1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007, 2008, 2009, 2010 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"
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_ = -1U;
64 this->binding_ = binding;
65 this->visibility_ = visibility;
66 this->nonvis_ = nonvis;
67 this->is_def_ = false;
68 this->is_forwarder_ = false;
69 this->has_alias_ = false;
70 this->needs_dynsym_entry_ = false;
71 this->in_reg_ = false;
72 this->in_dyn_ = false;
73 this->has_warning_ = false;
74 this->is_copied_from_dynobj_ = false;
75 this->is_forced_local_ = false;
76 this->is_ordinary_shndx_ = false;
77 this->in_real_elf_ = false;
78 this->is_defined_in_discarded_section_ = false;
79 this->undef_binding_set_ = false;
80 this->undef_binding_weak_ = false;
83 // Return the demangled version of the symbol's name, but only
84 // if the --demangle flag was set.
87 demangle(const char* name)
89 if (!parameters->options().do_demangle())
92 // cplus_demangle allocates memory for the result it returns,
93 // and returns NULL if the name is already demangled.
94 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
95 if (demangled_name == NULL)
98 std::string retval(demangled_name);
104 Symbol::demangled_name() const
106 return demangle(this->name());
109 // Initialize the fields in the base class Symbol for SYM in OBJECT.
111 template<int size, bool big_endian>
113 Symbol::init_base_object(const char* name, const char* version, Object* object,
114 const elfcpp::Sym<size, big_endian>& sym,
115 unsigned int st_shndx, bool is_ordinary)
117 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
118 sym.get_st_visibility(), sym.get_st_nonvis());
119 this->u_.from_object.object = object;
120 this->u_.from_object.shndx = st_shndx;
121 this->is_ordinary_shndx_ = is_ordinary;
122 this->source_ = FROM_OBJECT;
123 this->in_reg_ = !object->is_dynamic();
124 this->in_dyn_ = object->is_dynamic();
125 this->in_real_elf_ = object->pluginobj() == NULL;
128 // Initialize the fields in the base class Symbol for a symbol defined
129 // in an Output_data.
132 Symbol::init_base_output_data(const char* name, const char* version,
133 Output_data* od, elfcpp::STT type,
134 elfcpp::STB binding, elfcpp::STV visibility,
135 unsigned char nonvis, bool offset_is_from_end)
137 this->init_fields(name, version, type, binding, visibility, nonvis);
138 this->u_.in_output_data.output_data = od;
139 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
140 this->source_ = IN_OUTPUT_DATA;
141 this->in_reg_ = true;
142 this->in_real_elf_ = true;
145 // Initialize the fields in the base class Symbol for a symbol defined
146 // in an Output_segment.
149 Symbol::init_base_output_segment(const char* name, const char* version,
150 Output_segment* os, elfcpp::STT type,
151 elfcpp::STB binding, elfcpp::STV visibility,
152 unsigned char nonvis,
153 Segment_offset_base offset_base)
155 this->init_fields(name, version, type, binding, visibility, nonvis);
156 this->u_.in_output_segment.output_segment = os;
157 this->u_.in_output_segment.offset_base = offset_base;
158 this->source_ = IN_OUTPUT_SEGMENT;
159 this->in_reg_ = true;
160 this->in_real_elf_ = true;
163 // Initialize the fields in the base class Symbol for a symbol defined
167 Symbol::init_base_constant(const char* name, const char* version,
168 elfcpp::STT type, elfcpp::STB binding,
169 elfcpp::STV visibility, unsigned char nonvis)
171 this->init_fields(name, version, type, binding, visibility, nonvis);
172 this->source_ = IS_CONSTANT;
173 this->in_reg_ = true;
174 this->in_real_elf_ = true;
177 // Initialize the fields in the base class Symbol for an undefined
181 Symbol::init_base_undefined(const char* name, const char* version,
182 elfcpp::STT type, elfcpp::STB binding,
183 elfcpp::STV visibility, unsigned char nonvis)
185 this->init_fields(name, version, type, binding, visibility, nonvis);
186 this->dynsym_index_ = -1U;
187 this->source_ = IS_UNDEFINED;
188 this->in_reg_ = true;
189 this->in_real_elf_ = true;
192 // Allocate a common symbol in the base.
195 Symbol::allocate_base_common(Output_data* od)
197 gold_assert(this->is_common());
198 this->source_ = IN_OUTPUT_DATA;
199 this->u_.in_output_data.output_data = od;
200 this->u_.in_output_data.offset_is_from_end = false;
203 // Initialize the fields in Sized_symbol for SYM in OBJECT.
206 template<bool big_endian>
208 Sized_symbol<size>::init_object(const char* name, const char* version,
210 const elfcpp::Sym<size, big_endian>& sym,
211 unsigned int st_shndx, bool is_ordinary)
213 this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
214 this->value_ = sym.get_st_value();
215 this->symsize_ = sym.get_st_size();
218 // Initialize the fields in Sized_symbol for a symbol defined in an
223 Sized_symbol<size>::init_output_data(const char* name, const char* version,
224 Output_data* od, Value_type value,
225 Size_type symsize, elfcpp::STT type,
227 elfcpp::STV visibility,
228 unsigned char nonvis,
229 bool offset_is_from_end)
231 this->init_base_output_data(name, version, od, type, binding, visibility,
232 nonvis, offset_is_from_end);
233 this->value_ = value;
234 this->symsize_ = symsize;
237 // Initialize the fields in Sized_symbol for a symbol defined in an
242 Sized_symbol<size>::init_output_segment(const char* name, const char* version,
243 Output_segment* os, Value_type value,
244 Size_type symsize, elfcpp::STT type,
246 elfcpp::STV visibility,
247 unsigned char nonvis,
248 Segment_offset_base offset_base)
250 this->init_base_output_segment(name, version, os, type, binding, visibility,
251 nonvis, offset_base);
252 this->value_ = value;
253 this->symsize_ = symsize;
256 // Initialize the fields in Sized_symbol for a symbol defined as a
261 Sized_symbol<size>::init_constant(const char* name, const char* version,
262 Value_type value, Size_type symsize,
263 elfcpp::STT type, elfcpp::STB binding,
264 elfcpp::STV visibility, unsigned char nonvis)
266 this->init_base_constant(name, version, type, binding, visibility, nonvis);
267 this->value_ = value;
268 this->symsize_ = symsize;
271 // Initialize the fields in Sized_symbol for an undefined symbol.
275 Sized_symbol<size>::init_undefined(const char* name, const char* version,
276 elfcpp::STT type, elfcpp::STB binding,
277 elfcpp::STV visibility, unsigned char nonvis)
279 this->init_base_undefined(name, version, type, binding, visibility, nonvis);
284 // Return true if SHNDX represents a common symbol.
287 Symbol::is_common_shndx(unsigned int shndx)
289 return (shndx == elfcpp::SHN_COMMON
290 || shndx == parameters->target().small_common_shndx()
291 || shndx == parameters->target().large_common_shndx());
294 // Allocate a common symbol.
298 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
300 this->allocate_base_common(od);
301 this->value_ = value;
304 // The ""'s around str ensure str is a string literal, so sizeof works.
305 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
307 // Return true if this symbol should be added to the dynamic symbol
311 Symbol::should_add_dynsym_entry(Symbol_table* symtab) const
313 // If the symbol is used by a dynamic relocation, we need to add it.
314 if (this->needs_dynsym_entry())
317 // If this symbol's section is not added, the symbol need not be added.
318 // The section may have been GCed. Note that export_dynamic is being
319 // overridden here. This should not be done for shared objects.
320 if (parameters->options().gc_sections()
321 && !parameters->options().shared()
322 && this->source() == Symbol::FROM_OBJECT
323 && !this->object()->is_dynamic())
325 Relobj* relobj = static_cast<Relobj*>(this->object());
327 unsigned int shndx = this->shndx(&is_ordinary);
328 if (is_ordinary && shndx != elfcpp::SHN_UNDEF
329 && !relobj->is_section_included(shndx)
330 && !symtab->is_section_folded(relobj, shndx))
334 // If the symbol was forced local in a version script, do not add it.
335 if (this->is_forced_local())
338 // If the symbol was forced dynamic in a --dynamic-list file, add it.
339 if (parameters->options().in_dynamic_list(this->name()))
342 // If dynamic-list-data was specified, add any STT_OBJECT.
343 if (parameters->options().dynamic_list_data()
344 && !this->is_from_dynobj()
345 && this->type() == elfcpp::STT_OBJECT)
348 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
349 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
350 if ((parameters->options().dynamic_list_cpp_new()
351 || parameters->options().dynamic_list_cpp_typeinfo())
352 && !this->is_from_dynobj())
354 // TODO(csilvers): We could probably figure out if we're an operator
355 // new/delete or typeinfo without the need to demangle.
356 char* demangled_name = cplus_demangle(this->name(),
357 DMGL_ANSI | DMGL_PARAMS);
358 if (demangled_name == NULL)
360 // Not a C++ symbol, so it can't satisfy these flags
362 else if (parameters->options().dynamic_list_cpp_new()
363 && (strprefix(demangled_name, "operator new")
364 || strprefix(demangled_name, "operator delete")))
366 free(demangled_name);
369 else if (parameters->options().dynamic_list_cpp_typeinfo()
370 && (strprefix(demangled_name, "typeinfo name for")
371 || strprefix(demangled_name, "typeinfo for")))
373 free(demangled_name);
377 free(demangled_name);
380 // If exporting all symbols or building a shared library,
381 // and the symbol is defined in a regular object and is
382 // externally visible, we need to add it.
383 if ((parameters->options().export_dynamic() || parameters->options().shared())
384 && !this->is_from_dynobj()
385 && this->is_externally_visible())
391 // Return true if the final value of this symbol is known at link
395 Symbol::final_value_is_known() const
397 // If we are not generating an executable, then no final values are
398 // known, since they will change at runtime.
399 if (parameters->options().output_is_position_independent()
400 || parameters->options().relocatable())
403 // If the symbol is not from an object file, and is not undefined,
404 // then it is defined, and known.
405 if (this->source_ != FROM_OBJECT)
407 if (this->source_ != IS_UNDEFINED)
412 // If the symbol is from a dynamic object, then the final value
414 if (this->object()->is_dynamic())
417 // If the symbol is not undefined (it is defined or common),
418 // then the final value is known.
419 if (!this->is_undefined())
423 // If the symbol is undefined, then whether the final value is known
424 // depends on whether we are doing a static link. If we are doing a
425 // dynamic link, then the final value could be filled in at runtime.
426 // This could reasonably be the case for a weak undefined symbol.
427 return parameters->doing_static_link();
430 // Return the output section where this symbol is defined.
433 Symbol::output_section() const
435 switch (this->source_)
439 unsigned int shndx = this->u_.from_object.shndx;
440 if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
442 gold_assert(!this->u_.from_object.object->is_dynamic());
443 gold_assert(this->u_.from_object.object->pluginobj() == NULL);
444 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
445 return relobj->output_section(shndx);
451 return this->u_.in_output_data.output_data->output_section();
453 case IN_OUTPUT_SEGMENT:
463 // Set the symbol's output section. This is used for symbols defined
464 // in scripts. This should only be called after the symbol table has
468 Symbol::set_output_section(Output_section* os)
470 switch (this->source_)
474 gold_assert(this->output_section() == os);
477 this->source_ = IN_OUTPUT_DATA;
478 this->u_.in_output_data.output_data = os;
479 this->u_.in_output_data.offset_is_from_end = false;
481 case IN_OUTPUT_SEGMENT:
488 // Class Symbol_table.
490 Symbol_table::Symbol_table(unsigned int count,
491 const Version_script_info& version_script)
492 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
493 forwarders_(), commons_(), tls_commons_(), small_commons_(),
494 large_commons_(), forced_locals_(), warnings_(),
495 version_script_(version_script), gc_(NULL), icf_(NULL)
497 namepool_.reserve(count);
500 Symbol_table::~Symbol_table()
504 // The hash function. The key values are Stringpool keys.
507 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
509 return key.first ^ key.second;
512 // The symbol table key equality function. This is called with
516 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
517 const Symbol_table_key& k2) const
519 return k1.first == k2.first && k1.second == k2.second;
523 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
525 return (parameters->options().icf_enabled()
526 && this->icf_->is_section_folded(obj, shndx));
529 // For symbols that have been listed with -u option, add them to the
530 // work list to avoid gc'ing them.
533 Symbol_table::gc_mark_undef_symbols(Layout* layout)
535 for (options::String_set::const_iterator p =
536 parameters->options().undefined_begin();
537 p != parameters->options().undefined_end();
540 const char* name = p->c_str();
541 Symbol* sym = this->lookup(name);
542 gold_assert(sym != NULL);
543 if (sym->source() == Symbol::FROM_OBJECT
544 && !sym->object()->is_dynamic())
546 Relobj* obj = static_cast<Relobj*>(sym->object());
548 unsigned int shndx = sym->shndx(&is_ordinary);
551 gold_assert(this->gc_ != NULL);
552 this->gc_->worklist().push(Section_id(obj, shndx));
557 for (Script_options::referenced_const_iterator p =
558 layout->script_options()->referenced_begin();
559 p != layout->script_options()->referenced_end();
562 Symbol* sym = this->lookup(p->c_str());
563 gold_assert(sym != NULL);
564 if (sym->source() == Symbol::FROM_OBJECT
565 && !sym->object()->is_dynamic())
567 Relobj* obj = static_cast<Relobj*>(sym->object());
569 unsigned int shndx = sym->shndx(&is_ordinary);
572 gold_assert(this->gc_ != NULL);
573 this->gc_->worklist().push(Section_id(obj, shndx));
580 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
582 if (!sym->is_from_dynobj()
583 && sym->is_externally_visible())
585 //Add the object and section to the work list.
586 Relobj* obj = static_cast<Relobj*>(sym->object());
588 unsigned int shndx = sym->shndx(&is_ordinary);
589 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
591 gold_assert(this->gc_!= NULL);
592 this->gc_->worklist().push(Section_id(obj, shndx));
597 // When doing garbage collection, keep symbols that have been seen in
600 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
602 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
603 && !sym->object()->is_dynamic())
605 Relobj* obj = static_cast<Relobj*>(sym->object());
607 unsigned int shndx = sym->shndx(&is_ordinary);
608 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
610 gold_assert(this->gc_ != NULL);
611 this->gc_->worklist().push(Section_id(obj, shndx));
616 // Make TO a symbol which forwards to FROM.
619 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
621 gold_assert(from != to);
622 gold_assert(!from->is_forwarder() && !to->is_forwarder());
623 this->forwarders_[from] = to;
624 from->set_forwarder();
627 // Resolve the forwards from FROM, returning the real symbol.
630 Symbol_table::resolve_forwards(const Symbol* from) const
632 gold_assert(from->is_forwarder());
633 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
634 this->forwarders_.find(from);
635 gold_assert(p != this->forwarders_.end());
639 // Look up a symbol by name.
642 Symbol_table::lookup(const char* name, const char* version) const
644 Stringpool::Key name_key;
645 name = this->namepool_.find(name, &name_key);
649 Stringpool::Key version_key = 0;
652 version = this->namepool_.find(version, &version_key);
657 Symbol_table_key key(name_key, version_key);
658 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
659 if (p == this->table_.end())
664 // Resolve a Symbol with another Symbol. This is only used in the
665 // unusual case where there are references to both an unversioned
666 // symbol and a symbol with a version, and we then discover that that
667 // version is the default version. Because this is unusual, we do
668 // this the slow way, by converting back to an ELF symbol.
670 template<int size, bool big_endian>
672 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
674 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
675 elfcpp::Sym_write<size, big_endian> esym(buf);
676 // We don't bother to set the st_name or the st_shndx field.
677 esym.put_st_value(from->value());
678 esym.put_st_size(from->symsize());
679 esym.put_st_info(from->binding(), from->type());
680 esym.put_st_other(from->visibility(), from->nonvis());
682 unsigned int shndx = from->shndx(&is_ordinary);
683 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
689 if (parameters->options().gc_sections())
690 this->gc_mark_dyn_syms(to);
693 // Record that a symbol is forced to be local by a version script or
697 Symbol_table::force_local(Symbol* sym)
699 if (!sym->is_defined() && !sym->is_common())
701 if (sym->is_forced_local())
703 // We already got this one.
706 sym->set_is_forced_local();
707 this->forced_locals_.push_back(sym);
710 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
711 // is only called for undefined symbols, when at least one --wrap
715 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
717 // For some targets, we need to ignore a specific character when
718 // wrapping, and add it back later.
720 if (name[0] == parameters->target().wrap_char())
726 if (parameters->options().is_wrap(name))
728 // Turn NAME into __wrap_NAME.
735 // This will give us both the old and new name in NAMEPOOL_, but
736 // that is OK. Only the versions we need will wind up in the
737 // real string table in the output file.
738 return this->namepool_.add(s.c_str(), true, name_key);
741 const char* const real_prefix = "__real_";
742 const size_t real_prefix_length = strlen(real_prefix);
743 if (strncmp(name, real_prefix, real_prefix_length) == 0
744 && parameters->options().is_wrap(name + real_prefix_length))
746 // Turn __real_NAME into NAME.
750 s += name + real_prefix_length;
751 return this->namepool_.add(s.c_str(), true, name_key);
757 // This is called when we see a symbol NAME/VERSION, and the symbol
758 // already exists in the symbol table, and VERSION is marked as being
759 // the default version. SYM is the NAME/VERSION symbol we just added.
760 // DEFAULT_IS_NEW is true if this is the first time we have seen the
761 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
763 template<int size, bool big_endian>
765 Symbol_table::define_default_version(Sized_symbol<size>* sym,
767 Symbol_table_type::iterator pdef)
771 // This is the first time we have seen NAME/NULL. Make
772 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
775 sym->set_is_default();
777 else if (pdef->second == sym)
779 // NAME/NULL already points to NAME/VERSION. Don't mark the
780 // symbol as the default if it is not already the default.
784 // This is the unfortunate case where we already have entries
785 // for both NAME/VERSION and NAME/NULL. We now see a symbol
786 // NAME/VERSION where VERSION is the default version. We have
787 // already resolved this new symbol with the existing
788 // NAME/VERSION symbol.
790 // It's possible that NAME/NULL and NAME/VERSION are both
791 // defined in regular objects. This can only happen if one
792 // object file defines foo and another defines foo@@ver. This
793 // is somewhat obscure, but we call it a multiple definition
796 // It's possible that NAME/NULL actually has a version, in which
797 // case it won't be the same as VERSION. This happens with
798 // ver_test_7.so in the testsuite for the symbol t2_2. We see
799 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
800 // then see an unadorned t2_2 in an object file and give it
801 // version VER1 from the version script. This looks like a
802 // default definition for VER1, so it looks like we should merge
803 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
804 // not obvious that this is an error, either. So we just punt.
806 // If one of the symbols has non-default visibility, and the
807 // other is defined in a shared object, then they are different
810 // Otherwise, we just resolve the symbols as though they were
813 if (pdef->second->version() != NULL)
814 gold_assert(pdef->second->version() != sym->version());
815 else if (sym->visibility() != elfcpp::STV_DEFAULT
816 && pdef->second->is_from_dynobj())
818 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
819 && sym->is_from_dynobj())
823 const Sized_symbol<size>* symdef;
824 symdef = this->get_sized_symbol<size>(pdef->second);
825 Symbol_table::resolve<size, big_endian>(sym, symdef);
826 this->make_forwarder(pdef->second, sym);
828 sym->set_is_default();
833 // Add one symbol from OBJECT to the symbol table. NAME is symbol
834 // name and VERSION is the version; both are canonicalized. DEF is
835 // whether this is the default version. ST_SHNDX is the symbol's
836 // section index; IS_ORDINARY is whether this is a normal section
837 // rather than a special code.
839 // If IS_DEFAULT_VERSION is true, then this is the definition of a
840 // default version of a symbol. That means that any lookup of
841 // NAME/NULL and any lookup of NAME/VERSION should always return the
842 // same symbol. This is obvious for references, but in particular we
843 // want to do this for definitions: overriding NAME/NULL should also
844 // override NAME/VERSION. If we don't do that, it would be very hard
845 // to override functions in a shared library which uses versioning.
847 // We implement this by simply making both entries in the hash table
848 // point to the same Symbol structure. That is easy enough if this is
849 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
850 // that we have seen both already, in which case they will both have
851 // independent entries in the symbol table. We can't simply change
852 // the symbol table entry, because we have pointers to the entries
853 // attached to the object files. So we mark the entry attached to the
854 // object file as a forwarder, and record it in the forwarders_ map.
855 // Note that entries in the hash table will never be marked as
858 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
859 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
860 // for a special section code. ST_SHNDX may be modified if the symbol
861 // is defined in a section being discarded.
863 template<int size, bool big_endian>
865 Symbol_table::add_from_object(Object* object,
867 Stringpool::Key name_key,
869 Stringpool::Key version_key,
870 bool is_default_version,
871 const elfcpp::Sym<size, big_endian>& sym,
872 unsigned int st_shndx,
874 unsigned int orig_st_shndx)
876 // Print a message if this symbol is being traced.
877 if (parameters->options().is_trace_symbol(name))
879 if (orig_st_shndx == elfcpp::SHN_UNDEF)
880 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
882 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
885 // For an undefined symbol, we may need to adjust the name using
887 if (orig_st_shndx == elfcpp::SHN_UNDEF
888 && parameters->options().any_wrap())
890 const char* wrap_name = this->wrap_symbol(name, &name_key);
891 if (wrap_name != name)
893 // If we see a reference to malloc with version GLIBC_2.0,
894 // and we turn it into a reference to __wrap_malloc, then we
895 // discard the version number. Otherwise the user would be
896 // required to specify the correct version for
904 Symbol* const snull = NULL;
905 std::pair<typename Symbol_table_type::iterator, bool> ins =
906 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
909 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
910 std::make_pair(this->table_.end(), false);
911 if (is_default_version)
913 const Stringpool::Key vnull_key = 0;
914 insdefault = this->table_.insert(std::make_pair(std::make_pair(name_key,
919 // ins.first: an iterator, which is a pointer to a pair.
920 // ins.first->first: the key (a pair of name and version).
921 // ins.first->second: the value (Symbol*).
922 // ins.second: true if new entry was inserted, false if not.
924 Sized_symbol<size>* ret;
929 // We already have an entry for NAME/VERSION.
930 ret = this->get_sized_symbol<size>(ins.first->second);
931 gold_assert(ret != NULL);
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);
941 if (is_default_version)
942 this->define_default_version<size, big_endian>(ret, insdefault.second,
947 // This is the first time we have seen NAME/VERSION.
948 gold_assert(ins.first->second == NULL);
950 if (is_default_version && !insdefault.second)
952 // We already have an entry for NAME/NULL. If we override
953 // it, then change it to NAME/VERSION.
954 ret = this->get_sized_symbol<size>(insdefault.first->second);
956 was_undefined = ret->is_undefined();
957 was_common = ret->is_common();
959 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
961 if (parameters->options().gc_sections())
962 this->gc_mark_dyn_syms(ret);
963 ins.first->second = ret;
967 was_undefined = false;
970 Sized_target<size, big_endian>* target =
971 parameters->sized_target<size, big_endian>();
972 if (!target->has_make_symbol())
973 ret = new Sized_symbol<size>();
976 ret = target->make_symbol();
979 // This means that we don't want a symbol table
981 if (!is_default_version)
982 this->table_.erase(ins.first);
985 this->table_.erase(insdefault.first);
986 // Inserting INSDEFAULT invalidated INS.
987 this->table_.erase(std::make_pair(name_key,
994 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
996 ins.first->second = ret;
997 if (is_default_version)
999 // This is the first time we have seen NAME/NULL. Point
1000 // it at the new entry for NAME/VERSION.
1001 gold_assert(insdefault.second);
1002 insdefault.first->second = ret;
1006 if (is_default_version)
1007 ret->set_is_default();
1010 // Record every time we see a new undefined symbol, to speed up
1012 if (!was_undefined && ret->is_undefined())
1013 ++this->saw_undefined_;
1015 // Keep track of common symbols, to speed up common symbol
1017 if (!was_common && ret->is_common())
1019 if (ret->type() == elfcpp::STT_TLS)
1020 this->tls_commons_.push_back(ret);
1021 else if (!is_ordinary
1022 && st_shndx == parameters->target().small_common_shndx())
1023 this->small_commons_.push_back(ret);
1024 else if (!is_ordinary
1025 && st_shndx == parameters->target().large_common_shndx())
1026 this->large_commons_.push_back(ret);
1028 this->commons_.push_back(ret);
1031 // If we're not doing a relocatable link, then any symbol with
1032 // hidden or internal visibility is local.
1033 if ((ret->visibility() == elfcpp::STV_HIDDEN
1034 || ret->visibility() == elfcpp::STV_INTERNAL)
1035 && (ret->binding() == elfcpp::STB_GLOBAL
1036 || ret->binding() == elfcpp::STB_GNU_UNIQUE
1037 || ret->binding() == elfcpp::STB_WEAK)
1038 && !parameters->options().relocatable())
1039 this->force_local(ret);
1044 // Add all the symbols in a relocatable object to the hash table.
1046 template<int size, bool big_endian>
1048 Symbol_table::add_from_relobj(
1049 Sized_relobj<size, big_endian>* relobj,
1050 const unsigned char* syms,
1052 size_t symndx_offset,
1053 const char* sym_names,
1054 size_t sym_name_size,
1055 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1060 gold_assert(size == parameters->target().get_size());
1062 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1064 const bool just_symbols = relobj->just_symbols();
1066 const unsigned char* p = syms;
1067 for (size_t i = 0; i < count; ++i, p += sym_size)
1069 (*sympointers)[i] = NULL;
1071 elfcpp::Sym<size, big_endian> sym(p);
1073 unsigned int st_name = sym.get_st_name();
1074 if (st_name >= sym_name_size)
1076 relobj->error(_("bad global symbol name offset %u at %zu"),
1081 const char* name = sym_names + st_name;
1084 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1087 unsigned int orig_st_shndx = st_shndx;
1089 orig_st_shndx = elfcpp::SHN_UNDEF;
1091 if (st_shndx != elfcpp::SHN_UNDEF)
1094 // A symbol defined in a section which we are not including must
1095 // be treated as an undefined symbol.
1096 bool is_defined_in_discarded_section = false;
1097 if (st_shndx != elfcpp::SHN_UNDEF
1099 && !relobj->is_section_included(st_shndx)
1100 && !this->is_section_folded(relobj, st_shndx))
1102 st_shndx = elfcpp::SHN_UNDEF;
1103 is_defined_in_discarded_section = true;
1106 // In an object file, an '@' in the name separates the symbol
1107 // name from the version name. If there are two '@' characters,
1108 // this is the default version.
1109 const char* ver = strchr(name, '@');
1110 Stringpool::Key ver_key = 0;
1112 // IS_DEFAULT_VERSION: is the version default?
1113 // IS_FORCED_LOCAL: is the symbol forced local?
1114 bool is_default_version = false;
1115 bool is_forced_local = false;
1119 // The symbol name is of the form foo@VERSION or foo@@VERSION
1120 namelen = ver - name;
1124 is_default_version = true;
1127 ver = this->namepool_.add(ver, true, &ver_key);
1129 // We don't want to assign a version to an undefined symbol,
1130 // even if it is listed in the version script. FIXME: What
1131 // about a common symbol?
1134 namelen = strlen(name);
1135 if (!this->version_script_.empty()
1136 && st_shndx != elfcpp::SHN_UNDEF)
1138 // The symbol name did not have a version, but the
1139 // version script may assign a version anyway.
1140 std::string version;
1142 if (this->version_script_.get_symbol_version(name, &version,
1146 is_forced_local = true;
1147 else if (!version.empty())
1149 ver = this->namepool_.add_with_length(version.c_str(),
1153 is_default_version = true;
1159 elfcpp::Sym<size, big_endian>* psym = &sym;
1160 unsigned char symbuf[sym_size];
1161 elfcpp::Sym<size, big_endian> sym2(symbuf);
1164 memcpy(symbuf, p, sym_size);
1165 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1166 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1168 // Symbol values in object files are section relative.
1169 // This is normally what we want, but since here we are
1170 // converting the symbol to absolute we need to add the
1171 // section address. The section address in an object
1172 // file is normally zero, but people can use a linker
1173 // script to change it.
1174 sw.put_st_value(sym.get_st_value()
1175 + relobj->section_address(orig_st_shndx));
1177 st_shndx = elfcpp::SHN_ABS;
1178 is_ordinary = false;
1182 // Fix up visibility if object has no-export set.
1183 if (relobj->no_export()
1184 && (orig_st_shndx != elfcpp::SHN_UNDEF || !is_ordinary))
1186 // We may have copied symbol already above.
1189 memcpy(symbuf, p, sym_size);
1193 elfcpp::STV visibility = sym2.get_st_visibility();
1194 if (visibility == elfcpp::STV_DEFAULT
1195 || visibility == elfcpp::STV_PROTECTED)
1197 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1198 unsigned char nonvis = sym2.get_st_nonvis();
1199 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1203 Stringpool::Key name_key;
1204 name = this->namepool_.add_with_length(name, namelen, true,
1207 Sized_symbol<size>* res;
1208 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1209 is_default_version, *psym, st_shndx,
1210 is_ordinary, orig_st_shndx);
1212 // If building a shared library using garbage collection, do not
1213 // treat externally visible symbols as garbage.
1214 if (parameters->options().gc_sections()
1215 && parameters->options().shared())
1216 this->gc_mark_symbol_for_shlib(res);
1218 if (is_forced_local)
1219 this->force_local(res);
1221 if (is_defined_in_discarded_section)
1222 res->set_is_defined_in_discarded_section();
1224 (*sympointers)[i] = res;
1228 // Add a symbol from a plugin-claimed file.
1230 template<int size, bool big_endian>
1232 Symbol_table::add_from_pluginobj(
1233 Sized_pluginobj<size, big_endian>* obj,
1236 elfcpp::Sym<size, big_endian>* sym)
1238 unsigned int st_shndx = sym->get_st_shndx();
1239 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1241 Stringpool::Key ver_key = 0;
1242 bool is_default_version = false;
1243 bool is_forced_local = false;
1247 ver = this->namepool_.add(ver, true, &ver_key);
1249 // We don't want to assign a version to an undefined symbol,
1250 // even if it is listed in the version script. FIXME: What
1251 // about a common symbol?
1254 if (!this->version_script_.empty()
1255 && st_shndx != elfcpp::SHN_UNDEF)
1257 // The symbol name did not have a version, but the
1258 // version script may assign a version anyway.
1259 std::string version;
1261 if (this->version_script_.get_symbol_version(name, &version,
1265 is_forced_local = true;
1266 else if (!version.empty())
1268 ver = this->namepool_.add_with_length(version.c_str(),
1272 is_default_version = true;
1278 Stringpool::Key name_key;
1279 name = this->namepool_.add(name, true, &name_key);
1281 Sized_symbol<size>* res;
1282 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1283 is_default_version, *sym, st_shndx,
1284 is_ordinary, st_shndx);
1286 if (is_forced_local)
1287 this->force_local(res);
1292 // Add all the symbols in a dynamic object to the hash table.
1294 template<int size, bool big_endian>
1296 Symbol_table::add_from_dynobj(
1297 Sized_dynobj<size, big_endian>* dynobj,
1298 const unsigned char* syms,
1300 const char* sym_names,
1301 size_t sym_name_size,
1302 const unsigned char* versym,
1304 const std::vector<const char*>* version_map,
1305 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1310 gold_assert(size == parameters->target().get_size());
1312 if (dynobj->just_symbols())
1314 gold_error(_("--just-symbols does not make sense with a shared object"));
1318 if (versym != NULL && versym_size / 2 < count)
1320 dynobj->error(_("too few symbol versions"));
1324 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1326 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1327 // weak aliases. This is necessary because if the dynamic object
1328 // provides the same variable under two names, one of which is a
1329 // weak definition, and the regular object refers to the weak
1330 // definition, we have to put both the weak definition and the
1331 // strong definition into the dynamic symbol table. Given a weak
1332 // definition, the only way that we can find the corresponding
1333 // strong definition, if any, is to search the symbol table.
1334 std::vector<Sized_symbol<size>*> object_symbols;
1336 const unsigned char* p = syms;
1337 const unsigned char* vs = versym;
1338 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1340 elfcpp::Sym<size, big_endian> sym(p);
1342 if (sympointers != NULL)
1343 (*sympointers)[i] = NULL;
1345 // Ignore symbols with local binding or that have
1346 // internal or hidden visibility.
1347 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1348 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1349 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1352 // A protected symbol in a shared library must be treated as a
1353 // normal symbol when viewed from outside the shared library.
1354 // Implement this by overriding the visibility here.
1355 elfcpp::Sym<size, big_endian>* psym = &sym;
1356 unsigned char symbuf[sym_size];
1357 elfcpp::Sym<size, big_endian> sym2(symbuf);
1358 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1360 memcpy(symbuf, p, sym_size);
1361 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1362 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1366 unsigned int st_name = psym->get_st_name();
1367 if (st_name >= sym_name_size)
1369 dynobj->error(_("bad symbol name offset %u at %zu"),
1374 const char* name = sym_names + st_name;
1377 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1380 if (st_shndx != elfcpp::SHN_UNDEF)
1383 Sized_symbol<size>* res;
1387 Stringpool::Key name_key;
1388 name = this->namepool_.add(name, true, &name_key);
1389 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1390 false, *psym, st_shndx, is_ordinary,
1395 // Read the version information.
1397 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1399 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1400 v &= elfcpp::VERSYM_VERSION;
1402 // The Sun documentation says that V can be VER_NDX_LOCAL,
1403 // or VER_NDX_GLOBAL, or a version index. The meaning of
1404 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1405 // The old GNU linker will happily generate VER_NDX_LOCAL
1406 // for an undefined symbol. I don't know what the Sun
1407 // linker will generate.
1409 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1410 && st_shndx != elfcpp::SHN_UNDEF)
1412 // This symbol should not be visible outside the object.
1416 // At this point we are definitely going to add this symbol.
1417 Stringpool::Key name_key;
1418 name = this->namepool_.add(name, true, &name_key);
1420 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1421 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1423 // This symbol does not have a version.
1424 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1425 false, *psym, st_shndx, is_ordinary,
1430 if (v >= version_map->size())
1432 dynobj->error(_("versym for symbol %zu out of range: %u"),
1437 const char* version = (*version_map)[v];
1438 if (version == NULL)
1440 dynobj->error(_("versym for symbol %zu has no name: %u"),
1445 Stringpool::Key version_key;
1446 version = this->namepool_.add(version, true, &version_key);
1448 // If this is an absolute symbol, and the version name
1449 // and symbol name are the same, then this is the
1450 // version definition symbol. These symbols exist to
1451 // support using -u to pull in particular versions. We
1452 // do not want to record a version for them.
1453 if (st_shndx == elfcpp::SHN_ABS
1455 && name_key == version_key)
1456 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1457 false, *psym, st_shndx, is_ordinary,
1461 const bool is_default_version =
1462 !hidden && st_shndx != elfcpp::SHN_UNDEF;
1463 res = this->add_from_object(dynobj, name, name_key, version,
1464 version_key, is_default_version,
1466 is_ordinary, st_shndx);
1471 // Note that it is possible that RES was overridden by an
1472 // earlier object, in which case it can't be aliased here.
1473 if (st_shndx != elfcpp::SHN_UNDEF
1475 && psym->get_st_type() == elfcpp::STT_OBJECT
1476 && res->source() == Symbol::FROM_OBJECT
1477 && res->object() == dynobj)
1478 object_symbols.push_back(res);
1480 if (sympointers != NULL)
1481 (*sympointers)[i] = res;
1484 this->record_weak_aliases(&object_symbols);
1487 // This is used to sort weak aliases. We sort them first by section
1488 // index, then by offset, then by weak ahead of strong.
1491 class Weak_alias_sorter
1494 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1499 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1500 const Sized_symbol<size>* s2) const
1503 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1504 gold_assert(is_ordinary);
1505 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1506 gold_assert(is_ordinary);
1507 if (s1_shndx != s2_shndx)
1508 return s1_shndx < s2_shndx;
1510 if (s1->value() != s2->value())
1511 return s1->value() < s2->value();
1512 if (s1->binding() != s2->binding())
1514 if (s1->binding() == elfcpp::STB_WEAK)
1516 if (s2->binding() == elfcpp::STB_WEAK)
1519 return std::string(s1->name()) < std::string(s2->name());
1522 // SYMBOLS is a list of object symbols from a dynamic object. Look
1523 // for any weak aliases, and record them so that if we add the weak
1524 // alias to the dynamic symbol table, we also add the corresponding
1529 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1531 // Sort the vector by section index, then by offset, then by weak
1533 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1535 // Walk through the vector. For each weak definition, record
1537 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1539 p != symbols->end();
1542 if ((*p)->binding() != elfcpp::STB_WEAK)
1545 // Build a circular list of weak aliases. Each symbol points to
1546 // the next one in the circular list.
1548 Sized_symbol<size>* from_sym = *p;
1549 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1550 for (q = p + 1; q != symbols->end(); ++q)
1553 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1554 || (*q)->value() != from_sym->value())
1557 this->weak_aliases_[from_sym] = *q;
1558 from_sym->set_has_alias();
1564 this->weak_aliases_[from_sym] = *p;
1565 from_sym->set_has_alias();
1572 // Create and return a specially defined symbol. If ONLY_IF_REF is
1573 // true, then only create the symbol if there is a reference to it.
1574 // If this does not return NULL, it sets *POLDSYM to the existing
1575 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1576 // resolve the newly created symbol to the old one. This
1577 // canonicalizes *PNAME and *PVERSION.
1579 template<int size, bool big_endian>
1581 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1583 Sized_symbol<size>** poldsym,
1584 bool* resolve_oldsym)
1586 *resolve_oldsym = false;
1588 // If the caller didn't give us a version, see if we get one from
1589 // the version script.
1591 bool is_default_version = false;
1592 if (*pversion == NULL)
1595 if (this->version_script_.get_symbol_version(*pname, &v, &is_global))
1597 if (is_global && !v.empty())
1599 *pversion = v.c_str();
1600 // If we get the version from a version script, then we
1601 // are also the default version.
1602 is_default_version = true;
1608 Sized_symbol<size>* sym;
1610 bool add_to_table = false;
1611 typename Symbol_table_type::iterator add_loc = this->table_.end();
1612 bool add_def_to_table = false;
1613 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1617 oldsym = this->lookup(*pname, *pversion);
1618 if (oldsym == NULL && is_default_version)
1619 oldsym = this->lookup(*pname, NULL);
1620 if (oldsym == NULL || !oldsym->is_undefined())
1623 *pname = oldsym->name();
1624 if (!is_default_version)
1625 *pversion = oldsym->version();
1629 // Canonicalize NAME and VERSION.
1630 Stringpool::Key name_key;
1631 *pname = this->namepool_.add(*pname, true, &name_key);
1633 Stringpool::Key version_key = 0;
1634 if (*pversion != NULL)
1635 *pversion = this->namepool_.add(*pversion, true, &version_key);
1637 Symbol* const snull = NULL;
1638 std::pair<typename Symbol_table_type::iterator, bool> ins =
1639 this->table_.insert(std::make_pair(std::make_pair(name_key,
1643 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
1644 std::make_pair(this->table_.end(), false);
1645 if (is_default_version)
1647 const Stringpool::Key vnull = 0;
1649 this->table_.insert(std::make_pair(std::make_pair(name_key,
1656 // We already have a symbol table entry for NAME/VERSION.
1657 oldsym = ins.first->second;
1658 gold_assert(oldsym != NULL);
1660 if (is_default_version)
1662 Sized_symbol<size>* soldsym =
1663 this->get_sized_symbol<size>(oldsym);
1664 this->define_default_version<size, big_endian>(soldsym,
1671 // We haven't seen this symbol before.
1672 gold_assert(ins.first->second == NULL);
1674 add_to_table = true;
1675 add_loc = ins.first;
1677 if (is_default_version && !insdefault.second)
1679 // We are adding NAME/VERSION, and it is the default
1680 // version. We already have an entry for NAME/NULL.
1681 oldsym = insdefault.first->second;
1682 *resolve_oldsym = true;
1688 if (is_default_version)
1690 add_def_to_table = true;
1691 add_def_loc = insdefault.first;
1697 const Target& target = parameters->target();
1698 if (!target.has_make_symbol())
1699 sym = new Sized_symbol<size>();
1702 Sized_target<size, big_endian>* sized_target =
1703 parameters->sized_target<size, big_endian>();
1704 sym = sized_target->make_symbol();
1710 add_loc->second = sym;
1712 gold_assert(oldsym != NULL);
1714 if (add_def_to_table)
1715 add_def_loc->second = sym;
1717 *poldsym = this->get_sized_symbol<size>(oldsym);
1722 // Define a symbol based on an Output_data.
1725 Symbol_table::define_in_output_data(const char* name,
1726 const char* version,
1732 elfcpp::STB binding,
1733 elfcpp::STV visibility,
1734 unsigned char nonvis,
1735 bool offset_is_from_end,
1738 if (parameters->target().get_size() == 32)
1740 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1741 return this->do_define_in_output_data<32>(name, version, defined, od,
1742 value, symsize, type, binding,
1750 else if (parameters->target().get_size() == 64)
1752 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1753 return this->do_define_in_output_data<64>(name, version, defined, od,
1754 value, symsize, type, binding,
1766 // Define a symbol in an Output_data, sized version.
1770 Symbol_table::do_define_in_output_data(
1772 const char* version,
1775 typename elfcpp::Elf_types<size>::Elf_Addr value,
1776 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1778 elfcpp::STB binding,
1779 elfcpp::STV visibility,
1780 unsigned char nonvis,
1781 bool offset_is_from_end,
1784 Sized_symbol<size>* sym;
1785 Sized_symbol<size>* oldsym;
1786 bool resolve_oldsym;
1788 if (parameters->target().is_big_endian())
1790 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1791 sym = this->define_special_symbol<size, true>(&name, &version,
1792 only_if_ref, &oldsym,
1800 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1801 sym = this->define_special_symbol<size, false>(&name, &version,
1802 only_if_ref, &oldsym,
1812 sym->init_output_data(name, version, od, value, symsize, type, binding,
1813 visibility, nonvis, offset_is_from_end);
1817 if (binding == elfcpp::STB_LOCAL
1818 || this->version_script_.symbol_is_local(name))
1819 this->force_local(sym);
1820 else if (version != NULL)
1821 sym->set_is_default();
1825 if (Symbol_table::should_override_with_special(oldsym, defined))
1826 this->override_with_special(oldsym, sym);
1837 // Define a symbol based on an Output_segment.
1840 Symbol_table::define_in_output_segment(const char* name,
1841 const char* version,
1847 elfcpp::STB binding,
1848 elfcpp::STV visibility,
1849 unsigned char nonvis,
1850 Symbol::Segment_offset_base offset_base,
1853 if (parameters->target().get_size() == 32)
1855 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1856 return this->do_define_in_output_segment<32>(name, version, defined, os,
1857 value, symsize, type,
1858 binding, visibility, nonvis,
1859 offset_base, only_if_ref);
1864 else if (parameters->target().get_size() == 64)
1866 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1867 return this->do_define_in_output_segment<64>(name, version, defined, os,
1868 value, symsize, type,
1869 binding, visibility, nonvis,
1870 offset_base, only_if_ref);
1879 // Define a symbol in an Output_segment, sized version.
1883 Symbol_table::do_define_in_output_segment(
1885 const char* version,
1888 typename elfcpp::Elf_types<size>::Elf_Addr value,
1889 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1891 elfcpp::STB binding,
1892 elfcpp::STV visibility,
1893 unsigned char nonvis,
1894 Symbol::Segment_offset_base offset_base,
1897 Sized_symbol<size>* sym;
1898 Sized_symbol<size>* oldsym;
1899 bool resolve_oldsym;
1901 if (parameters->target().is_big_endian())
1903 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1904 sym = this->define_special_symbol<size, true>(&name, &version,
1905 only_if_ref, &oldsym,
1913 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1914 sym = this->define_special_symbol<size, false>(&name, &version,
1915 only_if_ref, &oldsym,
1925 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1926 visibility, nonvis, offset_base);
1930 if (binding == elfcpp::STB_LOCAL
1931 || this->version_script_.symbol_is_local(name))
1932 this->force_local(sym);
1933 else if (version != NULL)
1934 sym->set_is_default();
1938 if (Symbol_table::should_override_with_special(oldsym, defined))
1939 this->override_with_special(oldsym, sym);
1950 // Define a special symbol with a constant value. It is a multiple
1951 // definition error if this symbol is already defined.
1954 Symbol_table::define_as_constant(const char* name,
1955 const char* version,
1960 elfcpp::STB binding,
1961 elfcpp::STV visibility,
1962 unsigned char nonvis,
1964 bool force_override)
1966 if (parameters->target().get_size() == 32)
1968 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1969 return this->do_define_as_constant<32>(name, version, defined, value,
1970 symsize, type, binding,
1971 visibility, nonvis, only_if_ref,
1977 else if (parameters->target().get_size() == 64)
1979 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1980 return this->do_define_as_constant<64>(name, version, defined, value,
1981 symsize, type, binding,
1982 visibility, nonvis, only_if_ref,
1992 // Define a symbol as a constant, sized version.
1996 Symbol_table::do_define_as_constant(
1998 const char* version,
2000 typename elfcpp::Elf_types<size>::Elf_Addr value,
2001 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
2003 elfcpp::STB binding,
2004 elfcpp::STV visibility,
2005 unsigned char nonvis,
2007 bool force_override)
2009 Sized_symbol<size>* sym;
2010 Sized_symbol<size>* oldsym;
2011 bool resolve_oldsym;
2013 if (parameters->target().is_big_endian())
2015 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2016 sym = this->define_special_symbol<size, true>(&name, &version,
2017 only_if_ref, &oldsym,
2025 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2026 sym = this->define_special_symbol<size, false>(&name, &version,
2027 only_if_ref, &oldsym,
2037 sym->init_constant(name, version, value, symsize, type, binding, visibility,
2042 // Version symbols are absolute symbols with name == version.
2043 // We don't want to force them to be local.
2044 if ((version == NULL
2047 && (binding == elfcpp::STB_LOCAL
2048 || this->version_script_.symbol_is_local(name)))
2049 this->force_local(sym);
2050 else if (version != NULL
2051 && (name != version || value != 0))
2052 sym->set_is_default();
2057 || Symbol_table::should_override_with_special(oldsym, defined))
2058 this->override_with_special(oldsym, sym);
2069 // Define a set of symbols in output sections.
2072 Symbol_table::define_symbols(const Layout* layout, int count,
2073 const Define_symbol_in_section* p,
2076 for (int i = 0; i < count; ++i, ++p)
2078 Output_section* os = layout->find_output_section(p->output_section);
2080 this->define_in_output_data(p->name, NULL, PREDEFINED, os, p->value,
2081 p->size, p->type, p->binding,
2082 p->visibility, p->nonvis,
2083 p->offset_is_from_end,
2084 only_if_ref || p->only_if_ref);
2086 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2087 p->type, p->binding, p->visibility, p->nonvis,
2088 only_if_ref || p->only_if_ref,
2093 // Define a set of symbols in output segments.
2096 Symbol_table::define_symbols(const Layout* layout, int count,
2097 const Define_symbol_in_segment* p,
2100 for (int i = 0; i < count; ++i, ++p)
2102 Output_segment* os = layout->find_output_segment(p->segment_type,
2103 p->segment_flags_set,
2104 p->segment_flags_clear);
2106 this->define_in_output_segment(p->name, NULL, PREDEFINED, os, p->value,
2107 p->size, p->type, p->binding,
2108 p->visibility, p->nonvis,
2110 only_if_ref || p->only_if_ref);
2112 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2113 p->type, p->binding, p->visibility, p->nonvis,
2114 only_if_ref || p->only_if_ref,
2119 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2120 // symbol should be defined--typically a .dyn.bss section. VALUE is
2121 // the offset within POSD.
2125 Symbol_table::define_with_copy_reloc(
2126 Sized_symbol<size>* csym,
2128 typename elfcpp::Elf_types<size>::Elf_Addr value)
2130 gold_assert(csym->is_from_dynobj());
2131 gold_assert(!csym->is_copied_from_dynobj());
2132 Object* object = csym->object();
2133 gold_assert(object->is_dynamic());
2134 Dynobj* dynobj = static_cast<Dynobj*>(object);
2136 // Our copied variable has to override any variable in a shared
2138 elfcpp::STB binding = csym->binding();
2139 if (binding == elfcpp::STB_WEAK)
2140 binding = elfcpp::STB_GLOBAL;
2142 this->define_in_output_data(csym->name(), csym->version(), COPY,
2143 posd, value, csym->symsize(),
2144 csym->type(), binding,
2145 csym->visibility(), csym->nonvis(),
2148 csym->set_is_copied_from_dynobj();
2149 csym->set_needs_dynsym_entry();
2151 this->copied_symbol_dynobjs_[csym] = dynobj;
2153 // We have now defined all aliases, but we have not entered them all
2154 // in the copied_symbol_dynobjs_ map.
2155 if (csym->has_alias())
2160 sym = this->weak_aliases_[sym];
2163 gold_assert(sym->output_data() == posd);
2165 sym->set_is_copied_from_dynobj();
2166 this->copied_symbol_dynobjs_[sym] = dynobj;
2171 // SYM is defined using a COPY reloc. Return the dynamic object where
2172 // the original definition was found.
2175 Symbol_table::get_copy_source(const Symbol* sym) const
2177 gold_assert(sym->is_copied_from_dynobj());
2178 Copied_symbol_dynobjs::const_iterator p =
2179 this->copied_symbol_dynobjs_.find(sym);
2180 gold_assert(p != this->copied_symbol_dynobjs_.end());
2184 // Add any undefined symbols named on the command line.
2187 Symbol_table::add_undefined_symbols_from_command_line(Layout* layout)
2189 if (parameters->options().any_undefined()
2190 || layout->script_options()->any_unreferenced())
2192 if (parameters->target().get_size() == 32)
2194 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2195 this->do_add_undefined_symbols_from_command_line<32>(layout);
2200 else if (parameters->target().get_size() == 64)
2202 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2203 this->do_add_undefined_symbols_from_command_line<64>(layout);
2215 Symbol_table::do_add_undefined_symbols_from_command_line(Layout* layout)
2217 for (options::String_set::const_iterator p =
2218 parameters->options().undefined_begin();
2219 p != parameters->options().undefined_end();
2221 this->add_undefined_symbol_from_command_line<size>(p->c_str());
2223 for (Script_options::referenced_const_iterator p =
2224 layout->script_options()->referenced_begin();
2225 p != layout->script_options()->referenced_end();
2227 this->add_undefined_symbol_from_command_line<size>(p->c_str());
2232 Symbol_table::add_undefined_symbol_from_command_line(const char* name)
2234 if (this->lookup(name) != NULL)
2237 const char* version = NULL;
2239 Sized_symbol<size>* sym;
2240 Sized_symbol<size>* oldsym;
2241 bool resolve_oldsym;
2242 if (parameters->target().is_big_endian())
2244 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2245 sym = this->define_special_symbol<size, true>(&name, &version,
2254 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2255 sym = this->define_special_symbol<size, false>(&name, &version,
2263 gold_assert(oldsym == NULL);
2265 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2266 elfcpp::STV_DEFAULT, 0);
2267 ++this->saw_undefined_;
2270 // Set the dynamic symbol indexes. INDEX is the index of the first
2271 // global dynamic symbol. Pointers to the symbols are stored into the
2272 // vector SYMS. The names are added to DYNPOOL. This returns an
2273 // updated dynamic symbol index.
2276 Symbol_table::set_dynsym_indexes(unsigned int index,
2277 std::vector<Symbol*>* syms,
2278 Stringpool* dynpool,
2281 for (Symbol_table_type::iterator p = this->table_.begin();
2282 p != this->table_.end();
2285 Symbol* sym = p->second;
2287 // Note that SYM may already have a dynamic symbol index, since
2288 // some symbols appear more than once in the symbol table, with
2289 // and without a version.
2291 if (!sym->should_add_dynsym_entry(this))
2292 sym->set_dynsym_index(-1U);
2293 else if (!sym->has_dynsym_index())
2295 sym->set_dynsym_index(index);
2297 syms->push_back(sym);
2298 dynpool->add(sym->name(), false, NULL);
2300 // Record any version information.
2301 if (sym->version() != NULL)
2302 versions->record_version(this, dynpool, sym);
2304 // If the symbol is defined in a dynamic object and is
2305 // referenced in a regular object, then mark the dynamic
2306 // object as needed. This is used to implement --as-needed.
2307 if (sym->is_from_dynobj() && sym->in_reg())
2308 sym->object()->set_is_needed();
2312 // Finish up the versions. In some cases this may add new dynamic
2314 index = versions->finalize(this, index, syms);
2319 // Set the final values for all the symbols. The index of the first
2320 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2321 // file offset OFF. Add their names to POOL. Return the new file
2322 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2325 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2326 size_t dyncount, Stringpool* pool,
2327 unsigned int* plocal_symcount)
2331 gold_assert(*plocal_symcount != 0);
2332 this->first_global_index_ = *plocal_symcount;
2334 this->dynamic_offset_ = dynoff;
2335 this->first_dynamic_global_index_ = dyn_global_index;
2336 this->dynamic_count_ = dyncount;
2338 if (parameters->target().get_size() == 32)
2340 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2341 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2346 else if (parameters->target().get_size() == 64)
2348 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2349 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2357 // Now that we have the final symbol table, we can reliably note
2358 // which symbols should get warnings.
2359 this->warnings_.note_warnings(this);
2364 // SYM is going into the symbol table at *PINDEX. Add the name to
2365 // POOL, update *PINDEX and *POFF.
2369 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2370 unsigned int* pindex, off_t* poff)
2372 sym->set_symtab_index(*pindex);
2373 pool->add(sym->name(), false, NULL);
2375 *poff += elfcpp::Elf_sizes<size>::sym_size;
2378 // Set the final value for all the symbols. This is called after
2379 // Layout::finalize, so all the output sections have their final
2384 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2385 unsigned int* plocal_symcount)
2387 off = align_address(off, size >> 3);
2388 this->offset_ = off;
2390 unsigned int index = *plocal_symcount;
2391 const unsigned int orig_index = index;
2393 // First do all the symbols which have been forced to be local, as
2394 // they must appear before all global symbols.
2395 for (Forced_locals::iterator p = this->forced_locals_.begin();
2396 p != this->forced_locals_.end();
2400 gold_assert(sym->is_forced_local());
2401 if (this->sized_finalize_symbol<size>(sym))
2403 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2408 // Now do all the remaining symbols.
2409 for (Symbol_table_type::iterator p = this->table_.begin();
2410 p != this->table_.end();
2413 Symbol* sym = p->second;
2414 if (this->sized_finalize_symbol<size>(sym))
2415 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2418 this->output_count_ = index - orig_index;
2423 // Compute the final value of SYM and store status in location PSTATUS.
2424 // During relaxation, this may be called multiple times for a symbol to
2425 // compute its would-be final value in each relaxation pass.
2428 typename Sized_symbol<size>::Value_type
2429 Symbol_table::compute_final_value(
2430 const Sized_symbol<size>* sym,
2431 Compute_final_value_status* pstatus) const
2433 typedef typename Sized_symbol<size>::Value_type Value_type;
2436 switch (sym->source())
2438 case Symbol::FROM_OBJECT:
2441 unsigned int shndx = sym->shndx(&is_ordinary);
2444 && shndx != elfcpp::SHN_ABS
2445 && !Symbol::is_common_shndx(shndx))
2447 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2451 Object* symobj = sym->object();
2452 if (symobj->is_dynamic())
2455 shndx = elfcpp::SHN_UNDEF;
2457 else if (symobj->pluginobj() != NULL)
2460 shndx = elfcpp::SHN_UNDEF;
2462 else if (shndx == elfcpp::SHN_UNDEF)
2464 else if (!is_ordinary
2465 && (shndx == elfcpp::SHN_ABS
2466 || Symbol::is_common_shndx(shndx)))
2467 value = sym->value();
2470 Relobj* relobj = static_cast<Relobj*>(symobj);
2471 Output_section* os = relobj->output_section(shndx);
2473 if (this->is_section_folded(relobj, shndx))
2475 gold_assert(os == NULL);
2476 // Get the os of the section it is folded onto.
2477 Section_id folded = this->icf_->get_folded_section(relobj,
2479 gold_assert(folded.first != NULL);
2480 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2481 unsigned folded_shndx = folded.second;
2483 os = folded_obj->output_section(folded_shndx);
2484 gold_assert(os != NULL);
2486 // Replace (relobj, shndx) with canonical ICF input section.
2487 shndx = folded_shndx;
2488 relobj = folded_obj;
2491 uint64_t secoff64 = relobj->output_section_offset(shndx);
2494 bool static_or_reloc = (parameters->doing_static_link() ||
2495 parameters->options().relocatable());
2496 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2498 *pstatus = CFVS_NO_OUTPUT_SECTION;
2502 if (secoff64 == -1ULL)
2504 // The section needs special handling (e.g., a merge section).
2506 value = os->output_address(relobj, shndx, sym->value());
2511 convert_types<Value_type, uint64_t>(secoff64);
2512 if (sym->type() == elfcpp::STT_TLS)
2513 value = sym->value() + os->tls_offset() + secoff;
2515 value = sym->value() + os->address() + secoff;
2521 case Symbol::IN_OUTPUT_DATA:
2523 Output_data* od = sym->output_data();
2524 value = sym->value();
2525 if (sym->type() != elfcpp::STT_TLS)
2526 value += od->address();
2529 Output_section* os = od->output_section();
2530 gold_assert(os != NULL);
2531 value += os->tls_offset() + (od->address() - os->address());
2533 if (sym->offset_is_from_end())
2534 value += od->data_size();
2538 case Symbol::IN_OUTPUT_SEGMENT:
2540 Output_segment* os = sym->output_segment();
2541 value = sym->value();
2542 if (sym->type() != elfcpp::STT_TLS)
2543 value += os->vaddr();
2544 switch (sym->offset_base())
2546 case Symbol::SEGMENT_START:
2548 case Symbol::SEGMENT_END:
2549 value += os->memsz();
2551 case Symbol::SEGMENT_BSS:
2552 value += os->filesz();
2560 case Symbol::IS_CONSTANT:
2561 value = sym->value();
2564 case Symbol::IS_UNDEFINED:
2576 // Finalize the symbol SYM. This returns true if the symbol should be
2577 // added to the symbol table, false otherwise.
2581 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2583 typedef typename Sized_symbol<size>::Value_type Value_type;
2585 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2587 // The default version of a symbol may appear twice in the symbol
2588 // table. We only need to finalize it once.
2589 if (sym->has_symtab_index())
2594 gold_assert(!sym->has_symtab_index());
2595 sym->set_symtab_index(-1U);
2596 gold_assert(sym->dynsym_index() == -1U);
2600 // Compute final symbol value.
2601 Compute_final_value_status status;
2602 Value_type value = this->compute_final_value(sym, &status);
2608 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2611 unsigned int shndx = sym->shndx(&is_ordinary);
2612 gold_error(_("%s: unsupported symbol section 0x%x"),
2613 sym->demangled_name().c_str(), shndx);
2616 case CFVS_NO_OUTPUT_SECTION:
2617 sym->set_symtab_index(-1U);
2623 sym->set_value(value);
2625 if (parameters->options().strip_all()
2626 || !parameters->options().should_retain_symbol(sym->name()))
2628 sym->set_symtab_index(-1U);
2635 // Write out the global symbols.
2638 Symbol_table::write_globals(const Stringpool* sympool,
2639 const Stringpool* dynpool,
2640 Output_symtab_xindex* symtab_xindex,
2641 Output_symtab_xindex* dynsym_xindex,
2642 Output_file* of) const
2644 switch (parameters->size_and_endianness())
2646 #ifdef HAVE_TARGET_32_LITTLE
2647 case Parameters::TARGET_32_LITTLE:
2648 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2652 #ifdef HAVE_TARGET_32_BIG
2653 case Parameters::TARGET_32_BIG:
2654 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2658 #ifdef HAVE_TARGET_64_LITTLE
2659 case Parameters::TARGET_64_LITTLE:
2660 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2664 #ifdef HAVE_TARGET_64_BIG
2665 case Parameters::TARGET_64_BIG:
2666 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2675 // Write out the global symbols.
2677 template<int size, bool big_endian>
2679 Symbol_table::sized_write_globals(const Stringpool* sympool,
2680 const Stringpool* dynpool,
2681 Output_symtab_xindex* symtab_xindex,
2682 Output_symtab_xindex* dynsym_xindex,
2683 Output_file* of) const
2685 const Target& target = parameters->target();
2687 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2689 const unsigned int output_count = this->output_count_;
2690 const section_size_type oview_size = output_count * sym_size;
2691 const unsigned int first_global_index = this->first_global_index_;
2692 unsigned char* psyms;
2693 if (this->offset_ == 0 || output_count == 0)
2696 psyms = of->get_output_view(this->offset_, oview_size);
2698 const unsigned int dynamic_count = this->dynamic_count_;
2699 const section_size_type dynamic_size = dynamic_count * sym_size;
2700 const unsigned int first_dynamic_global_index =
2701 this->first_dynamic_global_index_;
2702 unsigned char* dynamic_view;
2703 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2704 dynamic_view = NULL;
2706 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2708 for (Symbol_table_type::const_iterator p = this->table_.begin();
2709 p != this->table_.end();
2712 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2714 // Possibly warn about unresolved symbols in shared libraries.
2715 this->warn_about_undefined_dynobj_symbol(sym);
2717 unsigned int sym_index = sym->symtab_index();
2718 unsigned int dynsym_index;
2719 if (dynamic_view == NULL)
2722 dynsym_index = sym->dynsym_index();
2724 if (sym_index == -1U && dynsym_index == -1U)
2726 // This symbol is not included in the output file.
2731 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2732 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2733 elfcpp::STB binding = sym->binding();
2734 switch (sym->source())
2736 case Symbol::FROM_OBJECT:
2739 unsigned int in_shndx = sym->shndx(&is_ordinary);
2742 && in_shndx != elfcpp::SHN_ABS
2743 && !Symbol::is_common_shndx(in_shndx))
2745 gold_error(_("%s: unsupported symbol section 0x%x"),
2746 sym->demangled_name().c_str(), in_shndx);
2751 Object* symobj = sym->object();
2752 if (symobj->is_dynamic())
2754 if (sym->needs_dynsym_value())
2755 dynsym_value = target.dynsym_value(sym);
2756 shndx = elfcpp::SHN_UNDEF;
2757 if (sym->is_undef_binding_weak())
2758 binding = elfcpp::STB_WEAK;
2760 binding = elfcpp::STB_GLOBAL;
2762 else if (symobj->pluginobj() != NULL)
2763 shndx = elfcpp::SHN_UNDEF;
2764 else if (in_shndx == elfcpp::SHN_UNDEF
2766 && (in_shndx == elfcpp::SHN_ABS
2767 || Symbol::is_common_shndx(in_shndx))))
2771 Relobj* relobj = static_cast<Relobj*>(symobj);
2772 Output_section* os = relobj->output_section(in_shndx);
2773 if (this->is_section_folded(relobj, in_shndx))
2775 // This global symbol must be written out even though
2777 // Get the os of the section it is folded onto.
2779 this->icf_->get_folded_section(relobj, in_shndx);
2780 gold_assert(folded.first !=NULL);
2781 Relobj* folded_obj =
2782 reinterpret_cast<Relobj*>(folded.first);
2783 os = folded_obj->output_section(folded.second);
2784 gold_assert(os != NULL);
2786 gold_assert(os != NULL);
2787 shndx = os->out_shndx();
2789 if (shndx >= elfcpp::SHN_LORESERVE)
2791 if (sym_index != -1U)
2792 symtab_xindex->add(sym_index, shndx);
2793 if (dynsym_index != -1U)
2794 dynsym_xindex->add(dynsym_index, shndx);
2795 shndx = elfcpp::SHN_XINDEX;
2798 // In object files symbol values are section
2800 if (parameters->options().relocatable())
2801 sym_value -= os->address();
2807 case Symbol::IN_OUTPUT_DATA:
2808 shndx = sym->output_data()->out_shndx();
2809 if (shndx >= elfcpp::SHN_LORESERVE)
2811 if (sym_index != -1U)
2812 symtab_xindex->add(sym_index, shndx);
2813 if (dynsym_index != -1U)
2814 dynsym_xindex->add(dynsym_index, shndx);
2815 shndx = elfcpp::SHN_XINDEX;
2819 case Symbol::IN_OUTPUT_SEGMENT:
2820 shndx = elfcpp::SHN_ABS;
2823 case Symbol::IS_CONSTANT:
2824 shndx = elfcpp::SHN_ABS;
2827 case Symbol::IS_UNDEFINED:
2828 shndx = elfcpp::SHN_UNDEF;
2835 if (sym_index != -1U)
2837 sym_index -= first_global_index;
2838 gold_assert(sym_index < output_count);
2839 unsigned char* ps = psyms + (sym_index * sym_size);
2840 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2841 binding, sympool, ps);
2844 if (dynsym_index != -1U)
2846 dynsym_index -= first_dynamic_global_index;
2847 gold_assert(dynsym_index < dynamic_count);
2848 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2849 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2850 binding, dynpool, pd);
2854 of->write_output_view(this->offset_, oview_size, psyms);
2855 if (dynamic_view != NULL)
2856 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2859 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2860 // strtab holding the name.
2862 template<int size, bool big_endian>
2864 Symbol_table::sized_write_symbol(
2865 Sized_symbol<size>* sym,
2866 typename elfcpp::Elf_types<size>::Elf_Addr value,
2868 elfcpp::STB binding,
2869 const Stringpool* pool,
2870 unsigned char* p) const
2872 elfcpp::Sym_write<size, big_endian> osym(p);
2873 osym.put_st_name(pool->get_offset(sym->name()));
2874 osym.put_st_value(value);
2875 // Use a symbol size of zero for undefined symbols from shared libraries.
2876 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2877 osym.put_st_size(0);
2879 osym.put_st_size(sym->symsize());
2880 elfcpp::STT type = sym->type();
2881 // Turn IFUNC symbols from shared libraries into normal FUNC symbols.
2882 if (type == elfcpp::STT_GNU_IFUNC
2883 && sym->is_from_dynobj())
2884 type = elfcpp::STT_FUNC;
2885 // A version script may have overridden the default binding.
2886 if (sym->is_forced_local())
2887 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type));
2889 osym.put_st_info(elfcpp::elf_st_info(binding, type));
2890 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2891 osym.put_st_shndx(shndx);
2894 // Check for unresolved symbols in shared libraries. This is
2895 // controlled by the --allow-shlib-undefined option.
2897 // We only warn about libraries for which we have seen all the
2898 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2899 // which were not seen in this link. If we didn't see a DT_NEEDED
2900 // entry, we aren't going to be able to reliably report whether the
2901 // symbol is undefined.
2903 // We also don't warn about libraries found in a system library
2904 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2905 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2906 // can have undefined references satisfied by ld-linux.so.
2909 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2912 if (sym->source() == Symbol::FROM_OBJECT
2913 && sym->object()->is_dynamic()
2914 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2915 && sym->binding() != elfcpp::STB_WEAK
2916 && !parameters->options().allow_shlib_undefined()
2917 && !parameters->target().is_defined_by_abi(sym)
2918 && !sym->object()->is_in_system_directory())
2920 // A very ugly cast.
2921 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2922 if (!dynobj->has_unknown_needed_entries())
2923 gold_undefined_symbol(sym);
2927 // Write out a section symbol. Return the update offset.
2930 Symbol_table::write_section_symbol(const Output_section* os,
2931 Output_symtab_xindex* symtab_xindex,
2935 switch (parameters->size_and_endianness())
2937 #ifdef HAVE_TARGET_32_LITTLE
2938 case Parameters::TARGET_32_LITTLE:
2939 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2943 #ifdef HAVE_TARGET_32_BIG
2944 case Parameters::TARGET_32_BIG:
2945 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2949 #ifdef HAVE_TARGET_64_LITTLE
2950 case Parameters::TARGET_64_LITTLE:
2951 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2955 #ifdef HAVE_TARGET_64_BIG
2956 case Parameters::TARGET_64_BIG:
2957 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2966 // Write out a section symbol, specialized for size and endianness.
2968 template<int size, bool big_endian>
2970 Symbol_table::sized_write_section_symbol(const Output_section* os,
2971 Output_symtab_xindex* symtab_xindex,
2975 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2977 unsigned char* pov = of->get_output_view(offset, sym_size);
2979 elfcpp::Sym_write<size, big_endian> osym(pov);
2980 osym.put_st_name(0);
2981 if (parameters->options().relocatable())
2982 osym.put_st_value(0);
2984 osym.put_st_value(os->address());
2985 osym.put_st_size(0);
2986 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2987 elfcpp::STT_SECTION));
2988 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2990 unsigned int shndx = os->out_shndx();
2991 if (shndx >= elfcpp::SHN_LORESERVE)
2993 symtab_xindex->add(os->symtab_index(), shndx);
2994 shndx = elfcpp::SHN_XINDEX;
2996 osym.put_st_shndx(shndx);
2998 of->write_output_view(offset, sym_size, pov);
3001 // Print statistical information to stderr. This is used for --stats.
3004 Symbol_table::print_stats() const
3006 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
3007 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
3008 program_name, this->table_.size(), this->table_.bucket_count());
3010 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
3011 program_name, this->table_.size());
3013 this->namepool_.print_stats("symbol table stringpool");
3016 // We check for ODR violations by looking for symbols with the same
3017 // name for which the debugging information reports that they were
3018 // defined in different source locations. When comparing the source
3019 // location, we consider instances with the same base filename and
3020 // line number to be the same. This is because different object
3021 // files/shared libraries can include the same header file using
3022 // different paths, and we don't want to report an ODR violation in
3025 // This struct is used to compare line information, as returned by
3026 // Dwarf_line_info::one_addr2line. It implements a < comparison
3027 // operator used with std::set.
3029 struct Odr_violation_compare
3032 operator()(const std::string& s1, const std::string& s2) const
3034 std::string::size_type pos1 = s1.rfind('/');
3035 std::string::size_type pos2 = s2.rfind('/');
3036 if (pos1 == std::string::npos
3037 || pos2 == std::string::npos)
3039 return s1.compare(pos1, std::string::npos,
3040 s2, pos2, std::string::npos) < 0;
3044 // Check candidate_odr_violations_ to find symbols with the same name
3045 // but apparently different definitions (different source-file/line-no).
3048 Symbol_table::detect_odr_violations(const Task* task,
3049 const char* output_file_name) const
3051 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
3052 it != candidate_odr_violations_.end();
3055 const char* symbol_name = it->first;
3056 // Maps from symbol location to a sample object file we found
3057 // that location in. We use a sorted map so the location order
3058 // is deterministic, but we only store an arbitrary object file
3059 // to avoid copying lots of names.
3060 std::map<std::string, std::string, Odr_violation_compare> line_nums;
3062 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
3063 locs = it->second.begin();
3064 locs != it->second.end();
3067 // We need to lock the object in order to read it. This
3068 // means that we have to run in a singleton Task. If we
3069 // want to run this in a general Task for better
3070 // performance, we will need one Task for object, plus
3071 // appropriate locking to ensure that we don't conflict with
3072 // other uses of the object. Also note, one_addr2line is not
3073 // currently thread-safe.
3074 Task_lock_obj<Object> tl(task, locs->object);
3075 // 16 is the size of the object-cache that one_addr2line should use.
3076 std::string lineno = Dwarf_line_info::one_addr2line(
3077 locs->object, locs->shndx, locs->offset, 16);
3078 if (!lineno.empty())
3080 std::string& sample_object = line_nums[lineno];
3081 if (sample_object.empty())
3082 sample_object = locs->object->name();
3086 if (line_nums.size() > 1)
3088 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3089 "places (possible ODR violation):"),
3090 output_file_name, demangle(symbol_name).c_str());
3091 for (std::map<std::string, std::string>::const_iterator it2 =
3093 it2 != line_nums.end();
3095 fprintf(stderr, _(" %s from %s\n"),
3096 it2->first.c_str(), it2->second.c_str());
3099 // We only call one_addr2line() in this function, so we can clear its cache.
3100 Dwarf_line_info::clear_addr2line_cache();
3103 // Warnings functions.
3105 // Add a new warning.
3108 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3109 const std::string& warning)
3111 name = symtab->canonicalize_name(name);
3112 this->warnings_[name].set(obj, warning);
3115 // Look through the warnings and mark the symbols for which we should
3116 // warn. This is called during Layout::finalize when we know the
3117 // sources for all the symbols.
3120 Warnings::note_warnings(Symbol_table* symtab)
3122 for (Warning_table::iterator p = this->warnings_.begin();
3123 p != this->warnings_.end();
3126 Symbol* sym = symtab->lookup(p->first, NULL);
3128 && sym->source() == Symbol::FROM_OBJECT
3129 && sym->object() == p->second.object)
3130 sym->set_has_warning();
3134 // Issue a warning. This is called when we see a relocation against a
3135 // symbol for which has a warning.
3137 template<int size, bool big_endian>
3139 Warnings::issue_warning(const Symbol* sym,
3140 const Relocate_info<size, big_endian>* relinfo,
3141 size_t relnum, off_t reloffset) const
3143 gold_assert(sym->has_warning());
3144 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3145 gold_assert(p != this->warnings_.end());
3146 gold_warning_at_location(relinfo, relnum, reloffset,
3147 "%s", p->second.text.c_str());
3150 // Instantiate the templates we need. We could use the configure
3151 // script to restrict this to only the ones needed for implemented
3154 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3157 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3160 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3163 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3166 #ifdef HAVE_TARGET_32_LITTLE
3169 Symbol_table::add_from_relobj<32, false>(
3170 Sized_relobj<32, false>* relobj,
3171 const unsigned char* syms,
3173 size_t symndx_offset,
3174 const char* sym_names,
3175 size_t sym_name_size,
3176 Sized_relobj<32, false>::Symbols* sympointers,
3180 #ifdef HAVE_TARGET_32_BIG
3183 Symbol_table::add_from_relobj<32, true>(
3184 Sized_relobj<32, true>* relobj,
3185 const unsigned char* syms,
3187 size_t symndx_offset,
3188 const char* sym_names,
3189 size_t sym_name_size,
3190 Sized_relobj<32, true>::Symbols* sympointers,
3194 #ifdef HAVE_TARGET_64_LITTLE
3197 Symbol_table::add_from_relobj<64, false>(
3198 Sized_relobj<64, false>* relobj,
3199 const unsigned char* syms,
3201 size_t symndx_offset,
3202 const char* sym_names,
3203 size_t sym_name_size,
3204 Sized_relobj<64, false>::Symbols* sympointers,
3208 #ifdef HAVE_TARGET_64_BIG
3211 Symbol_table::add_from_relobj<64, true>(
3212 Sized_relobj<64, true>* relobj,
3213 const unsigned char* syms,
3215 size_t symndx_offset,
3216 const char* sym_names,
3217 size_t sym_name_size,
3218 Sized_relobj<64, true>::Symbols* sympointers,
3222 #ifdef HAVE_TARGET_32_LITTLE
3225 Symbol_table::add_from_pluginobj<32, false>(
3226 Sized_pluginobj<32, false>* obj,
3229 elfcpp::Sym<32, false>* sym);
3232 #ifdef HAVE_TARGET_32_BIG
3235 Symbol_table::add_from_pluginobj<32, true>(
3236 Sized_pluginobj<32, true>* obj,
3239 elfcpp::Sym<32, true>* sym);
3242 #ifdef HAVE_TARGET_64_LITTLE
3245 Symbol_table::add_from_pluginobj<64, false>(
3246 Sized_pluginobj<64, false>* obj,
3249 elfcpp::Sym<64, false>* sym);
3252 #ifdef HAVE_TARGET_64_BIG
3255 Symbol_table::add_from_pluginobj<64, true>(
3256 Sized_pluginobj<64, true>* obj,
3259 elfcpp::Sym<64, true>* sym);
3262 #ifdef HAVE_TARGET_32_LITTLE
3265 Symbol_table::add_from_dynobj<32, false>(
3266 Sized_dynobj<32, false>* dynobj,
3267 const unsigned char* syms,
3269 const char* sym_names,
3270 size_t sym_name_size,
3271 const unsigned char* versym,
3273 const std::vector<const char*>* version_map,
3274 Sized_relobj<32, false>::Symbols* sympointers,
3278 #ifdef HAVE_TARGET_32_BIG
3281 Symbol_table::add_from_dynobj<32, true>(
3282 Sized_dynobj<32, true>* dynobj,
3283 const unsigned char* syms,
3285 const char* sym_names,
3286 size_t sym_name_size,
3287 const unsigned char* versym,
3289 const std::vector<const char*>* version_map,
3290 Sized_relobj<32, true>::Symbols* sympointers,
3294 #ifdef HAVE_TARGET_64_LITTLE
3297 Symbol_table::add_from_dynobj<64, false>(
3298 Sized_dynobj<64, false>* dynobj,
3299 const unsigned char* syms,
3301 const char* sym_names,
3302 size_t sym_name_size,
3303 const unsigned char* versym,
3305 const std::vector<const char*>* version_map,
3306 Sized_relobj<64, false>::Symbols* sympointers,
3310 #ifdef HAVE_TARGET_64_BIG
3313 Symbol_table::add_from_dynobj<64, true>(
3314 Sized_dynobj<64, true>* dynobj,
3315 const unsigned char* syms,
3317 const char* sym_names,
3318 size_t sym_name_size,
3319 const unsigned char* versym,
3321 const std::vector<const char*>* version_map,
3322 Sized_relobj<64, true>::Symbols* sympointers,
3326 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3329 Symbol_table::define_with_copy_reloc<32>(
3330 Sized_symbol<32>* sym,
3332 elfcpp::Elf_types<32>::Elf_Addr value);
3335 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3338 Symbol_table::define_with_copy_reloc<64>(
3339 Sized_symbol<64>* sym,
3341 elfcpp::Elf_types<64>::Elf_Addr value);
3344 #ifdef HAVE_TARGET_32_LITTLE
3347 Warnings::issue_warning<32, false>(const Symbol* sym,
3348 const Relocate_info<32, false>* relinfo,
3349 size_t relnum, off_t reloffset) const;
3352 #ifdef HAVE_TARGET_32_BIG
3355 Warnings::issue_warning<32, true>(const Symbol* sym,
3356 const Relocate_info<32, true>* relinfo,
3357 size_t relnum, off_t reloffset) const;
3360 #ifdef HAVE_TARGET_64_LITTLE
3363 Warnings::issue_warning<64, false>(const Symbol* sym,
3364 const Relocate_info<64, false>* relinfo,
3365 size_t relnum, off_t reloffset) const;
3368 #ifdef HAVE_TARGET_64_BIG
3371 Warnings::issue_warning<64, true>(const Symbol* sym,
3372 const Relocate_info<64, true>* relinfo,
3373 size_t relnum, off_t reloffset) const;
3376 } // End namespace gold.