1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
32 #include "dwarf_reader.h"
36 #include "workqueue.h"
44 // Initialize fields in Symbol. This initializes everything except u_
48 Symbol::init_fields(const char* name, const char* version,
49 elfcpp::STT type, elfcpp::STB binding,
50 elfcpp::STV visibility, unsigned char nonvis)
53 this->version_ = version;
54 this->symtab_index_ = 0;
55 this->dynsym_index_ = 0;
56 this->got_offset_ = 0;
57 this->plt_offset_ = 0;
59 this->binding_ = binding;
60 this->visibility_ = visibility;
61 this->nonvis_ = nonvis;
62 this->is_target_special_ = false;
63 this->is_def_ = false;
64 this->is_forwarder_ = false;
65 this->has_alias_ = false;
66 this->needs_dynsym_entry_ = false;
67 this->in_reg_ = false;
68 this->in_dyn_ = false;
69 this->has_got_offset_ = false;
70 this->has_plt_offset_ = false;
71 this->has_warning_ = false;
72 this->is_copied_from_dynobj_ = false;
75 // Return the demangled version of the symbol's name, but only
76 // if the --demangle flag was set.
79 demangle(const char* name)
81 if (!parameters->demangle())
84 // cplus_demangle allocates memory for the result it returns,
85 // and returns NULL if the name is already demangled.
86 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
87 if (demangled_name == NULL)
90 std::string retval(demangled_name);
96 Symbol::demangled_name() const
98 return demangle(this->name());
101 // Initialize the fields in the base class Symbol for SYM in OBJECT.
103 template<int size, bool big_endian>
105 Symbol::init_base(const char* name, const char* version, Object* object,
106 const elfcpp::Sym<size, big_endian>& sym)
108 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
109 sym.get_st_visibility(), sym.get_st_nonvis());
110 this->u_.from_object.object = object;
111 // FIXME: Handle SHN_XINDEX.
112 this->u_.from_object.shndx = sym.get_st_shndx();
113 this->source_ = FROM_OBJECT;
114 this->in_reg_ = !object->is_dynamic();
115 this->in_dyn_ = object->is_dynamic();
118 // Initialize the fields in the base class Symbol for a symbol defined
119 // in an Output_data.
122 Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type,
123 elfcpp::STB binding, elfcpp::STV visibility,
124 unsigned char nonvis, bool offset_is_from_end)
126 this->init_fields(name, NULL, type, binding, visibility, nonvis);
127 this->u_.in_output_data.output_data = od;
128 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
129 this->source_ = IN_OUTPUT_DATA;
130 this->in_reg_ = true;
133 // Initialize the fields in the base class Symbol for a symbol defined
134 // in an Output_segment.
137 Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type,
138 elfcpp::STB binding, elfcpp::STV visibility,
139 unsigned char nonvis, Segment_offset_base offset_base)
141 this->init_fields(name, NULL, type, binding, visibility, nonvis);
142 this->u_.in_output_segment.output_segment = os;
143 this->u_.in_output_segment.offset_base = offset_base;
144 this->source_ = IN_OUTPUT_SEGMENT;
145 this->in_reg_ = true;
148 // Initialize the fields in the base class Symbol for a symbol defined
152 Symbol::init_base(const char* name, elfcpp::STT type,
153 elfcpp::STB binding, elfcpp::STV visibility,
154 unsigned char nonvis)
156 this->init_fields(name, NULL, type, binding, visibility, nonvis);
157 this->source_ = CONSTANT;
158 this->in_reg_ = true;
161 // Allocate a common symbol in the base.
164 Symbol::allocate_base_common(Output_data* od)
166 gold_assert(this->is_common());
167 this->source_ = IN_OUTPUT_DATA;
168 this->u_.in_output_data.output_data = od;
169 this->u_.in_output_data.offset_is_from_end = false;
172 // Initialize the fields in Sized_symbol for SYM in OBJECT.
175 template<bool big_endian>
177 Sized_symbol<size>::init(const char* name, const char* version, Object* object,
178 const elfcpp::Sym<size, big_endian>& sym)
180 this->init_base(name, version, object, sym);
181 this->value_ = sym.get_st_value();
182 this->symsize_ = sym.get_st_size();
185 // Initialize the fields in Sized_symbol for a symbol defined in an
190 Sized_symbol<size>::init(const char* name, Output_data* od,
191 Value_type value, Size_type symsize,
192 elfcpp::STT type, elfcpp::STB binding,
193 elfcpp::STV visibility, unsigned char nonvis,
194 bool offset_is_from_end)
196 this->init_base(name, od, type, binding, visibility, nonvis,
198 this->value_ = value;
199 this->symsize_ = symsize;
202 // Initialize the fields in Sized_symbol for a symbol defined in an
207 Sized_symbol<size>::init(const char* name, Output_segment* os,
208 Value_type value, Size_type symsize,
209 elfcpp::STT type, elfcpp::STB binding,
210 elfcpp::STV visibility, unsigned char nonvis,
211 Segment_offset_base offset_base)
213 this->init_base(name, os, type, binding, visibility, nonvis, offset_base);
214 this->value_ = value;
215 this->symsize_ = symsize;
218 // Initialize the fields in Sized_symbol for a symbol defined as a
223 Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize,
224 elfcpp::STT type, elfcpp::STB binding,
225 elfcpp::STV visibility, unsigned char nonvis)
227 this->init_base(name, type, binding, visibility, nonvis);
228 this->value_ = value;
229 this->symsize_ = symsize;
232 // Allocate a common symbol.
236 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
238 this->allocate_base_common(od);
239 this->value_ = value;
242 // Return true if this symbol should be added to the dynamic symbol
246 Symbol::should_add_dynsym_entry() const
248 // If the symbol is used by a dynamic relocation, we need to add it.
249 if (this->needs_dynsym_entry())
252 // If exporting all symbols or building a shared library,
253 // and the symbol is defined in a regular object and is
254 // externally visible, we need to add it.
255 if ((parameters->export_dynamic() || parameters->output_is_shared())
256 && !this->is_from_dynobj()
257 && this->is_externally_visible())
263 // Return true if the final value of this symbol is known at link
267 Symbol::final_value_is_known() const
269 // If we are not generating an executable, then no final values are
270 // known, since they will change at runtime.
271 if (!parameters->output_is_executable())
274 // If the symbol is not from an object file, then it is defined, and
276 if (this->source_ != FROM_OBJECT)
279 // If the symbol is from a dynamic object, then the final value is
281 if (this->object()->is_dynamic())
284 // If the symbol is not undefined (it is defined or common), then
285 // the final value is known.
286 if (!this->is_undefined())
289 // If the symbol is undefined, then whether the final value is known
290 // depends on whether we are doing a static link. If we are doing a
291 // dynamic link, then the final value could be filled in at runtime.
292 // This could reasonably be the case for a weak undefined symbol.
293 return parameters->doing_static_link();
296 // Class Symbol_table.
298 Symbol_table::Symbol_table(unsigned int count)
299 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
300 forwarders_(), commons_(), warnings_()
302 namepool_.reserve(count);
305 Symbol_table::~Symbol_table()
309 // The hash function. The key values are Stringpool keys.
312 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
314 return key.first ^ key.second;
317 // The symbol table key equality function. This is called with
321 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
322 const Symbol_table_key& k2) const
324 return k1.first == k2.first && k1.second == k2.second;
327 // Make TO a symbol which forwards to FROM.
330 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
332 gold_assert(from != to);
333 gold_assert(!from->is_forwarder() && !to->is_forwarder());
334 this->forwarders_[from] = to;
335 from->set_forwarder();
338 // Resolve the forwards from FROM, returning the real symbol.
341 Symbol_table::resolve_forwards(const Symbol* from) const
343 gold_assert(from->is_forwarder());
344 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
345 this->forwarders_.find(from);
346 gold_assert(p != this->forwarders_.end());
350 // Look up a symbol by name.
353 Symbol_table::lookup(const char* name, const char* version) const
355 Stringpool::Key name_key;
356 name = this->namepool_.find(name, &name_key);
360 Stringpool::Key version_key = 0;
363 version = this->namepool_.find(version, &version_key);
368 Symbol_table_key key(name_key, version_key);
369 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
370 if (p == this->table_.end())
375 // Resolve a Symbol with another Symbol. This is only used in the
376 // unusual case where there are references to both an unversioned
377 // symbol and a symbol with a version, and we then discover that that
378 // version is the default version. Because this is unusual, we do
379 // this the slow way, by converting back to an ELF symbol.
381 template<int size, bool big_endian>
383 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
384 const char* version ACCEPT_SIZE_ENDIAN)
386 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
387 elfcpp::Sym_write<size, big_endian> esym(buf);
388 // We don't bother to set the st_name field.
389 esym.put_st_value(from->value());
390 esym.put_st_size(from->symsize());
391 esym.put_st_info(from->binding(), from->type());
392 esym.put_st_other(from->visibility(), from->nonvis());
393 esym.put_st_shndx(from->shndx());
394 this->resolve(to, esym.sym(), esym.sym(), from->object(), version);
401 // Add one symbol from OBJECT to the symbol table. NAME is symbol
402 // name and VERSION is the version; both are canonicalized. DEF is
403 // whether this is the default version.
405 // If DEF is true, then this is the definition of a default version of
406 // a symbol. That means that any lookup of NAME/NULL and any lookup
407 // of NAME/VERSION should always return the same symbol. This is
408 // obvious for references, but in particular we want to do this for
409 // definitions: overriding NAME/NULL should also override
410 // NAME/VERSION. If we don't do that, it would be very hard to
411 // override functions in a shared library which uses versioning.
413 // We implement this by simply making both entries in the hash table
414 // point to the same Symbol structure. That is easy enough if this is
415 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
416 // that we have seen both already, in which case they will both have
417 // independent entries in the symbol table. We can't simply change
418 // the symbol table entry, because we have pointers to the entries
419 // attached to the object files. So we mark the entry attached to the
420 // object file as a forwarder, and record it in the forwarders_ map.
421 // Note that entries in the hash table will never be marked as
424 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
425 // symbol exactly as it existed in the input file. SYM is usually
426 // that as well, but can be modified, for instance if we determine
427 // it's in a to-be-discarded section.
429 template<int size, bool big_endian>
431 Symbol_table::add_from_object(Object* object,
433 Stringpool::Key name_key,
435 Stringpool::Key version_key,
437 const elfcpp::Sym<size, big_endian>& sym,
438 const elfcpp::Sym<size, big_endian>& orig_sym)
440 Symbol* const snull = NULL;
441 std::pair<typename Symbol_table_type::iterator, bool> ins =
442 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
445 std::pair<typename Symbol_table_type::iterator, bool> insdef =
446 std::make_pair(this->table_.end(), false);
449 const Stringpool::Key vnull_key = 0;
450 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
455 // ins.first: an iterator, which is a pointer to a pair.
456 // ins.first->first: the key (a pair of name and version).
457 // ins.first->second: the value (Symbol*).
458 // ins.second: true if new entry was inserted, false if not.
460 Sized_symbol<size>* ret;
465 // We already have an entry for NAME/VERSION.
466 ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (ins.first->second
468 gold_assert(ret != NULL);
470 was_undefined = ret->is_undefined();
471 was_common = ret->is_common();
473 this->resolve(ret, sym, orig_sym, object, version);
479 // This is the first time we have seen NAME/NULL. Make
480 // NAME/NULL point to NAME/VERSION.
481 insdef.first->second = ret;
483 else if (insdef.first->second != ret)
485 // This is the unfortunate case where we already have
486 // entries for both NAME/VERSION and NAME/NULL.
487 const Sized_symbol<size>* sym2;
488 sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) (
491 Symbol_table::resolve SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
492 ret, sym2, version SELECT_SIZE_ENDIAN(size, big_endian));
493 this->make_forwarder(insdef.first->second, ret);
494 insdef.first->second = ret;
500 // This is the first time we have seen NAME/VERSION.
501 gold_assert(ins.first->second == NULL);
503 was_undefined = false;
506 if (def && !insdef.second)
508 // We already have an entry for NAME/NULL. If we override
509 // it, then change it to NAME/VERSION.
510 ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (
513 this->resolve(ret, sym, orig_sym, object, version);
514 ins.first->second = ret;
518 Sized_target<size, big_endian>* target =
519 object->sized_target SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
520 SELECT_SIZE_ENDIAN_ONLY(size, big_endian));
521 if (!target->has_make_symbol())
522 ret = new Sized_symbol<size>();
525 ret = target->make_symbol();
528 // This means that we don't want a symbol table
531 this->table_.erase(ins.first);
534 this->table_.erase(insdef.first);
535 // Inserting insdef invalidated ins.
536 this->table_.erase(std::make_pair(name_key,
543 ret->init(name, version, object, sym);
545 ins.first->second = ret;
548 // This is the first time we have seen NAME/NULL. Point
549 // it at the new entry for NAME/VERSION.
550 gold_assert(insdef.second);
551 insdef.first->second = ret;
556 // Record every time we see a new undefined symbol, to speed up
558 if (!was_undefined && ret->is_undefined())
559 ++this->saw_undefined_;
561 // Keep track of common symbols, to speed up common symbol
563 if (!was_common && ret->is_common())
564 this->commons_.push_back(ret);
569 // Add all the symbols in a relocatable object to the hash table.
571 template<int size, bool big_endian>
573 Symbol_table::add_from_relobj(
574 Sized_relobj<size, big_endian>* relobj,
575 const unsigned char* syms,
577 const char* sym_names,
578 size_t sym_name_size,
579 typename Sized_relobj<size, big_endian>::Symbols* sympointers)
581 gold_assert(size == relobj->target()->get_size());
582 gold_assert(size == parameters->get_size());
584 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
586 const unsigned char* p = syms;
587 for (size_t i = 0; i < count; ++i, p += sym_size)
589 elfcpp::Sym<size, big_endian> sym(p);
590 elfcpp::Sym<size, big_endian>* psym = &sym;
592 unsigned int st_name = psym->get_st_name();
593 if (st_name >= sym_name_size)
595 relobj->error(_("bad global symbol name offset %u at %zu"),
600 const char* name = sym_names + st_name;
602 // A symbol defined in a section which we are not including must
603 // be treated as an undefined symbol.
604 unsigned char symbuf[sym_size];
605 elfcpp::Sym<size, big_endian> sym2(symbuf);
606 unsigned int st_shndx = psym->get_st_shndx();
607 if (st_shndx != elfcpp::SHN_UNDEF
608 && st_shndx < elfcpp::SHN_LORESERVE
609 && !relobj->is_section_included(st_shndx))
611 memcpy(symbuf, p, sym_size);
612 elfcpp::Sym_write<size, big_endian> sw(symbuf);
613 sw.put_st_shndx(elfcpp::SHN_UNDEF);
617 // In an object file, an '@' in the name separates the symbol
618 // name from the version name. If there are two '@' characters,
619 // this is the default version.
620 const char* ver = strchr(name, '@');
622 Sized_symbol<size>* res;
625 Stringpool::Key name_key;
626 name = this->namepool_.add(name, true, &name_key);
627 res = this->add_from_object(relobj, name, name_key, NULL, 0,
632 Stringpool::Key name_key;
633 name = this->namepool_.add_prefix(name, ver - name, &name_key);
643 Stringpool::Key ver_key;
644 ver = this->namepool_.add(ver, true, &ver_key);
646 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
650 (*sympointers)[i] = res;
654 // Add all the symbols in a dynamic object to the hash table.
656 template<int size, bool big_endian>
658 Symbol_table::add_from_dynobj(
659 Sized_dynobj<size, big_endian>* dynobj,
660 const unsigned char* syms,
662 const char* sym_names,
663 size_t sym_name_size,
664 const unsigned char* versym,
666 const std::vector<const char*>* version_map)
668 gold_assert(size == dynobj->target()->get_size());
669 gold_assert(size == parameters->get_size());
671 if (versym != NULL && versym_size / 2 < count)
673 dynobj->error(_("too few symbol versions"));
677 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
679 // We keep a list of all STT_OBJECT symbols, so that we can resolve
680 // weak aliases. This is necessary because if the dynamic object
681 // provides the same variable under two names, one of which is a
682 // weak definition, and the regular object refers to the weak
683 // definition, we have to put both the weak definition and the
684 // strong definition into the dynamic symbol table. Given a weak
685 // definition, the only way that we can find the corresponding
686 // strong definition, if any, is to search the symbol table.
687 std::vector<Sized_symbol<size>*> object_symbols;
689 const unsigned char* p = syms;
690 const unsigned char* vs = versym;
691 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
693 elfcpp::Sym<size, big_endian> sym(p);
695 // Ignore symbols with local binding.
696 if (sym.get_st_bind() == elfcpp::STB_LOCAL)
699 unsigned int st_name = sym.get_st_name();
700 if (st_name >= sym_name_size)
702 dynobj->error(_("bad symbol name offset %u at %zu"),
707 const char* name = sym_names + st_name;
709 Sized_symbol<size>* res;
713 Stringpool::Key name_key;
714 name = this->namepool_.add(name, true, &name_key);
715 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
720 // Read the version information.
722 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
724 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
725 v &= elfcpp::VERSYM_VERSION;
727 // The Sun documentation says that V can be VER_NDX_LOCAL,
728 // or VER_NDX_GLOBAL, or a version index. The meaning of
729 // VER_NDX_LOCAL is defined as "Symbol has local scope."
730 // The old GNU linker will happily generate VER_NDX_LOCAL
731 // for an undefined symbol. I don't know what the Sun
732 // linker will generate.
734 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
735 && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
737 // This symbol should not be visible outside the object.
741 // At this point we are definitely going to add this symbol.
742 Stringpool::Key name_key;
743 name = this->namepool_.add(name, true, &name_key);
745 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
746 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
748 // This symbol does not have a version.
749 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
754 if (v >= version_map->size())
756 dynobj->error(_("versym for symbol %zu out of range: %u"),
761 const char* version = (*version_map)[v];
764 dynobj->error(_("versym for symbol %zu has no name: %u"),
769 Stringpool::Key version_key;
770 version = this->namepool_.add(version, true, &version_key);
772 // If this is an absolute symbol, and the version name
773 // and symbol name are the same, then this is the
774 // version definition symbol. These symbols exist to
775 // support using -u to pull in particular versions. We
776 // do not want to record a version for them.
777 if (sym.get_st_shndx() == elfcpp::SHN_ABS
778 && name_key == version_key)
779 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
783 const bool def = (!hidden
784 && (sym.get_st_shndx()
785 != elfcpp::SHN_UNDEF));
786 res = this->add_from_object(dynobj, name, name_key, version,
787 version_key, def, sym, sym);
792 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
793 && sym.get_st_type() == elfcpp::STT_OBJECT)
794 object_symbols.push_back(res);
797 this->record_weak_aliases(&object_symbols);
800 // This is used to sort weak aliases. We sort them first by section
801 // index, then by offset, then by weak ahead of strong.
804 class Weak_alias_sorter
807 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
812 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
813 const Sized_symbol<size>* s2) const
815 if (s1->shndx() != s2->shndx())
816 return s1->shndx() < s2->shndx();
817 if (s1->value() != s2->value())
818 return s1->value() < s2->value();
819 if (s1->binding() != s2->binding())
821 if (s1->binding() == elfcpp::STB_WEAK)
823 if (s2->binding() == elfcpp::STB_WEAK)
826 return std::string(s1->name()) < std::string(s2->name());
829 // SYMBOLS is a list of object symbols from a dynamic object. Look
830 // for any weak aliases, and record them so that if we add the weak
831 // alias to the dynamic symbol table, we also add the corresponding
836 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
838 // Sort the vector by section index, then by offset, then by weak
840 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
842 // Walk through the vector. For each weak definition, record
844 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
849 if ((*p)->binding() != elfcpp::STB_WEAK)
852 // Build a circular list of weak aliases. Each symbol points to
853 // the next one in the circular list.
855 Sized_symbol<size>* from_sym = *p;
856 typename std::vector<Sized_symbol<size>*>::const_iterator q;
857 for (q = p + 1; q != symbols->end(); ++q)
859 if ((*q)->shndx() != from_sym->shndx()
860 || (*q)->value() != from_sym->value())
863 this->weak_aliases_[from_sym] = *q;
864 from_sym->set_has_alias();
870 this->weak_aliases_[from_sym] = *p;
871 from_sym->set_has_alias();
878 // Create and return a specially defined symbol. If ONLY_IF_REF is
879 // true, then only create the symbol if there is a reference to it.
880 // If this does not return NULL, it sets *POLDSYM to the existing
881 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
883 template<int size, bool big_endian>
885 Symbol_table::define_special_symbol(const Target* target, const char** pname,
886 const char** pversion, bool only_if_ref,
887 Sized_symbol<size>** poldsym
891 Sized_symbol<size>* sym;
892 bool add_to_table = false;
893 typename Symbol_table_type::iterator add_loc = this->table_.end();
897 oldsym = this->lookup(*pname, *pversion);
898 if (oldsym == NULL || !oldsym->is_undefined())
901 *pname = oldsym->name();
902 *pversion = oldsym->version();
906 // Canonicalize NAME and VERSION.
907 Stringpool::Key name_key;
908 *pname = this->namepool_.add(*pname, true, &name_key);
910 Stringpool::Key version_key = 0;
911 if (*pversion != NULL)
912 *pversion = this->namepool_.add(*pversion, true, &version_key);
914 Symbol* const snull = NULL;
915 std::pair<typename Symbol_table_type::iterator, bool> ins =
916 this->table_.insert(std::make_pair(std::make_pair(name_key,
922 // We already have a symbol table entry for NAME/VERSION.
923 oldsym = ins.first->second;
924 gold_assert(oldsym != NULL);
928 // We haven't seen this symbol before.
929 gold_assert(ins.first->second == NULL);
936 if (!target->has_make_symbol())
937 sym = new Sized_symbol<size>();
940 gold_assert(target->get_size() == size);
941 gold_assert(target->is_big_endian() ? big_endian : !big_endian);
942 typedef Sized_target<size, big_endian> My_target;
943 const My_target* sized_target =
944 static_cast<const My_target*>(target);
945 sym = sized_target->make_symbol();
951 add_loc->second = sym;
953 gold_assert(oldsym != NULL);
955 *poldsym = this->get_sized_symbol SELECT_SIZE_NAME(size) (oldsym
961 // Define a symbol based on an Output_data.
964 Symbol_table::define_in_output_data(const Target* target, const char* name,
965 const char* version, Output_data* od,
966 uint64_t value, uint64_t symsize,
967 elfcpp::STT type, elfcpp::STB binding,
968 elfcpp::STV visibility,
969 unsigned char nonvis,
970 bool offset_is_from_end,
973 if (parameters->get_size() == 32)
975 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
976 return this->do_define_in_output_data<32>(target, name, version, od,
977 value, symsize, type, binding,
985 else if (parameters->get_size() == 64)
987 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
988 return this->do_define_in_output_data<64>(target, name, version, od,
989 value, symsize, type, binding,
1001 // Define a symbol in an Output_data, sized version.
1005 Symbol_table::do_define_in_output_data(
1006 const Target* target,
1008 const char* version,
1010 typename elfcpp::Elf_types<size>::Elf_Addr value,
1011 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1013 elfcpp::STB binding,
1014 elfcpp::STV visibility,
1015 unsigned char nonvis,
1016 bool offset_is_from_end,
1019 Sized_symbol<size>* sym;
1020 Sized_symbol<size>* oldsym;
1022 if (parameters->is_big_endian())
1024 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1025 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1026 target, &name, &version, only_if_ref, &oldsym
1027 SELECT_SIZE_ENDIAN(size, true));
1034 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1035 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1036 target, &name, &version, only_if_ref, &oldsym
1037 SELECT_SIZE_ENDIAN(size, false));
1046 gold_assert(version == NULL || oldsym != NULL);
1047 sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1048 offset_is_from_end);
1051 && Symbol_table::should_override_with_special(oldsym))
1052 this->override_with_special(oldsym, sym);
1057 // Define a symbol based on an Output_segment.
1060 Symbol_table::define_in_output_segment(const Target* target, const char* name,
1061 const char* version, Output_segment* os,
1062 uint64_t value, uint64_t symsize,
1063 elfcpp::STT type, elfcpp::STB binding,
1064 elfcpp::STV visibility,
1065 unsigned char nonvis,
1066 Symbol::Segment_offset_base offset_base,
1069 if (parameters->get_size() == 32)
1071 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1072 return this->do_define_in_output_segment<32>(target, name, version, os,
1073 value, symsize, type,
1074 binding, visibility, nonvis,
1075 offset_base, only_if_ref);
1080 else if (parameters->get_size() == 64)
1082 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1083 return this->do_define_in_output_segment<64>(target, name, version, os,
1084 value, symsize, type,
1085 binding, visibility, nonvis,
1086 offset_base, only_if_ref);
1095 // Define a symbol in an Output_segment, sized version.
1099 Symbol_table::do_define_in_output_segment(
1100 const Target* target,
1102 const char* version,
1104 typename elfcpp::Elf_types<size>::Elf_Addr value,
1105 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1107 elfcpp::STB binding,
1108 elfcpp::STV visibility,
1109 unsigned char nonvis,
1110 Symbol::Segment_offset_base offset_base,
1113 Sized_symbol<size>* sym;
1114 Sized_symbol<size>* oldsym;
1116 if (parameters->is_big_endian())
1118 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1119 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1120 target, &name, &version, only_if_ref, &oldsym
1121 SELECT_SIZE_ENDIAN(size, true));
1128 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1129 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1130 target, &name, &version, only_if_ref, &oldsym
1131 SELECT_SIZE_ENDIAN(size, false));
1140 gold_assert(version == NULL || oldsym != NULL);
1141 sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1145 && Symbol_table::should_override_with_special(oldsym))
1146 this->override_with_special(oldsym, sym);
1151 // Define a special symbol with a constant value. It is a multiple
1152 // definition error if this symbol is already defined.
1155 Symbol_table::define_as_constant(const Target* target, const char* name,
1156 const char* version, uint64_t value,
1157 uint64_t symsize, elfcpp::STT type,
1158 elfcpp::STB binding, elfcpp::STV visibility,
1159 unsigned char nonvis, bool only_if_ref)
1161 if (parameters->get_size() == 32)
1163 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1164 return this->do_define_as_constant<32>(target, name, version, value,
1165 symsize, type, binding,
1166 visibility, nonvis, only_if_ref);
1171 else if (parameters->get_size() == 64)
1173 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1174 return this->do_define_as_constant<64>(target, name, version, value,
1175 symsize, type, binding,
1176 visibility, nonvis, only_if_ref);
1185 // Define a symbol as a constant, sized version.
1189 Symbol_table::do_define_as_constant(
1190 const Target* target,
1192 const char* version,
1193 typename elfcpp::Elf_types<size>::Elf_Addr value,
1194 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1196 elfcpp::STB binding,
1197 elfcpp::STV visibility,
1198 unsigned char nonvis,
1201 Sized_symbol<size>* sym;
1202 Sized_symbol<size>* oldsym;
1204 if (parameters->is_big_endian())
1206 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1207 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, true) (
1208 target, &name, &version, only_if_ref, &oldsym
1209 SELECT_SIZE_ENDIAN(size, true));
1216 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1217 sym = this->define_special_symbol SELECT_SIZE_ENDIAN_NAME(size, false) (
1218 target, &name, &version, only_if_ref, &oldsym
1219 SELECT_SIZE_ENDIAN(size, false));
1228 gold_assert(version == NULL || oldsym != NULL);
1229 sym->init(name, value, symsize, type, binding, visibility, nonvis);
1232 && Symbol_table::should_override_with_special(oldsym))
1233 this->override_with_special(oldsym, sym);
1238 // Define a set of symbols in output sections.
1241 Symbol_table::define_symbols(const Layout* layout, const Target* target,
1242 int count, const Define_symbol_in_section* p)
1244 for (int i = 0; i < count; ++i, ++p)
1246 Output_section* os = layout->find_output_section(p->output_section);
1248 this->define_in_output_data(target, p->name, NULL, os, p->value,
1249 p->size, p->type, p->binding,
1250 p->visibility, p->nonvis,
1251 p->offset_is_from_end, p->only_if_ref);
1253 this->define_as_constant(target, p->name, NULL, 0, p->size, p->type,
1254 p->binding, p->visibility, p->nonvis,
1259 // Define a set of symbols in output segments.
1262 Symbol_table::define_symbols(const Layout* layout, const Target* target,
1263 int count, const Define_symbol_in_segment* p)
1265 for (int i = 0; i < count; ++i, ++p)
1267 Output_segment* os = layout->find_output_segment(p->segment_type,
1268 p->segment_flags_set,
1269 p->segment_flags_clear);
1271 this->define_in_output_segment(target, p->name, NULL, os, p->value,
1272 p->size, p->type, p->binding,
1273 p->visibility, p->nonvis,
1274 p->offset_base, p->only_if_ref);
1276 this->define_as_constant(target, p->name, NULL, 0, p->size, p->type,
1277 p->binding, p->visibility, p->nonvis,
1282 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1283 // symbol should be defined--typically a .dyn.bss section. VALUE is
1284 // the offset within POSD.
1288 Symbol_table::define_with_copy_reloc(const Target* target,
1289 Sized_symbol<size>* csym,
1290 Output_data* posd, uint64_t value)
1292 gold_assert(csym->is_from_dynobj());
1293 gold_assert(!csym->is_copied_from_dynobj());
1294 Object* object = csym->object();
1295 gold_assert(object->is_dynamic());
1296 Dynobj* dynobj = static_cast<Dynobj*>(object);
1298 // Our copied variable has to override any variable in a shared
1300 elfcpp::STB binding = csym->binding();
1301 if (binding == elfcpp::STB_WEAK)
1302 binding = elfcpp::STB_GLOBAL;
1304 this->define_in_output_data(target, csym->name(), csym->version(),
1305 posd, value, csym->symsize(),
1306 csym->type(), binding,
1307 csym->visibility(), csym->nonvis(),
1310 csym->set_is_copied_from_dynobj();
1311 csym->set_needs_dynsym_entry();
1313 this->copied_symbol_dynobjs_[csym] = dynobj;
1315 // We have now defined all aliases, but we have not entered them all
1316 // in the copied_symbol_dynobjs_ map.
1317 if (csym->has_alias())
1322 sym = this->weak_aliases_[sym];
1325 gold_assert(sym->output_data() == posd);
1327 sym->set_is_copied_from_dynobj();
1328 this->copied_symbol_dynobjs_[sym] = dynobj;
1333 // SYM is defined using a COPY reloc. Return the dynamic object where
1334 // the original definition was found.
1337 Symbol_table::get_copy_source(const Symbol* sym) const
1339 gold_assert(sym->is_copied_from_dynobj());
1340 Copied_symbol_dynobjs::const_iterator p =
1341 this->copied_symbol_dynobjs_.find(sym);
1342 gold_assert(p != this->copied_symbol_dynobjs_.end());
1346 // Set the dynamic symbol indexes. INDEX is the index of the first
1347 // global dynamic symbol. Pointers to the symbols are stored into the
1348 // vector SYMS. The names are added to DYNPOOL. This returns an
1349 // updated dynamic symbol index.
1352 Symbol_table::set_dynsym_indexes(const Target* target,
1354 std::vector<Symbol*>* syms,
1355 Stringpool* dynpool,
1358 for (Symbol_table_type::iterator p = this->table_.begin();
1359 p != this->table_.end();
1362 Symbol* sym = p->second;
1364 // Note that SYM may already have a dynamic symbol index, since
1365 // some symbols appear more than once in the symbol table, with
1366 // and without a version.
1368 if (!sym->should_add_dynsym_entry())
1369 sym->set_dynsym_index(-1U);
1370 else if (!sym->has_dynsym_index())
1372 sym->set_dynsym_index(index);
1374 syms->push_back(sym);
1375 dynpool->add(sym->name(), false, NULL);
1377 // Record any version information.
1378 if (sym->version() != NULL)
1379 versions->record_version(this, dynpool, sym);
1383 // Finish up the versions. In some cases this may add new dynamic
1385 index = versions->finalize(target, this, index, syms);
1390 // Set the final values for all the symbols. The index of the first
1391 // global symbol in the output file is INDEX. Record the file offset
1392 // OFF. Add their names to POOL. Return the new file offset.
1395 Symbol_table::finalize(const Task* task, unsigned int index, off_t off,
1396 off_t dynoff, size_t dyn_global_index, size_t dyncount,
1401 gold_assert(index != 0);
1402 this->first_global_index_ = index;
1404 this->dynamic_offset_ = dynoff;
1405 this->first_dynamic_global_index_ = dyn_global_index;
1406 this->dynamic_count_ = dyncount;
1408 if (parameters->get_size() == 32)
1410 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1411 ret = this->sized_finalize<32>(index, off, pool);
1416 else if (parameters->get_size() == 64)
1418 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1419 ret = this->sized_finalize<64>(index, off, pool);
1427 // Now that we have the final symbol table, we can reliably note
1428 // which symbols should get warnings.
1429 this->warnings_.note_warnings(this, task);
1434 // Set the final value for all the symbols. This is called after
1435 // Layout::finalize, so all the output sections have their final
1440 Symbol_table::sized_finalize(unsigned index, off_t off, Stringpool* pool)
1442 off = align_address(off, size >> 3);
1443 this->offset_ = off;
1445 size_t orig_index = index;
1447 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1448 for (Symbol_table_type::iterator p = this->table_.begin();
1449 p != this->table_.end();
1452 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1454 // FIXME: Here we need to decide which symbols should go into
1455 // the output file, based on --strip.
1457 // The default version of a symbol may appear twice in the
1458 // symbol table. We only need to finalize it once.
1459 if (sym->has_symtab_index())
1464 gold_assert(!sym->has_symtab_index());
1465 sym->set_symtab_index(-1U);
1466 gold_assert(sym->dynsym_index() == -1U);
1470 typename Sized_symbol<size>::Value_type value;
1472 switch (sym->source())
1474 case Symbol::FROM_OBJECT:
1476 unsigned int shndx = sym->shndx();
1478 // FIXME: We need some target specific support here.
1479 if (shndx >= elfcpp::SHN_LORESERVE
1480 && shndx != elfcpp::SHN_ABS)
1482 gold_error(_("%s: unsupported symbol section 0x%x"),
1483 sym->demangled_name().c_str(), shndx);
1484 shndx = elfcpp::SHN_UNDEF;
1487 Object* symobj = sym->object();
1488 if (symobj->is_dynamic())
1491 shndx = elfcpp::SHN_UNDEF;
1493 else if (shndx == elfcpp::SHN_UNDEF)
1495 else if (shndx == elfcpp::SHN_ABS)
1496 value = sym->value();
1499 Relobj* relobj = static_cast<Relobj*>(symobj);
1501 Output_section* os = relobj->output_section(shndx, &secoff);
1505 sym->set_symtab_index(-1U);
1506 gold_assert(sym->dynsym_index() == -1U);
1510 if (sym->type() == elfcpp::STT_TLS)
1511 value = sym->value() + os->tls_offset() + secoff;
1513 value = sym->value() + os->address() + secoff;
1518 case Symbol::IN_OUTPUT_DATA:
1520 Output_data* od = sym->output_data();
1521 value = sym->value() + od->address();
1522 if (sym->offset_is_from_end())
1523 value += od->data_size();
1527 case Symbol::IN_OUTPUT_SEGMENT:
1529 Output_segment* os = sym->output_segment();
1530 value = sym->value() + os->vaddr();
1531 switch (sym->offset_base())
1533 case Symbol::SEGMENT_START:
1535 case Symbol::SEGMENT_END:
1536 value += os->memsz();
1538 case Symbol::SEGMENT_BSS:
1539 value += os->filesz();
1547 case Symbol::CONSTANT:
1548 value = sym->value();
1555 sym->set_value(value);
1557 if (parameters->strip_all())
1558 sym->set_symtab_index(-1U);
1561 sym->set_symtab_index(index);
1562 pool->add(sym->name(), false, NULL);
1568 this->output_count_ = index - orig_index;
1573 // Write out the global symbols.
1576 Symbol_table::write_globals(const Input_objects* input_objects,
1577 const Stringpool* sympool,
1578 const Stringpool* dynpool, Output_file* of) const
1580 if (parameters->get_size() == 32)
1582 if (parameters->is_big_endian())
1584 #ifdef HAVE_TARGET_32_BIG
1585 this->sized_write_globals<32, true>(input_objects, sympool,
1593 #ifdef HAVE_TARGET_32_LITTLE
1594 this->sized_write_globals<32, false>(input_objects, sympool,
1601 else if (parameters->get_size() == 64)
1603 if (parameters->is_big_endian())
1605 #ifdef HAVE_TARGET_64_BIG
1606 this->sized_write_globals<64, true>(input_objects, sympool,
1614 #ifdef HAVE_TARGET_64_LITTLE
1615 this->sized_write_globals<64, false>(input_objects, sympool,
1626 // Write out the global symbols.
1628 template<int size, bool big_endian>
1630 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1631 const Stringpool* sympool,
1632 const Stringpool* dynpool,
1633 Output_file* of) const
1635 const Target* const target = input_objects->target();
1637 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1638 unsigned int index = this->first_global_index_;
1639 const off_t oview_size = this->output_count_ * sym_size;
1640 unsigned char* const psyms = of->get_output_view(this->offset_, oview_size);
1642 unsigned int dynamic_count = this->dynamic_count_;
1643 off_t dynamic_size = dynamic_count * sym_size;
1644 unsigned int first_dynamic_global_index = this->first_dynamic_global_index_;
1645 unsigned char* dynamic_view;
1646 if (this->dynamic_offset_ == 0)
1647 dynamic_view = NULL;
1649 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1651 unsigned char* ps = psyms;
1652 for (Symbol_table_type::const_iterator p = this->table_.begin();
1653 p != this->table_.end();
1656 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1658 // Possibly warn about unresolved symbols in shared libraries.
1659 this->warn_about_undefined_dynobj_symbol(input_objects, sym);
1661 unsigned int sym_index = sym->symtab_index();
1662 unsigned int dynsym_index;
1663 if (dynamic_view == NULL)
1666 dynsym_index = sym->dynsym_index();
1668 if (sym_index == -1U && dynsym_index == -1U)
1670 // This symbol is not included in the output file.
1674 if (sym_index == index)
1676 else if (sym_index != -1U)
1678 // We have already seen this symbol, because it has a
1680 gold_assert(sym_index < index);
1681 if (dynsym_index == -1U)
1687 typename elfcpp::Elf_types<32>::Elf_Addr value = sym->value();
1688 switch (sym->source())
1690 case Symbol::FROM_OBJECT:
1692 unsigned int in_shndx = sym->shndx();
1694 // FIXME: We need some target specific support here.
1695 if (in_shndx >= elfcpp::SHN_LORESERVE
1696 && in_shndx != elfcpp::SHN_ABS)
1698 gold_error(_("%s: unsupported symbol section 0x%x"),
1699 sym->demangled_name().c_str(), in_shndx);
1704 Object* symobj = sym->object();
1705 if (symobj->is_dynamic())
1707 if (sym->needs_dynsym_value())
1708 value = target->dynsym_value(sym);
1709 shndx = elfcpp::SHN_UNDEF;
1711 else if (in_shndx == elfcpp::SHN_UNDEF
1712 || in_shndx == elfcpp::SHN_ABS)
1716 Relobj* relobj = static_cast<Relobj*>(symobj);
1718 Output_section* os = relobj->output_section(in_shndx,
1720 gold_assert(os != NULL);
1721 shndx = os->out_shndx();
1727 case Symbol::IN_OUTPUT_DATA:
1728 shndx = sym->output_data()->out_shndx();
1731 case Symbol::IN_OUTPUT_SEGMENT:
1732 shndx = elfcpp::SHN_ABS;
1735 case Symbol::CONSTANT:
1736 shndx = elfcpp::SHN_ABS;
1743 if (sym_index != -1U)
1745 this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1746 sym, sym->value(), shndx, sympool, ps
1747 SELECT_SIZE_ENDIAN(size, big_endian));
1751 if (dynsym_index != -1U)
1753 dynsym_index -= first_dynamic_global_index;
1754 gold_assert(dynsym_index < dynamic_count);
1755 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
1756 this->sized_write_symbol SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1757 sym, value, shndx, dynpool, pd
1758 SELECT_SIZE_ENDIAN(size, big_endian));
1762 gold_assert(ps - psyms == oview_size);
1764 of->write_output_view(this->offset_, oview_size, psyms);
1765 if (dynamic_view != NULL)
1766 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
1769 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1770 // strtab holding the name.
1772 template<int size, bool big_endian>
1774 Symbol_table::sized_write_symbol(
1775 Sized_symbol<size>* sym,
1776 typename elfcpp::Elf_types<size>::Elf_Addr value,
1778 const Stringpool* pool,
1780 ACCEPT_SIZE_ENDIAN) const
1782 elfcpp::Sym_write<size, big_endian> osym(p);
1783 osym.put_st_name(pool->get_offset(sym->name()));
1784 osym.put_st_value(value);
1785 osym.put_st_size(sym->symsize());
1786 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
1787 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
1788 osym.put_st_shndx(shndx);
1791 // Check for unresolved symbols in shared libraries. This is
1792 // controlled by the --allow-shlib-undefined option.
1794 // We only warn about libraries for which we have seen all the
1795 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
1796 // which were not seen in this link. If we didn't see a DT_NEEDED
1797 // entry, we aren't going to be able to reliably report whether the
1798 // symbol is undefined.
1800 // We also don't warn about libraries found in the system library
1801 // directory (the directory were we find libc.so); we assume that
1802 // those libraries are OK. This heuristic avoids problems in
1803 // GNU/Linux, in which -ldl can have undefined references satisfied by
1807 Symbol_table::warn_about_undefined_dynobj_symbol(
1808 const Input_objects* input_objects,
1811 if (sym->source() == Symbol::FROM_OBJECT
1812 && sym->object()->is_dynamic()
1813 && sym->shndx() == elfcpp::SHN_UNDEF
1814 && sym->binding() != elfcpp::STB_WEAK
1815 && !parameters->allow_shlib_undefined()
1816 && !input_objects->target()->is_defined_by_abi(sym)
1817 && !input_objects->found_in_system_library_directory(sym->object()))
1819 // A very ugly cast.
1820 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
1821 if (!dynobj->has_unknown_needed_entries())
1822 gold_error(_("%s: undefined reference to '%s'"),
1823 sym->object()->name().c_str(),
1824 sym->demangled_name().c_str());
1828 // Write out a section symbol. Return the update offset.
1831 Symbol_table::write_section_symbol(const Output_section *os,
1835 if (parameters->get_size() == 32)
1837 if (parameters->is_big_endian())
1839 #ifdef HAVE_TARGET_32_BIG
1840 this->sized_write_section_symbol<32, true>(os, of, offset);
1847 #ifdef HAVE_TARGET_32_LITTLE
1848 this->sized_write_section_symbol<32, false>(os, of, offset);
1854 else if (parameters->get_size() == 64)
1856 if (parameters->is_big_endian())
1858 #ifdef HAVE_TARGET_64_BIG
1859 this->sized_write_section_symbol<64, true>(os, of, offset);
1866 #ifdef HAVE_TARGET_64_LITTLE
1867 this->sized_write_section_symbol<64, false>(os, of, offset);
1877 // Write out a section symbol, specialized for size and endianness.
1879 template<int size, bool big_endian>
1881 Symbol_table::sized_write_section_symbol(const Output_section* os,
1885 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1887 unsigned char* pov = of->get_output_view(offset, sym_size);
1889 elfcpp::Sym_write<size, big_endian> osym(pov);
1890 osym.put_st_name(0);
1891 osym.put_st_value(os->address());
1892 osym.put_st_size(0);
1893 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
1894 elfcpp::STT_SECTION));
1895 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
1896 osym.put_st_shndx(os->out_shndx());
1898 of->write_output_view(offset, sym_size, pov);
1901 // Print statistical information to stderr. This is used for --stats.
1904 Symbol_table::print_stats() const
1906 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
1907 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
1908 program_name, this->table_.size(), this->table_.bucket_count());
1910 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
1911 program_name, this->table_.size());
1913 this->namepool_.print_stats("symbol table stringpool");
1916 // We check for ODR violations by looking for symbols with the same
1917 // name for which the debugging information reports that they were
1918 // defined in different source locations. When comparing the source
1919 // location, we consider instances with the same base filename and
1920 // line number to be the same. This is because different object
1921 // files/shared libraries can include the same header file using
1922 // different paths, and we don't want to report an ODR violation in
1925 // This struct is used to compare line information, as returned by
1926 // Dwarf_line_info::one_addr2line. It implements a < comparison
1927 // operator used with std::set.
1929 struct Odr_violation_compare
1932 operator()(const std::string& s1, const std::string& s2) const
1934 std::string::size_type pos1 = s1.rfind('/');
1935 std::string::size_type pos2 = s2.rfind('/');
1936 if (pos1 == std::string::npos
1937 || pos2 == std::string::npos)
1939 return s1.compare(pos1, std::string::npos,
1940 s2, pos2, std::string::npos) < 0;
1944 // Check candidate_odr_violations_ to find symbols with the same name
1945 // but apparently different definitions (different source-file/line-no).
1948 Symbol_table::detect_odr_violations(const Task* task,
1949 const char* output_file_name) const
1951 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
1952 it != candidate_odr_violations_.end();
1955 const char* symbol_name = it->first;
1956 // We use a sorted set so the output is deterministic.
1957 std::set<std::string, Odr_violation_compare> line_nums;
1959 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
1960 locs = it->second.begin();
1961 locs != it->second.end();
1964 // We need to lock the object in order to read it. This
1965 // means that we have to run in a singleton Task. If we
1966 // want to run this in a general Task for better
1967 // performance, we will need one Task for object, plus
1968 // appropriate locking to ensure that we don't conflict with
1969 // other uses of the object.
1970 Task_lock_obj<Object> tl(task, locs->object);
1971 std::string lineno = Dwarf_line_info::one_addr2line(
1972 locs->object, locs->shndx, locs->offset);
1973 if (!lineno.empty())
1974 line_nums.insert(lineno);
1977 if (line_nums.size() > 1)
1979 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
1980 "places (possible ODR violation):"),
1981 output_file_name, demangle(symbol_name).c_str());
1982 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
1983 it2 != line_nums.end();
1985 fprintf(stderr, " %s\n", it2->c_str());
1990 // Warnings functions.
1992 // Add a new warning.
1995 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
1998 name = symtab->canonicalize_name(name);
1999 this->warnings_[name].set(obj, shndx);
2002 // Look through the warnings and mark the symbols for which we should
2003 // warn. This is called during Layout::finalize when we know the
2004 // sources for all the symbols.
2007 Warnings::note_warnings(Symbol_table* symtab, const Task* task)
2009 for (Warning_table::iterator p = this->warnings_.begin();
2010 p != this->warnings_.end();
2013 Symbol* sym = symtab->lookup(p->first, NULL);
2015 && sym->source() == Symbol::FROM_OBJECT
2016 && sym->object() == p->second.object)
2018 sym->set_has_warning();
2020 // Read the section contents to get the warning text. It
2021 // would be nicer if we only did this if we have to actually
2022 // issue a warning. Unfortunately, warnings are issued as
2023 // we relocate sections. That means that we can not lock
2024 // the object then, as we might try to issue the same
2025 // warning multiple times simultaneously.
2027 Task_lock_obj<Object> tl(task, p->second.object);
2028 const unsigned char* c;
2030 c = p->second.object->section_contents(p->second.shndx, &len,
2032 p->second.set_text(reinterpret_cast<const char*>(c), len);
2038 // Issue a warning. This is called when we see a relocation against a
2039 // symbol for which has a warning.
2041 template<int size, bool big_endian>
2043 Warnings::issue_warning(const Symbol* sym,
2044 const Relocate_info<size, big_endian>* relinfo,
2045 size_t relnum, off_t reloffset) const
2047 gold_assert(sym->has_warning());
2048 Warning_table::const_iterator p = this->warnings_.find(sym->name());
2049 gold_assert(p != this->warnings_.end());
2050 gold_warning_at_location(relinfo, relnum, reloffset,
2051 "%s", p->second.text.c_str());
2054 // Instantiate the templates we need. We could use the configure
2055 // script to restrict this to only the ones needed for implemented
2058 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2061 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2064 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2067 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2070 #ifdef HAVE_TARGET_32_LITTLE
2073 Symbol_table::add_from_relobj<32, false>(
2074 Sized_relobj<32, false>* relobj,
2075 const unsigned char* syms,
2077 const char* sym_names,
2078 size_t sym_name_size,
2079 Sized_relobj<32, true>::Symbols* sympointers);
2082 #ifdef HAVE_TARGET_32_BIG
2085 Symbol_table::add_from_relobj<32, true>(
2086 Sized_relobj<32, true>* relobj,
2087 const unsigned char* syms,
2089 const char* sym_names,
2090 size_t sym_name_size,
2091 Sized_relobj<32, false>::Symbols* sympointers);
2094 #ifdef HAVE_TARGET_64_LITTLE
2097 Symbol_table::add_from_relobj<64, false>(
2098 Sized_relobj<64, false>* relobj,
2099 const unsigned char* syms,
2101 const char* sym_names,
2102 size_t sym_name_size,
2103 Sized_relobj<64, true>::Symbols* sympointers);
2106 #ifdef HAVE_TARGET_64_BIG
2109 Symbol_table::add_from_relobj<64, true>(
2110 Sized_relobj<64, true>* relobj,
2111 const unsigned char* syms,
2113 const char* sym_names,
2114 size_t sym_name_size,
2115 Sized_relobj<64, false>::Symbols* sympointers);
2118 #ifdef HAVE_TARGET_32_LITTLE
2121 Symbol_table::add_from_dynobj<32, false>(
2122 Sized_dynobj<32, false>* dynobj,
2123 const unsigned char* syms,
2125 const char* sym_names,
2126 size_t sym_name_size,
2127 const unsigned char* versym,
2129 const std::vector<const char*>* version_map);
2132 #ifdef HAVE_TARGET_32_BIG
2135 Symbol_table::add_from_dynobj<32, true>(
2136 Sized_dynobj<32, true>* dynobj,
2137 const unsigned char* syms,
2139 const char* sym_names,
2140 size_t sym_name_size,
2141 const unsigned char* versym,
2143 const std::vector<const char*>* version_map);
2146 #ifdef HAVE_TARGET_64_LITTLE
2149 Symbol_table::add_from_dynobj<64, false>(
2150 Sized_dynobj<64, false>* dynobj,
2151 const unsigned char* syms,
2153 const char* sym_names,
2154 size_t sym_name_size,
2155 const unsigned char* versym,
2157 const std::vector<const char*>* version_map);
2160 #ifdef HAVE_TARGET_64_BIG
2163 Symbol_table::add_from_dynobj<64, true>(
2164 Sized_dynobj<64, true>* dynobj,
2165 const unsigned char* syms,
2167 const char* sym_names,
2168 size_t sym_name_size,
2169 const unsigned char* versym,
2171 const std::vector<const char*>* version_map);
2174 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2177 Symbol_table::define_with_copy_reloc<32>(const Target* target,
2178 Sized_symbol<32>* sym,
2179 Output_data* posd, uint64_t value);
2182 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2185 Symbol_table::define_with_copy_reloc<64>(const Target* target,
2186 Sized_symbol<64>* sym,
2187 Output_data* posd, uint64_t value);
2190 #ifdef HAVE_TARGET_32_LITTLE
2193 Warnings::issue_warning<32, false>(const Symbol* sym,
2194 const Relocate_info<32, false>* relinfo,
2195 size_t relnum, off_t reloffset) const;
2198 #ifdef HAVE_TARGET_32_BIG
2201 Warnings::issue_warning<32, true>(const Symbol* sym,
2202 const Relocate_info<32, true>* relinfo,
2203 size_t relnum, off_t reloffset) const;
2206 #ifdef HAVE_TARGET_64_LITTLE
2209 Warnings::issue_warning<64, false>(const Symbol* sym,
2210 const Relocate_info<64, false>* relinfo,
2211 size_t relnum, off_t reloffset) const;
2214 #ifdef HAVE_TARGET_64_BIG
2217 Warnings::issue_warning<64, true>(const Symbol* sym,
2218 const Relocate_info<64, true>* relinfo,
2219 size_t relnum, off_t reloffset) const;
2222 } // End namespace gold.