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().output_is_position_independent()
398 || parameters->options().relocatable())
401 // If the symbol is not from an object file, and is not undefined,
402 // then it is defined, and known.
403 if (this->source_ != FROM_OBJECT)
405 if (this->source_ != IS_UNDEFINED)
410 // If the symbol is from a dynamic object, then the final value
412 if (this->object()->is_dynamic())
415 // If the symbol is not undefined (it is defined or common),
416 // then the final value is known.
417 if (!this->is_undefined())
421 // If the symbol is undefined, then whether the final value is known
422 // depends on whether we are doing a static link. If we are doing a
423 // dynamic link, then the final value could be filled in at runtime.
424 // This could reasonably be the case for a weak undefined symbol.
425 return parameters->doing_static_link();
428 // Return the output section where this symbol is defined.
431 Symbol::output_section() const
433 switch (this->source_)
437 unsigned int shndx = this->u_.from_object.shndx;
438 if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
440 gold_assert(!this->u_.from_object.object->is_dynamic());
441 gold_assert(this->u_.from_object.object->pluginobj() == NULL);
442 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
443 return relobj->output_section(shndx);
449 return this->u_.in_output_data.output_data->output_section();
451 case IN_OUTPUT_SEGMENT:
461 // Set the symbol's output section. This is used for symbols defined
462 // in scripts. This should only be called after the symbol table has
466 Symbol::set_output_section(Output_section* os)
468 switch (this->source_)
472 gold_assert(this->output_section() == os);
475 this->source_ = IN_OUTPUT_DATA;
476 this->u_.in_output_data.output_data = os;
477 this->u_.in_output_data.offset_is_from_end = false;
479 case IN_OUTPUT_SEGMENT:
486 // Class Symbol_table.
488 Symbol_table::Symbol_table(unsigned int count,
489 const Version_script_info& version_script)
490 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
491 forwarders_(), commons_(), tls_commons_(), small_commons_(),
492 large_commons_(), forced_locals_(), warnings_(),
493 version_script_(version_script), gc_(NULL), icf_(NULL)
495 namepool_.reserve(count);
498 Symbol_table::~Symbol_table()
502 // The hash function. The key values are Stringpool keys.
505 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
507 return key.first ^ key.second;
510 // The symbol table key equality function. This is called with
514 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
515 const Symbol_table_key& k2) const
517 return k1.first == k2.first && k1.second == k2.second;
521 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
523 return (parameters->options().icf_enabled()
524 && this->icf_->is_section_folded(obj, shndx));
527 // For symbols that have been listed with -u option, add them to the
528 // work list to avoid gc'ing them.
531 Symbol_table::gc_mark_undef_symbols()
533 for (options::String_set::const_iterator p =
534 parameters->options().undefined_begin();
535 p != parameters->options().undefined_end();
538 const char* name = p->c_str();
539 Symbol* sym = this->lookup(name);
540 gold_assert (sym != NULL);
541 if (sym->source() == Symbol::FROM_OBJECT
542 && !sym->object()->is_dynamic())
544 Relobj* obj = static_cast<Relobj*>(sym->object());
546 unsigned int shndx = sym->shndx(&is_ordinary);
549 gold_assert(this->gc_ != NULL);
550 this->gc_->worklist().push(Section_id(obj, shndx));
557 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
559 if (!sym->is_from_dynobj()
560 && sym->is_externally_visible())
562 //Add the object and section to the work list.
563 Relobj* obj = static_cast<Relobj*>(sym->object());
565 unsigned int shndx = sym->shndx(&is_ordinary);
566 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
568 gold_assert(this->gc_!= NULL);
569 this->gc_->worklist().push(Section_id(obj, shndx));
574 // When doing garbage collection, keep symbols that have been seen in
577 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
579 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
580 && !sym->object()->is_dynamic())
582 Relobj *obj = static_cast<Relobj*>(sym->object());
584 unsigned int shndx = sym->shndx(&is_ordinary);
585 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
587 gold_assert(this->gc_ != NULL);
588 this->gc_->worklist().push(Section_id(obj, shndx));
593 // Make TO a symbol which forwards to FROM.
596 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
598 gold_assert(from != to);
599 gold_assert(!from->is_forwarder() && !to->is_forwarder());
600 this->forwarders_[from] = to;
601 from->set_forwarder();
604 // Resolve the forwards from FROM, returning the real symbol.
607 Symbol_table::resolve_forwards(const Symbol* from) const
609 gold_assert(from->is_forwarder());
610 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
611 this->forwarders_.find(from);
612 gold_assert(p != this->forwarders_.end());
616 // Look up a symbol by name.
619 Symbol_table::lookup(const char* name, const char* version) const
621 Stringpool::Key name_key;
622 name = this->namepool_.find(name, &name_key);
626 Stringpool::Key version_key = 0;
629 version = this->namepool_.find(version, &version_key);
634 Symbol_table_key key(name_key, version_key);
635 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
636 if (p == this->table_.end())
641 // Resolve a Symbol with another Symbol. This is only used in the
642 // unusual case where there are references to both an unversioned
643 // symbol and a symbol with a version, and we then discover that that
644 // version is the default version. Because this is unusual, we do
645 // this the slow way, by converting back to an ELF symbol.
647 template<int size, bool big_endian>
649 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
651 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
652 elfcpp::Sym_write<size, big_endian> esym(buf);
653 // We don't bother to set the st_name or the st_shndx field.
654 esym.put_st_value(from->value());
655 esym.put_st_size(from->symsize());
656 esym.put_st_info(from->binding(), from->type());
657 esym.put_st_other(from->visibility(), from->nonvis());
659 unsigned int shndx = from->shndx(&is_ordinary);
660 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
666 if (parameters->options().gc_sections())
667 this->gc_mark_dyn_syms(to);
670 // Record that a symbol is forced to be local by a version script or
674 Symbol_table::force_local(Symbol* sym)
676 if (!sym->is_defined() && !sym->is_common())
678 if (sym->is_forced_local())
680 // We already got this one.
683 sym->set_is_forced_local();
684 this->forced_locals_.push_back(sym);
687 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
688 // is only called for undefined symbols, when at least one --wrap
692 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
694 // For some targets, we need to ignore a specific character when
695 // wrapping, and add it back later.
697 if (name[0] == parameters->target().wrap_char())
703 if (parameters->options().is_wrap(name))
705 // Turn NAME into __wrap_NAME.
712 // This will give us both the old and new name in NAMEPOOL_, but
713 // that is OK. Only the versions we need will wind up in the
714 // real string table in the output file.
715 return this->namepool_.add(s.c_str(), true, name_key);
718 const char* const real_prefix = "__real_";
719 const size_t real_prefix_length = strlen(real_prefix);
720 if (strncmp(name, real_prefix, real_prefix_length) == 0
721 && parameters->options().is_wrap(name + real_prefix_length))
723 // Turn __real_NAME into NAME.
727 s += name + real_prefix_length;
728 return this->namepool_.add(s.c_str(), true, name_key);
734 // This is called when we see a symbol NAME/VERSION, and the symbol
735 // already exists in the symbol table, and VERSION is marked as being
736 // the default version. SYM is the NAME/VERSION symbol we just added.
737 // DEFAULT_IS_NEW is true if this is the first time we have seen the
738 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
740 template<int size, bool big_endian>
742 Symbol_table::define_default_version(Sized_symbol<size>* sym,
744 Symbol_table_type::iterator pdef)
748 // This is the first time we have seen NAME/NULL. Make
749 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
752 sym->set_is_default();
754 else if (pdef->second == sym)
756 // NAME/NULL already points to NAME/VERSION. Don't mark the
757 // symbol as the default if it is not already the default.
761 // This is the unfortunate case where we already have entries
762 // for both NAME/VERSION and NAME/NULL. We now see a symbol
763 // NAME/VERSION where VERSION is the default version. We have
764 // already resolved this new symbol with the existing
765 // NAME/VERSION symbol.
767 // It's possible that NAME/NULL and NAME/VERSION are both
768 // defined in regular objects. This can only happen if one
769 // object file defines foo and another defines foo@@ver. This
770 // is somewhat obscure, but we call it a multiple definition
773 // It's possible that NAME/NULL actually has a version, in which
774 // case it won't be the same as VERSION. This happens with
775 // ver_test_7.so in the testsuite for the symbol t2_2. We see
776 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
777 // then see an unadorned t2_2 in an object file and give it
778 // version VER1 from the version script. This looks like a
779 // default definition for VER1, so it looks like we should merge
780 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
781 // not obvious that this is an error, either. So we just punt.
783 // If one of the symbols has non-default visibility, and the
784 // other is defined in a shared object, then they are different
787 // Otherwise, we just resolve the symbols as though they were
790 if (pdef->second->version() != NULL)
791 gold_assert(pdef->second->version() != sym->version());
792 else if (sym->visibility() != elfcpp::STV_DEFAULT
793 && pdef->second->is_from_dynobj())
795 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
796 && sym->is_from_dynobj())
800 const Sized_symbol<size>* symdef;
801 symdef = this->get_sized_symbol<size>(pdef->second);
802 Symbol_table::resolve<size, big_endian>(sym, symdef);
803 this->make_forwarder(pdef->second, sym);
805 sym->set_is_default();
810 // Add one symbol from OBJECT to the symbol table. NAME is symbol
811 // name and VERSION is the version; both are canonicalized. DEF is
812 // whether this is the default version. ST_SHNDX is the symbol's
813 // section index; IS_ORDINARY is whether this is a normal section
814 // rather than a special code.
816 // If DEF is true, then this is the definition of a default version of
817 // a symbol. That means that any lookup of NAME/NULL and any lookup
818 // of NAME/VERSION should always return the same symbol. This is
819 // obvious for references, but in particular we want to do this for
820 // definitions: overriding NAME/NULL should also override
821 // NAME/VERSION. If we don't do that, it would be very hard to
822 // override functions in a shared library which uses versioning.
824 // We implement this by simply making both entries in the hash table
825 // point to the same Symbol structure. That is easy enough if this is
826 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
827 // that we have seen both already, in which case they will both have
828 // independent entries in the symbol table. We can't simply change
829 // the symbol table entry, because we have pointers to the entries
830 // attached to the object files. So we mark the entry attached to the
831 // object file as a forwarder, and record it in the forwarders_ map.
832 // Note that entries in the hash table will never be marked as
835 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
836 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
837 // for a special section code. ST_SHNDX may be modified if the symbol
838 // is defined in a section being discarded.
840 template<int size, bool big_endian>
842 Symbol_table::add_from_object(Object* object,
844 Stringpool::Key name_key,
846 Stringpool::Key version_key,
848 const elfcpp::Sym<size, big_endian>& sym,
849 unsigned int st_shndx,
851 unsigned int orig_st_shndx)
853 // Print a message if this symbol is being traced.
854 if (parameters->options().is_trace_symbol(name))
856 if (orig_st_shndx == elfcpp::SHN_UNDEF)
857 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
859 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
862 // For an undefined symbol, we may need to adjust the name using
864 if (orig_st_shndx == elfcpp::SHN_UNDEF
865 && parameters->options().any_wrap())
867 const char* wrap_name = this->wrap_symbol(name, &name_key);
868 if (wrap_name != name)
870 // If we see a reference to malloc with version GLIBC_2.0,
871 // and we turn it into a reference to __wrap_malloc, then we
872 // discard the version number. Otherwise the user would be
873 // required to specify the correct version for
881 Symbol* const snull = NULL;
882 std::pair<typename Symbol_table_type::iterator, bool> ins =
883 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
886 std::pair<typename Symbol_table_type::iterator, bool> insdef =
887 std::make_pair(this->table_.end(), false);
890 const Stringpool::Key vnull_key = 0;
891 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
896 // ins.first: an iterator, which is a pointer to a pair.
897 // ins.first->first: the key (a pair of name and version).
898 // ins.first->second: the value (Symbol*).
899 // ins.second: true if new entry was inserted, false if not.
901 Sized_symbol<size>* ret;
906 // We already have an entry for NAME/VERSION.
907 ret = this->get_sized_symbol<size>(ins.first->second);
908 gold_assert(ret != NULL);
910 was_undefined = ret->is_undefined();
911 was_common = ret->is_common();
913 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
915 if (parameters->options().gc_sections())
916 this->gc_mark_dyn_syms(ret);
919 this->define_default_version<size, big_endian>(ret, insdef.second,
924 // This is the first time we have seen NAME/VERSION.
925 gold_assert(ins.first->second == NULL);
927 if (def && !insdef.second)
929 // We already have an entry for NAME/NULL. If we override
930 // it, then change it to NAME/VERSION.
931 ret = this->get_sized_symbol<size>(insdef.first->second);
933 was_undefined = ret->is_undefined();
934 was_common = ret->is_common();
936 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
938 if (parameters->options().gc_sections())
939 this->gc_mark_dyn_syms(ret);
940 ins.first->second = ret;
944 was_undefined = false;
947 Sized_target<size, big_endian>* target =
948 parameters->sized_target<size, big_endian>();
949 if (!target->has_make_symbol())
950 ret = new Sized_symbol<size>();
953 ret = target->make_symbol();
956 // This means that we don't want a symbol table
959 this->table_.erase(ins.first);
962 this->table_.erase(insdef.first);
963 // Inserting insdef invalidated ins.
964 this->table_.erase(std::make_pair(name_key,
971 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
973 ins.first->second = ret;
976 // This is the first time we have seen NAME/NULL. Point
977 // it at the new entry for NAME/VERSION.
978 gold_assert(insdef.second);
979 insdef.first->second = ret;
984 ret->set_is_default();
987 // Record every time we see a new undefined symbol, to speed up
989 if (!was_undefined && ret->is_undefined())
990 ++this->saw_undefined_;
992 // Keep track of common symbols, to speed up common symbol
994 if (!was_common && ret->is_common())
996 if (ret->type() == elfcpp::STT_TLS)
997 this->tls_commons_.push_back(ret);
998 else if (!is_ordinary
999 && st_shndx == parameters->target().small_common_shndx())
1000 this->small_commons_.push_back(ret);
1001 else if (!is_ordinary
1002 && st_shndx == parameters->target().large_common_shndx())
1003 this->large_commons_.push_back(ret);
1005 this->commons_.push_back(ret);
1008 // If we're not doing a relocatable link, then any symbol with
1009 // hidden or internal visibility is local.
1010 if ((ret->visibility() == elfcpp::STV_HIDDEN
1011 || ret->visibility() == elfcpp::STV_INTERNAL)
1012 && (ret->binding() == elfcpp::STB_GLOBAL
1013 || ret->binding() == elfcpp::STB_GNU_UNIQUE
1014 || ret->binding() == elfcpp::STB_WEAK)
1015 && !parameters->options().relocatable())
1016 this->force_local(ret);
1021 // Add all the symbols in a relocatable object to the hash table.
1023 template<int size, bool big_endian>
1025 Symbol_table::add_from_relobj(
1026 Sized_relobj<size, big_endian>* relobj,
1027 const unsigned char* syms,
1029 size_t symndx_offset,
1030 const char* sym_names,
1031 size_t sym_name_size,
1032 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1037 gold_assert(size == parameters->target().get_size());
1039 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1041 const bool just_symbols = relobj->just_symbols();
1043 const unsigned char* p = syms;
1044 for (size_t i = 0; i < count; ++i, p += sym_size)
1046 (*sympointers)[i] = NULL;
1048 elfcpp::Sym<size, big_endian> sym(p);
1050 unsigned int st_name = sym.get_st_name();
1051 if (st_name >= sym_name_size)
1053 relobj->error(_("bad global symbol name offset %u at %zu"),
1058 const char* name = sym_names + st_name;
1061 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1064 unsigned int orig_st_shndx = st_shndx;
1066 orig_st_shndx = elfcpp::SHN_UNDEF;
1068 if (st_shndx != elfcpp::SHN_UNDEF)
1071 // A symbol defined in a section which we are not including must
1072 // be treated as an undefined symbol.
1073 if (st_shndx != elfcpp::SHN_UNDEF
1075 && !relobj->is_section_included(st_shndx))
1076 st_shndx = elfcpp::SHN_UNDEF;
1078 // In an object file, an '@' in the name separates the symbol
1079 // name from the version name. If there are two '@' characters,
1080 // this is the default version.
1081 const char* ver = strchr(name, '@');
1082 Stringpool::Key ver_key = 0;
1084 // DEF: is the version default? LOCAL: is the symbol forced local?
1090 // The symbol name is of the form foo@VERSION or foo@@VERSION
1091 namelen = ver - name;
1098 ver = this->namepool_.add(ver, true, &ver_key);
1100 // We don't want to assign a version to an undefined symbol,
1101 // even if it is listed in the version script. FIXME: What
1102 // about a common symbol?
1105 namelen = strlen(name);
1106 if (!this->version_script_.empty()
1107 && st_shndx != elfcpp::SHN_UNDEF)
1109 // The symbol name did not have a version, but the
1110 // version script may assign a version anyway.
1111 std::string version;
1112 if (this->version_script_.get_symbol_version(name, &version))
1114 // The version can be empty if the version script is
1115 // only used to force some symbols to be local.
1116 if (!version.empty())
1118 ver = this->namepool_.add_with_length(version.c_str(),
1125 else if (this->version_script_.symbol_is_local(name))
1130 elfcpp::Sym<size, big_endian>* psym = &sym;
1131 unsigned char symbuf[sym_size];
1132 elfcpp::Sym<size, big_endian> sym2(symbuf);
1135 memcpy(symbuf, p, sym_size);
1136 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1137 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1139 // Symbol values in object files are section relative.
1140 // This is normally what we want, but since here we are
1141 // converting the symbol to absolute we need to add the
1142 // section address. The section address in an object
1143 // file is normally zero, but people can use a linker
1144 // script to change it.
1145 sw.put_st_value(sym.get_st_value()
1146 + relobj->section_address(orig_st_shndx));
1148 st_shndx = elfcpp::SHN_ABS;
1149 is_ordinary = false;
1153 // Fix up visibility if object has no-export set.
1154 if (relobj->no_export())
1156 // We may have copied symbol already above.
1159 memcpy(symbuf, p, sym_size);
1163 elfcpp::STV visibility = sym2.get_st_visibility();
1164 if (visibility == elfcpp::STV_DEFAULT
1165 || visibility == elfcpp::STV_PROTECTED)
1167 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1168 unsigned char nonvis = sym2.get_st_nonvis();
1169 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1173 Stringpool::Key name_key;
1174 name = this->namepool_.add_with_length(name, namelen, true,
1177 Sized_symbol<size>* res;
1178 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1179 def, *psym, st_shndx, is_ordinary,
1182 // If building a shared library using garbage collection, do not
1183 // treat externally visible symbols as garbage.
1184 if (parameters->options().gc_sections()
1185 && parameters->options().shared())
1186 this->gc_mark_symbol_for_shlib(res);
1189 this->force_local(res);
1191 (*sympointers)[i] = res;
1195 // Add a symbol from a plugin-claimed file.
1197 template<int size, bool big_endian>
1199 Symbol_table::add_from_pluginobj(
1200 Sized_pluginobj<size, big_endian>* obj,
1203 elfcpp::Sym<size, big_endian>* sym)
1205 unsigned int st_shndx = sym->get_st_shndx();
1206 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1208 Stringpool::Key ver_key = 0;
1214 ver = this->namepool_.add(ver, true, &ver_key);
1216 // We don't want to assign a version to an undefined symbol,
1217 // even if it is listed in the version script. FIXME: What
1218 // about a common symbol?
1221 if (!this->version_script_.empty()
1222 && st_shndx != elfcpp::SHN_UNDEF)
1224 // The symbol name did not have a version, but the
1225 // version script may assign a version anyway.
1226 std::string version;
1227 if (this->version_script_.get_symbol_version(name, &version))
1229 // The version can be empty if the version script is
1230 // only used to force some symbols to be local.
1231 if (!version.empty())
1233 ver = this->namepool_.add_with_length(version.c_str(),
1240 else if (this->version_script_.symbol_is_local(name))
1245 Stringpool::Key name_key;
1246 name = this->namepool_.add(name, true, &name_key);
1248 Sized_symbol<size>* res;
1249 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1250 def, *sym, st_shndx, is_ordinary, st_shndx);
1253 this->force_local(res);
1258 // Add all the symbols in a dynamic object to the hash table.
1260 template<int size, bool big_endian>
1262 Symbol_table::add_from_dynobj(
1263 Sized_dynobj<size, big_endian>* dynobj,
1264 const unsigned char* syms,
1266 const char* sym_names,
1267 size_t sym_name_size,
1268 const unsigned char* versym,
1270 const std::vector<const char*>* version_map,
1271 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1276 gold_assert(size == parameters->target().get_size());
1278 if (dynobj->just_symbols())
1280 gold_error(_("--just-symbols does not make sense with a shared object"));
1284 if (versym != NULL && versym_size / 2 < count)
1286 dynobj->error(_("too few symbol versions"));
1290 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1292 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1293 // weak aliases. This is necessary because if the dynamic object
1294 // provides the same variable under two names, one of which is a
1295 // weak definition, and the regular object refers to the weak
1296 // definition, we have to put both the weak definition and the
1297 // strong definition into the dynamic symbol table. Given a weak
1298 // definition, the only way that we can find the corresponding
1299 // strong definition, if any, is to search the symbol table.
1300 std::vector<Sized_symbol<size>*> object_symbols;
1302 const unsigned char* p = syms;
1303 const unsigned char* vs = versym;
1304 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1306 elfcpp::Sym<size, big_endian> sym(p);
1308 if (sympointers != NULL)
1309 (*sympointers)[i] = NULL;
1311 // Ignore symbols with local binding or that have
1312 // internal or hidden visibility.
1313 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1314 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1315 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1318 // A protected symbol in a shared library must be treated as a
1319 // normal symbol when viewed from outside the shared library.
1320 // Implement this by overriding the visibility here.
1321 elfcpp::Sym<size, big_endian>* psym = &sym;
1322 unsigned char symbuf[sym_size];
1323 elfcpp::Sym<size, big_endian> sym2(symbuf);
1324 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1326 memcpy(symbuf, p, sym_size);
1327 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1328 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1332 unsigned int st_name = psym->get_st_name();
1333 if (st_name >= sym_name_size)
1335 dynobj->error(_("bad symbol name offset %u at %zu"),
1340 const char* name = sym_names + st_name;
1343 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1346 if (st_shndx != elfcpp::SHN_UNDEF)
1349 Sized_symbol<size>* res;
1353 Stringpool::Key name_key;
1354 name = this->namepool_.add(name, true, &name_key);
1355 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1356 false, *psym, st_shndx, is_ordinary,
1361 // Read the version information.
1363 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1365 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1366 v &= elfcpp::VERSYM_VERSION;
1368 // The Sun documentation says that V can be VER_NDX_LOCAL,
1369 // or VER_NDX_GLOBAL, or a version index. The meaning of
1370 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1371 // The old GNU linker will happily generate VER_NDX_LOCAL
1372 // for an undefined symbol. I don't know what the Sun
1373 // linker will generate.
1375 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1376 && st_shndx != elfcpp::SHN_UNDEF)
1378 // This symbol should not be visible outside the object.
1382 // At this point we are definitely going to add this symbol.
1383 Stringpool::Key name_key;
1384 name = this->namepool_.add(name, true, &name_key);
1386 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1387 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1389 // This symbol does not have a version.
1390 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1391 false, *psym, st_shndx, is_ordinary,
1396 if (v >= version_map->size())
1398 dynobj->error(_("versym for symbol %zu out of range: %u"),
1403 const char* version = (*version_map)[v];
1404 if (version == NULL)
1406 dynobj->error(_("versym for symbol %zu has no name: %u"),
1411 Stringpool::Key version_key;
1412 version = this->namepool_.add(version, true, &version_key);
1414 // If this is an absolute symbol, and the version name
1415 // and symbol name are the same, then this is the
1416 // version definition symbol. These symbols exist to
1417 // support using -u to pull in particular versions. We
1418 // do not want to record a version for them.
1419 if (st_shndx == elfcpp::SHN_ABS
1421 && name_key == version_key)
1422 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1423 false, *psym, st_shndx, is_ordinary,
1427 const bool def = (!hidden
1428 && st_shndx != elfcpp::SHN_UNDEF);
1429 res = this->add_from_object(dynobj, name, name_key, version,
1430 version_key, def, *psym, st_shndx,
1431 is_ordinary, st_shndx);
1436 // Note that it is possible that RES was overridden by an
1437 // earlier object, in which case it can't be aliased here.
1438 if (st_shndx != elfcpp::SHN_UNDEF
1440 && psym->get_st_type() == elfcpp::STT_OBJECT
1441 && res->source() == Symbol::FROM_OBJECT
1442 && res->object() == dynobj)
1443 object_symbols.push_back(res);
1445 if (sympointers != NULL)
1446 (*sympointers)[i] = res;
1449 this->record_weak_aliases(&object_symbols);
1452 // This is used to sort weak aliases. We sort them first by section
1453 // index, then by offset, then by weak ahead of strong.
1456 class Weak_alias_sorter
1459 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1464 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1465 const Sized_symbol<size>* s2) const
1468 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1469 gold_assert(is_ordinary);
1470 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1471 gold_assert(is_ordinary);
1472 if (s1_shndx != s2_shndx)
1473 return s1_shndx < s2_shndx;
1475 if (s1->value() != s2->value())
1476 return s1->value() < s2->value();
1477 if (s1->binding() != s2->binding())
1479 if (s1->binding() == elfcpp::STB_WEAK)
1481 if (s2->binding() == elfcpp::STB_WEAK)
1484 return std::string(s1->name()) < std::string(s2->name());
1487 // SYMBOLS is a list of object symbols from a dynamic object. Look
1488 // for any weak aliases, and record them so that if we add the weak
1489 // alias to the dynamic symbol table, we also add the corresponding
1494 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1496 // Sort the vector by section index, then by offset, then by weak
1498 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1500 // Walk through the vector. For each weak definition, record
1502 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1504 p != symbols->end();
1507 if ((*p)->binding() != elfcpp::STB_WEAK)
1510 // Build a circular list of weak aliases. Each symbol points to
1511 // the next one in the circular list.
1513 Sized_symbol<size>* from_sym = *p;
1514 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1515 for (q = p + 1; q != symbols->end(); ++q)
1518 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1519 || (*q)->value() != from_sym->value())
1522 this->weak_aliases_[from_sym] = *q;
1523 from_sym->set_has_alias();
1529 this->weak_aliases_[from_sym] = *p;
1530 from_sym->set_has_alias();
1537 // Create and return a specially defined symbol. If ONLY_IF_REF is
1538 // true, then only create the symbol if there is a reference to it.
1539 // If this does not return NULL, it sets *POLDSYM to the existing
1540 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1541 // resolve the newly created symbol to the old one. This
1542 // canonicalizes *PNAME and *PVERSION.
1544 template<int size, bool big_endian>
1546 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1548 Sized_symbol<size>** poldsym,
1549 bool *resolve_oldsym)
1551 *resolve_oldsym = false;
1553 // If the caller didn't give us a version, see if we get one from
1554 // the version script.
1556 bool is_default_version = false;
1557 if (*pversion == NULL)
1559 if (this->version_script_.get_symbol_version(*pname, &v))
1562 *pversion = v.c_str();
1564 // If we get the version from a version script, then we are
1565 // also the default version.
1566 is_default_version = true;
1571 Sized_symbol<size>* sym;
1573 bool add_to_table = false;
1574 typename Symbol_table_type::iterator add_loc = this->table_.end();
1575 bool add_def_to_table = false;
1576 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1580 oldsym = this->lookup(*pname, *pversion);
1581 if (oldsym == NULL && is_default_version)
1582 oldsym = this->lookup(*pname, NULL);
1583 if (oldsym == NULL || !oldsym->is_undefined())
1586 *pname = oldsym->name();
1587 if (!is_default_version)
1588 *pversion = oldsym->version();
1592 // Canonicalize NAME and VERSION.
1593 Stringpool::Key name_key;
1594 *pname = this->namepool_.add(*pname, true, &name_key);
1596 Stringpool::Key version_key = 0;
1597 if (*pversion != NULL)
1598 *pversion = this->namepool_.add(*pversion, true, &version_key);
1600 Symbol* const snull = NULL;
1601 std::pair<typename Symbol_table_type::iterator, bool> ins =
1602 this->table_.insert(std::make_pair(std::make_pair(name_key,
1606 std::pair<typename Symbol_table_type::iterator, bool> insdef =
1607 std::make_pair(this->table_.end(), false);
1608 if (is_default_version)
1610 const Stringpool::Key vnull = 0;
1611 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
1618 // We already have a symbol table entry for NAME/VERSION.
1619 oldsym = ins.first->second;
1620 gold_assert(oldsym != NULL);
1622 if (is_default_version)
1624 Sized_symbol<size>* soldsym =
1625 this->get_sized_symbol<size>(oldsym);
1626 this->define_default_version<size, big_endian>(soldsym,
1633 // We haven't seen this symbol before.
1634 gold_assert(ins.first->second == NULL);
1636 add_to_table = true;
1637 add_loc = ins.first;
1639 if (is_default_version && !insdef.second)
1641 // We are adding NAME/VERSION, and it is the default
1642 // version. We already have an entry for NAME/NULL.
1643 oldsym = insdef.first->second;
1644 *resolve_oldsym = true;
1650 if (is_default_version)
1652 add_def_to_table = true;
1653 add_def_loc = insdef.first;
1659 const Target& target = parameters->target();
1660 if (!target.has_make_symbol())
1661 sym = new Sized_symbol<size>();
1664 Sized_target<size, big_endian>* sized_target =
1665 parameters->sized_target<size, big_endian>();
1666 sym = sized_target->make_symbol();
1672 add_loc->second = sym;
1674 gold_assert(oldsym != NULL);
1676 if (add_def_to_table)
1677 add_def_loc->second = sym;
1679 *poldsym = this->get_sized_symbol<size>(oldsym);
1684 // Define a symbol based on an Output_data.
1687 Symbol_table::define_in_output_data(const char* name,
1688 const char* version,
1693 elfcpp::STB binding,
1694 elfcpp::STV visibility,
1695 unsigned char nonvis,
1696 bool offset_is_from_end,
1699 if (parameters->target().get_size() == 32)
1701 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1702 return this->do_define_in_output_data<32>(name, version, od,
1703 value, symsize, type, binding,
1711 else if (parameters->target().get_size() == 64)
1713 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1714 return this->do_define_in_output_data<64>(name, version, od,
1715 value, symsize, type, binding,
1727 // Define a symbol in an Output_data, sized version.
1731 Symbol_table::do_define_in_output_data(
1733 const char* version,
1735 typename elfcpp::Elf_types<size>::Elf_Addr value,
1736 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1738 elfcpp::STB binding,
1739 elfcpp::STV visibility,
1740 unsigned char nonvis,
1741 bool offset_is_from_end,
1744 Sized_symbol<size>* sym;
1745 Sized_symbol<size>* oldsym;
1746 bool resolve_oldsym;
1748 if (parameters->target().is_big_endian())
1750 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1751 sym = this->define_special_symbol<size, true>(&name, &version,
1752 only_if_ref, &oldsym,
1760 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1761 sym = this->define_special_symbol<size, false>(&name, &version,
1762 only_if_ref, &oldsym,
1772 sym->init_output_data(name, version, od, value, symsize, type, binding,
1773 visibility, nonvis, offset_is_from_end);
1777 if (binding == elfcpp::STB_LOCAL
1778 || this->version_script_.symbol_is_local(name))
1779 this->force_local(sym);
1780 else if (version != NULL)
1781 sym->set_is_default();
1785 if (Symbol_table::should_override_with_special(oldsym))
1786 this->override_with_special(oldsym, sym);
1797 // Define a symbol based on an Output_segment.
1800 Symbol_table::define_in_output_segment(const char* name,
1801 const char* version, Output_segment* os,
1805 elfcpp::STB binding,
1806 elfcpp::STV visibility,
1807 unsigned char nonvis,
1808 Symbol::Segment_offset_base offset_base,
1811 if (parameters->target().get_size() == 32)
1813 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1814 return this->do_define_in_output_segment<32>(name, version, os,
1815 value, symsize, type,
1816 binding, visibility, nonvis,
1817 offset_base, only_if_ref);
1822 else if (parameters->target().get_size() == 64)
1824 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1825 return this->do_define_in_output_segment<64>(name, version, os,
1826 value, symsize, type,
1827 binding, visibility, nonvis,
1828 offset_base, only_if_ref);
1837 // Define a symbol in an Output_segment, sized version.
1841 Symbol_table::do_define_in_output_segment(
1843 const char* version,
1845 typename elfcpp::Elf_types<size>::Elf_Addr value,
1846 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1848 elfcpp::STB binding,
1849 elfcpp::STV visibility,
1850 unsigned char nonvis,
1851 Symbol::Segment_offset_base offset_base,
1854 Sized_symbol<size>* sym;
1855 Sized_symbol<size>* oldsym;
1856 bool resolve_oldsym;
1858 if (parameters->target().is_big_endian())
1860 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1861 sym = this->define_special_symbol<size, true>(&name, &version,
1862 only_if_ref, &oldsym,
1870 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1871 sym = this->define_special_symbol<size, false>(&name, &version,
1872 only_if_ref, &oldsym,
1882 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1883 visibility, nonvis, offset_base);
1887 if (binding == elfcpp::STB_LOCAL
1888 || this->version_script_.symbol_is_local(name))
1889 this->force_local(sym);
1890 else if (version != NULL)
1891 sym->set_is_default();
1895 if (Symbol_table::should_override_with_special(oldsym))
1896 this->override_with_special(oldsym, sym);
1907 // Define a special symbol with a constant value. It is a multiple
1908 // definition error if this symbol is already defined.
1911 Symbol_table::define_as_constant(const char* name,
1912 const char* version,
1916 elfcpp::STB binding,
1917 elfcpp::STV visibility,
1918 unsigned char nonvis,
1920 bool force_override)
1922 if (parameters->target().get_size() == 32)
1924 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1925 return this->do_define_as_constant<32>(name, version, value,
1926 symsize, type, binding,
1927 visibility, nonvis, only_if_ref,
1933 else if (parameters->target().get_size() == 64)
1935 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1936 return this->do_define_as_constant<64>(name, version, value,
1937 symsize, type, binding,
1938 visibility, nonvis, only_if_ref,
1948 // Define a symbol as a constant, sized version.
1952 Symbol_table::do_define_as_constant(
1954 const char* version,
1955 typename elfcpp::Elf_types<size>::Elf_Addr value,
1956 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1958 elfcpp::STB binding,
1959 elfcpp::STV visibility,
1960 unsigned char nonvis,
1962 bool force_override)
1964 Sized_symbol<size>* sym;
1965 Sized_symbol<size>* oldsym;
1966 bool resolve_oldsym;
1968 if (parameters->target().is_big_endian())
1970 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1971 sym = this->define_special_symbol<size, true>(&name, &version,
1972 only_if_ref, &oldsym,
1980 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1981 sym = this->define_special_symbol<size, false>(&name, &version,
1982 only_if_ref, &oldsym,
1992 sym->init_constant(name, version, value, symsize, type, binding, visibility,
1997 // Version symbols are absolute symbols with name == version.
1998 // We don't want to force them to be local.
1999 if ((version == NULL
2002 && (binding == elfcpp::STB_LOCAL
2003 || this->version_script_.symbol_is_local(name)))
2004 this->force_local(sym);
2005 else if (version != NULL
2006 && (name != version || value != 0))
2007 sym->set_is_default();
2011 if (force_override || Symbol_table::should_override_with_special(oldsym))
2012 this->override_with_special(oldsym, sym);
2023 // Define a set of symbols in output sections.
2026 Symbol_table::define_symbols(const Layout* layout, int count,
2027 const Define_symbol_in_section* p,
2030 for (int i = 0; i < count; ++i, ++p)
2032 Output_section* os = layout->find_output_section(p->output_section);
2034 this->define_in_output_data(p->name, NULL, os, p->value,
2035 p->size, p->type, p->binding,
2036 p->visibility, p->nonvis,
2037 p->offset_is_from_end,
2038 only_if_ref || p->only_if_ref);
2040 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2041 p->binding, p->visibility, p->nonvis,
2042 only_if_ref || p->only_if_ref,
2047 // Define a set of symbols in output segments.
2050 Symbol_table::define_symbols(const Layout* layout, int count,
2051 const Define_symbol_in_segment* p,
2054 for (int i = 0; i < count; ++i, ++p)
2056 Output_segment* os = layout->find_output_segment(p->segment_type,
2057 p->segment_flags_set,
2058 p->segment_flags_clear);
2060 this->define_in_output_segment(p->name, NULL, os, p->value,
2061 p->size, p->type, p->binding,
2062 p->visibility, p->nonvis,
2064 only_if_ref || p->only_if_ref);
2066 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2067 p->binding, p->visibility, p->nonvis,
2068 only_if_ref || p->only_if_ref,
2073 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2074 // symbol should be defined--typically a .dyn.bss section. VALUE is
2075 // the offset within POSD.
2079 Symbol_table::define_with_copy_reloc(
2080 Sized_symbol<size>* csym,
2082 typename elfcpp::Elf_types<size>::Elf_Addr value)
2084 gold_assert(csym->is_from_dynobj());
2085 gold_assert(!csym->is_copied_from_dynobj());
2086 Object* object = csym->object();
2087 gold_assert(object->is_dynamic());
2088 Dynobj* dynobj = static_cast<Dynobj*>(object);
2090 // Our copied variable has to override any variable in a shared
2092 elfcpp::STB binding = csym->binding();
2093 if (binding == elfcpp::STB_WEAK)
2094 binding = elfcpp::STB_GLOBAL;
2096 this->define_in_output_data(csym->name(), csym->version(),
2097 posd, value, csym->symsize(),
2098 csym->type(), binding,
2099 csym->visibility(), csym->nonvis(),
2102 csym->set_is_copied_from_dynobj();
2103 csym->set_needs_dynsym_entry();
2105 this->copied_symbol_dynobjs_[csym] = dynobj;
2107 // We have now defined all aliases, but we have not entered them all
2108 // in the copied_symbol_dynobjs_ map.
2109 if (csym->has_alias())
2114 sym = this->weak_aliases_[sym];
2117 gold_assert(sym->output_data() == posd);
2119 sym->set_is_copied_from_dynobj();
2120 this->copied_symbol_dynobjs_[sym] = dynobj;
2125 // SYM is defined using a COPY reloc. Return the dynamic object where
2126 // the original definition was found.
2129 Symbol_table::get_copy_source(const Symbol* sym) const
2131 gold_assert(sym->is_copied_from_dynobj());
2132 Copied_symbol_dynobjs::const_iterator p =
2133 this->copied_symbol_dynobjs_.find(sym);
2134 gold_assert(p != this->copied_symbol_dynobjs_.end());
2138 // Add any undefined symbols named on the command line.
2141 Symbol_table::add_undefined_symbols_from_command_line()
2143 if (parameters->options().any_undefined())
2145 if (parameters->target().get_size() == 32)
2147 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2148 this->do_add_undefined_symbols_from_command_line<32>();
2153 else if (parameters->target().get_size() == 64)
2155 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2156 this->do_add_undefined_symbols_from_command_line<64>();
2168 Symbol_table::do_add_undefined_symbols_from_command_line()
2170 for (options::String_set::const_iterator p =
2171 parameters->options().undefined_begin();
2172 p != parameters->options().undefined_end();
2175 const char* name = p->c_str();
2177 if (this->lookup(name) != NULL)
2180 const char* version = NULL;
2182 Sized_symbol<size>* sym;
2183 Sized_symbol<size>* oldsym;
2184 bool resolve_oldsym;
2185 if (parameters->target().is_big_endian())
2187 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2188 sym = this->define_special_symbol<size, true>(&name, &version,
2197 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2198 sym = this->define_special_symbol<size, false>(&name, &version,
2206 gold_assert(oldsym == NULL);
2208 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2209 elfcpp::STV_DEFAULT, 0);
2210 ++this->saw_undefined_;
2214 // Set the dynamic symbol indexes. INDEX is the index of the first
2215 // global dynamic symbol. Pointers to the symbols are stored into the
2216 // vector SYMS. The names are added to DYNPOOL. This returns an
2217 // updated dynamic symbol index.
2220 Symbol_table::set_dynsym_indexes(unsigned int index,
2221 std::vector<Symbol*>* syms,
2222 Stringpool* dynpool,
2225 for (Symbol_table_type::iterator p = this->table_.begin();
2226 p != this->table_.end();
2229 Symbol* sym = p->second;
2231 // Note that SYM may already have a dynamic symbol index, since
2232 // some symbols appear more than once in the symbol table, with
2233 // and without a version.
2235 if (!sym->should_add_dynsym_entry())
2236 sym->set_dynsym_index(-1U);
2237 else if (!sym->has_dynsym_index())
2239 sym->set_dynsym_index(index);
2241 syms->push_back(sym);
2242 dynpool->add(sym->name(), false, NULL);
2244 // Record any version information.
2245 if (sym->version() != NULL)
2246 versions->record_version(this, dynpool, sym);
2248 // If the symbol is defined in a dynamic object and is
2249 // referenced in a regular object, then mark the dynamic
2250 // object as needed. This is used to implement --as-needed.
2251 if (sym->is_from_dynobj() && sym->in_reg())
2252 sym->object()->set_is_needed();
2256 // Finish up the versions. In some cases this may add new dynamic
2258 index = versions->finalize(this, index, syms);
2263 // Set the final values for all the symbols. The index of the first
2264 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2265 // file offset OFF. Add their names to POOL. Return the new file
2266 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2269 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2270 size_t dyncount, Stringpool* pool,
2271 unsigned int *plocal_symcount)
2275 gold_assert(*plocal_symcount != 0);
2276 this->first_global_index_ = *plocal_symcount;
2278 this->dynamic_offset_ = dynoff;
2279 this->first_dynamic_global_index_ = dyn_global_index;
2280 this->dynamic_count_ = dyncount;
2282 if (parameters->target().get_size() == 32)
2284 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2285 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2290 else if (parameters->target().get_size() == 64)
2292 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2293 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2301 // Now that we have the final symbol table, we can reliably note
2302 // which symbols should get warnings.
2303 this->warnings_.note_warnings(this);
2308 // SYM is going into the symbol table at *PINDEX. Add the name to
2309 // POOL, update *PINDEX and *POFF.
2313 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2314 unsigned int* pindex, off_t* poff)
2316 sym->set_symtab_index(*pindex);
2317 pool->add(sym->name(), false, NULL);
2319 *poff += elfcpp::Elf_sizes<size>::sym_size;
2322 // Set the final value for all the symbols. This is called after
2323 // Layout::finalize, so all the output sections have their final
2328 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2329 unsigned int* plocal_symcount)
2331 off = align_address(off, size >> 3);
2332 this->offset_ = off;
2334 unsigned int index = *plocal_symcount;
2335 const unsigned int orig_index = index;
2337 // First do all the symbols which have been forced to be local, as
2338 // they must appear before all global symbols.
2339 for (Forced_locals::iterator p = this->forced_locals_.begin();
2340 p != this->forced_locals_.end();
2344 gold_assert(sym->is_forced_local());
2345 if (this->sized_finalize_symbol<size>(sym))
2347 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2352 // Now do all the remaining symbols.
2353 for (Symbol_table_type::iterator p = this->table_.begin();
2354 p != this->table_.end();
2357 Symbol* sym = p->second;
2358 if (this->sized_finalize_symbol<size>(sym))
2359 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2362 this->output_count_ = index - orig_index;
2367 // Compute the final value of SYM and store status in location PSTATUS.
2368 // During relaxation, this may be called multiple times for a symbol to
2369 // compute its would-be final value in each relaxation pass.
2372 typename Sized_symbol<size>::Value_type
2373 Symbol_table::compute_final_value(
2374 const Sized_symbol<size>* sym,
2375 Compute_final_value_status* pstatus) const
2377 typedef typename Sized_symbol<size>::Value_type Value_type;
2380 switch (sym->source())
2382 case Symbol::FROM_OBJECT:
2385 unsigned int shndx = sym->shndx(&is_ordinary);
2388 && shndx != elfcpp::SHN_ABS
2389 && !Symbol::is_common_shndx(shndx))
2391 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2395 Object* symobj = sym->object();
2396 if (symobj->is_dynamic())
2399 shndx = elfcpp::SHN_UNDEF;
2401 else if (symobj->pluginobj() != NULL)
2404 shndx = elfcpp::SHN_UNDEF;
2406 else if (shndx == elfcpp::SHN_UNDEF)
2408 else if (!is_ordinary
2409 && (shndx == elfcpp::SHN_ABS
2410 || Symbol::is_common_shndx(shndx)))
2411 value = sym->value();
2414 Relobj* relobj = static_cast<Relobj*>(symobj);
2415 Output_section* os = relobj->output_section(shndx);
2416 uint64_t secoff64 = relobj->output_section_offset(shndx);
2418 if (this->is_section_folded(relobj, shndx))
2420 gold_assert(os == NULL);
2421 // Get the os of the section it is folded onto.
2422 Section_id folded = this->icf_->get_folded_section(relobj,
2424 gold_assert(folded.first != NULL);
2425 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2426 os = folded_obj->output_section(folded.second);
2427 gold_assert(os != NULL);
2428 secoff64 = folded_obj->output_section_offset(folded.second);
2433 bool static_or_reloc = (parameters->doing_static_link() ||
2434 parameters->options().relocatable());
2435 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2437 *pstatus = CFVS_NO_OUTPUT_SECTION;
2441 if (secoff64 == -1ULL)
2443 // The section needs special handling (e.g., a merge section).
2445 value = os->output_address(relobj, shndx, sym->value());
2450 convert_types<Value_type, uint64_t>(secoff64);
2451 if (sym->type() == elfcpp::STT_TLS)
2452 value = sym->value() + os->tls_offset() + secoff;
2454 value = sym->value() + os->address() + secoff;
2460 case Symbol::IN_OUTPUT_DATA:
2462 Output_data* od = sym->output_data();
2463 value = sym->value();
2464 if (sym->type() != elfcpp::STT_TLS)
2465 value += od->address();
2468 Output_section* os = od->output_section();
2469 gold_assert(os != NULL);
2470 value += os->tls_offset() + (od->address() - os->address());
2472 if (sym->offset_is_from_end())
2473 value += od->data_size();
2477 case Symbol::IN_OUTPUT_SEGMENT:
2479 Output_segment* os = sym->output_segment();
2480 value = sym->value();
2481 if (sym->type() != elfcpp::STT_TLS)
2482 value += os->vaddr();
2483 switch (sym->offset_base())
2485 case Symbol::SEGMENT_START:
2487 case Symbol::SEGMENT_END:
2488 value += os->memsz();
2490 case Symbol::SEGMENT_BSS:
2491 value += os->filesz();
2499 case Symbol::IS_CONSTANT:
2500 value = sym->value();
2503 case Symbol::IS_UNDEFINED:
2515 // Finalize the symbol SYM. This returns true if the symbol should be
2516 // added to the symbol table, false otherwise.
2520 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2522 typedef typename Sized_symbol<size>::Value_type Value_type;
2524 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2526 // The default version of a symbol may appear twice in the symbol
2527 // table. We only need to finalize it once.
2528 if (sym->has_symtab_index())
2533 gold_assert(!sym->has_symtab_index());
2534 sym->set_symtab_index(-1U);
2535 gold_assert(sym->dynsym_index() == -1U);
2539 // Compute final symbol value.
2540 Compute_final_value_status status;
2541 Value_type value = this->compute_final_value(sym, &status);
2547 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2550 unsigned int shndx = sym->shndx(&is_ordinary);
2551 gold_error(_("%s: unsupported symbol section 0x%x"),
2552 sym->demangled_name().c_str(), shndx);
2555 case CFVS_NO_OUTPUT_SECTION:
2556 sym->set_symtab_index(-1U);
2562 sym->set_value(value);
2564 if (parameters->options().strip_all()
2565 || !parameters->options().should_retain_symbol(sym->name()))
2567 sym->set_symtab_index(-1U);
2574 // Write out the global symbols.
2577 Symbol_table::write_globals(const Stringpool* sympool,
2578 const Stringpool* dynpool,
2579 Output_symtab_xindex* symtab_xindex,
2580 Output_symtab_xindex* dynsym_xindex,
2581 Output_file* of) const
2583 switch (parameters->size_and_endianness())
2585 #ifdef HAVE_TARGET_32_LITTLE
2586 case Parameters::TARGET_32_LITTLE:
2587 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2591 #ifdef HAVE_TARGET_32_BIG
2592 case Parameters::TARGET_32_BIG:
2593 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2597 #ifdef HAVE_TARGET_64_LITTLE
2598 case Parameters::TARGET_64_LITTLE:
2599 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2603 #ifdef HAVE_TARGET_64_BIG
2604 case Parameters::TARGET_64_BIG:
2605 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2614 // Write out the global symbols.
2616 template<int size, bool big_endian>
2618 Symbol_table::sized_write_globals(const Stringpool* sympool,
2619 const Stringpool* dynpool,
2620 Output_symtab_xindex* symtab_xindex,
2621 Output_symtab_xindex* dynsym_xindex,
2622 Output_file* of) const
2624 const Target& target = parameters->target();
2626 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2628 const unsigned int output_count = this->output_count_;
2629 const section_size_type oview_size = output_count * sym_size;
2630 const unsigned int first_global_index = this->first_global_index_;
2631 unsigned char* psyms;
2632 if (this->offset_ == 0 || output_count == 0)
2635 psyms = of->get_output_view(this->offset_, oview_size);
2637 const unsigned int dynamic_count = this->dynamic_count_;
2638 const section_size_type dynamic_size = dynamic_count * sym_size;
2639 const unsigned int first_dynamic_global_index =
2640 this->first_dynamic_global_index_;
2641 unsigned char* dynamic_view;
2642 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2643 dynamic_view = NULL;
2645 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2647 for (Symbol_table_type::const_iterator p = this->table_.begin();
2648 p != this->table_.end();
2651 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2653 // Possibly warn about unresolved symbols in shared libraries.
2654 this->warn_about_undefined_dynobj_symbol(sym);
2656 unsigned int sym_index = sym->symtab_index();
2657 unsigned int dynsym_index;
2658 if (dynamic_view == NULL)
2661 dynsym_index = sym->dynsym_index();
2663 if (sym_index == -1U && dynsym_index == -1U)
2665 // This symbol is not included in the output file.
2670 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2671 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2672 switch (sym->source())
2674 case Symbol::FROM_OBJECT:
2677 unsigned int in_shndx = sym->shndx(&is_ordinary);
2680 && in_shndx != elfcpp::SHN_ABS
2681 && !Symbol::is_common_shndx(in_shndx))
2683 gold_error(_("%s: unsupported symbol section 0x%x"),
2684 sym->demangled_name().c_str(), in_shndx);
2689 Object* symobj = sym->object();
2690 if (symobj->is_dynamic())
2692 if (sym->needs_dynsym_value())
2693 dynsym_value = target.dynsym_value(sym);
2694 shndx = elfcpp::SHN_UNDEF;
2696 else if (symobj->pluginobj() != NULL)
2697 shndx = elfcpp::SHN_UNDEF;
2698 else if (in_shndx == elfcpp::SHN_UNDEF
2700 && (in_shndx == elfcpp::SHN_ABS
2701 || Symbol::is_common_shndx(in_shndx))))
2705 Relobj* relobj = static_cast<Relobj*>(symobj);
2706 Output_section* os = relobj->output_section(in_shndx);
2707 if (this->is_section_folded(relobj, in_shndx))
2709 // This global symbol must be written out even though
2711 // Get the os of the section it is folded onto.
2713 this->icf_->get_folded_section(relobj, in_shndx);
2714 gold_assert(folded.first !=NULL);
2715 Relobj* folded_obj =
2716 reinterpret_cast<Relobj*>(folded.first);
2717 os = folded_obj->output_section(folded.second);
2718 gold_assert(os != NULL);
2720 gold_assert(os != NULL);
2721 shndx = os->out_shndx();
2723 if (shndx >= elfcpp::SHN_LORESERVE)
2725 if (sym_index != -1U)
2726 symtab_xindex->add(sym_index, shndx);
2727 if (dynsym_index != -1U)
2728 dynsym_xindex->add(dynsym_index, shndx);
2729 shndx = elfcpp::SHN_XINDEX;
2732 // In object files symbol values are section
2734 if (parameters->options().relocatable())
2735 sym_value -= os->address();
2741 case Symbol::IN_OUTPUT_DATA:
2742 shndx = sym->output_data()->out_shndx();
2743 if (shndx >= elfcpp::SHN_LORESERVE)
2745 if (sym_index != -1U)
2746 symtab_xindex->add(sym_index, shndx);
2747 if (dynsym_index != -1U)
2748 dynsym_xindex->add(dynsym_index, shndx);
2749 shndx = elfcpp::SHN_XINDEX;
2753 case Symbol::IN_OUTPUT_SEGMENT:
2754 shndx = elfcpp::SHN_ABS;
2757 case Symbol::IS_CONSTANT:
2758 shndx = elfcpp::SHN_ABS;
2761 case Symbol::IS_UNDEFINED:
2762 shndx = elfcpp::SHN_UNDEF;
2769 if (sym_index != -1U)
2771 sym_index -= first_global_index;
2772 gold_assert(sym_index < output_count);
2773 unsigned char* ps = psyms + (sym_index * sym_size);
2774 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2778 if (dynsym_index != -1U)
2780 dynsym_index -= first_dynamic_global_index;
2781 gold_assert(dynsym_index < dynamic_count);
2782 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2783 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2788 of->write_output_view(this->offset_, oview_size, psyms);
2789 if (dynamic_view != NULL)
2790 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2793 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2794 // strtab holding the name.
2796 template<int size, bool big_endian>
2798 Symbol_table::sized_write_symbol(
2799 Sized_symbol<size>* sym,
2800 typename elfcpp::Elf_types<size>::Elf_Addr value,
2802 const Stringpool* pool,
2803 unsigned char* p) const
2805 elfcpp::Sym_write<size, big_endian> osym(p);
2806 osym.put_st_name(pool->get_offset(sym->name()));
2807 osym.put_st_value(value);
2808 // Use a symbol size of zero for undefined symbols from shared libraries.
2809 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2810 osym.put_st_size(0);
2812 osym.put_st_size(sym->symsize());
2813 // A version script may have overridden the default binding.
2814 if (sym->is_forced_local())
2815 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2817 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2818 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2819 osym.put_st_shndx(shndx);
2822 // Check for unresolved symbols in shared libraries. This is
2823 // controlled by the --allow-shlib-undefined option.
2825 // We only warn about libraries for which we have seen all the
2826 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2827 // which were not seen in this link. If we didn't see a DT_NEEDED
2828 // entry, we aren't going to be able to reliably report whether the
2829 // symbol is undefined.
2831 // We also don't warn about libraries found in a system library
2832 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2833 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2834 // can have undefined references satisfied by ld-linux.so.
2837 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2840 if (sym->source() == Symbol::FROM_OBJECT
2841 && sym->object()->is_dynamic()
2842 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2843 && sym->binding() != elfcpp::STB_WEAK
2844 && !parameters->options().allow_shlib_undefined()
2845 && !parameters->target().is_defined_by_abi(sym)
2846 && !sym->object()->is_in_system_directory())
2848 // A very ugly cast.
2849 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2850 if (!dynobj->has_unknown_needed_entries())
2851 gold_undefined_symbol(sym);
2855 // Write out a section symbol. Return the update offset.
2858 Symbol_table::write_section_symbol(const Output_section *os,
2859 Output_symtab_xindex* symtab_xindex,
2863 switch (parameters->size_and_endianness())
2865 #ifdef HAVE_TARGET_32_LITTLE
2866 case Parameters::TARGET_32_LITTLE:
2867 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2871 #ifdef HAVE_TARGET_32_BIG
2872 case Parameters::TARGET_32_BIG:
2873 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2877 #ifdef HAVE_TARGET_64_LITTLE
2878 case Parameters::TARGET_64_LITTLE:
2879 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2883 #ifdef HAVE_TARGET_64_BIG
2884 case Parameters::TARGET_64_BIG:
2885 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2894 // Write out a section symbol, specialized for size and endianness.
2896 template<int size, bool big_endian>
2898 Symbol_table::sized_write_section_symbol(const Output_section* os,
2899 Output_symtab_xindex* symtab_xindex,
2903 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2905 unsigned char* pov = of->get_output_view(offset, sym_size);
2907 elfcpp::Sym_write<size, big_endian> osym(pov);
2908 osym.put_st_name(0);
2909 if (parameters->options().relocatable())
2910 osym.put_st_value(0);
2912 osym.put_st_value(os->address());
2913 osym.put_st_size(0);
2914 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2915 elfcpp::STT_SECTION));
2916 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2918 unsigned int shndx = os->out_shndx();
2919 if (shndx >= elfcpp::SHN_LORESERVE)
2921 symtab_xindex->add(os->symtab_index(), shndx);
2922 shndx = elfcpp::SHN_XINDEX;
2924 osym.put_st_shndx(shndx);
2926 of->write_output_view(offset, sym_size, pov);
2929 // Print statistical information to stderr. This is used for --stats.
2932 Symbol_table::print_stats() const
2934 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2935 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2936 program_name, this->table_.size(), this->table_.bucket_count());
2938 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2939 program_name, this->table_.size());
2941 this->namepool_.print_stats("symbol table stringpool");
2944 // We check for ODR violations by looking for symbols with the same
2945 // name for which the debugging information reports that they were
2946 // defined in different source locations. When comparing the source
2947 // location, we consider instances with the same base filename and
2948 // line number to be the same. This is because different object
2949 // files/shared libraries can include the same header file using
2950 // different paths, and we don't want to report an ODR violation in
2953 // This struct is used to compare line information, as returned by
2954 // Dwarf_line_info::one_addr2line. It implements a < comparison
2955 // operator used with std::set.
2957 struct Odr_violation_compare
2960 operator()(const std::string& s1, const std::string& s2) const
2962 std::string::size_type pos1 = s1.rfind('/');
2963 std::string::size_type pos2 = s2.rfind('/');
2964 if (pos1 == std::string::npos
2965 || pos2 == std::string::npos)
2967 return s1.compare(pos1, std::string::npos,
2968 s2, pos2, std::string::npos) < 0;
2972 // Check candidate_odr_violations_ to find symbols with the same name
2973 // but apparently different definitions (different source-file/line-no).
2976 Symbol_table::detect_odr_violations(const Task* task,
2977 const char* output_file_name) const
2979 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2980 it != candidate_odr_violations_.end();
2983 const char* symbol_name = it->first;
2984 // We use a sorted set so the output is deterministic.
2985 std::set<std::string, Odr_violation_compare> line_nums;
2987 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2988 locs = it->second.begin();
2989 locs != it->second.end();
2992 // We need to lock the object in order to read it. This
2993 // means that we have to run in a singleton Task. If we
2994 // want to run this in a general Task for better
2995 // performance, we will need one Task for object, plus
2996 // appropriate locking to ensure that we don't conflict with
2997 // other uses of the object. Also note, one_addr2line is not
2998 // currently thread-safe.
2999 Task_lock_obj<Object> tl(task, locs->object);
3000 // 16 is the size of the object-cache that one_addr2line should use.
3001 std::string lineno = Dwarf_line_info::one_addr2line(
3002 locs->object, locs->shndx, locs->offset, 16);
3003 if (!lineno.empty())
3004 line_nums.insert(lineno);
3007 if (line_nums.size() > 1)
3009 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3010 "places (possible ODR violation):"),
3011 output_file_name, demangle(symbol_name).c_str());
3012 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
3013 it2 != line_nums.end();
3015 fprintf(stderr, " %s\n", it2->c_str());
3018 // We only call one_addr2line() in this function, so we can clear its cache.
3019 Dwarf_line_info::clear_addr2line_cache();
3022 // Warnings functions.
3024 // Add a new warning.
3027 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3028 const std::string& warning)
3030 name = symtab->canonicalize_name(name);
3031 this->warnings_[name].set(obj, warning);
3034 // Look through the warnings and mark the symbols for which we should
3035 // warn. This is called during Layout::finalize when we know the
3036 // sources for all the symbols.
3039 Warnings::note_warnings(Symbol_table* symtab)
3041 for (Warning_table::iterator p = this->warnings_.begin();
3042 p != this->warnings_.end();
3045 Symbol* sym = symtab->lookup(p->first, NULL);
3047 && sym->source() == Symbol::FROM_OBJECT
3048 && sym->object() == p->second.object)
3049 sym->set_has_warning();
3053 // Issue a warning. This is called when we see a relocation against a
3054 // symbol for which has a warning.
3056 template<int size, bool big_endian>
3058 Warnings::issue_warning(const Symbol* sym,
3059 const Relocate_info<size, big_endian>* relinfo,
3060 size_t relnum, off_t reloffset) const
3062 gold_assert(sym->has_warning());
3063 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3064 gold_assert(p != this->warnings_.end());
3065 gold_warning_at_location(relinfo, relnum, reloffset,
3066 "%s", p->second.text.c_str());
3069 // Instantiate the templates we need. We could use the configure
3070 // script to restrict this to only the ones needed for implemented
3073 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3076 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3079 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3082 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3085 #ifdef HAVE_TARGET_32_LITTLE
3088 Symbol_table::add_from_relobj<32, false>(
3089 Sized_relobj<32, false>* relobj,
3090 const unsigned char* syms,
3092 size_t symndx_offset,
3093 const char* sym_names,
3094 size_t sym_name_size,
3095 Sized_relobj<32, false>::Symbols* sympointers,
3099 #ifdef HAVE_TARGET_32_BIG
3102 Symbol_table::add_from_relobj<32, true>(
3103 Sized_relobj<32, true>* relobj,
3104 const unsigned char* syms,
3106 size_t symndx_offset,
3107 const char* sym_names,
3108 size_t sym_name_size,
3109 Sized_relobj<32, true>::Symbols* sympointers,
3113 #ifdef HAVE_TARGET_64_LITTLE
3116 Symbol_table::add_from_relobj<64, false>(
3117 Sized_relobj<64, false>* relobj,
3118 const unsigned char* syms,
3120 size_t symndx_offset,
3121 const char* sym_names,
3122 size_t sym_name_size,
3123 Sized_relobj<64, false>::Symbols* sympointers,
3127 #ifdef HAVE_TARGET_64_BIG
3130 Symbol_table::add_from_relobj<64, true>(
3131 Sized_relobj<64, true>* relobj,
3132 const unsigned char* syms,
3134 size_t symndx_offset,
3135 const char* sym_names,
3136 size_t sym_name_size,
3137 Sized_relobj<64, true>::Symbols* sympointers,
3141 #ifdef HAVE_TARGET_32_LITTLE
3144 Symbol_table::add_from_pluginobj<32, false>(
3145 Sized_pluginobj<32, false>* obj,
3148 elfcpp::Sym<32, false>* sym);
3151 #ifdef HAVE_TARGET_32_BIG
3154 Symbol_table::add_from_pluginobj<32, true>(
3155 Sized_pluginobj<32, true>* obj,
3158 elfcpp::Sym<32, true>* sym);
3161 #ifdef HAVE_TARGET_64_LITTLE
3164 Symbol_table::add_from_pluginobj<64, false>(
3165 Sized_pluginobj<64, false>* obj,
3168 elfcpp::Sym<64, false>* sym);
3171 #ifdef HAVE_TARGET_64_BIG
3174 Symbol_table::add_from_pluginobj<64, true>(
3175 Sized_pluginobj<64, true>* obj,
3178 elfcpp::Sym<64, true>* sym);
3181 #ifdef HAVE_TARGET_32_LITTLE
3184 Symbol_table::add_from_dynobj<32, false>(
3185 Sized_dynobj<32, false>* dynobj,
3186 const unsigned char* syms,
3188 const char* sym_names,
3189 size_t sym_name_size,
3190 const unsigned char* versym,
3192 const std::vector<const char*>* version_map,
3193 Sized_relobj<32, false>::Symbols* sympointers,
3197 #ifdef HAVE_TARGET_32_BIG
3200 Symbol_table::add_from_dynobj<32, true>(
3201 Sized_dynobj<32, true>* dynobj,
3202 const unsigned char* syms,
3204 const char* sym_names,
3205 size_t sym_name_size,
3206 const unsigned char* versym,
3208 const std::vector<const char*>* version_map,
3209 Sized_relobj<32, true>::Symbols* sympointers,
3213 #ifdef HAVE_TARGET_64_LITTLE
3216 Symbol_table::add_from_dynobj<64, false>(
3217 Sized_dynobj<64, false>* dynobj,
3218 const unsigned char* syms,
3220 const char* sym_names,
3221 size_t sym_name_size,
3222 const unsigned char* versym,
3224 const std::vector<const char*>* version_map,
3225 Sized_relobj<64, false>::Symbols* sympointers,
3229 #ifdef HAVE_TARGET_64_BIG
3232 Symbol_table::add_from_dynobj<64, true>(
3233 Sized_dynobj<64, true>* dynobj,
3234 const unsigned char* syms,
3236 const char* sym_names,
3237 size_t sym_name_size,
3238 const unsigned char* versym,
3240 const std::vector<const char*>* version_map,
3241 Sized_relobj<64, true>::Symbols* sympointers,
3245 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3248 Symbol_table::define_with_copy_reloc<32>(
3249 Sized_symbol<32>* sym,
3251 elfcpp::Elf_types<32>::Elf_Addr value);
3254 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3257 Symbol_table::define_with_copy_reloc<64>(
3258 Sized_symbol<64>* sym,
3260 elfcpp::Elf_types<64>::Elf_Addr value);
3263 #ifdef HAVE_TARGET_32_LITTLE
3266 Warnings::issue_warning<32, false>(const Symbol* sym,
3267 const Relocate_info<32, false>* relinfo,
3268 size_t relnum, off_t reloffset) const;
3271 #ifdef HAVE_TARGET_32_BIG
3274 Warnings::issue_warning<32, true>(const Symbol* sym,
3275 const Relocate_info<32, true>* relinfo,
3276 size_t relnum, off_t reloffset) const;
3279 #ifdef HAVE_TARGET_64_LITTLE
3282 Warnings::issue_warning<64, false>(const Symbol* sym,
3283 const Relocate_info<64, false>* relinfo,
3284 size_t relnum, off_t reloffset) const;
3287 #ifdef HAVE_TARGET_64_BIG
3290 Warnings::issue_warning<64, true>(const Symbol* sym,
3291 const Relocate_info<64, true>* relinfo,
3292 size_t relnum, off_t reloffset) const;
3295 } // End namespace gold.