NAME/NULL. Make
635 // NAME/NULL point to NAME/VERSION.
636 insdef.first->second = ret;
638 else if (insdef.first->second != ret
639 && insdef.first->second->is_undefined())
641 // This is the unfortunate case where we already have
642 // entries for both NAME/VERSION and NAME/NULL. Note
643 // that we don't want to combine them if the existing
644 // symbol is going to override the new one. FIXME: We
645 // currently just test is_undefined, but this may not do
646 // the right thing if the existing symbol is from a
647 // shared library and the new one is from a regular
650 const Sized_symbol<size>* sym2;
651 sym2 = this->get_sized_symbol<size>(insdef.first->second);
652 Symbol_table::resolve<size, big_endian>(ret, sym2, version);
653 this->make_forwarder(insdef.first->second, ret);
654 insdef.first->second = ret;
662 // This is the first time we have seen NAME/VERSION.
663 gold_assert(ins.first->second == NULL);
665 if (def && !insdef.second)
667 // We already have an entry for NAME/NULL. If we override
668 // it, then change it to NAME/VERSION.
669 ret = this->get_sized_symbol<size>(insdef.first->second);
671 was_undefined = ret->is_undefined();
672 was_common = ret->is_common();
674 this->resolve(ret, sym, orig_sym, object, version);
675 ins.first->second = ret;
679 was_undefined = false;
682 Sized_target<size, big_endian>* target =
683 object->sized_target<size, big_endian>();
684 if (!target->has_make_symbol())
685 ret = new Sized_symbol<size>();
688 ret = target->make_symbol();
691 // This means that we don't want a symbol table
694 this->table_.erase(ins.first);
697 this->table_.erase(insdef.first);
698 // Inserting insdef invalidated ins.
699 this->table_.erase(std::make_pair(name_key,
706 ret->init(name, version, object, sym);
708 ins.first->second = ret;
711 // This is the first time we have seen NAME/NULL. Point
712 // it at the new entry for NAME/VERSION.
713 gold_assert(insdef.second);
714 insdef.first->second = ret;
719 // Record every time we see a new undefined symbol, to speed up
721 if (!was_undefined && ret->is_undefined())
722 ++this->saw_undefined_;
724 // Keep track of common symbols, to speed up common symbol
726 if (!was_common && ret->is_common())
728 if (ret->type() != elfcpp::STT_TLS)
729 this->commons_.push_back(ret);
731 this->tls_commons_.push_back(ret);
735 ret->set_is_default();
739 // Add all the symbols in a relocatable object to the hash table.
741 template<int size, bool big_endian>
743 Symbol_table::add_from_relobj(
744 Sized_relobj<size, big_endian>* relobj,
745 const unsigned char* syms,
747 const char* sym_names,
748 size_t sym_name_size,
749 typename Sized_relobj<size, big_endian>::Symbols* sympointers)
751 gold_assert(size == relobj->target()->get_size());
752 gold_assert(size == parameters->target().get_size());
754 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
756 const bool just_symbols = relobj->just_symbols();
758 const unsigned char* p = syms;
759 for (size_t i = 0; i < count; ++i, p += sym_size)
761 elfcpp::Sym<size, big_endian> sym(p);
762 elfcpp::Sym<size, big_endian>* psym = &sym;
764 unsigned int st_name = psym->get_st_name();
765 if (st_name >= sym_name_size)
767 relobj->error(_("bad global symbol name offset %u at %zu"),
772 const char* name = sym_names + st_name;
774 // A symbol defined in a section which we are not including must
775 // be treated as an undefined symbol.
776 unsigned char symbuf[sym_size];
777 elfcpp::Sym<size, big_endian> sym2(symbuf);
778 unsigned int st_shndx = psym->get_st_shndx();
779 if (st_shndx != elfcpp::SHN_UNDEF
780 && st_shndx < elfcpp::SHN_LORESERVE
781 && !relobj->is_section_included(st_shndx))
783 memcpy(symbuf, p, sym_size);
784 elfcpp::Sym_write<size, big_endian> sw(symbuf);
785 sw.put_st_shndx(elfcpp::SHN_UNDEF);
789 // In an object file, an '@' in the name separates the symbol
790 // name from the version name. If there are two '@' characters,
791 // this is the default version.
792 const char* ver = strchr(name, '@');
794 // DEF: is the version default? LOCAL: is the symbol forced local?
800 // The symbol name is of the form foo@VERSION or foo@@VERSION
801 namelen = ver - name;
809 // We don't want to assign a version to an undefined symbol,
810 // even if it is listed in the version script. FIXME: What
811 // about a common symbol?
812 else if (!version_script_.empty()
813 && psym->get_st_shndx() != elfcpp::SHN_UNDEF)
815 // The symbol name did not have a version, but
816 // the version script may assign a version anyway.
817 namelen = strlen(name);
819 // Check the global: entries from the version script.
820 const std::string& version =
821 version_script_.get_symbol_version(name);
822 if (!version.empty())
823 ver = version.c_str();
824 // Check the local: entries from the version script
825 if (version_script_.symbol_is_local(name))
832 memcpy(symbuf, p, sym_size);
833 elfcpp::Sym_write<size, big_endian> sw(symbuf);
834 sw.put_st_shndx(elfcpp::SHN_ABS);
835 if (st_shndx != elfcpp::SHN_UNDEF
836 && st_shndx < elfcpp::SHN_LORESERVE)
838 // Symbol values in object files are section relative.
839 // This is normally what we want, but since here we are
840 // converting the symbol to absolute we need to add the
841 // section address. The section address in an object
842 // file is normally zero, but people can use a linker
843 // script to change it.
844 sw.put_st_value(sym2.get_st_value()
845 + relobj->section_address(st_shndx));
850 Sized_symbol<size>* res;
853 Stringpool::Key name_key;
854 name = this->namepool_.add(name, true, &name_key);
855 res = this->add_from_object(relobj, name, name_key, NULL, 0,
858 this->force_local(res);
862 Stringpool::Key name_key;
863 name = this->namepool_.add_with_length(name, namelen, true,
865 Stringpool::Key ver_key;
866 ver = this->namepool_.add(ver, true, &ver_key);
868 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
872 (*sympointers)[i] = res;
876 // Add all the symbols in a dynamic object to the hash table.
878 template<int size, bool big_endian>
880 Symbol_table::add_from_dynobj(
881 Sized_dynobj<size, big_endian>* dynobj,
882 const unsigned char* syms,
884 const char* sym_names,
885 size_t sym_name_size,
886 const unsigned char* versym,
888 const std::vector<const char*>* version_map)
890 gold_assert(size == dynobj->target()->get_size());
891 gold_assert(size == parameters->target().get_size());
893 if (dynobj->just_symbols())
895 gold_error(_("--just-symbols does not make sense with a shared object"));
899 if (versym != NULL && versym_size / 2 < count)
901 dynobj->error(_("too few symbol versions"));
905 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
907 // We keep a list of all STT_OBJECT symbols, so that we can resolve
908 // weak aliases. This is necessary because if the dynamic object
909 // provides the same variable under two names, one of which is a
910 // weak definition, and the regular object refers to the weak
911 // definition, we have to put both the weak definition and the
912 // strong definition into the dynamic symbol table. Given a weak
913 // definition, the only way that we can find the corresponding
914 // strong definition, if any, is to search the symbol table.
915 std::vector<Sized_symbol<size>*> object_symbols;
917 const unsigned char* p = syms;
918 const unsigned char* vs = versym;
919 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
921 elfcpp::Sym<size, big_endian> sym(p);
923 // Ignore symbols with local binding or that have
924 // internal or hidden visibility.
925 if (sym.get_st_bind() == elfcpp::STB_LOCAL
926 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
927 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
930 unsigned int st_name = sym.get_st_name();
931 if (st_name >= sym_name_size)
933 dynobj->error(_("bad symbol name offset %u at %zu"),
938 const char* name = sym_names + st_name;
940 Sized_symbol<size>* res;
944 Stringpool::Key name_key;
945 name = this->namepool_.add(name, true, &name_key);
946 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
951 // Read the version information.
953 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
955 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
956 v &= elfcpp::VERSYM_VERSION;
958 // The Sun documentation says that V can be VER_NDX_LOCAL,
959 // or VER_NDX_GLOBAL, or a version index. The meaning of
960 // VER_NDX_LOCAL is defined as "Symbol has local scope."
961 // The old GNU linker will happily generate VER_NDX_LOCAL
962 // for an undefined symbol. I don't know what the Sun
963 // linker will generate.
965 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
966 && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
968 // This symbol should not be visible outside the object.
972 // At this point we are definitely going to add this symbol.
973 Stringpool::Key name_key;
974 name = this->namepool_.add(name, true, &name_key);
976 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
977 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
979 // This symbol does not have a version.
980 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
985 if (v >= version_map->size())
987 dynobj->error(_("versym for symbol %zu out of range: %u"),
992 const char* version = (*version_map)[v];
995 dynobj->error(_("versym for symbol %zu has no name: %u"),
1000 Stringpool::Key version_key;
1001 version = this->namepool_.add(version, true, &version_key);
1003 // If this is an absolute symbol, and the version name
1004 // and symbol name are the same, then this is the
1005 // version definition symbol. These symbols exist to
1006 // support using -u to pull in particular versions. We
1007 // do not want to record a version for them.
1008 if (sym.get_st_shndx() == elfcpp::SHN_ABS
1009 && name_key == version_key)
1010 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1014 const bool def = (!hidden
1015 && (sym.get_st_shndx()
1016 != elfcpp::SHN_UNDEF));
1017 res = this->add_from_object(dynobj, name, name_key, version,
1018 version_key, def, sym, sym);
1023 // Note that it is possible that RES was overridden by an
1024 // earlier object, in which case it can't be aliased here.
1025 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
1026 && sym.get_st_type() == elfcpp::STT_OBJECT
1027 && res->source() == Symbol::FROM_OBJECT
1028 && res->object() == dynobj)
1029 object_symbols.push_back(res);
1032 this->record_weak_aliases(&object_symbols);
1035 // This is used to sort weak aliases. We sort them first by section
1036 // index, then by offset, then by weak ahead of strong.
1039 class Weak_alias_sorter
1042 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1047 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1048 const Sized_symbol<size>* s2) const
1050 if (s1->shndx() != s2->shndx())
1051 return s1->shndx() < s2->shndx();
1052 if (s1->value() != s2->value())
1053 return s1->value() < s2->value();
1054 if (s1->binding() != s2->binding())
1056 if (s1->binding() == elfcpp::STB_WEAK)
1058 if (s2->binding() == elfcpp::STB_WEAK)
1061 return std::string(s1->name()) < std::string(s2->name());
1064 // SYMBOLS is a list of object symbols from a dynamic object. Look
1065 // for any weak aliases, and record them so that if we add the weak
1066 // alias to the dynamic symbol table, we also add the corresponding
1071 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1073 // Sort the vector by section index, then by offset, then by weak
1075 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1077 // Walk through the vector. For each weak definition, record
1079 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1081 p != symbols->end();
1084 if ((*p)->binding() != elfcpp::STB_WEAK)
1087 // Build a circular list of weak aliases. Each symbol points to
1088 // the next one in the circular list.
1090 Sized_symbol<size>* from_sym = *p;
1091 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1092 for (q = p + 1; q != symbols->end(); ++q)
1094 if ((*q)->shndx() != from_sym->shndx()
1095 || (*q)->value() != from_sym->value())
1098 this->weak_aliases_[from_sym] = *q;
1099 from_sym->set_has_alias();
1105 this->weak_aliases_[from_sym] = *p;
1106 from_sym->set_has_alias();
1113 // Create and return a specially defined symbol. If ONLY_IF_REF is
1114 // true, then only create the symbol if there is a reference to it.
1115 // If this does not return NULL, it sets *POLDSYM to the existing
1116 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1118 template<int size, bool big_endian>
1120 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1122 Sized_symbol<size>** poldsym)
1125 Sized_symbol<size>* sym;
1126 bool add_to_table = false;
1127 typename Symbol_table_type::iterator add_loc = this->table_.end();
1129 // If the caller didn't give us a version, see if we get one from
1130 // the version script.
1131 if (*pversion == NULL)
1133 const std::string& v(this->version_script_.get_symbol_version(*pname));
1135 *pversion = v.c_str();
1140 oldsym = this->lookup(*pname, *pversion);
1141 if (oldsym == NULL || !oldsym->is_undefined())
1144 *pname = oldsym->name();
1145 *pversion = oldsym->version();
1149 // Canonicalize NAME and VERSION.
1150 Stringpool::Key name_key;
1151 *pname = this->namepool_.add(*pname, true, &name_key);
1153 Stringpool::Key version_key = 0;
1154 if (*pversion != NULL)
1155 *pversion = this->namepool_.add(*pversion, true, &version_key);
1157 Symbol* const snull = NULL;
1158 std::pair<typename Symbol_table_type::iterator, bool> ins =
1159 this->table_.insert(std::make_pair(std::make_pair(name_key,
1165 // We already have a symbol table entry for NAME/VERSION.
1166 oldsym = ins.first->second;
1167 gold_assert(oldsym != NULL);
1171 // We haven't seen this symbol before.
1172 gold_assert(ins.first->second == NULL);
1173 add_to_table = true;
1174 add_loc = ins.first;
1179 const Target& target = parameters->target();
1180 if (!target.has_make_symbol())
1181 sym = new Sized_symbol<size>();
1184 gold_assert(target.get_size() == size);
1185 gold_assert(target.is_big_endian() ? big_endian : !big_endian);
1186 typedef Sized_target<size, big_endian> My_target;
1187 const My_target* sized_target =
1188 static_cast<const My_target*>(&target);
1189 sym = sized_target->make_symbol();
1195 add_loc->second = sym;
1197 gold_assert(oldsym != NULL);
1199 *poldsym = this->get_sized_symbol<size>(oldsym);
1204 // Define a symbol based on an Output_data.
1207 Symbol_table::define_in_output_data(const char* name,
1208 const char* version,
1213 elfcpp::STB binding,
1214 elfcpp::STV visibility,
1215 unsigned char nonvis,
1216 bool offset_is_from_end,
1219 if (parameters->target().get_size() == 32)
1221 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1222 return this->do_define_in_output_data<32>(name, version, od,
1223 value, symsize, type, binding,
1231 else if (parameters->target().get_size() == 64)
1233 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1234 return this->do_define_in_output_data<64>(name, version, od,
1235 value, symsize, type, binding,
1247 // Define a symbol in an Output_data, sized version.
1251 Symbol_table::do_define_in_output_data(
1253 const char* version,
1255 typename elfcpp::Elf_types<size>::Elf_Addr value,
1256 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1258 elfcpp::STB binding,
1259 elfcpp::STV visibility,
1260 unsigned char nonvis,
1261 bool offset_is_from_end,
1264 Sized_symbol<size>* sym;
1265 Sized_symbol<size>* oldsym;
1267 if (parameters->target().is_big_endian())
1269 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1270 sym = this->define_special_symbol<size, true>(&name, &version,
1271 only_if_ref, &oldsym);
1278 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1279 sym = this->define_special_symbol<size, false>(&name, &version,
1280 only_if_ref, &oldsym);
1289 gold_assert(version == NULL || oldsym != NULL);
1290 sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1291 offset_is_from_end);
1295 if (binding == elfcpp::STB_LOCAL
1296 || this->version_script_.symbol_is_local(name))
1297 this->force_local(sym);
1301 if (Symbol_table::should_override_with_special(oldsym))
1302 this->override_with_special(oldsym, sym);
1307 // Define a symbol based on an Output_segment.
1310 Symbol_table::define_in_output_segment(const char* name,
1311 const char* version, Output_segment* os,
1315 elfcpp::STB binding,
1316 elfcpp::STV visibility,
1317 unsigned char nonvis,
1318 Symbol::Segment_offset_base offset_base,
1321 if (parameters->target().get_size() == 32)
1323 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1324 return this->do_define_in_output_segment<32>(name, version, os,
1325 value, symsize, type,
1326 binding, visibility, nonvis,
1327 offset_base, only_if_ref);
1332 else if (parameters->target().get_size() == 64)
1334 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1335 return this->do_define_in_output_segment<64>(name, version, os,
1336 value, symsize, type,
1337 binding, visibility, nonvis,
1338 offset_base, only_if_ref);
1347 // Define a symbol in an Output_segment, sized version.
1351 Symbol_table::do_define_in_output_segment(
1353 const char* version,
1355 typename elfcpp::Elf_types<size>::Elf_Addr value,
1356 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1358 elfcpp::STB binding,
1359 elfcpp::STV visibility,
1360 unsigned char nonvis,
1361 Symbol::Segment_offset_base offset_base,
1364 Sized_symbol<size>* sym;
1365 Sized_symbol<size>* oldsym;
1367 if (parameters->target().is_big_endian())
1369 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1370 sym = this->define_special_symbol<size, true>(&name, &version,
1371 only_if_ref, &oldsym);
1378 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1379 sym = this->define_special_symbol<size, false>(&name, &version,
1380 only_if_ref, &oldsym);
1389 gold_assert(version == NULL || oldsym != NULL);
1390 sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1395 if (binding == elfcpp::STB_LOCAL
1396 || this->version_script_.symbol_is_local(name))
1397 this->force_local(sym);
1401 if (Symbol_table::should_override_with_special(oldsym))
1402 this->override_with_special(oldsym, sym);
1407 // Define a special symbol with a constant value. It is a multiple
1408 // definition error if this symbol is already defined.
1411 Symbol_table::define_as_constant(const char* name,
1412 const char* version,
1416 elfcpp::STB binding,
1417 elfcpp::STV visibility,
1418 unsigned char nonvis,
1420 bool force_override)
1422 if (parameters->target().get_size() == 32)
1424 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1425 return this->do_define_as_constant<32>(name, version, value,
1426 symsize, type, binding,
1427 visibility, nonvis, only_if_ref,
1433 else if (parameters->target().get_size() == 64)
1435 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1436 return this->do_define_as_constant<64>(name, version, value,
1437 symsize, type, binding,
1438 visibility, nonvis, only_if_ref,
1448 // Define a symbol as a constant, sized version.
1452 Symbol_table::do_define_as_constant(
1454 const char* version,
1455 typename elfcpp::Elf_types<size>::Elf_Addr value,
1456 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1458 elfcpp::STB binding,
1459 elfcpp::STV visibility,
1460 unsigned char nonvis,
1462 bool force_override)
1464 Sized_symbol<size>* sym;
1465 Sized_symbol<size>* oldsym;
1467 if (parameters->target().is_big_endian())
1469 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1470 sym = this->define_special_symbol<size, true>(&name, &version,
1471 only_if_ref, &oldsym);
1478 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1479 sym = this->define_special_symbol<size, false>(&name, &version,
1480 only_if_ref, &oldsym);
1489 gold_assert(version == NULL || version == name || oldsym != NULL);
1490 sym->init(name, value, symsize, type, binding, visibility, nonvis);
1494 // Version symbols are absolute symbols with name == version.
1495 // We don't want to force them to be local.
1496 if ((version == NULL
1499 && (binding == elfcpp::STB_LOCAL
1500 || this->version_script_.symbol_is_local(name)))
1501 this->force_local(sym);
1505 if (force_override || Symbol_table::should_override_with_special(oldsym))
1506 this->override_with_special(oldsym, sym);
1511 // Define a set of symbols in output sections.
1514 Symbol_table::define_symbols(const Layout* layout, int count,
1515 const Define_symbol_in_section* p,
1518 for (int i = 0; i < count; ++i, ++p)
1520 Output_section* os = layout->find_output_section(p->output_section);
1522 this->define_in_output_data(p->name, NULL, os, p->value,
1523 p->size, p->type, p->binding,
1524 p->visibility, p->nonvis,
1525 p->offset_is_from_end,
1526 only_if_ref || p->only_if_ref);
1528 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1529 p->binding, p->visibility, p->nonvis,
1530 only_if_ref || p->only_if_ref,
1535 // Define a set of symbols in output segments.
1538 Symbol_table::define_symbols(const Layout* layout, int count,
1539 const Define_symbol_in_segment* p,
1542 for (int i = 0; i < count; ++i, ++p)
1544 Output_segment* os = layout->find_output_segment(p->segment_type,
1545 p->segment_flags_set,
1546 p->segment_flags_clear);
1548 this->define_in_output_segment(p->name, NULL, os, p->value,
1549 p->size, p->type, p->binding,
1550 p->visibility, p->nonvis,
1552 only_if_ref || p->only_if_ref);
1554 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1555 p->binding, p->visibility, p->nonvis,
1556 only_if_ref || p->only_if_ref,
1561 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1562 // symbol should be defined--typically a .dyn.bss section. VALUE is
1563 // the offset within POSD.
1567 Symbol_table::define_with_copy_reloc(
1568 Sized_symbol<size>* csym,
1570 typename elfcpp::Elf_types<size>::Elf_Addr value)
1572 gold_assert(csym->is_from_dynobj());
1573 gold_assert(!csym->is_copied_from_dynobj());
1574 Object* object = csym->object();
1575 gold_assert(object->is_dynamic());
1576 Dynobj* dynobj = static_cast<Dynobj*>(object);
1578 // Our copied variable has to override any variable in a shared
1580 elfcpp::STB binding = csym->binding();
1581 if (binding == elfcpp::STB_WEAK)
1582 binding = elfcpp::STB_GLOBAL;
1584 this->define_in_output_data(csym->name(), csym->version(),
1585 posd, value, csym->symsize(),
1586 csym->type(), binding,
1587 csym->visibility(), csym->nonvis(),
1590 csym->set_is_copied_from_dynobj();
1591 csym->set_needs_dynsym_entry();
1593 this->copied_symbol_dynobjs_[csym] = dynobj;
1595 // We have now defined all aliases, but we have not entered them all
1596 // in the copied_symbol_dynobjs_ map.
1597 if (csym->has_alias())
1602 sym = this->weak_aliases_[sym];
1605 gold_assert(sym->output_data() == posd);
1607 sym->set_is_copied_from_dynobj();
1608 this->copied_symbol_dynobjs_[sym] = dynobj;
1613 // SYM is defined using a COPY reloc. Return the dynamic object where
1614 // the original definition was found.
1617 Symbol_table::get_copy_source(const Symbol* sym) const
1619 gold_assert(sym->is_copied_from_dynobj());
1620 Copied_symbol_dynobjs::const_iterator p =
1621 this->copied_symbol_dynobjs_.find(sym);
1622 gold_assert(p != this->copied_symbol_dynobjs_.end());
1626 // Set the dynamic symbol indexes. INDEX is the index of the first
1627 // global dynamic symbol. Pointers to the symbols are stored into the
1628 // vector SYMS. The names are added to DYNPOOL. This returns an
1629 // updated dynamic symbol index.
1632 Symbol_table::set_dynsym_indexes(unsigned int index,
1633 std::vector<Symbol*>* syms,
1634 Stringpool* dynpool,
1637 for (Symbol_table_type::iterator p = this->table_.begin();
1638 p != this->table_.end();
1641 Symbol* sym = p->second;
1643 // Note that SYM may already have a dynamic symbol index, since
1644 // some symbols appear more than once in the symbol table, with
1645 // and without a version.
1647 if (!sym->should_add_dynsym_entry())
1648 sym->set_dynsym_index(-1U);
1649 else if (!sym->has_dynsym_index())
1651 sym->set_dynsym_index(index);
1653 syms->push_back(sym);
1654 dynpool->add(sym->name(), false, NULL);
1656 // Record any version information.
1657 if (sym->version() != NULL)
1658 versions->record_version(this, dynpool, sym);
1662 // Finish up the versions. In some cases this may add new dynamic
1664 index = versions->finalize(this, index, syms);
1669 // Set the final values for all the symbols. The index of the first
1670 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1671 // file offset OFF. Add their names to POOL. Return the new file
1672 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1675 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
1676 size_t dyncount, Stringpool* pool,
1677 unsigned int *plocal_symcount)
1681 gold_assert(*plocal_symcount != 0);
1682 this->first_global_index_ = *plocal_symcount;
1684 this->dynamic_offset_ = dynoff;
1685 this->first_dynamic_global_index_ = dyn_global_index;
1686 this->dynamic_count_ = dyncount;
1688 if (parameters->target().get_size() == 32)
1690 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1691 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
1696 else if (parameters->target().get_size() == 64)
1698 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1699 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
1707 // Now that we have the final symbol table, we can reliably note
1708 // which symbols should get warnings.
1709 this->warnings_.note_warnings(this);
1714 // SYM is going into the symbol table at *PINDEX. Add the name to
1715 // POOL, update *PINDEX and *POFF.
1719 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
1720 unsigned int* pindex, off_t* poff)
1722 sym->set_symtab_index(*pindex);
1723 pool->add(sym->name(), false, NULL);
1725 *poff += elfcpp::Elf_sizes<size>::sym_size;
1728 // Set the final value for all the symbols. This is called after
1729 // Layout::finalize, so all the output sections have their final
1734 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
1735 unsigned int* plocal_symcount)
1737 off = align_address(off, size >> 3);
1738 this->offset_ = off;
1740 unsigned int index = *plocal_symcount;
1741 const unsigned int orig_index = index;
1743 // First do all the symbols which have been forced to be local, as
1744 // they must appear before all global symbols.
1745 for (Forced_locals::iterator p = this->forced_locals_.begin();
1746 p != this->forced_locals_.end();
1750 gold_assert(sym->is_forced_local());
1751 if (this->sized_finalize_symbol<size>(sym))
1753 this->add_to_final_symtab<size>(sym, pool, &index, &off);
1758 // Now do all the remaining symbols.
1759 for (Symbol_table_type::iterator p = this->table_.begin();
1760 p != this->table_.end();
1763 Symbol* sym = p->second;
1764 if (this->sized_finalize_symbol<size>(sym))
1765 this->add_to_final_symtab<size>(sym, pool, &index, &off);
1768 this->output_count_ = index - orig_index;
1773 // Finalize the symbol SYM. This returns true if the symbol should be
1774 // added to the symbol table, false otherwise.
1778 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
1780 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
1782 // The default version of a symbol may appear twice in the symbol
1783 // table. We only need to finalize it once.
1784 if (sym->has_symtab_index())
1789 gold_assert(!sym->has_symtab_index());
1790 sym->set_symtab_index(-1U);
1791 gold_assert(sym->dynsym_index() == -1U);
1795 typename Sized_symbol<size>::Value_type value;
1797 switch (sym->source())
1799 case Symbol::FROM_OBJECT:
1801 unsigned int shndx = sym->shndx();
1803 // FIXME: We need some target specific support here.
1804 if (shndx >= elfcpp::SHN_LORESERVE
1805 && shndx != elfcpp::SHN_ABS
1806 && shndx != elfcpp::SHN_COMMON)
1808 gold_error(_("%s: unsupported symbol section 0x%x"),
1809 sym->demangled_name().c_str(), shndx);
1810 shndx = elfcpp::SHN_UNDEF;
1813 Object* symobj = sym->object();
1814 if (symobj->is_dynamic())
1817 shndx = elfcpp::SHN_UNDEF;
1819 else if (shndx == elfcpp::SHN_UNDEF)
1821 else if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
1822 value = sym->value();
1825 Relobj* relobj = static_cast<Relobj*>(symobj);
1826 section_offset_type secoff;
1827 Output_section* os = relobj->output_section(shndx, &secoff);
1831 sym->set_symtab_index(-1U);
1832 gold_assert(sym->dynsym_index() == -1U);
1836 if (sym->type() == elfcpp::STT_TLS)
1837 value = sym->value() + os->tls_offset() + secoff;
1839 value = sym->value() + os->address() + secoff;
1844 case Symbol::IN_OUTPUT_DATA:
1846 Output_data* od = sym->output_data();
1847 value = sym->value();
1848 if (sym->type() != elfcpp::STT_TLS)
1849 value += od->address();
1852 Output_section* os = od->output_section();
1853 gold_assert(os != NULL);
1854 value += os->tls_offset() + (od->address() - os->address());
1856 if (sym->offset_is_from_end())
1857 value += od->data_size();
1861 case Symbol::IN_OUTPUT_SEGMENT:
1863 Output_segment* os = sym->output_segment();
1864 value = sym->value();
1865 if (sym->type() != elfcpp::STT_TLS)
1866 value += os->vaddr();
1867 switch (sym->offset_base())
1869 case Symbol::SEGMENT_START:
1871 case Symbol::SEGMENT_END:
1872 value += os->memsz();
1874 case Symbol::SEGMENT_BSS:
1875 value += os->filesz();
1883 case Symbol::CONSTANT:
1884 value = sym->value();
1891 sym->set_value(value);
1893 if (parameters->options().strip_all())
1895 sym->set_symtab_index(-1U);
1902 // Write out the global symbols.
1905 Symbol_table::write_globals(const Input_objects* input_objects,
1906 const Stringpool* sympool,
1907 const Stringpool* dynpool, Output_file* of) const
1909 switch (parameters->size_and_endianness())
1911 #ifdef HAVE_TARGET_32_LITTLE
1912 case Parameters::TARGET_32_LITTLE:
1913 this->sized_write_globals<32, false>(input_objects, sympool,
1917 #ifdef HAVE_TARGET_32_BIG
1918 case Parameters::TARGET_32_BIG:
1919 this->sized_write_globals<32, true>(input_objects, sympool,
1923 #ifdef HAVE_TARGET_64_LITTLE
1924 case Parameters::TARGET_64_LITTLE:
1925 this->sized_write_globals<64, false>(input_objects, sympool,
1929 #ifdef HAVE_TARGET_64_BIG
1930 case Parameters::TARGET_64_BIG:
1931 this->sized_write_globals<64, true>(input_objects, sympool,
1940 // Write out the global symbols.
1942 template<int size, bool big_endian>
1944 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1945 const Stringpool* sympool,
1946 const Stringpool* dynpool,
1947 Output_file* of) const
1949 const Target& target = parameters->target();
1951 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1953 const unsigned int output_count = this->output_count_;
1954 const section_size_type oview_size = output_count * sym_size;
1955 const unsigned int first_global_index = this->first_global_index_;
1956 unsigned char* psyms;
1957 if (this->offset_ == 0 || output_count == 0)
1960 psyms = of->get_output_view(this->offset_, oview_size);
1962 const unsigned int dynamic_count = this->dynamic_count_;
1963 const section_size_type dynamic_size = dynamic_count * sym_size;
1964 const unsigned int first_dynamic_global_index =
1965 this->first_dynamic_global_index_;
1966 unsigned char* dynamic_view;
1967 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
1968 dynamic_view = NULL;
1970 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1972 for (Symbol_table_type::const_iterator p = this->table_.begin();
1973 p != this->table_.end();
1976 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1978 // Possibly warn about unresolved symbols in shared libraries.
1979 this->warn_about_undefined_dynobj_symbol(input_objects, sym);
1981 unsigned int sym_index = sym->symtab_index();
1982 unsigned int dynsym_index;
1983 if (dynamic_view == NULL)
1986 dynsym_index = sym->dynsym_index();
1988 if (sym_index == -1U && dynsym_index == -1U)
1990 // This symbol is not included in the output file.
1995 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
1996 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
1997 switch (sym->source())
1999 case Symbol::FROM_OBJECT:
2001 unsigned int in_shndx = sym->shndx();
2003 // FIXME: We need some target specific support here.
2004 if (in_shndx >= elfcpp::SHN_LORESERVE
2005 && in_shndx != elfcpp::SHN_ABS
2006 && in_shndx != elfcpp::SHN_COMMON)
2008 gold_error(_("%s: unsupported symbol section 0x%x"),
2009 sym->demangled_name().c_str(), in_shndx);
2014 Object* symobj = sym->object();
2015 if (symobj->is_dynamic())
2017 if (sym->needs_dynsym_value())
2018 dynsym_value = target.dynsym_value(sym);
2019 shndx = elfcpp::SHN_UNDEF;
2021 else if (in_shndx == elfcpp::SHN_UNDEF
2022 || in_shndx == elfcpp::SHN_ABS
2023 || in_shndx == elfcpp::SHN_COMMON)
2027 Relobj* relobj = static_cast<Relobj*>(symobj);
2028 section_offset_type secoff;
2029 Output_section* os = relobj->output_section(in_shndx,
2031 gold_assert(os != NULL);
2032 shndx = os->out_shndx();
2034 // In object files symbol values are section
2036 if (parameters->options().relocatable())
2037 sym_value -= os->address();
2043 case Symbol::IN_OUTPUT_DATA:
2044 shndx = sym->output_data()->out_shndx();
2047 case Symbol::IN_OUTPUT_SEGMENT:
2048 shndx = elfcpp::SHN_ABS;
2051 case Symbol::CONSTANT:
2052 shndx = elfcpp::SHN_ABS;
2059 if (sym_index != -1U)
2061 sym_index -= first_global_index;
2062 gold_assert(sym_index < output_count);
2063 unsigned char* ps = psyms + (sym_index * sym_size);
2064 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2068 if (dynsym_index != -1U)
2070 dynsym_index -= first_dynamic_global_index;
2071 gold_assert(dynsym_index < dynamic_count);
2072 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2073 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2078 of->write_output_view(this->offset_, oview_size, psyms);
2079 if (dynamic_view != NULL)
2080 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2083 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2084 // strtab holding the name.
2086 template<int size, bool big_endian>
2088 Symbol_table::sized_write_symbol(
2089 Sized_symbol<size>* sym,
2090 typename elfcpp::Elf_types<size>::Elf_Addr value,
2092 const Stringpool* pool,
2093 unsigned char* p) const
2095 elfcpp::Sym_write<size, big_endian> osym(p);
2096 osym.put_st_name(pool->get_offset(sym->name()));
2097 osym.put_st_value(value);
2098 osym.put_st_size(sym->symsize());
2099 // A version script may have overridden the default binding.
2100 if (sym->is_forced_local())
2101 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2103 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2104 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2105 osym.put_st_shndx(shndx);
2108 // Check for unresolved symbols in shared libraries. This is
2109 // controlled by the --allow-shlib-undefined option.
2111 // We only warn about libraries for which we have seen all the
2112 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2113 // which were not seen in this link. If we didn't see a DT_NEEDED
2114 // entry, we aren't going to be able to reliably report whether the
2115 // symbol is undefined.
2117 // We also don't warn about libraries found in the system library
2118 // directory (the directory were we find libc.so); we assume that
2119 // those libraries are OK. This heuristic avoids problems in
2120 // GNU/Linux, in which -ldl can have undefined references satisfied by
2124 Symbol_table::warn_about_undefined_dynobj_symbol(
2125 const Input_objects* input_objects,
2128 if (sym->source() == Symbol::FROM_OBJECT
2129 && sym->object()->is_dynamic()
2130 && sym->shndx() == elfcpp::SHN_UNDEF
2131 && sym->binding() != elfcpp::STB_WEAK
2132 && !parameters->options().allow_shlib_undefined()
2133 && !parameters->target().is_defined_by_abi(sym)
2134 && !input_objects->found_in_system_library_directory(sym->object()))
2136 // A very ugly cast.
2137 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2138 if (!dynobj->has_unknown_needed_entries())
2139 gold_error(_("%s: undefined reference to '%s'"),
2140 sym->object()->name().c_str(),
2141 sym->demangled_name().c_str());
2145 // Write out a section symbol. Return the update offset.
2148 Symbol_table::write_section_symbol(const Output_section *os,
2152 switch (parameters->size_and_endianness())
2154 #ifdef HAVE_TARGET_32_LITTLE
2155 case Parameters::TARGET_32_LITTLE:
2156 this->sized_write_section_symbol<32, false>(os, of, offset);
2159 #ifdef HAVE_TARGET_32_BIG
2160 case Parameters::TARGET_32_BIG:
2161 this->sized_write_section_symbol<32, true>(os, of, offset);
2164 #ifdef HAVE_TARGET_64_LITTLE
2165 case Parameters::TARGET_64_LITTLE:
2166 this->sized_write_section_symbol<64, false>(os, of, offset);
2169 #ifdef HAVE_TARGET_64_BIG
2170 case Parameters::TARGET_64_BIG:
2171 this->sized_write_section_symbol<64, true>(os, of, offset);
2179 // Write out a section symbol, specialized for size and endianness.
2181 template<int size, bool big_endian>
2183 Symbol_table::sized_write_section_symbol(const Output_section* os,
2187 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2189 unsigned char* pov = of->get_output_view(offset, sym_size);
2191 elfcpp::Sym_write<size, big_endian> osym(pov);
2192 osym.put_st_name(0);
2193 osym.put_st_value(os->address());
2194 osym.put_st_size(0);
2195 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2196 elfcpp::STT_SECTION));
2197 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2198 osym.put_st_shndx(os->out_shndx());
2200 of->write_output_view(offset, sym_size, pov);
2203 // Print statistical information to stderr. This is used for --stats.
2206 Symbol_table::print_stats() const
2208 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2209 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2210 program_name, this->table_.size(), this->table_.bucket_count());
2212 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2213 program_name, this->table_.size());
2215 this->namepool_.print_stats("symbol table stringpool");
2218 // We check for ODR violations by looking for symbols with the same
2219 // name for which the debugging information reports that they were
2220 // defined in different source locations. When comparing the source
2221 // location, we consider instances with the same base filename and
2222 // line number to be the same. This is because different object
2223 // files/shared libraries can include the same header file using
2224 // different paths, and we don't want to report an ODR violation in
2227 // This struct is used to compare line information, as returned by
2228 // Dwarf_line_info::one_addr2line. It implements a < comparison
2229 // operator used with std::set.
2231 struct Odr_violation_compare
2234 operator()(const std::string& s1, const std::string& s2) const
2236 std::string::size_type pos1 = s1.rfind('/');
2237 std::string::size_type pos2 = s2.rfind('/');
2238 if (pos1 == std::string::npos
2239 || pos2 == std::string::npos)
2241 return s1.compare(pos1, std::string::npos,
2242 s2, pos2, std::string::npos) < 0;
2246 // Check candidate_odr_violations_ to find symbols with the same name
2247 // but apparently different definitions (different source-file/line-no).
2250 Symbol_table::detect_odr_violations(const Task* task,
2251 const char* output_file_name) const
2253 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2254 it != candidate_odr_violations_.end();
2257 const char* symbol_name = it->first;
2258 // We use a sorted set so the output is deterministic.
2259 std::set<std::string, Odr_violation_compare> line_nums;
2261 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2262 locs = it->second.begin();
2263 locs != it->second.end();
2266 // We need to lock the object in order to read it. This
2267 // means that we have to run in a singleton Task. If we
2268 // want to run this in a general Task for better
2269 // performance, we will need one Task for object, plus
2270 // appropriate locking to ensure that we don't conflict with
2271 // other uses of the object.
2272 Task_lock_obj<Object> tl(task, locs->object);
2273 std::string lineno = Dwarf_line_info::one_addr2line(
2274 locs->object, locs->shndx, locs->offset);
2275 if (!lineno.empty())
2276 line_nums.insert(lineno);
2279 if (line_nums.size() > 1)
2281 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2282 "places (possible ODR violation):"),
2283 output_file_name, demangle(symbol_name).c_str());
2284 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
2285 it2 != line_nums.end();
2287 fprintf(stderr, " %s\n", it2->c_str());
2292 // Warnings functions.
2294 // Add a new warning.
2297 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
2298 const std::string& warning)
2300 name = symtab->canonicalize_name(name);
2301 this->warnings_[name].set(obj, warning);
2304 // Look through the warnings and mark the symbols for which we should
2305 // warn. This is called during Layout::finalize when we know the
2306 // sources for all the symbols.
2309 Warnings::note_warnings(Symbol_table* symtab)
2311 for (Warning_table::iterator p = this->warnings_.begin();
2312 p != this->warnings_.end();
2315 Symbol* sym = symtab->lookup(p->first, NULL);
2317 && sym->source() == Symbol::FROM_OBJECT
2318 && sym->object() == p->second.object)
2319 sym->set_has_warning();
2323 // Issue a warning. This is called when we see a relocation against a
2324 // symbol for which has a warning.
2326 template<int size, bool big_endian>
2328 Warnings::issue_warning(const Symbol* sym,
2329 const Relocate_info<size, big_endian>* relinfo,
2330 size_t relnum, off_t reloffset) const
2332 gold_assert(sym->has_warning());
2333 Warning_table::const_iterator p = this->warnings_.find(sym->name());
2334 gold_assert(p != this->warnings_.end());
2335 gold_warning_at_location(relinfo, relnum, reloffset,
2336 "%s", p->second.text.c_str());
2339 // Instantiate the templates we need. We could use the configure
2340 // script to restrict this to only the ones needed for implemented
2343 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2346 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2349 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2352 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2355 #ifdef HAVE_TARGET_32_LITTLE
2358 Symbol_table::add_from_relobj<32, false>(
2359 Sized_relobj<32, false>* relobj,
2360 const unsigned char* syms,
2362 const char* sym_names,
2363 size_t sym_name_size,
2364 Sized_relobj<32, true>::Symbols* sympointers);
2367 #ifdef HAVE_TARGET_32_BIG
2370 Symbol_table::add_from_relobj<32, true>(
2371 Sized_relobj<32, true>* relobj,
2372 const unsigned char* syms,
2374 const char* sym_names,
2375 size_t sym_name_size,
2376 Sized_relobj<32, false>::Symbols* sympointers);
2379 #ifdef HAVE_TARGET_64_LITTLE
2382 Symbol_table::add_from_relobj<64, false>(
2383 Sized_relobj<64, false>* relobj,
2384 const unsigned char* syms,
2386 const char* sym_names,
2387 size_t sym_name_size,
2388 Sized_relobj<64, true>::Symbols* sympointers);
2391 #ifdef HAVE_TARGET_64_BIG
2394 Symbol_table::add_from_relobj<64, true>(
2395 Sized_relobj<64, true>* relobj,
2396 const unsigned char* syms,
2398 const char* sym_names,
2399 size_t sym_name_size,
2400 Sized_relobj<64, false>::Symbols* sympointers);
2403 #ifdef HAVE_TARGET_32_LITTLE
2406 Symbol_table::add_from_dynobj<32, false>(
2407 Sized_dynobj<32, false>* dynobj,
2408 const unsigned char* syms,
2410 const char* sym_names,
2411 size_t sym_name_size,
2412 const unsigned char* versym,
2414 const std::vector<const char*>* version_map);
2417 #ifdef HAVE_TARGET_32_BIG
2420 Symbol_table::add_from_dynobj<32, true>(
2421 Sized_dynobj<32, true>* dynobj,
2422 const unsigned char* syms,
2424 const char* sym_names,
2425 size_t sym_name_size,
2426 const unsigned char* versym,
2428 const std::vector<const char*>* version_map);
2431 #ifdef HAVE_TARGET_64_LITTLE
2434 Symbol_table::add_from_dynobj<64, false>(
2435 Sized_dynobj<64, false>* dynobj,
2436 const unsigned char* syms,
2438 const char* sym_names,
2439 size_t sym_name_size,
2440 const unsigned char* versym,
2442 const std::vector<const char*>* version_map);
2445 #ifdef HAVE_TARGET_64_BIG
2448 Symbol_table::add_from_dynobj<64, true>(
2449 Sized_dynobj<64, true>* dynobj,
2450 const unsigned char* syms,
2452 const char* sym_names,
2453 size_t sym_name_size,
2454 const unsigned char* versym,
2456 const std::vector<const char*>* version_map);
2459 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2462 Symbol_table::define_with_copy_reloc<32>(
2463 Sized_symbol<32>* sym,
2465 elfcpp::Elf_types<32>::Elf_Addr value);
2468 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2471 Symbol_table::define_with_copy_reloc<64>(
2472 Sized_symbol<64>* sym,
2474 elfcpp::Elf_types<64>::Elf_Addr value);
2477 #ifdef HAVE_TARGET_32_LITTLE
2480 Warnings::issue_warning<32, false>(const Symbol* sym,
2481 const Relocate_info<32, false>* relinfo,
2482 size_t relnum, off_t reloffset) const;
2485 #ifdef HAVE_TARGET_32_BIG
2488 Warnings::issue_warning<32, true>(const Symbol* sym,
2489 const Relocate_info<32, true>* relinfo,
2490 size_t relnum, off_t reloffset) const;
2493 #ifdef HAVE_TARGET_64_LITTLE
2496 Warnings::issue_warning<64, false>(const Symbol* sym,
2497 const Relocate_info<64, false>* relinfo,
2498 size_t relnum, off_t reloffset) const;
2501 #ifdef HAVE_TARGET_64_BIG
2504 Warnings::issue_warning<64, true>(const Symbol* sym,
2505 const Relocate_info<64, true>* relinfo,
2506 size_t relnum, off_t reloffset) const;
2509 } // End namespace gold.