1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007, 2008, 2009 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.
35 #include "dwarf_reader.h"
39 #include "workqueue.h"
41 #include "demangle.h" // needed for --dynamic-list-cpp-new
49 // Initialize fields in Symbol. This initializes everything except u_
53 Symbol::init_fields(const char* name, const char* version,
54 elfcpp::STT type, elfcpp::STB binding,
55 elfcpp::STV visibility, unsigned char nonvis)
58 this->version_ = version;
59 this->symtab_index_ = 0;
60 this->dynsym_index_ = 0;
61 this->got_offsets_.init();
62 this->plt_offset_ = 0;
64 this->binding_ = binding;
65 this->visibility_ = visibility;
66 this->nonvis_ = nonvis;
67 this->is_target_special_ = false;
68 this->is_def_ = false;
69 this->is_forwarder_ = false;
70 this->has_alias_ = false;
71 this->needs_dynsym_entry_ = false;
72 this->in_reg_ = false;
73 this->in_dyn_ = false;
74 this->has_plt_offset_ = false;
75 this->has_warning_ = false;
76 this->is_copied_from_dynobj_ = false;
77 this->is_forced_local_ = false;
78 this->is_ordinary_shndx_ = false;
79 this->in_real_elf_ = false;
82 // Return the demangled version of the symbol's name, but only
83 // if the --demangle flag was set.
86 demangle(const char* name)
88 if (!parameters->options().do_demangle())
91 // cplus_demangle allocates memory for the result it returns,
92 // and returns NULL if the name is already demangled.
93 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
94 if (demangled_name == NULL)
97 std::string retval(demangled_name);
103 Symbol::demangled_name() const
105 return demangle(this->name());
108 // Initialize the fields in the base class Symbol for SYM in OBJECT.
110 template<int size, bool big_endian>
112 Symbol::init_base_object(const char* name, const char* version, Object* object,
113 const elfcpp::Sym<size, big_endian>& sym,
114 unsigned int st_shndx, bool is_ordinary)
116 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
117 sym.get_st_visibility(), sym.get_st_nonvis());
118 this->u_.from_object.object = object;
119 this->u_.from_object.shndx = st_shndx;
120 this->is_ordinary_shndx_ = is_ordinary;
121 this->source_ = FROM_OBJECT;
122 this->in_reg_ = !object->is_dynamic();
123 this->in_dyn_ = object->is_dynamic();
124 this->in_real_elf_ = object->pluginobj() == NULL;
127 // Initialize the fields in the base class Symbol for a symbol defined
128 // in an Output_data.
131 Symbol::init_base_output_data(const char* name, const char* version,
132 Output_data* od, elfcpp::STT type,
133 elfcpp::STB binding, elfcpp::STV visibility,
134 unsigned char nonvis, bool offset_is_from_end)
136 this->init_fields(name, version, type, binding, visibility, nonvis);
137 this->u_.in_output_data.output_data = od;
138 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
139 this->source_ = IN_OUTPUT_DATA;
140 this->in_reg_ = true;
141 this->in_real_elf_ = true;
144 // Initialize the fields in the base class Symbol for a symbol defined
145 // in an Output_segment.
148 Symbol::init_base_output_segment(const char* name, const char* version,
149 Output_segment* os, elfcpp::STT type,
150 elfcpp::STB binding, elfcpp::STV visibility,
151 unsigned char nonvis,
152 Segment_offset_base offset_base)
154 this->init_fields(name, version, type, binding, visibility, nonvis);
155 this->u_.in_output_segment.output_segment = os;
156 this->u_.in_output_segment.offset_base = offset_base;
157 this->source_ = IN_OUTPUT_SEGMENT;
158 this->in_reg_ = true;
159 this->in_real_elf_ = true;
162 // Initialize the fields in the base class Symbol for a symbol defined
166 Symbol::init_base_constant(const char* name, const char* version,
167 elfcpp::STT type, elfcpp::STB binding,
168 elfcpp::STV visibility, unsigned char nonvis)
170 this->init_fields(name, version, type, binding, visibility, nonvis);
171 this->source_ = IS_CONSTANT;
172 this->in_reg_ = true;
173 this->in_real_elf_ = true;
176 // Initialize the fields in the base class Symbol for an undefined
180 Symbol::init_base_undefined(const char* name, const char* version,
181 elfcpp::STT type, elfcpp::STB binding,
182 elfcpp::STV visibility, unsigned char nonvis)
184 this->init_fields(name, version, type, binding, visibility, nonvis);
185 this->dynsym_index_ = -1U;
186 this->source_ = IS_UNDEFINED;
187 this->in_reg_ = true;
188 this->in_real_elf_ = true;
191 // Allocate a common symbol in the base.
194 Symbol::allocate_base_common(Output_data* od)
196 gold_assert(this->is_common());
197 this->source_ = IN_OUTPUT_DATA;
198 this->u_.in_output_data.output_data = od;
199 this->u_.in_output_data.offset_is_from_end = false;
202 // Initialize the fields in Sized_symbol for SYM in OBJECT.
205 template<bool big_endian>
207 Sized_symbol<size>::init_object(const char* name, const char* version,
209 const elfcpp::Sym<size, big_endian>& sym,
210 unsigned int st_shndx, bool is_ordinary)
212 this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
213 this->value_ = sym.get_st_value();
214 this->symsize_ = sym.get_st_size();
217 // Initialize the fields in Sized_symbol for a symbol defined in an
222 Sized_symbol<size>::init_output_data(const char* name, const char* version,
223 Output_data* od, Value_type value,
224 Size_type symsize, elfcpp::STT type,
226 elfcpp::STV visibility,
227 unsigned char nonvis,
228 bool offset_is_from_end)
230 this->init_base_output_data(name, version, od, type, binding, visibility,
231 nonvis, offset_is_from_end);
232 this->value_ = value;
233 this->symsize_ = symsize;
236 // Initialize the fields in Sized_symbol for a symbol defined in an
241 Sized_symbol<size>::init_output_segment(const char* name, const char* version,
242 Output_segment* os, Value_type value,
243 Size_type symsize, elfcpp::STT type,
245 elfcpp::STV visibility,
246 unsigned char nonvis,
247 Segment_offset_base offset_base)
249 this->init_base_output_segment(name, version, os, type, binding, visibility,
250 nonvis, offset_base);
251 this->value_ = value;
252 this->symsize_ = symsize;
255 // Initialize the fields in Sized_symbol for a symbol defined as a
260 Sized_symbol<size>::init_constant(const char* name, const char* version,
261 Value_type value, Size_type symsize,
262 elfcpp::STT type, elfcpp::STB binding,
263 elfcpp::STV visibility, unsigned char nonvis)
265 this->init_base_constant(name, version, type, binding, visibility, nonvis);
266 this->value_ = value;
267 this->symsize_ = symsize;
270 // Initialize the fields in Sized_symbol for an undefined symbol.
274 Sized_symbol<size>::init_undefined(const char* name, const char* version,
275 elfcpp::STT type, elfcpp::STB binding,
276 elfcpp::STV visibility, unsigned char nonvis)
278 this->init_base_undefined(name, version, type, binding, visibility, nonvis);
283 // Return true if SHNDX represents a common symbol.
286 Symbol::is_common_shndx(unsigned int shndx)
288 return (shndx == elfcpp::SHN_COMMON
289 || shndx == parameters->target().small_common_shndx()
290 || shndx == parameters->target().large_common_shndx());
293 // Allocate a common symbol.
297 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
299 this->allocate_base_common(od);
300 this->value_ = value;
303 // The ""'s around str ensure str is a string literal, so sizeof works.
304 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
306 // Return true if this symbol should be added to the dynamic symbol
310 Symbol::should_add_dynsym_entry() const
312 // If the symbol is used by a dynamic relocation, we need to add it.
313 if (this->needs_dynsym_entry())
316 // If this symbol's section is not added, the symbol need not be added.
317 // The section may have been GCed. Note that export_dynamic is being
318 // overridden here. This should not be done for shared objects.
319 if (parameters->options().gc_sections()
320 && !parameters->options().shared()
321 && this->source() == Symbol::FROM_OBJECT
322 && !this->object()->is_dynamic())
324 Relobj* relobj = static_cast<Relobj*>(this->object());
326 unsigned int shndx = this->shndx(&is_ordinary);
327 if (is_ordinary && shndx != elfcpp::SHN_UNDEF
328 && !relobj->is_section_included(shndx))
332 // If the symbol was forced local in a version script, do not add it.
333 if (this->is_forced_local())
336 // If the symbol was forced dynamic in a --dynamic-list file, add it.
337 if (parameters->options().in_dynamic_list(this->name()))
340 // If dynamic-list-data was specified, add any STT_OBJECT.
341 if (parameters->options().dynamic_list_data()
342 && !this->is_from_dynobj()
343 && this->type() == elfcpp::STT_OBJECT)
346 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
347 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
348 if ((parameters->options().dynamic_list_cpp_new()
349 || parameters->options().dynamic_list_cpp_typeinfo())
350 && !this->is_from_dynobj())
352 // TODO(csilvers): We could probably figure out if we're an operator
353 // new/delete or typeinfo without the need to demangle.
354 char* demangled_name = cplus_demangle(this->name(),
355 DMGL_ANSI | DMGL_PARAMS);
356 if (demangled_name == NULL)
358 // Not a C++ symbol, so it can't satisfy these flags
360 else if (parameters->options().dynamic_list_cpp_new()
361 && (strprefix(demangled_name, "operator new")
362 || strprefix(demangled_name, "operator delete")))
364 free(demangled_name);
367 else if (parameters->options().dynamic_list_cpp_typeinfo()
368 && (strprefix(demangled_name, "typeinfo name for")
369 || strprefix(demangled_name, "typeinfo for")))
371 free(demangled_name);
375 free(demangled_name);
378 // If exporting all symbols or building a shared library,
379 // and the symbol is defined in a regular object and is
380 // externally visible, we need to add it.
381 if ((parameters->options().export_dynamic() || parameters->options().shared())
382 && !this->is_from_dynobj()
383 && this->is_externally_visible())
389 // Return true if the final value of this symbol is known at link
393 Symbol::final_value_is_known() const
395 // If we are not generating an executable, then no final values are
396 // known, since they will change at runtime.
397 if (parameters->options().shared() || parameters->options().relocatable())
400 // If the symbol is not from an object file, and is not undefined,
401 // then it is defined, and known.
402 if (this->source_ != FROM_OBJECT)
404 if (this->source_ != IS_UNDEFINED)
409 // If the symbol is from a dynamic object, then the final value
411 if (this->object()->is_dynamic())
414 // If the symbol is not undefined (it is defined or common),
415 // then the final value is known.
416 if (!this->is_undefined())
420 // If the symbol is undefined, then whether the final value is known
421 // depends on whether we are doing a static link. If we are doing a
422 // dynamic link, then the final value could be filled in at runtime.
423 // This could reasonably be the case for a weak undefined symbol.
424 return parameters->doing_static_link();
427 // Return the output section where this symbol is defined.
430 Symbol::output_section() const
432 switch (this->source_)
436 unsigned int shndx = this->u_.from_object.shndx;
437 if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
439 gold_assert(!this->u_.from_object.object->is_dynamic());
440 gold_assert(this->u_.from_object.object->pluginobj() == NULL);
441 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
442 return relobj->output_section(shndx);
448 return this->u_.in_output_data.output_data->output_section();
450 case IN_OUTPUT_SEGMENT:
460 // Set the symbol's output section. This is used for symbols defined
461 // in scripts. This should only be called after the symbol table has
465 Symbol::set_output_section(Output_section* os)
467 switch (this->source_)
471 gold_assert(this->output_section() == os);
474 this->source_ = IN_OUTPUT_DATA;
475 this->u_.in_output_data.output_data = os;
476 this->u_.in_output_data.offset_is_from_end = false;
478 case IN_OUTPUT_SEGMENT:
485 // Class Symbol_table.
487 Symbol_table::Symbol_table(unsigned int count,
488 const Version_script_info& version_script)
489 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
490 forwarders_(), commons_(), tls_commons_(), small_commons_(),
491 large_commons_(), forced_locals_(), warnings_(),
492 version_script_(version_script), gc_(NULL), icf_(NULL)
494 namepool_.reserve(count);
497 Symbol_table::~Symbol_table()
501 // The hash function. The key values are Stringpool keys.
504 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
506 return key.first ^ key.second;
509 // The symbol table key equality function. This is called with
513 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
514 const Symbol_table_key& k2) const
516 return k1.first == k2.first && k1.second == k2.second;
520 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
522 return (parameters->options().icf_enabled()
523 && this->icf_->is_section_folded(obj, shndx));
526 // For symbols that have been listed with -u option, add them to the
527 // work list to avoid gc'ing them.
530 Symbol_table::gc_mark_undef_symbols()
532 for (options::String_set::const_iterator p =
533 parameters->options().undefined_begin();
534 p != parameters->options().undefined_end();
537 const char* name = p->c_str();
538 Symbol* sym = this->lookup(name);
539 gold_assert (sym != NULL);
540 if (sym->source() == Symbol::FROM_OBJECT
541 && !sym->object()->is_dynamic())
543 Relobj* obj = static_cast<Relobj*>(sym->object());
545 unsigned int shndx = sym->shndx(&is_ordinary);
548 gold_assert(this->gc_ != NULL);
549 this->gc_->worklist().push(Section_id(obj, shndx));
556 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
558 if (!sym->is_from_dynobj()
559 && sym->is_externally_visible())
561 //Add the object and section to the work list.
562 Relobj* obj = static_cast<Relobj*>(sym->object());
564 unsigned int shndx = sym->shndx(&is_ordinary);
565 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
567 gold_assert(this->gc_!= NULL);
568 this->gc_->worklist().push(Section_id(obj, shndx));
573 // When doing garbage collection, keep symbols that have been seen in
576 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
578 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
579 && !sym->object()->is_dynamic())
581 Relobj *obj = static_cast<Relobj*>(sym->object());
583 unsigned int shndx = sym->shndx(&is_ordinary);
584 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
586 gold_assert(this->gc_ != NULL);
587 this->gc_->worklist().push(Section_id(obj, shndx));
592 // Make TO a symbol which forwards to FROM.
595 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
597 gold_assert(from != to);
598 gold_assert(!from->is_forwarder() && !to->is_forwarder());
599 this->forwarders_[from] = to;
600 from->set_forwarder();
603 // Resolve the forwards from FROM, returning the real symbol.
606 Symbol_table::resolve_forwards(const Symbol* from) const
608 gold_assert(from->is_forwarder());
609 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
610 this->forwarders_.find(from);
611 gold_assert(p != this->forwarders_.end());
615 // Look up a symbol by name.
618 Symbol_table::lookup(const char* name, const char* version) const
620 Stringpool::Key name_key;
621 name = this->namepool_.find(name, &name_key);
625 Stringpool::Key version_key = 0;
628 version = this->namepool_.find(version, &version_key);
633 Symbol_table_key key(name_key, version_key);
634 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
635 if (p == this->table_.end())
640 // Resolve a Symbol with another Symbol. This is only used in the
641 // unusual case where there are references to both an unversioned
642 // symbol and a symbol with a version, and we then discover that that
643 // version is the default version. Because this is unusual, we do
644 // this the slow way, by converting back to an ELF symbol.
646 template<int size, bool big_endian>
648 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
650 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
651 elfcpp::Sym_write<size, big_endian> esym(buf);
652 // We don't bother to set the st_name or the st_shndx field.
653 esym.put_st_value(from->value());
654 esym.put_st_size(from->symsize());
655 esym.put_st_info(from->binding(), from->type());
656 esym.put_st_other(from->visibility(), from->nonvis());
658 unsigned int shndx = from->shndx(&is_ordinary);
659 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
665 if (parameters->options().gc_sections())
666 this->gc_mark_dyn_syms(to);
669 // Record that a symbol is forced to be local by a version script or
673 Symbol_table::force_local(Symbol* sym)
675 if (!sym->is_defined() && !sym->is_common())
677 if (sym->is_forced_local())
679 // We already got this one.
682 sym->set_is_forced_local();
683 this->forced_locals_.push_back(sym);
686 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
687 // is only called for undefined symbols, when at least one --wrap
691 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
693 // For some targets, we need to ignore a specific character when
694 // wrapping, and add it back later.
696 if (name[0] == parameters->target().wrap_char())
702 if (parameters->options().is_wrap(name))
704 // Turn NAME into __wrap_NAME.
711 // This will give us both the old and new name in NAMEPOOL_, but
712 // that is OK. Only the versions we need will wind up in the
713 // real string table in the output file.
714 return this->namepool_.add(s.c_str(), true, name_key);
717 const char* const real_prefix = "__real_";
718 const size_t real_prefix_length = strlen(real_prefix);
719 if (strncmp(name, real_prefix, real_prefix_length) == 0
720 && parameters->options().is_wrap(name + real_prefix_length))
722 // Turn __real_NAME into NAME.
726 s += name + real_prefix_length;
727 return this->namepool_.add(s.c_str(), true, name_key);
733 // This is called when we see a symbol NAME/VERSION, and the symbol
734 // already exists in the symbol table, and VERSION is marked as being
735 // the default version. SYM is the NAME/VERSION symbol we just added.
736 // DEFAULT_IS_NEW is true if this is the first time we have seen the
737 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
739 template<int size, bool big_endian>
741 Symbol_table::define_default_version(Sized_symbol<size>* sym,
743 Symbol_table_type::iterator pdef)
747 // This is the first time we have seen NAME/NULL. Make
748 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
751 sym->set_is_default();
753 else if (pdef->second == sym)
755 // NAME/NULL already points to NAME/VERSION. Don't mark the
756 // symbol as the default if it is not already the default.
760 // This is the unfortunate case where we already have entries
761 // for both NAME/VERSION and NAME/NULL. We now see a symbol
762 // NAME/VERSION where VERSION is the default version. We have
763 // already resolved this new symbol with the existing
764 // NAME/VERSION symbol.
766 // It's possible that NAME/NULL and NAME/VERSION are both
767 // defined in regular objects. This can only happen if one
768 // object file defines foo and another defines foo@@ver. This
769 // is somewhat obscure, but we call it a multiple definition
772 // It's possible that NAME/NULL actually has a version, in which
773 // case it won't be the same as VERSION. This happens with
774 // ver_test_7.so in the testsuite for the symbol t2_2. We see
775 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
776 // then see an unadorned t2_2 in an object file and give it
777 // version VER1 from the version script. This looks like a
778 // default definition for VER1, so it looks like we should merge
779 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
780 // not obvious that this is an error, either. So we just punt.
782 // If one of the symbols has non-default visibility, and the
783 // other is defined in a shared object, then they are different
786 // Otherwise, we just resolve the symbols as though they were
789 if (pdef->second->version() != NULL)
790 gold_assert(pdef->second->version() != sym->version());
791 else if (sym->visibility() != elfcpp::STV_DEFAULT
792 && pdef->second->is_from_dynobj())
794 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
795 && sym->is_from_dynobj())
799 const Sized_symbol<size>* symdef;
800 symdef = this->get_sized_symbol<size>(pdef->second);
801 Symbol_table::resolve<size, big_endian>(sym, symdef);
802 this->make_forwarder(pdef->second, sym);
804 sym->set_is_default();
809 // Add one symbol from OBJECT to the symbol table. NAME is symbol
810 // name and VERSION is the version; both are canonicalized. DEF is
811 // whether this is the default version. ST_SHNDX is the symbol's
812 // section index; IS_ORDINARY is whether this is a normal section
813 // rather than a special code.
815 // If DEF is true, then this is the definition of a default version of
816 // a symbol. That means that any lookup of NAME/NULL and any lookup
817 // of NAME/VERSION should always return the same symbol. This is
818 // obvious for references, but in particular we want to do this for
819 // definitions: overriding NAME/NULL should also override
820 // NAME/VERSION. If we don't do that, it would be very hard to
821 // override functions in a shared library which uses versioning.
823 // We implement this by simply making both entries in the hash table
824 // point to the same Symbol structure. That is easy enough if this is
825 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
826 // that we have seen both already, in which case they will both have
827 // independent entries in the symbol table. We can't simply change
828 // the symbol table entry, because we have pointers to the entries
829 // attached to the object files. So we mark the entry attached to the
830 // object file as a forwarder, and record it in the forwarders_ map.
831 // Note that entries in the hash table will never be marked as
834 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
835 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
836 // for a special section code. ST_SHNDX may be modified if the symbol
837 // is defined in a section being discarded.
839 template<int size, bool big_endian>
841 Symbol_table::add_from_object(Object* object,
843 Stringpool::Key name_key,
845 Stringpool::Key version_key,
847 const elfcpp::Sym<size, big_endian>& sym,
848 unsigned int st_shndx,
850 unsigned int orig_st_shndx)
852 // Print a message if this symbol is being traced.
853 if (parameters->options().is_trace_symbol(name))
855 if (orig_st_shndx == elfcpp::SHN_UNDEF)
856 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
858 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
861 // For an undefined symbol, we may need to adjust the name using
863 if (orig_st_shndx == elfcpp::SHN_UNDEF
864 && parameters->options().any_wrap())
866 const char* wrap_name = this->wrap_symbol(name, &name_key);
867 if (wrap_name != name)
869 // If we see a reference to malloc with version GLIBC_2.0,
870 // and we turn it into a reference to __wrap_malloc, then we
871 // discard the version number. Otherwise the user would be
872 // required to specify the correct version for
880 Symbol* const snull = NULL;
881 std::pair<typename Symbol_table_type::iterator, bool> ins =
882 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
885 std::pair<typename Symbol_table_type::iterator, bool> insdef =
886 std::make_pair(this->table_.end(), false);
889 const Stringpool::Key vnull_key = 0;
890 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
895 // ins.first: an iterator, which is a pointer to a pair.
896 // ins.first->first: the key (a pair of name and version).
897 // ins.first->second: the value (Symbol*).
898 // ins.second: true if new entry was inserted, false if not.
900 Sized_symbol<size>* ret;
905 // We already have an entry for NAME/VERSION.
906 ret = this->get_sized_symbol<size>(ins.first->second);
907 gold_assert(ret != NULL);
909 was_undefined = ret->is_undefined();
910 was_common = ret->is_common();
912 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
914 if (parameters->options().gc_sections())
915 this->gc_mark_dyn_syms(ret);
918 this->define_default_version<size, big_endian>(ret, insdef.second,
923 // This is the first time we have seen NAME/VERSION.
924 gold_assert(ins.first->second == NULL);
926 if (def && !insdef.second)
928 // We already have an entry for NAME/NULL. If we override
929 // it, then change it to NAME/VERSION.
930 ret = this->get_sized_symbol<size>(insdef.first->second);
932 was_undefined = ret->is_undefined();
933 was_common = ret->is_common();
935 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
937 if (parameters->options().gc_sections())
938 this->gc_mark_dyn_syms(ret);
939 ins.first->second = ret;
943 was_undefined = false;
946 Sized_target<size, big_endian>* target =
947 parameters->sized_target<size, big_endian>();
948 if (!target->has_make_symbol())
949 ret = new Sized_symbol<size>();
952 ret = target->make_symbol();
955 // This means that we don't want a symbol table
958 this->table_.erase(ins.first);
961 this->table_.erase(insdef.first);
962 // Inserting insdef invalidated ins.
963 this->table_.erase(std::make_pair(name_key,
970 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
972 ins.first->second = ret;
975 // This is the first time we have seen NAME/NULL. Point
976 // it at the new entry for NAME/VERSION.
977 gold_assert(insdef.second);
978 insdef.first->second = ret;
983 ret->set_is_default();
986 // Record every time we see a new undefined symbol, to speed up
988 if (!was_undefined && ret->is_undefined())
989 ++this->saw_undefined_;
991 // Keep track of common symbols, to speed up common symbol
993 if (!was_common && ret->is_common())
995 if (ret->type() == elfcpp::STT_TLS)
996 this->tls_commons_.push_back(ret);
997 else if (!is_ordinary
998 && st_shndx == parameters->target().small_common_shndx())
999 this->small_commons_.push_back(ret);
1000 else if (!is_ordinary
1001 && st_shndx == parameters->target().large_common_shndx())
1002 this->large_commons_.push_back(ret);
1004 this->commons_.push_back(ret);
1007 // If we're not doing a relocatable link, then any symbol with
1008 // hidden or internal visibility is local.
1009 if ((ret->visibility() == elfcpp::STV_HIDDEN
1010 || ret->visibility() == elfcpp::STV_INTERNAL)
1011 && (ret->binding() == elfcpp::STB_GLOBAL
1012 || ret->binding() == elfcpp::STB_WEAK)
1013 && !parameters->options().relocatable())
1014 this->force_local(ret);
1019 // Add all the symbols in a relocatable object to the hash table.
1021 template<int size, bool big_endian>
1023 Symbol_table::add_from_relobj(
1024 Sized_relobj<size, big_endian>* relobj,
1025 const unsigned char* syms,
1027 size_t symndx_offset,
1028 const char* sym_names,
1029 size_t sym_name_size,
1030 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1035 gold_assert(size == parameters->target().get_size());
1037 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1039 const bool just_symbols = relobj->just_symbols();
1041 const unsigned char* p = syms;
1042 for (size_t i = 0; i < count; ++i, p += sym_size)
1044 (*sympointers)[i] = NULL;
1046 elfcpp::Sym<size, big_endian> sym(p);
1048 unsigned int st_name = sym.get_st_name();
1049 if (st_name >= sym_name_size)
1051 relobj->error(_("bad global symbol name offset %u at %zu"),
1056 const char* name = sym_names + st_name;
1059 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1062 unsigned int orig_st_shndx = st_shndx;
1064 orig_st_shndx = elfcpp::SHN_UNDEF;
1066 if (st_shndx != elfcpp::SHN_UNDEF)
1069 // A symbol defined in a section which we are not including must
1070 // be treated as an undefined symbol.
1071 if (st_shndx != elfcpp::SHN_UNDEF
1073 && !relobj->is_section_included(st_shndx))
1074 st_shndx = elfcpp::SHN_UNDEF;
1076 // In an object file, an '@' in the name separates the symbol
1077 // name from the version name. If there are two '@' characters,
1078 // this is the default version.
1079 const char* ver = strchr(name, '@');
1080 Stringpool::Key ver_key = 0;
1082 // DEF: is the version default? LOCAL: is the symbol forced local?
1088 // The symbol name is of the form foo@VERSION or foo@@VERSION
1089 namelen = ver - name;
1096 ver = this->namepool_.add(ver, true, &ver_key);
1098 // We don't want to assign a version to an undefined symbol,
1099 // even if it is listed in the version script. FIXME: What
1100 // about a common symbol?
1103 namelen = strlen(name);
1104 if (!this->version_script_.empty()
1105 && st_shndx != elfcpp::SHN_UNDEF)
1107 // The symbol name did not have a version, but the
1108 // version script may assign a version anyway.
1109 std::string version;
1110 if (this->version_script_.get_symbol_version(name, &version))
1112 // The version can be empty if the version script is
1113 // only used to force some symbols to be local.
1114 if (!version.empty())
1116 ver = this->namepool_.add_with_length(version.c_str(),
1123 else if (this->version_script_.symbol_is_local(name))
1128 elfcpp::Sym<size, big_endian>* psym = &sym;
1129 unsigned char symbuf[sym_size];
1130 elfcpp::Sym<size, big_endian> sym2(symbuf);
1133 memcpy(symbuf, p, sym_size);
1134 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1135 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1137 // Symbol values in object files are section relative.
1138 // This is normally what we want, but since here we are
1139 // converting the symbol to absolute we need to add the
1140 // section address. The section address in an object
1141 // file is normally zero, but people can use a linker
1142 // script to change it.
1143 sw.put_st_value(sym.get_st_value()
1144 + relobj->section_address(orig_st_shndx));
1146 st_shndx = elfcpp::SHN_ABS;
1147 is_ordinary = false;
1151 // Fix up visibility if object has no-export set.
1152 if (relobj->no_export())
1154 // We may have copied symbol already above.
1157 memcpy(symbuf, p, sym_size);
1161 elfcpp::STV visibility = sym2.get_st_visibility();
1162 if (visibility == elfcpp::STV_DEFAULT
1163 || visibility == elfcpp::STV_PROTECTED)
1165 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1166 unsigned char nonvis = sym2.get_st_nonvis();
1167 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1171 Stringpool::Key name_key;
1172 name = this->namepool_.add_with_length(name, namelen, true,
1175 Sized_symbol<size>* res;
1176 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1177 def, *psym, st_shndx, is_ordinary,
1180 // If building a shared library using garbage collection, do not
1181 // treat externally visible symbols as garbage.
1182 if (parameters->options().gc_sections()
1183 && parameters->options().shared())
1184 this->gc_mark_symbol_for_shlib(res);
1187 this->force_local(res);
1189 (*sympointers)[i] = res;
1193 // Add a symbol from a plugin-claimed file.
1195 template<int size, bool big_endian>
1197 Symbol_table::add_from_pluginobj(
1198 Sized_pluginobj<size, big_endian>* obj,
1201 elfcpp::Sym<size, big_endian>* sym)
1203 unsigned int st_shndx = sym->get_st_shndx();
1205 Stringpool::Key ver_key = 0;
1211 ver = this->namepool_.add(ver, true, &ver_key);
1213 // We don't want to assign a version to an undefined symbol,
1214 // even if it is listed in the version script. FIXME: What
1215 // about a common symbol?
1218 if (!this->version_script_.empty()
1219 && st_shndx != elfcpp::SHN_UNDEF)
1221 // The symbol name did not have a version, but the
1222 // version script may assign a version anyway.
1223 std::string version;
1224 if (this->version_script_.get_symbol_version(name, &version))
1226 // The version can be empty if the version script is
1227 // only used to force some symbols to be local.
1228 if (!version.empty())
1230 ver = this->namepool_.add_with_length(version.c_str(),
1237 else if (this->version_script_.symbol_is_local(name))
1242 Stringpool::Key name_key;
1243 name = this->namepool_.add(name, true, &name_key);
1245 Sized_symbol<size>* res;
1246 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1247 def, *sym, st_shndx, true, st_shndx);
1250 this->force_local(res);
1255 // Add all the symbols in a dynamic object to the hash table.
1257 template<int size, bool big_endian>
1259 Symbol_table::add_from_dynobj(
1260 Sized_dynobj<size, big_endian>* dynobj,
1261 const unsigned char* syms,
1263 const char* sym_names,
1264 size_t sym_name_size,
1265 const unsigned char* versym,
1267 const std::vector<const char*>* version_map,
1268 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1273 gold_assert(size == parameters->target().get_size());
1275 if (dynobj->just_symbols())
1277 gold_error(_("--just-symbols does not make sense with a shared object"));
1281 if (versym != NULL && versym_size / 2 < count)
1283 dynobj->error(_("too few symbol versions"));
1287 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1289 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1290 // weak aliases. This is necessary because if the dynamic object
1291 // provides the same variable under two names, one of which is a
1292 // weak definition, and the regular object refers to the weak
1293 // definition, we have to put both the weak definition and the
1294 // strong definition into the dynamic symbol table. Given a weak
1295 // definition, the only way that we can find the corresponding
1296 // strong definition, if any, is to search the symbol table.
1297 std::vector<Sized_symbol<size>*> object_symbols;
1299 const unsigned char* p = syms;
1300 const unsigned char* vs = versym;
1301 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1303 elfcpp::Sym<size, big_endian> sym(p);
1305 if (sympointers != NULL)
1306 (*sympointers)[i] = NULL;
1308 // Ignore symbols with local binding or that have
1309 // internal or hidden visibility.
1310 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1311 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1312 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1315 // A protected symbol in a shared library must be treated as a
1316 // normal symbol when viewed from outside the shared library.
1317 // Implement this by overriding the visibility here.
1318 elfcpp::Sym<size, big_endian>* psym = &sym;
1319 unsigned char symbuf[sym_size];
1320 elfcpp::Sym<size, big_endian> sym2(symbuf);
1321 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1323 memcpy(symbuf, p, sym_size);
1324 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1325 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1329 unsigned int st_name = psym->get_st_name();
1330 if (st_name >= sym_name_size)
1332 dynobj->error(_("bad symbol name offset %u at %zu"),
1337 const char* name = sym_names + st_name;
1340 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1343 if (st_shndx != elfcpp::SHN_UNDEF)
1346 Sized_symbol<size>* res;
1350 Stringpool::Key name_key;
1351 name = this->namepool_.add(name, true, &name_key);
1352 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1353 false, *psym, st_shndx, is_ordinary,
1358 // Read the version information.
1360 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1362 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1363 v &= elfcpp::VERSYM_VERSION;
1365 // The Sun documentation says that V can be VER_NDX_LOCAL,
1366 // or VER_NDX_GLOBAL, or a version index. The meaning of
1367 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1368 // The old GNU linker will happily generate VER_NDX_LOCAL
1369 // for an undefined symbol. I don't know what the Sun
1370 // linker will generate.
1372 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1373 && st_shndx != elfcpp::SHN_UNDEF)
1375 // This symbol should not be visible outside the object.
1379 // At this point we are definitely going to add this symbol.
1380 Stringpool::Key name_key;
1381 name = this->namepool_.add(name, true, &name_key);
1383 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1384 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1386 // This symbol does not have a version.
1387 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1388 false, *psym, st_shndx, is_ordinary,
1393 if (v >= version_map->size())
1395 dynobj->error(_("versym for symbol %zu out of range: %u"),
1400 const char* version = (*version_map)[v];
1401 if (version == NULL)
1403 dynobj->error(_("versym for symbol %zu has no name: %u"),
1408 Stringpool::Key version_key;
1409 version = this->namepool_.add(version, true, &version_key);
1411 // If this is an absolute symbol, and the version name
1412 // and symbol name are the same, then this is the
1413 // version definition symbol. These symbols exist to
1414 // support using -u to pull in particular versions. We
1415 // do not want to record a version for them.
1416 if (st_shndx == elfcpp::SHN_ABS
1418 && name_key == version_key)
1419 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1420 false, *psym, st_shndx, is_ordinary,
1424 const bool def = (!hidden
1425 && st_shndx != elfcpp::SHN_UNDEF);
1426 res = this->add_from_object(dynobj, name, name_key, version,
1427 version_key, def, *psym, st_shndx,
1428 is_ordinary, st_shndx);
1433 // Note that it is possible that RES was overridden by an
1434 // earlier object, in which case it can't be aliased here.
1435 if (st_shndx != elfcpp::SHN_UNDEF
1437 && psym->get_st_type() == elfcpp::STT_OBJECT
1438 && res->source() == Symbol::FROM_OBJECT
1439 && res->object() == dynobj)
1440 object_symbols.push_back(res);
1442 if (sympointers != NULL)
1443 (*sympointers)[i] = res;
1446 this->record_weak_aliases(&object_symbols);
1449 // This is used to sort weak aliases. We sort them first by section
1450 // index, then by offset, then by weak ahead of strong.
1453 class Weak_alias_sorter
1456 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1461 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1462 const Sized_symbol<size>* s2) const
1465 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1466 gold_assert(is_ordinary);
1467 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1468 gold_assert(is_ordinary);
1469 if (s1_shndx != s2_shndx)
1470 return s1_shndx < s2_shndx;
1472 if (s1->value() != s2->value())
1473 return s1->value() < s2->value();
1474 if (s1->binding() != s2->binding())
1476 if (s1->binding() == elfcpp::STB_WEAK)
1478 if (s2->binding() == elfcpp::STB_WEAK)
1481 return std::string(s1->name()) < std::string(s2->name());
1484 // SYMBOLS is a list of object symbols from a dynamic object. Look
1485 // for any weak aliases, and record them so that if we add the weak
1486 // alias to the dynamic symbol table, we also add the corresponding
1491 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1493 // Sort the vector by section index, then by offset, then by weak
1495 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1497 // Walk through the vector. For each weak definition, record
1499 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1501 p != symbols->end();
1504 if ((*p)->binding() != elfcpp::STB_WEAK)
1507 // Build a circular list of weak aliases. Each symbol points to
1508 // the next one in the circular list.
1510 Sized_symbol<size>* from_sym = *p;
1511 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1512 for (q = p + 1; q != symbols->end(); ++q)
1515 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1516 || (*q)->value() != from_sym->value())
1519 this->weak_aliases_[from_sym] = *q;
1520 from_sym->set_has_alias();
1526 this->weak_aliases_[from_sym] = *p;
1527 from_sym->set_has_alias();
1534 // Create and return a specially defined symbol. If ONLY_IF_REF is
1535 // true, then only create the symbol if there is a reference to it.
1536 // If this does not return NULL, it sets *POLDSYM to the existing
1537 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1538 // resolve the newly created symbol to the old one. This
1539 // canonicalizes *PNAME and *PVERSION.
1541 template<int size, bool big_endian>
1543 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1545 Sized_symbol<size>** poldsym,
1546 bool *resolve_oldsym)
1548 *resolve_oldsym = false;
1550 // If the caller didn't give us a version, see if we get one from
1551 // the version script.
1553 bool is_default_version = false;
1554 if (*pversion == NULL)
1556 if (this->version_script_.get_symbol_version(*pname, &v))
1559 *pversion = v.c_str();
1561 // If we get the version from a version script, then we are
1562 // also the default version.
1563 is_default_version = true;
1568 Sized_symbol<size>* sym;
1570 bool add_to_table = false;
1571 typename Symbol_table_type::iterator add_loc = this->table_.end();
1572 bool add_def_to_table = false;
1573 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1577 oldsym = this->lookup(*pname, *pversion);
1578 if (oldsym == NULL && is_default_version)
1579 oldsym = this->lookup(*pname, NULL);
1580 if (oldsym == NULL || !oldsym->is_undefined())
1583 *pname = oldsym->name();
1584 if (!is_default_version)
1585 *pversion = oldsym->version();
1589 // Canonicalize NAME and VERSION.
1590 Stringpool::Key name_key;
1591 *pname = this->namepool_.add(*pname, true, &name_key);
1593 Stringpool::Key version_key = 0;
1594 if (*pversion != NULL)
1595 *pversion = this->namepool_.add(*pversion, true, &version_key);
1597 Symbol* const snull = NULL;
1598 std::pair<typename Symbol_table_type::iterator, bool> ins =
1599 this->table_.insert(std::make_pair(std::make_pair(name_key,
1603 std::pair<typename Symbol_table_type::iterator, bool> insdef =
1604 std::make_pair(this->table_.end(), false);
1605 if (is_default_version)
1607 const Stringpool::Key vnull = 0;
1608 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
1615 // We already have a symbol table entry for NAME/VERSION.
1616 oldsym = ins.first->second;
1617 gold_assert(oldsym != NULL);
1619 if (is_default_version)
1621 Sized_symbol<size>* soldsym =
1622 this->get_sized_symbol<size>(oldsym);
1623 this->define_default_version<size, big_endian>(soldsym,
1630 // We haven't seen this symbol before.
1631 gold_assert(ins.first->second == NULL);
1633 add_to_table = true;
1634 add_loc = ins.first;
1636 if (is_default_version && !insdef.second)
1638 // We are adding NAME/VERSION, and it is the default
1639 // version. We already have an entry for NAME/NULL.
1640 oldsym = insdef.first->second;
1641 *resolve_oldsym = true;
1647 if (is_default_version)
1649 add_def_to_table = true;
1650 add_def_loc = insdef.first;
1656 const Target& target = parameters->target();
1657 if (!target.has_make_symbol())
1658 sym = new Sized_symbol<size>();
1661 Sized_target<size, big_endian>* sized_target =
1662 parameters->sized_target<size, big_endian>();
1663 sym = sized_target->make_symbol();
1669 add_loc->second = sym;
1671 gold_assert(oldsym != NULL);
1673 if (add_def_to_table)
1674 add_def_loc->second = sym;
1676 *poldsym = this->get_sized_symbol<size>(oldsym);
1681 // Define a symbol based on an Output_data.
1684 Symbol_table::define_in_output_data(const char* name,
1685 const char* version,
1690 elfcpp::STB binding,
1691 elfcpp::STV visibility,
1692 unsigned char nonvis,
1693 bool offset_is_from_end,
1696 if (parameters->target().get_size() == 32)
1698 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1699 return this->do_define_in_output_data<32>(name, version, od,
1700 value, symsize, type, binding,
1708 else if (parameters->target().get_size() == 64)
1710 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1711 return this->do_define_in_output_data<64>(name, version, od,
1712 value, symsize, type, binding,
1724 // Define a symbol in an Output_data, sized version.
1728 Symbol_table::do_define_in_output_data(
1730 const char* version,
1732 typename elfcpp::Elf_types<size>::Elf_Addr value,
1733 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1735 elfcpp::STB binding,
1736 elfcpp::STV visibility,
1737 unsigned char nonvis,
1738 bool offset_is_from_end,
1741 Sized_symbol<size>* sym;
1742 Sized_symbol<size>* oldsym;
1743 bool resolve_oldsym;
1745 if (parameters->target().is_big_endian())
1747 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1748 sym = this->define_special_symbol<size, true>(&name, &version,
1749 only_if_ref, &oldsym,
1757 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1758 sym = this->define_special_symbol<size, false>(&name, &version,
1759 only_if_ref, &oldsym,
1769 sym->init_output_data(name, version, od, value, symsize, type, binding,
1770 visibility, nonvis, offset_is_from_end);
1774 if (binding == elfcpp::STB_LOCAL
1775 || this->version_script_.symbol_is_local(name))
1776 this->force_local(sym);
1777 else if (version != NULL)
1778 sym->set_is_default();
1782 if (Symbol_table::should_override_with_special(oldsym))
1783 this->override_with_special(oldsym, sym);
1794 // Define a symbol based on an Output_segment.
1797 Symbol_table::define_in_output_segment(const char* name,
1798 const char* version, Output_segment* os,
1802 elfcpp::STB binding,
1803 elfcpp::STV visibility,
1804 unsigned char nonvis,
1805 Symbol::Segment_offset_base offset_base,
1808 if (parameters->target().get_size() == 32)
1810 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1811 return this->do_define_in_output_segment<32>(name, version, os,
1812 value, symsize, type,
1813 binding, visibility, nonvis,
1814 offset_base, only_if_ref);
1819 else if (parameters->target().get_size() == 64)
1821 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1822 return this->do_define_in_output_segment<64>(name, version, os,
1823 value, symsize, type,
1824 binding, visibility, nonvis,
1825 offset_base, only_if_ref);
1834 // Define a symbol in an Output_segment, sized version.
1838 Symbol_table::do_define_in_output_segment(
1840 const char* version,
1842 typename elfcpp::Elf_types<size>::Elf_Addr value,
1843 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1845 elfcpp::STB binding,
1846 elfcpp::STV visibility,
1847 unsigned char nonvis,
1848 Symbol::Segment_offset_base offset_base,
1851 Sized_symbol<size>* sym;
1852 Sized_symbol<size>* oldsym;
1853 bool resolve_oldsym;
1855 if (parameters->target().is_big_endian())
1857 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1858 sym = this->define_special_symbol<size, true>(&name, &version,
1859 only_if_ref, &oldsym,
1867 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1868 sym = this->define_special_symbol<size, false>(&name, &version,
1869 only_if_ref, &oldsym,
1879 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1880 visibility, nonvis, offset_base);
1884 if (binding == elfcpp::STB_LOCAL
1885 || this->version_script_.symbol_is_local(name))
1886 this->force_local(sym);
1887 else if (version != NULL)
1888 sym->set_is_default();
1892 if (Symbol_table::should_override_with_special(oldsym))
1893 this->override_with_special(oldsym, sym);
1904 // Define a special symbol with a constant value. It is a multiple
1905 // definition error if this symbol is already defined.
1908 Symbol_table::define_as_constant(const char* name,
1909 const char* version,
1913 elfcpp::STB binding,
1914 elfcpp::STV visibility,
1915 unsigned char nonvis,
1917 bool force_override)
1919 if (parameters->target().get_size() == 32)
1921 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1922 return this->do_define_as_constant<32>(name, version, value,
1923 symsize, type, binding,
1924 visibility, nonvis, only_if_ref,
1930 else if (parameters->target().get_size() == 64)
1932 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1933 return this->do_define_as_constant<64>(name, version, value,
1934 symsize, type, binding,
1935 visibility, nonvis, only_if_ref,
1945 // Define a symbol as a constant, sized version.
1949 Symbol_table::do_define_as_constant(
1951 const char* version,
1952 typename elfcpp::Elf_types<size>::Elf_Addr value,
1953 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1955 elfcpp::STB binding,
1956 elfcpp::STV visibility,
1957 unsigned char nonvis,
1959 bool force_override)
1961 Sized_symbol<size>* sym;
1962 Sized_symbol<size>* oldsym;
1963 bool resolve_oldsym;
1965 if (parameters->target().is_big_endian())
1967 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1968 sym = this->define_special_symbol<size, true>(&name, &version,
1969 only_if_ref, &oldsym,
1977 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1978 sym = this->define_special_symbol<size, false>(&name, &version,
1979 only_if_ref, &oldsym,
1989 sym->init_constant(name, version, value, symsize, type, binding, visibility,
1994 // Version symbols are absolute symbols with name == version.
1995 // We don't want to force them to be local.
1996 if ((version == NULL
1999 && (binding == elfcpp::STB_LOCAL
2000 || this->version_script_.symbol_is_local(name)))
2001 this->force_local(sym);
2002 else if (version != NULL
2003 && (name != version || value != 0))
2004 sym->set_is_default();
2008 if (force_override || Symbol_table::should_override_with_special(oldsym))
2009 this->override_with_special(oldsym, sym);
2020 // Define a set of symbols in output sections.
2023 Symbol_table::define_symbols(const Layout* layout, int count,
2024 const Define_symbol_in_section* p,
2027 for (int i = 0; i < count; ++i, ++p)
2029 Output_section* os = layout->find_output_section(p->output_section);
2031 this->define_in_output_data(p->name, NULL, os, p->value,
2032 p->size, p->type, p->binding,
2033 p->visibility, p->nonvis,
2034 p->offset_is_from_end,
2035 only_if_ref || p->only_if_ref);
2037 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2038 p->binding, p->visibility, p->nonvis,
2039 only_if_ref || p->only_if_ref,
2044 // Define a set of symbols in output segments.
2047 Symbol_table::define_symbols(const Layout* layout, int count,
2048 const Define_symbol_in_segment* p,
2051 for (int i = 0; i < count; ++i, ++p)
2053 Output_segment* os = layout->find_output_segment(p->segment_type,
2054 p->segment_flags_set,
2055 p->segment_flags_clear);
2057 this->define_in_output_segment(p->name, NULL, os, p->value,
2058 p->size, p->type, p->binding,
2059 p->visibility, p->nonvis,
2061 only_if_ref || p->only_if_ref);
2063 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2064 p->binding, p->visibility, p->nonvis,
2065 only_if_ref || p->only_if_ref,
2070 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2071 // symbol should be defined--typically a .dyn.bss section. VALUE is
2072 // the offset within POSD.
2076 Symbol_table::define_with_copy_reloc(
2077 Sized_symbol<size>* csym,
2079 typename elfcpp::Elf_types<size>::Elf_Addr value)
2081 gold_assert(csym->is_from_dynobj());
2082 gold_assert(!csym->is_copied_from_dynobj());
2083 Object* object = csym->object();
2084 gold_assert(object->is_dynamic());
2085 Dynobj* dynobj = static_cast<Dynobj*>(object);
2087 // Our copied variable has to override any variable in a shared
2089 elfcpp::STB binding = csym->binding();
2090 if (binding == elfcpp::STB_WEAK)
2091 binding = elfcpp::STB_GLOBAL;
2093 this->define_in_output_data(csym->name(), csym->version(),
2094 posd, value, csym->symsize(),
2095 csym->type(), binding,
2096 csym->visibility(), csym->nonvis(),
2099 csym->set_is_copied_from_dynobj();
2100 csym->set_needs_dynsym_entry();
2102 this->copied_symbol_dynobjs_[csym] = dynobj;
2104 // We have now defined all aliases, but we have not entered them all
2105 // in the copied_symbol_dynobjs_ map.
2106 if (csym->has_alias())
2111 sym = this->weak_aliases_[sym];
2114 gold_assert(sym->output_data() == posd);
2116 sym->set_is_copied_from_dynobj();
2117 this->copied_symbol_dynobjs_[sym] = dynobj;
2122 // SYM is defined using a COPY reloc. Return the dynamic object where
2123 // the original definition was found.
2126 Symbol_table::get_copy_source(const Symbol* sym) const
2128 gold_assert(sym->is_copied_from_dynobj());
2129 Copied_symbol_dynobjs::const_iterator p =
2130 this->copied_symbol_dynobjs_.find(sym);
2131 gold_assert(p != this->copied_symbol_dynobjs_.end());
2135 // Add any undefined symbols named on the command line.
2138 Symbol_table::add_undefined_symbols_from_command_line()
2140 if (parameters->options().any_undefined())
2142 if (parameters->target().get_size() == 32)
2144 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2145 this->do_add_undefined_symbols_from_command_line<32>();
2150 else if (parameters->target().get_size() == 64)
2152 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2153 this->do_add_undefined_symbols_from_command_line<64>();
2165 Symbol_table::do_add_undefined_symbols_from_command_line()
2167 for (options::String_set::const_iterator p =
2168 parameters->options().undefined_begin();
2169 p != parameters->options().undefined_end();
2172 const char* name = p->c_str();
2174 if (this->lookup(name) != NULL)
2177 const char* version = NULL;
2179 Sized_symbol<size>* sym;
2180 Sized_symbol<size>* oldsym;
2181 bool resolve_oldsym;
2182 if (parameters->target().is_big_endian())
2184 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2185 sym = this->define_special_symbol<size, true>(&name, &version,
2194 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2195 sym = this->define_special_symbol<size, false>(&name, &version,
2203 gold_assert(oldsym == NULL);
2205 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2206 elfcpp::STV_DEFAULT, 0);
2207 ++this->saw_undefined_;
2211 // Set the dynamic symbol indexes. INDEX is the index of the first
2212 // global dynamic symbol. Pointers to the symbols are stored into the
2213 // vector SYMS. The names are added to DYNPOOL. This returns an
2214 // updated dynamic symbol index.
2217 Symbol_table::set_dynsym_indexes(unsigned int index,
2218 std::vector<Symbol*>* syms,
2219 Stringpool* dynpool,
2222 for (Symbol_table_type::iterator p = this->table_.begin();
2223 p != this->table_.end();
2226 Symbol* sym = p->second;
2228 // Note that SYM may already have a dynamic symbol index, since
2229 // some symbols appear more than once in the symbol table, with
2230 // and without a version.
2232 if (!sym->should_add_dynsym_entry())
2233 sym->set_dynsym_index(-1U);
2234 else if (!sym->has_dynsym_index())
2236 sym->set_dynsym_index(index);
2238 syms->push_back(sym);
2239 dynpool->add(sym->name(), false, NULL);
2241 // Record any version information.
2242 if (sym->version() != NULL)
2243 versions->record_version(this, dynpool, sym);
2247 // Finish up the versions. In some cases this may add new dynamic
2249 index = versions->finalize(this, index, syms);
2254 // Set the final values for all the symbols. The index of the first
2255 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2256 // file offset OFF. Add their names to POOL. Return the new file
2257 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2260 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2261 size_t dyncount, Stringpool* pool,
2262 unsigned int *plocal_symcount)
2266 gold_assert(*plocal_symcount != 0);
2267 this->first_global_index_ = *plocal_symcount;
2269 this->dynamic_offset_ = dynoff;
2270 this->first_dynamic_global_index_ = dyn_global_index;
2271 this->dynamic_count_ = dyncount;
2273 if (parameters->target().get_size() == 32)
2275 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2276 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2281 else if (parameters->target().get_size() == 64)
2283 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2284 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2292 // Now that we have the final symbol table, we can reliably note
2293 // which symbols should get warnings.
2294 this->warnings_.note_warnings(this);
2299 // SYM is going into the symbol table at *PINDEX. Add the name to
2300 // POOL, update *PINDEX and *POFF.
2304 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2305 unsigned int* pindex, off_t* poff)
2307 sym->set_symtab_index(*pindex);
2308 pool->add(sym->name(), false, NULL);
2310 *poff += elfcpp::Elf_sizes<size>::sym_size;
2313 // Set the final value for all the symbols. This is called after
2314 // Layout::finalize, so all the output sections have their final
2319 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2320 unsigned int* plocal_symcount)
2322 off = align_address(off, size >> 3);
2323 this->offset_ = off;
2325 unsigned int index = *plocal_symcount;
2326 const unsigned int orig_index = index;
2328 // First do all the symbols which have been forced to be local, as
2329 // they must appear before all global symbols.
2330 for (Forced_locals::iterator p = this->forced_locals_.begin();
2331 p != this->forced_locals_.end();
2335 gold_assert(sym->is_forced_local());
2336 if (this->sized_finalize_symbol<size>(sym))
2338 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2343 // Now do all the remaining symbols.
2344 for (Symbol_table_type::iterator p = this->table_.begin();
2345 p != this->table_.end();
2348 Symbol* sym = p->second;
2349 if (this->sized_finalize_symbol<size>(sym))
2350 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2353 this->output_count_ = index - orig_index;
2358 // Compute the final value of SYM and store status in location PSTATUS.
2359 // During relaxation, this may be called multiple times for a symbol to
2360 // compute its would-be final value in each relaxation pass.
2363 typename Sized_symbol<size>::Value_type
2364 Symbol_table::compute_final_value(
2365 const Sized_symbol<size>* sym,
2366 Compute_final_value_status* pstatus) const
2368 typedef typename Sized_symbol<size>::Value_type Value_type;
2371 switch (sym->source())
2373 case Symbol::FROM_OBJECT:
2376 unsigned int shndx = sym->shndx(&is_ordinary);
2379 && shndx != elfcpp::SHN_ABS
2380 && !Symbol::is_common_shndx(shndx))
2382 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2386 Object* symobj = sym->object();
2387 if (symobj->is_dynamic())
2390 shndx = elfcpp::SHN_UNDEF;
2392 else if (symobj->pluginobj() != NULL)
2395 shndx = elfcpp::SHN_UNDEF;
2397 else if (shndx == elfcpp::SHN_UNDEF)
2399 else if (!is_ordinary
2400 && (shndx == elfcpp::SHN_ABS
2401 || Symbol::is_common_shndx(shndx)))
2402 value = sym->value();
2405 Relobj* relobj = static_cast<Relobj*>(symobj);
2406 Output_section* os = relobj->output_section(shndx);
2407 uint64_t secoff64 = relobj->output_section_offset(shndx);
2409 if (this->is_section_folded(relobj, shndx))
2411 gold_assert(os == NULL);
2412 // Get the os of the section it is folded onto.
2413 Section_id folded = this->icf_->get_folded_section(relobj,
2415 gold_assert(folded.first != NULL);
2416 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2417 os = folded_obj->output_section(folded.second);
2418 gold_assert(os != NULL);
2419 secoff64 = folded_obj->output_section_offset(folded.second);
2424 bool static_or_reloc = (parameters->doing_static_link() ||
2425 parameters->options().relocatable());
2426 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2428 *pstatus = CFVS_NO_OUTPUT_SECTION;
2432 if (secoff64 == -1ULL)
2434 // The section needs special handling (e.g., a merge section).
2436 value = os->output_address(relobj, shndx, sym->value());
2441 convert_types<Value_type, uint64_t>(secoff64);
2442 if (sym->type() == elfcpp::STT_TLS)
2443 value = sym->value() + os->tls_offset() + secoff;
2445 value = sym->value() + os->address() + secoff;
2451 case Symbol::IN_OUTPUT_DATA:
2453 Output_data* od = sym->output_data();
2454 value = sym->value();
2455 if (sym->type() != elfcpp::STT_TLS)
2456 value += od->address();
2459 Output_section* os = od->output_section();
2460 gold_assert(os != NULL);
2461 value += os->tls_offset() + (od->address() - os->address());
2463 if (sym->offset_is_from_end())
2464 value += od->data_size();
2468 case Symbol::IN_OUTPUT_SEGMENT:
2470 Output_segment* os = sym->output_segment();
2471 value = sym->value();
2472 if (sym->type() != elfcpp::STT_TLS)
2473 value += os->vaddr();
2474 switch (sym->offset_base())
2476 case Symbol::SEGMENT_START:
2478 case Symbol::SEGMENT_END:
2479 value += os->memsz();
2481 case Symbol::SEGMENT_BSS:
2482 value += os->filesz();
2490 case Symbol::IS_CONSTANT:
2491 value = sym->value();
2494 case Symbol::IS_UNDEFINED:
2506 // Finalize the symbol SYM. This returns true if the symbol should be
2507 // added to the symbol table, false otherwise.
2511 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2513 typedef typename Sized_symbol<size>::Value_type Value_type;
2515 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2517 // The default version of a symbol may appear twice in the symbol
2518 // table. We only need to finalize it once.
2519 if (sym->has_symtab_index())
2524 gold_assert(!sym->has_symtab_index());
2525 sym->set_symtab_index(-1U);
2526 gold_assert(sym->dynsym_index() == -1U);
2530 // Compute final symbol value.
2531 Compute_final_value_status status;
2532 Value_type value = this->compute_final_value(sym, &status);
2538 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2541 unsigned int shndx = sym->shndx(&is_ordinary);
2542 gold_error(_("%s: unsupported symbol section 0x%x"),
2543 sym->demangled_name().c_str(), shndx);
2546 case CFVS_NO_OUTPUT_SECTION:
2547 sym->set_symtab_index(-1U);
2553 sym->set_value(value);
2555 if (parameters->options().strip_all()
2556 || !parameters->options().should_retain_symbol(sym->name()))
2558 sym->set_symtab_index(-1U);
2565 // Write out the global symbols.
2568 Symbol_table::write_globals(const Stringpool* sympool,
2569 const Stringpool* dynpool,
2570 Output_symtab_xindex* symtab_xindex,
2571 Output_symtab_xindex* dynsym_xindex,
2572 Output_file* of) const
2574 switch (parameters->size_and_endianness())
2576 #ifdef HAVE_TARGET_32_LITTLE
2577 case Parameters::TARGET_32_LITTLE:
2578 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2582 #ifdef HAVE_TARGET_32_BIG
2583 case Parameters::TARGET_32_BIG:
2584 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2588 #ifdef HAVE_TARGET_64_LITTLE
2589 case Parameters::TARGET_64_LITTLE:
2590 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2594 #ifdef HAVE_TARGET_64_BIG
2595 case Parameters::TARGET_64_BIG:
2596 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2605 // Write out the global symbols.
2607 template<int size, bool big_endian>
2609 Symbol_table::sized_write_globals(const Stringpool* sympool,
2610 const Stringpool* dynpool,
2611 Output_symtab_xindex* symtab_xindex,
2612 Output_symtab_xindex* dynsym_xindex,
2613 Output_file* of) const
2615 const Target& target = parameters->target();
2617 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2619 const unsigned int output_count = this->output_count_;
2620 const section_size_type oview_size = output_count * sym_size;
2621 const unsigned int first_global_index = this->first_global_index_;
2622 unsigned char* psyms;
2623 if (this->offset_ == 0 || output_count == 0)
2626 psyms = of->get_output_view(this->offset_, oview_size);
2628 const unsigned int dynamic_count = this->dynamic_count_;
2629 const section_size_type dynamic_size = dynamic_count * sym_size;
2630 const unsigned int first_dynamic_global_index =
2631 this->first_dynamic_global_index_;
2632 unsigned char* dynamic_view;
2633 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2634 dynamic_view = NULL;
2636 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2638 for (Symbol_table_type::const_iterator p = this->table_.begin();
2639 p != this->table_.end();
2642 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2644 // Possibly warn about unresolved symbols in shared libraries.
2645 this->warn_about_undefined_dynobj_symbol(sym);
2647 unsigned int sym_index = sym->symtab_index();
2648 unsigned int dynsym_index;
2649 if (dynamic_view == NULL)
2652 dynsym_index = sym->dynsym_index();
2654 if (sym_index == -1U && dynsym_index == -1U)
2656 // This symbol is not included in the output file.
2661 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2662 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2663 switch (sym->source())
2665 case Symbol::FROM_OBJECT:
2668 unsigned int in_shndx = sym->shndx(&is_ordinary);
2671 && in_shndx != elfcpp::SHN_ABS
2672 && !Symbol::is_common_shndx(in_shndx))
2674 gold_error(_("%s: unsupported symbol section 0x%x"),
2675 sym->demangled_name().c_str(), in_shndx);
2680 Object* symobj = sym->object();
2681 if (symobj->is_dynamic())
2683 if (sym->needs_dynsym_value())
2684 dynsym_value = target.dynsym_value(sym);
2685 shndx = elfcpp::SHN_UNDEF;
2687 else if (symobj->pluginobj() != NULL)
2688 shndx = elfcpp::SHN_UNDEF;
2689 else if (in_shndx == elfcpp::SHN_UNDEF
2691 && (in_shndx == elfcpp::SHN_ABS
2692 || Symbol::is_common_shndx(in_shndx))))
2696 Relobj* relobj = static_cast<Relobj*>(symobj);
2697 Output_section* os = relobj->output_section(in_shndx);
2698 if (this->is_section_folded(relobj, in_shndx))
2700 // This global symbol must be written out even though
2702 // Get the os of the section it is folded onto.
2704 this->icf_->get_folded_section(relobj, in_shndx);
2705 gold_assert(folded.first !=NULL);
2706 Relobj* folded_obj =
2707 reinterpret_cast<Relobj*>(folded.first);
2708 os = folded_obj->output_section(folded.second);
2709 gold_assert(os != NULL);
2711 gold_assert(os != NULL);
2712 shndx = os->out_shndx();
2714 if (shndx >= elfcpp::SHN_LORESERVE)
2716 if (sym_index != -1U)
2717 symtab_xindex->add(sym_index, shndx);
2718 if (dynsym_index != -1U)
2719 dynsym_xindex->add(dynsym_index, shndx);
2720 shndx = elfcpp::SHN_XINDEX;
2723 // In object files symbol values are section
2725 if (parameters->options().relocatable())
2726 sym_value -= os->address();
2732 case Symbol::IN_OUTPUT_DATA:
2733 shndx = sym->output_data()->out_shndx();
2734 if (shndx >= elfcpp::SHN_LORESERVE)
2736 if (sym_index != -1U)
2737 symtab_xindex->add(sym_index, shndx);
2738 if (dynsym_index != -1U)
2739 dynsym_xindex->add(dynsym_index, shndx);
2740 shndx = elfcpp::SHN_XINDEX;
2744 case Symbol::IN_OUTPUT_SEGMENT:
2745 shndx = elfcpp::SHN_ABS;
2748 case Symbol::IS_CONSTANT:
2749 shndx = elfcpp::SHN_ABS;
2752 case Symbol::IS_UNDEFINED:
2753 shndx = elfcpp::SHN_UNDEF;
2760 if (sym_index != -1U)
2762 sym_index -= first_global_index;
2763 gold_assert(sym_index < output_count);
2764 unsigned char* ps = psyms + (sym_index * sym_size);
2765 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2769 if (dynsym_index != -1U)
2771 dynsym_index -= first_dynamic_global_index;
2772 gold_assert(dynsym_index < dynamic_count);
2773 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2774 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2779 of->write_output_view(this->offset_, oview_size, psyms);
2780 if (dynamic_view != NULL)
2781 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2784 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2785 // strtab holding the name.
2787 template<int size, bool big_endian>
2789 Symbol_table::sized_write_symbol(
2790 Sized_symbol<size>* sym,
2791 typename elfcpp::Elf_types<size>::Elf_Addr value,
2793 const Stringpool* pool,
2794 unsigned char* p) const
2796 elfcpp::Sym_write<size, big_endian> osym(p);
2797 osym.put_st_name(pool->get_offset(sym->name()));
2798 osym.put_st_value(value);
2799 // Use a symbol size of zero for undefined symbols from shared libraries.
2800 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2801 osym.put_st_size(0);
2803 osym.put_st_size(sym->symsize());
2804 // A version script may have overridden the default binding.
2805 if (sym->is_forced_local())
2806 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2808 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2809 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2810 osym.put_st_shndx(shndx);
2813 // Check for unresolved symbols in shared libraries. This is
2814 // controlled by the --allow-shlib-undefined option.
2816 // We only warn about libraries for which we have seen all the
2817 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2818 // which were not seen in this link. If we didn't see a DT_NEEDED
2819 // entry, we aren't going to be able to reliably report whether the
2820 // symbol is undefined.
2822 // We also don't warn about libraries found in a system library
2823 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2824 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2825 // can have undefined references satisfied by ld-linux.so.
2828 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2831 if (sym->source() == Symbol::FROM_OBJECT
2832 && sym->object()->is_dynamic()
2833 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2834 && sym->binding() != elfcpp::STB_WEAK
2835 && !parameters->options().allow_shlib_undefined()
2836 && !parameters->target().is_defined_by_abi(sym)
2837 && !sym->object()->is_in_system_directory())
2839 // A very ugly cast.
2840 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2841 if (!dynobj->has_unknown_needed_entries())
2842 gold_undefined_symbol(sym);
2846 // Write out a section symbol. Return the update offset.
2849 Symbol_table::write_section_symbol(const Output_section *os,
2850 Output_symtab_xindex* symtab_xindex,
2854 switch (parameters->size_and_endianness())
2856 #ifdef HAVE_TARGET_32_LITTLE
2857 case Parameters::TARGET_32_LITTLE:
2858 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2862 #ifdef HAVE_TARGET_32_BIG
2863 case Parameters::TARGET_32_BIG:
2864 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2868 #ifdef HAVE_TARGET_64_LITTLE
2869 case Parameters::TARGET_64_LITTLE:
2870 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2874 #ifdef HAVE_TARGET_64_BIG
2875 case Parameters::TARGET_64_BIG:
2876 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2885 // Write out a section symbol, specialized for size and endianness.
2887 template<int size, bool big_endian>
2889 Symbol_table::sized_write_section_symbol(const Output_section* os,
2890 Output_symtab_xindex* symtab_xindex,
2894 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2896 unsigned char* pov = of->get_output_view(offset, sym_size);
2898 elfcpp::Sym_write<size, big_endian> osym(pov);
2899 osym.put_st_name(0);
2900 if (parameters->options().relocatable())
2901 osym.put_st_value(0);
2903 osym.put_st_value(os->address());
2904 osym.put_st_size(0);
2905 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2906 elfcpp::STT_SECTION));
2907 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2909 unsigned int shndx = os->out_shndx();
2910 if (shndx >= elfcpp::SHN_LORESERVE)
2912 symtab_xindex->add(os->symtab_index(), shndx);
2913 shndx = elfcpp::SHN_XINDEX;
2915 osym.put_st_shndx(shndx);
2917 of->write_output_view(offset, sym_size, pov);
2920 // Print statistical information to stderr. This is used for --stats.
2923 Symbol_table::print_stats() const
2925 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2926 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2927 program_name, this->table_.size(), this->table_.bucket_count());
2929 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2930 program_name, this->table_.size());
2932 this->namepool_.print_stats("symbol table stringpool");
2935 // We check for ODR violations by looking for symbols with the same
2936 // name for which the debugging information reports that they were
2937 // defined in different source locations. When comparing the source
2938 // location, we consider instances with the same base filename and
2939 // line number to be the same. This is because different object
2940 // files/shared libraries can include the same header file using
2941 // different paths, and we don't want to report an ODR violation in
2944 // This struct is used to compare line information, as returned by
2945 // Dwarf_line_info::one_addr2line. It implements a < comparison
2946 // operator used with std::set.
2948 struct Odr_violation_compare
2951 operator()(const std::string& s1, const std::string& s2) const
2953 std::string::size_type pos1 = s1.rfind('/');
2954 std::string::size_type pos2 = s2.rfind('/');
2955 if (pos1 == std::string::npos
2956 || pos2 == std::string::npos)
2958 return s1.compare(pos1, std::string::npos,
2959 s2, pos2, std::string::npos) < 0;
2963 // Check candidate_odr_violations_ to find symbols with the same name
2964 // but apparently different definitions (different source-file/line-no).
2967 Symbol_table::detect_odr_violations(const Task* task,
2968 const char* output_file_name) const
2970 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2971 it != candidate_odr_violations_.end();
2974 const char* symbol_name = it->first;
2975 // We use a sorted set so the output is deterministic.
2976 std::set<std::string, Odr_violation_compare> line_nums;
2978 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2979 locs = it->second.begin();
2980 locs != it->second.end();
2983 // We need to lock the object in order to read it. This
2984 // means that we have to run in a singleton Task. If we
2985 // want to run this in a general Task for better
2986 // performance, we will need one Task for object, plus
2987 // appropriate locking to ensure that we don't conflict with
2988 // other uses of the object. Also note, one_addr2line is not
2989 // currently thread-safe.
2990 Task_lock_obj<Object> tl(task, locs->object);
2991 // 16 is the size of the object-cache that one_addr2line should use.
2992 std::string lineno = Dwarf_line_info::one_addr2line(
2993 locs->object, locs->shndx, locs->offset, 16);
2994 if (!lineno.empty())
2995 line_nums.insert(lineno);
2998 if (line_nums.size() > 1)
3000 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3001 "places (possible ODR violation):"),
3002 output_file_name, demangle(symbol_name).c_str());
3003 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
3004 it2 != line_nums.end();
3006 fprintf(stderr, " %s\n", it2->c_str());
3009 // We only call one_addr2line() in this function, so we can clear its cache.
3010 Dwarf_line_info::clear_addr2line_cache();
3013 // Warnings functions.
3015 // Add a new warning.
3018 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3019 const std::string& warning)
3021 name = symtab->canonicalize_name(name);
3022 this->warnings_[name].set(obj, warning);
3025 // Look through the warnings and mark the symbols for which we should
3026 // warn. This is called during Layout::finalize when we know the
3027 // sources for all the symbols.
3030 Warnings::note_warnings(Symbol_table* symtab)
3032 for (Warning_table::iterator p = this->warnings_.begin();
3033 p != this->warnings_.end();
3036 Symbol* sym = symtab->lookup(p->first, NULL);
3038 && sym->source() == Symbol::FROM_OBJECT
3039 && sym->object() == p->second.object)
3040 sym->set_has_warning();
3044 // Issue a warning. This is called when we see a relocation against a
3045 // symbol for which has a warning.
3047 template<int size, bool big_endian>
3049 Warnings::issue_warning(const Symbol* sym,
3050 const Relocate_info<size, big_endian>* relinfo,
3051 size_t relnum, off_t reloffset) const
3053 gold_assert(sym->has_warning());
3054 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3055 gold_assert(p != this->warnings_.end());
3056 gold_warning_at_location(relinfo, relnum, reloffset,
3057 "%s", p->second.text.c_str());
3060 // Instantiate the templates we need. We could use the configure
3061 // script to restrict this to only the ones needed for implemented
3064 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3067 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3070 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3073 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3076 #ifdef HAVE_TARGET_32_LITTLE
3079 Symbol_table::add_from_relobj<32, false>(
3080 Sized_relobj<32, false>* relobj,
3081 const unsigned char* syms,
3083 size_t symndx_offset,
3084 const char* sym_names,
3085 size_t sym_name_size,
3086 Sized_relobj<32, false>::Symbols* sympointers,
3090 #ifdef HAVE_TARGET_32_BIG
3093 Symbol_table::add_from_relobj<32, true>(
3094 Sized_relobj<32, true>* relobj,
3095 const unsigned char* syms,
3097 size_t symndx_offset,
3098 const char* sym_names,
3099 size_t sym_name_size,
3100 Sized_relobj<32, true>::Symbols* sympointers,
3104 #ifdef HAVE_TARGET_64_LITTLE
3107 Symbol_table::add_from_relobj<64, false>(
3108 Sized_relobj<64, false>* relobj,
3109 const unsigned char* syms,
3111 size_t symndx_offset,
3112 const char* sym_names,
3113 size_t sym_name_size,
3114 Sized_relobj<64, false>::Symbols* sympointers,
3118 #ifdef HAVE_TARGET_64_BIG
3121 Symbol_table::add_from_relobj<64, true>(
3122 Sized_relobj<64, true>* relobj,
3123 const unsigned char* syms,
3125 size_t symndx_offset,
3126 const char* sym_names,
3127 size_t sym_name_size,
3128 Sized_relobj<64, true>::Symbols* sympointers,
3132 #ifdef HAVE_TARGET_32_LITTLE
3135 Symbol_table::add_from_pluginobj<32, false>(
3136 Sized_pluginobj<32, false>* obj,
3139 elfcpp::Sym<32, false>* sym);
3142 #ifdef HAVE_TARGET_32_BIG
3145 Symbol_table::add_from_pluginobj<32, true>(
3146 Sized_pluginobj<32, true>* obj,
3149 elfcpp::Sym<32, true>* sym);
3152 #ifdef HAVE_TARGET_64_LITTLE
3155 Symbol_table::add_from_pluginobj<64, false>(
3156 Sized_pluginobj<64, false>* obj,
3159 elfcpp::Sym<64, false>* sym);
3162 #ifdef HAVE_TARGET_64_BIG
3165 Symbol_table::add_from_pluginobj<64, true>(
3166 Sized_pluginobj<64, true>* obj,
3169 elfcpp::Sym<64, true>* sym);
3172 #ifdef HAVE_TARGET_32_LITTLE
3175 Symbol_table::add_from_dynobj<32, false>(
3176 Sized_dynobj<32, false>* dynobj,
3177 const unsigned char* syms,
3179 const char* sym_names,
3180 size_t sym_name_size,
3181 const unsigned char* versym,
3183 const std::vector<const char*>* version_map,
3184 Sized_relobj<32, false>::Symbols* sympointers,
3188 #ifdef HAVE_TARGET_32_BIG
3191 Symbol_table::add_from_dynobj<32, true>(
3192 Sized_dynobj<32, true>* dynobj,
3193 const unsigned char* syms,
3195 const char* sym_names,
3196 size_t sym_name_size,
3197 const unsigned char* versym,
3199 const std::vector<const char*>* version_map,
3200 Sized_relobj<32, true>::Symbols* sympointers,
3204 #ifdef HAVE_TARGET_64_LITTLE
3207 Symbol_table::add_from_dynobj<64, false>(
3208 Sized_dynobj<64, false>* dynobj,
3209 const unsigned char* syms,
3211 const char* sym_names,
3212 size_t sym_name_size,
3213 const unsigned char* versym,
3215 const std::vector<const char*>* version_map,
3216 Sized_relobj<64, false>::Symbols* sympointers,
3220 #ifdef HAVE_TARGET_64_BIG
3223 Symbol_table::add_from_dynobj<64, true>(
3224 Sized_dynobj<64, true>* dynobj,
3225 const unsigned char* syms,
3227 const char* sym_names,
3228 size_t sym_name_size,
3229 const unsigned char* versym,
3231 const std::vector<const char*>* version_map,
3232 Sized_relobj<64, true>::Symbols* sympointers,
3236 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3239 Symbol_table::define_with_copy_reloc<32>(
3240 Sized_symbol<32>* sym,
3242 elfcpp::Elf_types<32>::Elf_Addr value);
3245 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3248 Symbol_table::define_with_copy_reloc<64>(
3249 Sized_symbol<64>* sym,
3251 elfcpp::Elf_types<64>::Elf_Addr value);
3254 #ifdef HAVE_TARGET_32_LITTLE
3257 Warnings::issue_warning<32, false>(const Symbol* sym,
3258 const Relocate_info<32, false>* relinfo,
3259 size_t relnum, off_t reloffset) const;
3262 #ifdef HAVE_TARGET_32_BIG
3265 Warnings::issue_warning<32, true>(const Symbol* sym,
3266 const Relocate_info<32, true>* relinfo,
3267 size_t relnum, off_t reloffset) const;
3270 #ifdef HAVE_TARGET_64_LITTLE
3273 Warnings::issue_warning<64, false>(const Symbol* sym,
3274 const Relocate_info<64, false>* relinfo,
3275 size_t relnum, off_t reloffset) const;
3278 #ifdef HAVE_TARGET_64_BIG
3281 Warnings::issue_warning<64, true>(const Symbol* sym,
3282 const Relocate_info<64, true>* relinfo,
3283 size_t relnum, off_t reloffset) const;
3286 } // End namespace gold.