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()
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(Object* object, const char* name,
692 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] == object->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(object, 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 object->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_WEAK)
1014 && !parameters->options().relocatable())
1015 this->force_local(ret);
1020 // Add all the symbols in a relocatable object to the hash table.
1022 template<int size, bool big_endian>
1024 Symbol_table::add_from_relobj(
1025 Sized_relobj<size, big_endian>* relobj,
1026 const unsigned char* syms,
1028 size_t symndx_offset,
1029 const char* sym_names,
1030 size_t sym_name_size,
1031 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1036 gold_assert(size == relobj->target()->get_size());
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();
1207 Stringpool::Key ver_key = 0;
1213 ver = this->namepool_.add(ver, true, &ver_key);
1215 // We don't want to assign a version to an undefined symbol,
1216 // even if it is listed in the version script. FIXME: What
1217 // about a common symbol?
1220 if (!this->version_script_.empty()
1221 && st_shndx != elfcpp::SHN_UNDEF)
1223 // The symbol name did not have a version, but the
1224 // version script may assign a version anyway.
1225 std::string version;
1226 if (this->version_script_.get_symbol_version(name, &version))
1228 // The version can be empty if the version script is
1229 // only used to force some symbols to be local.
1230 if (!version.empty())
1232 ver = this->namepool_.add_with_length(version.c_str(),
1239 else if (this->version_script_.symbol_is_local(name))
1244 Stringpool::Key name_key;
1245 name = this->namepool_.add(name, true, &name_key);
1247 Sized_symbol<size>* res;
1248 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1249 def, *sym, st_shndx, true, st_shndx);
1252 this->force_local(res);
1257 // Add all the symbols in a dynamic object to the hash table.
1259 template<int size, bool big_endian>
1261 Symbol_table::add_from_dynobj(
1262 Sized_dynobj<size, big_endian>* dynobj,
1263 const unsigned char* syms,
1265 const char* sym_names,
1266 size_t sym_name_size,
1267 const unsigned char* versym,
1269 const std::vector<const char*>* version_map,
1270 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1275 gold_assert(size == dynobj->target()->get_size());
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 gold_assert(target.get_size() == size);
1665 gold_assert(target.is_big_endian() ? big_endian : !big_endian);
1666 typedef Sized_target<size, big_endian> My_target;
1667 const My_target* sized_target =
1668 static_cast<const My_target*>(&target);
1669 sym = sized_target->make_symbol();
1675 add_loc->second = sym;
1677 gold_assert(oldsym != NULL);
1679 if (add_def_to_table)
1680 add_def_loc->second = sym;
1682 *poldsym = this->get_sized_symbol<size>(oldsym);
1687 // Define a symbol based on an Output_data.
1690 Symbol_table::define_in_output_data(const char* name,
1691 const char* version,
1696 elfcpp::STB binding,
1697 elfcpp::STV visibility,
1698 unsigned char nonvis,
1699 bool offset_is_from_end,
1702 if (parameters->target().get_size() == 32)
1704 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1705 return this->do_define_in_output_data<32>(name, version, od,
1706 value, symsize, type, binding,
1714 else if (parameters->target().get_size() == 64)
1716 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1717 return this->do_define_in_output_data<64>(name, version, od,
1718 value, symsize, type, binding,
1730 // Define a symbol in an Output_data, sized version.
1734 Symbol_table::do_define_in_output_data(
1736 const char* version,
1738 typename elfcpp::Elf_types<size>::Elf_Addr value,
1739 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1741 elfcpp::STB binding,
1742 elfcpp::STV visibility,
1743 unsigned char nonvis,
1744 bool offset_is_from_end,
1747 Sized_symbol<size>* sym;
1748 Sized_symbol<size>* oldsym;
1749 bool resolve_oldsym;
1751 if (parameters->target().is_big_endian())
1753 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1754 sym = this->define_special_symbol<size, true>(&name, &version,
1755 only_if_ref, &oldsym,
1763 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1764 sym = this->define_special_symbol<size, false>(&name, &version,
1765 only_if_ref, &oldsym,
1775 sym->init_output_data(name, version, od, value, symsize, type, binding,
1776 visibility, nonvis, offset_is_from_end);
1780 if (binding == elfcpp::STB_LOCAL
1781 || this->version_script_.symbol_is_local(name))
1782 this->force_local(sym);
1783 else if (version != NULL)
1784 sym->set_is_default();
1788 if (Symbol_table::should_override_with_special(oldsym))
1789 this->override_with_special(oldsym, sym);
1800 // Define a symbol based on an Output_segment.
1803 Symbol_table::define_in_output_segment(const char* name,
1804 const char* version, Output_segment* os,
1808 elfcpp::STB binding,
1809 elfcpp::STV visibility,
1810 unsigned char nonvis,
1811 Symbol::Segment_offset_base offset_base,
1814 if (parameters->target().get_size() == 32)
1816 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1817 return this->do_define_in_output_segment<32>(name, version, os,
1818 value, symsize, type,
1819 binding, visibility, nonvis,
1820 offset_base, only_if_ref);
1825 else if (parameters->target().get_size() == 64)
1827 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1828 return this->do_define_in_output_segment<64>(name, version, os,
1829 value, symsize, type,
1830 binding, visibility, nonvis,
1831 offset_base, only_if_ref);
1840 // Define a symbol in an Output_segment, sized version.
1844 Symbol_table::do_define_in_output_segment(
1846 const char* version,
1848 typename elfcpp::Elf_types<size>::Elf_Addr value,
1849 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1851 elfcpp::STB binding,
1852 elfcpp::STV visibility,
1853 unsigned char nonvis,
1854 Symbol::Segment_offset_base offset_base,
1857 Sized_symbol<size>* sym;
1858 Sized_symbol<size>* oldsym;
1859 bool resolve_oldsym;
1861 if (parameters->target().is_big_endian())
1863 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1864 sym = this->define_special_symbol<size, true>(&name, &version,
1865 only_if_ref, &oldsym,
1873 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1874 sym = this->define_special_symbol<size, false>(&name, &version,
1875 only_if_ref, &oldsym,
1885 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1886 visibility, nonvis, offset_base);
1890 if (binding == elfcpp::STB_LOCAL
1891 || this->version_script_.symbol_is_local(name))
1892 this->force_local(sym);
1893 else if (version != NULL)
1894 sym->set_is_default();
1898 if (Symbol_table::should_override_with_special(oldsym))
1899 this->override_with_special(oldsym, sym);
1910 // Define a special symbol with a constant value. It is a multiple
1911 // definition error if this symbol is already defined.
1914 Symbol_table::define_as_constant(const char* name,
1915 const char* version,
1919 elfcpp::STB binding,
1920 elfcpp::STV visibility,
1921 unsigned char nonvis,
1923 bool force_override)
1925 if (parameters->target().get_size() == 32)
1927 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1928 return this->do_define_as_constant<32>(name, version, value,
1929 symsize, type, binding,
1930 visibility, nonvis, only_if_ref,
1936 else if (parameters->target().get_size() == 64)
1938 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1939 return this->do_define_as_constant<64>(name, version, value,
1940 symsize, type, binding,
1941 visibility, nonvis, only_if_ref,
1951 // Define a symbol as a constant, sized version.
1955 Symbol_table::do_define_as_constant(
1957 const char* version,
1958 typename elfcpp::Elf_types<size>::Elf_Addr value,
1959 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1961 elfcpp::STB binding,
1962 elfcpp::STV visibility,
1963 unsigned char nonvis,
1965 bool force_override)
1967 Sized_symbol<size>* sym;
1968 Sized_symbol<size>* oldsym;
1969 bool resolve_oldsym;
1971 if (parameters->target().is_big_endian())
1973 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1974 sym = this->define_special_symbol<size, true>(&name, &version,
1975 only_if_ref, &oldsym,
1983 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1984 sym = this->define_special_symbol<size, false>(&name, &version,
1985 only_if_ref, &oldsym,
1995 sym->init_constant(name, version, value, symsize, type, binding, visibility,
2000 // Version symbols are absolute symbols with name == version.
2001 // We don't want to force them to be local.
2002 if ((version == NULL
2005 && (binding == elfcpp::STB_LOCAL
2006 || this->version_script_.symbol_is_local(name)))
2007 this->force_local(sym);
2008 else if (version != NULL
2009 && (name != version || value != 0))
2010 sym->set_is_default();
2014 if (force_override || Symbol_table::should_override_with_special(oldsym))
2015 this->override_with_special(oldsym, sym);
2026 // Define a set of symbols in output sections.
2029 Symbol_table::define_symbols(const Layout* layout, int count,
2030 const Define_symbol_in_section* p,
2033 for (int i = 0; i < count; ++i, ++p)
2035 Output_section* os = layout->find_output_section(p->output_section);
2037 this->define_in_output_data(p->name, NULL, os, p->value,
2038 p->size, p->type, p->binding,
2039 p->visibility, p->nonvis,
2040 p->offset_is_from_end,
2041 only_if_ref || p->only_if_ref);
2043 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2044 p->binding, p->visibility, p->nonvis,
2045 only_if_ref || p->only_if_ref,
2050 // Define a set of symbols in output segments.
2053 Symbol_table::define_symbols(const Layout* layout, int count,
2054 const Define_symbol_in_segment* p,
2057 for (int i = 0; i < count; ++i, ++p)
2059 Output_segment* os = layout->find_output_segment(p->segment_type,
2060 p->segment_flags_set,
2061 p->segment_flags_clear);
2063 this->define_in_output_segment(p->name, NULL, os, p->value,
2064 p->size, p->type, p->binding,
2065 p->visibility, p->nonvis,
2067 only_if_ref || p->only_if_ref);
2069 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2070 p->binding, p->visibility, p->nonvis,
2071 only_if_ref || p->only_if_ref,
2076 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2077 // symbol should be defined--typically a .dyn.bss section. VALUE is
2078 // the offset within POSD.
2082 Symbol_table::define_with_copy_reloc(
2083 Sized_symbol<size>* csym,
2085 typename elfcpp::Elf_types<size>::Elf_Addr value)
2087 gold_assert(csym->is_from_dynobj());
2088 gold_assert(!csym->is_copied_from_dynobj());
2089 Object* object = csym->object();
2090 gold_assert(object->is_dynamic());
2091 Dynobj* dynobj = static_cast<Dynobj*>(object);
2093 // Our copied variable has to override any variable in a shared
2095 elfcpp::STB binding = csym->binding();
2096 if (binding == elfcpp::STB_WEAK)
2097 binding = elfcpp::STB_GLOBAL;
2099 this->define_in_output_data(csym->name(), csym->version(),
2100 posd, value, csym->symsize(),
2101 csym->type(), binding,
2102 csym->visibility(), csym->nonvis(),
2105 csym->set_is_copied_from_dynobj();
2106 csym->set_needs_dynsym_entry();
2108 this->copied_symbol_dynobjs_[csym] = dynobj;
2110 // We have now defined all aliases, but we have not entered them all
2111 // in the copied_symbol_dynobjs_ map.
2112 if (csym->has_alias())
2117 sym = this->weak_aliases_[sym];
2120 gold_assert(sym->output_data() == posd);
2122 sym->set_is_copied_from_dynobj();
2123 this->copied_symbol_dynobjs_[sym] = dynobj;
2128 // SYM is defined using a COPY reloc. Return the dynamic object where
2129 // the original definition was found.
2132 Symbol_table::get_copy_source(const Symbol* sym) const
2134 gold_assert(sym->is_copied_from_dynobj());
2135 Copied_symbol_dynobjs::const_iterator p =
2136 this->copied_symbol_dynobjs_.find(sym);
2137 gold_assert(p != this->copied_symbol_dynobjs_.end());
2141 // Add any undefined symbols named on the command line.
2144 Symbol_table::add_undefined_symbols_from_command_line()
2146 if (parameters->options().any_undefined())
2148 if (parameters->target().get_size() == 32)
2150 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2151 this->do_add_undefined_symbols_from_command_line<32>();
2156 else if (parameters->target().get_size() == 64)
2158 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2159 this->do_add_undefined_symbols_from_command_line<64>();
2171 Symbol_table::do_add_undefined_symbols_from_command_line()
2173 for (options::String_set::const_iterator p =
2174 parameters->options().undefined_begin();
2175 p != parameters->options().undefined_end();
2178 const char* name = p->c_str();
2180 if (this->lookup(name) != NULL)
2183 const char* version = NULL;
2185 Sized_symbol<size>* sym;
2186 Sized_symbol<size>* oldsym;
2187 bool resolve_oldsym;
2188 if (parameters->target().is_big_endian())
2190 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2191 sym = this->define_special_symbol<size, true>(&name, &version,
2200 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2201 sym = this->define_special_symbol<size, false>(&name, &version,
2209 gold_assert(oldsym == NULL);
2211 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2212 elfcpp::STV_DEFAULT, 0);
2213 ++this->saw_undefined_;
2217 // Set the dynamic symbol indexes. INDEX is the index of the first
2218 // global dynamic symbol. Pointers to the symbols are stored into the
2219 // vector SYMS. The names are added to DYNPOOL. This returns an
2220 // updated dynamic symbol index.
2223 Symbol_table::set_dynsym_indexes(unsigned int index,
2224 std::vector<Symbol*>* syms,
2225 Stringpool* dynpool,
2228 for (Symbol_table_type::iterator p = this->table_.begin();
2229 p != this->table_.end();
2232 Symbol* sym = p->second;
2234 // Note that SYM may already have a dynamic symbol index, since
2235 // some symbols appear more than once in the symbol table, with
2236 // and without a version.
2238 if (!sym->should_add_dynsym_entry())
2239 sym->set_dynsym_index(-1U);
2240 else if (!sym->has_dynsym_index())
2242 sym->set_dynsym_index(index);
2244 syms->push_back(sym);
2245 dynpool->add(sym->name(), false, NULL);
2247 // Record any version information.
2248 if (sym->version() != NULL)
2249 versions->record_version(this, dynpool, sym);
2253 // Finish up the versions. In some cases this may add new dynamic
2255 index = versions->finalize(this, index, syms);
2260 // Set the final values for all the symbols. The index of the first
2261 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2262 // file offset OFF. Add their names to POOL. Return the new file
2263 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2266 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2267 size_t dyncount, Stringpool* pool,
2268 unsigned int *plocal_symcount)
2272 gold_assert(*plocal_symcount != 0);
2273 this->first_global_index_ = *plocal_symcount;
2275 this->dynamic_offset_ = dynoff;
2276 this->first_dynamic_global_index_ = dyn_global_index;
2277 this->dynamic_count_ = dyncount;
2279 if (parameters->target().get_size() == 32)
2281 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2282 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2287 else if (parameters->target().get_size() == 64)
2289 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2290 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2298 // Now that we have the final symbol table, we can reliably note
2299 // which symbols should get warnings.
2300 this->warnings_.note_warnings(this);
2305 // SYM is going into the symbol table at *PINDEX. Add the name to
2306 // POOL, update *PINDEX and *POFF.
2310 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2311 unsigned int* pindex, off_t* poff)
2313 sym->set_symtab_index(*pindex);
2314 pool->add(sym->name(), false, NULL);
2316 *poff += elfcpp::Elf_sizes<size>::sym_size;
2319 // Set the final value for all the symbols. This is called after
2320 // Layout::finalize, so all the output sections have their final
2325 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2326 unsigned int* plocal_symcount)
2328 off = align_address(off, size >> 3);
2329 this->offset_ = off;
2331 unsigned int index = *plocal_symcount;
2332 const unsigned int orig_index = index;
2334 // First do all the symbols which have been forced to be local, as
2335 // they must appear before all global symbols.
2336 for (Forced_locals::iterator p = this->forced_locals_.begin();
2337 p != this->forced_locals_.end();
2341 gold_assert(sym->is_forced_local());
2342 if (this->sized_finalize_symbol<size>(sym))
2344 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2349 // Now do all the remaining symbols.
2350 for (Symbol_table_type::iterator p = this->table_.begin();
2351 p != this->table_.end();
2354 Symbol* sym = p->second;
2355 if (this->sized_finalize_symbol<size>(sym))
2356 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2359 this->output_count_ = index - orig_index;
2364 // Finalize the symbol SYM. This returns true if the symbol should be
2365 // added to the symbol table, false otherwise.
2369 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2371 typedef typename Sized_symbol<size>::Value_type Value_type;
2373 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2375 // The default version of a symbol may appear twice in the symbol
2376 // table. We only need to finalize it once.
2377 if (sym->has_symtab_index())
2382 gold_assert(!sym->has_symtab_index());
2383 sym->set_symtab_index(-1U);
2384 gold_assert(sym->dynsym_index() == -1U);
2390 switch (sym->source())
2392 case Symbol::FROM_OBJECT:
2395 unsigned int shndx = sym->shndx(&is_ordinary);
2398 && shndx != elfcpp::SHN_ABS
2399 && !Symbol::is_common_shndx(shndx))
2401 gold_error(_("%s: unsupported symbol section 0x%x"),
2402 sym->demangled_name().c_str(), shndx);
2403 shndx = elfcpp::SHN_UNDEF;
2406 Object* symobj = sym->object();
2407 if (symobj->is_dynamic())
2410 shndx = elfcpp::SHN_UNDEF;
2412 else if (symobj->pluginobj() != NULL)
2415 shndx = elfcpp::SHN_UNDEF;
2417 else if (shndx == elfcpp::SHN_UNDEF)
2419 else if (!is_ordinary
2420 && (shndx == elfcpp::SHN_ABS
2421 || Symbol::is_common_shndx(shndx)))
2422 value = sym->value();
2425 Relobj* relobj = static_cast<Relobj*>(symobj);
2426 Output_section* os = relobj->output_section(shndx);
2427 uint64_t secoff64 = relobj->output_section_offset(shndx);
2429 if (this->is_section_folded(relobj, shndx))
2431 gold_assert(os == NULL);
2432 // Get the os of the section it is folded onto.
2433 Section_id folded = this->icf_->get_folded_section(relobj,
2435 gold_assert(folded.first != NULL);
2436 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2437 os = folded_obj->output_section(folded.second);
2438 gold_assert(os != NULL);
2439 secoff64 = folded_obj->output_section_offset(folded.second);
2444 sym->set_symtab_index(-1U);
2445 bool static_or_reloc = (parameters->doing_static_link() ||
2446 parameters->options().relocatable());
2447 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2452 if (secoff64 == -1ULL)
2454 // The section needs special handling (e.g., a merge section).
2456 value = os->output_address(relobj, shndx, sym->value());
2461 convert_types<Value_type, uint64_t>(secoff64);
2462 if (sym->type() == elfcpp::STT_TLS)
2463 value = sym->value() + os->tls_offset() + secoff;
2465 value = sym->value() + os->address() + secoff;
2471 case Symbol::IN_OUTPUT_DATA:
2473 Output_data* od = sym->output_data();
2474 value = sym->value();
2475 if (sym->type() != elfcpp::STT_TLS)
2476 value += od->address();
2479 Output_section* os = od->output_section();
2480 gold_assert(os != NULL);
2481 value += os->tls_offset() + (od->address() - os->address());
2483 if (sym->offset_is_from_end())
2484 value += od->data_size();
2488 case Symbol::IN_OUTPUT_SEGMENT:
2490 Output_segment* os = sym->output_segment();
2491 value = sym->value();
2492 if (sym->type() != elfcpp::STT_TLS)
2493 value += os->vaddr();
2494 switch (sym->offset_base())
2496 case Symbol::SEGMENT_START:
2498 case Symbol::SEGMENT_END:
2499 value += os->memsz();
2501 case Symbol::SEGMENT_BSS:
2502 value += os->filesz();
2510 case Symbol::IS_CONSTANT:
2511 value = sym->value();
2514 case Symbol::IS_UNDEFINED:
2522 sym->set_value(value);
2524 if (parameters->options().strip_all())
2526 sym->set_symtab_index(-1U);
2533 // Write out the global symbols.
2536 Symbol_table::write_globals(const Stringpool* sympool,
2537 const Stringpool* dynpool,
2538 Output_symtab_xindex* symtab_xindex,
2539 Output_symtab_xindex* dynsym_xindex,
2540 Output_file* of) const
2542 switch (parameters->size_and_endianness())
2544 #ifdef HAVE_TARGET_32_LITTLE
2545 case Parameters::TARGET_32_LITTLE:
2546 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2550 #ifdef HAVE_TARGET_32_BIG
2551 case Parameters::TARGET_32_BIG:
2552 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2556 #ifdef HAVE_TARGET_64_LITTLE
2557 case Parameters::TARGET_64_LITTLE:
2558 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2562 #ifdef HAVE_TARGET_64_BIG
2563 case Parameters::TARGET_64_BIG:
2564 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2573 // Write out the global symbols.
2575 template<int size, bool big_endian>
2577 Symbol_table::sized_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 const Target& target = parameters->target();
2585 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2587 const unsigned int output_count = this->output_count_;
2588 const section_size_type oview_size = output_count * sym_size;
2589 const unsigned int first_global_index = this->first_global_index_;
2590 unsigned char* psyms;
2591 if (this->offset_ == 0 || output_count == 0)
2594 psyms = of->get_output_view(this->offset_, oview_size);
2596 const unsigned int dynamic_count = this->dynamic_count_;
2597 const section_size_type dynamic_size = dynamic_count * sym_size;
2598 const unsigned int first_dynamic_global_index =
2599 this->first_dynamic_global_index_;
2600 unsigned char* dynamic_view;
2601 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2602 dynamic_view = NULL;
2604 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2606 for (Symbol_table_type::const_iterator p = this->table_.begin();
2607 p != this->table_.end();
2610 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2612 // Possibly warn about unresolved symbols in shared libraries.
2613 this->warn_about_undefined_dynobj_symbol(sym);
2615 unsigned int sym_index = sym->symtab_index();
2616 unsigned int dynsym_index;
2617 if (dynamic_view == NULL)
2620 dynsym_index = sym->dynsym_index();
2622 if (sym_index == -1U && dynsym_index == -1U)
2624 // This symbol is not included in the output file.
2629 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2630 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2631 switch (sym->source())
2633 case Symbol::FROM_OBJECT:
2636 unsigned int in_shndx = sym->shndx(&is_ordinary);
2639 && in_shndx != elfcpp::SHN_ABS
2640 && !Symbol::is_common_shndx(in_shndx))
2642 gold_error(_("%s: unsupported symbol section 0x%x"),
2643 sym->demangled_name().c_str(), in_shndx);
2648 Object* symobj = sym->object();
2649 if (symobj->is_dynamic())
2651 if (sym->needs_dynsym_value())
2652 dynsym_value = target.dynsym_value(sym);
2653 shndx = elfcpp::SHN_UNDEF;
2655 else if (symobj->pluginobj() != NULL)
2656 shndx = elfcpp::SHN_UNDEF;
2657 else if (in_shndx == elfcpp::SHN_UNDEF
2659 && (in_shndx == elfcpp::SHN_ABS
2660 || Symbol::is_common_shndx(in_shndx))))
2664 Relobj* relobj = static_cast<Relobj*>(symobj);
2665 Output_section* os = relobj->output_section(in_shndx);
2666 if (this->is_section_folded(relobj, in_shndx))
2668 // This global symbol must be written out even though
2670 // Get the os of the section it is folded onto.
2672 this->icf_->get_folded_section(relobj, in_shndx);
2673 gold_assert(folded.first !=NULL);
2674 Relobj* folded_obj =
2675 reinterpret_cast<Relobj*>(folded.first);
2676 os = folded_obj->output_section(folded.second);
2677 gold_assert(os != NULL);
2679 gold_assert(os != NULL);
2680 shndx = os->out_shndx();
2682 if (shndx >= elfcpp::SHN_LORESERVE)
2684 if (sym_index != -1U)
2685 symtab_xindex->add(sym_index, shndx);
2686 if (dynsym_index != -1U)
2687 dynsym_xindex->add(dynsym_index, shndx);
2688 shndx = elfcpp::SHN_XINDEX;
2691 // In object files symbol values are section
2693 if (parameters->options().relocatable())
2694 sym_value -= os->address();
2700 case Symbol::IN_OUTPUT_DATA:
2701 shndx = sym->output_data()->out_shndx();
2702 if (shndx >= elfcpp::SHN_LORESERVE)
2704 if (sym_index != -1U)
2705 symtab_xindex->add(sym_index, shndx);
2706 if (dynsym_index != -1U)
2707 dynsym_xindex->add(dynsym_index, shndx);
2708 shndx = elfcpp::SHN_XINDEX;
2712 case Symbol::IN_OUTPUT_SEGMENT:
2713 shndx = elfcpp::SHN_ABS;
2716 case Symbol::IS_CONSTANT:
2717 shndx = elfcpp::SHN_ABS;
2720 case Symbol::IS_UNDEFINED:
2721 shndx = elfcpp::SHN_UNDEF;
2728 if (sym_index != -1U)
2730 sym_index -= first_global_index;
2731 gold_assert(sym_index < output_count);
2732 unsigned char* ps = psyms + (sym_index * sym_size);
2733 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2737 if (dynsym_index != -1U)
2739 dynsym_index -= first_dynamic_global_index;
2740 gold_assert(dynsym_index < dynamic_count);
2741 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2742 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2747 of->write_output_view(this->offset_, oview_size, psyms);
2748 if (dynamic_view != NULL)
2749 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2752 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2753 // strtab holding the name.
2755 template<int size, bool big_endian>
2757 Symbol_table::sized_write_symbol(
2758 Sized_symbol<size>* sym,
2759 typename elfcpp::Elf_types<size>::Elf_Addr value,
2761 const Stringpool* pool,
2762 unsigned char* p) const
2764 elfcpp::Sym_write<size, big_endian> osym(p);
2765 osym.put_st_name(pool->get_offset(sym->name()));
2766 osym.put_st_value(value);
2767 // Use a symbol size of zero for undefined symbols from shared libraries.
2768 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2769 osym.put_st_size(0);
2771 osym.put_st_size(sym->symsize());
2772 // A version script may have overridden the default binding.
2773 if (sym->is_forced_local())
2774 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2776 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2777 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2778 osym.put_st_shndx(shndx);
2781 // Check for unresolved symbols in shared libraries. This is
2782 // controlled by the --allow-shlib-undefined option.
2784 // We only warn about libraries for which we have seen all the
2785 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2786 // which were not seen in this link. If we didn't see a DT_NEEDED
2787 // entry, we aren't going to be able to reliably report whether the
2788 // symbol is undefined.
2790 // We also don't warn about libraries found in a system library
2791 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2792 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2793 // can have undefined references satisfied by ld-linux.so.
2796 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2799 if (sym->source() == Symbol::FROM_OBJECT
2800 && sym->object()->is_dynamic()
2801 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2802 && sym->binding() != elfcpp::STB_WEAK
2803 && !parameters->options().allow_shlib_undefined()
2804 && !parameters->target().is_defined_by_abi(sym)
2805 && !sym->object()->is_in_system_directory())
2807 // A very ugly cast.
2808 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2809 if (!dynobj->has_unknown_needed_entries())
2810 gold_undefined_symbol(sym);
2814 // Write out a section symbol. Return the update offset.
2817 Symbol_table::write_section_symbol(const Output_section *os,
2818 Output_symtab_xindex* symtab_xindex,
2822 switch (parameters->size_and_endianness())
2824 #ifdef HAVE_TARGET_32_LITTLE
2825 case Parameters::TARGET_32_LITTLE:
2826 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2830 #ifdef HAVE_TARGET_32_BIG
2831 case Parameters::TARGET_32_BIG:
2832 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2836 #ifdef HAVE_TARGET_64_LITTLE
2837 case Parameters::TARGET_64_LITTLE:
2838 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2842 #ifdef HAVE_TARGET_64_BIG
2843 case Parameters::TARGET_64_BIG:
2844 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2853 // Write out a section symbol, specialized for size and endianness.
2855 template<int size, bool big_endian>
2857 Symbol_table::sized_write_section_symbol(const Output_section* os,
2858 Output_symtab_xindex* symtab_xindex,
2862 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2864 unsigned char* pov = of->get_output_view(offset, sym_size);
2866 elfcpp::Sym_write<size, big_endian> osym(pov);
2867 osym.put_st_name(0);
2868 if (parameters->options().relocatable())
2869 osym.put_st_value(0);
2871 osym.put_st_value(os->address());
2872 osym.put_st_size(0);
2873 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2874 elfcpp::STT_SECTION));
2875 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2877 unsigned int shndx = os->out_shndx();
2878 if (shndx >= elfcpp::SHN_LORESERVE)
2880 symtab_xindex->add(os->symtab_index(), shndx);
2881 shndx = elfcpp::SHN_XINDEX;
2883 osym.put_st_shndx(shndx);
2885 of->write_output_view(offset, sym_size, pov);
2888 // Print statistical information to stderr. This is used for --stats.
2891 Symbol_table::print_stats() const
2893 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2894 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2895 program_name, this->table_.size(), this->table_.bucket_count());
2897 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2898 program_name, this->table_.size());
2900 this->namepool_.print_stats("symbol table stringpool");
2903 // We check for ODR violations by looking for symbols with the same
2904 // name for which the debugging information reports that they were
2905 // defined in different source locations. When comparing the source
2906 // location, we consider instances with the same base filename and
2907 // line number to be the same. This is because different object
2908 // files/shared libraries can include the same header file using
2909 // different paths, and we don't want to report an ODR violation in
2912 // This struct is used to compare line information, as returned by
2913 // Dwarf_line_info::one_addr2line. It implements a < comparison
2914 // operator used with std::set.
2916 struct Odr_violation_compare
2919 operator()(const std::string& s1, const std::string& s2) const
2921 std::string::size_type pos1 = s1.rfind('/');
2922 std::string::size_type pos2 = s2.rfind('/');
2923 if (pos1 == std::string::npos
2924 || pos2 == std::string::npos)
2926 return s1.compare(pos1, std::string::npos,
2927 s2, pos2, std::string::npos) < 0;
2931 // Check candidate_odr_violations_ to find symbols with the same name
2932 // but apparently different definitions (different source-file/line-no).
2935 Symbol_table::detect_odr_violations(const Task* task,
2936 const char* output_file_name) const
2938 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2939 it != candidate_odr_violations_.end();
2942 const char* symbol_name = it->first;
2943 // We use a sorted set so the output is deterministic.
2944 std::set<std::string, Odr_violation_compare> line_nums;
2946 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2947 locs = it->second.begin();
2948 locs != it->second.end();
2951 // We need to lock the object in order to read it. This
2952 // means that we have to run in a singleton Task. If we
2953 // want to run this in a general Task for better
2954 // performance, we will need one Task for object, plus
2955 // appropriate locking to ensure that we don't conflict with
2956 // other uses of the object. Also note, one_addr2line is not
2957 // currently thread-safe.
2958 Task_lock_obj<Object> tl(task, locs->object);
2959 // 16 is the size of the object-cache that one_addr2line should use.
2960 std::string lineno = Dwarf_line_info::one_addr2line(
2961 locs->object, locs->shndx, locs->offset, 16);
2962 if (!lineno.empty())
2963 line_nums.insert(lineno);
2966 if (line_nums.size() > 1)
2968 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2969 "places (possible ODR violation):"),
2970 output_file_name, demangle(symbol_name).c_str());
2971 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
2972 it2 != line_nums.end();
2974 fprintf(stderr, " %s\n", it2->c_str());
2977 // We only call one_addr2line() in this function, so we can clear its cache.
2978 Dwarf_line_info::clear_addr2line_cache();
2981 // Warnings functions.
2983 // Add a new warning.
2986 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
2987 const std::string& warning)
2989 name = symtab->canonicalize_name(name);
2990 this->warnings_[name].set(obj, warning);
2993 // Look through the warnings and mark the symbols for which we should
2994 // warn. This is called during Layout::finalize when we know the
2995 // sources for all the symbols.
2998 Warnings::note_warnings(Symbol_table* symtab)
3000 for (Warning_table::iterator p = this->warnings_.begin();
3001 p != this->warnings_.end();
3004 Symbol* sym = symtab->lookup(p->first, NULL);
3006 && sym->source() == Symbol::FROM_OBJECT
3007 && sym->object() == p->second.object)
3008 sym->set_has_warning();
3012 // Issue a warning. This is called when we see a relocation against a
3013 // symbol for which has a warning.
3015 template<int size, bool big_endian>
3017 Warnings::issue_warning(const Symbol* sym,
3018 const Relocate_info<size, big_endian>* relinfo,
3019 size_t relnum, off_t reloffset) const
3021 gold_assert(sym->has_warning());
3022 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3023 gold_assert(p != this->warnings_.end());
3024 gold_warning_at_location(relinfo, relnum, reloffset,
3025 "%s", p->second.text.c_str());
3028 // Instantiate the templates we need. We could use the configure
3029 // script to restrict this to only the ones needed for implemented
3032 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3035 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3038 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3041 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3044 #ifdef HAVE_TARGET_32_LITTLE
3047 Symbol_table::add_from_relobj<32, false>(
3048 Sized_relobj<32, false>* relobj,
3049 const unsigned char* syms,
3051 size_t symndx_offset,
3052 const char* sym_names,
3053 size_t sym_name_size,
3054 Sized_relobj<32, false>::Symbols* sympointers,
3058 #ifdef HAVE_TARGET_32_BIG
3061 Symbol_table::add_from_relobj<32, true>(
3062 Sized_relobj<32, true>* relobj,
3063 const unsigned char* syms,
3065 size_t symndx_offset,
3066 const char* sym_names,
3067 size_t sym_name_size,
3068 Sized_relobj<32, true>::Symbols* sympointers,
3072 #ifdef HAVE_TARGET_64_LITTLE
3075 Symbol_table::add_from_relobj<64, false>(
3076 Sized_relobj<64, false>* relobj,
3077 const unsigned char* syms,
3079 size_t symndx_offset,
3080 const char* sym_names,
3081 size_t sym_name_size,
3082 Sized_relobj<64, false>::Symbols* sympointers,
3086 #ifdef HAVE_TARGET_64_BIG
3089 Symbol_table::add_from_relobj<64, true>(
3090 Sized_relobj<64, true>* relobj,
3091 const unsigned char* syms,
3093 size_t symndx_offset,
3094 const char* sym_names,
3095 size_t sym_name_size,
3096 Sized_relobj<64, true>::Symbols* sympointers,
3100 #ifdef HAVE_TARGET_32_LITTLE
3103 Symbol_table::add_from_pluginobj<32, false>(
3104 Sized_pluginobj<32, false>* obj,
3107 elfcpp::Sym<32, false>* sym);
3110 #ifdef HAVE_TARGET_32_BIG
3113 Symbol_table::add_from_pluginobj<32, true>(
3114 Sized_pluginobj<32, true>* obj,
3117 elfcpp::Sym<32, true>* sym);
3120 #ifdef HAVE_TARGET_64_LITTLE
3123 Symbol_table::add_from_pluginobj<64, false>(
3124 Sized_pluginobj<64, false>* obj,
3127 elfcpp::Sym<64, false>* sym);
3130 #ifdef HAVE_TARGET_64_BIG
3133 Symbol_table::add_from_pluginobj<64, true>(
3134 Sized_pluginobj<64, true>* obj,
3137 elfcpp::Sym<64, true>* sym);
3140 #ifdef HAVE_TARGET_32_LITTLE
3143 Symbol_table::add_from_dynobj<32, false>(
3144 Sized_dynobj<32, false>* dynobj,
3145 const unsigned char* syms,
3147 const char* sym_names,
3148 size_t sym_name_size,
3149 const unsigned char* versym,
3151 const std::vector<const char*>* version_map,
3152 Sized_relobj<32, false>::Symbols* sympointers,
3156 #ifdef HAVE_TARGET_32_BIG
3159 Symbol_table::add_from_dynobj<32, true>(
3160 Sized_dynobj<32, true>* dynobj,
3161 const unsigned char* syms,
3163 const char* sym_names,
3164 size_t sym_name_size,
3165 const unsigned char* versym,
3167 const std::vector<const char*>* version_map,
3168 Sized_relobj<32, true>::Symbols* sympointers,
3172 #ifdef HAVE_TARGET_64_LITTLE
3175 Symbol_table::add_from_dynobj<64, false>(
3176 Sized_dynobj<64, 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<64, false>::Symbols* sympointers,
3188 #ifdef HAVE_TARGET_64_BIG
3191 Symbol_table::add_from_dynobj<64, true>(
3192 Sized_dynobj<64, 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<64, true>::Symbols* sympointers,
3204 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3207 Symbol_table::define_with_copy_reloc<32>(
3208 Sized_symbol<32>* sym,
3210 elfcpp::Elf_types<32>::Elf_Addr value);
3213 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3216 Symbol_table::define_with_copy_reloc<64>(
3217 Sized_symbol<64>* sym,
3219 elfcpp::Elf_types<64>::Elf_Addr value);
3222 #ifdef HAVE_TARGET_32_LITTLE
3225 Warnings::issue_warning<32, false>(const Symbol* sym,
3226 const Relocate_info<32, false>* relinfo,
3227 size_t relnum, off_t reloffset) const;
3230 #ifdef HAVE_TARGET_32_BIG
3233 Warnings::issue_warning<32, true>(const Symbol* sym,
3234 const Relocate_info<32, true>* relinfo,
3235 size_t relnum, off_t reloffset) const;
3238 #ifdef HAVE_TARGET_64_LITTLE
3241 Warnings::issue_warning<64, false>(const Symbol* sym,
3242 const Relocate_info<64, false>* relinfo,
3243 size_t relnum, off_t reloffset) const;
3246 #ifdef HAVE_TARGET_64_BIG
3249 Warnings::issue_warning<64, true>(const Symbol* sym,
3250 const Relocate_info<64, true>* relinfo,
3251 size_t relnum, off_t reloffset) const;
3254 } // End namespace gold.